Part 4: Coherent optics drive efficiency

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Having previously overseen the build out of the Connecticut Education Network, one of the first K-20 networks in the United States leveraging an optical gigabit network to every school district and college in a state, Vietzke has knows first-hand the challenges of building a large-scale optical network.

But what's made Internet2's life easier in taking on this new 100 Gbps network initiative forward is the advent of coherent optics.

When service providers deploy systems that coherent optics with technologies such as technologies such as coherent detection, Dual Polarization Quadrature Phase Shift Keying modulation, and advanced electronic digital signal processing techniques, they can corrects signal degradations caused by fiber impairments.

Having coherent technology in Internet2's arsenal has made the migration to 100 Gbps for Internet2 more efficient than what they could have done it could have been even just a decade ago.

For one, service providers had to figure out what dispersion compensation elements they needed for each network site, meaning they had to keep a large inventory of spare parts on hand. 

"In a national network like the one we're building, the reach and simplicity of coherent optics that has been introduced into the optical system has made it easier," Vietzke said. "When I built optical networks 10 years ago, we spent a lot of time figuring out what dispersion compensation to put in what site and a lot of custom modeling tools, but the coherent technology makes all of that a lot simpler."

With the first route set to be operational by mid-summer, Internet2 does not plan to mix 10 Gbps wavelengths with 40 Gbps and 100 Gbps wavelengths because Vietzke says doing that could dilute the benefits of the coherent optics. 

"We're going to go straight to 40 and 100 Gbps, but if we need a 10 Gbps wave we'll build it on a 4 X 10 on a 40 Gbps wavelength wavelength or a 10 x 10 on a 100 Gbps wavelength," he said. "That's probably not happening anywhere else because most folks that are deploying 100 Gbps are doing it on an overlay on something they already have."

But the initial 100 Gbps network is not the last stop in its network journey as Internet2 is working on an overlay project connecting other cities.

When it completes its new 100 Gbps network upgrade to serve as part of the U.S. Unified Community Anchor Network (U.S. UCAN) project, Internet2 believes they will reestablish themselves not only as a bandwidth provider, but also a driver of community research services.

Internet2 combined infrastructure topology

Part 4: Coherent optics drive efficiency
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