[IP] more on Is broadband set to make power lines sing? - alreadydoes in the UK
-----Original Message-----
From: Rahul Tongia <tongia@xxxxxxxxxxxxxx>
Date: Wed, 25 Feb 2004 08:47:32
To:dave@xxxxxxxxxx
Subject: Re: [IP] more on Is broadband set to make power lines sing? - already
does in the UK
Dave,
A few observations [if readers wish, I presented an analysis of PLC at TPRC
2003:
http://intel.si.umich.edu/tprc/papers/2003/246/Tongia-PLC.pdf
]
1) This boils down to not technology, but the business case and execution.
Most consumers (and being a shared medium like cable implies largely
consumer usage) really care about price. Electricity's 99.98% reliability
is not what they care about.
2) The US is particularly at a disadvantage when it comes to PLC (or BPL as
some call it) since the number of homes per distribution transformers is
typically 4-7, unlike Europe or Asia where it can be 30-50 times higher.
The use of PLC as an uplinking backhaul technology with wireless last few
hundred feet implies a limit of 10s of Mbps (and eventually, 100 Mbps) for
the entire feeder line coming out of the substation, which is okay for the
hundreds of potential users, but not earth-shattering. Deep fiber, like in
Japan and Korea, may be more important if we aim to do the triple play,
which certainly requires more bandwidth than the competition for "basic
broadband" (i.e., <1 Mbps).
3) I find it misleading that that the FCC (and proponents) tout PLC as the
alternative for rural areas. PLC becomes much more expensive when we have
to do long runs. Sure it can be done. But at a price, just like other
copper-based solutions. WiMax or the equivalent may be a better solution.
Rahul
tongia@xxxxxxx
--On Wednesday, February 25, 2004 6:30 AM -0500 Dave Farber
<dave@xxxxxxxxxx> wrote:
>
> Delivered-To: dfarber+@xxxxxxxxxxxxxxxxxx
> Date: Wed, 25 Feb 2004 09:06:12 +0100
> From: Andrew Bale <andrewbale@xxxxxxxxxxx>
> Subject: Re: [IP] Is broadband set to make power lines sing? - already
> does in the UK
> X-Originating-IP: [213.69.211.246]
> X-Sender: andrewbale@xxxxxxxxxxx
> To: dave@xxxxxxxxxx
>
> There have always been three major problems for powerline:
> 1) can you get data reliably over the (very noisy) power cables themselves
> 2) can you do it without using so much transmit power that it interferes
> with every device in the neighbourhood
> 3) can you do it economically
>
> (1) has (in most deployment scenarios) been solved by the use of advanced
> signal processing techniques (for example home powerline LANs now work
> very well - though have been completely overtaken by the even greater
> convenience of in-home wireless)
> (2) is largely solved - better receive signal processing reduces the need
> for power in the transmitter
> (3) remains - largely due to the architecture with which power is
> distributed
>
> Power systems rely on step-down transformers located close to the
> consumer - each tending to serve a relatively small number of homes.
> It's practically impossible to get a data signal through a transformer(!)
> which means that data has to be passed from the core network to a
> head-end device on the far side of the transformer. The hardware and
> deployment costs of this head-end device has to be shared amongst the
> users of the system. Since the transformers are generally only supplying
> a small user base the economics demand a VERY high take-up - something
> that experience shows is highly unlikely, unless you are in an area of
> zero competition. With all the competing options (cable, DSL, satellite)
> that is unlikely. While the UK trials below are clearly working, that
> does not imply that they are demonstrating a good commercial model.
> Power companies (especially in the UK and Germany) have been trying this
> for years, largely in attempts to see whether they can persuade a high
> enough density of customers to adopt the service to solve this economic
> problem.
>
> Interestingly - the service described in a previous [IP] mail used
> wireless for the last leg to the customer - which (I think) implies that
> they are inverting the more usual powerline scenario, where fiber is used
> to the distribution box and powerline gets to the customer (as in the UK
> trial below). In the wireless scheme I think they are proposing to use
> powerline over the main distribution network to replace fiber, and then
> using wireless instead of powerline in the local loop. Interesting, but
> hardly earth-shattering.
