Analytical results for optimal choice of location update interval for mobility database failure restoration in PCS networks

When the location information for a mobile user in the Home Location Register (HLR) is corrupted or obsolete, the new arriving calls to the user may be lost. In order to minimize the effect of such HLR mobility database failure, a location update scheme called period location updating is proposed, and the cost analysis is performed. Analytical results for the failure recovery time distribution and the average number of call losses, which are crucial for cost analysis, are presented. The optimal location update period is given analytically as a function of other traffic parameters. This optimal choice of location update period lays the foundation for the adaptive adjustment of the location update period in failure restoration for PCS networks.