22.5.7b NB-IoT / Normal tracking area update Rejected ( Tracking area not allowed / No suitable cells in tracking area / Roaming not allowed in this tracking area / Congestion) / UE initiated detach Abnormal case Change of cell into a new tracking area

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

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

22.5.7b.1 Test Purpose (TP)

(1)

with { UE has sent a TRACKING AREA UPDATE REQUEST message}

ensure that {

when { UE receives a TRACKING AREA UPDATE REJECT message with the reject cause set to "Tracking area not allowed " }

then { shall delete any GUTI, last visited registered TAI, TAI list and KSI. The UE shall reset the tracking area updating attempt counter and shall enter the state EMM-DEREGISTERED.LIMITED-SERVICE and store the current TAI in the list of "forbidden tracking areas for regional provision of service" }

(2)

with { UE is in EMM-DEREGISTERED.LIMITED-SERVICE state and has a TAI in the list of "forbidden tracking areas for regional provision of service"}

ensure that {

when { UE is in the serving cell which the UE is rejected }

then { UE does not attempt an attach procedure on any other cell}

}

(3)

with { UE is in EMM-DEREGISTERED.LIMITED-SERVICE state and the current TAI in the list of "forbidden tracking areas for regional provision of service"}

ensure that {

when { UE enters a new cell in the same TAI it was rejected }

then { UE does not initiate an attach procedure}

}

(4)

with { UE is in EMM-DEREGISTERED.LIMITED-SERVICE state and the current TAI in the list of "forbidden tracking areas for regional provision of service"}

ensure that {

when { UE enters a new cell with different TAI without in the list of "forbidden tracking areas for regional provision of service"}

then { UE initiates attach procedure with IMSI }

}

(5)

with { UE is switched off }

ensure that {

when { UE is powered on and enters the cell with "forbidden tracking areas for regional provision of service" before the UE was switched off }

then { UE initiates attach procedure on the cell }

(6)

with { the UE has sent TRACKING AREA UPDATE REQUEST message }

ensure that {

when { the UE receives TRACKING AREA UPDATE REJECT message with the reject cause set to "roaming not allowed in this tracking area" }

then { the UE sets the EPS update status to EU3 ROAMING NOT ALLOWED and the UE deletes the last visited registered TAI and the UE enters the state EMM-REGISTERED.PLMN-SEARCH and the UE stores the current TAI in the list of "forbidden tracking areas for roaming" }

}

(7)

with { the UE is in EMM-REGISTERED.PLMN-SEARCH state and the current TAI in the list of "forbidden tracking areas for roaming"}

ensure that {

when { the serving NB-IoT cell Belongs to TAI where UE was rejected }

then { the UE does not attempt to send TRACKING AREA UPDATE REQUEST message }

}

(8)

with { the UE is in EMM-REGISTERED.PLMN-SEARCH state and the TAI of the current NB-IoT cell Belongs to the list of "forbidden tracking areas for roaming"}

ensure that {

when { the UE enters a NB-IoT cell Belonging to same PLMN and TAI not in the list of "forbidden tracking areas for roaming"}

then { the UE sends TRACKING AREA UPDATE REQUEST message }

}

(9)

with { the UE is in EMM-REGISTERED.PLMN-SEARCH state and the TAI of the current NB-IoT cell Belongs to the list of "forbidden tracking areas for roaming"}

ensure that {

when { the UE enters a NB-IoT cell Belonging to another PLMN }

then { the UE sends TRACKING AREA UPDATE REQUEST message }

}

(10)

with { UE is sending a TRACKING AREA UPDATE REQUEST message}

ensure that {
when { UE receives a TRACKING AREA UPDATE REJECT message with the EMM cause set to ‘No Suitable Cells In tracking area’ }

then { UE selects a suitable cell in another tracking area in the same PLMN and performs the tracking area updating procedure and UE does not select a suitable cell in another PLMN}

