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3GPP TS 23.237 V13.1.0 (2015-12)Technical Specification

3rd Generation Partnership Project;Technical Specification Group Services and System Aspects;

IP Multimedia Subsystem (IMS Service !ontinuity;Sta"e #

($elease %3

The present document has been developed within the 3rd Generation Partnership Project (3GPP TM) and may be further elaborated for the purposes of 3GPP.

The present document has not been subject to any approval process by the 3GPP Orani!ational Partners and shall not be implemented.

This "pecification is provided for future development wor# within 3GPPonly. The Orani!ational Partners accept no liability for any use of this

"pecification."pecifications and reports for implementation of the 3GPPTMsystem should be obtained via the 3GPP Orani!ational Partners$ Publications Offices.

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%eywordsIMS, Multimedia, IP, LTE, UMTS, GSM

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Copyright Notification

'o part may be reproduced ecept as authori!ed by written permission.The copyriht and the foreoin restriction etend to reproduction in all media.

*+,- 3GPP Orani!ational Partners (/0&1 /T&" 22"/ T"& T"4"& TT/ TT2).

/ll rihts reserved.

5MT"6 is a Trade Mar# of T"& reistered for the benefit of its members

3GPP6 is a Trade Mar# of T"& reistered for the benefit of its Members and of the 3GPP Orani!ational Partners

7T6 is a Trade Mar# of T"& reistered for the benefit of its Members and of the 3GPP Orani!ational PartnersG"M8 and the G"M loo are reistered and owned by the G"M /ssociation

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+!'te't"

9oreword..........................................................................................................................................................

&ntroduction......................................................................................................................................................

, "cope....................................................................................................................................................

* 0eferences............................................................................................................................................

3 4efinitions symbols and abbreviations................................................................................................3., 4efinitions.........................................................................................................................................................

3.* /bbreviations.....................................................................................................................................................

: ;ih level principles and architectural re

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-.:.* "essions with P" media flow(s)...................................................................................................................-.:.*a "essions with P" media flow(s) usin /T29...............................................................................................-.:.3 "essions with 2" media...............................................................................................................................-.:.3a "essions with 2" media flow(s) usin /T29..............................................................................................

-.- &5T 2ollaborative "essions...............................................................................................................................-.A 0eference /rchitecture for "0?22 emerency session....................................................................................

A Procedures and flows for /ccess Transfer............................................................................................A.+ &ntroduction.......................................................................................................................................................A., 0eistration........................................................................................................................................................A.,., General.........................................................................................................................................................A.,.* 0eistration usin /T29 enhancements......................................................................................................A.,.3 0eistrationC 2" to P" = "inle 0adio.........................................................................................................

A.,.3., &M" 0eistration by 5.........................................................................................................................A.,.3.* 5 &M" 0eistration chane update......................................................................................................A.* Oriination and Termination..............................................................................................................................A.*., Oriination...................................................................................................................................................A.*.,., Oriination Procedures...........................................................................................................................A.*.,.* Oriinatin sessions that use 2" media.................................................................................................

A.*.,.3 Oriinatin sessions that use only P" media flow(s).............................................................................A.*.,.: Oriinatin sessions for (v)"0?22 that use /T29 enhancements........................................................A.*.,.- Oriinatin sessions for 2" to P" = "inle 0adio..................................................................................A.*.* Termination..................................................................................................................................................A.*.*., Termination Procedures..........................................................................................................................A.*.*.* Terminatin sessions that use 2" media................................................................................................

A.*.*.3 Terminatin sessions that use only P" media flow(s)............................................................................A.*.*.: Terminatin sessions over Gm where speech media is not accepted by the 5....................................A.*.*.- Terminatin sessions for (v)"0?22 that use /T29 enhancements.......................................................A.*.*.A Terminatin sessions for 2" to P" = "inle 0adio.................................................................................A.3 /ccess Transfer..................................................................................................................................................A.3., /ccess Transfer Procedure...........................................................................................................................

A.3.,., &ntroduction............................................................................................................................................

A.3.,.* /ccess Transfer Procedures...................................................................................................................A.3.,.*a /ccess Transfer Procedures usin /T29 enhancements........................................................................A.3.,.3 nablement of /ccess Transfer procedures...........................................................................................A.3.,.3a nablement of /ccess Transfer procedures usin /T29 enhancements................................................A.3.,.: ecution of /ccess Transfer procedures..............................................................................................

A.3.,.:a ecution of /ccess Transfer procedures usin /T29 enhancements..................................................A.3.,.- 0emote 7e 5pdate................................................................................................................................A.3.,.A "ource /ccess 7e 0elease....................................................................................................................A.3.,.B /ccess Transfer &nformation for /T29..................................................................................................A.3.* /ccess Transfer &nformation flows..............................................................................................................A.3.*.+ General...................................................................................................................................................

A.3.*., P" > 2" /ccess Transfer........................................................................................................................A.3.*.,., P" > 2" /ccess TransferC P" to 2" = 4ual 0adio............................................................................

A.3.*.,.,a P" > 2" /ccess TransferC P" to 2" > 4ual 0adio with "ession "tate &nformation.........................A.3.*.,.* P" > 2" /ccess TransferC 2" to P" = 4ual 0adio............................................................................A.3.*.,.*a P" > 2" /ccess TransferC 2" to P" > 4ual 0adio with "ession "tate &nformation.........................A.3.*.,.*b 2" = P" /ccess TransferC 2" to P" = 4ual 0adio incomin voice call in alertin phase................

A.3.*.,.*c 2" = P" /ccess TransferC 2" to P" = 4ual 0adio outoin voice call in pre=alertin state orin alertin phase................................................................................................................................

A.3.*.,.*d P" = 2" /ccess TransferC P" to 2" = 4ual 0adio outoin voice or video call in pre=alertinstate or in alertin phase...................................................................................................................

A.3.*.,.*e P" = 2" /ccess TransferC P" to 2" = 4ual 0adio incomin voice call in alertin phase................A.3.*.,.3 "ubse "inle 0adio.........................................................................A.3.*.,.:a P" > 2" /ccess TransferC P" to 2" > "inle 0adio with "ession "tate &nformation.......................A.3.*.,.:b P" to 2" /ccess TransferC P" to 2" > "inle 0adioD usin &, reference point................................

A.3.*.,.:c P" = 2" /ccess TransferC P" to 2" = "inle 0adio incomin voice or video call in alertinphase............................................................................................................................................ .....A.3.*.,.:d P" = 2" /ccess TransferC P" to 2" = "inle 0adio outoin voice or video call in pre=

alertin state or in alertin phase......................................................................................................

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A.3.*.,.:e P" = 2" /ccess TransferC P" to 2" = "inle 0adio voice and video...............................................A.3.*.,.- P" > 2" /ccess Transfer for voice and video 4ual 0adio..............................................................A.3.*.,.A P" > 2" /ccess TransferC P" to 2" > 4ual 0adio mid=call service with an active speech and

video session.....................................................................................................................................

A.3.*.,.B P" > 2" /ccess TransferC P" to 2" > 4ual 0adio mid=call service with one inactive speechand video session..............................................................................................................................

A.3.*.,.Ba P" = 2" /ccess TransferC P" to 2" = "inle 0adio mid=call service with an incomin waitincall in alertin phase.........................................................................................................................

A.3.*.,.Bb P" = 2" /ccess TransferC P" to 2" = "inle 0adio mid=call service with an outoin call inpre=alertin state or in alertin phase................................................................................................

A.3.*.,.Bc P" = 2" /ccess TransferC P" to 2" = "inle 0adio mid=call service with an incomin call inalertin phase and a held session......................................................................................................

A.3.*.,.E P" = 2" /ccess TransferC 2onferencin = for 5s not usin &2" capabilities.................................A.3.*.,.F P" > 2" /ccess TransferC P" to 2" > "inle 0adio usin /T29 enhancements.............................A.3.*.,.,+ P" = 2" /ccess TransferC 2" to P" = "inle 0adio..........................................................................A.3.*.* P" = P" /ccess Transfer.........................................................................................................................

A.3.*.*., P"=P" /ccess Transfer with full media transfer...............................................................................A.3.*.*.* P"=P" /ccess Transfer with partial media transfer..........................................................................A.3.*.*.3 P"=P" /ccess Transfer with full media transfer for an incomin call in early dialo phase...........

A.3.*.*.: P"=P" /ccess Transfer with full media transfer for an outoin call in early dialo phase............A.3.*.3 P" = P" in conjunction with P" = 2" /ccess Transfer...........................................................................

A.3.*.3., P" = P" in conjunction with P" = 2" /ccess TransferC P" to 2" for 5s not usin &2"capabilities........................................................................................................................................

