Escaping the Tyranny of Line of Sight in WLANs

By Ed Sutherland

February 15, 2002

Several companies described herein are developing technologies that obviate Line of Sight (LoS) issues in 802.11 wireless LANs.

When the fixed-wireless industry imploded last year, carriers such as AT&T Wireless and Sprint said the technology's dependence on a clear line of sight made delivering broadband wireless service to residential customers unprofitable. Today, as AT&T Wireless sheds the last vestige of its foray into fixed-wireless, companies see a bright future in "non-line-of-sight" alternatives.

Pointred Technologies' MicroRed Wireless Broadband Access product uses the 2.5 GHz band to route around "shadow areas" which previously required first-generation fixed-wireless systems to have a clear line of sight to their base stations.

The MicroRed base station, with its tiny footprint, can be installed on any elevated point -- a telephone pole, high building or water tower. Because of its "pay-as-you-grow" nature, MicroRed Wireless Broadband Access can be easily expanded to fill any gaps in coverage.

PointRed says that one MicroRed base station is capable of supporting multiple 802.11 connections to Wi-Fi hot spots.

Iospan Wireless, like PointRed has changed the fixed-wireless landscape by both beefing up the technology and bringing access closer to Earth.

In January, Iospan showed off its non-line-of-sight service at a gathering of broadband companies meeting in San Jose, California.

Iospan demonstrated its technology by blasting a highly-targeted and compressed beam of radio waves through the hotel wall where the meeting was held and then through a metal cookie sheet placed in front of an indoor antenna. Iospan told the assembled crowd that previous fixed-wireless signals would have stopped at the wall and been killed by the cookie sheet.

Another difference between the fixed-wireless of today and the first-generation of last year is the physical height operators must utilize to ensure a clear signal. Previously, fixed-wireless required a 1,000-foot tower to reach rooftop antennas. Today's systems need to be only 50 to 100 feet above ground to reach antennas little bigger than a pizza box located indoors or outdoors.

Netro, which recently paid $54 million in cash and stock for AT&T Wireless' failed fixed-wireless unit, shares the playing field with another maker of non-line-of-sight equipment called NextNet.

NextNet, which claims to have been the first company to offer non-line-of-sight gear in the U.S., is among the many fixed-wireless companies lured to rural areas -- the most attractive market for broadband wireless. Since late 2001, NextNet has beamed the wireless Internet to about 130 residents of Pocahontas, Iowa.

A survey by the Broadband Wireless Exchange shows fixed wireless coverage more than doubling during 2001. The survey of wireless ISPs found 1,966 markets where fixed wireless is available -- up from the year 2000 when there were just 723 markets.

Of those markets listed in the survey, the top 10 locations for fixed wireless are in rural areas of states such as California, Illinois and Texas. While served by major telecom firms such as Qwest Communications or SBC Communications, the areas weren't offered DSL access to the Internet.

Susan Lee, Pointred president and CEO, says she considers "areas with lower population densities" where it is not cost-effective for wired or wireless broadband services as being ripe for the latest version of fixed wireless Internet access.

Carriers fled the fixed-wireless arena last year, saying there were just too few markets for a faulty technology. Now, giants like Sprint are taking their first tentative steps using new non-line-of-sight systems. While publicly saying fixed-wireless remains in the distant future, Sprint is actively testing next-generation equipment in Montreal, Houston, and San Jose, California.

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