Is ADVA Optical Networking looking to buy ECI Telecom?
Is ADVA Optical Networking preparing a bid for private company ECI Telecom? The latest consolidation rumour involving the two mid-tier metro players comes after Infinera’s announcement that it is acquiring Coriant, a deal that is expected to close this quarter.
According to a source in the financial sector, ADVA wanted to acquire Coriant but failed to raise the required funds. Infinera’s successful bid for Coriant has led ADVA to consider alternatives as it looks to secure its future in a consolidating marketplace, with ECI Telecom being viewed as an attractive target.
ECI Telecom is reportedly considering an initial public offering (IPO) on the London Stock Exchange to raise $170 million. A source close to ADVA confirmed that ‘ECI is looking for a home’ but declined to comment on whether ADVA is involved. Another source close to ADVA suggested that there may be some truth in such a bid.
ADVA declined to comment.
An ECI spokesperson said the company has issued no statement regarding an IPO and expressed surprise when asked if ECI was looking to merge. The spokesperson declined to comment when asked about ADVA acquiring ECI.
I wouldn't doubt that there are talks going on, I just don’t know how far they are. And, of course, things can always fall through.
If ADVA and ECI are in discussions, they are doing a good job keeping it quiet. This contrasts with Coriant where rumours started to circulate before the deal was announced.
Mike Genovese, managing director and senior equity research analyst at MKM Partners, who broke the news that Infinera was acquiring Coriant, has no knowledge of any ADVA deal. But he says such a deal fits the industry trend of vendors looking for scale and combining to focus their R&D resources on coherent optics.
Another financial analyst, George Notter, managing director, equity research, telecom and networking equipment analyst at Jefferies, is also unaware of any deal.
“It is a plausible concept,” says Sterling Perrin, principal analyst, optical networking and transport at Heavy Reading. He can see why ADVA is looking and why ECI might be a good fit. “I wouldn't doubt that there are talks going on, I just don’t know how far they are,” says Perrin. “And, of course, things can always fall through.”
Acquisition benefits
Perrin points to ADVA’s Euro 111 million ($131 million) revenues in 3Q 2017, a drop from its Euro 144 million ($165 million) revenues reported in the previous quarter.
ADVA attributed the drop in revenues to two major customers, one an internet content provider (ICP) and the other a large US carrier that was going through a merger. Amazon was the ICP, with ADVA losing some business to Ciena, says Heavy Reading. ADVA’s quarterly revenues have still not returned to their former levels.
“It made ADVA think of how they are going to replace that [business] going forward,” says Perrin. “The webscale business that they bet so heavily on is very competitive, and as they learned with Amazon, the customers are not very loyal.”
By acquiring ECI, ADVA would gain a packet-optical transport platform, a product it lacks, as well as a presence in new markets. ECI has benefitted in recent years from the growing telecom market in India. “Half of ECI’s revenues are coming from Asia, most of that being India,” says Perrin. In contrast, ADVA’s Asian business accounts for over 10 percent of in revenues.
The two firms overlap in wavelength-division multiplexing equipment but not in the data centre interconnect market.
“ADVA might be looking for a land grab and to essentially double down in traditional telecom to make up for losses on the webscale side,” says Perrin.
ADVA’s optical revenues in 2017 were $370 million while Heavy Reading estimates ECI’s optical revenues were $350 million last year
Mature market
Optical transport equipment has become a mature market with fewer than a dozen players remaining. Outside of Asia, the main players are Ciena, Nokia, Cisco, Infinera-Coriant, ADVA and ECI Telecom.
ADVA reported revenues of Euro 514 million in 2017 ($617 million). Heavy Reading says the two companies’ optical revenues are comparable: ADVA’s optical revenues in 2017 were $370 million while Heavy Reading estimates ECI’s optical revenues were $350 million last year. To put that in perspective, market leader Huawei’s optical revenues were $4 billion in 2017.
Both Coriant and ECI are privately held but Perrin says the fortunes of the two firms are very different.
Coriant was a company in decline which explains why its owners, Oaktree Capital Management, was keen for its sale. “ECI is doing really well right now,” says Perrin. ECI's revenues grew over 15 percent in 2017 compared to 2016 and the growth has continued this year. “Which is why you are hearing rumours of them floating publicly.”
ECI is thus in a strong position in any potential negotiations.
Infinera buying Coriant will bring welcome consolidation
Infinera is to purchase privately-held Coriant for $430 million. The deal will effectively double Infinera’s revenues, add 100 new customers and expand the systems vendor’s product portfolio.
Infinera's CEO, Tom FallonBut industry analysts, while welcoming the consolidation among optical systems suppliers, highlight the challenges Infinera faces making the Coriant acquisition a success.
“The low price reflects that this isn't the best asset on the market,” says Sterling Perrin, principal analyst, optical networking and transport at Heavy Reading. “They are buying $1 of revenue for 50 cents; the price reflects the challenges.”
Benefits
According to Perrin, there are still too many vendors facing "brutal price pressures" despite the optical industry being mature. Removing one vendor that has been cutting prices to win business is good news for the rest.
For Infinera, the acquisition of Coriant promises three main benefits, as outlined by its CEO, Tom Fallon, during a briefing addressing the acquisition.
The first is expanding its vertically-integrated business model across a wider portfolio of products. Infinera develops its own optical technology: its indium-phosphide photonic integrated circuits (PICs) and accompanying coherent DSPs that power its platforms. Having its own technology differentiates the optical performance of its platforms and helps it achieve leading gross margins of over 40 percent, said Fallon.
Exploiting the vertical integration model will be a central part of the Coriant acquisition. Indeed, the company mentioned vertical integration 21 times in as many minutes during its briefing outlining the deal. Infinera expects to deliver industry-leading growth and operating margins once it exploits the benefits of vertical integration across an expanded portfolio of platforms, said Fallon.
Having a seat at the table with the largest global service providers to strategise about where their business is going will be invaluable
Buying Coriant also gives Infinera much-needed scale. Not only will Infinera double its revenues - Coriant’s revenues were about $750 million in 2017 while Infinera’s were $741 million for the same period - but it will expand its customer base including key tier-one service providers and webscale players. According to Fallon, the newly combined company will include nine of the top 10 global tier-one service providers and the six leading global internet content providers.
Infinera admits it has struggled to break into the tier-one operators and points out that trying to enter is an expensive and time-consuming process, estimated at between $10 million to $20 million each time. “[Now, with Coriant,] having a seat at the table with the largest global service providers to strategise about where their business is going will be invaluable,” said Fallon.
Sterling Perrin of Heavy Reading The third benefit Infinera gains is an expanded product portfolio. Coriant has expertise in layer 3 networking, in the metro core with its mTera universal transport platform as well as SDN orchestration and white box technologies. Heavy Reading’s Perrin says Coriant has started development of a layer-3 router white box for edge applications.
Combining the two companies also results in a leading player in data centre interconnect.
“Coriant expands our portfolio, particularly in packet and automation where significant network investment is expected over the next decade,” said Fallon. The deal is happening at the right time, he said, as operators ramp spending as they undertake network transformation.
Infinera will pay $230 million in cash - $150 million up front and the rest in increments - and a further $200 million in shares for Coriant. The company expects to achieve cost savings of $250 million between 2019 and 2021 by combining the two firms, $100 million in 2019 alone. The deal is expected to close in the third quarter of 2018.
