DWDM and EDFA and DCM

Rodrigo 1telecom rodrigo at 1telecom.com.br
Wed Apr 22 22:43:22 UTC 2015


Nothing is wrong with the fiber... Attenuation is good... Gbics specs says -23db as a limit of your sensibility ...i have tried to put bidi sfp+ 80km on this fiber and have -25dbi on other side( not connect) this module have -20dbi sensibility ...
This scenario have a 4 channels... And i use 2 10gb channels... C21 and c22 on side A and c51 and c52 on side B....

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Grupo Connectoway

> Em 22/04/2015, às 19:01, Evelio Vila <evelio at thousandeyes.com> escreveu:
> 
> I think the OP is asking about whether it should account for chromatic dispersion or not. Intramodal dispersion may very well be a limit on your link even the power budget (as presented before) is fine.  As Mikael said, I would stick to the specs from the manufacturer for that specific module, or rent an OTDR and make the measurements.
> 
> --
> Evelio
> 
>> On Wed, Apr 22, 2015 at 1:51 PM, Baldur Norddahl <baldur.norddahl at gmail.com> wrote:
>> First: buy a power meter. They are really cheap and the only way to know
>> for sure how much signal you got. It will also tell you how much launch
>> power you have. The fiberstore modules are listed as 0 to +5 dBm launch
>> power - if you got lucky it might be +5 and if you got a lower end module
>> it might be close to 0. Obviously this makes a huge difference for how much
>> power you get on the other end. Also it is said that the laser will lose
>> power over time.
>> 
>> Second you need to think in terms of power budget, not distance. So you got
>> 68 km and the module is rated for 80 km - but not all fiber is not born
>> equal. A power meter allows you to measure the true link loss.
>> 
>> Third you did not tell what DWDM multiplexer you are using. A 44 channel
>> DWDM multiplexer from Fiberstore can have up to 4.5 dB insertion loss. You
>> might have two of those on your link for a total of 9 dB loss. Your 80 km
>> module has a 23 dB link budget, so this leaves you with 23-9 = 14 dB
>> budget. If your fiber has 0.25 dB loss per km, that is only 56 km.
>> 
>> Regards,
>> 
>> Baldur
> 



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