Improving mac performance in wireless ad-hoc networks using enhanced carrier sensing (ecs

Abstract. In IEEE 802.11, whenever a node detects an erroneous frame (e.g., a sensing range frame) on the medium, it defers the transmission by a fixed duration (represented by EIFS). We show that this duration is sometimes smaller and sometimes larger than the desired period by which the transmission should be deferred, and it leads to substantial unfairness and throughput degradation. We propose an enhanced carrier sensing (ECS) scheme, which distinguishes among the type of the erroneous frames based on their lengths and defers the transmission accordingly. Simulation results show that the ECS improves the fairness as well as the throughput substantially