8.4.8 WLAN Offload EUTRA RRC Connected

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

8.4.8.1 WLAN Offload / Offload Success / EUTRA RRC_Connected to/from WLAN (Qrxlevmeas, BackhaulRateUlWLAN)

8.4.8.1.1 Test Purpose (TP)

(1)

with { UE in E-UTRA RRC_CONNECTED state }

ensure that {

when { UE receives an RRCConnectionReconfiguration message containing wlan-OffloadConfigDedicated with thresholdRSRP-Low, thresholdRSRP-High, thresholdBackhaulUL-BandwidthLow and thresholdBackhaulUL-BandwidthHigh }

then { UE configures dedicated WLAN offload and sends an RRCConnectionReconfigurationComplete message }

}

(2)

with { UE in E-UTRA RRC_CONNECTED state }

ensure that {

when { RSRPmeas < ThreshServingOffloadWLAN, LowP and BackhaulRateUlWLAN > ThreshBackhRateULWLAN, High }

then { UE offload PDN connections to WLAN }

}

(3)

with { UE in E-UTRA RRC_CONNECTED state }

ensure that {

when { RSRPmeas > ThreshServingOffloadWLAN, HighP and BackhaulRateUlWLAN < ThreshBackhRateULWLAN, Low }

then { UE offload PDN connections to 3GPP }

}

8.4.8.1.2 Conformance requirements

References: The conformance requirements covered in the current TC is specified in: TS 36.331, clauses 5.3.5.3, 5.6.12.2, 5.6.12.3, TS 36.304, clause 5.6.2 and TS 24.302, clause 6.10.4.

[TS 36.331, clause 5.3.5.3]

If the RRCConnectionReconfiguration message does not include the mobilityControlInfo and the UE is able to comply with the configuration included in this message, the UE shall:

…

1> if the RRCConnectionReconfiguration message includes wlan-OffloadInfo:

2> perform the dedicated WLAN offload configuration procedure as specified in 5.6.12.2;

1> submit the RRCConnectionReconfigurationComplete message to lower layers for transmission using the new configuration, upon which the procedure ends;

[TS 36.331, clause 5.6.12.2]

The UE shall:

1> if the received wlan-OffloadInfo is set to release:

2> release wlan-OffloadConfigDedicated and t350;

2> if the wlan-OffloadConfigCommon corresponding to the RPLMN is broadcast by the cell:

3> apply the wlan-OffloadConfigCommon corresponding to the RPLMN included in SystemInformationBlockType17;

1> else:

2> apply the received wlan-OffloadConfigDedicated:

[TS 36.331, clause 5.6.12.3]

The UE shall:

1> if the UE is configured with either wlan-OffloadConfigCommon or wlan-OffloadConfigDedicated:

2> provide measurement results required for the evaluation of the network selection and traffic steering rules as defined in TS 24.312 to upper layers;

2> evaluate the network selection and traffic steering rules as defined in TS 36.304;

[TS 36.304, clause 5.6.2]

The rules in this sub-clause are only applicable for WLANs for which identifiers has been signalled to the UE by E-UTRAN and the UE is capable of RAN-assisted WLAN interworking based on access network selection and traffic steering rules. Coexistence with ANDSF based WLAN selection and traffic steering methods on the UE is based on mechanism described in TS 23.402. The rules refer to the following quantities:

ChannelUtilizationWLAN

WLAN channel utilization as defined in subclause 8.4.2.30 in [26].

BackhaulRateDlWLAN

WLAN DLBandwidth as defined in subclause 9.1.2 in [27].

BackhaulRateUlWLAN

WLAN ULBandwidth as defined in subclause 9.1.2 in [27].

BeaconRSSI

WLAN Beacon RSSI as defined in [7].

RSRPmeas

Qrxlevmeas in RRC_IDLE, and PCell RSRP in RRC_CONNECTED as defined in TS 36.331 [3].

RSRQmeas

Qqualmeas in RRC_IDLE, and PCell RSRQ in RRC_CONNECTED as defined in TS 36.331 [3].

The upper layers in the UE shall be notified (see TS 24.302) when and for which WLAN(s), that matches all the provided identifiers (in subclause 5.6.3) for a specific entry in the list, the following conditions 1 and 2 for steering traffic from E-UTRAN to WLAN are satisfied for a time interval TsteeringWLAN:

In the E-UTRAN serving cell:

RSRPmeas < ThreshServingOffloadWLAN, LowP; or

RSRQmeas < ThreshServingOffloadWLAN, LowQ;

In the target WLAN:

ChannelUtilizationWLAN < ThreshChUtilWLAN, Low; and

BackhaulRateDlWLAN > ThreshBackhRateDLWLAN, High; and

BackhaulRateUlWLAN > ThreshBackhRateULWLAN, High; and

BeaconRSSI > ThreshBeaconRSSIWLAN, High;

The UE shall not consider the metrics for which a threshold has not been provided. The UE shall evaluate the E-UTRAN conditions on PCell only. If not all metrics related to the provided thresholds can be acquired for a WLAN BSS, the UE shall exclude that WLAN BSS from the evaluation of the above rule.

