+me45 at commands pdf
All mobiles, that expose a serial interface, can be expected to support some AT commands. The interesting question is, what type of AT command, e.g. SMS in PDU mode, SMS in text mode, circuits switched data calls, GPRS data connections, TCP/IP sockets? You may want to ask more specific and possibly mention specific mobiles.
I have an Siemens ME45, it supports e.g. PDU SMS, data calls and GPRS and some Siemens specific network monitoring commands.