ARRL

Technical Papers and Studies

Web Links for ARRL Technical Papers

FCC BPL Notice of Inquiry Filings

BPL Feed Method Analysis

Fields Near Large Radiators

Power Lines as Antennas

Calculated Impact of BPL Signals on Amateur Radio

Exhibit A: Summary of ARRL Studies of BPL Field Trial Areas

FCC BPL Notice of Proposed Rulemaking Filings

Exhibit A:  (Metavox testing in Emmaus and Whitehall, PA) 

Exhibits B-E:

Exhibit B: PLC/HF compatibility: Written by Dr. David Cohen. This paper outlines the reasons to base interference assessment on a reasonable value of I/N (interference to noise) and the reasons that BPL operating at the FCC limits would be tens of dB higher than that. It cites several peer-reviewed papers published in various IEEE publications.  
Exhibit C: Extrapolation, point sources vs line sources
Exhibit D: Proposed test methods
Exhibit E: Amateur Service protection requirements, mobile measurements. This filing, written by various ARRL staff, outlines the levels of noise that can be expected during HF operation and a reasonable protection requirement for such operation.  This paper references the ITU-R P372-8 document, outlining the median values of man-made noise in residential environments and how the noise levels permitted under Part 15 rules are tens of dB greater than the present median levels of man-made noise. This premise was supported by measurements of man-made noise in typical residential environments.

 

Exhibit A: NEC Analysis of Power Lines as Radiators (Docuement 6516214646)
Exhibit B:
Analysis of verification testing done at BPL test site (Documenmt 6516214647)
Exhibits C-E: Metavox testing at several BPL test sites

Citation of Additional Authority

 

Analysis of FCC and NTIA BPL Data    Part 1: http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6517395395    (See Exhibit B in above document)    Part 2: http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6517395396

 

Other Technical Papers

10/05/2007 - NTIA has released its Phase 2 BPL Study on Ionospheric Propagation and Aggregation of BPL Emissions as the sequel to its Phase 1 BPL Study, NTIA Report 04-413 on the Potentential Interference from Broadband Over Power Line (BPL) Systems to Federal Government Radiocommunications, originally released 01/29/05.

6/2007 - The Information Systems Technology group, part of the North Atlantic Treaty Organization's (NATO) Research and Technology Organization, has released RTO Technical Report TR-IST-050 on the negative impact of broadband over powerlines (BPL) on amateur and emergency radio operations.

Amperion PLC Measurements in Crieff

ASCOM PLT Measurements in Winchester

DS2 PLT Measurements in Crieff

Broadband over Powerlines: Regulatory and Policy Issues
8/4/2006 - Patricia Moloney Figliola, Congressional Research Service
Broadband over Powerlines (BPL) has the potential to play a significant role in increasing the competitive landscape of the communications industry but also has the potential to extend the reach of broadband to a greater number of Americans. BPL, like any technology, has its advantages and disadvantages. This congressional report lightly covers these issues with an optimistic overview of the technology and its interference potential.

San Diego Smart Grid Study Final Report
10/1/2006 - ASIC Smart Grid Team
San Diego Gas and Electric is unique in that it has been studying and testing BPL from muliple vendors, including Ambient, Current Technologies, Motorola and Mitsubishi, among others. This independent report outlines the practicalities of BPL for grid control, leaning strongly toward HomePlug technology as a viable solution.

High-Speed Services for Internet Access: Status as of June 30, 2006
January 7, 2006, FCC - This report shows that as of June 30, 2006 there were approximately 5200 BPL lines in the United States our of a total of 64,600,000 broadband lines. At this time, BPL had captured 0.008% of the marketplace.  The numbers of BPL lines being used to provide access BPL to consumers and businesses decreased from the number cited in the report on the status as of December 31, 2005. Previous versions of this report can also be downloaded from the FCC site

High-Speed Services for Internet Access: Status as of December 31, 2005
July 1, 2006, FCC -- This is the latest report from the FCC about high-speed digital lines in the United States. It shows that as December 31, 2005, there were approximately 5900 BPL lines in the United States out of a total of 50,200,000 broadband lines. After several years of trying, BPL enjoys 0.012% market penetration..

