Autonomous and traffic-aware scheduling for TSCH networks

Abstract

Abstract-Wireless Sensor Networks (WSNs) have been recognized as a promising communication technology for smart grid monitoring and control applications. However, the deployment of WSNs in smart grid brought new challenges that pertain to the harsh electrical grid nature, and the different and often contradicting communication requirements of smart grid monitoring applications. MAC protocols play a crucial role to meet the reliability and latency requirements of WSN-based smart grid communications. In particular, the IEEE 802.15.4 TSCH (Time Slotted Channel Hopping), the latest generation of low-power and highly reliable MAC protocols, orchestrates the medium access according to a time-frequency communication schedule. However, TSCH specification does not provide any practical solution for the establishment of the schedule. Orchestra is a recent scheduling solution for TSCH that brings significant advantages such as, the use of simple scheduling rules, the low signaling overhead, and the high delivery ratio. Despite its unique features, Orchestra has the limitation of computing the TSCH schedule at each node independently from its traffic load, which can drastically affect the communication delay. This limitation makes Orchestra not sufficiently convenient for several delaysensitive smart grid applications. Further, the current TSCH specification does not support traffic differentiation (i.e. handle all packets equally regardless of their criticality levels). In this paper, we propose an enhanced Orchestra-based TSCH protocol, called e-TSCH-Orch, that dynamically adjusts time slots assignment according to traffic load and criticality level. The performance analysis of e-TSCH-Orch shows that it significantly reduces the communication delay compared to the original Orchestra-based TSCH, while preserving the low signaling overhead and the high packet delivery ratio.

An Empirical Survey of Autonomous Scheduling Methods for TSCH

“…For example, let us assume a TSCH network that uses 15, 11, 19, 13 as its FHS. Then, the FHS of channel offset 0 will be 15,11,19,13, that of channel offset 1 will be 11,19,13,15, and that of channel offset 2 will be 19, 13, 15, 11. Thereby, the channel to be used at ASN time slot is:…”

“…However, their simplicity can be traded off in order to achieve better performance in networks where the packet rate cannot be reliably known at the time of deployment, or is significantly different on different links or in different periods. Consequently, in adaptive approaches [15], [18], [19], the nodes typically start with a purely autonomous schedule, which is subsequently modified and improved through a distributed negotiation process. Table 1 lists the main autonomous scheduling approaches.…”

“…However, it achieves higher packet reception ratio and lower latency at the same energy efficiency compared with Orchestra. e-TSCH-Orch [19] schedules the slotframe based on the Orchestra. The authors of e-TSCH-Orch also points out that Orchestra provides fixed schedule based on the number of routing-layer neighbor.…”

An Adaptive Schedule for TSCH Networks in the Industry 4.0

“…In the state of the art, many researchers have investigated the schedule of network communications to meet some requirements in terms of latency [5], [6], energy efficiency [7], [8], reliability [9], or scalability [10], etc.. The solutions proposed are either centralized like in [11], [12], distributed like in [13], [14] or autonomous like in [15]. The performances achieved strongly depend on the assumptions made concerning the network usage conditions (e.g.…”

OSCAR: An Optimized Scheduling Cell Allocation Algorithm for Convergecast in IEEE 802.15.4e TSCH Networks

“…A certain number of studies, which aims at the development of these algorithms, have emerged to try to answer these different challenges. These scheduling algorithms can be classified either as centralized [ 7 , 8 , 9 ], distributed [ 10 , 11 , 12 , 13 ], or autonomous [ 14 , 15 , 16 , 17 ]. Centralized scheduling allows a central entity collect all the information of the network, then it calculates the link schedules.…”