Design Architectures for 3G and IEEE 802.11 WLAN Integration

Wireless LAN access networks show a strong potential in providing a broadband complement to Third Generation (3G) cellular systems. 3G networks provide a wider service area, and ubiquitous connectivity with low-speed data rates as compared to Wireless Local Area Networks (WLANs). WLAN networks offer higher data rate and the easy compatibility to wired Internet, but cover smaller areas. Integrating 3G and WLAN networks can offer subscribers high-speed wireless data services as well as ubiquitous connectivity. The key issue involved in achieving these objectives is the development of integration architectures of WLAN and 3G technologies. The choice of the integration point depends on a number of factors including handoff latency, mobility support, cost-performance benefit, security, authentication, accounting and billing mechanisms. We review 3G-WLAN integration architectures and investigate two such architectures in the case when the Universal Mobile Telecommunications Network (UMTS) network is connected to a WLAN network at different integration points, namely the Serving GPRS Support Node (SGSN) and the Gateway GPRS Support Node (GGSN). The evaluation of these integration architectures were conducted through experimental simulation tests using OPNET.