Deterministic Asynchronous Scheduling with Probabilistic Reliability Guarantee in Industrial Wireless Networks

Industrial Wireless Networks (IWNs) play a critical role in industry 4.0 applications. However, industrial control processes require deterministic data delivery with an extremely high reliability, which is challenging in harsh IWN environments. Existing scheduling schemes rely mainly on accurate global synchronization to ensure deterministic transmission, which incurs additional hardware cost and a large communication overhead. To eliminate the synchronization requirements, we propose an asynchronous scheduling model that supports arbitrary time offset between any node pairs. As finding a solution with a given reliability guarantee in this model is a NP-hard problem, we design a probabilistic algorithm based on the Monte Carlo tree search (MCTS) method to generate and verify feasible schedules. The simulation results show that E-MCTS is significantly better in transmission reliability if compared to the classic Monte Carlo tree search algorithm.