Abstract
Authentication and roaming are critical issues for wireless data applications. Due to the strong points of mobile cellular network - large subscriber base, secure authentication mechanism, well established roaming agreements and well defined service entries -, it is favorable to integrate the authentication mechanism of WLAN into that of mobile cellular network. For GSM/GPRS cellular systems, the subscriber identity module (SIM) card is used for user identification, authentication and message encryption. Thus, it is feasible to authenticate the subscribers in WLAN via exchanging the authentication information between mobile cellular network and subscribers' SIM cards. In this work, the issue of SIM-based subscriber authentication for WLAN is investigated. By utilizing the GSM authentication information, an authentication mechanism is proposed and an experimental system is implemented.