研究者情報

マスター

アカウント（マスター）

• 氏名

  ABOLHASAN　MEHRAN(アボルハサン　メーラン), アボルハサン　メーラン

所属（マスター）

• 情報科学研究院　ビッグデータとIoTに関する共同センター

所属（マスター）

• 情報科学研究院　ビッグデータとIoTに関する共同センター

researchmap

プロフィール情報

所属

• シドニー工科大学, Professor
• 北海道大学, 准教授

学位

• PhD, Wireless Networking（2003年12月 University of Wollongong, Wollongong, Australia）

プロフィール情報

• 姓

  Abolhasan

• 名

  Mehran

• ID各種

  202401008874008059

所属

• シドニー工科大学, Professor
• 北海道大学, 准教授

業績リスト

論文

• Multitone PSK Modulation Design for Simultaneous Wireless Information and Power Transfer

  Prerna Dhull, Dominique Schreurs, Giacomo Paolini, Alessandra Costanzo, Mehran Abolhasan, Negin Shariati

  IEEE Transactions on Microwave Theory and Techniques 72 1 446 - 460 2024年01月01日 

  Far-field wireless power transfer (WPT), based on radio frequency (RF) waves, came into the picture to fulfill the power need of large Internet-of-Things (IoT) networks, the backbone of the 5G and beyond era. However, RF communication signals carry both information as well as energy. Therefore, recently, simultaneous wireless information and power transfer (SWIPT) has attracted much attention in order to wirelessly charge these IoT devices. In this article, we propose a novel $N$ -tone multitone phase shift keying (PSK) modulation scheme, taking advantage of the nonlinearity of integrated receiver rectifier architecture. The main advantage of the proposed modulation scheme is the reduction in ripple voltage, introduced by the symbol transmission through phases. Achievable power conversion efficiency (PCE) and bit-error-rate (BER) at the output are considered to measure the efficacy of the proposed modulation scheme. Simulation results are verified by the measurements over the designed rectifier circuitry. The effect of symbol phase range, modulation order, and the number of tones are analyzed. In the future, this transmission scheme can be utilized to satisfy the data and power requirements of low-power IoT sensor networks.
• Multi-Agent Multi-Armed Bandit Learning for Grant-Free Access in Ultra-Dense IoT Networks

  Muhammad Ahmad Raza, Mehran Abolhasan, Justin Lipman, Negin Shariati, Wei Ni, Abbas Jamalipour

  IEEE Transactions on Cognitive Communications and Networking 2024年 

  Meeting the diverse quality-of-service (QoS) requirements in ultra-dense Internet of Things (IoT) networks operating under varying network loads is challenging. Moreover, latency-critical IoT applications cannot afford excessive control signaling overheads caused by centralized access control methods. A distributed network access approach can potentially address this problem. In this regard, multi-agent multi-armed bandit (MAB) learning is a promising tool for designing distributed network access protocols. This paper proposes a multi-agent MAB learning-based grant-free access mechanism for ultra-dense networks, where multiple base stations (BSs) serve massive delay-sensitive and delay-tolerant IoT devices. Delay-sensitive devices are prioritized to choose the BSs with larger numbers of channels in a probabilistic manner. The proposed mechanism enables the devices to improve their BS selection over time to accommodate the maximum number of devices that can meet a prescribed latency-reliability criterion. Simulation results show that the proposed MAB learning-based network access mechanism outperforms the random BS selection strategy in which end devices do not employ any learning scheme to adapt to the network dynamics.
• Multiservice Compact Pixelated Stacked Antenna With Different Pixel Shapes for IoT Applications

  Md Amanath Ullah, Rasool Keshavarz, Mehran Abolhasan, Justin Lipman, Negin Shariati

  IEEE Internet of Things Journal 10 22 19883 - 19897 2023年11月15日 

  This article presents a multiservice pixelated stacked antenna for dual-band application at 5.2 and 5.8-GHz bands. An efficient method for designing multilayer or stacked antennas for multistandard Internet of Things (IoT) applications is proposed in this article. The proposed antenna topology is based on two different pixel shapes and offers essential aspects, such as flexibilities in the design of low-profile single-band or multiband antennas for wireless systems. The antenna design consists of two pixelated layers of radiating patch, consisting of different shaped pixels. The V-shaped binary particle swarm optimization (VBPSO) algorithm has been implemented for the optimization of pixel positions. Only by considering the predefined regions, the antenna can be designed and optimized for various design goals. In the design procedure, triangular-shaped pixels are used to form the principal radiating patch, while square-shaped pixels are implemented on the stacked parasitic patch. Measurement and simulation results are in good agreement which proves the accuracy of the design and simulation procedure. The antenna operates at 5.16-5.21 GHz and 5.79-5.86 GHz. With a compact design, the proposed antenna achieves 4.7 and 4.4-dBi gain at 5.2 and 5.8 GHz, respectively. The proposed antenna design methodology offers great potentials to be aligned with specific design requirements of wireless low-profile IoT devices.
• Statistical Learning-Based Adaptive Network Access for the Industrial Internet of Things

  Muhammad Ahmad Raza, Mehran Abolhasan, Justin Lipman, Negin Shariati, Wei Ni, Abbas Jamalipour

  IEEE Internet of Things Journal 10 14 12219 - 12233 2023年07月15日 

  Industrial Internet of Things (IIoT) applications generate data in varying amounts with diverse quality of service requirements. The adaptive network access approach and distributed resource management in IIoT networks can reduce the communication overheads caused by centralized resource management approaches. In this regard, statistical learning is a promising tool for addressing decision-making problems in a dynamic environment. This article considers uplink dominant IIoT networks in which massive devices generate delay-sensitive and delay-tolerant data and communicate over shared radio resources. We propose a novel grant-free access scheme using a statistical learning approach that enables IIoT entities to perform delay-sensitive and delay-tolerant transmissions over dynamically partitioned resources in a prioritized manner. In order to improve utilization of available radio resources, we design an adaptive network access mechanism operating in a semi-distributed manner. This mechanism enables end devices to use their transmission history to choose between static and dynamic resource allocation-based grant-free schemes in a dynamic environment. Simulation results show that average latency and resource utilization vary in grant-free access schemes employing static and dynamic resource allocations. Thus, compared to a single transmission scheme, the proposed adaptive network access offers better channel utilization while meeting the application-specific latency bound in IIoT networks.
• Intelligent spatial interpolation-based frost prediction methodology using artificial neural networks with limited local data

  Ian Zhou, Justin Lipman, Mehran Abolhasan, Negin Shariati

  Environmental Modelling and Software 165 2023年07月 

  The weather phenomenon of frost poses great threats to agriculture. As recent frost prediction methods are based on on-site historical data and sensors, extra development and deployment time are required for data collection in any new site. The aim of this article is to eliminate the dependency on on-site historical data and sensors for frost prediction methods. In this article, a frost prediction method based on spatial interpolation is proposed. The models use climate data from existing weather stations, digital elevation models surveys, and normalized difference vegetation index data to estimate a target site's next hour minimum temperature. The proposed method utilizes ensemble learning to increase the model accuracy. Climate datasets are obtained from 75 weather stations across New South Wales and Australian Capital Territory areas of Australia. The results show that the proposed method reached a detection rate up to 92.55%.
• RF-Self-Powered Sensor for Fully Autonomous Soil Moisture Sensing

  Majid Amiri, Mehran Abolhasan, Negin Shariati, Justin Lipman

  IEEE Transactions on Microwave Theory and Techniques 71 3 1374 - 1387 2023年03月01日 

  Soil moisture monitoring and irrigation scheduling are essential parameters in farming efficiency. Internet-of-Things (IoT) technology is a promising solution for automating irrigation procedures and improving farming efficiency by removing human faults. In this article, a new method is introduced to measure soil moisture level along with providing energy to run a low-power transmitter as an alarm signal. A combination of a metamaterial perfect absorber (MPA) and two rectifiers that are designed at different frequencies specifies 5% and 25% soil moisture levels. The sensor monitors the soil moisture continuously without consuming energy. Once the soil moisture becomes 5% of the first rectifier starts working and provides 65 uW dc output, while the second rectifier is off. Increasing the soil moisture to 25%, the second rectifier creates 100 uW dc output when the first rectifier is off. The designed structure is fabricated on RO4003 in a $4 \times 4$ array. The measurement results are provided by performing a set of different experiments. Initially, the MPA's absorption characteristics are validated facing different polarization and incident angles. Then, the sensing capability is proven by burying the proposed sensor under sand and measuring the dc outputs of rectifiers. A strong correlation between simulation and measurement results validates the design procedure.
• Dual-Band, Slant-Polarized MIMO Antenna Set for Vehicular Communication

  Rasool Keshavarz, Dan Winson, Justin Lipman, Mehran Abolhasan, Negin Shariati

  17th European Conference on Antennas and Propagation, EuCAP 2023 2023年 

  Slant-polarized Multi Input Multi Output (MIMO) antennas are able to improve the performance of mobile communication systems in terms of channel capacity. Specifically, the implementation of MIMO configurations for automotive applications requires the consideration of high gain, wideband, low-profile and affordable antennas in the communication link. In this work, design, simulation and measurement of a new dual-band slant-polarized MIMO antenna with HPBW (Half Power Beam Width) of around 900 are presented. Then, four replicas of the proposed antenna set are placed at four different poles (North, South, West and East) to cover 3600 around the vehicle in an omni-directional pattern. In a real-world scenario, the proper antenna set is selected to communicate with the intended user. Each slant MIMO antenna set consists of two inclined (450) low band (LB: 700 to 900 MHz) and two inclined high band (HB: 1.7 to 2.7 GHz) log-periodic antennas. The measured gain of LB and HB antennas are 7 dBi and 8 dBi, respectively. Strong correlation between simulation and measurement results confirms the accuracy of the design and simulation procedures of the proposed antenna system, obtained using a genetic optimization algorithm. The fabricated antenna was also measured in the field for industrial applications.
• Low-profile dual-band pixelated defected ground antenna for multistandard IoT devices

  Md Amanath Ullah, Rasool Keshavarz, Mehran Abolhasan, Justin Lipman, Negin Shariati

  Scientific Reports 12 1 2022年12月 

  A low-profile dual-band pixelated defected ground antenna has been proposed at 3.5 GHz and 5.8 GHz bands. This work presents a flexible design guide for achieving single-band and dual-band antenna using pixelated defected ground (PDG). The unique pixelated defected ground has been designed using the binary particle swarm optimization (BPSO) algorithm. Computer Simulation Technology Microwave Studio incorporated with Matlab has been utilized in the antenna design process. The PDG configuration provides freedom of exploration to achieve the desired antenna performance. Compact antenna design can be achieved by making the best use of designated design space on the defected ground (DG) plane. Further, a V-shaped transfer function based on BPSO with fast convergence allows us to efficiently implement the PDG technique. In the design procedure, pixelization is applied to a small rectangular region of the ground plane. The square pixels on the designated defected ground area of the antenna have been formed using a binary bit string, consisting of 512 bits taken during each iteration of the algorithm. The PDG method is concerned with the shape of the DG and does not rely on the geometrical dimension analysis used in traditional defected ground antennas. Initially, three single band antennas have been designed at 3.5 GHz, 5.2 GHz and 5.8 GHz using PDG technique. Finally, same PDG area has been used to design a dual-band antenna at 3.5 GHz and 5.8 GHz. The proposed antenna exhibits almost omnidirectional radiation performance with nearly 90% efficiency. It also shows dual radiation pattern property with similar patterns having different polarizations at each operational band. The antenna is fabricated on a ROGERS RO4003 substrate with 1.52 mm thickness. Reflection coefficient and radiation patterns are measured to validate its performance. The simulated and measured results of the antenna are closely correlated. The proposed antenna is suitable for different applications in Internet of Things.
• Intelligent and Reliable Millimeter Wave Communications for RIS-Aided Vehicular Networks

  Madyan Alsenwi, Mehran Abolhasan, Justin Lipman

  IEEE Transactions on Intelligent Transportation Systems 23 11 21582 - 21592 2022年11月01日 

  Utilizing the millimeter-wave (mmWave) frequency is a promising solution to meet fast-growing traffic demand over wireless networks. However, mmWave communications are sensitive to physical obstructions on signal propagation. In this paper, the reconfigurable intelligent surfaces (RISs) are investigated to overcome the limitations of mmWave communications. Particularly, an RIS is deployed to reflect the mmWave signals towards vehicular users who experience direct link blockages that may occur due to static or dynamic obstacles. To this end, a risk-averse optimization problem is designed to optimize the Base Station (BS) precoding matrix and the RIS phase shifts under stochastic link blockages. A solution approach is developed in two phases: the BS precoding optimization and the RIS phase shift control phases. In the first phase, a Decomposition and Relaxation-based Precoding Optimization (DRPO) algorithm is developed to obtain the optimal precoding matrix. In the second phase, a learning-based method is introduced to dynamically adjust the direction of reflected signals under channel uncertainty. Extensive simulations are presented to validate the efficacy of the developed algorithms. The obtained results show that the developed algorithms can ensure reliable transmissions to users in non-LoS areas and improve network performance.
• Dynamic Routing Protocol Selection in Multi-Hop Device-to-Device Wireless Networks

  Mahrokh Abdollahi, Sepehr Ashtari, Mehran Abolhasan, Negin Shariati, Justin Lipman, Abbas Jamalipour, Wei Ni

  IEEE Transactions on Vehicular Technology 71 8 8796 - 8809 2022年08月01日 

  Until now, multi-hop device-to-device (MD2D) routing in mobile wireless networks has been designed to operate over a single-protocol routing framework. Consequently, to the best of our knowledge, no framework has been developed to enable the dynamic deployment and switching of multiple MD2D routing protocols under one framework. This paper proposes a multi-protocol framework to introduce the idea of clustering a cell and deploying different MD2D routing protocols for each cluster based on the cluster requirements. To this end, four clusters are developed with varying network conditions (i.e., node density, mobility rate, and the number of flows). Then, the performance of our two previously designed multi-hop routing protocols, namely hybrid SDN architecture for wireless distributed networks (HSAW) and source-based virtual ad hoc routing protocol (VARP-S), are investigated in each cluster in terms of energy consumption, end-to-end (E2E) delay, packet loss, and cellular-band overhead. Based on the achieved simulation results, a multiple-criteria decision-making (MCDM) approach based on the analytic hierarchy process (AHP) is developed to choose the most suitable protocol for each cluster to provide the best performance. The simulation results indicate that our proposed multi-protocol framework provides better performance compared to traditional single-protocol architectures.
• Minute-wise frost prediction: An approach of recurrent neural networks

  Ian Zhou, Justin Lipman, Mehran Abolhasan, Negin Shariati

  Array 14 2022年07月 

  Frost events incur substantial economic losses to farmers. These events could induce damage to plants and crops by damaging the cells. In this article, a recurrent neural network-based method, automating the frost prediction process, is proposed. The recurrent neural network-based models leveraged in this article include the standard recurrent neural network, long short-term memory, and gated recurrent unit. The proposed method aims to increase the prediction frequency from once per 12–24 h for the next day or night events to minute-wise predictions for the next hour events. To achieve this goal, datasets from NSW and ACT of Australia are obtained. The experiments are designed considering the scene of deploying the model to the Internet of Things systems. Factors such as model processing speed, long-term error and data availability are reviewed. After model construction, there are three experiments. The first experiment tests the errors between different model types. The second and third experiments test the effect of sequence length on error and performance for recurrent neural network-based models. All tests introduce artificial neural network models as the baseline. Also, all tests for model error are conducted in two rounds with testing datasets from the current year (2016) and next year (2017). As a result, recurrent neural network-based models are more suitable for short-term deployment with a smaller sequence length. In contrast, artificial neural network models demonstrate a lower error over the long term with faster processing time. With the results presented, the limitations of the proposed method are discussed.
• A multi-layered intrusion detection system for software defined networking ^☆

  Hamideh Bour, Mehran Abolhasan, Saber Jafarizadeh, Justin Lipman, Imran Makhdoom

  Computers and Electrical Engineering 101 2022年07月 

  The majority of existing DDoS defense mechanisms in SDN impose a significant computational burden on the controller and employ limited flow statistics and packet features. Tackling these issues, this paper presents a multi-layer defense mechanism that detects and mitigates three distinct types of flooding DDoS attacks. In the proposed framework, the detection process consists of flow-based and packet-based attack detection mechanisms employing Extreme Learning Machine-based Single-hidden Layer Feedforward Networks (ELM-SLFNs) and Case-based Information Entropy (C-IE), respectively. Moreover, the affected switches are avoided in the optimal path determined by the Floyd-Warshall algorithm, where the switches are classified based on the Hidden Markov Model (HMM) using the extracted packet features. Our simulation demonstrates the improved performance of our framework compared to similar schemes proposed in the literature in terms of different metrics, including attack detection rate, detection accuracy, false-positive rate, switch failure ratio, packet loss rate, response time, and CPU utilization.
• Statistical Learning-Based Grant-Free Access for Delay-Sensitive Internet of Things Applications

  Muhammad Ahmad Raza, Mehran Abolhasan, Justin Lipman, Negin Shariati, Wei Ni, Abbas Jamalipour

  IEEE Transactions on Vehicular Technology 71 5 5492 - 5506 2022年05月01日 

  Mission-critical Internet-of-Things (IoT) applications require communication interfaces that provide ultra-reliability and low latency. Acquiring knowledge regarding the number of active devices and their latency-reliability requirements becomes essential to optimize resource allocation in heterogeneous networks. Due to the inherent heavy computation overheads, the conventional centralized decision-making approaches result in large latency. The distributed computing and device-level prediction of network parameters can play a significant role in designing mission-critical IoT applications operating in dynamic environments. This paper considers the medium access control (MAC) layer of heterogeneous networks employing a framed-ALOHA-based restricted transmission strategy to enhance reliability. We present a statistical learning-based device-level network exploration mechanism in which end-devices use their transmission history to predict different network parameters. The IoT devices share the learned parameters with the base station (BS) to identify different groups presented in the network. The simulation results show that the mean square error (MSE) in predicting different network parameters can be reduced by increasing the history window size. In this regard, the optimal size of the history window under the given accuracy constraints is also determined. We demonstrate that the proposed device-level network load prediction mechanism is more robust as compared to the BS-centered approach.
• Performance analysis of multi-hop routing protocols in SDN-based wireless networks

  Sepehr Ashtari, Mahrokh Abdollahi, Mehran Abolhasan, Negin Shariati, Justin Lipman

  Computers and Electrical Engineering 97 2022年01月 

  Wireless cellular networks have rapidly evolved to be software-defined in nature. This has created opportunities to improve their performance. One such opportunity is through enabling programming and integration of multi-hop device-to-device (MD2D) at the edge. However, efficient integration of MD2D at the edge requires a highly adaptable and scalable routing protocol, where its development is underpinned through understanding of which type of current routing characteristics and architectures are suitable over dynamic networking conditions. To develop such understanding, we conducted a detailed analysis and performance study on three routing protocols, namely virtual ad-hoc routing protocol-source based (VARP-S) Abolhasan et al. (2018), SDN-based multi-hop device-to-device routing protocol (SMDRP) Abdollahi et al. (2019) and hybrid SDN architecture for wireless distributed networks (HSAW) Abolhasan et al. (2015). Our investigations illustrate that VARP-S and SMDRP perform best in terms of energy consumption and cellular routing overhead. However, HSAW shows better performance in terms of end-to-end (E2E) delay and packet loss over lower network and traffic densities.
• Mobility Model for Contact-Aware Data Offloading through Train-to-Train Communications in Rail Networks

  Mahdi Saki, Mehran Abolhasan, Justin Lipman, Abbas Jamalipour

  IEEE Transactions on Intelligent Transportation Systems 23 1 597 - 609 2022年01月01日 

  In this paper, we propose a novel mobility model providing train traffic traces essential for train-to-train communication models. As the proposed mobility model works only based on trip timetables and train timetables are currently available in real-time, the produced mobility traces will be also in real-time. Additionally, as no GPS module is used in this method, our proposed model can provide a practical solution when signal from GPS or Assisted GPS is poor or unavailable such as in urban area or inside tunnels. Furthermore, as we used an energy optimization function, the proposed mobility model will provide a guidance trajectory for trains to have an energy-optimized operation. We also develop an algorithm that can determine the specifications of contacts between trains based on the traffic traces obtained from the mobility model. Such specifications includes duration, rate and location of train contacts used for estimation of data exchange capacity between trains through train-to-train communications. We validate our proposed model using data collected from Sydney Trains of Australia. The results obtained from our proposed model show over 98 percent accuracy in comparison with the real data collected via a GPS module from Sydney Trains.
• Science and Technology Parks: A Futuristic Approach

  Imran Makhdoom, Justin Lipman, Mehran Abolhasan, Duncan Challen

  IEEE Access 10 31981 - 32021 2022年 

  Most of the existing science and technology parks resort to various conventional ways to attract different stakeholders to the park. Some of these traditional measures include business support, workspaces, laboratories, networking events, accommodation, and essential commodities. Besides, with rampantly changing multidisciplinary technologies and increased data-oriented business models, the classic science and technology park value-creation strategies may not be instrumental in the near future. Hence, we foresee that future science and a technology parks should be fully integrated, sustainable, and innovative living science cities. Where park tenants can actively interact and contribute to emerging technologies. Therefore, this paper carries out an in-depth study of world s best practices in smart cities and science and technology parks, their characteristics, and value-added contributions that excite the prospective tenants. Developing on the detailed survey, we propose a unique feature of Autonomous Systems as a Service to bestow a futuristic look to the science and technology parks. It is envisaged that autonomous systems will not only provide value-added services to the park tenants but will also provide an infrastructure for testing new technologies within park premises. Furthermore, this study evaluates security and privacy challenges associated with autonomous systems and data-oriented services and recommends appropriate security measures. The role of universities in the success of a science and technology park is also delineated. Finally, the components deemed essential for the attainment of science and technology parks objectives are highlighted.
• Remote Water Salinity Sensor Using Metamaterial Perfect Absorber

  Majid Amiri, Mehran Abolhasan, Negin Shariati, Justin Lipman

  IEEE Transactions on Antennas and Propagation 2022年 

  Controlling water salinity plays a key role in farming efficiency. Current sensors are mostly expensive and need regular maintenance. In addition, they require electrical connections or extra power supply that leads to difficult and costly implementation in remote sensing scenarios. In this paper, an accurate and low-profile sensor is developed using a metamaterial perfect absorber (MPA) structure. The proposed sensor works based on the level and frequency of absorbed signals. Hence, there is no need for electrical connections, which enables remote sensing applications. Square shape channels have been created in a regular FR-4 substrate to facilitate sensing of water salinity level. A 7×7 array with a total size of 140mm×160mm has been fabricated that shows a resolution of 10 MHz per percentage of water salinity. The absorption frequency shifts from f=3.12 GHz to f=3.59 GHz for salinity level from 0% to 50%. A strong correlation between measurement and simulation results validates the design procedure.
• Toward Integrating Intelligence and Programmability in Open Radio Access Networks: A Comprehensive Survey

