| The application of Wireless Sensor Networks which is developede with the development of sensor techniques, nested techniques and wireless communication techniques in Xinjiang Coalfiled Fire Monitoring, is a concrete realization of this technology used in large remote environmental monitoring. Therein, we should solve some fundamental problems, for example, how to efficiently transport data to the remote monitoring center, reversal control the monitor network, manage data which is received by the monitoring center server and reliable communication between network nodes. Among them, the problem of the remote bidirectional communication in fire area monitoring is one of the key technologies which this paper emphatically studies.By investigating the existing remote data transmission modes, according to the practical monitoring environment of Xinjiang Coalfiled Fire Area, GPRS transmission is selected as the measure, finally, the remote transmission from WSN to monitor centre is realized. The GPRS module is added to the base node and the remote transmission control program is developed, first, when the data collected by sensors is transmitted to the base node, it is processed by Micro Controller Unit (MCU) ATmega128L and then transported to GPRS network through GPRS module SIM300 , and at last it is sent to the computer end via Internet. On the basis, further realized bidirectional communication function and make it possible for monitoring center to reversal control the monitor nodes. The paper deeply research and analyze the process of sending control command by interrupt program and transmiting back the collected data, the control program is tested in Xinjiang Coalfiled Fire Area, the results show that this system can realize the function of remote realtime bidirectional communication. At the same time, the center server use network communcation software which is designed by Windows Socket programming technology to receive and management data, also center staff can send the task instructions to the sensor nodes through this software.In addition, When the general antennas the existing sensor nodes used on geotechnical ground, their communication distance decline rapidly, therefore, the new inverted F antenna this paper developed improve the communication distance between the nodes by increasing the antenna gain and without increasing power consumption of the communication module, and the coverage area of WSN is expanded.The paper based on WSN remote monitoring scheme with GPRS makes use of Mobile Network which cover most of our land, Internet, after completing send the data to the server from the monitoring nodes, further realized bidirectional communication function. It has important significance for us to associate physical world on site with Network, whether for treating Xinjiang Fire Area, or the WSN technology its own development, or as part of the development of future Internet of things. |
