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25th Anniversary of FCC Decision Enabling Wi-Fi and Bluetooth

25th Anniversary of FCC Decision Enabling Wi-Fi and Bluetooth
A series of posts describing how this all came about. (Click on picture above)

Monday, November 26, 2007

700 MHz Auction About to Start - But FCC Hasn't Evicted Wireless Microphones Yet

In Docket 04-186, the "TV Whitespace" rulemaking, there has been a lot of discussion about wireless microphones. These are devices supposedly used only by TV broadcasters and other broadcast industry eligibles defined in 74.832. Of course, most users are other audio-visual operators whose use is illegal. Indeed, today I spoke at IEEE Globecom and used a Shure wireless microphone operating at 525 MHz. This is a misdemeanor violation of 47 USC 301. I feel guilty so I am confessing to my blog readers. (Perhaps this confession will make FCC come after me!)

January 24, 2008 the 700 MHz auction starts. But a review today of the current text of 47 CFR 74.802 shows , guess what, wireless microphones are still there and have no stated eviction date!

Here's the current text:

§ 74.802 Frequency assignment.

(a) Frequencies within the following bands may be assigned for use by low power auxiliary stations:

26.100–26.480 MHz

54.000–72.000 MHz

76.000–88.000 MHz

161.625–161.775 MHz (except in Puerto Rico or the Virgin Islands)

174.000–216.000 MHz

450.000–451.000 MHz

455.000–456.000 MHz

470.000–488.000 MHz

488.000–494.000 MHz (except Hawaii)

494.000–608.000 MHz

614.000–806.000 MHz

944.000–952.000 MHz

(Emphasis added)

Then the current text of 47 CFR 74.803 deals with who they can't interfere with:

§ 74.803 Frequency selection to avoid interference.

(a) Where two or more low power auxiliary licensees need to operate in the same area, the licensees shall endeavor to select frequencies or schedule operation in such manner as to avoid mutual interference. If a mutually satisfactory arrangement cannot be reached, the Commission shall be notified and it will specify the frequency or frequencies to be employed by each licensee.

(b) The selection of frequencies in the bands allocated for TV broadcasting for use in any area shall be guided by the need to avoid interference to TV broadcast reception. In these bands, low power auxiliary station usage is secondary to TV broadcasting and land mobile stations operating in the UHF-TV spectrum and must not cause harmful interference. If such interference occurs, low power auxiliary station operation must immediately cease and may not be resumed until the interference problem has been resolved.

See any requirement not to interfere with 700 MHz CMRS licensees? So before you bid a few billion dollars, you might want to ask FCC to clarify what is going on here.


Anonymous said...

With regards to your statement, ". . . guess what, wireless microphones are still there and have no stated eviction date!"

I disagree. Reading the FCC's own NPRMs I've interpreted that they have made determinations BAS devices must vacate 698-806MHz come 17 February 2009.

For the "lower 700MHz" band (698 - 746MHz):
Then select document "Rule section supporting collection - GN Docket No. 01-74, FCC 01-364, Report and Order (http://www.fcc.gov/omd/pra/docs/
Paragraph 14, second sentence.

For the "upper 700MHz" band (746 - 806MHz):
Paragraph 29 in the January 6 1998 R&O http://www.fcc.gov/Bureaus/Engineering_

I've not been able to find any newer Further Notices or Addendums to alter these paragraphs or offer a differing interpretation.

Henry Cohen
Production Radio Rentals
249 Ferris Ave.
White Plains, New York 10603
+1 914.686.3525
+1 914.686.3374 facsimile

MJM said...

You are right that FCC has said in some decisions that both Part 73 and Part 74 users must vacate 700 MHz after the 2/09 DTV transition.

Updating Part 74 appears to have fallen between the cracks. (After all the FCC has been busy dealing with global issues like broadcast station ownership and content.)

The current situation creates a legal ambiguity and generally muddies the water. In view of the pending multibillion dollar auction this seems strange.

FCC may be able to update Part 74 without a new rulemaking if it finds the change is only editorial.

Of course, the vast majority of present users of this band are illegal under Part 74 already so it is not clear what the impact will be on them.

The new 700 MHz licensees will use the band much more intensively than NTSC stations even did - NTSC "TV taboos" only allow every sixth UHF channel to be used in a given city.

If the wireless mikes don't move on their own in 2/09 there will be a "cat and mouse" game between them and the new licensees.

Having created much of this mess though mass marketing to noneligible users, Shure, Inc. doesn't seem to be doing anything to avoid a major confrontation in 2/09. As of today their Wireless Frequency Finder website,http://www.shure.com/

"Shure wireless microphones and PSM systems designed for use in the United States operate on standard VHF (TV channels 7-13, 174-216 MHz) and UHF, TV channels 14-69, 470-806 MHz, frequencies. Most U.S. cities have any number of local televisions stations, whose operating frequencies must be taken into account before choosing a wireless system frequency.

The UK's FCC, Ofcom, is working with their wireless mike industry to make a transition plan as DTV is phased in. Don't see what the US wireless mike industry is doing other than continuing their illegal marketing, condoning of illegal use, and complaining about Docket 04-186.

Even if 04-286 is "taken off the table", the wireless mike industry has a real problem ahead in 2/09.

Most wireless mike users serve useful functions in our society and economy. This "benign neglect" from both FCC and many of their manufacturers is not in the public interest. They deserve better from both.

MJM said...

Let me clarify what I wrote yesterday: for legal wireless mike users spectrum below channel 51 will become less crowded in 2/09 as NTSC stations turn off. However, above channel 51 things will be much more crowded and unambiguously illegal for all wireless mikes - when the FCC clears up the ambiguities in its rules. The 700 MHz auction winners, having paid billions for the spectrum, will be much less tolerant of illegal use than the TV broadcasters who know that 90+% of all homes don't tune to over-the-air broadcast signals anyway for the ever decreasing fraction of time they spend watching network programming.

Already Qualcomm is using channel 55 for its MediaFLO service which is wholesaled to cell phone operators and retailed under a variety of names for music and video downloads. MediaFLO is already in use in all major cities where there is not an interference issue to adjacent channel NTSC.

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