Delay-Controlled Bidirectional Traffic Setup Scheme to Enhance the Network Coding Opportunity in Real-Time Industrial IoT Networks

Recently, network coding has become a promising transmission approach to support high throughput and low latency in distributed multi-hop networks. In this paper, we develop a delay-controlled distributed route establishment scheme that can provide maximal bidirectional transmission to enhance network coding gain while satisfying a time-critical route setup. The scheme is called network coding-aware delayed store and forwarding (NC-DSF). It delays the received route information packets before forwarding them according to the link status and network topology. We propose a tight delay function derived using a strict end-to-end delay bound for delay control. Subsequently, we suggest a relaxed delay function derived using realistic and practical conditions. Finally, we propose a load-weighted delay function considering the trade-off between bidirectionality and network-load balancing. The simulations confirm that the proposed scheme offers increased throughput and decreased latency in mesh and random multi-hop networks. The proposed transmission scheme, NC-DSF, can be efficiently employed in future industrial internet of things networks requiring a time-constrained route setup, high throughput, and low latency.