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RE: PAM-5, what are your BERs ?




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.

As we discussed on the reflector several months ago, FEC is not free, which
adds cost and overhead to the link.  We may consider using FEC, if we really
need it.


Regards,

Edward S. Chang
NetWorth Technologies, Inc.
EChang@NetWorthtech.com
Tel: (610)292-2870
Fax: (610)292-2872



-----Original Message-----
From: owner-stds-802-3-hssg@ieee.org
[mailto:owner-stds-802-3-hssg@ieee.org]On Behalf Of Sean Leighton
Sent: Wednesday, March 01, 2000 10:15 AM
To: stds-802-3-hssg@ieee.org
Subject: Re: PAM-5, what are your BERs ?



Hello,

With regards to the BER problem, are we open to the possible use of forward
error
correction to correct for bit errors in the transmission stream. Currently
in
T1X1.5, there is a submission for inband FEC based on a BCH-3 code that
turns a
1x10**-7 BER into a corrected BER of 1x10**-17. Prehaps a BCH-1 code could
be used?
Using FEC would introduce the need for some additional bits within the frame
format
and it would probably introduce some latency, but it would introduce some
coding
gain.

Cheers,
Sean