A.3.*.3.* P" = P" in conjunction with P" = 2" /ccess TransferC 2" to P" for 5s not usin &2"capabilities........................................................................................................................................

A.3.*.3.3 P" > P" in conjunction with P" = 2" /ccess TransferC P" to 2" for 5s with &2" capabilities= 5sin Gm reference point..............................................................................................................

A.3.*.3.: P" = P" in conjunction with P" = 2" /ccess TransferC 2" to P" for 5s with &2" capabilities= 5sin Gm reference point..............................................................................................................

A.3.*.3.- P" > P" in conjunction with P" > 2" /ccess TransferC /ctive;eld sessions = 5sin Gmreference point..................................................................................................................................

A.3.*.3.A P" > P" in conjunction with P" > 2" /ccess TransferC plicit 2ommunication Transfer =

5sin Gm reference point.................................................................................................................A.3.*.3.B P" > P" in conjunction with P" > 2" /ccess TransferC 2onferencin = 5sin Gm reference

point.............................................................................................................................................. ....A.3.*.3.E P" > P" in conjunction with P" > 2" /ccess TransferC P" to 2" > usin &, reference point..........A.3.*.3.F P" = P" in conjunction with P" = 2" /ccess TransferC 2" to P" = usin &, reference point............A.3.*.3.,+ P" = P" in conjunction with P" = 2" /ccess TransferC P" to 2" for /ctive;eld sessions =

usin &, reference point....................................................................................................................

A.3.*.3.,, P" = P" in conjunction with P" = 2" /ccess TransferC 2" to P" for /ctive;eld sessions =usin &, reference point....................................................................................................................

A.3.3 Media /ddin4eletin................................................................................................................................A.3.3., 7ocal nd &nitiation caseC /ddin new P" media to eistin 2" session..............................................A.3.3.* 7ocal nd &nitiation caseC &ncorporatin eistin 2" media in new &M" "ession and Gm "ervice

2ontrol....................................................................................................................................................

A.3.3.3 7ocal nd &nitiation caseC /ddin P" media to &M" session with 2" media........................................A.3.3.: 0emote nd &nitiation caseC /ddin new P" media to eistin 2" session...........................................A.3.3.- 0emote nd &nitiation caseC &ncorporatin eistin 2" media in new &M" "ession and Gm

"ervice 2ontrol.......................................................................................................................................A.3.3.A 0emote nd &nitiation caseC /ddin P" media to &M" session with 2" media.....................................A.3.3.B 7ocal nd &nitiation case > 0emovin media from split 2" and P" sessions........................................

A.3.3.E 0emote nd &nitiation case > 0emovin media from split 2" and P" sessions....................................A.3.3.F 7ocal nd &nitiation caseC /ddin new P" media to eistin P" session..............................................A.3.3.,+ 0emote nd &nitiation caseC /ddin new P" media to eistin P" session...........................................A.3.3.,, 7ocal nd &nitiation caseC 0emovin media from split P" sessions......................................................A.3.3.,* 0emote nd &nitiation caseC 0emovin media from split P" sessions...................................................A.3.: ?oid..............................................................................................................................................................

A.3.- "ervice continuity for &2" 5 usin M"2 "erver assisted mid=call feature while maintainin 2"

media............................................................................................................................................................A.: Operator Policy and 5ser Preferences...............................................................................................................A.- ecution of supplementary services................................................................................................................A.-., General.........................................................................................................................................................

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A.-.* Oriinatin &dentification Presentation (O&P)..............................................................................................A.-.3 Oriinatin &dentification 0estriction (O&0)..............................................................................................A.-.: Terminatin &dentification Presentation (T&P)...........................................................................................A.-.- Terminatin &dentification 0estriction (T&0).............................................................................................

A.-.A 2ommunication 4iversion (24&?)............................................................................................................A.-.B 2ommunication ;old (;O74)..................................................................................................................

A.-.E 2ommunication 1arrin (21)....................................................................................................................A.-.F Messae @aitin &ndication (M@&)...........................................................................................................A.-.,+ 2onference (2O'9)...................................................................................................................................A.-.,, plicit 2ommunication Transfer (2T)...................................................................................................

A.-.,* /dvice of 2hare (/O2)...........................................................................................................................A.-.,3 2losed 5ser Groups (25G).......................................................................................................................A.-.,: Three=Party (3PTH)...................................................................................................................................A.-.,- 9leible /lertin (9/)................................................................................................................................A.-.,A 2ommunication @aitin (2@)..................................................................................................................A.-.,B 2ompletion of 2ommunications to 1usy "ubscriber (221")2ompletion of 2ommunications by 'o

0eply (22'0)...........................................................................................................................................A.-.,E 2ustomi!ed /lertin Tones (2/T).............................................................................................................A.-.,F Malicious 2ommunication &4entification (M2&4)...................................................................................

A.-.*+ 0everse 2harin.......................................................................................................................................A.-.*, Personal 'etwor# Manaement (P'M).....................................................................................................

A.-.** 2ustomi!ed 0inin "inal (20")............................................................................................................

Aa Procedures and flows for &nter=5 Transfer.......................................................................................Aa.+ &ntroduction.....................................................................................................................................................

Aa.+., ?oid............................................................................................................................................................Aa., &5T eneral procedures...................................................................................................................................Aa.,., General.......................................................................................................................................................Aa.,.* 0emote 7e 5pdate...................................................................................................................................Aa.* &nformation flows for 2ollaborative "ession establishment............................................................................Aa.*., stablish 2ollaborative "ession by transferrin media..............................................................................

Aa.*.* stablish 2ollaborative "ession with new media......................................................................................

Aa.*.3 stablish 2ollaborative "ession at oriinatin &M" session setup............................................................Aa.*.: stablish 2ollaborative "ession at terminatin &M" session setup............................................................Aa.3 Media Transfer within 2ollaborative "ession.................................................................................................Aa.3., 2ontroller 5 initiated media transfer from 2ontroller 5 to 2ontrollee 5..........................................Aa.3.,., 2ontroller 5 and 2ontrollee 5 belon to the same subscription.....................................................

Aa.3.,.* 2ontroller 5 and 2ontrollee 5 belon to different subscriptions...................................................Aa.3.* 2ontroller 5 initiated media transfer from 2ontrollee 5 to 2ontroller 5..........................................Aa.3.3 2ontroller 5 initiated media transfer from 2ontrollee 5 to another 2ontrollee 5.............................Aa.3.3., 2ontroller 5 and 2ontrollee 5s belon to the same subscription...................................................Aa.3.3.* 2ontroller 5 and 2ontrollee 5s belon to different subscriptions..................................................Aa.3.3a 2ontrollee 5 &nitiated Transfer Media from one 2ontrollee 5 to another 2ontrollee 5....................

Aa.3.: ?oid............................................................................................................................................................Aa.3.:., ?oid.......................................................................................................................................................

Aa.3.:.* ?oid.......................................................................................................................................................Aa.: Media addindeletinmodifyin within 2ollaborative "ession....................................................................Aa.:., 2ontroller 5 initiated add new media on 2ontroller 5.........................................................................Aa.:.* 2ontroller 5 initiated add new media on 2ontrollee 5........................................................................

Aa.:.*., 2ontroller 5 and 2ontrollee 5 belon to the same subscription.....................................................Aa.:.*.* 2ontroller 5 and 2ontrollee 5 belon to different subscriptions....................................................Aa.:.3 2ontroller 5 &nitiated 0elease Media (media flow on the 2ontroller 5)..............................................Aa.:.: 2ontroller 5 &nitiated 0elease Media (media flow on the 2ontrollee 5).............................................Aa.:.:., 2ontroller 5 and 2ontrollee 5 belon to the same subscription.....................................................Aa.:.:.* 2ontroller 5 and 2ontrollee 5 belon to different subscriptions...................................................

Aa.:.:a 2ontroller 5 initiated modify media (media flow on the 2ontrollee 5)...............................................Aa.:.:a., 2ontroller 5 and 2ontrollee 5 belon to the same &M" subscription............................................Aa.:.:a.* 2ontroller 5 and 2ontrollee 5 belon to different &M" subscriptions under the same operator

..............................................................................................................................................................Aa.:.- 2ontrollee 5 initiated release media on itself.........................................................................................Aa.:.A 2ontrollee 5 initiated modify media on itself.........................................................................................

Aa.:.A.+ General.................................................................................................................................................

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Aa.:.A., 2ontroller 5 and 2ontrollee 5 belon to the same &M" subscription............................................Aa.:.A.* 2ontroller 5 and 2ontrollee 5 belon different &M" subscriptions under the same operator

..............................................................................................................................................................Aa.:.Aa 2ontrollee 5 initiated add new media on another 2ontrollee 5...........................................................

