BIOS: Biogeography Inspired Optimal Scheduling Algorithm for TSCH Networks

IEEE 802.15.4e Time Slotted Channel Hopping (TSCH) standard has gained prominence in the Industrial Internet of Things (IIoT) research community due to its potency in improving reliability, providing low latency and low power consumption. In TSCH, a schedule orchestrates the communication in the networks between the nodes. The design and maintenance of the schedule are out of the standard's scope, and is open for implementation. In this paper, we address the design problem of an optimal scheduling algorithm in TSCH networks. We design a TSCH schedule inspired by a biogeographical aspect of bird flocking. Like bird flocks, which migrate to find a suitable habitat depending on several features like seasons, food availability, etc., a TSCH network can also end up in an optimal schedule for its dynamic requirements. With this motivation, we design a biogeography inspired optimal schedule (BIOS) for TSCH networks incorporating the features such as migration and mutation to learn the best schedule. We show that the proposed BIOS-TSCH schedule is also suited for the sporadic and dynamic networks. We evaluate the performance of BIOS-TSCH in terms of convergence, delay and radio duty cycle. We show that the proposed BIOS-TSCH schedule achieves an improvement of 60% in delay performance and up to 40% in energy efficiency compared to the minimal scheduling function.