TOSHIHIKO KATO
| Emeritus Professor etc. | Emeritus Professor |
- Profile:
Engaged in research activities on communication protocols, including TCP, Mobile IP, Multicast, Ad hoc network, and Wireless LAN.
Researcher Information
Research Keyword
Educational Background
Research Activity Information
Paper
- リカレントニューラルネットワークを用いた双方向通信ログに基づくTCP輻輳制御の推定方式
大関尚紀; 山本嶺; 大坐畠智; 加藤聰彦
情報処理学会論文誌, 61, 2, 287-296, Feb. 2020, Peer-reviwed
Scientific journal, Japanese - Flying Control of Multiple UAVs through Wireless Ad-Hoc Network
Takayuki Kashiwa; Ryo Yamamoto; Satoshi Ohzahata; Toshihiko Kato
Proceedings of 3rd International Conference on Communication and Network Technology (ICCNT 2019), 1-7, Sep. 2019, Peer-reviwed
International conference proceedings, English - Implementation and Performance Evaluation of Eavesdropping Protection Method over MPTCP Using Data Scrambling and Path Dispersion
Toshihiko Kato; Shihan Cheng; Ryo Yamamoto; Satoshi Ohzahata; Nobuo Suzuki
International Journal on Advances in Security, 12, 1, 69-78, Jul. 2019, Peer-reviwed
Scientific journal, English - A Study on Round-trip Time Estimation from Unidirectional Packet Traces Using Different TCP Congestion Control Algorithms
Toshihiko Kato; Xiaofan Yan; Ryo Yamamoto; Satoshi Ohzahata
International Journal On Advances in Networks and Services, 12, 1, 1-9, Jul. 2019, Peer-reviwed
Scientific journal, English - Experimental Analysis of MPTCP Congestion Control Algorithms: LIA, OLIA and BALIA
Toshihiko Kato; Adhikari Diwakar; Ryo Yamamoto; Satoshi Ohzahata; Nobuo Suzuki
Proceedings of 8th International Conference on Theory and Practice in Modern Computing (TPMC 2019), 105-112, Jul. 2019, Peer-reviwed
International conference proceedings, English - Performance Evaluation of Named Data Networking Based Ad Hoc Network Focusing on Node Moving
Ngo Quang Minh; Ryo Yamamoto; Satoshi Ohzahata; Toshihiko Kato
Proceedings of 15th Advanced International Conference on Telecommunications (AICT 2019), 46-51, Jul. 2019, Peer-reviwed
International conference proceedings, English - Estimating TCP Congestion Control Algorithms from Passively Collected Packet Traces Using Recurrent Neural Network
Naoki Ohzeki; Ryo Yamamoto; Satoshi Ohzahata; Toshihiko Kato
Proceedings of 10th International Conference on Data Communication Networking (DCNET 2019), 33-42, Jul. 2019, Peer-reviwed
International conference proceedings, English - 輻輳ウィンドウとその増加分に着目したパッシブなTCP輻輳制御アルゴリズムの推定方法
加藤 聰彦; 小田 淳; 厳 笑凡; 山本 嶺; 大坐畠 智
情報処理学会論文誌, 情報処理学会, 60, 2, 479-490, Feb. 2019, Peer-reviwed
Scientific journal, Japanese - Impacts of System Clock Granularity on Performance of NDN Rate-based Congestion Control
Toshihiko Kato; Kazuki Osada; Ryo Yamamoto; Satoshi Ohzahata
International Journal On Advances in Telecommunications, IARIA, 11, 3&4, 135-143, Jan. 2019, Peer-reviwed
Scientific journal, English - Performance Evaluation of TCP Spurious Timeout Detection Methods under Delay Spike and Packet loss Emulating LTE Handover
Toshihiko Kato; Masahito Moriyama; Ryo Yamamoto; Satoshi Ohzahata
IADIS International Journal on Computer Science and Information Systems, IADIS, 13, 2, 16-29, Dec. 2018, Peer-reviwed
Scientific journal, English - How to Implement NDN MANET over ndnSIM Simulator
Toshihiko Kato; Ngo Quang Minh; Ryo Yamamoto; Satoshi Ohzahata
IEEE 4th International Conference on Computer Communications (ICCC 2018), 451-456, Dec. 2018, Peer-reviwed
International conference proceedings, English - Implementation of Eavesdropping Protection Method over MPTCP Using Data Scrambling and Path Dispersion
Toshihiko Kato; Shihan Cheng; Ryo Yamamoto; Satoshi Ohzahata; Nobuo Suzuki
Proceedings of The Twelfth International Conference on Emerging Security Information, Systems and Technologies (SECURWARE 2018), 108-113, Sep. 2018, Peer-reviwed
International conference proceedings, English - Identification of TCP Congestion Control Algorithms from Unidirectional Packet Traces
Toshihiko Kato; Xiaofan Yan; Ryo Yamamoto; Satoshi Ohzahata
Proceedings of 2nd International Conference on Communication and Network Technology (ICCNT 2018), 1-6, Sep. 2018, Peer-reviwed
International conference proceedings, English - Experimental Analysis and Resolution Proposal on Performance Degradation of TCP over IEEE 802.11n Wireless LAN Caused by Access Point Scanning
Toshihiko Kato; Kento Kobayashi; Sota Tasaki; Masataka Nomoto; Ryo Yamamoto; Satoshi Ohzahata
International Journal On Advances in Telecommunications, 11, 1&2, 10-19, Jul. 2018, Peer-reviwed
Scientific journal, English - Proposal and Performance Analysis of Hybrid NDN Based Ad Hoc Routing Combining Proactive and Reactive Mechanisms
Ngo Quang Minh; Ryo Yamamoto; Satoshi Ohzahata; Toshihiko Kato
International Journal On Advances in Networks and Services, 11, 1&2, 1-10, Jul. 2018, Peer-reviwed
Scientific journal, English - Proposal and Study on Implementation of Data Eavesdropping Protection Method over Multipath TCP Communication Using Data Scrambling and Path Dispersion
Toshihiko Kato; Shihan Cheng; Ryo Yamamoto; Satoshi Ohzahata; Nobuo Suzuki
International Journal On Advances in Security, 11, 1&2, 118-126, Jul. 2018, Peer-reviwed
Scientific journal, English - IEEE802.11ac無線LANのMU-MIMOダウンリンク伝送における動的フレームアグリゲーションサイズ選択によるスループット改善手法
森山 友和; 山本 嶺; 大坐畠 智; 加藤 聰彦
電子情報通信学会論文誌 B, J101-B, 7, 1-12, Jul. 2018, Peer-reviwed
Scientific journal, Japanese - Experimental Analysis of Spurious Timeout Detection Methods with LTE Handover Emulation
Toshihiko Kato; Masahito Moriyama; Ryo Yamamoto; Satoshi Ohzahata
Proceedings of 7th International Conference on Theory and Practice in Modern Computing (TPMC 2018), 105-112, Jul. 2018, Peer-reviwed
International conference proceedings, English - Applying Lomb Periodogram to Round-trip Time Estimation from Unidirectional Packet Traces with Different TCP Congestion Controls
Toshihiko Kato; Xiaofan Yan; Ryo Yamamoto; Satoshi Ohzahata
Proceedings of The Thirteenth International Conference on Internet Monitoring and Protection (ICIMP 2018), 1-6, Jul. 2018, Peer-reviwed
International conference proceedings, English - Reducing Link Failure Test Cases for Telecom Networks by Focusing on Topological Similarity
Megumi Shibuya; Toshihiko Kato; Teruyuki Hasegawa; Hirozumi Yamaguchi
Proceedings of The Fourteenth Advanced International Conference on Telecommunications (AICT 2018), 46-51, Jul. 2018, Peer-reviwed
International conference proceedings, English - TCP Congestion Control over IEEE 802.11 Wireless LANs Based on K-means Clustering Focusing on Congestion Window Size and Round-trip Time
Tomokazu Moriyama; Ryo Yamamoto; Satoshi Ohzahata; Toshihiko Kato
Proceedings of 9th International Conference on Data Communication Networking (DCNET 2018), 25-32, Jul. 2018, Peer-reviwed
International conference proceedings, English - A Study on How Coarse-grained Clock System Influences NDN Rate-based Congestion Control
Toshihiko Kato; Kazuki Osada; Ryo Yamamoto; Satoshi Ohzahata
Proceedings of The Seventeenth International Conference on Networks (ICN 2018), 35-40, Apr. 2018, Peer-reviwed
International conference proceedings, English - How Insufficient Send Socket Buffer Affects MPTCP Performance over Paths with Different Delay
Toshihiko Kato; Adhikari Diwakar; Ryo Yamamoto; Satoshi Ohzahata
6th World Conference on Information Systems and Technologies (WorldCist ’18), 614-624, Mar. 2018, Peer-reviwed
International conference proceedings, English - A Solution for Bufferbloat Problem in Upload TCP Communication over IEEE 802.11n WLAN Only by Modifying Access Point
Masataka Nomoto; Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
The Sixth International Conference on Communications, Computation, Networks and Technologies (INNOV 2017), 8-13, Oct. 2017, Peer-reviwed
International conference proceedings, English - Protecting Eavesdropping over Multipath TCP Communication Based on Not-Every-Not-Any Protection
Toshihiko Kato; Shihan Cheng; Ryo Yamamoto; Satoshi Ohzahata; Nobuo Suzuki
The Eleventh International Conference on Emerging Security Information, Systems and Technologies (SECURWARE 2017), 87-92, Sep. 2017, Peer-reviwed
International conference proceedings, English - A QoS Aware Ad Hoc Multicast by Combining TDMA and IEEE 802.11 DCF
Jing Lin; Ryo Yamamoto; Satoshi Ohzahata; Toshihiko Kato
International Conferences Computer Graphics, Visualization, Computer Vision and Image Processing 2017 and Big Data Analysis, Data Mining and Computational Intelligence 2017, 204-211, Jul. 2017, Peer-reviwed
International conference proceedings, English - Frame Aggregation Size Determination for IEEE 802.11ac WLAN Considering Channel Utilization and Transfer Delay
Tomokazu Moriyama; Ryo Yamamoto; Satoshi Ohzahata; Toshihiko Kato
14th International Conference on Wireless Networks and Mobile Systems (WINSYS 2017), 89-94, Jul. 2017, Peer-reviwed
International conference proceedings, English - A Routing Protocol Proposal for NDN Based Ad Hoc Networks Combining Proactive and Reactive Routing Mechanisms
Ngo Quang Minh; Ryo Yamamoto; Satoshi Ohzahata; Toshihiko Kato
The Thirteenth Advanced International Conference on Telecommunications (AICT 2017), 80-86, Jun. 2017, Peer-reviwed
International conference proceedings, English - Resolving Bufferbloat in TCP Communication over IEEE 802.11n WLAN by Reducing MAC Retransmission Linit at Low Data Rate
Masataka Nomoto; Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Sixteenth International Conference on Networks (ICN 2017), 69-74, Apr. 2017, Peer-reviwed
International conference proceedings, English - IEEE 802.11n無線LANのアップロードTCP通信におけるBufferbloat問題に対するアクセスポイントでの対応方式
野元 祐孝; 策力木格; 大坐畠智; 加藤 聰彦
情報処理学会論文誌, 情報処理学会, 58, 2, 427-438, 01 Feb. 2017, Peer-reviwed, IEEE 802.11n無線アクセスポイントを経由するTCP通信では，低いMACレベルデータレートが使用される場合に，往復遅延が増加するBufferbloat問題が発生し，同じキューを共通する他の通信の遅延時間が増加し，ユーザレベルの品質の悪化となる．この対処として，アクティブキュー管理方式，筆者らが先に示した無線LANの最大再送回数を制限する方法，遅延増加時にTCP通信を停止する方法などが提案されている．しかしこれらはすべて，データの送信側に実装する必要がある．このため，端末からアクセスポイントへのアップロード転送においては，端末のすべてにこのような方式を導入しなければならない．そこで本稿では，データの受信側であるアクセスポイントにおいて，低いMACレベルデータレートで無線LANフレームの最大再送回数を制限したと同様な効果を与えることにより，TCPの輻輳ウィンドウを減少させ，Bufferbloat問題に対応する方法を提案する．パソコンを用いたアクセスポイントに提案方式を実装することにより，Bufferbloat問題に対応していない端末で，低いMACレベルデータレートでの往復遅延を減少させられること，さらにBufferbloat問題に対する方法を実装している端末においてもTCP通信のスループットを悪化させることがないことを明らかにした．IEEE 802.11n wireless LANs provides a Bufferbloat problem such that the round-tirp delay increases in TCP communications when the MAC level data is low such as 6.5Mbps. This problem degrades user level quality of service for communications sharing the transmission queue with the TCP communications. In order to resolve this problem, several schemes are proposed such as a scheme based on active queue management, our previous scheme reducing the retry-out limit at low data rate, and a scheme stopping sending TCP level data when the queue contains more than a specific number of packes. However, those schemes need to be implemented at the sender side. In this paper, we propose a new scheme resolving a Bufferbloat problem in the upload TCP communications by providing an effect at a receiving side access point similar to reducing the retry-out limit when the MAC level data rate is low. This decreases the congestion window size in the sending side and can reduce the delay. This paper also shows the results of the performance evaluation by implementing the proposed method in a PC based access point. According to the results, the proposed method decreases the round-trip time in the low MAC data rate and does not reduce the TCP throughput. It does not give any influences on the TCP thoughput for the terminals supporting the conventional schemes for Bufferbroat problems.
Scientific journal, Japanese - A TDMA/DCF Hybrid QoS Scheme for Ad Hoc Networks
Jing Lin; Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E100B, 1, 42-53, Jan. 2017, Peer-reviwed, We propose a QoS scheme for ad hoc networks by combining TDMA and IEEE 802.11 DCF, and present performance evaluation results of the scheme. In the proposed scheme, the channel time is composed of two different periods, specifically TDMA period and DCF period. The TDMA period provides contention free transmission opportunities for QoS flows, and the DCF period provides contention-based access for best effort or low priority flows. We evaluate the proposed scheme for various numbers of TCP flows and different CBR data rates with QualNet simulator. Simulation results show that the protocol is able to provide an efficient solution for QoS control in ad hoc networks.
Scientific journal, English - A Hierarchical Opportunistic Routing with Moderate Clustering for Ad Hoc Networks
Ryo Yamamoto; Satoshi Ohzahata; Toshihiko Kato
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E100B, 1, 54-66, Jan. 2017, Peer-reviwed, The self-organizing nature of ad hoc networks is a good aspect in that terminals are not dependent on any infrastructure, that is, networks can be formed with decentralized and autonomous manner according to communication demand. However, this characteristic might affect the performance in terms of stability, reliability and so forth. Moreover, ad hoc networks face a scalability problem, which arise when the number of terminals in a network increases or a physical network domain expands, due to the network capacity limitation caused by the decentralized and the autonomous manner. Regarding this problem, some hierarchical and cluster-based routings have been proposed to effectively manage the networks. In this paper, we apply the concept of hierarchical routing and clustering to opportunistic routing, which can forward packets without using any pre-established path to achieve a path diversity gain with greater reachability. The simulation results show that the proposed method can achieve 110'o higher reliability with a reasonable end-to-end delay in dense environments and 30010 higher in large-scale networks.
Scientific journal, English - Experimental Analysis on How Access Point Scanning Impacts on TCP Throughput over IEEE 802.11n Wireless LAN
Kento Kobayashi; Yoshiki Hashimoto; Ryo Yamamoto; Satoshi Ohzahata; Toshihiko Kato
Twelfth International Conference on Wireless and Mobile Communications (ICWMC 2016), 115-120, Nov. 2016, Peer-reviwed
International conference proceedings, English - Microscopic Approach for Experimental Analysis of Multipath TCP Troughput under Insufficient Send/Receive Socket Buffers
Toshihiko Kato; Masaaki Tenjin; Ryo Yamamoto; Satoshi Ohzahata; Hiroyuki Shinbo
15th International Conference WWW/Internet 2016 (ICWI 2016), 191-199, Oct. 2016, Peer-reviwed
International conference proceedings, English - Performance Anomaly in Download TCP Flows Over IEEE 802.11n Wireless LAN
Yoshiki Hashimoto; Masataka Nomoto; Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
The Fifth International Conference on Communications, Computation, Networks and Technologies (INNOV 2016), 13-18, Aug. 2016, Peer-reviwed
International conference proceedings, English - How to Utilize Interflow Network Coding in VANETs: A Backbone-Based Approach
Celimuge Wu; Satoshi Ohzahata; Yusheng Ji; Toshihiko Kato
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 17, 8, 2223-2237, Aug. 2016, Peer-reviwed, It is particularly challenging to design an efficient routing protocol for vehicular ad hoc networks due to the vehicle movement, limited wireless resources, and lossy feature of the wireless channel. We propose a protocol which uses common backbone vehicles for different traffic flows, as well as employs interflow network coding to encode packets at the backbone vehicles. A reliably connected backbone is selected by taking into account vehicle movement dynamics and link quality between vehicles. By using interflow network coding at the backbone vehicles, the protocol is able to reduce the number of generated packets by 25% in most cases compared with the conventional routing approach. As a result, the proposed protocol can provide a high packet delivery ratio, low overhead, and low delay. We show the effectiveness of the protocol using theoretical analysis and computer simulations.
