Global networking conceptual image

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Editor's note: OFC, the optical networking and communication conference, kicks off in a few days. In this special guest post, and a companion piece tomorrow, the meeting’s general chairs—Gabriella Bosco, Politecnico di Torino, Italy; Jörg-Peter Elbers, ADVA Optical Networking, Germany; and Laurent Schares, IBM Research, USA—reflect on the hot topics that will be front and center at the conference.

As OFC draws near, we’ve spent time together, preparing for the plenary session and the exciting discussions we expect to have onsite. A few topics rise to the surface in every conversation, including advances in modulation formats and the move toward faster optical interface speeds.

Increasing capacity and flexibility

Thanks to high-order modulation with coherent detection and advanced digital signal processing (DSP) techniques, the capacity of optical networks experienced a huge growth in the past few years. Integrated optics, high-speed analog-to-digital/digital-to-analog converters (ADCs/DACs) and advanced CMOS nodes propelled the line and symbol rate in commercial coherent products up to 600Gbps and ~70Gbaud, respectively. This facilitates the transport of six times 100GbE on one, or three times 400GbE on two optical carriers.

The traffic growth foreseen in the near future cannot be efficiently supported by static increases in network capacity. Flexible coherent transponders will play a key role in optimizing network efficiency, as they can adapt the bit rate, modulation format and symbol rate to the actual conditions of a lightpath. The same transponder can then be configured to operate over metro, long-haul, and submarine distances.

Improving coherent transponder technology

While increasing the interface speeds and flexibility is one development direction, there is also strong market demand for cheaper, smaller, energy-efficient coherent transponder technology. Targets are pluggable digital coherent optical transceiver modules, such as for 400GbE datacenter interconnect (400G-ZR) and 100–400Gbps metro-regional applications.

There’s much to discuss and discover as we unpack where we are today and where the industry will go, yet one thing is certain: We have to continue to push the limits of technology.

What will the next symbol rates be? How can we design simpler yet efficient modulation schemes and signal-processing algorithms? Can we increase the robustness against fiber nonlinearities? How will we manage complexity? Will we look to AI, and how will we use it?

OFC offers a great opportunity to get together and debate these topics; we hope to continue the dialogue with you in San Diego.