Content for TS 24.337 Word version: 18.0.0

3.1 Definitions 3.2 Abbreviations 4.1 General 4.2 Underlying network capabilities 4.3 URI and address assignments 5.1 Introduction 5.2 User Equipment (UE) 5.3 Application Server (AS)
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1 Scope p. 10

IP Multimedia (IM) Core Network (CN) subsystem inter-UE transfer (IUT) provides the capability of continuing ongoing communication sessions with multiple media across different user equipments (UEs) under the control of the same or different subscribers, and as part of Service Continuity (SC).

The present document provides the protocol details for enabling IMS inter-UE transfer based on the Session Initiation protocol (SIP) and the Session Description Protocol (SDP).

The present document is applicable to User Equipment (UEs) and Application Servers (AS).

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 22.173: "IP Multimedia Core Network Subsystem (IMS) Multimedia Telephony Service and supplementary services; Stage 1".

[3]

TS 23.003: "Numbering, addressing and identification".

[4]

TS 23.237: "IP Multimedia subsystem (IMS) Service Continuity; Stage 2".

[5]

TS 24.008: "Mobile radio interface layer 3 specification; Core Network protocols; Stage 3".

[6]

TS 24.228: Release 5: "Signalling flows for the IP multimedia call control based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3".

[7]

TS 24.229: "IP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3".

[8]

TS 24.238: "Session Initiation Protocol (SIP) based user configuration; Stage 3".

[9]

TS 24.292: "IP Multimedia (IM) Core Network (CN) subsystem Centralized Services (ICS); Stage 3".

[10]

TS 24.604: "Communication Diversion (CDIV) using IP Multimedia (IM)Core Network (CN) subsystem; Protocol specification".

[11]

TS 24.605: "Conference (CONF) using IP Multimedia (IM) Core Network (CN) subsystem; Protocol specification".

[12]

TS 24.606: "Message Waiting Indication (MWI) using IP Multimedia (IM) Core Network (CN) subsystem; Protocol specification".

[13]

TS 24.607: "Originating Identification Presentation (OIP) and Originating Identification Restriction (OIR) using IP Multimedia (IM) Core Network (CN) subsystem; Protocol Specification".

[14]

TS 24.608: "Terminating Identification Presentation (TIP) and Terminating Identification Restriction (TIR) using IP Multimedia (IM)Core Network (CN) subsystem; Protocol Specification".

[15]

TS 24.610: "Communication HOLD (HOLD) using IP Multimedia (IM) Core Network (CN) subsystem; Protocol specification".

[16]

TS 24.611: "Anonymous Communication Rejection (ACR) and Communication Barring (CB); using IP Multimedia (IM) Core Network (CN) subsystem; Protocol specification".

[17]

TS 24.629: "Explicit Communication Transfer (ECT) using IP Multimedia (IM) Core Network (CN) subsystem; Protocol specification".

[18]

TS 24.239: "Flexible Alerting (FA) using IP Multimedia (IM) Core Network (CN) subsystem; Protocol specification".

[19]

TS 24.259: "Personal Network Management (PNM); Stage 3".

[20]

TS 24.615: "Communication Waiting (CW) using IP Multimedia (IM) Core Network (CN) subsystem; Protocol Specification".

[21]

TS 24.616: "Malicious Communication Identification (MCID) using IP Multimedia (IM) Core Network (CN) subsystem; Protocol Specification".

[22]

TS 24.642: "Completion of Communications to Busy Subscriber (CCBS) and Completion of Communications by No Reply (CCNR) using IP Multimedia (IM)Core Network (CN) subsystem; Protocol Specification".

[23]

TS 24.647: "Advice Of Charge (AOC) using IP Multimedia (IM)Core Network (CN) subsystem; Protocol Specification".

[24]

TS 24.654: "Closed User Group (CUG) using IP Multimedia (IM) Core Network (CN) subsystem, Protocol Specification".

[25]

TS 29.292: "Interworking between the IP Multimedia (IM) Core Network (CN) subsystem and MSC Server for IMS Centralized Services (ICS)".

