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BPL
BROADBAND OVER POWELINES
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| FCC adopts rules for broadband over power line. |
ARRL BPL PAGE |
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Reply Comments to Notice of Proposed Rule Making (04-37) |
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Before the Federal Communications Commission Washington, D.C. 20554 In the Matter of Carrier Current Systems, including Broadband over Power Line Systems )ET Docket No. 03-104 Amendment of Part 15 regarding new requirements and measurement guidelines for Access Broadband over Power Line Systems ) ET Docket No. 04-37 To: The Commission Reply Comments to Notice of Proposed Rule Making (04-37) Reply Comments by to the Notice of Proposed Rulemaking by Benjamin S. Gelb I have been a licensed Amateur Radio operator for eight years, completed multiple physics and electronics courses and have countless hours of hands-on experience experimenting with radio and electronics equipment. I am a graduating senior at Thomas Jefferson High School for Science and Technology in Alexandria, Virginia and will be attending MIT in the fall. The following are reply comments to various comments on the NRPM (04-37) by Current Technologies and Ambient Corporation. Current Technologies asserts that "Current Technologies implementation of BPL is noninterfering." I dispute Current Technologies' assertion that "Current Technologies implementation of BPL is non-interfering." There seems to be a great division between those who believe BPL will be a source of harmful interference, and those who do not. I contend this division is not a result of "misunderstandings about how BPL works" on the part of amateur radio operators and many other individuals and organizations but rather a misunderstanding of basic physics on the part of both the Commission and Current Technologies. Current Technologies states on page 14 that "Access BPL devices do not use power lines as antennas. They use power lines to conduct data signals, not radiate them." I'm sure that Current Technologies' goal is to conduct signals rather than radiate them. Unfortunately, Current Technologies, no matter how much they wish to deny it, is bound by the same laws of physics as every one else. When an RF current is coupled into a conductor, that conductor will radiate. Period. This is because of the electric and magnetic fields created by the charge and current on the conductor. In coaxial cable the fields are contained by a shield at ground potential. In balanced line, equal and opposite fields from correctly spaced parallel conductors mathematically cancel. Power lines have RF characteristics that are irregular and variable, and do not resemble either type of feed line. Therefore, BPL systems that couple RF to the power line will cause the power line to radiate. Period. This has been shown to be true in the real world. A video1 produced by the American Radio Relay League demonstrates actual received interference in four trial areas, one of which is operated by Current Technologies. Because of the great disagreement between BPL promoters and those who stand to be impacted by the implementations of BPL systems, it seems that the Commission ought to be obligated to, at the very least, conduct some sort of real world testing of its own to determine the radiation characteristics of power lines. To date, no effort to validate the claims of either side has been made by the Commission. So far, the Commission’s attitude seems to be to accept the word of BPL manufacturers as fact, no questions asked, despite the fact that many statements made by BPL proponents and subsequently parroted by the Commission are embarrassingly nonsensical to someone with even the most rudimentary technical education (e.g. stating that the characteristics of a power line are “somewhere between a waveguide and an antenna” in the NPRM). Meanwhile, the Commission has dismissed actual testing and analysis conducted by many technically adept individuals, as well as organizations such as the ARRL, AMRAD, and the NTIA as “unsupported claims” that cannot “stand in the way of such an innovation as BPL.”2 Current Technologies states that the debate has been "complicated further by the existence of several different technical approaches to BPL, each of which works differently." Current Technologies seems to say that while some implementations of BPL may cause power line radiation, its own implementation does not. This cannot be for the reason addressed previously - all BPL systems will cause power line radiation - but assuming for a moment that Current has found a way around the laws of physics, it is clear that each of the "different technical approaches" to BPL needs to be addressed individually in the new rules, because even if Current Technologies' implementation may not cause interference, other implementations will. More curiously, no sufficient detail has been provided regarding the operations of ANY of the "different technical approaches" or what technical property gives Current Technolgies' system the ability to prevent power lines from radiating. It boggles the mind to think that the Commission plans to implement effective new rules without evaluating such technical details. 