802.11 based Wireless-LAN and UMTS interworking: requirements, proposed solutions and open issues

A consequence of the fast spreading of WLAN implementations aiming at offering communications capability in public hot-spot locations, such as airports and stations, is the growing need of studying possible WLAN and UMTS cellular network integration solutions in a unique augmented infrastructure. In this paper the prospects of an efficient interaction between UMTS and 802.11-based networks are analysed in view of the achievement of a ‘‘Global IP’’ idea. The authors intention is to give a picture of the current standardisation activities in this field, to enable the reader to better understand what has been done and what can still be done towards an efficient joint exploitation of both technologies. Therefore, possible scenarios of WLAN–UMTS interconnection/integration are investigated to point out requirements, enabling technologies, proposed solutions and open issues. Furthermore, for some of the scenarios highlighted, preliminary studies of the authors on AAA (Authentication, Authorisation and Accounting) and QoS management are presented.