I found this @ XDA....
1. In the phone dialpad press: *#*#4636#*#*
2. Press Phone Information
3. In the upper right hand corner, press the (ICS) Menu icon
4. Choose "Select radio band"
5. Switch it to Cellular (800-Mhz Band)
6. I immediately start roaming, test calls completed
**BOOST YOUR SIGNAL STRENGTH** [YMMV] bar = ucwords - xda-developers