robert casey wrote:
John Smith wrote:

Len:

Phone lines are limited to roughly 38K by using the full audio
bandwidth a
phone line is filtered to, with the early compression techniques. 56K is
obtained by improved data compression techniques.

Any line capable of supporting transmission of these audio freaks can
carry that much digital data (roughly +/-300hz to +/-5,000hz.

DSL is obtained by pulling all the filters from the line, audio bandwidth
is much expanded and much greater data can be crammed into that
bandwidth,
with even greater efficient compression techniques.

Powerlines can support near/equal such bandwidths. With a bandwidth
allowing freqs to climb into the LF RF freqs, tremendous data speeds are
possible.... very localized interference to some rf freqs may be
generated... this is now in a testing phase...

Why this is so misunderstood is beyond explanation, or perhaps it is only
limited to the older generations, for some unknown reason--as any
familiar
with technical details of data transmission methods and protocols should
know this, it is very basic stuff...


Only thing is that a DSL connection has a dedicated twisted pair
of wires, but BPL you have to share with everyone else in town.
Like cable modems, though the cable company cuts up their network so
only a handful of users share. With BPL the entire towns' users
have to share one channel. Now if you're the only user in town,
you got it made (unless a ham fires up his linear...)

NO linear needed! 5 Watts can do it. 100 watts is more than enough.

The very most interesting thing about BPL is that what goes on the
power lines is only the very last leg of the system. Power lines are not
particularly good at carrying digital signals. The signal gets mushed
up, and it won't survive the trip though the pole transformers. So they
carry the signal through the higher voltage lines, put a box that pops
the BPL signal onto the low voltage side of the transformer, then that
is what goes into your house.

But the big kicker is this. Since the digital signal has a lot of
trouble surviving the trip on the power lines, fiber is run to the point
where a tap is made to the HV-lines. It's a last block sort of thing. So
unless you are on the end of the line, you will probably have a nice
high-speed fiber going right past your place in a BPL scheme.

THAT'S the signal I want Fiber! Not a stinking, degraded, vulnerable,
spectrum polluting BPL signal. I want Fiber - lots of fiber in my diet!

Besides, fiber is good for you! ;^)

- Mike KB3EIA -