Subject: (Philips) (Huuva), DECT phone safety..... (fwd)
Date: Wed, 3 Feb 1999 085227 -0600 (CST)
From: "Roy L. Beavers" <rbeavers@llion.org>
To: emfguru <rbeavers@llion.org>
--------------------------------------------------
.......Alasdair: Don't apologize because the info has been published here
before......(1) An important principle of successful public
communications is; repeat, repeat, repeat......Also, (2) given the
frequency at which people are joining EMF-L these days, you can always be
sure that you are reaching a score or more new people who were not with us
the last time you sent the info......In the case of the DECT info below, I
would say we have "scores" of new readers since that was published......
Again, I emphasize Alasdair's remark about the "different bioeffects" from
different metrics (or exposure parameters).....See ******
below.....guru....
---------- Forwarded message ----------
Date: Wed, 03 Feb 1999 14:34:07
From: Alasdair Philips
To: "Roy L. Beavers"
Cc: Adam Huuva
Subject: Re: (Huuva), DECT phone safety.....
Roy I'm copying this to you but EMF-L'ers have seen much of it before.
Dear Adam
The max peak power from Class 4 GSM handsets (the usual ones) is 2W with an
8:1 mark-space ratio giving a maximum average power of 0.25W.
As you will know, the system is intelligent and once the comms link is
established the base station directs the set to turn down its output in 2dB
steps to the lowest level adequate to maintain the integrity of the link.
In city areas and near to base stations this can be as low as 0.008W peak
power in the 577us pulses every 4.62ms - giving an average power of only
1mW !!!!!!
DECT uses a FIXED power data pulses of 0.25W ALL OF THE TIME. It hasa 1:24
duty-cycle and so the average power is only 0.01W - but the pulses are
still 0.25W for 417us every 10ms - and I believe that we are NOT talking
about SAR (i.e. heating effects) but about signalling and informational
effects - the regular tapping disrupts intercellular signalling processes.
(DECT is the new Digital European Cordless Telephone Standard)
GSM mobiles use the following (peak pulse) power steps:
2, 1.25, 0.8, 0.5, 0.3, 0.2, 0.125, 0.08, 0.05, 0.03, 0.02, 0.0125, 0.008
+ + + + + + + + + + + + - - - - - - - - - - - - - - - - - - - - - - - -
so for most of its operating power levels it is operating below the
signal level of the DECT cordless phones of 0.25W. Interesting, eh?
Anyway, HOW CAN you work out what is going into the user's head when it
is in the near-field of the transmitter? As Kuster's results showed when
operated at 2W the SAR's into the phantom head ranged from under 0.3 W/kg
to almost 1.6 W/kg (the ANSI thermal limit) when operating at full power.
########################################
I suppose the best way is to multiply these figures by 8 and get 2.4 W/kg
to 14 W/kg during the actual pulses!!!!
########################################
Also, the DECT phones tend to use lower battery voltages than GSM phones
which means that the current pulses to power the transmitter are higher and
therefore the real ELF magnetic field pulses into the side of the users
head are about the same or even higher. These ELF magnetic field pulses of
217 Hz + harmonics for GSM and 100 Hz + harmonics for DECT are several
microtesla in strength (typically 1 to 5 uT). Childhood leukaemia has
repeatedly been linked with power line ELF fields of above 0.25uT and
important enzyme changes (eg ODC activity - Prof.Ted Litovitz) occur by
1uT. I actually suspect the real ELF magnetic field pulses as the main
cause of the memory and concentration effects and not the actual pulsed
microwaves. Mobile comms & health is a complex issue!!!!!!!!!
I as understand the situation:
Official power classes for mobile transmitters:
Power class TACS GSM(900) DCS1800/GSM1800
----------- ---- --- ---------------
1 10 W 20 W 1 W
2 4 W 8 W 0.25 W (DECT cordless)
3 1.6 W 5 W -
4(usual handsets)0.6 W 2 W -
5 - 0.8 W -
Comments & varients:
TACS, JTACS, ETACS, AMPS & NAMPS analogue handsets are by default
0.6 W which can be decreased to 0.006 W in five -4dB steps depending
on the signal strength in the area and handset antenna efficiency.
