1. My Research Themes Dr. Tarik TALEB, Ph. D Assistant Professor Graduate School of Information Sciences Tohoku University, Sendai, Japan

2. 1 Research Projects Next Generation Wireless Communications Systems Transmission protocols Mobility management and QoS Routing Protocols On-Demand Multimedia Transmission Internet Security Internet Worms Trace back of DoS Attacks Intrusion Detection Systems

3. 2 REFWA Recursive, Explicit, and Fair Window Adjustment A new transport protocol to efficiently and fairly adjust the sending rates of TCP connections in broadband satellite communication systems DSBP Dummy Segment-based Bandwidth Probing A novel technique to improve the efficiency of TCP in heterogeneous wireless networks Transmission Protocols for Wireless Commun.

4. 3 REFWA: Recursive, Explicit, and Fair Window Adjustment T. Taleb, N. Kato, and Y. Nemoto, "REFWA: An Efficient and Fair Congestion Control Scheme for LEO Satellite Networks", in IEEE/ACM Transactions on Networking Journal, Oct. 2006. T. Taleb, N. Kato, and Y. Nemoto, "An Explicit and Fair Window Adjustment Method to Enhance TCP Efficiency and Fairness over Multi-Hops Satellite Networks", IEEE J. Select. Areas in Commun., Feb. 2004. Aim: To find optimum sending rates for TCP connections in NGEO broadband satellite systems To solve issues related to handoff and unfairness due to RTT variance Concept: Use of hops count to estimate connections RTT Use of RTT to compute the optimum sending rates of each TCP sender Further applications: Multi-homing over hybrid wired/wireless networks Satellite Network Terrestrial/Wireless Networks Direct Users

5. 4 Aim: To solve issues related to the bandwidth disparity in heterogeneous wireless networks Concept: Use of low-priority dummy segments to probe bandwidth of the new network Further applications: RTP/RTCP-based multimedia streaming DSBP: Dummy Segment-based Bandwidth Probing BS1 BS2 Correspondent Node Home Agent Mobile Node Dummy Segments Data Traffic (TCP) T. Taleb, K. Kashibuchi, N. Kato, and Y. Nemoto, “A Dummy Segment Based Bandwidth Probing Technique to Enhance the Performance of TCP over Heterogeneous Networks”, IEEE WCNC 2005. K. Kashibuchi, T. Taleb, A. Jamalipour, N. Kato, and Y. Nemoto, “A New Smooth Handoff Scheme for Mobile Multimedia Streaming using RTP Dummy Packets and RTCP Explicit Handoff Notification”, IEEE WCNC 2006.

6. 5 ELB (Explicit Load Balancing) A new routing protocol to better distribute traffic and to accordingly alleviate congestion in Non-Geostationary satellite systems VHRP (Vehicle-Heading based Routing Protocol) A stable and reliable routing mechanism for Inter-Vehicular Communications to reduce the number of link breakage events and increase the end-to-end throughput in VANET networks DEMAPS (Dynamic & Efficient MAP Selection) A dynamic MAP management strategy for the selection of the most appropriate MAP with the lightest traffic load based on an estimation of MAP load transition. Mobility Management and Routing QoS Protocols

7. 6 Aim: To deal with scenarios where some satellites get congested while others remain underutilized To better distribute traffic over the entire constellation, reduce congestion due packet drops, and to improve network utilization Concept: Explicit & periodic exchange of information on queue status among neighboring satellites Applications: Delay insensitive applications Possible application to terrestrial networks ELB: Explicit Load Balancing T. Taleb, A. Jamalipour, N. Kato, and Y. Nemoto, "IP Traffic Load Distribution in NGEO Broadband Satellite Networks", in Proc. of 20th Int. Symposium on Computer & Information Sciences, Oct. 2005. (Invited Paper) SenderReceiver Congested

8. 7 VHRP: Vehicle-Heading based Routing Protocol Aim: To guarantee stable and reliable routes for communication To reduce the number of link breakage events To increase E2E throughput and to guarantee routing QoS in VANET networks Concept: To group vehicles based on their velocity headings and to establish routes among vehicles from same groups Applications: Inter-Vehicular Communications Hotspots-to-Vehicles communications T. Taleb, M. Ochi, A. Jamalipour, N. Kato, and Y. Nemoto, " An Efficient Vehicle-Heading Based Routing Protocol for VANET Networks", in Proc. of IEEE WCNC 2006

