GSM roaming question

[Al Johnson]

On Tuesday 29 September 2009, Mikhail Umorin wrote:
> Hello --
>
> I cannot access network in certain locations (in Texas, USA) on my FR using
> ATT SIM card. However, when I use the same SIM in the ATT GoPhone that came
> with the card, I have access to a network. "Operators" button in the phone
> settings in SHR-U shows only "Automatic" and "T-Mobile".
>
> So, is this roaming problem a bug? misconfiguration? not implemented? not
> possible?

It could be as simple as the GoPhone being more sensitive than the Freerunner. 
Which network does the GoPhone connect to?

The Freerunner should default to Automatic mode. You can find this if you 
press the Modem information button in the settings app and scroll down a 
little. It should also tell you the network it's registered with (if any) and 
whether it's your home network or not. Signal strength should be in there too 
with more detail than bars/blobs.

Automatic mode means the gsm firmware is in control of which network it 
registers to. This should be the home network if available, or any other 
allowed network if not. There is an AT command to list the order of preference 
for picking other networks, but I don't remember what it is, or whether it is 
provided by the SIM. It's not something you should normally need to touch 
though.

If it says "T-Mobile" instead of "T-Mobile [forbidden]" you should be able to 
click on it to register with T-Mobile. I don't know enough about the US GSM 
market to know if this is likely though.