Abstract: WSN is the branch of sensing information from the external environment where human interaction is not possible. In WSN various approaches have been used for data sensing and transmission over the networks. In this paper various researches has been reviewed for extraction of valuable information for efficient energy management and data transmission in WSN. In this paper various approaches that are cluster based, relay based and chain based has been illustrated. Relay based WSN use a relay node for receiving information from the sensor node that cause problem in large scale networks. On the basis of analysis of these different approaches dynamic clustering approach provides efficient energy utilization in WSN.

Keywords: LEACH, BEC, LEACH-M, C-LEACH, MWSN and Radio Propagation.