Performance of an Efficient Scheduling Approach to Network Coding For Wireless Local Repair

—We propose a new XOR based scheduling algorithm for network coding in cooperative local repair. The algorithm makes use of knowledge of the packets availability at neighboring nodes to improve the overall network throughput. In our proposed algorithm, we use network coding to determine which node should transmit and in which time slot (sequential MAC) that would provide the best improvement. The proposed algorithm proceeds in three phases. First, the nodes exchange their packet's availability vectors. This is followed by a short period of distributed scheduling, during which the nodes execute the processing algorithm, developed to minimize the total transmission time. In the third phase, nodes transmit the encoded packets as per the decision of the scheduling algorithm. The upper bound on the improvement factor is also derived. In addition, we study the effects and trade-offs of file sizes, processing delays, number of users and packet availabilities. In the sequel, we show the favorable effects of file segmentation. Simulation results show improvement in the system throughput and in the processing delay of the proposed algorithm. These results also show that the improvement factor of the proposed scheduling algorithm is close to the upper bound.