Researcher Profile and Settings

Affiliation

• Information Initiative Center　Cyber Security

Job Title

• Associate Professor

Degree

• Ph.D in Computer Science and Systems Engineering（Kyushu Institute of Technology）

Research funding number

• 00332768

J-Global ID

• 200901048611539410

Research Interests

• Other applications of communication   Communication theory   Computer networks   その他の通信応用   通信理論   計算機網   

Research Areas

• Informatics / Information networks

Academic & Professional Experience

• 2016/09 - Today Hokkaido University Information Initiative Center Associate Professor
• 2007/04 - 2016/08 Tokyo Institute of Technology Global Scientific Information and Computing Center
• 2004 - 2007 :Tokyo Institute of Technology Global Scientific Computer Center Associate Professor
• 2004 - 2007 Tokyo Institute of Technology Global Scientific Information and Computing Center
• 2007 -:Tokyo Institute of Technology Global Scientific Information and Computing Center Associate Professor
• 2000 - 2004 :Nara Institute of Science and Technology Graduate School of Information Science Assistant Professor
• 2000 - 2004 :奈良先端科学技術大学院大学 情報科学研究科 助手
• 2001 - 2002 :University of California, Irvine Department of Computer Science Visiting Researcher
• 2001 - 2002 米国カリフォルニア大学アーバイン校 計算機科学科 客員研究員

Education

•        - 2000  Kyushu Institute of Technology  Graduate School, Division of Information Engineering
•        - 2000  Kyushu Institute of Technology
•        - 1996  Kyushu Institute of Technology  School of Computer Science and Systems Engineering  Department of Computer Science and Electronics

Association Memberships

• IEEE   Wide Project   IEICE   IEEE   WIDEプロジェクト   電子情報通信学会   

Research Activities

Conference Activities & Talks

• A relative bandwidth allocation method achieving fast convergence time in XCP,  [Not invited]

  IEICE Tech. Rep  2010
• A Content and Peer Reputation Method for Suppressing Harmful Content in Relay-Transfer P2P File Sharing  [Not invited]

  Proc. IARIA 6th Intn'l Conference on Networking and Services (ICNS2010)  2010
• 複数端末環境における通信中の端末の遮断に対応するセッションマイグレーション方式に関する一検討  [Not invited]

  IA研究会  2010
• 通信回線の品質が仮想マシンのライブマイグレーションの品質に与える影響の調査  [Not invited]

  IA研究会  2010
• 仮想ネットワーク技術を用いたキャンパスネットワークの設計と構築  [Not invited]

  電子情報通信学会・技術研究報告  2010
• TFRC型ストリーミング通信におけるハンドオーバ時の品質向上に関する一検討  [Not invited]

  2010
• A relative bandwidth allocation method achieving fast convergence time in XCP,  [Not invited]

  IEICE Tech. Rep  2010
• ウェブシングルサインオン認証と無線LAN認証の連携に関する研究  [Not invited]

  電子情報通信学会・2010総合大会  2010
• A Content and Peer Reputation Method for Suppressing Harmful Content in Relay-Transfer P2P File Sharing  [Not invited]

  Proc. IARIA 6th Intn'l Conference on Networking and Services (ICNS2010)  2010
• キャンパスネットワークにおけるセキュリティ運用の実態と技術動向  [Not invited]

  2009
• プロキシ型モバイル通信におけるノードの位置情報漏洩の分析と許容遅延を考慮した対策の提案  [Not invited]

  電子情報通信学会  2009
• 有害コンテンツ抑制を目的としたピアとコンテンツ双方にレピュテーションを用いるP2Pコンテンツ流通手法の提案  [Not invited]

  電子情報通信学会  2009
• キャンパスネットワークの運用と管理の最前線  [Not invited]

  電子情報通信学会・第7回QoSワークショップ  2009
• A Study on Cross-Layer Network Architecture in Inter-AS Overlay Routing for Decreasing Overlapped Links  [Not invited]

  Technical Report of IEICE  2008
• Hose bandwidth allocation method to achieve minimum throughput assurance service for provider provisioned VPNs  [Not invited]

  IPSJ Journal  2008
• 東京工業大学におけるキャンパス共通認証認可システムを用いた安全なソフトウェア配布機構の設計と実装  [Not invited]

  電子情報通信学会  2008
• NSF FIND におけるポストIPネットワークの研究動向―仮想化、情報トランスポート、プライバシー、レイヤ構造―  [Not invited]