9. 8 Aim: To solve issues related to handoff management in Mobile IPv6 networks To better distribute traffic among MAPs To alleviate congestion, to enhance network resources utilization, and to ultimately guarantee QoS Concept: Use of Exponential Moving Average to predict transitions of MAPS load Applications: Mobile IPv6 networks DEMAPS: Dynamic & Efficient MAP Selection T. Taleb, T. Suzuki, N. Kato, and Y. Nemoto, "A Dynamic and Efficient MAP Selection for Mobile IPv6 Networks ", in Proc. of IEEE Globecomm 2005. AR3 Internet MAP2MAP1 MAP4MAP3 AR1AR2 AR4 MN Correspondent Node Home Agent

10. 9 NBB VoD (Neighbors Buffering Based VoD) An interactive and scalable scheme for the provision of VoD service in multicast environments Theatre in the Sky An architecture based on Quasi-GEO Stationary Satellites for global streaming of on-demand multimedia services to hybrid networks made of both mobile and fixed users On-Demand Multimedia Transmission

11. 10 NBB-VoD: Neighbors Buffering Based VoD Aim: To increase the capacity of VoD servers and the scalability of the system To efficiently utilize the network resources (e.g. bandwidth) Concept: Serve new users willing to join a session from their neighbors, already members of the session Applications: On-demand multimedia services in multicast environments, distance learning… T. Taleb, N. Kato, and Y. Nemoto, "On-Demand Media Streaming to Hybrid Wired/Wireless Networks over Quasi-Geo Stationary Satellite Systems", Elsevier Journal on Computer Networks, Feb. 2005. T. Taleb, T. Suzuki, N. Kato, and Y. Nemoto, "Neighbors-Buffering Based Video-on-Demand Architecture", Signal Processing: Image Communication, Aug. 2003. Request New UserOld User Already transmitted portion To be transmitted Server

12. 11 Theatre in the Sky (1) Metropolitan Server Storage Data (Popular Video) Core Network Local Service Manager Replicated Data Multicast (data) Control Message Current Channel Upcoming Channel Request Time Unicast (data)

13. 12 Theatre in the Sky (2) The Quasi-Geostationary Satellites Constellation Inter-System Links A Quasi-GSO system Metropolitan Service Areas T. Taleb, A. Jamalipour, N. Kato, and Y. Nemoto, "A Theatre in the Sky: A Ubiquitous Broadband Multimedia-on-Demand Service over a Novel Constellation Composed of Quasi-Geostationary Satellites", to appear in Wiley Int. J. of Satellite Commun. and Networking.

14. 13 DoS Attacks in Mobile Networks Design of a prevention system to secure mobile networks from high Rate TCP-based DoS attacks originated from malicious mobile users Intrusion Detection System Development of a hybrid system for the detection, prevention, and trace back of cryptographic protocol intrusions Internet Worms An Efficient Signature-Based Framework for Early Detection of Internet Worms over Large Scale Networks Internet Security

15. 14 Securing Hybrid Wired/Mobile IP Networks T. Taleb, H. Nishiyama, N. Kato, and Y. Nemoto, "Securing Hybrid Wired/Mobile IP Networks from TCP-Flooding Based Denial-of-Service Attacks", in Proc. of IEEE Globecomm 2005. Aim: To demonstrate the inefficiency of trace back techniques in mobile networks To design a prevention system to secure hybrid wired/mobile networks from high Rate TCP- based DoS attacks coming from malicious mobile users Concept: Send suspicious TCP senders a test feedback requesting them to decrease their sending rates Judge senders’ legitimacy based on their responsiveness Applications: Security in mobile networks, WIMAX, WLAN…. Server (Victim) Internet BS AR Attacker Tracing fails Attack Attacker Attack Change point of attachment

16. 15 Early Detection of Internet Worms Aim To detect Internet worms and generate their signatures at the early stage of their propagations Concept Information-sharing among hierarchically placed security managers Local managers: Collect worm-like or suspicious flows Metropolitan managers: Sort worms and generate worm signature Global manager: relays worm signature Applications worm detection in large scale networks (e.g. universities, large enterprises,...) K. Simkhada, T. Taleb, Y. Waizumi, A. Jamalipour, N. Kato, and Y. Nemoto, "An Efficient Signature-Based Approach for Automatic Detection of Internet Worms over Large-Scale Networks," In Proc. of IEEE ICC, Istanbul, Turkey, Jun. 2006.