11.2.2 Emergency bearer services / Normal cell / LIMITED-SERVICE / Attach / PDN connect

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

11.2.2.1 Test Purpose (TP)

(1)

with { UE in EMM-DEREGISTERED.LIMITED-SERVICE state }

ensure that {

when { UE is requested to make an outgoing emergency call }

then { UE establishes the RRC connection with the RRC establishmentCause set to ‘emergency’ and transmits an ATTACH REQUEST message to attach for emergency bearer services, together with a PDN CONNECTIVITY REQUEST message for emergency bearer services }

}

11.2.2.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.304 clause 4.3, 5.2.3.1 and TS 36.331 clauses 5.3.3.2 and 5.3.3.3, and, TS 24.301 clauses 5.2.2.3.2, 5.5.1.2.2, 5.5.2.1 and 6.5.1.2. Unless otherwise stated these are Rel-9 requirements.

[TS 36.304, clause 4.3]

This clause defines the level of service that may be provided by the network to a UE in Idle mode.

The action of camping on a cell is necessary to get access to some services. Three levels of services are defined for UE:

– Limited service (emergency calls, ETWS and CMAS on an acceptable cell)

– Normal service (for public use on a suitable cell)

– Operator service (for operators only on a reserved cell)

Furthermore, the cells are categorised according to which services they offer:

acceptable cell:

An "acceptable cell" is a cell on which the UE may camp to obtain limited service (originate emergency calls and receive ETWS and CMAS notifications). Such a cell shall fulfil the following requirements, which is the minimum set of requirements to initiate an emergency call and to receive ETWS and CMAS notification in a E-UTRAN network:

– The cell is not barred, see subclause 5.3.1;

– The cell selection criteria are fulfilled, see subclause 5.2.3.2;

suitable cell:

A "suitable cell" is a cell on which the UE may camp on to obtain normal service. The UE shall have a valid USIM and such a cell shall fulfil all the following requirements.

The cell is part of either:

the selected PLMN, or:

the registered PLMN, or:

a PLMN of the Equivalent PLMN list

according to the latest information provided by NAS:

– The cell is not barred, see subclause 5.3.1;

– The cell is part of at least one TA that is not part of the list of "forbidden tracking areas for roaming", which belongs to a PLMN that fulfils the first bullet above;

– The cell selection criteria are fulfilled, see subclause 5.2.3.2;

– For a CSG cell, the CSG ID is part of the CSG whitelist of the UE.

If more than one PLMN identity is broadcast in the cell, the cell is considered to be part of all TAs with TAIs constructed from the PLMN identities and the TAC broadcast in the cell.

[TS 36.304, clause 5.2.3.1]

The UE shall use one of the following two cell selection procedures:

a) Initial Cell Selection

This procedure requires no prior knowledge of which RF channels are E-UTRA carriers. The UE shall scan all RF channels in the E-UTRA bands according to its capabilities to find a suitable cell. On each carrier frequency, the UE need only search for the strongest cell. Once a suitable cell is found this cell shall be selected.

b) Stored Information Cell Selection

This procedure requires stored information of carrier frequencies and optionally also information on cell parameters, from previously received measurement control information elements or from previously detected cells. Once the UE has found a suitable cell the UE shall select it. If no suitable cell is found the Initial Cell Selection procedure shall be started.

NOTE: Priorities between different frequencies or RATs provided to the UE by system information or dedicated signalling are not used in the cell selection process.

[TS 36.331, clause 5.3.3.2]

The UE initiates the procedure when upper layers request establishment of an RRC connection while the UE is in RRC_IDLE.

Upon initiation of the procedure, the UE shall:

…

1> else if the UE is establishing the RRC connection for emergency calls:

2> if SystemInformationBlockType2 includes the ac-BarringInfo:

…

2> else:

3> consider access to the cell as not barred;

…

1> if access to the cell, as specified above, is not barred:

2> apply the default physical channel configuration as specified in 9.2.4;

2> apply the default semi-persistent scheduling configuration as specified in 9.2.3;

2> apply the default MAC main configuration as specified in 9.2.2;

2> apply the CCCH configuration as specified in 9.1.1.2;

2> apply the timeAlignmentTimerCommon included in SystemInformationBlockType2;

2> start timer T300;

2> initiate transmission of the RRCConnectionRequest message in accordance with 5.3.3.3;

[TS 36.331, clause 5.3.3.3]

The UE shall set the contents of RRCConnectionRequest message as follows:

…

1> set the establishmentCause in accordance with the information received from upper layers;

The UE shall submit the RRCConnectionRequest message to lower layers for transmission.

[TS 36.331, clause 6.2.2]

SystemInformationBlockType1 field descriptions

…

ims-EmergencySupport

Indicates whether the cell supports IMS emergency bearer services for UEs in limited service mode. If absent, IMS emergency call is not supported by the network in the cell for UEs in limited service mode.

[TS 24.301, clause 5.2.2.3.2]

The UE shall initiate an attach or combined attach procedure when entering a cell which provides normal service.

The UE may initiate attach for emergency bearer services.

[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.

…

The UE shall send the ATTACH REQUEST message together with a PDN CONNECTIVITY REQUEST message contained in the ESM message container information element to request PDN connectivity.