  ネットワークシステム研究会  2008
• 分散センサーによる異常トラヒック検出機構の評価モデルと性能解析  [Not invited]

  ネットワークシステム研究会  2008
• DCCPを用いたネットワークゲームの品質制御に関する評価実験  [Not invited]

  ネットワークシステム研究会  2008
• DCCPを用いたネットワークゲームのトラヒック制御に関する研究  [Not invited]

  電子情報通信学会2008年総合大会  2008
• 東京工業大学におけるキャンパス共通認証認可システムを用いた安全なソフトウェア配布機構  [Not invited]

  電子情報通信学会2008年総合大会  2008
• 自動シグネチャ生成システムにおけるトラヒック情報収集方式に関する検討  [Not invited]

  第70回情報処理学会全国大会  2008
• センサーからの情報に基づいたシグネチャ自動生成システムのモデル化と基礎検討  [Not invited]

  第70回情報処理学会全国大会  2008
• [パネル討論] ネットワーク仮想化／オーバレイネットワーク技術への期待  [Not invited]

  電子情報通信学会  2008
• 重複経路の削減を目的とするAS間オーバレイ経路制御のためのクロスレイヤアーキテクチャの一検討  [Not invited]

  ネットワークシステム研究会  2008
• Hose bandwidth allocation method to achieve minimum throughput assurance service for provider provisioned VPNs  [Not invited]

  IPSJ Journal  2008
• Novel Link Weight for Path Construction Based on Overall QoS Index  [Not invited]

  Proc. of IEEE ICC2007  2007
• Media-Handover-Aware TCP: Preventing Quality Degradation on Co-existing Real-Time Communications  [Not invited]

  Proc. of WiMob 2007  2007
• Provisioning algorithm for minimum throughput assurance service in VPNs using nonlinear programming  [Not invited]

  IEEE Australasian Telecommunication Networks and Applications Conference 2007  2007
• 大学内の業務・システムと連携するキャンパス共通認証認可システムの構築と運用  [Not invited]

  ネットワークシステム研究会  2007
• DoS環境下におけるサーバ負荷制御方式  [Not invited]

  ネットワークシステム研究会  2007
• DoS攻撃による実時間通信品質低下の基礎モデルの検討  [Not invited]

  ネットワークシステム研究会  2007
• Novel Link Weight for Path Construction Based on Overall QoS Index  [Not invited]

  Proc. of IEEE ICC2007  2007
• Media-Handover-Aware TCP: Preventing Quality Degradation on Co-existing Real-Time Communications  [Not invited]

  Proc. of WiMob 2007  2007
• 最低帯域保証を実現するVPNサービスにおける非線形計画法を用いたプロビジョニングアルゴリズム  [Not invited]

  情報ネットワーク研究会  2007
• Provisioning algorithm for minimum throughput assurance service in VPNs using nonlinear programming  [Not invited]

  IEEE Australasian Telecommunication Networks and Applications Conference 2007  2007
• Handover Latency Reduction on Host-based Mobility in Multihomed Networks  [Not invited]

  Vehicular Technology Conference 2006 Spring (VTC2006-Spring)  2006
• Improved TCP Fairness in DCCP Flow Control for Bursty Real-Time Applications  [Not invited]

  First Int'l Conference on Communications and Electronics (ICCE'06)  2006
• 大学間連携のための全国共同電子認証基盤UPKIにおける認証連携方式の検討  [Not invited]

  インターネットアーキテクチャ研究会  2006
• 高品質実時間通信を維持するためのメディア間フロー制御手法の提案  [Not invited]

  情報ネットワーク研究会  2006
• 通信品質を考慮したマルチホーム通信メディア最適化機構の設計と実装  [Not invited]

  ネットワークシステム研究会  2006
• 組織ネットワークの全内部端末に強制を行う自動生成不正トラヒック遮断システムの設計と評価  [Not invited]

  ネットワークシステム研究会  2006
• VPNホース帯域割り当て手法におけるプロビジョニングアルゴリズムに関する研究  [Not invited]

  ネットワークシステム研究会  2006
• 高機能ノードの特性を考慮した新しいリンク評価値による経路構成  [Not invited]

  情報ネットワーク研究会  2006
• Handover Latency Reduction on Host-based Mobility in Multihomed Networks  [Not invited]

