Content for TR 23.700-87 Word version: 18.0.0

3.1 Terms 3.2 Abbreviations 4.1 Architectural Assumptions 4.2 Architectural Principles
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1 Scope p. 10

The scope of this document is to study IMS architecture enhancements to support new real time communication services based on requirements of e.g. eMMTEL and 5G_MEDIA_MTSI_ext.

The study in this document includes the following aspects:

Study the enhancement of IMS architecture and procedures to support Data Channel usage in IMS network, including whether and which functionalities are defined in IMS architecture for Data Channel server, with separate control plane and media plane, and Data Channel application repository, which procedures are needed between Data channel server and IMS AS to support call event notifications.
Study whether and how IMS architecture and functions are supported for the requirements from SA WG1 Rel-18 eMMTEL WID impacts:
- to support AR telephony communication.
- to support 3rd party to verify via operator network that the caller is authorized to use or reference specific identity information which can be securely signalled to the callee when placing a call.
Study whether and which IMS media control interfaces can be potentially applied for service based architecture, supporting both existing capabilities and new capabilities for possible new applications and efficient media processing.

2 References p. 10

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]

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

[3]

TS 23.502: "Procedures for the 5G system, Stage 2".

[4]

TS 23.503: "Policy and Charging Control Framework for the 5G System".

[5]

TS 23.228: "IP Multimedia Subsystem (IMS)".

[6]

TS 26.114: "Media handling and interaction".

[7]

TS 22.261: "Service requirements for the 5G system".

[8]

TS 24.229: "IP Multimedia Call Control based on SIP and SDP; Stage 3".

[9]

TS 29.165: "Inter-IMS Network to Network Interface (NNI)".

[10]

RFC 5688: "A Session Initiation Protocol (SIP) Media Feature Tag for MIME Application Subtypes".

[11]

RFC 6809: "Mechanism to Indicate Support of Features and Capabilities in the Session Initiation Protocol (SIP)".

[12]

RFC 3264: "An Offer/Answer Model with the Session Description Protocol (SDP)".

[13]

RFC 3261: "SIP: Session Initiation Protocol".

[14]

TR 26.998: "Support of 5G Glass-type Augmented Reality / Mixed Reality (AR/MR) devices".

[15]

TS 26.928: "Extended Reality (XR) in 5G".

[16]

draft-ietf-stir-passport-rcd-18 "PASSporT Extension for Rich Call Data".

[17]

ATIS-1000074: "Signature-based Handling of Asserted information using toKENs (SHAKEN)". https://access.atis.org/apps/group_public/download.php/62391/ATIS-1000074.v002.pdf.

[18]

RFC 8224: "Authenticated Identity Management in the Session Initiation Protocol (SIP)".

[19]

RFC 6749: "The OAuth 2,0 Authorization Framework".

[20]

TS 24.183: "IP Multimedia Subsystem (IMS) Customized Ring Signal (CRS)".

[21]

TS 23.256: "Support of Uncrewed Aerial Systems (UAS) connectivity, identification and tracking".

[22]

RFC 8226: "Secure Telephone Identity Credentials: Certificates".

[23]

draft-ietf-stir-cert-delegation-04 "STIR Certificate Delegation".

[24]

ATIS-1000092: "Signature-based Handling of Asserted information using toKENs (SHAKEN): Delegate Certificates". https://access.atis.org/apps/group_public/download.php/56801/ATIS-1000092.zip.

[25]

TR 22.873: "Study on evolution of IMS multimedia telephony service".

[26]

TS 29.214: "Policy and Charging Control over Rx reference point".

[27]

TS 29.514: "5G System; Policy Authorization Service; Stage 3".

[28]

draft-ietf-sipcore-callinfo-rcd-04 "SIP Call-Info Parameters for Rich Call Data".

[29]

TS 26.511: "5G Media Streaming (5GMS); Profiles, codecs and formats".

[30]

TS 26.116: "Television (TV) over 3GPP services; Video profiles".

[31]

TS 26.117: "5G Media Streaming (5GMS); Speech and audio profiles".

[32]

TS 26.118: "Virtual Reality (VR) profiles for streaming applications".

[33]

TS 26.119: "Media Capabilities for Augmented Reality".
→ to date, still a draft

3 Definitions of terms and abbreviations p. 11

3.1 Terms p. 11

For the purposes of the present document, the terms given in TR 21.905, in TS 23.501 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 or in TS 23.501.

Application data channel:

It is used to transfer data of data channel applications between the UEs or between the UE and the network. The application data channel should be established only after the application has been downloaded. As specified in TS 26.114, the stream ID for application data channel can be integers starting from 1000.

AR Application Server:

It is used to control the service logic related to AR communication. The functional definition of the AR Application Server is out of scope of 3GPP.

Bootstrap data channel:

It is used to transfer data channel application list and data channel applications between the UE and the network. The bootstrap data channel is based on HTTP protocol. As specified in TS 26.114, the stream ID for bootstrap data channel can be integers below 1000.

Data channel application:

The HTML web content includes JavaScript(s), and optionally image(s) and style sheet(s). It is accessible at the HTTP root ("/") URL through a bootstrap data channel and describes the graphical user interface and the interactive service logic.

DC Application Server:

It interacts with DCSF and DC media function (either DCMF or enhanced MRF) for data channel traffic handling in P2A/A2P scenario. The functional definition of the DC Application Server is out of scope of 3GPP.

Ms reference point:

This reference point is used to request signing of an Identity header field or request verification of a signed assertion in an Identity header field.

Secure Telephone Identity Authentication Service (STI-AS):

The SIP application server that performs the function of the authentication service defined in IETF RFC 8224 [18].

Secure Telephone Identity Verification Service (STI-VS):

The SIP application server that performs the function of the verification service defined in IETF RFC 8224 [18].

3.2 Abbreviations p. 12

For the purposes of the present document, the abbreviations given in TR 21.905, in TS 23.501 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 or in TS 23.501.

5QI

5G QoS Identifier

A2P

Application to Person

Data Channel

DCAR

Data Channel Application Repository

DCMF

Data Channel Media Function

DCMTSI

Data Channel Multimedia Telephony Service for IMS

DCS

Data Channel Server

DCS-C

Control Function of Data Channel Server

DCS-M

Media Function of Data Channel Server

DCSF

Data Channel Signalling Function

P2A

Person to Application

P2P

Person to Person

PASSporT

Personal Assertion Token

QCI

QoS Class Identifier

QoS

Quality of Service

RCD

Rich Call Data

SHAKEN

Signature-based Handling of Asserted information using toKENs

STI

Secure Telephone Identity

STI-AS

Secure Telephone Identity Authentication Service

STI-VS

Secure Telephone Identity Verification Service

STIR

Secure Telephone Identity Revisited

Telephone Number

4 Architectural Assumptions and Principles p. 12

4.1 Architectural Assumptions p. 12

The following architecture assumptions are applied to all KIs in the study:

Reference architecture of IMS defined in TS 23.228 is used as basis architecture for supporting next generation real time communication.
Call control protocol is based on SIP.

4.2 Architectural Principles p. 13

The following architectural principles apply for all KIs in the study:

Solutions shall be access agnostic.

The following architectural principles apply for Data Channel usage in IMS:

Solutions shall have minimal impacts to IMS architecture and procedures.
Solutions shall use functionality and procedures for data channel as defined in TS 26.114 as a baseline.