F.2 PS to CS SRVCC

24.2373GPPIP Multimedia (IM) Core Network (CN) subsystem IP Multimedia Subsystem (IMS) service continuityRelease 17Stage 3TS

F.2.1 Key to interpret PS to CS SRVCC access transfer scenarios

The key to interpret the PS to CS SRVCC access transfer scenarios given in tables F.2. 2-1, F.2.2-2 and F.2.3-1 is specified below:

– "MAM" represents support of MSC server assisted mid-call feature

– "ALP" represents support of PS to CS SRVCC for calls in alerting phase

– "PAP" represents support of PS to CS SRVCC for originating calls in pre-alerting phase

– "CAS" represents a session with active speech media component, which is a confirmed dialog

– "CIS" represents a session with inactive speech media component, which is a confirmed dialog

– "EAS" represents a session with active speech media component in alerting phase

– "EAST" represents a terminating session with active speech media component in alerting phase

– "EASO" represents an originating session with active speech media component in alerting phase

– "EPS" represents a session with active speech media component in pre-alerting phase

– "EPST" represents a terminating session with active speech media component in pre-alerting phase

– "EPSO" represents an originating session with active speech media component in pre-alerting phase

– "CACS" represents a session with active speech media component and with conference control, which is a confirmed dialog

– "CICS" represents a session with inactive speech media component and with conference control, which is a confirmed dialog

– "Transfer CACS as CAS" refers to the behaviour of the SCC AS to transfer CACS, but without conference control

– "Transfer CICS as CIS" refers to the behaviour of the SCC AS to transfer CICS, but without conference control

– When "Result in network" is to transfer a session, the Transaction Identifier (TI) assigned to the call is shown in brackets, e.g. Transfer CAS (TI=0) refers to a TI of zero assigned to this call that is transferred.

F.2.2 PS to CS SRVCC access transfer scenarios

Table  F.2.2-1 describes PS to CS SRVCC access transfer scenarios considering only cases when only one session in an early phase exists.

Table F.2.2-1: PS to CS SRVCC access transfer scenarios, single early session

UE and Network Support Combination

Access Transfer Scenario

Result in network

UE supports at least MAM and Network supports MAM only

or

UE supports MAM only and Network supports at least MAM

CAS only

Transfer CAS (TI=0)

CIS only

Transfer CIS (TI=0)

EAS only

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

EPS only

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

CAS + CIS

Transfer CAS (TI=0) and transfer CIS (TI=1)

CAS + EAST

Transfer CAS (TI=0) and release EAST

CAS + EPST

Transfer CAS (TI=0) and release EPST

CIS + EASO

Transfer CIS (TI=0) and release EASO

CIS + EAST

Transfer CIS (TI=0) and release EAST

CIS + EPSO

Transfer CIS (TI=0) and release EPSO

CAS + CIS + EAST

Transfer CAS (TI=0), transfer CIS (TI=1) and release EAST

CAS + CIS + EPST

Transfer CAS (TI=0), transfer CIS (TI=1) and release EPST

UE supports ALP only and Network supports at least ALP

or

UE supports at least ALP and network supports ALP only

CAS only

Transfer CAS (TI=0)

CIS only

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

EAS only

Transfer EAS (TI=0)

EPS only

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

CAS + CIS

Transfer CAS (TI=0) and release CIS

CAS + EAST

Transfer CAS (TI=0) and transfer EAST (TI=1)

CAS + EPST

Transfer CAS (TI=0) and release EPST

CIS + EASO

Transfer EASO (TI=0) and release CIS

CIS + EAST

Transfer EAST (TI=0) and release CIS

CIS + EPSO

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

CAS + CIS + EAST

Transfer CAS (TI=0), transfer EAST (TI=1) and release CIS

CAS + CIS + EPST

Transfer CAS (TI=0), release CIS, release EPST

UE supports ALP+PAP only and Network supports at least ALP+PAP

or

UE supports at least ALP+PAP and Network supports ALP+PAP only

CAS only

Transfer CAS (TI=0)

