In article , Mike Coslo writes:

Carl R. Stevenson wrote:
"N2EY" wrote in message
...

Then there's the fact that the HF losses on power lines are so high that

BPL

systems need a repeater every few thousand feet. In rural areas that may

mean a

repeater for each customer, or more. Plus couplers and other hardware for
*each* customer.


The slides I've seen presented by BPL marketing fluff folks show repeaters
every
300 meters ... that's a hell of a lot of repeaters to "serve rural America"
... yet they
claimed in the same presentation that it was "low cost because no
infrastructure was
required because the wires were already (presumably) there."

I pointed to their block diagrams with fiber to the area, "head-ends" to go
from fiber
to the MV/HV lines, repeaters every 300 meters, couplers, etc. and asked
"How can
you claim with a straight face that this "doesn't require the installation
of infrastructure?""


Good work!

Right there is the evidence that the proponents are being less than
accurate in their portrayal of BPL.

Actually, no more "inaccurate" than any other MARKETING and PR
group for any communications carrier service.

There is NO factual, detailed technical description available in the
electronics or communications industry trade publications about any
proposed or in-test Access BPL system.

The public doesn't know the conducted BPL signal levels, doesn't
know the (presumably) tested losses along electric power distribution
lines, the BPL coupler and other interface equipment losses. Nor is
there any specific data on the range of impedance/admittance of
installed electric power lines throughout the USA. Those electric
power lines were NEVER standardized to be RF transmission lines.

Without detailed information to make judgements from, there is no
telling what the RF radiation levels might be. It is obvious from
monitoring installed test systems that it DOES radiate RF over
a broad spectrum.

Since BPL is slower than some other broadband services, and the
infrastructure appears to be similar to running fiber, is the slowing
attributed to the "existing infrastructure" part of the line?

Not a good question since there is not enough detail to determine
any data rate.

Access BPL is essentially a very new way to distribute data. From
the allegedly-needed bandwidth requirements covering most of HF
and part of VHF spectrum, the fastest data rate could be greater
than 10 Megabits per second, certainly faster than a T1 line at
1.54 MBPS. Without any detailed system information it is very
broad conjecture.

I'm ignorant of the finer details of BPL, so I may be way off here.

So are we all. :-(

Seems like if they have to run fiber, and do all the repeaters, etc.
why not just........ run fiber and put the signals into the houses as
they should be?

Good question.

Any good sources of the nitty-gritty of BPL technology?

Look at the websites for industry magazines EDN, Electronic Design,
and RFDESIGN, even Microwaves & RF. I get all four and there's
not been any nitty-gritty data yet. Lots of PR generalities.

As an IEEE Life Member, I get their membership magazine free each
month and SPECTRUM is well-regarded as giving detailed explains
on many electronic systems. Excellent articles, informative. None
there yet. The SPECTRUM is on-line and with free access at
www.ieee.org.

A website search turns up most of the BPL proponents' sites but
you won't find any details there, just the same PR slide-show
material they showed to the FCC.

The FCC Office of Engineering and Technology isn't telling. They
might not know any more than anyone else, hence their NOI of
last year.

Access BPL is going to be bad for HF. We just don't know HOW
bad. Kiss your HF receiver sensitivity ratings goodbye...it won't
matter if BPL goes past your house.

LHA / WMD