An Integrated Approach to Efficiently Providing Fault Tolerance for Mobile Multicast

The paper presents an efficient approach to providing fault-tolerant capability for mobile multicast. In multicast communication, packets can be concurrently sent from a source node to all members by a multicast tree. If failures occur in nodes (links) of the multicast tree, the faulty tree will be partitioned into several disconnected subtrees. For the subtrees without the source node, it cannot deliver multicast packets to the members under its delivery range again. The main goal of this paper is to make members immune from failure affection. The proposed fault-tolerant approach contains two schemes. The first scheme uses the redundant resources of a mobile network to reconnect all the disconnected subtrees. Compared to previous approaches, the first scheme does not generate loops. In addition, it can control the maximum delivery delay of the new reconnected multicast tree. The second scheme is initiated when the first scheme cannot reconnect all the subtrees. It extracts the failure-free part of the faulty multicast tree to form a safe multicast subtree. Then, multicast packets are only delivered along the safe multicast subtree to all the members. Unlike the first scheme, the second scheme is not based on the network topology support to achieve fault tolerance. Finally, simulations are performed to compare the proposed approach and previous approaches in terms of the fault-tolerant capability and various performance overheads.