16th July 2006 at 03:11
#43285
switch
Guest
Hi Sathya!
12KHz metering pulse or line reversal concept is used only in land line for STD PCO and coin operated PCO.
In landline exchanges between phone and telphone exchange signalling is different.
In GSM, between mobille and MSC is C7 signalling.when ANM message is received call is metured