OPERA D52
Specification for EMC measurements to be performed. Uses common test equipment instead of actual PLC emitters to perform standardized measurements .A CW signal is coupled into the powerline using a standardised equipment. The main measurement quantities are common/differential mode voltages at certain points, common mode currents on the power line at locations, which are accessible, and E as well as H-field measurements." Measurement procedores only; no results or limits. However references ITU BS 703, which calls for HF broadcast signals of 40 dBuV (100uV). NOTE: Opera is the Open PLC European Research Alliance for new generation PLC integrated network.

RADIO SPECTRUM COMMITTEE Working Document, Subject: ETSI Report to RSC#13
21-22 Feb 2006 Meeting to set European BPL Interference Standard
10/7/2005 RSCOM RADIO SPECTRUM COMMITTEE excerpt: ":ETSI/CENELEC Joint Working Group on EMC of conducted telecommunications networks The Joint Working Group continues to work on mandate M/313 on EMC requirements for conducted transmission networks. Following the publication of Commission Recommendation 2005/292/EC on the introduction of power line telecommunication, the JWG have decided to concentrate on the development of the Harmonised Standard originally requested under mandate M/313. The draft Harmonised Standard EN 302 282 is due to complete Public Enquiry on 18 November 2005. A joint meeting with CENELEC to resolve Public Enquiry comments has been arranged on 21 and 22 February 2006. The standard is scheduled to be published in June 2006."

PLC Network Solutions ASCOM equipment specifications

ASCOM BPL Gateway
Technical data Powerline masters: PLC signaling; Outdoor band 1.6 - 12 MHz; Indoor band 15 - 30 MHz; Carriers 3 in one band; Data rate 0.75 - 1.5 Mbps/carrier; Modulation GMSK; Bandwidth 2 MHz/carrier; Coverage Outdoor up to 300 m; Coverage Indoor up to 100 m; Delay < 25 ms

ASCOM BPL modem
Technical data APA-15 adapters: PLC signalling; Outdoor band 1.6 - 12 MHz; Indoor band 15 - 30 MHz; Carriers 1; Data rate 0.75 - 1.5 Mbps; Modulation GMSK; Bandwidth 2 MHz; Cverage Outdoor up to 300 m; verage Indoor up to 100 m; lay < 25 ms. Cpliance is shown for European Safety, Immunity and (for the BPL gateway) oervoltage standards, but not for EMI.

Deployment of Power Line Communications Systems in Malaysia Public Consultation
The Public Consultation Paper was issued to ascertain the views of the public on the introduction of Power Line Communications (PLC) systems in Malaysia, gauge public readiness towards its deployment and determine whether and how the Malaysian Communications and Multimedia Commission should regulate PLC services. Issued in February 2005, it discusses PLC systems trialed and deployed wordlwide as of that date, and examines regulatory issues the MCMC would face in deploying PLC. The word "interference" appears 40 times in the 33-page document, and the Commission cites reports from other countries: Excerpt (page 17): "There are also concerns that PLC may mar the performance of some sensitive equipment. In Switzerland where PLC has been deployed and is currently in service, the regulator has imposed special condition whereby PLC installation must be some 500 meters away from the so-called 'sensitive sites' such as medical facilities and military sites."

N6GN HomePlug Testing
10/18/2005 -- In order to get a better understanding of how HomePlug hardware might interact with the amateur HF spectrum, N6GN thoroughly tested a pair of Netgear XE602 Powerline HomePlug Ethernet Adapters.

Access BPL Trials in Australia
ACMA will measure electromagnetic emissions levels at some BPL trials.  This information will be made available to the public in due course. Note: The ACA lists seven Access BPL trials locations; four in Hobart, Tasmania, and three in New South Wales. As of 3 March 2006 the site above contains links to results taken at Moruya, NSW, in October adn December 2004, and at Queanbeyan. NSW in February 2005.

Broadband Access Networks Systems - - Last Mile
Penn State University -- Center for Information and Communications Technology Research (CICTR). A number of technologies for broadband connectivity are dealt with.

Broadband RF emission from networks
An excellent overview of the issues and some of the difficulties BPL is facing on the international regulatory/standardization front.