}

(11)

with { UE has sent a TRACKING AREA UPDATE REQUEST message}

ensure that {

when { UE receives an integrity protected TRACKING AREA UPDATE REJECT message with the reject cause set to "Congestion" and the T3346 value IE present }

then { The UE shall abort the tracking area updating procedure, reset the tracking area updating attempt counter and set the EPS update status to EU2 NOT UPDATED. The UE shall also start timer T3346 with the value provided in the T3346 IE as received in the TRACKING AREA UPDATE REJECT message, UE initiates the tracking area updating procedure when timer T3346 expires}

(12) Void

(13) Void

22.5.7b.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: 3GPP TS 24.301 clauses 5.5.3.2.4 , 5.5.3.2.5 , 5.5.2.2.4 ,

[TS 24.301, clause 5.5.3.2.4]

The MME may also include a list of equivalent PLMNs in the TRACKING AREA UPDATE 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 there is no PDN connection for emergency bearer services established, 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". If the UE is not attached for emergency bearer services and there is a PDN connection for emergency bearer services established, the UE shall remove from the list of equivalent PLMNs any PLMN code present in the list of forbidden PLMNs or in the list of "forbidden PLMNs for GPRS service" when the PDN connection for emergency bearer services is released. 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 TRACKING AREA UPDATE ACCEPT message. If the TRACKING AREA UPDATE ACCEPT message does not contain a list, then the UE shall delete the stored list.

[TS 24.301 clause5.5.3.2.5]

If the tracking area updating cannot be accepted by the network, the MME sends a TRACKING AREA UPDATE REJECT message to the UE including an appropriate EMM cause value.

If a tracking area update request from a UE with a LIPA PDN connection is not accepted due to the reasons specified in subclause 5.5.3.2.4, the MME shall send the TRACKING AREA UPDATE REJECT message with EMM cause value #10 "Implicitly detached".

If the tracking area update request is rejected due to general NAS level mobility management congestion control, the network shall set the EMM cause value to #22 "congestion" and assign a back-off timer T3346.

If the tracking area update request is rejected due to incompatibility between the CIoT EPS optimizations supported by the UE and what the network supports and the network sets the EMM cause value to #15 "no suitable cells in tracking area", the network may additionally include the Extended EMM cause IE with value "requested EPS optimization not supported".

NOTE 1: How the UE uses the Extended EMM cause IE with value "requested EPS optimization not supported" is implementation specific. The UE still behaves according to the EMM cause value #15.

Upon receiving the TRACKING AREA UPDATE REJECT message, if the message is integrity protected or contains a reject cause other than EMM cause value #25, the UE shall stop timer T3430 and stop any transmission of user data.

….

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

…

#12 (Tracking area 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. The UE shall reset the tracking area updating attempt counter and shall enter the state EMM-DEREGISTERED.LIMITED-SERVICE.

The UE shall store the current TAI in the list of "forbidden tracking areas for regional provision of service".

If A/Gb mode or Iu mode is supported by the UE, the UE shall handle the GMM parameters GMM state, GPRS update status, P-TMSI, P-TMSI signature, RAI, GPRS ciphering key sequence number and routing area updating attempt counter as specified in 3GPP TS 24.008 [13] for the case when the normal routing area updating procedure is rejected with the GMM cause with the same value.

#13 (Roaming not allowed in this tracking area);

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 the list of equivalent PLMNs. The UE shall reset the tracking area updating attempt counter and shall change to state EMM-REGISTERED.PLMN-SEARCH.

The UE shall store the current TAI in the list of "forbidden tracking areas for roaming" and shall remove the current TAI from the stored TAI list if present.

The UE shall perform a PLMN selection according to 3GPP TS 23.122 [6].

If A/Gb mode or Iu mode is supported by the UE, the UE shall handle the GMM parameters GMM state, GPRS update status and routing area updating attempt counter as specified in 3GPP TS 24.008 [13] for the case when the normal routing area updating procedure is rejected with the GMM cause with the same value.

….

#15 (No suitable cells in tracking area);

The UE shall set the EPS update status to EU3 ROAMING NOT ALLOWED (and shall store it according to subclause 5.1.3.3). The UE shall reset the tracking area updating attempt counter and shall enter the state EMM-REGISTERED.LIMITED-SERVICE.

