This paper proposes RR-MAC, a medium-access control (MAC) protocol used for sensor networks. Wireless sensor networks uses battery power to sense the devices. It consists of spatially distributed autonomous sensors to monitor physical or environmental conditions, such as temperature, sound, pressure and to cooperatively pass the data through the network to a main location. These characteristics of sensor networks and applications motivate a MAC that is different from traditional wireless MACs such as IEEE 802.11 in almost every way: energy conservation and self-configuration are primary goals, while per-node fairness and latency are less important. EM-MAC uses novel techniques to reduce power consummation. First pseudo number generator to reduce power consumption, Ready-to-Receive beacon and Collision avoidance. Inspired by EM-MAC, RR-MAC also subjects radios to wake up in various frequency channels at different times, in which the frequency and times are determined by pseudo number sequences. Finally, RR-MAC applies central registry to minimize power consumption in wireless sensor-network applications that require store-and-forward processing as data moves through the network.