矿井无线传感器网络不同信道传输特性试验研究

为研究无线传感器网络信号在矿井巷道中的传播特性，解决无线传感器节点在巷道中合理布设等问题，采用CC2420、CC1020和CC1100 3种无线射频芯片，设计出分别在2.4 GHz、780 MHz和433 MHz频段工作的无线传感器节点，并选用某矿井作为试验环境，采用3种不同的发射功率（15，5，-5 dBm）对节点在矿井巷道中的接收信号强度（RSSI）和丢包率（PLR）进行了测试分析。试验结果表明，3种不同频段的无线传感器节点的接收信号强度值均随着收发距离的增大而减小，且信号的衰减符合对数模型。通过仿真发现，布设的节点采用15 dBm和5 dBm 2种发射功率时，无线信号基本覆盖了所有巷道，能满足矿井的数据通信需求。若考虑节点的功耗，优先选择5 dBm发射功率；若考虑无线通信距离和质量，优先选择15 dBm发射功率。因此，在矿井巷道环境中应用无线传感器网络时，780 MHz频段的传输性能最佳，发射功率可根据实际情况进行选择。

Experiment Research on Propagation Characteristics of WSN at Different Channel in Mine

In order to study the propagation characteristics of the wireless sensor network（WSN） signal and deploy reasonable wireless sensor nodes in the mine roadway.Three types of wireless sensor nodes were designed，which work on 2.4 GHz，780 MHz and 433 MHz with three chips of CC2420，CC1020 and CC1100.The received signal strength index （RSSI） and the average packet loss rate （PLR） of the wireless sensor node was tested and analyzed by changing the wireless communication distance and transmission power in a typical mine working as the experimental environment.The experimental results showed that RSSI of wireless sensor nodes in three different bands decreased with the increasing of communication distance.The experiments demonstrated that the relationship of the received signal strength and communication distance caused attenuation to exist according to a logarithmic model.Through simulation found that wireless signal can cover all mine roadway when using both 15 dBm and 5 dBm transmission power.When the transmitting power was 15 dBm，the wireless signal communication success rate got higher.Therefore，when the wireless sensor network was applied in the mine roadway environment，the 780 MHz band WSN was even superior as to transmission and communication quality performance.Transmitted power can be chosed according to the actual situation.