The present document specifies the protocols for Proximity-based Services (ProSe) in 5G system as specified in TS 23.304 for:
5G ProSe direct discovery;
5G ProSe communication over the PC5 interface;
5G ProSe-enabled UE-to-network relay; and
5G ProSe-enabled UE-to-UE relay.
The present document defines the associated procedures for 5G ProSe service authorization, 5G ProSe direct discovery (e.g. the procedures between 5G ProSe-enabled UE and 5G Direct Discovery Name Management Function (DDNMF) over the PC3a interface, the procedures over the PC5 interface), 5G ProSe UE-to-network relay discovery, 5G ProSe UE-to-UE relay discovery and 5G ProSe direct communication.
The present document also defines the message format, message contents, error handling and system parameters applied by the protocols for ProSe in 5GS.
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
For the purposes of the present document, the terms given in TR 21.905 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905.
5G DDNMF CTF (ADF):
Accounting Data Forwarding (ADF) function block of the Charging Trigger Function (CTF) in the 5G DDNMF.
5G ProSe Direct Communication:
A function that supports the communications between two or more UEs in proximity that are 5G ProSe-enabled, by means of user plane transmission using NR technology via a path not traversing any network node.
5G ProSe Direct Discovery:
A function employed by a 5G ProSe-enabled UE to discover other 5G ProSe-enabled UEs in its vicinity based on direct radio transmissions between the two UEs with NR technology.
5G ProSe UE-to-network relay:
A function employed by a 5G ProSe-enabled UE to support the communications between a 5G ProSe remote UE and DN.
5G ProSe multi-hop UE-to-network relay:
A function employed by a 5G ProSe UE-to-network relay UE to support the multi-hop communications between a 5G ProSe remote UE and DN.
5G ProSe layer-2 UE-to-network relay:
A function employed by a 5G ProSe-enabled UE to support the communications between a 5G ProSe layer-2 remote UE and DN.
5G ProSe multi-hop layer-2 UE-to-network relay:
A function employed by a 5G ProSe layer-2 UE-to-network relay UE to support the multi-hop communications between a 5G ProSe layer-2 remote UE and DN.
5G ProSe layer-3 UE-to-network relay:
A function employed by a 5G ProSe-enabled UE to support the communications between a 5G ProSe layer-3 remote UE and DN.
5G ProSe multi-hop layer-3 UE-to-network relay:
A function employed by a 5G ProSe layer-3 UE-to-network relay UE to support the multi-hop communications between a 5G ProSe layer-3 remote UE and DN.
5G ProSe UE-to-UE relay:
A function employed by a 5G ProSe-enabled UE to support the communications between two 5G ProSe end UEs.
5G ProSe layer-2 UE-to-UE relay:
A function employed by a 5G ProSe-enabled UE to support the communications between two 5G ProSe layer-2 end UEs.
5G ProSe layer-3 UE-to-UE relay:
A function employed by a 5G ProSe-enabled UE to support the communications between two 5G ProSe layer-3 end UEs.
5G ProSe multi-hop layer-3 UE-to-UE relay:
A function employed by a 5G ProSe layer-3 UE-to-UE relay UE to support the multi-hop communications between two 5G ProSe layer-3 end UEs.
5G ProSe UE-to-network relay UE:
A 5G ProSe-enabled UE that provides functionality to support connectivity to the network for 5G ProSe remote UE(s).
5G ProSe multi-hop UE-to-network relay UE:
A 5G ProSe UE-to-network relay UE that supports 5G ProSe multi-hop UE-to-network relay.
5G ProSe intermediate UE-to-network relay UE:
A 5G ProSe-enabled UE that provides functionality to support connectivity to the network for 5G ProSe remote UE(s) by using the PC5 reference point with other 5G ProSe-enabled UEs. The 5G ProSe intermediate UE-to-network relay UE is located on the path between the 5G ProSe remote UE and the 5G ProSe UE-to-network relay UE.
A 5G ProSe-enabled UE that provides functionality to support connectivity to the network for 5G ProSe layer-2 remote UE(s) by using the PC5 reference point with other 5G ProSe-enabled UEs via layer-2 protocol.
A 5G ProSe-enabled UE that provides functionality to support connectivity to the network for 5G ProSe layer-3 remote UE(s) by using the PC5 reference point with other 5G ProSe-enabled UEs via layer-3 protocol.
5G ProSe layer-2 UE-to-network relay UE:
A 5G ProSe-enabled UE that provides functionality to support connectivity to the network for 5G ProSe layer-2 remote UE(s) via layer-2 protocol.
A 5G ProSe layer-3 UE-to-network relay UE that supports 5G ProSe multi-hop layer-3 UE-to-network relay.
5G ProSe UE-to-UE relay UE:
A 5G ProSe-enabled UE that provides functionality to support connectivity between two 5G ProSe end UEs.
5G ProSe layer-2 UE-to-UE relay UE:
A 5G ProSe-enabled UE that provides functionality to support connectivity between two 5G ProSe layer-2 end UEs via layer-2 protocol.
5G ProSe layer-3 UE-to-UE relay UE:
A 5G ProSe-enabled UE that provides functionality to support connectivity between two 5G ProSe layer-2 end UEs via layer-3 protocol.
5G ProSe multi-hop parent UE-to-network relay UE:
When one or more 5G ProSe intermediate UE-to-network relay UEs are used on the path between a 5G ProSe multi-hop remote UE and the DN, a 5G ProSe multi-hop parent UE-to-network relay UE is a 5G ProSe intermediate UE-to-network relay UE or a 5G ProSe multi-hop UE-to-network relay UE, which has one less hop to the NG-RAN compared to another 5G ProSe intermediate UE-to-network relay UE or to the 5G ProSe multi-hop remote UE on the path.
