From: Matti Aarnio (xgxfxd@canford.com)
Date: Thu May 02 2002 - 02:47:38 EEST
On Wed, May 01, 2002 at 06:51:58PM -0400, Jack Zielke wrote:
> Hello,
> We want to modify the frequency so that we can use part 97 rules
> instead of part 15. If anyone sees anything wrong...please correct me.
> As long as the device stays on the frequency for non-hams everyone,
> including hams, have to obey the part 15 rules. If we change the
> frequency to a ham band that allows spread spectrum we can use the part 97
> rules instead.
> As I understand it the main goal is to get away from the 1 Watt limit
> and the 6dB antenna gain limit. If we change to a ham band we can use up
> to 100 Watts and any dB gain antenna.
Rules vary a bit from country to country (or at least between the
IARU regions), but having hardware operate in HAM frequency allocations
by a HAM identifying as an automatic HAM station (e.g. 47 bits of MAC
header gets encoded something looking like a call-sign..), we can do
all manner of nasty things, like put 0.1-1.0 kW PA and 30-35 dB antenna
gain..
Nastiness of course is just to those hapless people who have to abide
to unlicensed ISM rules ( 100 mW/6dBi in Finland ) when hams blow over
them with high power and big antennae.
Most WLAN cards have extremely wide receivers, which drown out their
AGC when they receive powerfull RF within 200-400 MHz. Narrow Rx
pre-filter helps, but does not appear at commodity pcmcia cards.
For that matter, separate Rx/Tx paths, and PTT signal are not
available at commodity stuff either.
> Jack
/Matti Aarnio -- OH2MQK
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