Performance Evaluation of Adaptive Backoff Algorithms in Ad Hoc Networks

In this paper, the performance of traffic based adaptive (TBA) and size based adaptive (SBA) backoff algorithms for IEEE 802.11 DCF has been evaluated. TBA backoff algorithm utilizes contention status in the channel for adjusting the backoff algorithm but SBA backoff algorithm assigns different priority levels based on packet size to traffic loads which is involved with best effort and real time traffic. Meanwhile, TBA and SBA backoff algorithms are implemented in the mobile ad-hoc network (MANET), which is a collection of mobile independent nodes. Because of dynamic topology, IEEE 802.11 DCF backoff algorithm suffers from a lack of adequate performance in MANETs. Quality of service (QoS) requirements such as throughput, end to end delay and jitter were enhanced by applying TBA and SBA backoff algorithm in the MAC layer.