Towards co-located TSCH networks: an inter-network interference perspective

The future Internet of Things (IoT) is expected to be dense with multiple independently administered co-located wireless sensor networks operating in close proximity, especially in e-health and industrial automotive applications. Recent advances in wireless technologies and standards for IoT communication such as IEEE 802.15.4, WLAN, ZigBEE, and WirelessHART make use of unlicensed bands and several networks may co-exist in close locations. This results co-located networks acting as interferer and interference victim for one another, hence affecting network reliability and energy costs. In this regard, the case of IEEE 802.15.4-time-slotted channel hopping (TSCH) protocol is of particular importance because of its widespread acceptance as a reliable MAC layer protocol for industrial low-power IoT. This paper studies closely co-located TSCH networks from the interference perspective and shows how it impacts the network performance in terms of successful communication and periodic communication blockage. Our results demonstrate that co-located TSCH networks periodically interfere with one another if they do not cooperate. The impact of inter-network interference can be reduced when there are less time-sources. Exploiting 16 channels of the IEEE 802.15.4-TSCH with channel hopping mechanism greatly reduces inter-network interference.