## 1 Introduction  
When summer comes, the risk of fire is high. Unfortunately, numerous fire foci appear in the Mediterranean zone countries. Hundreds of thousands of hectares are destroyed every year, which produces disastrous environmental, economical, social, material and general infrastructure consequences. Some cases could even cause the death of the inhabitants of the affected zone. Fire entails pollution and water contamination as well as a loss of nutrients and ground microorganisms [1]. Besides, it causes vegetation degradation and flora and fauna diminution because they disappear from the affected zone and are not reintegrated into other environments. The causes that start the forest and rural fires can be classified into six main groups: flashes of lightning, human negligence, fortuitous natural causes, deliberate causes, the reappearance of a previous fire and unknown causes. Governmental and national authorities, citizens, owners of the lands and the administrations are responsible for taking care of forest and rural places. Spain has a lot of legislation on this matter [2]. New technologies and tools are constantly adapted to the fight against rural and forest fires. Both preventive and post fire detection systems are useful to defend the areas against fire. The fire fighters in charge of the parks and forest zones must have the latest technology and must be equipped to be able to forecast the fire. They must know how it spreads and how to combat it. This is an important issue in order to lower the risk, and to avoid an environmental disaster. The use of sensors to detect and monitor fire behavior has enhanced the application of new technologies in the fire field. Sensors are able to consider certain dynamic and static variables such as humidity, the type of fuel, slope of the land, the direction and the speed of the wind, smoke, etc. They allow us to determine the direction and possible evolution of the flame front. The sensor-based systems can be very useful to detect a fire and to take decisions to eradicate it. A sensor is able to transform physical or chemical readings gathered from the environment into signals that can be measured by a system. In our case we have deployed a multisensor node that is able to sense several magnitudes in the same device. In a multisensor, the input variables could be temperature (it is also able to capture quick changes of temperature), fire infrared radiation, humidity, smoke and CO\({}_{2}\). A Wireless Sensor Network (WSN) could be a useful architecture for the deployment of the sensors used for fire detection and verification. A WSN consists of many small devices called sensors which measure physical parameters from the environment [3]. The nodes mainly use a broadcast communication and the network topology can change constantly due, for example, to the fact that nodes are prone to fail. They have limited power, computational capabilities and memory. One of the main issues in WSNs is their scalability [4] and their connection strategy for communication [5]. If there is a central server in the sensor network, the sensors can transmit their observations to this central server directly without any processing or they can extract the useful information from their measurements and make decisions to be sent to the central server in distributed detection. The objective of this paper is to show all the steps followed to perform the design, research and development of an optimized Wireless IP multisensor Network to detect and locate the focus of the fire, and verify it by means of images, and monitor fires in wide extension fields of rural, agricultural and forest using the Wireless Local Area Network (WLAN) technology. First, we studied the number of cameras, multisensors, a device developed by us that is able to sense different type of parameters, and access points that are needed to cover a rural or forest area. We also studied the scalability of the system.