NEWINGTON, CT, Feb 25, 2004--The FCC this week released its Notice of Proposed Rule Making (NPRM) on Broadband over Power Line (BPL) systems. The 38-page NPRM--in ET Dockets 03-104 and 04-37--proposes amendments to FCC Part 15 rules to define so-called "access BPL," make rules specific to BPL systems and provide measurement guidelines for BPL devices and systems. It would make no changes to Part 15 emission limits for unintentional radiators, however. ARRL CEO David Sumner, K1ZZ, says that while Part 15's current limits on unintentional radiators on HF may be appropriate for short-duration, narrowband emissions, they are inappropriate for the sort of long-duration, broadband emissions BPL would employ. He compared short-duration, narrowband emissions at the Part 15 radiated emission limit to a helicopter flying overhead.

"The noise is deafening, but is tolerable because it doesn't happen very often nor last very long," he observed. "To a radio user, having BPL in the neighborhood would be like having the helicopter hovering constantly overhead."

ARRL Lab Manager Ed Hare, W1RFI, offered an example that most hams can relate to. "The limit for an unintentional emitter on HF is 30 uV/m at 30 meters from the source," he said. "If you take a dipole cut for 3.5 MHz and put it in a 30 uV/m field, you'll have a noise reading of S9 plus 16 dB at your transceiver."

Access BPL, a form of carrier current or power line carrier (PLC) communication, would apply RF in the HF to low-VHF range to existing low and medium-voltage exterior power lines to distribute Internet and broadband services. It was the aspect of feeding RF signals into outdoor power lines that initially raised Amateur Radio concerns regarding potential interference. Such carrier current or PLC systems are subject to the FCC's Part 15 rules governing unlicensed devices.

In its proposal, the FCC took a broader view of interference issues. "There is significant disagreement among the commenting parties regarding the interference potential of Access BPL," the NPRM declares. "Amateur operators and amateur organizations in general are opposed to Access BPL and advocate emission limits that are lower than the existing Part 15 limits."

In a statement attached to the NPRM, however, FCC Chairman Michael Powell expressed confidence that the new requirements it spells out balance BPL's potential benefits with concerns of potential interference "by establishing new requirements that will help minimize harmful interference that may occur and guidelines for measurement of radio frequency emissions from carrier current systems."

Continued @ ARRL.org