U
U-plane User plane
U-RNTI UTRAN Radio Network Temporary Identity
UARFCN UTRA Absolute Radio Frequency Channel Number
UARFN UTRA Absolute Radio Frequency Number
UART Universal Asynchronous Receiver and Transmitter
UAV Unmanned Aerial Vehicle
UCS2 Universal Character Set 2
UDD Unconstrained Delay Data
UDI Unrestricted Digital Information
UDP User Datagram Protocol
UDUB User Determined User Busy
UDCH User-plane Dedicated CHannel
UE User Equipment
UER User Equipment with ODMA relay operation enabled
UEM operating band Unwanted Emissions Mask
UHD Ultra-High Definition
UI User Interface
Unnumbered Information (Frame)
UIA 3G Integrity Algorithm
UIC Union Internationale des Chemins de Fer
UL Uplink (Reverse Link)
UL-SCH Uplink Shared channel
UM Unacknowledged Mode
UML Unified Modelling Language
UMS User Mobility Server
UMSC UMTS Mobile Services Switching Centre
UMTS Universal Mobile Telecommunications System
UNI User-Network Interface
UP User Plane
UPCMI Uniform PCM Interface (13-bit)
UPE User Plane Entity
UPD Up to date
UpPTS Uplink Pilot Timeslot
UPT Universal Personal Telecommunication
URA User Registration Area
UTRAN Registration Area
URAN UMTS Radio Access Network
URB User Radio Bearer
URI Uniform Resource Identifier
URL Uniform Resource Locator
URLLC Ultra-Reliable Low Latency Communication
USAT USIM Application Toolkit
USB Universal Serial Bus
USC UE Service Capabilities
USCH Uplink Shared Channel
USF Uplink State Flag
USIM Universal Subscriber Identity Module
USSD Unstructured Supplementary Service Data
UT Universal Time
UTRA Universal Terrestrial Radio Access
UTRAN Universal Terrestrial Radio Access Network
UUI User-to-User Information
UUS Uu Stratum
User-to-User Signalling
V
V Value only
V2X Vehicle-to-Everything
VA Voice Activity factor
VAD Voice Activity Detection
VAP Videotex Access Point
VASP Value Added Service Provider
VBR Variable Bit Rate
VBS Voice Broadcast Service
VC Virtual Circuit
VGCS Voice Group Call Service
VHE Virtual Home Environment
VLAN Virtual LAN
VLR Visitor Location Register
VMSC Visited MSC
VoIP Voice Over IP
VPLMN Visited Public Land Mobile Network
VPN Virtual Private Network
VR Virtual Reality
VRB Virtual Resource Block
VSC Videotex Service Centre
V(SD) Send state variable
VTX host The components dedicated to Videotex service
W
WA Wide Area
WAAS Wide Area Augmentation System
WAE Wireless Application Environment
WAP Wireless Application Protocol
WBEM Web Based Enterprise Management
WCDMA Wideband Code Division Multiple Access
WDP Wireless Datagram Protocol
WG Working Group
WGS-84 World Geodetic System 1984
WIM Wireless Identity Module
WIN Wireless Intelligent Network
WLAN Wireless Local Area Network
WLAN UE WLAN User Equipment
WPA Wrong Password Attempts (counter)
WS Work Station
WSP Wireless Session Protocol
WTA Wireless Telephony Applications
WTAI Wireless Telephony Applications Interface
WTDD Wideband Time Division Duplexing
WTLS Wireless Transport Layer Security
WTP Wireless Transaction Protocol
WTX Waiting Time eXtenstion
WWT Work Waiting Time
WWW World Wide Web
X
X2-C X2-Control plane
X2-U X2-User plane
XID eXchange IDentifier
XMAC exXpected Message Authentication Code (calculated by the USIM application in 3G AKA)
XML eXtensible Markup Language
XRES EXpected user RESponse
Y
Null.
Z
ZC Zone Code