Do you mean something like this:



Do you mean one of these:


If so, beware that the "USB HSDPA Mocem" probably only has a low purchase price because it is tied to an airtime deal - and the airtime provider will recover the cost from you in fees and charges!

If you you just want something to integrate with an 8051 for SMS only, you should probably be looking at a low-cost, bare module - not an expensive, cased modem like the Maestro.

examples:

http://www.wavecom.com/modules/m.../products/ (note that it is a Wavecom module inside the Maestro)

http://www.telit.com/en/produc...=show&p=10

http://www.sagem-communications.com/index.php...id=921&L=0

You will find a lot of references to Siemens as a module provider - they are now called Cinterion: http://www.cinterion.com/home.html

Note also that you don't need a modem (or, possibly more importantly, a GSM subscription) at the PC end to send the SMS - there are services available (some even free) for sending SMS via an internet connection...