There’s a lot going on with ultra-high-speed optical transmission lately. Several manufacturers – including Huawei, Infinera, and NEC, as well as Bell Labs -- have demonstrated some really high speeds of a terabit or more per second.
This wave of optical networking one-upmanship has been made possible by the industry’s move toward a flexible grid that gives manufacturers the ability to tweak the spacing in between wavelengths, thereby enabling manufacturers to squeeze more wavelengths onto a fiber. Manufacturers also are combining multiple wavelengths, known in this context as sub-carriers, into a single logical connection, known as a carrier.

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If you combine a lot of subcarriers, use a flexible grid and reduce the distance covered or distance between regeneration points on the network, you can get some impressive data rates.
Here’s a summary of what’s been demonstrated in the last couple of months:
Manufacturer
|
Speed
|
Subcarriers
|
Distance (km)
|
Amplification/Regeneration
|
Comments
|
Bell Labs
|
1 Tbps
|
8
|
5600
|
In-line amplifiers at terrestrial amplifier spacing- no repeaters
|
Lab results
|
Bell Labs
|
1 Tbps
|
4
|
2400
|
See above
|
Lab results
|
Bell Labs
|
1 Tbps
|
2
|
3200
|
See above
|
Lab results
|
Huawei
|
2 Tbps
|
20
|
3325
|
No regeneration
|
Live network trial with Vodafone
|
Infinera
|
10 Tbps
|
Ten 1 Tbps superchannels (not a single 10 Tbps superchannel)
|
Not disclosed
|
Not disclosed
|
“Technology showcase” with Telefonica
|
NEC Corp.
|
1 Tbps
|
10
|
5400
|
60 km amplifier spacing
|
Lab experiment
|
NEC Corp.
|
1 Tbps
|
10
|
7200
|
See above
|
Lab experiment
|
Considering all the variables that can come into play, it would appear that resolving standards for the next optical speed tier will be a complex process. Complicating matters is the fact that the industry has not yet agreed on standards for 400 Gbps equipment – although the lack of standards hasn’t prevented at least one carrier from deploying 400 G equipment (as we noted last week in our coverage of France Telecom/ Orange’s 400 Gbps deployment).
When standards bodies undertake the task of determining standards for optical transmission at speeds of 1 Tbps or greater, I would expect that service providers would like the ability to minimize regeneration requirements and the number of wavelengths used when shorter distances are involved. Accordingly I would expect to see the industry adopt several different 1 Tbps standards for different requirements -- particularly different distance requirements. Ditto for 2 Tbps or 10 Tbps standards.
What I wouldn’t expect to see is service providers waiting for standards before deploying equipment supporting 1 Tbps or higher speeds. Service providers often don’t mix optical transport equipment from multiple manufacturers in their networks, so a lack of vendor interoperability – at least for initial deployments -- may not be a deal breaker.
NEC said 1Tbps equipment could be ready as soon as 2015 if the company decides to undertake such a project. Huawei said commercial availability of 2 Tbps equipment would be “after 2015.”
Edited by
Rich Steeves