University of California Santa Cruz Reliable Multicasting in Ad Hoc Networks

Reliable Multicasting in Ad Hoc Networks by Venkatesh Rajendran This thesis presents the Reliable, Adaptive, Congestion controlled multicasT protocol, or ReACT, designed to provide reliable and timely multicast delivery in a wide range of mobile ad hoc network (MANET) scenarios. ReACT combines source-based congestionand error control with receiver-initiated localized recovery. It demonstrates the importance of congestion control in wireless networks; even a simple stop-and-wait scheme significantly improves protocol performance. To recover from the different types of losses that may occur in MANETs, ReACT uses both source-based and local recovery. While the latter attempts to recover localized losses caused by transmission errors or “local” congestion, the former is only used when receivers experience “global” congestion. In this case, congestion control will also be triggered. Through extensive simulations, we evaluate ReACT’s performance and compare it against other reliable multicast mechanisms for a wide range of MANET conditions. Results show that ReACT is the best performer in terms of reliability when compared to the other protocols. Results also showcase the effect of ReACT’s local recovery mechanism which protects the source and prevents it from reducing the rate unnecessarily, thus achieving acceptable throughput. In our experiments we run ReACT over meshand tree-based multicast routing protocols to show that its performance is fairly insensitive to the underlying routing structure. To Mahima and Madhumita