  Azadeh Arnaz, Justin Lipman, Mehran Abolhasan, Matti Hiltunen

  IEEE Access 10 67747 - 67770 2022年 

  Open RAN is an emerging vision and an advancement of the Radio Access Network (RAN). Its purpose is to implement a vendor and network-generation agnostic RAN, provide networking solutions across all service requests, and implement artificial intelligence solutions in different stages of an end-to-end communication path. The 5th Generation (5G) and beyond the 5th Generation (B5G) of networking introduce and support new use cases, such as tactile internet and autonomous driving. The complexity and innovative nature of these use cases require continuous innovation at a high pace in the RAN. The traditional approach of building end-to-end RAN solutions by only one vendor hampers the speed of innovation - furthermore, the lack of a standard approach to implementing artificial intelligence complicates the compatibility of products with the RAN ecosystem. O-RAN Alliance, a community of industry and academic experts in RAN, works on writing Open RAN specifications on top of the 3rd Generation Partnership Project (3GPP) standards. Founded on these specifications, the aim of this paper is to introduce open research topics in Open RAN that overlap the interests of both AI and telecommunication researchers. The paper provides an overview of the architecture and components of Open RAN, then explores AI use cases in Open RAN. Also, this survey includes some plausible AI deployment scenarios that the specifications have not covered. Open RAN in future cities creates opportunities for various use cases across different sectors, including engineering, operations, and research that this paper addresses.
• Joint Mobile Node Participation and Multihop Routing for Emerging Open Radio-Based Intelligent Transportation System

  Sepehr Ashtari, Mehran Abolhasan, Justin Lipman, Negin Shariati, Wei Ni, Abbas Jamalipour

  IEEE Access 10 85228 - 85242 2022年 

  This paper proposes joint mobile node participation and routing protocol for multi-hop device-to-device (MD2D) networking in intelligent transportation systems, called fuzzy-based participation and routing protocol for MD2D (FPRM). Our proposed protocol is designed to operate over future open-radio access networks (O-RANs). We introduce a sub-layer at the network layer that can determine nodes with the highest participation probability in routing using a fuzzy logic system, thus building a framework to create more stable routes. To ensure the participating nodes are capable of handling the data traffic, two constraints are proposed, mobility and coverage constraints. The former enables the creation of sustainable communication links, and the latter enforces the communication service to the entire MD2D network. Simulation results show that our approach can increase the network lifetime, decrease the end-to-end (E2E) delay, and increase the packet delivery ratio (PDR) compared to the existing proactive routing protocol. Our protocol outperforms the benchmarked MD2D protocols and other investigated ad hoc protocols.
• Efficient Dual-Band Single-Port Rectifier for RF Energy Harvesting at FM and GSM Bands

  Nastouh Nikkhah, Rasool Keshavarz, Mehran Abolhasan, Justin Lipman, Negin Shariati

  2022 Wireless Power Week, WPW 2022 - Proceedings 141 - 145 2022年 

  This paper presents an efficient dual-band rectifier for radiofrequency energy harvesting (RFEH) applications at FM and GSM bands. The single-port rectifier circuit, which comprises a 3-port network, optimized T-matching circuits and voltage doubler, is designed, simulated and fabricated to obtain a high RF-to-DC power conversion efficiency (PCE). Measurement results show PCE of26% and 22% at -20dBm, and also 58% and 51% at -10dBm with a maximum amount of 69% and 65% at -2.5dBm and -5dBm, with single tone at 95 and 925 MHz, respectively. Besides, the fractional bandwidth of 21% at FM and 11% at GSM band is achieved. The measurement and simulation results are in good agreement. Consequently, the proposed rectifier can be a potential candidate for ambient RF energy harvesting and wireless power transfer (WPT). It should be noted that a 3-port network as a duplexer is designed to be integrated with single-port antennas which cover both FM and GSM bands as a low-cost solution. Moreover, based on simulation results, PCE has small variations when the load resistor varies from 10 to 18 kΩ. Therefore, this rectifier can be utilized for any desired resistance within the range, such as sensors and IoT devices.
• ProML: A Decentralised Platform for Provenance Management of Machine Learning Software Systems

  Nguyen Khoi Tran, Bushra Sabir, Muhammad Ali Babar, Nini Cui, Mehran Abolhasan, Justin Lipman

  Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 13444 LNCS 49 - 65 2022年 

  Large-scale Machine Learning (ML) based Software Systems are increasingly developed by distributed teams situated in different trust domains. Insider threats can launch attacks from any domain to compromise ML assets (models and datasets). Therefore, practitioners require information about how and by whom ML assets were developed to assess their quality attributes such as security, safety, and fairness. Unfortunately, it is challenging for ML teams to access and reconstruct such historical information of ML assets (ML provenance) because it is generally fragmented across distributed ML teams and threatened by the same adversaries that attack ML assets. This paper proposes ProML, a decentralised platform that leverages blockchain and smart contracts to empower distributed ML teams to jointly manage a single source of truth about circulated ML assets’ provenance without relying on a third party, which is vulnerable to insider threats and presents a single point of failure. We propose a novel architectural approach called Artefact-as-a-State-Machine to leverage blockchain transactions and smart contracts for managing ML provenance information and introduce a user-driven provenance capturing mechanism to integrate existing scripts and tools to ProML without compromising participants’ control over their assets and toolchains. We evaluate the performance and overheads of ProML by benchmarking a proof-of-concept system on a global blockchain. Furthermore, we assessed ProML’s security against a threat model of a distributed ML workflow.
• An agent-based approach to disintegrate and modularise Software Defined Networks controller

  Vijaya Durga Chemalamarri, Mehran Abolhasan, Robin Braun

  Proceedings - Conference on Local Computer Networks, LCN 407 - 413 2022年 

  The Software Defined Network paradigm deviates from traditional networks by logically centralising and physically separating the control plane from the data plane. In this work, we present the idea of a modular, agent-based SDN controller. We first highlight issues with current SDN controller designs, followed by a description of the proposed framework. We present a prototype for our design to demonstrate the controller in action using a few common use-cases. We continue the discussion by highlighting areas that require further research.
• Soil moisture remote sensing using SIW cavity based metamaterial perfect absorber

  Majid Amiri, Mehran Abolhasan, Negin Shariati, Justin Lipman

  Scientific Reports 11 1 2021年12月 

  Continuous and accurate sensing of water content in soil is an essential and useful measure in the agriculture industry. Traditional sensors developed to perform this task suffer from limited lifetime and also need to be calibrated regularly. Further, maintenance, support, and deployment of these sensors in remote environments provide additional challenges to the use of conventional soil moisture sensors. In this paper, a metamaterial perfect absorber (MPA) based soil moisture sensor is introduced. The ability of MPAs to absorb electromagnetic signals with near 100% efficiency facilitates the design of highly accurate and low-profile radio frequency passive sensors. MPA based sensor can be fabricated from highly durable materials and can therefore be made more resilient than traditional sensors. High resolution sensing is achieved through the creation of physical channels in the substrate integrated waveguide (SIW) cavity. The proposed sensor does not require connection for both electromagnetic signals or for adding a testing sample. Importantly, an external power supply is not needed, making the MPA based sensor the perfect solution for remote and passive sensing in modern agriculture. The proposed MPA based sensor has three absorption bands due to the various resonance modes of the SIW cavity. By changing the soil moisture level, the absorption peak shifts by 10 MHz, 23.3 MHz, and 60 MHz, which is correlated with the water content percentage at the first, second and third absorption bands, respectively. Finally, a 6 × 6 cell array with a total size of 312mm×312mm has been fabricated and tested. A strong correlation between measurement and simulation results validates the design procedure.
• Software-defined networking-based adaptive routing for multi-hop multi-frequency wireless mesh

  Mahrokh Abdollahi, Wei Ni, Mehran Abolhasan, Shenghong Li

  IEEE Transactions on Vehicular Technology 70 12 13073 - 13086 2021年12月01日 

  While multi-hop multi-frequency mesh has been extensively studied in the past decades, only several deployable and relatively bulky systems have been developed to support small numbers of hops under stationary settings. This paper presents a new Software-Defined Networking (SDN)-based design of multihop multi-frequency mesh. A new lightweight hardware platform is developed to support adaptive routing and frequency selection, by modifying and integrating commercial-off-the-shelf WiFi modules. We also extend the celebrated Dijkstra’s algorithm in support of the new multi-hop multi-frequency platform, where non-overlapping frequency bands are selected together with the routing paths by maintaining N2 Dijkstra processes for N frequency bands. These processes interact to recursively select the optimal upstream node and frequency for each downstream frequency of a node. Mininet-WiFi is used to evaluate the routing of the new system under dense network settings. The results indicate that our system improves the end-to-end throughput by taking background WiFi traffic into account and adaptively selecting the routes and frequencies, as compared to the shortest-path-based routing strategy.
• An End-to-End (E2E) Network Slicing Framework for 5G Vehicular Ad-Hoc Networks

  Ammara Anjum Khan, Mehran Abolhasan, Wei Ni, Justin Lipman, Abbas Jamalipour

  IEEE Transactions on Vehicular Technology 70 7 7103 - 7112 2021年07月 

  Network slicing is emerging as a promising solution for end-to-end resource management and orchestration together with Software Defined Networking (SDN) and Network Function Virtualization (NFV) technologies. In this paper, a comprehensive network slicing framework is presented to achieve end-to-end (E2E) QoS provisioning among customized services in 5G-driven VANETs. The proposed scheme manages the cooperation of both RAN and Core Network (CN), using SDN, NFV and Edge Computing technologies. Furthermore, a dynamic radio resource slice optimization scheme is formulated mathematically, that handles a mixture of mission-critical and best effort traffic, by delivering the QoS provisioning of Ultra-reliability and low latency. The proposed scheme adjusts the optimal bandwidth slicing and dynamically adapts to instantaneous network load conditions in a way that a targeted performance is guaranteed. The problem is solved using a Genetic Algorithm (GA) and results are compared with the previously proposed 5 G VANET architecture. Simulation reveal that the proposed slicing framework is able to optimize resources and deliver on the key performance metrics for mission critical communication.
• Optimal Synchronizability in Networks of Coupled Systems: Topological View

  Saber Jafarizadeh, Darryl Veitch, Farzad Tofigh, Justin Lipman, Mehran Abolhasan

  IEEE Transactions on Network Science and Engineering 8 2 1517 - 1530 2021年04月 

  Many engineered and natural systems are modeled as networks of coupled systems. Synchronization is one of their crucial and well-studied behaviors. Uniform coupling strength has been the benchmark practice in the majority of the literature. This paper considers nonuniform coupling strength, and a modified approach to the problem of synchronizability optimization, enabling a reduction to a spectral radius minimization problem, which can reach a unique optimal point on the Pareto Frontier. It is established that adding any edge to a connected graph can only improve synchronizability in this optimal measure. This result is utilized for developing a hierarchy between topologies. It is shown that several proposed structural parameters, including betweenness centrality, do not have any simple relationship to the optimal synchronizability measure.
• Internet of Things 2.0: Concepts, Applications, and Future Directions

  Ian Zhou, Imran Makhdoom, Negin Shariati, Muhammad Ahmad Raza, Rasool Keshavarz, Justin Lipman, Mehran Abolhasan, Abbas Jamalipour

  IEEE Access 9 70961 - 71012 2021年 

  Applications and technologies of the Internet of Things are in high demand with the increase of network devices. With the development of technologies such as 5G, machine learning, edge computing, and Industry 4.0, the Internet of Things has evolved. This survey article discusses the evolution of the Internet of Things and presents the vision for Internet of Things 2.0. The Internet of Things 2.0 development is discussed across seven major fields. These fields are machine learning intelligence, mission critical communication, scalability, energy harvesting-based energy sustainability, interoperability, user friendly IoT, and security. Other than these major fields, the architectural development of the Internet of Things and major types of applications are also reviewed. Finally, this article ends with the vision and current limitations of the Internet of Things in future network environments.
• Multi-band SIW Cavity Based Metamaterial Perfect Absorber

  Majid Amiri, Mehran Abolhasan, Negin Shariati, Justin Lipman

  Asia-Pacific Microwave Conference Proceedings, APMC 2021-November 347 - 349 2021年 

  Absorbing ambient electromagnetic (EM) signals is required in some applications such as energy harvesting and sensing. Metamaterial perfect absorbers (MPAs) are a promising candidate to absorb the EM signal with near-unity efficiency. However, designing a structure with multi absorption bands is still challenging among researchers due to the requiring multi-layer and multi-resonators structures. Herein, a multi-band MPA based on SIW cavity structure is introduced. Taking advantage of various resonance modes of the cavity at higher order, a low-profile, highly efficient, and easy to implement MPA is achieved. In addition, the proposed structure is completely polarization angle insensitive, which is crucial to have a highly efficient EM waves absorber.
• Optimisation of monolithic nanocomposite and transparent ceramic scintillation detectors for positron emission tomography

  Keenan J. Wilson, Roumani Alabd, Mehran Abolhasan, Mitra Safavi-Naeini, Daniel R. Franklin

  Scientific Reports 10 1 2020年12月01日 

  High-resolution arrays of discrete monocrystalline scintillators used for gamma photon coincidence detection in PET are costly and complex to fabricate, and exhibit intrinsically non-uniform sensitivity with respect to emission angle. Nanocomposites and transparent ceramics are two alternative classes of scintillator materials which can be formed into large monolithic structures, and which, when coupled to optical photodetector arrays, may offer a pathway to low cost, high-sensitivity, high-resolution PET. However, due to their high optical attenuation and scattering relative to monocrystalline scintillators, these materials exhibit an inherent trade-off between detection sensitivity and the number of scintillation photons which reach the optical photodetectors. In this work, a method for optimising scintillator thickness to maximise the probability of locating the point of interaction of 511 keV photons in a monolithic scintillator within a specified error bound is proposed and evaluated for five nanocomposite materials (LaBr3:Ce-polystyrene, Gd2O3-polyvinyl toluene, LaF3:Ce-polystyrene, LaF3:Ce-oleic acid and YAG:Ce-polystyrene) and four ceramics (GAGG:Ce, GLuGAG:Ce, GYGAG:Ce and LuAG:Pr). LaF3:Ce-polystyrene and GLuGAG:Ce were the best-performing nanocomposite and ceramic materials, respectively, with maximum sensitivities of 48.8% and 67.8% for 5 mm localisation accuracy with scintillator thicknesses of 42.6 mm and 27.5 mm, respectively.
• Wide-angle metamaterial absorber with highly insensitive absorption for TE and TM modes

  Majid Amiri, Farzad Tofigh, Negin Shariati, Justin Lipman, Mehran Abolhasan

  Scientific Reports 10 1 2020年12月01日 

  Being incident and polarization angle insensitive are crucial characteristics of metamaterial perfect absorbers due to the variety of incident signals. In the case of incident angles insensitivity, facing transverse electric (TE) and transverse magnetic (TM) waves affect the absorption ratio significantly. In this scientific report, a crescent shape resonator has been introduced that provides over 99% absorption ratio for all polarization angles, as well as 70% and 93% efficiencies for different incident angles up to θ= 80 ∘ for TE and TM polarized waves, respectively. Moreover, the insensitivity for TE and TM modes can be adjusted due to the semi-symmetric structure. By adjusting the structure parameters, the absorption ratio for TE and TM waves at θ= 80 ∘ has been increased to 83% and 97%, respectively. This structure has been designed to operate at 5 GHz spectrum to absorb undesired signals generated due to the growing adoption of Wi-Fi networks. Finally, the proposed absorber has been fabricated in a 20 × 20 array structure on FR-4 substrate. Strong correlation between measurement and simulation results validates the design procedure.
• Constraint-based rerouting mechanism to address congestion in software defined networks

  Vijaya Durga Chemalamarri, Robin Braun, Mehran Abolhasan

  2020 30th International Telecommunication Networks and Applications Conference, ITNAC 2020 2020年11月25日 

  In this paper, we propose a traffic rerouting mechanism to address congestion in Software-Defined networks. We employ back-tracking and constraint propagation techniques to find alternate paths to reroute multiple active flows simultaneously. Cost function is based on standard deviation of link-loads. We then compare traffic distribution and link utilisation with and without rerouting active flows. We measure and compare network performance using parameters such as total rate of transfer, jitter, and packet loss with that of Shortest Path First with no rerouting. Our proposed solution produces lower jitter, packet drops, and higher transfer rate. We finally conclude the paper by making observations and discussing the scope of the future work.
• PLEDGE: An IoT-oriented Proof-of-Honesty based Blockchain Consensus Protocol

  Imran Makhdoom, Farzad Tofigh, Ian Zhou, Mehran Abolhasan, Justin Lipman

  Proceedings - Conference on Local Computer Networks, LCN 2020-November 54 - 64 2020年11月16日 

  The existing lottery-based consensus algorithms, such as Proof-of-Work, and Proof-of-Stake, are mostly used for blockchain-based financial technology applications. Similarly, the Byzantine Fault Tolerance algorithms do provide consensus finality, yet they are either communications intensive, vulnerable to Denial-of-Service attacks, poorly scalable, or have a low faulty node tolerance level. Moreover, these algorithms are not designed for the Internet of Things systems that require near-real-time transaction confirmation, maximum fault tolerance, and appropriate transaction validation rules. Hence, we propose "Pledge, "a unique Proof-of-Honesty based consensus protocol to reduce the possibility of malicious behavior during blockchain consensus. Pledge also introduces the Internet of Things centric transaction validation rules. Initial experimentation shows that Pledge is economical and secure with low communications complexity and low latency in transaction confirmation.
• Statistical Learning-Based Dynamic Retransmission Mechanism for Mission Critical Communication: An Edge-Computing Approach

  Muhammad Ahmad Raza, Mehran Abolhasan, Justin Lipman, Negin Shariati, Wei Ni

  Proceedings - Conference on Local Computer Networks, LCN 2020-November 393 - 396 2020年11月16日 

  Mission-critical machine type communication (MC-MTC) systems in which machines communicate to perform various tasks such as coordination, sensing, and actuation, require stringent requirements of ultra-reliable and low latency communications (URLLC). Edge computing being an integral part of future wireless networks, provides services that support URLLC applications. In this paper, we use the edge computing approach and present a statistical learning-based dynamic retransmission mechanism. The proposed approach meets the desired latency-reliability criterion in MC-MTC networks employing framed ALOHA. The maximum number of retransmissions Nr under a given latency-reliability constraint is learned statistically by the devices from the history of their previous transmissions and shared with the base station. Simulations are performed in MATLAB to evaluate a framed-ALOHA system's performance in which an active device can have only one successful transmission in one round composed of (Nr + 1) frames, and the performance is compared with the diversity transmission-based framed-ALOHA.
• A Comprehensive Access Point Placement for IoT Data Transmission through Train-Wayside Communications in Multi-Environment Based Rail Networks

  Mahdi Saki, Mehran Abolhasan, Justin Lipman, Abbas Jamalipour

  IEEE Transactions on Vehicular Technology 69 10 11937 - 11949 2020年10月 

  In this paper, we propose three algorithms for placement of access points (APs) for the purpose of data transportation via train-to-wayside (T2W) communications along a rail network. The first algorithm is proposed to find the minimum number of APs so that the path-loss (PL) does not exceed a desired threshold. Through the second algorithm, the most optimal places for a desired number of APs are determined so that the average PL is minimum. The goal of the third algorithm is to determine the required number and optimal places of APs in a rail network. Furthermore, we propose a model to consider the effects of changes of communication characteristics on the efficiency of the network in different environments. Through such model, the algorithms proposed for placement of APs can be used in different railway scenarios. The proposed algorithms are validated through extensive simulations in Sydney Trains of Australia. The simulation results show that the proposed approach can improve the efficiency of the system at least 21% and up to 165% within 10 different scenarios. We also show that we can approximately transmit over 250 Gigabit data through T2W communications over common WiFi networks.
• PLEDGE: A Proof-of-Honesty based Consensus Protocol for Blockchain-based IoT Systems

  Imran Makhdoom, Farzad Tofigh, Ian Zhou, Mehran Abolhasan, Justin Lipman

  IEEE International Conference on Blockchain and Cryptocurrency, ICBC 2020 2020年05月 

  Exhibition of malicious behavior during blockchain consensus, threats against reputation systems, and high TX latency are significant issues for blockchain-based IoT systems. Hence, to mitigate such challenges we propose Pledge, a unique Proof-of-Honesty based consensus protocol. Initial experimentation shows that Pledge is economical with low computations and communications complexity and low latency in transaction confirmation.
• A novel approach for big data classification and transportation in rail networks

  Mahdi Saki, Mehran Abolhasan, Justin Lipman

  IEEE Transactions on Intelligent Transportation Systems 21 3 1239 - 1249 2020年03月 

  This paper introduces a new framework into future data-driven railway condition monitoring systems (RCM). For this purpose, we have proposed an edge processing unit that includes two main parts: a data classification model that classifies Internet of Things (IoT) data into maintenance-critical data (MCD) and maintenance-non-critical data (MNCD) and a data transmission unit that, based on the class of data, employs appropriate communication methods to transmit data to railway control centers. For the transmission of MNCD, we propose a travel pattern method that employs train stations as points of data offloading so that trains can deliver data as well as passengers at stations. The performance of our proposed solution is successfully validated via three various data sets under different operating conditions.
• Polarization-Insensitive Metamaterial Absorber for Crowd Estimation Based on Electromagnetic Energy Measurements

  Farzad Tofigh, Majid Amiri, Negin Shariati, Justin Lipman, Mehran Abolhasan

  IEEE Transactions on Antennas and Propagation 68 3 1458 - 1467 2020年03月 

  Noninvasive crowd estimation has remained a challenging issue among researchers. Methods such as image analysis and Wi-Fi/Bluetooth probing can always be used to identify and track people. Lately, authors have introduced a noninvasive method for crowd estimation based on ambient RF energy measurements. In this article, a polarization-insensitive multilayer metamaterial absorber is introduced to measure the variation in the available RF energy levels for crowd estimation purposes. The proposed dual-band absorber is designed to absorb and transfer the maximum of the available Wi-Fi energy to a lumped element to enable proper and accurate measurements. To evaluate the design, the proposed structure is fabricated as an array, and its performance is tested, proving perfect absorption at the desired frequencies, 2.4 and 5 GHz.
• Ultra Wideband Dual Polarization Metamaterial Absorber for 5G frequency spectrum

  Majid Amiri, Farzad Tofigh, Negin Shariati, Justin Lipman, Mehran Abolhasan

  14th European Conference on Antennas and Propagation, EuCAP 2020 2020年03月 

  Implementing 5G technology contributes to improve communication quality and facilitate several interesting applications in daily life such as Internet of things. Despite outstanding features of 5G, the amount of ambient electromagnetic waves will be increased significantly in the environment, which may be undesired. Ultra-wideband metamaterial perfect absorber is a promising solution to collect these undesired signals. Using lumped elements in absorber structure to increase the absorption bandwidth leads to design and fabrication process complexity. In this paper, a low profile polarization angle selective metamaterial absorber has been designed to absorb signals in the frequency range of 21.79 GHz to 53.23 GHz with more than 90% efficiency. The relative absorption bandwidth of the final structure is 83.81%. Moreover, the final structure is reasonably insensitive facing different incident angle up to 40 degree.
• Optimizing synchronizability in networks of coupled systems

  Saber Jafarizadeh, Farzad Tofigh, Justin Lipman, Mehran Abolhasan

  Automatica 112 2020年02月 

  Of collective behaviors in networks of coupled systems, synchronization is of central importance and an extensively studied area. This is due to the fact that it is essential for the proper functioning of a wide variety of natural and engineered systems. Traditionally, uniform coupling strength has been the default choice and the synchronizability measure has been employed for analysis and enhancement of synchronizability. The main drawback of optimizing the synchronizability measure is that it can reach the Pareto frontier but not necessarily a unique point on the Pareto frontier. Additionally, the shortcoming of uniform coupling strength is that it can reach Pareto frontier in specific topologies including edge-transitive graphs. To achieve a unique optimal answer on the Pareto frontier, this paper takes a different approach and addresses the synchronizability in networks of coupled dynamical systems with nonuniform coupling strength and optimizing the synchronizability via maximizing the minimum distance between the nonzero eigenvalues of the Laplacian and the acceptable boundaries for the stability of the system. Furthermore, two solution methods, namely the concave–convex fractional programming and the Semidefinite Programming (SDP) formulations of the problem have been provided. The proposed solution methods have been compared over different topologies and branches of an arbitrary network, where the SDP based approach has shown to be less restricted and more suitable for a wider range of topologies.
• PrivySharing: A blockchain-based framework for privacy-preserving and secure data sharing in smart cities

