Research On Publish/Subscribe Self-reconfiguration Algorithm In Mobile Ad Hoc Networks

Publish / Subscribe (P/S) is an event-based communication model and has many advantages, such as asynchronous, multi-point communications. The static network P/S system has been well-studied and widely applied in finance, logistics, and so on. As the development of Mobile Ad-hoc Networks (MANETs) technology, the P/S system is deployed in MANETs. The dynamic topology of MANETs requires a Self-Reconfiguration algorithm with higher performance. Self-Reconfiguration has two parts: route repair in network layer and subscription reconfiguration in event notification layer. This paper researches the algorithms of route repair and subscription reconfiguration in P/S system.Firstly, several common route reconfiguration strategies in route repair are analyzed; Aiming at the high implementation cost of the Shortest Reconfiguration Path strategy, the Basic Reconfiguration Path strategy is proposed as its predigestion. Then the extending methods for routing protocol are designed to implement the two strategies, support local subscription reconfiguration and finally improve the whole performance of Self-Reconfiguration.Secondly, the local subscription algorithm deals with subscription list of node on reconfiguration path and make sure the subscription is consistent with network topology. The existing Asynchronous Subscription Reconfiguration method forwards too many messages and some unnecessary messages which increase the reconfiguration delay. In view of these problems, the following research work has done. By introducing All-Subscribe operation instead of Subscribe operation to exchange subscription, improve the Asynchronous Subscription Reconfiguration method and proposed the Subscription Reconfiguration Algorithm with All-Subscribe, which avoids mass message forwarding and processing. Then, a new Synchronous Subscription Reconfiguration method is proposed, in which private and intersection subscriptions have their own reconfiguration process. The Symmetrical and Continuous Synchronous Subscription Reconfiguration Algorithm are proposed based on the new method. The former aims at less message forwarding, while the latter aims at lower reconfiguration delay.Finally, A new content-based publish/subscribe routing protocol that supports Self-Reconfiguration in MANETs is proposed by integrating the traditional conent-based routing and the local subscription reconfiguration algorithm. Then we developed a publish/subscribe prototype system based on the new routing protocol and tested the performance of main algorithms in the new protocol. The test result shows the local subscription reconfiguration algorithm has light message forwarding and short reconfiguration time and is not influenced by the network scale. The research result of this thesis is valuable for popularizing the application of publish/subscribe system.