## 3 Implementation of X-IoCA for SAR Missions: SAR-IoCA
### Feedback Information System for SAR Missions
#### 3.2.2 SAR-FIS  
The other part of the sensory information flowing through the presented system is directly and automatically managed by an ad hoc software called search and rescue  
Figure 3: Proposed H2 WTN architecture for the SAR field experiment. feedback information system (SAR-FIS). This software is replicated at both MEC centers (BCC and FCC) and integrates the LoRa H-WSN and a global path planner. Figure 4 shows the information flow to SAR-FIS, which comes from the LoRa sensor-nodes and on-board GPS devices and IP cameras. The LoRa packets transmitted by the sensor-nodes are received by the concentrator-nodes within their reception coverage. The concentrator-nodes can operate in either edge mode or cloud mode. Thus, each concentrator-node operating in edge mode hosts a local MQTT broker, i.e., hosted on its own host. Instead, the concentrator-nodes operating in cloud mode link to an application developed in The Things Network (TTN) that has a common MQTT broker hosted on a web server in the cloud. By publishing MQTT topics, the concentrator-nodes send the data received from the sensor-nodes to their respective MQTT brokers. SAR-FIS subscribes to the topics associated with the different MQTT brokers, hosted in local edges or in the cloud, to receive the data coming from LoRa H-WSN. SAR-FIS automatically registers each SG when it receives information related to a LoRa sensor-node. In this way, SAR-FIS updates, in real time, the sensory information coming from the LoRa H-WSN. This sensory data are monitored on the user interface, together with the images captured by the onboard IP cameras. SAR-FIS distinguishes four basic elements: (i) agents: UGVs with the ability to move through the environment and to embark elements of the sensor network; (ii) sensory targets: static SGs; (iii) points of interest: locations in the environment that represent areas of interest for path planning; and (iv) environment: area of operations defined using a DEM and an orthophoto or zenith aerial photograph, where the multi-sensor network and agents are deployed. SAR-FIS integrates a global path planner that generates the sequence of waypoints in the environment that an agent must travel from its current position to reach a target point. Each agent publishes the geolocation coming from the onboard GPS device through MQTT topics in order to let its current position be known. The sensory targets and points of interest constitute the possible target points of the path planner. The path-planning process can be enabled by the user or triggered by a sensory event. Figure 4: Integration of the LoRa H-WSN with a path planner in SAR-FIS. A sensory event is triggered when a physical quantity acquired by a sensor-node does not belong to a predefined range of values. When a sensory event is detected, SAR-FIS automatically plans a path for a UGV to travel to the location of the sensor-node involved. The sensory events allow one to respond to possible risks efficiently, as the displacement of an agent can be planned when a magnitude associated to a risk is detected by the sensor network. By contrast, when the user enables path planning, the user determines which agent and which target point are considered in the path-planning process. Figure 5 shows an example of the graphical interface during deployment of a realistic exercise, which is divided into two main areas: (i) the environment map with selective monitoring of agents, sensory targets, and points of interest, and (ii) the status or the configuration parameters of environment, agents, sensory targets, points of interest, path planner, or general system. The environment map shows an aerial orthophoto of the area of operations where symbols are displayed to locate each agent, sensory target, and point of interest defined in SAR-FIS. The user can selectively enable the monitoring of physical magnitudes acquired by each SG. For instance, the temperature (27.7 \({}^{\circ}\)C) in Cuadriga's immediate surroundings is displayed on the environment map.