Group registration with distributed databases for location tracking in 3G wireless networks

The increase of subscribers in wireless networks has led to the need for efficient location tracking strategies. Location tracking is used to keep track of a Mobile Terminal (MT). The network retains the Registration Area (RA), where the MT last updated its location, so when an incoming call arrives for the MT, the network with the help of a location tracking strategy can find the area where the MT resides and then deliver the call. In this paper, we introduce a 2-level distributed database architecture combined with the Group Registration (GR) location tracking strategy to be used in 3G wireless networks. The GR strategy reduces the location management total cost, by updating the location of MTs in an RA with a single route response message to the HSS (Home Subscriber Server). More specifically, the IDs of the MTs newly moving into an RA are buffered and sent to the HSS for location updating in the route response message of the next incoming call to any MT in the RA. An analytical model is developed and numerical results are presented. It is shown that the GR strategy integrated with a 2-level distributed databases architecture in 3G networks can achieve location management cost reduction compared to costs of the distributed databases without the GR strategy and the GR strategy without distributed databases. Moreover, the proposed strategy results in small call delivery latency.