U

UART

Universal Asynchronous Receiver - Transmitter

UDP

User Datagram Protocol (layer 4)

UHF

Ultra High Frequency (300-3000 MHz)

UIT

Union Internationale des T‰l‰communications (ITU - Genˆve)

UJT

UniJunction Transistor

UL

Underwriters Laboratories (USA)

ULS

User Location Service

UMTS

Universal Mobile Telecommunications System

UNI

User to Network Interface

UPC

Universal Product Code (bar code)

UPS

Uninterruptible Power Supply

UPS

United Parcel Service (USA)

UPT

Universal Personal Telecommunications

URL

Universal Resource Locator (Internet)

USAT

Ultra-Small Aperture Terminal

USB

Universal Serial Bus (Intel)

USD

United States' Dollar

USDC

United States' Digital Communications

UT

Universal Time

UTC

Universal Time Coordinated

UTE

Union Technique de l'Electricit‰ (Paris)

UTP

Unshielded Twisted Pair (Ethernet)

UUCP

Unix to Unix Copy Protocol

UV

UltraViolet