1. A numeric code assigned by the North American Numbering Plan (NANP) Administrator for the provisioning of selected switched services. The numeric code is unique to each entity and is used by the telephone company to route the call to the trunk group designated by the entity to which the code was assigned. [FCC]
2. A 4-digit code that controls… (Read More →)

The carrier remaining after carrier suppression in a suppressed carrier transmission system.
Note: Sometimes the residual carrier is used to provide the reference for an automatic frequency control system.

The level of a carrier signal at a specified point in a communications system.
Note: The carrier level is usually expressed in dB relative to a specified reference level.

See frequency-division multiplexing.

The noise level resulting from undesired variations of a carrier in the absence of any intended modulation. Synonym residual modulation.

1. The average power supplied to the antenna transmission line by a transmitter during one radio frequency cycle taken under the condition of no modulation. [NTIA] [RR]
Note: The concept does not apply to pulse modulation or frequency-shift keying.
2. The average unmodulated power supplied to a transmission line.

A code that identifies whether the caller dialed the elected or chosen carrier and whether the caller presubscribed to the elected or chosen carrier. [T1.667-1999]

In a local area network, an ongoing activity of a data station to detect whether another station is transmitting.

A network control scheme in which a node verifies the absence of other traffic before transmitting.

A network control protocol in which (a) a carrier sensing scheme is used, (b) a data station that intends to transmit sends a jam signal, (c) after waiting a sufficient time for all stations to receive the jam signal, the data station transmits a frame, and (d) while transmitting, if the data station detects a jam signal from another station,… (Read More →)