RF (WiFi) Power Control

Hello, all, and as this still appears to be an active newsgroup:

I have a Dell laptop computer running Win7 Professional that is sharing
an internet connection (via Microsoft Virtual Wifi Miniport Adapter)
with another device. I'm using Chris Pietschmann's "VirtualRouter"
utility that makes this setup easy. Everything's working fine but I'd
like to throttle back the RF power so that this hotspot is very local
(say a couple of feet). Right now the hotspot is usable over a much
longer distance. Does anyone know if this can be easily accomplished?
Thanks for your time and comment. Sincerely,
--
J. B. Wood e-mail:

On 02/20/2018 10:37 AM, KenW wrote:
Power setting is usually in the WiFi adapter settings Control Panel
Device Manager Network Adapters look for Advanced tab


KenW

Hello. and thanks for the tip. I checked the settings for the "DW1501
Wireless-N WLAN Half-Mini Card" network adapter and there are beaucoup
settings/properties listed and I can only guess what they're all for. I
don't see anything specific to RF output power control. Sincerely,

--
J. B. Wood e-mail:

J.B. Wood wrote:
Hello, all, and as this still appears to be an active newsgroup:

I have a Dell laptop computer running Win7 Professional that is sharing an internet
connection (via Microsoft Virtual Wifi Miniport Adapter) with another device. I'm using
Chris Pietschmann's "VirtualRouter" utility that makes this setup easy. Everything's
working fine but I'd like to throttle back the RF power so that this hotspot is very local
(say a couple of feet). Right now the hotspot is usable over a much longer distance.
Does anyone know if this can be easily accomplished? Thanks for your time and comment.
Sincerely,

A couple of things come to mind assuming that there are no power settings:
Use the 5 ghz band only. It has a shorter distance.
Unplug the antennas.

Paul in Houston TX wrote:
J.B. Wood wrote:
Hello, all, and as this still appears to be an active newsgroup:

I have a Dell laptop computer running Win7 Professional that is
sharing an internet
connection (via Microsoft Virtual Wifi Miniport Adapter) with another
device. I'm using
Chris Pietschmann's "VirtualRouter" utility that makes this setup
easy. Everything's
working fine but I'd like to throttle back the RF power so that this
hotspot is very local
(say a couple of feet). Right now the hotspot is usable over a much
longer distance.
Does anyone know if this can be easily accomplished? Thanks for your
time and comment.
Sincerely,

A couple of things come to mind assuming that there are no power settings:
Use the 5 ghz band only. It has a shorter distance.
Unplug the antennas.


You can place an inline attenuator between the mini PCIe card
and the antennas. There are a number of parameters you'd need
to meet, before selecting for purchase. These things can range
from "insanely expensive" to "expensive". In the laptop, size
and orientation would be an issue (there's no room to work in there).

https://www.minicircuits.com/WebStore/Attenuators.html

Making your own attenuators with carbon composition resistors
is good up to about 1GHz. Above 1GHz, the component selection
is going to be "more tricky" (a resistor no longer behaves like
a resistor, but is some kind of RLC circuit - you can use a
network analyzer to make an equivalent ladder network model
from the scan).

The basic topic, and some balanced and unbalanced attenuator
designs, are shown here.

http://www.radio-electronics.com/inf...s-tutorial.php

The attenuator converts the RF to heat, and the package is usually
shielded. As a result, there should not be local RF leakage coming
from the attenuator itself. I can see some bullet-style ones for
sale (unbalanced) but they're probably not going to fit in the
laptop.

The impedance looking into either port on the attenuator, should
be a match for the impedance of the RF circuit. If the mini PCIe
module is 50 ohms, the antennas are 50ohms, the attenuators should
also be 50 ohms "looking into" either port. This keeps the standing
wave ratio low. In addition, when working with RF, you have to be
careful to not put "energy on the shield", which happens unintentionally
with things like ham radio setups. And then you have to deduce from
behavior, just exactly what you did wrong :-) Get out that Ouiji board.

Paul

"J.B. Wood" wrote in message news

Hello, all, and as this still appears to be an active newsgroup:

I have a Dell laptop computer running Win7 Professional that is sharing an
internet connection (via Microsoft Virtual Wifi Miniport Adapter) with
another device. I'm using Chris Pietschmann's "VirtualRouter" utility that
makes this setup easy. Everything's working fine but I'd like to throttle
back the RF power so that this hotspot is very local (say a couple of
feet). Right now the hotspot is usable over a much longer distance. Does
anyone know if this can be easily accomplished? Thanks for your time and
comment. Sincerely,


Setting to a lower power (if possible) will only give you slower speed, more
power, faster speed. Routers are typically designed to negotiate the speed
based on power levels they receive and transmit. So to make it simple,
don't worry that your signal can be seen a few houses away. Just make sure
you are using correct security levels and a good password to join the
network.
--

Bob S.

