new security context

When this parameter is present the SS will establish and take into account a new security context.

existing EPS security context

When this parameter is present the SS will take into account an existing EPS security context. A prerequisite for using this condition is the existence of an EPS security context

NOTE 1: If none of the defined condition parameters is present when the procedure is referred to then the SS will apply mapped 5G security context. A prerequisite for using this condition is the existence of 5G security context.

U – S

Message/PDU/SDU

–

EXCEPTION: Unless otherwise stated all the messages below are transmitted on the cell specified in the test case.

–

–

–

–

1

The UE transmits an RRCConnectionRequest message on the cell specified in the test case.

–>

RRC: RRCConnectionRequest

–

–

2

SS transmits an RRCConnectionSetup message.

<–

RRC: RRCConnectionSetup

–

–

3

The UE transmits an RRCConnectionSetupComplete message to confirm the successful completion of the connection establishment and a TRACKING AREA UPDATE REQUEST message is sent to update the registration of the actual tracking area.

For some consequences related to the content of the TRACKING AREA UPDATE REQUEST message see the Notes in Table 4.9.7.2.3-1.

–>

RRC: RRCConnectionSetupComplete NAS: TRACKING AREA UPDATE REQUEST

–

–

–

EXCEPTION: Steps 4a1-4b2 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

–

–

–

–

4a1

IF ‘new security context‘ THEN the SS transmits an AUTHENTICATION REQUEST message to initiate the EPS authentication and AKA procedure.

<–

RRC: DLInformationTransfer

NAS: AUTHENTICATION REQUEST

–

–

4a2

The UE transmits an AUTHENTICATION RESPONSE message and establishes mutual authentication.

–>

RRC: ULInformationTransfer

NAS: AUTHENTICATION RESPONSE

–

–

4a3

The SS transmits a NAS SECURITY MODE COMMAND message to activate NAS security.

<–

RRC: DLInformationTransfer

NAS: SECURITY MODE COMMAND

–

–

4a4

The UE transmits a NAS SECURITY MODE COMPLETE message and establishes the initial security configuration.

–>

RRC: ULInformationTransfer

NAS: SECURITY MODE COMPLETE

–

–

4b1

IF ‘existing EPS security context‘ THEN the SS transmits a NAS SECURITY MODE COMMAND message to activate NAS security.

<–

RRC: DLInformationTransfer

NAS: SECURITY MODE COMMAND

–

–

4b2

The UE transmits a NAS SECURITY MODE COMPLETE message and establishes the initial security configuration.

–>

RRC: ULInformationTransfer

NAS: SECURITY MODE COMPLETE

–

–

–

EXCEPTION: If none of the branches 4a or 4b takes place then the SS shall apply mapped 5G security context, otherwise the SS shall apply the security context depending on the branch.

–

–

–

–

5

SS responds with TRACKING AREA UPDATE ACCEPT message.

<–

RRC: DLInformationTransfer

NAS: TRACKING AREA UPDATE ACCEPT

–

–

6

Check: Does the UE transmit TRACKING AREA UPDATE COMPLETE?

–>

RRC: ULInformationTransfer

NAS: TRACKING AREA UPDATE COMPLETE

–

P

7a1

Void

–

–

–

–

–

EXCEPTION: Steps 8a1 to 8b2a8 describe a step sequence depending on test case scenario; the left-most "lower case letter" identifies a step sequence that take place if the test procedure is called in a particular scenario.

(NOTE 1)

–

–

–

–

8a1

IF Interworking without N26 interface supported THEN

The generic procedure for UE-requested PDN connection establishment, specified in subclause 4.5A.2B, takes place performing establishment of UE-requested PDN connection(s) with ExpectedNumberOfNewPDNConnections = pc_noOf_PDNsSameConnection.

–

–

–

–

–

EXCEPTION: Steps 8a2a1 to 8a2b1 describe a step sequence depending on test case scenario; the right-most "lower case letter" identifies a step sequence that take place if the UE performs a specific action.

–

–

–

–

8a2a1

IF pc_noOf_PDNsNewConnection>0 THEN the SS transmits an RRCConnectionRelease message to release RRC connection and moves the UE to RRC_IDLE.

<–

RRC: RRCConnectionRelease

–

–

8a2a2

The procedure E-UTRA RRC_IDLE Unrestricted nr PDN Extension as specified in Table 4.5.2.2-6 takes place.

–

–

–

–

8a2b1

ELSE IF connected without release is not present THEN, the SS transmits an RRCConnectionRelease message to release RRC connection and move to E-UTRA RRC_IDLE (State 2).

