Design around _this_!

[Mark Fergerson]

What the hell are they thinking?

http://www.arrl.org/tis/info/HTML/plc/

For those who hate to click-through, the FCC is about to
approve something we were previously told was "impossible",
or at least "unfeasible"; namely, Broadband Over Powerline
(previously known as "carrier current", but at lower
frequencies). Idea is you won't need a modem or cable to get
Internet connectivity, just a plain old power socket.

Great idea, right? Except the frequencies they want to
use (1.7-80 MHz) to get past the transmission limitations of
the 60 Hz US power grid will make a large swath of the EM
spectrum utterly useless, including much of the AM broadcast
band, parts of the FM and TV spectrum, the entire shortwave
spectrum, many police and other emergency radio systems,
FEMA's radio setup, and so on throughout the continental US
and more. This is because powerlines make dandy transmitting
and receiving antennas over the band considered.

Not to mention there'll be no such thing as a
"standalone" computer invulnerable to hacking afterward.

This was apparently test-marketed in parts of the US and
worldwide:

http://www.arrl.org/tis/info/HTML/plc/#Field

and generally rejected for the interference it caused. Are
we going to sit still for this?

I haven't seen any mention of this here and was wondering
who else knew. If it's news to everyone, know that the FCC
is taking public opinions on the matter before finalizing
this stupidity. However, be aware that it used to be
comprised mostly of people with engineering degrees, but is
now dominated by PHB types with industry loyalties.

Mark L. Fergerson

 

[Tim Auton]

For those who hate to click-through, the FCC is about to
approve something we were previously told was "impossible",
or at least "unfeasible"; namely, Broadband Over Powerline
(previously known as "carrier current", but at lower
frequencies). Idea is you won't need a modem or cable to get
Internet connectivity, just a plain old power socket. [snip]
Not to mention there'll be no such thing as a
"standalone" computer invulnerable to hacking afterward.

Of course there will be. You still need some kind of modem to hook up
to the network. Any computer without a power-line modem thingy will be
just as isolated as it is now.


Tim

 

[Scott Stephens]

What the hell are they thinking?

http://www.arrl.org/tis/info/HTML/plc/

Broadband Over Powerline (previously known as
"carrier current", but at lower frequencies) ....
Not to mention there'll be no such thing as a "standalone" computer
invulnerable to hacking afterward.

and generally rejected for the interference it caused. Are we going to
sit still for this?

Like electronic voting machines and M$ Windows, we are going to let them
try, spend lots of money.

Then we are going to hack them at their own game;

We will never surrender. We will never give up. We will hack them in the
office. We will hack them in the home. We will hack them in the coffee
shops. We will hack them on the road. We will hack them to the edge of
the universe and eternity, but we will never, never, Never, Never, NEVER
SURRENDER!"

--
Scott

**********************************

DIY Piezo-Gyro, PCB Drill Bot & More Soon!

http://home.comcast.net/~scottxs/

**********************************

 

[Reg Edwards]

Data over phone wires, and now data over power cables, are currently the
cheapest stop gaps. There are also fixed radio links.

But ultimately, everything will be via optical fiber. We must wait
patiently until service providers have made as much profit as they can from
the exixting systems.

 

[John Larkin]

What the hell are they thinking?

http://www.arrl.org/tis/info/HTML/plc/

For those who hate to click-through, the FCC is about to
approve something we were previously told was "impossible",
or at least "unfeasible"; namely, Broadband Over Powerline
(previously known as "carrier current", but at lower
frequencies). Idea is you won't need a modem or cable to get
Internet connectivity, just a plain old power socket.

Great idea, right? Except the frequencies they want to
use (1.7-80 MHz) to get past the transmission limitations of
the 60 Hz US power grid will make a large swath of the EM
spectrum utterly useless, including much of the AM broadcast
band, parts of the FM and TV spectrum, the entire shortwave
spectrum, many police and other emergency radio systems,
FEMA's radio setup, and so on throughout the continental US
and more. This is because powerlines make dandy transmitting
and receiving antennas over the band considered.