  Imran Makhdoom, Ian Zhou, Mehran Abolhasan, Justin Lipman, Wei Ni

  Computers and Security 88 2020年01月 

  The ubiquitous use of Internet of Things (IoT) ranges from industrial control systems to e-Health, e-commerce, smart cities, agriculture, supply chain management, smart cars, cyber-physical systems and a lot more. However, the data collected and processed by IoT systems especially the ones with centralized control are vulnerable to availability, integrity, and privacy threats. Hence, we present “PrivySharing,” a blockchain-based innovative framework for privacy-preserving and secure IoT data sharing in a smart city environment. The proposed scheme is distinct from existing strategies on many aspects. The data privacy is preserved by dividing the blockchain network into various channels, where every channel comprises a finite number of authorized organizations and processes a specific type of data such as health, smart car, smart energy or financial details. Moreover, access to users’ data within a channel is controlled by embedding access control rules in the smart contracts. In addition, data within a channel is further isolated and secured by using private data collection and encryption respectively. Likewise, the REST API that enables clients to interact with the blockchain network has dual security in the form of an API Key and OAuth 2.0. The proposed solution conforms to some of the significant requirements outlined in the European Union General Data Protection Regulation. We also present a system of reward in the form of a digital token named “PrivyCoin” for users sharing their data with stakeholders/third parties. Lastly, the experimental outcomes advocate that a multi-channel blockchain scales well as compared to a single-channel blockchain system.
• Crowd Estimation Using Electromagnetic Wave Power-Level Measurements: A Proof of Concept

  Farzad Tofigh, Majid Amiri, Negin Shariati, Justin Lipman, Mehran Abolhasan

  IEEE Transactions on Vehicular Technology 69 1 784 - 792 2020年01月 

  Current crowd density estimation technologies that leverage IR depth perception, video and image processing or WiFi/BLE-based sniffing and probing have privacy and deployment issues. This paper presents a novel method for non-intrusive crowd density estimation that monitors variation in EM radiation within an environment. The human body's electrical and magnetic characteristics can be correlated with variations in available EM energy. This allows for the determination of the number of people within a room. Simulations conducted using Comsol to analyse and measure electromagnetic energy levels inside a room containing human bodies. Experimental analysis provides validation of the simulation results by showing $\text{0.8}\;\text{dBm}$ drop on the average level of EM energy per person.
• SDN Controllers Scalability and Performance Study

  Alvaro Mauricio Diaz Tello, Mehran Abolhasan

  2019, 13th International Conference on Signal Processing and Communication Systems, ICSPCS 2019 - Proceedings 2019年12月 

  Software Defined Networks (SDN) is a networking approach that decouples the intelligent control plane from networking devices and establishes a separate entity called 'controller' that rule the behaviour of the data plane on physical networking devices. Due to the rapid evolution and growth of SDN controllers in the market, this paper aims to present an extensive study on performance and scalability of different open source SDN controllers available in the existing literature. This work covers previous studies and expands them with updated information and official benchmarking methodologies. The study provides a framework based on the standards recommended by the IETF (Internet Engineering Task Force) and it will serve as a guideline to the SDN community to benchmark different SDN controllers.
• A Blockchain-based File-sharing System for Academic Paper Review

  Ian Zhou, Imran Makhdoom, Mehran Abolhasan, Justin Lipman, Negin Shariati

  2019, 13th International Conference on Signal Processing and Communication Systems, ICSPCS 2019 - Proceedings 2019年12月 

  As a tool for human technological advancement, the peer-review system acts as a gateway for ensuring academic paper qualities. However, the system has proven to be slow and expensive. Also, biasedness remains an unsolved problem. Such issues could become a major bottleneck, which can adversely impact research progress and dissemination of knowledge. This paper aims to propose a double-blind paper review system to preserve the authors and reviewers anonymity. This system also addresses issues concerning the reviewers payment, inconsistent review metrics, and biased reviews. The proposed solution utilizes the Hyperledger Fabric blockchain with the InterPlanetary File System (IPFS). The blockchain smart contracts provide a base for financial transactions between paper publishers and the reviewers. Hence, we introduce AcadCoin, a novel cryptocurrency used for supporting said financial transactions. Also, the Hyperledger blockchain provides user access control to achieve double-blindness in reviews. Along with the Hyperledger blockchain, the IPFS is used to store the paper documents, review documents and open metrics documents to reduce the storage requirement of the blockchain. A broad system architecture is constructed to combine the blockchain and the file storage system. This system architecture distributes nodes of the system to related parties. Finally, the blockchain network is implemented and tested using the Hyperledger Composer Playground environment.
• Low-Frequency Metamaterial Absorber Using Space-Filling Curve

  Farzad Tofigh, Majid Amiri, Negin Shariati, Justin Lipman, Mehran Abolhasan

  Journal of Electronic Materials 48 10 6451 - 6459 2019年10月01日 

  The extensive use of metamaterials and metamaterial absorbers increases the demand for compact structures in various frequencies. Designing electrically small absorbers for lower frequencies, especially sub-gigahertz applications, is one of the open issues in this field. In this paper, a space filling curve is used to design an absorber operating on low frequencies. The unit cell design is based on a Sierpinski curve with the size of 25×25×1.6mm3 and air-gap of 10 mm. The structure shows 99.9% absorption at 900 MHz on the third step. The system also shows multiple resonances due to its structure. The proposed structure is fabricated and tested and shows a good agreement with simulation results.
• Mapping and scheduling for non-uniform arrival of virtual network function (VNF) requests

  Mahmoud Gamal, Saber Jafarizadeh, Mehran Abolhasan, Justin Lipman, Wei Ni

  IEEE Vehicular Technology Conference 2019-September 2019年09月 

  As a new research concept for both academia and industry, there are several challenges faced by the Network Function Virtualization (NFV). One such challenge is to find the optimal mapping and scheduling for the incoming service requests which is the focus of this study. This optimization has been done by maximizing the number of accepted service requests, minimizing the number of bottleneck links and the overall processing time. The resultant problem is formulated as a multi- objective optimization problem, and two novel algorithms based on genetic algorithm have been developed. Through simulations, it has been shown that the developed algorithms can converge to the near to optimal solutions and they are scalable to large networks.
• Mapping and Scheduling of Virtual Network Functions using Multi Objective Optimization Algorithm

  Mahmoud Gamal, Mehran Abolhasan, Saber Jafarizadeh, Justin Lipman, Wei Ni

  Proceedings - 2019 19th International Symposium on Communications and Information Technologies, ISCIT 2019 328 - 333 2019年09月 

  Within the context of Software-Defined Networking (SDN), the problem of resource allocation for a set of incoming Virtual Network Functions (VNF) service requests has been the focus of many studies. In this paper, a new optimization model has been developed to find the near to optimal mapping and scheduling for the incoming VNF service requests. This model while considering delay, aims to achieve three objectives functions, namely, minimizing the transmission delays occurring in every link, minimizing the processing capacity for every Virtual Machine (VM) and minimizing the processing delay at every VM. The resultant problem is formulated as a multi-objective optimization problem and the developed solution is based on a multi-objective evolutionary algorithm utilizing the decomposition algorithm. Simulation results illustrate that the resulting algorithm is scalable while considering delay and it outperforms the genetic bandwidth link allocation (GA-BA) and genetic non-bandwidth link allocation (GA-NBA) algorithms.
• Enabling Technologies for Ultra-Reliable and Low Latency Communications: From PHY and MAC Layer Perspectives

  Gordon J. Sutton, Jie Zeng, Ren Ping Liu, Wei Ni, Diep N. Nguyen, Beeshanga A. Jayawickrama, Xiaojing Huang, Mehran Abolhasan, Zhang Zhang, Eryk Dutkiewicz, Tiejun Lv

  IEEE Communications Surveys and Tutorials 21 3 2488 - 2524 2019年07月 

  Future 5th generation networks are expected to enable three key services-enhanced mobile broadband, massive machine type communications and ultra-reliable and low latency communications (URLLC). As per the 3rd generation partnership project URLLC requirements, it is expected that the reliability of one transmission of a 32 byte packet will be at least 99.999% and the latency will be at most 1 ms. This unprecedented level of reliability and latency will yield various new applications, such as smart grids, industrial automation and intelligent transport systems. In this survey we present potential future URLLC applications, and summarize the corresponding reliability and latency requirements. We provide a comprehensive discussion on physical (PHY) and medium access control (MAC) layer techniques that enable URLLC, addressing both licensed and unlicensed bands. This paper evaluates the relevant PHY and MAC techniques for their ability to improve the reliability and reduce the latency. We identify that enabling long-term evolution to coexist in the unlicensed spectrum is also a potential enabler of URLLC in the unlicensed band, and provide numerical evaluations. Lastly, this paper discusses the potential future research directions and challenges in achieving the URLLC requirements.
• A hybrid-fuzzy logic guided genetic algorithm (H-FLGA) approach for resource optimization in 5G VANETs

  Ammara Anjum Khan, Mehran Abolhasan, Wei Ni, Justin Lipman, Abbas Jamalipour

  IEEE Transactions on Vehicular Technology 68 7 6964 - 6974 2019年07月 

  To support diversified quality of service demands and dynamic resource requirements of users in 5G driven VANETs, network resources need flexible and scalable resource allocation strategies. Current heterogeneous vehicular networks are designed and deployed with a connection-centric mindset with fixed resource allocation to a cell regardless of traffic conditions, static coverage, and capacity. In this paper, we propose a hybrid-fuzzy logic guided genetic algorithm (H-FLGA) approach for the software defined networking controller, to solve a multi-objective resource optimization problem for 5G driven VANETs. Realizing the service oriented view, the proposed approach formulates five different scenarios of network resource optimization in 5G VANETs. Furthermore, the proposed fuzzy inference system is used to optimize weights of multi-objectives, depending on the type of service requirements of customers. The proposed approach shows the minimized value of multi-objective cost function when compared with the GA. The simulation results show the minimized value of end-to-end delay as compared to other schemes. The proposed approach will help the network service providers to implement a customer-centric network infrastructure, depending on dynamic customer needs of users.
• Localisation of the Lines of Response in a Continuous Cylindrical Shell PET Scanner

  Keenan J. Wilson, Roumani Alabd, Mehran Abolhasan, Daniel R. Franklin, Mitra Safavi-Naeini

  Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS 4844 - 4850 2019年07月 

  This work presents a technique for localising the endpoints of the lines of response in a PET scanner based on a continuous cylindrical shell scintillator. The technique is demonstrated by applying it to a simulation of a sensitivity-optimised continuous cylindrical shell PET system using two novel scintillator materials -a transparent ceramic garnet, GLuGAG:Ce, and a LuF3:Ce-polystyrene nanocomposite. Error distributions for the endpoints of the lines of response in the axial, tangential and radial dimension as well as overall endpoint spatial error are calculated for three source positions; the resultant distribution of error in the placement of the lines of response is also estimated.
• Miniature tri-wideband Sierpinski-Minkowski fractals metamaterial perfect absorber

  Majid Amiri, Farzad Tofigh, Negin Shariati, Justin Lipman, Mehran Abolhasan

  IET Microwaves, Antennas and Propagation 13 7 991 - 996 2019年06月12日 

  With rapidly growing adoption of wireless technologies, requirements for the design of a miniature wideband multiresonators are increasing. In this study, a compact fractal-based metamaterial structure with lumped resistors is described. The structure of the authors proposed absorber is a combination of Sierpinski curve and Minkowski fractal. The new combination provides larger capacitance and inductance in the system enabling perfect absorption at lower frequencies. The final structure with dimensions of 20 × 20 × 1.6 mm3 and an air gap of 12.5 mm provides three main resonances at frequencies of 2.1, 5.1, and 12.8 GHz with bandwidth (absorption ratio over 90%) of 840 MHz, 1.05 GHz, and 910 MHz, respectively.
• Reinforcement Learning for Scheduling Wireless Powered Sensor Communications

  Kai Li, Wei Ni, Mehran Abolhasan, Eduardo Tovar

  IEEE Transactions on Green Communications and Networking 3 2 264 - 274 2019年06月 

  In a wireless powered sensor network, a base station transfers power to sensors by using wireless power transfer (WPT). Inadequately scheduling WPT and data transmission causes fast battery drainage and data queue overflow of some sensors who could have potentially gained high data reception. In this paper, scheduling WPT and data transmission is formulated as a Markov decision process (MDP) by jointly considering sensors' energy consumption and data queue. In practical scenarios, the prior knowledge about battery level and data queue length in MDP is not available at the base station. We study reinforcement learning at the sensors to find a transmission scheduling strategy, minimizing data packet loss. An optimal scheduling strategy with full-state information is also investigated, assuming that the complete battery level and data queue information are well known by the base station. This presents the lower bound of the data packet loss in wireless powered sensor networks. Numerical results demonstrate that the proposed reinforcement learning scheduling algorithm significantly reduces network packet loss rate by 60%, and increases network goodput by 67%, compared to existing non-MDP greedy approaches. Moreover, comparing the optimal solutions, the performance loss due to the lack of sensors' full-state information is less than 4.6%.
• Anatomy of Threats to the Internet of Things

  Imran Makhdoom, Mehran Abolhasan, Justin Lipman, Ren Ping Liu, Wei Ni

  IEEE Communications Surveys and Tutorials 21 2 1636 - 1675 2019年04月 

  The world is resorting to the Internet of Things (IoT) for ease of control and monitoring of smart devices. The ubiquitous use of IoT ranges from industrial control systems (ICS) to e-Health, e-Commerce, smart cities, supply chain management, smart cars, cyber physical systems (CPS), and a lot more. Such reliance on IoT is resulting in a significant amount of data to be generated, collected, processed, and analyzed. The big data analytics is no doubt beneficial for business development. However, at the same time, numerous threats to the availability and privacy of the user data, message, and device integrity, the vulnerability of IoT devices to malware attacks and the risk of physical compromise of devices pose a significant danger to the sustenance of IoT. This paper thus endeavors to highlight most of the known threats at various layers of the IoT architecture with a focus on the anatomy of malware attacks. We present a detailed attack methodology adopted by some of the most successful malware attacks on IoT, including ICS and CPS. We also deduce an attack strategy of a distributed denial of service attack through IoT botnet followed by requisite security measures. In the end, we propose a composite guideline for the development of an IoT security framework based on industry best practices and also highlight lessons learned, pitfalls and some open research challenges.
• A big sensor data offloading scheme in rail networks

  Mahdi Saki, Mehran Abolhasan, Justin Lipman

  IEEE Vehicular Technology Conference 2019-April 2019年04月 

  In this paper, we propose an offloading scheme to transfer massive stored sensor data from rolling stock to railway data centers. We apply a delayed offloading strategy for non-critical stored data assuming that the critical data has been already separated through an appropriate edge processing task and has been sent via a real-time communication such as cellular networks. We propose train stations as potential and feasible spots for data offloading via available wireless local area networks (WLAN) such as existing WiFi network at stations. Thus, stations will not only be the places of passenger exchange but also data exchange. We develop an analytical model customized for the proposed offloading strategy in rail applications. Then we validate the performance of our model through simulation in various scenarios in Omnet. The simulation results shows an accuracy of %98.67 for the proposed analytical model with reference to the simulation results in Omnetpp. Additionally, by using our proposed scheme, we can theoretically offload up to 5.43 GB per each stopping station.
• Efficient cellular base stations sleep mode control using image matching

  Sepehr Ashtari, Farzad Tofigh, Mehran Abolhasan, Justin Lipman, Wei Ni

  IEEE Vehicular Technology Conference 2019-April 2019年04月 

  Green cellular network helps to decrease environmental pollution. In contrast, massive connectivity and demand for higher data rate promise the presence of new generation of cellular system (5G) and small cell networks. Hence, expectation on increasing the number of base stations (BSs), which leads to increase in energy usage. One way to improve energy consumption is by shutting down the redundant BSs while sustaining the Quality-of-Service (QoS) for each user. In this paper, we propose a dynamic structural algorithm based on transportation problem, to switch on/off the BSs in cellular networks without compromising its coverage, and maintain the networks load by neighboring cells. We use weighted graphs to translate our problem as a transportation problem and then use linear programming to solve it. The cost of transport, turning a BS into sleep mode, is illustrated as a function of energy usage,coverage area and load on the BSs. Running the propose method consecutively provides the maximum number of BSs whom are at sleep mode. The methodology explained in this paper reduces energy consumption to almost 40%, whereas maintaining all the existing loads in the network.
• A Routing Protocol for SDN-based Multi-hop D2D Communications

  M. Abdollahi, M. Abolhasan, N. Shariati, J. Lipman, A. Jamalipour, W. Ni

  2019 16th IEEE Annual Consumer Communications and Networking Conference, CCNC 2019 2019年02月25日 

  This paper presents a new Multi-hop Device-to-Device (MD2D) routing protocol, referred to as SMDRP (SDN-based Multi-hop D2D Routing Protocol), for SDN-based wireless networks. Our proposed protocol can be considered as a semi-distributed routing protocol, where an SDN controller manages and controls part of the overall MD2D routing functionality to increase scalability while enabling network operators to control and maintain the out-of-band packet forwarding network. This paper also extends prior work on the Hybrid SDN Architecture for Wireless Distributed Networks (HSAW) [1] and is adapted to the framework presented in this paper. In HSAW, since all link state information is flooded by the controller to the nodes, the network will experience scalability problem. In our approach, this problem is overcome by only passing the next hop for each active route to the mobile nodes. To investigate this, we performed a theoretical and simulation studies comparing HSAW with SMDRP. From our result, it can be seen that for larger density populated networks, SMDRP shows better scalability than HSAW. In addition, mobile nodes need less memory and energy for their communications.
• PrivySharing: A Blockchain-based framework for integrity and privacy-preserving data sharing in Smart Cities

  Imran Makhdoom, Ian Zhou, Mehran Abolhasan, Justin Lipman, Wei Ni

  ICETE 2019 - Proceedings of the 16th International Joint Conference on e-Business and Telecommunications 2 363 - 371 2019年 

  The ubiquitous use of Internet of Things (IoT) ranges from industrial control systems to e-Health, e-commerce, smart cities, supply chain management, smart cars, cyber-physical systems and a lot more. However, the data collected and processed by IoT systems especially the ones with centralized control are vulnerable to availability, integrity, and privacy threats. Hence, we present “PrivySharing,” a blockchain-based innovative framework for integrity and privacy-preserving IoT data sharing in a smart city environment. The proposed scheme is distinct from existing technologies on many aspects. The data privacy is preserved by dividing the blockchain network into various channels, where every channel processes a specific type of data such as health, smart car, smart energy or financial data. Moreover, access to user data within a channel is controlled by embedding access control rules in the smart contracts. In addition, users' data within a channel is further isolated and secured by using private data collection. Likewise, the REST API that enables clients to interact with the blockchain network has dual security in the form of an API Key and OAuth 2.0. The proposed solution also conforms to some of the significant requirements outlined in the European Union General Data Protection Regulation. Lastly, we present a system of reward in the form of a digital token “PrivyCoin” for the users for sharing their data with the stakeholders/third parties.
• PCF-based LTE Wi-Fi aggregation for coordinating and offloading the cellular traffic to D2D network

  Bushra Ismaiel, Mehran Abolhasan, Wei Ni, David Smith, Daniel Franklin, Eryk Dutkiewicz, Marwan M. Krunz, Abbas Jamalipour

  IEEE Transactions on Vehicular Technology 67 12 12193 - 12203 2018年12月 

  Device-to-device (D2D) communication is a promising technology towards 5G networks. D2D communication can offload traffic using licensed/unlicensed band by establishing a direct communication between two users without traversing the base station or core network. However, one of the major challenges of D2D communication is resource allocation and guaranteeing quality-of-service (QoS). In this paper, we establish an optimal queuing scheduling and resource allocation problem for three-tier heterogeneous network based on LTE Wi-Fi aggregation, to offload voice/multimedia traffic from licensed band to unlicensed band using scalable MAC protocol (SC-MP) under various static delay constraints. The access mechanism used for Wi-Fi in SC-MP is point coordination function, which further offloads the multimedia traffic using D2D communication in unlicensed band. Resource allocation and optimal joint queuing scheduling problems are formulated with diverse QoS guarantee between licensed and unlicensed band to minimize the bandwidth of licensed band. Furthermore, an iterative algorithm is proposed to express the nonconvex problem as a series of subproblems based on block coordinate descent and difference of two convex functions (D.C) program. We have simulated the proposed scheme using two scenarios: Voice traffic using licensed band and voice traffic using both licensed and unlicensed band, whereas multimedia traffic uses unlicensed band for both the scenarios. The simulation results show that both the schemes perform better than the existing scheme and scenario 2 outperforms scenario 1.
• A Routing Framework for Offloading Traffic from Cellular Networks to SDN-Based Multi-Hop Device-to-Device Networks

  Mehran Abolhasan, Mahrokh Abdollahi, Wei Ni, Abbas Jamalipour, Negin Shariati, Justin Lipman

  IEEE Transactions on Network and Service Management 15 4 1516 - 1531 2018年12月 

  Device-to-device (D2D) communications are set to form an integral part of future 5G wireless networks. D2D communications have a number of benefits such as improving energy efficiency and spectrum utilization. Until now much of the D2D research in LTE and 5G-type network scenarios have focused on direct (one-hop) communications between two adjacent mobile devices. In this paper, we propose a new routing framework called virtual ad hoc routing protocol (VARP). This framework introduces significant advantages such as better security, lower routing overheads, and higher scalability, when compared to conventional ad hoc routing protocols. It also reduces traffic overhead in LTE networks using multi-hop D2D communications under management of a software defined networking (SDN)-controller. Further, it enables the development of various types of routing protocols for different networking scenarios. To this end, a source-routing based protocol was developed on top of VARP, referred to as VARP-S. We present a detailed analytical study of routing overhead in the VARP-S protocol, as compared to overhead analysis of our previous proposed hybrid SDN architecture for wireless distributed networks (HSAW) Our results show that VARP-S, compared to HSAW, achieves higher network scalability and lower power consumption for mobile nodes.
• Analysis of effective capacity and throughput of polling-based device-to-device networks

  Bushra Ismaiel, Mehran Abolhasan, Wei Ni, David Smith, Daniel Franklin, Abbas Jamalipour

  IEEE Transactions on Vehicular Technology 67 9 8656 - 8666 2018年09月 

  Next-generation wireless networks will give rise to heterogeneous networks by integrating multiple wireless access technologies to provide seamless mobility to mobile users with high-speed wireless connectivity. Device-to-device (D2D) communication has proven to be a promising technology that can increase the capacity and coverage of wireless networks. The D2D communication was first introduced in long-term evolution advanced (LTE-A) and has gained immense popularity for the offloading traffic using the licensed and unlicensed band. Challenges arise from resource allocation, provision of quality-of-service (QoS), and the quantification of capacity in an unlicensed band due to the distributed nature of Wi-Fi. In this paper, we propose an analytical performance model for the scalable MAC protocol (SC-MP) in which a resource allocation mechanism is based on the IEEE 802.11 point coordinated function to access the Wi-Fi channel for voice and video/multimedia traffic. In the SC-MP, D2D communication is applied to further offload the video/multimedia traffic. In particular, this paper establishes a three-state semi-Markovian model to derive a closed-form expression of effective capacity in terms of transmission rate and quality-of-service. Further, the SC-MP is analytically modeled using the four-state traditional Markov model to derive the saturation throughput. The analytical results are validated through simulations, hence, proving the appropriateness of the model.
• A Multi-agent Controller to enable Cognition in Software Defined Networks

