###### Abstract
In addition to an adequate ITS architecture for, the service was considered as an IoT-based solution, because the transit vehicle tracking service requires a device in each vehicle, which will sense a number of variables and transmit them to a central server. Information collected by these devices allows to perform an adequate control of transit vehicles and other related services, e.g., traveler information and traffic control. LoRa's communication performance can be tuned by modifying several physical layer settings, including transmission power (TP), carrier frequency (CF), bandwidth (BW), spreading factor (SF), and coding rate (CR) [17,18]. In a field test environment, where the equipment (LoRa devices and gateways) is already selected, it is difficult to modify the TP and CF parameters in the tests, because the devices are already factory-configured to use a fixed set of TP and CF values; however, it is more feasible to modify SF, BW and CR in each test. SF is the ratio between the symbol and chip rates. SF can take integer values ranging from 6 to 12. BW is the width of frequencies in the transmission band. A typical LoRa network operates at a BW of either 500 kHz, 250 kHz or 125 kHz. Finally, CR is the forward error correction (FEC) rate used by the LoRa modem that offers protection against bursts of interference, and can be set to either 4/5, 4/6, 4/7 or 4/8 [18]. In the surveyed related work [2,10,13,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33], although some experiments are performed using LoRa (in some cases using only LoRa transmission technology, and in some cases using the LoRa Wide Area Network protocol, LoRaWAN), most of these works are not focused on the application of this technology in mobility services. Furthermore, in works such as [2,10,13,19,18,19,20,33,31,32,33] a wide range of possible settings (i.e., specific sets of SF, BW and CR values) are not explored. In works such as [17,18,23], although numerous of possible settings is evaluated, the characteristics of the performed experiments, such as distance between devices, number of devices, packet rate, or stationary devices,means that these works do not have a similar context to this work, which is focused on a transit vehicle tracking service. This research evaluated the operation of LoRa in a transit vehicle tracking service in an intermediate city (based on an ITS architecture and IoT), and investigated the optimal LoRa technology configuration parameters for the service. Research was conducted in four stages: (a) determining an adequate ITS architecture of the tracking service; (b) designing and developing a prototype of the service; (c) designing and developing experiments to evaluate LoRa in the prototype; (d) obtaining the optimal LoRa parameter values for the service. In the authors' previous works [13; 15], stage (a) was developed in detail, for this reason the results from [13; 15] are used in this work. Regarding stage (b), a proof of concept was developed in [13], so this work makes an incremental contribution to the development of the system, moving from proof of concept to a prototype. In [13], five very basic experiments using LoRa were designed and developed, only two devices were used and only one of the setting parameters (spreading factor) was varied within a limited set of values; in contrast, this work includes much more robust experiments for finding the optimal values of the LoRa configuration parameters. The number of devices was increased (up to four devices in some experiments) and all the 72 possible settings obtained by combining all possible values of the three LoRa parameters were evaluated. Therefore, the greatest contribution of this work is made in stages (c) and (d). Considering the limitations of the studies of LoRa technology reviewed in the literature (limited number of parameter combinations and lack of sufficient field tests), experiments were performed in a semi-controlled environment using LoRa devices and a gateway in the 915 MHz radio band (band allocated to LoRa in the American continent).