signal strength problem for multiple ap's w/ the same essid

[Sven <sr12 duke edu>]

related to multiple AP's: i'm just trying out NM again, forcing the card
in b-mode with at least 4 ap broadcasting in b-mode, all with the same
essid. the signal strengths of the ap's are 
    ...:D2 : Quality=7/94  Signal level=-88 dBm  Noise level=-95 dBm
    ...:CB : Quality=23/94  Signal level=-72 dBm  Noise level=-95 dBm
    ...:27 : Quality=37/94  Signal level=-58 dBm  Noise level=-95 dBm
    ...:E1 : Quality=2/94  Signal level=-93 dBm  Noise level=-95 dBm

iwconfig says
ath0      IEEE 802.11b  ESSID:"xxx"  Nickname:"laptop.localdomain"
          Mode:Managed  Frequency:2.437 GHz  Access Point: ...:27   
          Bit Rate:11 Mb/s   Tx-Power:50 dBm   Sensitivity=0/3  
          Retry:off   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=38/94  Signal level=-57 dBm  Noise level=-95 dBm
          Rx invalid nwid:913  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

and my wireless link monitor says the signal strength is ~80%

but: the NM applet shows only 1 bar, and tells me "Wireless network
connection (24%)"

not quite correct, i would say...

Sven

On Mon, 2005-01-31 at 13:44 -0500, Dan Williams wrote: 
> On Mon, 2005-01-31 at 13:08 -0500, Sven wrote:
> > also, i noticed that in a network environment with many ap's with the
> > same essid NM only shows one entry in the wireless networks - should one
> > not be able to choose between the ap's if one wanted to? but that's just
> > a minor question on the side...
> 
> Unless we're displaying the MAC address too (which we're not going to
> do) it doesn't really make any sense to show multiple access points in
> the menu.  In the future, I hope to be able to pick a certain access
> point based on signal strength, or at least fix card drivers to be able
> to correctly roam to different access points in the same ESSID.  Some
> drivers have private ioctl()s to be able to do that but AFAIK almost all
> cards support that capability.
> 
> The problem with specifying a particular MAC address to associate with
> is that the card can't roam and is locked to that MAC until we change
> it.  Which would be OK, except that scanned quality information is even
> worse than associated AP quality information.  Some drivers (atmel,
> ipw2100) don't even return quality information for scanned access
> points, and other drivers give totally different and inconsistent
> quality levels for scanned access points in relation to the
> noise/max_quality levels they advertise (for example, the currently
> associated AP's quality information returned by SIOCGIWSTATS is
> completely different than the quality information _for that same AP_ as
> returned in the scan list).
> 
> In short, drivers really need to be fixed.
> 
> Dan