Cell phone antenna boosters
Interesting what you are saying about your t-mobile device. You should have it checked out. GSM is supposed to give superior signal coverage over regular cell phones. unless you live right outside of a coverage area.
I don't see why your wireless broadband would effect your cell. Wireless broadband is line of site (i think) which basically means your antenna is pointed right at another antenna that is feeding it the signal.
oh well, its 10:20 and i still haven't finished my first cup of coffee....