Aa.:.B 0emote party initiated add new media.......................................................................................................Aa.:.E 0emote party initiated release media.........................................................................................................

Aa.:.F 0emote party initiated media modification................................................................................................Aa.:a Transfer of 2ollaborative "ession 2ontrol......................................................................................................Aa.:a., 2ontroller 5 transfers 2ollaborative "ession 2ontrol to a 2ontrollee 5 without Media Transfer

....................................................................................................................................................................

Aa.:a.* 2ontroller 5 transfers 2ollaborative "ession 2ontrol to another 5 with Media Transfer....................Aa.:a.3 Transfer of 2ollaborative "ession 2ontrol upon loss of 2ontroller 5....................................................Aa.:a.: Transfer of 2ollaborative "ession 2ontrol with media flows upon loss of 2ontroller 5........................Aa.:a.- Transfer of 2ollaborative "ession 2ontrol initiated by the taret 5.......................................................Aa.- 2ollaborative "ession release..........................................................................................................................Aa.-., 2ontroller 5 &nitiated 0elease 2ollaborative "ession.............................................................................

Aa.-.* 0emote Party &nitiated 0elease 2ollaborative "ession..............................................................................Aa.A &nter=5 Transfer without establishin a 2ollaborative "ession.....................................................................Aa.A., &nter=5 Transfer initiated by the source 5............................................................................................

Aa.A.* &nter=5 Transfer initiated by the taret 5..............................................................................................Aa.B ecution of supplementary services..............................................................................................................

Aa.B., General.......................................................................................................................................................Aa.B.* Oriinatin &dentification Presentation (O&P)............................................................................................Aa.B.3 Oriinatin &dentification 0estriction (O&0)..............................................................................................Aa.B.: Terminatin &dentification Presentation (T&P)...........................................................................................Aa.B.- Terminatin &dentification 0estriction (T&0).............................................................................................Aa.B.A 2ommunication 4iversion (24&?)............................................................................................................

Aa.B.B 2ommunication ;old (;O74)..................................................................................................................Aa.B.B., 2ontroller 5 invo#in the ;O74 service on the media flow on a 2ontrollee 5............................Aa.B.E 2ommunication 1arrin (21)....................................................................................................................Aa.B.F Messae @aitin &ndication (M@&)...........................................................................................................Aa.B.,+ 2onference (2O'9)...................................................................................................................................

Aa.B.,, plicit 2ommunication Transfer (2T)...................................................................................................Aa.B.,* /dvice of 2hare (/O2)...........................................................................................................................Aa.B.,3 2losed 5ser Groups (25G).......................................................................................................................Aa.B.,: Three=Party (3PTH)...................................................................................................................................Aa.B.,- 9leible /lertin (9/)................................................................................................................................Aa.B.,A 2ommunication @aitin (2@)..................................................................................................................Aa.B.,B 2ompletion of 2ommunications to 1usy "ubscriber (221")2ompletion of 2ommunications by 'o

0eply (22'0)...........................................................................................................................................Aa.B.,E 2ustomi!ed /lertin Tones (2/T).............................................................................................................Aa.B.,F Malicious 2ommunication &4entification (M2&4)...................................................................................Aa.B.*+ 0everse 2harin.......................................................................................................................................Aa.B.*, Personal 'etwor# Manaement (P'M).....................................................................................................Aa.B.** 2ustomi!ed 0inin "inal (20")............................................................................................................

Aa.E &5T taret discovery........................................................................................................................................Aa.E., General.......................................................................................................................................................Aa.E.* &nformation flow for &5T taret availability and capabilities discovery...................................................Aa.E.3 "ession 4iscovery......................................................................................................................................Aa.E.3., General.................................................................................................................................................Aa.E.3.* 4iscovery of onoin session information on other 5(s) belonin to same &M" subscription

..............................................................................................................................................................Aa.E.3.3 4iscovery of onoin session information on other 5(s) belonin to different &M"

subscription..........................................................................................................................................Aa.F &nter=5 Transfer &nitiated by Taret 5........................................................................................................Aa.F., 2ontroller 5 and 2ontrollee 5 belon to same &M" subscription........................................................Aa.F.,., &nitiated by 5 not participatin in onoin 2ollaborative "ession....................................................

Aa.F.,.* &nitiated by 2ontrollee 5 in onoin 2ollaborative "ession.............................................................

Aa.F.,.3 &5T solicited by a taret 5 without prior information about the eistin sessions...........................Aa.F.* 2ontroller 5 and 2ontrollee 5 belon to different &M" subscriptions.................................................Aa.F.*., &nitiated by 5 not participatin in the session = 2ollaborative "ession established..........................Aa.F.*.* &nitiated by 5 not participatin in onoin 2ollaborative "ession = media on 2ontrollee 5.........

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Aa.,+ Media 9low 0eplication by networ#...............................................................................................................Aa.,+., 0eplicatin media in networ# from 2ontroller 5 to another 5 belonin to same &M"

subscription................................................................................................................................................Aa.,+.* 0eplicatin media in networ# from 2ontroller 5 to another 5 belonin to different &M"

subscription................................................................................................................................................Aa.,+.3 0eplicatin media in networ# from 2ontroller 5 to another 5 belonin to same &M"

subscription = pull mode.............................................................................................................................Aa.,+.: 0eplicatin media in networ# from 2ontroller 5 to another 5 belonin to different &M"

subscription = pull mode.............................................................................................................................Aa.,, "ession 0eplication by remote party...............................................................................................................

Aa.,,., "ession replication initiated by taret 5..................................................................................................Aa.,,.* "ession replication initiated by source 5................................................................................................Aa.,,.3 "ession replication initiated by source 5 (different subscription)..........................................................Aa.,,.: "ession replication initiated by taret 5 (different subscription)............................................................Aa.,* 5ser authorisation and preferences..................................................................................................................

Ab ?oid....................................................................................................................................................

Ac Procedures and flows for "0?22 merency "ession.......................................................................Ac., &M" merency oriination flow for P" to 2" "0?22.................................................................................

Ac.* "0?22 session transfer of &M" emerency session for P" to 2"..................................................................Ac.3 "0?22 "upport for 5s in 'ormal Mode......................................................................................................Ac.: "0?22 "upport for 5s in 7imited "ervice Mode........................................................................................

B "ecurity...............................................................................................................................................B., General.............................................................................................................................................................B.* /ccess security for 2" 4omain.......................................................................................................................B.3 /ccess security for &M"..................................................................................................................................

E 2harin.............................................................................................................................................E., 2harin stratey.............................................................................................................................................E.* /ccountin stratey.........................................................................................................................................

Annex A (informative): Controller UE and Controllee UE operations...........................................

/., General...............................................................................................................................................

Annex B (informative): Change history............................................................................................

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!4e!4d

This Technical 0eport has been produced by the 3rd Generation Partnership Project (3GPP).

The contents of the present document are subject to continuin wor# within the T"G and may chane followin formalT"G approval. "hould the T"G modify the contents of the present document it will be re=released by the T"G with anidentifyin chane of release date and an increase in version number as followsC

?ersion .y.!

whereC

the first diitC

, presented to T"G for informationD

* presented to T"G for approvalD

3 or reater indicates T"G approved document under chane control.

y the second diit is incremented for all chanes of substance i.e. technical enhancements correctionsupdates etc.

! the third diit is incremented when editorial only chanes have been incorporated in the document.

I't4!du#ti!'

&M" based services can be provided with use of P" bearers and 2" bearers for the media. @hen usin 2" bearer formedia transport of &M" sessions interwor#in solutions for &M" 2entrali!ed "ervices as specified in T" *3.*F* I-J areused. &2" allows &M" sessions usin 2" bearers to be treated as standard &M" sessions for the purpose of &M" "ervice

2ontinuity. &2" defines sinallin mechanisms between the 5 and &M" for transport of information as neededfor service continuity when usin 2" access for media transport.

1oth &M" 2entrali!ed "ervices and &M" "ervice 2ontinuity specify functions which are provided by a "&P applicationserver.

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1 S#!$e

The present document specifies the architectural re

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I3J 3GPP T" *3.*+AC K?oice 2all 2ontinuity between 2" and &M"K.

I:J 3GPP T" *3.**EC K&P Multimedia "ubsystem (&M")D "tae *K.

I-J 3GPP T" *3.*F*C K&P Multimedia "ubsystem (&M") centrali!ed servicesD "tae *K.

IAJ ?oid.

IBJ OM/=074=4M=?,L*=*++A+A+*=2C Knabler 0elease 4efinition for OM/ 4eviceManaement 2andidate ?ersion ,.*K.

