802.11b at 20 to 72 Miles

It is possible to have point-to-multipoint links in excess of over 1,500 feet with ordinary equipment at the client side. Using high-gain antennas, sensitive receivers, and amplifiers, if necessary, it is possible to achieve Ethernet-like speeds over point-to-point links that exceed 20 miles. An experiment proved that it is theoretically possible to drive 802.11b signals well over 20 miles using stock equipment.[2] In fact, a 72-mile link from San Diego to San Clemente Island has been established by Hans Werner-Braun using some specialized 802.11 equipment on the 2.4 GHz band.[3] Figure 3-2 illustrates the range of 802.11b.

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Figure 3-2: The range of 802.11b exceeds 20 miles.

In summary, 802.11b, by itself, is not limited to a range of 100 meters. Its maximum range is in excess of 20 miles. A scatological comparison is that of the telephone central office, where the maximum range of the signal over copper wire is 18,000 feet (3 miles) without a repeater. It could be argued that the maximum, unboosted range of 802.11b exceeds that of the PSTN.

[2]Rob Flickinger, "A Wireless Long Shot," O'Reilly Network, www.oreillynet.com/pub/a/wireless/2001/05/03/longshot.html, May 3, 2001.

[3]Bob Brewin, "San Diego Wireless Net Installs 72-Mile, 2.4-GHz Link," Computer World, www.computerworld.com/mobiletopics/mobile/story/0,10801,75830,00.html, November 12, 2002.



Wi-Fi Handbook(c) Building 802.11b Wireless Networks
Wi-Fi Handbook : Building 802.11b Wireless Networks
ISBN: 0071412514
EAN: 2147483647
Year: 2003
Pages: 96

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