There is
inherently no “framing
block” if you are encoding the control symbols into the TCM
constellation
mapping directly.
Hence you
won’t find a “framing
proposal” – it’s covered in the PAM-10 TCM mapping.
This reduces the overhead and simplifies operation, and is similar to
1000BASE-T, where the control symbols are part of the constellation
mapping
itself. Optical systems, which tend to have bit-to-bit errors, often
have
such framing to help in protection against single-bit errors.
Multi-level
copper transmission systems, as you know, will generally have errors
covering
much more than 1 bit, and hence lend themselves to different approaches
for
encoding control bits.
I’m really
not trying to be obtuse
here, but can you point me to an example of the block diagram that you
are
looking for, when applied to a coded modulation system? (just reference
a
figure number in 802.3?) Perhaps then I can get you something more in
line with
what you’re looking for.
-george
-----Original
Message-----
From:
stds-802-3-10gbt@IEEE.ORG
[mailto:stds-802-3-10gbt@IEEE.ORG] On
Behalf
Of Sanjay Kasturia
Sent: Tuesday, May 11,
2004 9:39
AM
To:
STDS-802-3-10GBT@listserv.ieee.org
Subject: Re: [10GBT]
Framing for
10GBASE-T
George,
Could you
either send me a summary of your
framing proposal or point me to where there is one on line? I would
like
to see if I can come up with one block diagram that captures all
framing
proposals.
Alternatively,
if you and Sailesh can come
up with a unified framing approach, that would make my job easier.
Regards,
Sanjay
sanjay@teranetics.com
cell (650) 704-7686
office (408) 653-2235
From:
stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On Behalf Of George Zimmerman
Sent: Monday, May 10,
2004 3:29 PM
To:
STDS-802-3-10GBT@listserv.ieee.org
Subject: Re: [10GBT]
Framing for
10GBASE-T
No, our
proposal does not call for
additional framing at the bitstream level. They are instead,
incorporated
into the 10,000-8192 = 1808 4D PAM-10 constellation points beyond what
is
needed for shaping gain and carrying the information bits. By
incorporating the control symbols directly into the PAM-10 codeword,
and using
receiver-based equalization, we require neither the feedback channel,
nor
additional baud rate overhead for control symbols.
In contrast,
the TH precoded proposals may
require an additional framing for updating the coefficients of the
precoder,
and this overhead was included in Sailesh’s original proposal, along
with
a much less efficient way to deal with the control symbols. The rate
for
such update would need some extensive study, as I haven’t seen ANY data
on the variability of the LAN cabling characteristics over time,
temperature,
or equalizer variations with time-varying EMI.
On another
note, thanks for the
clarification on the process. We can discuss, making decisions easier
and
better informed, but try not to drive agreements on email, without a
meeting of
the group.
-george
-----Original
Message-----
From:
stds-802-3-10gbt@IEEE.ORG
[mailto:stds-802-3-10gbt@IEEE.ORG] On
Behalf
Of Sanjay Kasturia
Sent: Monday, May 10,
2004 3:19 PM
To:
STDS-802-3-10GBT@LISTSERV.IEEE.ORG
Subject: Re: [10GBT]
Framing for
10GBASE-T
George,
Thanks. I
did think the 64B/66B was at the
bit-stream level and Sailesh (at the Albuquerque meeting) had also
some framing at the symbol level over and beyond bit-level framing
Is there a
need for framing at the
bitstream level over and beyond what you do in the TCM mapping in your
proposal?
You are
correct in pointing out that group
decisions must be formalized at a formal meeting through the voting
process but I am not suggesting we bypass that process. Reaching
agreement earlier (if it happens!) will will enable us to get the
specific
decision through the voting process quicker and possible let us address
more
issues within the time constraints of the next meeting.
Regards,
Sanjay
sanjay@teranetics.com
cell (650) 704-7686
office (408) 653-2235
From:
stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On Behalf Of George Zimmerman
Sent: Monday, May 10,
2004 3:03 PM
To:
STDS-802-3-10GBT@LISTSERV.IEEE.ORG
Subject: Re: [10GBT]
Framing for 10GBASE-T
Sanjay – I
have seen 2 other
proposals, one by Sailesh, in his original procedure, and the other by
myself
(to incorporate the control symbols directly into the TCM mapping, and
thus
avoid the higher baud rates). There may be more brought to the group
at
the next meeting.
Discussion
of these items might be
useful on the reflector, however, we should refrain from trying to make
group
decisions without a formal meeting and voting process.
-george
-----Original
Message-----
From:
stds-802-3-10gbt@IEEE.ORG
[mailto:stds-802-3-10gbt@IEEE.ORG] On
Behalf
Of Sanjay Kasturia
Sent: Monday, May 10,
2004 2:46 PM
To:
STDS-802-3-10GBT@LISTSERV.IEEE.ORG
Subject: [10GBT]
Framing for
10GBASE-T
I don't recall seeing any
other framing proposal. Is
everyone in favor of using 64B/66B framing? If not, can you point me to
alternative framing proposals?
If there aren't any
alternative proposals, shall we, as a
group, focus on developing this further?
Regards,
Sanjay Kasturia
Editor-in-chief
802.3an
sanjay@teranetics.com
cell (650) 704-7686
office (408) 653-2235
fax (408) 844-8187
Teranetics Inc.
2953 Bunker Hill Lane,
Suite 204
Santa Clara, CA 95054