Adtran broadens its OLS and access module offerings
Adtran has unveiled two products before the OFC show in San Francisco taking place at the end of the month.
One is a 50 gigabit-per second (Gbps) SFP56 optical transceiver that uses 4-level pulse-amplitude modulation (PAM-4) for 5G front-haul and enhanced broadband applications.
The second product is the FSP 3000 IP OLS, a compact open line system (OLS) designed for point-to-point links between sites 120km apart.
The OLS has been developed to simplify the setting up of dense wavelength division multiplexing (DWDM) optical links.
Enhancing broadband
Adtran has been developing a range of transceiver products to address specific requirements in the access-aggregation marketplace.
These include the MicroMux Edge Bidi, a QSFP+ pluggable module that supports 4×10 gigabit signals over 40km for mobile backhaul and enterprise wireless applications.
Adtran also offers the AccessWave25, a 25-gigabit tunable wavelength transceiver in an SFP28 form factor with a reach of 40km.
The pluggable module is used to link remote physical layer devices (RPDs) in cable operators’ networks. Cable operators are upgrading their infrastructure from 10 gigabits to 25 gigabits to support DOCSIS 4.0.
“You can argue if DOCSIS 4.0 is here or coming at the year-end,” says Saeid Aramideh, vice president of business development, optical engines business unit, at Adtran. “But there is no argument about the need for 25-gigabit uplinks for the cable MSO market.”
Now Adtran is announcing the AccessWave50, a 50-gigabit SFP56 optical module for fronthaul, part of the radio access network (RAN) and for other developments driving traffic such as smart homes, Internet of Things, and Smart Cities.
Aramideh refers to these applications as driving ‘enhanced’ broadband networks, requiring the upgrading of 25 gigabit links to 50- and even 100-gigabit ones.
Front-haul networks
For mobile, telco operators and RAN equipment makers are working with optical component makers to drive innovation in pluggables for emerging architectures such as enhanced 5G and 6G, says Aramideh.
In mobile networks, the front-haul network carries radio signals using the CPRI (common public radio interface) or enhanced CPRI protocols between the remote radio heads and the baseband units.
For 5G front-haul, the modules used are mainly at 10 gigabits-per-second (Gbps) with some 25-gigabit modules deployed. Adtran’s AccessWave50 addresses the next speed hike.
Adtran has designed the AccessWave50 using proprietary signal-shaping and distance optimisation techniques along with 4-level pulse amplitude modulation (PAM-4) to achieve the 50Gbps line rate.
“PAM-4 is proving itself to be a cost-performance-optimised technology and give you spectral efficiency as you go to higher data rates,” says Aramideh. “Of course, it’s not coherent optics, but you don’t need coherent for all applications.”
AccessWave50 uses a tunable laser and has a 15km, not 40km reach, but that is sufficient, says Aramideh, since front-haul networks are latency-constrained. The SFP56 module consumes 2.5W only.
Compact networking
Adtran has also unveiled its latest open line system (OLS) for C-band coherent transceivers.
The company has been providing bespoke OLS systems for hyperscalers. ADVA, the company Adtran acquired in 2022, provided Microsoft with the OLS that, working with the original ColorZ modules from Marvell, enabled 100 gigabit PAM-4 transmissions over 80km links.
Adtran also provides an OLS for data centre interconnects using 400ZR coherent modules for reaches of 120km.
The latest FSP 3000 IP OLS platform is a compact one-rack (1RU) high box that supports eight wavelengths over 120km.
The platform also includes an OTDR (optical time domain reflectometer) for fibre diagnostics.
The OLS can be used with 400-gigabit, 800-gigabit, and ultimately 1.6 terabit coherent pluggable modules once available.
The OLS is also designed for telecom metro interconnect networks. “Telcos, in response to AI, are also looking for OLS technology tailored to coherent transceivers,” says Stephan Rettenberger, senior vice president of marketing and corporate communications at Adtran.
A chief design challenge has been to fit the OLS into a 1 RU form factor, requiring integration and packaging work. The OLS has also been designed to be set up and operated straightforwardly.
The platform is scalable: two racks stacked double the wavelength counts to 16.
