The year ahead for optical networking

2020 changed everything, both in our personal lives and in our working lives. In particular, it saw a major shift in how we connect with each other, with digital links replacing face-to-face ones. This inevitably had consequences for the type of networks we rely on to provide that connectivity.

As a unique and challenging year finally ends, here are some trends in optical networking that we are expecting to see in 2021.

The pandemic recedes, but leaves a lasting legacy

We all hope to emerge from the COVID-19 pandemic in 2021, but it will inevitably leave behind it some permanent changes in how we work, and in particular to how we connect and communicate.

One of the biggest shifts that we’ve already seen is the rise of the remote worker. With so many people working from home, companies have in effect been forced to undergo a global workforce experiment. Some companies have announced that employees will be able to choose where they work from. Facebook estimates that half its people will continue to work remotely for the next several years. Google is experimenting with a hybrid home and office model.

What this amounts to is that the pandemic has driven increased work flexibility for many workers, with work location defined more by access to appropriate tools and network connectivity than a physical space.

Public appreciation of broadband networks will increase

COVID-19 proved how critical our broadband networks are. Remote education and remote work are simply not possible without access to a reliable, high-capacity broadband connection. If we needed any additional proof that broadband connectivity is critical to our lives, 2020 gave it to us.

As a result, we expect to see increased support for public funding of broadband networks to ensure quality high-speed connections across physical geographies. As one example, the United States Department of Agriculture (USDA) ReConnect Program is investing hundreds of millions of dollars in grants and loans to bring high-speed broadband connectivity to rural and undeserved areas. We can expect to see a lot more initiatives like this one as the year unfolds.

800G coherent DWDM goes mainstream

So what about the technology behind all this? For one thing, we expect to see 800G fifth-generation coherent DWDM optical solutions ramping up deployments in 2021.

It is a commonplace assumption that the headline rate of each successive generation of coherent DWDM technology is limited to 100-200 km reach. But fifth-generation technology is now changing the game. Now 800 Gb/s per wavelength transmission has been demonstrated in live service provider networks, including 950 km with a well-known operator.

The underlying technologies like 96 GBaud symbol rates, third-generation digital subcarriers, and longcodeword probabilistic constellation shaping are enabling dramatically better performance. The ability to provide increased capacity per fibre with fewer wavelengths and less equipment creates a great argument for adoption.

Open and disaggregated becomes the norm

Tightly integrated networking solutions like routers and packet optical transport equipment, where one vendor supplies all hardware and embedded software, has been the way we have always done things. But in truth such solutions can limit the pace of innovation and stifle choice for service providers.

By disaggregating and utilising well-defined open interfaces such as OpenConfig and Open ROADM, it is possible to isolate portions of a networking solution to speed innovation, enable choice, and improve costs. Service providers that are upgrading their 5G transport networks are increasingly interested in disaggregated routing solutions like the Telecom Infra Project’s Disaggregated Cell Site Gateway (DCSG).

We are also seeing the rise of open optical networking, where transponder/muxponder modules powered by next-generation optical engines are disaggregated from the underlying optical line system. Open optical networking means that the speed of optical engine innovation and the associated transponder/muxponder functionality can be accelerated while enabling broader industry deployment, as these modules can be run over any vendor’s optical line system. We expect 2021 to see a change in service provider thinking whereby ‘open and disaggregated’ becomes the new norm.

Multipoint pluggable optics have their moment

As the optical networking industry optimises packaging and power, we are getting the emergence of coherent DWDM pluggable modules like 400G ZR which can be plugged directly into a network infrastructure, like optical transport equipment and switches and routers. While beneficial for some applications, such solutions are not architecturally innovative.

Point-to-multipoint pluggable optics, on the other hand, are about truly reinventing network architectures. With support for 16 individually assignable 25 Gb/s subcarriers in a single pluggable 400G optic, service providers can reduce and/or eliminate intermediate electrical aggregation points in the network. An analysis recently showed that multipoint optics can deliver a 76% total cost of ownership savings for a major operator over a five-year period.

We expect 2021 to be the year when multipoint optics emerge from the lab and move into service provider networks.