Cooperative communication MAC (CMAC) - A new MAC protocol for next generation wireless LANs

Reliability is a big challenge to any wireless transmission as wireless networks tend to drop a large proportion of frames due to channel errors. To improve reliability over the noisy wireless channels, Forward Error Correction (FEC) schemes can be employed for wireless networks. Static and adaptable FEC algorithms can improve or degrade the performance of the wireless networks if their overheads are not matched properly to the underlying channel error, especially when the path loss fluctuates widely. This paper provides a new approach of alleviating the problem from a pure Medium Access Control (MAC) centric perspective. The new MAC protocol, called cooperative MAC (CMAC) enhances the existing IEEE 802.11e Wireless Local Area Network (WLAN) MAC protocol by introducing spatial diversity which is provided via user cooperation. We prove that this protocol greatly enhances the robustness of the WLAN operation. Additionally we compare the performance of CMAC protocol with the direct and multi-hop transmissions.