Design and Implementation of CLASS: A Cross-Layer ASSociation Scheme for Wireless Mesh Networks

A widely-used association strategy in current 802.11 networks is to allow a Mobile Station (MS) to associate with the Access Point (AP) which has the best Received Signal Strength Indication (RSSI) value during its scanning. However, in 802.11-based wireless mesh networks, the conditions of the access link (e.g., traffic load of associated stations, and the frame error rate between the MS and the Mesh Router (MR)) and the conditions of the mesh backhaul (e.g., end-to-end latency, and asymmetric uplink and downlink transportation costs) have a significant impact on the network performance of the MS after its association. In this work, we propose a cross-layer association scheme for wireless mesh networks. The end-to-end airtime cost is used to determine the MR to which the MS should associate, comprising the access link airtime cost and the backhaul airtime cost. Our experimental results on a Linux-based testbed show that the proposed association scheme is capable of providing the mobile stations with the highest end-to-end network performance after their association.