22.5.17 NB-IoT / Attach Success /Normal tracking area update accepted / Periodic tracking area update T3412 Extended Value / PSM

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

22.5.17.1 Test Purpose (TP)

(1)

with { the UE is switched-off with a valid USIM inserted and the UE is configured to attach with PSM }

ensure that {

when { UE is powered on }

then { the UE transmits an ATTACH REQUEST message including the T3324 IE }

}

(2)

with { the UE in IDLE mode }

ensure that {

when { UE receives a paging message before timer T3324 is expired }

then { the UE responds to the paging request }

}

(3)

with { UE in state EMM-REGISTERED and EMM-IDLE mode}

ensure that {

when { PSM is activated }

then { UE send TRACKING AREA UPDATE REQUEST message including the T3324 IE }

}

(4)

with { UE in state EMM-REGISTERED.NO-CELL-AVAILABLE }

ensure that {

when { the SS sends a Paging-NB message }

then { the UE does not answer the Paging-NB message }

}

(5)

Void

(6)

with { UE in state EMM-REGISTERED and EMM-IDLE mode with timer T3412 “normal” and extended values being allocated by the SS during Tracking Area Update procedure }

ensure that {

when { timer T3412 extended value expires }

then { UE sends TRACKING AREA UPDATE REQUEST message with EPS update type = “Periodic updating” }

}

22.5.17.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: 3GPP TS 24.301 clauses 5.3.11, 5.5.1.2.2, 5.5.3.2.2, and 5.5.1.2.4.

[TS 24.301, clause 5.3.11]

The UE can request the use of power saving mode (PSM) during an attach or tracking area updating procedure (see 3GPP TS 23.682 [11A] and 3GPP TS 23.401 [10]). The UE shall not request the use of PSM during:

– an attach for emergency bearer services procedure;

– an attach procedure for initiating a PDN connection for emergency bearer services with attach type not set to "EPS emergency attach";

– a tracking area updating procedure for initiating a PDN connection for emergency bearer services; or

– a tracking area updating procedure when the UE has a PDN connection established for emergency bearer services.

The network accepts the use of PSM by providing a specific value for timer T3324 when accepting the attach or tracking area updating procedure. The UE may use PSM only if the network has provided the T3324 value IE during the last attach or tracking area updating procedure with a value different from "deactivated".

NOTE: Timer T3324 is specified in 3GPP TS 24.008 [13].

Upon expiry of the timer T3324 or if the T3324 value provided by the network is zero, the UE may deactivate the AS layer and activate PSM by entering the state EMM-REGISTERED.NO-CELL-AVAILABLE if:

a) the UE is not attached for emergency bearer services;

b) the UE has no PDN connection for emergency bearer services;

c) the UE is in EMM-IDLE mode; and

d) in the EMM-REGISTERED.NORMAL-SERVICE state.

If conditions a, b and c are fulfilled, but the UE is in a state other than EMM-REGISTERED.NORMAL-SERVICE when timer T3324 expires, the UE may activate PSM when the MS returns to state EMM-REGISTERED.NORMAL-SERVICE.

A UE that has already been allocated timer T3324 with a value different from "deactivated" and the timer T3324 has expired, may activate PSM if it receives an "Extended wait time" from lower layers.

If the UE is attached for emergency bearer services or has a PDN connection for emergency bearer services, the UE shall not activate PSM.

The UE may deactivate PSM at any time (e.g. for the transfer of mobile originated signalling or user data), by activating the AS layer before initiating the necessary EMM procedures. When PSM is activated all NAS timers are stopped and associated procedures aborted except for T3412, T3346 and T3396.

[TS 24.301, clause 5.5.1.2.2]

If the UE supports PSM and requests the use of PSM, then the UE shall include the T3324 value IE with a requested timer value in the ATTACH REQUEST message. When the UE includes the T3324 value IE and the UE indicates support for extended periodic timer value in the MS network feature support IE, it may also include the T3412 extended value IE to request a particular T3412 value to be allocated.

[TS 24.301, clause 5.5.3.2.2]

The UE in state EMM-REGISTERED shall initiate the tracking area updating procedure by sending a TRACKING AREA UPDATE REQUEST message to the MME,

……..

t) when the UE needs to request the use of PSM or needs to stop the use of PSM; or

u) when a change in the PSM usage conditions at the UE requires a different timer T3412 value or different timer T3324 value.

NOTE: A change in the PSM usage conditions at the UE can include e.g. a change in the UE configuration, a change in requirements from upper layers or the battery running low at the UE.

[TS 24.301 clause 5.5.1.2.4]

If the attach request is accepted by the network, the MME shall send an ATTACH ACCEPT message to the UE and start timer T3450. The MME shall send the ATTACH ACCEPT message together with an ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message contained in the ESM message container information element to activate the default bearer (see subclause 6.4.1). The network may also initiate the activation of dedicated bearers towards the UE by invoking the dedicated EPS bearer context activation procedure (see subclause 6.4.2).

…

If the ATTACH ACCEPT message contains a T3412 extended value IE, then the UE shall use the value in T3412 extended value IE as periodic tracking area update timer (T3412). If the ATTACH ACCEPT message does not contain T3412 extended value IE, then the UE shall use the value in T3412 value IE as periodic tracking area update timer (T3412).

