Any 5G ProSe-enabled UE may support the following functions:
Exchange of information for 5G ProSe Direct Discovery between 5G ProSe-enabled UE and the 5G DDNMF over PC3a reference point.
Procedures for 5G ProSe Direct Discovery of other 5G ProSe-enabled UEs over PC5 reference point.
Procedures for 5G ProSe Direct Communication over PC5 reference point, including Broadcast, Groupcast and Unicast mode 5G ProSe Direct Communication.
Procedures to act as a 5G ProSe Layer-2 UE-to-Network Relay.
Procedures to act as a 5G ProSe Layer-3 UE-to-Network Relay.
Procedures to act as a 5G ProSe Intermediate UE-to-Network Relay.
Procedures to act as a 5G ProSe Layer-2 Remote UE.
Procedures to act as a 5G ProSe Layer-3 Remote UE.
Procedures to act as a 5G ProSe Layer-2 UE-to-UE Relay.
Procedures to act as a 5G ProSe Layer-3 UE-to-UE Relay.
Procedures to act as a 5G ProSe Layer-2 End UE.
Procedures to act as a 5G ProSe Layer-3 End UE.
Procedures for communication path switching between PC5 and Uu reference points.
Procedures for Multi-path communication via Uu and via 5G ProSe UE-to-Network Relay.
Indicating UE Policy Provisioning Request in UE Policy Container for UE triggered 5G ProSe Policy provisioning, which requests one or multiple types of policies/parameters as listed below:
Policy/parameters for 5G ProSe Direct Discovery;
Policy/parameters for 5G ProSe Direct Communication;
Policy/parameters for 5G ProSe Layer-2 Remote UE;
Policy/parameters for 5G ProSe Layer-3 Remote UE;
Policy/parameters for 5G ProSe Layer-2 UE-to-Network Relay;
Policy/parameters for 5G ProSe Layer-3 UE-to-Network Relay;
Policy/parameters for 5G ProSe Layer-3 Intermediate UE-to-Network Relay;
Policy/parameters for 5G ProSe Layer-2 End UE;
Policy/parameters for 5G ProSe Layer-3 End UE;
Policy/parameters for 5G ProSe Layer-2 UE-to-UE Relay;
Policy/parameters for 5G ProSe Layer-3 UE-to-UE Relay;
Policy/parameters for 5G ProSe Multi-hop Layer-3 UE-to-Network Relay Discovery;
Policy/parameters for 5G ProSe Multi-hop Layer-3 UE-to-UE Relay Discovery;
Policy/parameters for 5G ProSe Communication via Multi-hop Layer-3 UE-to-Network Relay;
Policy/parameters for 5G ProSe Communication via Multi-hop Layer-3 UE-to-UE Relay.
Receiving the 5G ProSe Policy from 5GC over N1 reference point.
Configuration of parameters for 5G ProSe Direct Discovery, 5G ProSe Direct Communication, 5G ProSe Single-hop UE-to-Network Relay (e.g. including IP addresses, ProSe Layer-2 Group IDs, see clause 5.1), 5G ProSe Multi-hop Layer-3 UE-to-Network Relay, 5G ProSe Single-hop UE-to-UE Relay and 5G ProSe Multi-hop Layer-3 UE-to-UE Relay. These parameters can be pre-configured in the UE, or, if in coverage, provisioned or updated by signalling over the N1 reference point from the PCF in the HPLMN or over PC1 reference point from the ProSe Application Server.
Reporting the following capabilities to 5GC over the N1 reference point:
The 5G DDNMF is the logical function handling network related actions required for dynamic 5G ProSe Direct Discovery. In this version of the specification, it is assumed that there is only one logical 5G DDNMF in each PLMN that supports 5G ProSe Direct Discovery service.
The 5G DDNMF interacts with the 5G ProSe-enabled UE using procedures over PC3a reference point defined in clause 6.3.1 to allocate and resolve the mapping of ProSe Applications IDs and ProSe Application Codes used in 5G ProSe Direct Discovery. It uses ProSe related subscriber data stored in UDM for the authorisation of each discovery request. It also provides the UE with the necessary security material in order to protect discovery messages transmitted over the air. In restricted 5G ProSe Direct Discovery, it also interacts with the Application Server via Npc2 reference points or with other 5G DDNMFs via Npc6/Npc7 reference points for the authorization of the discovery requests.
