1、 1700 单词， 2950 汉字 Wi-Fi Technology Wi-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
2、 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 sho
3、rt: 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-F
4、i 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 us
5、ers, 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.
6、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
7、-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 th
8、e 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
9、 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 lon
10、ger 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
11、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 ba
12、sic 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,
13、 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 combin
14、ation 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 us
15、es 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
16、 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,
17、 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 (
18、Privacy), MAC data transmission (the MSDU delivery). The main technical advantage of the Wi-Fi First 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
19、 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 g
20、ood 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
21、 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 wirel
22、ess 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 organizing Wi-Fi is a wireless network by the AP (Access Point) and Wireless LAN. Generally set up a wireless ne
23、twork 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
24、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
25、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, wir
26、eless 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.
