On Optimal Admission Control for Multi-Service Cellular/WLAN Interworking

The complementary characteristics of cellular systems and wireless local area networks (WLANs) make them attractive candidates to jointly offer a seamless wireless solution. In an integrated cellular/WLAN system, the quality of service (QoS) requirements for different services (e.g., voice and real-time video) require adequate admission control policies to limit the number of connections in each network. In this paper, we analytically develop a comprehensive model to facilitate the optimal evaluation of different admission control policies in a multi-service integrated cellular/WLAN system. Given the model, we formulate two optimization problems to adjust admission control parameters. The first problem is to maximize the network revenue while the second problem is to minimize the required network resources subject to QoS constraints. We evaluate each problem when different combinations of cutoff priority and fractional guard channel admission control policies are being used. We show that a combination of two cutoff priority policies achieves the best solution for both problems.