Recent developments in Micro–Electro-Mechanical Systems technology lined up a way for low power wireless applications. Sensor networks are highly resource constrained network where networking of sensors enhances the collection of information where human interventions are difficult. The major research challenges in the fields of Wireless Sensor Networks (WSN) are to maintain the battery of sensor node thereby increasing the life time of the network. There are many schemes through which the battery life could be increased. One such technique is increasing the lifetime using routing. Hence the paper focuses a detailed survey study on various routing protocols of WSN.
