A METHODOLOGY FOR THE PERFORMANCE EVALUATION OF DATA QUERY STRATEGIESIN UNIVERSAL MOBILE TELECOMMUNICATION SYSTEMS (UMTS)

The anticipated emergence of third-generation mobile systems, referred to as universal mobile telecommunication systems (UMTS), raises the p roblem of reconsidering the design of the databases destined to contai n the user information, In particular, it is expected that the key con cepts of the new database architectures will be high distribution and fast updating of information. So far, the problem of determining the m ost appropriate distributed database (DDB) architectures for third-gen eration mobile systems has not been widely dealt with in literature, T his paper presents a methodology for evaluating hierarchical DDB archi tectures by means of an analytical model of the data querying operatio n, This methodology allows for structural alternatives, differing on a ccount of the number of levels and branches in the hierarchy, to be ev aluated in terms of query loads and mean response times, according to a given user mobility characterization and a given search protocol ope ration, By way of illustration, the paper discusses a case study, conc erning a query operation arising from a location updating procedure an d applied to a hierarchical tree-like DDB in which some structural alt ernatives are considered.