1 ARRL BPL Video. http://216.167.96.120/BPL_Trial-web.mpg 2 The statement of Commissioner Adelstein on the NPRM. Current Technologies' assertion that "BPL bandwidth has no effect on interference" is incorrect. This is not a matter of science, but one merely of common sense. A wider signal bandwidth means that BPL signals will occupy a greater set of frequencies. Therefore there are more frequencies where interference may occur. An isolated interfering signal of narrow bandwidth often does not constitute harmful interference because, while annoying, it can be easily avoided by simply moving to another frequency. A broad band BPL signal, on the other hand, could quite easily consume an entire BAND of operating frequencies, which are normally only a few hundred kHz wide in the HF range. There is a grave difference between a single narrow band signal and a broad band one like BPL. In its comments, Ambient cites President George W. Bush’s recent speech on broadband technology. "So how is some guy in remote Wyoming going to get any broadband technology? Regulatory policy has got to be wise and smart as we encourage the spread of this important technology. There needs to be technical standards to make possible new broadband technologies, such as the use of high-speed communication directly over power lines. Power lines were for electricity; power lines can be used for broadband technology. So the technical standards need to be changed to encourage that. Ambient strongly supports the President's conclusion that ‘ ... technical standards need to be changed to encourage ...’ the use of high-speed communication directly over power lines.” Ambient supports the conclusion that “technical standards need to be changed,” but what about that guy out in Wyoming? Ambient seems to have artfully chosen its words so it can later deny promises of rural broadband. This is because, as I explained in my original comments to the NPRM, Access BPL is no more viable in a rural area than cable or DSL service. For the benefit of the Commission, I have reproduced those earlier comments here (paragraph references refer to paragraphs in the NPRM). Access BPL will not provide service to rural areas for the same reasons that cable and DSL are not available in rural areas. As is stated in paragraph 3, access BPL is a means of “‘last mile’ delivery.” A BPL signal can only travel a few thousand feet down a power line. Neighborhood distribution lines still must be connected to the Internet via fiber optic cable, as is outlined in paragraph 4. This is viable in an urban or suburban setting, where the number of potential customers can justify the cost of the fiber backhaul, but will not float in a rural environment. The Commission seems to subscribe to a misconception that the national power grid can be magically connected to BPL and turn every outlet in America into an Internet connection. This is not the case. A substantial amount of new infrastructure must be constructed in the area of BPL service, and therefore will not promote BPL in rural areas any more than other broadband technologies. As the promise of rural service is the sole pretense for the Commission’s blind rush to deploy BPL at all costs, perhaps it might behoove the Commission to consider BPL for what it really is and reconsider its motivation for promoting it so relentlessly. Ambient states that it “believes that such coexistence of BPL with other critical uses of spectrum is a goal which can be achieved.” The coexistence of Access BPL with other critical uses of spectrum is not a goal to be achieved; it is a BEDROCK REQUIREMENT for operation under the non-interferences conditions of the Part 15 rules. Compliance to this condition must be demonstrated PRIOR to operation of Access BPL systems. To apply regulatory power in any other way would simply turn Part 15 on its head. To quote from the Part 15 label on the back of a small electronic device on my desk, “this device may not cause harmful interference.” This is a stark contrast from the interpretation of the rules