The FSP 3000 IP OLS product is already in the hands of one telco customer, says Rettenberger.
ADVA targets access with its latest pluggable module
- The 25 gigabit-per-second (Gbps) SFP28 is self-tuning and has a reach of 40km
- ADVA’s CEO, Christoph Glingener, in his plenary talk at ECOC 2022 addressed the unpredictable nature of technology adoption.
ADVA has expanded its portfolio of optical modules with an SFP28 for the access market.
The AccessWave25 is a self-tuning dense wavelength division multiplexing (DWDM) pluggable.
The SFP28 is designed to enable communications service providers to straightforwardly upgrade their access networks from 10Gbps to 25Gbps.
ADVA made the announcement just before ECOC 2022.
Features
The SFP28 module links switches and routers to DWDM open-line systems (see diagram below).
The 40km-reach pluggable uses 4-level pulse amplitude modulation (PAM-4) and supports 25 gigabit Ethernet and eCPRI traffic.
The module uses the G.metro self-tuning standard to coordinate with the remote-end transceiver a chosen channel in the C-band, simplifying configuration and removing human error.
The G.metro communication channel also enables remote monitoring of the module.
The SFP28 consumes 3W and works over the extended temperature of -40 to 85oC.
Strategy
ADVA says vertical integration is a critical part of its Optical Engine unit’s strategy.
Saeid Aramideh, ADVA’s Optical Engine’s vice president of business development, says the unit focusses on such technology disciplines as silicon photonics, laser technology and digital signal processing.
The digital signal processing includes aggregation as with ADVA‘s MicroMux module products, PAM-4 used by the AccessWave25, and coherent as with its 100ZR module announced in June.
Advanced packaging is another technology area of interest.
“These are the fundamental innovation areas we focus on,” says Aramideh. “We build our product portfolio based on these platforms.”
ADVA also looks at the market to identify product gaps.
“Not so much every MSA module, but what is happening on the aggregation side,” says Aramideh. “What is it that other people are not paying attention to?”
This is what motivated ADVA’s MicroMux products. The MicroMux module family includes a 10-by-10 gigabit going into 100 gigabits, a 10-by-one gigabit into 10 gigabits, and a four-by-100 gigabit going into 400 gigabits.
“The reality is over 10,000 MicroMux modules are carrying traffic with a top tier-one network provider in Europe,“ says Aramideh. “Not on ADVA equipment but on other network equipment maker, which we haven’t made public.”
For access aggregation, ADVA unveiled at OFC its four-by-10 gigabit MicroMux Edge BiDi with a 40km reach.
“This is for Ethernet, backhaul, and services where fibre is limited and symmetric latency is important,” says Aramideh.
ADVA’s 100ZR module uses a coherent digital signal processor (DSP) developed with Coherent. The 100ZR is a QSFP28 module that dissipates 5W and reaches 300km.
Now, ADVA has added the AccessWave25, a tunable SFP28 that uses direct-detect technology and PAM-4, including ADVA’s IP for distance optimisation.
“The AccessWave25 works on legacy, so if you have a 10-gigabit network, you don’t have to change anything on the physical layer,” he says.
ADVA also looks at metro applications and says it will announce lower-power, smaller form factor coherent designs.
ECOC plenary talk
The CEO of ADVA, Christoph Glingener, gave a plenary talk at ECOC.
Entitled Never say never, Glingener reflected on technology adoption and its timing.
He pointed out how technologies that, at first, seem impractical or too difficult to adopt can subsequently become mainstream. He cited coherent optical communication as one example.
Glingener also discussed how such unpredictability impacts business, citing supply-chain issues, the global pandemic, and sovereignty.
Sovereignty and the influx of government capital for fibre rollout and semiconductors confirm that the optical communications industry is in a good place. But Glingener worries how the industry’s practitioners are ageing and stresses more needs to be done to attract graduates.
Tracing optical communications’ progress, he talked about the 15-year cycles of first direct detect and then fibre amplification. Coherent then followed in 2010.
The industry is thus ripe for breakthrough technology.
Reaching limits
Shannon’s limit means spectral efficiency no longer improves while Moore’s law’s demise continues. Near-term trends are clear, he says, parallelism, whether it is multiple spectrum bands, multiple fibres, or multiple fibre cores. This, in turn, will drive new optical amplifier and wavelength-selective switch designs.
