Archived from groups: microsoft.public.windows.networking.wireless (More info?)

I am looking for any help and any experiences of any 802.11g roaming
issues; that is any device equipped with a 802.11g card communicating
with Access Points with 802.11g cards. Take in mind that this is in a
facility. The issue with the roaming is that when a device that is
communicating with an Access Point and it is moved down the hall right
under another Access Point the device is still associated with the AP
(Access Point) from where it left and will not associate the other APs
until two minutes have past or until the device is rebooted. This is
not what we want.

Access Points have 802.11g cards from Proxim (I believe originally
Lucent then Orinoco) with latest firmware. The devices using 802.11g
cards are IBM ThinkPad R50 (Model: 18306FU) with XP Pro SP1 using the
IBM 11a/b/g Wireless LAN Mini PCI Adapter with latest driver (no
firmware available), IBM ThinkPad R51 (Model: 288868U) with XP Pro SP1
using the Intel PRO/Wireless 2200BG adapter with latest driver (no
firmware available) and Motion Computing M1400 Tablet PC with XP Tablet
Edition SP1 using the Intel PRO/Wireless 2200BG adapter. Also an IBM
ThinkPad T41 or T42 with XP Pro SP2 using the Intel PRO/Wireless 2200BG
adapter.

Our network engineer had spoke with someone from Proxim and after some
amount of time emailed a possible solution which was a
registry string value named: ScanTimeValid

Proxim default value for ScanTimeValid is: 120000 ms (milliseconds)
which should equate to 120 seconds (2 minutes)

Proxim suggestion was to make the value at 30000 ms which would be 30
seconds

This registry string value is to be put where the wireless adapter is
located in the registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\

expand the Class folder then arrow down the folders that have keys that
look like this example:
{4D36E972-E325-11CE-BFC1-08002bE10318}

and in the right pane you will see at very top in the Name column
things like Windows CE USB Devices, Universal Serial Bus controllers,
etc...until you arrow down and see Network adapters in the right pane.
Expand the key that references the Network adapters and you will see
keys that are numbered 0000, 0002, 0003 and so on. One of these will
list the wireless adapter. You can see string values like DriverDate,
DriverDesc, NameProvider, etc. This is where Proxim says to add the
string value ScanTimeValid and to put the value at 30000.

This helps the roaming issue on the IBM ThinkPad R50 (Model: 18306FU)
using the IBM 11a/b/g Wireless LAN Mini PCI Adapter and I noticed that
more recent drivers actually put the ScanTimeValid string in the
registry but I do not recall the default value (I believe it was 45
seconds). The adapter now switches over to the other Access Points
with no problem.

Adding the ScanTimeValid string value to the devices (IBM ThinkPad R51,
IBM ThinkPad T41 or T42 and Motion Computing 1400 Tablet PC) that use
the Intel PRO/Wireless 2200BG Adapter does not solve the roaming issue.
Our engineer has open tickets to IBM and Intel; IBM has nothing now
and Intel said try their latest driver (Version 9.0.1.9) and not to use
their client software but it has not solved the roaming issue.

Does anyone have this problem, know of it, solved it and can anyone
help?