How to initiate a conference call?

My GPRS shield is connected to Arduino uno and I am successfully sending AT commands to the shield. Now I want to know how I can initiate a conference call between two numbers. Please respond, if you can manage the AT commands to initiate a conference call. Thanks !

initiate a conference call between two numbers.

A conference call typically involves three or more numbers.

Yes ofcourse. I meant, two numbers other than the number which is already inside the GPRS shield. All I want is this, GPRS shield (has it's own sim) to initiate a conference call. That is to say, the GPRS shield first call a number and if the call is answered then the shield put the current call on hold and initiate another call to other number. If the other number also pick up then merge the callers. IS IT POSSIBLE? Please help if someone know exactly what AT commands will help me do this. Thanks !


Have you talked to your telephone service provider?

I have managed to do so. AT+CHLD = 3 is the command to merge two parties.

Hello Hafij,

That's true? Really? Do you a made conference call with GPRS Shield?

Can you give the example code? I'm trying but i don't made.