Abstract
A SIM-based authentication is preferable for GPRS operators for the integrated GPRS-WLAN networks. It requires WLAN system process the GPRS-based authentication and transport the GPRS authentication messages back to the GPRS networks. This thesis presents an alternative WLAN-centric approach based on the perspective of WLAN providers. The proposed WLAN-centric authentication instead leverages the widely used WLAN-based authentication and requires the GPRS operator install an AAA (Authentication, Authorization, and Accounting) server. The proposed approach is based on loose coupling architecture. In addition, it assumes that the GPRS and WLAN systems are two parallel networks and work independently. Scenarios for GPRS subscribers and WLAN users roaming between two systems are detailed. The proposed approach is implemented in a GPRS and WLAN testbed, which comprises most of the components in GPRS and WLAN systems. Performance analysis based on empirical experiments is also discussed.