What is the frequency of callwaiting in telephone system ?

[haerifar]

callwaiting tone ???

what is the frequency of callwaiting in telephone system ?
and how can i detect it ?
:?: :?:

 

[kang_computer_01]

Re: callwaiting tone ???

you can detect the signal of ringing tone to send to phone so that by PLL

 

[stephen_h]

Re: callwaiting tone ???

what is the frequency of callwaiting in telephone system ?
and how can i detect it ?
:?: :?:

Modern Detection is used by DSP techniques as there will have near-end voice to "jam" the Call waiting FSK signalling.