[MLB-WIRELESS] Bullet2 output power, why 1W or 100mW

[hannah commodore]

mw at freenet.net.au wrote:
> I don't get it...
>
> As far as I can figure it out, you can only transmit in the wifi channels
> 1,2,& 3 with max width of 100K - that's obviously why a bit of HAM activity
> in the background probably dosn't hurt wifi that much.
>   
The use of OFDM and DSSS (wikipedia them) modulation/frequency hoping
techniques make it much less susceptible to single channel interference
anyway. The advantage to that is it also prevents multiple wifi signals
on the same "channel" from preventing each other access.
> The rest of the wifi spectrum, though, is used up by amateur TV - that can
> be (am I reading it right?) up to 18Meg each channel - that would be a
> killer for any nearby wifi links.
>   
Instead of wifi spectrum, a better term may be the approximate frequency
or wavelength, since many other things use 2.4GHz

The WIA band plan is not law, but merely an agreement when one becomes
licensed in Australia. You could operate any bandwidth on any frequency
with any power, as long as it fits the legally binding LCD set forth by ACMA
> I don't see any indication that amateur license gives anyone to the right to
> run wifi abve 36dB EIRP!  
Amatuers do quite often run more than 36dB ERP on 2.4GHz. Have a search
for "13cm EME" sometime.

In the US, Part97 (licensed) radio regulations allow for 1.5kW (>60dBm)
PEP for 2.4GHz, while Part15 (unlicensed) is limited to some 1mV/m (~1W
ERP).
> I can't understand why amateur license would
> override normal class licenses, but hey - it's the first time I've ever
> looked at that doc ;-)
>   
Well, because it's licensed. The limits of unlicensed radio use are
obviously much more restrictive than that of amatuer.

You may also notice the band plan shows primary and secondary services.
In some cases, unlicensed transmissions are more restrictive than
amatuer, who are more restricted than secondary, and then primary.
Primary service is often military or medical, where they can run as much
power as they damn well please.