5G ProSe multi-hop child UE-to-network relay UE:
When one or more 5G ProSe intermediate UE-to-network relay UEs are used on the path between a 5G ProSe multi-hop remote UE and the DN, a 5G ProSe multi-hop child UE-to-network relay UE is a 5G ProSe intermediate UE-to-network relay UE, which has one more hop to the NG-RAN compared to another 5G ProSe intermediate UE-to-network relay UE or 5G ProSe multi-hop UE-to-network relay UE on the path.
5G ProSe multi-hop layer-3 UE-to-UE relay UE:
A 5G ProSe layer-3 UE-to-UE relay UE that supports 5G ProSe multi-hop layer-3 UE-to-UE relay.
5G ProSe layer-2 remote UE:
A 5G ProSe-enabled UE that communicates with a DN via a 5G ProSe layer-2 UE-to-network relay UE.
5G ProSe multi-hop layer-2 remote UE:
A 5G ProSe-enabled UE that communicates with a DN via zero or more 5G ProSe layer-2 intermediate UE-to-network relay UE and a 5G ProSe layer-2 UE-to-network relay UE.
5G ProSe layer-3 remote UE:
A 5G ProSe-enabled UE that communicates with a DN via a 5G ProSe layer-3 UE-to-network relay UE.
5G ProSe multi-hop layer-3 remote UE:
A 5G ProSe-enabled UE that communicates with a DN via zero or more 5G ProSe layer-3 intermediate UE-to-network relay UE and a 5G ProSe layer-3 UE-to-network relay UE.
5G ProSe layer-2 end UE:
A 5G ProSe-enabled UE that communicates with another 5G ProSe-enabled UE via a 5G ProSe layer-2 UE-to-UE relay UE.
5G ProSe layer-3 end UE:
A 5G ProSe-enabled UE that communicates with another 5G ProSe-enabled UE via a 5G ProSe layer-3 UE-to-UE relay UE.
5G ProSe multi-hop layer-3 end UE:
A 5G ProSe-enabled UE that communicates with another 5G ProSe-enabled UE via one or more 5G ProSe layer-3 UE-to-UE relay UE.
Open 5G ProSe direct discovery:
A 5G ProSe direct discovery that takes place without explicit permission from the 5G ProSe-enabled UE being discovered.
Restricted 5G ProSe direct discovery:
A 5G ProSe direct discovery that only takes place with explicit permission from the 5G ProSe-enabled UE being discovered.
Usage information report:
Usage information related to one collection period.
Usage information report list:
One or more usage information report(s) associated with the UE identity of a 5G ProSe-enabled UE.
For the purposes of the present document, the following terms and definitions given in TS 23.304 apply:
5G ProSe-enabled UE
5G ProSe remote UE
Application layer ID
Application layer group ID
Destination layer-2 ID
Direct network communication
Discovery entry ID
Discovery filter
Discovery query filter
Discovery response filter
Geographical area
Indirect network communication
Local PLMN
Member ID
Metadata index
Metadata index mask
Model A
Model B
Mode of communication
ProSe application code
ProSe application mask
ProSe application ID
ProSe discovery UE ID
ProSe identifier
ProSe layer-2 group ID
ProSe query code
ProSe response code
ProSe restricted code
ProSe restricted code prefix
ProSe restricted code suffix
Relay service code
Restricted ProSe application user ID
User info ID
Source layer-2 ID
NR Tx profile
User info ID
For the purposes of the present document, the following terms and definitions given in TS 23.501 apply:
For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.
5G DDNMF
5G Direct Discovery Name Management Function
5G PKMF
5G ProSe Key Management Function
5G ProSe
5G Proximity-based Services
AA
Authentication and Authorization
AKMA
Authentication and Key Management for Applications
CP-PRUK
Control Plane ProSe Remote User Key
CTF (ADF)
Charging Trigger Function (Accounting Data Forwarding)
DN
Data Network
DNS
Domain Name System
DUCK
Discovery User Confidentility Key
DUIK
Discovery User Integrity Key
DUSK
Discovery User Scrambling Key
FQDN
Fully Qualified Domain Name
GBA
Generic Bootstrapping Architecture
GFBR
Guaranteed Flow Bit Rate
GPI
GBA Push Information
LSB
Least Significant 8 Bits
MSB
Most Significant 8 Bits
MFBR
Maximum Flow Bit Rate
MIC
Message Integrity Check
MOBIKE
IKEv2 Mobility and Multihoming Protocol
NAI
Network Access Identifier
NCGI
NG-RAN Cell Global ID
NID
Network Identifier
NR
New Radio
PC3
Reference point between UE and the ProSe Function
PC3a
Reference point between the UE and the 5G DDNMF
PC3ach
PC3a for charging
PC5
Reference point between ProSe-enabled UEs used for control and user plane
5G Proximity-based Services (ProSe) are services that can be provided by the 3GPP system based on UEs being in proximity to each other. In this release of the document, the 3GPP system enablers for 5G ProSe include the following functions:
5G ProSe direct discovery;
5G ProSe direct communication;
5G ProSe UE-to-network relay; and
5G ProSe UE-to-UE relay.
The above functions are applicable for both public safety UE and commercial UEs.
The above functions are applicable in PLMN and SNPN, with considering the adaptations for SNPN specified in this specification.
The security aspects for 5G ProSe features are specified in TS 33.503.