Modeling Location Management in Personal Communications Services

Abstract

This paper presents a realistic modeling framework for ev aluating the performance of location management schemes in PCS networks. The framework captures complex human behaviors and has been v alidated through analysis of actual call and mobility data. Simulation results, showing the performance of IS-41, are presented. I. Introduction Personal Communications Services (PCS) [2] presents many challenging problems in network data management [6;18]. A key problem in this area is location management. Location management refers to accessing and maintaining user information for call routing purposes. Important per-user information, such as current location, authentication information, and billing information, are stored in user profiles. From an operational perspective, location management relies on two functions: profile lookups and profile updates. The performance of any location management scheme is a function of the underlying database architecture and the location management algorithms. Performance variables of interest are: profile lookup and update response times, memory cost, and system equipment price. Previous studies [10] have shown that for projected numbers of PCS users, existing location management standards, IS-41 [4;11] and GSM [12], will incur a large increase in database loads over the current levels. In recent years, many sophisticated location management schemes [7;14] have been proposed to reduce profile lookup and update response times and signaling traffc. These methods utilize techniques such as data replication and caching. It is important to note that actual performance of these proposals depends strongly upon user behavior.