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[Ham-80211] OT??? High power 2.4 GHz rules change

Jeff King jeff at aerodata.net
Sat May 20 00:28:18 UTC 2006

On Fri, 19 May 2006 17:38:27 -0500, Tim Gorman wrote:

>OFDM, if the frequency span occupied is much, much greater than the
>modulating bandwidth, will probably also be considered spread
>spectrum based on my reading of the FCC rules and regulations under
>CFR 47.

Nope. While OFDM may appear spectrally as "spread spectrum like", it is not. This is exactly why when the first 802.11a products came out, the makers had to get a wavier from the FCC for Part 15. Then they came out with the DTC rules, which addressed spectral density and allowed this emission types to run the same power levels as traditional spread spectrum part 15 devices. Also, Pactor3 and MT63 are popular HF modes, and are OFDM modes.

>802.11h has been specifically designed to work in conjunction with
>802.11a (an OFDM system) to provide APC functions. And it works! So
>saying that it is a "Practical Impossibility" has already been
>proved wrong.

For a large company. I think the ARRL was referring to some Joe working in his shack. Don't forget that one of the basis and purposes of ham radio is experimentation, and the fewer rules that get in the way of this, generally the better. I am in support of the removal of the APC rule just as I am against the HF regulation by bandwidth giveback. The fewer rules we have, the better.

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