22.5.15 NB-IoT / Normal tracking area update / low priority override
36.523-13GPPEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Packet Core (EPC)Part 1: Protocol conformance specificationRelease 17TSUser Equipment (UE) conformance specification
22.5.15.1 Test Purpose (TP)
(1)
with { the UE is switched-off with a valid USIM inserted and the UE is configured to override NAS signalling low priority }
ensure that {
when { UE is powered on }
then { the UE transmits an ATTACH REQUEST message including the Device properties IE set to “MS is not configured for NAS signalling low priority” }
}
(2)
with { UE in state EMM-REGISTERED and EMM-IDLE mode and UE configured for low priority NAS signalling and low priority NAS signalling override }
ensure that {
when { UE detects entering a new tracking area not included in the TAI list }
then { UE sends TRACKING AREA UPDATE REQUEST message with the low priority indicator set to "MS is not configured for NAS signalling low priority"}
}
22.5.15.2 Conformance requirements
References: The conformance requirements covered in the present TC are specified in: 3GPP TS 24.301 clauses 4.2A
[TS 24.301 clause 4.2A]
A UE configured for NAS signalling low priority (see 3GPP TS 24.368 [15A], 3GPP TS 31.102 [17]) indicates this by including the Device properties IE in the appropriate NAS message and setting the low priority indicator to "MS is configured for NAS signalling low priority", except for the following cases in which the UE shall set the low priority indicator to "MS is not configured for NAS signalling low priority":
– the UE is performing an attach for emergency bearer services;
– the UE has a PDN connection for emergency bearer services established and is performing EPS mobility management procedures, or is establishing a PDN connection for emergency bearer services;
– the UE configured for dual priority is requested by the upper layers to establish a PDN connection with the low priority indicator set to "MS is not configured for NAS signalling low priority";
– the UE configured for dual priority is performing EPS session management procedures related to the PDN connection established with low priority indicator set to "MS is not configured for NAS signalling low priority";
– the UE configured for dual priority has a PDN connection established by setting the low priority indicator to "MS is not configured for NAS signalling low priority" and is performing EPS mobility management procedures;
– the UE is performing a service request procedure for a CS fallback emergency call or 1xCS fallback emergency call;
– the UE is a UE configured to use AC11 – 15 in selected PLMN; or
– the UE is responding to paging.
The network may use the NAS signalling low priority indication for NAS level mobility management congestion control and APN based congestion control.
If the NAS signalling low priority indication is provided in a PDN CONNECTIVITY REQUEST message, the MME stores the NAS signalling low priority indication within the default EPS bearer context activated due to the PDN connectivity request procedure.
22.5.15.3 Test description
22.5.15.3.1 Pre-test conditions
System Simulator:
– Ncell 50 (belongs to TAI-1, home PLMN) is set to "Serving cell";
– Ncell 51 (belongs to TAI-2, home PLMN) is set to "Non-suitable cell";
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 for low priority NAS signalling
– The UE is configured for low priority NAS signalling override
The UE is equipped with a USIM containing values shown in Table 22.5.15.3.1-1.
Table 22.5.15.3.1-1: USIM Configuration
|
USIM field |
Value |
|
EFUST |
Service 96 is supported. |
|
EFNASCONFIG |
“NAS_SignallingPriority is set to “NAS signalling low priority” as defined in TS 24.368, clause 5.3. |
|
EFNASCONFIG |
“Override_NAS_SignallingLowPriority” is set to “UE can override the NAS signalling low priority indicator” as defined in TS 24.368, clause 5.9. |
|
EFNASCONFIG |
“ExtendedAccessBarring is set to extended access barring is applied for the UE” as defined in TS 24.368, clause 5.8 |
|
EFNASCONFIG |
“Override_ExtendedAccessBarring is set to UE can override extended access barring” as defined in TS 24.368, clause 5.10. |
|
EFACC |
Type “B” as defined in TS 34.108 clause 8.3.2.15 |
|
Note: As per TS 23.401 [22] clause 4.3.17.4, UE’s configuration of low access priority and Extended Access Barring shall match each other and so do their corresponding override configuration. |
|
Preamble:
– UE is in State 1-NB switched off.
22.5.15.3.2 Test procedure sequence
Table 22.5.15.3.2-1: Main behaviour
|
St |
Procedure |
Message Sequence |
TP |
Verdict |
||
|
U – S |
Message |
|||||
|
1-4b1 |
Steps 1 – 4b1 of the generic procedure specified in TS 36.508 subclause 8.1.5.2.3 is performed. |
– |
– |
– |
– |
|
|
5 |
Check: Does the UE transmit an ATTACH REQUEST message including the Device properties IE set to “MS is not configured for NAS signalling low priority”? |
–> |
ATTACH REQUEST |
1 |
P |
|
|
6-15b1 |
Steps 5 – 14b1 of the generic procedure specified in TS 36.508 subclause 8.1.5.2.3 is performed |
– |
– |
– |
– |
|
|
16 |
The SS releases the RRC connection. |
– |
– |
|||
|
– |
The following messages are sent and shall be received on Ncell 51. |
– |
– |
– |
– |
|
|
17 |
Set the cell type of Ncell 50 to the "Non-Suitable cell". Set the cell type of Ncell 51 to the " Serving cell" |
– |
– |
– |
– |
|
|
18 |
Check: Does the UE transmit a TRACKING AREA UPDATE REQUEST message with the Device properties IE set to “MS is not configured for NAS signalling low priority”? |
–> |
TRACKING AREA UPDATE REQUEST |
2 |
P |
|
|
19 |
The SS transmits a TRACKING AREA UPDATE ACCEPT message. |
<– |
TRACKING AREA UPDATE ACCEPT |
– |
– |
|
|
20 |
The UE transmits a TRACKING AREA UPDATE COMPLETE message |
–> |
TRACKING AREA UPDATE COMPLETE |
– |
– |
|
|
21 |
The SS releases the RRC connection. |
– |
– |
– |
||
22.5.15.3.3 Specific message contents
Table 22.5.15.3.3-1: Message ATTACH REQUEST (step 5, Table 22.5.15.3.2-1)
|
Derivation Path: TS 36.508 Table 8.1.7 |
|||
|
Information Element |
Value/remark |
Comment |
Condition |
|
Device properties |
0 |
‘MS is not configured for NAS signalling low priority’ |
|
Table 22.5.15.3.3-2: Message TRACKING AREA UPDATE REQUEST (step 18, Table 22.5.15.3.2-1)
|
Derivation path: 36.508 table 4.7.2-27 |
|||
|
Information Element |
Value/Remark |
Comment |
Condition |
|
Device properties |
0 |
‘MS is not configured for NAS signalling low priority’ |
|
|
Last visited registered TAI |
TAI-1 |
||