Optical components enter an era of technology-pull

Gazettabyte asked ADVA Optical Networking, Ciena, Cisco Systems and Ovum about their impressions following the recent OFC/NFOEC 2012 exhibition and conference.

OFC/NFOEC reflections: Part 2 

"As the economy continues to navigate its way through yet another very difficult period, it was good to see so many companies innovating and introducing solutions."

Massimo Prati, Cisco Systems

Massimo Prati, Cisco Systems

For Cisco Systems, 100 Gigabit was a key focus at the show. "There were many system and component vendors, including Cisco, demonstrating newly available, economically feasible 100 Gig innovations," says Massimo Prati, vice president and general manager for Cisco.

Linking data centres was another conference theme. "Inter-data centre connectivity continues to focus on scalable and simple solutions in long-haul and metro networks connecting data centres worldwide." Cisco believes metro 100 Gigabit deployments will become prevalent in 2013 and 2014, especially if low‐cost coherent technology becomes available.  

"A dedicated workshop focused on data centre architectures, held on the first day of the conference, was heavily attended," says Prati. "So certainly the link between cloud and optical is being established and is a key driver for high-speed transport networks."  

Another conference theme was interconnect within the data centre, and the need for photonic integration for low‐cost, low‐power links, says Prati: "From a Cisco standpoint, several of our customers were pleasantly surprised by our recently completed acquisition of Lightwire, which develops advanced optical interconnect technology for high-speed networking applications." Lightwire is a silicon photonics startup that Cisco acquired recently for US $271 million.

What Cisco says it learned from OFC/ NFOEC was that service providers are planning 100Gbps deployments within the next 12 months and are looking at second- and third-generation solutions. "There is quite a bit of energy around future upgrades to 400 Gig and one Terabit transport solutions, but service providers continue to monitor if and how these solutions will operate within their existing fibre plants."  

Prati expects more industry consolidation. "With the influx of 100 Gig solutions, it appears we may be ripe for further consolidation within the industry, particularly further down the technology food chain," he says.

He also remains optimistic about the industry's prospects.  

"We believe that the excitement around high-speed, long-haul transport, combined with cloud and data centre innovation, continues to fuel a lot of new product solutions and architectures," he says. "Content providers like Google and Facebook have clearly expressed interest in optical technologies addressing their issues with bandwidth demands and need for high-speed interconnect for their data centres." 

Joe Berthold, Ciena

Whereas last year there was much discussion about of the next rate for Ethernet - 400 Gig or one Terabit - this year 400 Gigabit had most mindshare, says Joe Berthold, vice president of network architecture at Ciena. "I barely heard any mention of one Terabit in the context of a contest with 400 Gigabit," he says.

"I could hear some rumblings about alternative form factors – which might lead to fragmentation of the market"

Joe Berthold, Ciena

400 Gigabit was given a boost with the line-side transmission component announcements. Ciena announced its WaveLogic3 and Alcatel-Lucent detailed its Photonic Service Engine.

Another noteworthy development was the buzz around silicon photonics, stirred in part by Cisco's Lightwire acquisition. "Silicon photonics has passed from a technology of research interest to one that has progressed to serious development," says Berthold. "Data centre interconnects look like a promising initial application."

There was no developments at the show that surprised Berthold. But he is concerned about the potential for proliferation of 100 Gigabit client-side form factors, especially for pluggable modules.

"I am going under the assumption that there is still broad industry support for the CFP progression - from the current CFP to a CFP2 followed by a CFP4 for single-mode fiber applications over metro distances," he says. 

Even though there are a variety of technologies appearing in the CFP form factor, this common physical module has helped control system development cost. "I could hear some rumblings about alternative form factors – which might lead to fragmentation of the market," he says.

Berthold is encouraged by the broad base of development efforts underway, particularly for 100Gbps transceivers, but also lower-cost 10Gbps and 40Gbps client-side modules. He notes the progress in reducing the cost of 100 Gigabit client interfaces over the next year. "Their high cost has held back adoption of 100 Gig," says Berthold. "We have had very cost effective 10 Gig multiplexing technology to fall back on, but it looks like native 100G interfaces are poised for growth."

