Enhanced Channel Access Mechanism for IEEE 802.11s Mesh Deterministic Access

This paper presents an enhanced channel access mechanism for the newly introduced Mesh Deterministic Access (MDA) mechanism for IEEE 802.11s based Wireless Mesh Networks (WMNs). The MDA is an optional scheduled access mechanism which enables mesh nodes to negotiate periodic transmission opportunity (referred to as Mesh Deterministic Access Opportunity (MDAOP)) for a collision free transmission of QoS frames. However, the performance of MDA is affected by the presence of contention from non-MDA nodes in the neighborhood. In this work, we first identify how a non-MDA node affects the operation of MDA and then, propose an enhanced channel access mechanism referred to as Enhanced Mesh Deterministic Access (EMDA) that ensures guaranteed access to the medium during an MDAOP by an MDA-owner by means of reduced Interframe Space (IFS) and the preemption capability. Finally, we study the performance of EMDA through simulation, and results show that EMDA outperforms others in terms of throughput, end-to-end delay, packet loss rate and MDA utilization.