regarding BPL, which goes something like, “BPL systems may cause interference, as long as some effort is made to correct said interference once it is identified by a party receiving interference.” This is simply backward. The responsibility of identifying and initiating corrective action for interference must not fall on the licensed user of spectrum. Access BPL equipment must be conclusively proven to be able to operate under non-interference conditions through a thorough, documented technical analysis. To date, no such analysis exists. There is a growing body of evidence, however, that suggests that Access BPL systems cannot be implemented without causing interference. Technical analyses by AMRAD, the ARRL and the NTIA point to a severe interference problem. An official interference complaint3 has been filed by E. Alan Croswell, a resident who lives in the area of Ambient’s BPL trial in New York. In the interest of protecting licensed users of spectrum, the Commission must undertake some effort to more thoroughly evaluate the interferences risks of BPL. To date, no thorough technical analysis exists that suggests BPL can be implemented in a manner consistent with the noninterference conditions of the Part 15 rules, and many analyses, as well as real world observation and simple physics, suggest the contrary. Respectfully submitted, Ben Gelb A.R.S. KF4KJQ 104 Windover Avenue Vienna, VA 22180 (703) 281-1371 ben@gelbnet.com 3 E. Alan Crosswell. “Harmful interference from experimental license WD2XEQ.” http://www.columbia.edu/~alan/bpl/complaint-fcc.pdf http://gullfoss2.fcc.gov/prod....6184039 |
CONTACT INFORMATION |
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Grassroots Campaign on BPLNow that President Bush has gone on record as encouraging broadband over power line (BPL) technology while the FCC Notice of Proposed Rule Making is still pending, it is important for radio amateurs to get the facts across to the White House as well as to our Congressional Representatives and Senators. Having Members of Congress contact the FCC and the White House with concern about BPL's interference potential is the best step that amateurs can take on Capitol Hill. Not only will it provide an elevated status to this NPRM -- the FCC takes significant notice of issues that are being raised by Congress and they certainly will keep Congress' views in mind as they proceed with this docket -- it will also raise the general awareness level in Congress of BPL and its potential problems and may well change the Administration's course on this issue in a tight election year. The ARRL's Washington Team can target key Members of Congress; however, for a noticeable impact to be made, dozens of Representatives and Senators need to weigh in. This can only happen if amateurs take a few minutes of their time to alert their senators and representatives about the impending communications calamity should BPL deployment be allowed to move forward. Contacting the White House Any communication with the White House should say right up front that you oppose Mr. Bush's encouragement of broadband over power lines in the April 26 speech in Minneapolis. Then say why: there are several broadband technologies, and BPL is the only one that causes severe interference to radio communication. Emails can be sent directly to the White House using president@whitehouse.gov or the online form that is available at: https://sawho14.eop.gov/PERSdata/intro.htm. Telephone calls can be made to either: (202) 456-1111 (comments) or (202) 456-1414 (switchboard). Be ready to give a very short, concise statement. The operators are very good -- they will tally the calls. Letters and Emails to Congress The easiest and most common way to communicate with Congress is through letters and E-mails. Many people question whether there is a difference between a letter and an e-mail to a Member of Congress. The answer is no and yes. Both are treated equally as they come into the office. Postal mail is opened, scanned to identify an issue and then forwarded to the appropriate legislative staff. E-mails move through in a similar manner. The difference comes in timeliness. Due to security procedures, an e-mail may arrive at its intended recipient a bit quicker. Draft letters for your Senators and Congressman are available. The following guide includes keys to a well-constructed correspondence to a member of Congress. One final thought on letters and e-mails. Members of Congress are impressed by large volumes of mail from their constituents on a particular issue. They are decidedly not impressed by 300 copies of the identical letter, however. If you decide to use the draft letters, please