The UE shall store the current TAI in the list of "forbidden tracking areas for roaming" and shall remove the current TAI from the stored TAI list if present.

If the Extended EMM cause IE with value "E-UTRAN not allowed" is included in the TRACKING AREA UPDATE REJECT message, the UE supports "E-UTRA Disabling for EMM cause #15", and the "E-UTRA Disabling Allowed for EMM cause #15" parameter as specified in 3GPP TS 24.368 [15A] or 3GPP TS 31.102 [17] is present and set to enabled; then the UE shall disable the E-UTRA capability as specified in subclause 4.5 and search for a suitable cell in another location area; otherwise, the UE shall search for a suitable cell in another tracking area or in another location area according to 3GPP TS 36.304 [21].

#22 (Congestion);

If the T3346 value IE is present in the TRACKING AREA UPDATE REJECT message and the value indicates that this timer is neither zero nor deactivated, the UE shall proceed as described below, otherwise it shall be considered as an abnormal case and the behaviour of the UE for this case is specified in subclause 5.5.3.2.6.

The UE shall abort the tracking area updating procedure, reset the tracking area updating attempt counter and set the EPS update status to EU2 NOT UPDATED. If the rejected request was not for initiating a PDN connection for emergency bearer services, the UE shall change to state EMM-REGISTERED.ATTEMPTING-TO-UPDATE.

The UE shall stop timer T3346 if it is running.

If the TRACKING AREA UPDATE REJECT message is integrity protected, the UE shall start timer with the value provided in the T3346 value IE.

If the TRACKING AREA UPDATE REJECT message is not integrity protected, the UE shall start timer T3346 with a random value from the default range specified in 3GPP TS 24.008 [13].

The UE stays in the current serving NB-IoT cell And applies the normal cell reselection process. The tracking area updating procedure is started, if still necessary, when timer T3346 expires or is stopped.

[TS 24.301 clause5.5.2.2.4]

The following abnormal cases can be identified:

…

b) Lower layer failure or release of the NAS signalling connection before reception of DETACH ACCEPT message

The detach procedure shall be aborted and the UE proceeds as follows:

– if the detach procedure was performed due to disabling of EPS services, the UE shall enter the EMM-NULL state;

– if "EPS detach" was requested for reasons other than disabling of EPS services, the UE shall enter the EMM-DEREGISTERED state;

– if "IMSI detach" was requested, the UE shall enter the EMM-REGISTERED.NORMAL-SERVICE state and the MM-NULL state; or

– if "combined EPS/IMSI detach" was requested, the UE shall enter the EMM-DEREGISTERED state and the MM-NULL state.

…

f) Change of cell into a new tracking area

If a cell change into a new tracking area that is not in the stored TAI list occurs before the UE initiated detach procedure is completed, the detach procedure shall be aborted and re-initiated after successfully performing a tracking area updating procedure. If the detach procedure was initiated due to removal of the USIM or the UE is to be switched off, the UE shall abort the detach procedure and enter the state EMM-DEREGISTERED.

22.5.7b.3 Test description

22.5.7b.3.1 Pre-test conditions

System Simulator:

– Maximum 2 Ncells are on at any given time

– Ncell 55, Ncell 56 belong to PLMN2

– Ncell 50, Ncell 51, Ncell 52, Ncell 53, Ncell 55, Ncell 56, Ncell 61 are defined in subclause 8.1.4.2 in TS 36.508[18]

– NB-IOT system information combination 2 as defined in TS 36.508[18] clause 8.1.4.3.1.1 is used in all cells

