Link Quality Estimation in 6TiSCH Networks: A Review

The Industrial Internet of Things (IIoT) uses reliable wireless network solutions such as Time-Slotted Channel Hopping (TSCH) to integrate cyber-physical systems with industrial environments via the IPv6 over TSCH (6TiSCH) protocol stack. The quality of 6TiSCH radio links affects the network performance significantly in terms of energy consumption, latency, and reliability. Therefore, accurate link quality estimation (LQE) is an important feature influencing the design and optimization of higher-layer protocols. Indeed, accurate link quality estimation helps predict link failure and avoid packet loss, which ensures good routes and better quality of service. This paper surveys and discusses existing link quality estimators used in 6TiSCH networks and proposes a taxonomy that captures the fundamental differences among them. Besides, comparisons between different LQE solutions are performed to provide a comprehensive view of the state-of-the-art and useful insights. The paper ends by highlighting open problems in this active area of research.