Architectural reference model is specified in
clause 4.2.1,
4.2.2,
4.2.3, and
4.2.7 of
TS 23.304.
In addition to the architectural reference model specified in
TS 23.304, the architectural reference model shall support the functional entity 5G ProSe Key Management Function (5G PKMF) which is the logical function handling network related actions required for the key management and the security material for discovery of a 5G ProSe UE-to-Network Relay by a 5G ProSe Remote UE, and for establishing a secure PC5 communication link between a 5G ProSe Remote UE and 5G ProSe UE-to-Network Relay.
The 5G ProSe Remote UE and the 5G ProSe UE-to-Network Relay know from which 5G ProSe Key Management Function(s) to get the needed discovery security materials for protecting discovery messages and UP-PRUK(s) for establishing a secure PC5 link between the 5G ProSe Remote UE and the UE-to-Network Relay as the address of the 5G PKMF(s) is either pre-provisioned or provided by the 5G DDNMF (or the PCF) in the HPLMN of the 5G ProSe Remote UE to the 5G ProSe Remote UE, and by the 5G DDNMF (or the PCF) in the HPLMN of the 5G ProSe UE-to-Network Relay to the 5G ProSe UE-to-Network Relay.
The 5G PKMF interacts with the 5G ProSe-enabled UE using procedures over PC8 reference point defined in
clause 4.2.2. The protection for the key request/response messages are described in
clause 5.2.5.
The 5G PKMF of the 5G ProSe Remote UE shall request the discovery security materials from the 5G PKMFs of the potential 5G ProSe UE-to-Network Relays from which the 5G ProSe Remote UE gets the relay services.
The 5G PKMF of the 5G ProSe UE-to-Network Relay shall request the security materials (e.g. Knrp and Knrp freshness parameter) from the 5G PKMF of the 5G ProSe Remote UE for PC5 communication.
In addition to the architectural reference model specified in
TS 23.304, the architectural reference model shall support the functional entity Prose Anchor Function (PAnF) which is the logical function handling network related actions required for the key management and the security material for establishing a secure PC5 communication link between a 5G ProSe Remote UE and 5G ProSe UE-to-Network Relay over Control Plane.
The PAnF shall store the Prose context info (i.e. SUPI, RSC, CP-PRUK, CP-PRUK ID) for a 5G ProSe Remote UE.
The PAnF interacts with AUSF using procedures over Npc11 reference point defined in
clause 4.2.2. The PAnF interacts with UDM using procedures over Npc12 reference point defined in
clause 4.2.2.