The throughput benefits of network coding for SR ARQ communication

Network coding can greatly influence the performance of flow control schemes. In this paper, the throughput of end-to-end Selective Repeat (SR) Automatic Repeat request (ARQ) of an intermediate communication link is investigated based on the Network Coding (NC) technique. Through MATLAB SimEvents® Simulink, we shall show that the throughput performance is sensitive to a number of the node incoming links and the available bandwidth at which the channel is operating. The throughput performance is studied as a function of the factor a, which represents the ratio of the propagation time to the packet transmission time. For a low bandwidth error-free unicast, NC showed a throughput improvement of between 100% and 400% when a is high, and between 1% and 5% for a low value of a, depending on the number of the incoming node links. In erroneous scenarios, the comparative results show that NC lends itself perfectly to fulfilling between 22% and 40% throughput achievement gain over the traditional SR ARQ for a small value of a and Packet Error Rate (PER) equal to 0.01. Furthermore, the improvement reaches between 47% and 153% if the channel is susceptible to a PER of 0.1.