22.4.16 NB-IoT / RRC connection suspend-resume / Failure / Network reject

36.523-13GPPEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Packet Core (EPC)Part 1: Protocol conformance specificationRelease 16TSUser Equipment (UE) conformance specification

22.4.16.1 Test Purpose (TP)

(1)

with { NB-IoT UE transmitting RRCConnectionResumeRequest-NB message including the stored resumeIdentity and AS security context }

ensure that {

when { NB-IoT UE receives a RRCConnectionReject-NB message without including rrc-SuspendIndication IE }

then { NB-IoT UE discards the stored resumeIdentity along with AS security context and transmits RRCConnectionRequest-NB message to establish a new RRC Connection }

}

(2)

with { NB-IoT UE transmitting RRCConnectionResumeRequest-NB message including the stored new resumeIdentity and AS security context to initiate Tracking Area Update procedure on a new Ncell }

ensure that {

when { NB-IoT UE receives a RRCConnectionReject-NB message including rrc-SuspendIndication IE }

then { NB-IoT UE stores the resumeIdentity along with AS security context and resumes RRC Connection by sending RRCConnectionResumeRequest-NB message including the stored resumeIdentity and AS security context to restart the ongoing Tracking Area Update procedure }

}

22.4.16.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.331, clause 5.3.3.3a, 5.3.3.8, 5.3.8.3, and 5.3.12 and TS 24.301, clause 5.3.1.3.

[TS 36.331, clause 5.3.3.3a]

The UE shall set the contents of RRCConnectionResumeRequest message as follows:

1> if the UE is a NB-IoT UE; or

1> if field useFullResumeID is signalled in SystemInformationBlockType2:

2> set the resumeID to the stored resumeIdentity;

1> else

2> set the truncatedResumeID to include bits in bit position 9 to 20 and 29 to 40 from the left in the stored resumeIdentity.

[TS 36.331, clause 5.3.3.8]

The UE shall:

1> stop timer T300;

1> reset MAC and release the MAC configuration;

1> except for NB-IoT, start timer T302, with the timer value set to the waitTime;

1> if the UE is a NB-IoT UE; or

1> if the extendedWaitTime is present and the UE supports delay tolerant access:

2> forward the extendedWaitTime to upper layers;

1> if deprioritisationReq is included and the UE supports RRC Connection Reject with deprioritisation:

2> start or restart timer T325 with the timer value set to the deprioritisationTimer signalled;

2> store the deprioritisationReq until T325 expiry;

NOTE: The UE stores the deprioritisation request irrespective of any cell reselection absolute priority assignments (by dedicated or common signalling) and regardless of RRC connections in E-UTRAN or other RATs unless specified otherwise.

1> if the RRCConnectionReject is received in response to an RRCConnectionResumeRequest:

2> if the rrc-SuspendIndication is not present:

3> discard the stored UE AS context and resumeIdentity;

3> inform upper layers about the failure to resume the RRC connection without suspend indication and that access barring for mobile originating calls, mobile originating signalling, mobile terminating access and except for NB-IoT for mobile originating CS fallback is applicable, upon which the procedure ends;

2> else:

3> inform upper layers about the failure to resume the RRC connection with suspend indication and that access barring for mobile originating calls, mobile originating signalling, mobile terminating access and except for NB-IoT for mobile originating CS fallback is applicable, upon which the procedure ends;

1> else

2> inform upper layers about the failure to establish the RRC connection and that access barring for mobile originating calls, mobile originating signalling, mobile terminating access and except for NB-IoT, for mobile originating CS fallback is applicable, upon which the procedure ends;

[TS 36.331, clause 5.3.8.3]

The UE shall:

1> delay the following actions defined in this sub-clause 60 ms from the moment the RRCConnectionRelease message was received or optionally when lower layers indicate that the receipt of the RRCConnectionRelease message has been successfully acknowledged, whichever is earlier;

1> if the RRCConnectionRelease message includes the idleModeMobilityControlInfo:

2> store the cell reselection priority information provided by the idleModeMobilityControlInfo;

2> if the t320 is included:

3> start timer T320, with the timer value set according to the value of t320;

1> else:

2> apply the cell reselection priority information broadcast in the system information;

1> if the releaseCause received in the RRCConnectionRelease message indicates loadBalancingTAURequired:

2> perform the actions upon leaving RRC_CONNECTED as specified in 5.3.12, with release cause ‘load balancing TAU required’;

1> else if the releaseCause received in the RRCConnectionRelease message indicates cs-FallbackHighPriority:

2> perform the actions upon leaving RRC_CONNECTED as specified in 5.3.12, with release cause ‘CS Fallback High Priority’;

