Coding-Based Contention Forwarding Protocol for Cyber-Physical Systems

The COPE network coding system proposed and implemented by Sachin Katti et al. exploits a physical-layer broadcast characteristic and network coding technique. Though previous studies focus on estimating COPE performance or proposed methods to improve it, there is currently no effective approach to increase network coding throughput. Network coding techniques can be applied to high-traffic network environments, but a large number of transmissions leads to a high collision rate. This paper proposes three mechanisms to exploit the characteristic of network coding. Applying intra-node contention, inter-node contention, and coding-based contention forwarding protocol provides a packet with more coding opportunities from the source to the destination. This system also considers the issue of multiple access categories in large wireless environments, such as a Cyber-Physical System. Simulation result shows that two-stage contentions and coding-based contention forwarding can significantly increase throughput in a network coding network.