Deterministic Scheduling Methods with Conflict Degree and Proportional Deadline in Industrial Wireless Sensor Networks

Abstract

Deterministic scheduling is a key technology in industrial wireless sensor networks. It aims to complete the end-to-end transmission of each data flow within the required deadline by allocating the time slot and channel resources in the networks, so as to meet the real-time communication demand of industrial control network. Based on the deterministic scheduling technology, considering the number of link conflicts and deadline requirements, two scheduling algorithms, called the ratio of local link conflict degree to deadline and the ratio of path-link conflict degree to deadline are proposed. The first algorithm calculated the number of conflicts in the release state of the data flows, the ratio of the remaining unscheduled links of the data flows to the deadline in each slot, and then completed the networks scheduling according to the size of the ratio. It can obtain a higher scheduling ratio with lower complexity, and is suitable for networks with limited computing resources. The latter further improves the scheduling ratio of the networks by considering the conflicts of all unscheduled links on the entire transmission path of the data flows, and can be used in networks with rich computing resources. The effectiveness of the two proposed deterministic scheduling algorithms is verified by the simulation results.