A wireless data network that provides communications with a Point-to-Point Protocol (PPP) server is disclosed. A home network includes a home mobile switching center and a wireless end system, the home mobile switching center including a home registration server and a home inter-working function, the...http://www.google.de/patents/US6421714?utm_source=gb-gplus-sharePatent US6421714 - Efficient mobility management scheme for a wireless internet access system
