DWDM's so-called life

Everything is as cyclical in telecom as it is in real life. Services launch, carriers boast, customers scoff, nobody buys, services flop, new services launch. Technologies surface, everyone cheers, euphoria ensues, problems emerge, reality sets in, technologies mature, new technologies surface.

Dense wave division multiplexing is a good example of that round-and-round tendency. For all of its potential to fatten fiber capacity, DWDM has been showing some blemishes lately. The technology is coming under increasing scrutiny-not so much for its overall performance potential, but rather for its network management tangles, its efficacy in the metro and short-haul markets and, in particular, its cost.

So are the high hopes everyone had for DWDM beginning to turn?

Probably not. DWDM has simply entered the "reality sets in" stage of its cycle. It's sort of a gawky teenager. For DWDM to mature, all these issues and any others that come up will need to be carefully and completely addressed by its developers and its users.

The metro and short-haul migration is DWDM's next big thing. The technology had an early puberty of sorts out in the field-specifically, along long-haul network routes where fiber capacity needed a boost. Now, the increasingly fiber-rich short-haul links-and even the city-dwelling networks-are starting to feel the need for a similar fix to solve their own set of problems.

They're getting it. A whole new crop of vendors has joined with existing manufacturers to tackle this emerging market. All of them have set their sights on the newcomers to the local scene that are trying to do new and innovative things with fiber. But new applications bring new challenges, so few vendors are able to show mature product as yet.

There's a direct correlation between DWDM's movement into the metro and the network management problems that are being confronted. It's a fairly simple phenomenon: In the long-haul network the transmission of light is pretty much point-to-point, no matter how many times it's divided and multiplexed. Metro and short-haul networks involve more complicated maneuvering, so wavelengths need more guidance.

Signs from the carrier community suggest that solving the management conundrum is going to be the job of their vendors. In other words, carriers may consider buying DWDM systems for their metro efforts, but they will want to make sure the vendors have a handle on management.

Proprietary development could end up contributing to operations support system integration problems down the line, but if OSS history has taught us anything, it's that carriers are probably not worrying about that at this point. Still, standards bodies like the International Telecommunication Union and the Optical Interoperability Forum are beginning to get involved, which could help spark the interest of the software community.

Both metro momentum and management requirements are also directly related to cost. Cost is not a new concern for DWDM-since systems have been expensive for vendors to build and for carriers to deploy for a long time. As often happens with new technologies, however, DWDM's costs have been dropping as the technology develops.

But new capabilities cost more money: A stripped-down DWDM platform for the long-haul network may be less expensive now, but when you add enhancements to make it work in the metro and address bandwidth management concerns, costs are going to have a tendency to creep back up again. That could be bad news for new carriers with intense cost pressures and for vendors that feel the need to finance equipment to get the business.

These kinds of issues and technological hurdles tend to set off alarms, particularly when you're talking money. New and incumbent carriers are probably all feeling uncertain about DWDM deployment decisions they have already made, or about ones that certain equipment vendors are now pressuring them to make. Signs from the vendor, carrier and standards communities, however, suggest that DWDM is getting the help it needs to get over this.

So there's no need for DWDM to feel like a teenage outcast. All technologies go through this kind of thing. It's nothing to be ashamed of. It will pass.