How to transmit pin values via gsm systems

Hi everyone! I have a question about MKR GSM 1400 module and generally about gsm communication.

I've figured out that you can transmit pin values via gsm through the following systems:

  • sms
  • DTFM
  • web server / web client communication (GPRS)

But I'm wondering if there is some other system, like "translate" the pin value in a audio signal and send it to the receiver through a simple call (and of course the reverse too).

Or is there any other way?

Thank you!

Is this an academical question or do you have a special purpose in mind?

Ah ah, no, no, I'm not a student... Thank you for replying...
I'm thinking of a remote controlled robot... so, I'm looking for different ways to do it...

I'm thinking of a remote controlled robot... so, I'm looking for different ways to do it...

In that case use GPRS, it's the only suitable way to get enough data to the robot and back in a timely manner.