Enabling cooperation in mobile ad hoc networks

Spatial diversity achieved via nodal cooperation is known to alleviate the ill effects of channel fading in wireless networks. But to exploit this phenomenon the idea of node cooperation needs to be extended to other layers of the protocol stack, especially the MAC layer. This paper takes a close look at Synergy MAC, a cooperative MAC protocol, proposed for wireless mobile ad hoc networks. The studied protocol also leverages on the multi-rate capability of 802.11b to allow nodes with low SNR to their destination make use of intermediate relays, to transmit data at rates higher than otherwise possible. The performance improvement achieved by this protocol in comparison to 802.11b is then evaluated through extensive simulations.