ABSTRACT

Wireless Sensor Networks (WSNs) contains a large number of sensor nodes that can sense, compute data, communicate with each other, and monitor the physical condition of the environment surrounding. These sensor nodes have limited energy and storage capability. Therefore, energy optimization, to increase the network lifetime is one of the challenging topics in WSN. Other challenges are routing protocol design, Scalability, Selection of the sensor location, Cluster improvement, and security issues. To overcome these challenges to some extent, one of the effective ways is clustering, but it leads to an energy hole or hot spot problem. Unequal clustering is a solution to this problem. This paper provides a broad overview of various unequal clustering methods with its purpose, features.

Keywords: - Energy Efficiency, Hotspot problem, Network lifetime, Unequal clustering, Wireless sensor networks