Scientific journal, English - iBGP Solution by Combining Route Reflection and Shared Tree Based Multicast
Toshihiko Kato; Yao Koffi; Hubert Wilfried; Celimuge Wu; Satoshi Ohzahata
5th International Conference on Theory and Practice in Modern Computing (TPMC 2016), 203-210, Jul. 2016, Peer-reviwed
International conference proceedings, English - Improving the Tor Traffic Distribution with Circuit Switching Method
Timothy Girry Kale; Satoshi Ohzahata; Celimuge Wu; Toshihiko Kato
IEEE HPSR 2016, 1-2, Jun. 2016, Peer-reviwed
International conference proceedings, English - A Study on How to Characterize TCP Congestion Control Algorithms from Unidirectional Packet Traces
Toshihiko Kato; Leelianou Yongxialee; Ryo Yamamoto; Satoshi Ohzahata
The Eleventh International Conference on Internet Monitoring and Protection (ICIMP 2016), 23-28, May 2016, Peer-reviwed
International conference proceedings, English - A Practical and Efficient Overhearing Strategy for Reliable Content Distribution over a Single Hop Ad Hoc Network
Hiroaki Yokose; Koji Nitta; Satoshi Ohzahata; Toshihiko Kato
IPSJ, 情報処理学会, 24, 2, 292-301, Feb. 2016, Peer-reviwed, Nowadays, wireless LAN is equipped in most portable devices and widely deployed, and then we can communicate over wireless link with low cost. However, when the same content is simultaneously downloaded by several terminals with unicast in a wireless LAN, the bandwidth must be divided among the terminals and the download speed is reduced. With using the broadcast nature of wireless media, pseudo multicasting methods, which overhear the unicast flow to realize multicast like communication, have been proposed. In the pseudo multicasting methods, since parts of the content is obtained by overhearing the TCP/UDP flows of a specific content going to other terminals in a wireless LAN, and the server need not send the content for each client repeatedly. These methods enable to realize multicasting with a practical way. However, redundant unicast traffic is still generated because the receivers do not obtain contents via overhearing in an efficient way. Based on the pseudo multicasting, we propose an efficient, flexible and reliable content distribution method over single hop wireless ad hoc network in this paper. In the proposed method a content is divided into pieces and the server distributes it according to the download status of each receivers at the application level. To accelerate downloading, we propose a method for selecting the piece and the terminal for transmission taking the effect of network coding for efficient overhearing. We developed a testbed and confirmed that the proposed scheduling accelerates the download speed even when the communication speed of each terminal is different.
Scientific journal, English - Experimental Analysis on Performance Anomaly for Download Data Transfer at IEEE 802.11n Wireless LAN
Yoshiki Hashimoto; Masataka Nomoto; Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
ICN 2016, 22-27, Feb. 2016, Peer-reviwed
International conference proceedings, English - Evaluating Tor Modified Switching Algorithm in the Emulation Environment
Timothy Girry Kale; Satoshi Ohzahata; Celimuge Wu; Toshihiko Kato
2016 22ND ASIA-PACIFIC CONFERENCE ON COMMUNICATIONS (APCC), IEEE, 510-516, 2016, Peer-reviwed, The Tor network is an open network that helps its users to defend against adversaries who performed traffic analysis and threatens the personal privacy and confidential security. Tor protects its users by preventing the sites they visit from revealing their physical location. As the number of Tor user increases, the performance of Tor degrades badly due to Tor's scheduler is not fairly distributing the traffic in Tor. In this paper, we highlight the problems in Tor performance due to scheduling design of Tor, which degrades the web and bulk traffic performances that multiplexes on a single TCP connection. To solve these problems, this paper emphasis on applying a simple method of active circuit switching on Tor application level, in order to distribute the bulk and web traffics on different TCP connections when congestion is detected in the Tor network. We evaluate our modified switching algorithm with the other default schedulers in Tor, such as vanilla Tor and priority EWMA scheduler in a shadow wide deployment network emulator. The experimental results show that our switching technique considerably offers stable improvement of traffic performance for all the web and bulk traffics.
International conference proceedings, English - Towards Practical and Intelligent Routing in Vehicular Ad Hoc Networks
Celimuge Wu; Yusheng Ji; Fuqiang Liu; Satoshi Ohzahata; Toshihiko Kato
IEEE Transactions on Vehicular Technology, IEEE, 64, xx, 1-17, Dec. 2015, Peer-reviwed
Scientific journal, English - Sequential Combination of Two Classifier Algorithms for Binary Classification to Improve the Accuracy
Sornxayya Phetlasy; Satoshi Ohzahata; Celimuge Wu; Toshihiko Kato
WANC in Candar 2015, 576-580, Dec. 2015, Peer-reviwed
International conference proceedings, English - Efficient Broadcasting in VANETs Using Dynamic Backbone and Network Coding
Celimuge Wu; Xianfu Chen; Yusheng Ji; Satoshi Ohzahata; Toshihiko Kato
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 14, 11, 6057-6071, Nov. 2015, Peer-reviwed, Multihop data dissemination in vehicular ad hoc networks (VANETs) is very important for the realization of collision avoidance systems and many other interesting applications. However, designing an efficient data dissemination protocol for VANETs has been a challenging issue due to vehicle movements, limited wireless resources, and the lossy characteristics of wireless communication. In this paper, we propose a protocol that can provide a lightweight and reliable solution for data dissemination in VANETs. The protocol employs dynamically generated backbone vehicles to disseminate broadcast packets to reduce the MAC-layer contention time at each node while maintaining a high packet dissemination ratio by taking into account vehicle movement dynamics and the link quality between vehicles for the backbone selection. The protocol also uses network coding to reduce the protocol overhead and to improve the packet reception probability as compared with conventional approaches. We use theoretical analysis and computer simulations to show the advantage of the proposed protocol over other existing alternatives.
Scientific journal, English - Comparing TCP Congestion Control Algorithms Based on Passively Collected Packet Traces
Toshihiko Kato; Atsushi Oda; Celimuge Wu; Satoshi Ohzahata
ICSNC 2015, 135-141, Nov. 2015, Peer-reviwed
International conference proceedings, English - Reducing Congestion in the Tor Network with Circuit Switching
Timothy Girry Kale; Satoshi Ohzahata; Celimuge Wu; Toshihiko Kato
Journal of Information Processing, 情報処理学会, 23, 5, 589-602, Sep. 2015, Peer-reviwed
Scientific journal, English - A Packet Size-aware Multi-hop Broadcast Protocol for VANETs Based on Adaptive Redundancy
Celimuge Wu; Xianfu Chen; Yusheng Ji; Satoshi Ohzahata; Toshihiko Kato
The 24th International Conference on Computer Communications and Networks (ICCCN), xx, xx, 1-8, Aug. 2015, Peer-reviwed
International conference proceedings, English - Performance Evaluation of Time Slot Based QoS Aware Ad Hoc Network Scheme for CBR and TCP Flows
Jing Lin; Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Asia-Pacific Network Operations and Management Symposium (APNOMS), xx, xx, 1-6, Aug. 2015, Peer-reviwed
International conference proceedings, English - A Routing Protocol for VANETs with Adaptive Frame Aggregation and Packet Size Awareness
Celimuge Wu; Yusheng Ji; Satoshi Ohzahata; Toshihiko Kato
IEEE International Conference on Communications (ICC), xx, xx, 8193-8198, Jun. 2015, Peer-reviwed
International conference proceedings, English - Joint Fuzzy Relays and Network-Coding-Based Forwarding for Multihop Broadcasting in VANETs
Celimuge Wu; Satoshi Ohzahata; Yusheng Ji; Toshihiko Kato
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 16, 3, 1415-1427, Jun. 2015, Peer-reviwed, In vehicular ad hoc networks (VANETs), due to the limited radio propagation range of wireless devices, many safety applications require a multihop broadcast protocol to disseminate traffic warning information. However, providing an efficient multihop forwarding of broadcast messages has been a challenging problem due to vehicle movement, limited wireless resources, and unstable signal strength. In this paper we propose a broadcast protocol that can provide a low message overhead and a high packet dissemination ratio. The proposed scheme uses a fuzzy logic algorithm to choose the next hop relay nodes and uses network coding to improve the packet dissemination ratio without increasing the message overhead. By using the fuzzy logic algorithm, the protocol can choose the best relay node by taking intervehicle distance, vehicle velocity, and link quality into account. Network coding is used to improve the packet reception ratio by utilizing the broadcast nature of wireless channels. We show the effectiveness of the proposed scheme by using both theoretical analysis and computer simulations.
Scientific journal, English - An Intelligent Broadcast Protocol for VANETs Based on Transfer Learning
Celimuge Wu; Xianfu Chen; Yusheng Ji; Satoshi Ohzahata; Toshihiko Kato
IEEE 81st Vehicular Technology Conference (VTC2015-Spring), xx, xx, 1-6, May 2015, Peer-reviwed
International conference proceedings, English - Design of EV Common Service Platform
Jing Wei; Jinglin Li; Zhihan Liu; Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
The 2015 Fourth ICT International Student Project Conference, xx, xx, 1-4, May 2015, Peer-reviwed
International conference proceedings, English - Future Channel Utilization-Aware Routing for Cognitive Radio Ad Hoc Networks
Celimuge Wu; Juan Xu; Yusheng Ji; Satoshi Ohzahata; Toshihiko Kato
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E98B, 1, 107-115, Jan. 2015, Peer-reviwed, Cognitive radio ad hoc networks can be used to solve the problems of limited available spectrum and inefficient spectrum usage by adaptively changing their transmission parameters. Routing protocol design has a significant impact on the network performance. However, an efficient protocol that takes account of primary user flows and the long-term channel assignment issue in route selection is still missing. In this paper, we propose AODV-cog, a cognitive routing protocol for CSMA/CA ad hoc networks based on AODV. AODV-cog chooses a route by considering the effect on the primary users, available channel bandwidth and link reliability. AODV-cog also takes account of future channel utilization which is an important but underexplored issue. AODV-cog switches channels for secondary user flows when network congestion occurs. We use theoretical analysis and computer simulations to show the advantage of AODV-cog over existing alternatives.
Scientific journal, English - Can DTN Improve the Performance of Vehicle-to-roadside Communication?
Celimuge Wu; Yusheng Ji; Satoshi Ohzahata; Toshihiko Kato
2015 IEEE 26TH ANNUAL INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR, AND MOBILE RADIO COMMUNICATIONS (PIMRC), IEEE, 1934-1939, 2015, Peer-reviwed, We propose a routing protocol for drive-thru Internet access in delay tolerant vehicular networks. The contribution of this paper is two-folds. First, we propose a new approach which utilizes the concept of delay tolerant network (DTN) to supplement the conventional communication approach. Second, we propose an algorithm to schedule DTN transmissions in order to maximize the system throughput. The proposed protocol is able to attain higher TCP throughput than the conventional approach by providing more efficient wireless resource utilization. We use theoretical analysis and computer simulations to evaluate the proposed protocol.
International conference proceedings, English - Packet Size-Aware Broadcasting in VANETs With Fuzzy Logic and RL-Based Parameter Adaptation
Celimuge Wu; Xianfu Chen; Yusheng Ji; Fuqiang Liu; Satoshi Ohzahata; Tsutomu Yoshinaga; Toshihiko Kato
IEEE ACCESS, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 3, 2481-2491, 2015, Peer-reviwed, Most existing multi-hop broadcast protocols for vehicular ad hoc networks do not consider the problem of how to adapt transmission parameters according to the network environment. Besides the propagation environment that determines the channel bit error rate, packet payload size has a significant effect on the packet loss rate. In this paper, we first discuss the effect of packet size on the packet reception ratio, and then propose a broadcast protocol that is able to specify the best relay node by taking into account the data payload size. The proposed protocol employs a fuzzy logic-based algorithm to jointly consider multiple metrics (link quality, inter-vehicle distance, and vehicle mobility) and uses a redundancy transmission approach to ensure high reliability. Since the fuzzy membership functions are tuned by using reinforcement learning, the protocol can adapt to various network scenarios. We use both real-world experiments and computer simulations to evaluate the proposed protocol.
Scientific journal, English - Making Inter-flow Network Coding Possible for Unicast Routing in VANETs
Celimuge Wu; Satoshi Ohzahata; Yusheng Ji; Toshihiko Kato
2014 International Conference on Connected Vehicles & Expo, xx, xx, 1-7, Nov. 2014, Peer-reviwed
International conference proceedings, English - Inferring TCP Congestion Control Algorithms by Correlating Congestion Window Sizes and their Differences
Toshihiko Kato; Atsushi Oda; Shun Ayukawa; Celimuge Wu; Satoshi Ohzahata
Proceedings of The Ninth International Conference on Systems and Networks Communications (ICSNC 2014), xx, xx, 42-47, Oct. 2014, Peer-reviwed
International conference proceedings, English - A Distributed Dynamic Channel Assignment and Routing Framework for Cognitive Sensor Systems
Celimuge Wu; Satoshi Ohzahata; Yusheng Ji; Toshihiko Kato
IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E97D, 10, 2613-2622, Oct. 2014, Peer-reviwed, With the increase of the number of wireless sensing or metering devices, the collection of sensing data using wireless communication becomes an important part of a smart grid system. Cognitive radio technology can be used to facilitate the deployment of smart grid systems. In this paper, we propose a data collection and dissemination framework for cognitive radio smart grid systems to fully utilize wireless resources while maintaining a reliably connected and efficient topology for each channel. In the proposed framework, each sensor node selects a channel considering the primary user (PU) channel utilization and network connectivity. In this way, the data collection and dissemination can be performed with a high reliability and short delay while avoiding a harmful effect on primary users. We use computer simulations to evaluate the proposed framework.
Scientific journal, English - A QoS Supporting Ad Hoc Networks Combing Admission Based TDMA and 802.11 DCF
Jing Lin; Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Proceedings of Asia-Pacific Network Operations and Management Symposium (APNOMS), xx, xx, 1-4, Sep. 2014, Peer-reviwed
International conference proceedings, English - Coded packets over lossy links: A redundancy-based mechanism for reliable and fast data collection in sensor networks
Celimuge Wu; Yusheng Ji; Juan Xu; Satoshi Ohzahata; Toshihiko Kato
COMPUTER NETWORKS, ELSEVIER SCIENCE BV, 70, 179-191, Sep. 2014, Peer-reviwed, In wireless sensor networks (WSNs), many applications require a high degree of reliability with low delay. Due to the lossy nature of wireless channels, achieving reliable communication can be very challenging. The most commonly adopted approach for achieving reliability is the acknowledgment based retransmission mechanism; however, this approach is inefficient in terms of end-to-end delay especially when there are a large number of hops from a sensor to the sink node. In this paper, we propose a redundancy-based approach that achieves high reliability and low end-to-end delay. The proposed protocol employs a network coding-based approach to improve packet redundancy when a link is unreliable or there is a strict end-to-end delay requirement. The protocol adaptively changes the redundancy level according to the application requirements and link loss rate. The protocol can be implemented easily because modification of the application layer at the source node and destination node is the only mandatory requirement. We implement the proposed mechanism on a real testbed which consists of IRIS motes, and evaluate the performance of the proposed mechanism using real-world experiments, network simulations and theoretical analysis. (C) 2014 Elsevier B.V. All rights reserved.
