A Fuzzy Distance-Based Location Management Scheme for PCS Networks

It is well-known that, among dynamic location management schemes, the lowest total signaling cost is achieved by the distance-based scheme, which invokes a location update when the moving distance of a mobile terminal measured in number of cells exceeds a predefined distance threshold. The cost performance of the distance-based scheme is highly dependent on the distance threshold, as the paging cost increases and location update cost decreases with the distance threshold. Hence, how to choose a suitable distance threshold is critical for a distance-based scheme to be effectively and efficiently applied. In this paper, a fuzzy distance-based location management scheme (FDLMS) is proposed, which employs a fuzzy logic controller to dynamically adjust the distance threshold for each mobile terminal so that optimal or near-optimal cost performance can be obtained regardless of the mobile terminals´ changing mobility and traffic patterns. Simulation results are presented to compare the cost of FDLMS with that of distance-based schemes with different fixed distance thresholds