[EFM] RE: [EFM-Copper] [EFM-copper] update of carrier perspective on SH DSL presentation
Dear John and All,
I will respond on item 2 as ANSI DSM-standard editor and
someone involved in the DSM area heavily. The ANSI DSM group
is also copied.
DSM standardization is underway with increasing contribution
from many. There are two main categories in the document:
1. no coordination (unbundled) so no central coordination or
interaction between lines -- autonomous - today's exact situation
2. coordination (basically for remote terminals where many
if not all in same binder terminate on same DSLAM/box)
There is at least one large American operator very close to
deploying some early DSM methods in item 1, so that area is
not 5 years away. Some of Doug's results are for 4 bonded
lines (2.5 Mbps each to add to 10), but also fall under category 1.
These are also near term, and at least one company has implemented
DSL systems that so operate (Voyan, San Jose) -- you might
want to see this yourself by contacting them.
There are other areas, particularly under the coordination category
that may take longer to gain acceptance. Just as with
spectrum management standards -- some parts are implemented
now, some will be a while. That is true for DSM also.
DSL field will gain from the DSM area, shortly and long term.
several operators are actually putting money into this area, so its
more than just the standards people involved.
If you would like to learn more - see Chapter 11
of the book
DSL Advances - T. Starr, M. Sorbara, J. Cioffi, and P. Silverman,
We already had a decision on DSM in ANSI, and it passed
to go forward so all operators, vendors, chip suppliers, and a
professor/editor were in agreement. I hope EFM will find a
forward also that is productive for the DSL industry. I'm
confident DSM will become a strong component of that success
in the future.
At 05:52 AM 1/5/2003 -0800, John.Egan@xxxxxxxxxxxx wrote:
John M. Cioffi
I have some questions for you,
as well. There seems to be some misunderstandings occurring here that I
hope you folks from the ADSL/DMT side could clear up. These are related
to the use of the "generic" term "ADSL." Is not the
EFM proposal from Doug based on Annex J and not the whole family of ADSL
(the generic ADSL term), as ADSL per se would not meet the Long Reach
Objective (generic ADSL is low bandwidth, asymmetric, etc.)? I believe
any discussion of ADSL should center not on the family of Annexes but on
Annex J itself.
1) If we consider Annex J then
many answers to your points immediately become apparent. For example,
your item 1, which you partially answer yourself by mentioning the
embedded base and investment in ATM ADSL, has a more complete answer when
considering the incompatible nature of Annex J and this base. To deploy
Annex J and cause service deterioration in the existing base would be
foolish for an Operator.
2) As to DSM in item 2... isn't
this a "house of cards" theoretical technology that would only
work in a fully closed environment where only one DSL technology is
deployed from a single carrier? Otherwise, wouldn't this be problematic
where the service would be frequently disrupted by new disturbers added
by others that are outside the DSM domain? Well, I suppose this
discussion is all academic as DSM is not going to be anything more than
theoretical for at least 4-5 years.
3) Your item 3 b) appears to
use the generic ADSL term instead of Annex J. The incompatibility of
Annex J with existing base of ADSL should be made clear. I hope that an
open discussion occurs Monday as to the conflicts and incompatibilities
of Annex J and not a discussion of ADSL in a generic sense, otherwise we
are not doing a real comparison of Long Reach technologies.
4) By the way, what is the
official title for Annex J anyway? I believe it is "ADSL for
operation above ISDN." If this Annex defines service as this, does
this mean we have a technology proposal based on one that would have
limited in deployment in NAFTA as well (few BRIs)? To be POTS compatible
versus ISDN would mean Annex J must be modified from the existing
recommendation to some new DSL definition which in turn makes this a
comparison of a well defined and standardized technology (g.SHDSL) and
one that is not standardized (Annex J changed for POTS)?
Behrooz, Happy New Year to you.
I look forward to the conclusion of this step in Vancouver and the
opportunity for the Copper track to make some serious headway. I expect
many at EFM would like to see the year plus delaying efforts in Copper
stopped and some conclusions reached so that we finally move
- -----Original Message-----
- From: Behrooz Rezvani
- Sent: Sunday, January 05, 2003 1:06 AM
- To: MARC KIMPE; email@example.com;
- Cc: 'Hugh Barrass'; Howard Frazier
- Subject: Re: [EFM-Copper] [EFM-copper] update of carrier
perspective on SHDSL presentation
- Marc thanks :-)
- I have few questions for the operators (either arms of
business/technical/regulatory representatives) to help me understand the
situation a little bit better:
- 1) Do carriers think that it may not be necessary to offer Ethernet
to residential market using ADSL. Could the reason be that they have
invested so much into ATM/ADSL that in fact it does not make sense to
change strategy at this point. In other words the ADSL volume already is
so high (therefore ADSL chipset cost so low) that it would cost them more
money try to introduce Ethernet over ADSL. Why mess with it when finally
the inter-op is working very well and all the operational stuff with $B
dollars into it is now mature
- 2) The other question could be regarding the performance of
SHDSL: is it as good or better than ADSL. I am not sure what is
real answer to this. There are two good presentations on Monday, and to a
large extend the performance data depends on the assumptions on reach,
binder composition, etc. So these will go thru acid test on Monday.
<However from the perspective of roadmap, some new work and
actual data based on DSM suggests for multi-pair operation the results
are very good based on ADSL-dmt >
- 3) Is binder segregation allowed. Some operators may allow that, but
in general my understanding is that will make it more expensive. This is
at least the comments I received from some international operators. For
example consider this:
- a) If we assume binder segregation is allowed then what is the
segregation rule. Does it mean we separate all SHDSL and T1 in the same
binder (symm) and all ADSLs, and POTs in other binders. In that case the
ADSL binder will outperform the SHDSL/T1 binder simply because it is
wider band and has more transmit power and it does not have to deal with
T1 Jammer PSD.
- b) If we assume that binder segregation is not allowed then it seems
to me that ADSL will dominate the composition of the binder by almost 4
to 1 and in that case we have to make simulation assumptions based on
those consideration, which again I would see the results favor ADSL in
- Anyway I don't think there are simple answers and I will be happy to
receive my answers off line.
- I have also made a contribution recommending to support both SHDSL
and ADSL. I think this would result to a bigger footprint for
- Best Regards
- ----- Original Message -----
- From: MARC KIMPE
firstname.lastname@example.org ; email@example.com
- Cc: 'Hugh Barrass' ; Howard Frazier
- Sent: Saturday, January 04, 2003 11:05 AM
- Subject: [EFM-Copper] [EFM-copper] update of carrier perspective on SHDSL presentation
- Since there are additional names and the file is small, we thought it would be relevant to send the latest carrier perspective on SHDSL presentation (easley_copper_1_0103) by email as well as uploading it on the server.
- See you in Vancouver,
Hitachi America Professor of Electrical Engineering
363 Packard Electrical Engineering Bldg.
350 Serra Mall
Stanford, CA 94305-9515
+1-650-723-2150 Fax: +1-650-724-3652