A joint uplink/downlink connection admission control in WLAN/cellular integrated systems

Although different connection admission control schemes in wireless local area network (WLAN)/cellular integrated systems have been proposed in the literature, they do not exploit unique features in uplink and downlink connections. In this paper, we propose a joint uplink/downlink connection admission control scheme in WLAN/cellular integrated systems, in which thresholds for admission control are adaptively determined to maximize the network capacity depending on the uplink and downlink characteristics. We develop an analytical model for the connection blocking cost by means of multi-dimensional Markov chains and present an optimization problem for the thresholds to minimize the blocking cost. Analytical and simulation results show that the proposed connection admission control scheme can reduce the number of blocked connections compared with the WLAN-first scheme.