[26]

TS 29.328: "IP Multimedia Subsystem (IMS) Sh interface; Signalling flows and message contents".

[27]

TS 29.329: "Sh interface based on the Diameter protocol; Protocol details".

[28]

RFC 792 (September 1981): "INTERNET CONTROL MESSAGE PROTOCOL".

[29]

RFC 3023: "XML Media Types".

[30]

RFC 3261: "SIP: Session Initiation Protocol".

[31]

RFC 3264 (June 2002): "An Offer/Answer Model with the Session Description Protocol (SDP)".

[32]

RFC 3515: "The Session Initiation Protocol (SIP) Refer Method".

[33]

RFC 3556 (July 2003): "Session Description Protocol (SDP) Bandwidth Modifier".

[34]

RFC 3840 (August 2004): "Indicating User Agent Capabilities in the Session Initiation Protocol (SIP)".

[35]

RFC 3891: "The Session Initiation Protocol (SIP) "Replaces" Header".

[36]

RFC 3892 (September 2004) "The Session Initiation Protocol (SIP) Referred-By Mechanism".

[37]

RFC 4028: "Session Timers in the Session Initiation Protocol (SIP)".

[38]

RFC 4235 (November 2005): "An INVITE-Initiated Dialog Event Package for the Session Initiation Protocol (SIP)".

[39]

RFC 4353 (February 2006): "A Framework for Conferencing with the Session Initiation Protocol (SIP)".

[40]

RFC 4538: "Request Authorization through Dialog Identification in the Session Initiation Protocol (SIP)".

[41]

RFC 4566: "SDP: Session Description Protocol".

[42]

RFC 4745: "Common Policy: A Document Format for Expressing Privacy Preferences".

[43]

RFC 6157 (April 2011): "IPv6 Transition in the Session Initiation Protocol (SIP)".

[44]

RFC 6809 (November 2012): "Mechanism to Indicate Support of Features and Capabilities in the Session Initiation Protocol (SIP)".

[45]

OMA-TS-XDM-Core-V1_1: "XML Document Management (XDM) Specification", Version 1.1.

[46]

TS 24.141: "Presence service using IP Multimedia (IM) Core Network (CN) subsystem; Protocol specification".

[47]

RFC 3863: "Presence Information Data Format (PIDF)".

[48]

RFC 6665 (July 2012): "SIP-Specific Event Notification".

[49]

RFC 3856 (August 2004): "A Presence Event Package for the Session Initiation Protocol (SIP)".

[50]

RFC 4661 (September 2006): "An Extensible Markup Language (XML) Based Format for Event Notification Filtering".

[51]

RFC 4660 (September 2006): "Functional Description of Event Notification Filtering".

[52]

RFC 3903 (October 2004): "Session Initiation Protocol (SIP) for Event State Publication".

[53]

RFC 4480 (July 2006): "RPID: Rich Presence Extensions to the Presence Information Data Format (PIDF)".

[54]

RFC 7647 (September 2015): "Clarifications for the Use of REFER with RFC6665".

3 Definitions and abbreviations p. 13

3.1 Definitions p. 13

For the purposes of the present document, the terms and definitions 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.

Controller capable UE:

A UE that is capable of becoming a controller UE.

Inter UE Transfer SCC AS URI:

A SIP URI which is a public service identity hosted by SCC AS and which is used in inter UE transfer procedures.

For the purposes of the present document, the following terms and definitions given in TS 23.237 apply:

Remote Leg

Collaborative session

Controllee UE

Controller UE

Inter-UE transfer

Service Continutiy

For the purposes of the present document, the following terms and definitions given in IETF RFC 4353 [39] apply:

Conference

Conference URI

Focus

Participant

For the purposes of the present document, the following terms and definitions given in IETF RFC 3264 [31] apply:

Directionality

3.2 Abbreviations p. 13

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.

