Orphan Node Connected Management in Multi-Hop Clustering-Based Routing Protocols for Wireless Sensor Networks

In distributed clustering protocols, the selection of a cluster head CH presents a major constraint to the proper functioning of the network. Generally, the process begins with a random choice of CHs at the time of cluster formation. A selective process is then used based on a probabilistic or iterative calculation in order to choose the different CHs. This approach leads to a non-uniform distribution of the different CHs. Indeed, in some cycles, the CHs may be concentrated in a part of the monitored area, some CH nodes fail to reach its neighbor CH. They are considered as isolated nodes in the network. The major contribution of this article is to propose a solution to maximize the number of nodes connected to the networks, in order to have an improved connectivity. However, the coverage of the entire monitored area can provide persistent information to WSN applications. The work in this paper resulted in the design and development of a new distributed clustering protocol called Orphan_Nodes_Connected (ONC) protocol that significantly improves the connectivity of the monitored area.