Jörg-Peter Elbers, ADVA Optical Networking

Jörg-Peter Elbers, vice president, advanced technology at ADVA Optical Networking, was struck by the wide range of hot topics discussed at the show.

These include software-defined optics based on programmable transceivers that use advanced DSP technology and flexgrid ROADMs as the basis of a new coherent express layer. He also notes that control plane technologies are becoming an essential asset in managing network complexity when unleashing untapped network capacity.

"Traffic and content keeps growing at exponential scale - the fundamental demand-drivers are intact"

Jörg-Peter Elbers, ADVA Optical Networking

Meanwhile, the rapid increase in end-user traffic, specifically mobile, is driving PON. As a result WDM is moving closer to the network edge, entering aggregation and access networks. He believes dense WDM-PON is gaining traction for mobile backhaul as fibre becomes the bottleneck when moving from Long Term Evolution (LTE) to the LTE-Advanced cellular technology.  

Other trends to note, he says, are software-defined networking (SDN) and OpenFlow. "Originating from the campus and data centre world, network programmability is increasingly seen as key for tighter integration, more automation, and virtualisation of IT and computing services," says Elbers.

The industry increasingly sees the metro market as important to ramp up 100Gbps volumes, with different modulation solutions being promoted by vendors. These include performance reduced 100Gbps DP-QPSK (dual polarisation, quadrature phase-shift keying), 200Gbps DP-16QAM (dual polarisation, 16-quadrature amplitude modulation) and 4x28G direct-detection. 

While some people expressed concerns about a fragmentation of the 100 Gig market, power consumption, footprint and cost are of primary importance in the metro, he says.  "One analyst at the Ovum 100Gbps metro workshop at OFC said: 'Maybe, for a hammer everything looks like a nail…'," says Elbers. "With 4x28G optical duobinary being able to make use of 10Gbps T-XFP/SFP+, IEEE 802.3ba and CFP technologies, we believe there is a justification to differentiate."

ADVA demonstrated its 4x28Gbps optical duobinary direct-detection product at the show.

Elbers noted an interest in multi-core and few-mode fibres. "The next x10 in bandwidth is difficult to reach as additional gains from amplification, modulation, FEC and denser carrier spacing will be limited." he says. "The research community therefore is looking into new fibre types to add the spatial and modal dimensions alongside the current optimisation strategy." An area interesting to watch, but fundamental technical and economic challenges remain, he says.

He too is optimistic about the industry's prospects: "Traffic and content keeps growing at exponential scale - the fundamental demand drivers are intact." As a result, optical innovation will play an even bigger role in the future to keep pace with the bandwidth growth, he says.

Karen Liu, Ovum

"We're clearly in a technology-pull phase rather than technology-push phase with multiple system vendors doing 400Gbps-capable stuff instead of component guys showing demonstrations years in advance of system activity," says Karen Liu, principal analyst, components telecoms at Ovum. 

"Optical burst mode switching may be crossing over from rather 'pie-in-the-sky' to practical"

Karen Liu, Ovum 

It is not that that the components vendors aren't making innovative products, she says, just that they are not making announcements until there is real demand. "Corning, for example, showed a fiber that has already been shipping into Lightpeak," says Liu.

What surprised Liu at the show was Huawei's optical burst transport network prototype. "Optical burst mode switching may be crossing over from rather 'pie-in-the-sky' to practical," says Liu. 

She notes how there isn't as much optics-versus-electronics positioning anymore but more a case of optics working with electronics. "Huawei's OBTN is an example," says Liu. "Instead of using optical burst mode to make an all-optical network, optics is part of a hybrid design."

Liu says there are now multiple relationships between silicon and optics including the two working together instead of in competition. "In networking, the term translucent networks seems to have gained popularity."

Part 1: OFC/NFOEC 2012 industry reflections - Part-1