U-RNTI
UTRAN Radio Network Temporary Identifier
The UE (User Equipment) having an RRC (Radio Resource Control) connection will be allocated a S-RNTI (Serving Radio Network Temporary Identifier). The SRNC (Serving Radio Network Controller) identifier together with S-RNTI is a unique identifier of the RRC connection within a network. The combination of SRNC identifier and S-RNTI is referred to as U-RNTI (UTRAN Radio Network Temporary Identifier), which is used on the radio interface.