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

hal hfeinstein at cox.net
Sun May 21 04:14:38 UTC 2006


Tim Gorman wrot
> Those multiple stations have to be able to communicate or they are worthless. 
> The higher power they run the more they interfere with each other. It's why 
> the cell phone people don't just increase their cell site power in order to 
> increase capacity (i.e. they can reach further distances and cover more 
> people). They actually lower the cell site power and put more cell sites in. 
>
>
>   
You seem have a pretty strong opinion on high power spread spectrum so I 
am amazed you have not
heard of the overlay concept that was the original reason the FCC 
authorized Part 97 use of spread
spectrum in the first place. If I choose to experiment with a multipoint 
frequency hopping system on 2.4Ghz and pick the power, dwell time and 
channel spread, modulation type, etc .correctly there will be little 
interference to other fixed carriers in minimal.  The analogy with cell 
phones is bogus and led to the introduction of APC to start with..  I 
spoke up against inclusion of APC when it was proposed but it was 
politics, not experimental evidence or experience with Part 97 SS 
systems that championed into the rules.
There was no experimental experience, then or now, that this feature in 
any way
promotes experimentation, enhances innovation or is required to 
safeguards shared users. 
 The attempt to pull the Red Cross emergency
communications in this argument is shameful.  Hams have always shut down 
their systems when it
in anyway had the potential to interfere with an emergency operation.  
Its amazing how little people
have learned.  I thought these arguments were put to rest when the FCC 
first authorized
spread spectrum use in Part 97. Certainly we hams are our own worst 
enemies in this respect.
You only needed to look at the reply comments, filed by hams 
themselves,  arguing against letting hams have any spread spectrum 
authorization at all.  And its not that we are grossly under-regulated. 
The authorized
code sequences we received after a lot of behind the scenes back and 
forth are so limited as to be pathetic.
The FCC essentially shutdown all planned experimentation with advanced 
code sequences, one of the most
promising and fruitful areas of spread spectrum research.  A few weeks 
after this debacle they authorized practically  any sequence for 
commercial users.   Hams themselves killed  Part 97 spread spectrum  off 
2meters because of imagined fears of interference. After reading the 
reply comments the Commission imagined all kind of complaints from the 
repeater operators who where themselves unaware of spread spectrum 
testing right on top of their allocation when it actually happened. 
 There continues to be a profound misunderstanding within amateur 
circles on spread spectrum.  Correctly
chosen system parameters will produce a spread spectrum system that will 
be difficult to even detect
without specialized equipment.  As an argument against high power 802.11 
that uses spread spectrum
(as opposed to OFDM or other modulation techniques) it is full of holes.
All this is argued even when it is a  known fact that there are very few 
such experimental spread
spectrum amateur systems anywhere in the US.  APC does nothing to 
safeguard 802.11 users who have
valid concerns over badly engineered high powered 802.11 systems.  Maybe 
thats where the APC  belongs,
not as part of the spread spectrum rules.
 In short, APC is a bad idea for Part 97 spread spectrum,  it adds 
complexity without purpose, it stifles innovation and doesn't protect 
anyone in an already overly regulated Amateur service.  

BTW has anyone really checked if the spread spectrum code sequences used 
by some 802.11 in amateur operation are Part 97 legal?  
Maybe not -- STA anyone?

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