CCMAC: Coordinated cooperative MAC for wireless LANs

In wireless LANs, throughput is one of, if not the most, important performance metric. This metric becomes more critical at the bottleneck area of the network, which is normally the area around the Access Point (AP). In this paper, we propose CCMAC, a coordinated cooperative MAC for wireless LANs. It is designed to improve the throughput performance in the region near the AP through cooperative communication, where data is forwarded through a two-hop high data rate link instead of a low data rate direct link. The most unique feature is that, it can coordinate nodes to perform concurrent transmissions which can further increase the throughput. To optimize the performance, the coordination problem is formulated as a Partially Observable Markov Decision Process and solved by a Reinforcement Learning algorithm. Through analysis and simulation, we show that CCMAC can significantly shorten the transmission time for stations with low data rate links to the AP and CCMAC has better throughput performance than other MAC protocols, such as CoopMAC and legacy IEEE 802.11.