毕业论文外文翻译Wi-Fi技术.doc

河南科技学院 2012 届本科毕业设计中英文翻译学生姓名： 所在院系： 信息工程学院 所学专业： 信息工程 导师姓名： 完成时间： 2010-05-10 Wi-Fi TechnologyWi-Fi stands for Wireless Fidelity, also known as the 802.11b standard. Its biggest advantage is the high transmission speed can reach 11Mbps, another effective long distance, at the same time compatible with the existing variety of 802.11DSSS equipment. Along with Intels laptop chipset,Centrino is recognized by more and more people, this technology has become a topic of concern to everyone. However, since the end of 2005, many mobile phone manufacturers, especially the production of smart phones based brand Wi-Fi began to introduce their own products. In short: Wi-Fi wireless networks .Wi-Fi has been widely used in notebook computers, mobile phones, PDAs, digital cameras and other mobile devices.With Wi-Fi, no cable can be linked into the network. More and more devices installed in the factory, Wi-Fi module, but also more and more places to offer Wi-Fi signal coverage. In this way, the Wi-Fi formed from research to equipment production, from network access to network services is a huge industrial chain. In 2007, the value of the national the wlan industry, including Wi-Fi industry is expected to exceed 100 million U.S. dollars. For individual users, the popularity of Wi-Fi, it will be a leap forward in user experience.Laptop users will be able to any one with Wi-Fi signal coverage fast access to the Internet without the need to go looking for network cable, a growing number of airports, hotels, public places, offer Wi-Fi signal coverage. In a timely manner with a laptop computer to meetings, do not worry do not have enough network cable jack in the conference room. At home, you can even in any corner of the coverage of wireless signals, without having to worry about the alignment of the cable affect the overall indoor appearance.Wi-Fi in handheld devices are widely used, and smart phones is part of it. Different from the earlier Bluetooth technology used in mobile phones, Wi-Fi has a greater coverage and higher transmission rates, Wi-Fi phones has become a fashion trend of the mobile communications industry.Wi-Fi bands in the world without any telecom operator license free band, WLAN wireless devices provides a worldwide can be used, the cost is extremely low and very high data bandwidth wireless air interface. Users can browse the web quickly in the Wi-Fi coverage area, anytime, anywhere and receive phone calls. Other WLAN-based broadband data applications such as streaming media, online games and other functions more user should expect. With Wi-Fi capability, long-distance calls (including international long distance), browse the Web, send and receive e-mail, music downloads, digital photo transfer, will no longer have to worry about slow and costly problem.Wi-Fi flip range more widely in the country, luxury hotels, luxury residential, airports and coffee shops class area has Wi-Fi interface. When we went to the tourist office, you can use our handheld devices in such places and enjoy surfing the web.A Wi-Fi connection point network members and structure of the site (Station), the network of basic components. The basic service unit (Basic service the Set, BSS). Network basic service unit. The most simple unit can only be composed by the two sites. The site can be dynamic link (associate) to the basic service unit.Distribution System Distribution System (DS). The distribution system used to connect different basic service unit. The media distribution system medium (Medium) logic and the basic service unit is completely separate, even though they physically may be the same media, for example, the same radio frequency band.Access point (Acess Point, AP). Access point that the identity of the ordinary sites, and access to the distribution function of the system.Extended Service Unit (Extended Service Set ESS). A combination of the distribution system and basic services unit. This combination is logical, not physical - the basic service unit of matter may be geographically far removed from. Distribution system can also use a variety of techniques.Mark (Portal) is a logical composition. For wireless LAN and wired LAN or other network link.Here are three kinds of media, the site uses wireless media distribution system to use the media, and other LAN and wireless LAN integration together media. Physically, they