Transcript Document

BPL and Amateur Radio
W4FAL
N4TAB
KN4AQ
BPL and Amateur Radio
What we’ll cover tonight:
What is BPL?
How does it affect Amateur Radio?
Where do we stand?
Media Wars
Progress Energy Trials
What can we do about it?
What is BPL?
Broadband over Power Lines
High Speed Internet delivery
Radio Frequency signals applied to
power lines used to transport data
more…
What is BPL?
Three flavors:
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PLC (Power Line Carrier)
In-Building (Home Plug)
Access (neighborhood distribution)
details…
PLC (Power Line Carrier)
Old news…
Low freq (below 500 kHz), used by
utility companies for control of their
own equipment.
No threat to ham radio
But, it’s why we didn’t get spectrum
around 130 kHz.
In-Building (Home Plug)
High Speed LAN in one building using
AC power wiring
Uses RF across much of the HF
spectrum.
Causes significant interference
Ham bands notched out

(but, not 5 MHz)
Wi-Fi much more popular
Access BPL
This is the big problem
Neighborhood distribution

from substation to home/business
RF on power lines from 2 to 80 MHz
Internet access from your AC wall plug
Cheaper than Cable/DSL?
More available, especially rural?

That’s what they say…
How does BPL affect Hams?
Interference to HF, low VHF
Internet service disruption from Ham
transmitters
details…
BPL Interference
Low power RF energy applied to
unshielded AC wires
AC wires act as antennas
Signals radiate for hundreds of feet
Can be strong – S9+
more…
BPL Interference
Signals cover broad swaths of spectrum
Different modulation schemes made
different sound


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Geiger-counter clicks
Hash
Carriers
more…
BPL Interference
BPL industry initially denied that
there is interference
Examination of field trials shows
there substantial interference
ARRL’s Ed Hare W1RFI examined
four areas with special mobile setup.
W1RFI Video
Test site #1 : Potomac, MD. July 27, 2003
 overhead
Test Site #2: Manassas, VA. July 29, 2003
 underground
 Duke Power testing similar system
Test site #3 : Emmaus, PA, July 29, 2003
 underground and overhead
Test site #4 : Briarcliff Manor, NY, July 27-28, 2003
 Overhead
 Progress Energy testing similar system
W1RFI Video
Notes on Video
These signal levels will cause harmful
interference to nearby HF stations
The listening that ARRL did in the trial
areas was extensive. The video shows
only representative examples of what
was heard.
BPL signals heard from several blocks
to as much as a half mile from the
wires.
Interference goes both ways
Ham signals can interfere with BPL,
slowing or stopping data transfer.
BPL signals are a few hundred
milliwatts on the wire, but ham station
can induce several watts.
Overload amplifiers.
AMRAD study…
AMRAD Study
AMRAD conducted an RF Susceptibility
experiment at the Potomac BPL test
site on November 9, 2003.
A mobile amateur radio station
equipped with an HF transmit
capability was used…..
AMRAD Results
When transmitting at the street curb
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
Data transfer ceased in all but one case at
a transmitter power of 4 watts in the BPL
operating band.
12 and 35 watts caused data transfer to
cease in two of the bands tested even
though they were above the BPL operating
band.
more…
AMRAD Results
Effect dropped with distance, but some
data loss occurred at ¼ mile and more.
Where do we stand?
Part 15 Rules
Notice of Inquiry/NPRM
FCC Commissioner statements
Comments on NOI/NPRM
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NTIA
FEMA
Industry
Hams
details…
Part 15
Permits some unlicensed transmissions