  Vehicular Technology Conference 2006 Spring (VTC2006-Spring)  2006
• DCCPを用いたバースト的実時間通信におけるTCP親和性向上手法の提案とその性能評価  [Not invited]

  ネットワークシステム研究会  2006
• DCCPを用いたバースト的実時間通信におけるTCP親和性向上手法  [Not invited]

  ソサエティ大会  2006
• 高機能ノードの特性を考慮したリンク評価値による経路構成の特性評価  [Not invited]

  情報ネットワーク研究会  2006
• Improved TCP Fairness in DCCP Flow Control for Bursty Real-Time Applications  [Not invited]

  First Int'l Conference on Communications and Electronics (ICCE'06)  2006
• キャンパス共通認証・認可システムが拓く高度な研究・教育のための情報通信基盤  [Not invited]

  インターネットアーキテクチャ研究会  2006
• Performance Evaluations of DCCP for Bursty Traffic in Real-time Applications  [Not invited]

  Proceddings of IEEE/IPSJ 2005 Intl Symposium on Applications and the Internet (SAINT2005)  2005
• Performance Evaluation of Hose Bandwidth Allocation Method Using Feedback Control and Class-based Queueing for VPNs  [Not invited]

  IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PacRim 2005)  2005
• A Framework for Network Media Optimization in Multihomed QoS Networks  [Not invited]

  Proc. ACM First International Workshop on Dynamic Interconnection of Networks (DIN2005) in conjunction with MobiCom2005  2005
• Performance Evaluations of DCCP for Bursty Traffic in Real-time Applications  [Not invited]

  Proceddings of IEEE/IPSJ 2005 Intl Symposium on Applications and the Internet (SAINT2005)  2005
• 学習メディアへのアクセスを可能とするセキュアキャンパス公衆LANの構築  [Not invited]

  第33回年次大会  2005
• ユーザ単位でのMACアドレス認証による運用コスト低減を目的としたセキュアキャンパス公衆LANの構築  [Not invited]

  ネットワークシステム研究会  2005
• Performance Evaluation of Hose Bandwidth Allocation Method Using Feedback Control and Class-based Queueing for VPNs  [Not invited]

  IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PacRim 2005)  2005
• A Framework for Network Media Optimization in Multihomed QoS Networks  [Not invited]

  Proc. ACM First International Workshop on Dynamic Interconnection of Networks (DIN2005) in conjunction with MobiCom2005  2005
• マルチホーム環境における通信メディア最適化方式の実装と評価  [Not invited]

  通信ソサエティ大会  2005
• マルチホーム環境における通信品質を考慮した通信メディア最適化機構の提案  [Not invited]

  ネットワークシステム研究会  2005

MISC

• A study on XCP routers' misbehaviors on congestion control

  Hieu Hanh Le, unknown unknown, Kenji Masui, KATSUYOSHI IIDA  108-  (460)  49  -54  2009  [Not refereed][Not invited]
  
• A study on XCP routers' misbehaviors on congestion control

  Hieu Hanh Le, unknown unknown, Kenji Masui, KATSUYOSHI IIDA  108-  (460)  49  -54  2009  [Not refereed][Not invited]
  
• キャンパス共通認証認可システムの構築と運用

  飯田勝吉, 新里卓史, 伊東利哉, 渡辺治  電子情報通信学会  J92-B-  (10)  1554  -1565  2009  [Not refereed][Not invited]
  
• Proposal for adaptive bandwidth allocation using one-way feedback control for MPLS networks

  Teruaki Yokoyama, Katsuyoshi Iida, Hiroyuki Koga, Suguru Yamaguchi  IEICE TRANSACTIONS ON COMMUNICATIONS  E90B-  (12)  3530  -3540  2007/12  [Not refereed][Not invited]
   

