Tunable pluggable transceivers reaching market in non-standard form factors
JULY 17, 2008 By Stephen Hardy -- Bookham Inc. (search for Bookham) has announced that is has begun to supply 10-Gbit/sec tunable pluggable transceivers to Ciena Corp. (search for Ciena) for use in a variety of platforms. A Bookham source says the transceivers are not in a standard 10G format; a Ciena source says this isn't a problem because they have a second source lined up to make a device in the same format.
Ciena will use Bookham's LambdaFLEX TL8000 modules on the line side of the CoreDirector Multiservice Switch, CoreStream Agility Optical Transport System, and CN 4200 FlexSelect Advanced Services Platform for core and metro network applications. Bookham debuted the module at this year's OFC/NFOEC in February. While the company has XFP-E and XFP form factors on its roadmap, Bookham VP Telecom Sales Yves LeMaitre confirmed that the modules Ciena will receive won't be in a 10G MSA-compliant form factor. Instead, the devices will be packaged in a footprint roughly the size of an X2 (see photo above).
LeMaitre indicated that Ciena was willing to work with a non-standard module size in the interests of getting tunable pluggable technology into the field. James Zik, senior product marketing manager at Ciena, confirmed that his engineers were willing to trade a standard form factor for the functions they wanted. The deployment of the tunable pluggables will allow Ciena to increase shelf port density (when paired with other design enhancements) by a factor of 4, Zik says; this will enable the company to rival densities achievable with "integrated photonics" technology, he says. These shelf designs will be less expensive than if Ciena integrated DWDM optics directly onto the board, Zik continued. And in addition to the standard sparing-related advantages, the pluggable devices also will simplify maintenance for carriers, who will now only have to replace a transceiver if a line goes down.
Beside the desire to get the benefits of tunable pluggable transceivers into the field, the availability of a second source also led Ciena to adopt the non-standard form factor, Zik reveals. The supplier, whom Zik would not identify, has not yet begun shipping modules but is not "too far behind" Bookham, he says.
Zik expects to be able to ship demonstration platforms using the new modules to potential customers by the end of this year, with fieldable systems following at the beginning of next year.
Ciena is the first systems house to announce that it will use such devices. LeMaitre declined to talk about specific conversations with other platform vendors so as not to steal Ciena's thunder, but indicated that he expects that the tunable pluggable market will settle on three or four form factors -- in particular, XFP-E, XFP, and something bigger than those modules along the lines of what Ciena will receive. He added that a technology advancement will be necessary before module vendors will be able to supply tunable XFPs or SFPs. This means initial deployments will be in the XFP-E and larger formats. Bookham is considering a tunable X2 module, LeMaitre added.
Zik says that Ciena is comfortable with the current form factor and would not be interested in switching to a more conventional size unless the change provided a significant economic benefit. The availability of a tunable XFP might fit that description, he indicated.
The TL8000 features Bookham's tunable transmitter with an indium phosphide Mach Zehnder modulator and DSDBR wideband tunable laser. The module also includes the company's 10-Gbit/sec avalanche photodiode receiver combined with electronic dispersion compensation to enable use in metro and long-haul applications.
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