Practical considerations on end-to-end cellular/PWLAN architecture in support of bilateral roaming

To offer a more efficient wireless data access service than 2G/2.5G/3G networks, public WLAN (PWLAN) stands in a predominant position to embrace the wireless broadband era. Reusing existing mechanisms for user authentication, access control, billing and roaming handling procedures in the mobile territory to construct a complementary network, PWLAN attracts the attention of cellular operators. We investigate a practical end-to-end PWLAN architecture capable of using 2G/3G SIM-based authentication for current mobile users and of simultaneously carrying out Web-based authentication for ordinary users without SIMs (subscriber identity modules). Additionally, we give consideration to confederating various wireless Internet service providers (WISPs) by the RADIUS based roaming mechanism and leverage the existing cellular resource. The proposed considerations and guidelines provide a baseline skeleton for building an extendable and flexible cellular/PWLAN architecture.