Information exchange in wireless networks with noisy transmission links

An information exchange problem is considered where there are a number of terminal nodes, each of which transmits a broadcast-encoded version of individual information streams uplink to a network hub node that in turn transmits a network-coded version of these information streams downlink in a single transmission broadcast to all of the terminal nodes. All uplink broadcast transmissions from the terminal nodes are sent over a shared wireless broadcast medium where terminal nodes can listen opportunistically to transmissions sent by neighboring terminal nodes to enable an opportunistic network coding scheme. All information streams are encoded into a stream of binary code bits. We assume that all transmission channels are binary symmetric channels (BSCs) and all decoding is performed in a maximum likelihood manner. A network coding scheme is devised for the special case of two terminal nodes where uplink broadcast transmissions are designed to maximize the reliable rate at which opportunistic listening by neighboring nodes is achieved while simultaneously reducing the downlink channel capacities required for reliable direct broadcast transmissions from the network hub to the terminal nodes. Channel capacity requirements are determined for all the transmission channels.