WNL Design on Energy Harvesting Wireless Sensor Networks is Published in MDPI Sensors Journal

The article “Resource Allocation for Machine-Type Communication of Energy-Harvesting Devices in Wi-Fi HaLow Networks” by WNL members Dmitry Bankov, Evgeny Khorov, Andrey Lyakhov and Jeroen Famaey has been published in the Sensors journal.

Internet of Things (IoT) is a significant motivator for the development of modern wireless network technologies. New technologies appear and old technologies are modified to support IoT scenarios such as smart metering or environmental monitoring which involve numerous sensors that gather information and transmit it to a server. It is feasible to use wireless technologies to connect big numbers of devices, and a good candidate for wireless sensor networks is the Wi-Fi HaLow technology.

Wi-Fi HaLow is a long-range version of Wi-Fi which has numerous special solutions that enable support of big numbers of devices in IoT scenarios. One such solution is the Restricted Access Window (RAW) mechanism, which allows an access point to divide the sensors into groups and to assign each group time intervals when only the devices of the group can transmit their data. Such a division of channel time decreases the contention between the sensors and their mutual interference and thus increases the chances that the sensors will be able to deliver their data.

An important feature of wireless sensors is that they are usually battery-powered and thus have limited energy supply. In order to prolong their operation time, different energy-harvesting approaches are used that enable the sensors to gather solar, wind, vibration, and many other kinds of energy from the environment. Energy harvesting allows us to use batteries of lower capacity or even super-capacitors to store the energy for the sensors, but environmental energy sources can be unstable. This peculiarity of energy-harvesting sensors should be taken into account while configuring wireless sensor networks, e.g. while selecting the parameters of RAW in Wi-Fi HaLow networks.

The WNL members have developed a solution for Wi-Fi HaLow networks to divide the energy-harvesting sensors into groups and to assign them the time intervals in such a way, that the sensors can deliver their data with the required reliability and at the same time consume a minimal amount of channel time. The WNL Lab solution is designed to avoid the possibility of sensors running out of energy during the transmission and thus losing their data and enables the support of thousands of energy-harvesting sensors in a Wi-Fi HaLow network.

Wireless Networks Lab is a ‘Megagrant’ lab established in 2017 around the project on Cloudified Wireless Networks for 5G and beyond, led by Prof. Ian F. Akyildiz. The team regularly reports at leading IEEE conferences, runs industrial projects, and contributes to the standardization of wireless networks.