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Top1. Introduction
The advancement of wireless sensor technology has improved communication and monitoring the environment surrounding us. Several research studies have been carried out on the WSNs. Not all sensor nodes are able to reach the base station in a single message because the monitored area can be so wide and the range of the signal is limited. The cluster head nodes send their data over multi-hop paths to the base station. Routing paths should be created to route data to the sink. The range of the signal is proportional to the remaining energy of the node. The sensor nodes are equipped with a microcontroller, a memory and a radio module with low power consumption. At T rounds, the energy of the node will be dissipated so the signal weakens. New perspectives have emerged in various fields such as agriculture, civil protection and environmental control the focus of this study is forest fires. However, these sensor nodes have limitations in terms of memory size, processing power, communication range and power supply. There are several families of routing protocols defined for WSN, for instance, flat routing, hierarchical routing, data centric routing, location-based routing protocols ... The routing protocols belonging to these families take account of the specificities of the sensor nodes described and above all they ensure energy saving. Hierarchical protocols based on clustering are designed to save more energy. These protocols assign different roles to the sensor nodes, such as the role of an ordinary node, the role of cluster head and the role of a Gateway node. The cluster head collects data from member nodes. Then, it performs data aggregation treatments before sending the aggregated data to the base station. From one cycle to another, a sensor node can change its role. This organizational dynamic makes it possible to standardize the energy consumption. The processes carried out by the clustering theory, such as merging, aggregating, data compression, eliminating redundant data and reducing the number of messages circulating in the network, have resulted in better consumption of data energy for WSN.
The clustering technique makes it possible to partition the network into a subset of clusters. The latter are more homogeneous according to a specific metric. Each cluster consists of a particular sensor node called the cluster head (CH). The role of CH consists in coordinating among the members of its cluster, thus collecting the data and aggregating them and then transmitting them to the base station. The CH is selected to facilitate this role according to very specific metrics. the most answered protocols run as follows:
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Each sensor node should know its neighbors;
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Each node takes the decision (autonomous) according to its local knowledge of the topology to be chief cluster or not according to metrics used for each type of protocol;
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Sensor node elected as the cluster head broadcasts its status to all neighboring nodes that are within its reach, and invites its neighbors that are not yet connected to other clusters to join it.
Among the best-known protocols, we can single out LEACH (Heinzelman, Chandrakasan & Balakrishnan, 2000), HEED (Younis & Fahmy, 2004), PEGASIS (Lindsey, Raghavendra & Sivalingam, 2002), TEEN (Manjeshwar & Agrawal, 2001), APTEEN (Manjeshwar & Agrawal, 2002) and CPCP (Soro & Heinzelman, 2009).
The LEACH protocol (Low-Energy Adaptive Clustering Hierarchy) is known as a pioneering protocol of distributed clustreing. It is based on a probabilistic calculation to select the cluster head. Successive LEACH protocols have involved other parameters for the selection of cluster head, such as residual energy (Perillo & Heinzelman, 2004; Singh, Kumar, and Singh, 2017), location, signal strength, etc. However, most of these protocols do not guarantee full coverage of the network for all cycles. Indeed, in some cycles, cluster head may be concentrated in a part of the monitored area, some ordinary nodes fail to reach a cluster head. They are considered orphaned nodes in the network.