Low-cost and accurate intra-flow contention-based admission control for IEEE 802.11 ad hoc networks

Abstract

In this paper, we propose a new admission control method for IEEE 802.11 ad hoc networks, called Low-cost and Accurate Admission control (LAAC). The proposed method has two variants: LAAC-Power and LAAC-CS. LAAC-Power estimates channel bandwidth availability through high power transmissions and LAAC-CS through passive monitoring of the channel. Due to the shared nature of the wireless medium, contention occurs among the nodes along a multi-hop path, which leads to intra-flow contention. LAAC accurately estimates the intra-flow contention. In addition, an analytical study demonstrates that LAAC achieves optimal results in terms of overhead and delay compared to the existing intra-flow contention-based admission control methods. LAAC also utilizes two criteria for accepting flows: one during the route request phase and the other during the route reply phase, which helps to reduce message overhead and avoid flooding route requests in hot spots. Simulation results show that LAAC-CS outperforms LAAC-Power in terms of packet delivery ratio, throughput, message overhead, and energy consumption. © 2008 Springer-Verlag Berlin Heidelberg.