Ciena becomes a computer weaver
- Ciena is to buy optical interconnect start-up Nubis Communications for $270 million.
- The deal covers optical and copper interconnect technology for data centres
Ciena has announced its intention to buy optical engine specialist Nubis Communications for $270 million. If the network is the computer, Nubis’ optical engine and copper integrated circuit (IC) expertise will help Ciena better stitch together AI’s massive compute fabric.
Ciena signalled its intention to target the data centre earlier this year at the OFC show when it showcased its high-speed 448-gigabit serialiser-deserialiser IC technology and coherent lite modem. Now, Ciena has made a move for start-up Nubis, which plays at the core of AI data centres.
“Ciena’s expertise in high-speed components is relevant to 400G per lane Ethernet transceivers, but they never sold any products to this market,” says Vladimir Kozlov, CEO of LightCounting. “Nubis offers them an entry point with several designs and customer engagements.”
With the deal, Ciena is extending its traditional markets of wide area networks (WAN), metro, and short-reach dense wavelength division multiplexing (DWDM) to include AI networking opportunities. These opportunities include scale-across networks, where AI workloads are shared across multiple data centres, something Ciena can address, to now scale-out and scale-up networks for AI clusters in the data centre.
Puma optical engine
Nubis has developed two generations of compact optical engines for near-package optics (NPO) and co-package optics (CPO) applications. Its first-generation engine operates at 100 gigabits per second (Gbps), while its second, dubbed Puma, operates at 200 Gbps.
Nubis’s optical engine philosophy is based on escaping the optical channels from the surface of the optical engine, not its edge. The start-up also matches the number of optical channels to the electrical ones. The optical engine can be viewed as a sieve: data from the input channels flow through the chip and emerge in the same number of channels at the output. The engine acts as a two-way gateway, with one side handling electrical signals and the other, optical ones.
The Puma optical engine uses 16 channels in each direction, 16 by 200Gbps electrical signals for a total of 3.2 terabits per second (Tbps), and 16 fibres, each fibre carrying 200Gbps of data in the form of a wavelength. Puma’s total capacity is thus 6.4 terabits per second (Tbps). The engine also needs four external lasers to drive the optics, each laser feeding four channels or four fibres. The total fibre bundle of the device consists of 36 fibres: 32 for data (16 for receive and 16 for transmit), and four for the laser light sources.
Nubis is also a proponent of linear drive technology. Here, the advanced serdes on the adjacent semiconductor chip drives the optical engine, thereby avoiding the need for an on-engine digital signal processor (DSP) that requires power. The start-up has also developed a system-based simulator software tool that it uses to model the channel, from the transmitter to the receiver. The tool models not only the electrical and optical components within the channel but also the endpoints, such as the serdes.
Nitro
Nubis has an analogue IC team that designs its trans-impedance amplifiers (TIAs) and drivers used for the optical engine. The hardware compensates for channel impairments with low noise, high linearity, and at high speed. It is this channel simulator tool that Nubis used to optimise its optical engine, and to develop its second key technology, which Nubis calls Nitro —a chip that extends the reach of copper cabling.
“We use our linear optics learning and apply it to copper straight out of the gate, “said Peter Winzer, founder & CTO at Nubis, earlier this year. By using its end-to-end simulator tool, Nubis developed the Nitro IC, which extends the 1m reach of direct-attached copper to 4m using an active copper cable design. “We don’t optimise the driver chip, we optimise the end-to-end system,” says Winzer.
Nubis was also part of a novel design based on a vertical line card to shorten the trace length between an ASIC and pluggable modules.
Ciena’s gain
The acquisition of Nubis places Ciena at the heart of the electrical-optical transition inside the data centre. Ciena will cover both options: copper and optical interconnect. Ciena will gain direct-drive technology expertise for electrical and optical interfaces, enabling scale-up, as well as optical engine technology for scale-out, adding to its coherent technology expertise.
Ciena’s technologies will span coherent ultra-long-haul links all the way to AI accelerators, the heart of AI clusters. By combining Ciena’s 448-gigabit serdes with Nubis’s optical engine expertise, Ciena has a roadmap to develop 12.8Tbps and faster optical engines.
The acquisition places Ciena among new competitors that have chip and optical expertise and deliver co-packaged optics solutions alongside complex ICs such as Broadcom and Marvell.
The deal adds differentiation from Ciena’s traditional system vendor competitors, such as Cisco/ Acacia and Nokia. Huawei is active in long-haul optical and makes AI clusters. Ciena will also compete with existing high-speed optical players, including co-packaged optics specialists Ayar Labs and Ranovus, microLED player Avicena, and optical/IC fabric companies such as LightMatter and Celestial AI.
“Ciena will be a unique supplier in the co-packaged optics/near-packaged optics/active copper cabling data centre interconnect market,” says Daryl Inniss, Omdia’s thought lead of optical components and advanced fibre. “The other suppliers either have multiple products in the intra data centre market, like Broadcom and Nvidia, or they are interconnect-focused start-ups. These suppliers should all wonder what Ciena will do next inside the data centre.”
Ciena will enhance its overall expertise in chips, optics, and signal processing with the Nubis acquisition. It will also put Ciena in front of key processor players and different hyperscaler engineering teams, which drive next-generation AI systems.
Ciena will also have all the necessary parts for the various technologies, regardless of the evolving timescales associated with the copper-to-optical transition within AI systems. Ciena will add direct-detect technology and copper interconnect. On the optical side, it has coherent optical expertise, now coupled with near-package optics and co-packaged optics.
Nubis’ gain
Nubis’ 50-plus staff get a successful exit. The start-up was founded in 2020. Nubis will become a subsidiary of Ciena.
Nubis will be joining a much bigger corporate entity with deep expertise and pockets. Ciena has a good track record with its mergers. Think Nortel at the system level and Blue Planet, a software acquisition. Now the Nubis deal will bring Ciena firmly inside the data centre.
“This is a great deal for Nubis,” says Kozlov. “Congratulations to their team.”
What next?
The deal is expected to close in the fourth quarter of this year. Ciena expects the deal to start adding to its revenues from 2028, requiring Ciena and Nubis to develop products and deliver design wins in the data centre.
“Given the breadth of Ciena’s capabilities, its deep pockets, and products like its data centre out-of-band (DCOM) measurement product, router, and coherent transceivers, one can imagine that Ciena would offer more than co-packaged optics/ near-packaged optics/ active copper cabling inside the data centre,” says Inniss.
OFC 2025: industry reflections
Gazettabyte is asking industry figures for their thoughts after attending the recent 50th-anniversary OFC show in San Francisco. Here are the first contributions from Huawei’s Maxim Kuschnerov, NLM Photonics’ Brad Booth, LightCounting’s Vladimir Kozlov, and Jürgen Hatheier, Chief Technology Officer, International, at Ciena.
Maxim Kuschnerov, Director of R&D, Huawei
The excitement of last year’s Nvidia’s Blackwell graphics processing unit (GPU) announcement has worn off, and there was a slight hangover at OFC from the market frenzy then.
The 224 gigabit-per-second (Gbps) opto-electronic signalling is reaching mainstream in the data centre. The last remaining question is how far VCSELs will go—30 m or perhaps even further. The clear focus of classical Ethernet data centre optics for scale-out architectures is on the step to 448Gbps-per-lane signalling, and it was great to see many feasibility demonstrations of optical signalling showing that PAM-4 and PAM-6 modulation schemes will be doable.
The show demonstrations either relied on thin-film lithium niobate (TFLN) or the more compact indium-phosphide-based electro-absorption modulated lasers (EMLs), with thin-film lithium niobate having the higher overall optical bandwidth.