The upper layers in the UE shall be notified (see TS 24.302) when the following conditions 3 or 4 for steering traffic from WLAN to E-UTRAN are satisfied for a time interval TsteeringWLAN:

In the source WLAN:

ChannelUtilizationWLAN > ThreshChUtilWLAN, High; or

BackhaulRateDlWLAN < ThreshBackhRateDLWLAN, Low; or

BackhaulRateUlWLAN < ThreshBackhRateULWLAN, Low; or

BeaconRSSI < ThreshBeaconRSSIWLAN, Low;

In the target E-UTRAN cell:

RSRPmeas > ThreshServingOffloadWLAN, HighP; and

RSRQmeas > ThreshServingOffloadWLAN, HighQ;

The UE shall not consider the metrics for which a threshold has not been provided. The UE shall evaluate the E-UTRAN conditions on PCell only.

[TS 24.302, clause 6.10.4]

This subclause applies if the RAN rules control the WLAN access selection and traffic routing as described in subclause 6.10.2.

The access stratum layer of the 3GPP access can provide:

1) move-traffic-to-WLAN indication, along with list of WLAN identifiers. An entry in the list of the WLAN identifiers consists of SSID, BSSID, HESSID, or any combination of them; and

2) move-traffic-from-WLAN indication.

The user preferences take precedence over the indications provided by the access stratum layer of the 3GPP access.

Upon:

– receiving move-traffic-to-WLAN indication, along with the list of the WLAN identifiers, if the user preferences are not present; or

– establishment of a new PDN connection in 3GPP access, if the PDN connection is an offloadable PDN connection, the access stratum indicated move-traffic-to-WLAN, the access stratum has not indicated the move-traffic-from-WLAN indication after indicating of the move-traffic-to-WLAN indication and the user preferences are not present;

and:

– the UE is capable to simultaneously route IP traffic to both 3GPP access and WLAN; or

– the UE is not capable to simultaneously route IP traffic to both 3GPP access and WLAN, and all the PDN connections of the UE in 3GPP access are offloadable PDN connections;

the UE:

a) shall perform the procedure in subclause 5.1.3.2.3 and in subclause 5.2.3.2 to select the selected WLAN and the NAI for authentication;

b) if not authenticated yet with the selected WLAN using the NAI for authentication in subclause 6.4, shall authenticate with the selected WLAN using the NAI for authentication in subclause 6.4. During authentication, if the selected WLAN is a trusted WLAN, SCM is supported by both UE and network, MCM is not supported by UE, network or both, and if:

– the UE is capable to simultaneously route IP traffic to both 3GPP access and WLAN; or

– the UE is not capable to simultaneously route IP traffic to both 3GPP access and WLAN, and the UE has only one PDN connection;

shall handover one offloadable PDN connection from 3GPP access to the WLAN access using procedures in subclause 6.4.2.6.2;

NOTE: When the UE already has one PDN connection established via WLAN in SCM, and if move-traffic-to-WLAN indication is received, it is up to the UE implementation to determine whether to offload a PDN connection from 3GPP access to WLAN. In that case, it is also up to the UE implementation to determine which one of the offloadable PDN connections will be offloaded.

c) if the selected WLAN is a trusted WLAN, and MCM is supported by both UE and network, shall handover all the offloadable PDN connections from 3GPP access to the WLAN access using procedures of 3GPP TS 24.244];

d) if the selected WLAN is an untrusted WLAN, and if the UE supports access to EPC via untrusted WLAN, shall handover all the offloadable PDN connections from 3GPP access to the WLAN access using procedures in subclause 7.2.1 and subclause 7.2.2; and

e) if the UE has a valid IARP rule for APN, shall use the IARP for APN using the procedures in subclause 6.8.2.2.4.5.

Upon receiving move-traffic-from-WLAN indication, and if the user preferences are not present, the UE shall handover all the PDN connections established in (or previously handed over to) WLAN access to the 3GPP access using procedures in 3GPP TS 24.301.

8.4.8.1.3 Test Description

8.4.8.1.3.1 Pre-test conditions

System Simulator:

– Cell 1.

– WLAN.

UE:

None.

Preamble:

– The UE is in state Generic RB Established (state 3) on Cell 1 according to [18].

– System information combination 22 as defined in TS 36.508 [18] clause 4.4.3.1 is used in E-UTRA cell.

8.4.8.1.3.2 Test procedure sequence

Table 8.4.8.1.3.2-1 illustrates the downlink power levels and other changing parameters to be applied for the cells at various time instants of the test execution. Row marked "T0" denotes the initial conditions after preamble, while the configuration marked "T1" and "T2" are applied at the point indicated in the Main behaviour description in Table 8.4.8.1.3.2-2.

Table 8.4.8.1.3.2-1: Time instances of cell power level and parameter changes

Parameter

Unit

Cell 1

WLAN

Remark

T0

Cell-specific RS EPRE

dBm/15kHz

-79

Off

The power level values are such that camping on Cell 1 is guarantee.

T1

Cell-specific RS EPRE

dBm/15kHz

-79

–

The power level values are such that measurement results for Cell 1 (M1) and Cell 3 (M3) satisfy entry condition for event A3 (M3 > M1).

