Group location management for transportation systems in wireless cellular systems

A location tracking scheme called as a group location tracking (GLT) is proposed to reduce the location update cost for terrestrial transportation systems (TSs) in personal communication networks. To provide user mobility in a TS, we introduce two new concepts, virtual visitor location register (VVLR) and representative identity (RID). A VVLR is used to provide current location of a TS and an RID of a TS is used to represent a TS and the group of all users on the TS. When a TS moves into a new registration area, the GLT scheme based on an RID of the TS and a VVLR updates location information by a group location update request message instead of individual location update request messages generated by each user in the TS. We analyze the performance of our proposed scheme in view of signaling load and call delivery failure. Compared with the IS-41 location tracking scheme, the GLT scheme significantly reduces frequent location updates caused by the high mobility of a TS and a large number of users in a TS.