Bangkok Sim Card for data roaming

[kktk]

Originally Posted by inquisitor

You don't necessarily need to buy the device from the operator which you intend to use. Just make sure it's unlocked and supports the required 3G frequency.

What they run on 900 MHz is a UMTS network, which sometimes is also designated as "WCDMA", "HSPA" or "3G" and in the US such networks are even considered "4G" once they support very high speeds using HSPA technology.
GSM in contrast is the predecessor standard that is also called "2G". UMTS evolved from the GSM standard, that's why UMTS devices are always backwards compatible to GSM.

Both are incompatible with the American CDMA/EV-DO standard which is also called "3G".

2G, 3G and 4G are rather non-technical terms that describe the 2nd, 3rd and 4th generation of radio standards which are not necessarily compatible with each other.

Perfect...thanks. The one listed on the AIS website only offers 7.2 Mbps/s.
I found a few more that support 21 Mbps/s here:
???????????? 3G Router ???? ??? ??? ???? ??? ??????? ????

I'll try and get one of these assuming that they are unlocked and can utilize some of the 42Mbps speeds being offered by AIS or TOT?

As far as the sim for the cell goes--it seems like both AIS or TOT would work as AIS would give me 3g on 900 and TOT on 2100(both which the Nexus S supports).

Anyone have real world experience with which of these services truly have good coverage at those speeds? I plan to stay in Bangkok throughout with little or no travel to other parts of the country.