IEJ &T9 092 3*A, (une *++*)C K"&PC "ession &nitiation ProtocolK.

IFJ 3GPP T" **.,+,C K"ervice aspectsD "ervice principlesK.

I,+J 3GPP T" *3.*,AC K "inle 0adio ?oice 2all 2ontinuity ("0?22)D "tae *K.

I,,J 3GPP T" 33.,+*C K3G securityD "ecurity architectureK.

I,*J 3GPP T" 33.*+3C K/ccess security for &P=based servicesK.

I,3J 3GPP T" *3.*,EC K&P Multimedia (&M) session handlinD &M call modelD "tae *K.

I,:J 3GPP T" *3.++3C K'umberin addressin and identificationK.

I,-J 3GPP T" **.,B3C K&P Multimedia 2ore 'etwor# "ubsystem (&M") Multimedia Telephony "erviceand supplementary servicesD "tae ,K.

I,AJ 3GPP T" *:.A,+C K2ommunication ;O74 (;O74) usin &P Multimedia (&M) 2ore 'etwor# (2')

subsystemD Protocol specificationK.

I,BJ 3GPP T" *:.A+-C K2onference (2O'9) usin &P Multimedia (&M) 2ore 'etwor# (2') subsystemDProtocol specificationK.

I,EJ 3GPP T" *:.A*FC Kplicit 2ommunication Transfer (2T) usin &P Multimedia (&M) 2ore

'etwor# (2') subsystemD Protocol specificationK.

I,FJ 3GPP T" *:.A:BC K/dvice Of 2hare (/O2) usin &P Multimedia (&M)2ore 'etwor# (2')subsystemD Protocol "pecificationK.

I*+J 3GPP T" *:.A,AC KMalicious 2ommunication &dentification (M24&) usin &P Multimedia(&M)2ore 'etwor# (2') subsystemD Protocol "pecificationK.

I*,J 3GPP T" *:.A+:C K2ommunication 4iversion (24&?) usin &P Multimedia (&M)2ore 'etwor#(2') subsystemD Protocol specificationK.

I**J 3GPP T" *:.A,-C K2ommunication @aitin (2@) usin &P Multimedia (&M) 2ore 'etwor# (2')subsystemD Protocol "pecificationK.

I*3J 3GPP T" *3.,ABC K&P Multimedia "ubsystem (&M") emerency sessionsK.

I*:J 3GPP T" *:.++EC KMobile radio interface 7ayer 3 specificationD 2ore networ# protocolsD "tae 3K.

I*-J 3GPP T" *:.,:BC K2onferencin usin the &P Multimedia (&M) 2ore 'etwor# (2') subsystemD"tae 3K.

I*AJ 3GPP T" *:.**FC K&P multimedia call control protocol based on "ession &nitiation Protocol ("&P)and "ession 4escription Protocol ("4P)D "tae 3K.

I*BJ 3GPP T" *3.+A+C KGeneral Pac#et 0adio "ervice (GP0")D "ervice descriptionD "tae *K.

I*EJ 3GPP T" *3.:+,C KGeneral Pac#et 0adio "ervice (GP0") enhancements for volved 5niversal

Terrestrial 0adio /ccess 'etwor# (=5T0/') accessK.

I*FJ 3GPP T0 *A.F,,C K2odec(s) for 2ircuit="witched (2") multimedia telephony serviceD Terminalimplementor$s uideK.

3GPP

3GPP TS #3' %3&%&) (#)%*+%#%%$elease %3

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I3+J 3GPP T" *3.33:C K&P Multimedia "ubsystem (&M") /pplication 7evel Gateway (&M"=/7G) = &M"/ccess Gateway (&M"=/G@) interfaceK.

I3,J 3GPP T" *F.,A*C K&nterwor#in between the &M 2' subsystem and &P networ#sK.

I3*J 3GPP T" *A.,,,C K2odec for circuit switched multimedia telephony serviceD Modifications to;.3*:K.

3 ei'iti!'", "m!l" a'd a4e8iati!'"

3.1 ei'iti!'"

9or the purposes of the present document the terms and definitions in T0 *,.F+- I,J and the followin apply.

Access Leg:This is the call control le between the 5 and the "22 /"D also see T" *3.*F* I-J for the definition of/ccess 7e for &M" sessions which use the 2" media.

Access Transfer: Transfer at the &M"=level of one or more media paths of an onoin &M" session on one 5 betweenP" to 2" accessD or transfer at the &M"=level of both the sinallin and the media path of an onoin &M" session on a5 between different &P=2/'s.

Collaorative !ession:/ set of two or more /ccess 7es and related media on two or more 5s havin &M"subscriptions under the same operator that are presented as one 0emote 7e by the "22 /".

Collaorative !ession Control:The control operations on the 2ollaborative "ession which can only be performed bythe 2ontroller 5 e.. ability to release the 2ollaborative "ession to invo#e supplementary services and to authori!ere

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Local ,perating Environment #nformation:This is a set of parameters which can include access networ#(s)conditions and other parameters implementation specific which describe the local environment in which the 5 isoperatin.

"!C !erver assisted mid*call feat&re:9unctionality of the M"2 "erver the "22 /" and the 5 enablin P" = 2"/ccess Transfer for 5s not usin &2" capabilities while preservin the provision of mid=call services (inactive

sessions or sessions usin the 2onference service).'OT *C This terminoloy is often abbreviated as Kmid=call featureK or even Kmid=callK throuhout this

specification.

+re*alerting state:This is the state where the 5 can receive early media in the early dialoue phase.

'emote Leg:This is the call control le between the "22 /" and the remote party from the subscriber$s perspectiveD

also see T" *3.*F* I-J for the definition of 0emote 7e for &M" sessions which use the 2" media.

!ervice Control !ignalling +ath:/s defined in T" *3.*F* I-J.

!ession 'eplication:0eplication at the &M"=level of a session onoin in a source 5 at a taret 5. @hen the newindependent session is established at the taret 5 the state of the oriinal media is replicated e.. same playbac# stateD

same used media etc. is replicated.!ession !tate #nformation:&nformation of &M" session state sent by the "22 /" for enablement of P"=2" and 2"=P"/ccess Transfer of &M" multimedia=sessions when &2" 5 capabilities can not be used.

!ession Transfer:Transfer at the &M"=level of one or more of the session sinallin paths andor associated media flowpaths of an onoin &M" session while maintainin service continuity. "ession Transfer incorporates /ccess Transferand or &nter=5 Transfer.

!ession Transfer #dentifier (!T#):/n identifier used by the 5 to re

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/T9 merency /ccess Transfer 9unctioni92 &nitial 9ilter 2riteria&M0' &P Multimedia 0outin 'umber.&5T &nter=5 Transfer

O2" Online 2harin "ystem"2 "ervice 2ontinuity

"22 /" "ervice 2entrali!ation and 2ontinuity /pplication "erver"0?22 "inle 0adio ?oice 2all 2ontinuity"T& "ession Transfer &dentifier "T&=r"0 "ession Transfer &dentifier for 2" to P" "0?22

"T' "ession Transfer 'umber "T'="0 "ession Transfer 'umber = "inle 0adio="T'="0 merency "ession Transfer 'umber for "0?22

9i% le8el $4i'#i$le" a'd a4#%ite#tu4al 4e:ui4eme't"

.1 ;a"i# &""um$ti!'"

.1.0 Ge'e4al

&t is assumed that the 5 may be capable of transmittin and receivin simultaneously in multiple /ccess 'etwor#s orit may be capable of transmittin and receivin in only one /ccess 'etwor# at a time.

.1.1 PS-+S #e"" T4a'"e4

The followin assumptions apply for P"=2" /ccess TransferC

= 9unctions of &M" 2entrali!ed "ervices and &M" "ervice 2ontinuity are collocated in a sinle "22 /". 'ot all

functions are always re

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= the M"2 "erver has indicated its capability to support mid=call services in the reistration or indicates itscapability in the /ccess Transfer re

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= /ll media flow(s) within a multimedia session or a subset of media flow(s) within a multimedia session could besubject to session transfer procedures.

= &t shall be possible to reister a Public 5ser &dentity with multiple contact addresses (at the same or via separate5s) via &M" reistration procedures as defined in T" *3.**E I:J clause -.*.,. The number of allowedsimultaneous reistrations is defined by home operator policy.

= &t shall be possible to perform correlation of charin data from different access networ#s when servicecontinuity between these networ#s is performed.

= The 5 shall be &M" reistered before invo#in any "ession Transfer procedures.

= The filter criteria shall contain a condition that a 3rd=party reistration is performed via the &"2 interface for the"22 /".