Higher bandwidth pure silicon Mach-Zehnder modulators have also been shown to work at a 160-175 gigabaud symbol rate, sufficient to enable PAM-6 but not high enough for PAM-4 modulation, which the industry prefers for the optical domain.
Since silicon photonics has been the workhorse at 224 gigabits per lane for parallel single-mode transceivers, a move away to thin-film lithium niobate would affect the density of the optics and make co-packaged optics more challenging.
With PAM-6 being the preferred modulation option in the electrical channel for 448 gigabit, it begs the question of whether the industry should spend more effort on enabling PAM-6 optical to kill two birds with one stone: enabling native signalling in the optical and electrical domains would open the door to all linear drive architectures, and keep the compact pure-silicon platform in the technology mix for optical modulators. Just as people like to say, “Never bet against copper,” I’ll add, “Silicon photonics isn’t done until Chris Doerr says so.”
If there was one topic hotter than the classical Ethernet evolution, it was the scale-up domain for AI compute architectures. The industry has gone from scale-up in a server to a rack-level scale-up based on a copper backplane. But future growth will eventually require optics.
While the big data centre operators have yet to reach a conclusion about the specifications of density, reach, or power, it is clear that such optics must be disruptive to challenge the classical Ethernet layer, especially in terms of cost.
Silicon photonics appears to be the preferred platform for a potential scale-up, but some vendors are also considering VCSEL arrays. The challenge of merging optics onto the silicon interposer along with the xPU is a disadvantage for VCSELs in terms of tolerance to high-temperature environments.
Reliability is always discussed when discussing integrated optics, and several studies were presented showing that optical chips hardly ever fail. After years of discussing how unreliable lasers seem, it’s time to shift the blame to electronics.
But before the market can reasonably attack optical input-output for scale-up, it has to be seen what the adoption speed of co-packaged optics will be. Until then, linear pluggable optics (LPO) or linear retimed optics (LRO) pluggables will be fair game in scaling up AI ‘pods’ stuffed with GPUs.
Brad Booth, CEO of NLM Photonics
At OFC, the current excitement in the photonics industry was evident due to the growth in AI and quantum technologies. Many of the industry’s companies were represented at the trade show, and attendance was excellent.
Nvidia’s jump on the co-packaged optics bandwagon has tipped the scales in favour of the industry rethinking networking and optics.
What surprised me at OFC was the hype around thin-film lithium niobate. I’m always concerned when I don’t understand why the hype is so large, yet I have still to see the material being adopted in the datacom industry.
Vladimir Kozlov, CEO of LightCounting
This year’s OFC was a turning point for the industry, a mix of excitement and concern for the future. The timing of the tariffs announced during the show made the event even more memorable.
This period might prove to be a peak of the economic boom enabled by several decades of globalisation. It may also be the peak in the power of global companies like Google and Meta and their impact on our industry.
More turbulence should be expected, but new technologies will find their way to the market.
Progress is like a flood. It flows around and over barriers, no matter what they are. The last 25 years of our industry is a great case study.
We are now off for another wild ride, but I look forward to OFC 2050.
Jürgen Hatheier, Chief Technology Officer, International, at Ciena
This was my first trip to OFC, and I was blown away. What an incredible showcase of the industry’s most innovative technology
One takeaway is how AI is creating a transformative effect on our industry, much like the cloud did 10 years ago and smartphones did 20 years ago.
This is an unsurprising observation. However, many outside our industry do not realise the critical importance of optical technology and its role in the underlying communication network. While most of the buzz has been on new AI data centre builds and services, the underlying network has, until recently, been something of an afterthought.
All the advanced demonstrations and technical discussions at OFC emphasise that AI would not be possible without high-performance network infrastructure.
There is a massive opportunity for the optical industry, with innovation accelerating and networking capacity scaling up far beyond the confines of the data centre.
The nature of AI — its need for intensive training, real-time inferencing at the edge, and the constant movement of data across vast distances between data centres — means that networks are evolving at pace. We’re seeing a significant architectural shift toward more agile, scalable, and intelligent infrastructure with networks that can adapt dynamically to AI’s distributed, data-hungry nature.
The diversity of optical innovation presented at the conference ranged from futuristic Quantum technologies to technology on the cusp of mainstream adoption, such as 448-gigabit electrical lanes.
The increased activity and development around high-speed pluggables also show how critical coherent optics has become for the world’s most prominent computing players.
Steve Alexander's 30-Year Journey at Ciena
After three decades of shaping optical networking technology, Steve Alexander is stepping down as Ciena’s Chief Technology Officer (CTO).
His journey, from working on early optical networking systems to helping to implement AI as part of Ciena’s products, mirrors the evolution of telecommunications itself.
The farewell
“As soon as you say, ‘Hey guys, you know, there’s an end date’, certain things start moving,” says Alexander reflecting on his current transition period. “Some people want to say goodbye, others want more of your time.”
After 30 years of work, the bulk of it as CTO, Alexander is ready to reclaim his time, starting with the symbolic act of shutting down Microsoft Outlook.
“I don’t want to get up at six o’clock and look at my email and calendar to figure out my day,” he says.
His retirement plans blend the practical and the fun. The agenda includes long-delayed home projects and traveling with his wife. “My kids gave us dancing lessons for a Christmas present, that sort of thing,” he says with a smile.
Career journey
The emergence of the erbium-doped fibre amplifier shaped Alexander’s career.
The innovation sparked the US DARPA’s (Defense Advanced Research Projects Agency) interest in exploring all-optical networks, leading to a consortium of AT&T, Digital Equipment Corp., and MIT Lincoln Labs, where Alexander was making his mark.
“I did coherent in the late 80s and early 90s, way before coherent was cool,” he recalls. The consortium developed a 20-channel wavelength division multiplexing (WDM) test bed, though data rates were limited to around 1 Gigabit-per-second due to technology constraints.
“It was all research with components built by PhD students, but the benefits for the optical network were pretty clear,” he says.
The question was how to scale the technology and make it commercial.
A venture capitalist’s tip about a start-up working on optical amplifiers for cable TV led Alexander to Ciena in 1994, where he became employee number 12.
His first role was to help build the optical amplifier. “I ended up doing what effectively was the first kind of end-to-end link budget system design,” says Alexander. “The company produced its first product, took it out into the industry, and it’s been a great result since.”
The CTO role
Alexander became the CTO at Ciena at the end of the 1990s.
A CTO needs to have a technology and architecture mindset, he says, and highlights three elements in particular.
The first includes such characteristics as education and experience, curiosity, and imagination. Education is essential, but over time, it is interchangeable with experience. “They are fungible,” says Alexander.
Another aspect is curiosity, the desire to know how things work and why things are the way they are. Imagination refers to the ability to envisage something different from what it is now.
“One of the nicest things about the engineering skill set, whatever the field of engineering you’re in, is that with the right tools and team of people, once you have the idea, you can make it happen,” says Alexander.
Other aspects of the CTO’s role are talking, travelling, trouble-making, and tantrum throwing. “Trouble-making comes from the imagination and curiosity, wanting to do things maybe a little bit different than the status quo,” says Alexander.
And tantrums? “When things get really bad, and you just have to make a change, and you stomp your foot and pound the table,” says Alexander.
The third aspect a CTO needs is being in the “crow’s nest”, the structure at the top of a ship’s mast: “The guy looking out to figure out what’s coming: is it an opportunity? A threat? And how do we navigate around it,” says Alexander.
Technology and business model evolution
Alexander’s technological scope has grown over time, coinciding with the company’s expanding reach to include optical access and its Blue Planet unit.
“One of the reasons I stayed at the company for 30 years is that it has required a constant refresh,” says Alexander. “It’s a challenge because technology expands and goes faster and faster.”
