Limitations of static autonomous scheduling for TSCH protocol and advances in adaptive scheduling

The demand for reliable and energy-efficient low-power wireless network protocols is growing up steadily with the flourish of the emerging Internet of Things (IoT) applications. The Time Slotted Channel Hopping (TSCH), part of the IEEE 802.15.4 standard, represents the latest generation of low-power and highly reliable MAC protocols. It orchestrates the medium access according to a time-frequency communication schedule. Several scheduling algorithms have been introduced for TSCH. In contrast to centralized and distributed scheduling approaches, autonomous scheduling does not occur any signaling overhead and appears as a promising approach. In this study, we review autonomous TSCH scheduling algorithms, including static and recently proposed adaptive algorithms. Then, we investigate, on a real-world testbed, the performance of representative static autonomous scheduling schemes for TSCH protocol. Experimental results show that they suffer from high number of queued packets and buffers overflow, which increase the network delay and decreases the delivery ratio. Finally, we qualitatively compare and discuss the performance of recent adaptive autonomous TSCH scheduling algorithms, showing that research on adaptive autonomous TSCH scheduling still has open issues.