If UE supports A/Gb mode or Iu mode or if the UE wants to indicate its UE specific DRX parameter to the network, the UE shall include the UE specific DRX parameter in the DRX parameter IE in the ATTACH REQUEST message.

If a valid NAS security context exists, the UE shall integrity protect the ATTACH REQUEST message combined with the PDN CONNECTIVITY REQUEST message. When the UE does not have a valid NAS security context, the ATTACH REQUEST message combined with the PDN CONNECTIVITY REQUEST message is not integrity protected.

[TS 24.301, clause 5.5.2.1]

After the completion of application for which the emergency services were invoked, in order to regain normal services, a UE attached for emergency bearer services may perform a detach procedure, followed by a subsequent re-attach, if the UE moves to a new cell that provides normal service.

[TS 24.301, clause 6.5.1.2]

When the PDN CONNECTIVITY REQUEST message is sent together with an ATTACH REQUEST message, the UE shall not include the APN.

11.2.2.3 Test description

11.2.2.3.1 Pre-test conditions

System Simulator:

– Cell A

– The PLMN is defined in Table 11.2.2.3.1-1.

Table 11.2.2.3.1–1: PLMN identifier

Cell

PLMN name

A

PLMN4

UE:

– The UE is equipped with either ISIM and USIM applications or only a USIM application on UICC. The USIM contains default values except for those listed in Table 11.2.2.3.1-2.

Table 11.2.2.3.1–2: USIM configuration

USIM field

Priority

Value

Access Technology Identifier

EFIMSI

The HPLMN (MCC+MNC) of the IMSI is set to PLMN1.

EFFPLMN

PLMN4

EFPLMNwAcT

1

Default

E-UTRAN

EFOPLMNwACT

1

PLMN1

E-UTRAN

EFHPLMNwAcT

1

PLMN1

E-UTRAN

Preamble:

– The UE is Switched OFF (State 1) according to [18].

11.2.2.3.2 Test procedure sequence

Table 11.2.2.3.2-1: Main behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

Power on the UE.

–

–

–

–

2

Wait 60s for the UE to camp on Cell A as an acceptable cell.

–

–

–

–

3

Make the UE attempt an IMS emergency call.

–

–

–

–

4

Check: Does the UE transmit an RRCConnectionRequest message with ‘establishmentCause’ set to ’emergency’?

–>

RRCConnectionRequest

1

P

5

SS transmits an RRCConnectionSetup message.

<–

RRC: RRCConnectionSetup

–

–

6

Check: Does the UE transmit an ATTACH REQUEST message to attach for emergency bearer services, together with a PDN CONNECTIVITY REQUEST message for emergency bearer services?

–>

ATTACH REQUEST

PDN CONNECTIVITY REQUEST

1

P

7-21

Steps 5 to 19 of the generic test procedure for IMS Emergency call establishment in EUTRA: Limited Service (TS 36.508 subclause 4.5A.5.3-1).

–

–

–

–

22

Release IMS Call (see Note 1)

–

–

–

–

–

EXCEPTION: Step 22Aa1 and 22Aa2 describes optional behaviour that depends on the UE implementation.

–

–

–

–

22Aa1

The UE transmits a DETACH REQUEST message with the Detach type IE indicating “EPS detach” to regain normal service.

–>

DETACH REQUEST

–

–

22Aa2

The SS responds the DETACH ACCEPT message.

<–

DETACH ACCEPT

–

–

23

The SS releases the RRC connection after 5sec of step22.

–

–

–

–

Note 1: The IMS Call is released using the generic procedure in TS 34.229-1 [35] subclause C.32.

Table 11.2.2.3.2-2: Void

11.2.2.3.3 Specific message contents

Table 11.2.2.3.3-0: RRCConnectionRequest (step 4, Table 11.2.2.3.2-1)

Derivation Path: 36.508, Table 4.6.1-16

Information Element

Value/remark

Comment

Condition

RRCConnectionRequest ::= SEQUENCE {

criticalExtensions CHOICE {

rrcConnectionRequest-r8 SEQUENCE {

establishmentCause

emergency

}

}

}

Table 11.2.2.3.3-1: ATTACH REQUEST (Step 6, Table 11.2.2.3.2-1)

Derivation Path: 36.508, Table 4.7.2-4

Information Element

Value/remark

Comment

Condition

EPS attach type

‘0110’B

EPS emergency attach

ESM message container

PDN CONNECTIVITY REQUEST message to request PDN connectivity to an emergency PDN

Table 11.2.2.3.3-2: PDN CONNECTIVITY REQUEST (Step 6, Table 11.2.2.3.2-1)

Derivation Path: 36.508, Table 4.7.3-20

Information Element

Value/remark

Comment

Condition

Request type

‘0100’B

emergency

Table 11.2.2.3.3-3: DETACH REQUEST (Step 22Aa1, Table 11.2.2.3.2-1)

Derivation Path: 36.508, Table 4.7.2-11

Information Element

Value/remark

Comment

Condition

Detach type

Type of detach

001

EPS detach

Switch off

0

normal detach

GUTI or IMSI

GUTI-1