22.5.5 NB-IoT / Attach Procedure / Success / List of equivalent PLMNs in the ATTACH ACCEPT message / Attach / Rejected / PLMN not allowed

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

22.5.5.1 Test Purpose (TP)

(1)

with { UE in EMM-REGISTERED-INITIATED state }

ensure that {

when { the UE receives ATTACH ACCEPT message including a list of equivalent PLMNs }

then { the UE stores correctly the list and does not consider forbidden PLMNs as equivalent PLMNs }

}

(2)

with { UE in EMM-REGISTERED-INITIATED state }

ensure that {

when { the UE receives ATTACH ACCEPT message without a list of equivalent PLMNs }

then { the UE deletes the stored list and applies a normal PLMN selection process }

}

(3)

with { the UE has sent an ATTACH REQUEST message }

ensure that {

when { the UE receives an ATTACH REJECT message with the reject cause set to "PLMN not allowed" }

then { the UE deletes the GUTI, the last visited registered TAI, KSI, the list of equivalent PLMNs and UE enters state EMM-DEREGISTERED.PLMN-SEARCH and UE stores the PLMN in the "forbidden PLMN list" in the USIM }

}

(4)

with { the UE is switched off and a PLMN is stored in the "forbidden PLMN list" in the USIM }

ensure that {

when { the UE is switched on }

then { the UE doesn’t attempt to attach on this PLMN }

}

(5)

with { the UE in EMM-DEREGISTERED.PLMN-SEARCH state and a PLMN is stored in the "forbidden PLMN list" }

ensure that {

when { the UE detects a cell belonging to a PLMN which is not in the "forbidden PLMN list" }

then { the UE attaches to this PLMN }

}

(6)

with {the UE in EMM-DEREGISTERED.PLMN-SEARCH state and a PLMN is stored in the "forbidden PLMN list" }

ensure that {

when { the forbidden PLMN is selected manually }

then { the UE attaches to the forbidden PLMN and deletes this PLMN from the USIM}

22.5.5.2 Conformance requirements

References: The conformance requirements covered in the current TC are specified in: TS 24.301, clause 5.5.1.2.4.

[TS 24.301, clause 5.5.1.2.4]

The MME may also include a list of equivalent PLMNs in the ATTACH ACCEPT message. Each entry in the list contains a PLMN code (MCC+MNC). The UE shall store the list as provided by the network, and if the attach procedure is not for emergency bearer services, the UE shall remove from the list any PLMN code that is already in the list of "forbidden PLMNs" or in the list of "forbidden PLMNs for GPRS service". In addition, the UE shall add to the stored list the PLMN code of the registered PLMN that sent the list. The UE shall replace the stored list on each receipt of the ATTACH ACCEPT message. If the ATTACH ACCEPT message does not contain a list, then the UE shall delete the stored list.

[TS 24.301, clause 5.5.1.2.2]

In state EMM-DEREGISTERED, the UE initiates the attach procedure by sending an ATTACH REQUEST message to the MME, starting timer T3410 and entering state EMM-REGISTERED-INITIATED (see example in figure 5.5.1.2.2.1). If timer T3402 is currently running, the UE shall stop timer T3402. If timer T3411 is currently running, the UE shall stop timer T3411.

If the UE supports neither A/Gb mode nor Iu mode:

– the UE shall include in the ATTACH REQUEST message a valid GUTI together with the last visited registered TAI, if available. In addition, the UE shall include Old GUTI type IE with GUTI type set to "native GUTI". If there is no valid GUTI available, the UE shall include the IMSI in the ATTACH REQUEST message.

[TS 24.301, clause 5.5.1.2.5]

If the attach request cannot be accepted by the network, the MME shall send an ATTACH REJECT message to the UE including an appropriate EMM cause value.

Upon receiving the ATTACH REJECT message, the UE shall stop timer T3410 and take the following actions depending on the EMM cause value received.

The UE shall take the following actions depending on the EMM cause value received in the ATTACH REJECT message.

#11 (PLMN not allowed);

The UE shall set the EPS update status to EU3 ROAMING NOT ALLOWED (and shall store it according to subclause 5.1.3.3) and shall delete any GUTI, last visited registered TAI, TAI list and eKSI. Additionally, the UE shall delete the list of equivalent PLMNs and reset the attach attempt counter.