His tenure saw the transformation from single-channel Sonet/ SDH to 16-channel WDM systems. But Alexander emphasizes that capacity wasn’t the only challenge.
“It’s not just delivering more capacity to more places, the business model of the service providers relies on more and more levels of intelligence to make it usable,” he says.
The gap between cloud operators’ agility and that of the traditional service providers became evident during Covid-19. “The reason we’re so interested in software and Blue Planet is changing that pretty big gap between the speed at which the cloud can operate and the speed at which the service provider can operate.”
Coherent optics
Ciena is shipping the highest symbol rate coherent modem, the WaveLogic 6 Extreme. This modem operates at up to 200 gigabaud and can send 1.6 terabits of data over a single carrier.
Alexander says coherent optics will continue to improve in terms of baud rate and optical performance. But he wonders about the desired direction the industry will take.
He marvels at the success of Ethernet whereas optical communications still has much to do in terms of standardization and interoperability.
There’s been tremendous progress by the OIF and initiatives such as 400ZR, says Alexander: “We are way better off than we were 10 years ago, but we’re still not at the point where it’s as ubiquitous and standardised as Ethernet.”
Such standardisation is key because it drives down cost.
“People have discussed getting on those Ethernet cost curves from the photonic side for years. But that is still a big hurdle in front of us,” he says.
AI’s growing impact
It is still early days for AI, says Alexander, but there are already glimmers of success. Longer term, the impact will likely be huge.
AI is already having an impact on software development and on network operations.
Ciena’s customers have started by looking to do simple things with AI, such as reconciling databases. Service providers have many such data stores: an inventory database, a customer database, a sales database, and a trouble ticket database.
“Sometimes you have a phone number here, an email there, a name elsewhere, things like a component ID, all these different things,” he says. ”If you can get all that reconciled into a consistent source of knowledge, that’s a huge benefit.”
Automation is another area that typically requires using multiple manual systems. There are also research papers appearing where AI is being used to design photonic components delivering novel optical performance.
AI will also impact the network. Humans may still be the drivers but it will be machines that do the bulk of the work and drive traffic.
“If you are going to centralize learning and distributed inferencing, it’s going to have to be closer to the end user,” says Alexander.
He uses a sports application as an example as to what could happen.
“If you’re a big soccer/ football fan, and you want to see every goal scored in every game that was broadcast anywhere in the world in the last 24 hours, ranked in a top-10 best goals listing, that’s an interesting task to give to a machine,” he says.
Such applications will demand unprecedented network capabilities. Data will need to be collected, and there will be a lot of machine-to-machine interactions to generate maybe a 10-minute video to watch.
“If you play those sorts of scenarios out, you can convince yourself that yes, networks are going to have lots of demand placed on them.”
Personal Reflection
While Alexander won’t miss his early morning Outlook checks, he’ll miss his colleagues and the laboratory environment.
A Ciena colleague, paying tribute to Alexander, describes him as being an important steward of Ciena’s culture. “He always has lived by the credo that if you care for your people, people will care for the company,” he says.
Alexander plans to keep up with technology developments, but he acknowledges that losing the inside view of innovation will be a significant change.
When people have asked him why he has stayed at Ciena, his always has answered the same way: “I joined Ciena for the technology but I stayed because of the people.”
Further Information
Ciena’s own tribute, click here
Books of 2024: Part 2
Gazettabyte asks industry figures to pick their reads of the year. In Part 2, Scott Wilkinson, Nigel Toon and Kailem Anderson select their best reads.
Scott Wilkinson, Lead Analyst, Networking Components, Cignal AI
I spent the year enjoying a poem a day from Brian Bilston’s Days Like These: An Alternative Guide to the Year in 366 Poems.
You may have seen his poems on social media, as he’s sometimes called The Poet Laureate of Twitter. It’s been a joy to end the day with one of his hilarious, occasionally poignant, and always topical poems.
I ended the year completing Andrew Roberts’ Napoleon: A Life. After the disappointing 2023 film, I wanted to know more about the person for whom an era of European history is named. At almost 1,000 pages, the author is remarkably thorough. Napoleon had a brilliant mind and his many achievements are lost in the legend of his military wins and losses. There’s no way I’ll remember all the details in the biography, but living in it for a few months was fascinating.
One book that I recommend to everyone is An Immense World: How Animal Senses Reveal the Hidden Realms Around Us by Ed Yong. In this amazing book, the author spends a chapter on the senses and looks at how animals experience the world around us. We have historically coloured the world based on our ability to perceive it, which is just a small fraction of the stimuli surrounding us. The author doesn’t just cover the five senses that humans rely on but investigates echolocation, the ability of seals to follow fish trails through water, magnetic navigation, and more.
I guarantee you won’t be able to read a chapter without relaying fascinating facts to anyone sitting nearby. The chapter on smell will change how you walk your dog. The chapter on sight will help you understand why we use RGB colour codes – and why they wouldn’t be the right choice for other animals. The chapters on senses humans don’t use will blow your mind and leave you wondering how much you’re missing on a casual walk through the park. It’s a book that any engineer, scientist, or curious mind will enjoy, and it is a great gift. And no, I don’t get residuals.
Every year at the holidays, I get a huge stack of books, a few of which I discovered through these articles. I didn’t get through my complete stack this year thanks to Mr. Bonaparte’s rich history, but that won’t stop me from picking up a few more again this holiday season. I look forward to seeing everyone else’s picks.
Nigel Toon, co-founder and CEO at Graphcore
My recommendation is Henry Kissinger on China. The book offers amazing insights into the relationship between the USA and China, which is as relevant today as when it was written in 2011.
Kailem Anderson, Vice President, Global Products & Delivery, Blue Planet
I love reading books on the history of technology. I’m currently reading Palo Alto: A History of Silicon Valley Capitalism and the World by Malcolm Harris. As an industry, it’s amazing how new technology can become old and then the old becomes new again. We forget the old and recycle many of the same issues from one technology transition to the next. I’m fascinated by learning from the past to see if solutions from our technology past can apply to the future.
I’m also reading Stephen Hawking’s Brief Answer to the Big Questions. This is a great book that stretches the mind on abstract concepts such as the universe, technology, predicting the future, and examining whether artificial intelligence will outsmart us. The book provides an insight into one of the most amazing minds, Stephen Hawking, and asks big-picture questions that we are afraid to ask ourselves.
Lastly, I would recommend Ali—A Life by Jonathan Eig. The book is an amazing read about Muhammad Ali’s life, how he took on the establishment, and how he broke down stereotypes and prejudices. Despite being rejected for his beliefs, Ali stood by his convictions to change people’s perceptions and become one of the greatest and most admired people of the 20th century.
Will AI spur revenue growth for the telcos?
- A global AI survey sponsored by Ciena highlights industry optimism
- The telcos have unique networking assets that can serve users of AI.
- Much is still to play out and telcos have a history of missed opportunities.
The leading communications service providers have been on a decade-long journey to transform their networks and grow their revenues.
To the list of technologies the operators have been embracing can now be added artificial intelligence (AI).
AI is a powerful tool for improving their business efficiency. The technology is also a revenue opportunity and service providers are studying how AI traffic will impact their networks.
“This is the single biggest question that everyone in this industry is struggling with,” says Jürgen Hatheier. “How can the service providers exploit the technology to grow revenues?”
However, some question whether AI will be an telecom opportunity.
“The current hype around AI has very little to do with telcos and is focused on hyperscalers and specifically the intra-data centre traffic driven by AI model training,” says Sterling Perrin, senior principal analyst at HeavyReading. “There is a lot of speculation that, ultimately, this traffic will spread beyond the data centre to data centre interconnect (DCI) applications. But there are too many unknowns right now.”
