Asynchronous Checkpointing and Optimistic Message Logging for Mobile Ad Hoc Networks

In recent years the advancements in wireless communication technology and mobile computing fueled a steady increase in both number and types of applications for wireless networks. Wireless networks can roughly be classified into cellular networks which use dedicated infrastructure (like base stations) and ad hoc networks without infrastructure. A Mobile Ad Hoc Network (MANET) is a collection of mobile nodes that can communicate with each other using Multihop wireless links without using any fixed infrastructure and centralized controller. Since this type of networks exhibits a dynamic topology, that is, the nodes move very frequently, it is hard to establish some intermittent connectivity in this scenario. Fault tolerance is one of the key issues for MANETs. In a cluster federation, clusters are gathered to provide huge computing power. Clustering methods allow fast connection and also better routing and topology management of mobile ad hoc networks (MANET). To work efficiently on such systems, networks characteristics have to be taken into account, for e.g. the latency between two nodes of different clusters is much higher than the latency between two nodes of the same cluster. In this paper, we present a message logging protocol well-suited to provide fault tolerance for cluster federations in mobile ad hoc networks. The proposed scheme is based on optimistic message logging.