Low Energy Adaptive Clustering Hierarchy protocol (LEACH)

A Famous Clustering Routing Protocol in WSN

LEACH operates as a hierarchical protocol, wherein the majority of nodes transmit data to designated cluster heads. These cluster heads undertake the task of aggregating and compressing data before forwarding it to the base station. To determine if they will function as cluster heads in a given round, nodes employ a stochastic algorithm. The protocol operates under the assumption that nodes possess radios capable of reaching the base station or the nearest cluster head directly, albeit using full power constantly would result in energy wastage.

Following the principle that nodes should not repeat as cluster heads immediately, a cooldown period of P rounds is enforced, where P denotes the desired percentage of cluster heads. Subsequently, each node has a probability of 1/P to serve as a cluster head in each round. At the conclusion of each round, nodes not serving as cluster heads align themselves with the nearest cluster head and join the respective cluster. Subsequently, the cluster head orchestrates a transmission schedule for each node within its cluster.

Non-cluster head nodes communicate solely with the cluster head in a Time Division Multiple Access (TDMA) manner, adhering to the schedule devised by the cluster head. They activate their radios solely during their designated time slot, minimizing energy consumption. Additionally, LEACH employs Code Division Multiple Access (CDMA) to assign distinct CDMA codes to each cluster, thereby reducing interference between clusters.