SODCA: A Self-Organized Distributed Channel Access scheme for IEEE 802.11 networks

Coordinating channel access is a fundamental task of the MAC layer in wireless networks. Whereas most proposed medium access techniques involve a pure contention-based mechanism or a centralized polling scheme, we explore distributed scheduling-based medium access. Intuitively, a scheduling-based scheme would achieve a higher bandwidth efficiency and a lower collision rate than contention-based mechanisms. We develop the Self-Organized Distributed Channel Access (SODCA) scheme, that combines the advantages of both contention and scheduling mechanisms. Distinctively from other proposed solutions, SODCA does not incur any additional overhead and is a distributed, highly efficient, compatible, and a dynamic schedule establishment scheme. Through simulation results based on the OMNeT++ network simulator, we demonstrate the high efficiency of SODCA compared to the IEEE 802.11 DCF contention mechanism in both static and dynamic scenarios. SODCA is proven to achieve a collision-free and fair medium access leading to a 20% higher network throughput than DCF in a static scenario, and a significantly lower collision rate in a dynamic scenario.