Assessing capacity in WLAN-UMTS integrated networks

In the very near future wireless LAN and UMTS technologies will have to co-exist in many populated areas. Since UMTS radio cells are more limited in capacity than WLAN access points (AP), this technology integration gives operators the opportunity to perform internetwork load balancing by transferring services to WLAN hotspots. By doing so, UMTS cell congestion can be alleviated and capacity can be freed for future real time connections. Several scenarios arise depending on the level of congestion of both networks. This research studies such scenarios by assessing the impact of performing internetwork load balancing when transferring non-real time traffic. Promising results show how light and intermediate loaded neighboring WLAN hotspots can absorb up to 50% of the load of a congested UMTS cell, enhancing the throughput for switched non-real time applications and freeing 50% capacity of for future real time UMTS calls. This is achieved without degrading the service of existing applications in the WLAN hotspot.