= &t shall be possible to provide "0=?22 support for &M" emerency call from P" to 2" /ccess Transfer.

'OT *C The 2" to P" /ccess transfer for &M" emerency call "0?22 is not supported in this 0elease of thespecification.

.2.2 #e"" T4a'"e4 e:ui4eme't"= &t shall be possible to provide /ccess Transfer in the home networ# or in the visited networ# (if roamin) when

the user is movin between 3GPP access systems.

= &t shall be possible to provide /ccess Transfer when the user is movin between 3GPP and non=3GPP accesssystems.

= &t shall be possible to provide /ccess Transfer when the user is movin between non=3GPP access systems.

= &t shall be possible to provide /ccess Transfer between an /ccess 'etwor# that supports real=time media on the2" domain and non=real=time media on the P" domain and an &P=2/' that supports transport of all mediatypes.

= &f it is not possible or not desired (e.. due to user preferences andor operator policies) to transfer all the mediaflow(s) then a subset of the media flow(s) shall be transferred (if possible) and the remainin flow(s) will bereleased or #ept in the transferred out access.

= &t shall be possible for the 5 to add or remove one or more media flow(s) tofrom an onoin multimedia

session that it controls durin /ccess Transfer.

= &t shall be possible to provide /ccess Transfer when the P=2"29 chanes.

= &t shall be possible for the 5 to use &M" mechanisms to transfer its onoin multimedia sessions to a taret/ccess 'etwor# without re

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= The networ# shall reject &5T between 5s that are not authorised.

= The ;ostin "22 /" shall maintain the end=to=end session service state of a 5 enaed in &5T.

= &t shall be possible to eecute &5T Media 2ontrol 0elated Procedures in any order and any number of times fora iven session.

= The 2ontroller 5 shall maintain the 2ollaborative "ession 2ontrol for the session until the 2ollaborative"ession is released or until the 2ollaborative "ession 2ontrol is transferred to another 2ontroller capable 5.

= &t shall be possible for a 2ontroller 5 to initiate transfer of 2ollaborative "ession 2ontrol to another 2ontrollercapable 5 that has reistered a Public 5ser identity that shares the service profile with the Public 5ser identityused in the 2ollaborative "ession.

= &t shall be possible for a 2ontroller capable 5 to re

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= The selection of the media flows to be transferred may be based on the onoin multimedia session(s) on thesource 5(s) discovered by the taret 5(s) in pull mode.

= &t shall be possible for a 5 to re

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.3.1.2.2 #e"" T4a'"e4 (PS < +S) #!'#e$t"

&M" sessions established in 2" or P" /ccess 'etwor#s are anchored at the "22 /". /dditionally &M" media sessions

subject to 2" to P" or P" to 2" "0?22 can be anchored by the /T29. &M" sessions usin 2" bearer are established atsession setup or upon /ccess Transfer usin procedures specified in T" *3.*F* I-J.

P"=2" /ccess Transfer shall be provided accordin to the re

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= &f the /ccess Transfer re

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/" associated with a 2ontrollee 5 or associated with another 5 not participatin in the 2ollaborative "ession thathas issued an &5T service re

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= needed "T&D

= further session information (e.. active inactive conference call initiator conference 50& identifier of all

participants) as re

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0i"ure *+%1 IMS Service !entrali2ation and !ontinuity $eference Architecture hen usin" AT!0enhancements

&f the M"2 "erver is not enhanced for &2" the interface between M"2 "erver and /T29 is Mw.

&f the M"2 "erver is enhanced for &2" the interface between M"2 "erver and /T29 is &*.

&f the /T29 is co=located with P=2"29 the interface between /T29 and /TG@ is &

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= when third=party reister is received (as a result of a 5 is reisterin) and this third=party reister is relatedto a contact address for which "0?22 is provided clears any eistin "T'="0 that has been set andprovides to the ;""C

= home=networ# confiured "T'="0 if a third=party reister without a "T'="0 is receivedD or

= "T'="0 received in a third=party reister different from the eistin "T'="0 that has been set into ;""D

= when an /T29 is used provides after successful &M" reistration procedure the 2=M"&"4' and a routable

/ccess Transfer 5pdate = "ession Transfer &dentifier (/T5="T&) to the /T29D

= eecutes the transfer of the &M" session between different access networ#sD

= implements 3rd party call control (3pcc) upon session establishmentD

= provides /ccess Transfer specific charin dataD

= decides based on analysis of the various service continuity related input factors whether to updateprovisioned operator policy for /ccess TransferD

= enerates and updates operator policy by sendin operator policy to the 5 via OM/ 4M IBJ includin the

priority between the operator policy and user preferences that could be used also to initiate /ccess Transferprocedure for onoin sessions.

= in case it supports v"0?22 it provides information to the M"2 related whether the most recently active bi=

directional sessions is voice or voice N video to determine if it is should perform v"0?22 or "0?22procedure.

= if 2" to P" "0?22 is supported and indicated by the M"2 "erver the "22 /" provides to M"2 "erverC

= updated /T29 manaement 50& for the 5$s &M" reistration when available.

= updated reistration status of the 5$s &M" reistration.

= #nter*UE Transfer:The "22 /" performs the functions for enablement and eecution of &nter=5 Transfer

proceduresC

= eecutes the &M" &nter=5 Transfer related procedures between different 5s havin &M" subscriptionsunder the same operator connected via the same or different access networ#sD

= authori!es re

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5 assisted T=/4" (5 T=/4") may be used in order to enforce user preferences for 2" bearer or P" bearer forvoicevideo on 3GPP accesses.

= andling of m&ltiple media flo-s:The "22 /" provides functionality to combine andor split media flowsover one or more /ccess 'etwor#s as needed for "ession Transfers session termination or upon re

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= The 2ontroller 5 can initiate the release of a 2ollaborative "ession.

= The 2ontroller 5 can add into a 2ollaborative "ession it controls a 5 not yet involved in this 2ollaborative

"ession.

= The 2ontroller 5 can initiate the transfer of 2ollaborative "ession 2ontrol.

5.3.2.2.3 +!'t4!llee UE !le

/ny &M" 5 can ta#e the role of a 2ontrollee 5. &n this role the 2ontrollee 5 canC

= initiate the modification of a media flow which terminates on it.

= initiate the release of a media flow which terminates on it.

= accept or refuseC

= media modifications initiated by the remote party or by the 2ontroller 5 or other 2ontrollee 5s of thesame 2ollaborative "ession for media flow(s) it terminatesD

= media additions initiated by the 2ontroller 5 or other 2ontrollee 5s of the same 2ollaborative "ession or

by a remote party (in the last case this assumes that the 2ontroller 5 has accepted the addition and selectedthe 2ontrollee 5)D

= media transfers initiated by the 2ontroller 5 or other 2ontrollee 5s of the same 2ollaborative "ession forwhich the 2ontrollee 5 is the taret.

= initiate &5T Media 2ontrol 0elated Procedures if the 2ontrollee 5 is capable of &5T.

5.3.3 Eme4e'# #e"" T4a'"e4 u'#ti!' (E&T)

The merency /ccess Transfer 9unction (/T9) provides &M"=based mechanisms for enablin service continuity of&M" emerency sessions. &t is a function in the servin (visited if roamin) &M" networ# providin the procedures for

&M" emerency session anchorin and P" to 2" /ccess Transfer. The /T9 acts as a routin 1*15/ which invo#esthird party call control (3pcc) for enablement of /ccess Transfer.

The /T9 performs the session continuity when the /ccess Transfer re

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= instruct the /TG@ to anchor the media path for oriinatin and terminatin sessionsD

= #eep trac# of sessions (either in pre=alertin state alertin state active or held) to be able to perform /ccess

Transfer of the selected sessionD

= perform the /ccess Transfer and update the /TG@ with the new media path for the (2") access le withoutre

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5.3.5 #e"" T4a'"e4 Gatea (&TG>)

The /ccess Transfer Gateway (/TG@) is controlled by the /T29 and if "0?22 enhanced with /T29 is used stays inthe session media path for the duration of the call and after /ccess Transfer based on the local policy of the servin

networ#.

&t supports transcodin after "0?22 handover in case the media that was used prior to the handover is not supported bythe M"2 server.

4ependin on placement of the /T29 different physical nodes may be considered for the /TG@ i.e. &M"=/G@ orTrG@.

5.3.6 9SS

The ;"" shall allow the "22 /" to update the user profile with a new "T'="0. &n the case the /T29 is involved the"T'="0 will address the /T29 otherwise it will address the "22 /".