Caslon Analytics Note: Powerline Communication
This report was written by Caslon Analytics, an Australian internet research, analysis and strategies consultancy. It may be one of the more definitive business and scientific treatments of BPL. It starts with a brief BPL tutorial, and then covers the technical and reliability aspects of BPL. It outlines the reasons for ongoing interference issues and describes the key impediments to BPL deployment, including interference, competition from other technologies, consumer anxieties and indifferent electric-utility industry support. Although written from an Australian perspective, its findings and conclusions have widespread application to BPL/PLC worldwide.

Wavelet 101 Course
This on-line tutorial explains the differences in performance between OFDM, QAM and wavelet broadband technologies.

National Association of Regulatory Utility Commissioners: Report of the Broadband Over Power Lines Task Force
Initial Report (February, 2005)
Final Report (February, 2006)
"It is important to note that BPL technology, in its current form, is not suitable for carrying broadband signals over long distances. . . . Certain frequency bands in the high-frequency range are used by amateur radio operators to communicate around the world using very low transmitted power levels. Harmful interference can occur if a BPL system operates in the vicinity of a licensed operator using the same frequency. Because electric distribution lines exist in most rural areas, many have hoped that BPL would help solve the problem of how to extend economical broadband services to underserved areas that are too sparsely populated to have broadband access through cable television lines or DSL. However, most observers close to the BPL industry are not optimistic with regard to this potential."

Low Frequency Radiated Fields: Equipment And Issues
July 1, 2005, Conformity magazine -- This article discusses in detail the difficulties of making measurements below 30 MHz in the near-field region of radiators. Figure 5 shows that over most of the HF range (3-30 MHz), for the distances used to make FCC BPL measurements, an extrapolation of 20 dB/decade should be made to determine compliance with the rules. It shows that at a distance if 1 / (2* pi * wavelength) from the source, the reactive region of an antenna no longer applies. In this region, it is not appropriate to apply a 1/r^2 distance extrapolation for the magnetic field strength being measured by the FCC BPL-test procedures. On 10 MHz, 1 / (2 * pi * wavelength) is a distance of 5.1 meters. This is typical of the slant-range distance used to estimate the field strength at 30 meters distance.

Great Britain (OFCOM)
Assessment of the EMI radiated by PLC Installations inside buildings

Technical Trial of Broadband IP/Internet over ESB Power Networks
This 49-page report discusses the problems with implementing both major types of European BPL products using DS2 and ITran chipsets. Engineers Ireland found that shortwave broadcasts and MV line noise caused poor operation. Their conclusions reads, in part: "Broadband Power Line Technology is nowhere near an appropriate state of development required for ‘mass market’ rollout."

Austrian Telecom Ministry testing of BPL in-premise modems
In German ·· English translation

Testing of Corinex BPL modems in Czechoslovakia
Although written in Czechoslovakian, the scientific data in these tests are self-explanatory.

Broadband Over Power Lines Analysis
By James K. Boomer, April 14, 2005 -- Successful Broadband Over Power Lines (BPL) implementation demands exhaustive engineering, and regulatory analyses, to arrive at a sound go/no-go decision. If the conclusion is "go," the FCC must develop new regulations that include licensing, and attendant specifications for maximum output power, bandwidth, spurious emissions limits, and frequency allocations. This will assure electromagnetic compatibility with licensed radio stations operating in the 1.705- to 28 MHz frequency range, and in other frequency ranges for that matter. BPL transmitters connected to power lines are intentional emitters connected to radiating antennas, not unintentional emitters. Therefore FCC Part 15 field strength regulations are not applicable to BPL.

Powerline Followup: Is DS2 For You? Part 1 Part 2
11/1/2005, EDN -- This blog entry outlines the tests done by the author on the installation of DS2 modems in his residence.

TEST RESULTS ON WIDE BAND IN-HOUSE PLC SYSTEM
These test results show strong interference from PLC modems tested in Belgium.

NTIA List and Links of Worldwide BPL studies and papers
This list published by the US NTIA has links to dozens of worldwide papers about BPL.

