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What You Need to Know About Super C Technology

Christain Uremovic

May 30, 2024
By Christian Uremovic
Senior Director, Solution Marketing

My Observations from OFC 2024

Super C is at the forefront of innovation in high-capacity optical transmission and represents one of the key technologies that will help network operators manage the ever-increasing demand for bandwidth. At OFC 2024, we were excited to include a live Super C technology demonstration as part of our open optical networking innovation showcase. The discussions we had with our service provider and internet content provider customers gave us further insights into the critical role Super C will play in the evolution of optical networks. In this blog, I’ll share these insights as well as details on our successful Super C demonstration.

Why the time for Super C is now

We all know traffic keeps growing at a fast pace. In the past decade, we have been able to improve fiber capacity and spectral efficiency with the coherent transceiver technology evolution. Starting with 100 Gb/s and PM-QPSK’s 4 bits per symbol, which enabled 9.6 Tb/s transmission over the extended C-band’s 4.8 THz of spectrum, we later evolved to 600 Gb/s with PM-64QAM’s 12 bits per symbol, which enabled up to 38.4 Tb/s transmission. This allowed us to boost fiber capacity by four times within the same 4.8 THz of extended C-band spectrum. However, as increasing the modulation beyond PM-64QAM’s 12 bits per symbol results in greatly diminished reach, subsequent embedded coherent technology generations, including 800 Gb/s, 1.2 Tb/s, and even 1.6 Tb/s per wavelength have kept leveraging PM-64QAM or PCS-64QAM as their highest-order modulation, with a maximum of 12 bits per symbol. As a consequence, spectral efficiency gains are now only incremental, and we are now at a turning point when we need to look elsewhere for fiber capacity increases.

One way to expand fiber capacity is to reach out into the L-band, which can double fiber capacity. However, L-band technology requires additional hardware, including amplifiers at each site, making it more costly and operationally more complex, especially when you only need a bit more fiber capacity than the extended C-band can deliver.

Another possibility is to increase fiber spectrum utilization within the C-band into the so-called Super C-band, with its 6.1 THz of spectrum. That’s 27% more spectrum for data transport. And the timing is just perfect. First, the equipment ecosystem has EDFA amplifiers supporting Super C-band now largely available. Second, many operators are upgrading their optical line systems or are about to consider upgrading soon in order to modernize their optical transport network environments by enabling open APIs on the optical layer, supporting an open networking environment, improving scalability, and reducing space and power with new line system technology.

Operators understand that Super C is not a proprietary technology

This progression to expand C-band operation is nothing new. As per ITU-T standards, the industry started standard C (3.2 THz) then expanded to Extended C (4.8 THz). There were also vendors using 4 THz of spectrum, and some have utilized 4.4 THz of spectrum. We are now ready to move to Super C (6.1 THz). As a matter of fact, ​Super C has already been deployed, predominately in the APAC region, for several years, which has resulted in the emergence of an optical component ecosystem to support it. Super C-band also interworks with standard and Extended C-band and is not proprietary, which brings me to the next point:

How does Super C technology interwork with Extended C-band technology?

Super C-band extends the spectrum at both ends of the extended C-band. We can directly connect extended C-band amplifiers and ROADMs with Super C-band amplifiers and ROADMs, as demonstrated at OFC in a live network. Additionally, Extended C-band and Super C-band components can also be mixed within a single node and site with our Infinera GX solution, enabling smooth migration toward Super C-band.

Am I locked into Super C-band once I deploy it?

As the extended C-band is a subset of the Super C-band, it does not lock operators into using only Super C-tunable transponders. If an operator deploys a system that has Super C + Super L line capability, they are not required to use Super C-band transponders when they add channels in the Extended C- and Extended L-band parts of the spectrum, and they do not need to use the additional spectrum if they don’t need it. As more vendors deliver transponders that support Super C + Super L spectrum, our system will support those too. Also, we optimize based on GOSNR principles for each channel regardless of whether the channel is an Infinera or a third-party wavelength. If operators want the added capacity of Super C and Super L, then our transponders will support that extra spectrum.

How about Super C performance?

We also get asked about performance, and specifically how the Super C-band impacts performance in our networks, as this is an important factor to realize the lowest total cost of ownership. Infinera’s implementation of Super C-band incorporates dedicated technology to flatten the wider gain and amplify the wider spectrum. To analyze performance in more detail, we have modeled 300 links of various lengths ranging from 200 km to 3,000 km using the latest coherent 1.2T transponder technology in the extended C-band and compared it to our Super C-band technology. The modeling results demonstrate that we can maintain the same average wavelength capacity across the 300 links on the Super C-band while increasing the number of channels and fiber capacity. In fact, average wavelength capacity is improved by about 2%, resulting in incremental Super C-band capacity of close to 30%.

And what about Super C power consumption?

With our latest GX technology implementation and our dual EDFA amplifier sleds, where a single module hosts both amplifier directions, we provide lower power consumption compared to our previous extended C-band EDFA technology that utilizes a dedicated module per direction. We also conducted measurement comparisons with our newest, most compact and flexible line system – the Infinera GX platform – between the extended C-band EDFA and ROADM solution and the Super C-band EDFA and ROADM solution. The results demonstrate lower watts per hertz, with power savings between 12% in maximum power configurations and up to 34% in typical operational environments.

OK, great, but what about the cost of Super C-band technology?

Super C technology has a lower loaded cost than Extended C-band solutions. The OLS Super C network design needs the same amount of equipment, such as amplifiers and ROADMs, compared to extended C-band designs. However, the minor cost increase for Super C components enables more capacity and results in lower cost per THz in total. Moreover, with 27+% capacity expansion, Super C also postpones the need and costs associated with adding L-band transmission if more capacity is needed than the extended C-band can provide alone.

Summary

We believe that more vendors will adopt Super C-band technology as the benefits are just too obvious. We are excited about the great opportunities we already have and see in front of us.

As always, it was very interesting to talk with operators at the OFC event and to showcase our Super C technology. We were happy to see their interest and curiosity during the many conversations.

Below you can see our demo setup, where we showed Super C-band interworking with extended C-band in the same network. And as a side note, we also demonstrated our Super C-tunable ICE7 1.2 Tb/s technology bridging 300 km at 1.2 Tb/s per wavelength. With Super C transponders and a Super C open optical line system enabled by the Infinera GX, we are able to provide up to 30% additional fiber capacity than what the rest of the industry is able to achieve, thus helping operators to lower their total cost of ownership further.

Tags: Optical