Scientific journal, English - TCP Performance Problem on timeout retransmission Triggered by Bursty packet Losses
Weikai Wang; Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Proceedings of IADIS Theory and Practice in Modern Computing 2014 (TPMC 2014), xx, xx, 141-148, Jul. 2014, Peer-reviwed
International conference proceedings, English - Toward a Totally Distributed Flat Location Service for Vehicular Ad Hoc Networks
Celimuge Wu; Satoshi Ohzahata; Yusheng Ji; Toshihiko Kato
Proceedings of IEEE 79th Vehicular Technology Conference (VTC2014-Spring), IEEE, xx, xx, 1-6, May 2014, Peer-reviwed
International conference proceedings, English - Experimental Analysis of TCP Behaviors against Bursty Packet Losses Caused by Transmission Interruption
Weikai Wang; Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
The Thirteenth International Conference on Networks, xx, xx, 136-141, Feb. 2014, Peer-reviwed
International conference proceedings, English - 無線LAN におけるアクセスポイントと端末の協調による送信機会確保のためのメディアアクセス制御
熊谷雄太; 大坐畠 智; 加藤聰彦
電子情報通信学会 和文論文誌Ｂ, 電子情報通信学会, J97-B, 2, 110-119, Feb. 2014, Peer-reviwed
Scientific journal, Japanese - A MAC Protocol for Delay-sensitive VANET Applications With Self-learning Contention Scheme
Celimuge Wu; Satoshi Ohzahata; Yusheng Ji; Toshihiko Kato
IEEE 11th Consumer Communications and Networking Conference (CCNC), xx, xx, 729-734, Jan. 2014, Peer-reviwed
International conference proceedings, English - Resolving bufferbloat problem in 802.11n WLAN by weakening MAC loss recovery for TCP stream
Masataka Nomoto; Toshihiko Kato; Celimuge Wu; Satoshi Ohzahata
Proceedings of the IASTED International Conference on Parallel and Distributed Computing and Networks, PDCN 2014, Acta Press, xx, xx, 293-300, 2014, Peer-reviwed, IEEE 802.11n wireless LANs provide high-speed data transfer. If the radio condition degrades, however, the transfer rate will be reduced significantly and there may be some problems in the data transfer. In order to clarify this problem, we have evaluated the TCP performance over IEEE 802.11n LAN by changing the distance between the access point and a terminal. As a result, a severe increase of round trip time has been measured in the case of low data rate. This is a sort of bufferbloat problem, which is being actively studied in recent years. The detailed analysis of this experiment is our first contribution. We have inferred that one of the reasons for this increased delay is the powerful retransmission function of 802.11n. So, we propose, as the second contribution, a method to improve TCP delay performance by reducing this retransmission capability and by generating TCP segment loss intentionally. This paper describes the performance evaluations for our proposal in comparison with CoDel, which is an active queue management approach, and with the native 802.11n.
International conference proceedings, English - Joint MAC and Network Layer Control for VANET Broadcast Communications Considering End-to-end Latency
Celimuge Wu; Satoshi Ohzahata; Yusheng Ji; Toshihiko Kato
2014 IEEE 28TH INTERNATIONAL CONFERENCE ON ADVANCED INFORMATION NETWORKING AND APPLICATIONS (AINA), IEEE, xx, xx, 689-696, 2014, Peer-reviwed, In vehicular ad hoc networks (VANETs), multi-hop broadcast communications are required for many applications including driver assistance systems. However, providing a low end-to-end latency has been very challenging. In this paper, we propose a joint MAC network layer multi-hop broadcast protocol. For the network layer, the proposed protocol reduces the number of sender nodes by using common forwarder nodes for different traffic flows. At the MAC layer, the proposed protocol uses a Q-Learning algorithm to adjust the contention window size. By interacting with the environment, the protocol can find the best contention window size to transmit data packets and therefore can provide a high packet dissemination ratio and low end-to-end delay for various scenarios. The simulation results demonstrate the advantage of the proposed protocol over other existing alternatives.
International conference proceedings, English - Providing Fast Broadcasting by Reserving Time Slots for Multi-hop Distance in VANETs
Celimuge Wu; Satoshi Ohzahata; Yusheng Ji; Toshihiko Kato
2014 INTERNATIONAL WIRELESS COMMUNICATIONS AND MOBILE COMPUTING CONFERENCE (IWCMC), IEEE, xx, xx, 213-218, 2014, Peer-reviwed, In vehicular ad hoc networks (VANETs), multi-hop broadcast protocols arc required for many applications including driver assistance systems. However, providing a low end-to-end latency has been very challenging. In this paper, we propose a protocol which can provide a fast channel access for broadcast traffic flows in %AMA's. The protocol introduces new control messages to reserve time slots fill- the li)rwarder nodes and eliminate the hidden terminal problem. By providing a contention-free multihop forwarding scheme based on reliably generated forwarding backbone, the protocol can provide low end-to-end delay and high packet dissemination ratio. The theoretical analysis and simulation results demonstrate the advantage of the proposed protocol over other existing alternatives.
International conference proceedings, English - Practical Solution for Broadcasting in VANETs using Neighbor Information
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
IEICE Transactions on Communications, E96-B, 11, 2856-2864, Nov. 2013, Peer-reviwed
Scientific journal, English - Flexible, Portable, and Practicable Solution for Routing in VANETs: A Fuzzy Constraint Q-Learning Approach
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 62, 9, 4251-4263, Nov. 2013, Peer-reviwed, Vehicular ad hoc networks (VANETs) have been attracting interest for their potential uses in driving assistance, traffic monitoring, and entertainment systems. However, due to vehicle movement, limited wireless resources, and the lossy characteristics of a wireless channel, providing a reliable multi-hop communication in VANETs is particularly challenging. In this paper, we propose PFQ-AODV, which is a portable VANET routing protocol that learns the optimal route by employing a fuzzy constraint Q-learning algorithm based on ad hoc on-demand distance vector (AODV) routing. The protocol uses fuzzy logic to evaluate whether a wireless link is good or not by considering multiple metrics, which are, specifically, the available bandwidth, link quality, and relative vehicle movement. Based on an evaluation of each wireless link, the proposed protocol learns the best route using the route request (RREQ) messages and hello messages. The protocol can infer vehicle movement based on neighbor information when position information is unavailable. PFQ-AODV is also independent of lower layers. Therefore, PFQ-AODV provides a flexible, portable, and practicable solution for routing in VANETs. We show the effectiveness of the proposed protocol by using both computer simulations and real-world experiments.
Scientific journal, English - A low latency path diversity mechanism for sender-oriented broadcast protocols in VANETs
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Ad Hoc Networks, 11, 7, 2059-2068, Sep. 2013, Peer-reviwed, In vehicular ad hoc networks, many applications require a low latency and high reliability especially the safety applications. Reliable multi-hop broadcast protocols have been widely discussed recently. However, most of them use explicit acknowledgments and timeout retransmissions to provide reliability. The retransmission method incurs delays when a packet loss cannot be detected on time. Acknowledgment messages also increase the MAC layer contention time at each node. In order to provide a high reliability and low latency with a low overhead, we propose a mechanism which utilizes path diversity. In the proposed mechanism, a message is delivered through two different paths. By cooperation of these different paths, broadcast messages can be disseminated with a short delay and a high reliability compared with the acknowledgment based retransmission approach. Since the proposed mechanism does not use any explicit acknowledgment message, the message overhead is low. We evaluate the proposed mechanism using both theoretical analysis and computer simulations. © 2012 Elsevier B.V. All rights reserved.
Scientific journal, English - Data Dissemination with Dynamic Backbone Selection in Vehicular Ad Hoc Networks
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
IEEE 78th Vehicular Technology Conference, xx, xx, 1-6, Sep. 2013, Peer-reviwed
International conference proceedings, English - Can We Generate Efficient Routes by Using Only Beacons? Backbone Routing in VANETs
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), xx, xx, 2944-2949, Sep. 2013, Peer-reviwed
International conference proceedings, English - Effectiveness of Performance Flag Selection for Enhancing the Tor Circuit
Timothy Girry Kale; Satoshi Ohzahata; Celimuge Wu; Toshihiko Kato
Asia-Pacific Network Operations and Management Symposium (APNOMS), xx, xx, 1-3, Sep. 2013, Peer-reviwed
International conference proceedings, English - An Improvement of OLSR Using Fuzzy Logic Based MPR selection
Narangerel Dashbyamba; Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Asia-Pacific Network Operations and Management Symposium (APNOMS), xx, xx, 1-6, Sep. 2013, Peer-reviwed
International conference proceedings, English - Optimization of Area Splitting To Minimize OSPF LSA Exchange
Toshihiko Kato; Tsukasa Miyamae; Celimuge Wu; Satoshi Ohzahata
IADIS Theory and Practice in Modern Computing, xx, xx, 11-18, Jul. 2013, Peer-reviwed
International conference proceedings, English - Joint MAC Network Layer Broadcast Protocol for Vehicular Ad Hoc Networks
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
IEEE International Conference on Communications Workshops, xx, xx, 505-509, Jun. 2013, Peer-reviwed
International conference proceedings, English - Network Coding Assisted Cooperative Relay Scheme for Sender-oriented Broadcast in VANETs
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Proceedings of IEEE Wireless Communications and Networking Conference (WCNC), xx, xx, xx, Apr. 2013, Peer-reviwed
International conference proceedings, English - A Loss-tolerant Scheme for Unicast Routing in VANETs using Network Coding
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
2013 9TH INTERNATIONAL WIRELESS COMMUNICATIONS AND MOBILE COMPUTING CONFERENCE (IWCMC), IEEE, xx, xx, 1058-1063, 2013, Peer-reviwed, In vehicular ad hoc networks (VANETs), designing an efficient routing protocol is particularly challenging due to the vehicle movement and lossy wireless channel. A packet can be lost at a forwarder node even when a proper node is selected as the forwarder. In this paper, we propose a loss-tolerant scheme for unicast routing protocols in VANETs. The proposed scheme uses multiple forwarder nodes to improve the packet reception ratio at the forwarders. The scheme uses network coding to reduce the number of required transmissions, resulting in a significant improvement of end-to-end packet delivery ratio without increasing the message overhead. We show the effectiveness of the proposed scheme by using both theoretical analysis and computer simulations.
International conference proceedings, English - A routing protocol for cognitive radio ad hoc networks giving consideration to future channel assignment
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Proceedings - 2013 1st International Symposium on Computing and Networking, CANDAR 2013, xx, xx, 227-232, 2013, Peer-reviwed, Cognitive radio technology can be used to solve the problems of limited available spectrum and inefficient spectrum usage by adaptively changing transmission parameters. By utilizing CR technology for dynamic and distributed multi-hop networks, cognitive radio ad hoc networks can efficiently utilize free wireless resources. However, the routing protocols for cognitive radio CSMA/CA ad hoc networks have not been discussed seriously. An efficient protocol considering primary user flows and channel assignment incurred network connectivity issue in the route selection is still missing. In this paper, we propose AODV-cog, a cognitive routing protocol for CSMA/CA ad hoc networks based on AODV. AODV-cog chooses a route by considering the effect on the primary users, available channel bandwidth and link reliability. AODV-cog also takes in account of future channel utilization which is important but overlooked by existing works. AODV-cog switches channels for secondary user flows when network congestion is occurred. We use computer simulations to show the advantage of AODV-cog over existing alternatives. © 2013 IEEE.
International conference proceedings, English - A reliable and flexible data gathering protocol for battery limited wireless sensor networks
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
International Journal of Communication Networks and Distributed Systems, 11, 2, 139-159, 2013, Peer-reviwed
Scientific journal, English - Routing in VANETs: A Fuzzy Constraint Q-Learning Approach
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Proceedings of IEEE Global Communications Conference (GLOBECOM), xx, xx, 213-218, Dec. 2012, Peer-reviwed
International conference proceedings, English - VANET Broadcast Protocol Based on Fuzzy Logic and Lightweight Retransmission Mechanism
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E95B, 2, 415-425, Feb. 2012, Peer-reviwed, Vehicular ad hoc networks have been attracting the interest of both academic and industrial communities on account of their potential role in Intelligent Transportation Systems (ITS). However, due to vehicle movement and fading in wireless communications, providing a reliable and efficient multi-hop broadcast service in vehicular ad hoc networks is still an open research topic. In this paper, we propose FUZZBR (FUZZy BRoadcast), a fuzzy logic based multi-hop broadcast protocol for information dissemination in vehicular ad hoc networks. FUZZBR has low message overhead since it uses only a subset of neighbor nodes to relay data messages. In the relay node selection. FUZZBR jointly considers multiple metrics of inter-vehicle distance, node mobility and signal strength by employing the fuzzy logic. FUZZBR also uses a lightweight retransmission mechanism to retransmit a packet when a relay fails. We use computer simulations to evaluate the performance of FUZZBR.
Scientific journal, English - An adaptive redundancy-based mechanism for fast and reliable data collection in WSNs
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
2012 IEEE 8TH INTERNATIONAL CONFERENCE ON DISTRIBUTED COMPUTING IN SENSOR SYSTEMS (DCOSS), IEEE, xx, xx, 347-352, 2012, Peer-reviwed, Wireless sensor networks (WSNs) can be used for a variety of applications. For many applications, a high reliability and low delay are required. Due to lossy feature of wireless channel, providing a reliable communication is very challenging. The most frequently used approach for providing the reliability is to use the acknowledgement based retransmission mechanism which increases the end-to-end delay especially when the number of hops from a sensor to the sink node is large. In this paper, we propose a redundancy-based approach to provide a high reliability while maintaining a low end-to-end delay. The proposed mechanism uses a redundant transmission when a link is unreliable or the end-to-end delay requirement is strict. We implement the proposed mechanism on a wireless sensor network which consists of IRIS motes, and evaluate the performance of the proposed mechanism.
International conference proceedings, English - How to Broadcast Efficiently in Vehicular Ad Hoc Networks Without GPS
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
2012 IEEE VEHICULAR NETWORKING CONFERENCE (VNC), IEEE, xx, xx, 258-264, 2012, Peer-reviwed, In vehicular ad hoc networks (VANETs), a multi-hop broadcast protocol is required to disseminate traffic warning information to multiple receivers. Reducing broadcast message overhead is important because it could directly affect the packet collision probability and MAC layer contention time at each node. There have been some broadcast protocols for VANETs. However, many of them assume the availability of the global positioning system. In this paper, we propose a broadcast protocol which does not require position information. The protocol uses two-hop neighbor information to select relay nodes which are used to forward a packet. The proposed protocol also uses a joint redundancy and opportunistic transmission approach to recover a packet loss. We show the effectiveness of the proposed protocol by evaluating in a real vehicular ad hoc network.
International conference proceedings, English - A Broadcast Path Diversity Mechanism for Delay Sensitive VANET Safety Applications
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Proceedings of IEEE Vehicular Networking Conference, xx, xx, 292-297, Nov. 2011, Peer-reviwed
International conference proceedings, English - A Dynamic Route Change Mechanism for Mobile Ad Hoc Networks
Celimuge Wu; Kazuya Kumekawa; Toshihiko Kato
International Journal of Communication Networks and Distributed Systems, 7, 1/2, 4-17, Jul. 2011, Peer-reviwed
Scientific journal, English - Fuzzy One-phase Pull Diffusion for WSNs in Fading Channel
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Proceedings of IEEE International Conference on Distributed Computing in Sensor Systems Workshops, xx, xx, 1-6, Jun. 2011, Peer-reviwed
International conference proceedings, English - Learning route from beaconing and interest dissemination in vehicular sensor networks
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
Proceedings of 2011 6th International Conference on Telecommunication Systems, Services, and Applications, TSSA 2011, xx, xx, 49-54, 2011, Peer-reviwed, Vehicular sensor networks can be used to collect information for the purpose of driving assistance, environment monitoring and entertainment. However, due to the vehicle movement and lossy feature of wireless channel, providing a reliable multi-hop communication between a sensor node and a sink node is particularly challenging. In this paper, we propose a protocol which learns the optimal route in the exchange of hello messages and interest messages. The proposed protocol uses a fuzzy logic to evaluate a direct wireless link and uses a Q-learning algorithm to learn the best route from a multi-hop perspective. We use computer simulations to show the effectiveness of the proposed protocol. © 2011 IEEE.
International conference proceedings, English - OFA: Opportunistic forwarding and acknowledgement for vehicular ad hoc networks
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
IB2COM 2011 - 6th International Conference on Broadband Communications and Biomedical Applications, Program, xx, xx, 213-218, 2011, Peer-reviwed, In vehicular ad hoc networks (VANETs), providing a multi-hop communication is challenging due to the vehicle movement and lossy feature of wireless channel. Opportunistic routing provides an alternative solution with its utilization of the broadcast nature of wireless communication and the diversity of packet reception. However, most of opportunistic routing protocols specify the forwarding nodes at the sender side and therefore the opportunism cannot be fully utilized. Moreover, existing opportunistic routing protocols cannot provide a high reliability because of the lack of efficient packet reception check mechanism. In this paper, we propose OFA, an opportunistic forwarding and acknowledgement protocol for vehicular ad hoc networks. OFA performs both data forwarding and acknowledgement by taking advantage of multiuser diversity and route opportunism. In OFA, the forwarder node selection occurs at receiver nodes. An intermediate node is selected opportunistically to acknowledge the sender on the behalf the forwarder node when the forwarder node cannot communicate with the sender node directly. The proposed protocol can fully utilize the path diversity and also can provide hop-by-hop reliability. © 2011 IEEE.
International conference proceedings, English - Distributed Reinforcement Learning Approach for Vehicular Ad Hoc Networks
Celimuge Wu; Kazuya Kumekawa; Toshihiko Kato
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E93B, 6, 1431-1442, Jun. 2010, Peer-reviwed, In Vehicular Ad hoc Networks (VANETs), general purpose ad hoc routing protocols such as AODV cannot work efficiently due to the frequent changes in network topology caused by vehicle movement. This paper proposes a VANET routing protocol QLAODV (Q-Learning AODV) which suits unicast applications in high mobility scenarios. QLAODV is a distributed reinforcement learning routing protocol, which uses a Q-Learning algorithm to infer network state information and uses unicast control packets to check the path availability in a real time manner in order to allow Q-Learning to work efficiently in a highly dynamic network environment. QLAODV is favored by its dynamic route change mechanism, which makes it capable of reacting quickly to network topology changes. We present an analysis of the performance of QLAODV by simulation using different mobility models. The simulation results show that QLAODV can efficiently handle unicast applications in VANETs.
