亚洲一区欧美在线,日韩欧美视频免费观看,色戒的三场床戏分别是在几段,欧美日韩国产在线人成

With the aim to deploy wireless sensor networks and accommodate to application in a peach garden, the frequency of 2.470MHz was selected, a distance of 40m was defined as a reliable communication distance based on the monitoring of variance of packet deliver rate in long term, the result and analysis of short term monitoring of packet delivery rate showed that quality of wireless links changed greatly in short term and there were no significant correlation between them. Then a communication protocol was designed based on the requirement of application and the characteristics of links:with the aim to reduce power consumption of listening ,the flooding time synchronization protocol was improved and flooding-stable root time synchronization protocol was designed; as the link quality changes greatly in short time the collection tree protocol was improved to enhance the packet deliver efficiency, a comparatively complete communication protocol was designed by combining these two protocols above. After that the protocol was implemented with nesC language in TinyOS, finally field tests were carried out in the peach garden, the result shows that the time synchronization errors are less than 10ms in the whole net, the packet delivery rate of communication protocol is 8%~15% higher than that of communication protocol based on MultihopLQI. A TelosB node can run 264d, with the supply power of two AA batteries, indicating that the communication protocol achieves very low power consumption.