release emergency PDU session

When this parameter is present the SS will release the emergency PDU session even if not requested by the UE after the release of the emergency call

keep emergency PDU session

When this parameter is present the SS will only release the emergency PDU session if requested by the UE, if not it will release the voice QoS after the release of the emergency call

NOTE 1: If the defined condition parameter is not present when the procedure is referred to then the default value ‘release emergency PDU session’ will apply

U – S

Message/PDU/SDU

1

Generic test procedure for MO Release of Voice Call / 5GS, as defined in Annex A.7 of TS 34.229-5 [47], is performed.

–

–

–

–

2-3

Void

–

–

–

–

3A1

SS starts timer T1 = 5 seconds.

–

–

–

–

–

EXCEPTION: Steps 3Ba1 to 3Bb2b3 describe a transaction that depends on the UE behaviour; the "lower case letter" identifies a step sequence that takes place if a specific behaviour happens.

–

–

–

–

3Ba1

The UE transmits a PDU SESSION RELEASE REQUEST message.

–>

NR RRC: ULInformationTransfer

5GMM: UL NAS TRANSPORT

5GSM: PDU SESSION RELEASE REQUEST

–

–

3Ba2

Stop timer T1

3Ba3

Test procedure for PDU Session Release specified in subclause 4.9.21 takes place

–

–

–

–

3Bb1

Timer T1 expires.

–

–

–

–

–

EXCEPTION: Steps 3Bb2a1 – 3Bb2b3 describe a step sequence depending on procedure parameters; the "lower case letter" identifies a step sequence that take place if a procedure parameter has a particular value

–

–

–

–

3Bb2a1

IF ‘release emergency PDU session’ THEN test procedure for PDU Session Release specified in subclause 4.9.21 takes place.

–

–

–

–

3Bb2b1

ELSE (i.e. ‘Keep emergency PDU session’) THEN the SS transmits a RRCReconfiguration message and a PDU SESSION MODIFICATION COMMAND message.

<–

NR RRC: RRCReconfiguration

5GMM: DL NAS TRANSPORT

5GSM: PDU SESSION MODIFICATION COMMAND

–

–

–

EXCEPTION: Steps 3Bb2b2 and 3Bb2b3 can occur in any order.

–

–

–

–

3Bb2b2

The UE transmits a RRCReconfigurationComplete

–

NR RRC: RRCReconfigurationComplete

–

–

3Bb2b3

Check: Does the UE transmit a PDU SESSION MODIFICATION COMPLETE message?

–>

NR RRC: ULInformationTransfer

5GMM: UL NAS TRANSPORT

5GSM: PDU SESSION MODIFICATION COMPLETE

–

P

4-5

Void

–

–

–

–

Information Element

Value/remark

Comment

Condition

RRCReconfiguration ::= SEQUENCE {

criticalExtensions CHOICE {

rrcReconfiguration SEQUENCE {

radioBearerConfig SEQUENCE {

drb-ToReleaseList SEQUENCE (SIZE (1..maxDRB)) OF DRB-Identity {

2 entries

DRB-Identity[1]

DRB-Identity linked to the IMS emergency signalling bearer

entry 1

DRB-Identity[2]

DRB-Identity linked to the IMS emergency speech bearer

entry 2

}

}

nonCriticalExtension SEQUENCE {

masterCellGroup SEQUENCE {

rlc-BearerToReleaseList SEQUENCE (SIZE (1..maxLC-ID)) OF LogicalChannelIdentity {

2 entries

logicalChannelIdentity[1]

Same value as drb-Identity[1] above

entry 1

logicalChannelIdentity[2]

Same value as drb-Identity[2] above

entry 2

}

}

}

}

}

}

Information Element

Value/remark

Comment

Condition

PDU session ID

Set according to the Emergency session ID.

5GSM cause

‘0010 0100’B

Regular deactivation

Information Element

Value/remark

Comment

Condition

PDU session ID

Set according to the Emergency session ID.

PTI

Any value from 1 to 254

Information Element

Value/remark

Comment

Condition

RRCReconfiguration ::= SEQUENCE {

criticalExtensions CHOICE {

rrcReconfiguration SEQUENCE {

radioBearerConfig SEQUENCE {

drb-ToReleaseList SEQUENCE (SIZE (1..maxDRB)) OF DRB-Identity {

1 entry

DRB-Identity

DRB-Identity linked to the IMS speech bearer

}

}

nonCriticalExtension SEQUENCE {

masterCellGroup SEQUENCE {

rlc-BearerToReleaseList SEQUENCE (SIZE (1..maxLC-ID)) OF LogicalChannelIdentity {

1 entry

LogicalChannelIdentity

Same value as drb-Identity above

}

}

}

}

}

}

Information Element

Value/remark

Comment

Condition

PDU session ID

Set according to the Emergency session ID

Authorized QoS rules

QoS rule

QoS rule identifier

‘00000011’B

QoS rule 3

Rule operation code

‘010’B

Delete existing QoS rule

Authorized QoS flow descriptions

QoS flow descriptions

QFI

‘00000111’B

QFI 7

Operation code

‘010’B

Delete existing QoS flow