hello to all...
i am new one here, i hope i would get some real good help here....
i just started experiments with my siemens A65 phone, i connected it to serial port of my PC and and send some AT Commands.
when i send AT, it returs OK.... means connection is working properly, but when i tried to dial a call by ATD command, the phone starts dialing but immediately ends and hyperterminal shows message of NO CARRIER.
i tried it on sony erricson K700i and got the same problem....

please tell me how i make ATD command to work....
Thanks
Bilal