Adaptive Control Packet Broadcasting Scheme for Faster 6TiSCH Network Bootstrapping

The IPv6 over the TSCH mode of IEEE 802.15.4e (6TiSCH) Working Group released 6TiSCH minimal configuration (6TiSCH-MC) standard for 6TiSCH network bootstrapping. 6TiSCH-MC allocates only one shared cell per slotframe, known as a minimal cell, to transmit all types of control packets. Our Markov Chain-based probabilistic analysis reveals that few network parameters have a high impact on the performance of 6TiSCH network formation due to increasing congestion in the minimal cell with the increased number of nodes. This work aims to improve the 6TiSCH network formation process by reducing congestion in the minimal cell. For this, the Trickle algorithm, which is used for controlling the rate of routing information-carrying packet transmission is modified so that sufficient routing information can be provided without congesting the minimal cell. To reduce the congestion further, a slotframe window (SW)-based adaptive scheme is proposed by which nodes are restricted to transmit their control packets frequently. The proposed dynamic Trickle algorithm and SW-based scheme are implemented on Contiki-NG and evaluated using FIT IoT-LAB testbed. The experimental results show that both the proposed schemes together improve the joining time and energy consumption of the pledges compared to the state-of-the-art schemes. Additionally, both the proposed schemes provide fair control packet transmission opportunities among the nodes in a network.