If a company is going to put that integrated product into their network, it’s a full-blown RFP process which Infinera may or may not win
Challenges
Industry analysts, while seeing positives for Infinera, have concerns regarding the deal.
A much-needed consolidation of weaker vendors is how George Notter, an analyst at the investment bank, Jefferies, describes the deal. For Infinera, however, continuing as before was not an option. Heavy Reading’s Perrin agrees: ”Infinera has been under a lot of pressure; their core business of long-haul has slowed.”
The deal brings benefits to Infinera: scale, complementary product sets, and the promise of being able to invest more in R&D to benefit its PIC technology, says Notter in a research note.
Gaining customers is also a key positive. “Infinera is really excited about getting the new set of customers and that is what they are paying for,” says Vladimir Kozlov, CEO of LightCounting Market Research. “However, these customers were gained by pricing products at steep discounts.”
What is vital for Infinera is that it delivers its upcoming 2.4-terabit Infinite Capacity Engine 5 (ICE5) optical engine on time. The ICE5 is expected to ship in early 2019. In parallel, Infinera is developing its ICE6 due two years later. Infinera is developing two generations of ICE designs in parallel after being late to market with its current 1.2-terabit optical engine.
Infinera is really excited about getting the new set of customers and that is what they are paying for
But even if the ICE5 is delivered on time, upgrading Coriant's platforms will be a major undertaking. “It sounds like they are going to fit their optical engines in all of Coriant’s gear; I don’t see how that is going to happen anytime quickly,” says Perrin.
Customers bought Coriant's equipment for a reason. Once upgraded with Infinera’s PICs, these will be new products that have to undergo extensive lab testing and full evaluations.
Perrin questions how moving customers off legacy platforms to the new will not result in the service providers triggering a new request-for-proposal (RFP). “If a company is going to put that integrated product into their network, it’s a full-blown RFP process which Infinera may or may not win,” says Perrin. “Infinera talked a lot about the benefits of vertical integration but they didn’t really address the challenges and the specific steps they would take to make that work.”
LightCounting's Vladimir KozlovLightCounting’s Kozlov also questions how this will work.
“The story about vertical integration and scaling up PIC production is compelling, but how will they support Coriant products with the PIC?” he says. “Will they start making pluggable modules internally? Will Coriant’s customers be willing to move away from the pluggables and get locked into Infinera’s PICs? Do they know something that we don’t?”
While Infinera is a top five optical platform supplier globally it hasn’t dominated the market with its PIC technologies, says Perrin. “Even if they technically pull off the vertical integration with the Coriant products, how much is that going to win business for them?” he says. “It is one architecture in a mix that has largely gone to pluggables.”
Transmode
Infinera already has experience acquiring a systems vendor when it bought in 2015 metro-access player, Transmode. Strategically, this was a very solid acquisition, says Perrin, but the jury is still out as to its success.
“The integration, making it work, how Transmode has performed within Infinera hasn’t gone as well as they wanted,” says Perrin. “That said, there are some good opportunities going forward for the Transmode group.”
Infinera also had planned to integrate its PIC technology within Transmode’s products but it didn't make economic sense for the metro market. There may also have been pushback from customers that liked the Transmode products, says Perrin: “With Coriant it looks like they really are going to force the vertical integration.”
Infinera acknowledges the challenges ahead and the importance of overcoming them if it is to secure its future.
“Given the comparable sizes of each company’s revenues and workforce, we recognise that integration will be challenging and is vital for our ultimate success,” said Fallon.
Juniper Networks opens up the optical line system
Juniper Networks has responded to the demands of the large-scale data centre players with an open optical line system architecture.
Donyel Jones-WilliamsThe system vendor has created software external to its switch, IP router and optical transport platforms that centrally controls the optical layer.
Juniper has also announced a reconfigurable optical add-drop multiplexer (ROADM) - the TCX1000 - that is Lumentum’s own white box ROADM design. Juniper will offer the Lumentum white box as its own, part of its optical product portfolio.
The open line system architecture, including the TCX1000, is also being pitched to communications service providers that want an optical line system and prefer to deal with a single vendor.
“Juniper plans to address the optical layer with a combination of software and open hardware in the common optical layer,” says Andrew Schmitt, founder and lead analyst at Cignal AI. “This is the solution it will bring to customers rather than partnering with an optical vendor, which Juniper has tried several times without great success.”
Open line systems
An optical line system comprises terminal and transmission equipment and network management software. The terminal equipment refers to coherent optics hosted on platforms, while line elements such as filters, optical amplifiers and ROADMs make up the transmission equipment. Traditionally, a single vendor has provided all these elements with the network management software embedded within the vendor’s platforms.
An open optical line system refers to line equipment and the network management system from a vendor such as Nokia, Infinera or Ciena that allows the attachment of independent terminal equipment. An example would be the Telecom Infra Project’s Voyager box linked to a Nokia line system, says Schmitt.
The open line system can also be implemented as a disaggregated design. Here, says Schmitt, the control software would be acquired from a vendor such as Juniper, Fujitsu, or Ciena with the customer buying open ROADMs, amplifiers and filters from various vendors before connecting them. Open software interfaces are used to communicate with these components. And true to an open line system, any terminal equipment can be connected.
The advantage of an open disaggregated optical line system is that elements can be bought from various sources to avoid vendor lock-in. It also allows the best components to be acquired and upgraded as needed.
Meanwhile, disaggregating the management and control software from the optical line system and equipment appeals to the way the internet content providers architect and manage their large-scale data centres. This is what Juniper’s proNX Optical Director platform enables, the second part of its open line system announcement.
Juniper believes its design is an industry first in how it separates the control plane from the optical hardware.
“We have taken the concept of disaggregation and software-defined networking to separate the control plane out of the hardware,” says Donyel Jones-Williams, director of product marketing management at Juniper Networks. “Our control plane is no longer tied to physical hardware.”
Having an open line system supplied by one vendor gets you 90% of the way there
Disaggregated control benefits the optimisation of the open line system, and enables flexible updates without disrupting the service.
Cignal AI’s Schmitt says that the cloud and co-location players are already using open line systems just not disaggregated ones.
“Having an open line system supplied by one vendor gets you 90% of the way there,” says Schmitt. For him, a key question is what problem is being solved by taking this one step further and disaggregating the hardware.
Schmitt’s view is that an operator introduces a lot of complexity into the network for the marginal benefit of picking hardware suppliers independently. “And realistically they are still single-sourcing the software from a vendor like Juniper or Ciena,” says Schmitt.
Juniper now can offer an open line system, and if a customer wants a disaggregated one, it can build it. “I don’t think users will choose to do that,” says Schmitt. “But Juniper is in a great position to sell the right open line system technology to its customer base and this announcement is interesting and important because Juniper is clearly stating this is the path it plans to take.”
TCX1000 and proNX
Juniper’s open optical line system announcement is the latest development in its optical strategy since it acquired optical transport firm, BTI Systems, in 2016.
BTI’s acquisition provided Juniper with a line system for 100-gigabit transport. “The filters and ROADMs didn’t allow the system to scale to 200-gigabit and 400-gigabit line rates and to support super-channels and flexgrid,” says Jones-Williams.
