name: U2U
full_form: UE-to-UE
context: 4a.The U2U Relay sends a U2U Key Request message that contains Source UE ID, RSC, Knrp freshness parameter 1 to its 5G PKMF, indicating that the U2U Rely is requesting the Knrp between the Source UE and U2U Relay. 4b. Once receiving the U2U Key Request message, the 5G PKMF of U2U Relay checks if the U2U Relay is authorized to provide U2U Relay service. If the U2U Relay is authorized, the 5G PKMF of U2U Relay sends the U2U Key Request to the 5G PKMF of the Source UE, which may contain the Source UE ID, RSC and the Knrp freshness parameter 1. Once receiving the U2U Key Request message, the 5G PKMF of Source UE identifies the PRUK of Source UE based on the received Source UE ID, then generates Knrp freshness parameter 2 and derives Knrp as specified in TS 33.503 [6]. The 5G PKMF of Source UE sends a U2U Key Response message that contains Knrp and Knrp freshness parameter 2. Note 5: It is not addressed in the present document about how PKMF discovers each other based the Application layer
description: The U2U interface refers to the communication pathway between two User Equipments (UEs) for UE-to-UE relay services. It enables secure key exchange and authentication.
explanation: The term 'U2U' describes a direct connection and data transfer path between two User Equipments, which aligns with the definition of an interface in telecommunications.
section_title: 6.20.2	Solution details
biotag_Context: O,B-Connection,O,O,O,B-Connection,O,O,O,O,O,O,B-Device,O,O,O,O,O,O,O,O,B-Technology,O,O,O,O,B-Connection,O,O,O,O,O,O,O,O,B-Device,O,B-Connection,O,O,O,O,O,B-Connection,O,O,O,O,B-Technology,B-Network Function,O,B-Connection,O,O,O,O,B-Connection,O,O,O,O,O,B-Connection,O,O,O,O,B-Connection,O,O,O,O,B-Technology,B-Network Function,O,B-Connection,O,O,O,B-Connection,O,O,O,O,B-Technology,B-Network Function,O,O,O,O,O,O,O,O,O,B-Device,O,B-Parameter,O,O,O,O,O,O,O,O,O,B-Connection,O,O,O,O,B-Technology,B-Network Function,O,O,B-Device,O,O,B-Parameter,O,O,B-Device,O,O,O,O,O,B-Device,O,O,O,O,O,O,O,O,O,O,O,O,O,B-Specification,O,O,O,B-Technology,B-Network Function,O,O,B-Device,O,O,B-Connection,O,O,O,O,O,O,O,O,O,O,O,O,O,O,O,O,O,O,O,O,O,O,O,B-Network Function,O,O,O,O,O,O,O
biotag_Description: O,B-Connection,O,O,O,O,O,O,O,O,B-Device,I-Device,O,O,B-Connection,O,O,O,O,O,O,O,O,O