No abstract

Cooperative communication refers to the collaborative processing and retransmission of the overheard information at those stations surrounding the source. It exhibits various forms at different protocol layers and introduces many opportunities for cross layer design and optimization. To fully reap the benefits of cooperative communications in wireless networks, the entire protocol stack -physical, MAC, and routing protocols -should be carefully redesigned or reengineered. In this paper, we first propose a cooperative MAC protocol by enhancing IEEE 802.11 DCF with minimal modifications to maximize the benefit of cooperative diversity. Its performance is compared to that of an existing cooperative MAC and legacy 802.11 DCF protocols and shown to be superior. We also propose a cluster based cooperative routing protocol which has minimal control overhead and time consumed in establishing the cooperative paths. Through extensive simulations, the performance of the proposed protocols are evaluated and compared to other combinations of MAC and routing protocols.

This work investigates a Cooperative Medium Access Control (CoopMAC) protocol that is backward compatible with the legacy 802.11 system, in which high data rate stations assist low data rate stations in their transmission by forwarding their traffic. New mathematical models have been developed in this work for the performance evaluation of this protocol under different channel conditions and for unsaturated traffic loads. Extensive simulation results validate the mathematical models developed and show that CoopMAC protocol can significantly improve system throughput, service delay, and energy efficiency for WLANs operating under realistic communication scenarios.978-1-4799-2178-2/13/$31.00 ©2013 IEEE