With the TCX1000, Juniper now has a one-rack-unit 20-degree ROADM that is colourless, directionless and which supports flexgrid to enable 400-gigabit, 600-gigabit and even higher capacity optical channels in future. The TCX1000 supports up to 25.6 terabits-per-second per line.
A customer can also buy the white box ROADM from Lumentum directly, says Juniper. “It gives our customers freedom as to how they want to source their product,” says Jones-Williams.
Competition between vendors is now in the software domain. We no longer believe that there is differentiation in the optical line system hardware
Juniper’s management and control software, the ProNX Optical Director, has been architected using microservices. Microservices offers a way to architect applications using virtualisation technology. Each application is run in isolation based on the service they provide. This allows a service to run and scale independently while application programming interfaces (APIs) enable communication with other services.
Container technology is used to implement microservices. Containers use fewer hardware resources than virtual machines, an alternative approach to server virtualisation.
Source: Juniper Networks.
“It is built for data centre operators,” says Don Frey, principal analyst, routers and transport at the market research firm, Ovum. “Microservices makes the product more modular.”
Juniper believes the competition between vendors is now in the software domain. “We no longer believe that there is differentiation in the optical line system hardware,” says Jones-Williams.
Data centre operators are not concerned about line system interoperability, they are just trying to remove the blade lock-in so they can get the latest technology.
Market demands
Most links between data centres are point-to-point networks yet despite that, the internet content providers are interested in ROADMs, says Juniper. What they want is to simplify network design using the ROADM’s colourless and flexible grid attributes. A directionless ROADM is only needed for complex hub sites that require flexibility in moving wavelengths through a mesh network.
The strategy of the large-scale data centre operators is to split the optical system between an open line system and purpose-built blades. The split allows them to upgrade to the best blades or pluggable optics while leaving the core untouched. “The concept is similar to the open submarine cables as the speed of innovation in core systems is not the same as the line optics,” says Frey. “Data centre operators are not concerned about line system interoperability, they are just trying to remove the blade lock-in so they can get the latest technology.”
Juniper says there is also interest from communications service providers in the ROADM as part of their embrace of open initiatives such as the Open ROADM MSA. Frey says AT&T will make its first deployment of the Open ROADM before the year-end or in early 2018.
“There are a lot of synergies in terms of what we have announced and things like Open ROADM,” says Jones-Williams. “But we know that there are customers out there that just want a line system and they do not care if it is open or not.”
Juniper is already working with customers with its open line system as part of the development of its proNX software.
The branded ROADM and the proNX Optical Director will be generally available in early 2018.
Finisar's 10 Gig bi-directional DWDM architecture
Finisar has developed a bi-directional 10-gigabit SFP+ module for the metro-access market. The dense wavelength-division multiplexing (DWDM) module is designed to expand capacity at locations where fibre is scarce. And being tunable, the SFP+ also simplifies network planning for the operators.
Finisar demonstrated the module working at the recent ECOC 2017 show held in Gothenburg.
Market applications
Interest is growing in using WDM optics for wireless, metro-access and cable networks that are undergoing upgrades. The interest in WDM at the network edge is due to a need to use fibre resources more efficiently. “We are seeing that globally, more and more dark fibre is being used up,” says Leo Lin, director of product line management at Finisar.
Leo LinGiven the cost of leasing and installing fibre, operators are keen to make the best use of their existing fibre and are willing to pay more for WDM optics.
According to Finisar, leasing a fibre can cost $250-$2,000 per fibre annually while the cost of installing fibre can be $500,000 per 10km. “Using WDM optics, you can get payback in less than a year,” says Lin.
LightCounting Market Research's latest forecast estimates that the global wireless transceiver market for 10 gigabit WDM will be approximately $400 million in 2022.
Finisar’s bi-directional 10-gigabit SFP+ product is also being aimed at two emerging ITU Telecom standards: G.metro and NG-PON2.
G.Metro and NG-PON2
The G.metro standard supports up to 40 DWDM wavelengths on a 100GHz wavelength grid. Tuneable transponders each at 10 gigabits-per-second (Gbps) are used and have a reach of up to 20km without amplification.
NG-PON2 is a time and wavelength division multiplexing, passive optical network (TWDM-PON) standard. “In addition to TWDM-PON, they want to have a few dedicated point-to-point WDM links, an overlay on top of the PON,” says Lin.
G.metro uses both the C-band and the L-band: one band is used for the sent wavelengths and the other band for the received wavelengths. In contrast, Finisar’s bi-directional approach sends and receives wavelengths using the C-band only.
“The G.metro standard calls out bi-directional and tuneable optics, and our bi-directional module product can be directly used here,” says Lin. “Since ECOC, we have had quite some support from operators and OEMs that will add our architecture as one of the channel options in both G.metro and NG-PON2.”
Bidi design
Finisar describes its design as a dual-band bi-directional DWDM approach. To understand the design, it helps to compare it to existing DWDM duplex and single fibre schemes.
Standard DWDM (A), a hybrid bi-directional scheme that uses 50GHz AWGs (B), and the bi-directional approach (C) using the C- and L-bands being proposed for G.metro and NG-PON2. Finisar's approach is shown in the diagram below. Source Finisar.
With standard DWDM, two fibres are used, each having a multiplexer and demultiplexer pair. The C-band is used with wavelengths sent down one fibre and received on the other (see diagram A).
The hybrid bi-directional DWDM design (diagram B) sends wavelengths in both directions on one fibre. The hybrid approach is growing in popularity, says Finisar, to address fibre scarcity, for example between a central office and a remote node. For the hybrid scheme, only a single multiplexer-demultiplexer pair is needed. But to fit all the wavelengths on one fibre, a 50GHz channel mux-demux is used rather than a cheaper 100GHz one.
Another bi-directional scheme - one that G.metro and NG-PON2 are promoting - uses 100GHz channels but requires both the C-band and the L-band (diagram C). Here, east-to-west traffic is sent across one band while west-to-east traffic is sent on the other.
“This approach requires cyclic arrayed-waveguide gratings,” says Lin. A cyclic or colourless arrayed-waveguide grating (AWG) can separate or combine wavelengths across multiple bands. But unlike the hybrid bi-directional case, one fibre only connects to each bi-directional transceiver hosting a C-band wavelength in one direction and an L-band one travelling in the opposite direction. Using fewer fibres saves cost and space.
Finisar’s bi-directional design is similar but with one important twist: only the C-band is used.
To do this, two carriers are placed into the single 100GHz channel: one an upstream wavelength and one a downstream one. The result is 40, 10Gbps wavelengths - 80 carriers in total - spread across the C-band (see diagram below).
Finisar's bi-directional architecture uses two carriers per channel spread across the C-band. Source: Finisar
A tuneable filter is used in the module not only to match the channel that the remote module’s tuneable laser will use, but also to select the particular band in a given channel, either the upstream or downstream band. The result is that one bi-directional module can be used for all 40 channels. “One single part number for the far end and the near end,” says Lin.
The technical challenge Finisar faced to make its design work is separating the two closely spaced carriers in a 100GHz channel.
Finisar says that with a 50GHz DWDM system, the wavelength must sit centrally in the channel and that requires a wavelength locker. The two carriers within its 100GHz band are not placed centrally yet Finisar has developed a way to separate the two without needing wavelength-locker technology.