AI survey
Hatheier is chief technology officer, international at Ciena. He oversees 30 staff, spanning Dublin to New Zealand, that work with the operators to understand their mid- to long-term goals.
Ciena recently undertook a global survey (see note 1, bottom) about AI, similar to one it conducted two years ago that looked at the Metaverse.
Conducting such surveys complements Ciena’s direct research with the service providers. However, there is only so much time a telco’s chief strategy officer (CSO) or chief technology officer (CTO) can spend with a vendor discussing strategy, vision, and industry trends.
“The survey helps confirm what we are hearing from a smaller set,” says Hatheier.
Surveys also uncover industry and regional nuances. Hatheier cites how sometimes it is the tier-two communications service providers are the trailblazers.
Lastly, telcos have their own pace. “It takes time to implement new services and change the underlying network architecture,” says Hatheier. “So it is good to plan.”
Findings
The sectors expected to generate the most AI traffic are financial services (46 per cent of those surveyed), media and entertainment (43 per cent), and manufacturing (38 per cent). Hatheier says these industries have already been using the technology for a while, so AI is not new to them.
Sterling Perrin
For financial services, an everyday use of AI is for security, detecting fraudulent transactions and monitoring video streams to detect anomalous behavior at a site. The amount of traffic AI applications generate can vary greatly. This is common, says Hatheier; it is the use that matters here, not the industry.
“I would not break it down by the industries to say, okay, this industry is going to create more traffic than another,” says Hatheier. “For financial services, if it is transaction data, it’s a few lines of text, but if it is video for branch security, the data volumes are far more significant.”
AI is also set to change the media and entertainment sector, challenging the way content is consumed. Video streaming uses content delivery networks (CDNs) to store the most popular video content close to users. But AI promises to enable more personalised video, tailored for the end-user. Such content will make the traffic more dynamic.
Another example of personalised content is for marketing and advertising. Such personalisation tends to achieve better results, says Hatheier.
AI is also being applied in the manufacturing sector. Examples include automating supply-chain operations, predictive maintenance, and quality assurance.
Car manufacturers check a vehicle for any blemishes at the end of a production line. This usually takes several staff and lasts 10-15 minutes. Now with AI, the inspection can be completed as the cars passes by. “This is a potent application that could run on infrastructure within the manufacturing site but use a service provider’s compute assets and connectivity,” says Hatheier.
The example shows how AI produces productivity gains. However, AI also promises unique abilities that staff cannot match.
Traffic trends
If the history of telecoms is anything to go by, applications that drove traffic in the network rarely lead to revenue growth for the service providers. Hatheier cites streaming video, gaming, and augmented reality as examples.
However, the operators have assets at network edge and the metro that can benefit AI usage. They also have central offices that can act is distributed data centres for the metro and network edge.
Hatheier says users have an advantage if they consume AI applications across a fibre-based broadband network. But certain countries, such as Saudi Arabia and India, mainly use wireless for connectivity.
“AI applications will need to adapt to what is available, and if people want to consume low-latency applications, there is 5G slicing,” says Hatheier. “At the end of the day, there is no way around fibre.”
Optical networking
Government policy regarding AI and regulations to ensure data does not cross borders also play a part.
“It’s an important decision criterion, as we saw in the survey response,” says Hatheier. “So private AI and local computing will be an important decision factor.”
Another critical decision influencing where data centres are built is power. “We see all the gold rush in the Nordics right now with their renewable power and cool climates,” says Hatheier. “You don’t need to cool your servers as much, and it requires a lot of connectivity.”
However, as well as these region-specific data centre builds, there will also be builds in metropolitan areas using smaller distributed data centres.
“Let’s say there are 20 sizable edge or metro compute centres for AI, and you would need three or four to run a big training job,” says Hatheier. “You will not create a permanent end-to-end connection between them because sometimes there will not be four that need to work together, but five, seven, and 11.”
Such a metro network would require reconfigurable optical add-drop multiplexer (ROADM) technology to connect wavelengths between those clusters based on demand to keep sites busy, to avoid expensive AI clusters being idle.
These are opportunities for the CSPs. And while much is still to happen, such discussions are taking place between systems vendors and the telcos.
For Heavy Reading’s Perrin, the more telling opportunity is the telcos’ own use of AI rather than the networking opportunity.
“As a vertical industry, telecom is not typically a leading-edge adopter of any new technology due to many factors, including culture, size, legacy infrastructure and processes, and government regulations,” he says. “I don’t believe AI will be any different.”
Hatheier points to the survey’s finding of general optimism that sees AI as an opportunity rather than a challenge or business risk.
“We have seen very little differences between countries,” says Hatheier. “That may have to do with the fact that emerging countries get as much attention of data centre investment than more developed ones.”
Nokia picks Infinera to boost its optical networking arm
Nokia has announced its intention to buy optical networking specialist Infinera for $2.3 billion.
The motivation for the Infinera acquisition is scale, said Nokia CEO Pekka Lundmark, during an analyst call detailing the announcement.
Optical networking is how communications service providers and hyperscalers cope with the exponential traffic growth.
Continual innovation is required to reduce the cost and power consumed to transport such traffic. For a systems vendor, having scale helps meet these aims.
Optical networking wasn’t always central to Nokia’s strategy. In 2013, Nokia sold its optical networking arm to Marlin Equity Partners, which became Coriant.
Now, Nokia wants to be a leading optical networking vendor by acquiring Infinera, a company that bought Coriant in 2018.
Nokia’s announcement regarding Infinera comes days after it sold its submarine optical networking business. “It’s part of a larger refocusing on core strengths and higher-growth areas,” says John Lively, principal analyst at market research company LightCounting.
Market share and geographical balance
“We estimate that the combined entity will have a 20 per cent market share,” says Jimmy Yu, vice president at market research firm Dell’Oro Group.
Dell’Oro’s vendor ranking data for 2023 gave Huawei a 30 per cent market share, Nokia+Infinera would be second (20 per cent), while Ciena had a 19 per cent share.
Nokia would also strengthen its sales and balance its presence in key markets globally. Infinera has gained webscale customers in recent years, a significant and growing market compared to telecoms.
“Nokia has had competitive long-haul coherent optics in terms of performance but has failed to get much traction outside its traditional CSP markets,” says Lively. “The Infinera deal gives Nokia access to the faster-growing data centre market and a pluggable coherent product line with a strong order pipeline.”
Nokia says the optical networking deal will also strengthen its overall Network Infrastructure business unit that includes IP Networks and Fixed Networks.
Technologies
Nokia and Infinera offer optical networking systems based on high-end embedded coherent modems and coherent pluggable optical modules.
In 2020, Nokia bought Elenion Technologies, giving the company a silicon photonics coherent design team and a way to address the growing pluggable coherent module marketplace.
Early last year, Nokia announced its 1.2-terabit PSE-6s coherent modem for demanding optical transport applications. Two PSE-6s coherent modems can be used to create a 2.4-terabit line card. Nokia started shipping the modem in late 2023 and already has 15 customers.
Infinera is known for its expertise in indium phosphide photonic integrated circuits. The systems vendor’s latest embedded coherent modem is the 1.2-terabit ICE-7 and it offers a range of coherent pluggable products.
Infinera has recently announced design wins for 800-gigabit ZR/ ZR+ for the hyperscale market, and bidirectional 400G ICE-X pluggables for the cable segment. It valued both opportunities at several hundred million dollars, says LightCounting
Dell’Oro’s Yu says Nokia’s acquisition of Infinera would allow it to develop the entire optical front end in-house. He highlights Infinera’s development of indium phosphide, its indium phosphide chip fabrication plants, and the additional optical front-end components such as the trans-impedance amplifier (TIA), driver, and laser.
