Content for TR 23.700-03 Word version: 19.0.0

3.1 Terms 3.2 Abbreviations 4.1 Architecture Requirements 4.2 Architecture Assumptions
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1 Scope p. 7

The present document will study and identify potential enhancements to the 5G Proximity-based Services (5G ProSe) system defined in TS 23.304 (beyond what has been specified in Rel-17 and Rel-18) considering the services requirements defined in TS 22.278, TS 22.261 and TS 22.115.

The study will investigate potential 5GS enhancements in the following areas:

Enhance ProSe to support multi-hop over NR PC5 reference point for UE-to-Network Relay for Layer-2 and Layer-3 Relays.
Enhance ProSe to support multi-hop over NR PC5 reference point for UE-UE Relay for Layer-3 Relays.

2 References p. 7

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.

[1]

TR 21.905: "Vocabulary for 3GPP Specifications".

[2]

TR 23.752: "Study on system enhancement for Proximity based Services (ProSe) in the 5G System (5GS)".

[3]

TR 23.700-33: "Study on system enhancement for Proximity based Services (ProSe) in the 5G System (5GS); Phase 2".

[4]

TS 23.304: "Proximity based Services (ProSe) in the 5G System (5GS)".

[5]

TS 22.278: "Service requirements for the Evolved Packet System (EPS); Stage 1".

[6]

TS 22.261: "Service requirements for next generation new services and markets; Stage 1".

[7]

TS 22.115: "Service aspects; Charging and billing; Stage 1".

[8]

TS 23.501: "System Architecture for the 5G System; Stage 2".

[9]

RFC 7181: "The Optimized Link State Routing Protocol Version 2".

[10]

RFC 6130: "Mobile Ad Hoc Network (MANET) Neighborhood Discovery Protocol (NHDP)".

[11]

RFC 5444: "Generalized Mobile Ad Hoc Network (MANET) Packet/Message Format".

[12]

TS 23.502: "Procedures for the 5G System (5GS)".

[13]

TS 25.303: "Interlayer procedures in Connected Mode".

[14]

TS 23.287: "Architecture enhancements for 5G System (5GS) to support Vehicle-to-Everything (V2X) services".

3 Definitions of terms and abbreviations p. 8

3.1 Terms p. 8

For the purposes of the present document, the terms given in TR 21.905, TS 23.304 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 and TS 23.304.

5G ProSe Intermediate Relay:

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 Relay is located on the path between 5G ProSe Remote UE and 5G ProSe UE-to-Network Relay.

5G ProSe Indirect Relay Discovery:

A procedure employed by a 5G ProSe-enabled UE to discover other 5G ProSe-enabled UEs in its vicinity based on in-direct radio transmissions through 5G ProSe Intermediate Relay UE(s) with NR technology.

5G ProSe Indirect Relay Communication:

A communication between two or more UEs in proximity that are 5G ProSe-enabled, by means of user plane transmission using NR technology through 5G ProSe Intermediate Relay UE(s) via a path not traversing any network node.

3.2 Abbreviations p. 8

For the purposes of the present document, the abbreviations given in TR 21.905, TS 23.304 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 and TS 23.304.

4 Architecture Requirements and Assumptions p. 8

4.1 Architecture Requirements p. 8

Solutions shall comply with and build on the 5G ProSe architecture principles as defined in TS 23.304 and 5G System architectural principles as defined in TS 23.501. To satisfy the normative stage-1 requirements in TS 22.261, the system shall:

Support multi-hop over NR PC5 reference point for Layer-2 and Layer-3 UE-to-Network Relays.
Support multi-hop over NR PC5 reference point for Layer-3 UE-to-UE Relays.

4.2 Architecture Assumptions p. 8

Architecture reference models defined in TS 23.304 are used as baseline architecture for supporting 5G ProSe Ph3.
NG-RAN for NR is used; non-3GPP access is not considered in this Release.
NR based PC5 and NR Uu are considered.
For multi-hop UE-to-Network Relay, all the relay entities on the path should be of the same type, either Layer-2 or Layer-3.
Multi-path communication via Uu and via multi-hop UE-to-Network Relay is not supported.