In S1 mode, the UE shall store the PLMN identity in the "forbidden PLMN list" and enter state EMM-DEREGISTERED.PLMN-SEARCH and if the UE is configured to use timer T3245 (see 3GPP TS 24.368 [15] or 3GPP TS 31.102 [17]) then the UE shall start timer T3245 and proceed as described in subclause 5.3.7a. The UE shall perform a PLMN selection according to 3GPP TS 23.122 [6].

22.5.5.3 Test description

22.5.5.3.1 Pre-test conditions

System Simulator:

– 4 Ncells: Ncell 50 (PLMN1, HPLMN), Ncell 55 (PLMN2, visited PLMN belongs to TAI-7, MCC=001 MNC=02) and Ncell 59 (PLMN3, another visited PLMN, belongs to TAI-9, MCC = 002 MNC=101) and Ncell 60 (belongs to TAI-11, visited PLMN, MCC = 002 MNC=101) are configured according to Table 8.1.4.2-3 and Table 8.1.4.2-5 in TS 36.508 [18]. System information combination 3 as defined in TS 36.508[18] clause 8.1.4.3.1.1 is used.

– At most 3 Ncells are active simultaneously

UE:

– The UE is previously registered on Ncell 50, and when on Ncell 50, the UE is last authenticated and registered using default message contents according to TS 36.508 [18].

Preamble:

– The UE is in state Switched OFF (state 1-NB) according to TS 36.508 [18].

22.5.5.3.2 Test procedure sequence

Table: 22.5.5.3.2-1: Main behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The SS configures:

– Ncell 59 as the "Serving cell".

– Ncell 60 as a "Suitable Neighbour cell".

– Ncell 55 as a "Non-Suitable Off cell".

– Ncell 50 as a "Non-Suitable Off cell".

Note: Ncell 59 and Ncell 60 are in the different TAI – same PLMN.

The following messages are to be observed on Ncell 59 unless explicitly stated otherwise.

2

The UE is switched on.

3

The UE transmits an ATTACH REQUEST message.

–>

ATTACH REQUEST

4

The SS transmits an ATTACH REJECT message including EMM cause = "PLMN not allowed".

<–

ATTACH REJECT

5

The SS releases the RRC connection.

6

Check: Does the UE transmit an ATTACH REQUEST message on Ncell 59 or 60 in the next 30 seconds?

–>

ATTACH REQUEST

3

F

7

If possible (see ICS) switch off is performed or the USIM is removed.

Otherwise the power is removed.

8

The UE is brought back to operation or the USIM is inserted.

9

Check: Does the UE transmit an ATTACH REQUEST message in the next 90 seconds?

–>

ATTACH REQUEST

4

F

10

The SS configures:

– Ncell 59 as the " Suitable neighbour intrafrequency cell"

– Ncell 60 as a "Non-Suitable Off cell"

– Ncell 55 as a "Serving cell".

11

The following messages are to be observed on Ncell 55 unless explicitly stated otherwise.

12

Check: Does the UE transmit an ATTACH REQUEST message?

–>

ATTACH REQUEST

5

P

13-27

The attach procedure is completed and the RRC connection is released by executing steps 5-14b1 of the UE registration procedure in TS 36.508 clause 8.1.5.2.3.

28

If possible (see ICS) switch off is performed or the USIM is removed.
Otherwise the power is removed.

EXCEPTION: Step 29 describes behaviour that depends on the UE capability.

29

If pc_SwitchOnOff or pc_USIM_Removal then the UE transmits a DETACH REQUEST message.

–>

DETACH REQUEST

30

The SS configures:

– Ncell 50 as the "Serving cell".

– Ncell 55 as a "Non-Suitable cell".

– Ncell 59 as a "Non-Suitable cell".

The following messages are to be observed on Ncell 50 unless explicitly stated otherwise.

31

The UE is switched on.

32-49

Steps 2-14b1 of the generic procedure for UE registration specified in TS 36.508 subclause 8.1.5.2.3 are performed.

50

If possible (see ICS) switch off is performed or the USIM is removed. Otherwise the power is removed.

EXCEPTION: Step 51 describes behaviour that depends on the UE capability.

51

If pc_SwitchOnOff or pc_USIM_Removal then UE sends DETACH REQUEST message

–>

DETACH REQUEST

52

The SS configures:

– Ncell 50 as the "Non-Suitable cell".

– Ncell 55 as a "Non-Suitable cell ".

– Ncell 59 as a "Serving cell".

Note: Ncell 59 belongs to the forbidden PLMN.

53

The UE is brought back to operation or the USIM is inserted.

