A multi-rate based router placement scheme for wireless mesh networks

Mesh router (MR) placement is one of the fundamental issues that need to be addressed carefully to achieve a desired performance of a wireless mesh network (WMN). The objective of the MR placement schemes is to systematically determine the minimal number of MRs and their positions while satisfying various constraints, such as coverage, connectivity, traffic demand, etc. This paper explores the solution for placing the MRs with multiple transmission rates, which influence both transmission range and wireless link capacity. In the paper, we first formulate the problem with a mixed integer programming model. We then present a heuristic placement algorithm called ILSearch which takes into account both multiple transmission rates and co-channel interference. The ILSearch consists of two components: (1) Coverage MR determination which greedily exploits the capability of each selected MR to cover mesh clients (MCs); and (2) Relay MR determination that incrementally chooses the additional MRs for traffic relaying through the local search. Our simulation has not only shown that ILSearch can effectively obtain the MR placement that meets all the constraints, but also demonstrated that a MR placement which considers the variable transmission rates outperforms those don't.