Modeling and Analysis of Forwarding and Resetting Strategies for Location Management in Mobile Environments

Abstract

“Forwarding and resetting” is a technique for reducing the signaling cost of the network for location management of mobile users who can move from one place to another while being called. With forwarding, the system follows a chain of databases to locate a mobile user; with resetting, the system updates the databases in the chain so that the current location of a mobile user can be known directly without having to follow a chain of databases. In this paper, we formulate the problem of finding the best time to perform resetting as an optimization problem. We consider the signaling network as a server and the operations for which the server must provide services to a mobile user include “updating the location of the user as the user moves across a database boundary” and “locating the user.” We use a Markov chain to describe the behavior of a mobile user and analyze the best time when forwarding and resetting should be performed in order to optimize the service rate of the mobile network with respect to the above two types of operations. We demonstrate the applicability of our approach with a case study and provide a physical interpretation of the result. Index Terms － Mobile computing, location management, forwarding and resetting, Markov models, performance evaluation, distributed systems.