Low Energy Adaptive Clustering Hierarchy ("LEACH") is a routing protocol in wireless sensor networks (WSNs).
The goal of LEACH is to provide data aggregation for sensor networks while providing energy efficient communication that does not predictably deplete some nodes more than others.
LEACH is a hierarchical protocol in which most nodes transmit to cluster heads, and the cluster heads aggregate and compress the data and forward it to the base station. Each node uses a stochastic algorithm at each round to determine whether it will become a cluster head in this round.
Nodes that have been cluster heads cannot become cluster heads again for P rounds, where P is the desired percentage of cluster heads. Thereafter, each node has a 1/P probability of becoming a cluster head in each round. At the end of each round, each node that is not a cluster head selects the closest cluster head and joins that cluster. The cluster head then creates a schedule for each node in its cluster to transmit its data.
All nodes that are not cluster heads only communicate with the cluster head in a TDMA fashion, according to the schedule created by the cluster head. They do so using the minimum energy needed to reach the cluster head, and only need to keep their radios on during their time slot.
LEACH also uses CDMA so that each cluster uses a different set of CDMA codes, to minimize interference between clusters.
Properties of this algorithm include:
- Cluster based
- Random cluster head selection each round with rotation
- Communication done with cluster head via TDMA
- Cluster membership adaptive
- Data aggregation at cluster head
- Cluster head communicate directly with sink or user
- TDMA within clusters
- CDMA across clusters
External Links
- A brief description of LEACH and SPIN
- The original LEACH paper (postscript) presented at the Hawaii International Conference on System Sciences, 2000.