SDIO WiFi roaming in iPAQ 6515

[fshguo]

Hi...We have about 20 iPAQ 6515 with Ambicom WLAN-11 WiFi card running in a multiple Colubris Access Point envrionment. We are having an issue of the roaming, we experience some difficulties for the SDIO WiFI card to roam to next access point which has better signal, it only roams when the signal strength is very low or even down to 0%, this ends up the application running on pocket IE times out or gets the error message. Not to mention we plan to run voice over IP on this device.

Is there a way to control or set the WLAN-11 card to roam (jump to the better AP) at a higher signal strength or quality?

Note. the APs are configured the same SSID, WPA-PSK with different channels.

Thanks,
fshguo.