personalize them in some way. Phone Calls It may be useful to telephone each of your Senators' offices as well as your Representative. You can follow the guide below. Personal Meetings One of the best ways to make a meaningful and lasting impact with your Member of Congress is to meet with them personally. Your congressional representatives likely spend at least a few weekends back in the state and district each month. During certain parts of the year, Members of Congress have an extended opportunity to work out of their home (state and district) offices. Unlike "meet and greets" during your family trips to Washington, DC, this is a real opportunity to get some quality face time with your elected officials. A well-orchestrated personal meeting can set the tone for all future interactions of amateurs when they contact the Representative or Senator. Key Targets Pay special attention to the Senators and Representatives on the following list. They serve on key telecom subcommittees of jurisdiction. If you determine that any of these Members of Congress represent you, please make note of it with your friends and urge that they pay special attention to contacting them. House Telecommunications Subcommittee
Senate Communications Subcommittee
HOW TO INTERACT WITH YOUR MEMBER OF CONGRESS AND ALERT THEM TO THE GROWING BPL THREAT AGAINST AMATEUR RADIO To start with, remember this key point: Keep it Simple! As you can probably imagine in just your own interactions with friends, coworkers and neighbors, trying to describe the intricacies of Amateur Radio can sometimes be a challenge. When you hear "Yagi" you think "antenna." On the other hand, most people probably think of a cartoon bear robbing picnic baskets. Technical equipment and operating issues that are the everyday norm for a ham may never register on the radar screen of a Member of Congress or their staff. Remember that whenever you speak with elected officials or their staff, you are serving as an ambassador of Amateur Radio. These people will be looking to you for guidance on ham radio issues as much as you will be looking to them for their support. Be patient in serving as a resource. Although there is no legislation pending before Congress on BPL, Members of Congress can still contact the FCC and express their concerns about BPL and its interference potentials. However, they will not do this unless there is a recognized need emanating from their constituents. At this point, BPL is not a very "hot" issue on Capitol Hill. Outside of a handful of people who work directly with Telecommunications related Committees and Subcommittees, most Members of Congress and staff are probably not even aware of what BPL is. When writing or speaking with Members of Congress and their staff, you will likely need to describe some background as to what BPL is and why it is a problem for amateur radio. Think basics. Also, remember that the ARRL website (www.arrl.org) offers an excellent array of resources and information on BPL if you are not sure of some specifics or are looking for additional points to raise. The accompanying paper, "Why is the ARRL Concerned About the FCC's NPRM on BPL?" may be helpful.
WRITING LETTERS AND EMAILS TO YOUR MEMBERS OF CONGRESS
The most important, yet often most overlooked, aspect of a written correspondence to a
Member of Congress (especially e-mails!) is including a mailing address. Without this
incredibly important piece of information, their Member of Congress, or more likely his
staff, will immediately stop reading and file it in the trash bin. With so many contrived
and mass mailings these days, legislative staff only has time to address letters and
e-mails that are certain to have come from their district.
When sending a letter to a Member of Congress, be sure it is to the person that represents you. Contacting a Member who does not represent you may be a bigger waste of time than failing to include an address. If you are unsure of whom your Members of Congress is refer to the search options on the following websites: www.house.gov and www.senate.gov. Each site includes complete contact information for every Representative and Senator.
Try to explain the BPL issue early in the correspondence. Alert them to the fact that there is a pending Notice of Proposed Rulemaking before the FCC on this issue and their attention to the matter in a timely manner is needed. Take a few sentences to describe the problems that BPL causes and how it impacts amateur radio. Describe the important role amateurs play in emergency communications as well. Most importantly, ask your Member of Congress to contact the FCC with concerns about BPL's interference potential.
