22.5.23 NB-IoT / NTN / GNSS position reporting / reject cause #78 "PLMN not allowed to operate at the present UE location"

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

22.5.23.1 Test Purpose (TP)

(1)

with { UE has sent an ATTACH REQUEST message with }

ensure that {

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

then { UE sets the EPS update status to EU3 ROAMING NOT ALLOWED, UE deletes the GUTI, last visited registered TAI, TAI list and eKSI, UE resets the registration attempt counter, UE enters the state EMM-DEREGISTERED.PLMN-SEARCH and perform a PLMN selection }

}

22.5.23.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 24.301 clauses 4.11.2, 5.5.1.2.5 and 5.5.1.2.6. Unless otherwise stated these are Rel-17 requirements.

[TS 24.301, clause 4.11.2]

The UE may be rejected with EMM cause #78 in ATTACH REJECT message, TRACKING AREA UPDATE REJECT message or DETACH REQUEST message. The EMM cause #78 is applicable for the UE only when the UE is accessing a PLMN using a satellite E-UTRAN access.

For the satellite E-UTRAN access the UE shall store a list of "PLMN not allowed to operate at the present UE location". Each entry in the list consists of:

a) PLMN identity of the PLMN which sent a message including EMM cause value #78 "PLMN not allowed to operate at the present UE location" via the satellite E-UTRAN access technology;

b) geographical location, if known by the UE, where the EMM cause value #78 was received over the satellite E-UTRAN access technology; and

c) if the geographical location exists, a UE implementation specific distance value.

Before storing a new entry in the list, the UE shall delete any existing entry with the same PLMN identity. Upon storing a new entry, the UE starts a timer instance associated with the entry with an implementation specific value that shall not be set to a value smaller than the timer value indicated by the network, if any.

Editor’s note: A minimum value for the timer can be optionally provided by the network in the same message as cause value #78, but IE naming and definition is FFS.

The UE shall not attempt to access a PLMN via the satellite E-UTRAN access technology which is part of the list of "PLMNs not allowed to operate at the present UE location" if:

a) the current UE location is known, a geographical location is stored for the entry of this PLMN, and the distance from location where EMM cause value #78 was received to the current UE location is smaller than a UE implementation specific value:

b) the timer associated with the entry of this PLMN has expired; or

c) the access is for emergency services (see 3GPP TS 23.122 [5] for further details).

NOTE: If the current location is not known or the geographic location is not stored for the entry of this PLMN, condition a) is ignored.

The list shall accommodate three or more entries. The maximum number of entries is an implementation decision. When the list is full and a new entry has to be inserted, the oldest entry shall be deleted.

Each entry shall be removed if for the entry:

a) the UE successfully registers via the satellite E-UTRAN access technology to the PLMN stored in the entry; or

b) the timer instance associated with the entry expires.

The UE may remove an entry in the list, if the UE’s current location is known, a geographical is stored for the entry of this PLMN, and the distance from location where EMM cause value #78 was received to the current UE location is larger than the UE implementation specific value.

When the UE is switched off, the UE shall keep the list of "PLMNs not allowed to operate at the present UE location" in its non-volatile memory together with the SUPI from the USIM. The UE shall delete the list of "PLMNs not allowed to operate at the present UE location" if the USIM is removed.

[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.

…

In NB-S1 mode or WB-S1 mode via satellite E-UTRAN access, if the attach request is from a UE via a satellite E-UTRA cell and the network using the User Location Information provided by the eNodeB (see 3GPP TS 36.413 [23]), is able to determine that the UE is in a location where the network is not allowed to operate, the network shall set the EMM cause value in the ATTACH REJECT message to #78 "PLMN not allowed to operate at the present UE location" and may include an information element in the ATTACH REJECT message to indicate the country of the UE location.

Editor’s note: [IoT_SAT_ARCH_EPS, CR#3620]: The name and the encoding of the information element providing the country of the UE location is FFS.

Editor’s note [IoT_SAT_ARCH_EPS, CR#3620]: It is FFS if and how the HPLMN can influence the validity and use of the indication of country of UE location in the UE.

…

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

…

#78 (PLMN not allowed to operate at the present UE location).

This cause value received from a non-satellite E-UTRA cell is considered as an abnormal case and the behaviour of the UE is specified in clause 5.5.1.2.6.

The UE shall set the EPS update status to EU3 ROAMING NOT ALLOWED (and shall store it according to clause 5.1.3.3) and shall delete any GUTI, last visited registered TAI, TAI list and eKSI. Additionally, the UE shall reset the registration attempt counter and shall enter state EMM-DEREGISTERED.PLMN-SEARCH and perform a PLMN selection according to 3GPP TS 23.122 [6].

Editor’s note: [IoT_SAT_ARCH_EPS, CR#3620]. It is FFS how to prevent the UE from making repeated attempts at selecting the same satellite access PLMN if there are no other available PLMNs at UE’s location.

Other values are considered as abnormal cases. The behaviour of the UE in those cases is specified in clause 5.5.1.2.6.