  Vijaya Durga Chemalamarri, Robin Braun, Justin Lipman, Mehran Abolhasan

  2018 28th International Telecommunication Networks and Applications Conference, ITNAC 2018 2018年07月02日 

  Current SDN controllers are not cognitive. We propose a new architecture for an SDN controller to enable intelligence. The proposed new architecture is based on Multi-agent systems. As a prototype, we have built a MAS-SDN controller using the GOAL agent programming language. We highlight the motivation behind the new architecture, describe the architecture and provide some initial results.
• Crowd Density Mapping Based on Wi-Fi Measurements on Train Platforms

  Farzad Tofigh, Guoqiang Mao, Justin Lipman, Mehran Abolhasan

  2018, 12th International Conference on Signal Processing and Communication Systems, ICSPCS 2018 - Proceedings 2018年07月02日 

  Crowd distribution is a challenging issue in the management and design levels. This paper provides a passive method to derive the crowd density distribution using Wi-Fi measurements on a real scenario. Six WiFi access points (AP) are deployed in the platform 2/3 of Redfern station, Sydney to monitor the platform for a week. Based on the probability maps that are built using RSSI measurements and prior knowledge, the crowd distribution is calculated on the platform and its results are compared with distributions acquired from CCTV images. Final density heat maps are in good agreement with the acquired results from CCTV cameras.
• Multi objective resource optimisation for network function virtualisation requests

  Mahmoud Gamal, Mehran Abolhasan, Justin Lipman, Ren Ping Liu, Wei Ni

  26th International Conference on Systems Engineering, ICSEng 2018 - Proceedings 2018年07月02日 

  Network function vitalization (NFV) as a new research concept, for both academia and industry, faces many challenges to network operators before it can be accepted into mainstream. One challenge addressed in this paper is to find the optimal placement f or a set of incoming requests with VNF service chains to serve in suitable Virtual Machines (VMs) such that a set of conflicting objectives are met. Mainly, focus is placed on maximizing the total saving cost by increasing the total CPU utilization during the processing time and increasing the processing time for every service request in the cloud network. Moreover, we aim to maximize the admitted traffic simultaneously while considering the system constraints. We formulate the problem as a multi-objective optimization problem and use a Resource Utilization Multi-Objective Evolutionary Algorithm based on Decomposition (RU-MOEA/D) algorithm to solve the problem considering the two objectives simultaneously. Extensive simulations are carried out to evaluate the effects of the different network sizes, genetic parameters and the number of server resources on the acceptable ratio of the arrival chains to serve in the available VMs. The empirical results illustrate that the proposed algorithm can solve the problem efficiently and compute the optimal solution for two objectives together within a reasonable running time.
• Antenna and Propagation Considerations for Amateur UAV Monitoring

  Nan Zhao, Xiaodong Yang, Aifeng Ren, Zhiya Zhang, Wei Zhao, Fangming Hu, Masood Ur Rehman, Haider Abbas, Mehran Abolhasan

  IEEE Access 6 28001 - 28007 2018年05月17日 

  The broad application spectrum of unmanned aerial vehicles is making them one of the most promising technologies of Internet of Things era. Proactive prevention for public safety threats is one of the key areas with vast potential of surveillance and monitoring drones. Antennas play a vital role in such applications to establish reliable communication in these scenarios. This paper considers line-of-sight and non-line-of-sight threat scenarios with the perspective of antennas and electromagnetic wave propagation.
• An evolutionary game theoretic approach for stable and optimized clustering in vanets

  Ammara Anjum Khan, Mehran Abolhasan, Wei Ni

  IEEE Transactions on Vehicular Technology 67 5 4501 - 4513 2018年05月 

  Discovering and maintaining efficient routes for data dissemination in vehicular ad hoc networks (VANETs) has proven to be a very challenging problem. Clustering is one of the control protocols used to provide efficient and stable routes for data dissemination. However, the rapid changes in network topology in VANETs creates frequent cluster reformation, which can seriously affect route stability. We propose a novel evolutionary game theoretic (EGT) framework to automate the clustering of nodes and nominations of cluster heads, to achieve cluster stability in VANETs. The equilibrium point is proven analytically and the stability is also tested using Lyapunov function. The performance of the proposed evolutionary game is empirically investigated with different cost functions using static and mobile scenarios. The simulation results demonstrate the effectiveness and robustness of our proposed EGT approach for different populations and speeds, thus reducing the overhead of frequent cluster reformation in VANETs.
• Analysis of Finite Buffer in Two-Way Relay: A Queueing Theoretic Point of View

  Wei Ni, J. Andrew Zhang, Zhaoxi Fang, Mehran Abolhasan, Ren Ping Liu, Yingjie Jay Guo

  IEEE Transactions on Vehicular Technology 67 4 3690 - 3694 2018年04月 

  The impact of a finite relay buffer on the throughput of two-way relay is analyzed from a new queueing theoretic point of view. Distinctively from recent Markov model based analyses, the proposed queueing theoretic analysis is able to infer closed-form asymptotic upper bounds for the throughput, shed valuable insights, and point out limitations in the recent analyses. Validated by simulations, our queueing theoretic analysis reveals that the throughput is increasingly insusceptible to the size of the relay buffer, as the buffer enlarges. Moreover, locking the relay in transmitting xored packets can hardly improve the throughput, especially under balanced channel conditions. This is due to the fact that the relay queues stabilize nonempty, and hence, xored packets are forwarded in most cases.
• 5G next generation VANETs using SDN and fog computing framework

  Ammara Anjum Khan, Mehran Abolhasan, Wei Ni

  CCNC 2018 - 2018 15th IEEE Annual Consumer Communications and Networking Conference 2018-January 1 - 6 2018年03月16日 

  The growth of technical revolution towards 5G Next generation networks is expected to meet various communication requirements of future Intelligent Transportation Systems (ITS). Motivated by the consumer needs for variety of ITS applications, bandwidth, high speed and ubiquity, researches are currently exploring different network architectures and techniques, which could be employed in Next generation ITS. To provide flexible network management, control and high resource utilization in Vehicular Ad-hoc Networks (VANETs) on large scale, a new hierarchical 5G Next generation VANET architecture is proposed. The key idea of this holistic architecture is to integrate the centralization and flexibility of Software Defined Networking (SDN) and Cloud-RAN (CRAN), with 5G communication technologies, to effectively allocate resources with a global view. Moreover, a fog computing framework (comprising of zones and clusters) has been proposed at the edge, to avoid frequent handovers between vehicles and RSUs. The transmission delay, throughput and control overhead on controller are analyzed and compared with other architectures. Simulation results indicate reduced transmission delay and minimized control overhead on controllers. Moreover, the throughput of proposed system is also improved.
• Wireless Power Transfer and Data Collection in Wireless Sensor Networks

  Kai Li, Wei Ni, Lingjie Duan, Mehran Abolhasan, Jianwei Niu

  IEEE Transactions on Vehicular Technology 67 3 2686 - 2697 2018年03月 

  In a rechargeable wireless sensor network, the data packets are generated by sensor nodes at a specific data rate, and transmitted to a base station. Moreover, the base station transfers power to the nodes by using wireless power transfer (WPT) to extend their battery life. However, inadequately scheduling WPT and data collection causes some of the nodes to drain their battery and have their data buffer overflow, whereas the other nodes waste their harvested energy, which is more than they need to transmit their packets. In this paper, we investigate a novel optimal scheduling strategy, called EHMDP, aiming to minimize data packet loss from a network of sensor nodes in terms of the nodes' energy consumption and data queue state information. The scheduling problem is first formulated by a centralized MDP model, assuming that the complete states of each node are well known by the base station. This presents the upper bound of the data that can be collected in a rechargeable wireless sensor network. Next, we relax the assumption of the availability of full state information so that the data transmission and WPT can be semidecentralized. The simulation results show that, in terms of network throughput and packet loss rate, the proposed algorithm significantly improves the network performance.
• Enabling Ultra-Reliable and Low-Latency Communications through Unlicensed Spectrum

  Gordon J. Sutton, Jie Zeng, Ren Ping Liu, Wei Ni, Diep N. Nguyen, Beeshanga A. Jayawickrama, Xiaojing Huang, Mehran Abolhasan, Zhang Zhang

  IEEE Network 32 2 70 - 77 2018年03月 

  In this article, we aim to address the question of how to exploit the unlicensed spectrum to achieve URLLC. Potential URLLC PHY mechanisms are reviewed and then compared via simulations to demonstrate their potential benefits to URLLC. Although a number of important PHY techniques help with URLLC, the PHY layer exhibits an intrinsic trade-off between latency and reliability, posed by limited and unstable wireless channels. We then explore MAC mechanisms and discuss multi-channel strategies for achieving low-latency LTE unlicensed band access. We demonstrate, via simulations, that the periods without access to the unlicensed band can be substantially reduced by maintaining channel access processes on multiple unlicensed channels, choosing the channels intelligently, and implementing RTS/CTS.
• Opportunistic spectrum allocation for interference mitigation amongst coexisting wireless body area networks

  Samaneh Movassaghi, David B. Smith, Mehran Abolhasan, Abbas Jamalipour

  ACM Transactions on Sensor Networks 14 2 2018年03月 

  Wireless Body Area Networks (WBANs) are seen as the enabling technology for developing new generations of medical applications, such as remote health monitoring. As such it is expected that WBANs will predominantly transport mission-critical and delay sensitive data. A key strategy towards building a reliable WBAN is to ensure such networks are highly immune to interference. To achieve this, new and intelligent wireless spectrum allocation strategies are required not only to avoid interference, but also to make best-use of the limited available spectrum. This article presents a new spectrum allocation scheme referred to as Smart Channel Assignment (SCA), which maximizes the resource usage and transmission speed by deploying a partially-orthogonal channel assignment scheme between coexisting WBANs as well as offering a convenient tradeoff among spectral reuse efficiency, transmission rate, and outage. Detailed analytical studies verify that the proposed SCA strategy is robust to variations in channel conditions, increase in sensor node-density within each WBAN, and an increase in number of coexisting WBANs.
• Blockchain for IoT: The challenges and a way forward

  Imran Makhdoom, Mehran Abolhasan, Wei Ni

  ICETE 2018 - Proceedings of the 15th International Joint Conference on e-Business and Telecommunications 2 428 - 439 2018年 

  Bitcoin has revolutionized the decentralized payment system by excluding the need for a trusted third party, reducing the transaction (TX) fee and time involved in TX confirmation as compared to a conventional banking system. The underlying technology of Bitcoin is Blockchain, which was initially designed for financial TXs only. However, due to its decentralized architecture, fault tolerance and cryptographic security benefits such as user anonymity, data integrity and authentication, researchers and security analysts around the world are focusing on the Blockchain to resolve security and privacy issues of IoT. But at the same time, default limitations of Blockchain, such as latency in transaction confirmation, scalability concerning Blockchain size and network expansion, lack of IoT-centric transaction validation rules, the absence of IoT-focused consensus protocols and insecure device integration are required to be addressed before it can be used securely and efficiently in an IoT environment. Therefore, in this paper we analyze some of the existing consensus protocols used in various Blockchain-based applications, with a focus on investigating significant limitations in TX (Transaction) validation and consensus mechanism that make them inappropriate to be implemented in Blockchain-based IoT systems. We also propose a way forward to address these issues.
• Effect of the number of participating nodes on recovery of WSN coverage holes

  Ali Rafiei, Mehran Abolhasan, Daniel R. Franklin, Farzad Safaei, Stephen Smith, Wei Ni

  2017 27th International Telecommunication Networks and Applications Conference, ITNAC 2017 2017-January 1 - 8 2017年12月15日 

  Coverage holes (CHs) due to the correlated node failures, if not appropriately addressed in a timely manner, not only disrupt network's operation but also can compromise its integrity. In the absence of centralised control, distributed node relocation can be an effective solution to recover CHs. Relocation algorithms that mainly applied to all nodes to address networks' coverage and unbalanced deployments problems, are not efficient as participating nodes beyond a certain distance and depth from the CHs do not significantly contribute to recovery of CHs. Here, the effects of the number of participating nodes and movement iterations on recovery of CHs are examined in two Voronoi-based and one force-based node relocation algorithms.
• A Survey and Comparison of Device-to-Device Architecture Using LTE Unlicensed Band

  Bushra Ismaiel, Mehran Abolhasan, David Smith, Wei Ni, Daniel Franklin

  IEEE Vehicular Technology Conference 2017-June 2017年11月14日 

  Due to the rapid increase in data traffic, one of the solutions provided by mobile operators is to operate Long Term Evolution (LTE) in the unlicensed 5GHz band, as the licensed spectrum is becoming scarce. Mobile operators can expand their network capacity by operating LTE in the unlicensed band at lower cost when compared with using other licensed bands. Device to Device (D2D) communication, proven to be another effective way to enhance the capacity of a network, enables direct data exchange of localized traffic of users in proximity. Applying D2D communication to LTE unlicensed 5GHz band will further improve the network performance and user experience. In this article, we will discuss the new type of solutions that have been proposed for LTE operating in an unlicensed 5GHz band that includes; LTE-Unlicensed (LTE-U), LTE-License Assisted Access (LTE-LAA), LTE WiFi Link Aggregation (LWA), and MuLTEfire. We will discuss the important features along with their advantages and disadvantages and compare these technologies as well. We simulate LTE-LAA, LWA and MuLTEfire technologies in the presence of Wi-Fi hotspot and compare their results. Furthermore, we apply D2D communication to these technologies and from the results we conclude that MuLTEfire can increase the throughput drastically but network saturates quickly. Whereas, applying D2D communication with LWA is beneficial for a scalable network as it will not only increase the network throughput but will increase the network capacity as well.
• Leveraging the Propagation Model to Make Greedy Routing Decisions in Urban Environments

  Abhinay Mukunthan, Craig Cooper, Farzad Safaei, Daniel Franklin, Mehran Abolhasan

  IEEE Vehicular Technology Conference 2017-June 2017年11月14日 

  The CORNER propagation model, first proposed in 2010, has been previously validated and found to be a reasonably accurate representation of propagation scenarios in urban Vehicular Ad Hoc Networks (VANETs). This paper considers the impact of the propagation environment on routing performance and reveals a pressing need to consider more accurate propagation models when designing urban VANET routing protocols. A greedy routing protocol, which uses CORNER's propagation estimates for neighbour selection, is then presented. The new protocol, named Corner Propagation Stateless Routing (CPSR) is compared to GPSR, a benchmark protocol for VANETs, showing between 87% and 300% improvement in packet delivery ratio at higher network loads.
• Biologically inspired self-organization and node-level interference mitigation amongst multiple coexisting wireless body area networks

  Samaneh Movassaghi, Behnam Maleki, David B. Smith, Mehran Abolhasan

  2017 13th International Wireless Communications and Mobile Computing Conference, IWCMC 2017 1221 - 1226 2017年07月19日 

  This paper presents a node-level self-organizing interference avoidance scheme (SIAC) between multiple coexisting wireless body area networks (WBANs) that incorporates self-organization and smart spectrum allocation. It follows a biologically inspired approach based on the theory of pulse-coupled oscillators for self-organization. The proposed scheme makes three major contributions as compared to the current literature. Firstly, it considers node-level interference for internetwork interference mitigation rather than considering each WBAN as a whole. Secondly, it allocates synchronous and parallel transmission intervals for interference avoidance in an optimal manner and dynamically adapts to changes in their coexistence. Finally, it achieves collision-free, self-organized communication with only information of the firing signal of each WBAN and does not require a global coordinator to manage its communications. It operates on a nodes traffic priority, signal strength, and density of sensors in a WBAN. Simulation results show that our proposal achieves a fast convergence time despite the little information it receives. Moreover, SIAC is shown to be robust to variations in signal strength, number of coexisting WBANs and number of sensor nodes within each WBAN.
• On improving the saturation performance of IEEE802.15.6-based MAC protocols in Wireless Body Area Networks

  Sarvin Sadra, Mehran Abolhasan

  2017 13th International Wireless Communications and Mobile Computing Conference, IWCMC 2017 1233 - 1238 2017年07月19日 

  Wireless Body Area Networks (WBANs) were designed to collect and transfer vital physiological parameters within a short distance of the human body by employing low-power, light-weight, small-sized and smart implantable or wearable sensor devices. Lately, WBANs are expected to support various types of applications with data rates from a few Kbps upto 10 Mbps and satisfy the heterogeneous requirements of both medical and consumer electronics applications. Hence, novel communication protocols that consider a unique set of constraints and demands of these networks need to be developed to provide optimum system efficiency and data transmission reliability. As the IEEE 802.15.6 Medium Access Control (MAC) protocol based on the latest WBANs standard, cannot maintain the balance between the strict energy limitation and Quality of Service (QoS) requirements of such networks, this paper focuses on developing MAC protocols to improve the performance of WBANs specifically in the saturation condition. Two IEEE802.15.6-based MAC protocols are proposed to enhance channel access for the highest user priority and the other user priorities in saturated networks. The simulation results show better network performance as well as lower energy consumption in the proposed MAC protocols compared to the IEEE 802.15.6 MAC protocol.
• Scalable MAC protocol for D2D communication for future 5G networks

  Bushra Ismaiel, Mehran Abolhasan, David Smith, Wei Ni, Daniel Franklin

  2017 14th IEEE Annual Consumer Communications and Networking Conference, CCNC 2017 542 - 547 2017年07月17日 

  Device-to-device communication (D2D) will be an integral part of 5G wireless networks. Device-to-Device (D2D) communication provide the additional resources to the cellular users for spatially reusing licensed/unlicensed spectrum by establishing direct communication. Although, D2D communication is gaining significant attention towards offloading traffic in heterogeneous networks in licensed band, no attention has been given to offload traffic in an unlicensed band in a centralized manner. However, a major challenge of D2D communication is managing resources in an efficient manner in a heterogeneous network. This paper will direct a new approach to D2D Communication and will present a scalable MAC protocol for D2D communications based on Point Coordination Function (PCF) access mechanism. The importance of PCF access mechanism is that it operates in a centralized manner and highly suitable for the dense environment, hence, can create a centralized control in a distributive manner. In this article, we propose an innovative three tier 5G architecture for D2D communication, which will offload cellular traffic from the cellular network to the WLAN in a dense environment. Moreover, we will present a new centralized scalable MAC protocol for D2D communication between WLAN users, based on the IEEE 802.11 Point Coordination Function (PCF) access mechanism. Our simulation results show that the proposed MAC scheme can increase the capacity of the network and perform better relative to the legacy Distributed coordination Function (DCF) defined in IEEE 802.11.
• Addressing coverage problem in wireless sensor networks based on evolutionary algorithms

  Sahar Chehrazad, Hadi S. Aghdasi, Negin Shariati, Mehran Abolhasan

  2017 23rd Asia-Pacific Conference on Communications: Bridging the Metropolitan and the Remote, APCC 2017 2018-January 1 - 5 2017年07月02日 

  Wireless Sensor Networks (WSNs) are the key part of Internet of Things, as they provide the physical interface between on-field information and backbone analytic engines. An important role of WSNs-when collecting vital information-is to provide a consistent and reliable coverage. To Achieve this, WSNs must implement a highly reliable and efficient coverage recovery algorithm. In this paper, we take a fresh new approach to coverage recovery based on evolutionary algorithms. We propose EMACB-SA, which introduces a new evolutionary algorithm that selects coverage sets using a fitness function that balances energy efficiency and redundancy. The proposed algorithm improves network's coverage and lifetime in areas with heterogeneous event rate in comparison to previous works and hence, it is suitable for using in disaster management.
• A new trellis model for MAC layer cooperative retransmission protocols

  Wei Ni, Mehran Abolhasan, Brett Hagelstein, Ren Ping Liu, Xin Wang

  IEEE Transactions on Vehicular Technology 66 4 3448 - 3461 2017年04月 

  Comparison studies on timer-based distributed cooperative retransmission protocols are challenging, given a variety of backoff techniques. We propose a new unified model, which can characterize a wide range of cooperative retransmission protocols. The key idea is a new trellis diagram that extrapolates the retransmission probabilities in each timeslot to the entire cooperative process. Following the trellis, performance metrics, such as success rate and collision intensity, can be derived in a structured manner. The new trellis model, coupled with Markov techniques, can be also extended to analyze the distributed binary exponential backoff processes of cooperative retransmissions. Confirmed by simulations, the proposed trellis model accurately reveals the impact of the relays' relative locations and density on different protocols. Our model also has the potential to be used as a management tool to adaptively configure protocol parameters.
• Exponential Antipodal Vivaldi Antenna with Exponential Dielectric Lens

  Majid Amiri, Farzad Tofigh, Ali Ghafoorzadeh-Yazdi, Mehran Abolhasan

  IEEE Antennas and Wireless Propagation Letters 16 1792 - 1795 2017年 

  The expansion of wireless technologies poses various requirements such as stable radiation characteristics in a wide frequency range. This letter presents an exponential antipodal Vivaldi antenna with a dielectric lens replacing part of the substrate in antenna aperture, with dimensions of 76 × 130 mm2. The shape of the lens also follows exponential structure in its inner (where lens meets the antenna substrate) and outer edges. Using a dielectric with higher constant in the proposed antenna provides 1 dB improvement in antenna gain and 24% of 3-dB beamwidth reduction.
• SWPT: A Joint-Scheduling Model for Wireless Powered Sensor Networks

  Kai Li, Wei Ni, Lingjie Duan, Mehran Abolhasan, Jianwei Niu

  Proceedings - IEEE Global Communications Conference, GLOBECOM 2018-January 1 - 6 2017年 

  In a rechargeable wireless sensor network, the data packets are generated by sensor nodes at a specific data rate, and transmitted to a base station. Moreover, the base station transfers power to the nodes by using Wireless Power Transfer (WPT) to extend their battery life. However, inadequately scheduling WPT and data collection causes some of the nodes to drain their battery and have their data buffer overflow, while the others waste their harvested energy, which is more than they need to transmit their packets. In this paper, we investigate a novel optimal scheduling strategy, called Scheduled WPT (SWPT), aiming to minimize data packet loss from a network of wireless powered sensor nodes by jointly considering the sensor nodes' energy consumption and data queue state information. The scheduling problem is formulated by a MDP model, assuming that the complete states of each sensor node are well known by the base station. This presents the best effort performance of the scheduling that can be collected in a wireless powered sensor network. The simulation results show that, in terms of network throughput and packet loss rate, the proposed scheduling model significantly improves the network performance.
• Distributed Hybrid Coverage Hole Recovery in Wireless Sensor Networks

  Mehran Abolhasan, Yashar Maali, Ali Rafiei, Wei Ni

  IEEE Sensors Journal 16 23 8640 - 8648 2016年12月01日 

  Coverage holes (CHs) can compromise the reliability and functionality of wireless sensor networks. The recovery of CHs is challenging, especially in distributed applications where sensors have little knowledge about other sensors' actions. We propose a new game theoretic approach for recovering the CHs in a distributed manner. The key idea is that we formulate a potential game between the sensors, where each mobile sensor in the network only depends on local knowledge of its neighboring nodes and takes CH recovery actions recursively with global convergence. An appropriate combined action of physical relocation and sensing range adjustment can be taken by each sensor to reduce the CHs in an energy-efficient way. Simulation results show that the proposed game theoretic approach is able to substantially increase network lifetime and maintain network coverage in the presence of random damage events, as compared with the prior counterpart(s).
• Utility-based resource allocation for interference limited OFDMA cooperative relay networks

