The word wireless usually conjures images of cell phones, handheld computers or other personal communication devices rather than the information moving among them. The gadget mind-set, however, is a recent phenomenon that disregards the history and evolution of the wireless medium. For the first hundred years after Guglielmo Marconi’s early radio experiments in 1895, wireless simply meant a way to transmit electrical signals without (duh) a wire. Wireless first entered the mainstream telecommunications space in 1969 when the FCC approved a plan by MCI (Microwave Communication Inc.) to provide long-distance telephone service with wireless radio signals. And despite the nation’s obsession with gadgets and gizmos, the wireless-way-to-deliver-information continues to evolve. (For a look at other wireless technologies, see "Wireless that Works," Page 60.)

To differentiate themselves from the mobile device world, companies using radio waves and stationary antennae have adopted the label "fixed wireless." Because there is no need for mobility, these companies can use relatively large transmitters (compared with mobile devices that need to be portable) and consequently achieve transmission rates comparable to or higher than T1 and DS-3. Since there is no cable to run, fixed wireless can be a significantly cheaper way to span the fabled last mile.

There are two different approaches to fixed wireless: point-to-point, which allows for large broadcasts between two points; and point-to-multipoint, which essentially creates a high-speed wireless network. Each is used in different situations and has distinct benefits and challenges.

Point-to-Point

Point-to-point is the basic form of fixed wireless: a small dish antenna transmits data over a distance to another dish. The range is limited by line-of-sight. Under ideal conditions, a signal can travel 30 miles, but if anything gets in the way, you don’t get your signal.

For the University of Texas at El Paso (UTEP), its 100Mbps antenna delivers data only a fifth of that distance, but it spans two countries. UTEP is a Gigapop (access point) for the Internet2 project, one of about 30 such points in the world that provide connections to the high-speed next-generation Internet being used by a handful of universities to share media-rich applications. Keeping with its close relationship with the University of Juarez just over the U.S.-Mexico border, UTEP decided to lay a dedicated Internet2 line to the Mexican school, which could, in turn, use existing landlines to share Internet2-based research with other schools in Mexico and Central America.