1> else:

2> if the extendedWaitTime is present; and

2> if the UE supports delay tolerant access or the UE is a NB-IoT UE:

3> forward the extendedWaitTime to upper layers;

2> if the releaseCause received in the RRCConnectionRelease message indicates rrc-Suspend:

3> perform the actions upon leaving RRC_CONNECTED as specified in 5.3.12, with release cause ‘RRC suspension’;

2> else:

3> perform the actions upon leaving RRC_CONNECTED as specified in 5.3.12, with release cause ‘other’;

[TS 36.331, clause 5.3.12]

Upon leaving RRC_CONNECTED, the UE shall:

1> reset MAC;

1> stop all timers that are running except T320, T325 and T330;

1> if leaving RRC_CONNECTED was triggered by suspension of the RRC:

2> re-establish RLC entities for all SRBs and DRBs;

2> store the UE AS Context including the current RRC configuration, the current security context, the PDCP state including ROHC state, C-RNTI used in the source PCell, the cellIdentity and the physical cell identity of the source PCell;

2> store the following information provided by E-UTRAN:

3> the resumeIdentity;

2> suspend all SRB(s) and DRB(s);

2> indicate the suspension of the RRC connection to upper layers;

[TS 24.301, clause 5.3.1.3]

Suspend of the NAS signalling connection can be initiated by the network in EMM-CONNECTED mode when user plane CIoT EPS optimization is used. Resume of the suspended NAS signalling connection is initiated by the UE.

In the UE, when user plane CIoT EPS optimization is used:

– Upon indication from the lower layers that the RRC connection has been suspended, the UE shall enter EMM-IDLE mode with suspend indication, but shall not consider the NAS signalling connection released. Based on further indications provided by the lower layers, the UE shall update the status of the suspend indication for the EMM-IDLE mode;

– Upon trigger of a procedure using an initial NAS message when in EMM-IDLE mode with suspend indication, the UE shall request the lower layer to resume the RRC connection. In this request to the lower layer the NAS shall provide to the lower layer the RRC establishment cause and the call type according to annex D of this document;

– Upon trigger of a tracking area update procedure initiated due to mobility into a tracking area that is not in the current TAI list, when in EMM-IDLE mode with suspend indication and camped on an E-UTRAN cell not supporting user plane CIoT EPS optimization, the UE should enter EMM-IDLE mode without suspend indication and start the procedure;

– Upon indication from the lower layers that the RRC connection has been resumed when in EMM-IDLE mode with suspend indication, the UE shall enter EMM-CONNECTED mode. If the pending NAS message is:

i) a SERVICE REQUEST message;

ii) a CONTROL PLANE SERVICE REQUEST message, and the UE did not include any ESM message container, NAS message container or EPS bearer context status information elements; or

iii) an EXTENDED SERVICE REQUEST message, and the Service type information element indicates "packet services via S1" and the UE did not include any EPS bearer context status information element,

the message shall not be sent. Otherwise the UE shall send the pending initial NAS message upon entering EMM-CONNECTED mode;

NOTE: If a NAS message is discarded and not sent to the network, the uplink NAS COUNT value corresponding to that message is reused for the next uplink NAS message to be sent.

– Upon indication from the lower layers that the RRC connection resume has been fallbacked when in EMM-IDLE mode with suspend indication, the UE shall enter EMM-IDLE mode without suspend indication, send any pending initial NAS message and proceed as if RRC connection establishment had been requested;

– Upon indication from the lower layers that the RRC connection resume has failed and indication from the lower layers that the RRC connection is suspended, the UE shall enter EMM-IDLE mode with suspend indication and restart the ongoing NAS procedure if required; and

– Upon indication from the lower layers that the RRC connection resume has failed and indication from the lower layers that the RRC connection is not suspended, the UE shall enter EMM-IDLE mode without suspend indication and restart the ongoing NAS procedure if required.

In the network, when user plane CIoT EPS optimization is used:

– Upon indication from the lower layers that the RRC connection has been suspended, the network shall enter EMM-IDLE mode with suspend indication, but shall not consider the NAS signalling connection released; and

– Upon indication from the lower layers that the RRC connection has been resumed when in EMM-IDLE mode with suspend indication, the network shall enter EMM-CONNECTED mode.

22.4.16.3 Test description

22.4.16.3.1 Pre-test conditions

System Simulator:

– Ncell 1 and Ncell 11.

– The Network and test case requires Attach with User Plane CIoT EPS optimisation.

– System information combination 3 as defined in TS 36.508[18] clause 8.1.4.3.1.1 is used in NB-IoT cells;

UE:

User Plane CIoT Optimisation is supported by UE (UE capability), pc_User_Plane_CIoT_Optimisation.