Scientific journal, English - Fuzzy logic based multi-hop broadcast for high-density vehicular ad hoc networks
Celimuge Wu; Satoshi Ohzahata; Toshihiko Kato
2010 IEEE Vehicular Networking Conference, VNC 2010, xx, xx, 17-24, 2010, Peer-reviwed, Vehicular ad hoc networks have been attracting the interest of both academic and industrial communities on account of their potential role in Intelligent Transportation Systems (ITS). In vehicular ad hoc networks, vehicles are usually located quite densely within the range of radio transmission. In this paper, we propose a fuzzy logic based multi-hop broadcast protocol for information dissemination in high-density vehicular ad hoc networks. The proposed protocol exhibits low message overheads by means of using only a subset of neighbor nodes to relay messages. In the relay node selection, the proposed protocol jointly considers multiple metrics of inter-vehicle distance, node mobility and signal strength by employing the fuzzy logic. We use computer simulations to evaluate the performance of the proposed protocol. © 2010 IEEE.
International conference proceedings, English - Movement Aware Routing for VANETs
Celimuge Wu; Toshihiko Kato
Proceedings of the 21st IASTED International Conference on Parallel and Distributed Computing and Systems, xx, xx, 315-320, Oct. 2009, Peer-reviwed
International conference proceedings, English - Reliable and Efficient Data Dissemination in VANETs
Celimuge Wu; Toshihiko Kato
Proceedings of IASTED International Conference on Internet and Multimedia Systems and Applications, xx, xx, 109-114, Jul. 2009, Peer-reviwed
International conference proceedings, English - An Enhanced Reinforcement Routing Protocol for Inter-vehicular Unicast Application
Celimuge Wu; Toshihiko Kato
Proceedings of IASTED International Conference on Internet and Multimedia Systems and Applications, xx, xx, 170-175, Mar. 2008, Peer-reviwed
International conference proceedings, English - Performance Evaluation of TCP Communication over Multihop Wireless Network Using Multiple Channels
S. Yokohama; K. Kumekawa; T. Kato
Proceeding ofIASTED International Conference on Communication Systems and Networks (CSN 2007), xx, xx, xx, Sep. 2007, Peer-reviwed
International conference proceedings, English - A High-Performance BGP Database System for Diagnosing Inter-Domain Connectivity Problems
T. Ogishi; S. Ano; T. Hasegawa; T. Kato
Proceedings of IASTED International Conference on Communication Systems and Networks (CSN 2007), xx, xx, xx, Sep. 2007, Peer-reviwed
International conference proceedings, English - A Hierarchical Group Key Management Scheme for Secure Multicast Increasing Efficiency of Key Distribution in Leave Operation
A. Nemaney Pour; K. Kumekawa; T. Kato; S. Itoh
Elsevier, Computer Networks, 51, 17, 4727-4743, Aug. 2007, Peer-reviwed
Scientific journal, English - An Experimental Study on HDTV Video Transmission over Wireless LAN
M. Nomoto; T. Kato; S. Itoh
Proceedings of IADIS International Wireless Applications and Computing 2007, xx, xx, xx, Jul. 2007, Peer-reviwed
International conference proceedings, English - Proposal of Layer 2 Based Approach for Constructing Wireless Mesh Networks
Akira Yanagisawa; Toshihiko Kato; Shuichi Itoh
Proceedings of IASTED European Conference on Internet and Multimedia Systems and Applications (EuroIMSA 2007), 88-93, Mar. 2007, Peer-reviwed
International conference proceedings, English - Mobile IP ネットワークにおける移動端末のデータ受信を対象とする，ハンドオフと伝送誤りの双方を考慮したTCP高速化方式の提案と評価
海老原成; 加藤聰彦; 伊藤秀一
情報処理学会論文誌, Information Processing Society of Japan (IPSJ), 48, 2, 434-447, Feb. 2007, Peer-reviwed, Recently, the mobile communication environment is widely spread and we can receive various information through the Internet even when we move at high-speed. But, in such an environment, it is pointed that the packet losses caused by transmission errors in wireless links and handoff during terminal moving degrade the TCP communication throughput, because many unnecessary congestion controls cause. There are a lot of researches for this problem, but most of them focus on only either transmission errors in wireless links or handoff, and do not take account of the coordination with Mobile IP procedures which give IP level mobility support. In this paper, we propose a high speed TCP communication procedure over Mobile IP taking account of both handoff and transmission errors when mobile node receives data. And we also show the results of performance evaluation of our procedure examined by software simulator.
Scientific journal, Japanese - Performance Evaluation of Reliable Data Transfer over Wireless LAN Based Ad hoc Network Considering Physical, MAC and TCP Level Behaviours
Masamune Okino; Toshihiko Kato; Shuichi Itoh
Proceedings of IASTED International Conference on Communications, Internet, and Information Technology (CIIT 2006), 253-258, Nov. 2006, Peer-reviwed
International conference proceedings, English - Performance Evaluation of Shortest Path Tree Based Dense Mode Ad hoc Multicast Routing Protocol
Tsutomu Kozaka; Toshihiko Kato; Shuichi Itoh; Yoshiyori Urano
Proceedings of IASTED International Conference on Communication Systems and Networks (CSN 2006), 20-25, Aug. 2006, Peer-reviwed
International conference proceedings, English - A New Group Re-keying Protocol with Smaller Computational and Key Storage Overhead
Alireza Nemaney Pour; Kazuya Kumekawa; Toshihiko Kato; Shuichi Itoh
Proceedings of IASTED International Conference on Communication Systems and Networks (CSN 2006), 165-170, Aug. 2006, Peer-reviwed
International conference proceedings, English - Peer to Peer Communications over Hierarchical Mobile IP Networks with Private Addresses Using SIP Based Signaling
Akira Idoue; Toshihiko Kato; Shuichi Itoh
Proceedings of IASTED International Conference on Communication Systems and Networks (CSN 2006), 202-207, Aug. 2006, Peer-reviwed
International conference proceedings, English - A Proposal of Photonic Network Using Wavelength Routing with Wavelength Conversion and TDMA with Time Slot Assignment Taking Account of Link Transmission Delay
Kayo Kurosaki; Kazuya Kumekawa; Toshihiko Kato; Shuichi Itoh
Proceedings of IASTED International Conference on Communication Systems and Networks (CSN 2006), 272-277, Aug. 2006, Peer-reviwed
International conference proceedings, English - A Dense Mode Ad hoc Multicast Routing Protocol Constructing Shortest Path Trees with Low Control Overhead
Tsutomu Kozaka; Toshihiko Kato; Shuichi Itoh; Yoshiyori Urano
Proceedings of 2006 6th International Conference on ITS Telecommunications (ITST 2006), 790-793, Jun. 2006, Peer-reviwed
International conference proceedings, English - High Performance TCP Scheme over Wireless LAN with Handoff and Transmission Error
Joe Ebihara; Masaki Kobayashi; Toshihiko Kato; Shuichi Itoh
Proceedings of IASTED International Conference on Networks and Communication Systems (NCS 2006), 411-416, Mar. 2006, Peer-reviwed
International conference proceedings, English - Selection of Landmark Nodes for Message Relaying in High Density Sensor Network Environment
Junichi Ushijima; Toshihiko Kato; Masamune Okino; Shuichi Itoh
Proceedings of IASTED International Conference on Networks and Communication Systems (NCS 2005), 186-190, Apr. 2005, Peer-reviwed
International conference proceedings, English - Design of Global Roaming Procedure among Independently Operated Mobile IP Networks
Koichiro Tsujino; Toshihiko Kato; Shuichi Itoh; Hidetoshi Yokota; Akira Idoue
Proceedings of IASTED International Conference on Networks and Communication Systems (NCS 2005), 302-307, Apr. 2005, Peer-reviwed
International conference proceedings, English - Design of scalable QoS guaranteed mobile IPv6 communication scheme using MPLS
W Liu; T Kato; S Itoh
Proceedings of the Fourth IASTED International Conference on Communication Systems and Networks, ACTA PRESS, 37-42, 2005, Peer-reviwed, Recently, the QoS guarantee is required to realize various mobile real time communications. So far, there are some studies focusing on QoS Mobile IP communication, but they require backbone routers to maintain per-flow QoS information for all individual Mobile Nodes. Therefore, these approaches suffer from the scalability problem at backbone routers. Against them, we have adopted a hierarchical method using MPLS to solve this problem in Mobile IPv6 environment. In this paper, we introduce Virtual Foreign Agent (VFA) in the foreign network of MN to manage the QoS communication paths, and develop an approach in which the per-flow QoS information is maintained only by HA, VFAs and CNs. MPLS paths with large bandwidth are introduced between VFAs and CNs, over which a per-flow path with small bandwidth called Pathlet is established for individual communication between MNs and CNs. The maintenance of Pathlets is only performed by VFAs and CNs, and backbone MPLS routers take care of only MPLS paths with large bandwidth. This paper describes the detailed procedure of QoS communication between MNs and Fixed Hosts by applying our scheme. With our new scheme, an MN can be provided QoS communication directly with Fixed Hosts without the triangle routing, the overhead of Return Routability Procedure, nor the latency of reserving QoS Path hop-by-hop.
International conference proceedings, English - Combining AODV Ad hoc routing and conventional IP routing over wireless and wired links
K Takanashi; T Kato; S Itoh; A Sugata; F Kojima; M Fujise
PROCEEDINGS OF THE FOURTH IASTED INTERNATIONAL CONFERENCE ON COMMUNICATION SYSTEMS AND NETWORKS, ACTA PRESS, 179-184, 2005, Peer-reviwed, Recently, ad hoc networks are being studied widely, and most of them are intended to consist of wireless links among mobile nodes. But, in order to construct practical networks, such as a network supporting fire fighting, it is sometimes required to use wired links in a portion where wireless propagation is degraded and to use conventional IP routing equipments within the existing network segments. In this paper, we propose a method for combining AODV (Ad hoc On-demand Distance Vector) routing and the conventional IP routing over a network including both wireless and wired links. We describe the detailed procedure and the result of implementation of our proposal.
International conference proceedings, English - DVMRP multicast LAN accommodation into ISP based on IGMP
Y Gong; T Kato; S Itoh
Proceedings of the Fourth IASTED International Conference on Communication Systems and Networks, ACTA PRESS, 207-212, 2005, Peer-reviwed, This paper presents a new scheme to accommodate DVMRP multicast capable LAN user into ISP based on IGMP. Currently, it is common that a user premises contains a single host or a LAN with a single segment. More advanced user, however, may introduce LAN with more complex topology and with multicast routing protocol running within its LAN. In order to let ISP have a uniform interface to users, we have been proposing an interworking system which allows ISP to accommodate multicast capable LAN using IGMP. In this paper, we describe the design of the interworking system for DVMRP LAN user.
International conference proceedings, English - An efficient approach to group key management in secure multicast
AN Pour; K Kumekawa; T Kato; S Itoh
Proceedings of the Fourth IASTED International Conference on Communication Systems and Networks, ACTA PRESS, 218-223, 2005, Peer-reviwed, This research proposes an efficient model and the associated algorithm for the group key management in secure multicast. The proposed model and algorithm are focusing on the communication where members of multicast groups join and leave the groups frequently. In this communication environment, it is pointed out that the group key delivery at the leave has more overhead than that at the join. In our model, the group key is constructed using secret values assigned to individual members, based on the difficulty of the discrete logarithm problem. The inverse values of the secret values are also used. Each member keeps the inverse values of the other members except that assigned to itself. When a new member joins a group, the group key is changed by the key server, and the new group key and the inverse values are sent to members by exploiting IP multicast. When a member leaves, the key server only informs remaining members who is leaving. The group key is changed by each of the remaining members using the inverse values. Using this approach, we can reduce computation complexity and communication overhead of the group key generation after a leave.
International conference proceedings, English - 高密度アドホックネットワークのためのAODVルーチングプロトコルの提案
沖野正宗; 加藤聰彦; 牛島準一; 伊藤秀一; 飯作俊一
情報処理学会論文誌, 45, 12, 580-590, Dec. 2004, Peer-reviwed
Scientific journal, Japanese - MNからの発呼トラヒックに対するHA機能をFAにもたせるMobile IP通信方式
加藤聰彦; 原正寛; 伊藤秀一; 飯作俊一
電子情報通信学会 論文誌, The Institute of Electronics, Information and Communication Engineers, J87-D-I, 5, 516-525, May 2004, Peer-reviwed, 携帯電話などを用いた大規模なモバイルインターネットの基本プロトコルとして,Mobile IPプロトコルが採用されつつある.ここでは,無線リンクを介してMNを収容する機能はFAにより実現され,HAはモバイルインターネットバックボーンの中で,MNの移動管理のみを行う構成になっている.このため大規模なモバイルインターネットにおいては,MNへのトラヒックをFAあてにフォワーデイングするというHAでのフォワーデイング処理のオーバヘッドが大きな課題になると考えられる.本論文では,この問題を解決するために,MNが移動先で発呼する場合は,移動先のFAにIPアドレスの割当を要求し,更にアドレスを割り当てられている間はそのFAがホームエージェントの機能を果たすMobile IPプロトコルを提案する.更にそれによるHAのフォワーデイング負荷の軽減及び移動先で用意すべきIPアドレス数についての評価結果を示す.
Scientific journal, Japanese - PIM-SMの解析に基づきマルチキャストトラヒックの振舞いを分析するパフォーマンスアナライザ
植野誠史; 加藤聰彦; 伊藤秀一
電子情報通信学会 論文誌, J87-D-I, 5, 580-590, May 2004, Peer-reviwed
Scientific journal, Japanese - A Proposal of Scalable QoS Guaranteed Mobile IP Communication Using MPLS Path with Pre-Allocated Bandwidth
Wei Liu; Toshihiko Kato; Seiji Ueno; Shuichi Itoh
IEICE Trans. Commun., E87-B, 3, 537-597, Mar. 2004, Peer-reviwed
Scientific journal, English - Improving scalability in QoS guarantee MN to MN mobile communication using traffic engineered MPLS path
W Liu; T Kato; S Itoh
Proceedings of the IASTED International Conference on Parallel and Distributed Computing and Networks, ACTA PRESS, 171-176, 2004, Peer-reviwed, Recently, the QoS guarantee is required in order to realize various mobile real time communications. So jar, there are some studies focusing on QoS Mobile IP communication, but they require back-bone routers to maintain per-flow QoS information for all individual Mobile Modes. Therefore, these approaches suffer from scalability problems at backbone routers. Against them, we are developing an approach in which the per-flow QoS information is maintained only by Mobile IP nodes, such as Home Agents and Foreign Agents. We have adopted a hierarchical method using MPLS in which traffic engineered MPLS paths with large bandwidth are introduced between Mobile IP nodes, and in which a per-flow path with small bandwidth called Pathlet is established for individual communication among Mobile nodes. The maintenance of Pathlets is only performed by Mobile IP nodes, and backbone MPLS routers take care of only MPLS paths with large bandwidth. In the simulation, we compare our scheme with conventional scheme by observing the total number of entries managed by routers and bandwidth prepared as individual links. The results show that that our scheme can reduce the number of QoS related management information at back-bone routers without large bandwidth pre-allocated for traffic engineered MPLS paths.
International conference proceedings, English - High performance TCP communication over mobile IP handoff for mobile node receiving data segments
J Ebihara; T Kato; S Itoh
Proceedings of the IASTED International Conference Communication Systems and Networks, ACTA PRESS, 35-40, 2004, Peer-reviwed, Recently, the mobile communication environment is widely spread. In such an environment, it is pointed out that the transmission errors over wireless links and/or the handoff during terminal movement cause more packet losses than wired fix networks and that those losses degrade the TCP communication throughput heavily. There are a lot of researches for this problem, but most of them focus mainly on the packet losses caused by transmission errors. However, in the Mobile IP networks, which is the backbone network architecture for 3rd generation cellular network, the packet losses caused by handoff is also very serious. Although there are a few studies focusing on handoff triggered packet losses, but they do not take account of the protocol procedures of the Mobile IP. In this paper, we propose a high speed TCP communication procedure dealing with handoff triggered packet losses for data transfer from fixed hosts to mobile nodes. We also show the results of performance evaluation exarmined by software simulator.