The tuneable bi-directional approach also simplifies network planning. If an operator wants to add a new wavelength and drop it at an existing node, the node’s optical add-drop multiplexer does not need to be upgraded.
“All operators have different channel plans and customised optical add-drop multiplexers in the field,” says Lin. “In our case, we are even simpler than the duplex. In duplex you need a multiplexer-demultiplexer pair; in our case, any AWG or thin-film filter based design can be used.”
Finisar uses an out-of-band communication channel for the central office module to co-ordinate the channel to be used with a newly inserted remote module. “You can plug in a module on any available port and it establishes a link by itself in under 10 seconds,” says Lin.
Roadmap
Finisar is working to extend the reach of its 10-gigabit bi-directional tuneable SFP+ DWDM architecture to beyond the current 40km to 60km with the use of a bi-directional EDFA.
The current 40km reach is determined by the link budget chosen for the expected use cases with the assumption being that multiple add-drop sites will exist between the central office and the remote end. “The tuneable laser used is the same that is used in our tuneable XFP+, so supporting beyond 80km is not a problem,” says Lin.
Finisar says it is working on a 25-gigabit bi-directional module that will be available in 2019.
Meanwhile, select customers are evaluating samples of the 10-gigabit bi-directional SFP+ module. General availability is expected by mid-2018.
Acacia announces a 1.2 terabit coherent module
Channel capacity and link margin can be maximised by using the fractional QAM scheme. Source: Acacia.
The company is facing increasing market competition. Ciena has teamed up with Lumentum, NeoPhotonics, and Oclaro, sharing its high-end coherent DSP expertise with the three optical module makers. Meanwhile, Inphi has started sampling its 16nm CMOS M200, a 100- and 200-gigabit coherent DSP suitable for CFP2-ACO, CFP-DCO, and CFP2-DCO module designs.
The AC1200 is Acacia’s response, extending its high-end module offering beyond a terabit to compete with the in-house system vendors and preserve its performance lead against the optical module makers.
Enhanced coherent techniques
The AC1200 has an architecture similar to the company’s AC400 5x7-inch 400-gigabit module announced in 2015. Like the earlier module, the AC1200 features a dual-core coherent DSP and two silicon photonics transceiver chips. But the AC1200 uses a much more sophisticated DSP - the 16nm CMOS Pico device announced earlier this year - capable of supporting such techniques as variable baud rate, advanced modulation and coding schemes so that the bits per symbol can be fine-tuned, and enhanced soft-decision forward error correction (SD-FEC). The AC400 uses the 1.3 billion transistor Denali dual-core DSP while the Pico DSP has more than 2.5 billion transistors.
The result is a two-wavelength module design, each wavelength supporting from 100-600 gigabits in 50-gigabit increments.
Acacia is able to triple the module’s capacity to 1.2 terabits by incorporating a variable baud rate up to at least 69 gigabaud (Gbaud). This doubles the capacity per wavelength compared to the AC400 module. The company also uses more modulation formats including 64-ary quadrature amplitude modulation (64-QAM), boosting capacity a further 1.5x compared to the AC400’s 16-QAM.
Acacia has not detailed the module’s dimensions but says it is a custom design some 40 percent smaller in area than a 5x7-inch module. Nor will it disclose the connector type and electrical interface used to enable the 1.2-terabit throughput. However, the AC1200 will likely support 50 gigabit-per-second (Gbps) 4-level pulse-amplitude modulation (PAM-4) electrical signals as it will interface to 400-gigabit client-side modules such as the QSFP-DD.
The AC1200’s tunable baud rate range is around 35Gbaud to 69Gbaud. “The clock design and the optics could truly be continuous and it [the baud rate] pairs with a matrix of modulation formats to define a certain resolution,” says Tom Williams, senior director of marketing at Acacia Communications. Whereas several of the system vendors’ current in-house coherent DSPs use two baud rates such as 33 and 45Gbaud, or 35 and 56Gbaud, Acacia says it uses many more rates than just two or three.
The result is that at the extremes, the module can deliver from 100 gigabits (a single wavelength at some 34Gbaud and quadrature phase-shift keying - QPSK) to 1.2 terabits (using two wavelengths, each 64-QAM at around 69Gbaud).
The module also employs what Acacia refers to as very fine resolution QAM constellations. The scheme enables the number of bits per symbol to be set to any value and not be limited to integer bits. Acacia is not saying how it is implementing this but says the end result is similar to probabilistic shaping. “Instead of 2 or 3 bits-per-symbol, you can be at 2.5 or 2.7 bits-per-symbol,” says Williams. The performance benefits include maximising the link margin and the capacity transmitted over a given link. (See diagram, top.)
The SD-FEC has also been strengthened to achieve a higher coding gain while still being a relatively low-power implementation.
Using a higher baud rate allows a lower order modulation scheme to be used. This can more than double the reach. Source: Acacia
The company says it is restricted in detailing the AC1200’s exact performance. “Because we are a merchant supplier selling into system vendors that do the link implementations, we have to be careful about the reach expectations we set,” says Williams. But the combination of fractional QAM, a tunable baud rate, and improved FEC means a longer reach for a given capacity. And the capacity can be tuned in 50-gigabit increments.
Platforms and status
ADVA Optical Networking is one vendor that has said it is using Acacia’s 1.2-terabit design for its Teraflex product, the latest addition to its CloudConnect family of data centre interconnect products.
Is ADVA Optical Networking using the AC1200? “Our TeraFlex data centre interconnect product uses a coherent engine specifically developed to meet the performance expectations that our customers demand,” says ADVA's spokesperson.
Teraflex is a one-rack-unit (1RU) stackable chassis that supports three hot-pluggable 1.2-terabit ‘sleds’. Each sled’s front panel supports various client-side interface module options: 12 x 100-gigabit QSFP28s, 3 x 400-gigabit QSFP-DDs and lower speed 10-gigabit and 40-gigabit modules using ADVA Optical Networking’s MicroMux technology.
Samples of the AC1200 module will be available in the first half of 2018, says Acacia. General availability will likely follow a quarter or two later.
Has coherent optical transmission run its course?
Feature: Coherent's future
Three optical systems vendors share their thoughts about coherent technology and the scope for further improvement as they look two generations ahead to symbol rates approaching 100 gigabaud
Optical transmission using coherent detection has made huge strides in the last decade. The latest coherent technology with transmitter-based digital signal processing delivers 25x the capacity-reach of 10-gigabit wavelengths using direct-detection, according to Infinera.
Since early 2016, the optical systems vendors Infinera, Ciena and Nokia have all announced new coherent digital signal processor (DSP) designs. Each new generation of coherent DSP improves the capacity that can be transmitted over an optical link. But given the effectiveness of the latest coherent systems, has most of the benefits already been achieved?
Source: Infinera
“It is getting harder and harder,” admits Kim Roberts, vice president, WaveLogic science at Ciena. “Unlike 10 years ago, there are no factors of 10 available for improvement.”
Non-linear Shannon limit
It is the non-linear Shannon limit that defines how much information can be sent across a fibre, a function of the optical signal-to-noise ratio.
Kim Roberts of CienaThe limit is based on the work of famed mathematician and information theorist, Claude Shannon. Shannon's work was based on a linear communication channel with added Gaussian noise. Optical transport over a fibre is a more complex channel but the same Shannon bound applies, although assumptions for the non-linearities in the fibre must be made.
