矿井WLAN终端设计及其漫游切换技术研究

发布时间：2018-10-09 10:34

【摘要】：随着煤矿信息化工作的不断推进,作为矿井有线通信网络的补充,无线网络在煤矿中的应用正逐步深入。在煤矿井下视频监控领域,传统有线视频监控系统由于缺乏移动性且在施工时存在大量的布线,已不能满足诸如移动目标监控及巡检等不便或无法使用有线视频监控的场合。采用有线结合无线的通信方式实现井下网络信号无缝覆盖,是今后煤矿井下通信系统的发展趋势。然而,由于无线局域网接入点的网络信号覆盖范围有限,用户只能在其通信范围内自由移动。当用户漫游至不同AP覆盖小区时,为防止通信中断,必然发生网络切换过程。此过程将产生相应的时延,假如时延过长,会明显影响到对实时性敏感类业务的通信质量。因此,如何缩短WLAN网络切换时延一直是人们研究的课题方向。本文围绕矿井WLAN终端设计及其漫游切换技术研究做了如下工作:(1)对矿井移动视频监控终端的实现所涉及的关键技术的研究。系统地分析了IEEE802.11网络切换发起条件和切换过程。分析了当前学者们对于提高切换性能做出的研究,并结合本文的研究背景探讨可行的改进方向。(2)完成基于WLAN技术的矿井移动视频监控终端的硬件设计。包括处理器、Wi-Fi模块的选择,视频采集模块、FLASH接口电路、SDRAM接口电路、DM9000以太网卡接口电路等外围接口电路的设计。(3)搭建绍嵌入式开发环境的,完成U-Boot的移植,完成根文件系统制作及Linux内核移植及主要驱动配置。(4)针对矿井特殊应用背景,通过分析传统IEEE802.11切换决策算法的特点,结合背景扫描的思想对漫游切换算法进行了有效的改进,提高了切换性能,保证切换过程的可靠性和有效性。搭建井下现场实验平台,验证理论分析结果。
[Abstract]:With the development of coal mine informatization, as a supplement of mine wired communication network, the application of wireless network in coal mine is deepening step by step. In the field of underground video surveillance in coal mine, the traditional wired video surveillance system is unable to meet the inconvenience or the use of wired video surveillance, such as moving target monitoring and patrol inspection, because of the lack of mobility and a large number of cabling during construction. It is the development trend of underground communication system in the future to use wired and wireless communication mode to realize seamless coverage of underground network signal. However, due to the limited coverage of WLAN access points, users can only move freely within their communication range. When the user roams to different AP coverage cells, in order to prevent the interruption of communication, the network switching process is inevitable. If the delay is too long, the communication quality of real-time sensitive services will be obviously affected. Therefore, how to shorten the handoff delay in WLAN networks has been the research direction. This paper focuses on the design of mine WLAN terminal and the research of roaming switching technology. (1) the key technologies involved in the realization of mine mobile video surveillance terminal are studied. The initiation conditions and handoff process of IEEE802.11 network are analyzed systematically. This paper analyzes the current research on improving the performance of handoff, and discusses the feasible direction of improvement. (2) the hardware design of mine mobile video monitoring terminal based on WLAN technology is completed. It includes the selection of processor / Wi-Fi module, video acquisition module flash interface circuit, SDRAM interface circuit, DM9000 Ethernet card interface circuit and other peripheral interface circuits. (3) to build an embedded development environment, complete the transplant of U-Boot, The root file system is made, the Linux kernel is transplanted and the main driving configuration is configured. (4) according to the special application background of mine, by analyzing the characteristics of the traditional IEEE802.11 switching decision algorithm and combining the idea of background scanning, the roaming switching algorithm is improved effectively. The switching performance is improved, and the reliability and effectiveness of the handover process are ensured. Build the underground field experiment platform to verify the theoretical analysis results.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD655;TN925.93

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