For basic-rate access in an Integrated Services Digital Network (ISDN) environment, a user-to-network interface reference point that is characterized by the use of a 2-wire-loop transmission system that (a) conveys information between the 4-wire user-to-network interface, i.e., the S/T reference point, and the local exchange, (b) is located in the servicing central office, and (c) is not as distance sensitive as a service using a T interface.

The conceptual reference point at the network side of the network termination 1 (NT1) in a particular ISDN access arrangement. [T1.615-1992] [T1.105-1988]

Universal Description, Discovery, and Integration

User Datagram Protocol

1. User Equipment, 2. User Element.

Abbreviation for ultra high frequency. See electromagnetic spectrum.

User Interface

Universal Integrated Circuit Card

unsigned integer, most significant bit first

Abbreviation for ultra low frequency. See electromagnetic spectrum.