Efficient Schemes for Improved Performance in 6TiSCH Networks.

The 6TiSCH (IPv6 over Time Slotted Channel Hopping (TSCH) mode of IEEE 802.15.4e) network is standardized to provide high reliability, higher throughput, delay-bounded, and energy-efficient communication in various resource-constrained Internet of Things (IoT) networks. However, it is observed that 6TiSCH network suffers from load balancing issue due to the default parent selection mechanism of its de-facto routing protocol, RPL (Routing Protocol for Low power and Lossy network). Furthermore, the performance of a 6TiSCH network degrades due to improper management of nodes' queue/buffer. None of the existing works studied these problems in RPL-based 6TiSCH networks. Therefore, in this work, we first validate these two problems using testbed experiments. Then, we propose an Early Parent Switching (EPS) scheme to deal with the load balancing problem of RPL by which nodes are allowed to change their parents depending on the remaining queue capacity of the parents. We propose another scheme named Parrondo’ Paradox based Queue Management (PPQM) for efficiently managing the nodes' queue so that buffer overflow can be reduced. We implement EPS and PPQM on Contiki-NG OS and perform testbed experiments on FIT IoT-LAB. Testbed experiment results show that both the proposed schemes can significantly improve the performance of 6TiSCH networks.