U - U (Unnumbered Information)LLC (Logical Link Control) U (Unnumbered Information) frames can be sent in both ADM (Asynchronous Disconnected Mode) and ABM (Asynchronous Balanced M... View more
U - U interfaceA user to network interface reference point that is characterized by the use of a 2 wire loop transmission system that conveys information between the... View more
U-CSIU-CSI - USSD – CAMEL Subscription InformationThe U-CSI contains trigger information which is used to invoke a USSD application in the CSE for CAMEL served subscribers. ... View more
U-RNTI - UTRAN Radio Network Temporary IdentifierThe UE (User Equipment) having an RRC (Radio Resource Control) connection will be allocated a S-RNTI (Serving Radio Network Temporary Identifier). The... View more
U/L - UplinkThe portion of a communications link used for the transmission of signals from a mobile to a base station or satellite. An uplink is the converse of a... View more
UA - Unnumbered AcknowledgementUnnumbered Acknowledgement encoding is used as a response only. It is used to positively acknowledge a SABM (Set Asynchronous Balance Mode) or a disco... View more
UA Channel - User Asynchronous data ChannelIn Bluetooth the UA (User Asynchronous data) Channel is used to carry L2CAP (Logical Link Control and Adaptation Protocol) transparent asynchronous us... View more
UAC - User Agent ClientThis is a SIP (Session Initiation Protocol) term for a function that performs client functionality. That is it generates a request which in turn is se... View more
UAN - Universal Access NumberThis service allows a subscriber to publish a national number and have the incoming calls routed to different destinations based on various criteria s... View more
UAPSD - Unscheduled Automatic Power Save DeliveryThe term U-APSD is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. It was introduced in order to support power m... View more
UARFCN - UMTS Absolute Radio Frequency Channel NumberThe carrier frequency is designated by the UTRA Absolute Radio Frequency Channel Number. The value of the UARFCN in the IMT2000 (International Mobile ... View more
UAS - User Agent ServerThis is a SIP (Session Initiation Protocol) term for a function that performs server functionality. That is it responds to a request made by a SIP UAC... View more
UCRP - Unique Challenge Response ProcedureA procedure by which the MS (Mobile Station) and the BS (Base Station) exchange information to confirm the mobile's identity. The procedure is initiat... View more
UDC - Unified Data ConvergenceUDC is a 3GPP initiative which seeks to rationalize the databases found across the key mobile technologies such as 2G, 3G, 4G, 5G and IMS. The general... View more
UDI - Unrestricted Digital InformationThis is an ISDN (Integrated Services Digital Network) term to describe the ability to transfer any bit pattern over a digital channel. ... View more
UDM - Unified Data ManagementThe Unified Data Management is related to the 3GPP 5G Architecture. This supports the ARPF (Authentication Credential Repository and Processing Functi... View more
UDP - User Datagram ProtocolUDP is a lightweight Transport Layer protocol, providing source and destination port addressing for the multiplexing/demultiplexing of higher layer ap... View more
UDR - Unified Data RepositoryThe UDR is a converged repository of subscriber information and can be used to service a number of network functions. For example, the 5G UDM (Unified... View more
UDSF - Unstructured Data Storage FunctionIn 5G, the UDSF supports data storage for stateless network functions. That is, rather than a given network function holding its own storage resources... View more
UDT - UNITDATAThe basic message of connectionless SCCP (Signalling Connection Control Part) is the UDT (UNITDATA) message. When SCCP detects that a destination for ... View more