The 5G ProSe-enabled UE use procedure defined in clause 4.3.2.2 to discovery the 5G DDNMF in the HPLMN. Based on the UE Local Configuration or URSP as defined in TS 23.503, an existing PDU session is selected or a new PDU session is established, to carry the control signalling between the UE and the 5G DDNMF in the HPLMN.
The 5G DDNMF provides the necessary charging functionality or charging information for the usage of 5G ProSe Direct Discovery and/or ProSe Direct Communication to interact with CHF or for the provision to CEF.
The 5G DDNMF in the HPLMN may interact with the 5G DDNMF in a VPLMN or Local PLMN in order to manage the 5G ProSe Direct Discovery service.
The 5G DDNMF gets the address of the PCF for the UE from the BSF.
The 5G DDNMF gets the PDUID from the PCF and subscribes to notifications on Change of PDUID.
The 5G DDNMF of HPLMN is discovered through interaction with the Domain Name Service function. The UE may have the 5G DDNMF address in the Home PLMN (either as a FQDN or an IP address) pre-configured or provisioned as specified in clause 5.1.2.1. If it is not pre-configured or provisioned then the UE self-constructs the FQDN for it using e.g. the PLMN ID of the HPLMN.
The 5G DDNMF in the HPLMN uses the NRF to discovery other 5G DDNMFs in a VPLMN or local PLMN.
In addition to the functions defined in TS 23.501 and TS 23.503, the PCF includes functions to provision the UE with necessary policies and parameters to use 5G ProSe services, as part of the UE ProSe Policy information as defined in clause 4.2.2 of TS 23.503:
PC5 usage reporting configuration.
Authorization policy and parameters for 5G ProSe Direct Discovery and Communication.
Authorization policy and parameters for 5G ProSe UE-to-Network Relay Discovery and Communication (i.e. as 5G ProSe Layer-2 Remote UE, as 5G ProSe Layer-3 Remote UE, as 5G ProSe Layer-2 UE-to-Network Relay, as 5G ProSe Layer-3 UE-to-Network Relay).
PDUID allocation with its validity timer.
Authorization policy and parameters for 5G ProSe UE-to-UE Relay Discovery and Communication.
Authorization policy and parameters for 5G ProSe Layer-3 multi-hop UE-to-Network Relay Discovery and Communication.
Authorization policy and parameters for 5G ProSe Layer-3 multi-hop UE-to-UE Relay Discovery and Communication.
The PCF may update the 5G ProSe policy and parameters to the UE under certain conditions.
When receiving the 5G ProSe Capability in Npcf_UEPolicyControl_Create Request from the AMF or when receiving the updated subscription data from UDR, the PCF generates the PC5 QoS parameters used by NG-RAN corresponding to a UE as defined in clause 5.4.2 of TS 23.287.
In addition to the functions defined in TS 23.501, the AMF performs the following functions:
Select a PCF supporting 5G ProSe Policy/Parameter provisioning based on indication of 5G ProSe Capability as part of the "5GMM capability" in the Registration Request.
Store the 5G ProSe Capability.
Forward the 5G ProSe Capability to PCF in Npcf_UEPolicyControl_Create Request.
Obtain from UDM the subscription information related to 5G ProSe and store them as part of the UE context data.
Obtain PC5 QoS parameters from the PCF and store them as part of the UE context data.
Provision the NG-RAN with indication about the UE authorization status about the following:
5G ProSe Direct Discovery and 5G ProSe Direct Communication (i.e. as 5G ProSe-enabled UE for ProSe Direct Discovery, as 5G ProSe-enabled UE for ProSe Direct Communication);
5G ProSe UE-to-Network Relay Discovery and Communication (i.e. as 5G ProSe Layer-2 Remote UE, as 5G ProSe Layer-2 UE-to-Network Relay, as 5G ProSe Layer-3 UE-to-Network Relay);
Multi-path communication via direct Uu path and via 5G ProSe Layer 2 UE-to-Network Relay as a 5G ProSe Layer-2 Remote UE;
5G ProSe UE-to-UE Relay Discovery and Communication (i.e. as 5G ProSe Layer-2 End UE, as 5G ProSe Layer-2 UE-to-UE Relay);
5G ProSe Layer-3 multi-hop UE-to-Network Relay Discovery and Communication (i.e. as 5G ProSe Layer-3 UE-to-Network Relay supporting 5G ProSe Layer-3 multi-hop UE-to-Network Relay, as 5G ProSe Layer-3 Intermediate UE-to-Network Relay).