Further optimisation will be needed, integration at the device level and the creation of denser systems. Network automation is also essential and that requires much work.
Glingener also argues for optical bypass rather than electrical packet processing. Large core routers overseeing routing at the IP and optical layer will not aid the greening of the internet.
Next wave
So what is the next technology wave?
Possibilities he cited include hollow-core fibre, photonic computing, and quantum entanglement for communications and the quantum internet.
Will they reach a large scale? Glingener is doubtful.
Whatever the technology proves to be, he said, it is likely already being discussed at ECOC 2022.
If he has a message for the audience, it is to apply their own filter whenever they hear people say, ‘it will never come,’ or ‘it is too difficult.’ Never say never, says Glingener.
ADVA Optical Engines adds bidirectional multiplexing
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ADVA expands its multiplexing modules to include the network edge
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The company is developing optical modules as part of a three-pillar business strategy
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ADVA’s merger with ADTRAN is approaching its conclusion
ADVA has expanded its family of multiplexing optical modules with a 40km bidirectional design for access networks.
Until now, ADVA’s three multiplexer optical module products have focussed on IP routing and switching.
The multiplexing modules combine lower-speed optical interfaces into a higher-speed port.
The company unveiled its 4-by-10-gigabit MicroMux Edge BiDi, its first multiplexer module for the network edge, at the OFC show held in March in San Diego.
ADVA Optical Engines
As the capacity of switching and routing equipment increases, so does the speed of the electrical serialiser/ deserialiser (serdes) interface. What was at 10 gigabits is now at 50 and 100 gigabits. Yet legacy 1-gigabit and 10-gigabit streams remain.
“You need to find a way to support these legacy services while your network capacity goes up,” says Saeid Aramideh, vice president of business development at Optical Engines, ADVA. “So you need a multiplexing solution.”
Aramideh joined ADVA after working at firms CoreOptics, acquired by Cisco Systems in 2010, and then Ranovus. He mentions how, at an analyst presentation day, the CEO of ADVA, Brian Protiva, detailed three focus areas: entering non-telecom markets, software services, and becoming a more vertically integrated company.
“That includes differentiated products, products that don’t exist in the industry, based on ADVA’s IP (intellectual property),” says Aramideh.
The IP covers lasers, silicon photonics, software, and integration. ADVA aims to make industry solutions that customers can’t get elsewhere.
ADVA will also make products that do exist in the marketplace in order to ensure security of supply for its customers while enabling ADVA to reduce its product costs.
“That is the spirit of the business unit that we call ADVA Optical Engines,” says Aramideh.
MicroMux product family
The advantage of fitting the multiplexing within a module is that there is no need for additional networking equipment or a multiplexing line card.
“There is nothing as good as a module that does muxing because the solution has zero-footprint,” says Aramideh. “There is a network element already there; just plug the module in and do the muxing.”
ADVA’s first multiplexing module product is the MicroMux, a 10-by-10-gigabit QSFP28 optical interface feeding into a 100-gigabit port.
The MicroMux has multi-mode and 10km single-mode variants. “Over 10,000 units are in deployment with probably one of the largest IP router companies out there, carrying traffic in the network,” says Aramideh.
ADVA has also developed the MicroMux Nano, a 10-by-1-gigabit design in an SFP+ pluggable that supports single-mode and multi-mode fibre.
The MicroMux Quattro addresses 400 gigabits. Here, a QSFP-DD module multiplexes four 100-gigabit optical streams.
As well as the -SR4 interface, the Quattro multiplexes 100-gigabit CWDM-4 and LR4. “Those are the two categories that don’t exist in the marketplace, so the product is unique,” says Aramideh.
MicroMux Edge BiDi
At OFC, ADVA announced its first access product, the 4-by-10-gigabit MicroMux Edge BiDi with a 40km reach, to address fixed and wireless traffic for consumers and enterprises.
One fibre sends and receives data in a bidirectional (BiDi) design. Data is transmitted using two wavelengths: 1270nm and 1330nm. Bidirectional communication benefits areas of the network where fibre is scarce.
