Uplink traffic cellular-first access scheme in cellular/WLAN integrated networks

In cellular/WLAN integrated networks, WLAN APs are usually deployed to offload the heavy traffic of cellular networks. Due to the inherent asymmetry of downlink and uplink in WLAN, competitions increase rapidly along with uplink traffic being offloaded to WLAN, which degrades system performance significantly. In this paper, we propose a new access scheme, i.e. uplink traffic cellular-first access (UTCFA) scheme. By offloading uplink traffic within WLAN coverage to contention-free cellular networks as much as possible, UTCFA scheme improves WLAN channel utilization significantly. We derive the throughput produced by UTCFA by theoretical analysis and perform extensive simulations to validate these theoretical results. Particularly, we find that the well-known WLAN-first access scheme is a special case of the proposed scheme. The simulation results also show that UTCFA can significantly improve the system performance and provide better support for quality of service guaranteed services.