  In this research, we focused on fair bandwidth allocation on the Internet. The Internet provides communication services based on exchanged packets. The bandwidth available for each customer is often fluctuated. Fair bandwidth allocation is an important issue for ISPs to gain customer satisfaction. Static bandwidth allocation allows an exclusive bandwidth for specific traffic. Although it gives communications a QoS guarantee, it requires muany bandwidth resources as known as over-provisioning. In contrast with static control, dynamic control allocates bandwidth resources dynamically. It therefore utilizes bandwidth use more effectively. However, it needs control overhead in monitoring traffic and estimating the optimum allocation. The Transmission Control Protocol, or TCP is the dominant protocol on the Internet. It is also equipped with a traffic-rate-control mechanism. An adaptive bandwidth-allocation mechanism must control traffic that is under TCP control. Rapid feedback makes it possible to gain an advantage over TCP control. In this paper, we propose an Adaptive Bandwidth Allocation (ABA) mechanism as a feedback system for MPLS. Our proposal allows traffic to be regulated adaptively as its own weight value which can be assigned by administrators. The feedback bandwidth allocation in the previous work needs round-trip control delay in collecting network status along the communication path. We call this "round-trip feedback control." Our proposal, called "one-way feedback control," collects network status in half the time of roundtrip delay. We compare the performance of our one-way feedback-based mechanism and traditional round-trip feedback control under a simulation environment. We demonstrate the advantages of our rapid feedback control has using experimental results.
• Proposal for adaptive bandwidth allocation using one-way feedback control for MPLS networks

  Teruaki Yokoyama, Katsuyoshi Iida, Hiroyuki Koga, Suguru Yamaguchi  IEICE TRANSACTIONS ON COMMUNICATIONS  E90B-  (12)  3530  -3540  2007/12  [Not refereed][Not invited]
   

  In this research, we focused on fair bandwidth allocation on the Internet. The Internet provides communication services based on exchanged packets. The bandwidth available for each customer is often fluctuated. Fair bandwidth allocation is an important issue for ISPs to gain customer satisfaction. Static bandwidth allocation allows an exclusive bandwidth for specific traffic. Although it gives communications a QoS guarantee, it requires muany bandwidth resources as known as over-provisioning. In contrast with static control, dynamic control allocates bandwidth resources dynamically. It therefore utilizes bandwidth use more effectively. However, it needs control overhead in monitoring traffic and estimating the optimum allocation. The Transmission Control Protocol, or TCP is the dominant protocol on the Internet. It is also equipped with a traffic-rate-control mechanism. An adaptive bandwidth-allocation mechanism must control traffic that is under TCP control. Rapid feedback makes it possible to gain an advantage over TCP control. In this paper, we propose an Adaptive Bandwidth Allocation (ABA) mechanism as a feedback system for MPLS. Our proposal allows traffic to be regulated adaptively as its own weight value which can be assigned by administrators. The feedback bandwidth allocation in the previous work needs round-trip control delay in collecting network status along the communication path. We call this "round-trip feedback control." Our proposal, called "one-way feedback control," collects network status in half the time of roundtrip delay. We compare the performance of our one-way feedback-based mechanism and traditional round-trip feedback control under a simulation environment. We demonstrate the advantages of our rapid feedback control has using experimental results.
• A quality-aware VoWLAN architecture and its quantitative evaluations

  Hiroyuki Koga, Shigeru Kashihara, Yutaka Fukuda, Katsuyoshi Iida, Yuji Oie  IEEE Wireless Communications  13-  (1)  52  -59  2006/02  [Not refereed][Not invited]
   

  The deployment of wireless LAN and other communication media, such as 3G cellular, is proceeding rapidly. In the near future, multiple WLAN carriers, together with 3G cellular and other communication carriers, will provide their services in a complementary fashion. Furthermore, next-generation mobile phones, which may use voice and data services simultaneously, will connect these networks. In the present article we design and evaluate a new network architecture that ensures appropriate QoS for next-generation mobile phones. Through performance evaluations, we show that our architecture improves QoS for voice communication. © 2006 IEEE.
• A quality-aware VoWLAN architecture and its quantitative evaluations

  H Koga, S Kashihara, Y Fukuda, K Iida, Y Oie  IEEE WIRELESS COMMUNICATIONS  13-  (1)  52  -59  2006/02  [Not refereed][Not invited]
   

  The deployment of wireless LAN and other communication media, such as 3G cellular, is proceeding rapidly. In the near future, multiple WLAN carriers, together with 3G cellular and other communication carriers, will provide their services in a complementary fashion. Furthermore, next-generation mobile phones, which may use voice and data services simultaneously, will connect these networks. In the present article we design and evaluate a new network architecture that ensures appropriate QoS for next-generation mobile phones. Through performance evaluations, we show that our architecture improves QoS for voice communication.
• Performance study and deployment strategies on the sender-initiated multicast

  Visoottiviseth, V, H Kido, K Iida, Y Kadobayashi, S Yamaguchi  IEICE TRANSACTIONS ON COMMUNICATIONS  E88B-  (4)  1383  -1394  2005/04  [Not refereed][Not invited]
   

