cheen said:
If I disable the WIFI card from the device manager, is it truly off?
My concern is the Electromagnetic energy that these cards put off...
new studies show that the amount of energy recieved from the user of a
laptop is very similar
as if you are using a cellphone, because it may be further away than a
cellphone but the duration of use is higher as well
as the frequency of the waves are lower thus they are being absorbed at a
higher rate by the body.
I am talking here about desktop computers with cards, but I would also like
to know if this applies to LAPTOP.
There is increasing concern about the negative effects of the EM waves...
I dont want to debate if there is danger or not since I posted this question
one time again in the past in another newsgroup
but only got wiseguy argumentive or joke responses and no one knew a real
answer.
If you dont know the answer to the question refrain from posting
your own theory about this phenomena please... and no tinfoil jokes please.
This is a serious matter.
so if I disable it from the device manager is the antenna truly off 100%?
THANKS
I found this reference, but don't know what the alternatives would be for
Windows.
http://rfswitch.sourceforge.net/?page=laptop_matrix
"RF Switch type definition:
*Hardware:
A Hardware RF Switch is a switch or toggle button that works by itself and
doesn't need a kernel driver or userspace application to make it work.
*Software
A Software RF Switch is a switch or toggle button that requires a kernel
driver or userspace application to make it work. Some laptops may not have
a specific switch/button but still have the hardware part that controls the
wireless radio state and can still be made to work with software."
The Wifi consists of two parts, Rx and Tx. Rx is the receiver, and the
receiver is listening for Wifi signals from other devices. The energy
level of those other devices would be small, due to distance and attenuation
by walls etc.
The other part is Tx, the transmitter. I cannot find enough info about the
transmitter, to be able to tell you whether it is continuous, or is only
activated when packets are being sent (i.e. whatever protocol is needed to
keep Wifi sessions active). But if you think about it, there are limited
channels, and the channels must be time shared, or otherwise few devices
could share one access point. The implication is, that the transmitter
probably is not active continuously.
Since you are serious, I see two alternatives.
1) Open up the laptop, and unplug the Wifi module. Simple and guaranteed.
2) Open up the laptop, and disconnect the antenna(s). Find and purchase
terminator plugs. This would consist of a resistor, mounted inside a
connector with metal cap. Since the antenna connectors in laptops are
tiny, this project is something you might not want to try yourself.
But if the Wifi is integrated onto the laptop motherboard, and is not
a removable module, then this technique could be an alternative.
The terminator plugs are important, as they convert the RF into heat,
and the resistor impedance has to match the rest of the RF setup, so
there are no reflections. That is better than just trying to short
the thing, which may not yield the results you'd expect.
(In the picture here, you can see how tiny the connectors are, for the two antennas)
(One of two available connectors, is occupied with a cable in this photo)
http://upload.wikimedia.org/wikiped...L-RSMA_pigtail_and_R52_miniPCI_Wi-Fi_card.jpg
(Hirose U.FL connector)
http://en.wikipedia.org/wiki/U.FL
In the first alternative above, there is no need to check whether it is
working. In the second case, you may want to use an external device,
to verify that the "surgery went well".
3) Use a software means to disable RF output. That means, not disabling
the device in Device Manager, but leaving the driver installed. Then,
you use software, to put the radio state in a disabled mode. That is
more deterministic than disabling in Device Manager, and not really
knowing how clever the hardware is. I note in the description of one
Wifi MAC, that it has a processor and firmware in it, so is an
autonomous subsystem. While it could start out, after reset, in a
benign state, I don't know that for sure.
In (2) and (3), you need an external means of determining whether it worked
or not. On the one hand, the market is saturated with cute little Wifi
chips inside a "detector", which is a protocol specific way to measure
RF energy. But if you want to survey the area you are in, for non-specific
RF, then a device like this might be handy. Unfortunately, the
devices I could find here, don't go all the way to 5GHz. For example,
maybe the following device could also detect a leaking microwave oven.
RF Field Strength Meter 0.5Mhz to 3000MHz
http://www.tomsgadgets.com/products/details.aspx?pc=ALRF05-7
Wifi frequencies are listed here.
http://en.wikipedia.org/wiki/IEEE_802.11
Paul