International conference proceedings, English - AODV routing protocol well suited to high density ad hoc network environment
N Okino; T Kato; J Ushijima; S Itoh
Proceedings of the IASTED International Conference Communication Systems and Networks, ACTA PRESS, 47-52, 2004, Peer-reviwed, Recently, ad hoc networks come to be actually used in sensor networks and in network construction in case of disaster. Accordingly, it is required to study the routing in high density ad hoc networks, where multiple nodes exist within radio propagation area. In such a network environment, it is important to decrease the overhead of route request messages flooded into the whole network. In this paper, we propose a modified AODV protocol well suited to high density ad hoc networks. Its feature includes that it does not introduce any additional message overhead, that it enables necessary and sufficient nodes to relay route request messages and that it copes with network configuration change. This paper also shows the performance evaluation indicating that our protocol can reduce the total number of route request messages compared with the original AODV.
International conference proceedings, English - Design of OSPF protocol for wireless IP networks
T Kato; K Takanashi; S Itoh; A Sugata; F Kojima; M Fujise
Proceedings of the IASTED International Conference Communication Systems and Networks, ACTA PRESS, 76-82, 2004, Peer-reviwed, Recently, wireless LAN is being widely used. In order to implement a large scale wireless network, it is useful to connect access points (APs) which cover individual subnetworks by wireless link. In this case, since those APs work as routers, some routing protocols needs to be introduced among them. We have proposed to use OSPF among those wireless routers. However, the current OSPF does not take account of wireless router networks which have limited broadcast capability among routers within radio propagation range. So we propose a new procedure in which the overhead of database exchange and flooding of link state advertisement. This paper describes the design principles and the detailed design including packet format, control data structures, state transitions and communication sequence.
International conference proceedings, English - Accommodation of PIM-SM based multicast capable LAN in ISP using IGMP
YP Gong; T Kato; S Itoh
Proceedings of the IASTED International Conference Communication Systems and Networks, ACTA PRESS, 184-189, 2004, Peer-reviwed, Recently, some ISPs have started to provide IP multicast information delivery services. In the IP multicast mechanism, IGMP is used between end hosts and last hop routers and multicast routing protocols are used between multicast routers in backbone networks. Currently, it is common that a customer premises contains a single host or a LAN with a single segment, and therefore, most ISPs use IGMP as the interface between the Customer premises and themselves. However, more advanced customers may introduce LAN with multiple segments and perforin their own multicast delivery within LAN. For those Customers, it is impossible to use IGMP at the ISP and customer boundary. On the other hand, from the standpoint of ISPs, it is inconvenient to introduce different kinds of protocols, IGMP and Multiple kinds of multicast routing protocols. In this paper, we propose a scheme to accommodate multicast capable LANs with PIM-SM into ISP based on IGMP.
International conference proceedings, English - A QoS Aware Multicast Routing Protocol with Scalability in Terms of Link State Advertisement
Toshihiko Kato; Seiji Ueno; Shigeki Mukaiyama
IEICE Trans. Inf. & Syst., E86-D, 11, 2352-2360, Nov. 2003, Peer-reviwed
Scientific journal, English - A QoS Guaranteed Mobile IP Communication Scheme with Scalability in Terms of Resource Management in Backbone Network
Toshihiko Kato; Wei Liu; Seiji Ueno; Shuichi Itoh
Proceedings of 2003 IEEE 18th Annual Workshop on Computer Communications (CCW 2003), pp.1-8, Oct. 2003
International conference proceedings, English - Implementation and evaluation of TCP protocol tester generating exceptional test sequences
T Ogishi; T Hasegawa; T Kato
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E86B, 2, 604-613, Feb. 2003, Although TCP is widely used in the Internet, new specifications are still proposed and implemented. In the circumstance above, it is highly possible that some errors are detected on the communication between new and old implementations. Several test tools were developed so far. However, they do not have enough functions to allow test operators to modify test sequences suitable for their test purposes. We have developed a TCP tester which generates test sequence using test scenario. The tester performs exceptional TCP protocol behavior only when the condition specified in the test scenario is satisfied. Otherwise, it performs normal TCP behavior. The tester is implemented by modifying TCP module of NetBSD with SACK code developed by Pittsburgh Supercomputing Center. We have also evaluated implementations of congestion control and SACK algorithms using the tester.
Scientific journal, English - Fast handoff method for Mobile IP over wireless LAN networks
H Yokota; A Idoue; T Hasegawa; T Kato
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E85B, 10, 2108-2116, Oct. 2002, In the Mobile IP handoff procedure, mobile node movement is detected from advertisements of foreign agents that differ from previously received advertisement arid the new "care-of" address is registered with the home agent. However, user packets are not forwarded to the new foreign agent until a registration is completed and this interruption may degrade the quality of service especially in real-time applications such as audio and video, or may lower the TCP throughput due to re-transmission timeout. To tackle these issues, we propose a new low latency handoff method, where access points used in a wireless LAN environment and a dedicated MAC bridge are jointly used to alleviate packet loss without altering the Mobile IP specifications. In this paper, we present design architecture of the proposed method and evaluate its performance in an actual network environment to verify the effectiveness of our approach.
Scientific journal, English - Link Layer Assisted Mobile IP Fast Handoff Method over Wireless LAN Network
Hidetoshi Yokota; Akira Idoue; Toru Hasegawa; Toshihiko Kato
Proceedings of Eighth Annual International Conference on Mobile Computing and Networking (MobiCom 2002), 131-139, Sep. 2002
International conference proceedings, English - 通信システムの内部動作を推定するインテリジェントTCPアナライザ
大岸智彦; 井戸上彰; 加藤聰彦
情報処理学会 論文誌, 43, 2, 418-426, Feb. 2002
Scientific journal, Japanese - DVMRPに基づくマルチキャスト・トラヒック用パフォーマンス・アナライザ
植野誠史; 加藤聰彦; 鈴木健二
情報処理学会 論文誌, 43, 2, 418-426, Feb. 2002
Scientific journal, Japanese - A New Round Robin Scheduling Algorithm for Multimedia Traffic and Differential Services Router Implementation
Hidetoshi Yokota; Toshihiko Kato; Hideyoshi Tominaga
情報処理学会 論文誌, 43, 2, 427-437, Feb. 2002
Scientific journal, English - TCPによるデータ転送速度を高速化する衛星インターネット用TCPゲートウェイの提案
三宅優; 長谷川輝之; 長谷川亨; 加藤聰彦
電子情報通信学会 論文誌, The Institute of Electronics, Information and Communication Engineers, J84-B, 12, 2330-2341, Dec. 2001, 高速な伝送路を提供可能な衛星インターネットは, 新しいインターネットアクセス方式として期待されている.しかし, 衛星通信区間で発生する伝送遅延の影響により, TCPを使用したデータ転送においてその伝送帯域を有効に利用できないという問題が生じている.そこで筆者らは, 衛星通信を使用したインターネットアクセスににおいて, 地球局側にのみゲートウェイ機器を設置することにより各加入者側の通信設備/通信パラメータをいっさい変更することなくTCPの通信速度を高速化する方式を提案し, 試作機による実験により提案方式の有効性を確認した.本論文では, 提案する衛星インターネット用TCPゲートウェイの動作原理と試作機による評価結果について述べる.
Scientific journal, Japanese - Proposal of hierarchical mobile IP supporting private addresses utilizing NAT function and its implementation on UNIX operating system
A Idoue; H Yokota; T Kato
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E84B, 12, 3155-3165, Dec. 2001, It is widely recognized that IP-based mobile network will be a dominant trend. For mobile IP networks, the address starvation problem and scalable mobility management for mobile nodes are important issues. In order to cope with these issues, we propose an approach to realize mobile IP network supporting private addresses for mobile nodes. Our approach introduces regional registration of mobile nodes (Hierarchical Mobile IPv4) and coordinates NAT and DNS functions with the Mobile IP protocol, It enables a mobile node to be assigned a global address temporally in a visited network and to accept a call initiated by a correspondent node connected to the global IP network. This paper describes the detailed design of our approach and the implementation of proposed procedures based on the Mobile IPv4 software developed by the CMU Monarch project.
Scientific journal, English - Design and implementation of Internet performance monitor with realtime TCP behavior analysis
T Ogishi; A Idoue; T Hasegawa; T Kato; K Suzuki
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E84B, 8, 2124-2133, Aug. 2001, Peer-reviwed, Nowadays, many IP based communication systems are connected by high-speed networks to realize high-speed TCP/IP communication, However, since the mechanism of TCP/IP protocols is based on a best effort service. the quality of the communication may change by the time or the route of the traffic. Therefore, it is important for network providers to investigate the quality of their users' communication. In order to analyze the traffic on an Internet backbone, the realtime analysis is one of the important factors. So far, several tools were developed for the purpose of the traffic measurement. However, none of them can analyze sufficient statistics to evaluate the quality for each end user's communication in realtime. Therefore, we have designed and implemented a performance monitor, which collects the statistics representing the performance such as TCP throughput while capturing the traffic. The statistics are collected by every pair of IP addresses and by every application. The monitor also provides the function to analyze, effectively for the statistics records Such as sorting and filtering of the records and the graphical user interface to operate the software tool. This paper describes the design and implementation of the performance monitor.
Scientific journal, English - QoS Routing-Based Congestion Management over Active Internetworking System Using Stream Code
Shigehiro Ano; Toru Hasegawa; Koji Nakao; Toshihiko Kato; Takashi Egawa; Koji Hino; Yoshiaki Kiriha; Fumito Kubota
IEICE Transactions on Communications, E84-B, 8, 2124-2133, Aug. 2001, Peer-reviwed
Scientific journal, English - Fast Handoff Method in Mobile IP Based on Coordination with Layer 2 Procedure
Koichi Hirose; Hidetoshi Yokota; Akira Idoue; Toshihiko Kato
Proceedings of IASTED International Conference Advances in Communications (AIC2001), 184-189, Jul. 2001
International conference proceedings, English - Video Transfer Protocol over Internet with Congestion Control Based on Two Level Rate Control
Teruyuki Hasegawa; Toru Hasegawa; Toshihiko Kato
情報処理学会 論文誌, Information Processing Society of Japan (IPSJ), 42, 6, 1703-1714, Jun. 2001, Video data transfer is one of the major type of traffic over the Internet. However, it is impossible for the current Internet to guarantee the network Qos for video transfer, and an influx of a large amount of video data into the Internet may cause serious network congestion. To resolve these problems, we previously proposed a protocol using congestion control based on rate control of video coding level and data transfer level, and evaluated this protocol using software simulation. However, in order to apply this protocol to real video communication, our previous protocol had some problems mainly with regard to efficiency. In this paper, we present an improved specification of a video transfer protocol with two level rate control. This paper also describes the results of implementation and evaluation of an actual video transfer system using our improved protocol, and a commercial video tool with H.261 encoding. The results show our protocol can transfer video data effectively and fairly through a congested network.
Scientific journal, English - High Performance TCP Communication over Wireless Access Link Using SSCOP with Segmenting/Reassembling Functions
Toshihiko Kato; Akira Idoue; Ayumi Hara; Kenji Suzuki
Proceedings of ITC Specialists Seminar on Access Networks and Systems, 245-252, Apr. 2001, Peer-reviwed
International conference proceedings, English - Mobile IP network supporting private IP addresses utilizing regional registration and NAT function
A Idoue; H Yokota; T Kato
PROCEEDINGS OF THE EIGHTH INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS, IEEE COMPUTER SOC, 141-146, 2001, It is winery recognized that IF-based mobile network will be a dominant trend and that the address starvation problem and scalable mobility management for mobile nodes ale important issues for mobile IP networks. In order to cope with these issues, we propose an approach to realize mobile IP network supporting private addresses for mobile nodes. Our approach introduces regional registration of mobile nodes (Hierarchical Mobile IPv4) and coordinates NAT and DNS functions with the Mobile IP protocol. It enables a mobile node to be assigned a global address temporally in a visited network and to accept a call initiated by a correspondent node connected to the global IP network. This paper describes the detailed design of our approach.
International conference proceedings, English - Mobile IP using private IP addresses
T Kato; A Idoue; H Yokota
PROCEEDINGS OF THE SIXTH IEEE SYMPOSIUM ON COMPUTERS AND COMMUNICATIONS, IEEE COMPUTER SOC, 491-497, 2001, Peer-reviwed, The mobile IP data communication is widely spreading. Accordingly, it is pointed out that the number of IP addresses in IPv4 will be short if every mobile terminal has its IP address. In order to solve this address starvation problem, we propose an approach to realize mobile IP protocol by assigning a private IP address to a mobile terminal. It installs foreign agent and home agent with NAT function, and it coordinates DNS procedure and NAT function in order to allow a correspondent node to make a connection to a mobile terminal. This paper describes the detailed design of our approach.
International conference proceedings, English - Making QoS aware multicast scalable in terms of link state advertisement
T Kato; S Ueno; S Mukaiyama; K Suzuki
NETWORK PROTOCOLS, IEEE COMPUTER SOC, 91-99, 2001, Peer-reviwed, Recently, routing protocols for QoS aware multicast are actively studied, but there are few studies focusing on the scalability of link state advertisement when the available bandwidth of a link is updated along with the QoS aware multicast tree construction. This paper proposes a new QoS aware multicast routing protocol that is scalable in terms of the link state advertisement exchange. Our protocol has the following features; (1) A multicast network is divided into domains, and the advertisement of information on links within a domain is limited within the domain. (2) Among the border multicast routers, only the link state information of interdomain links is advertised. As a result, the number of link state advertisement messages will he drastically, reduced. (3) When a multicast tree spreads over multiple domains, the tree construction needs to be performed without information on links in other domains, and it is possible that the construction may fail. In order to cope with this problem, the crank back mechanism of a tree construction is introduced. This paper describes the detailed procedures and the message formats of our protocol. It also describes the evaluation of the number of exchanged link state advertisement messages and shows that our protocol can reduce the number by the order of 11(number of domains) comparing with the conventional protocols.
International conference proceedings, English - An experimental study on performance during congestion for TCP/IP traffic over wide area ATM network using VBR with selective cell discard
S Ano; T Hasegawa; T Kato
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E83B, 2, 155-164, Feb. 2000, It is important to establish the technology to accommodate best effort TCP/IP traffic over wide area ATM networks. The UBR (Unspecified Bit Rate) service category is the most typical service category for the best effort traffic, especially in the LAN environment. On the other hand, the VER (Variable Bit Rate) service category with SCD (Selective Cell Discard) option is considered as the service category which is appropriate for wide area networks due to its fairness and minimum guarantee of the cell transmission using not only PCR (Peak Cell Rate) but SCR (Sustainable Cell Rate) and MBS (Maximum Burst Size). However, there is no actual evaluation for such service. We have, therefore, performed the experimental studies on TCP/IP over VER with SCD along with UBR and VER without SCD by VC (Virtual Channel) level policing when each TCP connection is mapped to a different VC. Through these experiments, we measured the link utilization of the effective data and the fairness between each obtained TCP throughput during the congestion of the ATM switch. From the results of the link utilization, the value is over 95% under the various conditions. Therefore, even in the case of the cell losses due to SCD or buffer overflow in ATM switch congestion, average throughput is almost the same as the value which equals the trunk line speed divided by the number of the accommodated TCP connections. From the results of the fairness, VER with SCD per VC is better than UBR and also obtains better TCP throughput than VER without SCD. Furthermore, to confirm those characteristics more generally, we adopt the accommodated TCP connections not only with the same TCP send/receive socket buffer size but with different sizes. Finally, we discuss the effectiveness between VER with SCD and the other service categories, such as UBR and ABR (Available Bit Rate) and GFR (Guaranteed Frame Rate), and conclude that VER with SCD is one of the most suitable ATM service categories for accommodating best effort traffic.
Scientific journal, English - Interoperability testing system of TCP/IP based communication systems in operational environment
T Kato; T Ogishi; H Shinbo; Y Miyake; A Idoue; K Suzuki
TESTING OF COMMUNICATING SYSTEMS, KLUWER ACADEMIC PUBLISHERS, 48, 143-157, 2000, Peer-reviwed, Recently, TCP/IP protocols are widely used. Here, although the protocols are realized in operating systems and users of communication systems pay no attention to their detail, some system errors are actually reported. Since those errors occur only in specific communication situations, the interoperability testing by watching communication by a testing system is appropriate to detect them. This interoperability testing has the following requirements. Firstly, since the system that includes system errors is not unidentified, the testing system needs to check all communication systems attached to a network. Secondly, for the similar reason, all protocols in the TCP/IP protocol stack need to be checked. Thirdly, the testing system needs to discriminate operational failures, such as server down and mis-configuration of parameters in clients, from system errors, when it detects any problems in the communication. Based on these considerations, we have designed an interoperability testing system of TCP/IP based communication systems applied in an operational environment. This paper describes the detailed design of our testing system and the testing algorithm for DHCP (Dynamic Host Configuration Protocol), for which some system errors are reported.
