On Tue, 25 Oct 2005 16:54:01 -0700, matt weber <mattheww50@cox.net>
wrote:

>Perhaps, but find me a home wireless access point that puts anywhere
>near 1 watt. Most are in fact in the 30-50 milliwatt category.

Reminder: The original question was about RF exposure and health
hazards.

You're correct that most consumer access points run 30-50 mw. It is
possible to hack some access points (WRT54G) up to about 250 mw.

However, if the mesh networks discussed for SF and Philadelphia are
deployed as planned, they may have as many as 100 1 watt and 6dBi (4
watts EIRP) Tropos access points per square mile. Now, that's
potential RF exposure.

>>Cellular handsets are limited to 0.6 watts.

>WRONG. .6 watts AVERAGE. In the case of GSM, 2 watts instantaneous
>power at 800/900, 1 watt at at 1800/1900.
> 2 watts is actually .25 watts average, 1 watt is .125 watts average.

RF exposure is measured using average power, not peak power, pulse
power, or whatever. The TDMA time slicers are allowed 0.6 watts
average, which they can slice up into 4 pieces for IS-136, or GSM in 8
time slices. Multiply the average power by the duty cycle to get peak
power.

>> Mobiles can go to 3
>>watts.

>Wrong again, mobile GSM is up to 5 watts instantanous, and 20 watts is
>defined in the standard (although I don't know of 20 watts being
>available anywhere)

True for GSM. Methinks it's 3 watts average for CDMA 800 and IS-136
800MHz. I don't recall the PCS (1900Mhz) limits. I vaguely recall
seeing some early GSM trunk mount mobiles that cranked out 20 watts
(peak).

>> All of the handsets have automatic power control to limit the
>>tx power to only as much as necessary. The tiny new phones barely
>>transmit at more than 0.1 watt.

>Wrong yet again, AMPS/D-AMPS phones have no power control loop.
>IS-136, GSM, and CDMA do have a power control loop.

I said "tiny new phones" which largely eliminates obsolete analog only
phones. The "tiny new phones" are all GSM, CDMA, and iDEN. I've
measured the average power output and monitored the output power in
the "test mode" on my assorted CDMA phones. 200 mw maximum (average).

--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558