###### Abstract  
Long-range (LoRa) technology is a low power wide area network (LPWAN) technology that is currently being used for development of Internet of things (IoT)-based solutions. Transit transport, mainly in medium-sized cities where transit vehicles do not have exclusive lanes, is a service that can be improved with a tracking service using technology such as LoRa. Although some proposals exist, there is not enough experimental information to validate the LoRa technology as adequate. This article: (a) evaluates the operation of LoRa technology in a transit vehicle tracking service in a medium-sized city, based on an Intelligent Transportation Systems architecture and IoT; and (b) investigates optimal LoRa technology configuration parameters for the service. Experiments were performed in a semi-controlled environment using LoRa devices and a gateway, by measuring the received packets and the receive signal strength indicator (RSSI) and modifying: (a) distance; (b) number of devices; and (c) the main LoRa transmission parameters. Obtained results show the ideal values of parameters vary considerably with distance and number of devices used. There were very few settings of the experiments in which the RSSI and packet levels were adequate while distance and number of devices were both changed. LoRa; Intelligent Transportation System; IoT; transit vehicle tracking service; experimental evaluation +
Footnote †: journal: ElectronicsAmong the LPWAN technologies, LoRa has been selected as suitable for mobility services (e.g., transit vehicle tracking service) due to its high range, low operation cost, use of unlicensed frequency spectrum, adequate data rate and low latency [3,4]. LoRa is adequate for communication between vehicles and information centers in a transit vehicle tracking service, in terms of frequency of messages, size of each message, and latency. A tracking service does not require a high frequency of messages, a maximum of 15 messages per minute from each vehicle is enough for locating a vehicle with enough accuracy; the principal data in each message are coordinates (latitude and longitude) that account for a relatively short message (which could also be encoded to reduce its size) [2]; and the latency of each of the messages is not critical, since the location of a vehicle can be reported with up to 1 s of delay without a considerable effect. LoRa technology has a high enough data rate to handle the required message rate; the size of the packet, although limited, is adequate for this type of service; and latency is low enough to have transmission delays of less than 1 s in the distances handled in a tracking service [3,4]. Implementing LoRa technology in a large-scale transit vehicle tracking system in an intermediate city in a developing country such as Colombia (or in intermediate cities in other countries, with similar transportation systems) involves a high risk, no evidence was found in industry or academy on the implementation of this technology for this type of services in a city. Although there are some related works [2,6,13,14, 13], there is no practical evidence regarding the number of end devices that can be served by a single gateway, maintaining the quality of service. In addition, there is no detailed analysis of the adequate values for the LoRa transmission parameters (spreading factor, bandwidth and coding rate), to achieve the best transmission efficiency at certain distances and with a certain number of LoRa devices. Additionally, no architecture has been adopted for design and development of most of these mobility services. An architecture is necessary for an adequate standardization and integration with other types of mobility services or smart cities services. Intelligent transportation systems (ITS) are a viable option to achieve an adequate standardization between the mobility services of a city; having an ITS architecture as a basis for the design of the tracking service is a relevant factor for guaranteeing a major improvement of mobility in a city [15,16].