PASSIVE [D]WDM... Like, Cisco 15216.

Frank Coluccio fcoluccio at dticonsulting.com
Thu Jul 25 07:32:25 UTC 2002


It would be nice if Transmode spent a little more attention to the detail in 
their data sheet and less on their art work. I can't discern what their CWDM 
spacings are either. If you return to the site you'll note that the 1.25 and 2.5 
Gxx numbers you cited were actually *bit rates*, not frequency separations on a 
grid. 

The ways in which grids are defined for DWDM and CWDM differ, with DWDM grids 
typically defined on the basis of frequency spacings. E.g., spacings between the 
center frequencies of lambdas at 200GHz, 100GHz and 50GHz proposed for the ITU 
grids. The proposed CWDM Grids, on the other hand, will use *wavelength* spacings 
(effectively the same thing after you do the arithmetic, it's just noted 
differently).

See the following TIA (Telecommunications Industry Association) paper at the url 
below.  E.g., CWDM grid spacings may be at 20 nanometers (20 nm), whereas a DWDM 
spacing might be 100 GHz.

http://ftp.tiaonline.org/fo-2/fo27/Public/2002-01-Kauai/FO27-2002-01-TD12.doc

I don't know how much this helps in the search for a mix and match wavelength 
conversion assembly, but it at least lays out all known and proposed grid formats 
so that we have a more factually-based starting point.

FAC

> 
> On Thu, 25 Jul 2002, Simon Lockhart wrote:
> 
> > I'm currently using the 15454 to wavelength convert OC48 signals, but have
> > not to date seen a black-box wavelength convertor - I would also be interested
> > to know if such a beast exists. I think if you want to do this, you're stuck
> > with the Metro 1500 (or equivalent from someone else), which becomes very
> > expensive quickly.
> 
> Transmode <http://www.transmode.com> has both 1.25Ghz and 2.5Ghz units
> with where you pretty much can pick and choose your optics from 850nm MM,
> 1310, 1510, 1530, 1550 and 1570nm when you order. This is not a complete
> ITU grid from what I can find (I don't know exactly what ITU grid is but I
> found some specs) but rather for CWDM use.
> 
> There should be quite a few manufacturers making units like these, I know 
> the MRV people does it as well (or some company within MRV).
> 
> -- 
> Mikael Abrahamsson    email: swmike at swm.pp.se
> 
> 





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