# Energy Efficient Routing Protocol for an IoT-Based WSN System to Detect Forest Fires
## 2 Related Work  
In this section, we first discuss some basic WSN models, designed to maximize the lifetime of WSNs. Next, we discuss some recently proposed WSN models, designed specifically to detect forest fires. LEACH [28] is a self-organizing, adaptable clustering protocol for WSNs that uses a cluster head rotation technique to distribute energy load uniformly among the network's sensors. Sensor nodes in the target area form groups called clusters, with one node performing as the cluster head of the cluster. LEACH incorporates a random CH rotation scheme, spreading the load across multiple sensors rather than continuously draining the power from a single sensor. An elected CH broadcasts an advertisement packet to inform the neighbouring non-CH nodes about its selection. A non-CH node sends a join request message to the CH from which the strongest advertisement signal was received. After cluster formation, the CH broadcasts a transmission schedule in its cluster to allocate each cluster member one data slot in a frame. A cluster member can transmit only in its own slot. It keeps its radio OFF in the other slots. The CH collects data from all the cluster members and sends an aggregate packet to the BS directly. The following protocols are the successors of LEACH that made modifications to LEACH. LEACH- C [29] is a clustering protocol in which the BS takes all the following decisions- selection of CHs, formation of clusters, and dissemination of data across the network. The first protocol that uses the SPINS protocol [30] to add security features to LEACH is SLEACH [31]. This protocol employs simple cryptographic methods for WSNs. Q-LEACH [32] is a quadrant-based routing protocol that combines the characteristics of the LEACH protocol and the Q-DIR [33] routing algorithms. LEACH-B [34] uses an innovative technique for the formation of clusters and the selection of CHs in the network. By allowing the CHs to interact with the BS via multi-hop routes, multi-hop LEACH [35] increases the network performance in terms of energy conservation. In MG-LEACH [36], nodes are divided into groups based on their locations, and the number of groups depends on the density of the nodes. The BS creates these groups during the deployment of the nodes. This step is an additional step called the Set Building Phase. The other two phases called Setup Phase and Steady State Phase are similar to LEACH. In BEE-MAC [37], the cluster formation process is also the same as in LEACH. Each CH broadcasts a TDMA plan during the announcement phase to allocate control slots to its members. A source node broadcasts a control packet in its control slot to claim one or more data slots. To know which data slots are available, a source node keeps its radio ON continuously from the beginning of the control period till its control slot. In ES-MAC [38], the cluster formation process is the same as in LEACH. ES-MAC introduces a small time duration called the Verification Period (VP) at the beginning of each slot. In this time duration, a CH checks the medium for any signal from the slot owner. If the CH does not receive any signal from the slot owner during this period, it turns its radio OFF till the beginning of the next slot. The VP ensures that idle listening in CHs is minimized. EE-MAC [39] uses four important parameters to minimize unnecessary energy consumption in sensor nodes and distribute the overall load uniformly among them. The Residual Energy (RE) of each node is compared with a TE value to decide if the node can participate in the CH selection process. A predefined value called the Proximity Threshold (PT) ensures that CHs are not located too close to each other in the network. Another parameter called the Maximum Cluster Size (MCS) puts a limit on the maximum size of clusters in the network. EE-MAC also uses the VP like ES-MAC to reduce idle listening in CHs. LEC-MAC [40] uses five parameters to do its job. A PT value is used to distribute CHs in the network uniformly. The PT value ensures that no region in the target area is crowded with CHs.