how does phones select the wi-fi when they roam to one Access point to another.

[AC Question]

iOS devices use -70dBm as a thereshold to trigger the roaming and check if the other access point is 8dB stronger or not? How does Android device do handoff..

 

[Rukbat]

That's in the modem firmware, and I doubt very many people (if any - I could but haven't) on this site have analyzed it down to that level. Why don't you try your device's forum on XDA Forums? Some of those devs play with Android source like toys.