Provision the NG-RAN with PC5 QoS parameters related to 5G ProSe Direct Communication.
Optionally support security procedures over Control Plane for 5G ProSe UE-to-Network relaying as defined in TS 33.503.
Both 5G ProSe Layer-2 and Layer-3 UE-to-Network Relay entity provides the relaying functionality to support connectivity to the network for 5G ProSe Remote UEs. It can be used for both public safety services and commercial services (e.g. interactive service).
Both 5G ProSe Layer-2 and Layer-3 UE-to-Network Relay supports the following functions to enable connectivity to the network:
5G ProSe UE-to-Network Relay Discovery service as defined in clause 6.3.2.3, to allow discovery by the 5G ProSe Remote UE;
access the 5GS as a UE as defined in TS 23.501 with the enhancements as specified in clauses 6.2 and 6.6;
relays unicast traffic (uplink and downlink) between the 5G ProSe Remote UE and the network, supporting IP, Ethernet or Unstructured traffic type.
In addition to the common 5G ProSe UE-to-Network Relay functions defined in clause 4.3.9.1, 5G ProSe Layer-3 UE-to-Network Relay supports the following functions to enable connectivity to the network:
5G ProSe Direct Communication via 5G ProSe Layer-3 UE-to-Network Relay as specified in clause 6.5.1, for the communication with the 5G ProSe Layer-3 Remote UEs for the relay operations;
end-to-end QoS treatment for the 5G ProSe Layer-3 Remote UE's traffic without N3IWF as defined in clause 5.6.2.1 and when accessing via an N3IWF as defined in clause 5.6.2.2;
IP address management for the 5G ProSe Layer-3 Remote UE as defined in clause 5.5.1.3 in case the 5G ProSe Layer-3 Remote UE uses IP traffic type.
Emergency PDU Session establishment for 5G ProSe Layer-3 Remote UE via 5G ProSe Layer-3 UE-to-Network Relay without N3IWF support.
If 5G ProSe Multi-hop UE-to-Network Relay is supported, a 5G ProSe Layer-3 UE-to-Network Relay supports the following functions:
5G ProSe Multi-hop UE-to-Network Relay Discovery.
5G ProSe Communication via Multi-hop UE-to-Network Relay as defined in clause 6.5.1.4.
Relay unicast traffic originating from the 5G ProSe Remote UE and received from a 5G ProSe Intermediate UE-to-Network Relay to the network supporting IP, Ethernet or Unstructured traffic type.
In addition to the common 5G ProSe UE-to-Network Relay functions defined in clause 4.3.9.1, 5G ProSe Layer-2 UE-to-Network Relay supports the following functions to enable connectivity to the network:
5G ProSe Direct Communication via 5G ProSe Layer-2 UE-to-Network Relay as specified in clause 6.5.2, for the communication with the 5G ProSe Layer-2 Remote UEs for the relay operations;
QoS handling for 5G ProSe Layer-2 UE-to-Network Relay and end-to-end QoS treatment as defined in clause 5.6.2.3.
For a 5G ProSe Layer-2 UE-to-Network Relay to participate in the 5G ProSe UE-to-Network Relay Discovery procedure for emergency service (i.e. sending the UE-to-Network Relay Discovery Announcement message or UE-to-Network Relay Discovery Response message), the serving NG-RAN support of emergency services is required as the Layer-2 Remote UE may select a different PLMN from the Layer-2 Relay.