Roberts stresses that despite much work, the industry still hasn't figured out just what the upper limit is over a fibre for a given optical signal-to-noise ratio.
It is getting harder and harder. Unlike 10 years ago, there are no factors of 10 available for improvement.
"There are papers that show that with this method and this method, you can do this much," says Roberts. "And there are other papers that show that as the power goes up, there is no theoretical limit until you melt the fibre."
These are theoretical things, he says, but the key is that the headroom available remains unknown. What is known is that the theoretical limit remains well ahead of practical systems. Accordingly, systems performance can be improved using a combination of techniques and protocols coupled with advances in electro-optics.
Design goals
A key goal when designing a new optical transmission system is to increase the data sent for a given cost i.e. decrease the cost-per-bit. This is an ongoing requirement as the service providers contend with ever growing network traffic.
Another challenge facing engineers is meeting the demanding power, density and thermal constraints of their next-generation optical transport system designs.
One way to reduce the cost-per-bit is to up the symbol rate to increase the data sent over a wavelength. Traditional 100-gigabit and 200-gigabit dense wavelength-division multiplexing (DWDM) systems use 32-35 gigabaud (GBaud). The latest coherent DSPs already support more than one baud rate: Nokia’s PSE-2s coherent DSP supports 33Gbaud or 45Gbaud while Ciena’s WaveLogic Ai chipset supports 35Gbaud or 56Gbaud.
Having a choice of baud rates coupled with the various modulation scheme options means the same number of bits can be sent over a range of optical reaches. The more complex the modulation scheme, the closer the points are in a constellation and the harder it is to correctly detect the data at the receiver in the presence of noise. Accordingly, using the combination of a simpler modulation scheme and a higher baud rate allows the same data to be sent further.
Capacity-reach is what matters: how much capacity you can extract for a given reach
Nokia's 1.4-billion transistor PSE-2s supports two 200 gigabit-per-second (Gbps) formats: polarisation-multiplexing, 16-ary quadrature amplitude modulation (PM-16QAM) at 33Gbaud, or using PM-8QAM at 45Gbaud. The 200-gigabit wavelength has an optical reach of some 800km using 16-QAM at 33Gbaud but this rises to 1,600km when PM-8QAM at 45Gbaud is used. Alternatively, using 45Gbaud and PM-16QAM, more data can be sent: 250 gigabits-per-wavelength over 800km.
Nokia's Randy EisenachCoherent systems designers are not stopping there. “The next higher baud rate the industry is targeting is 61-68 Gbaud,” says Randy Eisenach, senior product marketing manager, optical networks at Nokia.
Operating at the higher gigabaud range - Infinera talks of 65-70Gbaud - a single transmitter-receiver pair sends twice the amount of data of traditional 32-35Gbaud systems using the same modulation format. But the higher-baud rates require the electro-optics to operate twice as fast. The analogue-to-digital and digital-to-analogue converters of the coherent DSP must sample at twice the baud rate - at least 130 billion samples-per-second. A 65-70Gbaud rate also requires silicon implemented using a more advanced and expensive CMOS process mode - 16nm instead of 28nm. In turn, the optical modulator and drivers need to work well at these higher rates.
“The optical networking industry is well on its way to solving these engineering and component issues in the next year or so,” says Eisenach.
The capacity-per-wavelength also goes up with baud rate. For shorter reach links, 400-600 gigabits-per-wavelength are possible at 65-70Gbaud and, according to Pravin Mahajan, Infinera’s director of product and corporate marketing, power consumption in terms of watts-per-gigabit will improve by some 2.5x.
Pravin Mahajan of InfineraAnd the system vendors are not stopping there: the next baud rate hike after 65-70Gbaud will be in the region of 80-100 Gbaud. The coherent DSPs that will support such data rates will need to be implemented using 7nm CMOS process (see table).
“Capacity-reach is what matters: how much capacity you can extract for a given reach,” says Mahajan. “These successive generations [of faster baud rates] all keep moving that curve upwards.”
DSP features
In addition to the particular baud rates chosen by the vendors for their DSP designs, each includes unique features.
Instead of modulating the data onto a single carrier, Infinera’s FlexCoherent DSP uses multiple Nyquist sub-carriers spread across a channel. The number of subs-carriers varies depending on the link. The benefit of the approach, says Infinera, is that it allows a lowering of the baud rate used which increases the tolerance to non-linear channel impairments experienced during optical transmission.
The FlexCoherent DSP also supports enhanced soft-decision forward-error correction (SD-FEC) including the processing of two channels that need not be contiguous. This is possible as the FlexCoherent DSP is dual-channel which particularly benefits long-haul and subsea applications, claims Infinera. By pairing two channels, the FEC codes can be shared. Pairing a strong channel with a weak one and sharing the codes allows some of the strength of the strong signal to be used to bolster the weaker one, extending its reach or even allowing a more advanced modulation scheme to be used.
Infinera has just announced that by using Nyquist sub-carriers and the FEC gain sharing technologies, its customer, Seaborn Networks, is able delivering 11.8 terabits of capacity over a 10,600km submarine link.
Nokia’s PSE-2s DSP has sufficient processing performance to support two coherent channels. Each channel can implement a different modulation format if desired, or the two can be tightly coupled to form a super-channel. Using 45Gbaud and PM-16QAM, two 250-gigabit channels can be implemented to enable a 500-gigabit muxponder card. The PSE-2s can also implement 400-gigabit wavelength but that is the only format where only one channel can be supported by the PSE-2s.
Ciena’s WaveLogic Ai, meanwhile, uses advanced coding schemes such that it no longer mentions particular modulation schemes but rather a range of line rates in 50-gigabit increments.
Coding schemes with names such as set-partition QPSK, matrix-enhanced PM-BPSK, and 8D-2QAM, have already started to appear in the vendors’ coherent DSPs.
“Vendors use a lot of different terms essentially for the same thing: applying some type of coding to symbols to improve performance,” says Eisenach.
There are two main coding approaches: constellation shaping, also known as probabilistic shaping, and multi-dimensional coding. Combining the two - probabilistic shaping and multi-dimensional coding - promises enhanced performance in the presence of linear and non-linear transmission impairments. These are now detailed.
Probabilistic shaping
The four constellation points of QPSK modulation are equidistant from the origin. With more advanced modulation schemes such as 16-QAM, the constellation points differ in their distance from the origin and hence have different energies. Points in the corners of the constellation, furthest from the origin, have the most energy since a point’s power is the square of the distance from the origin.
Here the origin is at the centre of the square 64-QAM constellation. With probabilistic shaping, more of the points closer to the origin are chosen with the resulting data rate going down. Source: Nokia
Probabilistic shaping uses the inner constellation points more than the outer points, thereby reducing the overall average energy and this improves the signal-to-noise ratio. To understand why, Ciena points out that the symbol error rate at the receiver is dominated by the distance between neighbouring points of the constellation. Reduced the average energy still keeps the distance between the points the same, but when gain is applied to restore the signal’s power levels, the effect is to increase the distance between points. “It means we have better separation between the points, we’ve expanded everything,” says Roberts.
Using probabilistic shaping delivers a maximum 1.53dB of improvement in a linear transmission channel. “That is the theoretical limit,” says Roberts. “In a non-linear world, we get a greater benefit from shaping beyond just shaping the noise.”