5.3.7 MS+ Se48e4

The M"2 "erver enhanced for "0?22 shall not provide announcement or other in=band media for any calls that havebeen transferred or are in the process of bein transferred (e.. bein in active held or alertin state).

5. Si'alli' a'd ea4e4 $at%" !4 IMS Se48i#e +!'ti'uit

5..1 Ge'e4al

The "22 /" is inserted in the sinallin path of all the &M" user$s sessionsD the "22 /" behaves as a "&P=/" asdescribed in T" *3.**E I:J to set up a 3pcc to control the bearer path of the session for enablement and eecution of

"ession Transfer.

5..2 Se""i!'" it% PS media l!(")

9iure -.:.*=, shows 3pcc at the "22 /" for enablement and eecution of "ession Transfers when the media flow(s)for the /ccess 7e is established via &P=2/'.

The fiure is for illustration of the 3pcc at the "22 /" and its use for "ession TransferD hence it only shows thesinallin and bearer components relevant to the enablement and eecution of "ession Transfers.

0i"ure *&,+%1 Si"nallin" and bearer paths for sessions ith PS media

3GPP

3GPP TS #3' %3&%&) (#)%*+%##.$elease %3

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5..2a Se""i!'" it% PS media l!(") u"i' &T+

9iure -.:.*a=, shows 3pcc at the /T29 and "22 /" for enablement and eecution of /ccess Transfers when themedia flow(s) for the /ccess 7e is established via &P=2/'.

The fiure is for illustration of the 3pcc at the /T29 and "22 /" and its use for /ccess TransferD hence it only shows

the sinallin and bearer components relevant to the enablement and eecution of /ccess Transfers.

0i"ure *&,a+%1 Si"nallin" and bearer paths for sessions ith PS media usin" AT!0

5..3 Se""i!'" it% +S media

9or details of sinallin and bearer paths when the media for the /ccess 7e is established via the 2" access seeT" *3.*F* I-J clause B.,.,. 9or illustration of 3pcc at the "22 /" for enablement and eecution of "ession Transferswith use of the Gm reference point the &, reference point and when not usin Gm or &, for service control sinallin

respectively refer to fiures B.,.,=, B.,.,=* and B.,.*=, in T" *3.*F* I-J clause B.,.

5..3a Se""i!'" it% +S media l!(") u"i' &T+

9iure -.:.3a=, shows 3pcc at the /T29 and "22 /" for enablement and eecution of 2" to P" /ccess Transfers

when the media flow(s) for the /ccess 7e is established via 2".

The fiure is for illustration of the 3pcc at the /T29 and "22 /" and its use for /ccess TransferD hence it only showsthe sinallin and bearer components relevant to the enablement and eecution of /ccess Transfers.

0i"ure *&,&3a+%1 Si"nalin" and bearer paths for sessions ith !S media usin" AT!0

'OTC &f the media path is not anchored in the /TG@ the media will o directly to the remote side.

3GPP

3GPP TS #3' %3&%&) (#)%*+%##/$elease %3

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5.5 IUT +!lla!4ati8e Se""i!'"

&5T for service continuity allows a multi media session to be split on the local end across two or more 5s that are partof a 2ollaborative "ession. 5s that are part of a sinle 2ollaborative "ession may belon to different &M"subscriptions under the same operator. 9iure -.-=,C provides sinallin and bearer architecture for a 2ollaborative"ession that involves three 5s belonin to two &M" subscriptions.

0i"ure *&*+%1 !ollaborative Session Si"nallin" and 4earer architecture

'OTC The media in 2ontroller 5 /, is optional.

The 2ontroller 5 (5 /,) provides the control for a 2ollaborative "ession usin &M" sinallin on an /ccess 7ebetween 2ontroller 5 /, and "22 /"=/. The 2ontroller 5 may transfer one or more media flow(s) to one or moretaret 5s (includin itself) by usin 2ollaborative "ession control (e.. in the "4P).

2ontrollee 5 /* and 2ontrollee 5 1, provide the control for the media established on each respective 5 usin &M"

sinallin on the /ccess 7e associated for the media.

"22 /"=/ in this fiure is the ;ostin "22 /" of the illustrated 2ollaborative "ession. "22 /"=/ combines the mediadescriptions and 2ollaborative "ession 2ontrol on the /ccess 7es and presents one 0emote 7e towards the remoteend.

"22 /"=1 in this fiure relays service re

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5.6 ee4e'#e &4#%ite#tu4e !4 SV++ eme4e'# "e""i!'

To allow "0?22 for &M" emerency session with P" to 2" /ccess Transfer procedures an /T9 is used foremerency sessions anchorin and transferrin. 9or the overall &M" emerency reference architecture with /T9 referto the reference architecture in T" *3.,AB I*3J.

6 P4!#edu4e" a'd l!" !4 #e"" T4a'"e4

6.0 I't4!du#ti!'

"ome of the followin fiures contain a bo labelled 2"&M" &ntermediate 'odes. This is abstraction for 2"&M"

functional elements that eist between the 5 and the "22 /" which could include amonst others M"2 "erverenhanced for &2" M"2 "erver enhanced for "0?22 or an MG29 and an M"2 "erver not enhanced for &2".

6.1 ei"t4ati!'

6.1.1 Ge'e4al

@henever the 5 ac

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0i"ure -&%+%1 IMS $e"istration usin" AT!0 enhancements

,. 5=, sends an initial "&P 0G&"T0 re

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B. The "22=/" determines based on operator policy or based on the outcome of "h=pull procedure that the user issubscribed for "0?22 via the presence of "T'="0 and that the 5 is "0?22 capable. &f the "T'="0 from the;"" is different from the "T'="0 received from the /T29 the "22 /" sends a "h=5pdate to provide the "T'="0 received from the /T29 to the ;"" from the /T29 in order to replace the "T'="0 pointin to the "22 /"

or the previously stored "T'="0 pointin to other /T29.

'OT -C &f an /T29 does not eist or the /T29 decided not to be included in step * the "22 /" allocates a "T'="0 that can be used to route to this "22 /" and provides it to the ;"" thereby replacin any previouslystored "T'="0 if the user is subscribed for "0?22. &f the user is not subscribed for "0?22 no "T'="0

is set or provided to the MM"G"'. &f a user chanes to not bein subscribed for "0?22 by the ;""the ;"" deletes the "T'="0 from the MM"G"'.

'OT AC "22 /" only needs to update the "T'="0 in the ;"" at initial reistration. &f the "T'="0 has notchaned since previous initial reistration there no update is performed towards MM.

E. The ;"" responds by sendin "h=5pdate 0esponse messae to the "22 /".

F. &f for a user subscribed for "0?22 the ;"" received a "T'="0 in stepB that is different from the stored "T'="0 it updates the stored "T' "0 and provides the updated "T'="0 to the MM"G"'. Otherwise thisprocedure is s#ipped.

,+. The MM"G"' stores the updated "T'="0 and responds to the ;"" with &nsert "ubscriber 4ata /nswermessae.

,,. The "22 /" returns *++ O% to the "=2"29.

The "22 /" informs the 5 "0?22 capability to /T29 durin &M" reistration by addressin the /T29 usin the/T29 manaement 50&. The "22 /" is able to retrieve the updated 5 "0?22 capability status by sendin "h=Pullmessae to the ;"" at any point. &f "22 /" detects the 5 "0?22 capability chane "22 /" then informs the /T29about the updated "0?22 capability of the 5 and the /T29 stores this information for decidin whether anchorin&M" voice oriinatin sessions at the /TG@ or not.

'OT BC The trier for "22 /" to poll the ;"" for the updated 5 "0?22 capability status is not specified inthis release of the specification.

'OT EC &f the 5 switches onoff its "0?22 capability durin the lifetime of &M" reistration and the "22 /"has not polled the ;"" in the meantime the "22 /" and /T29 will not have the updated value of

"0?22 capability.

6.1.3 ei"t4ati!' +S t! PS - Si'le adi!

6.1.3.1 IMS ei"t4ati!' UE

/s a prere

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0i"ure -&%&3+%1 Subscription to 567s IMS re"istration status

,. /s part of the &M" reistration from the M"2 "erver the M"2 "erver may indicate to the "22 /" the wish tobe updated with the 5$s &M" reistration status andor chanes to the /T29 manaement 50&.

*=3. &f the 5$s &M" reistration status chanes or the /T29 manaement 50& chanes for the 5$s &M"

reistration the "22 /" provides the information to the M"2 "erver. The 5 2" to P" "0?22 capability isalso provided in this messae and is not updated further.

6.2 =4ii'ati!' a'd Te4mi'ati!'

6.2.1 =4ii'ati!'