CIS only

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

EAS only

Transfer EAS (TI=0)

EPSO only

Transfer EPSO (TI=0)

EPST only

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

CAS + CIS

Transfer CAS (TI=0) and release CIS

CAS + EAST

Transfer CAS (TI=0) and transfer EAST (TI=1)

CAS + EPST

Transfer CAS (TI=0) and release EPST

CIS + EASO

Transfer EASO (TI=0) and release CIS

CIS + EAST

Transfer EAST (TI=0) and release CIS

CIS + EPSO

Transfer EPSO (TI=0) and release CIS

CAS + CIS + EAST

Transfer CAS (TI=0), transfer EAST (TI=1) and release CIS

CAS + CIS + EPST

Transfer CAS (TI=0), release CIS, release EPST

UE and Network support MAM+ALP+PAP

CAS only

Transfer CAS (TI=0)

CIS only

Transfer CIS (TI=0)

EAS only

Transfer EAS (TI=0)

EPSO only

Transfer EPSO (TI=0)

EPST only

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

CAS + CIS

Transfer CAS (TI=0) and transfer CIS (TI=1)

CAS + EAST

Transfer CAS (TI=0) and transfer EAST (TI=1)

CAS + EPST

Transfer CAS (TI=0) and release EPST

CIS + EASO

Transfer CIS (TI=0) and transfer EASO (TI=1)

CIS + EAST

Transfer CIS (TI=0) and transfer EAST (TI=1)

CIS + EPSO

Transfer CIS (TI=0) and transfer EPSO (TI=1)

CAS + CIS + EAST

Transfer CAS (TI=0), transfer CIS (TI=1) and release EAST

NOTE 1: Even though the UE and network can support the transfer of EAST, the network will only transfer CAS and CIS and will release EAST.

CAS + CIS + EPST

Transfer CAS (TI=0), transfer CIS (TI=1) and release EPST

UE supports MAM+ ALP only and Network supports at least MAM+ALP

or

UE supports

at least MAM+

ALP and Network supports MAM+ALP only

CAS only

Transfer CAS (TI=0)

CIS only

Transfer CIS (TI=0)

EAS only

Transfer EAS (TI=0)

EPS only

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

CAS + CIS

Transfer CAS (TI=0) and transfer CIS (TI=1)

CAS + EAST

Transfer CAS (TI=0) and transfer EAST (TI=1)

CAS + EPST

Transfer CAS (TI=0) and release EPST

CIS + EASO

Transfer CIS (TI=0) and transfer EASO (TI=1)

CIS + EAST

Transfer CIS (TI=0) and transfer EAST (TI=1)

CIS + EPSO

Transfer CIS (TI=0) and release EPSO

CAS + CIS + EAST

Transfer CAS (TI=0), transfer CIS (TI=1) and release EAST

NOTE 2: Even though the UE and network can support the transfer of EAST, the network will only transfer CAS and CIS and will release EAST.

CAS + CIS + EPST

Transfer CAS (TI=0), Transfer CIS (TI=1), release EPST

UE has no MAM support and Network supports MAM only

or

UE supports MAM only and Network has no MAM support

CAS only

Transfer CAS (TI=0)

CIS only

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

EAS only

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

EPS only

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

CAS + CIS

Transfer CAS (TI=0) and release CIS

CAS + EAST

Transfer CAS (TI=0) and release EAST

CAS + EPST

Transfer CAS (TI=0) and release EPST

CIS + EASO

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

CIS + EAST

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

CIS + EPSO

Send SIP 480 (Temporary Unavailable) to reject SIP INVITE request due to STN-SR

CAS + CIS + EAST

Transfer CAS (TI=0), release CIS and release EAST

CAS + CIS + EPST

Transfer CAS (TI=0), release CIS and release EPST

Table F.2.2-2 below describes PS to CS SRVCC access transfer scenarios when more than one session in an early phase exists and when the UE and the network supports SRVCC access transfer for calls in an early phase.