The Micromux Edge Bidi supports four individual 10-gigabit optical channels multiplexed in the QSFP+ module, a single fibre carrying each stream.
An example application is sending 10-gigabit traffic between a wireless antenna site to a central office. “This is one connection on a single fibre, and four fibres are coming into the module,” says Aramideh.
Another benefit of using fibre for two-way communications is that latency is symmetrical.
This benefits applications where avoiding added latency is essential.
Mobile networks, especially in the fronthaul, need precise timing references for the radio heads for coordinated multi-point solutions. If the signals up and down travel on the same fiber, the dynamic delay variations are fewer. CIPRI fronthaul, for example, requires nanosecond accuracy and a single fibre is a solution of choice.
“As you start going into more enterprise applications, this becomes more and more important,” says Aramideh. “Some applications are susceptible to this.”
ADVA says one carrier customer for its edge multiplexer will start deployments this year.
Optical component innovation
The multiplexing products use ADVA’s vertical integration IP including laser and IC technologies.
ADVA has developed a multi-link gearbox chip based on OIF standards, for example, to enable aggregation of lower-speed data rates.
“We are working with a partner on the packaging capabilities to reduce that massive number of lasers and detectors into small form factors,” says Aramideh. “So there is a lot of innovation from an optical components perspective.”
ADTRAN merger
ADTRAN and ADVA announced their intention to merge in August last year.
Adtran’s shareholders have since approved the deal as have ADVA’s.
The deal has also gained UK approval and now requires the same in Germany.
Α closing date will then be set.
Ranovus readies its interfaces for deployment
- Products will be deployed in the first half of 2015
- Ranovus has raised US $24 million in a second funding round
- The start-up is a co-founder of the OpenOptics MSA; Oracle is now also an MSA member.
Ranovus says its interconnect products will be deployed in the first half of 2015. The start-up, which is developing WDM-based interfaces for use in and between data centres, has raised US $24 million in a second stage funding round. The company first raised $11 million in September 2013.
Saeid Aramideh"There is a lot of excitement around technologies being developed for the data centre," says Saeid Aramideh, a Ranovus co-founder and chief marketing and sales officer. He highlights such technologies as switch ICs, software-defined networking (SDN), and components that deliver cost savings and power-consumption reductions. "Definitely, there is a lot of money available if you have the right team and value proposition," says Aramideh. "Not just in Silicon Valley is there interest, but in Canada and the EU."
The optical start-up's core technology is a quantum dot multi-wavelength laser which it is combining with silicon photonics and electronics to create WDM-based optical engines. With the laser, a single gain block provides several channels while Ranovus is using a ring resonator implemented in silicon photonics for modulation. The company is also designing the electronics that accompanies the optics.
Aramideh says the use of silicon photonics is a key part of the design. "How do you enable cost-effective WDM?" he says."It is not possible without silicon photonics." The right cost points for key components such as the modulator can be achieved using the technology. "It would be ten times the cost if you didn't do it with silicon photonics," he says.
The firm has been working with several large internet content providers to turn its core technology into products. "We have partnered with leading data centre operators to make sure we develop the right products for what these folks are looking for," says Aramideh.
In the last year, the start-up has been developing variants of its laser technology - in terms of line width and output power - for the products it is planning. "A lot goes into getting a laser qualified," says Aramideh. The company has also opened a site in Nuremberg alongside its headquarters in Ottawa and its Silicon Valley office. The latest capital will be used to ready the company's technology for manufacturing and recruit more R&D staff, particularly at its Nuremberg site.
Ranovus is a founding member, along with Mellanox, of the 100 Gigabit OpenOptics multi-source agreement. Oracle, Vertilas and Ghiasi Quantum have since joined the MSA. The 4x25 Gig OpenOptics MSA has a reach of 2km-plus and will be implemented using a QSFP28 optical module. OpenOptics differs from the other mid-reach interfaces - the CWDM4, PSM4 and the CLR4 - in that it uses lasers at 1550nm and is dense wavelength-division multiplexed (DWDM) based.
