Autonomous Allocation and Scheduling of Minimal Cell in 6TiSCH Network

6TiSCH standardization helps the Industrial Internet of Things (IIoT) to achieve reliable and timed data delivery. It also deals with minimal resource allocation during network formation. However, faster network formation using minimum resources remains an active research issue. 6TiSCH minimal configuration standard (6TiSCH-MC) recommends to use only one cell per slotframe known as the minimal cell for all the nodes to transmit their network bootstrapping traffic. It is observed that, including 6TiSCH-MC, the existing schemes did not use all the available cells, and so, all the physical channels at the timeslot where this minimal cell resides, i.e., at timeslot zero. It results in underutilization of channel resources, and thus, higher network formation time. To leverage the available cells at timeslot zero of each slotframe, and thus to improve the network formation performance, an autonomous allocation and scheduling of minimal cell (TACTILE) is proposed. The main challenge is to utilize the available cells at timeslot zero as there is a minimal cell already scheduled for network bootstrapping. To address this issue, TACTILE distributes the location of the minimal cell as per nodes' EUI64 addresses along the different physical channels followed by scheduling them intelligently to avoid de-synchronization among nodes. Combined with Markov chain-based theoretical analysis, evaluation of TACTILE is done on the FIT IoT-LAB real testbed. The testbed results show that TACTILE can achieve 87% and 42% improvements in terms of joining time and energy consumption, respectively, compared to 6TiSCH-MC.