O-LEACH of Routing Protocol for Wireless Sensor Networks

LEACH protocol called Low Energy Adaptive Clustering Hierarchy, is a protocol that allows the formation of distributed cluster. In each cluster, LEACH randomly selects some sensor nodes called cluster heads (CHs). The selection of CHs is made with a probabilistic calculation. It is supposed that each non-CH node joins a cluster and becomes a cluster member. Nevertheless, some CHs can be concentrated in a specific part of the network. Thus several sensor nodes cannot reach any CH. to solve this problem. We created an O-LEACH Orphan nodes protocol, its role is to reduce the sensor nodes which do not belong the cluster. O-LEACH present two scenarios, the first scenario consists, a cluster member will be able to play the role of a gateway which allows the joining of orphan nodes. The gateway node has to connect a number of orphan nodes, thus the gateway node is considered as a CH' for connected orphans. As a result, orphan nodes become able to send their data messages to the CH' which performs in turn data aggregation and send aggregated data message to the CH. The second scenario consists, if in an area not covered, the number of orphan nodes is very important, if number of cluster member is superior to number of orphan nodes, a sub-cluster will be created. The first orphan node reached the gateway (member of cluster) will be a CH'. O-Leach enables the formation of a new method of cluster, leads to a long life and minimal energy consumption. In orphan node possess enough energy and seeks to be covered by the network. The principal novel contribution of the proposed work is O-LEACH protocol which provides coverage of the whole network with a minimum number of orphaned nodes and has a very high connectivity rates. The simulation results show that O-LEACH performs better than LEACH in terms of coverage, connectivity rate, energy and scalability.