Cooperative Communication in Mesh Networking Month Year doc.: IEEE 802.11-05/0143r0 March 2005 Cooperative Communication in Mesh Networking Date: 2005-03-11 Author: Name Company Address Phone email Klaus Fosmark University of Texas at Dallas Eng. Dept. MS EC 33 2601 North Floyd Richardson, TX 75080 214-674-9607 klaus.fosmark@utdallas.edu Notice: This document has been prepared to assist IEEE 802.11. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http:// ieee802.org/guides/bylaws/sb-bylaws.pdf>, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair <stuart.kerry@philips.com> as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at <patcom@ieee.org>. Klaus Fosmark, University of Texas at Dallas Klaus Fosmark, UTD

Month Year doc.: IEEE 802.11-05/0143r0 March 2005 Abstract This presentation will outline how “Cooperative Communication” can be shown to improve overall network performance. This proposal recommends Cooperative Communication be used as part of the Mesh protocol in 802.11s as it may be a very simple addition that can improve performance. Klaus Fosmark, University of Texas at Dallas Klaus Fosmark, UTD

What is Cooperative Communication? March 2005 What is Cooperative Communication? In normal 802.11, when a packet is not received at the Destination (or received with error), the following happens: The packet is lost (discarded) An ACK is NOT generated from the Destination The Source will retransmit the packet later With Cooperative Communication, when a packet is not received at the Destination (or received with error), the following happens: An ACK is NOT generated by the Destination A relay node that successfully overheard the packet may relay this to the Destination The Source will retransmit if there no successful relay Klaus Fosmark, University of Texas at Dallas

? Example March 2005 Klaus Fosmark, University of Texas at Dallas Destination Source Relay Klaus Fosmark, University of Texas at Dallas

Performance Benefit Simulations March 2005 Performance Benefit Simulations Academic and non-802.11 protocol simulation: Slotted, non-contention protocol Flat Rayleigh fading, constant over frame and independent of other frames ACKs are error free 3 nodes: Source and Destination and a Relay node One-way traffic only Poisson traffic arrival Relay node always attempts to retransmit (if there is an error) regardless of location Klaus Fosmark, University of Texas at Dallas

Simulation Results Fixed best case location of nodes: March 2005 Source Relay Destination Klaus Fosmark, University of Texas at Dallas

Latency improvement depending on location of relay node: March 2005 Latency improvement depending on location of relay node: Source: Destination: Relay: Klaus Fosmark, University of Texas at Dallas

Why is this Mesh relevant? March 2005 Why is this Mesh relevant? Could be used between Mesh points: Mesh Points are also Relays for each other Whatever mechanism used to define the Mesh Path could also identify possible Relay nodes for each Mesh Link Whenever a packet is lost, the predetermined Relay node will retransmit STAs could be Relays A more dynamic protocol needed to allow cooperation from STAs. (Could be an addition to 802.11 in general within each BSS) AP AP AP AP AP AP AP Klaus Fosmark, University of Texas at Dallas

Further work / Issues / Conclusion March 2005 Further work / Issues / Conclusion Determine relevance for Mesh and 802.11s Work into Mesh Protocol Performance analysis of protocol Academic references also incorporate forward error correction which improves the benefit of cooperation since the strength of the error correction can increase with a relay retransmission. Klaus Fosmark, University of Texas at Dallas

March 2005 References A. Nosratinia, T. Hunter, and A. Hedayat, “Cooperative Communication in Wireless Networks,” IEEE Communications Magazine, vol. 42, no. 10, pp. 74–80, October 2004, http://www.utdallas.edu/~thunter/CommMag03.pdf. E. Zimmermann, P. Herhold and G. Fettweis, “The Impact of Cooperation on Diversity-Exploiting Protocols,” 59th IEEE Vehicular Technology Conference (VTC Spring 2004), Milan, Italy, May 2004, http://www.ifn.et.tu-dresden.de/~zimmere/papers/impact_of_cooperation_on_diversity_exploiting_protocols_VTC_Spring_2004.pdf. P. Gupta, I. Cerutti, A. Fumagalli, “Three Transmission Scheduling Policies for a Cooperative ARQ Protocol in Radio Networks”, Proc. WNCG conference, Austin, October 2004. M. Tacca, P. Monti, A. Fumagalli, “Cooperative and Non-Cooperative ARQ Protocols for Microwave Recharged Sensor Nodes”, to be published in Proc. 2nd European Workshop on Wireless Sensor Networks (EWSN), Istanbul, Turkey, January-February 2005. Klaus Fosmark, University of Texas at Dallas