Not to mention there'll be no such thing as a
"standalone" computer invulnerable to hacking afterward.

This was apparently test-marketed in parts of the US and
worldwide:

http://www.arrl.org/tis/info/HTML/plc/#Field

and generally rejected for the interference it caused. Are
we going to sit still for this?

I haven't seen any mention of this here and was wondering
who else knew. If it's news to everyone, know that the FCC
is taking public opinions on the matter before finalizing
this stupidity. However, be aware that it used to be
comprised mostly of people with engineering degrees, but is
now dominated by PHB types with industry loyalties.

Mark L. Fergerson

But once you have universal powerline data connections, you won't need
ham radio any more. You can just chat over the internet.

John

 

[Joerg]

Hi Mark,

What frequently is overlooked is that interference tends to go
both directions. Just imagine what happens when an above-ground
powerline is close and maybe even parallel to a ham radio
antenna? I bet that the connected (and paying) Internet users
would grow pretty irate and the customer support rep at the other
end of the phone line would start losing their hair. Because they
probably wouldn't understand what's going on.

Sure, one can drop noisy frequency bins like DSL does. But past a
certain level the normal amount of corrosion in connections makes
sure that there is enough intermodulation that too much of the
PLC spectrum becomes polluted. Also, I doubt DSP filter
technology offers more than 60dB of true dynamic range and most
other methods cost too much. Then web browsing becomes really
slow.

Regards, Joerg

 

[Mark Fergerson]

Hi Mark,

What frequently is overlooked is that interference tends to go
both directions. Just imagine what happens when an above-ground
powerline is close and maybe even parallel to a ham radio
antenna? I bet that the connected (and paying) Internet users
would grow pretty irate and the customer support rep at the other
end of the phone line would start losing their hair. Because they
probably wouldn't understand what's going on.

Thing is, hams have to go off-air if they cause _any_
interference.

Sure, one can drop noisy frequency bins like DSL does. But past a
certain level the normal amount of corrosion in connections makes
sure that there is enough intermodulation that too much of the
PLC spectrum becomes polluted. Also, I doubt DSP filter
technology offers more than 60dB of true dynamic range and most
other methods cost too much. Then web browsing becomes really
slow.

Agree on all points. But remember I mentioned that the
FCC is dominated by industry-connected PHB types, not engineers.

Ah, well. I think it'll be a disaster that'll be dumped,
but only after screwing up lots of things we take for granted.

Mark L. Fergerson

 

[Dave VanHorn]

Thing is, hams have to go off-air if they cause _any_
interference.

No, they don't. They are primary users on their frequencies, and the part 15
devices are the ones that have to accept any and all interference, including
that which may cause undesired operation.

 

[Mark Fergerson]

But once you have universal powerline data connections, you won't need
ham radio any more. You can just chat over the internet.

Hell, I can do that now. FTM there's these things called
"telephones", remember?

Ham radio is just too "uncontrolled" for some people's
comfort, not to mention the CB band. But that's trivial
compared to interference certification for electronic
devices. Considering the EM environment that has to be
designed around today, how much more will it cost to proof
anything against this?

What really torques me is the potential for disruption of
first-responder radio systems. I'm sure the "fix" will be to
market new radio systems to them. And they'll be marketed by
companies who own the loyalties of those FCC board members I
mentioned...

Mark L. Fergerson

 

[Mark Fergerson]

Data over phone wires, and now data over power cables, are currently the
cheapest stop gaps. There are also fixed radio links.

Yeah, I understand "incremental" technology improvement.
But is it really necessary to use this idiocy as one of the
steps?

But ultimately, everything will be via optical fiber. We must wait
patiently until service providers have made as much profit as they can from
the exixting systems.

I already use optical. Well, sorta; like many "cable"
providers, Cox is optical to the little box in my alley,
then it's converted to cable to reach my computer, TV, and
phone. Plenty of room for interference.

Mark L. Fergerson

 

[Mark Fergerson]

Like electronic voting machines and M$ Windows, we are going to let them
try, spend lots of money.

