Implementation of a Centralized Scheduling Algorithm for IEEE 802.15.4e TSCH

Abstract

IEEE 802.15.4e Time Slotted Channel Hopping (TSCH) is an important standard in the actual scalable Internet of Things (IoT), to habilitate deterministic low-power mesh networking. In TSCH, scheduling can be distributed or centralized scheduling. In this paper we describe the implementation of a centralized link scheduling for IEEE 802.15.4e TSCH based industrial Low Power Wireless Networks, known as Path Conflict free Least Laxity First (PC-LLF) algorithm in Contiki OS, a real time operating system for wireless sensor by using RPL protocol for network topology construction. PC-LLF prioritizes the assignment of the communications resources for each transmission. For each node to know its assigned cell in the schedules, we implemented a method to broadcast the schedule information packets to all transmissions generator (nodes) with the aim to reduce packets collision and loss. We compared our method with the broadcast of the same packet by Minimum Schedule Function (MSF) and the results show that our method performs better than the MSF and use less number of packets messages than other CoAP and OCARI broadcasting method. The implementation devices are Texas instruments CC 2650 Launchpad. The implementation aim is to make a real IoT network running a centralized scheduling algorithm of TSCH which can be effectively applied in the industrial networks and the results proved that.