2G/3G SIM card

[MZurf]

In the place where I often go on vacation the AIS and DTAC coverage is very poor. Someone told me that True provides a much better coverage but that it had to be 2G, not 3G. I went to 7-11 and wanted to buy a sim card but they only sold 3G cards.

I thought that was something you could change the settings on in your phone but obviously I'm mistaking. Any suggestions?

[RichCor]

An article I just read stated that TrueMove only operated 2G service on the now EXPIRED 1800 MHz Band concession, and 3G Service on 850 and 2100.

It's a bit confusing, as 2G/3G/4G/LTE refers to Internet Data, while GSM refers to VOICE and SMS ability. TrueMove-H 3G SIM cards should still allow GSM (Voice and SMS) communications on 850 MHz and 2100 MHz.

It's possible, if a GSM/2G mobile phone has 850 or 2100 band coverage, that a TrueMove-H 3G SIM would still work but only provide Voice and SMS (GSM) coverage on 850 or 2100 MHz.