Then we are going to hack them at their own game;

We will never surrender. We will never give up. We will hack them in the
office. We will hack them in the home. We will hack them in the coffee
shops. We will hack them on the road. We will hack them to the edge of
the universe and eternity, but we will never, never, Never, Never, NEVER
SURRENDER!"

That's the spirit!

I'll have to cheer from the sidelines though; I just got
my first CueCat and did the hacks on it I found at some old
relevant sites. I'm kinda slow on some things. Besides, I'm
still screwing around on a couple of "educational" projects,
like a Dish-TV setup I got at a yard sale, among other
things. So many projects, so little time.

Mark L. Fergerson

 

[Mark Fergerson]

For those who hate to click-through, the FCC is about to
approve something we were previously told was "impossible",
or at least "unfeasible"; namely, Broadband Over Powerline
(previously known as "carrier current", but at lower
frequencies). Idea is you won't need a modem or cable to get
Internet connectivity, just a plain old power socket.
[snip]

Not to mention there'll be no such thing as a
"standalone" computer invulnerable to hacking afterward.

Of course there will be. You still need some kind of modem to hook up
to the network. Any computer without a power-line modem thingy will be
just as isolated as it is now.

Yeah, as long as you can still buy replacement PS's
without the built-in modem. But what are new computers going
to come with, after this is approved? Before long, if you
want a PS without the modem capability, you'll have to build
it (or hack it out), but Joe Average is screwed.

Hmmm, wait, there's a new "service" market for displaced
electronic workers to make money in...

Mark L. Fergerson

 

[Jan Panteltje]

What really torques me is the potential for disruption of
first-responder radio systems. I'm sure the "fix" will be to
market new radio systems to them. And they'll be marketed by
companies who own the loyalties of those FCC board members I
mentioned...

Mark L. Fergerson

OK, all this prompted me to do an experiment.
Because I have this ADSL telephone line, and, as you may know,
DSL uses frequency bands in the several 100kHz range, on
twisted pair, and these are rise time limited square waves
(I have scoped these) it seems.
So I took the LW radio (150 to 285kHz), and held the phone line
next to it.
Indeed some stations can be 'pushed out', on other places in the
band you get an awful lot of noise.
So it is clear that DSL lines cause interference, but the effect
does not seem noticeable if more the 30 cm away.
Twisted pair should cancel radiation though.
But nothing is 100% perfect symmetrical..
So, from this we can deduce that on (in house) power lines, if not twisted
(earth ground) it is going to radiate a bit (or a lot).
It was my impression however that on the HV lines they use glass fiber
cable hanging from the HV lines (or wrapped around it, this was discussed
here no so long ago), so living under such a thing would not be a problem.
I have not tried to find any effect on the short wave communication of DLS
yet.
My monitor causes more interference, and it is screened internally with a
Faraday cage..
Interesting.
JP

 

[Tim Auton]

Yeah, as long as you can still buy replacement PS's
without the built-in modem. But what are new computers going
to come with, after this is approved? Before long, if you
want a PS without the modem capability, you'll have to build
it (or hack it out), but Joe Average is screwed.

This is sci.electronics.design. The problem is to remove >1.7Mhz
"noise" from your 60Hz "signal". That's just a low-pass filter, albeit
one with a lot of juice going through it. Within a couple of hours
even I could come up with a decent solution. I have no doubt the
experts here could do it in minutes.

You also presume someone will be providing the network connectivity
for free without your intervention. I find this rather unlikely.


