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
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