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 |
2 Tbps |
20 |
3325 |
No regeneration |
Live network trial with Vodafone |
|
10 Tbps |
Ten 1 Tbps superchannels (not a single 10 Tbps superchannel) |
Not disclosed |
Not disclosed |
||
NEC Corp. |
1 Tbps |
10 |
5400 |
60 km amplifier spacing |
Lab experiment |
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 (News - Alert)/ 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.”