Call signaling
A call signaling signals a current call to a B-subscriber . As a rule, it takes place during an incoming telephone call in the telephony or in the case of an incoming call in digital radio .
species
In telecommunications, it takes place by means of sound and / or light signals and / or vibration alarms . The sound signals are ring tones , the light signals are generated by LEDs in or on the device (accessories). The accessory reacts to vibrations in the area around the phone when making calls, provided the phone is ready to receive. It must be in close proximity to the phone.
These functionalities are device and network dependent . Very different types of signaling are possible, especially in mobile communications . Here the notification via vibration or light signal is very discreet, while loud ring tones attract everyone's attention and can thus disturb others. As with radio data transmission (e.g. digital selective calling in maritime radio ), impulses are also sent that can trigger a signal to the receiver.
requirements
Call signaling in telephony is basically dependent on the functionality and programming of the telephone terminal of the B-subscriber. The signaling is also dependent on both the activated user profile and the caller group , the latter only if this is supported and the number is transmitted .
Caller side
The A-subscriber (caller) is usually informed in public telephone networks about the call signaling taking place at the network termination of the B-subscriber telephone connection by a ringing tone . Similar to the ring tones, the B-subscriber can have his network operator underlay the ringing tone for the caller with pieces of music, so-called dial tone tones , for a fee .
A ringing tone transmitted to the caller can also only be simulated if there is a false answer supervision .
literature
- Werner Bärwald: Expert practice lexicon communication technologies. Networks - Services - Applications, Expert Verlag, Renningen 2009, ISBN 978-3-8169-2843-0 .