“The only other vendors with this much done in-house are Huawei and Ciena,” says Yu. “Cisco has all of this except for indium phosphide development.”
Infinera’s success with webscale companies includes optical networking gear for data centre interconnect. The company is also eyeing the optical networking opportunity inside the data centre which promises significant unit volumes. To this aim, the company is developing a range of ICE-D optical engines.
The company has not detailed much about ICE-D besides claiming that it offers power savings of up to 75 per cent. The power-saving claim is based on using a direct-drive approach and a highly integrated design – optics and electronics. Infinera will likely detail first ICE-D offerings at the ECOC show in September.
Once the acquisition is approved, Nokia will have its own lasers and complement its silicon photonics technology with indium phosphide design expertise. Nokia expects to speed up its coherent modem and product roadmap by combining the DSP design teams.
Challenges and Opportunities
Nokia and Infinera are already advanced in the design of their next-generation coherent designs—the PSE-7 and ICE-8, respectively. These are the two companies responses to Ciena’s 200-gigabaud WaveLogic 6 Extreme, which supports up to a 1.6-terabit optical wavelength.
Developing a coherent DSP in a 3nm or 2nm CMOS process is costly. Both companies will continue to develop their designs for now, given that the deal is expected to close in the first half of 2025. However, they will be keen to agree on what design to choose. This had happened before when Infinera halted what would have been the ICE-5 in favour of Coriant’s design and turned its full attention to developing the ICE-6.
The industry is challenged to keep driving down the cost-per-bit and power-per-bit. The preferred approach is to keep increasing the symbol rate even if the spectral efficiency gains are more modest with each generation due to Shannon’s limit being approached.
However, increasing the baud rate is increasingly challenging and will lead to new parallel designs. Pooling the two companies’ coherent design expertise will help here.
Nokia says another factor for the deal is the expected growth in AI traffic. Such AI traffic is on top of fixed and mobile traffic growth. AI will drive intra-data and inter-data centre networking in the core and edge. Such traffic will be for training and inferencing.
The rest
There will be a notable gap between the top 3 and the remaining optical vendors, who all have a single digital market share. However, the consensus is that the niche players will have a role. Since telecom equipment is a critical infrastructure, operators and governments must promote using local vendors when available. Yu cites the examples of the Padtecs in South America and Tejas in India.
OFC 2024 industry reflections: Part 2
Gazettabyte is asking industry figures for their thoughts after attending the recent OFC show in San Diego. Here are the thoughts from Ciena, Celestial AI and Heavy Reading.
Dino DiPerna, Senior Vice President, Global Research and Development at Ciena.
Power efficiency was a key theme at OFC this year. Although it has been a prevalent topic for some time, it stood out more than usual at OFC 2024 as the industry strives to make further improvements.
There was a vast array of presentations focused on power efficiency gains and technological advancements, with sessions highlighting picojoule-per-bit (pJ/b) requirements, high-speed interconnect evolution including co-packaged optics (CPO), linear pluggable optics (LPO), and linear retimer optics (LRO), as well as new materials like thin-film lithium niobate, coherent transceiver evolution, and liquid cooling.
And the list of technologies goes on. The industry is innovating across multiple fronts to support data centre architecture requirements and carbon footprint reduction goals as energy efficiency tops the list of network provider needs.
Another hot topic at OFC was overcoming network scale challenges with various explorations in new frequency bands or fibre types.
One surprise from the show was learning of the achievement of less than 0.11dB/km loss for hollow-core optical fibre, which was presented in the post-deadline session. This achievement offers a new avenue to address the challenge of delivering the higher capacities required in future networks. So, it is one to keep an eye on for sure.
Preet Virk, Co-founder and Chief Operating Officer at Celestial AI.
This year’s OFC was all about AI infrastructure. Since it is an optical conference, the focus is on optical connectivity. A common theme was how interconnect bandwidth is the oxygen for AI infrastructure. Celestial AI agrees fully with this and adds the memory capacity issue to deal with the Memory Wall problem.
Traditionally, OFC has focused on inter- and intra-data centre connectivity. This year’s OFC clarified that chip-to-chip connectivity is also a critical bottleneck. We discussed our high-bandwidth, low-latency, and low-power photonic fabric solutions for compute-to-memory and compute-to-compute connectivity, which were well received at the show.
It seemed that we were the only company with optical connectivity that satisfies bandwidths for high-bandwidth memory—HBM3 and the coming HBM4—with our optical chiplet.
Sterling Perrin, Senior Principal Analyst, Heavy Reading.
OFC is the premier global event for the optics industry and the place to go to get up to speed quickly on trends that will drive the optics industry through the year and beyond. There’s always a theme that ties optics into the overall communications industry zeitgeist. This year’s theme, of course, is AI. OFC themes are sometimes a stretch – think connected cars – but this is not the case for the role of optics in AI where the need is immediate. And the role is clear: higher capacities and lower power consumption.
The fact that OFC took place one week after Nvidia’s GTC event during which President and CEO Jensen Huang unveiled the Grace-Blackwell Superchip was a perfect catalyst for discussions about the urgency for 800 gigabit and 1.6 terabit connectivity within the data centre.
At a Sunday workshop on linear pluggable optics (LPO), Alibaba’s Chongjin Xie presented a slide comparing LPO and 400 gigabit DR4 that showed 50 per cent reduction in power consumption, a 100 per cent reduction in latency, and a 30 per cent reduction in production cost. But, as Xie and many others noted throughout the conference, LPO feasibility at 200 gigabit per lane remains a major industry challenge that has yet to be solved.
Another topic of intense debate within the data centre is Infiniband versus Ethernet. Infiniband delivers high capacity and extremely low latency required for AI training, but it’s expensive, highly complex, and closed. The Ultra Ethernet Consortium aims to build an open, Ethernet-based alternative for AI and high-performance computing. But Nvidia product architect, Ashkan Seyedi, was skeptical about the need for high-performance Ethernet. During a media luncheon, he noted that InfiniBand was developed as a high-performance, low-latency alternative to Ethernet for high-performance computing. Current Ethernet efforts, therefore, are largely trying to re-create InfiniBand, in his view.
The comments above are all about connectivity within the data centre. Outside the data centre, OFC buzz was harder to find. What about AI and data centre interconnect? It’s not here yet. Connectivity between racks and AI clusters is measured in meters for many reasons. There was much talk about building distributed data centres in the future as a means of reducing the demands on individual power grids, but it’s preliminary at this point.
While data centres strive toward 1.6 terabit, 400 gigabit seems to be the data rate of highest interest for most telecom operators (i.e., non-hyperscalers), with pluggable optics as the preferred form factor. I interviewed the OIF’s inimitable Karl Gass, who was dressed in a shiny golden suit, about their impressive coherent demo that included 23 suppliers and demonstrated 400ZR, 400G ZR+, 800ZR, and OpenROADM.
Lastly, quantum safe networking popped up several times at Mobile World Congress this year and the theme continued at OFC. The topic looks poised to move out of academia and into networks, and optical networking has a central role to play. I learned two things.
First, “Q-Day”, when quantum computers can break public encryption keys, may be many years away, but certain entities such as governments and financial institutions want their traffic to be quantum safe well in advance of the elusive Q-Day.
Second, “quantum safe” may not require quantum technology though, like most new areas, there is debate here. In the fighting-quantum-without-quantum camp, Israel-based start-up CyberRidge has developed an approach to transmitting keys and data, safe from quantum computers, that it calls photonic level security.
ECOC 2023 industry reflections - Final Part
Gazettabyte has been asking industry figures to reflect on the recent ECOC show in Glasgow. The final instalment emphasises coherent technology with contributions from Adtran, Cignal AI, Infinera, Ciena, and Acacia.
