Access point selection in heterogeneous wireless networks using belief propagation

The next generation wireless network will be composed by various heterogenous wireless access networks, such as cellular network, worldwide interoperability for microwave access (WiMAX), wireless local area network (WLAN), etc. Different access networks cooperatively provide high-bandwidth connectivity with bandwidth guarantees. This paper proposes a utility-based access point selection scheme, which selects an accessible point for each user, such that the bandwidth requirement of each user is satisfied, and also the defined utility function is maximized. Due to the NP-complete nature of the problem, the existing proposals apply the greedy method to find a solution. We find that belief propagation is an efficient tool to solve this problem, and thus, we derive the same optimization objective in a new way, and then draw a factor graph representation which describes our combinatorial optimization problem. Afterwards, we develop the belief propagation algorithm, and show that our algorithm converges. Finally, we conduct numerical experiments to evaluate the convergency and accuracy of the belief propagation in load balancing problem.