13.1.5 Call setup from E-UTRAN RRC_CONNECTED / CS fallback to UTRAN with handover / MO call

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

13.1.5.1 Test Purpose (TP)

(1)

with { UE in E-UTRA RRC_CONNECTED state having requested CS call setup }

ensure that {
when { UE receives a MobilityFromEUTRACommand message including a cs-FallbackIndicator set to ‘true‘ and a targetRAT-Type set to ‘utra‘ }

then { UE transmits a HANDOVER TO UTRAN COMPLETE message and continues the PS data service }

}

13.1.5.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.331, clause 5.4.3.3.

[TS 36.331, clause 5.4.3.3]

The UE shall be able to receive a MobilityFromEUTRACommand message and perform a cell change order to GERAN, even if no prior UE measurements have been performed on the target cell.

The UE shall:

1> stop timer T310, if running;

1> if the MobilityFromEUTRACommand message includes the purpose set to ‘handover‘:

2> if the targetRAT-Type is set to ‘utra‘ or ‘geran‘:

3> consider inter-RAT mobility as initiated towards the RAT indicated by the targetRAT-Type included in the MobilityFromEUTRACommand message;

3> forward the nas-SecurityParamFromEUTRA to the upper layers;

3> access the target cell indicated in the inter-RAT message in accordance with the specifications of the target RAT;

13.1.5.3 Test description

13.1.5.3.1 Pre-test conditions

System Simulator:

– Cell 1 and Cell 5.

– System information combination 4 as defined in TS 36.508 [18] clause 4.4.3.1 is used in E-UTRA cells.

Table 13.1.5.3.1-1 shows the cell power levels after the preamble.

Table 13.1.5.3.1-1: Time instances of cell power level and parameter changes

	Parameter name	Unit	Cell 1	Cell 5
T0	RS EPRE	dBm/15kHz	-85
	CPICH_Ec	dBm/3.84 MHz		-70
	P-CCPCH	dBm/1.28 MHz		-72
T1	RS EPRE	dBm/15kHz	Non-suitable “Off”
	CPICH_Ec	dBm/3.84 MHz		-70
	P-CCPCH	dBm/1.28 MHz		-72

UE:

None.

Preamble:

– The UE is in state Loopback Activated (state 4) with condition UE TEST LOOP MODE B on Cell 1 according to [18].

13.1.5.3.2 Test procedure sequence

Table 13.1.5.3.2-1: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
1	The SS transmits one IP packet to the UE on the DRB associated with the default EPS bearer context on Cell 1.	<–	IP packet	–	–
2	The UE loops back the IP packet on the DRB associated with the default EPS bearer context on Cell 1.	–>	IP packet	–	–
3	Cause the UE to originate CS call. (see Note 1)	–	–	–	–
4	The UE transmits an ULInformationTransfer message on Cell 1. This message includes an EXTENDED SERVICE REQUEST message.	–>	ULInformationTransfer	–	–
4A	The SS transmits a UECapabilityEnquiry message to request UE radio access capability information for E-UTRA and UTRA.	<–	UECapabilityEnquiry	–	–
4B	The UE transmits a UECapabilityInformation message on Cell 1. NOTE: The start-PS values received, should be used to configure ciphering on cell 5.	–>	UECapabilityInformation	–	–
5	The SS transmits a MobilityFromEUTRACommand message on Cell 1.	<–	MobilityFromEUTRACommand	–	–
6	Check: Does the result of the “CS fallback to UTRAN with Handover / MO call” generic procedure from 36.508 clause 6.4.3.7.6 indicate that the UE performs CS fallback to UTRAN with Handover / MO Call on Cell 5?	–	–	1	P
6A	SS adjusts cell levels according to row T1 of table 13.1.5.3.1-1.
–	Void.	–	–	–	–
7-13	Void	–	–	–	–
14	The SS transmits one IP packet to the UE on the PS RAB on Cell 5.	<–	IP packet	–	–
15	Check: Does the UE loop back the IP packet on the PS RAB on Cell 5?	–>	IP packet	1	P
Note 1: The trigger in step 3 is the same as in the generic procedure in 36.508 clause 6.4.3.5.

13.1.5.3.3 Specific message contents

Table 13.1.5.3.3-1: MobilityFromEUTRACommand (step 5, Table 13.1.5.3.2-1)

Derivation Path: 36.508, Table 4.6.1-6
Information Element	Value/remark	Comment	Condition
MobilityFromEUTRACommand ::= SEQUENCE {
criticalExtensions CHOICE {
c1 CHOICE{
mobilityFromEUTRACommand-r8 SEQUENCE {
cs-FallbackIndicator	true
purpose CHOICE{
handover SEQUENCE {
targetRAT-Type	utra
targetRAT-MessageContainer	HANDOVER TO UTRAN COMMAND(UTRA RRC message)
nas-SecurityParamFromEUTRA	The 4 least significant bits of the NAS downlink COUNT value
systemInformation	Not present
}
}
}
}
}
}

Table 13.1.5.3.3-2: HANDOVER TO UTRAN COMMAND (Table 13.1.5.3.3-1)

Derivation Path: 36.508, Table 4.7B.1-1, condition UTRA PS RB

Table 13.1.5.3.3-3: EXTENDED SERVICE REQUEST (step 4, table 13.1.5.3.2-1)

Derivation path: 36.508 table 4.7.2-14A
Information Element	Value/Remark	Comment	Condition
Service type	0000 ‘mobile originating CS fallback or 1xCS fallback’
CSFB response	Not present

Table 13.1.5.3.3-4: UECapabilityEnquiry (step 4A, Table 13.1.5.3.2-1)

Derivation path: 36.508 clause 4.6.1 table 4.6.1-22
Information Element	Value/Remark	Comment	Condition
UECapabilityEnquiry ::= SEQUENCE {
criticalExtensions CHOICE {
c1 CHOICE {
ueCapabilityEnquiry-r8 SEQUENCE {
ue-CapabilityRequest SEQUENCE (SIZE (1..maxRAT-Capabilities)) OF SEQUENCE {	2 entry
RAT-Type[1]	Eutra
RAT-Type[2]	Utra
}
}
}
}
}

Table 13.1.5.3.3-5: ATTACH ACCEPT (Preamble)

Derivation Path: 36.508 Table 4.7.2-1
Information Element	Value/remark	Comment	Condition
EPS network feature support	Not present

Table 13.1.5.3.3-6: ROUTING AREA UPDATE ACCEPT (Step 10, TS 36.508 Table 6.4.3.7.6-1)

Derivation Path: 36.508 Table 4.7B.2-2
Information Element	Value/remark	Comment	Condition
Update result	0 ‘follow-on proceed’