Ciena goes stackable with 8180 'white box' and 6500 RLS
Ciena has unveiled two products - the 8180 coherent networking platform and the 6500 reconfigurable line system - that target cable and cellular operators that are deploying fibre deep in their networks, closer to subscribers.
The 6500 line system is also aimed at the data centre interconnect market given how the webscale players are experiencing a near-doubling of traffic each year.
Source: Ciena
The cable industry is moving to a distributed access architecture (DAA) that brings fibre closer to the network’s edge and splits part of the functionality of the cable modem termination system (CMTS) - the remote PHY - closer to end users. The cable operators are deploying fibre to boost the data rates they can offer homes and businesses.
Both Ciena’s 8180 modular switch and the 6500 reconfigurable line system are suited to the cable network. The 8180 is used to link the master headend with primary and secondary hub sites where aggregated traffic is collected from the digital nodes (see network diagram). The 8180 platforms will use the modular 6500 line system to carry the dense wavelength-division multiplexed (DWDM) traffic.
“The [cable] folks that are modernising the access network are not used to managing optical networking,” says Helen Xenos, senior director, portfolio marketing at Ciena (pictured). “They are looking for simple platforms, aggregating all the connections that are coming in from the access.”
The 8180 can play a similar role for wireless operators, using DWDM to carry aggregated traffic for 4G and 5G networks.
Ciena says the 6500 optical line system will also serve the data centre interconnect market, complementing the WaveServer Ai, Ciena’s second-generation 1RU modular platform that has 2.4 terabits of client-side interfaces and 2.4 terabits of coherent capacity.
With the 8180, you are only using the capacity on the fibre that you have traffic for
“They [the webscale players] are looking for as many efficiencies as they can get from the platforms they deploy,” says Xenos. “The 6500 reconfigurable line system gives them the flexibility they need - a colourless, directionless, contentionless [reconfigurable optical add-drop multiplexer] and a flexible grid that extends to the L-band.”
A research note from analyst house, Jefferies, published after the recent OFC show where Ciena announced the platforms, noted that in many cable networks, 6-strand fibre is used: two fibre pairs allocated for business services and one for residential. Adding the L-band to the existing C-band effectively doubles the capacity of each fibre pair, it noted.
The 8180
Ciena’s 8180 is a modular packet switch that includes coherent optics. The 8180 is similar in concept to the Voyager and Cassini white boxes developed by the Telecom Infra Project. However, the 8180 is a two-rack-unit (2RU) 6.4-terabit switch compared to the 1RU, 2-terabit Voyager and the 1.5RU 3.2-terabit Cassini. The 8180 also uses Ciena’s own 400-gigabit coherent DSP, the WaveLogic Ai, rather than merchant coherent DSP chips.
The platform comprises 32 QSFP+/ QSFP28 client-side ports, a 6.4-terabit switch chip and four replaceable modules or ‘sleds’, each capable of accommodating 800 gigabits of capacity. The options include an initial 400-gigabit line-side coherent interface (a sled with two coherent WaveLogic Ai DSPs will follow), an 8x100-gigabit QSFP28 sled, a 2x400-gigabit sled and also the option for an 800-gigabit module once they become available.
Source: Ciena
Using all four sleds as client-side options, the 8180 becomes a 6.4-terabit Ethernet switch. Using only coherent sleds instead, the packet-optical platform has a 1.6-terabit line-side capacity. And because there is a powerful switch chip integrated, the input ports can be over-subscribed.“With the 8180, you are only using the capacity on the fibre that you have traffic for,” says Xenos.
6500 line system
The 6500 reconfigurable line system is also a modular design. Aimed at the cable, wireless, and data centre interconnect markets, only a subset of Ciena’s existing optical line systems features is used.
“The 6500 software has a lot of capabilities that the content providers are not using,” says Xenos. “They just want to use it as a photonic layer.”
There are three 6500 reconfigurable line system platform sizes: 1RU, 2RU and 4RU. The chassis can be stacked and managed as one unit. Card options that fit within the chassis include amplifiers and reconfigurable optical add-drop multiplexers (ROADMs).
The amplifier options area dual-line Erbium-doped fibre amplifiercard that includes an integrated bi-directional optical time-domain reflectometer (OTDR) used to characterise the fibre. There is also a half-line-width RAMAN amplifier card. The line system will support the C and L bands, as mentioned.
The reconfigurable line system also has ROADM cards: a 1x12 wavelength-selective switch (WSS) with integrated amplifier, a colourless 16-channel add-drop that support channels of any size (flexible grid), and a full-width card 1x32 WSS. “The 1x32 would be used for colourless, directionless and directionless [ROADM] configurations,” says Xenos.
The 6500 reconfigurable line system also supports open application porgramming interfaces (APIs) for telemetry, with a user able to program the platform to define the data streamed.“The platform can also be provisioned via REST APIs; something a content provider will do,” she says.
Ciena is a member of the OpenROADM multi-source agreement and was involved in last year’s AT&T OpenROADM trial with its 6500 Converged Packet Optical Transport (POTS) platform.
Will the 6500 reconfigurable line system be OpenROADM-compliant?
“This card [and chassis form factor] could be used for OpenROADM if AT&T preferred this platform to the other [6500 Converged POTS] one,” says Xenos. “You also have to design the hardware to meet the specifications for OpenROADM.”
Ciena expects both platforms to be available by year-end. The 6500 reconfigurable line system will be in customer trials at the end of this quarter while the 8180 will be trialed by the end of the third quarter.