54

Check: Does the UE transmit an ATTACH REQUEST message in the next 60 seconds on Ncell 59

1

F

55

The SS configures:

– Ncell 50 as the "Non-Suitable cell".

– Ncell 55 as a "Serving cell".

– Ncell 59 as a "Non-Suitable cell".

The following messages are to be observed on Ncell 55 unless explicitly stated otherwise.

56

Check: Does the UE transmit an ATTACH REQUEST message?

–>

ATTACH REQUEST

1

P

57-71

Steps 5-14b1 of the generic procedure for UE registration specified in TS 36.508 subclause 8.1.5.2.3 are performed.

72

The SS releases the RRC connection.

73

The SS configures:

– Ncell 50 as a "Serving cell".

– Ncell 55 as a "Non-Suitable cell".

– Ncell 59 as a "Non-suitable "Off” cell".

The following messages are to be observed on Ncell 50 unless explicitly stated otherwise.

74

Check: Does the UE transmit a TRACKING AREA UPDATE REQUEST message?

–>

TRACKING AREA UPDATE REQUEST

2

P

75

SS responds with TRACKING AREA UPDATE ACCEPT message.

<–

TRACKING AREA UPDATE ACCEPT

76

The UE transmits a TRACKING AREA UPDATE COMPLETE message

–>

TRACKING AREA UPDATE COMPLETE

76A

The SS releases the RRC connection.

77

If possible (see ICS) switch off is performed or the USIM is removed. Otherwise the power is removed.

EXCEPTION: Step 77 describes behaviour that depends on the UE capability.

78

If pc_SwitchOnOff or pc_USIM_Removal then UE sends DETACH REQUEST message

–>

DETACH REQUEST

79

The SS configures:

– Ncell 50 as a "Non-Suitable Off cell".

– Ncell 59 as the "Serving cell"

– Ncell 55 as a "Non-suitable Off cell".

Note: Ncell 59 belongs to the forbidden PLMN.

80

The UE is brought back to operation or the USIM is inserted.

81

The following messages are to be observed on Ncell 59 unless explicitly stated otherwise.

82

The user sets the UE in manual PLMN selection mode or requests a PLMN search.

83

The user selects PLMN of Ncell 59.

84

Check: Does the UE transmit an ATTACH REQUEST message including a message as specified?

–>

ATTACH REQUEST

6

P

85-99

The attach procedure is completed by executing steps 5-14b1 of the UE registration procedure in TS 36.508 clause 8.1.5.2.3.

100

The SS transmits an RRCConnectionRelease-NB message to release RRC connection. The UE ends the test procedure sequence in NB-IoT manual selection (N5) state.

<–

RRC: RRCConnectionRelease-NB

22.5.5.3.3 Specific message contents

Table 22.5.5.3.3-1: Message ATTACH ACCEPT (step 45, Table 22.5.5.3.2-1)

Derivation path: 36.508 table 8.1.7

Information Element

Value/Remark

Comment

Condition

Equivalent PLMNs

Includes MCC and MNC digits for PLMN2, PLMN3 and PLMN4.

Table 22.5.5.3.3-2: Message ATTACH ACCEPT (step 67, Table 22.5.5.3.2-1)

Derivation path: 36.508 table 8.1.7

Information Element

Value/Remark

Comment

Condition

Equivalent PLMNs

Not present

Table 22.5.5.3.3-3: Message ATTACH REJECT (step 4, Table 22.5.5.3.2-1)

Derivation path: 36.508 table 8.1.7

Information Element

Value/Remark

Comment

Condition

EMM cause

00001011

#11 "PLMN not allowed"

ESM message container

Not present

Table 22.5.5.3.3-4: Message ATTACH REQUEST (step 12, Table 22.5.5.3.2-1)

Derivation path: 36.508 table 8.1.7

Information Element

Value/Remark

Comment

Condition

Old GUTI or IMSI

IMSI-1

GUTI has been deleted after receiving ATTACH REJECT at step 4; only IMSI is available.

Last visited registered TAI

Not present

TAI has been deleted after receiving ATTACH REJECT at step 4.

Table 22.5.5.3.3-5: Message ATTACH REQUEST (step 84, Table 22.5.5.3.2-1)

Derivation path: 36.508 table 8.1.7

Information Element

Value/Remark

Comment

Condition

Old GUTI or IMSI

IMSI

Last visited registered TAI

TAI-1

TAI 1 is allocated on Ncell 50 according to 36.508 table 8.1.4.2-3.