Delayed group registration scheme in group location tracking

In the conventional group location tracking (GLT) scheme, a mobile station (MS) performs a group location registration immediately after getting on a transportation system (TS), which is, however, unnecessary if the MS gets off the TS without any location area (LA) update. A delayed group registration scheme is proposed in order to avoid unnecessary group registrations and the resulting group registration cancellations, which take a major proportion in the total signalling cost of the GLT scheme. The result shows that the proposed scheme significantly outperforms the GLT scheme from the aspect of total signalling cost.