8 résultats pour "wireless"
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Wireless Communications.
were large, heavy units. After the invention of the transistor in 1948, radios shrank in size to small handheld radio transceivers. Public two-way radios with severalfrequency options are widely available as well. Usually limited in range to a few miles, these units are great aids for such mobile professionals as construction workers,film crews, event planners, and security personnel. Simpler two-way radios, called walkie-talkies, have been popular children’s toys for years. Most walkie-talkiesb...
- Wireless LAN - Informatik.
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Telecommunications.
commonly referred to as wireless communications, use technologies such as cordless telephones, cellular radio telephones, pagers, and satellites. Wirelesscommunications offer increased mobility and flexibility. In the future some experts believe that wireless devices will also offer high-speed Internet access. C Wires and Cables Wires and cables were the original medium for telecommunications and are still the primary means for telephone connections. Wireline transmission evolved fromtelegraph...
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Internet.
usually pays a fixed monthly fee for a dedicated connection. In exchange, the company providing the connection agrees to relay data between the user’s computer andthe Internet. Dial-up is the least expensive access technology, but it is also the least convenient. To use dial-up access, a subscriber must have a telephone modem, a device thatconnects a computer to the telephone system and is capable of converting data into sounds and sounds back into data. The user’s ISP provides software that con...
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Network (computer science).
computer. Since there is only one token in the network, only one computer can transmit information at a time. Token Ring networks are now quite rare. Most LANs nowuse Ethernet technology. International Business Machines Corporation (IBM), the company that invented Token Ring in the early 1980s, no longer promotes thetechnology. In the mid-1990s a new protocol called Asynchronous Transfer Mode (ATM) was introduced. This protocol encodes data in fixed-sized packets called cells rather thanvariable...
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Cellular Radio Telephone.
There were more than 120 million wireless subscribers in the United States in 2001, according to the Cellular Telecommunications and Internet Association, with thenumber of new users increasing significantly each year. Forecasters and regulators did not anticipate this growth, however. Network equipment and start-up costs weresubstantial, and the cost to consumers was high. Providers had limited their networks to a small group of high-volume business users. Eventually, the providersrecognized th...
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World Wide Web.
browser does not display the URL for the user. Instead, to indicate that an item is selectable, the browser changes the color of the item on the screen and keeps theURL associated with the link hidden. When a user clicks on an item that corresponds to a selectable link, the browser consults the hidden information to find theappropriate URL, which the browser then follows to the selected page. Because a link can point to any page in the Web, the links are known as hyperlinks. See also Hypermedia...
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Le Wi-Fi
~ 1 ~ Wi -f i i s a pr etty r e cen t w i r el es s r a di o co mm uni cati o n te c hno l o gy us e d i n par ti cul ar i n co mp uti n g a cti v i ti es . I t i s us ed i n p ar ti c ul ar f o r w i r el es s l o cal n etw o r ks , a nd no w ad ay s i t’s t he f i r s t w ay to ac ces s t he i nter net. What are the advantages and the drawbacks of Wi -Fi technology, and how safe is it ? SUMMARY I - General Presentation .............