Hücresel mobil bilgi sistemleri IN YERİ UPDATE ÜRETİM VE PERFORMANS ANALİZİ

The Global System for Mobile Communications (GSM) allows user universal and worldwide access to information and the ability to communicate with each other independently of their location and mobility. Tracking mobile users is one of the basic functions of the network system and one of the important issues in the design of a mobile computing system is how to manage the real-time locations of mobile clients. Most of the mobile computing applications are expected to support location-dependent continuous queries (LDCQs) in the near future and the result of a LDCQ depends on the current locations of the moving objects on which the query has been issued as well as the location of the mobile client, which issues the query. When the query is specified as continuous, the requesting client can get continuously changing result. In order to provide correct and timely results to requesting clients, the locations of moving objects as well as the locations of the requesting clients have to be closely monitored. The conventional database technology is not sufficient for processing of location-dependent continuous queries (LDCQs). In order to process LDCQs efficiently, a distance-based Adaptive Monitoring Method (AMM) was proposed in [LAM, ULUSOY, LEE, CHAN, Lİ, 2001]. The aim of AMM is to maintain the correctness of the results of query evaluation without significantly increasing the wireless bandwidth requirements. In this paper, we study how to generate location update with the distance-based update method in a GSM network. Extensive simulation experiments have been conducted to investigate the performance of AMM method in a GSM network.