Opportunistic Forwarding of Network-Coded Multicast Traffic in Wireless Sensor Networks

Wireless sensor networks (WSN) typically rely on application-specific tree-based communication topologies between source and sink nodes to transmit application specific messages. In this paper, the OCSSIM communication scheme is proposed to realize multicast communication for multiple applications with coinciding transmissions between any number of source and sink nodes. With often changing sink and source roles, WSNs are prone to perpetual changing topologies, causing overhead for continuous routing updates. Instead of applying an additional routing scheme, OCSSIM exploits overhearing in wireless communication and uses opportunistic multipath-forwarding of network coded messages between neighbor nodes. Therefore, mechanisms are introduced to prioritize messages, reassemble coded messages on intermediate nodes and acknowledge transmissions implicitly.