Coherent Super-Channels:
Long Haul DWDM Transmission at 100G and Beyond

With core network traffic increasing at about 40% per year, service providers need a long haul transmission technology that will deliver scalable, cost-effective capacity without compromising on optical reach. The DWDM industry is now aligned on the fact that multi-carrier super-channels are the way to quickly access the spectral capacity that coherent transmission delivers in a way that will scale WDM without scaling operations.

Building super-channel line modules requires both coherent electronics and optical components. Infinera’s FlexCoherent Processor provides the electronics function, delivering the industry’s first shipping coherent electronic ASIC featuring software selectable modulation. Infinera’s third generation 500 Gb/s Photonic Integrated Circuits provides the optical function in our super-channel implementation, integrating over 600 optical functions into a pair of small fingernail-sized chips.

Metro Reach Super-Channels Without Large Scale PICs
For companies who do not have access to large scale photonic integration they must use off the shelf optical components which consume more space and power than PICs – limiting single line card capacity to one long reach 100G channel using PM-QPSK modulation. In order to get more throughput they must use higher order 16QAM modulation in order to increase that to 200 Gb/s on a single on a single line card. Two of these line cards are then ganged together to create a 400 Gb/s, PM-16QAM super-channel. While 16QAM is spectrally efficient it will have a dramatically shorter optical reach compared to PM-QPSK. Additionally, these 16QAM multi-card super-channels are not production-ready today.

Long Haul Super-Channels With Large Scale PICs
Infinera is a world leader in photonic integration, and as a result we believe we are able to make a much better engineering decision when it comes to super-channels. Because PICs are extremely dense and use low power, we can fit 5 x 100 Gb/s PM-QPSK channels on a single line card. Infinera’s 500G super-channel can deliver full 500 Gb/s capacity with 3,000 km optical reach and is available today.

So don’t let your super-channels come up short – contact us today to arrange a demonstration of our flagship DTN-X platform.

1: Reach is estimated based on real world fiber and standard operational margins, not on lab conditions using specialized fiber

2: QPSK is highlighted for comparison because it is the most likely modulation technique to be used in long haul networks