Sensitivity study of location management area partitioning in cellular communication systems

The problem of finding the appropriate location area (LA) partitioning that minimizes the total signaling cost in cellular radio network location management is important since it maximizes the bandwidth available for revenue-generating services. All of the existing work involves finding the solution for a given fixed set of parameters. However, we feel that the result obtained is generally insufficient to the problem, since values taken by the parameters of a mathematical programming model at the time of its formulation are only estimates of real-life conditions. The optimal solution should instead be treated as a starting point for further sensitivity study of the problem. This is particularly important in helping to identify any vast deviation of the parameters that affect the system performance. Such a study is still lacking for in cellular communication systems, which normally have their design parameters varying or fluctuating due to unpredictable human movements. In this paper, we present the sensitivity study on the static location management design of a GSM cellular communication system which is modeled as a non-linear programming problem. We investigate the sensitiveness of the total signaling cost with one of these parameters: cell crossing rates, call arrival rates, paging and update costs, deviates from the design value. The bounds for these parameters within which the parameters can change but the LA partitioning remains still optimal are presented.