Performance Evaluation of Recent Traffic-Aware Scheduling Functions for 6TiSCH Networks

In the Internet of Things (IoT), IEEE 802.15.4-2015 Time Slotted Channel Hopping (TSCH) is a promising link-layer protocol for low-power wireless communications. The IPv6 over TSCH (6TiSCH) architecture integrates this MAC layer into the IoT due to its outstanding reliability and energy-saving performance to promote the so-called Industrial IoT. Within the 6TiSCH architecture, communications resources allocation is managed by a Scheduling Function (SF) to support critical applications. The construction of an efficient SF is an active research area, and many SFs have been proposed in the last few years. However, SFs are not all adaptable to applications with varying traffic loads. This paper conducts a performance evaluation study of recent traffic-aware SFs and quantitatively compares A3 and CRSF; two recent traffic-aware schedulers with the Minimal Scheduling Function (MSF); a reference SF that was recently standardized. We discuss their ability to satisfy the requirements of critical 6TiSCH applications by ensuring low latency and a high-reliability. We also study their awareness of traffic changes. Obtained results show that these SFs are not robust enough against bursty traffic patterns, which witness the need to devise new solutions that better meet such requirements.