Computing and Ad Hoc Communications. May 2007. Resilient-ODMRP: Resilient On-Demand Multicast Routing Protocol

ODMRP (On-Demand Multicast Routing Proto-col) [5] [7] [1] is a popular multicast protocol for wireless ad hoc networks. The strengths of ODMRP are simplicity, high packet delivery ratio, and non-dependency on a specific unicast protocol. ODMRP floods a route request over the entire network to select a set of forwarding nodes for packet delivery. However, a single forwarding path is vulnerable to node failures, which are common due to the dynamic nature of mobile ad hoc networks. Further-more, a set of misbehaving or malicious nodes can create network partitions and mount Denial-of-Service (DoS) attacks. We propose a ODMRP-based wireless multicast protocol named Resilient-ODMRP that offers more reliable forwarding paths in face of node and network failures. A subset of the nodes that are not on forwarding paths re-broadcast received packets to nodes in their neighborhoods to overcome perceived node failures. This rebroadcasting creates redundant forwarding paths to circumvent failed areas in the network. Each node makes this forwarding decision probabilistically. Our simulation results indicate that Resilient-ODMRP improves packet delivery ratio with minimal overheads, while retaining the original strengths of ODMRP. 1