New Technologies

Just when you thought you understood wireless, or at least were learning about the key technologies, along comes more systems to consider. Sprint (external link) is now using the fiercesomely titled Multi-channel multi-point distribution service, known as MMDS, to provide wireless broadband in. among other cities, Denver, Colorado, Salt Lake City, Utah, and Phoenix and Tucson Arizona. What they call Sprint Broadband Direct.You get an internet connection up to 4Mbps downstream and 512 Kbs upstream.

All this operaties in the 2,150 to MHz and 2,500 to 2,690 MHz band, for which Sprint paid to be licensed. I'm interested because it is wireless and because it offers a faster way to deliver a voice call over the internet. Using a single, centrally located antenna, Sprint claims a coverage area 35 mile in radius from the tower. Although the transmitter is fixed, could one do telephony and video-conferencing on a laptop while driving around a city?

And, in the hard to believe but really neat category, AirFiber (external link) and TeraBeam (external link) Networks have developed optical wireless networks, that is, information systems using light. Without any cable. Fiber optic cable, in other words, without the fiber. No need to dig up the street to place a high bandwidth network into place. Previously, if you wanted to hook up several companies in, say, the financial district of San Francisco or New York, you would have done just that, started digging and started paying the big bucks.

The only other options were to lease someone else's lines or build an urban microwave network, something near impossible, since most city microwave frequency assignments have been long taken. In the case of AirFiber, rooftop mounted transceivers pass laser generated light between building tops. At up to 622Mbs per second! TeraBeam connects buildings as well, but using near infra-red light beams. The neatest part? No need for roof mounted equipment. They use, instead, 20" dishes that are mounted in a window. No building permits either, any floor, depending on its orientation, could be engineered to be part of a network. Thinking fog and rain will ruin a TeraBeam day? They're building their first system in Seattle, Washington. As they say, if it works there, then it will work anywhere. At the least, these systems are worth keeping track of.