Wireless roaming aggressiveness

I was wondering if there was anyway to change the aggressiveness of wireless roaming between access points of the same SSID in ubuntu like there is in windows, I often times find that when I walk downstairs in my house that I have an awful wireless signal even though I'm basically next to an access point, so I have a feeling that its not switching access points when I move. I am running ubuntu 12.04 right now.

My understanding is that the sensitivity to Access Point roaming, can be setup using iwconfig;

iwconfig wlan0 sens <value>

On modern cards, this parameter usually controls handover/roaming threshold, the lowest signal level for which the hardware remains associated with the current Access Point. When the signal level goes below this threshold the card starts looking for a new/better Access Point. e.g.

iwconfig wlan0 sens -80
iwconfig wlan0 sens 2

(reference manual)