Time-Variant RGB Model for Minimal Cell Allocation and Scheduling in 6TiSCH Networks

Abstract

IEEE has standardized the 802.15.4e Time Slotted Channel Hopping (TSCH) mode to provide stringent latency, higher reliability, and low duty-cycle in various Internet of Things (IoT) applications. TSCH eliminates interference and multi-path fading on channels, but its channel hopping feature severely affects the 6TiSCH (IPv6 over IEEE 802.15.4e TSCH mode) network formation. Further, 6TiSCH Minimal Configuration standard does not provide sufficient bandwidth (i.e., minimal cell) for quick transmission of control packets required by the new nodes (i.e., pledges) during their network association. Many works have been proposed on 6TiSCH network formation as it has high impact on network performance and lifetime. However, the existing works either did not use all the available physical channels while allocating minimal cell(s) or are not stable with topology changes. Therefore, this work proposes a <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</u> ime-Variant <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RGB</u> (TRGB) model for minimal cell allocation and scheduling, which results in faster association of pledges and maintains network stability. We evaluate the TRGB using Markov Chain model and also on a real 60-node testbed in FIT IoT-LAB. Testbed results show that TRGB achieves 51% and 23% improvement over the state-of-the-art scheme in terms of joining time and energy consumption, respectively, while maintaining stability of the network.