Ad Hoc Network Services Based On Mobile Agents Drift

With the fast development of wireless communication technology, Mobile Ad hoc NETworks (MANETs) have attracted much more attention both in tactical battlefield and in civilian use, and offered more and more services. In most cases, these services execute their tasks on a particular node. But when the node hosting a certain service is busy or decreases in performance, it will lead to low service quality; and the service will be interrupted when the node is disconnected from network. Therefore, in these situations, we hope that the service can migrate to another node and continue to execute its task. For example, an arithmetic code designed to solve a certain problem can migrate to the node with better performance to finish its task; when the node hosting an information collecting service will leave the monitored area, to keep the collecting task continued, the service should migrate to the node which is still in that area. In these cases, service migration among nodes will highly improve the agility and validity of the services in ad hoc networks. It can not only improve the quality of service and guarantee the service continuation, but also can balance the load of nodes. This is a necessary and beneficial complement to today's services in ad hoc networks.Mobile Agent (MA) paradigm provides us with a research method to realize the service migration in ad hoc networks. After deep analysis of the problems about today's services deployed in ad hoc networks, this dissertation designs a service migratory solution based on Mobile Agent technology. It proposes a new novel service model—Mobile Service (MS) in ad hoc networks, and gives a detailed description about MS's deploying method. Its core idea is to build up a framework for service migration based on Mobile Agent platform, which provides MSs with back-up executing environment and manages all MSs. To assure the uninterrupted communication between MS and client after MS's migration, it also designs a communication mechanism.With deep understanding of the service migratory requirements in ad hoc networks, this dissertation describes the service migratory solution in ad hoc networks particularly, and sets up a service migration platform based on the Mobile Agent system—Aglets. At last, we execute a MS (File Information Collecting Service) in this platform. According to the performance of the nodes, this MS can migrate among them dynamically and maintain an uninterrupted communication with client. So, it proves that our service migratory solution in ad hoc networks is effective and feasible. Mobile Service is a new service model in response to the features of ad hoc networks. It expands and enriches the utility and flexibility of services in ad hoc networks, and has profound theoretical meaning and practical value.