Performance Analysis of UMTS and WLAN Interworking with Multi-service Load

Future generation wireless networks are expected to support multiple wireless access technologies, each with different access bandwidth and coverage range. Two of these technologies include Universal Mobile Telecommunications System (UMTS) and IEEE 802.11 Wireless Local Area Networks (WLANs). The internetworking architectures that enable interoperability between 3G (UMTS) and WLAN networks was done by connecting them at the Gateway GPRS Supporting Node (GGSN) node and evaluated via simulations using OPNET. In the GGSN integration, whenever a MN in a WLAN network wants to communicate with User Equipment (UE) in the UMTS network, it does so through the GGSN node. The UE in the UMTS network first activates the Packet Data Protocol (PDP) context that it wants to use. This operation makes the UE known to its GGSN and to external data networks, in this case, the WLAN network. Various simulations are done to measure the various application delays involved when users directly communicate across the UMTS-WLAN networks without actually accessing any external data networks. The performance evaluations on the various interworking architectures are done and the delays and other parameters involved when user data is exchanged across the UMTS and WLAN will be compared. The application types used included: FTP, HTTP and VOIP. The parameters measured include load, throughput end-to-end packet delay, file download response time, HTTP page response time.