부산대학교 도서관

We conduct communication environment measurement in Chikuma city, Nagano prefecture, Japan, utilizing community bus services via private Long Range (LoRa), which is one of the low-power wide area (LPWA) communication technologies. Chikuma city has approximately 119.8 km^2 area and a population of 59,380, which is a medium-sized rural city in Japan. In this experiment, we set up LoRa relay stations at three locations in the city: the Koshoku city hall building (at the northern part of the city), the Togura municipal building (at the southern part of the city), and the Amenomiya drainage station (at the eastern part of the city). In addition, beacon transmitters are installed in the community buses (nine routes in all). The location and time information are transferred from the routes of the buses to a cloud system in real time through the relay stations. Experimental results are summarized in an area map, indicating that we succeed in communicating in 61.3% of data points on the bus routes and confirm the possibility of covering the entire city by the LPWA. We are able to expand the LoRa communication area by adding more relay stations paying attention to terrain effects.