Table 22.5.7b.3-1: Time instances of cell power level and parameter changes

	Parameter	Unit	Ncell 50	Ncell 51	Ncell 52	Ncell 55	Ncell 56	Ncell 61	Ncell 53
T0	Cell-specific NRS EPRE	dBm/ 15kHz	Off	-85	Off	Off	Off	Off	Off
T1	Cell-specific NRS EPRE	dBm/ 15kHz	-85	Off	-91	Off	Off	Off	Off
T2	Cell-specific NRS EPRE	dBm/ 15kHz	-85	Off	Off	Off	Off	Off	Off
T3	Cell-specific NRS EPRE	dBm/ 15kHz	Off	Off	Off	Off	Off	-85	Off
T4	Cell-specific NRS EPRE	dBm/ 15kHz	Off	Off	-85	Off	Off	Off	Off
T5	Cell-specific NRS EPRE	dBm/ 15kHz	-85	Off	Off	Off	Off	Off	Off
T6	Cell-specific NRS EPRE	dBm/ 15kHz	-120	Off	Off	-85	Off	Off	Off
T7	Cell-specific NRS EPRE	dBm/ 15kHz	Off	Off	Off	-91	-85	Off	Off
T8	Cell-specific NRS EPRE	dBm/ 15kHz	Off	Off	Off	-85	-91	Off	Off
T9	Cell-specific NRS EPRE	dBm/ 15kHz	-85	Off	Off	Off	Off	Off	Off
T10	Cell-specific NRS EPRE	dBm/ 15kHz	Off	-85	Off	Off	Off	Off	Off
T11	Cell-specific NRS EPRE	dBm/ 15kHz	-85	-91	Off	Off	Off	Off	Off
T12	Cell-specific NRS EPRE	dBm/ 15kHz	-120	-91	Off	Off	Off	Off	-85

UE:

– The Test UICC shall be inserted. This shall contain a USIM application on UICC.

Preamble:

– the UE is in state Registered, Idle mode (State 3-NB) on Ncell 51 according to TS 36.508 [18].

