Multicast Routing Protocol with Low Transmission Delay in Multi-rate, Multi-radio Wireless Mesh Networks

With recent advances in wireless technology, the ability to use multiple transmission rates and multiple network interface cards (radios) in wireless networks has been widely recognized. In this paper, Multi-Rate and Multi-Radio (MR2) characteristics are exploited to reduce end-to-end transmission delay for reliable multicasts. To achieve this goal, a new routing metric, MR2_ETT, is introduced. It accounts for the link transmission time by considering the usable number of radios and the transmission rate on the link. This metric is used in a routing protocol that is also proposed in this work. The routing protocol, termed Multi-rate Multi-radio On-Demand Multicast Routing Protocol (MR2_ODMRP), makes ODMRP suitable for a MR2 environment. Simulation results show that MR2_ODMRP outperforms ODMRP in multi-rate or multi-radio wireless mesh networks.