## 4 Experimental Setup  
This section provides a detailed description of the experimental setup. We created an experimental area, illustrated in Figure 6 below, measuring 4 m \(\times\) 4 m, for collecting RSSI data. In the study [35], two configurations were used with different numbers of gateways (3 and 4) in practical experiments to evaluate different gateway placement strategies. The results showed that increasing the number of gateways improves the localization accuracy. Based on these results, we positioned four receivers at the corners of the experimental area. The reference point for the experimental area is set at coordinates (0,0), where the first receiver is located. All subsequent test routes originate from this reference point. For data collection, the TurtleBot3 Burger mobile robot (depicted as a green square in Figure 6), the LA66 LoRaWAN Shield (shown as a red square), and a LoRaWAN USB Adapter were utilized. Figure 7A illustrates the TurtleBot3 Burger, developed by Robotis [60]. This compact and lightweight robot is designed for educational and research purposes in robotics and is fully compatible with the Robot Operating System (ROS). The robot is equipped with a 360\({}^{\circ}\) LiDAR sensor, which is essential for mapping, localization (SLAM), and navigation. Its modular design allows for easy configuration changes based on specific tasks. The system is powered by a Raspberry Pi 4 single-board computer, which handles data processing and control, operating with the ROS Noetic version for seamless integration and management. Its dimensions are compact, with a length of 138 mm, width of 178 mm, and height of 192 mm. Additionally, the robot features an OpenCR controller based on a 32-bit ARM Cortex M7, providing high performance for managing robotic systems. The LA66 LoRaWAN Shield and the LoRaWAN USB Adapter were employed for collecting Received Signal Strength Indicator (RSSI) data using a fingerprinting method [61]. In our study, omnidirectional antennas were used at both the receiver and transmitter. The LA66 LoRaWAN served as the receiver, capturing data from devices utilizing the LoRaWAN protocol, while the LoRaWAN USB Adapter acted as the transmitter, connecting to the Raspberry Pi 4 of the TurtleBot3 mobile robot. The LA66 LoRaWAN (Figure 7B) operates in the frequency bands of 433 MHz, 868 MHz, and 915 MHz, achieving a maximum communication range of up to 15 km in open terrain, contingent upon environmental conditions. It is equipped with UART, SPI, and 12C interfaces, facilitating connections with  
Figure 6: Experimental setup. Figure 7: LoRaWAN data collection devices: (**A**) TurtleBot3 mobile robot, LoRaWAN LA66 Shield (**B**) and LoRaWAN USB Adapter (**C**). various sensors and devices, making it a versatile solution for numerous applications. The compact design of the LA66 enhances its integration into diverse systems. Meanwhile, the LoRaWAN USB Adapter (Figure 7C) connects to computers and laptops via USB 2.0, ensuring compatibility with most devices. It supports LoRaWAN protocols version 1.0 and above, rendering it adaptable for use with various LoRaWAN devices and platforms. Additionally, both modules exhibit low power consumption, making them suitable for autonomous applications. The parameters of the LA66 LoRaWAN module used in this experiment are presented in detail in Table 1.  
The radio map of the experimental area was generated using a TurtleBot3 robot moving at a low speed while transmitting signals at a frequency of 2 Hz. The movement trajectory for collecting training data is shown in Figure 8. The coordinates during the robot's movement were obtained using a wheel odometer, starting from the initial point (0,0) and ending at (44). The robot moves at a constant speed, with a step of 5 cm for each row. Four radio maps, one from each receiver, will serve as the foundation for building and training models capable of accurately identifying and predicting the object's location based on the received signals.