Jörg-Peter Elbers, head of advanced technology at Adtran
The ECOC 2023 conference and show was a great event. The exhibition floor was busy and offered ample networking opportunities. In turn, the conference and the Market Focus sessions provided information on the latest technologies, products, and developments.
One hot topic was coherent 800ZR modems. Several vendors demonstrated coherent 800ZR modules and related components. Importantly, these modules also boast new and improved 400 gigabit-per-second (Gbps) modes. The 120 gigabaud (GBd) symbol rate enables 400-gigabit dual-polarisation quadrature phase shift keying (DP-QPSK) transmission over demanding links and long-haul routes. In turn, the advent of 5nm CMOS digital signal processor (DSP) technology enables lower power DP-16QAM than 400ZR modules.
There is broad agreement that the next step in coherent transmission is a 240GBd symbol rate, paving the way to single-wavelength 1.6 terabit-per-second (Tbps) optical transport.
Meanwhile, the use of coherent optical technology closer to the network edge continues. Several players announced plans to follow Adtran and Coherent and jump on the low-power 100 gigabit-per-second ZR (100ZR) ‘coherent lite’ bandwagon. Whether passive optical networking (PON) systems will adopt coherent technology after 50G-PON sparked lively debate but no definitive conclusions.
The OIF 400ZR+ demonstration showed interoperability between a dozen optical module vendors over metro-regional distances. It also highlighted the crucial role of an intelligent optical line system such as Adtran’s FSP3000 OLS in automating operation and optimising transmission performance.
The post-deadline papers detailed fibre capacity records by combining multiple spectral bands and multiple fibre cores. The line-system discussions on the show floor focused on the practical implications of supporting C-, L-, extended, and combined band solutions for customers and markets.
From workshops to the regular sessions, the application of artificial intelligence (AI) was another prominent theme, with network automation a focus area. Examples show not only how discriminative AI can detect anomalies or analyse failures but also how generative AI can improve the interpretation of textual information and simplify human-machine and intent interfaces. For network engineers, ‘Copilot’-like AI assistance is close.
After ECOC is also before ECOC, so please mark in your calendars September 22-26, 2024. ECOC will celebrate its 50th anniversary next year and will take place in Frankfurt, Germany. As one of the General Chairs of the ECOC 2024 event, and on behalf of the entire organising committee, I look forward to welcoming you!
Andrew Schmitt, founder and directing analyst, Cignal AI
ECOC is a great show, it’s like OFC (the annual optical communications and networking event held in the US) but refined to only the critical elements. Here are my key takeaways.
The most impressive demonstration was 800ZR test boards and modules from Marvell and its partners Coherent and Lumentum. Within eight weeks of the first silicon, Marvell has demos up and running in-house and at its partners. The company has at least a 6-month lead in the 800ZR market, making intelligent tradeoffs to achieve this.
Lumentum showed an 8-QAM mode of operation that allows 800 gigabit transmission within a 100GHz channel spacing, which should be interesting. After the massive success of 400ZR, it’s natural to extrapolate the same success for 800ZR, but the use cases for this technology are substantially different. We also heard updates and broader support for 100ZR.
Linear drive pluggable optics (LPO) was a hot topic, although it was our impression that, while optimism ruled public discussion, scepticism was widely expressed in private. There was more agreement than disagreement with our recent report (see the Active Insight: The Linear Drive Market Opportunity). No one is more confident about LPO than the companies who view this as another opportunity to bid for business at hyperscale operators they don’t currently have.
The 200 gigabit per lane silicon/ physical media device (PMD)/ optics development continues, and it is on track to enable 1.6-terabit optics by 2024. Marvell had a more advanced and mature demo of what they showed behind closed doors at OFC. The advancements here are the real threat to adopting LPO, and people need to realise that LPO is competing with the power specs of 200 gigabits per lane, not 100 gigabits per lane solutions.
Also impressive was the comprehensive engineering effort by Eoptolink to show products that covered 100 gigabit and 200 gigabit per lane solutions, both retimed and linear. The company’s actions show that if you have the engineering resources and capital, rather than pick the winning technology, do everything and let the market decide. Also impressive is the CEO, who understood the demos and the seasoned application engineers. Kudos to keeping engaged with the products!
System vendors had a more significant presence at the show, particularly Ciena and Infinera. It’s unsurprising to see more system vendors since they are increasing investments in pluggables, particularly coherent pluggables.
We had many discussions about our forecasts for IPoDWDM deployment growth. This disruption is something that component vendors are excited about, and hardware OEMs view it as an opportunity to adjust how they deliver value to operators (see the Active Insight: Assessing the Impact of IP-over DWDM).
Lastly, the OIF coordinated 400ZR+ and OpenROADM interoperability testing despite the organisation not being directly involved in those industry agreements. The OIF is a fantastic organisation that gets valuable things done that its members need.
Paul Momtahan, director, solutions marketing, Infinera
ECOC 2023 provided an excellent opportunity to catch the latest trends regarding transponder innovation, coherent pluggables and optical line systems. A bonus was getting to the show without needing a passport.
Transponder innovation topics included coherent digital signal processor (DSP) evolution, novel modulators, and the maximum possible baud rate. DSP sessions included the possibility of offloading DSP functions into the photonic domain to reduce power consumption and latency.
There were also multiple presentations on constellation shaping, including enhanced nonlinear performance, reduced power consumption for probabilistic constellation shaping, and potential uses for geometric shaping.
Novel modulators with very high baud rates, including thin-film lithium niobate, barium titanate, plasmonic, and silicon-organic hybrid, were covered. The need for such modulators is the limited bandwidth potential of silicon photonics modulators, though each face challenges such as integration with silicon photonics and manufacturability.
From the baud rate session, the consensus was that 400GBd symbol rates are probable, up to 500GBd might be possible, but higher rates are unlikely. The critical challenges are the radio frequency (RF) interconnects and the digital-to-analogue and analogue-to-digital converters. However, several presenters wondered whether a multi-wavelength transponder might be more sensible for symbol rates above 200 to 250GBd.
Coherent pluggables were another topic, especially at 800 gigabit. However, one controversial topic was the longevity of coherent pluggables in routers (IPoDWDM). Several presenters argued the current period would pass once router port speeds and coherent port speeds no longer align.
As the coherent optical engines approach the Shannon limit, innovation is shifting towards optical line systems and fibres as alternative way to scale capacity.
Several presentations covered ROADM evolution to 64 degrees and even 128 degrees. A contrasting view is that ROADMs’ days are numbered to be replaced by fibre switches and full spectrum transponders, at least in core networks.
Additional options for scaling capacity included increasing the spectrum of existing bands with super-C and super-L. Lighting different bands, such as the S-band (in addition to C+L bands), is seen as the best candidate, with commercial solutions three to five years away.
Overall, it was a great event, and I look forward to seeing how things evolve by the time of next year’s ECOC show in Frankfurt. (For more, click here)
Helen Xenos, senior director, portfolio marketing, Ciena
This was my third year attending ECOC, and the show never disappoints. I always leave this event excited and energised about what we’ve accomplished as an industry.
Every year seems to bring new applications and considerations for coherent optical technology. This year, ECOC showcased the ever-growing multi-vendor ecosystem for 400-gigabit coherent pluggable transceivers, considerations in the evolution to 800-gigabit pluggables, evolution to coherent PON, quantum-secure coherent networking, and the evolution to 200 gigabaud and beyond. When will coherent technology make it into the data centre? A question still open for debate.
Ciena’s optical engineer wizards were on hand to share specifics about our recently announced 3nm CMOS-based WaveLogic 6 technology, which includes the industry’s first performance-optimised 1.6 teraburs-per-second (Tbps) optics as well as 800-gigabit pluggables.
