[Ham-80211] OT??? High power 2.4 GHz rules change
hal hfeinstein at cox.netSun May 21 04:14:38 UTC 2006
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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? > > _______________________________________________ > ham-80211 mailing list > ham-80211 at lists.tapr.org > https://lists.tapr.org/cgi-bin/mailman/listinfo/ham-80211 > > >
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