In addition to the functions defined in TS 23.501, the SMF supports the following function:
Receiving 5G ProSe Layer-3 Remote UE report and maintaining the information of 5G ProSe Layer-3 Remote UE(s) handled by a 5G ProSe Layer-3 UE-to-Network Relay in the 5G ProSe Layer-3 UE-to-Network Relay's SM context for the PDU Session associated with the relay.
In addition to the functions defined in TS 23.501, the NEF supports the following:
To enable AFs to provide service specific information to the 3GPP network, the NEF supports additional service parameters for ProSe policy as specified in clause 6.2.5.
Both 5G ProSe Layer-2 and Layer-3 UE-to-UE Relay provides the relaying functionality to support connectivity between 5G ProSe End UEs. 5G ProSe UE-to-UE Relay can be used for both public safety services and commercial services (e.g. interactive service).
Both 5G ProSe Layer-2 and Layer-3 UE-to-UE Relay supports the following functions to enable connectivity between 5G ProSe End UEs:
5G ProSe UE-to-UE Relay Discovery service as defined in clause 6.3.2.4, to allow discovery by the 5G ProSe End UE;
5G ProSe Discovery integrated into PC5 unicast link establishment as specified in clause 6.7.3;
Access 5GS as a UE as defined in TS 23.501 with the enhancements as specified in clauses 6.2;
Relay unicast traffic between the 5G ProSe End UEs directly in the case of 5G ProSe Single-hop UE-to UE Relay, or via one or more Layer-3 UE-to-UE Relays in the case of 5G ProSe Multi-hop Layer-3 UE-to-UE Relay, supporting IP, Ethernet or Unstructured traffic type.
In addition to the common 5G ProSe UE-to-UE Relay functionality defined in clause 4.3.12.1, a 5G ProSe Layer-3 UE-to-UE Relay supports the following functions:
5G ProSe Direct Communication via 5G ProSe Layer-3 UE-to-UE Relay as specified in clause 6.7.1, for the communication between 5G ProSe Layer-3 End UEs for relay operations;
QoS handling and end-to-end QoS treatment for the 5G ProSe Layer-3 End UE's traffic as defined in clause 5.6.3.1;
IP address management for the 5G ProSe Layer-3 End UE as defined in clause 5.5.1.4 when the 5G ProSe Layer-3 End UE uses IP traffic type;
5G ProSe UE-to-UE Relay reselection as specified in clause 6.7.4.3.
If 5G ProSe Multi-hop UE-to-UE Relay is supported, a 5G ProSe Layer-3 UE-to-UE Relay supports the following functions:
In addition to the common 5G ProSe UE-to-UE Relay functions defined in clause 4.3.12.1, 5G ProSe Layer-2 UE-to-UE Relay supports the following functions:
5G ProSe Direct Communication via 5G ProSe Layer-2 UE-to-UE Relay as specified in clause 6.7.2, for the communication between 5G ProSe Layer-2 End UEs for relay operations;
QoS handling and end-to-end QoS treatment for 5G ProSe Layer-2 End UE's traffic as defined in clause 5.6.3.2;
5G ProSe UE-to-UE Relay reselection as specified in clause 6.7.4.2.
The 5G ProSe Intermediate UE-to-Network Relay entity provides the relaying functionality to support multi-hop connectivity between the 5G ProSe Remote UEs and the 5G ProSe UE-to-Network Relay. It can be used for both public safety services and commercial services (e.g. interactive service). There can be more than one 5G ProSe Intermediate UE-to-Network Relay connecting the 5G ProSe Remote UEs and the 5G ProSe UE-to-Network Relay.
The 5G ProSe Intermediate UE-to-Network Relay supports the following functions to enable connectivity between the 5G ProSe Remote UEs and the 5G ProSe UE-to-Network Relay:
5G ProSe Multi-hop UE-to-Network Relay Discovery service to allow discovery by the 5G ProSe Remote UE as defined in clause 6.3.2.5.
Relays unicast traffic (uplink and downlink) between the 5G ProSe Remote UE and the 5G ProSe UE-to-Network Relay directly or via other 5G ProSe Intermediate UE-to-Network Relay(s), supporting IP, Ethernet or Unstructured traffic type.
5G ProSe Multi-hop Communication via 5G ProSe Layer-3 UE-to-Network Relay as specified in clause 6.5.1.4;