Probabilistic shaping also has another benefit: it allows the number of bits sent per symbol to be defined.
Using standard modulation schemes such as 64-QAM with no constellation shaping, 6 bits-per-symbol are sent. Using shaping and being selective in what points are used, fewer bits are sent and they don’t need to be integer values. “I can send 5.7, 5.6, 5.3, even 5.14 bits-per symbol,” says Roberts. “Until I get to 5 bits, and then I have a choice: do I use more shaping or do I start with 32-QAM, which is 5 bits-per-symbol.”
Technology A shows today's coherent DSPs: operating at 30-35Gbaud and delivering 100, 150 and 200Gbps capacities per wavelength. Technology B is Ciena's WaveLogic A. Operating at 56Gbaud, it delivers up to 400Gbps per wavelength in 50Gbps. Technology C will continue this trend. Operating around 70Gbaud, up to 600Gbps per wavelength will be possible in even finer speed increments of 25Gbps. Is this Ciena's next WaveLogic? Source: Ciena
This is very useful as it allows fine control of the data sent such that operators can squeeze just enough data to suit the margins available on a particular fibre link. “You don't have to choose between 100-gigabit and 200-gigabit wavelengths,” says Roberts. "You can use smaller jumps and that sometimes means sending more capacity.”
Three things are needed to fine-tune a link in this way. One is a coherent DSP that can deliver such variable increments on a wavelength using probabilistic shaping. Also needed is a flexible client signalling scheme such as the OIF’s Flexible Ethernet (FlexE) protocol, a protocol mechanism to vary the Ethernet payload for transmission. Lastly, intelligent networking software is required to determine what is happening in the network and the margins available to assess how much data can be squeezed down a link.
Ciena says it has not implemented probabilistic shaping in its latest WaveLogic Ai coherent DSP. But given the Ai will be a family of devices, the technique will feature in upcoming coherent DSPs.
Nokia published a paper at the OFC event held earlier this year showing the use of probabilistic shaping over a transatlantic link. Using probabilistic-shaped 64-QAM (PS-64QAM), a spectral efficiency of 7.46b/s/Hz was achieved over the 5,523km link. This equates to 32 terabits of capacity over the fibre, more than 2.5x the 12 terabits of the existing DWDM system that uses 100Gbps PM-QPSK.
Advanced coding
Multi-dimensional coding is another technique used to improve optical transmission. A 16-QAM constellation is a two-dimensional (2D) representation in one polarisation, says Roberts. But if both polarisations of light are considered as one signal then it becomes a 4D, 256-point (16x16) symbol. This can be further extended by including the symbols in adjacent time slots. This forms an 8D representation.
Non-linear compensation has been an interesting research topic. Nokia continues to investigate the topic and implementation methods but the benefits appear small for most real-world applications
The main two benefits of multi-dimensional coding are better noise performance and significantly better performance in the presence of non-linear impairments.
Nokia’s PSE-2s uses coding for its set-partition QPSK (SP-QPSK). Standard PM-QPSK uses amplitude and phase modulation, resulting in a 4-point constellation. With SP-QPSK, only three of the four constellation points are used for each symbol. A third fewer constellation points means less data is transported but the benefit of SP-QPSK is extended reach due to the greater Euclidean distance between the symbol points created by carefully mapping the sequence of symbols. This results in 2.5dB of extra gain compared to PM-QPSK, for a reach beyond 5,000km.
Using the PSE-2’s 45Gbaud symbol rate, the fewer constellation points of SP-QPSK can be compensated for to achieve the same overall 100Gbps capacity as PM-QPSK at 33Gbaud.
Infinera’s FlexCoherent uses what it calls matrix-enhanced PM-BPSK, a form of averaging that adds 1dB of gain. “Any innovation that adds gain to a link, the margin that you give to operators, is always welcome,” says Mahajan.
Ciena’s WaveLogic 3 Extreme coherent DSP supports the multi-dimension coding scheme 8D-2QAM to improve reach or capacity of long-reach spans.
Such techniques mean vendors have a wealth of available choices available. It is also why Ciena has stopped referring to modulation schemes and talks about its WaveLogic Ai at 35Gbaud supporting 100-250Gbps data rates in 50-gigabit increments while at 56Gbaud, the WaveLogic Ai delivers 100-400Gbps optical channels in 50-gigabit steps.
Probabilistic shaping and multi-dimensional coding are distinct techniques but combining the two means the shaping can be done across dimensions.
Design engineers thus have various techniques to keep improving performance and there are other directions too.
Forward-error correction is about 2dB from the theoretical limit and with improved design Ciena’s Roberts expects 1dB can be reclaimed.
In turn, signal processing techniques could be applied at the transmitter to compensate for expected non-linear effects. “Non-linear compensation has been an interesting research topic,” says Eisenach. “Nokia continues to investigate the topic and implementation methods but the benefits appear small for most real-world applications.”
So is there much scope for further overall improvement?
“There is still a lot more juice left," says Mahajan.
“It [coherent transmission improvement] is getting harder and harder,” adds Roberts. “It is taking more mathematics and more and more CMOS gates, but Moore’s law is providing lots of CMOS gates.”
This is an updated and extended version of an article that first appeared in Optical Connections magazine earlier this year.
Infinera inches closer to cognitive networking
The second and final part as to how optical networking is becoming smarter
Infinera says it has made it easier for operators to deploy optical links to accommodate traffic growth.
The system vendor says its latest capability, known as Instant Network, also paves the way for autonomous networks that will predict traffic trends and enable capacity as required.
The latest announcement builds on Infinera’s existing Instant Bandwidth feature, introduced in 2012, that uses its photonic integrated circuit (PIC) technology.
Instant Bandwidth exploits the fact that all five 100-gigabit wavelengths of a line card hosting Infinera’s 500-gigabit PIC are lit even though an operator may only need a subset of the 100-gigabit wavelengths. Using Instant Bandwidth, extra capacity can be added to a link - until all five wavelengths are used - in a matter of hours.
The technology allows 100-gigabit wavelengths to be activated in minutes, says Geoff Bennett, director, solutions and technology at Infinera (pictured). It takes several hours due to the processing time for the operator to raise a purchasing order for the new capacity and get it signed off.
Instant Bandwidth has been enhanced since its introduction. Infinera has introduced its latest generation 2.4 terabit PIC which is also sliceable. With a sliceable PIC, individual wavelengths can be sent to different locations using reconfigurable optical add-drop multiplexer (ROADM) technology within the network.
Another feature added is time-based Instant Bandwidth. This allows an operator to add extra capacity without first raising a purchase order. Paying for the extra capacity is dealt with at a later date. This feature has already benefited operators that have experienced a fibre cut and have used Instant Bandwidth to reroute traffic.
Infinera says over 70 of its customers use Instant Bandwidth. These include half of its long-haul customers, its top three submarine network customers and over 60 percent of its data centre interconnect players that use its Cloud Xpress and XTS products. Some of its data centre interconnect customers request boxes with all the licences already activated, says Bennett.
The internet content providers are banging the drum for cognitive networking
Instant Network
Now, with the Instant Network announcement, Infinera has added a licence pool and moveable licences. The result is that an operator can add capacity in minutes rather than hours by using its pool of prepaid licenses.
