In wireless sensor networks, wireless devices should wake up as necessary as possible to be able to communicate with neighbors and kept high... Show moreIn wireless sensor networks, wireless devices should wake up as necessary as possible to be able to communicate with neighbors and kept high quality performance. On the other hand, it is also important that wireless devices remain sleeping as much as possible to maintain low power consumption. Thus a power efficient duty cycle mac protocol is required in wireless sensor networks. This thesis proposed a mac layer duty cycle protocol which uses receiver initiated wake up mechanism to allow device to keep their transceivers off most of the time to maintain energy efficiency. Also this report measures the energy consumption of the protocol and made comparisons with other popular mechanisms which shows the approach have successfully reduced energy consumption in compare to other popular protocols. M.S. in Computer Science, May 2012 Show less