What US plans are people using?

Michael Shiloh michael at openmoko.org
Thu Apr 24 10:03:13 CEST 2008

I have a further question, perhaps best for someone who knows something 
about how the cellphone system operates:

I notice that with my T-Mobile SIM card, my GTA01 camps on the "home" 
network, but my AT&T card shows "roaming".

Is it possible that in roaming mode, the system keeps scanning and tries 
to connect on the home network? Would this explain the "oscillation" 
problem that Sean Chiang describes?


ian douglas wrote:
> Rivera wrote:
>> How do you tell which band the phone is currently connecting to?
> Someone stated in the last day or so that there's an AT command you can 
> send to the Neo's modem to tell which service.
>> how did you know the Blackjack 2 would only connect to the lower freq?
> The basis of my assumption is that only the higher-power 850MHz 
> frequency could make it through/around the concrete of our old apartment 
> building, especially since the Neo could not connect indoors on AT&T 
> whatsoever, but my Blackjack 2 could connect all the time, no matter 
> what. Also, the radio signal from the Blackjack 2 would cause any 
> speakers (computer, radio, tv) to buzz VERY loudly at the old apartment, 
> but at the new apartment where it shows me the 3G icon all the time 
> instead of the EDGE icon, it doesn't buzz any of our speakers even a 
> tiny bit.
> I don't know if there's any correlation between only seeing the EDGE 
> icon appear on my Blackjack 2 while indoors at the old apartment and 
> having the phone switch to 3G while outside as to which frequency I was 
> connecting on. I see from one source that EDGE can work on both 850MHz 
> and 1900MHz, the two frequencies used by AT&T, so perhaps I am still a 
> bit confused about it. I guess I thought EDGE only used 850MHz and 3G 
> was 1900MHz but I see from online documentation that that's not correct.
> -id
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