A design of multi-layered location registration areas in microcellular systems

Multi-layered location registration areas are considered to minimize the co ntrol signals at boundary cells in the microcellular systems. The decision of multi-layered location registration (LR) areas is formulated as an integ er programming problem by examining the regional subscriber densities, traf fic flows and call arrival rates. By relaxing the constraints of forward an d reverse control channels the problem is decomposed into a number of subpr oblems each of which corresponds to a layer. Each subproblem is solved via a modified graph partitioning algorithm. Feasible LR areas are obtained by considering the two relaxed constraints. Computational experiments are perf ormed in a system with 80 microcells to investigate the performance of the proposed multi-layer scheme. The simulation results indicate that the two-l ayer scheme generally outperforms the one-layer and three-layer methods in view of control signals.