Research On Energy-Efficient Real-Time Routing Protocol Of Wireless Sensor Network

Wireless sensor network(WSN) is a new kind of information-collecting network usually consisted of large quantities of sensor nodes deployed in an area to get the useful data of the area to the base station. In such networks there are requirements of data's real-time characteristics which require data to arrive at the destination from the source in a limited time. This goal can be achieved through the real-time routing protocol. Meanwhile because of the terrible working environments where WSN works, the sensor nodes can't change their batteries for new ones. So the protocols of WSN all have the requirement of energy efficiency. For these reasons a new real-time protocol is proposed in this paper that can coordinate the real-time and energy efficient aspects of the protocol.The goal of satisfying the real-time characteristic is achieved by the delay control strategies. In the part of the delay control strategies designing, according to the drawbacks of the old real-time routing protocol a new protocol is proposed by this paper that has some improvements, including introduce the perimeter mode to improve the path-find correctness, the priority relay mechanism and the contention control mechanism to improve the real-time ability of the routing protocol. The probability that the data arrive at the goal in the time limited can be increased by these strategies.On the energy-efficiency aspect, for the reason that none of the old real-time routing protocol ever considered the energy saving methods, the real-time protocol this paper designed is built with the sleeping schedules which can achieve the energy efficient goal by turn radios off when there is no traffic. A random wake up sleeping schedule and a laddering wake up sleeping schedule are proposed in this paper to match the routing protocol to improve the real-time ability. Both the energy efficiency and real-time requirements are satisfied through the coordination of the routing protocol and sleeping schedules. The relationship of the energy cost and the delay are analyzed in theory.At last this paper do some experiments on the new designed protocols. The results show that the new protocol can work very well on the WSN, and can decrease the data's average delay by 5%-10% compared with the old real-time protocols, and can also have a good effect in energy saving under the limit of delay constraint.