Joint Coding and Transmission Scheduling for Underwater Acoustic Networks

Efficient data broadcast is of critical importance for Underwater Acoustic Networks (UANs) since it provides essential services for various tasks. Due to the unique features of UANs including the long propagation delay, low bandwidth and high error probability, efficient data broadcast has been facing great challenges. In this paper, we study the problem of distributing data to a group of underwater sensor nodes in partially connected cooperative network using network coding. In such a scenario, the transmission conflicts occur from simultaneous transmissions of multiple nodes, where the scheduling decision should be made not only on the encoded packets but also on the set of transmitting nodes. We formulate the joint optimization problem over the set of transmitting nodes and the packet combinations with a conflict free graph model, which contains both coding conflict and transmission conflict. We also propose a heuristic solution for this setup by finding the maximum independent set in the conflict free graph. Simulation results show that our coding scheme significantly reduces the number of transmission slots.