Preamble:

– The UE is in state Switched OFF (State 1-NB) according to TS 36.508 Table 8.1.5.1-1.

22.4.16.3.2 Test procedure sequence

Table 22.4.16.3.2-1 illustrates the downlink power levels and other changing parameters to be applied for the cells at various time instants of the test execution. The configuration marked "T1" is applied at the point indicated in the Main behaviour description in Table 22.4.16.3.2-2.

Table 22.4.16.3.2-1: Time instances of cell power level and parameter changes

Parameter

Unit

Ncell 1

Ncell 11

Remark

T0

Cell-specific NRS EPRE

dBm/15kHz

-85

"Off"

T1

Cell-specific NRS EPRE

dBm/15kHz

-85

-73

Ncell 11 become stronger than Threshx, high.

Table 22.4.16.3.2-2: Main behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

Steps 1-14b1 of the generic procedure for UE registration specified in TS 36.508 subclause 8.1.5.2.3 are performed on Ncell1.

2

The SS transmits an RRCConnectionRelease-NB message including resumeIdentity and rrc-Suspend as releaseCause.

<–

RRC: RRCConnectionRelease-NB

3

The SS transmits a Paging-NB message including a matched identity.

<–

RRC: Paging-NB

4

Check: Does the UE transmit an RRCConnectionResumeRequest-NB message including the resumeIdentity and AS security context stored at Step 2?

–>

RRC: RRCConnectionResumeRequest-NB

5

The SS responds with RRCConnectionReject-NB message without including rrc-SuspendIndication IE.

<–

RRC: RRCConnectionReject-NB

6

The SS transmits a Paging-NB message including a matched identity.

<–

RRC: Paging-NB

7

Check: Does the UE transmit an RRCConnectionRequest-NB message discarding the stored resumeIdentity and AS security context?

–>

RRC: RRCConnectionRequest-NB

1

P

8

The SS transmits an RRCConnectionSetup-NB message.

<–

RRC: RRCConnectionSetup-NB

9

The UE transmits an RRCConnectionSetupComplete-NB message.

This message includes a SERVICE REQUEST message.

–>

RRC: RRCConnectionSetupComplete-NB

NAS: SERVICE REQUEST

10

The SS transmits a SecurityModeCommand message to activate AS security.

<–

RRC: SecurityModeCommand

11

The UE transmits a SecurityModeComplete message and establishes the security configuration.

–>

RRC: SecurityModeComplete

12

The SS transmits an RRCConnectionReconfiguration-NB message.

<–

RRC: RRCConnectionReconfiguration-NB

13

The UE transmits an RRCConnectionReconfigurationComplete-NB message.

–>

RRC: RRCConnectionReconfigurationComplete-NB

14

The SS transmits an RRCConnectionRelease-NB message including a new resumeIdentity and rrc-Suspend as releaseCause.

<–

RRCConnectionRelease-NB

15

The SS changes Ncell 11 power level according to the row "T1" in table 22.4.16.3.2-1.

16

Check: Does the UE transmit an RRCConnectionResumeRequest-NB message to initiate TAU on Ncell 11 including the new resumeIdentity and AS security context stored at Step 14?

–>

RRC: RRCConnectionResumeRequest-NB

17

The SS responds with RRCConnectionReject-NB message including rrc-SuspendIndication IE.

<–

RRC: RRCConnectionReject-NB

18

Check: Does the test result of generic test procedure in TS 36.508 subclause 8.1.5A.6 indicate that the UE successfully resumes RRC connection on Ncell 11 using the new resumeIdentity stored at Step 14?

2

P

22.4.16.3.3 Specific message contents

Table 22.4.16.3.3-1: RRCConnectionRelease-NB (step 2, table 22.4.16.3.2-2)

Derivation Path: 36.508 table 8.1.6.1-9

Information Element

Value/remark

Comment

Condition

RRCConnectionRelease-NB ::= SEQUENCE {

rrc-TransactionIdentifier

RRC-TransactionIdentifier-DL

criticalExtensions CHOICE {

c1 CHOICE {

rrcConnectionRelease-r13 SEQUENCE {

releaseCause-r13

rrc-Suspend

resumeIdentity-r13

BIT STRING (SIZE(40))

Any value

extendedWaitTime-r13

Not present

redirectedCarrierInfo

Not present

lateNonCriticalExtension

Not present

nonCriticalExtension SEQUENCE {}

Not present

}

}

}

}

Table 22.4.16.3.3-2: RRCConnectionResumeRequest-NB (step 4, Table 22.4.16.3.2-2)