Broadband Over Power Lines Analysis
The paper shows a glaring problem when hams are using PSK31, and similar modes that require only 6.5 dB pre-detectionS/N in a100 Hzbandwidth. This translates to -8.3 dB S/N in a 3 kHz bandwidth. In addition, the paper shows by well-known theory, the impossibility of successful BPL-licensed station peaceful coexistence. It also shows why field strength measurements are an impossible method for determining electromagnetic compatibility (EMC). Indeed, the combinations and permutations of BPL systems, which include the overhead and in-house power lines (antennas), and the virtually infinite number of licensed station frequencies, antenna gains, and modulations, preclude specification of field strength.

British Broadcasting Corporation BPL papers and presentations:
Cumulative effects of distributed interferers
Emission limits: A new proposal based on a limited increase in the noise floor
Do EMC limits protect broadcasting as intended?
How best to protect radio services as intended?
The effects of power-line telecommunications on broadcast reception: brief trial in Crieff
PLT and broadcasting - can they co-exist?
Co-existence of PLT and radio services -- A possibility?
The effects of power-line telecommunications on broadcast reception: second trial in Crieff

Australia
Australian Communications and Media Authority's (ACMA) discussion paper on BPL 
ACMA measurement reports:
Moruya Trial
Queanbeyan Trial

The Management of BPL Interference, David Burger, VK2CZ/K3HZ
This is a submission written by David Burger, presented tothe Australian Communications & Media Authority (ACMA) June 2005, canvassing 'The Management of BPL Interference".It highlights (lack of) standards, practical issues and to bridge the regulatory environment as it applies to BPL between Australia, EU and USA. A detailed EMC report is included with permission. It draws sources from both IEEE and the ARRL.

Electromagnetic Effect Due to PLC and Work Progress in Different Standardization Bodies
Feasibility studies performed in the last years have shown that the use of the low voltage distribution network can be used for data transmission. The main problem is the possible radiation of electromagnetic field and the disturbances which can affect radio transmission in the 1 to 30 MHz frequency band. This report presents the difficulties to choose a limit for the field radiated by this technology and also to find a suitable method for checking that the limit is respected in case of conflict. It presents also the state of the art <in 2002> in the work of different standardization bodies dealing presently with conducted and radiated limits.

Testing by the FEDERACION DE CLUBES DE RADIOAFICIONADOS DE CHILE
These tests done by the FCRC were part of the decision by Chilean regulators not to permit BPL in Chile until BPL equipment can be shown to be capable of operating without causing interference.

NTIA Report on BPL
Although this report has a cover letter that describes how NTIA is supportive of BPL, the content of the report demonstrates clearly that BPL has a strong interference potential locally.

Broadband Over Powerline (BPL) Signal Leakage Analysis Using NEC Modeling With Experimental Verification
Steve Cerwin, Institute Scientist, Southwest Research Institute
This paper describes a theoretical and experimental study conducted to assess the ability of transmission line structures modeled after power lines to contain radio frequency energy as a guided wave. Proponents of the Broadband-over-Power-Line (BPL) method of distributing high-speed Internet data have targeted the spectrum from 2 MHz (just above the AM broadcast band) to 80 MHz (just below the FM broadcast band) for delivery of wideband data signals to residential and rural neighborhoods using the overhead power lines as radio frequency transmission lines. This block of spectrum, while specifically excluding the AM and FM broadcast bands, encompasses the entire HF and low band VHF spectrum serving all HF over-the-horizon communications, many VHF land mobile services, and TV channels 2-5. With the exception of strong urban TV signals, the nature of these types of communications is mostly characterized as weak-signal work and the interference to these services by unwanted leakage of the wideband data signals from the power lines would seriously degrade their operation or make them entirely unusable. The study used the Numerical Electromagnetics Code (NEC) to model the radiation patterns and leakage levels of two-wire transmission lines representing simplified versions of the power line in various geometries. Selected results were verified experimentally through construction of a 1/60th scale model. At radio frequencies, transmission lines modeled after power lines were seen to radiate severely because they are spaced too far apart and have too many characteristics that destroy balanced operation. Many line geometries were predicted to radiate as much or more power than that delivered to loads placed directly across the line. The use of these structures to distribute wideband data signals in frequency bands used for weak-signal radio communications is technically flawed because of their inability to contain the radio frequency energy as a guided wave. An explanation of the paper is available in a PowerPoint presentation.

