Locating Mobile Agents in a Wide Distributed System: A Dynamic Approach

Managing location information of mobile agents (MAs) is an important issue in MA based mobile computing systems. There is a tradeoff between location update effort (when an agent moves) and agent finding effort. In this paper we present a dynamic location management strategy that has the following features: (i) all location servers (LSs) need not maintain location information of every MA, (ii) a coterie based approach is adopted for location update and find, (iii) every agent move does not result in location updates, (iv) location updates are done at a subset of LSs, (v) a subset of LSs are queried when a MA is to be located, (vi) the set of LSs, corresponding to a MA, for location update and find operations is dynamic, (vii) the dynamic nature of these sets helps alleviate situations of heavy burden on some LSs, when a large number of MAs are concentrated in a small geographical area. Thus, location management is done efficiently, and responsibility is shared fairly among LSs.