6.2.1.1 =4ii'ati!' P4!#edu4e"

5 initiated multimedia sessions are anchored at the "22 /" in order to enable &M" "ervice 2ontinuity. Oriinatini92 for the "2 subscriber results in routin of the session to the "22 /" in the home &M" networ# where the "22 /"

uses 3rd party call control as per T" *3.**E I:J to initiate a session to the remote party on behalf of the subscriber.

The "22 /" shall be the first /pplication "erver of any /pplication "ervers that need to remain in the path of the call

after "ession Oriination.

6.2.1.2 =4ii'ati' "e""i!'" t%at u"e +S media

The 5 oriinates sessions that use 2" media by followin the procedures specified in T" *3.*F* I-J clause B.3.*Oriinatin sessions that use 2" media.

3GPP

3GPP TS #3' %3&%&) (#)%*+%#3,$elease %3

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0i"ure -&%+%1 8ri"inatin" session that uses !S media

,. 5=, initiates a multimedia session to 5=* and ma#es use of 2" media. 5=, sends the re

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,. 5=, initiates an &M" multimedia session to 5=* and uses only P" media flow(s). The re

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Once the session is established the /T29 will act as the access transfer function in the call.

0i"ure -&3&3&*&3+%1 8ri"inatin" call setup over !S throu"h AT!0

,. The M"2 "erver receives the 2" setup messae.

*. The M"2 "erver initiates an &'?&T oriination accordin to T" *3.*F* I-J clause B.3 with the addition that itincludes the /T29 in the path durin the oriination (based on the retrieved /T29 manaement 50&). The&'?&T shall include the 2=M"&"4' to the /T29 for further correlation purposes.

3. The /T29 may decide whether to anchor the media session and allocate if needed /TG@ resources to it. Media

anchorin criteria used for /T29 enhancements apply.

:=-. The call setup proceeds and is routed to the remote 5=*.

A. The call setup is completed.

6.2.2 Te4mi'ati!'

6.2.2.1 Te4mi'ati!' P4!#edu4e"

&M" multimedia sessions towards "2 subscribers in the P" or in the 2" domain are anchored at the "22 /" to enable&M" "ervice 2ontinuity. The eecution of terminatin i92 results in routin of the sessions to the "22 /" in the home&M" networ# where the "22 /" uses 3rd party call control as per T" *3.**E I:J to terminate the session to the "2subscriber. The sessions may be delivered to the 5 via the P" or 2" access.

The "22 /" shall be the last /pplication "erver of any /pplication "ervers that need to remain in the path of the callafter "ession Termination.

6.2.2.2 Te4mi'ati' "e""i!'" t%at u"e +S media

The procedures specified in T" *3.*F* I-J clause B.:.* Terminatin sessions that use 2" media shall be followed to

terminate sessions that use 2" media to the "2 subscriber.

3GPP

3GPP TS #3' %3&%&) (#)%*+%#3'$elease %3

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0i"ure -+%1 Terminatin" session that uses !S media

,. / re

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0i"ure -&3+%1 Terminatin" session that uses only PS media

,. The re

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0i"ure -&*+%1 Terminatin" session that uses only PS media (AT!0 in si"nallin" path

,=*. / Terminatin session is sent towards 5=, from 5=*. The initial "&P &'?&T re

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0i"ure -&-+%1 Terminatin" call setup over !S throu"h AT!0

,=*. 5=* sends an &'?&T towards 5=,. The call is routed towards M"2 "erver usin procedure accordin toT" *3.*F* I-J clause B.:.

3. The M"2 "erver routes the &'?&T via /T29 usin the /T29 manaement 50& that it has received from "22/" (see clause A.,.3.*). The &'?&T shall include the 2=M"&"4' to the /T29 for further correlation purposes.

:. The /T29 may decide whether to anchor the media session and allocate if needed /TG@ resources to it. Mediaanchorin criteria used for /T29 enhancements apply.

-=A. The call setup proceeds and is routed toward 5=,.

B. The call setup is completed.

6.3 #e"" T4a'"e4

6.3.1 #e"" T4a'"e4 P4!#edu4e

6.3.1.1 I't4!du#ti!'

/ccess Transfer procedures enable service continuity between /ccess 'etwor#s. /ll /ccess Transfer proceduresassociated with a session includin initial and subse

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= &f the M"2 "erver assisted mid=call feature is used thenC

= if the 5 has more than one active bi=directional session selects the second most recently active bidirectional

session and it releases all remainin sessions ecept for the two most recently active bi=directional sessionsD

= if the 5 has one active bi=directional session and more than one inactive bi=directional session it releases allsessions ecept for the active session and the inactive session which became inactive most recently.

'OTC 9or the sinle=radio case the above applies but the 5 locally releases the sessions based on the

aforementioned priority.

9or v"0?22 procedure M"2 server enhanced for v"0?22 neotiates with the "22 /" to determine whether the mostrecently active bi=directional sessions is voice or voice N video.

/ new /ccess 7e is established by the 5 toward the "22 /" if needed. "inallin and bearer resources are allocatedin the transferrin=in /ccess 'etwor# and the user$s sessions are transferred from the transferrin=out /ccess 'etwor#.The "22 /" eecutes /ccess Transfer procedures. 0esources in the transferrin=out /ccess 'etwor# are subse

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The "T'="0 as specified in T" *3.*,A I,+J is used for P" to 2" /ccess Transfer usin "inle 0adio ?22.

6.3.1.3a E'aleme't ! #e"" T4a'"e4 $4!#edu4e" u"i' &T+ e'%a'#eme't"

&M" sessions and media flows are anchored by the /T29 upon session establishment for enablement of /ccess Transferusin /T29 enhancements. 9or both oriinatin and terminatin &M" sessions the /T29 subdivides the /ccess 7e

into a "ervin 7e and a ;ome 7e. 4urin reistration procedure the /T29 allocates an "T'="0 addressin itself andprovides it to the "22 /". The "22 /" provides the received "T'="0 to the ;"" and the ;"" provides the "T'="0to the servin node(s) i.e. to "G"' and or MM.

@hen 2" to P" "0?22 is supported a dynamic "T&=r"0 for /ccess Transfer shall be provided to the 5 by the /T29.

6.3.1. Ee#uti!' ! #e"" T4a'"e4 $4!#edu4e"

5pon detection of conditions re

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The remote end in fiure A.3.,.-=* represents an MG29 for 2"P"T' 0emote Party.

0i"ure -&3&%&*+#1 $emote 9e" 5pdate

,=*. These steps are the same procedures described in fiure A.3.,.-=,.

3. MG29 instructs MG@ to update a termination towards the Taret /ccess 7e to the contet and to release thetermination for the "ource /ccess 7e from the contet.

6.3.1.6 S!u4#e #e"" Le elea"e

@hen the session modification procedures are complete the "ource /ccess 7e 0elease is eecuted by initiatin asession release. This is done for the "ource /ccess 7e usin the /"5 session release procedures per T" *3.**E I:J.9or non=emerency sessions the 5 and the "22 /" shall initiate the "ession 0elease procedure when the switch tothe Taret /ccess 7e is complete. 9or emerency sessions the 5 and the /T9 shall initiate the "ession 0elease

procedure when the switch to the Taret /ccess 7e is complete. 9or (v)"0?22 the source access le release is onlyperformed if the 5 retains Gm after the P"=2" access transfer is completedD otherwise the 5 release the sourceaccess le locally.

6.3.1.7 #e"" T4a'"e4 I'!4mati!' !4 &T+

@hen "0?22 with /T29 enhancements are used a prere

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6.3.2 #e"" T4a'"e4 I'!4mati!' l!"

6.3.2.0 Ge'e4al

This clause details the procedures and flows for /ccess Transfers. &n the flows that pertain to &, the assumptionsspecified in clause B.+ of T" *3.*F* I-J apply.

9or P" = 2" /ccess Transfer both "inle 0adio and 4ual 0adio procedures are specified in the followin clauses. 4ual0adio is not supported between two different 3GPP 0/Ts (i.e. 3GPP specifications do not provide the possibility for a5 to transmitreceive on two 3GPP 0/Ts simultaneously). "inle 0adio P" = 2" /ccess Transfer re 2" /ccess TransferC P" to 2" = 4ual 0adio provides an information flow for /ccess Transferof an &M" session in P" to 2" direction. The flow re

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in the source /ccess 7e. The "22 /" performs the /ccess Transfer by updatin the 0emote 7e with theconnection information of the newly established /ccess 7e usin the 0emote 7e 5pdate procedure asspecified in clause A.3.,.-. The "22 /" completes the session setup towards 5 accordin to proceduresdefined in T" *3.**E I:J.