It is never good that an industry is fragmented
That there are as many as four competing mid-reach optical module developments, is that not a concern? "It is never good that an industry is fragmented," says Aramideh. He also dismisses a concern that the other MSAs have established large optical module manufacturers as members whereas OpenOptics does not.
"We ran a module company [in the past - CoreOptics]; we have delivered module solutions to various OEMs that are running is some of the largest networks deployed today," says Aramideh. "Mellanox [the other MSA co-founder] is also a very capable solution provider."
Ranovus plans to use contract manufacturers in Asia Pacific to make its products, the same contract manufacturers the leading optical module makers use.
Table 1: The OpenOptics MSA
End markets
"I don't think as a business, anyone can ignore the big players upgrading data centres," says Aramideh. "The likes of Google, Facebook, Amazon, Apple and others that are switching from a three-tier architecture to a leaf and spine need longer-reach connectivity and much higher capacity." The capacity requirements are much beyond 10 Gig and 40 Gig, and even 100 Gig, he says.
Ranovus segments the adopters of interconnect into two: the mass market and the technology adopters. "Mass adoption today is all MSA-based," says Aramideh. "The -LR4 and -SR10, and the same thing is happening at 100 Gig with the QSFP28." The challenge for the optical module companies is who has the lowest cost.
Then there are the industry leaders such as the large internet content providers that want innovative products that address their needs now. "They are less concerned about multi-source standard-based solutions if you can show them you can deliver a product they need at the right cost," says Aramideh.
Ranovus will offer an optical engine as well as the QSFP28 optical module. "The notion of the integration of an optical engine with switch ICs and other piece parts in the data centre are more of an urgent need," he says.
Using WDM technology, the company has a scalable roadmap that includes 8x25 Gig and 16x25 Gig (400 Gig) designs. Also, by adding higher-order modulation, the technology will scale to 1.6 Terabit (16x100 Gig), says Aramideh.
I don't see a roadmap for coherent to become cost-effective to address the smaller distances
Ranovus is also working on interfaces to link data centres.
"These are distances much shorter than metro/ regional networks," says Aramideh, with the bulk of the requirements being for links of 15 to 40km. For such relatively short distances, coherent detection technology has a high-power consumption and is expensive. "I don't see a roadmap for coherent to become cost-effective to address the smaller distances," says Aramideh.
Instead, the company believes that a direct-detection interconnect that supports 15 to 40km and which has a spectral efficiency that can scale to 9.6 Terabit is the right way to go. If that can be achieved, then switching from coherent to direct detection becomes a no-brainer, he says. "For inter-data-centres, we are really offering an alternative to coherent."
The start-up says its technology will be in product deployment with lead customers in the first half of 2015.
Ranovus developing DWDM links for the data centre
Ranovus has raised US $11 million in funding to develop Terabit capacity links for the data centre. The Ottawa-based start-up plans to use dense wavelength-division multiplexing (DWDM) technology to create huge data pipes that reduce significantly the power consumption, and cost, per bit.
The company says that it is not a silicon photonics start-up but rather a user of the technology to make its interface. Ranovus will use a foundry to make its optical chips.
Ranovus includes former staff of the coherent transmission and DSP specialist, CoreOptics, acquired by Cisco Systems in 2010. "Electronics, as we learnt from our previous endeavour, can impact in a big way the cost-performance of links," says Aramideh. "It doesn't have to be expensive equaliser technology we developed in the past, but there are ways of using similar technology in CMOS ICs to solve some of the network problems."
This suggests that DSP will be used to help cram the multiple channels in the fibre as well as achieve several hundred kilometers of reach. But the DSP will use simpler algorithms than those for long-distance coherent transmission.
Aramideh says its Terabit interface is inevitably a proprietary design. "[Industry] standards are important and you need to have dual sourcing, but people value having disruptive technologies," he says. "The challenge the industry has is that there hasn't been a lot of innovation going into technologies specifically for the data centre."
The start-up's technology is being validated with several lead customers. "It is early proof of technology and the platform in terms of configurations that the customers will be using," he says.
The $11m funding raised will be used to commercialise the technology and make the first products for lead customers. "We are very advanced in our plans with respect to delivery of our product," says Aramideh. Ranovus expects to provide first details of its product at OFC 2014.