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Re: PAM-5, what are your BERs ?

Edward Chang wrote:

> Sean:
> Thanks for reminding us FEC.
> The BER defined in the standard is the actual error rate without any error
> correction.  This establishes the fundamental reliability and quality
> criteria of components, systems, and technologies.
> The error correction techniques can be added as an option for applications
> which need better BER than what has been specified in the standard.
> However, this is outside of the standard.
> For cost-effectiveness, I believe users will request the specified BER in
> the standard should be sufficient without added error collection.
> Edward S. Chang

Hello Edward,

I can not agree with you on this, Edward. However, I understand
the philosophy behind this: a bare proposal without any
whistles and bells (like FEC) should still be technically
reasonable and achieve some basic reasonable and measurable

The proposal I presented, "PAM5 4-WDM at 1.25 Gbaud"
has these attributes: even without FEC the optical eye is
wide open at the input of the receiver and the static SNR
(even without FEC) is similar to the static SNR of another
respectable proposal: 8b/10b 4-WDM at 3.125 Gbaud.
In fact, without FEC it would still be 1 dB (optical) better.
(see my email "PAM-5, what are your BERs" from Feb 27).


Jaime E. Kardontchik
Micro Linear
San Jose, CA 95131