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.
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.
