One major challenge in the integration of wireless LAN (WLAN) and cellular networks is call admission control (CAC). Without a suitable CAC mechanism for the integrated network, the two networking systems will work independently and cannot simultaneously serve users properly. In the area covered by both access networks, if all calls are handed over to the hotspot unconditionally, the WLAN will be severely congested and its users will suffer from QoS degradation. Therefore, for downward vertical handover (DVHO) calls, we propose a CAC algorithm to improve resource utilization in the integrated WLAN and cellular networks. Numerical results demonstrate that our CAC scheme satisfies the hard constrains on the blocking rate of new calls in the double-coverage area while keeping DVHO failure rate within acceptable limits.
Citation: IEEE Transactions on Wireless Communications
Pub Type: Journals
call admission control, quality of service, vertical handovers