[TS 24.301, clause 5.5.1.2.6]

The following abnormal cases can be identified:

…

d) ATTACH REJECT, other EMM cause values than those treated in clause 5.5.1.2.5, and cases of EMM cause values #22, #25, #31 and #78, if considered as abnormal cases according to clause 5.5.1.2.5

…

The UE shall proceed as described below.

For the cases b, c, d, l, la and m:

– Timer T3410 shall be stopped if still running.

– For the cases b, c, d, l when the "Extended wait time" is ignored, and la when the "Extended wait time CP data" is ignored, if the attach request is neither for emergency bearer services nor for initiating a PDN connection for emergency bearer services with attach type not set to "EPS emergency attach", the attach attempt counter shall be incremented, unless it was already set to 5.

– If the attach attempt counter is less than 5:

– for the cases l, la and m, the attach procedure is started, if still necessary, when timer T3346 expires or is stopped;

– for the cases b, c, d, l when the "Extended wait time" is ignored, and la when the "Extended wait time CP data" is ignore, if the attach request is neither for emergency bearer services nor for initiating a PDN connection for emergency bearer services with attach type not set to "EPS emergency attach", timer T3411 is started and the state is changed to EMM-DEREGISTERED.ATTEMPTING-TO-ATTACH. When timer T3411 expires the attach procedure shall be restarted, if still required by ESM sublayer.

– If the attach attempt counter is equal to 5:

– the UE shall delete any GUTI, TAI list, last visited registered TAI, list of equivalent PLMNs and KSI, shall set the update status to EU2 NOT UPDATED, and shall start timer T3402. The state is changed to EMM-DEREGISTERED.ATTEMPTING-TO-ATTACH or optionally to EMM-DEREGISTERED.PLMN-SEARCH in order to perform a PLMN selection according to 3GPP TS 23.122 [6]; and

…

NOTE 5: Whether the UE requests RRC to treat the active E-UTRA cell as barred (see 3GPP TS 36.304 [21]) is left to the UE implementation.

22.5.23.3 Test description

22.5.23.3.1 Pre-test conditions

System Simulator:

– Ncell 50 (PLMN1, HPLMN) and Ncell 55 (PLMN2, visited PLMN belongs to TAI-7, MCC=001 MNC=02) 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 9 as defined in TS 36.508 [18] clause 8.1.4.3.1.1 is used.

UE:

– The UE is in Automatic PLMN selection mode.

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

– The UE’s positioning engine (e.g., standalone GNSS receiver) should be enabled to allow it to acquire the position. This could be done by use of AT command, such as AT+CPOS or other commands. Otherwise, or in addition any other suitable method may also be used, e.g., GNSS simulator.

Preamble:

– The UE is in State 1-NB switched off according to TS 36.508 [18].

22.5.23.3.2 Test procedure sequence

Table 22.5.23.3.2-1 shows the cell configurations used during the test. The configuration T0 indicates the initial conditions. Subsequent configurations marked “T1” is applied at the points indicated in the Main behaviour description in Table 22.5.23.3.2-2. Cell powers are chosen for a serving cell and a non-suitable “Off” cell as defined in TS 36.508 [18].

Table 22.5.23.3.2-1: Ncell configuration changes over time

	Parameter	Unit	Ncell 50	Ncell 55	Remarks
T0	NRS EPRE	dBm/15kHz	-85	“Off”	Power level “Off” is defined in TS 36.508 Table 6.2.2.1-1
T1	NRS EPRE	dBm/15kHz	-85	-73

Table 22.5.23.3.2-2: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
–	The following messages are to be observed on Ncell 50 unless explicitly stated otherwise.	–	–	–	–
1	The UE is switched on.	–	–	–	–
2	The UE transmits an ATTACH REQUEST message.	–>	ATTACH REQUEST	–	–
3	The SS transmits an ATTACH REJECT message including EMM cause = "PLMN not allowed to operate at the present UE location".	<–	ATTACH REJECT	–	–
4	The SS releases the RRC connection.	–	–	–	–
5	SS adjusts Ncell levels according to row T1 of table 22.5.23.3.2-1.	–	–	–	–
–	The following messages are to be observed on Ncell 55 unless explicitly stated otherwise.	–	–	–	–
6	Check: Does the UE transmit an ATTACH REQUEST message?	–>	ATTACH REQUEST	1	P

22.5.23.3.3 Specific message contents

Table 22.5.23.3.3-1: Message ATTACH REJECT (step 3, Table 22.5.23.3.2-2)

Derivation path: TS 36.508 [18], Table 8.1.7
Information Element	Value/Remark	Comment	Condition
EMM cause	01001110	#78 "PLMN not allowed to operate at the present UE location"
ESM message container	Not present

Table 22.5.23.3.3-2: Message ATTACH REQUEST (step 6, Table 22.5.23.3.2-2)

Derivation path: TS 36.508 [18], 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 3; only IMSI is available.
Last visited registered TAI	Not present	TAI has been deleted after receiving ATTACH REJECT at step 3.