3g Phones And 2g Sim Cards

[endure]

Does anyone know if a 2G SIM card will work OK in a network unlocked 3G phone?

[cdnvic]

I've taken 2g phone sim cards and put them in 3g phones before without a problem. Don't know if it'll work the other way.

[monty]

As long as you don't mix up systems it'll work!

Two main systems are the CDMA network and the GSM network. Both have their 3G offerings (CDMA2000 EV-DO and UMTS respectively)...

Since these two systems are technically pretty different, very few phones can handle both. There are some, but I doubt they are 3G capable...

[lomatopo]

For a definitive answer it would help to know the make and model number of the phone and the service provider for the SIM.

For Thailand if the phone supports GSM900 then a local SIM would work fine.

My phone supports GSM900/1800/1900 and WCDMA2000 (3G). I use a 1-2-Call pre-paid SIM here in Thailand successfully, and a T-Mobile pre-paid SIM in the U.S.A. successfully, and can ride on Vodafone's 3G network in Japan.

[bazmlb]

are there any plans for 3g to become available in thailand or are they going to wait for the 4g offering with the faster mobile data speeds

[astral]

Two main systems are the CDMA network and the GSM network. Both have their 3G offerings (CDMA2000 EV-DO and UMTS respectively)...

Nokia N series handles both.