  Nidhal Odeh, Mehran Abolhasan, Farzad Safaei, Daniel R. Franklin, Guoqiang Mao

  Physical Communication 20 74 - 84 2016年09月01日 

  This paper proposes a utility-based resource allocation algorithm for the uplink OFDMA Inter-cell Interference (ICI) limited cooperative relay network. Full channel state information (CSI) is assumed to be available at the resource controller at initial stage, then the work is extended to consider more realistic assumption, i.e., only partial channel state information (PCSI) is available. The proposed algorithm aims to maximize the total system utility while simultaneously satisfying the individual user's minimum data rate requirements. In the proposed algorithm, relay selection is initially performed based on the consideration of ICI. Then, subcarrier allocation is performed to achieve maximum utility assuming equal power allocation. Finally, based on the amount of ICI, a modified water-filling power distribution algorithm is proposed and used to optimize the per-carrier power allocation across the allocated set of subcarriers. The results show that, compared to conventional algorithms, the proposed algorithm significantly improves system performance in terms of total sum data rate, outage probability and fairness.
• Cooperative scheduling with graph coloring for interference mitigation in wireless body area networks

  Samaneh Movassaghi, Mehran Abolhasan, David Smith

  IEEE Wireless Communications and Networking Conference, WCNC 1691 - 1696 2016年04月 

  In this paper, a hybrid scheme incorporating graph coloring and cooperative scheduling schemes is proposed for interference mitigation amongst coexisting wireless body area networks (WBANs). The proposed approach pairs every two WBANs into a cluster and uses cooperative scheduling amongst the pairs in each cluster to minimize interference. A color based approach is used to allocate different colors to coexisting WBANs in a manner such that none of the two interfering WBANs have the same color. Simulation results show that our proposed scheme has far better spatial reuse when compared to the fully color-based scheme. We also provided theoretical analysis of our proposed scheme to validate its efficiency in avoiding interference and increasing spatial reuse.
• Energy scavenging for magnetically coupled communication devices

  Mehrnoush Masihpour, Johnson I. Agbinya, Mehran Abolhasan

  Green Mobile Devices and Networks: Energy Optimization and Scavenging Techniques 211 - 253 2016年04月
• Analytic Performance Model for State-Based MAC Layer Cooperative Retransmission Protocols

  Brett Hagelstein, Mehran Abolhasan, Daniel Franklin, Farzad Safaei, Wei Ni

  IEEE Transactions on Mobile Computing 15 1 32 - 44 2016年01月01日 

  Cooperative retransmission can significantly improve link reliability over lossy and time-varying wireless links. However, comparing retransmission protocols is challenging, and generally requires simplistic assumptions specific to each protocol. In this paper, we develop a general model to evaluate cooperative retransmission protocols with distributed, slot-based contention algorithms. Specifically, we propose to calculate the relay time-out probabilities at a MAC time-slot scale, formulate retransmission outcomes as functions of the time-out probabilities, and derive the probability of a retransmission process for every data frame. We also propose a Markov extension of our model to characterise the dependency between retransmissions of multiple frames. This enables our model to analyse continuous retransmissions of successive frames. Validated by QualNet simulations, our model can analytically predict the probabilities of cooperative retransmissions with an accuracy of ± 1%. As a result, direct comparisons between cooperative retransmission protocols become tangible, without implementing the full protocol in a state-based simulator.
• Enabling interference-aware and energy-efficient coexistence of multiple wireless body area networks with unknown dynamics

  Samaneh Movassaghi, Akbar Majidi, Abbas Jamalipour, David Smith, Mehran Abolhasan

  IEEE Access 4 2935 - 2951 2016年 

  This paper presents an adaptive interference mitigation scheme for multiple coexisting wireless body area networks (WBANs) based on social interaction. The proposed scheme considers the mobility of nodes within each WBAN as well as the relative movement of WBANs with respect to each other. With respect to these mobile scenarios traffic load, signal strength, and the density of sensors in a WBAN are incorporated to optimize transmission time with synchronous and parallel transmissions to significantly reduce the radio interference and energy consumption of nodes. This approach leads to higher packet delivery ratio (PDR) and longer network lifetime even with nodes dynamically moving into and out of each others interference region. We make channel assignment more energy-efficient and further reduce power consumption using transmit power control with simple channel prediction. Simulation results show that our approach maintains optimum spatial reuse with a range of channel dynamics within, and between, coexisting BANs. This protocol based on social interaction is shown to mitigate interference and minimize power consumption, and increase the spatial reuse and PDR of each WBAN, while increasing network lifetime. In the context of the adaptive interference mitigation scheme proposed, this paper also reviews the state of the art in literature on mobility, MAC layer, and power control solutions for WBANs, as well as providing a summary of interference mitigation schemes previously applied for the coexistence of WBANs.
• Diversity and cooperative communications in body area networks

  David B. Smith, Mehran Abolhasan

  Advances in Body-Centric Wireless Communication: Applications and State-of-the-Art 7 - 42 2016年01月01日 

  In this chapter, we investigate diversity and cooperative communications, and particularly cooperative diversity, for body-centric communications in wireless body area networks (BANs). Cooperative diversity for BANs is vitally important for required communications reliability, as well as increasing network and sensor lifetime by potentially reducing energy consumption, as will be shown here. We describe what is meant by cooperative communications and cooperative diversity, including a brief survey of the state-of-the-art. Description and analysis of the benefits of cooperative diversity in BANs is mainly with respect to the physical layer, but there is also some brief discussion of the MAC layer and network layer. In terms of cooperative receive diversity, feasible in IEEE 802.15.6 Standard compliant BAN, several cooperative receive combining techniques are described, which are all beneficial over single-link communications in terms of firstand second-order statistics. A simple, practical, technique of switch-and-examine combining shows good performance in terms of important metrics, and this can be further enhanced when combined with a simple "sample-and-hold" transmit power control, which can help reduce energy consumption for sensor radios.
• Self-organization amongst multiple co-existing wireless body area networks

  Samaneh Movassaghi, Akbar Majidi, David B. Smith, Mehran Abolhasan, Abbas Jamalipour

  IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2015-December 1323 - 1327 2015年12月01日 

  This paper presents a novel primitive for self-organization amongst multiple coexisting Wireless Body Area Networks (WBANs). It follows a biologically inspired approach based on the theory of pulse-coupled oscillators. Our proposal allows for coexisting WBANs to use delayed information from previous transmissions to adjust to a collision-free TDMA schedule amongst each other for future communications. Most importantly, it does not require a global coordinator as all nodes achieve synchronization in a completely self-organized manner. Simulation results show that our protocol achieves a significantly fast convergence time despite little information from its coexisting networks. Moreover, the proposed approach is shown to be robust to variations in channel conditions, density of sensor nodes within each network and the number of coexisting WBANs. We conduct extensive simulations to evaluate the efficiency of the proposed protocol using the NS-2 simulator.
• Software-defined wireless networking: Centralized, distributed, or hybrid?

  Mehran Abolhasan, Justin Lipman, Wei Ni, Brett Hagelstein

  IEEE Network 29 4 32 - 38 2015年07月01日 

  Scalability is a key issue in large scale WDNs, such as vehicular networks and device-to-device networks. To address the issue, this article extends the SDN concept, and presents a new network architecture that eliminates the need of multi-hop flooding for route discovery, thereby enabling WDNs to scale. The key idea of the new architecture is to split network control and data forwarding by using two separate frequency bands. Another important aspect of the architecture is that computational complexity of routing is split between the SDN controller and the forwarding nodes, thereby allowing nodes to make distributed routing decisions. As a result, network control of the new architecture has a hybrid structure, which improves the operability and scalability of large scale WDNs. Our case study shows that the new architecture is able to substantially improve scalability and reliability of WDNs, especially in mobile environments.
• Radio alignment for inductive charging of electric vehicles

  Wei Ni, Iain B. Collings, Xin Wang, Ren Ping Liu, Alija Kajan, Mark Hedley, Mehran Abolhasan

  IEEE Transactions on Industrial Informatics 11 2 427 - 440 2015年04月 

  To maximize power transfer for inductively charging electric vehicles (EVs), charger and battery coils must be aligned. Wireless sensors can be installed to estimate misalignments; however, existing ranging techniques cannot satisfy the precision requirements of the misalignment estimation. We propose a high-precision wireless ranging and misalignment estimation scheme, where high precision is achieved by iteratively measuring, estimating, and aligning the coils. Another key aspect is to convert the nonconvex misalignment estimation to a more tractable problem with a convex objective. We develop a conditional gradient descent method to solve the problem, which performs gradient descent (or conditional gradient descent on the boundary of the search space) and projects out-of-boundary points back into the space. Employing experimentally validated models, we show that our scheme can achieve 92% of the efficiency of perfectly aligned coils in 90% of operations, and tolerate correlated distance measurement errors. In contrast, the prior art is susceptible to correlation, undergoing a significant efficiency degradation of 18.5%.
• Including general environmental effects in K-factor approximation for rice-distributed VANET channels

  Craig Cooper, Abhinay Mukunthan, Farzad Safaei, Montserrat Ros, Daniel Franklin, Mehran Abolhasan

  Physical Communication 14 32 - 44 2015年03月01日 

  This paper presents a method of approximating the Rician K-factor based on the instantaneous static environment. The strongest signal propagation paths are resolved in order to determine specular and diffuse powers for approximation. The model is experimentally validated in two different urban areas in New South Wales, Australia. Good agreement between the model and experimental data was obtained over short-range communication links, demonstrating the suitability of the model in urban VANETs. The paper concludes with recommendations for methods to account for vehicles in the simulation and incorporating additional phenomena (such as scattering) in the approximation.
• Graph theory and its applications to future network planning: Software-defined online small cell management

  Wei Ni, Iain Collings, Justin Lipman, Xin Wang, Meixia Tao, Mehran Abolhasan

  IEEE Wireless Communications 22 1 52 - 60 2015年02月01日 

  Network planning is facing new and critical challenges due to ad hoc deployment, unbalanced and drastically varying traffic demands, as well as limited backhaul and hardware resources in emerging small cell architectures. We discuss the application of graph theory to address the challenges. A clique-based software-defined online network management approach is proposed that captures traffic imbalance and fluctuation of small cells and optimally plans frequencies, infrastructures, and network structure at any instant. Its applications to three important small cell scenarios of cloud radio, point-to-point microwave backhaul, and interoperator spectrum sharing are demonstrated. Comparison studies show that in each of the scenarios, this new approach is able to significantly outperform conventional static offline network planning schemes in terms of throughput and satisfaction levels of small cells with regard to allocated bandwidths. Specifically, the throughput can be improved by 155 percent for the cloud radio scenario and 110.95 percent for the microwave backhaul scenario. The satisfaction level can be improved by 40 percent for interoperator spectrum sharing.
• A geometrical sink-based cooperative coverage hole recovery strategy for WSNs

  Ali Rafiei, Yashar Maali, Mehran Abolhasan, Daniel Franklin

  2015, 9th International Conference on Signal Processing and Communication Systems, ICSPCS 2015 - Proceedings 2015年 

  Unlike sporadic node failures, coverage holes emerging from multiple temporally-correlated node failures can severely affect quality of service in a network and put the integrity of entire wireless sensor networks at risk. Conventional topology control schemes addressing such undesirable topological changes have usually overlooked the status of participating nodes in the recovery process with respect to the deployed sink node(s) in the network. In this paper, a cooperative coverage hole recovery model is proposed which utilises the simple geometrical procedure of circle inversion. In this model, autonomous nodes consider their distances to the deployed sink node(s) in addition to their local status, while relocating towards the coverage holes. By defining suitable metrics, the performance of our proposed model performance is compared with a force-based approach.
• Exploiting unknown dynamics in communications amongst coexisting wireless body area networks

  Samaneh Movassaghi, Akbar Majidi, David Smith, Mehran Abolhasan, Abbas Jamalipour

  Proceedings - IEEE Global Communications Conference, GLOBECOM 2015年 

  In this paper, we propose a prediction algorithm for dynamic channel allocation amongst coexisting Wireless body area networks (WBANs). Variations in channel assignment due to mobility scenarios within each WBAN as well as the movement of WBANs towards each other is investigated. The proposed scheme is further optimized to allocate the optimum transmission time with synchronous and parallel transmissions such that interference is fully avoided. This reduces the number of interfering nodes and leads to better usage of the scarce limitation of resources in these networks, larger network lifetime, higher energy savings and higher throughput. In fact, the aim of this protocol is to mitigate interference along with maintaining minimum power consumption in order to maximize network lifetime and increase the spatial reuse and throughput of each WBAN. Simulation results show that our approach achieves a much higher spatial reuse using the smart spectrum allocation scheme for interference mitigation in collocated WBANs. We conduct extensive simulations for coexistence prediction in different mobility scenarios using the NS-2 simulator. Consequently, we demonstrate the efficiency of the proposed protocol in providing interference-free channel assignments and higher energy savings.
• Simulation of contrasting clustering paradigms under an experimentally-derived channel model

  Craig Cooper, Montserrat Ros, Farzad Safaei, Daniel Franklin, Mehran Abolhasan

  IEEE Vehicular Technology Conference 2014年11月24日 

  This is a simulation study of weight-based and precedence-based clustering paradigms in VANETs under an experimentally-derived channel model. The study reveals that CH election schemes accounting for driver intention form more stable and long-lived clusters. The results also show that ignoring elements of the VANET channel (such as vehicular shadowing) results in an unreliable comparative analysis of protocol performance.
• Error exponent of amplify and forward relay networks in presence of I.I.D. interferers

  Bappi Barua, Farzad Safaei, Mehran Abolhasan

  IEEE Vehicular Technology Conference 2014年11月24日 

  In this paper, we derive the random coding error exponent of amplify-and-forward (AF) relay networks in presence of arbitrary number of independent and identically distributed (i.i.d.) interferers both at the relay and the destination. Multiuser networks are common examples of interference limited networks. We derive the ergodic capacity of the network and present simulation results on the performance of the network where we compare the capacity and error exponent performance of interference limited networks with noise limited networks. Numerical results show that noise limited networks outperform interference limited networks even when only a very few interferers exist in the network.
• Joint energy harvesting and internetwork interference mitigation amongst coexisting Wireless Body Area Networks

  Samaneh Movassaghi, Mehran Abolhasan, David Smith, Abbas Jamalipour

  BODYNETS 2014 - 9th International Conference on Body Area Networks 240 - 246 2014年11月21日 

  This paper investigates simultaneous transfer of information and energy for interference mitigation amongst multiple coexisting Wireless Body Area Networks (WBANs). We propose to utilize interference that falls into the network as a source of energy, which is mainly discarded in conventional interference mitigation schemes. More specifically, in each time slot, a single sensor node is scheduled to receive information whilst the remaining sensor nodes opportunistically harvest the ambient radio frequency energy. We develop a novel opportunistic scheduling scheme, which offers a significantly high network lifetime through a tradeoff between a sensor's spectral efficiency and average amount of energy harvested. Simulation results show that the proposed energy harvesting with smart channel allocation (E-SCA) scheme can achieve optimal spatial reuse and good energy harvesting. We also show that the proposed approach is robust to variations in channel conditions, density of sensor nodes in eachWBAN and increase in number of coexisting WBANs.
• Wireless body area networks: A survey

  Samaneh Movassaghi, Mehran Abolhasan, Justin Lipman, David Smith, Abbas Jamalipour

  IEEE Communications Surveys and Tutorials 16 3 1658 - 1686 2014年 

  Recent developments and technological advancements in wireless communication, MicroElectroMechanical Systems (MEMS) technology and integrated circuits has enabled low-power, intelligent, miniaturized, invasive/non-invasive micro and nano-technology sensor nodes strategically placed in or around the human body to be used in various applications, such as personal health monitoring. This exciting new area of research is called Wireless Body Area Networks (WBANs) and leverages the emerging IEEE 802.15.6 and IEEE 802.15.4j standards, specifically standardized for medical WBANs. The aim of WBANs is to simplify and improve speed, accuracy, and reliability of communication of sensors/actuators within, on, and in the immediate proximity of a human body. The vast scope of challenges associated with WBANs has led to numerous publications. In this paper, we survey the current state-of-art of WBANs based on the latest standards and publications. Open issues and challenges within each area are also explored as a source of inspiration towards future developments in WBANs. © 2014 IEEE.
• Smart spectrum allocation for interference mitigation in Wireless Body Area Networks

  Samaneh Movassaghi, Mehran Abolhasan, David Smith

  2014 IEEE International Conference on Communications, ICC 2014 5688 - 5693 2014年 

  In this paper, a dynamic resource allocation scheme is proposed to avoid interference amongst coexisting Wireless Body Area Networks (WBAN). In the proposed scheme, each WBAN generates a table consisting of interfering nodes from coexisting WBANs in its vicinity. Then each WBAN broadcasts this table to its neighbors, which allows for efficient interpretation of an Interference Region (IR) between each pair of WBANs. The nodes in the IR are later allocated orthogonal sub-channels; whilst nodes that do not exist in the IR can potentially transmit in the same time interval. We further demonstrate a precise tradeoff between the minimum interference level and spatial reuse. Simulation results show that our proposed scheme has far better spectral efficiency compared to the conventional orthogonal schemes, whilst maintaining an acceptable interference level. We also provide mathematical analysis on the proposed scheme to validate its efficiency for increasing spectral efficiency and avoiding interference. To further reduce the interference level, we propose a probabilistic approach, and analytically show that the outage probability can be effectively reduced at the cost of very small change in the spatial reuse factor. © 2014 IEEE.
• Dynamie environmental fading in urban VANETs

  Craig Cooper, Abhinay Mukunthan, Montserrat Ros, Daniel Franklin, Mehran Abolhasan

  2014 IEEE International Conference on Communications, ICC 2014 5641 - 5646 2014年 

  A method of approximating the Rician K-Factor with considerations of the local human-built environment is proposed for urban VANETs. The model is validated experimentally on a busy street in Australia, in the presence and absence of other vehicles. The model is found to accurately predict actual channel measurements in close-range communications scenarios. © 2014 IEEE.
• AIM: Adaptive Internetwork interference mitigation amongst co-existing wireless body area networks

  Samaneh Movassaghi, Mehran Abolhasan, David Smith, Abbas Jamalipour

  Proceedings - IEEE Global Communications Conference, GLOBECOM 2460 - 2465 2014年 

  This paper proposes a novel adaptive internetwork interference mitigation scheme, namely AIM, for environments with multiple coexisting Wireless Body Area Networks (WBANs). The proposed scheme, operating on a nodes' traffic priority, packet length, signal strength and density of sensors in a WBAN, makes three major contributions as compared to the current literature. Firstly, it considers node-level interference for internetwork interference mitigation rather than considering each WBAN as a whole. Secondly, it allocates synchronous and parallel transmission intervals for interference avoidance in an optimal manner. Finally, it significantly reduces the number of orthogonal channels assigned to achieve a higher throughput as well as better usage of the scarce limitation of resources in WBANs. Simulation results show that our protocol achieves a significantly higher spatial reuse compared to existing approaches for interference mitigation in WBANs.
• Intelligent hybrid cheapest cost and mobility optimization RAT selection approaches for heterogeneous wireless networks

  Abdallah A.L. Sabbagh, Robin Braun, Mehran Abolhasan

  Journal of Networks 9 2 297 - 305 2014年 

  The evolution of wireless networks has led to the deployment of different Radio Access Technologies (RATs) such as UMTS Terrestrial Radio Access Network (UTRAN), Long Term Evolution (LTE), Wireless Local Area Network (WLAN) and Mobile Worldwide Interoperability for Microwave Access (WiMAX) which are integrated through a common platform. Common Radio Resource Management (CRRM) was proposed to manage radio resource utilization in heterogeneous wireless networks and to provide the required Quality of Service (QoS) for allocated calls. RAT selection algorithms are an integral part of the CRRM algorithms. Their role is to decide, when a new or Vertical Handover (VHO) call is requested, which of the available RATs is most suitable to fit the need of the incoming call and when to admit them. This paper extends our earlier work on the proposed intelligent mobility optimization and proposes an intelligent hybrid cheapest cost RAT selection approach which aims to increase users' satisfaction by allocation users that are looking for cheapest cost connections to a RAT that offers the cheapest cost of service. A comparison for the performance of centralized load-balancing, proposed and distributed cheapest cost and mobility optimization algorithms is presented. Simulation results show that the proposed intelligent algorithms perform better than the centralized load-balancing and the distributed algorithms. © 2014 Academy Publisher.
• Performance analysis of the intelligent mobility optimization CRRM approach using a markovian chain model

  Abdallah A.L. Sabbagh, Robin Braun, Mehran Abolhasan

  Journal of Networks 9 3 635 - 644 2014年 

  Due to the increasing demand of wireless services, mobile technology has rapidly progressed towards the fourth generation (4G) networking paradigm. This generation will be heterogeneous in nature and it can be achieved through the integration of different Radio Access Technologies (RATs) over a common platform. Common Radio Resource Management (CRRM) was proposed to manage radio resource utilization in heterogeneous wireless networks and to provide required Quality of Service (QoS) for allocated calls. RAT selection algorithms are an integral part of the CRRM algorithms. Their role is to decide, when a new or Vertical Handover (VHO) call is requested, which of the available RATs is most suitable to fit the need of the incoming call and when to admit them. This paper extends our earlier work on the proposed intelligent hybrid mobility optimization RAT selection approach which allocates users in high mobility to the most suitable RAT and proposes an analytical presentation of the proposed approach in a multidimensional Markov chain model. A comparison for the performance of centralized load-balancing, distributed and the proposed intelligent mobility optimization algorithms is presented in terms of new calls blocking probability, VHO calls dropping probability, users' satisfactions probability, average networks load and average system throughput. Simulation and analytical results show that the proposed algorithm performs better than the centralized loadbalancing and distributed algorithms. © 2014 ACADEMY PUBLISHER.
• Improving fairness in IEEE 802.11 networks using MAC layer opportunistic retransmission

  B. Hagelstein, M. Abolhasan, D. Franklin, F. Safaei

  Computer Networks 57 17 3410 - 3427 2013年12月09日 

  This paper introduces DAFMAC (Decode And Forward MAC), a scalable opportunistic cooperative retransmission enhancement for the IEEE 802.11 MAC protocol which operates without the need for additional explicit control signalling. Distributed opportunistic retransmission algorithms rely on selecting a single suitable relay without direct arbitration between nodes. Simulations show that DAFMAC offers a significant improvement in fairness for both throughput and jitter, giving multiple parallel data flows a more equal opportunity to utilise the channel. DAFMAC cooperative retransmissions are shown to reduce node energy consumption for a given throughput. Further, the DAFMAC relay selection algorithm is shown to scale very well in terms of complexity and memory requirements in comparison to other cooperative retransmission schemes. © 2013 Elsevier B.V. All rights reserved.
• Optimised relay selection for route discovery in reactive routing

