Question

Describe the various signalling techniques. Compare in-channel signalling with common channel signaling, which is more advantageous.

Answer 1

Signaling systems link the variety of switching systems, transmission systems and subscriber equipments in telecommunication network to enable the network to function as a whole.

Three forms of signaling are involved in a telecommunication network:

1. Subscriber loop signaling.

2. Intra exchange or register signaling

3. Interexchange or inter register signaling 

In a telephone network, subscriber loop signaling depends upon the type of a telephone instrument used. The intra exchange signaling is internal to the switching system and is heavily dependent upon the type and design of a switching system .It varies from one model to another even with the same manufacturer. This signaling does not involve signaling system of the type required on the switching network. When interexchange signaling takes place between exchanges with common control subsystems, it is called Inter register signaling. The main purpose of Inter register signaling is the exchange of address digits which pass from exchange to exchange on a link by link basis. Network wide signaling also involves end to end signaling between the originating exchange and the terminating exchange. Such a form of signaling is called line signaling. CCS does not use the speech or the data path for signaling. It uses a separate common channel for passing control signals for a group of trunks or information