Be sure they tell the Member of Congress that you have been licensed by the federal government as an Amateur Radio operator. It will add some additional credibility to any technical aspects you may bring up in the letter. There is no need to provide an extensive resume of all of your Amateur Radio activities, such as your Extra Class license and ARES activities. Remember--be brief. Also, be sure to mention that you are a member of the ARRL. It is important for Members of Congress to know that you are part of a larger group that has an interest in the issue. CALLING YOUR MEMBERS OF CONGRESS Whom to speak with: Speaking directly with a legislator may not be feasible, especially if you do not have a prior personal relationship with him or her. Making a phone call to their office can be an important first step, however. Explain that you are a constituent and that you would like to speak with the staff person that handles telecommunications issues. Make sure you are ready to talk: Some people get a little stage fright when put on the spot. Staff has very limited time, even for constituents, to focus on an issue. Tell them who you are and that you are a constituent and licensed amateur and that you are calling with concerns regarding the FCC's Proposed Notice of Rulemaking on Broadband over Power Lines. Give them a brief overview of the situation (you may want to have a few notes of important points concerning BPL in front of you) and the implications its deployment has on amateur radio and other public safety communications technology. Ask that they look into the matter and offer to fax or email them a written follow up on your concerns over BPL. Also ask again that their boss (the Congressman or Senator) support your request to contact the FCC with concerns about BPL deployment and its affects on amateur radio and public safety communications. Don't be discouraged: If you are unable to speak with the staff person, leave a message. Staff are extremely busy and you should not feel offended in the least. Give the staff person a few days to return the call. If you don't hear back, try again. Use your best judgment in deciding when too many messages are enough. PERSONAL VISITS WITH YOUR MEMBERS OF CONGRESS Keep Leadership Informed: Before making an appointment let your Division Director, Vice Director or Section Manager know your intentions. A meeting may already be in place for your Representative or Senator which you could attend. If one isn't, you may be asked to take the lead. Also, you do not want to inundate your elected officials with too many meetings on the same issue, it may become overkill. Make an appointment in advance: Call your Senator or Representative's office and ask his or her staff about the possibility of setting up a meeting. Let them know that you would like to discuss BPL, and signal to them that you will keep the meeting brief. Be patient and open to scheduling an appointment several weeks in advance. Participants: You should certainly feel comfortable meeting on your own; however, if it would make the situation more relaxed, arrange to bring one or two other amateurs from the state or district to the meeting. Avoid walking in with a large group; it may be distracting. One or two people should be sufficient to deliver your message. Have a plan: In advance, know who will speak and how you will approach the legislator. You should be brief but concise in your issue. Having a handout with some key bullet points will help the legislator focus and understand the issue. Members of Congress and their staff are usually inundated with material that is hard to follow and never gets read. Do not offer something that will not be useful. Make your material stand out. If you need some assistance in developing a handout, contact ARRL Headquarters for assistance. Try to keep the meeting focused as well. Legislators are very busy and will appreciate a well-timed meeting. Get an answer before you leave: At the conclusion of your meeting, ask your legislator if they will support amateur radio operators on this issue. Also ask if they will send a letter to the FCC expressing concern over BPL deployment. KEEP THE ARRL INFORMED Whenever you make a contact with a Member of Congress or their staff, be sure to keep the ARRL informed. Any response or feedback you receive, please pass this information along to your Division Director, Vice Director, or Section Manager. Relaying responses will help the Washington Team develop a more precise agenda as to who needs to be contacted and targeted for opposing BPL. You should also copy your letters and emails that you send to Congress to your Division and Section leadership so the ARRL can ensure that the correct staff receives your correspondences in a timely manner and can follow up. |
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DRAFT LETTER TO SENATOR
[date]
Senator ______________
Dear Sen. ____________:
