Re: [8023-10GEPON] [power saving] New study shows FTTH is a green technology
Hi Vitor,
Nice to hear from You again.
The paper You referenced is only available at IEEE (LEOS) archive (I think,
I could not find it available online at any other location).
I did go through this paper as well as a few others which are referenced
therein and others I found on the web. As interesting the analysis of the
power consumption is in the majority of these publications, the more I read
the more I get the feeling that the conclusions are rather speculative and
the resulting power consumption of data networks is much higher than the
presented rough estimates. I would expect a higher impact of the core
systems and servers, which even though are shared by a large number of edge
users, they are still large and have to deal with large capacity data flows.
It is just enough to see the power consumption of a medium-size data center
to quickly realize that we are talking about a higher fraction that 1%
mentioned in the paper(s).
Do You believe any detailed power consumption analysis even for a single
country is at all possible ? After all, to do the calculations right, what
You need is to have a precise list of network equipment from all carriers in
the given country, starting from the access edge to the core. If You cannot
make such a list, anything You come up with using averaged numbers is just a
rough estimate, with no way to say whether we are underestimating or
overestimating the value. I am curious how many telcos would actually agree
to release such information if anyone were to set out and try to draw such a
power consumption estimate.
Regards
Marek
-----Original Message-----
From: Victor Blake [mailto:victorblake@xxxxxxx]
Sent: terça-feira, 30 de Setembro de 2008 17:37
To: 'Marek Hajduczenia'; STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: RE: [8023-10GEPON] [power saving] New study shows FTTH is a green
technology
Marek, et. al.
At OFC/NFOEC 2008 one author made a presentation based on his paper titled
"Energy Consumption in Access Networks." I could not readily find a working
link to the paper online, but it is in the IEEE (LEOS) archives.
I recall it was a basic comparison of access network technology (rated ?)
power consumption. If I recall correctly it was done on a per Mbps basis and
had a reasonable attempt at looking at electrical power consumption across
the network. I believe it was a useful but basic strategic comparison. The
risk is that it isn't really accurate when typical residential broadband
consumption rates remain below 100kbps average (over a 24x7x30 basis). It's
a bit like saying that my crew cab pickup is more efficient than a Prius per
pound of payload (which it is by the way). While true, it does not account
for what might be a typical use. In the case of a PON compared to VDSL or
DOCSIS, the efficiency is a more a capability than always a fact --
depending on the data load.
For the super-green analysis I am not sure that anyone has done any work
comparing the energy cost of manufacturing glass vs. coax or tp. And the
same would have to be done for the electronics and optics vs. the incumbent
technologies.
I would also point out that none of these studies adequately account for:
1. Opex and truck rolls (which would be a + for PON) 2. statistical
multiplexing, aggregation and IP routing (which would likely be a huge - for
most PON systems since nearly all are access multiplexers and do require a
second external box to do policing, subscriber management, lea, IP routing,
etc. In at least the case of DOCSIS, this doubles the # of boxes required
for PON vs. CMTS, etc.
3. The lack of CPE integration in PON. (again a - for PON since most systems
have not yet integrated PON ONU/ONT into customer premise routers, etc. --
one huge exception is Verizon's JI-ONU -- which is probably the single most
power, space, network, and energy efficient broadband customer access device
per Mbps for voice/data/video -- available).
Victor Blake
victorblake@xxxxxxxxxxxxxxx
-----Original Message-----
From: Marek Hajduczenia [mailto:marek_haj@xxxxxxx]
Sent: Tuesday, September 30, 2008 10:30 AM
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: [8023-10GEPON] [power saving] New study shows FTTH is a green
technology
Dear all,
Today I can across an interesting piece of an article on Lightwave at
http://lw.pennnet.com/display_article/340363/13/ARTCL/none/XMARK/1/New-study
-shows-FTTH-is-a-green-technology/ if anybody is interested in reading it in
more detail.
The results are quite interesting and I was wondering whether anybody had
any comments on how it is applicable to our power saving activities we spent
some time discussing at the last meeting.
Regards
Marek