Genetic algorithm based optimization for location update and paging in mobile networks

Abstract

When a call to a Mobile Terminal (MT) arrives, the network must locate the microcell where the MT is currently residing. The tracking problem is handled by two operations - Location Updating and Terminal Paging. The total cost per call is the sum of the cost for these two operations. It is difficult to optimize the total cost by classical calculus based techniques, as the expressions become very complex to handle. In this paper the total cost is optimized by finding the optimum distance threshold, value of the optimum distance required for a location update. Genetic Algorithm is proposed for optimization. Hexagonal cell structure and Shortest Distance First (SDF) algorithm are assumed for modeling. Effects of parameters - call to mobility ratio, maximum paging delay, cost ratio of location update to paging on optimized cost value are studied. The optimum cost per call is found to decrease for higher call to mobility ratio and also for larger paging delay. As the cost ratio of location update to paging increases the optimum cost increases. However the cost is found to be relatively less influenced by the statistical distribution of cell residence time. © Springer-Verlag 2004.