Default GSM Low Signal In Building

I'm operating on the Chinese Radio and on AT&T's network. In my area the coverage is great. Even in my basement I consistantly have 4bars. Outside 4 bars. In my school, no service - 2bars on 2G! Sometimes I can get 3G. The building has a steel flat roof and concrete walls, but I still had great signal on verizon. Is their any tweaks I could do? My build.prop I will list in a moment.
Galaxy Player 5.0 Running PAC ROM 4.2
Droid 2 Running Stock
Droid 3 Running Stock with Safestrap and Chinese radio for GSM