22.5.17.3 Test description

22.5.17.3.1 Pre-test conditions

System Simulator:

– NB-IoT Ncell 1, default parameters.

UE:

– The UE is previously registered on E-UTRAN, and when on E-UTRAN, the UE is last authenticated and registered on the NB-IoT cell using default message contents according to TS 36.508 [18].

– The UE is configured to use Power Saving Mode.

– The UE is configured to use the timer T3324 set to two minutes.

Preamble:

– UE is in State 1-NB switched off.

22.5.17.3.2 Test procedure sequence

Table 22.5.17.3.2-1: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
1-3	Steps 1 – 3 of the generic procedure specified in TS 36.508 subclause 8.1.5.2.3 is performed	–	–	–	–
4a1-4b1	Check: Does the UE transmit an ATTACH REQUEST message including the T3324 IE set to two minutes.	–>	ATTACH REQUEST	1	P
5	Void	–	–	–	–
6-15b1	Steps 5 – 14b1 of the generic procedure specified in TS 36.508 subclause 8.1.5.2.3 is performed	–	–	–	–
–	The SS shall wait for 1 minute and then execute the following steps before timer T3324 expires.	–	–	–	–
16-20	Check: Does the UE accept the paging request. Steps 1-5, from paging generic procedure in TS 36.508, clause 8.1.5A.2.3 are performed.	–	–	2	P
21	The user requests PSM by MMI or by AT command. The requested value of T3324 is 1 minute.	–	–	–	–
22	Check: Does the UE transmit a TRACKING AREA UPDATE REQUEST message?	–>	TRACKING AREA UPDATE REQUEST	3	P
23	The SS transmits a TRACKING AREA UPDATE ACCEPT message including GUTI-1.	<–	TRACKING AREA UPDATE ACCEPT	–	–
24	The UE transmits a TRACKING AREA UPDATE COMPLETE message.	–>	TRACKING AREA UPDATE COMPLETE	–	–
25	The SS releases the RRC connection.			–	–
26	When the T3324 timer expires the SS send Paging message including a matched identity	<–	Paging-NB	–	–
27	Check: Does the UE respond to the paging message?			4	F
28-37	Void	–	–	–	–
38	The SS waits 4 minutes. (Expiry of T3412 extended value)	–	–	–	–
39	Check: Does the UE transmit a TRACKING AREA UPDATE REQUEST message?	–>	TRACKING AREA UPDATE REQUEST	6	P
40	The SS transmits a TRACKING AREA UPDATE ACCEPT message	<–	TRACKING AREA UPDATE ACCEPT	–	–
41	The UE transmits a TRACKING AREA UPDATE COMPLETE message?	–>	TRACKING AREA UPDATE COMPLETE	–	–
42	The SS releases the RRC connection.	–	–	–	–

22.5.17.3.3 Specific message contents

Table 22.5.17.3.3-1: Message ATTACH REQUEST (step 5, Table 22.5.17.3.2-1)

Derivation path: TS 36.508 table 4.7.2-4
Information Element	Value/Remark	Comment	Condition
Old GUTI or IMSI	GUTI(belonging to PLMN with same MCC as stored in EF_IMSI on the test USIM card)	GUTI copied from USIM Old and valid GUTI is included by the UE
ESM message container	PDN CONNECTIVITY REQUEST message to request PDN connectivity to the default PDN
Last visited registered TAI	TAI1	GUTI copied from USIM If available, the last TAI is included by UE and will be used to establish a good list of TAIs in subsequent ATTACH ACCEPT message.
T3324	2 minutes

Table 22.5.17.3.3-2: Message ATTACH ACCEPT (step 15b1, Table 22.5.17.3.2-1)

Derivation path: TS 36.508 table 4.7.2-1
Information Element	Value/Remark	Comment	Condition
T3324	T3324 timer value	Timer set to the same value as in table 22.5.17.3.3-1

Table 22.5.17.3.3-3: Message TRACKING AREA UPDATE REQUEST (step 22, Table 22.5.17.3.2-1)

Derivation path: 36.508 table 4.7.2-27
Information Element	Value/Remark	Comment	Condition
EPS update type	000	TA updating
Old GUTI	GUTI-1	"Old GUTI is included by UE if valid, IMSI otherwise"
T3324 value	00100001 or 00011110	1 minute or 60 seconds

Table 22.5.17.3.3-4: Message TRACKING AREA UPDATE ACCEPT (step 23, Table 22.5.17.3.2-1)

Derivation path: 36.508 table 4.7.2-24
Information Element	Value/Remark	Comment	Condition
EPS update result	000	"TA only"
GUTI	GUTI-1
T3324 value	00100001	1 minute
T3412 extended value	‘10100100’B	4 minutes

Table 22.5.17.3.3-5: Void

Table 22.5.17.3.3-6: Void

Table 22.5.17.3.3-7: Void

Table 22.5.17.3.3-8: Void

Table 22.5.17.3.3-9: Message TRACKING AREA UPDATE REQUEST (step 39, Table 22.5.17.3.2-1)

Derivation path: 36.508 table 4.7.2-27
Information Element	Value/Remark	Comment	Condition
EPS update type	011	periodic updating’