On April 26, President Bush told the American Association of Community Colleges Annual Convention in Minneapolis: "There needs to be technical standards to make possible new broadband technologies, such as the use of high-speed communication directly over power lines. Power lines were for electricity; power lines can be used for broadband technology. So the technical standards need to be changed to encourage that." Mr. Bush is wrong. Although universal broadband service is a worthy goal, using power lines to distribute broadband services (called Broadband over Power Lines, or BPL) is a bad idea that should not be encouraged. There are better ways to do it. As a federally licensed Amateur Radio operator who has passed a Federal Communications Commission (FCC) examination in radiocommunication technology, I can tell you why. Power lines were designed to transmit electrical energy. They were not designed to transmit broadband signals, which is fact are radio-frequency (RF) signals. When a broadband signal is put on a power line, much of the RF energy leaks off the line and radiates, causing interference to nearby radio receivers. Interference has been documented at test sites throughout the country and overseas where BPL is in operation. Recordings of actual interference at several test sites are available at www.arrl.org/bpl. The nation's 680,000 radio amateurs are especially concerned about this interference because it affects the short waves -- a unique portion of the radio spectrum that supports long-distance, intercontinental radio communication. Licensed radio amateurs use these frequencies for hurricane reporting, disaster and emergency relief, and many other purposes in accordance with FCC regulations. The Amateur Radio Service is the only 100% failsafe emergency communications capability in the world. No matter what happens, radio amateurs will be able to communicate with one another without having to rely on the expensive and vulnerable infrastructure -- but we cannot maintain our emergency networks if BPL is deployed and interferes with the weak radio signals we are trying to hear. In addition to amateur operation, the short waves are used for international broadcasting, aeronautical, maritime, and other services including the military. Depending on the frequencies in use, BPL interference also could wipe out radio communication for many of our nation's First Responders -- police, fire, and emergency medical personnel -- who use low-band VHF radios operating in the 30-50 megahertz (MHz) range. Radio amateurs support expanded broadband services to consumers at lower cost. Indeed, they tend to be early adopters of new technology. However, there are ways to deliver broadband that do not pollute the radio spectrum as BPL does. These include fiber-to-the-home, cable, DSL, and Broadband Wireless Access. None of these technologies causes interference to short wave radio. BPL is sometimes touted as a solution for rural areas. It is not. A BPL signal only carries a few thousand feet down a power line and then must be repeated. This requires a lot of hardware and will not be economic in areas with low population densities. The FCC recognizes the interference potential of BPL and is in the midst of a rulemaking proceeding, ET Docket No. 04-37, that proposes new requirements and measurement guidelines for BPL systems. However, the FCC proposals do not go nearly far enough to protect over-the-air radiocommunication services. In short, BPL has a major disadvantage that is not shared by other broadband technologies and that outweighs whatever benefit it may offer. National broadband telecommunications policy should not include support for BPL, but should focus on other, more appropriate technologies. By encouraging broadband over power lines, the administration is heading in the wrong direction. Please do what you can to change its course. Thank you.
Sincerely,
[Name] |
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DRAFT LETTER TO REPRESENTATIVE
[date]
Rep. ______________
Dear [Mr./Ms.] ____________:
On April 26, President Bush told the American Association of Community Colleges Annual Convention in Minneapolis: "There needs to be technical standards to make possible new broadband technologies, such as the use of high-speed communication directly over power lines. Power lines were for electricity; power lines can be used for broadband technology. So the technical standards need to be changed to encourage that." Mr. Bush is wrong. Using power lines to distribute broadband services (called Broadband over Power Lines, or BPL) is a bad idea that should not be encouraged. As a federally licensed Amateur Radio operator who has passed a Federal Communications Commission (FCC) examination in radiocommunication technology, I can tell you why. Power lines were designed to transmit electrical energy. They were not designed to transmit broadband signals, which is fact are radio-frequency (RF) signals. When a broadband signal is put on a power line, much of the RF energy leaks off the line and radiates, causing interference to nearby radio receivers. Interference has been documented at test sites throughout the country and overseas where BPL is in operation. Recordings of actual interference at several test sites are available at www.arrl.org/bpl. The nation's 680,000 radio amateurs are especially concerned about this interference because it affects the short