Equally, if an operator wants to reroute a 100-gigabit or 200-gigabit wavelength to another destination, it can transfer the same licence from the original end-point to the new one.
“They [operators] can activate capacity when the revenue-generating service asks for it,” says Bennett.
Another element of Instant Network still to be introduced is the Automated Capacity Engineering that is part of Infinera’s Xceed software.
Source: Infinera
“Automated Capacity Engineering will be an application that runs on Xceed,” says Bennett. The Automated Capacity Engineering is an application running on the OpenDaylight open source software-defined networking (SDN) controller that takes advantage of plug-ins that Infinera has added to the Xceed platform such as multi-layer path computation and traffic monitoring.
Using this feature, the SDN orchestrator can request a 100 Gigabit Ethernet private line, for example. If there is insufficient capacity, the Automated Capacity Engineering app will calculate the most cost-effective path and install the necessary licences at the required locations, says Bennett.
“We think this is leading the way to cognitive networking,” he says. “We have the software foundation and the hardware foundation for this.”
Networks that think
With a cognitive network, data from the network is monitored and fed to a machine learning algorithm to predict when capacity will be exhausted. New capacity can then be added in a timely accordingly.
Bennett says internet content providers, the likes of Google, Microsoft and Facebook, will all deploy such technology in their networks.
Being consumers of huge amounts of bandwidth, they will be the first adopters. Wholesale operators which also serve the internet content providers will likely follow. Traditional telecom operators with their more limited traffic growth will be the last to adopt such technology.
But cognitive networking is not yet ready. “The machine learning algorithms are still basic,” says Bennett. “But the biggest thing that is missing is the acceptance [of such technology] by network operations staff.”
However, this is not an issue with the internet content providers. “They are banging the drum for cognitive networking,” says Bennett.
Part 1: Ciena's Liquid Spectrum, click here
Real-time visibility makes optical networking smarter
Systems vendors are making optical networks smarter. Their latest equipment, combining intelligent silicon and software, can measure the status of the network and enable dynamic network management.
Ciena recently announced its Liquid Spectrum networking product while Infinera has launched its Instant Network. Both vendors exploit the capabilities of their latest generation coherent DSPs to allow greater network automation and efficiency. The vendors even talk about their products being an important step towards autonomous or cognitive networks.
"Operators need to do things more efficiently," says Helen Xenos, director, portfolio solutions marketing at Ciena. "There is a lot of unpredictability in how traffic needs to be connected over the network." Moreover, demands on the network are set to increase with 5G and the billions of devices to be connected with the advent of Internet of Things.
Existing optical networks are designed to meet worse-case conditions. Margins are built into links based on the fibre used and assumptions are made about the equipment's end-of-life performance and the traffic to be carried. Now, with Ciena's latest WaveLogic Ai coherent DSP-ASIC, not only is the performance of the network measured but the coherent DSP can be used to exploit the network's state rather than use the worse-case end-of-life conditions. "With Liquid Spectrum, you now don't need to operate the network in a static mode," says Xenos.
We are at the beginning of this new world of operating networks
Software applications
Ciena has announced the first four software applications as part of Liquid Spectrum. The first, Performance Meter, uses measured signal-to-noise ratio data from the coherent DSP-ASICs to gauge the network's state to determine how efficiently the network is operating.
Bandwidth Optimiser acts on the network planner's request for bandwidth. The app recommends the optimum capacity that can be run on the link, based on exploiting baud rate and the reach, and also where to place the wavelengths within the C-band spectrum. Moreover, if service demands change, the network engineer can decide to reduce the built-in margins. "I may decide I don't need to reserve a 3dB margin right now and drop it down to 1dB," says Xenos. Bandwidth Optimiser can then be rerun to see how the new service demand can be met.
This approach contrasts with the existing way end points are connected, where all the wavelengths used are at the same capacity, a user decides their wavelengths and no changes are made once the wavelengths are deployed. "It is much simpler, it [the app] takes away complexity from the user," says Xenos.
The Liquid Restoration app ensuring alternative capacity in response to the loss of a 300-gigabit route due to a fault. Source: Ciena
The two remaining apps launched are Liquid Restoration and Wave-Line Synchroniser. Liquid Restoration looks at all the available options if a particular path fails. "It will borrow against margin to get as much capacity as possible," says Xenos. Wave-Line Synchroniser is a tool that helps with settings so that Ciena's optics can work with another vendor's line system or optics from another vendor work with Ciena's line system.
Liquid Spectrum will be offered as a bundle as part of Ciena's latest BluePlanet Manage, Control and Plan tool that combines service and network management, resource control and planning.
Xenos says Liquid Spectrum represents the latest, significant remaining piece towards the industry's goal of developing an agile optical infrastructure. Sophisticated reconfigurable optical add-drop multiplexers (ROADMs) and flexible coherent DSPs have existed for a while but how such flexible technology has been employed has been limited because of the lack of knowledge of the real-time state of the network. Moreover, with these latest Liquid Spectrum software tools, much of the manual link engineering and complexity regarding what capacity can be supported and where in the spectrum it should be placed, says Xenos.
"We are at the beginning of this new world of operating networks," says Xenos. "Going forward, there will be an increasingly level of sophistication that will be built into the software."
Ciena demonstrated Liquid Spectrum at the OFC show held in Los Angeles last month.
Part 2: Infinera's Instant Network, click here
TIP seeks to shake up the telecom marketplace
Niall Robinson
Now, ten telcos, systems vendors, component and other players have joined Facebook as part of the Telecom Infra Project, or TIP, to bring the benefits of open-source design and white-box platforms to telecoms. TIP has over 300 members and has seven ongoing projects across three network segments of focus: access, backhaul, and core and management.
Facebook's involvement in a telecoms project is to benefit its business. The social media giant has 1.79 billion active monthly users and wants to make Internet access more broadly available. Facebook also has demanding networking requirements, both the linking of its data centres and supporting growing video traffic. It also wants better networks to support emerging services using technologies such as virtual reality headsets.
It is time to disrupt this closed market; it is time to reinvent everything we have today
The telecom operators want to collaborate with Facebook having seen how its Open Compute Project has created flexible, scalable equipment for the data centre. The operators also want to shake up the telecom industry. At the inaugural TIP summit held in November, the TIP chairman and CTO of SK Telecom, Alex Jinsung Choi, discussed how the scale and complexity of telecom networks make it hard for innovators and start-ups to enter the market. “It is time to disrupt this closed market; it is time to reinvent everything we have today,” said Choi during his TIP Summit talk.
Voyager
TIP unveiled a white-box packet optical platform dubbed Voyager at the summit. The one rack-unit (1RU) box is a project for backhaul. Voyager has been designed by Facebook and the platform’s specification has been made available to TIP.
Voyager is based on another platform Facebook has developed: the Wedge top-of-rack switch for the data centre. Wedge switches are now being made by several contract manufacturers. Each can be customised based on the operating system used and the applications loaded onboard. The goal is to adopt a similar approach with Voyager.
“Eventually, there will be something that is definitely market competitive in terms of hardware cost,” says Niall Robinson, vice president, global business development at ADVA Optical Networking, one of the companies involved in the Voyager initiative. “And you have got an open-source community developing a feature set from a software perspective.”
