[LINK] Power to the People - Broadband over powerlines
rw at firstpr.com.au
Wed Sep 14 13:57:23 EST 2005
Broadband over powerlines (BPL) is a stinker and is going almost
nowhere, despite the hype. The dream of those power lines turning into
broadband pots of gold seems to have a profound effect on some folks.
Even if there were no interference problems, it is close to useless for
data rates above a few megabits per second, since there is no way of
separating the wires into segments within which to reuse frequencies.
Its just a big ugly hostile bunch of cables to which one can attach
various devices and get some communications. But trying to make a
reliable, commercial, service from this, except at data rates much lower
than common DSL, is never going to work.
I wrote about this in three reports 9a, 9b and 9c at:
(I wrote almost all the reports listed under:
I hesitate at trying to summarise the problems with BPL, but here goes:
There are no agreed technical standards, and no serious effort is going
into creating such standards. The task of making such standards is much
greater than for DSL or HFC, both of which operate over friendlier
cables, which are highly standardised the world over. Power systems
operate on all sorts of different technical principles which make it
impossible for one BPL approach to be used for them all.
For broadband data rates, the distance covered is so short that you need
fibre to within 50 to 100 metres of homes anyway. Even then, there's no
way of serving lots of customers on a system such as in Australia, since
the 240 wires go for hundreds of metres and must share the one set of RF
bandwidth for all customers.
HomePlug home networking devices in any home will screw up BPL in the
It is useless for broadband over long distances in the country - so it
is difficult or impossible to find a scenario where it can outperform
DSL. DSL is always cheaper than bringing fibre deep into the service
area and installing gear on exposed or buried power lines.
Wireless, especially WiMax, is or will be generally a better way of
competing with DSL.
I am not saying that interference problems are unimportant - just that
BPL will fail prosper for many other reasons in addition to these.
I think the best thing the power companies can do is forget BPL and
instead use their infrastructure, including overhead powerline drops to
the home, or underground ducts, to bring fibre to each home. A passive
optical network (PON) system with a single fibre branching to dozens of
homes has the ability to completely outperform DSL, WiMax and HFC.
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