Beyond the 5 bars...just what do they mean?

Oftentimes in a user provided machine environment (wifi hotspots and public
access areas), all support staff have to go on as a start are the mystical "5
bars" that Windows XP SP2 displays to represent the wireless connection
quality. However, despite countless search attempts, I have yet to find a
decent guide on what exactly the 5 bars mean, beyond the obvious text notes
at each level, here's what I'd like to know:

When does Windows decide when your connection is Excellent, Good, Low,
Terrible, etc?

How does Windows decide this, is it through driver information, or an
internal mechanism in Windows based on packet stats?

At what point does Wireless Zero Config start looking for other APs to jump
to in an Infrastructure environment? How much of this is determined at the
Windows/WZC level vs. the driver level?

What are some none-invasive client side checks (read: enabling WZC Tracing
is not an option) that can be from their end to give a quick report on their
connection health?

Thanks in advance for any and all tips on this matter.

On Fri, 15 Jun 2007 20:57:00 -0700, 80211FoilHat
<(E-Mail Removed)> wrote:

>
>Oftentimes in a user provided machine environment (wifi hotspots and public
>access areas), all support staff have to go on as a start are the mystical "5
>bars" that Windows XP SP2 displays to represent the wireless connection
>quality. However, despite countless search attempts, I have yet to find a
>decent guide on what exactly the 5 bars mean, beyond the obvious text notes
>at each level, here's what I'd like to know:
>
>When does Windows decide when your connection is Excellent, Good, Low,
>Terrible, etc?
>
>How does Windows decide this, is it through driver information, or an
>internal mechanism in Windows based on packet stats?
>
>At what point does Wireless Zero Config start looking for other APs to jump
>to in an Infrastructure environment? How much of this is determined at the
>Windows/WZC level vs. the driver level?
>
>What are some none-invasive client side checks (read: enabling WZC Tracing
>is not an option) that can be from their end to give a quick report on their
>connection health?
>
>Thanks in advance for any and all tips on this matter.

Zero Bars = No Signal.
Five Bars = Lots of signal.
Three Bars = Some Signal.

Want objective metrics? Get NetStumbler or a similar product. Forget about WZC
or any vendor supplied WiFi client.
<http://nitecruzr.blogspot.com/2006/06/analyse-your-wifi-environment.html>
http://nitecruzr.blogspot.com/2006/0...vironment.html

--
Cheers,
Chuck, MS-MVP [Windows - Networking]
http://nitecruzr.blogspot.com/
Paranoia is not a problem, when it's a normal response from experience.
My email is AT DOT
actual address pchuck mvps org.

Hi
he bars are just a general indicator to a presence of a signal.
The way it is implemented in End-Level Wireless services is actually double
nothing.
1. Because there is No precise quantitative standard that they related to.
2. Signal strength in general is Not a good measure to the quality of the
Signal.
Why? see here, http://www.ezlan.net/wbars.html
Jack (MVP-Networking).

"80211FoilHat" <(E-Mail Removed)> wrote in message
news:CD90882A-12D7-46E0-A9FB-(E-Mail Removed)...
>
> Oftentimes in a user provided machine environment (wifi hotspots and
> public
> access areas), all support staff have to go on as a start are the mystical
> "5
> bars" that Windows XP SP2 displays to represent the wireless connection
> quality. However, despite countless search attempts, I have yet to find a
> decent guide on what exactly the 5 bars mean, beyond the obvious text
> notes
> at each level, here's what I'd like to know:
>
> When does Windows decide when your connection is Excellent, Good, Low,
> Terrible, etc?
>
> How does Windows decide this, is it through driver information, or an
> internal mechanism in Windows based on packet stats?
>
> At what point does Wireless Zero Config start looking for other APs to
> jump
> to in an Infrastructure environment? How much of this is determined at the
> Windows/WZC level vs. the driver level?
>
> What are some none-invasive client side checks (read: enabling WZC Tracing
> is not an option) that can be from their end to give a quick report on
> their
> connection health?
>
> Thanks in advance for any and all tips on this matter.
>
>
>

It's all relative, free to interpretation, but
in most states and DC its

0 bars : Wrong town
1 : -82 dBm or weaker
2 : -76 to -81
3 : -68 to -75
4 : -59 to -67
5 : better than -58 dBm (-50 dBm could be considered ideal)
6+ : 0.08% BAC or higher

http://en.wikipedia.org/wiki/DBm has a table
of relative levels.

A typical wi-fi spec may show that the device
can work at up to (down to), say, -90 dBm,
though usually at its slowest rate, measured
against a given bit error rate (BER) of 8%.
By then, though, the level has gone lower
and you've already lost the signal.

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