Varying signal strength...

Now that I have the means to look at my signal strength, I of course
monitor it. What I've noticed is that it varies... sometimes down to
39 othertimes up to 54. The AP is not moving, the client is not
moving... walls are not moving... so what makes the signal strength
vary?

Thnx

On Thu, 23 Jun 2005 20:03:05 -0400, puzzled186
<(E-Mail Removed)> wrote:

>Now that I have the means to look at my signal strength, I of course
>monitor it. What I've noticed is that it varies... sometimes down to
>39 othertimes up to 54. The AP is not moving, the client is not
>moving... walls are not moving... so what makes the signal strength
>vary?

1. Reflections and multipath cause the reflected signal to either
cancel or reinforce the direct signal causing variations in signal
strength.

2. Interference and marginal signal levels will cause the access point
to slow down the connection speed to reduce error rate. This will
have an effect on indicated signal strength. 39 to 54 out of an
assumed possible 100 is not a very good signal.

When the wavelength of 2.4Ghz is only 12.5mm, it doesn't take much
movement to create reflected changes. The walls are not moving, but
you are and so are metal objects visible through windows and doors.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
# (E-Mail Removed)
# (E-Mail Removed) AE6KS

Jeff Liebermann wrote:

> On Thu, 23 Jun 2005 20:03:05 -0400, puzzled186
> <(E-Mail Removed)> wrote:
>
>>Now that I have the means to look at my signal strength, I of course
>>monitor it. What I've noticed is that it varies... sometimes down to
>>39 othertimes up to 54. The AP is not moving, the client is not
>>moving... walls are not moving... so what makes the signal strength
>>vary?
>
> 1. Reflections and multipath cause the reflected signal to either
> cancel or reinforce the direct signal causing variations in signal
> strength.
>
> 2. Interference and marginal signal levels will cause the access point
> to slow down the connection speed to reduce error rate. This will
> have an effect on indicated signal strength. 39 to 54 out of an
> assumed possible 100 is not a very good signal.
>
> When the wavelength of 2.4Ghz is only 12.5mm, it doesn't take much
> movement to create reflected changes. The walls are not moving, but
> you are and so are metal objects visible through windows and doors.
>
>
My slide rule sez that's 12.5cm. And what about Aether Drift?????

Roby

On Thu, 23 Jun 2005 20:03:05 -0400, puzzled186 <(E-Mail Removed)> wrote:

>Now that I have the means to look at my signal strength, I of course
>monitor it. What I've noticed is that it varies... sometimes down to
>39 othertimes up to 54. The AP is not moving, the client is not
>moving... walls are not moving... so what makes the signal strength
>vary?

People moving.

>Thanks

Barry
=====
Home page
http://members.iinet.net.au/~barry.og

On Fri, 24 Jun 2005 07:14:02 -0400, Roby <(E-Mail Removed)> wrote:

>Jeff Liebermann wrote:
>> When the wavelength of 2.4Ghz is only 12.5mm, it doesn't take much
>> movement to create reflected changes. The walls are not moving, but
>> you are and so are metal objects visible through windows and doors.

>My slide rule sez that's 12.5cm. And what about Aether Drift?????
>Roby

Oops. It was my proof readers day off. Y'er right. It's 12.5cm.
As for Ether Drift, I never touch the stuff during working hours.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

"puzzled186" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
| Now that I have the means to look at my signal strength, I of course
| monitor it. What I've noticed is that it varies... sometimes down to
| 39 other times up to 54. The AP is not moving, the client is not
| moving... walls are not moving... so what makes the signal strength
| vary?

Recall the days of off the air TV? Every time a bus passed or an airplane
flew over the picture would shimmy? Then it was called a ghosts now it's
called multi path but it's the same animal. So long as it does not effect
the performance why worry?

Barry OGrady <(E-Mail Removed)> wrote:
>On Thu, 23 Jun 2005 20:03:05 -0400, puzzled186 <(E-Mail Removed)> wrote:
>
>>Now that I have the means to look at my signal strength, I of course
>>monitor it. What I've noticed is that it varies... sometimes down to
>>39 othertimes up to 54. The AP is not moving, the client is not
>>moving... walls are not moving... so what makes the signal strength
>>vary?
>
>People moving.

Also it might not be true that those other object are not
moving. Given the wavelength of 12.5cm, that means merely a
6.25cm movement will produce *maximum* effect. Obviously it
takes very little movement to produce significant effects.

Over a period of time, things like the temperature change as
direct rays from the sun hit a wall or as the room temperature
varies with a forced air heating system are examples of long
term variations that might not be noticed as changes. Other odd
things too, like opening or closing of doors, people moving
about, or even vehicles being parked in different places just
outside of a building, can all cause multipath variations.

Changes in relative humidity would be another invisible
variable.

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) (E-Mail Removed)

If you can place V shaped card covered in aluminium foil behind the
aerial(s) you will find the signal much steadier. Bending the card in
parabolic shape might be even better.
Regards,
Martin