Feasibility of LoRa for Indoor Localization

The concepts of smart cities and smart communities have started to become a reality in this age of the Internet of Things (IoT). In the midst of this IoT revolution, recently, low power wide area networking (LPWAN) technologies[1, 2, 3, 4] have become very popular, as they are an excellent fit to the IoT data traffic that are generated and consumed by many smart cities applications. For instance, if we think of city-scale IoT applications like smart metering, environment monitoring, road traffic monitoring, facility management, smart parking, street lighting, vehicle tracking, waste management, precision agriculture, and home automation, we observe that the basic communication requirements in these applications include a long radio range (i.e. several hundred meters of range), low power (i.e. an extended battery-life of several months or years), and low bandwidth (i.e. a data rate of few kbps). Thus, low power WANs are being considered as the enablers of city-scale IoT. Among different choices of low power WANs, we study one of the most popular technologies of today, which is called the LoRa WAN [2]. LoRa has so far been mainly adopted by the European countries, although recently, over 100 cities in the USA have begun to deploy city-wide LoRa networks [5]. LoRa has an advertised radio range of up to 9 miles (in line-of-sight), a data rate of up to 50kbps, and a battery life of around 10 years. Though LoRa is considered for outdoor applications, its properties can also be leveraged for indoor scenarios. As LoRa operates in the sub-GHz band, it obtains more penetration ability making it more resilient to noise and multipath. This property makes LoRa a better choice for indoor localization. Recently for localizing in large facilities (e.g. multistory buildings, large warehouse), multiple access points or beacons need to be installed due to the short range of traditional RF signals e.g. WiFi, Bluetooth Low Energy (BLE). However, due to the long range of LoRa, fewer number of access points or node can perform similar operations. In this paper, we study the performance and prospect of LoRa in indoor localization. We observed that LoRa is more stable than WiFi and BLE and is more resilient to environment change. We achieved mean error of 1.19m and 1.72m with unprocessed RSSI value in line of sight and non-line of sight respectively.