Derivation Path: 36.508 table 8.1.6.1-13

Information Element

Value/remark

Comment

Condition

RRCConnectionResumeRequest-NB ::= SEQUENCE {

criticalExtensions CHOICE {

rrcConnectionResumeRequest-r13 SEQUENCE {

resumeID-r13

BIT STRING (SIZE(40))

Same value as Step2

resumeMAC-I-r13

The same value as the 16 least significant bits of the MAC-I value

calculated by SS.

resumeCause-r13

mt-Access

spare

Present but contents not checked

}

}

}

Table 22.4.16.3.3-3: RRCConnectionReject-NB (step 5, table 22.4.16.3.2-2)

Derivation Path: 36.508 table 8.1.6.1-8

Information Element

Value/remark

Comment

Condition

RRCConnectionReject-NB ::= SEQUENCE {

criticalExtensions CHOICE {

c1 CHOICE {

rrcConnectionReject-r13 SEQUENCE {

extendedWaitTime

3(seconds)

rrc-SuspendIndication-r13

False

lateNonCriticalExtension

Not present

nonCriticalExtension SEQUENCE {}

Not present

}

}

}

}

Table 22.4.16.3.3-4: RRCConnectionRequest-NB (step 7, Table 22.4.16.3.2-2)

Derivation Path: 36.508 table 8.1.6.1-10

Information Element

Value/remark

Comment

Condition

RRCConnectionRequest-NB ::= SEQUENCE {

criticalExtensions CHOICE {

rrcConnectionRequest-r13 SEQUENCE {

ue-Identity-r13 CHOICE {

s-TMSI

Any allowed value

}

establishmentCause-r13

mt-Access

multiToneSupport-r13

Not checked

multiCarrierSupport-r13

Not checked

spare

Present but contents not checked

}

}

}

Table 22.4.16.3.3-5: RRCConnectionRelease-NB (step 14, table 22.4.16.3.2-2)

Derivation Path: 36.508 table 8.1.6.1-9

Information Element

Value/remark

Comment

Condition

RRCConnectionRelease-NB ::= SEQUENCE {

rrc-TransactionIdentifier

RRC-TransactionIdentifier-DL

criticalExtensions CHOICE {

c1 CHOICE {

rrcConnectionRelease-r13 SEQUENCE {

releaseCause-r13

rrc-Suspend

resumeIdentity-r13

BIT STRING (SIZE(40))

New value (other than the value used in Step2)

extendedWaitTime-r13

Not present

redirectedCarrierInfo

Not present

lateNonCriticalExtension

Not present

nonCriticalExtension SEQUENCE {}

Not present

}

}

}

}

Table 22.4.16.3.3-6: RRCConnectionResumeRequest-NB (step 16, Table 22.4.16.3.2-2)

Derivation Path: 36.508 table 8.1.6.1-13

Information Element

Value/remark

Comment

Condition

RRCConnectionResumeRequest-NB ::= SEQUENCE {

criticalExtensions CHOICE {

rrcConnectionResumeRequest-r13 SEQUENCE {

resumeID-r13

BIT STRING (SIZE(40))

Same value as Step14

resumeMAC-I-r13

The same value as the 16 least significant bits of the MAC-I value calculated by SS.

resumeCause-r13

mo-Signalling

spare

Present but contents not checked

}

}

}

Table 22.4.16.3.3-7: RRCConnectionReject-NB (step 17, table 22.4.16.3.2-2)

Derivation Path: 36.508 table 8.1.6.1-8

Information Element

Value/remark

Comment

Condition

RRCConnectionReject-NB ::= SEQUENCE {

criticalExtensions CHOICE {

c1 CHOICE {

rrcConnectionReject-r13 SEQUENCE {

extendedWaitTime

3(seconds)

rrc-SuspendIndication-r13

True

lateNonCriticalExtension

Not present

nonCriticalExtension SEQUENCE {}

Not present

}

}

}

}

Table 22.4.16.3.3-8: RRCConnectionResumeRequest-NB (step 18, Table 22.4.16.3.2-2)

Derivation Path: 36.508 table 8.1.6.1-13

Information Element

Value/remark

Comment

Condition

RRCConnectionResumeRequest-NB ::= SEQUENCE {

criticalExtensions CHOICE {

rrcConnectionResumeRequest-r13 SEQUENCE {

resumeID-r13

BIT STRING (SIZE(40))

Same value as Step14

resumeMAC-I-r13

The same value as the 16 least significant bits of the MAC-I value

calculated by SS.

resumeCause-r13

mo-Signalling

spare

Present but contents not checked

}

}

}