Best Master Thesis Award in Information and Communication Technologies (ICT) – UiA, 2019

Master Thesis: “Design and implementation of wake-up radios for long-range wireless IoT devices”

Master Student Anders Frøytlog, did his Master Thesis under the main supervision of Associate professor Linga Reddy Cenkeramaddi and co-supervision of Assistant Professor Magne Arild Hauglund. Project task is defined by Assoc. Prof. Linga Reddy Cenkeramaddi. The solutions (especially DC-MAC protocol along with wakeup radio) proposed in the thesis greatly reduce the power consumption in the long-range wireless IoT devices. Summary of the thesis can be found below.

Summary of the thesis: As the development within Internet of things (IoT) increases rapidly and the market starts to utilize its potential, an enormous effort is being made in both academia and industry to optimize solutions according to the market demands. The demands vary from case to case and some of them include high data rate, long battery lifetime, low latency and long range/area coverage depending on application scenarios. The numerous use cases and demands for IoT resulted in various IoT technologies.

In many IoT applications, especially Wireless IoT applications, energy-efficiency and battery lifetime are the most important performance metrics. The wireless access mechanisms used in current technologies utilize Duty-cycling (DC) to reduce power consumption. DC allows a node to turn the radio on and off in specific intervals in order to reduce power consumption. These DC-MAC protocols suffer from overhearing, idle listening or unnecessary transmission of advertisement packets. The different protocols may also include long delay time caused by the inactive period in the MAC protocol. The recent research and development of Wake-up Radios (WuRs) address some of these problems. A WuR is a simple low power radio receiver which always listens to the channel to detect a Wake-up Call (WuC). A wake-up radio receiver (WuRx) is attached to the main radio which is always OFF, except when it is supposed to send data. The WuRx and the main radio (MR) are two parts of an IoT node. The use of WuRx eliminates the unnecessary power consumption caused by idle listening and reduce the overhearing consumption as well as the latency. Many articles have been published about WuRs. However, most of the current WuR solutions focus on short range applications. The objective of this thesis is to design a WuRx for long-range applications (10km to 15km range), implement a WuRx and evaluate the results and compare to existing solutions.

System Overview

To reduce the power consumption in long-range IoT applications, a WuRx has been proposed, tested and evaluated. Performance of the proposed WuRx integrated with LoRaWAN node is compared to a LoRaWAN node without a WuRx. A DC-MAC protocol which is combined with a WuRx to reduce the power consumption is also investigated. The result of this thesis is a Long-Range IoT node with an average power consumption of only 0.032mA.