High Throughput Interweave Cooperative Wireless MAC Protocol for Congested Environment

CSMA/CA wireless MAC protocol is adopted in many standards. However, its performance at high contention level is less than desirable due to prolonged backoff period and collisions. We propose a novel cooperative MAC based on the Interweave Cognitive framework to combat high contention. In our setup, we incorporate a subset of self-organizing advanced nodes that opportunistically switch to a contention-free MAC protocol to ease network congestion in a cognitive and cooperative manner. Consequently, the whole network benefits from a higher and more stable throughput even at high contention level. Our theoretical and simulation results demonstrate that IC-MAC is effective in reducing the number of backlogged nodes and improving the throughput of up to 20% relative to CSMA/CA MAC.