The Case for FEC-Based Reliable Multicast in Wireless Mesh Networks

Many important applications in wireless mesh networks require reliable multicast communication. Previously, forward error correction (FEC) techniques have been proved successful for providing reliability in the Internet, as they avoid the control packet implosion and scalability problems of ARQ-based protocols. In this paper, we examine if FEC can be equally efficient wireless mesh networks. We implement four reliable schemes initially proposed for wired networks on top of ODMRP, a popular unreliable multicast routing protocol for wireless networks. We compare the performance of the four schemes using extensive simulations. Our results show that the use of pure FEC can offer significant improvements in terms of reliability, increasing PDR up to 100% in many cases, but it can be very inefficient regarding the number of redundant packets it transmits. Moreover, a carefully designed hybrid protocol, such as RMDP, can maintain the same high level of reliability while improving the efficiency by up to 38% compared to a pure FEC scheme.