  Huda Alaamri, Mehran Abolhasan, Daniel Franklin, Justin Lipman

  Ad Hoc Networks 11 1 70 - 88 2013年01月 

  On-demand routing protocols have the potential to provide scalable information delivery in large ad hoc networks. The novelty of these protocols is in their approach to route discovery, where a route is determined only when it is required by initiating a route discovery procedure. Much of the research in this area has focused on reducing the route discovery overhead when prior knowledge of the destination is available at the source or by routing through stable links. Hence, many of the protocols proposed to date still resort to flooding the network when prior knowledge about the destination is un-available. This paper proposes a novel routing protocol for ad hoc networks, called On-demand Tree-based Routing Protocol (OTRP). This protocol combines the idea of hop-by-hop routing (as used by AODV) with an efficient route discovery algorithm called Tree-based Optimised Flooding (TOF) to improve scalability of ad hoc networks when there is no prior knowledge about the destination. To achieve this in OTRP, route discovery overheads are minimised by selectively flooding the network through a limited set of nodes, referred to as branching nodes. The key factors governing the performance of OTRP are theoretically analysed and evaluated, including the number of branch nodes, location of branching nodes and number of Route REQuest (RREQ) retries. It was found that the performance of OTRP (evaluated using a variety of well-known metrics) improves as the number of branching nodes increases and the number of consumed RREQ retries is reduced. Additionally, theoretical analysis and simulation results shows that OTRP outperforms AODV, DYMO, and OLSR with reduced overheads as the number of nodes and traffic load increases. © 2012 Elsevier B.V. All rights reserved.
• An energy efficient network coding approach for wireless body area networks

  Samaneh Movassaghi, Mahyar Shirvanimoghaddam, Mehran Abolhasan, David Smith

  Proceedings - Conference on Local Computer Networks, LCN 468 - 475 2013年 

  In this paper, we propose a practical network coding approach for wireless body are networks (WBANs) using decode-and-forward relays. In this scheme, namely decode and forward-network coding (DF-NC), each relay linearly combines different messages from different sources to generate one message, and then transmits that message to the destination. Each relay node in DF-NC requires only one transmission time slot to forward its message. Thus, in this approach, energy usage at each relay is minimized compared to existing cooperative schemes without network coding, which require Ns time slots per relay for relay transmissions; where Ns is the number of source nodes. Simulation results show that the proposed DF-NC scheme can achieve near optimal outage probability while minimizing the number of transmissions per node, maximizing the energy efficiency of WBANs, and minimizing the delay. © 2013 IEEE.
• EAR-BAN: Energy efficient adaptive routing in Wireless Body Area Networks

  Md Tanvir Ishtaique Ul Huque, Kumudu S. Munasinghe, Mehran Abolhasan, Abbas Jamalipour

  2013, 7th International Conference on Signal Processing and Communication Systems, ICSPCS 2013 - Proceedings 2013年 

  Wireless Body Area Network (WBAN), a neoteric intelligent monitoring system, is envisaged to unleash a wave of personalized, advanced and integrated applications in the field of medical, fitness, sports, entertainment, military and consumer electronics. In WBAN, network longevity is a major challenge due to the limitation in the availability of energy supply and routing protocol plays a key role towards making such networks energy efficient. In this paper, we propose an energy efficient cluster based routing protocol for WBANs, named as energy efficient adaptive routing in wireless body area network (EAR-BAN). Although EAR-BAN is a cluster based routing protocol, it also combines the benefits of direct and multi hop transmission methods, depending on the energy level and spatial information of body nodes, to formalize an energy efficient, adaptive and opportunistic routing. Moreover, its centralized operation reduces the computational burden of body nodes. © 2013 IEEE.
• SEA-BAN: Semi-autonomous adaptive routing in wireless body area networks

  Md Tanvir Ishtaique Ul Huque, Kumudu S. Munasinghe, Mehran Abolhasan, Abbas Jamalipour

  2013, 7th International Conference on Signal Processing and Communication Systems, ICSPCS 2013 - Proceedings 2013年 

  Wireless Body Area Network (WBAN), an intelligent health monitoring system, is introduced advanced and integrated applications in the field of medical, fitness, sports, entertainment, military and consumer electronics. In WBAN, due to the limitation in the availability of energy supply, network longevity is a major challenge. Since 80% of total energy is consumed only because of communication purpose in WBAN, routing protocols play a key role towards making such networks energy efficient. In this paper, we propose an energy efficient cluster-based routing protocol for WBANs, named as semiautonomous adaptive routing in wireless body area network (SEA-BAN). SEA-BAN distributes the energy dissipation evenly among the body nodes and enhances the network lifetime. It is not simply a cluster-based routing protocol; it also combines the benefits of direct transmission and multi-hop transmission methods, depending on the energy level and spatial information of the body nodes, to formalize an adaptive routing. Moreover, its centralized operation reduces the computational burden of body nodes. The comparative analysis of our simulation results show that SEA-BAN enhances the network lifetime by more than 2 times when compared to the multi-hop transmission model and about 8.5 times than the direct transmission model. © 2013 IEEE.
• An iteratively tuned fuzzy logic movement model in WSN using particle swarm optimization

  Ali Rafiei, Yashar Maali, Mehran Abolhasan, Daniel Franklin, Stephen Smith

  2013, 7th International Conference on Signal Processing and Communication Systems, ICSPCS 2013 - Proceedings 2013年 

  In contrast to adding new nodes, relocation of deployed nodes in mobile wireless sensor networks seems to be an effective solution to cope with undesirable, unpredictable and uncontrolled network topology changes due to nodes' drift and failure. At the price of less global control, there is a trend in recent years towards giving nodes more autonomy and devising localized relocation algorithms to address challenges of network topology control in harsh and hostile environments in the absence of centralized control. Inspired by laws of nature, a large variety of distributed node relocation algorithms have been designed to alleviate undesirable oscillations caused by local interactions and uncertainties among autonomous nodes as they reach their desired formations. Force-based distributed relocation algorithms governed by virtual push-pull forces among autonomous nodes are among such aforesaid algorithms. Adapting fuzzy logic model in exerting proper amount of forces to reduce node movement oscillation seems to be promising as its conforms well with uncertainties and interactions of autonomous nodes. However, parameters of fuzzy logic relocation model should be tuned so to enable nodes to exert proper amount of forces among their in-range neighbours. In this paper, by using particle swarm optimization, parameters of fuzzy relocation model are obtained based on the desired combinations of performance metrics within nodes' range in each movement iteration. The result shows that our model either outperforms or matches DSSA movement model. © 2013 IEEE.
• A general performance model for MAC layer cooperative retransmission contention protocols

  Brett Hagelstein, Mehran Abolhasan, Daniel Franklin, Farzad Safaei

  Proceedings - IEEE Global Communications Conference, GLOBECOM 1584 - 1589 2013年 

  Cooperative retransmission schemes can significantly improve transmission reliability and performance over high loss and time-varying links. However, analytically comparing performance between retransmission strategies is challenging and generally requires simplistic assumptions. This paper presents a general model for the performance of distributed, slot-based contention algorithms for opportunistic decode and forward retransmission algorithms. The model is independent of specific modulation or coding schemes and may be adapted to suit state-based transmission probability models. The model is validated through QualNet simulations. © 2013 IEEE.
• A review of routing protocols in wireless body area networks

  Samaneh Movassaghi, Mehran Abolhasan, Justin Lipman

  Journal of Networks 8 3 559 - 575 2013年 

  Recent technological advancements in wireless communication, integrated circuits and Micro-Electro-Mechanical Systems (MEMs) has enabled miniaturized, low-power, intelligent, invasive/ non-invasive micro and nano-technology sensor nodes placed in or on the human body for use in monitoring body function and its immediate environment referred to as Body Area Networks (BANs). BANs face many stringent requirements in terms of delay, power, temperature and network lifetime which need to be taken into serious consideration in the design of different protocols. Since routing protocols play an important role in the overall system performance in terms of delay, power consumption, temperature and so on, a thorough study on existing routing protocols in BANs is necessary. Also, the specific challenges of BANs necessitates the design of new routing protocols specifically designed for BANs. This paper provides a survey of existing routing protocols mainly proposed for BANs. These protocols are further classified into five main categories namely, temperature based, cross-layer, cluster based, cost-effective and QoS-based routing, where each protocol is described under its specified category. Also, comparison among routing protocols in each category is given. © 2013 ACADEMY PUBLISHER.
• Multihop relay techniques for communication range extension in near-field magnetic induction communication systems

  Mehrnoush Masihpour, Daniel Franklin, Mehran Abolhasan

  Journal of Networks 8 5 999 - 1011 2013年 

  In this paper, multihop relaying in RF-based com munications and near field magnetic induction communication (NFMIC) is discussed. Three multihop relay strategies for NFMIC are proposed: Non Line of Sight Magnetic Induction Relay (NLoS-MI Relay), Non Line of Sight Master/Assistant Magnetic Induction Relay1 (NLoS-MAMI Relay1) and Non Line of Sight Master/Assistant Magnetic Induction Relay2 (NLoSMAMI Relay2). In the first approach only one node contributes to the communication, while in the other two techniques (which are based on a master-assistant strategy), two relaying nodes are employed. This paper shows that these three techniques can be used to overcome the problem of dead spots within a body area network and extend the communication range without increasing the transmission power and the antenna size or decreasing receiver sensitivity. The impact of the separation distance between the nodes on the achievable RSS and channel data rate is evaluated for the three techniques. It is demonstrated that the technique which is most effective depends on the specific network topology. Optimum selection of nodes as relay master and assistant based on the location of the nodes is discussed. The paper also studies the impact of the quality factor on achievable data rate. It is shown that to obtain the highest data rate, the optimum quality factor needs to be determined for each proposed cooperative communication method. © 2013 ACADEMY PUBLISHER.
• Experimental validation of the CORNER urban propagation model based on signal power measurements in a vehicular environment

  Abhinay Mukunthan, Craig Cooper, Farzad Safaei, Daniel Franklin, Mehran Abolhasan, Montserrat Ros

  IEEE Wireless Communications and Networking Conference, WCNC 2626 - 2631 2013年 

  CORNER is an urban propagation model which simulates the presence of buildings in city scenarios and models radio propagation as a series of reflections and diffractions around buildings. CORNER was validated in the original publication with a series of packet-delivery-ratio measurements. However, the accuracy of these measurements is limited by interference from nearby networks. This paper independently evaluates the CORNER model using signal strength measurements across three separate sites in Sydney and Wollongong. The measurements are analysed and compared with the predicted analytical estimates. The fading model is also analysed with direct measurements. A new CORNER link classification algorithm is also proposed in this paper. © 2013 IEEE.
• Outage probability of multihop relay networks

  Bappi Barua, Mehran Abolhasan, Daniel R. Franklin, Farzad Safaei

  2013 9th International Wireless Communications and Mobile Computing Conference, IWCMC 2013 456 - 460 2013年 

  In this paper we analyze the outage performance of a multihop cooperative relay network where relays in the system can change positions dynamically and use all possible links to forward the message to the next hop over Rayleigh fading channels. We derive the general closed form expression of outage probability and asymptotic coding gain of the network. © 2013 IEEE.
• A cooperative network coding approach to reliable wireless body area networks with demodulate-and-forward

  Samaneh Movassaghi, Mahyar Shirvanimoghaddam, Mehran Abolhasan

  2013 9th International Wireless Communications and Mobile Computing Conference, IWCMC 2013 394 - 399 2013年 

  In this paper, a novel cooperative transmission scheme via network coding has been proposed for Wireless Body Area Networks (WBANs) to enhance reliability and throughput. In the proposed scheme, namely Random XOR Network Coding (RXNC), each relay demodulates the received signal from each sensor node and then selects d different coded symbols amongst them and XORs them to generate a network coded symbol. We have found the optimum value of d through an analytical approach by minimizing the probability that an XOR network coded symbol is incorrectly generated. Simulation results show that the proposed RXNC scheme outperforms the no-cooperation and conventional bitwise network coding schemes in all channel signal to noise ratios (SNRs) from 0 dB to 18 dB. © 2013 IEEE.
• A tuned fuzzy logic relocation model in WSNs using particle swarm optimization

  Ali Rafiei, Yashar Maali, Mehran Abolhasan, Daniel Franklin, Farzad Safaei, Stephen Smith

  IEEE Vehicular Technology Conference 2013年 

  In harsh and hostile environments, swift relocation of currently deployed nodes in the absence of centralized paradigm is a challenging issue in WSNs. Reducing the burden of centralized relocation paradigms by the distributed movement models comes at the price of unpleasant oscillations and excessive movements due to nodes' local and limited interactions. If the nodes' careless movements in the distributed relocation models are not properly addressed, their power will be exhausted. Therefore, in order to exert proper amount of virtual radial/angular push/pull forces among the nodes, a fuzzy logic relocation model is proposed and by considering linear combination of the presented performance metric(s)(i.e. coverage, uniformity, and average movement), its parameters are locally and globally tuned by particle swarm optimization(PSO). In order to tune fuzzy parameters locally and globally, PSO benefits respectively from nodes' neighbours within different ranges and all the given deployed area. Performance of locally and globally tuned fuzzy relocation models is compared with one another in addition to the distributed self-spreading algorithm (DSSA). It is shown that by applying PSO to the linear combinations of desired metric(s) to obtain tuned fuzzy parameters, the relocation model outperforms and/or is comparable to DSSA in one or more performance metric(s). Copyright © 2013 by the Institute of Electrical and Electronic Engineers, Inc.
• SEP of multihop relay networks in nakagami-m fading channels

  Bappi Barua, Mehran Abolhasan, Daniel R. Franklin, Farzad Safaei

  IEEE Vehicular Technology Conference 2013年 

  In this paper we analyze the error performance of a cooperative multihop parallel relay network over Nakagamim fading channels using M-ary Phase-shift keying (MPSK) modulation. We derive the general closed form expression of the symbol error probability (SEP) and present numerical results on the performance of the network. Copyright © 2013 by the Institute of Electrical and Electronic Engineers, Inc.
• Effect of conducting polypyrrole on the transport properties of carbon nanotube yarn

  Javad Foroughi, Bahram Kimiaghalam, Shaban Reza Ghorbani, Farzad Safaei, Mehran Abolhasan

  Thin Solid Films 520 24 7049 - 7053 2012年10月01日 

  Experiments were conducted to measure the electrical conductivity in three types of pristine and carbon nanotube-polypyrrole (CNT-PPy) composite yarns and its dependence on over a wide temperature range. The experimental results fit well with the analytical models developed. The effective energy separation between localized states of the pristine CNT yarn is larger than that for both the electrochemically and chemically prepared CNT-PPy yarns. It was found that all samples are in the critical regime in the insulator-metal transition, or close to the metallic regime at low temperature. The electrical conductivity results are in good agreement with a Three Dimensional Variable Range Hopping model at low temperatures, which provides a strong indication that electron hopping is the main means of current transfer in CNT yarns at T < 100 K. We found that the two shell model accurately describes the electronic properties of CNT and CNT-PPy composite yarns in the temperature range of 5-350 K. © 2012 Elsevier B.V. All rights reserved.
• NFMIC cooperative communication methods for body area networks

  Mehrnoush Masihpour, Mehran Abolhasan, Daniel Franklin

  Journal of Networks 7 9 1431 - 1440 2012年 

  To achieve higher data rate or to extend the coverage range of a wireless communication system, cooperative relay has been seen as a promising solution. This concept has been integrated in many traditional wireless communication networks. However, it has not been extensively examined for near field magnetic induction communication (NFMIC) systems. This paper ims to apply cooperative relay to NFMIC in a sense that is applicable to body area networking, since NFMIC is stated to be a suitable physical layer for body area networks. We have shown that using idle NFMIC nodes as relaying terminals, the system performance will be enhanced, as compared to a point to point communication system. In this context we have proposed three relaying methods to enhance the data rate and the received signal power in a personal area network. The relaying strategies are denoted as MI-Relay, MAMI Relay1 and MAMI Relay2. In this paper, using theoretical studies and simulation results, we have compared the performance of the three strategies and we have shown that higher data rates can be achieved through MAMI Relay1. However, we have discussed that the separation distance between relaying nodes and the source or destination can be a key factor for relay node selection. © 2012 ACADEMY PUBLISHER.
• A mobility optimization CRRM approach for next generation wireless networks

  Abdallah A.L. Sabbagh, Robin Braun, Mehran Abolhasan

  2012 International Conference on Computer and Information Science, ICCIS 2012 - A Conference of World Engineering, Science and Technology Congress, ESTCON 2012 - Conference Proceedings 2 609 - 613 2012年 

  Next Generation Wireless Networks (NGWN) are predicted to be heterogeneous in nature. This is achieved through the integration of different Radio Access Technologies (RATs) over a common platform. Common Radio Resource Management (CRRM) was proposed to manage radio resource utilization in heterogeneous wireless networks and to provide required Quality of Service (QoS) for allocated calls. RAT selection algorithms are an integral part of the CRRM algorithms. Their role is to decide, when a new or Vertical Handover (VHO) call is requested, which of the available RATs is most suitable to fit the need of the incoming call and when to admit them. In this paper, we propose an intelligent hybrid RAT selection approach for mobility optimization (patent pending) which includes sorting available RATs, collecting information on each RAT using the IEEE P1900.4 Protocol, and making decisions for selecting the most suitable RAT for incoming calls. A comparison for the performance of centralized load-balancing, distributed and the proposed mobility optimization algorithms is presented in terms of new calls blocking probability, VHO calls dropping probability and satisfactions probability. Simulation results show that the proposed algorithm performs better than the centralized load-balancing and distributed algorithms in terms of blocking, dropping and satisfactions probabilities. © 2012 IEEE.
• Energy efficient thermal and power aware (ETPA) routing in Body Area Networks

  Samaneh Movassaghi, Mehran Abolhasan, Justin Lipman

  IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 1108 - 1113 2012年 

  Research on routing in a network of intelligent, lightweight, micro and nano-technology sensors deployed in or around the body, namely Body Area Network (BAN), has gained great interest in the recent years. In this paper, we present an energy efficient, thermal and power aware routing algorithm for BANs named Energy Efficient Thermal and Power Aware routing (ETPA). ETPA considers a node's temperature, energy level and received power from adjacent nodes in the cost function calculation. An optimization problem is also defined in order to minimize average temperature rise in the network. Our analysis demonstrates that ETPA can significantly decrease temperature rise and power consumption as well as providing a more efficient usage of the available resources compared to the most efficient routing protocol proposed so far in BANs, namely PRPLC. Also, ETPA has a considerably higher depletion time that guarantees a longer lasting communication among nodes. © 2012 IEEE.
• On the impact of RD link in resource allocation for multi-cell OFDMA cooperative relay networks with partial CSI

  Nidhal Odeh, Mehran Abolhasan, Farzad Safaei, Daniel R. Franklin

  2012 International Symposium on Communications and Information Technologies, ISCIT 2012 690 - 695 2012年 

  This paper investigates the impact of the relay-to-destination channel gain on subcarrier allocation for uplink OFDMA based cooperative relay networks using multiple amplify-and- forward (AF) relaying protocols. The closed form outage probability is derived for the system under partial channel state information (PCSI) and considering the presence of intercell interference (ICI). The results show that the impact of the link between the relay station and the destination is very low when the ICI is high. Hence, under this condition, the channel information of this link can be ignored during the resource allocation which significantly reduces the complexity of the resource allocation processes. Furthermore, this paper quantifies the level of interference at which the RD link can be ignored. © 2012 IEEE.
• Wireless technologies for Body Area Networks: Characteristics and challenges

  Samaneh Movassaghi, Perzila Arab, Mehran Abolhasan

  2012 International Symposium on Communications and Information Technologies, ISCIT 2012 42 - 47 2012年 

  Body Area Networks (BANs) are an exciting new networking technology expected to cause a dramatic shift on the way people think and manage their health and the way they benefit from information technology and advancements in a wide range of medical and non-medical applications. Since BANs are in the early stages of their development, a number of fundamental features and challenges need to be investigated to overcome the stringent requirements tied with this technology. Also the choice of an appropriate wireless technology is required to enable BAN systems to communicate physiological data. This paper provides an overview of existing wireless technologies applicable to BANs. The specific features of each wireless technology is described along with their major advantages, drawbacks and most appropriate application in BANs. Comparison of the described technologies are provided from different aspects of frequency range, data rate, coverage area, modulation technique and network topology. © 2012 IEEE.
• A power efficient RAT selection algorithm for heterogeneous wireless networks

  Abdallah Al Sabbagh, Robin Braun, Mehran Abolhasan

  2012 International Symposium on Communications and Information Technologies, ISCIT 2012 997 - 1002 2012年 

  The Fourth Generation of wireless network (4G) is a heterogeneous network where different Radio Access Technologies (RATs) are integrated. This requires a need for Common Radio Resource Management (CRRM) to support efficient utilization of radio resources and to provide the required Quality of Service (QoS) for allocated calls. RAT selection algorithms are an important part of CRRM. This paper proposes an intelligent hybrid power efficient RAT selection algorithm (patent pending1). It is a battery power saver algorithm which includes sorting available RATs, collecting information on each RAT using the IEEE P1900.4 Protocol, and making decisions for selecting the most suitable RAT for incoming calls. The proposed power efficient algorithm is compared to centralized and distributed algorithms in terms of new call blocking and Vertical Handover (VHO) call dropping probabilities. Users' satisfactions probability and saving battery power percentage are also compared. Simulation results show that the proposed algorithm performs better than the centralized and distributed algorithms in terms of blocking, dropping and users' satisfactions probabilities. The proposed and the distributed algorithms have similar performance in term of saving battery power, and both perform better than the centralized algorithm. © 2012 IEEE.
• Studying the impact of the corner propagation model on VANET routing in urban environments

  Abhinay Mukunthan, Craig Cooper, Farzad Safaei, Daniel Franklin, Mehran Abolhasan

  IEEE Vehicular Technology Conference 2012年 

  Accurate modelling of the radio channel is often the most difficult aspect of a Vehicular Ad Hoc Network (VANET) simulation due to the large variability present in vehicular terrain. CORNER is a propagation model that calculates path-loss in an urban terrain with a large concentration of buildings, based on the position of the transmitter and receiver on a street map. This paper proposes additions to the CORNER propagation model to take selective multi-path fading into account and investigates the performance of the GPSR routing protocol under the CORNER propagation model in a realistic city environment. © 2012 IEEE.
• A fuzzy logic node relocation model in WSNs

  Yashar Maali, Ali Rafiei, Mehran Abolhasan, Daniel Franklin, Farzad Safaei

  6th International Conference on Signal Processing and Communication Systems, ICSPCS 2012 - Proceedings 2012年 

  Hostile and harsh environments may preclude the possibility of manual redeployment of new sensor nodes, especially in the areas suffering from widespread damage and unbalanced node deployments. Distributed local relocations of currently deployed nodes is one promising solution to this problem. By using expected global node density and force-based movement algorithms inspired by the laws of nature, it is possible to address the aforementioned challenge. Force-based movement algorithms steer nodes towards their new locations based on the aggregation of exerted virtual forces on the node from their neighborhood. Some implicit assumptions about nodes' global status such as expected global node density are not realistic in dynamic and harsh environments. Thus, to conform to the uncertain nature and local interactions of nodes, a combination of radial-angular force fuzzy movement algorithms is suggested. The performance of the proposed model in terms of percentage of coverage, uniformity and average movement under three different boundary conditions are evaluated and compared with distributed self-spreading algorithms (DSSA). The results show that the simple fuzzy movement algorithm either outperforms or matches DSSA even if nodes don't benefit from expected global node density as in DSSA. © 2012 IEEE.
• Addressing schemes for body area networks

  Samaneh Movassaghi, Mehran Abolhasan, Justin Lipman

  IEEE Communications Letters 15 12 1310 - 1313 2011年12月 

  This letter explores address allocation in Body Area Networks (BANs) and proposes two novel schemes - Optimized Prophet Address Allocation (OPAA) and Hierarchical Collision-free Address Protocol (HCAP). The aim of the schemes is to use fewer bits in the address space, solve address wastage problems, reduce collisions and improve power efficiency. The usability and efficiency of the proposed schemes is shown through simulation and analysis. © 2006 IEEE.
• On the error exponent of amplify and forward relay networks