Intentional radiators
 Wi-fi
 Cordless phones

Unintentional radiators
 Your computer, monitor
 Receivers, transceivers, TV sets
 BPL
more…
Part 15
Specifies radiation limits
Prohibits interference to licensed
services
Devices must accept interference from
licensed services
See the phone…
Part 15
Notice of Inquiry –
ET Docket No. 03-104
Issued by FCC April 2003
“Through this inquiry, we seek
information and technical data so that
we may evaluate the current state of
BPL technology and determine whether
changes to Part 15 of the Commission’s
rules are necessary to facilitate the
deployment of this technology.”
Notice of Inquiry –
ET Docket No. 03-104
18. Interference from BPL Emissions:
Multiple carriers spread signals over a
broad range of frequencies that are used
by other services that must be protected
from interference.
Comments closed last fall.
Notice of Proposed Rulemaking
ET Docket No. 04-37
Highlights:
No increase in Part 15 emission limits
Affirms that “operations must cease if
harmful interference to licensed
services is caused.
Requires “adaptive interference
mitigation techniques”
“Incorporate a shut-down feature”
Notification requirements and database
Sounds good, but…
Don’t Celebrate Yet!
Time for some details….
Progress Energy
Trial System Details:
How much spectrum?
6 MHz per “leg” in two blocks
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Uplink block – 2.5 MHz
Downlink block – 3.5 MHz
Between 7 and 50 MHz
“Leg” is about 2000 feet or less
Can’t re-use spectrum for several legs
to avoid self-interference
How much interference?
Home stations hear it:
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
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Half mile + to simple station with
diplole
1.5 miles to powerhouse with beam
(from overhead lines)
More Problems….
Will it fit?
Domino Effect
We are mobile
“Customer Service”
NPRM Note:
Turn your beam
35. We recognize that amateur operations
are likely to present a difficult challenge in
the deployment of Access BPL in cases
where amateurs use high gain outdoor
antennas that are located near power
lines… We therefore would expect that,
in practice, many amateurs already orient
their antennas to minimize the reception
of emissions from nearby electric power
lines.
What is “Harmful Interference”?
§97.3(a)
(23) Harmful interference:
Interference which… seriously
degrades, obstructs or repeatedly
interrupts a radio-communication
service operating in accordance with
the Radio Regulations.
FCC Commissioner statements
Initially very bullish on BPL, with no mention
of interference in public
More recent statements recognize our
complaints:

Abernathy “I recognize that amateur radio
licensees have raised concerns about harmful
interference, and that is something that will have
to be addressed before any mass market
deployment can occur.”
FCC Chairman
Powell in Raleigh:
NTIA Comments on NOI
NTIA: “believes that Broadband over
Power Line (BPL) holds great
promise…” but “the Commission must
be certain to provide all
communications stakeholders with
adequate protections against BPL
emissions that may cause unacceptable
radio frequency interference.”
FEMA Comments on NOI
“FEMA believes and recommends that
Part 15 of the FCC rules and
regulations should be
strengthened to ensure that there
will be no increase in interference
levels to existing communications
systems which are licensed by the FCC
or authorized by the NTIA.”
but then…
FEMA backpedals some
Comments on NOI
Others opposed:
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APCO (Public Safety radio)
Shortwave Broadcasters (and listeners)
ARINC (aviation radio)
Radio Astronomers
Comments on NOI
Industry Comments:
“(Interference) just doesn't exist.”
Jay Birnbaum, VP, Current Technologies LLC
“We're entirely satisfied that there
won't be any interference.”
Brett Kilbourne, United PowerLine Council
Comments on NOI
Industry Comments:
“No matter how loud opponents may
shout, they cannot point to evidence in
this country that BPL systems are
causing, have caused, or will cause,
harmful interference to other spectrum
users or other third parties.”
REPLY COMMENTS OF THE
POWER LINE COMMUNICATIONS ASSOCIATION
Comments on NOI
More than 5000 comments total, most
from hams opposing BPL.
ARRL: “The rules must insure that BPL
is not permitted to operate in or near
any Amateur Radio allocation…”
Media Wars:
Hearts and Minds
“Hams always have been a quirky bunch.
They haunt a series of short-wave radio
frequencies set aside for them by the
federal government in the 1930s…”
The Penn Yan Firestorm?
What really happened?
Progress Energy
Phase 1: Wakefield
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No Amateur Radio involvement
Significant signals crossing 10 and 12
meter bands (and CB)
Phase 2: southern Wake County
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Hams invited to observe
Seriously interested in our concerns
Phase 2 Observations
1st observation: January 15, 2004
Phase 2 Observation Team
AA4NC
N4TAB
W4FAL
(N9MN)
(KN4AQ)
System Design
Overhead feeder”
Underground Distribution
Wi-Fi access
System Design
Two spectrum blocks per BPL leg
Downstream: 3.5 MHz wide
 Upstream: 2.5 MHz wide
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Anywhere from 2 to 50 MHz
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(Amperion prefers 8 to 30 MHz)
Each leg runs up to 2000 feet
Different spectrum blocks
on adjacent legs
Interference Observed
Interference
Observed
Overhead feeder
used 25 and 29 MHz
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mobile to 300’
Home station .7 mi
Underground used
10, 11, 15 MHz and
more
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mobile to 100’
No home stations
Interference Resolution?
Equipment is frequency agile
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Move whole spectrum block
Drop out segments
Controlled remotely from Network
Operation Center
If you can get them on the phone!
more…
Interference Resolution?
They have moved!
Completely off ham bands on overhead
lines
But…
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Can they do it in a full rollout?
What about SWL, other HF users?
What can we do about it?
Join ARRL
Contribute to Spectrum Defense Fund
Write your utility
Write your congressman
Write NC Utility Commission
Send comments on NPRM
more…
What can we do about it?
If it takes me more than 15 minutes,
forget it…