Tim

 

[Tim Wescott]

OK, all this prompted me to do an experiment.
Because I have this ADSL telephone line, and, as you may know,
DSL uses frequency bands in the several 100kHz range, on
twisted pair, and these are rise time limited square waves
(I have scoped these) it seems.
So I took the LW radio (150 to 285kHz), and held the phone line
next to it.
Indeed some stations can be 'pushed out', on other places in the
band you get an awful lot of noise.
So it is clear that DSL lines cause interference, but the effect
does not seem noticeable if more the 30 cm away.
Twisted pair should cancel radiation though.
But nothing is 100% perfect symmetrical..
So, from this we can deduce that on (in house) power lines, if not twisted
(earth ground) it is going to radiate a bit (or a lot).
It was my impression however that on the HV lines they use glass fiber
cable hanging from the HV lines (or wrapped around it, this was discussed
here no so long ago), so living under such a thing would not be a problem.
I have not tried to find any effect on the short wave communication of DLS
yet.
My monitor causes more interference, and it is screened internally with a
Faraday cage..
Interesting.
JP

No, they're going to put the signal on the wires. They've already
tested it a couple of places. The power companies say "see, no one
complained!". The ham radio operators say "look! They selected an area
with no licensed hams!".

At the same time that the BPL folks are claiming low noise, etc., the
amateur radio community is noting interference severe enough to knock
out the kind of world-wide non-network assisted communications you can
get on HF (shortwave) radio.

 

[Jan Panteltje]

No, they're going to put the signal on the wires. They've already
tested it a couple of places. The power companies say "see, no one
complained!". The ham radio operators say "look! They selected an area
with no licensed hams!".

At the same time that the BPL folks are claiming low noise, etc., the
amateur radio community is noting interference severe enough to knock
out the kind of world-wide non-network assisted communications you can
get on HF (shortwave) radio.

If that is so, and I was thinking that some hundreds of meters of unscreened
cable makes a good antenna, you guys better get together and write some
politicians!
Or lose the amateur bands!
I am glad we do not have this here!
JP

 

[John Todd]

[snip]

This is sci.electronics.design. The problem is to remove >1.7Mhz
"noise" from your 60Hz "signal". That's just a low-pass filter, albeit
one with a lot of juice going through it. Within a couple of hours
even I could come up with a decent solution. I have no doubt the
experts here could do it in minutes.

You also presume someone will be providing the network connectivity
for free without your intervention. I find this rather unlikely.


Tim

Lessee...maybe we'll put a big RF choke on the line, an oil-filled
one...oh, wait, its done alread!

 

[Ken Smith]

This is sci.electronics.design. The problem is to remove >1.7Mhz
"noise" from your 60Hz "signal". That's just a low-pass filter, albeit
one with a lot of juice going through it. Within a couple of hours
even I could come up with a decent solution. I have no doubt the
experts here could do it in minutes.

You've done it the hard way. A two component solution can be done.

{1) Plug my electric drill into same power strip as the computer.
(2) Duct tape the trigger in.

Only 2 parts needed and not a huge amount of electronics knowledge is
needed to do it.

 

[Walter Harley]

This is sci.electronics.design. The problem is to remove >1.7Mhz
"noise" from your 60Hz "signal". That's just a low-pass filter, albeit
one with a lot of juice going through it. Within a couple of hours
even I could come up with a decent solution. I have no doubt the
experts here could do it in minutes.

Yep:

1. Go to store.
2. Purchase $20 power strip with RF filter.
3. Install.

Okay, it might take more than a couple minutes, depending on how far away
the store is. Oh, wait, never mind, I have a couple here in the closet
already.

 

[Tim Shoppa]

What the hell are they thinking?

http://www.arrl.org/tis/info/HTML/plc/

For those who hate to click-through, the FCC is about to
approve something we were previously told was "impossible",
or at least "unfeasible"; namely, Broadband Over Powerline
(previously known as "carrier current", but at lower
frequencies). Idea is you won't need a modem or cable to get
Internet connectivity, just a plain old power socket.

I'm still dubious that this concept will ever work on a large scale.
There have been several start-ups over the past decade with the same
idea and they've all gone down in flames before even coming close
to being practical.

Of course I was dubious when the FCC, in the mid-90's, said there
would be no more NTSC broadcasts by 2003. Well, it's 2004, and...

Your best filter will, as always, be a motor-generator set. Put a
big enough flywheel in there and you'll be insensitive to power
fluctuations in the sub-Hz range too

Tim.