A review on energy efficient protocols in wireless sensor networks

In past decade, wireless sensor networks have gained attention by researchers, manufacturers as well as the users for remotely monitoring tasks and effective data gathering in diverse environment. The wireless sensor nodes are tiny battery powered devices having limited lifetime, hence for longevity and reliability, the foremost concern is minimizing energy consumption and maximizing network lifetime while designing protocols and applications. In this paper, we review the main design issues based on the model of wireless sensor networks: structure-free and structured for data collection and aggregation where role of clustering and routing is discussed for energy conservation and enhancing network lifetime. These design strategies are the foundation of any networking protocol from the energy saving point of view. A comprehensive tabular overview of different approaches under structure-free and structured wireless sensor networks for data collection and aggregation, clustering and routing is presented with key issues.