
The only current U.S. users of the spectrum segment
including the proposed 135.7-137.8 kHz band are power companies operating PLC
(power line carrier) systems for monitoring electrical infrastructure. Broadband
over Power Lines (BPL) is a form of PLC, but the systems at these frequencies
are used internally by the power companies. Ironically, if the amateur
allocation is approved here, the FCC says it is likely that hams will have to
coordinate with utilities and avoid causing interference to the PLC systems.
Comments on ET Docket 12-338 are due 60 days after
publication in the Federal Register, with reply comments due 30 days
later. As of this posting, the NPRM had not yet been published in the Register.