Other companies backing Voyager include Acacia Communications, Broadcom and Lumentum which are involved in the platform’s hardware design. Snaproute is delivering the software inside the box while first units are being made by the contract manufacturer, Celestica.
ADVA Optical Networking’s will provide a sales channel for Voyager and is interfacing it to its network management system. The system vendor will also provide services and software support. Coriant is another systems vendor backing the project. It is providing networking support including routeing and switching as well as dense WDM transmission capabilities.
This [initiative] has shown me that the whole supply and design chains for transport can be opened up; I find that fascinating.
Robinson describes TIP as one of the most ambitious and creative projects he has been involved in. “It is less around the design of the box," he says. "It is the shaking up of the ecosystem, that is what TIP is about.”
A 25-year involvement in transport has given Robinson an ingrained view that it is different to other aspects of telecom. For example, a vendor’s transport system must be at each end of the link due to the custom nature of platforms that are designed to squeeze maximum performance over a link. “In some cases, transport is different but what TIP maybe realises is that transport does not always have to be different,” says Robinson. “This [initiative] has shown me that the whole supply and design chains for transport can be opened up; I find that fascinating.”
Specification
At the core of the 1RU Voyager is the Broadcom StrataXGS Tomahawk. The 3.2-terabit switch chip is also the basis of the Wedge top-of-rack switch. The Tomahawk features 128 x 25 gigabit-per-second (Gbps) serdes to enable 32 x 100 gigabit ports, and supports layer-2 switching and layer-3 routeing.
Voyager uses 12, 100 Gigabit Ethernet client-side pluggable interfaces and four 200-gigabit networking interfaces based on Acacia’s AC-400 optical module. The AC-400 uses coherent optics and supports polarisation multiplexing, 16 quadrature amplitude modulation (PM-16QAM). “If it was a pure transport box the input rate would equal the output rate but because it is a packet box, you can take advantage of layer 2 over-subscription,” says Robinson.
At layer-3 the total routeing capacity is 2 terabits, the sum of the client and network interfaces. “At layer-3, the Tomahawk chip does not know what is a client port and what is a networking port; they are just Ethernet ports on that device,” says Robinson.
ADVA Optical Networking chose to back Voyager because it does not have a packet optical platform in its product portfolio. Until now, it has partnered with Juniper Networks and Arista Networks when such functionality has been needed. “We are chasing certain customers that are interested in Voyager,” says Robinson. “We are enabling ourselves to play in the packet optical space with a self-contained box.”
Status and roadmap
The Voyager is currently in beta-prototype status and has already been tested in trials. Equinix has tested the box working with Lumentum’s open line system over 140km of fiber, while operator MTN has also tested Voyager.
The platform is expected to be generally available in March or April 2017, by when ADVA Optical Networking will have completed the integration of Voyager with its network management system.
Robinson says there are two ways Voyager could develop.
Source: Gazettabyte
One direction is to increase the interface and switching capacities of the 1RU box. Next-generation coherent digital signal processors that support higher baud rates will enable 400Gbps and even 600Gbps wavelengths using PM-64QAM. This could enable the line-side capacity to increase from the current 800Gbps to 2 or 3 terabits. And soon, 400Gbps client-side pluggable modules will become available. Equally, Broadcom is already sampling its next-generation Tomahawk II chip that has 6.4 terabits of switching capacity.
Another direction the platform could evolve is to add an backplane to connect multiple Voyagers. This is something already done with the Wedge '6-pack' that combines six Wedge switch cards. A Voyager 6-pack would result in a packet-optical platform with multiple terabits of switching and routeing capacity.
“This is an industry-driven initiative as opposed to a company-driven one,” says Robinson. “Voyager will go whichever way the industry thinks the lowest cost is.”
Corrected on Dec 22nd. The AC-400 is a 5"x7" module and not as originally stated.
Juniper Networks to acquire Aurrion for $165 million
The announcement of the acquisition was low key. A CTO blog post and a statement that Juniper Networks had entered into an agreement to acquire Aurrion, the fabless silicon photonics start-up. No fee was mentioned.
However, in the company's US Securities and Exchange Commission filing, Juniper values the deal at approximately $165 million. "The Company believes the acquisition will help to fuel its long-term competitive advantage by enabling cost-effective, high-density, high-speed optical networks," it said. The deal is expected to be closed this quarter.
But the deal is significant for a number of reasons.
First, Aurrion, like Intel, is a proponent of heterogeneous integration, combining indium phosphide and other technologies on a silicon wafer platform through bonding. The approach has still to be proven in commercial volumes but it promises the use of III-V materials on 12-inch silicon wafers manufactured in a chip fabrication plant.
Aurrion has made tunable lasers for telecom that cover both the C- and L-bands, as well as uncooled laser arrays for datacom applications. The start-up has also been developing high-speed transceivers for the data centre.
The company has also been working on the manufacturing aspects of silicon photonics, a considerable undertaking. These include automated wafer-scale testing, connecting fibre to a silicon photonics chip, and packaging.
Juniper is thus getting an advanced silicon photonics technology suited for volume manufacturing that it will use to advance its data centre networking offerings.
Juniper may choose to make its own optical transceivers but, more likely, it will use silicon photonics as part of its switch designs to tackle issues of data centre scaling and the continual challenge of growing power consumption. It could also use the technology for its IP core routers and longer term, to tackle I/O issues alongside custom ASICs.
Systems vendors drive silicon photonics
The Aurrion acquisition also highlights how it is systems vendors that are acquiring silicon photonics start-ups rather than the traditional optical component and module makers.
This is partly a recognition that silicon photonics' main promise is as a systems technology. Acacia, the coherent transmission specialist, is one company that has shown how silicon photonics can benefit optical module design but the technology's longer-term promise is for systems design rather than optical modules.
A consequence of such acquisitions by systems vendors is that technology being developed by silicon-photonics start-ups is being swallowed within systems houses for their own use and not for the merchant market. Systems vendors have deep pockets to develop the technology but it will be for their own use. For the wider community, silicon photonics technology being developed by the likes of Aurrion is no longer available.
This is what AIM Photonics, the US public-private partnership that is developing technology for integrated photonics, is looking to address: to advance the manufacturing of silicon photonics, making the resulting technology available to small to medium sized businesses and entrepreneurial ventures. However, AIM Photonics is one year into a five-year venture.
Implications
Should major systems vendors owning silicon photonics technology in-house concern the traditional optical component vendors?
Not for now.
Optical transceiver sales continue to grow and the bulk of designs are not integrated. And while silicon photonics is starting to be used for integrated designs, it is competing against the established technologies of indium phosphide and gallium arsenide.
But as photonics moves closer to the silicon and away from a system's faceplate, silicon photonics becomes more strategically important and this is where systems vendors can start developing custom designs.
Must the systems houses own the technology to do that?
Not necessarily, but they will need silicon photonics design expertise, and in the case of Juniper, it can hit the ground running with Aurrion.
Longer term, it will be the much larger chip industry that will drive silicon photonics rather than the optical industry. There are chip foundries now that are making silicon photonic ICs as there are top-ten chip companies such as Intel and STMicroelectronics. But ultimately it will be a very different supply chain that will take shape.
It is early days but Juniper's acquisition is the latest indicator that it is the systems vendors that are moving first at the very beginnings of this new ecosystem.