ROADMs: reconfigurable but still not agile

Briefing: Dynamic optical networks

Part 2: Wavelength provisioning and network restoration

How are operators using reconfigurable optical add-drop multiplexers (ROADMs) in their networks? And just how often are their networks reconfigured? gazettabyte spoke to AT&T and Verizon Business.

Operators rarely make grand statements about new developments or talk in terms that could be mistaken for hyperbole. 

“You create new paths; the network is never finished”

Glenn Wellbrock, Verizon Business

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Still some way to go

Briefing: Dynamic optical networking 

Part 1: The vision .... back in 2000

I came across this article (below) on the intelligent all-optical network. I wrote it in 2000 while working at the EMAP magazine, Communications Week International, later to become Total Telecom.

What is striking is just how much of the vision of a dynamic photonic layer is still to be realised.  Back then it had also been discussed for over a decade. And bandwidth management, like in 2000, is still largely at the electrical layer.

And yet much progress has been made in networking technology. But the way the network has evolved means that a more flexible photonic layer, while wanted by operators, is only one aspect of the network optimisation they seek to reduce the cost of transporting bits.

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Optical transmission beyond 100Gbps

Briefing: High-speed optical transmission. 

Part 3: What's next?

Given the 100 Gigabit-per-second (Gbps) optical transmission market is only expected to take off from 2013, addressing what comes next seems premature. Yet operators and system vendors have been discussing just this issue for at least six months.

And while it is far too early to talk of industry consensus, all agree that optical transmission is becoming increasingly complex. As Karen Liu, vice president, components and video technologies at market research firm Ovum, observed at OFC 2010, bandwidth on the fibre is no longer plentiful.

“We need to keep a very close eye that we are not creating more problems than we are solving.”

Brandon Collings, JDS Uniphase.

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40 and 100Gbps: Growth assured yet uncertainty remains

Briefing: High-speed optical transmission.

Part 2: 40 and 100Gbps optical transmission

The market for 40 and 100 Gigabit-per-second optical transmission is set to grow over the next five years at a rate unmatched by any other optical networking segment.  Such growth may excite the industry but vendors have tough decisions to make as to how best to pursue the opportunity.

Market research firm Ovum forecasts that the wide area network (WAN) dense wavelength division multiplexing (DWDM) market for 40 and 100 Gigabit-per-second (Gbps) linecards will have a 79% compound annual growth rate (CAGR) till 2014.

In turn, 40 and 100Gbps transponder volumes will grow even faster, at 100% CAGR till 2015, while revenues from 40 and 100Gbps transponder sale will have a 65% CAGR during the same period.

Yet with such rude growth comes uncertainty.

“We upgraded to 40Gbps because we believe – we are certain, in fact – that across the router and backbone it [40Gbps technology] is cheaper”

Jim King, AT&T Labs.

Systems, transponder and component vendors all have to decide what next-generation modulation schemes to pursue for 40Gbps to complement the now established differential phase-shift keying (DPSK). There are also questions regarding the cost of the different modulation options, while vendors must assess what impact 100Gbps will have on the 40Gbps market and when the 100Gbps market will take off.  

“What is clear to us is how muddled the picture is,” says Matt Traverso, senior manager, technical marketing at Opnext.

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Ofidium to enter 100Gbps module market using OFDM

Briefing: High-speed optical transmission.

Part 1: The start-up

Ofidium is a 100 Gigabit start-up that refuses to follow the herd.

While the optical industry has chosen polarisation-multiplexing quadrature phase-shift keying (PM-QPSK) for 100 Gigabit-per-second (Gbps) transmission, the Australian start-up is developing a module based on orthogonal frequency division multiplexing (OFDM) modulation.

 "For data rates higher than 100Gbps, it [OFDM] is the only way to go"

Jonathan Lacey, CEO

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Optical transceivers: Pouring a quart into a pint pot

Transceiver feature - 3rd and final part

Optical equipment and transceiver makers have much in common.  Both must contend with the challenge of yearly network traffic growth and both are addressing the issue similarly: using faster interfaces, reducing power consumption and making designs more compact and flexible.  

Yet if equipment makers and transceiver vendors share common technical goals, the market challenges they face differ. For optical transceiver vendors, the challenges are particularly complex.

LightCounting's global optical transceiver sales forecast. In 2009 the market was $2.10bn and will rise to $3.42bn in 2013

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Differentiation in a market that demands sameness

Transceiver feature: Part 2

At first sight, optical transceiver vendors have little scope for product differentiation. Modules are defined through a multi-source agreement (MSA) and used to transport specified protocols over predefined distances.

 

“Their attitude is let the big guys kill themselves at 40 and 100 Gig while they beat down costs"

Vladimir Kozlov, LightCounting

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