Failure Recovery of HLR Mobility Databases and Parameter Optimization for PCS Networks

In PCS networks, new calls to a portable may be lost due to incorrect location information (due to either data corruption or outdated records) in the home location register mobility database. Such database failures can be recovered through the portable's registration when it initiates a call, through required registration (or deregistration for some systems) as it crosses the location area boundary, or through active location updates. In this paper we analyze the active location update scheme and failure restoration under several different mobile traffic distributions, propose a framework for the performance evaluation of this scheme, and present general analytical results for cost analysis. Through a systematic study, we show that there always exists an optimal choice of location update period to minimize the total cost, one that represents the tradeoffs between location update frequency and call losses. Our results can be used to provide design guidelines for active failure restoration of mobility databases in PCS networks. 2000 Academic Press