LMDS Elixir

Innovative laser technology could be a boon for LMDS carriers in the future. Lucent's new optical networking system allows carriers to transmit different wavelengths or colors of light on the same fiber strand simultaneously, thereby increasing the capacity or bandwidth on each fiber that's in the network.

The OpticAir system could benefit many types of carriers, including RBOCs, CLECs, enterprise companies, distributors, government agencies and LMDS carriers, but Global Crossing will be the first to test the system. It plans to conduct field trials by December.

The technology allows carriers to transmit large amounts of data from point to point. (Initially, it will support a single channel at speeds up to 2.5Gb/s.) For LMDS carriers, the technology could provide a boost for bandwidth-greedy customers.

As the radios exhaust, the next-generation solution may be the placement of these systems alongside the radio system, either to increase the bandwidth of a particular customer or to open up or replace the radios, said Frank Galuppo, WaveStar OpticAir market & product development director.

For example, if an LMDS carrier has one customer that has extraordinary demand and is eating up all of the bandwidth in the spectrum, it can continue to support its other customers with the radio system and put the OpticAir technology in place for the intensive-use customer.

"We're not going to play down in the range in terms of bandwidth that these radios are currently supporting," Galuppo said. "We don't see this as a threat; we see this as an evolution from the LMDS service levels to much higher bandwidth levels of service."

Although the benefits look good on paper, LMDS carriers are mum about any plans they might have to consider this technology, explaining that there is a long way to go before it could be deployed on a broad scale. However, carriers did concede that the technology wouldn't compete with their initiatives. They suggested that the technology could be used in a campus-type environment and could be viable as an adjunct for their service. They broached a couple of concerns. They said the price needs to come down before they would look seriously at the technology. They also said technology issues, including dealing with weather conditions such as fog, need to be overcome.

NUTS & BOLTSThe purpose of the technology is to boost capacity of local data networks dramatically but also to extend the reach of today's high-capacity fiber-optic systems further toward the desktop by using beams of light to transmit information through the air.

Lucent plans to deliver the technology to the marketplace in March 2000. The first release will support one wavelength at speeds up to 2.5Gb/s. By the middle of summer 2000, Lucent plans to deliver four wavelengths for a maximum capacity of 10Gb/s.

"This is like sending data on 15 CD/ROMs through the air in less than a second," said Harry Bosco, Lucent optical networking business unit COO.

The system is the size of a birdhouse or mailbox. Its lasers, amplifiers and receivers can be placed on rooftops or in office windows to transmit information point to point through the air. According to Lucent, these lasers are not like the laser pointers that emit tiny high-density streams of light. These are ultra-wide lasers that emit beams of light that are invisible to the human eye.

ENVIRONMENTAL CONSTRAINTSAs with radio systems, the atmosphere does affect system performance, but these systems deal with visibility conditions such as fog as opposed to rain. However, as in RF systems, engineering rules will be applied to ensure that the system will meet customers' expectations. Those rules, like in RF, dictate the distance you can broadcast, and that will vary in regions around the world, Galuppo said. Lucent has run performance tests in most major cities around the world, and based on the results, expects approximately 99% system availability.

A bird or a leaf flying through the signal will not disrupt it because the bird is moving at too fast a rate, Galuppo said.

"The beam is dispersed a bit, so there may be some bit errors, but there certainly is not going to be any loss of signal with a condition like that," Galuppo said. "If this thing is installed in a window, and the window washer steps in front of it and remains there for a while, then yes, that would block the signal, but I think he would block the signal on the radio system." He added that there are a lot of similarities between the engineering and behavior of this system and LMDS, given that it is transmitted through the atmosphere. The difference is that radios have 50 years of operational history that engineers can draw on when predicting various conditions that will affect radio performance; this doesn't have 50 years, Galuppo said.

"We are starting that process now, and over time we will learn more about what does and what does not affect it," he said.

Fog could cause a problem. If the signal is broken, it would restore itself as soon as the atmospheric conditions improve, Galuppo said. The plan is to engineer the system so that those atmospheric conditions will not affect the performance of the system.

THE BEST-LAID PLANS ...No matter how well you plan, however, you can't predict Mother Nature.

"It could hail for some reason where it usually doesn't hail," said Andy Fuertes, Allied Business Intelligence senior analyst. "What if the bird decided to sit there for a while. These are all things that could happen, especially if it's on the roof."

He conceded that Lucent seems to be targeting specific types of applications, and for those applications, it would be a good product.

According to Lucent, one application might be shuttling data between high-rise office buildings separated by a river. A ship anchored off shore could transmit critical data to a base station on land, or a temporary data link could be installed between a company's headquarters and a stadium hosting an event across town.

It obviously has some good capabilities, Fuertes said. He added that the problem with this technology is much the same as with all optical systems -- the reliability and the number of applications.

"It sounds like a good complement to certain LMDS applications," Fuertes said. "Short-range, line-of-sight (where) interference wouldn't be an issue."

In these days of increased competition, the scramble for bandwidth and fast data transfers becomes intense. It's difficult to rule out any advantage that could spring you ahead. This type of technology could provide that boost for LMDS carriers.