Cell Towers

 It is not always easy to know the location of nearby cell towers.

If you need this info here is one link which can help:
All US cell carriers:
http://www.cellreception.com/towers/or one for T-Mobile towers:
http://t-mobiletowers.com/towersearch.as…&zip=90025

AT&T VS T-Mobile Frequency

 T-Mobile

Frequency on UMTS (W-CDMA)/HSPA 3G (not true 4G)
1700 MHz/2100 MHz
Frequency on GSM/GPRS/EDGE 2G
850 MHz and 1900 MHz
http://en.wikipedia.org/wiki/T-Mobile_USA

AT&T
Frequency on UMTS/HSPA 3G
850 MHz/ 1900 MHz
Frequency on GSM/GPRS/EDGE 2G
850 MHz and 1900 MHz
http://en.wikipedia.org/wiki/AT&T_Mobility