Date Added: Apr 2012
The need for efficient energy utilization, scalability and load balancing has increased the interest in wireless sensor networks. WSNs are being widely used all over the world in many applications such as weather monitoring, combat field reconnaissance, intrusion detection, disaster management, traffic monitoring, etc. The clustering algorithms aim to prolong the lifetime of the sensor networks as the node batteries are not rechargeable in nature. Hierarchical clustering has proven to be an effective approach in energy efficiency. The authors further discuss various clustering algorithms that are used for energy efficiency and bandwidth utilization. Traffic at the sink node induces delay and destruction of the nodes colliding with each other and with cluster heads.