Greedy strategy for network coding based reliable broadcast in wireless mesh networks

Reliable broadcast is an important communication primitive for wireless mesh networks, which has many applications such as multimedia services and software upgrade. Recently, network coding is introduced into reliable broadcast to enhance the throughput of data transmissions. Existing network coding based reliable broadcast schemes, such as Pacifier and R-Code, fail to take advantage of the unique characteristic of reliable broadcast or the broadcast nature of wireless transmissions, which leads to redundant transmissions and performance degradation. In this paper, we propose a greedy strategy for network coding based reliable broadcast, which is called GreedyCode. GreedyCode opportunistically selects the forwarders with the highest transmission efficiency to transmit the encoded packets while the neighbors just listen. In order to measure the efficiency of broadcast transmission of a node, we also define a metric named One-hop Broadcast Throughput (OBT), which considers not only the current reception status of the destinations but also the quality of the broadcast link. Because GreedyCode only needs the information of its one-hop neighbors, so it can be distributed realized. The simulation results show that GreedyCode achieves 100% packet delivery ratio (PDR) and significantly reduces the number of transmissions and the broadcast delay.