An area not included in the subscribed service. An area may be defined in terms of a state/province, NPA, LATA, etc. [T1.207-1998]

Emission on a frequency or frequencies immediately outside the necessary bandwidth which results from the modulation process, but excluding spurious emission. [NTIA] [RR]

In encryption, notification using a communication means other than the primary communication means. [After X9.49]

1. Signaling that uses a portion of the channel bandwidth provided by the transmission medium, e.g., the carrier channel, which portion is above the highest frequency used by, and is denied to, the speech or intelligence path by filters.
Note: Out-of-band signaling results in a lowered high-frequency cutoff of the effective available bandwidth.
2. Signaling via a different channel (either… (Read More →)

The time during which frame alignment is effectively lost.
Note: The out-of-frame-alignment time includes the time to detect loss of frame alignment and the alignment recovery time.

Signaling performed in digital time slots that are not within the channel time slot.

A telecommunications system service condition in which a user is completely deprived of service by the system.
Note: For a particular system or a given situation, an outage may be a service condition that is below a defined system operational threshold, i.e., below a threshold of acceptable performance. See outage threshold.

That period of time between the onset of an outage and the restoration of service.

The probability that an outage will occur within a specified time period.

The sum of all the outage durations divided by the time period of measurement.