Key held only by one crypto-equipment and its associated distribution center.

In the representation of a character, a signal element that has a duration equal to the unit interval.

A mathematical artifice consisting of an impulse of infinite amplitude and zero width, and having an area of unity.
Note: The unit impulse is useful for the mathematical expression of the impulse response, i.e., the transfer function, of a device. Synonym Dirac delta function.

In isochronous transmission, the longest interval of which the theoretical durations of the significant intervals of a signal are all whole multiples.

An unweighted code that changes at only one digit position when going from one number to the next in a consecutive sequence of numbers.
Note 1: Use of one of the many unit-distance codes can minimize errors at symbol transition points when converting analog quantities into digital quantities.
Note 2: An example of a unit-distance code is the Gray code.… (Read More →)

A digital loop carrier (DLC) that uses a central office terminal (COT). [T1.216-1998]

A telecommunications service that provides personal mobility and service profile management.
Note 1: UPT service involves the network capability of identifying uniquely a UPT user by means of a UPT number.
Note 2: The general principles of UPT are given in ITU-T Recommendation F.85
0.
Note 3: UPT and PCS are sometimes mistakenly assumed to be the same service concept.… (Read More →)

Synonym UPT number.

The concept of making basic local telephone service (and, in some cases, certain other telecommunications and information services) available at an affordable price to all people within a country or specified jurisdictional area.

1. The basis for coordinated dissemination of time signals, counted from 0000 at midnight.
2. In celestial navigation applications, the time which gives the exact rotational orientation of the Earth obtained from UTC by applying increments determined by the U. S. Naval Observatory.
3. A measure of time that conforms, within a close approximation, to the mean diurnal rotation of… (Read More →)