  Although IP Multicast offers efficient data delivery for large group communications, the most critical issue delaying widespread deployment of IP Multicast is the scalability of multicast forwarding state as the number of multicast groups increases. Sender-Initiated Multicast (SIM) was proposed as an alternative multicast forwarding scheme for small group communications with incremental deployment capability. The key feature of SIM is in its Preset mode with the automatic SIM tunneling function, which maintaining forwarding information states only on the branching routers. To demonstrate how SIM increases scalability with respect to the number of groups, in this paper we evaluate the proposed protocol both through simulations and real experiments. As from the network operator's point of view, the bandwidth consumption, memory requirements on state-and-signaling per session in routers, and the processing overhead are considered as evaluation parameters. Finally, we investigated the strategies for incremental deployment.
• Performance study and deployment strategies on the sender-initiated multicast

  Visoottiviseth, V, H Kido, K Iida, Y Kadobayashi, S Yamaguchi  IEICE TRANSACTIONS ON COMMUNICATIONS  E88B-  (4)  1383  -1394  2005/04  [Not refereed][Not invited]
   

  Although IP Multicast offers efficient data delivery for large group communications, the most critical issue delaying widespread deployment of IP Multicast is the scalability of multicast forwarding state as the number of multicast groups increases. Sender-Initiated Multicast (SIM) was proposed as an alternative multicast forwarding scheme for small group communications with incremental deployment capability. The key feature of SIM is in its Preset mode with the automatic SIM tunneling function, which maintaining forwarding information states only on the branching routers. To demonstrate how SIM increases scalability with respect to the number of groups, in this paper we evaluate the proposed protocol both through simulations and real experiments. As from the network operator's point of view, the bandwidth consumption, memory requirements on state-and-signaling per session in routers, and the processing overhead are considered as evaluation parameters. Finally, we investigated the strategies for incremental deployment.
• Multi-path transmission algorithm for end-to-end seamless handover across heterogeneous wireless access networks

  S Kashihara, K Iida, H Koga, Y Kadobayashi, S Yamaguchi  IEICE TRANSACTIONS ON COMMUNICATIONS  E87B-  (3)  490  -496  2004/03  [Not refereed][Not invited]
   

  In future mobile networks, new technologies will be needed to enable a mobile host to move across heterogeneous wireless access networks without disruption of the connection. In the past, many researchers have studied handover in such IP networks. In almost all cases, special network devices are needed to maintain the host's mobility. Moreover, a host cannot move across heterogeneous wireless access networks without degradation of the goodput for real-time communication, although a mobile host with multiple network interfaces can connect to multiple wireless access networks. For these reasons, we consider that a mobile host needs to manage seamless handover on an end-to-end basis. In this paper, we propose a multi-path transmission algorithm for end-to-end seamless handover. The main purpose of this algorithm is to improve the goodput during handover by sending the same packets along multiple paths, minimizing unnecessary consumption of network resources. We evaluate our algorithm through simulations and show that a mobile host gains a better goodput.
• Multi-path transmission algorithm for end-to-end seamless handover across heterogeneous wireless access networks

  S Kashihara, K Iida, H Koga, Y Kadobayashi, S Yamaguchi  IEICE TRANSACTIONS ON COMMUNICATIONS  E87B-  (3)  490  -496  2004/03  [Not refereed][Not invited]
   

  In future mobile networks, new technologies will be needed to enable a mobile host to move across heterogeneous wireless access networks without disruption of the connection. In the past, many researchers have studied handover in such IP networks. In almost all cases, special network devices are needed to maintain the host's mobility. Moreover, a host cannot move across heterogeneous wireless access networks without degradation of the goodput for real-time communication, although a mobile host with multiple network interfaces can connect to multiple wireless access networks. For these reasons, we consider that a mobile host needs to manage seamless handover on an end-to-end basis. In this paper, we propose a multi-path transmission algorithm for end-to-end seamless handover. The main purpose of this algorithm is to improve the goodput during handover by sending the same packets along multiple paths, minimizing unnecessary consumption of network resources. We evaluate our algorithm through simulations and show that a mobile host gains a better goodput.
• Receiver-based flow control mechanism with interlayer collaboration for real-time communication quality in W-CDMA networks

  H Koga, K Iida, Y Oie  PERSONAL WIRELESS COMMUNICATIONS, PROCEEDINGS  3260-  286  -300  2004  [Not refereed][Not invited]
   

