Self-restraint Admission Control for adhoc WLANs

Abstract

Admission control is an important mechanism for sustaining throughput and supporting quality of service (QoS) for real-time traffic in a wireless local area network (WLAN). In an adhoc WLAN scenario where no access point (AP) is available, admission control has to be self-managed by each node. We propose a self-restraining admission control mechanism that works by monitoring the congestion level of the network in the adhoc WLAN. Wireless nodes can listen to all nodes within their range and be aware of the collision rates. A node wishing to join the network measures the current collision rate, and predicts the post-admission collision rate, on the basis of which the self-restraining mechanism in the node decides if it can join the network. We analyse the impact of key parameters, such as the collision threshold level, on the performance of the self-restraining mechanism and show that this mechanism works effectively in sustaining traffic in an adhoc WLAN.