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Proximity-Based Routing for Wireless Multi-hop Networks

Conducting research on routing in mobile ad hoc network environments and building wide-area multi-hop wireless network systems. Exploring factors like node mobility, radio wave quality, and strategic routing decisions.

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Proximity-Based Routing for Wireless Multi-hop Networks

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  1. タスク　A　ワイヤレスネットワークシステムタスク　A　ワイヤレスネットワークシステム 慶應義塾大学　徳田研究室 間　博人

  2. 概要 • モバイルアドホックネットワーク環境におけるルーティングに関する研究 • 広域マルチホップ無線ネットワークシステムの構築に関する研究

  3. モバイルアドホックネットワーク • ノードの移動によるトポロジの変動 • 電波品質による通信状況の変動 • ルーティングコスト • 経路短縮 • 経路切り替え • ブロードキャストの抑制

  4. 広域マルチホップ無線ネットワークシステム • マルチホップに適したマルチチャネルCSMA • シングルチャネル 　　同一チャネル干渉

  5. A Proximity-based Routing Protocol for Wireless Multi-hop Networks Tokuda Lab. Keio Univ. Masato Saito

  6. DoCoMo成果発表 Introduction • About Ad hoc Network • Current Problem • Solution: Optimized Re-Routing (OR2) • Main • Evaluation • Experiments • Simulation • Conclusion and Future Work

  7. DoCoMo成果発表 Introduction Mobile Ad Hoc Networks • Formed by wireless hosts which may be mobile • Without (necessarily) using a pre-existing infrastructure • Routes between nodes may potentially contain multiple hops • Node Mobility causes route changes → Ease of deployment, Speed of deployment, Decreased dependence on infrastructure

  8. DoCoMo成果発表 Many Applications • Personal area networking • cell phone, laptop, ear phone, wrist watch • Military environments • soldiers, tanks, planes • Civilian environments • taxi cab network • meeting rooms • Robot network • Emergency operations • search-and-rescue • policing and fire fighting

  9. Cannot connect to BS directly. Using multi-hop Connection to BS BS A B DoCoMo成果発表 An Application Scenario • Cellular and BS

  10. DoCoMo成果発表 Many Protocols Proposed … • ＤＳＲ　　　----- On-demand Source Routing • ＡＯＤＶ ----- On-demand Table Driven • ＬＡＲ ----- GPS-based Routing • ＺＲＰ ----- Proactive Zone Routing, Hybrid →But, these protocols mainly focus on connectivity and route discovery. Previous protocols realize efficient connectivity?

  11. 3 1 2 3 2 1 Problem Definition DoCoMo成果発表 Problems of Conventional protocols • Not identify the nearness of two nodes.For example, • Never change the route unless the links fails, So …..

  12. DoCoMo成果発表 Effect of Path Shortening DSR (http://www.monarch.cs.rice.edu/) on FreeBSD, 5 Laptops with 802.11b NICs

  13. 3 3 1 2 3 1 2 1 2 DoCoMo成果発表 OR2 Solution • Estimates the change of network topology (the nearness of two nodes) based on the local link state of SNR • Re-routes the path adaptive to node mobility when the links are still active. Optimized Re-Routing（OR2）

  14. Proximity of Node A B A Cell OR2 Solution DoCoMo成果発表 Proximity : to identify the nearness • The area around Node A where the received SNR value is more than a threshold. • suppose that Node A and B are the same location if Node B is in the proximity of A. We assume that all nodes in a network. Have the same NIC.

  15. C∈P(B) C Proximity of Node C movement B flow Proximity of Node B C Symbol Definition A • S(bc) is the received SNR value of C. • Smax is the threshold of proximity. • P(B) is the proximity of Node B. • S(bc) = S(cb) Proximity of Node A One-hop path shortening • IF S(bc) > Smax • THEN C∈P(B) • C sends REQ to A • A sends DATA to C

  16. time OR2_REQ C E SSNR > Smax B Smax > Smin OR2_REP D SSNR > Smin OR2_RREQ Shorten route F flow B A C DoCoMo成果発表 Exclusive Control • the cases that neighbor nodes initiate shortening the same path….. A

  17. DoCoMo成果発表 OR2 features • Local Decision using local link quality obtainable from own NIC. • No periodic control packets. • Network bandwidth, interference, power consumption • By the Iteration of one hop shortening, we can shorten any hop route as possible. • Applicable to previous routing protocols. • Simple.