may overlap each other.The IEEE802.11 only responsible for addressing (Addressing,) on the site uses the wireless medium. Distribution systems and other LAN addressing a range of wireless LAN.The IEEE802.11 no specific definition of the distribution system, but the definition of the distribution system should provide the services (Service). The entire wireless LAN defines nine kinds of service, five kinds of services are part of the task of distribution systems, respectively, joins (Association), the end connection (Diassociation), distribution (Distribution,), integration (Integration), to re-connect.Four kinds of services are the tasks of the site, respectively, authentication (Authentication), the end of the authentication (Deauthentication), privacy (Privacy), MAC data transmission (the MSDU delivery).The main technical advantage of the Wi-FiFirst A radio wave coverage, the coverage of radio based on Bluetooth technology is very small radius of only about 50 feet, or about 15 meters. Wi-Fi radius of up to about 300 feet, or about 100 meters. A new type of by Vivato company recently launched the switches, which products to current Wi-Fi wireless network 300 ft, close to 100 m communication distance expanded to four miles, about 6.5 km.Second Although the quality of wireless communications transmitted by the Wi-Fi technology is not very good performance of data security than Bluetooth worse, the transmission quality to be improved, but the transfer speed is very fast, you can reach 11Mbps, in line with the needs of personal and social information.Third manufacturers to enter the field is relatively low threshold. Vendors set up hot spots in airports, railway stations, coffee shops, libraries and other personnel intensive, and high-speed line Internet access to these places. Such hot spots to emit radio waves can reach tens of meters to 100 meters away from the radius of the access point, as long as the user will support wireless LAN notebook or PDA to get the region to high-speed Internet access. Means that manufacturers do not have expensive network cabling access, thus saving a lot of cost.Wi-Fi methods of organizingWi-Fi is a wireless network by the AP (Access Point) and Wireless LAN. Generally set up a wireless network equipped with a wireless card and the AP, so will be able to wireless mode, with both wired architecture to share network resources, erection cost and complexity of the program is far lower than a traditional wired network. If only a few computers, peer-to-peer network, can also be not to the AP, only require each computer is equipped with a wireless card. AP is generally translated as wireless access point, or bridge. It is mainly as a bridge between traditional wired local area networks and wireless local area network, a PC equipped with a wireless card can be wired local area network or wide area network to share resources through the AP, and its working principle is equivalent to a built-in wireless transmitter HUB or routing, wireless NIC is responsible for receiving the transmitted signal by the AP client premise equipment. With the AP as the wired network Hub in general, wireless stations can be quickly and easily connected to the network. Especially for the use of broadband, Wi-Fi even more advantages, cable broadband networks (ADSL, residential LAN, etc.) to the home, connecting to an AP, then install a wireless card in the computer. Ordinary families have an AP is enough, even the neighborhood of the users authorization, you do not need to add ports to a shared Internet.Wi-Fi is the complement of high-speed wired access technologiesAt present, the wired access technologies including Ethernet, xDSL, etc. Wi-Fi technology as a complement of high-speed wired access technology, has the advantage of mobility, inexpensive Wi-Fi technology is widely used in the field of need a wireless extension of wired access, such as the temporary venue. Data rate, coverage and reliability of the difference, Wi-Fi technology in broadband applications will be as a complement of high-speed wired access technologies. The key technology is no doubt decided to supplement efforts of the Wi-Fi. The OFDM, MIMO (Multiple Input Multiple Output) smart antennas and software radio, etc., are beginning to be applied to wireless local area network in order to enhance the performance of Wi-Fi, such as 802.11n plans