Optimization of packet transmission scheduling and node parent selection for 802.15.4e Time Slotted Channel Hopping (TSCH)

This work investigates the problem of efficient packet scheduling and transmission for IEEE 802.15.4e TSCH based on the Traffic-Aware Scheduling Algorithm (TASA). Three Integer Linear Programming (ILP) formulations are proposed, namely ILP1, ILP2, and ILP3, to comprehensively address key aspects of how packets are optimally delivered from child nodes to the root node, including node parent selection, packet scheduling, and frequency assignment. ILP1 is proposed to model the fundamental operations of TASA including packet scheduling and frequency assignment, while ILP2 further takes node parent selection into consideration for jointly optimizing node parent selection, packet scheduling, and frequency assignment. Despite its superior performance, ILP2 is only applicable to relatively small network problems due to high computational complexity. Therefore, we finally propose ILP3 for fast and efficient node parent selection. ILP3 can be combined with ILP1 and, most importantly, TASA for achieving effective node parent selection atop packet scheduling and frequency assignment for practical TSCH networks. ILP3 combined with ILP 1 led to computational complexity while ILP3 combined with TASA yielded good performance where it required less than one second of execution time and less packet delivery time.