Résumé
Wireless broadband is a telecommunications technology that provides high-speed wireless Internet access or computer networking access over a wide area. The term encompasses both fixed and mobile broadband. Originally the word "broadband" had a technical meaning, but became a marketing term for any kind of relatively high-speed computer network or Internet access technology. According to the 802.16-2004 standard, broadband means "having instantaneous bandwidths greater than 1 MHz and supporting data rates greater than about 1.5 Mbit/s." The Federal Communications Commission (FCC) recently re-defined the definition to mean download speeds of at least 25 Mbit/s and upload speeds of at least 3 Mbit/s. A wireless broadband network is an outdoor fixed and/or mobile wireless network providing point-to-multipoint or point-to-point terrestrial wireless links for broadband services. Wireless networks can feature data rates exceeding 1 Gbit/s. Many fixed wireless networks are exclusively half-duplex (HDX), however, some licensed and unlicensed systems can also operate at full-duplex (FDX) allowing communication in both directions simultaneously. Outdoor fixed wireless broadband networks commonly utilize a priority TDMA based protocol in order to divide communication into timeslots. This timeslot technique eliminates many of the issues common to 802.11 Wi-Fi protocol in outdoor networks such as the hidden node problem. Few wireless Internet service providers (WISPs) provide download speeds of over 100 Mbit/s; most broadband wireless access (BWA) services are estimated to have a range of from a tower. Technologies used include Local Multipoint Distribution Service (LMDS) and Multichannel Multipoint Distribution Service (MMDS), as well as heavy use of the industrial, scientific and medical (ISM) radio bands and one particular access technology was standardized by IEEE 802.16, with products known as WiMAX. WiMAX is highly popular in Europe but has not met full acceptance in the United States because cost of deployment does not meet return on investment figures.
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