Table F.2.2-2: PS to CS SRVCC access transfer scenarios, multiple early sessions

UE and Network Support Combination

Access Transfer Scenario

Result in network

UE supports ALP only and Network supports at least ALP

or

UE supports at least ALP and network supports ALP only

EASO + EAST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

EPSO + EPST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

EAS + EPS

Transfer EAS (TI=0) and release EPS

CAS + EAS + EPS

Transfer CAS (TI=0), transfer EAS (TEI=1) and release EPS

CAS + EASO + EAST

Transfer CAS (TI=0), release EASO and release EAST

CIS + EAS + EPS

Transfer EAS (TI=0), release CIS and release EPS

CIS + EASO + EAST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

CIS + EPSO + EPST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

UE supports ALP+PAP only and Network supports at least ALP+PAP

or

UE supports at least ALP+PAP and Network supports ALP+PAP only

EASO + EAST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

EPSO + EPST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

EAS + EPS

Transfer EAS (TI=0) and release EPS

CAS + EAS + EPS

Transfer CAS (TI=0), transfer EAS (TI=1) and release EPS

CAS + EASO + EAST

Transfer CAS (TI=0), release EASO and release EAST

CIS + EAS + EPS

Transfer EAS (TI=0), release CIS and release EPS

CIS + EASO + EAST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

CIS + EPSO + EPST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

UE and Network support MAM+ALP+PAP

EASO + EAST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

EPSO + EPST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

EAS + EPS

Transfer EAS (TI=0) and release EPS

CAS + EAS + EPS

Transfer CAS (TI=0), transfer EAS (TI=1) and release EPS

CAS + EASO + EAST

Transfer CAS (TI=0), release EASO and release EAST

CIS + EAS + EPS

Transfer CIS (TI=0), transfer EAS (TI=1) and release EPS

CIS + EASO + EAST

Transfer CIS (TI=0), release EASO and release EAST

CIS + EPSO + EPST

Transfer CIS (TI=0), release EPSO and release EPST

UE supports MAM+ ALP only and Network supports at least MAM+ALP

or

UE supports

at least MAM+

ALP and Network supports MAM+ALP only

EASO + EAST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

EPSO + EPST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

EAS + EPS

Transfer EAS (TI=0) and release EPS

CAS + EAS + EPS

Transfer CAS (TI=0), transfer EAS (TI=1) and release EPS

CAS + EASO + EAST

Transfer CAS (TI=0), release EASO and release EAST

CIS + EAS + EPS

Transfer CIS (TI=0), transfer EAS (TI=1) and release EPS

CIS + EASO + EAST

Transfer CIS (TI=0), release EASO and release EAST

CIS + EPSO + EPST

Transfer CIS (TI=0), release EPSO and release EPST

F.2.3 PS to CS SRVCC access transfer scenarios with conference control

Table F.2.3-1: PS to CS SRVCC access transfer scenarios with conference control

UE and Network Support Combination

Access Transfer Scenario

Result in network

UE supports at least MAM and Network supports MAM only

or

UE supports MAM only and Network supports at least MAM

CACS only

Transfer CACS (NOTE 1)

CICS only

Transfer CICS (NOTE 1)

CACS + CIS

Transfer CACS (NOTE 1) and transfer CIS (TI=1)

CAS + CICS

Transfer CAS (TI=0) and transfer CICS (NOTE 2)

CACS + EAST

Transfer CACS (NOTE 1) and release EAST

CACS + EPST

Transfer CACS (NOTE 1) and release EPST

CICS + EASO

Transfer CICS (NOTE 1) and release EASO

CICS + EAST

Transfer CICS (NOTE 1) and release EAST

CICS + EPSO

Transfer CICS (NOTE 1) and release EPSO

CACS + CIS + EAST

Transfer CACS (NOTE 1), transfer CIS (TI=1) and release EAST

CAS + CICS + EAST

Transfer CAS (TI=0), transfer CICS (NOTE 2) and release EAST

CACS + CIS + EPST

Transfer CACS (NOTE 1), transfer CIS (TI=1) and release EPST

CAS + CICS + EPST

Transfer CAS (TI=0), transfer CICS (NOTE 2) and release EPST

CACS + CICS

Transfer CACS (NOTE 1) and transfer CICS as CIS (TI=1)

