ROADMS: When "-less" is more
Thursday, July 22, 2010 at 10:21AM The telecom industry is right up there when it comes to acronyms and complex naming schemes but it is probably no worse than other industries.
One only has to look at neighbouring IT and cloud computing in particular with its PaaS, IaaS and SaaS (Platform-, Infrastructure- and Software-as-a-Service).
But when it comes to agile optical networking and the reconfigurable optical add-drop multiplexer (ROADM), what is notable is the smarts that are being added and yet all are described using the “-less” suffix: colourless, directionless, contentionless and gridless.
These are all logical names once the enhancements they add are explained. But as Infonetics Research analyst Andrew Schmitt has pointed out, the industry could do better with its naming schemes. Even the most gifted sales person may be challenged selling the merits of a colourless, directionless product.
Colourless is a term long in use for such optical devices as arrayed-waveguide gratings. So to expect the industry to change now is perhaps unrealistic. But could better names be chosen? And does it matter?
Well, yes, if it undersells the benefits new products deliver.
The four smarts
Colourless refers to the decoupling of the wavelength dependency, so is “wavelength independent” better? What about colourful? Sales people are on a better footing already.
Then there is directionless. The idea here is that the latest ROADMs have full flexibility in routing a lightpath to any of the network interface ports. So instead of directionless, what about ROADMs that are omnidirectional or all-directional?
"Even the most gifted sales person may be challenged selling the merits of a colourless, directionless product."
Contentionless means non-blocking, a well-known term widely used to describe switch and router designs.
And gridless comes from the concept of relaxing the rigid ITU grid for wavelengths. Again, a perfectly logical name. But it sells short the adaptive channel widths that new ROADMs will support for data rates above 100 Gigabit-per-second.
So third-generation ROADMs are colourless, directionless, contentionless and gridless products. But does colourful, all-directional, non-blocking and adaptive-channel ROADMs sound better?
Suggestions welcome.
Reader Comments (5)
How about 360-degree instead of directionless?
Comment from the LinkedIn Optical networking group:
"Leading with a negative is probably not the best choice of words. However, it does open the door to a conversation, which addresses the benefits, and solves customers' problems."
Posted by Fred Haas
The terms colorless, directionless and so on represent the direct opposite of what they supposed to be capable of doing. Colourless actually means all colors and directionless means "directionable”. I think the terms are confusing and should be clarified.
I just do not believe that homeless means you can stay in any home and senseless means you have a lot of sense. This may be a good example of senseless after all.
Bill Szeto, Xtera.
Comment from the LinkedIn Optical networking group:
"It is always a cost-performance trade-off. In the framework of the EU research project DICONET, we have done the techno-economic comparison of various ROADM types and can provide some info to those interested."
Ioannis Tomkos
Comment from the LinkedIn optical networking group:
To Igor's comment... it does appear that a lot of what was developed in the optical boom of the late 90s to 2001 is being needed. In a sense it seems like a 10-year hibernation mode was in affect while all the bits, bytes and photons were sorted out.
Meanwhile, all the dark fiber was recapitilised. Now all that dark fibre is being lit up because the killer app for the internet is officially in full swing and that is pushing video everywhere. Also the higher speeds of 40G and 100G are finally here as well.
Couple this with the evolution of the new data centre (the old data centre was IBM and the 80s with network management and terminals) and boom you have a need for ROADMs.
Michael Bustamante