  Mobile networks are becoming increasingly prevalent, and this has led to an increase in the bandwidth available over wireless links in IMT-2000. Both non-real-time forms of communication, such as e-mail and web browsing, and real-time forms of communication, such as audio and video applications, are well suited to wireless networks. However, wireless networks axe subject to relatively long transmission delays because of the need to recover lost packets caused by high bit error rates. This degrades the quality of real-time communications. Therefore, in the present paper, we propose a receiver-based flow control mechanism employing an interlayer collaboration concept to improve the quality of real-time communications without adversely affecting the performance of non-real-time communications on IMT-2000 networks. In addition, simulations are performed in order to evaluate the performance of the proposed mechanism and demonstrate its effectiveness.
• Receiver-based flow control mechanism with interlayer collaboration for real-time communication quality in W-CDMA networks

  H Koga, K Iida, Y Oie  PERSONAL WIRELESS COMMUNICATIONS, PROCEEDINGS  3260-  286  -300  2004  [Not refereed][Not invited]
   

  Mobile networks are becoming increasingly prevalent, and this has led to an increase in the bandwidth available over wireless links in IMT-2000. Both non-real-time forms of communication, such as e-mail and web browsing, and real-time forms of communication, such as audio and video applications, are well suited to wireless networks. However, wireless networks axe subject to relatively long transmission delays because of the need to recover lost packets caused by high bit error rates. This degrades the quality of real-time communications. Therefore, in the present paper, we propose a receiver-based flow control mechanism employing an interlayer collaboration concept to improve the quality of real-time communications without adversely affecting the performance of non-real-time communications on IMT-2000 networks. In addition, simulations are performed in order to evaluate the performance of the proposed mechanism and demonstrate its effectiveness.
• マルチホーム環境下においてホストモビリティがトランスポートフローに与える影響～激しい移動強度と長いRTTへの対応～

  岡本拓二, 古閑宏幸, 飯田勝吉, 門林雄基, 山口英  電子情報通信学会 技術研究報告  104-  (514)  67  -72  2004  [Not refereed][Not invited]
  
• マルチホームを有効に活用する高速データ転送プロトコルの検討

  大塚敏晴, 飯田勝吉, 門林雄基, 山口英  電子情報通信学会 技術研究報告  104-  (514)  37  -72  2004  [Not refereed][Not invited]
  
• Performance Evaluation of Inter-domain IP Traceback

  Y. Sawai, M. Oe, K. Iida, Y. Kadobayashi  Proceedings of IEEE ICT2003  2003  [Not refereed][Not invited]
  
• Performance Evaluation of Inter-domain IP Traceback

  Y. Sawai, M. Oe, K. Iida, Y. Kadobayashi  Proceedings of IEEE ICT2003  2003  [Not refereed][Not invited]
  
• Delay analysis for CBR traffic under static-priority scheduling

  K Iida, T Takine, H Sunahara, Y Oie  IEEE-ACM TRANSACTIONS ON NETWORKING  9-  (2)  177  -185  2001/04  [Not refereed][Not invited]
   

  We examine the delay performance of packets from constant-bit-rate (CBR) traffic whose delay is affected by non-real-time traffic. The delay performance is analyzed by solving the nD/D/1 queue with vacations. We obtain an exact and closed form solution, hence obviating the need of any approximations or numerical Laplace inversions. We then provide various numerical results for low-bit-rate transmission links, in which packets can experience large delay. From our quantitative evaluation, we conclude that there exists an optimum packet size for a given delay bound. In extremely slow links, such as modem links, transmission control protocol (TCP) packets should be segmented to reduce the CBR delay. We therefore investigate the delay impact of TCP packet sizes as well.
• Delay analysis for CBR traffic under static-priority scheduling

  K Iida, T Takine, H Sunahara, Y Oie  IEEE-ACM TRANSACTIONS ON NETWORKING  9-  (2)  177  -185  2001/04  [Not refereed][Not invited]
   

  We examine the delay performance of packets from constant-bit-rate (CBR) traffic whose delay is affected by non-real-time traffic. The delay performance is analyzed by solving the nD/D/1 queue with vacations. We obtain an exact and closed form solution, hence obviating the need of any approximations or numerical Laplace inversions. We then provide various numerical results for low-bit-rate transmission links, in which packets can experience large delay. From our quantitative evaluation, we conclude that there exists an optimum packet size for a given delay bound. In extremely slow links, such as modem links, transmission control protocol (TCP) packets should be segmented to reduce the CBR delay. We therefore investigate the delay impact of TCP packet sizes as well.
• Delay analysis for CBR traffic in multimedia enterprise network

