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 Previous: Two-Ham Crew Set to Fly to International Space Station |  Next: The K7RA Solar Update |
 The FCC will seek comments on the advisability of using powerlines to deliver broadband and Internet services to homes and businesses. |
NEWINGTON, CT, Apr 25, 2003--The FCC soon will invite public comment on the concept of using existing electrical power lines to deliver Internet and broadband service to homes and offices. The Commission this week initiated a Notice of Inquiry (NOI) in ET Docket 03-104. A form of carrier-current technology typically known as power line communication (PLC), it's also been called "PowerWiFi" and now--by the FCC--"Broadband over Power Line" (BPL). Whatever its name, the technology is raising serious interference concerns within the Amateur Radio community, since BPL would apply high-frequency RF to parts of the power grid. One aspect of the NOI is to gather information on potential interference effects on authorized spectrum users.
"Entire communities will be affected, so every amateur in that community could have part of the radiating system 'next door' on the power wiring on his or her street," cautioned ARRL Lab Supervisor Ed Hare, W1RFI. Hare chairs the PLC Work Group of the IEEE C63 Accredited Standards Committee on Electromagnetic Compatibility, which develops standards for emissions and immunity for a wide range of commercial and consumer products.
The complete NOI has not yet been released, and until that happens, the FCC will not formally accept comments in the proceeding. The ARRL will be among those expected to submit detailed comments in ET 03-104.
ARRL CEO David Sumner, K1ZZ, editorialized on the subject of PLC in "It Seems to Us . . ." in the October issue of 2002 QST. "Is it possible to do power line communications without causing interference to over-the-air communications?" Sumner asked. "Count us among the skeptics. What may be a fine transmission line at 60 Hz looks more like an antenna at HF. And that's a matter of physics, not economics." Concluded Sumner, "Radio smog results from putting RF where it doesn't belong."
FCC Upbeat about BPL/PLC
The FCC appears enthusiastic about BPL, however, saying it has the potential to "provide consumers with the freedom to access broadband services from any room in the house without adding or paying for additional connections."
FCC Chairman Michael Powell led this week's love fest in a separate statement. "Broadband over Power Line has the potential to provide consumers with a ubiquitous third broadband pipe to the home," the chairman enthused. "The development of multiple broadband-capable platforms--be it power lines, Wi-Fi, satellite, laser or licensed wireless--will transform the competitive broadband landscape and reap dramatic windfalls for American consumers and the economy."
The inquiry addresses the two types of BPL--"access" and "in-house." Access BPL would use medium-voltage (1 kV to 40 kV) power lines to deliver Internet and broadband applications. Hare says access BPL is likely to be a more significant interference source "because overhead electrical wiring is a much better antenna than the electrical wiring within a building." Hare said the industry would likely be unable to offer sufficient protection for Amateur Radio bands.
Analyses Suggest "Significant" Interference Potential
Hare said his own analyses of interference potential from access BPL/PLC using computer models of simple power wiring and estimates of the levels of PLC signals suggest "a significant increase in noise levels" from deployed BPL/PLC systems.
In-house BPL--already deployed under the HomePlug industry specification--uses existing electric utility wiring to network computer devices and smart appliances within a building. After consultation with ARRL, manufacturers included 30-dB notches for ham bands for this technology, however.
 ARRL Lab Supervisor Ed Hare, W1RFI, says his computer models suggest "a significant increase in noise levels" from deployed BPL/PLC systems. |
The FCC notes that the availability of faster chipsets and the development of sophisticated modulation techniques have produced new digital power line designs that use multiple carriers spread over a wide frequency range--from 2 MHz up to 80 MHz--and capable of high data rates--up to 20 MB/s, although that bandwidth would be shared among all users on-line in a given neighborhood.
FCC NOI Focus Includes Interference
According to the FCC, providers of BPL equipment "are free to continue to deploy their networks in conformance with existing Part 15 rules." But, the FCC said, rule changes resulting from the NOI "will address prospective compliance."
In addition to viewpoints on interference potential, the FCC also has requested comments on the current state of high-speed BPL technology, test results from BPL experimental sites, appropriate measurement procedure for testing emission characteristics for all types of carrier-current systems, changes that may be needed in Part 15 technical rules, and the equipment approval process to foster the development of BPL.
Bridging the Last Mile
The FCC says BPL "may be able to provide an additional means for so-called 'last-mile' delivery of broadband services and may offer a competitive alternative to digital subscriber line and cable modem services," especially in remote areas of the country where alternatives to dial-up service might not be available.
The FCC has declared BPL as a top priority for its Office of Engineering and Technology (OET) in 2003. Powell, who recently witnessed a BPL demonstration, calls its potential "immense." As the chairman sees it, BPL "can offer consumers freedom to access broadband services from any room in their home without need to pay for additional wiring, by simply plugging an adapter into an existing electrical outlet."
Tests of BPL are under way in several states, including Alabama, Maryland, Missouri, New York, Ohio, Pennsylvania and Virginia. Hare says none of the trials has enjoyed any formal coordination with Amateur Radio, although he's working with hams in Maryland and Pennsylvania.
 One technical issue involves the best method to bridging or bypass the typical step-down pole transformer to deliver BPL from the power grid into an office or dwelling. |
ARRL Lab personnel will be visiting some of the test cities this spring to take field measurements to quantify the potential for interference to Amateur Radio operations. BPL/PLC technology already has been deployed in some European countries, and amateurs there have complained about interference from the systems. Japan--responding in part to concerns expressed by its amateur community--decided last year not to adopt the technology because of its interference potential.
BPL/PLC industry groups filed a report with the FCC even before the formal announcement of the BPL proceeding. In an apparent effort to clear the path of any potential regulatory obstacles, the United PowerLine Council (UPLC), a consortium of PLC manufacturers, and the PowerLine Communications Association (PLCA) have asked the OET to proceed with all deliberate speed on the BPL issue. The PLCA called the FCC's NOI "a historic moment for the power line communications industry."
The UPLC-PLCA report to the FCC claimed, "None of these field trials have caused any interference to home entertainment equipment, licensed wireless services or other spectrum users." The report failed to describe any tests to support the claim.
Further Study Needed
Hare said that ARRL and other International Amateur Radio Union member-societies have been studying PLC field trials and preparing information. A BPL/PLC Web page is under development for the ARRL Web site that will contain all of the League's information and links to a number of sites and studies that show that PLC--especially access BPL/PLC--poses a significant interference potential to Amateur Radio.
As Sumner's QST editorial concluded last fall: "New
sources of radio smog are no more acceptable than are new sources of the visible kind [of smog].
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