External Interference Free Channel Access Strategy Dedicated to TSCH

Power consumption is one of the main challenging issues in Internet of Things (IoT). The 2.4 GHZ band authorizes many different wireless technologies to exploit the same spectrum, which yields a severe interference environment. The IEEE 802.15.4 proposed the Time Slotted Channel Hopping (TSCH) designed for low-power and lossy networks (LLNs). The TSCH aims to improve the reliability of sensed data transmission by adapting the channel hopping technique to alleviate the external interference. Because channels can be affected by Wi-Fi signals, hopping blindly from one channel to another may also deteriorate the data transmission performance. To overcome such a problem, we propose a new strategy dedicated to TSCH that makes sensors intelligent and enables them to hop channels in a wise manner. The strategy presents a new link quality estimator used to identify and exclude undesirable channels that are congested with Wi-Fi interference. To evaluate the performance of our proposal, we implemented our techniques in Network Simulator 3 (NS3) and compared it to TSCH. The results show significant improvements in terms of number of retransmitted packets, packet delivery ratio, and energy consumption.