With the charge pulse ( Gbi , collective unit impulse) in analog to telephone networks information on during a connection incurred costs to the caller transmitted. In its terminal device ( telephone with built-in charge display, independent charge display , long-distance dialing coin operated telephone ), the charge pulse is filtered out of the overall signal transmitted and converted into a corresponding charge display.
- Frequency: In Germany 16 kHz (± 80 Hz), in Austria and Switzerland 12 kHz
- Length: 78 - 170 ms
- Power level: −23 dB (950mV) to +21 dB (950mV), this corresponds to a voltage of approx. 67 mV to 10.7 V.
Metering pulses are handset audible as a quiet and high-frequency beeping or crackling and can by keying transmission problems with fax - and data transmission ( modem result). To avoid these undesirable effects are
- Corresponding filters built into the charge displays
- separate filters available for looping into the line .
- 1 TR 110-1; Technical description of the analog dial-up connections on the T-Net / ISDN of the T-Com; August 2007