Mobile agent location management in global networks

Mobility management is a necessity in highly dynamic and large-scale mobile agents network, especially in a multi-region environment in order to control and communicate with agents after launching. Existing mechanisms for locating mobile agents are not efficient as these do not consider the effect of location updates on migration time and produce network overload. A location management protocol consists of location updates, searches and search updates. An update occurs when a mobile agent changes location. A search occurs when a mobile agent needs to be located. A search–update occurs after a successful search. This paper presents a hierarchical model for location management of mobile agents in global networks. Three protocols are developed, namely search, update and search-update. The location management technique uses one combination of search, update and search-update protocols throughout execution. Three cases are considered for Update and Search-Update Protocols. Thus nine combinations of location management protocols are generated, from which an agent can dynamically select one as per requirement, to communicate with other agents on the global network. We have implemented these protocols on the PMADE system developed at IIT Roorkee, to evaluate the performance of different protocols for various communication and mobility patterns. Results indicate that performing search –updates significantly reduces the message overhead of location management.