Infinera Boasts Long-Haul Optical Network Breakthrough

Infinera believes it has cracked one of the major challenges of the optical networking world -- how to increase network capacity without sacrificing transmission distance.

The vendor has developed a new set of transport capacity tools, collectively called the Advance Coherent Toolkit (ACT), that it has tested with Telstra Corp. Ltd. (ASX: TLS; NZK: TLS) over part of the Australian operator's subsea network. The results appear to show that Infinera's package of next-generation coherent optical and signal processing technologies will boost fiber capacity over longer distances: That's important, as most technologies that increase fiber capacity can do so only at the expense of network reach.

It's also important because operators need to find ways to economically enhance their networks in order to cope with the expected further increases in data volumes (particularly from video traffic) and to prepare for a 5G world. (See Ericsson Predicts 150M 5G Subs in 2021 and Cisco's Visual Networking Index.)

Infinera Corp. (Nasdaq: INFN)'s ACT comprises a number of photonic and signal processing advances -- including polarization-multiplexed 8QAM and 16QAM (quadrature amplitude modulation), the addition of digital signal processing at the transmitter as well as the receiver, and high-gain Soft Decision Forward Error Correction (SD-FEC) -- that build on the company's existing 500Gbit/s and 1Tbit/s super-channel capabilities. (See Telstra Tries Infinera's New Optical Toolkit.)

Of particular interest, though, is the introduction of Nyquist capabilities. Nyquist is a particular technique that enables an optical carrier to be split into a number of subcarriers that can transmit data over greater distances. As Infinera explains in a new white paper:

    In a conventional super-channel, multiple coherent optical carriers are implemented on a single PIC [photonic integrated circuit], on which each laser produces a single modulated carrier. By using the advanced functions of Infinera's FlexCoherent DSP [digital signal processor] and DAC [digital-to-analog converter], each optical carrier can be further synthesized into multiple quasi-Nyquist subcarriers that are closely spaced to each other.

Source: Infinera
Source: Infinera

The full range of Infinera's new capabilities "optimize the fiber resource for capacity and reach -- usually it's a trade-off between them but this does both," Pravin Mahajan, the company's director of product and corporate marketing, tells Light Reading. "This was successfully validated by Telstra late last year in the most challenging environment… on a 9,000km subsea link between Sydney and Hawaii."

Telstra is supporting Infinera's publicity about its new capabilities but details of the gains that the operator experienced during the trial have not been shared: The Infinera team will only say that average distance gains from subcarrier implementation are about 20%, so not insignificant on long-distance routes.

Mahajan is particularly bullish about Infinera's Nyquist subcarrier capabilities. "This will be the first commercial implementation … we are pioneering this," says the Infinera executive.

That development is significant, says Heavy Reading senior analyst and optical networking specialist Sterling Perrin. He notes that "jamming a lot of carriers into a smaller amount of spectrum" and being able to boost both capacity and distance is a big deal, and "Nyquist is the key here -- it looks like Infinera might be the first to get this to product."

But Perrin has no doubt that Infinera's rivals will be working to achieve the same goals. "This is an application for long-haul terrestrial and submarine networks and the long-haul 100G-plus market is a four-horse race between Infinera, Alcatel-Lucent (now Nokia), Ciena and Huawei … There's a chance that those other companies could announce something soon too."

Announcing something is one thing -- making it commercially available is another. Mahajan says some of Infinera's new capabilities will be made available this year and others at unspecified later dates. "Yes, it's going to be a while" before the full set of advanced coherent technologies are commercialized, he concedes.

— Ray Le Maistre, Circle me on Google+ Follow me on TwitterVisit my LinkedIn profile, Editor-in-Chief, Light Reading

Keebler 1/18/2016 | 11:32:29 AM
Subcarrier Modulation never quite goes away If I recall my signal processing courses correctly, the "Nyquist" promoted here is subcarrier modulation (idealized, but the same technology). It's interesting to see how that technology has gone in and out of fashion as digitial signal processing has improved. Remember the olden days of companies like Silk Road and Kestrel Solutions proposing SCM for 10G? Then the 40G SCM announcements? And the direct-detect 100G SCM modules?

Perhaps SCM has finally found its long-term niche. Getting symbol rates down via SCM means longer distance transmission due to lowered sensitivity to impairments. I imagine that every one of the big 4 mentioned in the article are very familiar with SCM and have research dollars already allocated to it. The trick is to find the balance between SCM and DSP. It should be interesting to watch how it plays out across the industry.
[email protected] 1/18/2016 | 9:12:56 AM
More important than being first - being trusted Being first is usually a good thing but being trusted is, I would say, more important.

The good news for Infinera is that, at least in my experience of talking to operators that have used its technology, its tech tends to do 'what it says on the tin'.

IF Infinera can be first or at least not far behind in boosting capacity and distance on long-haul networks IN AN AFFORDABLE WAY then it should get new/more business.

The cost to an operator, of course, is also very important -- the case-by-case ROI story will also determine uptake. 

Expect to hear more on this topic in general and Nyquist in particular, at OFC... 

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