Oclaro makes available its EMLs and backs 400G-FR4
Lumentum’s plan to acquire Oclaro for $1.8 billion may have dominated the news at last month’s OFC show held in San Diego, but it was business as usual for Oclaro with its product and strategy announcements.
Adam Carter, chief commercial officer (pictured), positions Oclaro’s announcements in terms of general industry trends.
“On the line side, everywhere there are 100-gigabit and 200-gigabit wavelengths, you will see that transition to 400 gigabit and 600 gigabit,” he says. “And on the client side, you have 100 gigabit going to 400 gigabit.”
400G-FR
Oclaro announced it will offer the QSFP56-DD module implementing 400-FR4, the four-wavelength 400-gigabit 2km client-side interface. The 400G-FR4 is a design developed by the 100G Lambda MSA.
“This [QSFP-DD FR4] will enable our customers, particularly network equipment manufacturers, to drive 400 gigabit up to 36 ports in a one-rack-unit [platform],” says Carter.
Oclaro has had the required optical components - its 53-gigabaud lasers and high-end photo-detectors - for a while. What Oclaro has lacked is the accompanying 4-level pulse amplitude modulation (PAM-4) gearbox chip to take the 8x50 gigabits-per-second electrical signals and encode them into four 50-gigabaud ones.
The chips have now arrived for testing and if the silicon meets the specs, Oclaro will deliver the first modules to customers later this year.
Oclaro chose the QSFP-DD first as it expects the form factor to sell in higher volumes but it will offer the 400G-FR4 in the OSFP module.
Certain customers prefer the OSFP, in part because of its greater power-handling capabilities. “Some people believe that the OSFP’s power envelope gives you a little bit more freedom,” he says. “There is still a debate in the industry whether the QSFP-DD will be able to do long-reach [80km data centre interconnect] types of products.”
Oclaro says its transmit and receive optical sub-assemblies (TOSAs and ROSAs) are designed to fit within the more demanding QSFP-DD such they will also suit the OSFP.
If people want to buy the [EML] chips and do next-generation designs, they can come to Oclaro
EMLs for sale
Oclaro has decided to sell its electro-absorption modulated lasers (EMLs), capable of 25, 50 and 100-gigabit speeds.
“If people want to buy the chips and do next-generation designs, they can come to Oclaro for some top-end single-mode chipsets that we have developed for our own use,” says Carter.
Oclaro's EMLs are used for both coarse wavelength-division multiplexing (CWDM) and the tighter LAN-WDM wavelength grid based client-side interfaces and are available in uncooled and cooled packages.
Until now the company only sold its 25-gigabit directly modulated lasers (DMLs). “We have been selling [EMLs] strategically to one very large customer who consigns them to a manufacturer,” says Carter.
The EMLs are being made generally available due to demand. “There are not many manufacturers of this chip in the world,” says Carter, adding that the decision also reflects an evolving climate for business models.
5G and cable
Oclaro claims it is selling the industry’s first 10-gigabit tunable SFP+ operating over industrial temperature (I-temp) ranges: -40 to 85oC. There are two tunable variants spanning 40km and 80km, both supporting up to 96 dense WDM (DWDM) channels on a fibre. The module was first announced at OFC 2017.
Oclaro says cable networks and 5G wireless will require the I-temp tunable SFP+.
The cable industry’s adoption of a distributed access architecture (DAA) brings fibre closer to the network’s edge and splits part of the functionality of the cable modem termination system (CMTS) - the remote PHY - closer to the residential units. This helps cable operators cope with continual traffic growth and their facilities becoming increasingly congested with equipment. Comcast, for example, says it is seeing an annual growth in downstream traffic (to the home) of 40-50 percent.
The use of tunable SFP+ modules boost the capacity that can be sent over a fibre, says Carter. But the tunable SFP+ modules are now located at the remote PHY, an uncontrolled temperature environment.
For 5G, the 10Gbps tunables will carry antenna traffic to centralised base stations. Carter points out that the 40km and 80km reach of the tunable SFP+ will not be needed in all geographies but in China, for example, the goal is to limit the number of central offices such that the distances are greater.
Oclaro also offers an I-temp fixed-wavelength 25-gigabit SFP28 LR module. “It is lower cost than the tunable SFP+ so if you need 10km [for mobile fronthaul], you would tend to go for this transceiver,” says Carter.
Also unveiled is an optical chip combining a 1310nm distributed feedback laser (DFB) laser and a Mach-Zehnder modulator. “The 1310nm device will be used in certain applications inside the data centre,” says Carter. “There are customers that are looking at using PAM-4 interfaces for short-reach connections between leaf and spine switches.” The device will support 50-gigabit and 100-gigabit PAM-4 wavelengths.
Line-side optics
Oclaro announced it is extending its integrated coherent transmitter and integrated coherent receiver to operate in the L-band. The coherent optical devices support a symbol rate of up to 64 gigabaud to enable 400-gigabit and 600-gigabit wavelengths.
Telcos want to use the L-band alongside the C-band to effectively double the capacity of a fibre.
Also announced by Oclaro at OFC was a high-bandwidth co-packaged modulator driver, an indium phosphide-based Mach-Zehnder modulator.
Oclaro was part of the main news story at last year’s OFC when Ciena announced it would share its 400-gigabit WaveLogic Ai coherent digital signal processor (DSP) with three module makers: Oclaro, Lumentum and NeoPhotonics. Yet there was no Oclaro announcement at this year’s OFC regarding the transponder.
Carter says the WaveLogic Ai transponder is sampling and that it has been demonstrated to customers and used in several field trials: “It is still early right now with regard volume deployments so there is nothing to announce yet."