DCS goes from 1 W to 0.01W in ten -2dB steps (for same reasons)
GSM goes from 5W to 0.02 W, or usually 2 W to 0.008 W, in 12 -2dB steps.
4.615ms (217 Hz) time frames (basic pulsing frequency)
DECT is like GSM but pulses at 100 Hz and the ouput is fixed at
0.25W peak, 11 mW average power. It does not turn up and down.
NADC (USA) & PDC (Japan) from 0.6 - 0.006 W in five -4dB steps.
20ms (50Hz) time frames (basic pulsing frequency)
CDMA (Qualcom etc) 1W to 0.01 microWatt (!) in 1dB steps (!)
No visible time slots ~ looks like an analogue signal spectrum
ESMR (USA & Japan) 1 to 0.01 W in four -5dB steps
90ms (11Hz) time frames (basic pulsing frequency)
All the main analogue systems (NMT, JTACS, AMPS, ETACS, etc) were FM.
No reports of mental problems with these (eg memory, concentration, etc)
though some suspicion of brain tumour promotion or even cause.
The digital systems are very complicated. As you state GSM (& DCS) gives
off primarily 217 Hz (+ LOTS of harmonics) and has GMSK (Gaussian Minimum
Shift Keying) modulation which actually is a sort of FM put out in time
domain bursts every 4.6ms. Because the transmitters keeps powering off &
off you also get real ELF magnetic field pulses of up to 6 microtesla
(60mG) into the side of the user's head!! (again, 217 Hz + high harmonic
content)
US Digital Cellular (IS-54) is again TDMA this time using quadrature phase
modulation(QPSK). The pulses have a square-root raised cosine spectrum with
35% excess bandwidth.
NADC and PDC use pi/4 QPSK modulation with pulses at 50Hz repetition rate.
ESMR uses 16-QAM modulation. This is a 16 point Quadrature Amplitude
Modulation obtained by separately modulating the amplitude of components of
a sinusoidal carrier differing in phase.
CDMA again uses QPSK but encodes the speech as QCELP resulting in a spread
spectrum signal very similar to an noisy analogue AM signal. This broadcasts
all the time and doesn't have a local ELF pulsing nature.
Iridium uses DEQPSK modulation with time domain pulses every 90 ms!!
(11.1 Hz !!! ugh!!!! brainwave region)
Do you get the feeling, like I do, that I am getting to be "an old fogey",
left behind on the sands of time. Trying to understand what all these
different systems do really makes my brain hurt.
**** And, of course, they are all likely to have DIFFERENT bio-effects!!
Great for confusing the epidemiology so that "no clear pattern" of
health problems emerges!! Hence no "official" and "clear" problem.****
So my advice always is avoid them all!
Good lukck
Alasdair
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alasdair Philips (aphilips@gn.apc.org)
Director, UK Powerwatch,
EMC Engineer and EMF-bioeffects researcher
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
At 04:09 03/02/99 -0600, you wrote:
>
>........Welcome back! Adam...... I welcome you particularly because
>our participation from Sweden seems to have fallen off
>recently....guru....
>
>---------- Forwarded message ----------
>Date: Wed, 03 Feb 1999 10:36:09 +0100
>From: Adam Huuva
>To: rbeavers@llion.org
>Subject: subscribe emf-l
>
>subscribe emf-l
>
>I suppose that wont work. :) Anyway, greetings Guru. I am an old
>subscriber who wants to resubscribe now since we are possibly getting
>DECT-phones at my job. I would like to get the FACTS on those. I hope
>that the emf-l community can help.
>
>Adam Huuva
>Software Engineer
>Interbizz Financial Systems AB
>Luleå, Sweden
>
>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alasdair Philips (aphilips@gn.apc.org)
Director, UK Powerwatch,
EMC Engineer and EMF-bioeffects researcher
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Archive provided courtesy of WaveGuide, http://www.wave-guide.org
Reprinted with permission of Roy Beavers, http://www.feb.se/EMF-L/EMF-L.html