Exploration Of Wireless Transmission Network Research And Implementation Of Time Synchronization And Data Transmission

With the development of wireless communication technology, data can be gatheredby wireless transmission during the process of resource exploration. This approach cangreatly reduce the costs and workload compared with wired transmission method.Time synchronization plays a crucial role in the wireless transmission system.Node data fusion, node localization, node state switch as well as the implementation ofTDMA are all based on time synchronization. When it comes to wireless transmissions,there are techniques based on Bluetooth, Zigbee and IEEE802.11a/b/g/n. We shouldchose a proper protocol, according to the specific hardware resource and applicationrequirements.This thesis first introduces the present research status of both the data transmissionsystem and time synchronization technology during the process of resource exploration,then analysis the necessity of time synchronization in the wireless network, at the sametime, a brief descriptions of GPS is made, after a detailed analysis of commonly usedtime synchronization technology, a preliminary study and comparison is done to thetypical time synchronization algorithm. This thesis lucubrate NTP protocol, includingFiltering Algorithm, Selection Algorithm, Combination Algorithm and ClockAdjustment Algorithm. The platform is based on ARM (TI AM3517) and Linux system.We apply NTP on the platform, and then use GPS to make a further improvement ofsynchronization accuracy. Finally, synchronous data acquisition and real-timetransmission is realized based on IEEE802.11n and network programming method.A lot of indoor and outdoor tests are done which shows that the synchronizationaccuracy can achieve the average of3.109ms, the precision is enhanced to748ns afterthe implementation of PPS. The functions of data transfer software are fully achieved,and the maximum throughput of the network can achieve up to28Mbps when aappropriate network routing scheme is selected. Finally, the time synchronizationaccuracy and data transfer software are all meet the demands of the project.