In wireless communication systems, the network keeps track of a user's location through an up-to-date user profile stored in various databases. A user profile contains not only a user's current location information, but also service information, such as billing and authentication. The cov- age area of an access network is divided into registration areas (RAs), and each RA is associated with a location database. The two basic op- ations in mobility management are location update and location lookup. When a user moves across the boundaries of these RAs, the network updates his location...

In wireless communication systems, the network keeps track of a user's location through an up-to-date user profile stored in various databases. A user profile contains not only a user's current location information, but also service information, such as billing and authentication. The cov- age area of an access network is divided into registration areas (RAs), and each RA is associated with a location database. The two basic op- ations in mobility management are location update and location lookup. When a user moves across the boundaries of these RAs, the network updates his location...