It was exciting for me to introduce customers, suppliers and research graduates to their first view of 3nm chip performance results and show how these enable the next generation of products. And, of course, Ciena was thrilled that WaveLogic 6 was awarded the Most Innovative Coherent Module Product at the event.
Tom Williams, director of technical marketing at Acacia
From my perspective, while there weren’t as many major product announcements as OFC, several trends and technologies continued to progress, including OIF interoperability, 800ZR/ZR+, linear pluggable optics (LPO) and terabit optics.
The OIF interop demonstration was once again a highlight of the show. The booth was at the entrance to the exhibition and seemed to be packed with people each time I passed by.
OIF has expanded the scope of these demonstrations with each show, and this year was the largest ever. In addition to having the participation of 12 module vendors (with 34 modules), the focus was on the ZR+ operation. What was successfully demonstrated was a single-span 400ZR network and a multi-span network.
As co-chair of the OpenZR+ MSA, I was excited by the great collaboration with OIF. These efforts help to drive the industry forward. Karl Gass is not only the most creatively dressed person at every trade show; he is exceptional at coordinating these activities.
It is clear that linear drive pluggable optics (LPO) works in some situations, but views differ about how widespread its adoption will be and how standardisation should be addressed. I lived through the analogue coherent optics (ACO) experience. ACO was essentially a linear interface for a coherent module where the digital processing happened outside the module. For ACO, it was a DSP on the host board and for LPO it is the switch ASIC. The parameters that need to be specified are similar. There is a precedent for this kind of effort. Hopefully, lessons learned there will be helpful for those driving LPO. I am interested to see how this discussion progresses in the industry as some of the challenges are discussed, such as its current limited interoperability and support for 200 gigabits per lane.
There have been announcements from several companies about performance-optimised coherent optics in what we call Class 3 (symbol rates around 140 gigabaud), which support up to 1.2 terabits on a wavelength. Our CIM 8 module has been used in multiple field trials, demonstrating the performance benefits of these solutions.
Our CIM 8 (Coherent Interconnect Module 8) achieves this performance in a pluggable form factor. The CIM 8 uses the same 3D siliconisation technology we introduced for our 400-gigabit pluggables and enables operators to scale their network capacity in a cost- and power-efficient way.
ECOC 2023 industry reflections - Part 3
Gazettabyte is asking industry figures for their thoughts after attending the recent ECOC show in Glasgow. In particular, what developments and trends they noted, what they learned and what, if anything, surprised them. Here are responses from Coherent, Ciena, Marvell, Pilot Photonics, and Broadcom.
Julie Eng, CTO of Coherent
It had been several years since I’d been to ECOC. Because of my background in the industry, with the majority of my career in data communications, I was pleasantly surprised to see that ECOC had transitioned from primarily telecommunications, and largely academic, into more industry participation, a much bigger exhibition, and a focus on datacom and telecom. There were many exciting talks and demos, but I don’t think there were too many surprises.
In datacom, the focus, not surprisingly, was on architectures and implementations to support artificial intelligence (AI). The dramatic growth of AI, the massive computing time, and the network interconnect required to train models are driving innovation in fibre optic transceivers and components.
There was significant discussion about using Ethernet for AI compared to protocols such as InfiniBand and NVLink. For us as a transceiver vendor, the distinction doesn’t have a significant impact as there is little if any, difference in the transceivers we make for Ethernet compared to the transceivers we make for InfiniBand/NVLink. However, the impact on the switch chip market and the broader industry are significant, and it will be interesting to see how this evolves.
Linear pluggable optics (LPO) was a hot topic, as it was at OFC 2023, and multiple companies, including Coherent, demonstrated 100 gigabit-per-lane LPO. The implementation has pros and cons, and we may find ourselves in a split ecosystem, with some customers preferring LPO and others preferring traditional pluggable optics with DSP inside the module. The discussion is now moving to the feasibility of 200 gigabit-per-lane LPO.
Discussion and demonstrations of co-packaged optics also continued, with switch vendors starting to show Ethernet switches with co-packaged optics. Interestingly, the success of LPO may push out the implementation of co-packaged optics, as LPO realizes some of the advantages of co-packaged optics with a much less dramatic architectural change.
One telecom trend was the transition to 800-gigabit digital coherent optical modules, as customers and suppliers plan for and demonstrate the capability to make this next step. There was also significant interest in and discussion about 100G ZR. We demonstrated a new version with 0dBm high optical output power at ECOC 2023 while other companies showed components to support it. This is interesting for cable providers and potentially for data centre interconnect and mobile fronthaul and backhaul.
I was very proud that our 200 gigabit-per-lane InP-based DFB-MZ laser won the 2023 ECOC Exhibition Industry Award for Most Innovative Product in the category of Innovative Photonics Component.
ECOC was a vibrant conference and exhibition, and I was pleased to attend and participate again.
Loudon Blair, senior director, corporate strategy, Ciena
ECOC 2023 in Glasgow gave me an excellent perspective on the future of optical technology. In the exhibition, integrated photonic solutions, high-speed coherent pluggable optical modules, and an array of testing and interoperability solutions were on display.
I was especially impressed by how high-bandwidth optics is being considered beyond traditional networking. Evolving use cases include optical cabling, the radio access network (RAN), broadband access, data centre fabrics, and quantum solutions. The role of optical connectivity is expanding.
In the conference, questions and conversations revolved around how we solve challenges created by the expanding use cases. How do we accommodate continued exponential traffic growth on our fibre infrastructure? Coherent optics supports 1.6Tbps today. How many more generations of coherent can we build before we move on to a different paradigm? How do we maximize density and continue to minimize cost and power? How do we solve the power consumption problem? How do we address the evolving needs of data centre fabrics in support of AI and machine learning? What is the role of optical switching in future architectures? How can we enhance the optical layer to secure our information traversing the network?
As I revisited my home city and stood on the banks of the river Clyde – at a location once the shipbuilding centre of the world – I remembered visiting my grandfather’s workshop where he built ships’ compasses and clocks out of brass.
It struck me how much the area had changed from my childhood and how modern satellite communications had disrupted the nautical instrumentation industry. In the same place where my grandfather serviced ships’ compasses, the optical industry leaders were now gathering to discuss how advances in optical technology will transform how we communicate.
It is a good time to be in the optical business, and based on the pace of progress witnessed at ECOC, I look forward to visiting San Diego next March for OFC 2024.
Dr Loi Nguyen, executive vice president and general manager of the cloud optics business group, Marvell
What was the biggest story at ECOC? That the story never changes! After 40 years, we’re still collectively trying to meet the insatiable demand for bandwidth while minimizing power, space, heat, and cost. The difference is that the stakes get higher each year.
The public debut of 800G ZR/ZR+ pluggable optics and a merchant coherent DSP marked a key milestone at ECOC 2023. For the first time, small-form-factor coherent optics delivers performance at a fraction of the cost, power, and space compared to traditional transponders. Now, cloud and service providers can deploy a single coherent optics in their metro, regional, and backbone networks without needing a separate transport box. 800 ZR/ZR+ can save billions of dollars for large-scale deployment over the programme’s life.
Another big topic at the show was 800G linear drive pluggable optics (LPO). The multi-vendor live demo at the OIF booth highlighted some of the progress being made. Many hurdles, however, remain. Open standards still need to be developed, which may prove difficult due to the challenges of standardizing analogue interfaces among multiple vendors. Many questions remain about whether LPO can be scaled beyond limited vendor selection and bookend use cases.
Frank Smyth, CTO and founder of Pilot Photonics
ECOC 2023’s location in Glasgow brought me back to the place of my first photonics conference, LEOS 2002, which I attended as a postgrad from Dublin City University. It was great to have the show close to home again, and the proximity to Dublin allowed us to bring most of the Pilot team.
