Computing Coding Solutions for Opportunistic Network Coding Used in Wireless Mesh Networks

Wireless mesh networks represent a key architecture on which several communication systems are relaying. Implementations of these networks which apply contention-based user access control and classical routing techniques suffer throughput limitations and scale poorly with the number of network nodes. One of the solutions proposed to overcome the throughput limitations and improve scalability is the use of network coding (NC) techniques. This paper proposes three algorithms for computing the coding solutions in the network’s nodes when opportunistic NC techniques are employed. The proposed algorithms, applicable in fixed or nomadic networks, rely on the availability of the topology information in the relay nodes which perform NC coding and are strongly related to the transmission buffer management and neighbor nodes selection algorithms. The first two algorithms have lower complexity and the potential to be used in time constrained applications, while the third algorithm is a brute force like one, which can exploit most of the coding opportunities offered by the mesh architecture. Computer simulations performed on test scenarios with large number of nodes and data flows show that all proposed algorithms can achieve significant throughput improvements compared to the uncoded transmissions.