Performance analysis of location updating in UMTS services deployed in an urban area

Design of distributed databases (DDBs) destined to store user information in third-generation mobile systems such as UMTS has not been widely dealt with. Nevertheless, the problem of determining the most appropriate DDB architectures for UMTS is critical due to the anticipated requirements of high distribution and adaptability of information. This paper presents an algorithm which allows us to evaluate different alternatives of hierarchical DDB architectures, in terms of query loads and average search times. The algorithm is based on an analytical model which puts no constraints on either the DDB structure arrangement or the user mobility characterization. The paper also discusses a real, significant case study, concerning a query operation arising from a location updating procedure performed on a DDB covering a typical urban area.