Paul wrote:
Paul in Houston TX wrote:
J.B. Wood wrote:
Hello, all, and as this still appears to be an active newsgroup:

I have a Dell laptop computer running Win7 Professional that is sharing an internet
connection (via Microsoft Virtual Wifi Miniport Adapter) with another device. I'm using
Chris Pietschmann's "VirtualRouter" utility that makes this setup easy. Everything's
working fine but I'd like to throttle back the RF power so that this hotspot is very local
(say a couple of feet). Right now the hotspot is usable over a much longer distance.
Does anyone know if this can be easily accomplished? Thanks for your time and comment.
Sincerely,

A couple of things come to mind assuming that there are no power settings:
Use the 5 ghz band only. It has a shorter distance.
Unplug the antennas.


You can place an inline attenuator between the mini PCIe card
and the antennas. There are a number of parameters you'd need
to meet, before selecting for purchase. These things can range
from "insanely expensive" to "expensive". In the laptop, size
and orientation would be an issue (there's no room to work in there).

https://www.minicircuits.com/WebStore/Attenuators.html

Making your own attenuators with carbon composition resistors
is good up to about 1GHz. Above 1GHz, the component selection
is going to be "more tricky" (a resistor no longer behaves like
a resistor, but is some kind of RLC circuit - you can use a
network analyzer to make an equivalent ladder network model
from the scan).

The basic topic, and some balanced and unbalanced attenuator
designs, are shown here.

http://www.radio-electronics.com/inf...s-tutorial.php


The attenuator converts the RF to heat, and the package is usually
shielded. As a result, there should not be local RF leakage coming
from the attenuator itself. I can see some bullet-style ones for
sale (unbalanced) but they're probably not going to fit in the
laptop.

The impedance looking into either port on the attenuator, should
be a match for the impedance of the RF circuit. If the mini PCIe
module is 50 ohms, the antennas are 50ohms, the attenuators should
also be 50 ohms "looking into" either port. This keeps the standing
wave ratio low. In addition, when working with RF, you have to be
careful to not put "energy on the shield", which happens unintentionally
with things like ham radio setups. And then you have to deduce from
behavior, just exactly what you did wrong :-) Get out that Ouiji board.

Paul

I was thinking of something easier like a wifi cable with U.FL mini plug on
one end. Cut off what ever is on the other end and let about 1/4 wave stick
out of the shield. That should attenuate the power level.
If still too high power then cut more off of the center lead.
The short piece of cable would stay in the laptop.
Or use the entire cable with SMA plug and keep it all in the laptop.
On my Lenovos it would be easy to do. 10 min at most.

In message , Paul
writes:
[]
You can place an inline attenuator between the mini PCIe card
[wow, this request for "is there a command to reduce the power of my
wifi" question has really got out of hand!]
behavior, just exactly what you did wrong :-) Get out that Ouiji board.

That's Ouija (from the French and German words for yes).

Paul
John
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

I'm the oldest woman on primetime not baking cakes.
- Anne Robinson, RT 2015/8/15-21

In message , Bob_S writes:
"J.B. Wood" wrote in message news

Hello, all, and as this still appears to be an active newsgroup:

I have a Dell laptop computer running Win7 Professional that is
sharing an internet connection (via Microsoft Virtual Wifi Miniport
Adapter) with another device. I'm using Chris Pietschmann's
"VirtualRouter" utility that makes this setup easy. Everything's
working fine but I'd like to throttle back the RF power so that this
hotspot is very local (say a couple of feet). Right now the hotspot
is usable over a much longer distance. Does anyone know if this can
be easily accomplished? Thanks for your time and comment. Sincerely,


Setting to a lower power (if possible) will only give you slower speed,
more power, faster speed. Routers are typically designed to negotiate

If he's talking about a couple of feet range, then even if we do find a
way of reducing the power (I think there's a chance there might be a
setting - probably behind an "advanced" button - in the details of the
adapter in Device Manager), he's still going to show full scale on the
interacting equipment, so I don't think speed will suffer. (I must say
if it's that sort of range I'm wondering why he doesn't use a cable, but
I suppose wireless _is_ more convenient if you want to take one end away
some of the time.)

the speed based on power levels they receive and transmit. So to make
it simple, don't worry that your signal can be seen a few houses away.
Just make sure you are using correct security levels and a good
password to join the network.

In my Device Manager, under Network adapters, I have (as well as
Bluetooth and Gigabit) "Intel(R) Centrino(R) Advanced-N 6200 AGN" and
"Microsoft Virtual WiFi Miniport Adapter" (I imagine the second one
isn't real hardware). If I right-click and select Properties, then
Details, and scroll through the Property list, one of the entries is
Power Data; I don't actually understand what it says there, and I don't
think this is where you can _change_ these settings, but it looks to me
as if there are _capabilities_ to do so within the hardware.