waves -- a unique portion of the radio spectrum that supports long-distance, intercontinental radio communication. Licensed radio amateurs use these frequencies for hurricane reporting, disaster and emergency relief, and many other purposes in accordance with FCC regulations. The Amateur Radio Service is the only 100% failsafe emergency communications capability in the world. No matter what happens, radio amateurs will be able to communicate with one another without having to rely on the expensive and vulnerable infrastructure -- but we cannot maintain our emergency networks if BPL is deployed and interferes with the weak radio signals we are trying to hear. In addition to amateur operation, the short waves are used for international broadcasting, aeronautical, maritime, and other services including the military. Depending on the frequencies in use, BPL interference also could wipe out radio communication for many of our nation's First Responders -- police, fire, and emergency medical personnel -- who use low-band VHF radios operating in the 30-50 megahertz (MHz) range. Radio amateurs support expanded broadband services to consumers at lower cost. Indeed, they tend to be early adopters of new technology. However, there are ways to deliver broadband that do not pollute the radio spectrum as BPL does. These include fiber-to-the-home, cable, DSL, and Broadband Wireless Access. None of these technologies causes interference to short wave radio. BPL is sometimes touted as a solution for rural areas. It is not. A BPL signal only carries a few thousand feet down a power line and then must be repeated. This requires a lot of hardware and will not be economic in areas with low population densities. The FCC recognizes the interference potential of BPL and is in the midst of a rulemaking proceeding, ET Docket No. 04-37, that proposes new requirements and measurement guidelines for BPL systems. However, the FCC proposals do not go nearly far enough to protect over-the-air radiocommunication services. In short, BPL has a major disadvantage that is not shared by other broadband technologies and that outweighs whatever benefit it may offer. National broadband telecommunications policy should not include support for BPL, but should focus on other, more appropriate technologies. By encouraging broadband over power lines, the administration is heading in the wrong direction. Please do what you can to change its course. Thank you.
Sincerely,
[Name] |
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BPL Full Report from |
| What's New at NTIA? |
| Summary of NTIA report to the FCC on BPL: NTIA concluded. 1) .that the methods currently used to measure noise levels and interference potential are inadequate: "(A)pplication of existing Part 15 measurement procedures for BPL systems results in a significant underestimation of peak field strength. Underestimation of the actual peak field strength is the leading contributor to high interference risks. As applied in current practice to BPL systems, Part 15 measurement guidelines to not address unique physical and electromagnetic characteristics of BPL radiated emissions." (Executive Summary) 2) .that noise levels must be measured from BPL-energized power lines as well as the "device" coupling the signal to the power lines: "BPL systems generate the highest electric field strength near the BPL device for horizontal-parallel polarized signals. However, these systems generate peak vertically-polarized field strength under and adjacent to the power lines and at impedance discontinuities at substantial distances from the BPL device." (Executive Summary) 3) .that interference to weak-to-medium strength signals is likely out to 460 meters (1500 feet; more than 1/4 mile) from a BPL noise source at ground level and out to a 40-kilometer (25 mile) radius from the signal source for an airplane at an altitude of up to 6 kilometers (approx. 20,000 feet): "Interference to land vehicle, boat, and fixed stations receiving moderate-to-strong radio signals is likely in areas extending to 30 meters, 55 meters, and 230 meters, respectively, from one BPL device and the power lines to which it is connected. With low-to-moderate desired signal levels, interference is likely at these receivers within areas extending to 75 meters, 100 meters and 460 meters from the power lines . (I)nterference to aircraft reception of moderate-to-strong radio signals is likely to occur below 6 km altitude within 12 km center of the BPL deployment. Interference likely would occur to aircraft reception of weak-to-moderate radio signals within 40 miles of the center of the BPL deployment area. (Executive Summary) 4) .that results of BPL tests and implementations in other countries have been mixed: "BPL apparently has been implemented with success in some countries, while other countries have postponed implementation of BPL systems until further interference studies are . conducted. Still others have withdrawn their approval for operation of BPL systems after experiencing interference problems." (Section 9, Summary of Results). One example cited was that "(d)uring an emergency exercise of the Austrian Red Cross in