Two things caught my eye. One was 100G ZR. We noted several companies working on their 100G ZR implementations beyond Coherent and Adtran (formerly Adva) who announced the product as a joint development over a year ago.
100G ZR has attracted much interest for scaling and aggregation in the edge network. Its 5W power dissipation is disruptive, and we believe it could find use in other network segments, potentially driving significant volume. Our interest in 100G ZR is in supplying the light source, and we had a working demo of our low linewidth tunable laser and mechanical samples of our nano-iTLA at the booth.
Another topic was carrier and spatial division multiplexing. Brian Smith from Lumentum gave a Market Focus talk on carrier and spatial division multiplexing (CSDM), which Lumentum believes will define the sixth generation of optical networking.
Highlighting the approaching technological limitation on baud rate scaling, the ‘carrier’ part of CSDM refers to interfaces built from multiple closely-spaced wavelengths. We know that several system vendors have products with interfaces based on two wavelengths, but it was interesting to see this from a component/ module vendor.
We argue that comb lasers come into their own when you go beyond two to four or eight wavelengths and offer significant benefits over independent lasers. So CSDM aligns well with Pilot’s vision and roadmap, and our integrated comb laser assembly (iCLA) will add value to this sixth-generation optical networking.
Speaking of comb lasers, I attended an enjoyable workshop on comb lasers on the Sunday before the meetings got too hectic. The title was ‘Frequency Combs for Optical Communications – Hype or Hope’. It was a lively session featuring a technology push team and a market pull team presenting views from academia and industry.
Eric Bernier offered an important observation from HiSilicon. He pointed to a technology gap between what the market needs and what most comb lasers provide regarding power per wavelength, number of wavelengths, and data rate per lane. Pilot Photonics agrees and spotted the same gap several years ago. Our iCLA bridges it, providing a straightforward upgrade path to scaling to multi-wavelength transceivers but with the added benefits that comb lasers bring over independent lasers.
The workshop closed with an audience participation survey in which attendees were asked: Will frequency combs play a major role in short-reach communications? And will they play a major role in long-reach communications?
Unsurprisingly, given an audience interested in comb lasers, the majority’s response to both questions was yes. However, what surprised me was that the short-reach application had a much larger majority on the yes side: 78% to 22%. For long-reach applications the majority was slim: 54% to 46%.
Having looked at this problem for many years, I believe the technology gap mentioned is easier to bridge and delivers greater benefits for long-reach applications than for short-reach, at least in the near term.
Natarajan Ramachandran, director of product marketing, physical layer products division, Broadcom
Retimed pluggables have repeatedly shown resiliency due to their standards-based approach, offering reliable solutions, manufacturing scale, and balancing metrics around latency, cost and power.
At ECOC this year, multiple module vendors demonstrated 800G DR4 and 1.6T DR8 solutions with 200 gigabit-per-lane optics. As the IEEE works towards ratifying the specs around 200 gigabit per lane, one thing was clear at ECOC: the ecosystem – comprising DSP vendors, driver and transimpedence amplifier (TIA) vendors, and VCSEL/EML/silicon photonics vendors – is ready and can deliver.
Several vendors had module demonstrations using 200 gigabit-per-lane DSPs. What also was apparent at ECOC was that the application space and use cases, be it within traditional data centre networks, AI and machine learning clusters and telcom, continue to grow. Multiple technologies will find the space to co-exist.
Optical networking's future
Should the industry do more to support universities undertaking optical networking research? Professor Polina Bayvel thinks so and addressed the issue in her plenary talk at the ECOC conference and exhibition held in Glasgow, Scotland, earlier this month.
In 1994, Bayvel set up the Optical Networks Group at University College London (UCL). Telecom operators and vendors like STC, GPT, and Marconi led optical networking research. However, setting up the UCL’s group proved far-sighted as industry players cut their research budgets or closed.
Universities continue to train researchers, yet firms do not feel a responsibility to contribute to the costs of their training to ensure the flow of talent. One optical systems vendor has hired eight of her team.
In her address, Bayvel outlined how her lab should be compensated. For example, when a club sells a soccer player, the team that developed him should also get part of the fee.
Such income would be welcome, says Bayvel, citing how she has a talented student from Brazil who needs help to fund his university grant. Her lab would also benefit. During a visit, a pile of boxes – state-of-the-art test equipment – had just arrived.
Plenary talk
Bayvel mentioned how the cloud didn’t exist 18 years ago and that what has enabled it is optical networking and Moore’s law. She also tackled how technology will likely evolve in the next 18 years.
Digital data is being created at a remarkable rate, she said. Three exabytes (a billion billion bytes) are being added to the cloud, which holds several zettabytes (1,000 exabytes or ZB) of data. By 2025, data in the cloud will be 275ZB.
The cited stats continued: 6.2 billion kilometres of fibre have been deployed between 2005 and 2023, having 60Zbits of capacity. In comparison, all data satellite systems now deployed offer 100Tb, less than the capacity of one fibre.
Moore’s law has enabled complex coherent digital signal processors (DSPs) that clean up the distortions of an optical signal sent over a fibre. The first coherent DSPs consumed 1W for each gigabit of data sent. Over a decade later, DSPs use 0.1W to send a gigabit.
Data growth will keep driving capacity, says Bayvel. Engineers have had to fight hard to squeeze more capacity using coherent optical technology. Further improvement will come from techniques such as non-linear compensation. One benefit of Moore’s law is that coherent DSPs will be more capable of tasks such as non-linear compensation. For example, Ciena’s latest 3nm CMOS process, the WaveLogic 6e DSP, uses one billion digital logic gates.
Extra wide optical comms
But only so much can be done by the DSP and increasing the symbol rate. The next step will be to ramp the bandwidth by combining a fibre’s O, S, C, L, E and U spectrum bands. New optical devices, such as hybrid amplifiers, will be needed, and pushing transmission distance over these bands will be hard.
“We fought for fractions of a decibel [of signal-to-noise ratio]; surely we’re not going to give up the wavelengths available through this [source of] bandwidth?” said Bayvel.
In his Market Focus talk at ECOC, BT’s Professor Andrew Lord argued the opposite. There will be places where combining the C- and L-bands will make sense, but why bother when spatial division multiplexing fibre deployments in the network are inevitable, he said.
“It is not spatial division multiplexing versus extra wide optical comms; they can co-exist,” said Bayvel.
Bayvel describes work to model the performance of such a large amount of spectrum that has been done in her lab using data collected from the MAREA sub-sea cable. Combining the fibre’s spectral bands – a total of 60 terahertz of spectrum – promises to quadruple the bandwidth currently available. However, this will require more powerful DSPs than are available today.
Another area ripe for development is intelligent optical networking using machine learning.
An ideas lag
Bayvel used her talk to pay tribute to her mentor, Professor John Midwinter.
Midwinter was an optical communications pioneer at BT and then UCL. He headed the team that developed the first trial systems that led to BT becoming the first company in the world to introduce optical fibre communications systems in the network.
In 1983, his last year at BT, Midwinter wrote in the British Telecom Technology Journal that this was the year coherent optical systems would be taken seriously. It took another 20-plus years.
Bayvel noted how many ideas developed in optical research take considerable time before the industry adopts them. “Changes in the network are much slower,” she said. “Operators are conservative and focus on solving today’s problems.”
Another example she cited is Google’s Apollo optical switch being used in its data centres. Bayvel noted that the switch is relatively straightforward, using MEMS technology that has been around for 25 years.
Bayvel used her keynote to attack the telecom regulators.
“It is simply unfair that the infrastructure providers get such a small part of the profits compared to the content providers,” she said. “The regulators have done a terrible job.”