## 5 Proposed Dynamic Cluster Head Election Algorithm
### Proposed Dynamic Re-Clustering and Self-Organization Method
#### 5.2.2 Dead Nodes and Re-Clustering Organization
and fast to deliver, but its main drawback appears when the network size grows. To overcome this problem, LEDCHE-WSN architecture is enhanced by using a single-hop model at the cluster core where it nodes are a small size have a short distance between one another. Moreover, using a multiple-hop model at the cluster core causes multiple congestion points in the cluster, which in turn results in quick node energy depletion. Consequently, the core becomes lightweight and the loss ratio is improved. The LEACH FBCFP protocols adopted a multiple-hop model at cluster core, producing a very high load and data transmission among nodes, causing more packet delay, packet loss and, therefore, quick energy depletion. Furthermore, repetitive checking at each round/cycle for dead nodes, in the LEACH and FBCFP protocols, caused more delays and increased the loss ratio. The proposed LEDCHE-WSN protocol is distinguished by deleting the failure and/or dead nodes from the network topology during the re-clustering process to address the black holes and routing delay problems. ### Proposed Protocol Strength Points Compared with LEACH and FBCFP Protocols

The proposed LEDCHE-WSN protocol is preferable to the benchmark LEACH and FBCFP protocols, taking into account the following aspects:

* The LEDCHE-WSN protocol adopted a hybrid clustering model. A single-hop model is used at the cluster core, where the nodes are a small size and have a short distance between one another, making it more simple, fast, lightweight, and easy to deploy. On the other hand, a multi-hop model is used at the cluster edge to make it more connective and scalable. LEACH and FBCFP protocols use the multi-hop model at the cluster core. Despite the fact a multi-hop model can improve connectivity and extend network coverage, it causes more packet delay and packet loss, especially at the cluster core. As is well-known, the direct routing approach (single-hop model) is easy to deploy and provides fast delivery, but its drawback appears when the network size grows. Therefore, this problem was overcome by improving the LEDCHE-WSN architecture through distributing sink nodes, and using the multi-hop model at the edge of the cluster to make it much more connective and scalable;
* The LEACH protocol elects the cluster-head randomly, which results in an unbalanced energy level and thus dissipates the total network energy. The proposed algorithm performs a periodical election by excluding failed or dead nodes, which leads to a balanced energy level;
* The proposed algorithm works randomly only at the beginning of each round, to enhance the privacy of location, minimize hackers' chances of successive packets, and further complicate guessing the next packet;
* The random method in the LEACH protocol caused much more delay, due to the false election of the failure nodes (black holes) and much more time needed to get out of

Figure 9: Percentage of packets loss ratio for the 100 \(\times\) 100 m network size for LEACH, FBCFP, and LEDCHE-WSN protocols. those holes. On the other hand, the proposed protocol ensures the living of the node by checking the remaining power during the random election for the CH candidate to overcome the black holes problem, and that happened only at the beginning of each round;
* The LEACH protocol calculates the remaining energy and times of being elected as a cluster head for each sensor node adds more burden to the network. Moreover, the FBCFP protocol is more complicated, focusing on the degree of accuracy to choose the cluster head performing complex mathematical operations and measuring multiple factors (such as node density, CH degree count, traffic level, and bandwidth availability), causing more delays and increasing complexity. The LEDCHE-WSN algorithm checks the remaining energy just to ensure that a CH candidate is alive, without adding a burden in calculation and comparison for the remaining energy of the CH candidate with all the other sensor nodes as detailed in Section 6.2.