Optical components

ROADMs: Almost Famous

The metro networking market needs and wants reconfigurable add/drop multiplexers (ROADMs), though the products are likely to remain a niche play for now. But that niche is still an important part of U.S. RBOCs' metro growth plans, according to "ROADMs and the Future of Metro Optical Networks," a report issued this week by Heavy Reading, Light Reading's paid research arm.

ROADMs are the latest iteration of optical add/drop multiplexers. They are traffic cops of Wavelength Division Multiplexing (WDM) nodes, stopping some wavelengths for termination, allowing others to pass through, and adding new wavelengths to the stream. The result is an optical network that can more easily adjust to changes in traffic patterns.

The concept has been around for a few years now, and vendors at Light Reading's Future of Optical Networking conference in April noted that the technology is ripe for mass deployement (see Optical Networking: All Grown Up).

The problem is price. "The marketplace has long been rather wary of ROADMs" because of the price premium commanded and the fact that the products tend to incorporate new technologies, writes Heavy Reading analyst Scott Clavenna in the report. "The market seems to be in a 'chicken/egg' situation: The volumes necessary to drive down pricing will be difficult to achieve in a cautious spending environment."

Even so, ROADMs appear to be entrenched in carrier plans, with most service providers expecting to begin bulk deployments in 2006 or 2007, according to the report.

Recent triple-play initiatives provide a nice opportunity for ROADMs because they will lead to growth of metro networks in general. Along the same lines, cable network expansion is helping the ROADM cause.

Among the equipment vendors offering ROADMs, the report ranks Fujitsu Network Communications Inc. (FNC) and its Flashwave 7500 offerings at the top of the class (see Fujitsu Firms Its ROADM Resolve). Private vendors Movaz Networks Inc. and Tropic Networks Inc. scored among the leaders as well.

ROADMs are difficult to judge as a group, because so many approaches are offered, from older wavelength-blocker techniques to the more flexible wavelength-selective switch. Most ROADMs use an all-optical approach to adding and dropping wavelengths, but it's also possible to perform the function with a conversion to electrical traffic. Infinera Inc. and Meriton Networks Inc., both included in the report, exemplify this "OEO" method.

The report, available for $3,495, surveys 20 equipment vendors and includes feedback from 10 major carriers.

— Craig Matsumoto, Senior Editor, Light Reading

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