International conference proceedings, English - Analysis of Internet multicast traffic performance considering multicast routing protocol
S Ueno; T Kato; K Suzuki
2000 INTERNATIONAL CONFERENCE ON NETWORK PROTOCOLS, PROCEEDINGS, IEEE COMPUTER SOC, 95-104, 2000, Peer-reviwed, Recenlty audio and video delivery services ore widely spread in the Internet. In order to deliver these data to multiple receivers at the same time, the multicast technologies are indispensable. in such a situation, the performance analysis of,multicast traffic will be important in order to design and operate the Internet. Multicast traffic is controlled by its own routing: protocol and the multicast routing protocol is more complex than conventional unicast routing protocols. In this paper we propose a neu multicast performance analyzer considering DVMRP and PIM-SM routing protocols, it captures messages of a multicast routing protocol as well as multicast IP datagrams. It also analyzes DVMRP nod PIM-SM messages in order to investigate the behaviors of multicast IP datagrams and measures the statistics of multicast traffic in detail. This paper describes the detailed design of the multicast performance analyzer and the results of analyzing multicast datagrams transmitted over networks.
International conference proceedings, English - A Protocol Analyzer for Operational Testing of TCP/IP based Communication Systems
Tomohiko Ogishi; Akira Idoue; Toshihiko Kato; Kenji Suzuki
Proceedings of International Conference on Computer Communication 1999 (ICCC '99), 1, 348-355, Sep. 1999, Peer-reviwed
International conference proceedings, English - Performance Monitor for TCP/IP Traffic Analyzing Application Level Performance
Toshihiko Kato; Tomohiko Ogishi; Akira Idoue; Kenji Suzuki
Proceedings of International Conference on Computer Communication 1999 (ICCC '99), 2, 114-121, Sep. 1999, Peer-reviwed
International conference proceedings, English - Design and Implementation of Virtual Subnetwork System Supporting IP Terminal Mobility
Teruyuki Hasegawa; Akira Idoue; Toshihiko Kato
IEICE Transactions on Communications, E82-B, 6, 897-905, Jun. 1999
Scientific journal, English - A continuous media transfer protocol with congestion control using two level rate control
T Kato; A Kimura; T Hasegawa; K Suzuki
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E82B, 6, 827-833, Jun. 1999, Recently, it is required to transfer continuous media over networks without QoS guarantee. In these networks, network congestion will cause transmission delay variance which degrades the quality of continuous media itself. This paper proposes a new protocol using a congestion control with two level rate control in the data transfer level and the coding level. It introduces a TCP-like congestion control mechanism to the rate control of data transfer level, which can detect the QoS change quickly, and adjust the coding rate of continuous media with time interval long enough for its quality. The performance evaluation through software simulation with multiplexing continuous media traffics and TCP traffics shows that the proposed protocol works effectively in the case of network congestion.
Scientific journal, English - ROSE上で動作するOSI応用層プログラムの完全な自動生成方式の提案とその評価
長谷川亨; 井戸上彰; 加藤聰彦; 鈴木健二
電子情報通信学会 論文誌, J82-B, 5, 868-876, May 1999
Scientific journal, Japanese - A Study on Accommodation of TCP/IP Best Effort Traffic to Wide Area ATM Network with VBR Service Category Using Selective Cell Discard
Shigehiro Ano; Toru Hasegawa; Toshihiko Kato
Proceedings of IEEE ATM Workshop '99, 535-540, May 1999, Peer-reviwed
International conference proceedings, English - Implementation and evaluation of video transfer system over Internet with congestion control based on two level rate control
T. Hasegawa; T. Hasegawa; T. Kato
Proceedings - 6th International Conference on Real-Time Computing Systems and Applications, RTCSA 1999, Institute of Electrical and Electronics Engineers Inc., 141-148, 1999, Peer-reviwed, Recently, video data transfer is one of the major types of traffic over the Internet. However, it is impossible for the current Internet to guarantee the quality of service (QoS) for video transfer and an influx of a large amount of video data into the Internet may cause serious network congestion. To resolve these problems, we previously proposed a protocol using congestion control based on rate control of the video coding level and data transfer level, and evaluated this protocol using software simulation. However, in order to apply this protocol to real video communication, our previous protocol had some problems, mainly with regard to efficiency. In this paper we present an improved specification of a video transfer protocol with two level rate control. This paper also describes the results of implementation and evaluation of an actual video transfer system using our improved protocol, and a commercial video tool with H.261 encoding. The results show our protocol can transfer video data effectively and fairly through a congested network.
International conference proceedings, English - Performance evaluation of TCP/IP traffic using window scale option over wide area ATM network with VBR service category
S Ano; T Hasegawa; T Kato; K Narita; K Hokamura
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E81B, 11, 2090-2099, Nov. 1998, In ATM Network. the VER (Variable Bit Rate) service category is used to accommodate TCP/IP traffic. In an international ATM network with large propagation delay, higher TCP throughput can be obtained by use of window scale option. In order to accommodate TCP traffic with window scale option effectively, it is required to select appropriate values of VER parameters. i.e. SCR (Sustainable Cell Rate) and MBS (Maximum Burst Size). and to evaluate the impact of UPC (Usage Parameter Control) function on TCP throughput. We have studied those technical issues for the conventional TCP. but the results cannot be applied to TCP traffic with the window scale option due to the TCP terminal performance and the large window size. In this paper, we proposed VER parameter determination method for TCP with the window scale option and evaluated the values in each condition. These results show that the determined MBS is much smaller than the burst length of TCP segments especially using low performance TCP terminals. Furthermore, we also discuss some experimental results of TCP throughput degradation due to UPC function. It shows that the throughput of TCP with large window size is degraded when the SCR and MBS values used in ATM switch are smaller than the determined values.
Scientific journal, English - 高速・広域ネットワークにおける輻輳回避手順の改良によるTCPの高速化
三宅優; 神崎昭浩; 加藤聰彦; 鈴木健二
電子情報通信学会 論文誌, J81-B-I, 11, 741-752, Nov. 1998
Scientific journal, Japanese - Full-Automatic Implementation of Protocol Programs for OSI Application Protocols over ROSE
Toru Hasegawa; Akira Idoue; Toshihiko Kato; Kenji Suzuki
Proceedings of IFIP TC6 WG6.1 Joint International Conference on Formal Description Techniques for Distributed Systems and Communication Protocols (FORTE XI) and Protocol Specification, Testing and Verification (PSTV XVIII), 309-324, Nov. 1998, Peer-reviwed
International conference proceedings, English - Impacts of PCR Value on Accommodation of TCP/IP Traffic to VBR based Wide Area ATM Networks
Toshihiko Kato; Yoichi Nakahashi; Kenji Suzuki
Proceeding of 11th International Teletraffic Congress Specialist Seminar, 88-93, Oct. 1998, Peer-reviwed
International conference proceedings, English - 共有メモリ型マルチプロセッサを対象としたレイヤ単位の並列処理による通信プロトコルの実装方式
佐藤友実; 加藤聰彦; 鈴木健二
情報処理学会 論文誌, 39, 9, 2727-2740, Sep. 1998
Scientific journal, Japanese - High Speed TCP/IP Experiment over International ATM Test Bed
Toru Hasegawa; Mitsuru Yamada; Kanji Hokamura; Kohei Yoshiizumi; Teruyuki Hasegawa; Toshihiko Kato; Linda Galasso; Hiroyuki Fujii
Proceedings of IFIP TC6/WG6.2 Fourth International Conference on Broadband Communications (BC '98), 300-311, Mar. 1998, Peer-reviwed
International conference proceedings, English - Protocol architecture of high speed TCP/IP service over international ATM network
T Hasegawa; T Hasegawa; T Kato; K Yoshiizumi; T Miki; K Hokamura; K Sawada
1998 IEEE ATM WORKSHOP PROCEEDINGS, IEEE, 159-168, 1998, Peer-reviwed, The TCP/IP based data communication is one of the most promising application in wide area ATM services. However, it is noticed that TCP becomes the throughput bottleneck over an international ATM network with large propagation delay. The major reason for this problem is that TCP performs the window based flow control and the maximum value of window size is limited by 64 K bytes. Against this problem, we proposed a high speed TCP/IP service using TCP gateway, where a pair of TCP gateways are introduced in international ATM networks, and each of them works as an intermediate system along a TCP connection. They improve the TCP throughput by introducing a link-by-link flow control and a sufficient window size between the gateways, without any modifications to end terminals. In the design of TCP gateway, we have also taken account of the mechanisms avoiding the performance degradation due to transmission errors and congestion. In this paper, we describe the protocol architecture of TCP gateway and its performance by comparing with conventional TCP and TCP with window scale option. The results of performance evaluation show that the TCP gateway can provide more than 20 times higher throughput than conventional TCP, and that it can attain higher performance in the sense of the throughput and fairness than the case where TCP with window scale option is used in customer terminals.
International conference proceedings, English - A study on accommodation of TCP/IP traffic using window scale option to international ATM network with VBR service category
S Ano; T Hasegawa; T Kato; K Narita; K Hokamura
ICAATM'98: 1998 1ST IEEE INTERNATIONAL CONFERENCE ON ATM, IEEE, 484-491, 1998, Peer-reviwed, For ATM Network, VER (Variable Bit Rate) service category is used to accommodate TCP/IP traffic. In an international ATM network with large propagation delay, higher TCP throughput can be obtained by use of window scale option. In order to accommodate TCP traffic with window scale option effectively, it is required to select optimum values of VER parameters, i.e. SCR (Sustainable Cell Rate) and MBS (Maximum Burst Size), and to evaluate the impact of UPC (Usage Parameter Control) function on TCP throughput. We have studied those technical issues for conventional TCP: but the results cannot be applied to TCP traffic with the window scale option due to the TCP terminal performance and the large window size. In this paper, we proposed VER parameter determination method for TCP with the window scale option and evaluated the values in each condition. These results shows that the optimum MBS is much smaller than the burst length of TCP segments especially using low performance TCP terminal or the PCR (Peak Cell Rate) below the calculated TCP throughput. Furthermore, we also discusses some experimental results of TCP throughput degradation due to UPC function. It shows that the throughput of TCP with large window size dramatically degraded when the SCR and MBS values used in ATM switch are smaller than the optimum values.
International conference proceedings, English - Intelligent protocol analyzer for WWW server accesses with exception handling function
T Ogishi; A Idoue; T Kato; K Suzuki
TESTING OF COMMUNICATING SYSTEMS, KLUWER ACADEMIC PUBLISHERS, 49-64, 1998, Peer-reviwed, Recently, the TCP/IP protocols are widely used and it is mentioned that there are problems such that the throughput is limited due to protocol procedures such as retransmission and congestion control of TCP. In order to analyze these problems, we have developed an "intelligent" protocol analyzer which can estimate what communication has taken place by emulating the behaviors of the IF, TCP and HTTP protocol entities, which are used for WWW server access communications. This analyzer also supports the handling of exceptional situations such as monitoring errors and network misbehaviors. This paper describes the details of the emulation functions of HTTP and the exception handing functions, and shows some results of applying the analyzer to actual WWW server accesses.
International conference proceedings, English - Design and implementation of reliable protocol for video data produced in real time manner
T Hasegawa; T Hasegawa; T Kato
FIFTH INTERNATIONAL CONFERENCE ON REAL-TIME COMPUTING SYSTEMS AND APPLICATIONS, PROCEEDINGS, IEEE COMPUTER SOC, 200-206, 1998, Peer-reviwed, Most of current systems which play video data produced remotely in a real rime manner transfer video packets without retransmission. However corrupted packets can be retransmitted if the time of playing is delayed for the fixed amount time. This paper proposes a new reliable real time protocol, based on SSCOP for ATM networks, which retransmits the only corrupted packets which reach the receiver before the dead line. It also describes the implementation method of the proposed protocol in UNIX kernel using STREAMS mechanism and its performance evaluation. This protocol can be applied to vic (video conference tool) application and reduce the packet loss rate to less than 1/100.
International conference proceedings, English - Congestion control with two level rate control for continuous media traffic in network without QoS guarantee
T Kato; A Kimura; T Hasegawa; K Suzuki
FIFTH INTERNATIONAL CONFERENCE ON REAL-TIME COMPUTING SYSTEMS AND APPLICATIONS, PROCEEDINGS, IEEE COMPUTER SOC, 207-214, 1998, Peer-reviwed, Recently, it is required to transfer continuous media over networks without QoS guarantee. In these networks, network congestion will cause transmission delay variance which degrades the quality of continuous media itself This paper proposes a new protocol using a congestion control with two level rate control in the data transfer level and the coding level. It introduces a TCP-like congestion control mechanism to the rate control of data transfer level, which can detect the QoS change quickly, and adjust the coding rate of continuous media with time interval long enough for its quality. The performance evaluation through software simulation with multiplexing continuous media traffics and TCP traffics shows that the proposed protocol works effectively in the case of network congestion.
International conference proceedings, English - Intelligent Protocol Analyzer with TCP Behavior Emulation for Interoperability Testing of TCP/IP Protocols
Toshihiko Kato; Tomohiko Ogishi; Akira Idoue; Kenji Suzuki
Proceedings of IFIP TC6 WG6.1 Joint International Conference on Formal Description Techniques for Distributed Systems and Communication Protocols (FORTE X) and Protocol Specification, Testing and Verification (PSTV XVII), 449-464, Nov. 1997, Peer-reviwed
International conference proceedings, English - Applying reliable data transfer protocol to real time video retrieval system
T Hasegawa; T Hasegawa; T Kato; K Suzuki
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E80B, 10, 1482-1492, Oct. 1997, Most of current real time video retrieval systems use video transfer protocols such that servers simply transmit video packets in the same rate as clients play them. If any packets are corrupted during transmission, they will be lost and cannot be recovered by retransmission. In video retrieval systems, however, the video data are stored in servers and clients can prefetch them prior to playing. So, it might be possible for the video retrieval systems to make corrupted video packets retransmitted before the play-out dead line. But the application of existing reliable protocols causes problems such that, if a packet does not arrive before the dead line due to retransmission, the packets following it will not be delivered to the upper layer even if they have already arrived. In this paper, we discuss how to apply reliable protocols to real time video retrieval systems and propose a new real time video transfer protocol over ATM network, which provides the video data prefetch, the flow control for video buffer, the selective retransmission with skipping function for video packets late for the play-out dead line, and the resynchronization function for video buffer. We have implemented an experimental system using our protocol and evaluated the performance. The results of performance evaluation shows that the proposed protocol decreases the number of unplayed video data largely when transmission errors are inserted in an ATM network.
Scientific journal, English - TCP Gateway Improving Throughput of TCP/IP over Wide Area ATM Networks
Toshihiko Kato; Kanji Hokamura; Mitsuru Yamada; Toru Hasegawa; Teruyuki Hasegawa; Kazuyoshi Sawada
Proceedings of ISS’97: World Telecommunications Congress, 1, 35-42, Sep. 1997, Peer-reviwed
International conference proceedings, English - Implementation and performance evaluation of high performance CMIP software over ATM network
T Hasegawa; A Idoue; T Kato; K Suzuki
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E80B, 6, 869-880, Jun. 1997, As the Asynchronous Transfer Mode (ATM) technology comes to be used widely, the Telecommunications Management Network (TMN) over ATM networks becomes an important issue. Since TMN uses the OSI protocols including the Common Management Information Protocol (CMIP), it is required to implement CMIP communication over ATM networks. In order to realize OSI over ATM, ITU-T SG13 has standardized the Service Specific Coordination Function for Connection Oriented Network Service (SSCF-CONS), Service Specific Connection Oriented Protocol (SSCOP), and the Synchronization and Coordination Function (SCF). We have developed the CMIP software over ATM networks adopting these protocols. The CMIP software is designed so that it achieves both high throughput for large data transfer and short response time for small message exchange. The software adopts the implementation mechanisms commonly applied for protocol modules to reduce the overheads for controlling OSI protocol modules, and some protocol specific mechanisms especially for protocols with heavy processing overheads, i.e. SSCOP and CMIP. The performance evalua tion shows that the developed CMIP software achieves more than 200 message exchanges per second for messages whose length is 64 Byte long, and achieves about 36 Mbps throughput for transferring data whose length is more than 100 KByte.
Scientific journal, English - VBRを用いた広域ATM網上のTCPトラヒックの性能評価
阿野茂浩; 長谷川亨; 加藤聰彦; 成田憲治; 外村幹治
電子情報通信学会 論文誌, J80-B-I, 6, 375-386, Jun. 1997
Scientific journal, Japanese - Performance evaluation of TCP traffic over VBR in wide area ATM network
S Ano; T Hasegawa; T Kato; K Narita; K Hokamura
IEEE ATM '97 WORKSHOP, PROCEEDINGS, I E E E, 73-82, 1997, Peer-reviwed, For ATM networks, Variable Bit Rate (VER) is one of the effective solutions to accommodate TCP/IP based LAN traffic. In order to guarantee high quality for the TCP traffic: it, is important to select VER parameter values appropriate for the TCP traffic and to clarify the interaction between the TCP flow control mechanism and the UPC (Usage Parameter Control) function of ATM switch. We have, therefore, performed the experimental studies on TCP traffic over VER based ATM networks. Through these experiments, we present the method for estimation of VER parameters for the: TCP traffic. Moreover: we investigate the TCP throughput degradation due to the discard of non-conforming cells by the UPC function where the insufficient UPC parameters are applied.
