A Model-based Beacon Scheduling Algorithm for IEEE 802.15.4e TSCH Networks

Time Slotted Channel Hopping (TSCH) is an emerging MAC protocol defined in the IEEE 802.15.4e standard. By combining time slotted access with multi-channel and channel hopping capabilities, it is particularly suitable for critical applications that require high reliability and deterministic latency. In this paper we focus on the formation process of TSCH networks. This relies on periodic advertisement of Enhanced Beacons (EBs), however, the standard does not specify any advertising strategy. By taking a theoretical approach, we first derive a general model of the network formation process and provide an analytical formulation of the average joining time (i.e., the time taken by a node to join the network). Then, we derive an optimal strategy for scheduling EB transmissions that minimizes the average joining time. Finally, we propose a new Model-based Beacon Scheduling (MBS) algorithm that approximates the optimal strategy in real networks. We evaluate the performance of MBS by simulation. Our results show that the proposed algorithm outperforms previous solutions present in the literature.