In communications systems, pertaining to communications facilities and services provided to essentially all users in the area served by the system, rather than to one user or to a relatively small number of users, such as a closed user group with outgoing access.

A circuit designated to furnish a communication service to a number of users.

A system of circuits or channels allocated to furnish communication paths between switching centers to provide communication service on a common basis to all connected stations or subscribers. It is sometimes described as a general purpose network. [JP1]

Signaling in which the signaling power of a telephone is supplied by the serving switch.
Note: In common-battery signaling, "talking power" may be supplied by common or local battery.

In multichannel switched networks, a method of transmitting all signaling information for a group of trunks by encoding it and transmitting it over a separate channel using time-division digital techniques.

1. In a multichannel communications system, signaling in which one channel in each link is used for signaling to control, account for, and manage traffic on all channels of the link.
Note: The channel used for common-channel signaling does not carry user information.
2. A signaling method in which a single channel conveys, by means of labeled messages, signaling information… (Read More →)

1. Interference that appears between signal leads, or the terminals of a measuring circuit, and ground.
2. A form of coherent interference that affects two or more elements of a network in a similar manner (i.e., highly coupled) as distinct from locally generated noise or interference that is statistically independent between pairs of network elements.

The ratio of the common-mode interference voltage at the input of a circuit, to the corresponding interference voltage at the output.

1. The voltage common to both input terminals of a device.
2. In a differential amplifier, the unwanted part of the voltage between each input connection point and ground that is added to the voltage of each original signal. Synonym longitudinal voltage.

1. A quality that applies to materiel or systems: (a) possessing like and interchangeable characteristics enabling each to be utilized, or operated and maintained by personnel trained on the others without additional specialized training; (b) having interchangeable repair parts and/or components; (c) applying to consumable items interchangeably equivalent without adjustment.
2. Pertaining to equipment or systems that have the quality… (Read More →)