  18. Evaluation by simulation • Simulation Parameters • 1500 m x 300 m, flat field, 50 mobile nodes. • Speed uniformly distributed between 0 – 20 m/sec. • Constant Bit Ratio UDP traffic (512 packet). • Five runs with different mobility scenarios • Variable • The number of traffic sources • Node Mobility Model (& Node Pause Time) • Evaluation Metric • Average Data Packet Delay • Packet Delivery Ratio (PDR) • Normalized routing overhead

  19. Classified Mobility Models • Random Way-Point Mobility • Our Random Oriented Mobility • Makes some node congestion points. • This model is favorable for OR2. • Our Random Escape Mobility • Makes some network partition areas intentionally. • Heavy loads to OR2. dst dst

  20. Core Nodes Core Nodes 2 Escape Nodes Oriented Nodes 6 6 4 1 3 3 5 5 5 3 1 1 4 4 6 2 2 Random Oriented Mobility Model Random Escape Mobility Model

  21. Evaluation: 10 sources Avg. Delay Routing Overhead Packet Delivery Ratio

  22. Evaluation: 30 sources Avg. Delay Routing Overhead Packet Delivery Ratio

  23. Evaluation: in Oriented Mobility Avg. Delay Routing Overhead Packet Delivery Ratio

  24. Simulation Results Summary • OR2 improves the end-to-end delay as expected and reduces the routing control packet overhead effectively. • In the packet delivery ration (PDR) of light traffic load scenario , OR2 loses about 5 % packets. • In heavytraffic loads, OR2 has the highest performance of PDR. • AODV with OR2 does not show the improved performance as salient as DSR with OR2. • In our Random Oriented Mobility, we can see that the improved delay reduction is significant.

  25. DoCoMo成果発表 Implementation in our testbed • As an extension to DSR on FreeBSD-4.4R • SNR (from NIC driver) monitoring module • OR2 routing table to maintain the upstream two-hop-away node’s information • OR2 control packet for path shortening • Using MELCO 802.11b NICs 　

  26. Ｂ Ｃ Ａ Evaluation DoCoMo成果発表 Latency of Path Shortening • Shortening time is the order of 10 ms. • It is suitable for slow mobility (pedestrians and slow vehicle) Ｂ Ｃ Ａ

  27. DoCoMo成果発表 Future Works • Simulation analysis. • Development of Signal power and supplemental location information based Wireless Routing Protocol in our testbed (iPAQs running Linux). • Design of Transport protocol for Ad Hoc Networks. • Simulation evaluation in popular 802.11b & 802.11a wireless LAN environments (in this work, we used 802.11[2Mbps] wireless LAN Network).

  28. Today’s Summary • We proposed Proximity-based Re-Routing Algorithm for Mobile Ad Hoc Networks. • OR2 dynamically shortens active paths based on the proximity. • Previously proposed routing protocols (e.g., DSR & AODV) were effectively enhanced by OR2. • OR2 remarkably reduced the routing packet overhead and data packet latency.

  29. DoCoMo成果発表 Publications • M. Saito, H. Aida, Y. Tobe, Y. Tamura, and H. Tokuda"A Dynamic Path Shortening Scheme in Ad Hoc Networks",情報処理学会 マルチメディア通信と分散処理ワークショップ (DPS)、2001年１０月、 • Winner of the Best Presentation Award and Winner of the Young Researcher’s Award • M. Saito, H. Aida, Y. Tobe, Y. Tamura, and H. Tokuda　"OR2: A Path Tuning Algorithm for Routing in Ad Hoc Network”, IEEE LCN on Wireless Local Networks (WLN), Tampa, FL, Nov. 2001.

  30. DoCoMo成果発表 FIN Masato Saito, Tokuda Lab., Keio Univ.

  31. Multi Hop Shortening

  32. Evaluation: 10 sources Avg. Delay Routing Overhead Packet Delivery Ratio

  33. Evaluation: in Escape Mobility Avg. Delay Routing Overhead Packet Delivery Ratio

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