CACS + CICS + EAST

Transfer CACS (NOTE 1), transfer CICS as CIS (TI=1) and release EAST

CACS + CICS + EPST

Transfer CACS (NOTE 1), transfer CICS as CIS (TI=1) and release EPST

UE supports ALP only and Network supports at least ALP

or

UE supports at least ALP and network supports ALP only

CACS only

Transfer CACS as CAS (TI=0)

CICS only

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

CACS + CIS

Transfer CACS as CAS (TI=0) and release CIS

CAS + CICS

Transfer CAS (TI=0) and release CICS

CACS + EAST

Transfer CACS as CAS (TI=0) and transfer EAST (TI=1)

CACS + EPST

Transfer CACS as CAS (TI=0) and release EPST

CICS + EASO

Transfer EASO (TI=0) and release CICS

CICS + EAST

Transfer EAST (TI=0) and release CICS

CICS + EPSO

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

CACS + CIS + EAST

Transfer CACS as CAS (TI=0), transfer EAST (TI=1) and release CIS

CAS + CICS + EAST

Transfer CAS (TI=0), transfer EAST (TI=1) and release CICS

CACS + CIS + EPST

Transfer CACS as CAS (TI=0), release CIS and release EPST

CAS + CICS + EPST

Transfer CAS (TI=0), release CICS and release EPST

CACS + CICS

Transfer CACS as CAS (TI=0) and release CICS

CACS + CICS + EAST

Transfer CACS as CAS (TI=0), transfer EAST (TI=1) and release CICS

CACS + CICS + EPST

Transfer CACS as CAS (TI=0), release CICS and release EPST

UE supports ALP+PAP only and Network supports at least ALP+PAP

or

UE supports at least ALP+PAP and Network supports ALP+PAP only

CACS only

Transfer CACS as CAS (TI=0)

CICS only

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

CACS + CIS

Transfer CACS as CAS (TI=0) and release CIS

CAS + CICS

Transfer CAS (TI=0) and release CICS

CACS + EAST

Transfer CACS as CAS (TI=0) and transfer EAST (TI=1)

CACS + EPST

Transfer CACS as CAS (TI=0) and release EPST

CICS + EASO

Transfer EASO (TI=0) and release CICS

CICS + EAST

Transfer EAST (TI=0) and release CICS

CICS + EPSO

Transfer EPSO (TI=0) and release CICS

CACS + CIS + EAST

Transfer CACS as CAS (TI=0), transfer EAST (TI=1) and release CIS

CAS + CICS + EAST

Transfer CAS (TI=0), transfer EAST (TI=1) and release CICS

CACS + CIS + EPST

Transfer CACS as CAS (TI=0), release CIS and release EPST

CAS + CICS + EPST

Transfer CAS (TI=0), release CICS and release EPST

CACS + CICS

Transfer CACS as CAS (TI=0) and release CICS

CACS + CICS + EAST

Transfer CACS as CAS (TI=0), transfer EAST (TI=1) and release CICS

CACS + CICS + EPST

Transfer CACS as CAS (TI=0), release CICS and release EPST

UE and Network support MAM+ALP+PAP

CACS only

Transfer CACS (NOTE 1)

CICS only

Transfer CICS (NOTE 1)

CACS + CIS

Transfer CACS (NOTE 1) and transfer CIS (TI=1)

CAS + CICS

Transfer CAS (TI=0) and transfer CICS (NOTE 2)

CACS + EAST

Transfer CACS (NOTE 1) and transfer EAST (TI=1)

CACS + EPST

Transfer CACS (NOTE 1) and release EPST

CICS + EASO

Transfer CICS (NOTE 1) and transfer EASO (TI=1)

CICS + EAST

Transfer CICS (NOTE 1) and transfer EAST (TI=1)

CICS + EPSO

Transfer CICS (NOTE 1) and transfer EPSO (TI=1)