-. The "ource /ccess 7e (which is the /ccess 7e previously established over P" access) is released as specified

in clause A.3.,.A'OT *C "teps : and - consist of a se 4ual 0adio with "ession "tate &nformation provides aninformation flow for /ccess Transfer of an &M" session in P" to 2" direction. The flow re

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'OT *C The M"2 "erver has indicated its capability to support M"2 "erver assisted mid=call feature durin/ccess Transfer in the reistration.

3. "tandard procedures are used at &"=2"29 for routin of the &'?&T to the "22 /".

:. The "22 /" completes the establishment of the /ccess 7e via the 2" access. The "22 /" is able to identifythe correct anchored session usin the G055 for session identification. The "22 /" performs the /ccessTransfer of the recently added active session or if there is no active session the inactive session which wasactive most recently with bi=directional speech for the 5 by updatin the 0emote 7e with the connection

information of the newly established /ccess 7e usin the 0emote 7e 5pdate procedure as specified inclause A.3.,.-. The "22 /" completes the session setup towards the 5 accordin to procedures defined inT" *3.**E I:J.

-. The "22 /" provides "ession "tate &nformation on the transferrin=in le. &f there are more than two sessionswith speech media before session transfer in the source /ccess 7e the "22 /" performs the followinC

&f there are no active sessions the "22 /" performs the followinC

= besides the inactive session already handled in step : releases all other remainin inactive sessionsD

= includes the information that the session is inactive in the transfer response sent to the M"2 "erverD= s#ips followin handlin of step - A and B directly oes to step E in the information flow.

&f there are at least one active session the "22 /" performs the followinC

= if there are two or more active speech sessions selects the second=most recently active speech session puts iton hold and releases all remainin active sessionsD

= selects the held session that has been most recently made inactive. /ny other in=active sessions are released.

the "ession "tate &nformation of the selected inactive session is sent to the M"2 "erver.

A. The "=2"29 forwards the "ession "tate &nformation to the M"2 "erver.

B. &f the M"2 "erver receives the "ession "tate &nformation on more than one active or inactive speech sessions itinitiates /ccess Transfer towards the "22 /" for the additional session.

E. The "ource /ccess 7e (which is the /ccess 7e previously established over P" access) is released as specifiedin clause A.3.,.A.

'OT 3C "teps : and E consist of a se

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0i"ure -&3&%+%1 PS : !S Access Transfer1 !S to PS + ual $adio

,. @hen the 5 determines a need for /ccess Transfer the 5 initiates reistration with &M" (if not alreadyreistered in &M") as specified in clause A.,. &t subse

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0i"ure -&3&%a+%1 !S to PS Access Transfer + ual $adio ith Session State Information

,. @hen the 5 determines a need for /ccess Transfer the 5 initiates reistration with &M" (if not alreadyreistered in &M") as specified in T" *3.**E I:J. &t subse

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6.3.2.1.2# +S - PS #e"" T4a'"e4 +S t! PS - ual adi!, !ut!i' 8!i#e #all i' $4e-ale4ti' "tate !4 i' ale4ti' $%a"e

This procedure done accordin to the procedure in clause A.3.*.*.: with the followin amendment for steps ,=:C The5 has started a 2" session that is centrali!ed in &M" accordin to in T" *3.*F* I-J. The 5 is awaitin answer fromthe remote end.

1efore the remote end answers the 5 decides to move to P". The procedure follows as from step - in clause A.3.*.*.3.&P=2/' * represents the new P" le. The 5 uses the statically confiured "T& for the transfer.

6.3.2.1.2d PS - +S #e"" T4a'"e4 PS t! +S - ual adi!, !ut!i' 8!i#e !4 8ide! #all i'$4e-ale4ti' "tate !4 i' ale4ti' $%a"e

9iure A.3.*.,.*d=, P"=2"C P" to 2" = 4ual 0adio outoin voice or video call in early dialoue phase (alertin or pre=alertin) provides an information flow for 4ual 0adio /ccess Transfer of media of an &M" session in early dialouestate for the P" to 2" direction.

The flow re

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A. 5 starts the 4ual 0adio /ccess Transfer procedure by sendin a 2" setup messae destined to "T' accordinto T" *:.++E I*:J.

B. M"2 "erver routes the call towards the "T' received in -. &f the M"2 is not enhanced "2 sinallin will beused and the call setup messae will be routed throuh an MG29.

E. "tandard procedures are used at &"=2"29 for routein of the &'?&T to the "22 /".

F. The "22 /" uses the "T' to determine that /ccess Transfer usin 4ual 0adio ?22 is re

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0i"ure -&3&%e+%1 PS+!S1 PS to !S + ual $adio< incomin" voice or video call in alertin" phase

,=:. "tandard procedures are used to initiate a "&P session towards the 5. The 5 is alertin the user for the

incomin voice or video=call session.

-. 5 determines a need for /ccess Transfer to 2". &f the user is not attached to the 2" domain at this time the 5performs a 2" /ttach as specified in T" *3.*F* I-J clause B.*.,.

A. &n the onoin "&P session the 5 sends a "&P messae towards "22 /" which includes a re

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,*. 1ased on the response from the 5 the "22 /" performs a remote end update accordin to clause A.3.,.-.

,3. The source access le is released accordin to clause A.3.,.A as a conse

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,. Procedures specified in T" *3.*,A I,+J result in an &'?&T to be sent with an "T'="0 indicatin use of "0?22procedures for /ccess Transfer to 2" access. The M"2 "erver enhanced for "0?22 includes the 2=M"&"4' ascallin party number. &f "0?22 with priority is supported M"2 "erver enhanced for "0?22 also includes apriority indication if received.

*. "tandard procedures are used at &"=2"29 for routin of the &'?&T to the "22 /".

3. The "22 /" uses the "T'="0 to determine that /ccess Transfer usin "0?22 is re

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0i"ure -&3&%&,a+%1 PS+!S1 PS to !S : Sin"le $adio ith Session State Information

,. Procedures specified in T" *3.*,A I,+J result in an &'?&T to be sent with an "T'="0 indicatin use of "inle

0adio ?22 procedures for /ccess Transfer to 2" access. &f the user is not &M" reistered by the M"2 "erverthe M"2 "erver enhanced for "0?22 includes the 2=M"&"4' as callin party number. &f the user is reisteredin the &M" by the M"2 "erver then the M"2 "erver includes the G055 into the /ccess Transfer re

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= selects the held session that has been most recently made inactive. /ny other inactive sessions are releasedD

= the "ession "tate &nformation of the selected inactive session is sent to the M"2 "erver.

-. The "=2"29 forwards the "ession "tate &nformation to the M"2 "erver.

A. &f the M"2 "erver receives the "ession "tate &nformation of more than one active or inactive speech sessions it

initiates /ccess Transfer towards "22 /" for the additional session.

'OT :C The "22 /" uses the 2=M"&"4' or G055 to correlate the /ccess Transfer re

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0i"ure -&3&%&,b+%1 PS+!S1 PS to !S : Sin"le $adio; usin" I% reference point

,. /ccess Transfer of the active session with bi=directional speech is performed as defined in clause A.3.*.,.:steps ,=3.

*. The 5 sends an &,C &2" 2all &nitiation via the 2" access as specified in T" *3.*F* I-J includin an "T& forcontinuation of establishment of the /ccess 7e usin "inle 0adio ?22 for the active session.

3. The "22 /" uses the "T& to correlate the /ccess Transfer re

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6.3.2.1.# PS - +S #e"" T4a'"e4 PS t! +S - Si'le adi!, i'#!mi' 8!i#e !4 8ide! #all i'ale4ti' $%a"e

9iure A.3.*.,.:c=, P"=2"C P" to 2" = "inle 0adio incomin call in alertin phase provides an information flow for/ccess Transfer of media of an &M" session in P" to 2" direction for /ccess Transfers as specified in T" *3.*,A I,+J.

The flow re

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session transfer. 9or P"=2" transfer for v"0?22 the video 2odecs are also included in the session transferre

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directional speech and synchronised video for the 5 by updatin the 0emote 7e with the media descriptionand other information usin the 0emote 7e 5pdate procedure as specified in clause A.3.,.-.

'OT ,C &t is assumed the initial "4P neotiation has been completed prior to trierin the (v)"0?22 thus the"22 /" can update the remote le.

'OT *C The "22 /" uses the 2=M"&"4' or G055 to correlate the /ccess Transfer re

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0i"ure -&3&%&,e+%1 Information flo for voice and video transfer from PS to !S+ sin"le radio

,=*. "ee clause A.3.*.,.: steps , and *. M"2 "erver includes the "4P of the voice and video "4P of thepredefined 2odecs. &f v"0?22 with priority is supported M"2 "erver enhanc