>
> Andrew Bale
>
> ----- Original Message -----
> From: "Dave Farber" <dave@xxxxxxxxxx>
> To: <ip@xxxxxxxxxxxxxx>
> Sent: Tuesday, February 24, 2004 7:13 PM
> Subject: [IP] Is broadband set to make power lines sing? - already does in
> the UK
>
>
>
> Delivered-To: dfarber+@xxxxxxxxxxxxxxxxxx
> Date: Tue, 24 Feb 2004 18:05:18 +0000
> From: "Charles Arthur, The Independent" <carthur@xxxxxxxxxxxxxxxxx>
> Subject: Re: [IP] Is broadband set to make power lines sing? - already
> does in
> the UK
> X-Sender: Charles_main@localhost
> To: dave@xxxxxxxxxx
>
> Hi ...
>
> At 11:51 am -0500 on 24/2/04, you wrote:
>
> ><x-flowed>
> >
> >Is broadband set to make power lines sing?
>
> It already does, in the UK. From an article in The Independent on February
> 4 (now behind a paywall on the site, so here's an extract):
>
> ".....
> Scottish and Southern Energy have chosen Winchester and Stonehaven (near
> Aberdeen) for full-scale commercial trials following successful pilots in
> Crieff and Campbeltown. The company is expecting up to 1,000 users in
> Winchester alone. Professor Cochrane's [former head of BT Research] views
> are clear: "The laws of physics have not changed and the telephone line
> well outperforms them. What these guys have and do promise, and what they
> deliver, are worlds apart."
> So who's right? The answer, of course, is to spend some time in Winchester
> finding out. Among the first users - just 33 of them in early December -
> are Liz Galfskiy and her son, Adam. Mrs Galfskiy relies on her computer
> for an Open University course. A fixed price dial-up AOL connection was
> essential, especially as Adam is a keen user too. Several broadband offers
> had left her unmoved until she heard about the Southern Electric trial.
> In mid-November, engineers installed a booster box adjacent to her
> electricity meter and provided a powerline broadband modem. For most
> properties nearer a substation, only the modem is needed. Setting up the
> broadband connection is trivial; plug in the modem (£50) and connect it
> with an Ethernet cable to your PC. The service (£29.99 monthly) includes
> unlimited e-mail addresses and web space too.
> But is it strange to have your broadband connection through a 13-Amp
> socket? Mrs Galfskiy doesn't think so. Thanks to her
> technically-knowledgeable son, who installed a router, several PCs share
> the single connection. Broadband allows them to watch BBC news items
> online and listen to "crystal clear" radio: "It's excellent. I'd throughly
> recommend it," she says.
> A test with the speed checker on adslguide.org.uk confirmed an impressive
> 980 Kbps download - 20 times dial-up speeds. The upload result was a poor
> 478 Kbps given the advertised "up to" 1 Mbps for both directions. Adam
> claims he's seen 1.7 Mbps connections.
> But what happens when you turn on a hairdryer, run the washing machine or
> vacuum the carpet? "We haven't noticed any effects on the connection,"
> responds Mrs Galfskiy. However, choose the electrical socket with care
> as, in her experience, powerline broadband dislikes multiple adaptors. .."
>
>
> Not everything gets implemented first, or even best, in the US, you know.
>
>
>
> best
> Charles
> --
> -------------------------------------------------------------------
> The Independent newspaper on the Web: http://www.independent.co.uk/
> It's even better on paper
>
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************************************************************************
Rahul Tongia, Ph.D.
Systems Scientist
School of Computer Science (ISRI) / Dept. of Engineering & Public Policy
Carnegie Mellon University
Pittsburgh, PA 15213 USA
tel: 412-268-5619
fax: 412-268-2338
email: tongia@xxxxxxx
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