Short-haul solutions
Not all the physics challenges have to do with more wavelengths traveling greater distances. ONI Systems CEO Hugh Martin says his company is more interested in moving traffic down the street, across town and from suburb to suburb.
On the long-haul network, information can travel from Los Angeles to Dallas without being touched by an optical switch. But the metro area is crowded with switches and couplers. It has its own regeneration and reamplification rules, and as speeds begin to zoom, the solutions get more complex.
"One minute, the traffic has to move down the street to the next building; the next, most of the traffic has to get 20 miles away," Martin says. On a 20-mile trek across a metro area, the signal passes through dozens of switches, each robbing the pulse of some of its accuracy.
ONI Systems builds a platform that incorporates devices from companies like Avanex, LaserComm and Xtera with its own Dynamic Power Control technology.
ONI's variable-gain amplifiers monitor the optical power of every wavelength in the metro area and change how much amplification exists in the system at any moment.
If the blue wavelength is on a milk run to the office down the street, the signal won't degrade, even if it's not on full power. But if blue suddenly is switched to a crosstown route, signal clarity becomes a factor and ONI's intelligent switch turns up the juice.
Most networks use a fixed system, adjusting, say, the blue wavelength to travel a 20-mile route, never longer than that, never shorter than that. ONI's dynamic power control can tweak the power and correct the dispersion, so that any wavelength can travel any distance and deliver intelligible data, voice or video.
"In real time, we adjust the power level of every colour," Martin says.
Ciena and Nortel Networks reportedly are working on similar systems, but ONI so far is the only company with announced customers - Qwest Communications International and Williams Communications.
"We either make the signal much brighter at the input, or have amplifiers along the way to juice the wavelength," Martin says. "At 10 gigs the signal-to-noise ratio gets important, and at 40 gigs it gets even worse."
