On an assignment problem for wireless LAN and the voronoi diagram

In wireless LAN, like IEEE802.11x, the number of accessible terminal is limited for each access point. Therefore, it is necessary to assign each terminal to the access points under the limitation. It is well-known that this problem can be solved in polynomial time by solving a maximum flow problem in graph theory. However, there is a weak point in the above solution. If a terminal newly tries to access an access point, many terminals may change the access points. Therefore, this solution is not realistic. It is important to minimize the number of terminals that change the access points. In this paper, we propose a polynomial algorithm to solve the problem.