International conference proceedings, English - Design of protocol monitor emulating behaviors of TCP/IP protocols
T Kato; T Ogishi; A Idoue; K Suzuki
TESTING OF COMMUNICATING SYSTEMS, VOL 10, CHAPMAN & HALL, 416-431, 1997, Peer-reviwed, Recently, the TCP/IP protocols are widely used and it is mentioned that, in some cases, throughput is limited due to problems such as network congestion. To solve such problems, the details of communication need to be examined. In order to support these examinations, we are developing an 'intelligent' protocol monitor which can estimate what communication has taken place by emulating the behaviors of the TCP protocol entities in a pair of communicating computers. This paper describes the overview of the monitor and the detailed design of the TCP behavior emulation function for both the state transition based behaviors and the internal procedures for the flow control, such as the slow start algorithm.
International conference proceedings, English - 広域ATM網を介したLAN間接続のためのTCPゲートウェイの実装と性能評価
長谷川輝之; 長谷川亨; 加藤聰彦; 鈴木健二
電子情報通信学会 論文誌, J79-B-I, 5, 262-270, May 1996
Scientific journal, Japanese - A video retrieval protocol with video data prefetch and packet retransmission considering play-out dead line
T Hasegewa; T Hasegawa; T Kato; K Suzuki
1996 INTERNATIONAL CONFERENCE ON NETWORK PROTOCOLS, PROCEEDINGS, I E E E, COMPUTER SOC PRESS, 32-39, 1996, Peer-reviwed, Most of current video retrieval systems use video transfer protocols such that servers simply Transmit video packets in the same rate as clients play them If any packets are corrupted during transmission, they will be lost and cannot be recovered by retransmission. In video retrieval systems, however the video data are stored in servers and clients can prefetch them prior to playing. So, it might be possible for the video retrieval systems to make corrupted video packets retransmitted before play-out dead line. But the application of existing reliable protocols causes problems such that ifa packet does not arrives before the dead line due to retransmission, the packets following it will not be delivered to the upper layer even if they have already arrived.
In this paper we proposed a new video transfer protocol for video retrieval systems over ATM network, which provides the video data prefetch, the flow control for video buffer; the selective retransmission with skipping function for video packers late far the play-out dead line, and the resynchronaization function for video buffer. We have implemented an experimental system using our protocol and evaluated the performance. The results of performance evaluation shows that the proposed protocol decreases the number of unplayed video data to less than 1/70 compared with the conventional non-retransmission protocol when random bit errors with BER of 10(-6) are inserted in an ATM network
International conference proceedings, English - A High-Speed Remote Procedure Call Based on Adaptive Data Representation Conversion
Masahiko Fujinaga; Toshihiko Kato; Kenji Suzuki
情報処理学会 論文誌, Information Processing Society of Japan (IPSJ), 36, 11, 2711-2719, Nov. 1995, Remote procedure call (RPC) mechanism based on the client-server model is widely accepted as a basic technology for the development of distributed systems. The runtime structure of an RPC can be modeled by using a stub layer and a transport layer. The stub layer includes specialized communication routines called stubs, which pack and unpack arguments of RPCs into and from RPC messages, respectively. The transport layer provides the stub layer with network-transparent message transfer functions. In order to increase the performance of RPC, the cost of both the stub layer and the transport layer should be reduced. This paper proposes "adaptive data representation conversion," which completely eliminates unnecessary data representation conversion in the stub layer, and describes the design and performance of a new high-speed RPC system called "KoKo" based on this technique. In KoKo, the data representation used in an RPC is negotiated prior to its execution. If no conversion is necessary, the arguments of the RPC are conveyed as they are, using the internal data representation regardless of their structure. The performance evaluation shows that KoKo outperforms other existing RPC systems.
Scientific journal, English - Implementation Method of High Speed Protocol as Transport Library
Yutaka Miyake; Toshihiko Kato; Kenji Suzuki
Proceedings of 1995 International Conference on Network Protocols (ICNP-95), 172-179, Nov. 1995, Peer-reviwed
International conference proceedings, English - Design of Intelligent OSI Protocol Monitor
Tomohiko Ogishi; Akira Idoue; Toshihiko Kato; Kenji Suzuki
Proceedings of the 8th IFIP WG6.1 International Workshop on Protocol Test Systems (IWPTS '95), 342-357, Sep. 1995, Peer-reviwed
International conference proceedings, English - Design of High Performance OSI Software over ATM Network
Toshihiko Kato; Toru Hasegawa; Akira Idoue; Kenji Suzuki; Yoshiyori Urano
Proceedings of the Twelfth International Conference on Computer Communication (ICCC '95), Aug. 1995, Peer-reviwed
International conference proceedings, English - パーソナルコンピュータおよびワークステーションのためのOSI 7層ボードの実装と評価
井戸上彰; 加藤聰彦; 鈴木健二
情報処理学会 論文誌, 36, 3, 763-774, Mar. 1995
Scientific journal, Japanese - A Design Method of Distributed Telecommunication System Based on the ODP Viewpoint Approach
Masahiko Fujinaga; Toshihiko Kato; Kenji Suzuki
IEICE Transactions on Communications, E77-B, 11, 1398-1406, Nov. 1994
Scientific journal, English - OSI Protocol Testing System based on User Friendly Test Scenario Specification Functions
Toshihiko Kato; Tomohiko Ogishi; Toru Hasegawa; Kenji Suzuki
Proceedings of the 7th IFIP WG6.1 International Workshop on Protocol Test Systems (IWPTS '94), 19-34, Nov. 1994, Peer-reviwed
International conference proceedings, English - A Study on Implementation of a Rate Control Mechanism for High Speed Networks
Yutaka Miyake; Masami Ishikura; Toshihiko Kato; Kenji Suzuki
Proceedings of the 6th European Research Consortium for Informatics and Mathematics (ERCIM) Workshop, 145-157, Jun. 1994, Peer-reviwed
International conference proceedings, English - OSI 7層ボードのためのオペレーティング・システム
井戸上彰; 加藤聰彦; 鈴木健二; 小野欽司
情報処理学会 論文誌, 35, 5, 865-874, May 1994
Scientific journal, Japanese - AN IMPLEMENTATION METHOD OF IN FUNCTIONAL ENTITIES ON TOP OF DISTRIBUTED OPERATING SYSTEM AND ITS PERFORMANCE EVALUATION USING EXPERIMENTAL SYSTEM
M FUJINAGA; T KATO; K SUZUKI
IEICE TRANSACTIONS ON COMMUNICATIONS, IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, E75B, 10, 1043-1051, Oct. 1992, In order to make the implementation of network components flexible and cost effective, it is required to use widely available technologies as the implementation platform. The distributed operating systems can be adopted as such a platform, because they allow to implement a network component using multiple computers connected through a local area network. In this paper, we focus on the Intelligent Network (IN) whose network components are modelled as Functional Entities (FEs), and describe an implementation method of FEs using distributed operating systems. Our method is summarized as follows: The remote procedure call (RPC) is used for the access transparent inter-process communication. The lightweight process mechanism is used for handling concurrent requests. CCF/SSF (Call Control Function/Service Control Function) and SDF (Service Data Function) are implemented as an SSF server and an SDF server, respectively. SCF (Service Control Function) is composed of a Service Dispatcher and a set of Service Executors. The Service Dispatcher accepts all the requests for IN call processing and dispatches them to appropriate Service Executors. Service Executors are created for the individual IN services and execute the service logics. SDF server and Service Executor may be replicated for load partitioning.
This paper has also described the implementation of experimental system supporting "Freephone" service based on our method, and showed the performance evaluation of the experimental system in terms of the real-time and concurrent call processing of IN services. We used Mach and SUN OS as a platform for implementing the servers for FEs. The experimental system using four workstations shows that it can handle up to 170 IN calls in one second with the additional response time of less than 200 msec, which is small enough compared with the response time for the basic connection control. those results prove that our method is feasible for implementing practical FEs.
Scientific journal, English - Implementing IN Functional Entities on top of Distributed Operating System
Masahiko Fujinaga; Toshihiko Kato; Kenji Suzuki
Proceedings of the Fourteenth International Switching Symposium (ISS '92), 268-272, Oct. 1992, Peer-reviwed
International conference proceedings, English - Implementation and Evaluation of ASN.1 Compiler
Toru Hasegawa; Shingo Nomura; Toshihiko Kato
Journal of Information Processing, 15, 2, 157-167, Feb. 1992
Scientific journal, English - A Study on Implementation of Intelligent Network using RPC based Distributed Operating System
Toshihiko Kato; Masahiko Fujinaga; Kenji Suzuki
Proceedings of the Third Telecommunications Information Networking Architecture Workshop (TINA '92), 12-4-1 - 12-4-4, Jan. 1992, Peer-reviwed
International conference proceedings, English - ユニバーサルパーソナル通信(UPT)へのOSIディレクトリの適用と評価
小花貞夫; 堀内浩規; 加藤聰彦; 鈴木健二
電子情報通信学会 論文誌, J74-B-I, 11, 959-970, Nov. 1991
Scientific journal, Japanese - APPLYING DISTRIBUTED-PROCESSING TECHNOLOGIES TO INTELLIGENT NETWORK
T KATO; M FUJINAGA; S OBANA; K SUZUKI
IEICE TRANSACTIONS ON COMMUNICATIONS ELECTRONICS INFORMATION AND SYSTEMS, IEICE-INST ELECTRON INFO COMMUN ENG, 74, 11, 3672-3682, Nov. 1991, The Intelligent Network (IN) provides advanced telecommunication services by use of network components distributed over the telecommunication networks. Therefore, the distributed processing technologies are the key to IN and the distribution transparencies which are the purpose of the distributed processing technologies are useful to reduce the difficulties of the IN development. This paper proposes two approaches to apply distributed processing technologies to IN considering on which plane to use the distribution transparencies in the IN conceptual model. The first approach applies distributed processing technologies to the implementation of the functional entities defined in the IN distributed functional plane. The second approach uses distributed processing technologies as the service independent building blocks defined in the IN global functional plane. This paper also presents the results of some typical case studies of the proposed two approaches, the implementation of the functional entities using the remote procedure call and the use of the global naming service as the number translation service independent building block, which show that the distributed processing technologies are highly applicable to IN.
Scientific journal, English - A Study on Applicability of Distributed Processing Technologies to Intelligent Network
Toshihiko Kato; Masahiko Fujinaga; Sadao Obana; Kenji Suzuki
Proceedings of the Second Telecommunications Information Networking Architecture Workshop (TINA '91), 95-108, Mar. 1991, Peer-reviwed
International conference proceedings, English - Design and Implementation of OSI Communication Board for Personal Computers and Workstations
Akira Idoue; Toshihiko Kato; Kenji Suzuki; Yoshiyori Urano
Proceedings of the Tenth International Conference on Computer Communication (ICCC '90), 585-592, Nov. 1990, Peer-reviwed
International conference proceedings, English - パケット通信プロトコルX.25とX.32のパーソナルコンピュータへの実装と評価
鈴木健二; 加藤聰彦; 小花貞夫
電子情報通信学会 論文誌, J73-B-I, 6, 579-587, Jun. 1990
Scientific journal, Japanese - EstelleおよびASN.1に基づくプロトコル仕様からAdaへのトランスレータの作成
長谷川亨; 堀内浩規; 加藤聰彦
電子情報通信学会 論文誌, 73-B-I, 4, 317-327, Apr. 1990
Scientific journal, Japanese - OSIプレゼンテーション、ACSE、FTAMプロトコルの実装と評価
小花貞夫; 加藤聰彦; 鈴木健二
情報処理学会 論文誌, 30, 7, 895-907, Jul. 1989
Scientific journal, Japanese - OSIトランスポートおよびセション・プロトコルの実装
鈴木健二; 加藤聰彦; 浦野義頼
情報処理学会 論文誌, 29, 12, 1180-1192, Dec. 1988
Scientific journal, Japanese - Automatic Ada Program Generation from Protocol Specifications based on Estelle and ASN.1
Toru Hasegawa; Hiroki Horiuchi; Toshihiko Kato; Kenji Suzuki; Yoshiyori Urano
Proceedings of the Ninth International Conference on Computer Communication (ICCC '88), 181-185, Nov. 1988, Peer-reviwed
International conference proceedings, English - Conformance Testing for OSI Protocols in the Multiple Layer Environment Based on Automaton Model
Toshihiko Kato; Kenji Suzuki; Yoshiyori Urano
Proceedings of the Eighth International Conference on Computer Communication (ICCC '86), 519-524, Sep. 1986, Peer-reviwed
International conference proceedings, English - Implementation and Testing of OSI Protocols
Kenji Suzuki; Toshihiko Kato; Yoshiyori Urano; Kinji Ono
Proceedings of the Third International Conference on Introduction of Open Systems Interconnection Standards, 453-461, Sep. 1985
International conference proceedings, English - Implementation and Testing of Transport Protocol
Kenji Suzuki; Toshihiko Kato; Kinji Ono
Proceedings of the Second International Conference on Introduction of Open Systems Interconnection Standards, 245-282, May 1984, Peer-reviwed
International conference proceedings, English - オートマトンモデルによるパケットレベルプロトコルの製品検証の一方式
斎藤忠夫; 加藤聰彦; 猪瀬博
電子通信学会 論文誌, J65-D, 12, 1499-1506, Dec. 1982
Scientific journal, Japanese - オートマトンモデルによるHDLCプロトコル製品検証方式の実験的考察
斎藤忠夫; 加藤聰彦; 榊修二; 猪瀬博
電子通信学会 論文誌, J65-D, 2, 155-162, Feb. 1982
Scientific journal, Japanese - オートマトンモデルによるHDLCプロトコル製品検証の一方式
斎藤忠夫; 加藤聰彦; 猪瀬博
電子通信学会 論文誌, J63-D, 8, 642-649, Aug. 1980
Scientific journal, Japanese
Books and other publications
Lectures, oral presentations, etc.
