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BPL and Amateur Radio
W4FALN4TABKN4A
Q
BPL and Amateur Radio
What we’ll cover tonight: What is BPL?How does it affect Amateur Radio?Where do we stand?Media WarsProgress Energy TrialsWhat can we do about it?
What is BPL?
Broadband over Power LinesHigh Speed Internet deliveryRadio Frequency signals applied to power lines used to transport data
more…
What is BPL?
Three flavors: 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 radioBut, 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 interferenceHam bands notched out (but, not 5 MHz)
Wi-Fi much more popular
Access BPLThis is the big problemNeighborhood distribution from substation to home/business
RF on power lines from 2 to 80 MHzInternet access from your AC wall plugCheaper than Cable/DSL?More available, especially rural? That’s what they say…
How does BPL affect Hams?
Interference to HF, low VHFInternet service disruption from Ham transmitters
details…
BPL Interference
Low power RF energy applied to unshielded AC wiresAC wires act as antennasSignals radiate for hundreds of feetCan be strong – S9+
more…
BPL Interference
Signals cover broad swaths of spectrumDifferent modulation schemes made different sound
Geiger-counter clicks Hash Carriers
more…
BPL Interference
BPL industry initially denied that there is interferenceExamination of field trials shows there substantial interferenceARRL’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 stationsThe 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 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 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 limitsProhibits interference to licensed servicesDevices 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 RulemakingET Docket No. 04-37
Highlights:No increase in Part 15 emission limitsAffirms 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 EnergyTrial System
Details:
How much spectrum?
6 MHz per “leg” in two blocks Uplink block – 2.5 MHz Downlink block – 3.5 MHz Between 7 and 50 MHz
“Leg” is about 2000 feet or lessCan’t re-use spectrum for several legs to avoid self-interference
How much interference?
Home stations hear it: Half mile + to simple station with
diplole 1.5 miles to powerhouse with
beam (from overhead lines)
More Problems….
Will it fit?Domino EffectWe 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 publicMore 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 ChairmanPowell 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: 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 No Amateur Radio involvement Significant signals crossing 10 and 12
meter bands (and CB)
Phase 2: southern Wake County Hams invited to observe Seriously interested in our concerns
Phase 2 Observations
1st observation: January 15, 2004
Phase 2 Observation Team
AA4NCN4TABW4FAL(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
Anywhere from 2 to 50 MHz (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 mobile to 300’ Home station .7 mi
Underground used10, 11, 15 MHz andmore mobile to 100’ No home stations
Interference Resolution?
Equipment is frequency agile Move whole spectrum block Drop out segments
Controlled remotely from Network Operation CenterIf you can get them on the phone!
more…
Interference Resolution?
They have moved!Completely off ham bands on overhead linesBut… Can they do it in a full rollout? What about SWL, other HF users?
What can we do about it?
Join ARRLContribute to Spectrum Defense FundWrite your utilityWrite your congressmanWrite NC Utility CommissionSend comments on NPRM
more…
What can we do about it?
If it takes me more than 15 minutes, forget it…