Service Continuity

SCC

Service Centralization and Continuity

STI

Session Transfer Identifier

XCAP

Extensible Markup Language (XML) Access Configuration Protocol

XML

Extensible Markup Language

4 Overview of IP Multimedia (IM) Core Network (CN) subsystem inter-UE transfer p. 13

4.1 General p. 13

Inter-UE transfer provides the capability of transferring the communication sessions with multiple media across different UEs and is part of Service Continuity (SC) as described in TS 23.237.

Inter-UE transfer does not apply to emergency calls as described in TS 24.229.

Inter-UE transfer is an optional part of SC.

The following procedures are provided within this document:

procedures for UE discovery for inter-UE transfer are specified in clause 9;
procedures for inter-UE transfer without establishment of collaborative session are specified in clause 10;
procedures for collaborative session establishment for inter-UE transfer are specified in clause 11;

NOTE 1:
The procedures in clause 11 are related to scenarios in which the collaborative session is set up by the controller UE when an end-to-end session already has been established with the remote UE.
procedures for media transfer within collaborative session for inter-UE transfer are specified in clause 12;
procedures for release of collaborative session for inter-UE transfer in clause 13;
procedures for addition and deletion of media with collaborative session for inter-UE transfer in clause 14;
procedures for session discovery in clause 15;
procedures for collaborative sessions of participants of different subscriptions are specified in clause 16;
procedures for establishment of collaborative sessions during session setup are specified in clause 17;

NOTE 2:
The procedures in clause 17 are related to scenarios in which the collaborative session and the session towards the remote UE are set up in parallel.
procedures for assignment and transfer of control of a collaborative session are specified in clause 18;
procedures for media flow transfer within a collaborative session are specified in clause 19;
procedures for session replication / media replication performed by the SCC AS are specified in clause 20;
procedures for session replication / media replication performed by the remote UE are specified in clause 21;
procedures for collaborative session handling upon loss of collaborative session are specified in clause 22;
procedures for collaborative session media modification are specified in clause 23; and
procedures for service continuity and MMTEL interactions are specified in clause 24.
Inter-UE transfer procedures are not limited by amount of established sessions.

4.2 Underlying network capabilities p. 14

Inter-UE transfer assumes the use of a number of underlying network capabilities:

provision by the home network operator of SCC AS on the IM CN subsystem, as specified in TS 24.229.

4.3 URI and address assignments p. 14

In order to support SC to a subscriber, the following URI and address assignments are assumed:

in this version of the document, the SC UE for inter-UE transfer will be configured with an Inter UE Transfer SCC AS URI. The Inter UE Transfer SCC AS URI is used in the inter UE transfer procedures.

5 Functional entities p. 15

5.1 Introduction p. 15

This clause associates the functional entities with the inter-UE transfer roles described in the stage 2 architecture document (see TS 23.237).

5.2 User Equipment (UE) p. 15

If the SC UE supports the Controller UE procedures for IUT transfer then the SC UE may include the g.3gpp.iut-controller media feature tag as described in annex B in the Contact header of SIP requests and SIP responses.

To be compliant with inter-UE transfer in this document, a UE shall implement the role of an SC UE:

by following the procedures specified in TS 24.229 for registration of the UE in the IM CN subsystem; and
dependent on the desired functionality, one or more of the procedures according to subclause 9.2, subclause 10.2, subclause 11.2, subclause 12.2, subclause 13.2, subclause 14.2, subclause 15.2, subclause 16.2, subclause 17.2, subclause 18.2, subclause 19.2, subclause 20.2, subclause 21.2, subclause 22.2, subclause 23.2 and subclause 24.2.

5.3 Application Server (AS) p. 15

To be compliant with inter-UE transfer in this document, an AS shall implement the role of an SCC AS according to subclause 9.3, subclause 10.3, subclause 11.3, subclause 12.3, subclause 13.3, subclause 14.3, subclause 15.3, subclause 16.3, subclause 17.3, subclause 18.3, subclause 19.3, subclause 20.3, subclause 21.3, subclause 22.3, subclause 23.3 and subclause 24.3.