An extended active access-point selection algorithm for link speed changes in wireless mesh networks

摘要

As an inexpensive, scalable internet-access network, a wireless internet-access mesh network (WIMNET) is composed of multiple access-points (APs) connected by wireless links. WIMNET can improve the dependability to link or AP failures by allocating APs redundantly in the network field. Because redundant APs may increase the operational cost and degrade the performance due to increasing radio interferences, only the necessary APs for communications between the hosts and the internet gateway should be activated in conventional situations. Previously, we proposed an active AP selection algorithm to select the minimum number of APs to be activated such that the overall throughput is maximised, assuming that every link has the same constant speed. However, our preliminary experiments for the emerging high-speed IEEE802.11n protocol that should be introduced into WIMNET, found that this speed is greatly affected by the link environment such as the distance. In this paper, we present an extension of the active AP selection algorithm to efficiently select active APs under link speed changes. Besides, we extend the routing tree algorithm used in the algorithm procedure and the WIMNET simulator for throughput evaluations. We verify the effectiveness through extensive simulations in three instances.