## 2 Background on Internet of Things (IoT) and Sensors
### IoT Technology and Generic IoT Architecture  
The Internet of Things (IoT) is a technology that enables the connection and communication of devices and objects over the internet [13; 14]. IoT devices are equipped with sensors, which allow them to collect data on a variety of physical and environmental conditions. This data can then be transmitted to other devices or systems, where it can be analyzed and used to inform decision making. IoT sensors come in a variety of forms, including temperature sensors, humidity sensors, motion sensors, and pressure sensors [15]. They can be used to collect data on a wide range of environmental conditions, such as temperature, humidity, air quality, and sound levels. They can also be used to monitor infrastructure, such as bridges, roads, and buildings, and to track the movement of people and goods. The development of IoT technology has been driven by the increasing availability of low-cost sensors, as well as advances in wireless communication [16; 17; 18] and cloud computing [19; 20; 21; 22]. These developments have made it possible to collect and process large amounts of data in real-time, enabling new possibilities for monitoring and analysis. One of the key benefits of IoT technology is its ability to provide real-time monitoring and response [23; 24]. By collecting data on environmental conditions and infrastructure status, IoT sensors can alert emergency responders to potential emergencies before they become critical. For example, an IoT sensor on a bridge can detect when the bridge is starting to deteriorate and send an alert to maintenance personnel, enabling them to take action before the bridge becomes unsafe [25]. IoT sensors can also be used to automate certain emergency response processes, such as sending alerts or deploying resources [26]. For example, an IoT sensor on a fire hydrant can detect when it has been opened and automatically send an alert to the fire department, enabling them to respond more quickly to the emergency. The development of IoT technology and sensors has opened up a range of new possibilities for emergency response and management. By harnessing the power of IoT technology, it is possible to improve the speed, accuracy, and effectiveness of emergency response efforts, and to minimize the impact of emergencies on individuals and communities. The generic architecture of the Internet of Things (IoT) shown in Figure 1 consists of three layers: the device layer, the network layer, and the application layer, as follows:  
* The device layer includes devices such as sensors, actuators, and other types of input/output devices that can be used to collect data from the physical environment or take action on it. Sensors are used to collect data on environmental conditions such as temperature, humidity, or air quality. Actuators, on the other hand, can be used to control devices or systems in response to data collected by sensors. * The network layer includes a network that connects the devices to the cloud, as well as a gateway that enables communication between the devices and the cloud. The cloud serves as a central hub for storing and processing the data collected by the devices. * The application layer includes the software applications that are used to analyze and make decisions based on the data collected by the devices. This layer is responsible for processing the data and presenting it to the user in a meaningful way. In this architecture, the flow of data starts with the environment, where sensors collect data on physical and environmental conditions. This data is then sent to the devices, where it is processed and sent to the gateway. The gateway then sends the data to the cloud, where it is stored and processed by the application layer. The application layer analyzes the data and sends reports to the user, who can then take action based on the information received. The application layer can also send feedback to the user based on the data collected by the devices.