Here you go, the NTIA is about to take some important steps as far as measuring interference levels from BPL.
This along with the ARRL's findings will be greatly needed proof that this technology is not very well engineered. read on....
NEWINGTON, CT, Aug 19, 2003--The National Telecommunications and Information Administration (NTIA) has weighed in on the FCC's Broadband over Power Line (BPL) initiative. While urging the FCC to "move forward expeditiously" with its inquiry into BPL, the NTIA expressed "broad concerns" about interference to government users. The NTIA also has launched an extensive modeling, analysis and measurement program for BPL. A Commerce Department branch, NTIA is the president's principal advisor on domestic and international telecommunications policy. It also administers spectrum allocated to federal government users.
"Notwithstanding BPL's potential benefits, the Commission must ensure that other communications services, especially government operations, are adequately protected from unacceptable interference," the NTIA said in late-filed comments in the BPL Notice of Inquiry (NOI) in ET 03-104. "In tailoring its rules to promote BPL deployment, the Commission must be certain to provide all communications stakeholders with adequate protections against BPL emissions that may cause unacceptable radio frequency interference."
A form of power line carrier (PLC) technology, BPL would use existing low and medium-voltage power lines to deliver broadband services to homes and businesses. Because it uses frequencies between 2 and 80 MHz, BPL could affect HF and low-VHF amateur allocations wherever it's deployed. BPL proponents--primarily electric power utilities--already are testing BPL systems in several markets, and one is said to be already offering the service. FCC rules already allow BPL, although industry proponents want the FCC to relax radiation limits.
ARRL President Jim Haynie, W5JBP, has called BPL "the most crucial issue facing Amateur Radio and the one that has the most devastating potential." ARRL Laboratory personnel already have visited several communities where BPL field testing is under way and documented the potential for extensive interference on HF frequencies in all field trial communities visited.
In its comments, the NTIA indicated its apprehension regarding "radiated emission limits and other measures" that may be needed to protect the more than 18,000 HF and low-VHF federal government frequency assignments that BPL could affect.
Until releasing its comments this month, the NTIA has been largely silent on the issue since last spring. In an April 24 letter, then-NTIA administrator Nancy J. Victory applauded the FCC's decision to launch its inquiry into BPL, but called on the Commission to make sure that BPL does not cause harmful interference to other services.
In early July, Frederick R. Wentland, NTIA's associate administrator in the Office of Spectrum Management, told the FCC that the NTIA did not favor Current Technologies LLC's request for a permanent waiver of the field strength limit specified for Class B emissions under FCC Part 15 rules. A Maryland BPL developer, Current Technologies already is field testing and marketing the technology.
Wentland worried that the pole-mounted interfaces and outdoor power lines used for BPL could interfere with public safety communication in the 30 to 50 MHz range. He told FCC Office of Engineering and Technology Chief Edmond J. Thomas that the "unobstructed and ubiquitous nature of this BPL application, and perhaps other aspects of BPL, differs considerably from the situations presently found in typical unintentional radiators" operating under Part 15. Wentland also expressed concerns regarding compliance measurement techniques for BPL and the characterization of BPL emissions for use in compatibility studies.
NTIA's technical studies will include detailed measurements and analyses to "help determine the least constraining BPL emission limits that would preclude unacceptable interference," Wentland told Thomas. Wentland, who has been named to succeed Victory as NTIA administrator on an interim basis, also invited the FCC to coordinate its own BPL measurement activities with those of the NTIA.
In an attachment to its comments, NTIA summarized its measurement plan, which, among other things, will take ambient noise measurements and also "quantify unknown aspects of BPL signals" at several BPL test sites. The plan noted that as a result of nonlinear elements in the electrical power distribution system, "BPL systems may radiate emissions at frequencies substantially higher than the frequencies actually used intentionally within the BPL system."
The NTIA's Institute of Telecommunication Science is carrying out the measurement program over a two-week period, coordinating its efforts with BPL network administrators. The data will be folded into the NTIA's BPL modeling and analysis initiative.
The NTIA said the results of its research will yield recommendations on radiated emission limits and other operational restrictions for BPL that are "necessary to preclude unacceptable interference to federal government systems." The agency said it planned to conclude its research by year's end.
A copy of the NTIA's comments--which had not been posted on the FCC Web site as of August 19--is available on the NTIA Web site.
The FCC extended the reply comment deadline in the BPL proceeding to August 20, and the ARRL plans to file reply comments.
The League's initial 120-page package of comments and technical exhibits is available on the ARRL Web site. There's additional information and additional video clips on the ARRL "Power Line Communications (PLC) and Amateur Radio" page.
To support the League's efforts in this area, visit the ARRL's secure BPL Web site.