Irony

The FCC issued Report and Order 17-33 which creates two new bands for amateur radio, 472-479 kHz (630 meters) and 135.7-137.8 kHz (2,200 meters).  As ARRL reported, it is a “big win” for amateur radio.  I’ve been waiting in anticipation for the 630 meter band as it’s an old yet new frontier for us.  With old Sol taking a bit of a nap for the past few years and perhaps for years or decades to come, lower frequencies are where we’re going to have to play for more fun.

There are a few caveats in using these bands.  The FCC is requiring radio amateurs be at least 1 km from electric power transmission lines using Power Line Carrier (PLC) systems on those bands.  PLC is a technology that uses low frequency signals on power lines to perform signaling and control functions, and often meter reading.  Amateurs will have to notify the Utilities Technology Council (UTC) of station location prior to operating on 630 and 2200 meters.  The UTC maintains an industry database for PLC operations.

Those who were around to experience the Broadband over Powerline (BPL) brouhaha around 2003 to 2005 may recall the UTC organization.  At the time BPL was billed by proponents as the next big thing in broadband Internet.  Amateur radio operators and ARRL argued vigorously against BPL, citing engineering and evidence that the HF signals on the power lines radiated into the ether and interfered with HF radio operations.  The FCC turned a blind eye to the issue.  Luckily market forces took out BPL as a viable broadband solution due to increasing bandwidth needs and numerous failed trials which uncovered its technical difficulties and business problems.  PLC and BPL are cousins, with PLC operating below 500 khz and HF BPL operating from 1.8 to 30 Mhz.

The UTC, several electric utilities, and a handful of BPL equipment vendors at the time claimed that BPL didn’t interfere with HF radio operations.  The explanations and claims baffled those of us experienced in wireless and RF engineering as it’s a fact that an unshielded conductor tens of wavelengths long, conducting RF signals, will radiate energy.  The math and science supported this and measurements in the field provided real life evidence.

The UTC notes the following about PLC operation:

“This Activity is established as provided for in the FCC Rules and Regulations, Part 90.35(g) (47 C.F.R. ‘ 90.35(g)) relative to PLC operation in the 10-490 kHz band, and the NTIA Manual of Regulations and Procedures for Federal Radio Frequency Management, in Part 8.3, under the heading “Notifications in the Band 10-490 kHz,” (see 47 C.F.R., Chapter III). Electric utilities are allowed to use power line carrier (PLC) transmitters and receivers for control signals and information transmission in the 10-490 kHz band without obtaining a license from the [FCC]. However, PLC users are not protected from interference from licensed radio transmitters.”

Part 90.35(g) states that PLC operates under Part 15.  With the distance separation and notification requirement for amateurs, the FCC has granted an unlicensed incidental radiating non-wireless service protection from a licensed wireless service.  This was essentially the case with BPL in the early 2000s with an unworkable process for resolving interference issues, and interference complaints from amateurs living in trial site areas languishing for months with no action.

With this latest frequency allocation to amateur radio and requirements for protecting PLC operations, the tables are turned.  It’s the electric utility industry, that once claimed power lines wouldn’t interact with wireless spectrum, that could potentially experience interference.  Undoubtedly many FCC staffers involved in BPL in the past are no longer at the agency and the electric utility industry has forgotten about the BPL fiasco and fail to realize the irony of needing to protect PLC from wireless.

All this being said, I’m not attempting to downplay or criticize the allocation of the two new bands.  I think it’s wonderful and I applaud ARRL’s success.  However, I hope amateurs wishing to enjoy these bands aren’t prevented in doing so.  While it’s unlikely a large number of amateurs will be excluded from operating due to PLC on high voltage transmission lines, PLC systems are used in meter reading applications in neighborhood power distribution systems.  Hopefully the majority of systems do not operate in the new 630 and 2200 meter amateur bands and we can peacefully coexist, unlike what occurred with BPL.

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