Optimal Configuration of Mobility Agents in Broadband Wireless Access Networks

The next generation broadband wireless access networks are expected to support a variety of multimedia rich applications which can lead to very high traffic demand. With the development of high speed radio access technologies the backhaul network can become the bottleneck if not upgraded and configured optimally to support the expected increase in date rates and traffic demands. To deliver high data rates, the cell sizes are expected to become smaller which would lead to an increase in handover frequency thus exemplifying the importance of micro- mobility support. This paper addresses the issue of optimizing the wireless access networks that deploy mobility agents (MA) for micro-mobility support. The novel contributions are in providing a solution for finding the optimal number and location of MAs and assignment of Access routers (AR) to MAs (MA domain) that minimize both the handover signaling and routing overheads. The location, number and the domain of MAs (number of ARs a MA serves) deployed within access networks can affect the performance of the entire network. We first analyze the significant impact that the MA location has on the routing and mobility overhead cost. We subsequently formulate the problem as a generalized facility location problem that takes into account the routing cost from the gateway to the ARs through the MA and also the local and global mobility management handover costs. The solution of the optimization problem shows that by having optimal configuration of MAs there can be considerable improvement in the network performance and overheads can be reduced considerably.