## 3 Implementation of X-IoCA for SAR Missions: SAR-IoCA
All the UGVs embark the same switch (Netgear MS510 TXPP Netgear 8-Port Multi-Gigabit PoE) to interconnect all their elements, and all of them use the same 5G CPE (Huawei 5G CPE Pro, model H122-373), from Huawei (Shenzhen, China) to access the Internet. The UAV used is the DJI Matrice 600 (Shenzhen, Hong Kong, China), a hexacopter drone assembled with six carbon fiber rotors, quick-release landing gear, and mounted folding arms. This robotic agent wights 9.5 kg, and its maximum takeoff weight is 15.5 kg. The drone uses six standard intelligent flight batteries with a capability of 4500 mAh, voltage of 22.2 V, and built-in smart charge-discharge function. In this case, the 5G communication is implemented by means of the router Inseego 5G MiFi M2000, from Inseego (San Diego, CA, USA). The following is a list and description of the sensory and computational elements embarked on the robots. * [PERSON] and [PERSON]'s sensors include an IMU, GPS with differential corrections, a pan-tilt-zoom (PTZ) camera, a LiDAR system, and transceivers from the H2 WTN, including environmental sensor nodes from the LoRa H-WSN (such as temperature, humidity, or gases probes) and BLE transmitters. Moreover, [PERSON] embarks a LoRa concentrator-node based on the Conduit IP67 Base Station (Multitech MTCDTIP 220L), from Multitech (Mounds View, MN, USA), which hosts an MQTT broker, for long-range gathering and event detection. [PERSON] embarks two different types of BLE scanners [48]: one low cost based on the ESP32 microcontroller and another commercial one (Meshlium Scanner) from Libelium (Zaragoza, Spain), for short-range event detection. In addition, Rambler embarks the AXIS 5522 camera, while Cuadriga embarks the AXIS P213 camera. These cameras from AXIS (Lund, Sweden) can transmit images through a cloud server or via ROS (through the fog), thanks to the existence of ROS packages for AXIS cameras (axis_camera package). To perform processing, both robots embark a local edge composed of two PCs each, with different operating systems: Windows 7, hosting an MQTT client using LabVIEW applications, and Ubuntu 18.04, operating with ROS Melodic. * Rover J8 includes a LiDAR to enable a follow-me navigation mode. Two PCs with Ubuntu 20.04 and ROS Noetic installed were mounted in order to perform the processing of heavy tasks, such as the acquisition and application of algorithms on the point cloud captured by the LiDAR. Finally, a 3D printed part was created to install a 5G smartphone on the front of this robot in order to transmit images via 5G during its navigation. In this case, the transmission of images was performed by using the UMA-ROS-Android application. * The Matrice 600 Pro UAV is equipped with a dedicated triple-modular redundancy system composed of three GPS modules and IMUs. As for Rover J8 robot, a 3D part was also designed to embed a 5G smartphone to the UAV in order to transmit images via 5G during its flights. In addition, this drone carried a LoRa concentrator-node, based on the module iC880A, using as host a Raspberry Pi 4B for long-range event detection, as well as an ESP32-based BLE scanner for short-distance detection of victims. Finally, the lowest level of location awareness is the cloud, where a computing center hosted in a virtual machine (at the core of the 5G pilot network) performs processing (cloud computing) and hosts the master node of the ROS network distributed along the fog.