Telit GM862 GPS United States Pre-paid Carrier Compatibility

Hopefully this will be of use to someone looking into GM862 US Prepaid carrier compatibility. I had some issues with AT&T, and T-Mobile turned out to be my carrier of choice.


My original intention was to use AT&T's 'GoPhone' service. This turned out to be a waste of money.
I purchased AT&T's cheapest prepaid phone, the Samsung SGH-A107, for $15. At the same time I also bought a refill card. After activating the AT&T SIM in the A107, I attempted to connect the GM862 to their network. Unable to successfully connect, I called AT&T and requested that they unlock the SIM. After much rigamaroo, I was unable to connect with the SIM unlocked. While I can't rule out problems with the GM862, it would seem AT&T does not want you doing this.
Forum posts would seem to suggest that activating the SIM in the GM862 would have enabled it to connect instead of the A107. I cannot confirm this.
It is possible to buy an AT&T SIM without the subsidized phone which may work. Again, I cannot confirm this.

My second, and successful choice was T-Mobile's prepaid service. Buying a prepaid SIM (without a phone) was painless and was successful. The GM862 immediately connects to T-Mobile's network and can SMS/Dial without any additional configuration.

GPRS access I haven't fully resolved on T-Mobile. I am able to get an IP address with the below AT commands, but I have not yet confirmed that I can send any data. This is not a limitation of T-Mobile as far as I am aware.
As you may notice, my APN and PDP are seemingly invalid. This setting was found by simply experimenting with different values. The GPRS information listed on T-Mobile's site doesn't seem to work with this module.
As I get more information I will update this.

 AT+CMEE=2  
 OK  
 AT+CGDCONT=1,"IP","","0.0.0.0",0,0  
 OK  
 AT#USERID=""  
 OK  
 AT#PASSW=""  
 OK  
 AT#GPRS=1  
 +IP: xxx.xxx.xxx.xx