CACS + CIS + EAST

Transfer CACS (NOTE 1), transfer CIS (TI=1), release EAST

CAS + CICS + EAST

Transfer CAS (TI=0), transfer CICS (NOTE 2), release EAST

CACS + CIS + EPST

Transfer CACS (NOTE 1), transfer CIS (TI=1), release EPST

CAS + CICS + EPST

Transfer CAS (TI=0), transfer CICS (NOTE 2), release EAST

CACS + CICS

Transfer CACS (NOTE 1) transfer CICS as CIS (TI=1)

CACS + CICS + EAST

Transfer CACS (NOTE 1), transfer CICS as CIS (TI=1) and release EAST

CACS + CICS + EPST

Transfer CACS (NOTE 1), transfer CICS as CIS (TI=1) and release EPST

UE supports MAM+ ALP only and Network supports at least MAM+ALP

or

UE supports

at least MAM+

ALP and Network supports MAM+ALP only

CACS only

Transfer CACS (NOTE 1)

CICS only

Transfer CICS (NOTE 1)

CACS + CIS

Transfer CACS (NOTE 1) and transfer CIS (TI=1)

CAS + CICS

Transfer CAS (TI=0) and transfer CICS (NOTE 2)

CACS + EAST

Transfer CACS (NOTE 1) and transfer EAST (TI=1)

CACS + EPST

Transfer CACS (NOTE 1) and release EPST

CICS + EASO

Transfer CICS (NOTE 1) and transfer EASO (TI=1)

CICS + EAST

Transfer CICS (NOTE 1) and transfer EAST (TI=1)

CICS + EPSO

Transfer CICS (NOTE 1) and release EPSO

CACS + CIS + EAST

Transfer CACS (NOTE 1), transfer CIS (TI=1), release EAST

CAS + CICS + EAST

Transfer CAS (TI=0), transfer CICS (NOTE 2), release EAST

CACS + CIS + EPST

Transfer CACS (NOTE 1), transfer CIS (TI=1), release EPST

CAS + CICS + EPST

Transfer CAS (TI=0), transfer CICS (NOTE 2), release EAST

CACS + CICS

Transfer CACS (NOTE 1) and transfer CICS as CIS (TI=1)

CACS + CICS + EAST

Transfer CACS (NOTE 1), transfer CICS as CIS (TI=1) and release EAST

CACS + CICS + EPST

Transfer CACS (NOTE 1), transfer CICS as CIS (TI=1) and release EPST

UE has no MAM support and Network supports MAM only

or

UE supports MAM only and Network has no MAM support

CACS only

Transfer CACS as CAS (TI=0)

CICS only

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

CACS + CIS

Transfer CACS as CAS (TI=0) and release CIS

CAS + CICS

Transfer CAS (TI=0) and release CICS

CACS + EAST

Transfer CACS as CAS (TI=0) and release EAST

CACS + EPST

CICS + EASO

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

CICS + EAST

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

CICS + EPSO

Send SIP 480 (Temporarily Unavailable) to reject SIP INVITE request due to STN-SR

CACS + CIS + EAST

Transfer CACS as CAS (TI=0), release CIS and release EAST

CAS + CICS + EAST

Transfer CAS (TI=0), release CICS and release EAST

CACS + CIS + EPST

Transfer CACS as CAS (TI=0), release CIS and release EPST

CAS + CICS + EPST

Transfer CAS (TI=0), release CICS and release EAST

CACS + CICS

Transfer CACS as CAS (TI=0) and release CICS

CACS + CICS + EAST

Transfer CACS as CAS (TI=0), release CICS and release EAST

CACS + CICS + EPST

Transfer CACS as CAS (TI=0), release CICS and release EPST

NOTE 1: TIs are calculated as in the table 9.2.1A-2 with the offsets 0, 2, 3, 4, 5 assigned to the participants in their order in the list of the extracted participants.

NOTE 2: TIs are calculated as in the table 9.2.1A-2 with the offsets 0, 1, 2, 3, 4 assigned to the participants in their order in the list of the extracted participants

F.2.4 Void