Just for interest, this is what it says (for the Virtual one):

Current power state:
D0

Power capabilities:
0000002B
PDCAP_D0_SUPPORTED
PDCAP_D1_SUPPORTED
PDCAP_D3_SUPPORTED
PDCAP_WAKE_FROM_D1_SUPPORTED

Power state mappings:
S0 - D1
S1 - D1
S2 - D2
S3 - D2
S4 - D3
S5 - D3
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

I'm the oldest woman on primetime not baking cakes.
- Anne Robinson, RT 2015/8/15-21

J. P. Gilliver (John) wrote:
In message , Bob_S writes:
"J.B. Wood" wrote in message news

Hello, all, and as this still appears to be an active newsgroup:

I have a Dell laptop computer running Win7 Professional that is
sharing an internet connection (via Microsoft Virtual Wifi Miniport
Adapter) with another device. I'm using Chris Pietschmann's
"VirtualRouter" utility that makes this setup easy. Everything's
working fine but I'd like to throttle back the RF power so that this
hotspot is very local (say a couple of feet). Right now the hotspot
is usable over a much longer distance. Does anyone know if this can
be easily accomplished? Thanks for your time and comment. Sincerely,


Setting to a lower power (if possible) will only give you slower
speed, more power, faster speed. Routers are typically designed to
negotiate

If he's talking about a couple of feet range, then even if we do find a
way of reducing the power (I think there's a chance there might be a
setting - probably behind an "advanced" button - in the details of the
adapter in Device Manager), he's still going to show full scale on the
interacting equipment, so I don't think speed will suffer. (I must say
if it's that sort of range I'm wondering why he doesn't use a cable, but
I suppose wireless _is_ more convenient if you want to take one end away
some of the time.)

the speed based on power levels they receive and transmit. So to make
it simple, don't worry that your signal can be seen a few houses away.
Just make sure you are using correct security levels and a good
password to join the network.

In my Device Manager, under Network adapters, I have (as well as
Bluetooth and Gigabit) "Intel(R) Centrino(R) Advanced-N 6200 AGN" and
"Microsoft Virtual WiFi Miniport Adapter" (I imagine the second one
isn't real hardware). If I right-click and select Properties, then
Details, and scroll through the Property list, one of the entries is
Power Data; I don't actually understand what it says there, and I don't
think this is where you can _change_ these settings, but it looks to me
as if there are _capabilities_ to do so within the hardware.

Just for interest, this is what it says (for the Virtual one):

Current power state:
D0

Power capabilities:
0000002B
PDCAP_D0_SUPPORTED
PDCAP_D1_SUPPORTED
PDCAP_D3_SUPPORTED
PDCAP_WAKE_FROM_D1_SUPPORTED

Power state mappings:
S0 - D1
S1 - D1
S2 - D2
S3 - D2
S4 - D3
S5 - D3

https://www.intel.com/content/dam/su...markings .pdf

"The device transmit power control (TPC) interface is part of the
Intel PROSet/Wireless WiFi Connection Utility Software.

Operational restrictions for Equivalent Isotropic Radiated Power (EIRP)
are provided by the system manufacturer. Any deviation from the
permissible power and frequency settings for the country of use
is an infringement of national law...
"

So on your Wifi, it's some sort of separate utility or something.

It could show up in a Properties box, but if it was there, you
probably would have spotted it by now.

Paul

In message , Paul
writes:
[]
Operational restrictions for Equivalent Isotropic Radiated Power (EIRP)
are provided by the system manufacturer. Any deviation from the
permissible power and frequency settings for the country of use
is an infringement of national law...
"

I don't _think_ that is _entirely_ correct. Deviation in the direction
of putting out _more_ power than permitted is indeed likely to be
considered naughty; I can't imagine any legislature making it an offence
to put out _less_ power than permitted, though. (At least not
intentionally! Legislatures haven't a great track record on technical
things.)

So on your Wifi, it's some sort of separate utility or something.

It could show up in a Properties box, but if it was there, you
probably would have spotted it by now.

Paul

The OP probably has a different hardware to the one in this (Toshiba)
laptop anyway; I just gave what I see as an example.
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

Radio 4 is one of the reasons being British is good. It's not a subset of
Britain - it's almost as if Britain is a subset of Radio 4. - Stephen Fry, in
Radio Times, 7-13 June, 2003.

J. P. Gilliver (John) wrote:


The OP probably has a different hardware to the one in this (Toshiba)
laptop anyway; I just gave what I see as an example.

But wouldn't it be fun to see what your options are ?

I'm kinda curious what kind of range the adjustment has.

Paul

In message , Paul
writes:
J. P. Gilliver (John) wrote:

The OP probably has a different hardware to the one in this
(Toshiba) laptop anyway; I just gave what I see as an example.

But wouldn't it be fun to see what your options are ?

Yes, but I'm reluctant to play with the wifi on this machine - it seems
robust, unlike that on my XP machine that just died (tended to lose
connection about once a day - a reboot cured it; a "repair" from the
tray icon got to the point "re-enabling wifi hardware" or something like
that, at which point the machine would reset. I never did get to the
bottom of that), and I rather like having wifi that stays up (-:

I'm kinda curious what kind of range the adjustment has.

Me too, in theory.

Paul
John
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

Old professors don't fade away - they just lose their faculties.