  Bappi Barua, Mehran Abolhasan, Farzad Safaei, Daniel R. Franklin

  IEEE Communications Letters 15 10 1047 - 1049 2011年10月 

  In this letter we derive the exact random coding error exponent of a dual hop amplify and forward (AF) relay network with channel state information (CSI) assisted ideal relay gain. Numerical results have been presented, which provide insight about the performance tradeoff between the error exponent and the data rate of the network. Finally we present the capacity analysis of this relay network. © 2006 IEEE.
• On the symbol error probability of multihop parallel relay networks

  Bappi Barua, Mehran Abolhasan, Farzad Safaei

  IEEE Communications Letters 15 7 719 - 721 2011年07月 

  In this paper we analyze the symbol error probability (SEP) of a cooperative multihop parallel relay network in Rayleigh fading channels for M-ary Phase-shift keying (M-PSK) modulation. The general closed form expression of the SEP is derived. We present numerical results on the performance of the network. © 2011 IEEE.
• A comprehensive survey on rat selection algorithms for heterogeneous networks

  Abdallah Al Sabbagh, Robin Braun, Mehran Abolhasan

  World Academy of Science, Engineering and Technology 73 141 - 145 2011年01月 

  Due to the coexistence of different Radio Access Technologies (RATs), Next Generation Wireless Networks (NGWN) are predicted to be heterogeneous in nature. The coexistence of different RATs requires a need for Common Radio Resource Management (CRRM) to support the provision of Quality of Service (QoS) and the efficient utilization of radio resources. RAT selection algorithms are part of the CRRM algorithms. Simply, their role is to verify if an incoming call will be suitable to fit into a heterogeneous wireless network, and to decide which of the available RATs is most suitable to fit the need of the incoming call and admit it. Guaranteeing the requirements of QoS for all accepted calls and at the same time being able to provide the most efficient utilization of the available radio resources is the goal of RAT selection algorithm. The normal call admission control algorithms are designed for homogeneous wireless networks and they do not provide a solution to fit a heterogeneous wireless network which represents the NGWN. Therefore, there is a need to develop RAT selection algorithm for heterogeneous wireless network. In this paper, we propose an approach for RAT selection which includes receiving different criteria, assessing and making decisions, then selecting the most suitable RAT for incoming calls. A comprehensive survey of different RAT selection algorithms for a heterogeneous wireless network is studied.
• Hierarchical collision-free addressing protocol(HCAP) for body area networks

  Samaneh Movassaghi, Mehran Abolhasan, Justin Lipman

  2011 IEEE Conference on Computer Communications Workshops, INFOCOM WKSHPS 2011 543 - 548 2011年 

  In Body Area Networks (BANs) the addressing scheme used to address nodes is fundamental to the effective operation of a BAN. This paper proposes a novel BAN addressing scheme called Hierarchical Collision-free Addressing Protocol (HCAP). Proposed scheme is collision free, reduces power consumption and tackles the address wastage problem. Two important scenarios (random location and fixed location) are defined and studied. Through a series of simulation results we show the efficiency and usability of the proposed scheme in Body Area Networks. © 2011 IEEE.
• Optimized prophet address allocation (OPAA) for Body Area Networks

  Samaneh Movassaghi, Mehran Abolhasan, Justin Lipman

  IWCMC 2011 - 7th International Wireless Communications and Mobile Computing Conference 2098 - 2102 2011年 

  Each node in a Body Area Network (BAN) needs to be assigned with a free IP address before it may participate in any sort of communication. This paper evaluates the performance of an IP address allocation scheme, namely Prophet allocation to be used for BANs. This allocation scheme is a fully decentralized addressing scheme which is applicable to BANs as it provides low latency, low communication overhead and low complexity. Relative theoretical analysis and simulation experiments have also been conducted to demonstrate its benefits which also represent the reason for the choice of this allocation scheme. It also solves the issues related to network partition and merger efficiently. © 2011 IEEE.
• Boundary node selection algorithms in WSNs

  Ali Rafiei, Mehran Abolhasan, Daniel Franklin, Farzad Safaei

  Proceedings - Conference on Local Computer Networks, LCN 251 - 254 2011年 

  Physical damage and/or node power exhaustion may lead to coverage holes in WSNs. Coverage holes can be directly detected by certain proximate nodes known as boundary nodes (B-nodes). Due to the sensor nodes' redundant deployment and autonomous fault detection, holes are surrounded by a margin of B-nodes (MB-nodes). If all B-nodes in the margin take part in the hole recovery processes, either by increasing their transmission power or by relocating towards region of interest (ROI), the probability of collision, interference, disconnection, and isolation may increase affecting the rest of the network's performance and QoS. Thus, distributed boundary node selection algorithms (BNS-Algorithms) are proposed to address these issues. BNS-algorithms allow B-nodes to self-select based on available 1-hop information extracted from nodes' simple geometrical and statistical features. Our results show that the performance of the proposed distributed BNS-algorithms approaches that of their centralized counterparts. © 2011 IEEE.
• Scalability of MANET routing protocols for heterogeneous and homogenous networks

  Huda Al Amri, Mehran Abolhasan, Tadeusz Wysocki

  Computers and Electrical Engineering 36 4 752 - 765 2010年07月 

  In Mobile Ad hoc Network (MANET), mobility, traffic and node density are main network conditions that significantly affect performance of routing protocols. Much of the previous research in MANET routing have focused on developing strategies, which suit one specific networking scenario. Therefore, there is no existing protocol that can work well in all different networking scenarios. This paper reviews characteristics of several different classes of routing protocols. Moreover, most of current routing protocols assume homogeneous networking conditions where all nodes have the same capabilities and resources. This paper presents extensive studies simulations for DSR, AODV, LAR1, FSR and WRP in homogenous and heterogeneous networks that consist of different nodes with different resources. The results showed that while all protocols perform reasonably well in homogenous networking conditions, their performance suffer significantly over heterogonous networks. © 2008 Elsevier Ltd. All rights reserved.
• An unequal clustering protocol for wireless sensor networks

  Fengjun Shang, Anping Xiong, Mehran Abolhasan, Tadeusz Wysocki

  Journal of Computational Information Systems 6 2 477 - 486 2010年02月 

  In this paper, a Single-Hop Unequal Clustering (SHUC) algorithm is proposed for wireless sensor networks. The SHUC algorithm consists of three different parts. Firstly, an average energy factor is introduced to balance the residual energy of the whole network during the tentative cluster-head selection process, which improves the network energy efficiency. Secondly, a cost function is proposed to balance energy-efficiency of each node. Finally, an unequal clustering algorithm is proposed for single-hop homogeneous networks. Through both theoretical analysis and numerical results, it is shown that SHUC prolongs the network lifetime significantly against other clustering protocols such as LEACH-C and EECS. Under general instance, SHUC may prolong the lifetime by up to 30% against EECS and 70% against LEACH-C. © 2010 Binary Information Press.
• Low complexity interference aware distributed resource allocation for multi-cell OFDMA cooperative relay networks

  Nidhal Odeh, Mehran Abolhasan, Farzad Safaei

  IEEE Wireless Communications and Networking Conference, WCNC 2010年 

  In this paper we focus on the subcarrier allocation for the uplink OFDMA based cooperative relay networks. Multiple cells were considered, each composed of a single base station (destination), multiple amplify and forward (AF) relay stations and multiple subscriber stations (sources). The effects of inter-cell interference (ICI) have been considered to optimize the subcarrier allocation with low complexity. The optimization problem aims to maximize the sum rate of all sources and at the same time maintain the fairness among them. Full channel state information (CSI) is assumed to be available at the base station. In the proposed algorithm the subcarrier allocation is performed in three steps; firstly the subcarriers are allocated to the Relay Stations (RSs) by which the received ICI on each RS is minimized. Then, the pre-allocated subcarriers are allocated to subscribers to achieve their individual rate requirements. Finally the remaining subcarriers are allocated to subscribers with the best channel condition to maximize the total sum of their data rates. The results show that the proposed algorithm significantly reduces the complexity with almost the same achievable rate of the optimal allocation in a single cell case. In case of multi-cell, the proposed algorithm outperforms the conventional algorithm in terms of total network achievable data rate and overall network complexity. ©2010 IEEE.
• An efficient opportunistic cooperative diversity protocol for IEEE 802.11 networks

  Brett Hagelstein, Mehran Abolhasan, Daniel Franklin, Farzad Safaei

  IWCMC 2010 - Proceedings of the 6th International Wireless Communications and Mobile Computing Conference 417 - 421 2010年 

  Opportunistic cooperation promises to enhance the user experience when streaming media over wireless devices by improving wireless network reliability at the link level. This paper presents DAFMAC, an efficient cooperative diversity partner selection algorithm for IEEE 802.11 devices. Simulation results show DAFMAC provides a significantly higher transmission reliability in poor channel conditions than traditional ARQ techniques without modifying the device hardware. Further analysis shows the low overhead of DAFMAC makes it highly competitive with other proposed cooperative retransmission mechanisms in an ad-hoc network. Copyright© 2010 ACM.
• On the outage of multihop parallel relay networks

  Bappi Barua, Farzad Safaei, Mehran Abolhasan

  IEEE Vehicular Technology Conference 2010年 

  In this paper we analyze the outage probability of a cooperative multihop parallel relay network in Nakagami-m fading channels. The general closed form expression of the outage probability is derived both for integer and arbitrary Nakagami parameter m. We present numerical results on the performance of the network. It shows a careful configuration of the network size and power sharing between nodes can ensure optimal outage performance in the network. ©2010 IEEE.
• On optimising route discovery for multi-interface and power-aware nodes in heterogeneous MANETs

  Huda AlAamri, Mehran Abolhasan, Tadeusz Wysocki, Justin Lipman

  Proceedings - 6th International Conference on Wireless and Mobile Communications, ICWMC 2010 244 - 249 2010年 

  This paper presents a new routing discovery strategy for heterogeneous MANETs. Node heterogeneity is modeled in terms of: types and number of different interfaces, power, and transmission ranges. Our proposed route discovery algorithm is implemented on the top of On-demand Tree-based Routing Protocol (OTRP) and hence it is called OTRP Heterogeneity-Aware (OTRP-HA). OTRP-HA utilizes node heterogeneity and optimizes route discovery to reduce overheads and ensures connectivities between different types of nodes with different interfaces. Each node makes its own decision to participate in the route discovery process according to its location, local density, and available resources. Simulation results show that OTRP-HA outperforms OTRP and AODV and it reduces overheads as a number of nodes and traffic increase, while it also further prolongs the lifetime of battery-powered single-interface nodes when compared to AODV. © 2010 IEEE.
• Experimental evaluation of IEEE 802.11s path selection protocols in a mesh testbed

  Jerry Chun Ping Wang, Brett Hagelstein, Mehran Abolhasan

  4th International Conference on Signal Processing and Communication Systems, ICSPCS'2010 - Proceedings 2010年 

  IEEE 802.11s is an upcoming standard that defines how wireless devices can interconnect in a multi-hop configuration. While there are several protocol stacks based on the IEEE 802.11s draft standard, there has not been a formal study or comparison examining their practical performance. This paper evaluates the routing performance of open80211s in a real-world mesh testbed. The experiments benchmark open80211s against two established network layer routing protocols - OLSR and B.A.T.M.A.N.. The experimental results show that open80211s does not outperform existing routing protocols in practice. This indicates that more design and development effort is required for IEEE 802.11s to yield the performance that is expected for an IEEE standard protocol. ©2010 IEEE.
• Distributed energy efficient unequal clustering algorithm for wireless sensor networks

  Feng Jun Shang, Mehran Abolhasan, Tadeusz Wysocki

  Tongxin Xuebao/Journal on Communications 30 10 34 - 43 2009年10月 

  A distributed energy-efficient unequal clustering (DEEUC) algorithm was proposed for wireless sensor networks by research current routing algorithms. The core of DEEUC has three parts. Firstly, when tentative clusterheads are selected, an average energy factor was introduced to balance the residual energy of the whole network nodes so that it may improve the network energy efficiency. Secondly, an energy consumption ratio function was proposed to balance energy-efficient of each node. Finally, an unequal clustering algorithm was proposed for single-hop homogeneous networks. Through both theoretical analysis and numerical results, it is shown that DEEUC prolongs the network lifetime significantly against the other clustering protocols such as LEACH-C and EECS. Under general instance, DEEUC may prolong the lifetime up to 30% against EECS.
• On optimising route discovery in absence of previous route information in MANETs

  Huda AlAamri, Mehran Abolhasan, Tadeusz Wysocki

  IEEE Vehicular Technology Conference 2009年 

  This paper present a new routing protocol for Ad hoc networks, called On-demand Tree-based Routing Protocol (OTRP). This protocol combines the idea of hop-by-hop routing such as AODV with an efficient route discovery algorithm called Tree-based Optimized Flooding (TOF) to improve scalability of Ad hoc networks when there is no previous knowledge about the destination. To achieve this in OTRP, route discovery overheads are minimized by selectively flooding the network through a limited set of nodes, referred to as branching-nodes. The theoretical analysis and simulation results showed that OTRP outperforms AODV, DYM0, and OLSR and it reduces overheads as number of nodes and traffic increase. © 2009 IEEE.
• Characterising the behaviour of IEEE 802.11 broadcast transmissions in ad hoc wireless LANs

  Jerry Chun Ping Wang, Mehran Abolhasan, Daniel R. Franklin, Farzad Safaei

  IEEE International Conference on Communications 2009年 

  This paper evaluates the performance of the IEEE 802.11 broadcast traffic under both saturation and non-saturation conditions. The evaluation highlights some important characteristics of IEEE 802.11 broadcast traffic as compared to corresponding unicast traffic. Moreover, it underlines the inaccuracy of the broadcast saturation model proposed by Ma and Chen due to the absence of backoff counter freeze process when channel is busy. Computer simulations are used to validate the accuracy of the new model and demonstrate the importance of capturing the freezing of backoff counter in the analytical study of IEEE 802.11 broadcast. ©2009 IEEE.
• Serially concatenated turbo codes

  Sina Vafi, Tadeusz Wysocki, Mehran Abolhasan

  Proceedings - 5th International Conference on Wireless Communications, Networking and Mobile Computing, WiCOM 2009 2009年 

  The paper presents a new scheme of concatenated codes, referred to as Serially Concatenated Turbo (SCT) codes. The code is constructed as the serial combinations of two turbo codes, i.e. turbo Recursive Systematic Convolutional (RSC) codes and turbo Bose Ray Chaudhuri Hocquenghem (BCH) codes, linked by a pseudo-random interleaver. In comparison with the conventional turbo RSC codes, SCT codes have higher minimum distance values. Based on conducted simulations, it is found that SCT codes outperform turbo RSC codes at the waterfall and error floor regions, while they require reasonable number of iterations at their iterative decoding structure to achieve good performance. ©2009 IEEE.
• OLSR-R³: Optimised link state routing with reactive route recovery

  Jerry Chun Ping Wang, Mehran Abolhasan, Daniel R. Franklin, Farzad Safaei

  2009 15th Asia-Pacific Conference on Communications, APCC 2009 359 - 362 2009年 

  The Optimised Link State Routing (OLSR) is a proactive routing protocol which relies on periodical broadcast of routing packets. However, due to the one-to-many relationship of broadcast traffic, the delivery of these packets can not be guaranteed by underlying MAC protocol, particularly in a congested condition. In this paper, the possible routing pathologies and failures of OLSR in a congested network are explored. In addition, a hybrid routing protocol which integrates OLSR with Reactive Route Recovery (OLSR-R3) is proposed to rectify the erratic routing behaviour described in this paper. Simulation studies are presented which show that the proposed solution is effective in addressing the underlining problems. ©2009 IEEE.
• Routing metric for multi-interface and power-aware nodes in heterogeneous MANETs

  Huda Alaamri, Mehran Abolhasan, Tadeusz Wysocki

  2009 15th Asia-Pacific Conference on Communications, APCC 2009 372 - 375 2009年 

  This paper presents Heterogeneity Ratio (HR) as a new routing metric for heterogeneous MANETs. This metric is the ratio of number of powerful nodes to hop count that is used to select the best path to destination. Node heterogeneity is modeled in terms of: types and number of different interfaces, power, and transmission ranges. Our proposed routing metric is based on developing route discovery algorithm that is implemented on the top of On-demand Tree-based Routing Protocol (OTRP)[2] to accommodate nodes heterogeneity. Simulation results show that using HR with OTRP Heterogeneity Aware outperforms other metrics like minimal hop count and maximal number of powerful nodes. ©2009 IEEE.
• Real-world performance of current proactive multi-hop mesh protocols

  M. Abolhasan, B. Hagelstein, J. C.P. Wang

  2009 15th Asia-Pacific Conference on Communications, APCC 2009 44 - 47 2009年 

  The proliferation of mesh or ad hoc network protocols has lead to a push for protocol standardisation. While there are a number of both open-source and proprietary mesh routing protocols being developed, there is only a small amount of literature available that shows relative strengths and weaknesses of different protocols. This paper investigates the performance of a number of available routing protocols using a real-world testbed. Three routing protocols - Optimised Link State Routing (OLSR), Better Approach To Mobile Ad hoc Network (B.A.T.M.A.N.) and BABEL - were chosen for this study. Our investigations focus on the multi-hopping performance and the ability of each routing protocol to recover from link failures. Our results show that B.A.T.M.A.N. and BABEL outperform OLSR both in terms of multi-hopping performance and in route re-discovery latency. ©2009 IEEE.
• End-to-end path stability of reactive routing protocols in IEEE 802.11 ad hoc networks

  Jerry Chun Ping Wang, Mehran Abolhasan, Daniel R. Franklin, Farzad Safaei

  Proceedings - Conference on Local Computer Networks, LCN 499 - 505 2009年 

  Over the years, a considerable research effort has been applied to the design of ad hoc network routing protocols. However, there is still a lack of understanding of the subtle interactions between routing protocols and lower layers in the protocol stack. In this paper, the instability which may arise when reactive routing protocols interact with the IEEE 802.11 MAC protocol is investigated. In particular, several erratic behaviours of the Ad hod On-demand Distance Vector (AODV) routing protocol in a congested IEEE 802.11 ad hoc network are demonstrated. A cross-layer solution is proposed based on an Adaptive Bulk Trigger policy and a Dynamic Window Selection scheme. Simulation studies are presented which show that the proposed solution is effective in alleviating erratic behaviour of AODV and improving the end-to-end path stability. ©2009 IEEE.
• Survey of the potential of emerging wireless technologies to improve telecommunication services in remote Australian settlements

  Mehran Abolhasan, Alyson Wright

  Rangeland Journal 30 1 157 - 165 2008年 

  Providing efficient yet cost effective telecommunication systems to Aboriginal people living in remote locations has proven to be a challenging task. This is primarily due to low population density and distance from major service centres. Extending high-capacity telecommunications infrastructure to these people would incur high costs of installation, maintenance and administration without significant financial returns. The cost of services such as cabled phone lines to all houses, satellite and wireless cellular networks are often unaffordable for people in remote settlements, and, as a result, the provision of telecommunication services is often subsidised by the government. New wireless standards and products are being developed which could provide broadband-type network connections to large areas at an affordable price. This paper describes these new standards and products and their potential applications in rural and remote regions. There is also a comparison of their transmission requirements, cost, performance and coverage with several currently available technologies. © Australian Rangeland Society 2008.
• Characterising the interactions between unicast and broadcast in IEEE 802.11 ad hoc networks

  Jerry Chun Ping Wang, Daniel R. Franklin, Mehran Abolhasan, Farzad Safaei

  Proceedings of the 2008 Australasian Telecommunication Networks and Applications Conference, ATNAC 2008 180 - 185 2008年 

  This paper investigates the relative performance of unicast and broadcast traffic traversing a one-hop ad hoc network utilising the 802.11 DCF. An extended Markov model has been developed and validated through computer simulation, which successfully predicts the respective performance of unicast and broadcast in a variety of mixed traffic scenarios. Under heavy network traffic conditions, a significant divergence is seen to develop between the performance of the two traffic classes - in particular, when network becomes saturated, unicast traffic is effectively given higher precedence over broadcast. As a result, the network becomes dominated by unicast frames, leading to poor rates of broadcast frame delivery. © 2008 IEEE.
• Development and performance evaluation of a flexible, low cost MANET

  M. Abolhasan, B. Hagelstein, J. C.P. Wang, D. R. Franklin, F. Safaei, T. Wysocki

  2nd International Conference on Signal Processing and Communication Systems, ICSPCS 2008 - Proceedings 2008年 

  Performance evaluations of multi-hop ad hoc network routing protocols have been primarily conducted through analytic and simulation-based studies, which frequently fail to accurately predict real-world performance and behaviour. One reason for this is the challenge in developing low cost, representative test beds with the degree of flexibility and mobility required. We have developed a Portable Wireless Ad hoc Node (PWAN) device which establishes multi-hop routes using the OLSR routing protocol. The PWAN's performance has been investigated using two test bed configurations to evaluate its capacity under conditions of high node density in a short-range, multi-hop environment. Our results illustrate that such networks are capable of providing high quality connections when traffic density is low. However, the network link quality deteriorates dramatically as the traffic level increases, and the network topology becomes unstable until the traffic level is reduced. © 2008 IEEE.
• Dynamic zone topology routing protocol for MANETs

  Mehran Abolhasan, Tadeusz A. Wysocki

  European Transactions on Telecommunications 18 4 351 - 368 2007年06月 

  The limited scalability of the proactive and reactive routing protocols have resulted in the introduction of new generation of routing in mobile ad hoc networks, called hybrid routing. These protocols aim to extend the scalability of such networks beyond several hundred to thousand of nodes by defining a virtual infrastructure in the network. However, many of the hybrid routing protocols proposed to date are designed to function using a common pre-programmed static zone map. Other hybrid protocols reduce flooding by grouping nodes into clusters, governed by a cluster-head, which may create performance bottlenecks or a single point of failures at each cluster-head node. We propose a new routing strategy in which zones are created dynamically, using a dynamic zone creation algorithm. Therefore, nodes are not restricted to a specific region. Additionally, nodes perform routing and data forwarding in a cooperative manner, which means that in the case failure, route recalculation is minimised. Routing overheads are also further reduced by introducing a number of GPS-based location tracking mechanisms, which reduces the route discovery area and the number of nodes queried to find the required destination. Copyright © 2006 AEIT.
• A survey on control separation techniques in multi-radio multi-channel MAC protocols

  J. C.P. Wang, M. Abolhasan, F. Safaei, D. Franklin

  ISCIT 2007 - 2007 International Symposium on Communications and Information Technologies Proceedings 854 - 859 2007年 

  The rapid diminishing in the cost of commodity wireless hardware in recent years has prompted the use of multiple radios to improve the capacity of wireless networks. However, the research has shown that the improvement obtained from using multiple radios does not solely depend on the number of radios, but primarily on how these radios can be integrated in a constructive manner. A common way of integration multiple radios is to use a dedicated radio for control. To date, a number of multi-radio MAC protocol are employing a dedicated radio to control and coordinate the other radios, though the approaches are varied from one to another. In this paper, the control separation techniques in the multi-radio multi-channel MAC have been surveyed, and a classification of control separation techniques is provided. Moreover, this study points out the open research issues and intends to spark new interests and developments in this field. © 2007 IEEE.
• Distributed MIMO systems using Asterism decoding

  Phillip Conder, Jason Gao, Mehran Abolhasan

  ISCIT 2007 - 2007 International Symposium on Communications and Information Technologies Proceedings 269 - 272 2007年 

