Common-channel signaling

In telecommunication, common-channel signaling (CCS), or common-channel interoffice signaling (CCIS), is the transmission of control information (signaling) via a separate channel than that used for the messages, The signaling channel usually controls multiple message channels. In the public switched telephone network (PSTN) one channel of a communications link is typically used for the sole purpose of carrying signaling for establishment and tear down of telephone calls. The remaining channels are used entirely for the transmission of voice messages. In most cases, a single 64 kbit/s channel is sufficient to handle the call setup and call clear-down traffic for numerous bearer (voice and data) channels. The technical alternative to CCS is channel-associated signaling (CAS), in which each bearer channel has a dedicated signaling channel. CCS offers the following advantages over CAS, in the context of the PSTN: Faster call set-up time Greater trunking efficiency due to the quicker set up and clearing, thereby reducing traffic on the network Can transfer additional information along with the signaling traffic, providing features such as caller ID Signaling can be performed mid-call The most common CCS signaling methods in use are Integrated Services Digital Network (ISDN) and Signalling System No. 7 (SS7). ISDN signaling is used primarily on trunks connecting end-user private branch exchange (PBX) systems to a central office. SS7 is primarily used within the PSTN. The two signaling methods are very similar since they share a common heritage and in some cases, the same signaling messages are transmitted in both ISDN and SS7. A CCS network provides signaling message transfer for participating Common Channel Signaling Switching Offices (CCSSOs), databases, and operator systems. It is a packet-switched communication network that allows call control and transaction messages from the voice and data networks to be transferred on communications paths that are separate from the voice and data connections.

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related publications (1)

Related concepts (5)

Related lectures (2)

Public switched telephone network

The public switched telephone network (PSTN) is the aggregate of the world's telephone networks that are operated by national, regional, or local telephony operators. It provides infrastructure and services for public telecommunication. The network consists of telephone lines, fiber optic cables, microwave transmission links, cellular networks, communications satellites, and undersea telephone cables interconnected by switching centers, such as central offices, network tandems, and international gateways, which allow telephone users to communicate with each other.

Multi-frequency signaling

In telephony, multi-frequency signaling (MF) is a type of signaling that was introduced by the Bell System after World War II. It uses a combination of audible tones for address (telephone number) transport and supervision signaling on trunk lines between central offices. The signaling is sent in-band over the same channel as the bearer channel used for voice traffic. Multi-frequency signaling defines electronic signals that consist of a combination of two audible frequencies, usually selected from a set of six frequencies.

Telephone exchange

A telephone exchange, telephone switch, or central office is a telecommunications system used in the public switched telephone network (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers. In historical perspective, telecommunication terms have been used with different semantics over time. The term telephone exchange is often used synonymously with central office, a Bell System term.

Dynamic simulation of regulatory networks using SQUAD

Giovanni De Micheli, Abhishek Garg, Ioannis Xenarios

Background The ambition of most molecular biologists is the understanding of the intricate network of molecular interactions that control biological systems. As scientists uncover the components and the connectivity of these networks, it becomes possible t ...

2007

Explores the capacity and limitations of analog channels in transmitting information effectively.

Covers the design of a practical system to send data over a telephone channel.