Environmental monitoring applications need tiny sensor nodes randomly embedded in the target area. As the wireless Sensor Networks are made up of tiny energy hungry sensor nodes, it is a challenging process to retain the energy level of those nodes for a long period. They are equipped with limited computing and radio communication capabilities. This work is on the attempt to reduce the power consumption of nodes , by concentrating on the radio, which has four states of operations at various time intervals . A proper sleep/wake up scheduling, when applied over these radios, can reduce the overall energy consumption of the Wireless Sensor Network minimally. The scheduling protocol used in this work is a TDMA based MAC protocol. When implemented in a simulated WSN, it reduces the energy consumption of the previously existing protocol and hence it proves to be efficient, when compared with other scheduling protocols. © 2011 Springer-Verlag.