22.5.7b.3.2 Test procedure sequence

Table 22.5.7b.3.2-1: Main behaviour

1	SS adjusts the cell power levels according to row T1 in table 22.5.7b.3-1.	–	–	–	–
2	The UE transmits a TRACKING AREA UPDATE REQUEST on Ncell 50.	–>	TRACKING AREA UPDATE REQUEST	–	–
3	The SS transmits a TRACKING AREA UPDATE REJECT message with EMM cause = "Tracking area not allowed" as specified.	<–	TRACKING AREA UPDATE REJECT	–	–
4	The SS releases the RRC connection.	–	–	–	–
5	Check: Does the UE transmit an ATTACH REQUEST message in the next 90 seconds on Ncell 52?	–>	ATTACH REQUEST	2	F
6	SS adjusts the cell power levels according to row T2 in table 22.5.7b.3-1.
7	The user initiates an attach by MMI or by AT command.	–	–	–	–
8	Check: Does the UE transmit an ATTACH REQUEST message in the next 90 seconds on Ncell 50?	–>	ATTACH REQUEST	1	F
9	SS adjusts the cell power levels according to row T3 in table 22.5.7b.3-1.	–	–	–	–
10	Check: Does the UE transmit an ATTACH REQUEST message in the next 90 seconds on Ncell 61?	–>	ATTACH REQUEST	3	F
11	SS adjusts the cell power levels according to row T4 in table 22.5.7b.3-1.	–	–	–	–
12	Check: Does the UE transmit an ATTACH REQUEST including a PDN CONNECTIVITY REQUEST or ESM DUMMY MESSAGE message on Ncell 52?	–>	ATTACH REQUEST	4	P
13-24b1	The attach procedure is completed by executing steps 5 to 14b1 of the UE registration procedure in TS 36.508 sub clause 8.1.5.2.	–	–	–	–
25	If possible (see ICS) switch off is performed or the USIM is removed. Otherwise the power is removed.	–	–	–	–
–	EXCEPTION: Step 26a1 describes behaviour that depends on the UE capability.
26a1	If pc_SwitchOnOff or pc_USIM_Removal then the UE transmits a DETACH REQUEST.	–>	DETACH REQUEST	–	–
27	The following messages are sent and shall be received on Ncell 50.	–	–	–	–
28	SS adjusts the cell power levels according to row T5 in table 22.5.7b.3-1.	–	–	–	–
29	The UE is brought back to operation or the USIM is inserted.	–	–	–	–
30	Check: Does the UE transmits ATTACH REQUEST message with a PDN CONNECTIVITY REQUEST message to request PDN connectivity to the default PDN or ESM DUMMY MESSAGE message on Ncell 50?	–>	ATTACH REQUEST	5	P
31-40b1	The attach procedure is completed executing steps 5 to 14b1 of the UE registration procedure in TS 36.508 sub clause 8.1.5.2.	–	–	–	–
41	The SS releases the RRC connection.	–	–	–	–
42	SS adjusts the cell power levels according to row T6 in table 22.5.7b.3-1.	–	–	–	–
43- 48	The UE performs steps 1 to 6 of the generic procedure in TS 36.508 subclause 8.1.5A.5 to camp on Ncell 55.
49	SS adjusts the cell power levels according to row T7 in table 22.5.7b.3-1.	–	–	–	–
50	The UE transmits TRACKING AREA UPDATE REQUEST on Ncell 56.	–>	TRACKING AREA UPDATE REQUEST	–	–
51	Void	–	–	–	–
52	The SS transmits a TRACKING AREA UPDATE REJECT message with EMM cause = ‘"Roaming not allowed in this tracking area"’ as specified.	<–	TRACKING AREA UPDATE REJECT	–	–
53	The SS releases the RRC connection.
53A	SS adjusts the cell power levels according to row T8 in table 22.5.7b.3-1.	–	–	–	–
54	Check: Does the UE transmit TRACKING AREA UPDATE REQUEST message on Ncell 55?	–>	TRACKING AREA UPDATE REQUEST	6, 7, 8	P
55	The SS transmits TRACKING AREA UPDATE REJECT message with EMM cause = "Roaming not allowed in this tracking area" as specified.	<–	TRACKING AREA UPDATE REJECT	–	–
56	The SS releases the RRC connection.
57 a1	SS adjusts the cell power levels according to row T9 in table 22.5.7b.3-1.	–	–	–	–
57a2	Check: Does the UE transmit TRACKING AREA REQUEST message on Ncell 50?	–>	TRACKING AREA UPDATE REQUEST	6, 9	P
57a3	The SS sends TRACKING AREA ACCEPT message.	<–	TRACKING AREA UPDATE ACCEPT	–	–
57a4	The UE transmits TRACKING AREA COMPLETE message.	–>	TRACKING AREA UPDATE COMPLETE	–	–
57a5	The SS releases the RRC connection.	–	–	–	–
58	SS adjusts the cell power levels according to row T10 in table 22.5.7b.3-1.	–	–	–	–
–	The following messages are sent and shall be received on NCell 51.	–	–	–	–
59	The UE transmits a TRACKING AREA UPDATE REQUEST message.	–>	TRACKING AREA UPDATE REQUEST	–	–
60	The SS transmits a TRACKING AREA UPDATE REJECT message with the EMM cause set to ‘No Suitable Cells In tracking area’.	<–	TRACKING AREA UPDATE REJECT	–	–
60A	The SS releases the RRC connection	–	–	–	–
61	SS adjusts the cell power levels according to row T11 in table 22.5.7b.3-1.
62	Void	–	–	–	–
–	The following messages are sent and shall be received on Ncell 50.	–	–	–	–
63	Check: Does the UE transmit a TRACKING AREA UPDATE REQUEST message?	–>	TRACKING AREA UPDATE REQUEST	10	P
64	The SS transmits a TRACKING AREA UPDATE ACCEPT message.	<–	TRACKING AREA UPDATE ACCEPT	–	–
65	The UE transmits a TRACKING AREA UPDATE COMPLETE message.	–>	TRACKING AREA UPDATE COMPLETE	–	–
65A	The SS releases the RRC connection.
66	SS adjusts the cell power levels according to row T12 in table 22.5.7b.3-1.	–	–	–	–
67	The UE transmits a TRACKING AREA UPDATE REQUEST on Ncell 53.	–>	TRACKING AREA UPDATE REQUEST	–	–
68	The SS transmits a TRACKING AREA UPDATE REJECT message with EMM cause = "Congestion " and T3346 IE set to 5 minutes. The UE starts timer T3346.	<–	TRACKING AREA UPDATE REJECT	–	–
69	The SS releases the RRC connection.	–	–	–	–
70	Check: Does the UE transmit a TRACKING AREA UPDATE REQUEST message before timer T3346 has expired?	–	–	11	F
71	Check: Does the UE transmit a TRACKING AREA UPDATE REQUEST message after timer T3346 has expired?	–>	TRACKING AREA UPDATE REQUEST	11	P
72	The SS transmits a TRACKING AREA UPDATE ACCEPT message.	<–	TRACKING AREA UPDATE ACCEPT	–	–
73	The UE transmits a TRACKING AREA UPDATE COMPLETE message.	–>	TRACKING AREA UPDATE COMPLETE	–	–
73A	The SS Releases the RRC Connection
74-82	Void
83a	Void
83b	Void