Why Broadband PLT is Bad for EMC
Posted: April 12, 2005 -- "Broadband Internet communication is here to stay, but its method of delivery is still controversial. This paper looks at the technology of Power Line Telecommunications (PLT) through the eyes of an ECM specialist, and attempts to explain why broadband through PLT is a dangerous and divisive issue. Although the author was initially neutral regarding this technology, that is no longer the case. Hopefully, this article will clarify the reasons."

Design of Broadband Coupling Circuits for PLC Communications
Abstract -- One of the most critical components of any Power Line Communication (PLC) system is its interface circuit (or coupling circuit) with the power distribution network. This is by no means a simple unit considering the challenging characteristics of the PLC channel. Due to high voltages, varying impedances, high amplitudes and time dependent disturbances, coupling circuits need to be carefully designed to provide both the specific signal transmission with the appropriate bandwidth, and the safety level required by the applicable domestic or international standard. This paper presents various aspects on practical coupling circuit design. We investigate inductive coupling, capacitive coupling and some hybrid designs. We present measurements of the coupling circuits in terms of transfer function and PLC channel measurements under practical power line noise and impedance loading. We demonstrate the influence of coupling circuit in measurements and show how to compensate its effects in order to measure the actual scattering parameters of the power lines. We compare and comment the various coupling circuit designs in order to define their applicability in practical power line communication systems.

Research Areas for More Efficient Power Line Communication Modems
Abstract -- The power line communication (PLC) is a new technology open to improvements in some key aspects. Some companies in the world provide broad band PLC devices and an increasing number of utility companies have already gone through field trials and commercial deployment of PLC services. From this experience it is necessary to decrease costs, and to improve the bandwidth and liability, and ease the installation procedures and access to technical support. This paper provides a review of the main problems that the PLC modem technology faces, problems representing the research areas for PLC where more studies are still necessary. It also enumerates some of the most interesting ideas proposed in the last years to solve these problems, finally describing our current research works in PLC modems.(ARRL note: The paper notes that for BPL to co-exist, more "robust" HF communications systems will have to be developed.)

Broadband Over Powerline: Status and Prospects 2004
October, 2004 -- The Electric Power Research Institute (EPRI) and its subsidiary Primen released Broadband Over Powerline: Status and Prospects 2004, a white paper summarizing the state of emerging technology that allows for high-speed data communications over existing electric power lines. Broadband over powerline (BPL) has been heralded as a potential "third wire," competing with DSL and cable as a means of providing Internet access to U.S. homes and businesses. "This white paper is a guide to where BPL stands right now, including information on vendors, projects, and commercial deployments," says Karen George, a principal at Primen, a Boulder, Colorado, U.S.-based energy market intelligence company affiliated with EPRI. George co-wrote the study with EPRI's Clark Gellings, vice president for Innovation.

United Powerline Council / Powerlines Communications Association joint report to the FCC 
This UPLC/PLCA joint paper reports that "successful" field trials have taken place in the US in AL MD MO NY OH PA and VA. Although the studies were not well publicized and did not include any direct participation by the Amateur Radio Service, this report concludes that "none of these field trials have caused any interference to home entertainment equipment, licensed wireless services and other spectrum users." ARRL believes that this conclusion is premature because none of these studies included any Amateur Radio involvment and no specific mention of measurements or tests to quantify interference levels appear to have been included. Author: UPLC/PCLA

Power Line Networking Technologies broadband potential
3/16/2003 - Shane Kirwan and Greg South -- This Computer Networking term paper discusses BPL. 


8/19/2003 -- ARRL testing in several BPL areas is described.

Exhibit B: Broadband Over Power Line Devices and Conducted Emissions
8/19/2003 -- The known power levels of BPL signals on MV or LV lines is 30 to 40 dB greater than the FCC Part-15 conducted emissions levels.

Exhibit C: Impact of Man-Made Noise From Broadband Over Power Line Systems Operating at the FCC Part-15 Radiated Emissions Limits on Worldwide HF
Communications

8/19/2003 -- This study, doing using ICEPAC, an IONCAP-based HF propagation-analysis software package, shows a dramatic impact of "Part-15 level" noise on HF communications.