to use MIMO and OFDM combined, so that the data rate has doubled and redoubled . In addition, the improvement of the antenna and transmission technology makes the wireless LAN transmission distance is greatly increased and can reach a few kilometers.Wi-Fi is the complement of cellular mobile communication and 3GSecondary positioning of the Wi-Fi technology - the complement of cellular mobile communication. Cellular mobile communication can provide a wide coverage, high mobility and the low data transfer rate, it can use the Wi-Fi high-speed data transmission characteristics to compensate for the deficiencies of their own data transfer rate is limited. Wi-Fi not only the use of cellular mobile communication network authentication and billing mechanisms, and characteristics of multi-access switching function can be combined with the wide coverage of cellular mobile communications network. This can be achieved the integration of Wi-Fi and cellular mobile communications, cellular mobile communications operators icing on the cake, to further expand its business volume. For telecom operators, Wi-Fi technology positioning is the complement of high-speed wired access technology, will gradually become the complement of cellular mobile communications. Of course, Wi-Fi and cellular mobile communications, there are a small amount of competition. On the one hand, for the Wi-Fi Voice over IP terminal has entered the market, part of the substitution effect on the cellular mobile communication. On the other hand, with the development of cellular mobile communication technology, Wi-Fi hotspots common application may be replaced by cellular mobile communication system part. But in general, the relationship of coexistence, such as some special occasions, high-speed data transfer must be by means of Wi-Fi, aircraft like the Boeing internal wireless LAN using Wi-Fi; while on other occasions can be more economical. like to achieve high-speed trains within the wireless LAN. It has a higher advanced technology, strong business skills and a wide range of applications. But the Wi-Fi can play in specific regions and within the important complementary role for 3G, Wi-Fi technology and 3G technology the combination will have broad prospects for development.Wi-Fi技术Wi-Fi的全称是Wireless Fidelity，又叫802.11b标准。它的最大优点就是传输速度较高，可以达到11Mbps，另外它的有效距离也很长，同时与已有的各种802.11DSSS设备兼容。伴随着Intel公司提出的笔记本电脑芯片组。“迅驰”被越来越多的人认可，这一技术也逐渐成为了大家关注的话题。不过自2005年底开始，很多手机厂商，特别是以生产智能手机为主的品牌便开始将Wi-Fi引入自己的产品当中。简而言之：Wi-Fi就是无线网络Wi-Fi已经广泛的应用在了笔记本电脑，手机掌上电脑，数码相机等移动终端上。有了Wi-Fi之后，不需要网线即可联入网络。越来越多的设备在出厂前安装了Wi-Fi模块，也有越来越多的场所提供了Wi-Fi信号覆盖。这样，Wi-Fi形成了一个从科研到设备生产、从网络接入到网络内容服务等一个庞大的产业链。2007年，全国包括Wi-Fi在内的wlan行业产业价值有望超亿美元。对于个人用户来说，Wi-Fi的普及，将是用户体验的一次飞跃。笔记本电脑用户将可以任意一个具备Wi-Fi信号覆盖的地方快速接入Internet而不需要再去寻找网线，越来越多的机场、酒店、公共场所都提供了Wi-Fi信号覆盖。及时带笔记本电脑开会，也不用担心会议室没有足够的网线插口。而在家中，您更可以在任何一个角落都覆盖无线信号，而不需要担心网线的走线影响整体室内美观。Wi-Fi在掌上设备上应用越来越广泛，而智能手机就是其中一份子。与早前应用 于手机上的蓝牙技术不同，Wi-Fi具有更大的覆盖范围和更高的传输速率，因此Wi-Fi手机成为了目前移动通信业界的时尚潮流。由于Wi-Fi的频段在世界范围内是无需任何电信运营执照的免费频段，因此WLAN无线设备提供了一个世界范围内可以使用的，费用极其低廉且数据带宽极高的无线空中接口。用户可以在Wi-Fi覆盖区域内快速浏览网页，随时随地接听拨打电话。而其它一些基于WLAN的宽带数据应用，如流媒体、网络游戏等功能更是值得用户期待。有了Wi-Fi功能我们打长途电话(包括国际长途哦)，浏览网页、收发电子邮件、音乐下载、数码照片传递等，再无需担心速度慢和花费高的问题。现在Wi-Fi翻盖范围在国内越来越广泛了，高级宾馆，豪华住宅区，飞机场以及咖啡厅之类的区域都有Wi-Fi接口。当我们去旅游，办公时，就可以在这些场所使用我们的掌上设备尽情网上冲浪了。一个Wi-Fi联接点网络成员和结构站点(Station) ，网络最基本的组成部分。基本服务单元(Basic Service Set, BSS) 。网络最基本的服务单元。最简单的服务单元可以只由两个站点组成。站点可以动态的联结(associate)到基本服务单元中。分配系统(Distribution System, DS) 分配系统用于连接不同的基本服务单元。分配系统使用的媒介(Medium) 逻辑上和基本服务单元使用的媒介是截然分开的，尽管它们物理上可能会是同一个媒介，例如同一个无线频段。接入点(Acess Point, AP) 接入点即有普通站点的身份，又有接入到分配系统的功能。扩展服务单元(Extended Service Set, ESS) 由分配系统和基本服务单元组合而成。这种组合是逻辑上，并非物理上的-不同的基本服务单元物有可能在地理位置相去甚远。分配系统也可以使用各种各样的技术。关口(Portal) 也是一个逻辑成分。用于将无线局域网和有线局域网或其它网络联系起来。这儿有3种媒介，站点使用的无线的媒介，分配系统使用的媒介，以及和无线局域网集成一起的其它局域网使用的媒介。物理上它们可能互相重迭。IEEE802.11只负责在站点使用的无线的媒介上的寻址(Addressing)。分配系统和其它局域网的寻址不属无线局域网的范围。IEEE802.11没有具体定义分配系统，只是定义了分配系统应该提供的服务(Service) 。整个无线局域网定义了9种服务，5种服务属于分配系统的任务，分别为，联接（Association), 结束联接(Diassociation), 分配(Distribution), 集成(Integration), 再联接(Reassociation) 。4种服务属于站点的任务，分别为，鉴权(Authentication), 结束鉴权(Deauthentication), 隐私(Privacy), MAC数据传输(MSDU delivery) 。Wi-Fi的主要技术优势1、无线电波的覆盖范围广，基于蓝牙技术的电波覆盖范围非常小，半径大约只有50英尺左右，约合15米。而Wi-Fi的半径则可达300英尺左右，约合100米。最近由Vivato公司推出的一款新型交换机，该款产品能够把目前Wi-Fi无线网络300英尺，接近100米的通信距离扩大到4英里，约6.5公里。2、虽然由Wi-Fi技术传输的无线通信质量不是很好，数据安全性能比蓝牙差一些，传输质量也有待改进，但传输速度非常快，可以达到11Mbps，符合个人和社会信息化的需求。 3、厂商进入该领域的门槛比较低。厂商只要在机场、车站、咖啡店、图书馆