22.4.21 NB-IoT / Radio link failure / Radio link recovery while T310 is running

36.523-13GPPEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Packet Core (EPC)Part 1: Protocol conformance specificationRelease 17TSUser Equipment (UE) conformance specification

22.4.21.1 Test Purpose (TP)

(1)

with { UE in E-UTRA RRC_CONNECTED state}

ensure that {
when { UE detecting physical layer recovery while T310 was running }

then {the UE resumes the RRC connection without explicit signalling }

}

22.4.21.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.331 clause 5.3.11.1 and 5.3.11.2.

[TS 36.331, clause 5.3.11.1]

The UE shall:

1> upon receiving N310 consecutive "out-of-sync" indications for the PCell from lower layers while neither T300, T301, T304 nor T311 is running:

2> start timer T310;

[TS 36.331, clause 5.3.11.2]

Upon receiving N311 consecutive "in-sync" indications for the PCell from lower layers while T310 is running, the UE shall:

1> stop timer T310;

1> stop timer T312, if running;

NOTE 1: In this case, the UE maintains the RRC connection without explicit signalling, i.e. the UE maintains the entire radio resource configuration.

NOTE 2: Periods in time where neither "in-sync" nor "out-of-sync" is reported by layer 1 do not affect the evaluation of the number of consecutive "in-sync" or "out-of-sync" indications.

22.4.21.3 Test description

22.4.21.3.1 Pre-test conditions

System Simulator:

– Ncell 1

UE:

None.

Preamble:

– The UE is in Connected Mode (State 2-NB) according to 36.508 clause 8.1.5.2.3.

22.4.21.3.2 Test procedure sequence

Table 22.4.21.3.2-1 illustrates the downlink power level to be applied for the cell at various time instants of the test execution. Row marked "T0" denotes the initial condition, while column marked "T1"is applied according the procedure.

Table 22.4.21.3.2-1: Time instances of cell power level

Parameter

Unit

Ncell 1

Remark

T0

NRS EPRE

dBm/15kHz

-85

Serving cell

T1

NRS EPRE

dBm/15kHz

Off

Non-suitable "Off" cell
(NOTE 1)

NOTE 1: Power level “Off” is ≤ -150.

Table 22.4.21.3.2-2: Main behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The SS changes Ncell 1 level according to the row "T1" in table 22.4.21.3.2-1.

2

SS waits for 1.5s. The T310 is 2s.

3

The SS changes Ncell 1 level according to the row "T0" in table 22.4.21.3.2-1.

4

SS waits for 5s.

Check: Does the UE transmit any signalling message?

1

F

5

Check: Does the test result of generic test procedure in TS 36.508 subclause 8.1.5A.8 indicate that the UE is in RRC_CONNECTED state on Ncell 1?

1

22.4.21.3.3 Specific message contents

Table 22.4.21.3.3-1: SystemInformationBlockType2-NB (preamble and all steps, Table 22.4.21.3.2-2)

Derivation Path: 36.508 table 8.1.4.3.3-1

Information Element

Value/remark

Comment

Condition

SystemInformationBlockType2-NB-r13 ::= SEQUENCE {

ue-TimersAndConstants-r13 SEQUENCE {

t310-r13

ms2000

}

}