May 2003, communication was massively disturbed by (BPL), with interference levels exceeding the limits by a factor of 10,000." (Appendix B) 5) .that more study is needed in several important areas, including skywave propagation of BPL signals, that it will conduct further studies and issue a report later this year: "NTIA will complete a Phase 2 study later this year that will assess the potential interference risks due to aggregation and ionospheric propagation of interfering signals from BPL systems; refine and apply BPL deployment models; and evaluate the effectiveness of proposed Part 15 measurement techniques." (NTIA News Release) NTIA is recommending more stringent measurement standards and procedures, along with several interference mitigation techniques, some not mentioned in the NPRM, although it admitted that the nature of power lines and of BPL would limit the effectiveness of some of them. Additional recommendations are likely after the second phase of the NTIA study is completed later this year. Acting NTIA Administrator Michael Gallagher called the NTIA recommendations "the technical foundation for the responsible deployment of broadband over power lines." CQ Opinion: It is clear from the results of the NTIA study that the FCC's rulemaking proposal is premature at best, and it would be irresponsible of the FCC to go forward in enacting BPL rules before the NTIA Phase 2 study is completed later this year. |
Broadband Over Powerline |
| ********************** 1. Editor's View -- Exclusive to Electronic Design UPDATE ********************** Broadband Over Powerline Should Boost Competition, Lower Prices By John Novellino, Executive Editor After years of technological development, testing, and regulatory wrangling, a new form of broadband access is poised for takeoff. Known as Broadband over Powerline (BPL), this technology offers high-speed Internet access similar to cable TV and digital subscriber line (DSL). BPL puts high-speed digital data on the existing ac power lines using special modulation techniques. The electrical utilities are excited about a potential new revenue stream from their existing infrastructure. Today, well over 20 million households have some form of high-speed broadband Internet access. Most of it is supplied by cable TV companies like Cox and Time Warner. Many local phone companies also supply DSL Internet access. The number of cable Internet subscribers is roughly twice the number of DSL subscribers. With BPL coming online, consumers will have a third choice that should kick the competition up a notch and help lower monthly rates. Furthermore, one of the real benefits of BPL is that for the first time, many small towns and rural areas will finally get some broadband service. BPL is expected to provide downloads at rates up to about 3 Mbits/s. That is almost as good as the best cable TV and DSL services. In general, the monthly rate should be on par or even less than the $30 to $50 per month for cable and DSL. In February, the Federal Communications Commission (FCC) fully authorized BPL service so the utilities could go ahead and implement systems. About a dozen test systems have been in operation for a year or so with great success. So, we can expect to see this new service coming soon. One of the potential downsides of BPL is interference. The broadband modulation techniques used cover a range of 1 to 30 MHz. With those signals floating around power lines, there could be interference to radio services. The amateur radio community is really up in arms about BPL possibly interfering with ham radio communications in their HF bands. The American Radio Relay League (ARRL), the official spokes-organization for amateur radio, has lobbied the FCC about BPL, but to little avail. The FCC says that there may be some interference even though BPL must conform to standards for radiation under Part 15 of the FCC rules and regulations. Despite the fuss, it looks like BPL will go ahead. While the radiation from the power lines will be real, I suspect the signal level to be pretty low. If a ham's station and antenna are close to the power lines, there may be some interference. How many hams will be impacted? Hard to say, but probably not many. This situation is like the outcry about ultra-wideband (UWB) communications from a few years ago. UWB uses short pulses with a huge bandwidth for short-range communications. The concern was that it would interfere with all manner of microwave communications, such as cell phones, GPS, and services in the unlicensed 2.4-GHz band. Did that occur? Not really, simply because the Part 15 radiation levels are so strict. I predict that the same will occur with BPL. Even though I am a licensed ham (W5LEF) and work the HF bands, I'm not that worried. My amateur radio colleagues will probably hate me for saying this, but I believe the ARRL's response was overkill. I've been a member of ARRL for practically all of my adult life, and I am happy the group is defending our turf. The hams' concern is valid, but let's wait and see what happens and then fix the problem, if it does actually occur. The FCC provides for that. Here's to the success of BPL. |