<–

RRC: RRCConnectionRelease

–

–

8b1

ELSE (i.e. ‘Interworking without N26 interface not supported’)

The generic procedure for UE-requested PDN connection establishment, specified in subclause 4.5A.2B, takes place performing establishment of UE-requested PDN connection(s) with ExpectedNumberOfNewPDNConnections = pc_noOf_PDNsSameConnection with the exception that IF step 2b1, Table 4.5A.2B.2.2-2 takes place THEN the SS shall not assign Fail but continue with the next step in the test sequence not expecting any additional connection establishment to take place (NOTE 2).

–

–

–

–

–

EXCEPTION: Steps 8b2a1 to 8b2b1 describe a step sequence depending on test case scenario; the right-most "lower case letter" identifies a step sequence that take place if the UE performs a specific action.

–

–

–

–

8b2a1

IF pc_noOf_PDNsNewConnection>0 THEN the SS transmits an RRCConnectionRelease message to release RRC connection and moves the UE to RRC_IDLE.

<–

RRC: RRCConnectionRelease

–

–

8b2a2

The procedure E-UTRA RRC_IDLE Unrestricted nr PDN Extension as specified in table 4.5.2.2-6 takes place.

For the referred in step 7, Table 4.5.2.2-6, generic procedure for UE-requested PDN connection establishment, specified in subclause 4.5A.2B, IF step 2b1, Table 4.5A.2B.2.2-2 takes place THEN the SS shall not assign Fail but continue with the next step in the test sequence not expecting any additional connection establishment to take place (NOTE 2).

–

–

–

–

8b2b1

ELSE IF connected without release is not present THEN, the SS transmits an RRCConnectionRelease message to release RRC connection and move to E-UTRA RRC_IDLE (State 2).

<–

RRC: RRCConnectionRelease

–

–

NOTE 1: The NWK will indicated whether Interworking without N26 interface is supported in the REGISTRATION ACCEPT message, IE ‘5GS network feature support’, IWK N26 bit. Consequently which branch would the procedure sequence go through will depend on the content of the REGISTRATION ACCEPT message applicable to e.g. the test case which calls the present test procedure.

NOTE 2: Depending on UE implementation and/or NWK behaviour, the UE may transfer some PDU sessions into PDN connections without re-establishing those utilising the relevant mapped QoS provided in the PDU SESSION ESTABLISHMENT ACCEPT message when the UE was on the NR cell. This will result in the number of established PDNs, if any, being lower than the pc_noOf_PDNsSameConnection or the pc_noOf_PDNsNewConnection which the UE will establish upon initial attach to the EPS.

Information Element

Value/remark

Comment

Condition

EPS update type

EPS update type Value

‘000’B or ‘001’B or ‘010’B

‘TA updating’ or ‘combined TA/LA updating’ or ‘combined TA/LA updating with IMSI attach’

"Active" flag

Any value

NAS key set identifier

the eKSI indicating the 5G NAS security context value assigned at the initial registration when the UE entered N1

Old GUTI

GUTI, mapped from the 5G-GUTI assigned at the initial registration when the UE entered N1

Additional GUTI

Not present or any allowed value

Last visited registered TAI

The TAI the last visited E-UTRA Cell belonged to, if any. Not included if the UE does not have last stored EPC TAI.

UE radio capability information update needed

‘1’B

UE radio capability information update needed

First-N1-to-S1

EPS bearer context status

Present, Content not checked

EBI corresponding to active PDN connections (transferred PDU Sessions) need to be set to 1

(NOTE 2)

Old GUTI type

"Native GUTI"

UE status

"UE is in 5GMM-REGISTERED state"

NOTE 1: The message shall be integrity protected using the 5GS security context available in the UE.

NOTE 2: There will be no PDN connection establishment nor explicit bearer configuration for the transferred PDU sessions. This means that the UE has created locally the default bearer context and the dedicated bearer context(s) based on the parameters of the mapped bearer contexts or the associations between QoS flow and mapped bearer in the PDU session. Although the contents of the IE is not required to be verified for PASS/FAIL purposes, the provided information shall be taken into account for building any subsequent RRC Reconfiguration message, and can be used e.g. for SS configuration purposes as well.

First-N1-to-S1

First N1 to S1 transition following UE registration in N1 mode

Information Element

Value/remark

Comment

Condition

NAS key set identifier_ASME

NAS key set identifier

An arbitrarily selected value between ‘000’B and ‘110’B, different from the valid NAS key set identifier of the UE if such a value exists.

Value shall be different to the 5G NAS security context value if there is one assigned

Information Element

Value/remark

Comment

Condition

NAS key set identifier_ASME

NAS key set identifier

The 4G NAS key set identifier assigned in step 4a1.

Information Element

Value/remark

Comment

Condition

NAS key set identifier_ASME

NAS key set identifier

The 4G NAS key set identifier assigned in the latest Authentication procedure.

Information Element

Value/remark

Comment

Condition

EPS network feature support

The IWK N26 (octet 4, bit 7) set to ‘1’

Interworking without N26 interface supported