Measurement and Analysis of LoRa Transmission Performance in Subway Station

Developing smart stations has become an important trend for the future rail traffic system, and the realization requires using Internet of Things (IoT) technology to improve performance. Although it has been widely considered to develop an IoT wireless sensor network to monitor subway station environment, there is still a lack of realistic measurement for deployment of IoT in station. In this paper, performances of long range (LoRa) and Narrow Band Internet of Things (NB-IoT) in subway station scenario are investigated. The transmission performances of LoRa in subway concourse, platforms, and passage scenarios are measured and evaluated. The received signal strength indication (RSSI), packet loss rate, and transmission delay are discussed based on measurements. It is found that LoRa performs fairly well in subway concourse and platform scenarios, with RSSI of more than -70 dBm and packet loss rate of less than 1%. However, in subway passage scenario, RSSI is relatively low and packet loss rate can be high. These results are helpful for deploying LoRa system in subway stations.