- 複数チャネルを用いたアドホックネットワークにおける最適チャネル割当て方法の提案
赤星雅也; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,第4回アドホックネットワーク・ワークショップ
Jun. 2006 - レイヤ2制御方式による無線メッシュネットワークの構築方法に関する検討
柳澤明; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,第4回アドホックネットワーク・ワークショップ
Jun. 2006 - 無線ノードからの送信を対象とするTCP通信の高速化の一検討
武田宙; 海老原成; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2006年総合大会
Mar. 2006 - リンクの伝送遅延を考慮したタイムスロット割当てを行う波長変換フォトニックネットワークの一検討
黒崎佳代; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2006年総合大会
Mar. 2006 - 複数チャネルを用いた無線アドホックネットワークの最適チャネル割当てに関する一考察
赤星雅也; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2006年総合大会
Mar. 2006 - 多段無線マルチホップ通信におけるTCPの性能に関する一考察
小池昌弘; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2006年総合大会
Mar. 2006 - レイヤ2制御方式を用いた無線メッシュネットワークの構築に関する一考察
柳澤明; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2006年総合大会
Mar. 2006 - バースト誤りと輻輳の双方を考慮したアドホックネットワークにおけるTCP通信高速化方式の検討
春原真人; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会,モバイルコンピューティングとユビキタス通信研究会
Feb. 2006 - 端末の高速移動に対応するOLSRの機能拡張に関する検討
近藤毅; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会,モバイルコンピューティングとユビキタス通信研究会
Feb. 2006 - SIPとの協調により経路最適化ピアツーピア通信を実現するMobile IPv6通信方式の提案
村井信彰; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会,モバイルコンピューティングとユビキタス通信研究会
Feb. 2006 - 階層化Mobile IPv6とMPLSを用いたスケーラブルなモバイルQoS通信方式
Parvez Sarwer; Hossain, 劉偉; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会,モバイルコンピューティングとユビキタス通信研究会
Feb. 2006 - 最短木による多対多通信を実現するアドホックネットワーク用マルチキャストルーチングプロトコルに関する評価
小坂努; 加藤聰彦; 伊藤秀一; 浦野義頼
Oral presentation, Japanese, 情報処理学会,モバイルコンピューティングとユビキタス通信研究会
Feb. 2006 - ns-2の利用方法
加藤聰彦
Public symposium, Japanese, 第3回QoSワークショップ, 電子情報通信学会コミュニケーションクオリティ研究会, 東京
Nov. 2005 - セキュアマルチキャストにおける効率的な階層型グループ鍵管理プロトコル
Alireza Nemaney Pour; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2005年ソサイエティ大会
Sep. 2005 - スプリアス再送時のTCPの振舞いに関する一検討
小池昌弘; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2005年ソサイエティ大会
Sep. 2005 - 気付アドレスに対する可動性を提供するMobile IPv6通信方式におけるアクセスルータとモバイルノードの間の認証手順の設計
村井信彰; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2005年ソサイエティ大会
Sep. 2005 - 階層化Mobile IPv6とMPLSを用いたスケーラブルなモバイルQoS通信方式
パルヴェズサロワホセイン; 劉偉; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2005年ソサイエティ大会
Sep. 2005 - リンク層レベルの再送を考慮したモバイルIPネットワーク環境におけるハンドオフと伝送誤りに対応するTCP高速化方式の評価
海老原成; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2005年ソサイエティ大会
Sep. 2005 - バースト誤りのある無線リンクを用いたアドホックネットワークにおけるTCP通信の性能に関する一検討
春原真人; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2005年ソサイエティ大会
Sep. 2005 - 高密度アドホックネットワークに適したAODVプロトコルのノード移動における性能評価
沖野正宗; 牛島準一; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2005年ソサイエティ大会
Sep. 2005 - 階層的な高密度センサーネットワークのための中継用ランドマークの評価
牛島準一; 沖野正宗; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,2005年ソサイエティ大会
Sep. 2005 - 最短木を用いたアドホックマルチキャストのための効率的なJOIN方式
小坂努; 加藤聰彦; 伊藤秀一; 浦野義頼
Oral presentation, Japanese, 電子情報通信学会,2005ソサイエティ大会
Sep. 2005 - 最短木を用いるアドホックネットワーク用マルチキャストルーチングプロトコルの設計
小坂努; 加藤聰彦; 伊藤秀一; 浦野義頼
Oral presentation, Japanese, 電子情報通信学会,ネットワークシステム研究会
Jul. 2005 - 気付アドレスに対する可動性を提供するMobile IPv6方式の設計
村井信彰; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,ネットワークシステム研究会
Jul. 2005 - アドホックネットワークにおけるTCP通信の性能に関する一考察
春原真人; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 第2回アドホックネットワーク・ワークショップ
May 2005 - 端末の高速移動に対応するOLSRの機能拡張に関する検討
近藤毅; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 第2回アドホックネットワーク・ワークショップ
May 2005 - 高密度なアドホックネットワークに対応するAODVプロトコルの性能評価
沖野正宗; 牛島準一; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会,コミュニケーションクオリティ研究会
Apr. 2005 - IGMPを用いたDVMRPベースマルチキャストLANのISPへの収容
ゴンヤピン; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Mar. 2005 - AODVとMobile IPを組み合わせたアドホックネットワークとインターネットの相互接続方法の性能評価
有本俊礼; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Mar. 2005 - 複数レイヤのモニタリングによる無線LAN通信の多重アクセス動作の解析
姫野正人; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Mar. 2005 - ハンドオフと伝送誤りを伴う無線LANネットワークにおけるTCP通信高速化方式の性能評価
小林正樹; 海老原成; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Mar. 2005 - 高密度アドホックネットワークを指向したAODVルーチングプロトコルの評価
沖野正宗; 牛島準一; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第67回全国大会
Mar. 2005 - 高密度センサーネットワークの階層化のための中継用ランドマークの選出方法
牛島準一; 沖野正宗; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第67回全国大会
Mar. 2005 - QoSを保証するスケーラブルなMobile IPv6通信方式の設計
劉偉; 加藤聰彦; 伊藤秀一
Oral presentation, 情報処理学会第67回全国大会
Mar. 2005 - モバイルIPネットワークにおけるハンドオフと伝送誤りの双方を考慮したTCP高速化方式の評価
海老原成; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第67回全国大会
Mar. 2005 - 有線リンクと無線リンクの混在するネットワークにおけるAODVルーチング方式に関する実験的検討
高梨健一; 加藤聰彦; 伊藤秀一; 菅田明則; 児島史秀; 藤瀬雅行
Oral presentation, Japanese, 情報処理学会第67回全国大会
Mar. 2005 - セキュアマルチキャストにおける効率的なグループ鍵管理に関する一考察
Alireza Nemaney Pour; 加藤聰彦; 粂川一也; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会2005総合大会
Mar. 2005 - リージョナル気付アドレスに対する可動性を提供するHMIPv6方式
加藤聰彦; パルヴェズサロワホセイン; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会2005総合大会
Mar. 2005 - 気付アドレスに対する可動性を提供するMobile IPv6通信方式の提案
加藤聰彦; 村井信彰; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会2005総合大会
Mar. 2005 - アドホックネットワークにおいて多対多通信を実現する最短木の構築方式
小坂努; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会2005総合大会
Mar. 2005 - OLSRにおけるノード移動時の通信開始遅延の低減手法の提案
近藤毅; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会2005総合大会
Mar. 2005 - アドホックネットワークにおけるTCP通信の振舞いに関する一検討
春原真人; 加藤聰彦; 粂川一也; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会2005総合大会
Mar. 2005 - MPLSを用いたスケーラブルなQoS保証Mobile IPv6通信方式
劉偉; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Nov. 2004 - 無線LAN通信の解析を補助するモニタリングシステムの設計
姫野正人; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Nov. 2004 - 有線リンクと無線リンクの混在するネットワークにおけるAODVルーチング方式に関する検討
高梨健一; 加藤聰彦; 伊藤秀一; 菅田明則; 児島史秀; 藤瀬雅行
Oral presentation, Japanese, 情報処理学会研究報告
Sep. 2004 - プライベートIPアドレスにより独立に管理されたMobile IPネットワーク間のグローバルローミング方式
辻野康一郎; 加藤聰彦; 伊藤秀一; 横田英俊; 井戸上彰
Oral presentation, Japanese, FIT2004
Sep. 2004 - ハンドオフ／伝送誤り／バックボーンの輻輳を考慮したモバイルIPのためのTCP通信高速化手法
海老原成; 粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, FIT2004
Sep. 2004 - 端末の移動を考慮したOLSRの性能評価
近藤毅; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, FIT2004
Sep. 2004 - モバイルIPによるAODVアドホックネットワークとインターネットの相互接続方式に対する制御オーバヘッドの評価
有本俊礼; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, FIT2004
Sep. 2004 - 消防活動のためのアドホックネットワークを指向したマルチキャストルーチングプロトコルに関する一検討
加藤聰彦; 高梨健一; 伊藤秀一; 浦野義頼
Oral presentation, Japanese, FIT2004
Sep. 2004 - 無線IPネットワーク用OSPFデーモンの実装と動作検証
高梨健一; 加藤聰彦; 伊藤秀一; 菅田明則; 児島史秀; 藤瀬雅行
Oral presentation, Japanese, 電子情報通信学会2004年ソサイエティ大会
Sep. 2004 - 無線ネットワークにおけるハンドオフ後にウィンドウサイズが変化する場合のTCP性能評価に関する検討
粂川一也; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会2004年ソサイエティ大会
Sep. 2004 - レイヤ2手順による無線LANにおける高速TCPハンドオフ手法の検討
小林正樹; 海老原成; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会2004年ソサイエティ大会
Sep. 2004 - 無線LAN通信の性能評価のためのモニタリングシステムに関する検討
姫野正人; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会2004年ソサイエティ大会
Sep. 2004 - 無線LAN通信の解析のためのモニタリングシステムに関する検討
姫野正人; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Jul. 2004 - ハンドオフと伝送誤りの双方を考慮したモバイルIPのためのTCP高速化方式の提案
海老原成; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Jul. 2004 - 無線LANネットワークにおけるハンドオフに対するTCP通信高速化手法
小林正樹; 海老原成; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Jul. 2004 - PIM-SMを用いたマルチキャスト対応LANのIGMPを用いた収容方法
ゴンヤピン; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Jun. 2004 - 高密度アドホックネットワークに適したAODV経路選択方式の提案と評価
沖野正宗; 牛島準一; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会研究報告
May 2004 - 独立なMobile IPネットワーク間のグローバルローミング方式
辻野康一郎; 加藤聰彦; 伊藤秀一; 横田英俊; 井戸上彰
Oral presentation, Japanese, 情報処理学会研究報告
May 2004 - AODVの機能を活用したアドホックネットワーク上でのMobile IP通信方式の検討
有本俊礼; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会研究報告
May 2004 - プライベートIPアドレスによるモバイルIPネットワークにおける経路最適化ピアツーピア通信の実現
加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会研究報告
Mar. 2004 - MPLSパスを用いたスケーラブルなQoS保証ピアツーピアモバイルIP通信方式
劉偉; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Mar. 2004 - 発呼トラヒックのためのHA機能をFAに持たせるモバイルIPプロトコルの実装
原正寛; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Mar. 2004 - モバイルIPのハンドオフ時におけるTCP通信高速化手法の評価
海老原成; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Mar. 2004 - MPLSを用いたスケーラブルなピアツーピアモバイルQoS通信
劉偉; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第66回全国大会
Mar. 2004 - HA機能を有するFAを用いたモバイルIPソフトウェアの設計
原正寛; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第66回全国大会
Mar. 2004 - モバイルIPとAODVを組み合わせたアドホックネットワークとインターネットの相互接続方式に関する一考察
有本俊礼; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第66回全国大会
Mar. 2004 - モバイルIPネットワーク間のグローバルローミング方式に関する一考察
加藤聰彦; 辻野康一郎; 伊藤秀一; 横田英俊; 井戸上彰
Oral presentation, Japanese, 情報処理学会第66回全国大会
Mar. 2004 - プライベートIPアドレスによるモバイルIPとSIPを用いたピアツーピア通信手法
加藤聰彦; 伊藤秀一; 横田英俊; 井戸上彰
Oral presentation, Japanese, 情報処理学会第66回全国大会
Mar. 2004 - 動的に確立するサブコネクションを用いた超高速TCP通信のための輻輳制御方式
堀内律之; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第66回全国大会
Mar. 2004 - 散在する無線LANネットワークの間の高速TCPハンドオフに関する検討
小林正樹; 海老原成; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会2004総合大会
Mar. 2004 - 無線IPネットワーク構築のためのOSPFのデータベース同期手続きに関する一検討
高梨健一; 加藤聰彦; 伊藤秀一; 菅田明則; 児島史秀; 藤瀬雅行
Oral presentation, Japanese, 電子情報通信学会2004総合大会
Mar. 2004 - 有線リンクと無線リンクの双方を用いるAODVネットワークの構築に関する検討
加藤聰彦; 高梨健一; 伊藤秀一; 菅田明則; 児島史秀; 藤瀬雅行
Oral presentation, Japanese, 電子情報通信学会2004総合大会
Mar. 2004 - モニタリングによる無線LAN上のTCP通信の解析実験
姫野正人; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会2004総合大会
Mar. 2004 - A Study on IGMP Based Internet Accommodation of Multicast-capable LANs with PIM-SM
Gong Yaping; Toshihiko Kato; Shuichi Itoh
Oral presentation, English, 電子情報通信学会2004総合大会
Mar. 2004 - 中継用ランドマークノードを有する高密度広域アドホックネットワークにおける階層化ルーチングに関する検討
牛島準一; 沖野正宗; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Dec. 2003 - AODVを高密度なアドホックネットワークに適用したオンデマンド型アドホックルーチングプロトコルの検討
沖野正宗; 牛島準一; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Dec. 2003 - ブロードキャスト型無線IPネットワークを指向したOSPFの拡張に関する検討
高梨健一; 加藤聰彦; 伊藤秀一; 菅田明則; 児島史秀; 藤瀬雅行
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Nov. 2003 - MPLSを用いたスケーラブルなQoS保証モバイルIP通信方式の評価
劉偉; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, FIT2003
Sep. 2003 - ハンドオフと伝送誤りの双方を考慮したモバイルIPのためのTCP通信高速化手法の検討
海老原成; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, FIT2003
Sep. 2003 - モバイルIPを用いたアドホックネットワークとインターネットの相互接続方式
加藤聰彦; 伊藤秀一
Oral presentation, Japanese, FIT2003
Sep. 2003 - HA機能を有するFAを用いたモバイルIPプロトコルの実装に関する検討
原正寛; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, FIT2003
Sep. 2003 - 中継用ランドマークノードを有する高密度アドホック網を用いた広域ネットワークに関する一考察
牛島準一; 沖野正宗; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, FIT2003
Sep. 2003 - 無線到達範囲のバウンダリノードを用いるオンデマンド型アドホックルーチングプロトコルの検討
沖野正宗; 牛島準一; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, FIT2003
Sep. 2003 - A New One-Pass Diffie-Hellman Protocol
Alireza Nemaney Pour; Toshihiko Kato; Shuichi Itoh
Oral presentation, English, 電子情報通信学会2003年ソサイエティ大会
Sep. 2003 - OSPFを用いた無線IPネットワークの構築に関する検討
加藤聰彦; 高梨健一; 伊藤秀一; 菅田明則; 児島史秀; 藤瀬雅行
Oral presentation, Japanese, 電子情報通信学会2003年ソサイエティ大会
Sep. 2003 - 無線IPネットワークに適したOSPF機能に関する検討
高梨健一; 加藤聰彦; 伊藤秀一; 菅田明則; 児島史秀; 藤瀬雅行
Oral presentation, Japanese, 電子情報通信学会2003年ソサイエティ大会
Sep. 2003 - モバイルIPハンドオフにおけるTCP通信の高速化手法に関する検討
海老原成; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会研究報告
Jul. 2003 - 発呼トラヒックに対するHA機能をFAに持たせるモバイルIPプロトコル
原正寛; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会研究報告
Jul. 2003 - A New Two Pass Diffie-Hellman Protocol with Key Confirmation
Alireza Nemaney Pour; Hajime Ishihara; Toshihiko Kato; Shuichi Itoh
Oral presentation, English, 電子情報通信学会技術研究報告
Jul. 2003 - 隣接ノード情報の交換を用いた無線フラッディングのための中継ノードの選択方法の提案と評価
沖野正宗; 牛島準一; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Jul. 2003 - 高密度アドホックネットワークにおける中継用ランドマークノードの選出方法の提案と評価
牛島準一; 沖野正宗; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会技術研究報告
Jul. 2003 - MPLSを用いたスケーラブルなQoS保証モバイルIP通信方式の検討
劉偉; 植野誠史; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会 技術研究報告
Apr. 2003 - 2レベルのレート制御を用いたマルチキャストトラヒックのための輻輳制御の検討
加藤聰彦; 植野誠史; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会 2003年総合大会
Mar. 2003 - 隣接ノード情報の交換に基づく無線フラッディングのための中継ノードの選択方法
沖野正宗; 牛島準一; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会 2003年総合大会
Mar. 2003 - 高密度アドホックネットワークにおける中継用ランドマークノードの選出方式
牛島準一; 沖野正宗; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 電子情報通信学会 2003年総合大会
Mar. 2003 - MPLSを用いたスケーラブルなQoSモバイル通信方式の設計
劉偉; 植野誠史; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第65回全国大会
Mar. 2003 - モバイルIPにおけるハンドオフ時のTCP通信高速化に関する検討
海老原成; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第65回全国大会
Mar. 2003 - 発呼トラヒックのためのHA機能をFAに持たせるモバイルIPプロトコルの設計
原正寛; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第65回全国大会
Mar. 2003 - PIM-SMによるマルチキャスト・トラヒックのための分散型モニタリング・システムの設計
植野誠史; 加藤聰彦; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第65回全国大会
Mar. 2003 - 並列に動作するサブコネクションを用いた超高速アプリケーション向けTCP輻輳制御方式の提案
加藤聰彦; 井上広喜; 伊藤秀一
Oral presentation, Japanese, 情報処理学会第65回全国大会
Mar. 2003 - 発着呼の区別により動的にHAを選択するMobile IP手順に関する検討
加藤聰彦; 伊藤秀一
Oral presentation, Japanese, FIT (情報科学技術フォーラム) 2002
Sep. 2002 - MPLSによる帯域保証パスを用いたQoSモバイル通信方式の提案
劉偉; 植野誠史; 加藤聰彦
Oral presentation, Japanese, FIT (情報科学技術フォーラム) 2002
Sep. 2002
Courses
- ユビキタスネットワーク
The University of Electro-Communications - ネットワークアーキテクチャ論
The University of Electro-Communications - ウェブデザインプログラム ネットワーク基礎
The University of Electro-Communications - セキュリティ情報学実験
The University of Electro-Communications - セキュリティ情報学実験
電気通信大学 - ウェブデザインプログラム ネットワーク基礎
The University of Electro-Communications - ウェブデザインプログラム ネットワーク基礎
電気通信大学 - Ubiquitious Networks
The University of Electro-Communications - ユビキタスネットワーク
電気通信大学 - Network Architecture
The University of Electro-Communications - ネットワークアーキテクチャ論
電気通信大学 - Network Architecture 1
The University of Electro-Communications - ネットワークアーキテクチャ論１
電気通信大学