22.5.7b.3.3 Specific message contents

Table 22.5.7b.3.3-1: Message TRACKING AREA UPDATE REQUEST (step 2, Table 22.5.7b.3.2-1)

Derivation path: 36.508 table 4.7.2-27
Information Element	Value/Remark	Comment	Condition
Old GUTI	GUTI-2

Table 22.5.7b.3.3-2: Message TRACKING AREA UPDATE REJECT (step 3, Table 22.5.7b.3.2-1)

Derivation path: 36.508 table 4.7.2-24
Information Element	Value/Remark	Comment	Condition
EMM cause	‘00001100’B	#12 "Tracking area not allowed"

Table 22.5.7b.3.3-3: Message ATTACH REQUEST (step 12, Table 22.5.7b.3.2-1)

Derivation path: 36.508 table 4.7.2-4
Information Element	Value/Remark	Comment	Condition
Old GUTI or IMSI	IMSI
Last visited registered TAI	Not present

Table 22.5.7b.3.3-4: Message ATTACH REQUEST (step 30, Table 22.5.7b.3.2-1)

Derivation path: 36.508 table 4.7.2-4
Information Element	Value/Remark	Comment	Condition
Old GUTI or IMSI	GUTI-6
Last visited registered TAI	TAI-6

Table 22.5.7b.3.3-5: Message TRACKING AREA UPDATE REQUEST (step 50, 54 and 57a2, Table 22.5.7b.3.2-1)

Derivation path: 36.508 table 4.7.2-27
Information Element	Value/Remark	Comment	Condition
Old GUTI	GUTI-9

Table 22.5.7b.3.3-6: TRACKING AREA UPDATE REJECT (step 52 and 55, Table 22.5.7b.3.2-1)

Derivation Path: 36.508, Table 4.7.2-26
Information Element	Value/remark	Comment	Condition
EMM cause	‘0000 1101’B	Roaming not allowed in this tracking area

Table 22.5.7b.3.3-7: TRACKING AREA UPDATE REJECT (step 60, Table 22.5.7b.3.2-1)

Derivation Path: 36.508, Table 4.7.2-26
Information Element	Value/remark	Comment	Condition
EMM cause	‘0000 1111’B	No Suitable Cells In tracking area

Table 22.5.7b.3.3-8: Message TRACKING AREA UPDATE REQUEST (step 63, Table 22.5.7b.3.2-1)

Derivation path: 36.508 table 4.7.2-27
Information Element	Value/Remark	Comment	Condition
Old GUTI	GUTI-1

Table 22.5.7b.3.3-9: Message TRACKING AREA UPDATE REJECT (step 68, 22.5.7b.3.2-1)

Derivation path: 36.508 table 4.7.2-26
Information Element	Value/Remark	Comment	Condition
EMM cause	‘00010110’B	#22 "Congestion"
T3346 value	00100101’B	5 min

Table 22.5.7b.3.3-10: Void

Table 22.5.7b.3.3-11: Void

Table 22.5.7b.3.3-12: Void

Table 22.5.7b.3.3-13: Void