Wireless Sensor Networks (WSN) constitute a special class of wireless data communication networks. In wireless sensor networks, sensor nodes are randomly deployed. Since the sensor nodes are required to operate under remote conditions without fresh supply of power to replenish itself, energy conservation becomes the major constraint. This necessitates the design of WSNs with the capability of prolonging the lifetime of network. To achieve minimum energy consumption, several MAC protocols have already proposed. This paper aims to survey and analyze the most energy efficient medium access control protocols and to compare their performances. Further, this paper proposes a new MAC protocol based on Orthogonal Frequency Division Multiplexing (OFDM).In ELE-MAC protocol, by employing OFDMA the energy consumption of the node can be minimized.
