I have seen that some online shops sell a Samsung Galaxy S3 dual SIM adapter. I haven't found much information about how does it work, but I have doubts about it.
In fact, I have a phone SIM card that I use for calling and receiving with my own number, and sometimes I can get a data SIM card with some free internet traffic.
The idea behind my interest for the dual SIM adapter for th GS3 is to tell the phone to call from SIM 1 and connect to UMTS from SIM 2. My simple doubt is that Android isn't simply supporting 2 cards on phones designed for 1.
I mean, if my phone had natively 2 SIM slots I could expect a menu option "default call with SIM 1/2", or "which SIM do you want to connect with?", but the official specs of GS3 offer 1 SIM only as standard cell phones.
The question is, then
How does a dual SIM adapter integrate with existing phone software?