Evaluation studies of DDB architecture with hierarchical structure

In this paper we analyse the performance of a distributed database (DDB) architecture for universal mobile telecommunication systems (UMTS), in the presence of location updating and interrogation mobility procedures. To that end, two data locating strategies have been considered; the R and the V strategies which determine the path to be followed by a query originated by a location updating or by an interrogation procedure. Concerning the geographical scenario, several suburban, urban and city center areas with different number of mobile users (MU) registered have been considered. During the rush hours (7 a.m.-9 a.m.), only location updating is taken into account and, the crossing rates between areas is counted. During the busy hour (11 a.m.-12 a.m.), only interrogation procedure has been assumed, under the hypothesis of uniform distribution of calls between MUs. The result of the study is that a trade off between R and V strategy is envisaged. While for location updating R strategy performs better that V strategy, for interrogation procedure V strategy provide better performance figures than R strategy