An Adaptive Distributed Scheduling Algorithm for IEEE 802.15.4e TSCH Protocol

Industrial Wireless Sensor Networks (IWSNs) can be flexibly deployed in industries with low cost. Thus, the industrial production process integrated with IWSNs can get more information to improve the performance of control and management. Due to the harsh environments and stringent reliability requirements in industries, Time-Slotted Channel Hopping (TSCH) is introduced in IEEE 802.15.4e-based wireless networks to improve their certainty and reliability. However, there is no explicit scheduling mechanism which should be made according to the industrial production requirements and the wireless environments. In this paper, the structure of transmission sequence of the TSCH networks is proposed and the adaptive scheduling algorithm is key of the structure. The scheduling algorithm takes the difference between the number of packets in the queue and the number of scheduled cells as the error of the incremental PID controller which can schedule the suitable number of cells to transmit the packets timely. When the quality of channels changes, each node can execute an adaptive channel selection procedure to predict the difference of using different channels. As a result, each node can dynamically select suitable channels to use. Simulations validate the effectiveness of the proposed scheduling algorithm.