U	UE/
U	Unnumbered
U	uplink
UA	UE Application
UA	UE, ATCF
UA	Unnumbered Acknowledge
UA	Unnumbered Acknowledgement
UA	Urban A
UA	User Agent
UAA	User-Authorization-Answer
UAC	Unified Access Control
UAC	User Agent Client
UAC	unified access control
UAN	Universal access number
UAR	User-Authorization-Request
UAS	Uncrewed Aerial System
UAS	Unmanned Aerial System
UAS	User Agent Server
UASSC	Unmanned Aircraft Systems Standardization Collaborative
UAV	Uncrewed Aerial Vehicle
UAV	Unmanned Aerial Vehicle
UB	Upper Bound
UBS	Upper band segment
UCI	Uplink control information
UCI	User CSG Information
UCSC	Uplink Capability Signalling Compression
UDA	User Data Answer
UDA	User-Data-Answer
UDC	User Data Convergence
UDHL	User Data Header Length
UDI	Unrestricted Digital Information
UDM	Unified Data Management
UDM	User Data Management
UDP	User Datagram Protocol
UDR	Unified Data Repository
UDR	User Data Repository
UDR	User-Data-Request
UDR	User-Defined Routing
UDRE	User Differential Range Error
UDUB	User Determined User Busy
UE	User Equipment
UESBI	User Equipment Specific Behaviour Information
UEUT	User Equipment Under Test
UFE	Uplink Frame Error
UFES	UAV Flight Enablement Subsystem
UFI	Unreliable Frame Indication
UFPS	Unique Frequency Parameter Set
UFR	Unreliable Frame Ratio
UHD	Ultra-High Definition
UI	Unconfirmed Information
UI	Unnumbered Information
UI	user interaction
UIA	UMTS Integrity Algorithm
UICC	Universal Integrated Circuit Card
UIL2P	User Info Layer 2Protocol
UIM	Umbrella Information Model
UL	Up Link
ULA	Update-Location-Answer
ULI	User Location Information
ULR	Update-Location-Request
UM	Unacknowledged Mode
UMF	UE Management Function
UML	Unified Modeling Language
UML	Unified Modelling Language
UMTS	Universal Mobile Telecommunication System
UMTS	Universal Mobile Telecommunications System
UNA	Uplink Network Assistance
UNI	User-Network Interface
UNRR	UE-Not-Reachable-Reason
UOCWR	UPT Originating Call without registration
UOM	Umbrella Operation Model
UP	User Plane
UP	user-plane
UPC	Usage Parameter Control
UPE	User Plane Entity
UPF	User Plane Function
UPH	UE Power Headroom
UPSC	UE policy section code
UPT	Universal Personal Telecommunications
UPT	User perceived throughput
UPU	UE Parameter Update
UR	User Rate
URA	UTRAN Registration Area
URCMP	UE Radio Capability Management Protocol
URI	Uniform Resource Identifier
URI	Uniform Resource Identifiers
URL	Uniform Resource Locator
URL	Uniform Resource Locators
URLLC	Ultra Reliable Low Latency Communication
URN	Uniform Resource Name
URR	Usage Reporting Rule
URR	Usage Reporting Rules
URRP	UE Reachability Request Parameter
URSP	UE Route Selection Policies
URSP	UE Route Selection Policy
US	User Status
USC	User Services Core
USD	User Service Description
USF	Uplink State Flag
USF	Uplink State Flags
USF	Uplink state flag
USF	uplink state flags
USI	User Service Interaction
USIM	Universal Subscriber Identity Module
USS	UAS Service Supplier
USS	User Security Setting
USSD	Unstructured Supplementary Service Data
USSD	Unstructured Supplementary Services Data
USSD	unstructured supplementary service data
UT	Universal Time
UT	Upper Tester
UT	Upper test
UTM	UAS Traffic Management
UTRA	Universal Terrestrial Radio Access
UTRAN	Universal Terrestrial Radio Access Network