【作者】 刘丽萍；

【导师】 孙弋；

【作者基本信息】 西安科技大学 ， 通信与信息系统， 2008， 硕士

【摘要】 煤炭是我国的基本能源和重要能源,它的安全生产直接关系到我国经济建设的能源保障和能源战略的实施。煤矿事故发生后,为了保证安全、不发生二次事故,井下电力供应完全切断,井下已有的各种通讯设备无法开启。因此,为了确保救援人员的人身安全,本文提出了一种基于Wi-Fi技术的井下应急救援无线通信系统,该系统可以快速建立一套应急通信链路,实现井下远端灾区目标位置环境状况的实时监测,为井下救援工作提供科学的决策依据。本文首先介绍无线MESH网络,它是一种新型宽带无线接入系统,可以看作是WLAN和移动Ad hoc网络的融合;接着描述了Wi-Fi技术,IEEE 802.11b规范也称为Wi-Fi,详细介绍了IEEE 802.11b MAC子层DCF方式中的基本访问机制CSMA/CA和RTS/CTS机制;然后简单介绍了井下Wi-Fi无线通信系统使用的软硬件平台;最后使用NS仿真软件对该应急无线通信系统进行了仿真。本文主要对井下Wi-Fi应急无线通信系统的通信信道进行仿真,其中每个节点表示系统中的一个Wi-Fi模块,在矿难事故发生后,该系统会由布放装置在救援中心站的遥控下自动搭建,并将数据传输到井下救援基地。本文在传统的单信道网络的基础上使用了多信道多接口网络,使用了Basic Access和RTS/CTS两种访问方式对该应急救援通信系统的信道进行仿真,通过系统仿真和分析得出本文所使用的多信道多接口网络在吞吐量、延时和丢包率等性能上都优于单信道网络。更多还原

【Abstract】 Coal is the basic energy and an important resource in china. The safe production of it is directly related to the implementation of the energy guarantee and the energy strategy in Economy Construction of China. When coal mine accident occurred, in order to ensure security and avoid the second accident, the power supply for coal mine would be cut off. All kinds of communication equipment in coal mine can not be used. Thus, for personal safety, a wireless communication system based on Wi-Fi about mine emergency rescue is put forward in this paper. A wireless channel is established rapidly throught the system. The environmental information transmitted from the spot to the base can provide a scientific reference for rescue task.In this paper, a new broadband wireless access system, wireless mesh network is used. It can be considered as the combination of WLAN and mobile Ad hoc. Then the Wi-Fi is introduced with IEEE 802.11b criterion. The access mechanism of CSMA/CA and RTS/CTS of DCF in MAC Layer in IEEE 802.11b is described in detail. The software and hardware platform of the emergency rescue radio communication system based on Wi-Fi are also briefly introduced. The system simulation has been carried out with NS software.The channel of emergency wireless communication based on Wi-Fi is simulated in this paper, where each node represents a Wi-Fi module. When accident occurred, the system would be constructed automatically by equipments under the remote control of the rescue center, and transmit data to coal mine rescue base. Two access modes, Basic Access and RTS/CTS, are used in simulation. The single-channel and multi-channel multi-interface network of the emergency rescue system under these two modes are simulated. According to the analysis and simulation, the result indicates that the multiple-channel multiple-interface network is better on throughput, delay time and packet loss rate than single-channel.更多还原