Mobile Laptop Continuous Connection through wireless network

Hi all,

I have a Dell Latitude D620 running their standard 1390 WLAN b/g
Mini-Card. I am doing some experiments at a college campus that has
complete b/g wireless coverage, this requires me to move to different
locations all over campus with the laptop. I am controlling other
devices over the network through the wireless laptop connection. I
have noticed though that as I move through the campus the laptop
software has a hard time keeping a continuous connection, i.e. as I
move to a new area I would hope that the laptop would start
communicating with the new closest router but it doesn't seem to be
doing that. Everytime I move to a new area I have to tell the driver
to repair my connection which renews my IP, registers the DNS, clears
some other settings, etc etc and then I'm good to go again. Is there
some standard fix for making this an automated process so that my
connection is continually updated and with the proper routers as I
move? Thanks for any suggestions,

Kev

kevin.pavin@gmail.com hath wroth:

>I have a Dell Latitude D620 running their standard 1390 WLAN b/g
>Mini-Card. I am doing some experiments at a college campus that has
>complete b/g wireless coverage, this requires me to move to different
>locations all over campus with the laptop.

Yep. Welcome to the joy of "seamless roaming" and other problems that
the 802.11r standard intends to address.
<http://en.wikipedia.org/wiki/IEEE_802.11r>
The problem is that your client is tenaciously hanging onto a given
access point and will not give up looking for a better signal until
the signal literally goes away for an extended period. That's both a
feature and a curse. You don't want the client scanning for other
conenctions all the time as this is disruptive. However, you also
don't want to have it glued to a lousy signal as you're moving.

Being in a college creates another problem. If you hop from one
access point to another, your authentication may not move with you.
Some Kerberos based authentication systems use the MAC address of the
access point to authenticate the port of entry. If that changes,
you'll also have to re-authenticate. (I found this out the hard way
trying to figure out how to make a wireless web cam run on a college
campus shuttle bus).

>I am controlling other
>devices over the network through the wireless laptop connection. I
>have noticed though that as I move through the campus the laptop
>software has a hard time keeping a continuous connection, i.e. as I
>move to a new area I would hope that the laptop would start
>communicating with the new closest router but it doesn't seem to be
>doing that. Everytime I move to a new area I have to tell the driver
>to repair my connection which renews my IP, registers the DNS, clears
>some other settings, etc etc and then I'm good to go again. Is there
>some standard fix for making this an automated process so that my
>connection is continually updated and with the proper routers as I
>move? Thanks for any suggestions,

The standard 802.11r fix is not ready for prime time. However,
various manufacturers have recognized the problem and implimented
tweaks to the wireless client driver settings to control the level of
tenacity. I know that Intel Proset 10.x, and HP Broadcom 4.x drivers
have these features. I don't know about the Dell 1390. Find the
wireless driver in the Control Panel -> Network window. Look through
the properties and settings for the wireless device. There may be
something useful in there. Also, be sure to record the original
settings as many such drivers have no "reset to defaults" or
indication of what the default values should be. I would be
interested in hearing if the Dell 1390 driver has such a feature.
Since the Dell 1390 is Broadcom 44xx(??) chipset based and the driver
is 4.x, the same feature may be present as in the HP versions.


--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558