I have a 3G modem, and have tried it's sim card in a couple different modens with success.
However, I tried to put in on my Nexus S and use wifi tether, but it didn't work - although it seemed to have network signal, the data was not working. My guess was it misses the authentication part (for each different modem I tried, I had to add the operator's credentials).
I was wondering how do I configure my smartphone so it would act like a modem?
I have a Nexus S
with Android 4.1.1