  K Iida, T Takine, H Sunahara, Y Oie  IEICE TRANSACTIONS ON COMMUNICATIONS  E84B-  (4)  1041  -1052  2001/04  [Not refereed][Not invited]
   

  We examine delay performance of packets from constant bit rate (CBR) traffic whose delay is affected by non-real-time traffic. The delay performance is analyzed bq solving the C D-i/G/1 queue with vacations. Our analysis allows heterogeneous service time and heterogeneous interarrival time. Thus, we can get the impact of packet length of a stream on the delay time of other streams. We then give various numerical results for enterprise multimedia networks, which include voice, video and data communication services. From our quantitative evaluation, we conclude that packet length of video traffic has large influence on the delay time of voice traffic while voice traffic gives a little impact on the delay time of video traffic.
• Delay Analysis for CBR Traffic in Multimedia Enterprise Network

  K. Iida, T, Takine, H. Sunahara, Y. Oie  IEICE Transactions on Communications  E84-B-  (4)  1041  -1052  2001  [Not refereed][Not invited]
  
• Performance evaluation of the architecture for end-to-end quality-of-service provisioning

  K Iida, K Kawahara, T Takine, Y Oie  IEEE COMMUNICATIONS MAGAZINE  38-  (4)  76  -81  2000/04  [Not refereed][Not invited]
   

  Real-time communications services over the Internet need a new architecture to meet their required quality. From a viewpoint of quality of service provisioning architecture, the Internet can mainly be divided into three types of subnetworks: domain networks, access networks, and stub networks. In this article we focus on issues arising in the former two networks for end-to-end QoS provisioning. First. the access networks are of rather low-speed links, so delay is still of major concern. We examine the statistical delay bound through numerical results derived from our analysis. Schemes to reduce delay are proposed, and their performance is evaluated. Next, domain networks are likely to be of very highspeed links, which can accommodate a huge number of voice flows of low bit rates. Thus, effective flow management will be of major concern because per-flow management is a very costly proposition. Therefore, we pay attention to a flow aggregation scheme, and evaluate its performance by analyzing its blocking probability.
• Performance evaluation of the architecture for end-to-end quality-of-service provisioning

  K Iida, K Kawahara, T Takine, Y Oie  IEEE COMMUNICATIONS MAGAZINE  38-  (4)  76  -81  2000/04  [Not refereed][Not invited]
   

  Real-time communications services over the Internet need a new architecture to meet their required quality. From a viewpoint of quality of service provisioning architecture, the Internet can mainly be divided into three types of subnetworks: domain networks, access networks, and stub networks. In this article we focus on issues arising in the former two networks for end-to-end QoS provisioning. First. the access networks are of rather low-speed links, so delay is still of major concern. We examine the statistical delay bound through numerical results derived from our analysis. Schemes to reduce delay are proposed, and their performance is evaluated. Next, domain networks are likely to be of very highspeed links, which can accommodate a huge number of voice flows of low bit rates. Thus, effective flow management will be of major concern because per-flow management is a very costly proposition. Therefore, we pay attention to a flow aggregation scheme, and evaluate its performance by analyzing its blocking probability.

Awards & Honors

• 2007 Research award, Technical committee on Network systems, IEICE
  
• 2007 電子情報通信学会・ネットワークシステム研究賞
  
• 2005 電子情報通信学会・通信ソサエティ・活動功労賞
  
• 2003 18th Telecom System Award, Telecommunications Advancement Foundation
  
• 2003 第１８回電気通信普及財団テレコムシステム技術賞
  

Research Grants & Projects

• Mobile Communication Architecture for Ubiquitous Networked Society

  Funded Research

  Date (from‐to) : 2004 -2006
• ユビキタス社会に向けたモバイル通信機構

  受託研究

  Date (from‐to) : 2004 -2006
• A Study on Reliable Communication using SCTP with Multi-Homed Networks

  Funded Research

  Date (from‐to) : 2002 -2004
• マルチホーミング環境におけるSCTPを用いた高信頼通信に関する研究

  受託研究

  Date (from‐to) : 2002 -2004

Educational Activities

Teaching Experience