  Multiple Input Multiple Output (MIMO) systems have received enormous attention by researchers as they can provide a roughly linear increase in capacity of wireless communications systems by using multiple transmit and receive antennas. Even with the larger raw data rates provided by MIMO, the throughput of these systems can be limited by the number of users (or networks) sharing the medium. This paper shows how multiple users (or networks) transmitting simultaneously can be represented as a MIMO system with a lager number of transmit than receive antennas. After reviewing existing decoders for such a MIMO system, this paper then proposes applying an Asterism based decoder to distinguish between multiple users transmitting simultaneously. This produces a new multi-user access scheme that can be applied in addition to a primary access method, such as CSMA-CA. © 2007 IEEE.
• On separating route control and data flows in multi-radio multi-hop ad hoc network

  J. C.P. Wang, M. Abolhasan, D. R. Franklin, F. Safaei, J. Lipmant

  ICON 2007 - Proceedings of the 2007 15th IEEE International Conference on Networks 19 - 24 2007年 

  Ad hoc networks typically require a significant amount of routing and control information to be distributed in a timely and reliable manner throughout the network, particularly in dynamic environments. As traffic levels increase and the network becomes more heavily congested, there is an increased probability that these critical packets are lost, resulting in obsolete control information being used to make important decisions. This would further compound the problem of network congestion and lead to a very rapid loss of connectivity and throughput. Given this, we argue the solutions to these problems should not rely on putting extra bandwidth on a radio interface. Instead, we should exploit the use of multiple radios to ensure the route can be firmly established. In this paper, we propose a multi-radio solution which reserves one radio channel exclusively for routing. Our simulation results have demonstrated that using a separate radio for routing protocol would dramatically improve reliability in heavily loaded ad hoc wireless networks, thereby effectively alleviating the impact of network congestion. © 2007 IEEE.
• On indoor multi-hopping capacity of wireless ad-hoc mesh networks

  M. Abolhasan, J. C.P. Wang, D. R. Franklin

  2007 IEEE Internatonal Conference on Mobile Adhoc and Sensor Systems, MASS 2007年 

  The capacity and multi-hopping performance of ad hoc mesh networks in dynamic environment still remains an open research issue. Previous theoretical studies suggest that they do not scale in densely distributed networks. However, a study has shown that scalability and hence the multihopping capacity of mesh network is not only bound by the number of nodes in the network but also the number of hops [3]. In this paper we investigate the performance of multihop ad hoc mesh networks, using both simulation studies and an experimental test-bed, and monitor the performance of the network as the number of hops in the network increases. Our results show that the drop in performance in multi-hopping is much more significant when the traffic levels are high. Furthermore our test-bed study shows that ad hoc mesh networks can maintain high levels of packet delivery and throughput when traffic levels are low, however, the delay experienced continues to increase after each hop. ©2007 IEEE.
• Self-selection route discovery strategies for reactive routing in Ad hoc Networks

  Mehran Abolhasan, Justin Lipman

  ACM International Conference Proceeding Series 138 2006年 

  Routing in Ad hoc Networks has received a significant amount of attention. In recent years, the focus of research has been in on-demand (or reactive) routing protocols due to the recognition that these protocols have the potential to achieve higher levels of scalability than proactive routing strategies. However, most on-demand routing protocols proposed to date attempt to increase routing efficiency by using existing knowledge about the destination or by increasing the stability of the routes. Little research has been done to reduce route discovery overhead when no previous destination information is available. We present a number of different strategies, which encourage a more distributed and localised approach to route discovery by allowing each intermediate node during route discovery to make forwarding decisions using localised knowledge and self-selection. The use of self-selection for route discovery enables nodes to independently make route request (RREQ) forwarding decisions based upon a selection criterion or by satisfying certain conditions. The nodes which do not satisfy the selection criterion do not rebroadcast the RREQs. This provides a more effective and efficient search strategy than the use of traditional brute force blind flooding. We implemented our self-selecting route discovery strategies over AODV using the GloMoSim network simulation package, and compared the performance with existing routing protocols. Our simulation results show that a significant drop in the number of control packets can be achieved by giving each intermediate node more authority for self-selection during route discovery. Furthermore, a significant increase in routing performance is achieved as the number of nodes in the network is increased. © 2006 ACM.
• UHF-based community voice service in ngannyatjarra lands of Australia

  Mehran Abolhasan, Paul Boustead

  Information Technology and Indigenous People 295 - 297 2006年
• An optimised resource aware approach to information collection in ad hoc networks

  Justin Lipman, Mehran Abolhasan, Paul Boustead, Joe Chicharo

  Ad Hoc Networks 3 5 643 - 655 2005年09月 

  In ad hoc networks there is a need for all-to-one protocols that allow for information collection or "sensing" of the state of an ad hoc network and the nodes that comprise it. Such protocols may be used for service discovery, auto-configuration, network management, topology discovery or reliable flooding. There is a parallel between this type of sensing in ad hoc networks and that of sensor networks. However, ad hoc networks and sensor networks differ in their application, construction, characteristics and constraints. The main priority of sensor networks is for the flow of data from sensors back to a sink, but in an ad hoc network this may be of secondary importance. Hence, protocols suitable to sensor networks are not necessarily suitable to ad hoc networks and vice versa. We propose, Resource Aware Information Collection (RAIC), a distributed two phased resource aware approach to information collection in ad hoc networks. RAIC utilises a resource aware optimised flooding mechanism to both disseminate requests and initialise a backbone of resource suitable nodes responsible for relaying replies back to the node collecting information. RAIC in the process of collecting information from all nodes in an ad hoc network is shown to consume less energy and introduce less overhead compared with Directed Diffusion and a brute force approach. Importantly, over multiple successive queries (in an energy constrained environment), the use of resource awareness allows for the load of relaying to be distributed to those nodes most suitable, thereby extending the lifetime of the network. © 2004 Elsevier B.V. All rights reserved.
• Ad hoc networks: A flexible and robust data communication

  Mehran Abolhasan, Tadeusz Wysocki

  Handbook on Theoretical and Algorithmic Aspects of Sensor, Ad Hoc Wireless, and Peer-to-Peer Networks 267 - 282 2005年01月01日 

  The 1990s witnessed a rapid growth in research interests in mobile ad hoc networks (MANETs). The infrastructureless and dynamic nature of these networks demand that a new set of networking strategies be implemented to provide efficient end-to-end communication. This, along with the diverse application of these networks in many different scenarios, such as battlefield and disaster recovery, have seen MANETs being researched by many different organizations. MANETs employ the traditional TCP/IP structure to provide end-to-end communication between nodes. However, due to their mobility and the limited resources in wireless networks, each layer in the TCP/IP model requires redefinition or modifications to function efficiently in a MANET. One interesting research area in MANETs is routing. Routing in MANETs is a challenging task and has received a tremendous amount of attention from researchers. This has led to the development of many different routing protocols for MANETs. This chapter presents a discussion on a number of different routing protocols proposed for ad hoc networks and presents a number of future challenges in ad hoc and mobile ad hoc networking.
• A new strategy to improve proactive route updates in mobile ad hoc networks

  Mehran Abolhasan, Tadeusz Wysocki, Justin Lipman

  Eurasip Journal on Wireless Communications and Networking 2005 5 828 - 837 2005年 

  This paper presents two new route update strategies for performing proactive route discovery in mobile ad hoc networks (MANETs). The first strategy is referred to as minimum displacement update routing (MDUR). In this strategy, the rate at which route updates are sent into the network is controlled by how often a node changes its location by a required distance. The second strategy is called minimum topology change update (MTCU). In this strategy, the route updating rate is proportional to the level of topology change each node experiences. We implemented MDUR and MTCU on top of the fisheye state routing (FSR) protocol and investigated their performance by simulation. The simulations were performed in a number of different scenarios, with varied network mobility, density, traffic, and boundary. Our results indicate that both MDUR and MTCU produce significantly lower levels of control overhead than FSR and achieve higher levels of throughput as the density and the level of traffic in the network are increased.
• Efficient and highly scalable route discovey for on-demand routing protocols in ad hoc networks

  Mehran Abolhasan, Justin Lipman

  Proceedings - Conference on Local Computer Networks, LCN 2005 358 - 365 2005年 

  This paper presents a number of different route discovery strategies for on-demand routing protocols, which provide more control to each intermediate node make during the route discovery phase to make intelligent forwarding decisions. This is achieved through the idea of self-selection. In self-selecting route discovery each node independently makes Route Request (RREQ) forwarding decisions based upon a selection criterion or by satisfying certain conditions. The nodes which do not satisfy the selection criterion do not rebroadcast the routing packets. We implemented our self-selecting route discovery strategies over AODV using the GloMoSim network simulation package, and compared the performance with existing route discovery strategies used in AODV. Our simulation results show that a significant drop in the number of control packets can be achieved by giving each intermediate node more authority for self-selection during route discovery. Furthermore, a significant increase in throughput is achieved as the number nodes in the network is increased. © 2005 IEEE.
• Performance investigation on three-classes of MANET routing protocols

  Mehran Abolhasn, Tadeusz Wysocki, Justin Lipman

  2005 Asia-Pacific Conference on Communications 2005 774 - 778 2005年 

  Routing in Ad hoc Networks has received significant attention with a number of different routing protocols proposed in recent years. These routing protocols may be classified into three main categories: proactive, reactive and hybrid. Prior work aimed at comparing the performance of routing protocols has mainly focused on comparing reactive and proactive protocols [6] [4] [1]. In this paper, we present a simulation study of different routing protocols from all three categories. We also explore the benefits and performance of each routing category. Further, we present a discussion of future research directions for routing in Ad hoc Networks. © 2005 IEEE.
• A review of routing protocols for mobile ad hoc networks

  Mehran Abolhasan, Tadeusz Wysocki, Eryk Dutkiewicz

  Ad Hoc Networks 2 1 1 - 22 2004年01月 

  The 1990s have seen a rapid growth of research interests in mobile ad hoc networking. The infrastructureless and the dynamic nature of these networks demands new set of networking strategies to be implemented in order to provide efficient end-to-end communication. This, along with the diverse application of these networks in many different scenarios such as battlefield and disaster recovery, have seen MANETs being researched by many different organisations and institutes. MANETs employ the traditional TCP/IP structure to provide end-to-end communication between nodes. However, due to their mobility and the limited resource in wireless networks, each layer in the TCP/IP model require redefinition or modifications to function efficiently in MANETs. One interesting research area in MANET is routing. Routing in the MANETs is a challenging task and has received a tremendous amount of attention from researches. This has led to development of many different routing protocols for MANETs, and each author of each proposed protocol argues that the strategy proposed provides an improvement over a number of different strategies considered in the literature for a given network scenario. Therefore, it is quite difficult to determine which protocols may perform best under a number of different network scenarios, such as increasing node density and traffic. In this paper, we provide an overview of a wide range of routing protocols proposed in the literature. We also provide a performance comparison of all routing protocols and suggest which protocols may perform best in large networks. © 2003 Elsevier B.V. All rights reserved.
• A routing strategy for heterogeneous mobile Ad Hoc networks

  Mehran Abolhasan, Justin Lipman, Joe Chicharo

  Proceedings of the IEEE 6th Circuits and Systems Symposium on Emerging Technologies: Frontiers of Mobile and Wireless Communication 1 13 - 16 2004年 

  This paper presents a new routing strategy for heterogeneous Mobile Ad Hoc Networks. We refer to this strategy as On-demand Utility-Based Routing Protocol (OUBRP). This protocol introduces a Utility-Based route discovery strategy, which aims to minimise the number of control packets disseminated into the network during route discovery by efficiently using available resources at each node. Furthermore, we propose a new strategy to eliminate uni-directional links during the route discovery phase. We refer to this strategy as Uni-directional Link Elimination (ULE). We performed a simulation study to compare the performance of OUBRP with a number of different routing protocols proposed for MANETs. Our results show that OUBRP compared to other routing strategies produces significantly fewer control packets and achieves higher levels of successful packet delivery with increasing number of nodes. Furthermore, we propose a number of alternative Uni-directional Link Elimination strategies.
• GPS-based route discovery algorithms for on-demand routing protocols in MANETs

  Mehran Abolhasan, Tadeusz Wysocki

  Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 2928 144 - 157 2003年 

  This papers presents new Global Positioning System (GPS)-based route discovery algorithms for on-demand routing in MANETs, called Position-based Selective Flooding (PSF). We applied our route discovery algorithm to our previous routing protocol, which is called Location-based Point-to-point Adaptive routing (LPAR) protocol and investigated its performance by simulation. Simulation results show that our position based flooding algorithm produce fewer routing overheads than the pure flooding, expanding ring search (used in AODV), LAR1 and our existing LPAR strategy, as network traffic and density is increased. Furthermore, we propose a number of improvements and variations which can be used instead of, or to further improve the performance of PSF under different network conditions. © IFIP International Federation for Information Processing 2004.
• Scalable routing strategy for dynamic zones-based MANETS

  Mehran Abolhasan, Tadeusz Wysocki, Eryk Dutkiewicz

  Conference Record / IEEE Global Telecommunications Conference 1 173 - 177 2002年 

  This paper presents a new routing strategy for Mobile Ad Hoc Networks, called Dynamic Zone-based Topology Routing protocol (DZTR). We introduce new strategies to maintain up-to-date intrazone and interzone topology information at each node. We also propose a GPS-based location tracking mechanism, which reduces route discovery area and the number of nodes queried to find the required destination. Our routing strategy has been designed to work with dynamic zone, which contains a set of member nodes. Every node outside a zone is called a single-state node. We perform theoretical performance analysis, which shows that our network topology creation process has significantly fewer overheads than flooding approaches.
• A review of current on-demand routing protocols

  Mehran Abolhasan, Tadeusz Wysocki, Eryk Dutkiewicz

  Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 2094 186 - 195 2001年 

  Mobile ad hoc networks are data networks entirely made up of enduser communication terminals (known as nodes). Each node in the network can act as an information sink (i.e. a receiver), a source and a router. All nodes have a transmission range, which is limited by their transmission power, attenuation and interference. Mobile ad hoc networks have a number of disadvantages over wired networks. These include limited bandwidth in the wireless medium, limited power supply and mobility. The traditional routing algorithms such as DBF will not work in such networks due to lack of scalability and ability to cope with highly mobile networks. Recently, a number of routing protocols have been designed to overcome these issues. These protocols can be classified into three different categories: global, on-demand and hybrid routing. In this paper, we provide a performance comparison for on-demand routing protocols, which is based on a number of different parameters. This paper also considers which protocol characteristics will produce better performance levels in these networks, and what improvements can be made to further increase the efficiency of some of these routing protocols.

MISC

• Detecting compromised IoT devices: Existing techniques, challenges, and a way forward

  Imran Makhdoom, Mehran Abolhasan, Daniel Franklin, Justin Lipman, Christian Zimmermann, Massimo Piccardi, Negin Shariati Moghadam Computers and Security 132 2023年09月 

  IoT devices, whether connected to the Internet or operating in a private network, are vulnerable to cyber attacks from external or internal attackers or insiders who may succeed in physically compromising an IoT device. Once compromised, the IoT device can join a botnet to participate in large-scale distributed attacks (potentially recruiting additional nodes), exfiltrating confidential data or injecting false data into critical data sets, corrupting subsequent data analytics. Although various device attestation techniques are available to detect malicious IoT devices, these methods do not fully address all aspects of a potentially compromised node. This study explores current state-of-the-art approaches for detecting a malicious/compromised node in the network, highlights related challenges, and proposes a way forward for developing secure and economical attestation protocols.
• A comprehensive survey of covert communication techniques, limitations and future challenges

  Imran Makhdoom, Mehran Abolhasan, Justin Lipman Computers and Security 120 2022年09月 

  Data encryption aims to protect the confidentiality of data at storage, during transmission, or while in processing. However, it is not always the optimum choice as attackers know the existence of the ciphertext. Hence, they can exploit various weaknesses in the implementation of encryption algorithms and can thus decrypt or guess the related cryptographic primitives. Moreover, in the case of proprietary applications such as online social networks, users are at the mercy of the vendor's security measures. Therefore, users are vulnerable to various security and privacy threats. Contrary to this, covert communication techniques hide the existence of communication and thus achieve security through obscurity and hidden communication channels. Over the period, there has been a significant advancement in this field. However, existing literature fails to encompass all the aspects of covert communications in a single document. This survey thus endeavors to highlight the latest trends in covert communication techniques, related challenges, and future directions.
• Knowledge-defined networking: Applications, challenges and future work

  Sepehr Ashtari, Ian Zhou, Mehran Abolhasan, Negin Shariati, Justin Lipman, Wei Ni Array 14 2022年07月 

  Future 6G wireless communication systems are expected to feature intelligence and automation. Knowledge-defined networking (KDN) is an evolutionary step toward autonomous and self-driving networks. The building blocks of the KDN paradigm in achieving self-driving networks are software-defined networking (SDN), packet-level network telemetry, and machine learning (ML). The KDN paradigm intends to integrate intelligence to manage and control networks automatically. In this study, we first introduce the disadvantages of current network technologies. Then, the KDN and associated technologies are explored with three possible KDN architectures for heterogeneous wireless networks. Furthermore, a thorough investigation of recent survey studies on different wireless network applications was conducted. The aim is to identify and review suitable ML-based studies for KDN-based wireless cellular networks. These applications are categorized as resource management, network management, mobility management, and localization. Resource management applications can be further classified as spectrum allocation, power management, quality-of-service (QoS), base station (BS) switching, cache, and backhaul management. Within network management configurations, routing strategies, clustering, user/BS association, traffic classification, and data aggregation were investigated. Applications in mobility management include user mobility prediction and handover management. To improve the accuracy of positioning in indoor environments, localization techniques were discussed. We classify existing research into the respective KDN architecture and identify how the knowledge obtained will enhance future networks; as a result, researchers can extend their work to empower intelligence and self-organization in the network using the KDN paradigm. Finally, the requirements, motivations, applications, challenges, and open issues are presented.
• A Review on Antenna Technologies for Ambient RF Energy Harvesting and Wireless Power Transfer: Designs, Challenges and Applications

  Md Amanath Ullah, Rasool Keshavarz, Mehran Abolhasan, Justin Lipman, Karu P. Esselle, Negin Shariati IEEE Access 10 17231 -17267 2022年 

  Radio frequency energy harvesting (RFEH) and wireless power transmission (WPT) are two emerging alternative energy technologies that have the potential to offer wireless energy delivery in the future. One of the key components of RFEH or WPT system is the receiving antenna. The receiving antenna's performance has a considerable impact on the power delivery capability of an RFEH or WPT system. This paper provides a well-rounded review of recent advancements of receiving antennas for RFEH and WPT. Antennas discussed in this paper are categorized as low-profile antennas, multi-band antennas, circularly polarized antennas, and array antennas. A number of contemporary antennas from each category are presented, compared, and discussed with particular emphasis on design approach and performance. Current design and fabrication challenges, future development, open research issues of the antennas and visions for RFEH and WPT are also discussed in this review.
• Review on Metamaterial Perfect Absorbers and Their Applications to IoT

  Majid Amiri, Farzad Tofigh, Negin Shariati, Justin Lipman, Mehran Abolhasan IEEE Internet of Things Journal 8 (6) 4105 -4131 2021年03月15日 

  Future Internet of Things (IoT) devices are expected to be fully ubiquitous. To achieve this vision, a new generation of IoT devices needs to be developed, which can operate autonomously. To achieve autonomy, IoT devices must be completely wireless, both in terms of transmission and power. Further, accurate sensing is another crucial parameter of autonomy. Several wireless standards have been developed for improving the efficiency of IoT applications. However, the powering of IoT devices, sensor accuracy, and efficiency of electronic devices are open research problems in literature. With the advent of metamaterial perfect absorbers (MPAs), electromagnetic waves can be used as a source of energy, to enable sensing of the phenomenon and as a carrier for exchanging data. In this article, an extensive application-based investigation has been conducted on design principles and various methods of enhancing MPA characteristics. Moreover, the current applications that benefit from MPA, such as absorption of undesired frequencies, optical switching, energy harvesting, and sensing, are investigated. Finally, some implemented examples of MPA in industrial applications are provided along with possible directions for future work and open research areas.
• Frost Monitoring Cyber-Physical System: A Survey on Prediction and Active Protection Methods

  Ian Zhou, Justin Lipman, Mehran Abolhasan, Negin Shariati, David W. Lamb IEEE Internet of Things Journal 7 (7) 6514 -6527 2020年07月 

  Frost damage in broadacre cropping and horticulture (including viticulture) results in substantial economic losses to producers and may also disrupt associated product value chains. Frost risk windows are changing in timing, frequency, and duration. Faced with the increasing cost of mitigation infrastructure and competition for resources (e.g., water and energy), multiperil insurance, and the need for supply chain certainty, producers are under pressure to innovate in order to manage and mitigate risk. Frost protection systems are cyber-physical systems (CPSs) consisting of sensors (event detection), intelligence (prediction), and actuators (active protection methods). The Internet-of-Things communication protocols joining the CPS components are also evaluated. In this context, this article introduces and reviews existing methods of frost management. This article focuses on active protection methods because of their potential for real-time deployment during frost events. For integrated frost prediction and active protection systems, prediction method, sensor types, and integration architecture are assessed, research gaps are identified and future research directions proposed.
• Blockchain's adoption in IoT: The challenges, and a way forward

  Imran Makhdoom, Mehran Abolhasan, Haider Abbas, Wei Ni Journal of Network and Computer Applications 125 251 -279 2019年01月01日 

  The underlying technology of Bitcoin is blockchain, which was initially designed for financial value transfer only. Nonetheless, due to its decentralized architecture, fault tolerance and cryptographic security benefits such as pseudonymous identities, data integrity and authentication, researchers and security analysts around the world are focusing on the blockchain to resolve security and privacy issues of IoT. However, presently, not much work has been done to assess blockchain's viability for IoT and the associated challenges. Hence, to arrive at intelligible conclusions, this paper carries out a systematic study of the peculiarities of the IoT environment including its security and performance requirements and progression in blockchain technologies. We have identified the gaps by mapping the security and performance benefits inferred by the blockchain technologies and some of the blockchain-based IoT applications against the IoT requirements. We also discovered some practical issues involved in the integration of IoT devices with the blockchain. In the end, we propose a way forward to resolve some of the significant challenges to the blockchain's adoption in IoT.
• A Comparative Survey of VANET Clustering Techniques

  Craig Cooper, Daniel Franklin, Montserrat Ros, Farzad Safaei, Mehran Abolhasan IEEE Communications Surveys and Tutorials 19 (1) 657 -681 2017年 

  A vehicular ad hoc network (VANET) is a mobile ad hoc network in which network nodes are vehicles - most commonly road vehicles. VANETs present a unique range of challenges and opportunities for routing protocols due to the semi-organized nature of vehicular movements subject to the constraints of road geometry and rules, and the obstacles which limit physical connectivity in urban environments. In particular, the problems of routing protocol reliability and scalability across large urban VANETs are currently the subject of intense research. Clustering can be used to improve routing scalability and reliability in VANETs, as it results in the distributed formation of hierarchical network structures by grouping vehicles together based on correlated spatial distribution and relative velocity. In addition to the benefits to routing, these groups can serve as the foundation for accident or congestion detection, information dissemination and entertainment applications. This paper explores the design choices made in the development of clustering algorithms targeted at VANETs. It presents a taxonomy of the techniques applied to solve the problems of cluster head election, cluster affiliation, and cluster management, and identifies new directions and recent trends in the design of these algorithms. Additionally, methodologies for validating clustering performance are reviewed, and a key shortcoming - the lack of realistic vehicular channel modeling - is identified. The importance of a rigorous and standardized performance evaluation regime utilizing realistic vehicular channel models is demonstrated.