[130546] in North American Network Operators' Group
Re: A New TransAtlantic Cable System
daemon@ATHENA.MIT.EDU (Heath Jones)
Tue Oct 5 13:33:00 2010
In-Reply-To: <1E696AE6-F5AB-41E7-A235-F234CAC930F7@es.net>
Date: Tue, 5 Oct 2010 18:32:46 +0100
From: Heath Jones <hj1980@gmail.com>
To: Chris Tracy <ctracy@es.net>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
>> Would it be possible to extract via PLL or similar the source clock
>> and use that to modulate the amplifier power?
> Although you can amplify just a single wavelength with an EDFA (has to be=
in the 1550nm range, not 1310nm), most deployments are using EDFAs in a DW=
DM environment. =A0The C-band alone consists of ~5THz (5000GHz) of spectrum=
between 191.00-195.95 Thz. =A0Some systems pack 40 wavelengths into this s=
pace at 100GHz spacing, some 80 channels @ 50GHz spacing, others 160 @ 25GH=
z. =A0Each of these signals is independent, they can each be using differen=
t modulation/bitrate/etc. =A0The amplifiers are completely ignorant to what=
is going on with each channel, only the devices performing conversion back=
to the electrical domain need to care about these details (after the incom=
ing light has been demultiplexed into individual signals, of course).
I'm wondering if it could be done per wavelength?
I guess that would be pretty ridiculous having demux + 160 * decoder +
160 * efda + mux..
Just wondering if the theory works though?
