Database architectures and location strategies for mobility management in mobile radio systems

With the increasing number of mobile service users, cellular systems must offer higher traffic capacities. Therefore, cells sizes are reduced which increases the mobility signalling load. Part of this signalling is due to handovers (''radio mobility'') and the other part to mobility management (''network mobility''). In this paper we combine location strategies and database architectures to evaluate their impact on user mobility management cost. Two location management strategies are studied: the classical strategy used in GSM, and the alternative strategy based on users' mobility patterns. The centralized, distributed and hybrid types of databases architectures are considered here and combined with the two location strategies. Evaluation of different scenarios is done analytically. We show that, for the values used here, the hybrid database architecture combined with the alternative strategy allows to save more than 50% of the costs involved by the classical strategy combined with the centralized database architecture (which last combination is used in most of current cellular systems).