BackhaulRateDLWLAN

kbps

–

r8192

BackhaulRateULWLAN

kbps

–

r16384

T2

Cell-specific RS EPRE

dBm/15kHz

-79

The power level values are such that measurement results for Cell 1 (M1) and Cell 3 (M3) satisfy the leave condition for event A3 (M3 < M1).

BeaconRSSI

dBm

–

off

Table 8.4.8.1.3.2-2: Main behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The SS transmits an RRCConnectionReconfiguration message on Cell 1 to setup WLAN offload configuration.

<–

RRCConnectionReconfiguration

–

–

2

The UE transmits an RRCConnectionReconfigurationComplete message on Cell 1.

–>

RRCConnectionReconfigurationComplete

1

P

3

The SS changes WLAN parameters according to the row "T1" in table 8.4.8.1.3.2-1.

–

–

–

–

4

Check: Does the test result of generic test procedure in TS 36.508 subclause 6.4.3.10 indicate that the PDN connections are offloaded from 3GPP access to the WLAN?

–

–

2

P

5

The SS changes WLAN parameters according to the row "T2" in table 8.4.8.1.3.2-1.

–

–

–

–

6

Check: Does the test result of generic test procedure in TS 36.508 subclause 6.4.3.11 indicate that the PDN connections are offloaded from the WLAN access to 3GPP?

–

–

3

P

8.4.8.1.3.3 Specific message contents

Table 8.4.8.1.3.3-1: RRCConnectionReconfiguration (step 1, Table 8.4.8.1.3.2-2)

Derivation Path: 36.508, Clause 4.6.1, Table 4.6.1-8, condition WLAN-OffloadSetup

Table 8.4.8.1.3.3-2: wlan-OffloadInfo-r12 (step 1, Table 8.4.8.1.3.2-2)

Derivation Path: 36.508, Clause 4.6.3, Table 4.6.3-30, condition RSRP and BackhaulBW

Information Element

Value/remark

Comment

Condition

WLAN-OffloadConfig-r12::= SEQUENCE {

thresholdRSRP-r12::= SEQUENCE {

thresholdRSRP-Low-r12

50

thresholdRSRP-High-r12

50

}

thresholdBackhaul-Bandwidth-r12::= SEQUENCE {

thresholdBackhaulDL-BandwidthLow-r12

r0

thresholdBackhaulDL-BandwidthHigh-r12

r2048

thresholdBackhaulUL-BandwidthLow-r12

r2048

thresholdBackhaulUL-BandwidthHigh-r12

r4096

}

}

8.4.8.2 WLAN Offload / Offload Success / EUTRA RRC_Connected to/from WLAN (Qrxlevmeas, ChannelUtilizationWLAN)

8.4.8.2.1 Test Purpose (TP)

(1)

with { UE in EUTRA RRC_CONNECTED state, and UE is configured with ThreshServingOffloadWLAN, LowP, ChannelUtilizationWLAN and ThreshChUtilWLAN, Low }

ensure that {

when { UE measures that Qrxlevmeas is less than ThreshServingOffloadWLAN, LowP and ChannelUtilizationWLAN is less than ThreshChUtilWLAN, Low}

then { UE offloads to WLAN AP after TsteeringWLAN }

}

(2)

with { UE is associated with WLAN AP and attached to WLAN ePDG and configured with ThreshChUtilWLAN, High and ChannelUtilizationWLAN }

ensure that {

when { UE measures that Qrxlevmeas is lower than ThreshServingOffloadWLAN, HighP and ChannelUtilizatioWLAN is greater than ThreshChUtilWLAN, High}

then { UE offloads to EUTRA Cell after TsteeringWLAN }

}

8.4.8.2.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.304 clause 5.6.2, TS 36.331 clause 5.6.12.2 and 5.6.12.3.

[TS 36.304, clause 5.6.2]

The rules in this sub-clause are only applicable for WLANs for which identifiers has been signalled to the UE by E-UTRAN and the UE is capable of RAN-assisted WLAN interworking based on access network selection and traffic steering rules. Coexistence with ANDSF based WLAN selection and traffic steering methods on the UE is based on mechanism described in TS 23.402 [25]. The rules refer to the following quantities:

ChannelUtilizationWLAN

WLAN channel utilization as defined in subclause 8.4.2.30 in [26].

BackhaulRateDlWLAN

WLAN DLBandwidth as defined in subclause 9.1.2 in [27].

BackhaulRateUlWLAN

WLAN ULBandwidth as defined in subclause 9.1.2 in [27].

BeaconRSSI

WLAN Beacon RSSI as defined in [7].

RSRPmeas

Qrxlevmeas in RRC_IDLE, and PCell RSRP in RRC_CONNECTED as defined in TS 36.331 [3].

RSRQmeas

Qqualmeas in RRC_IDLE, and PCell RSRQ in RRC_CONNECTED as defined in TS 36.331 [3].

The upper layers in the UE shall be notified (see TS 24.302 [28]) when and for which WLAN(s), that matches all the provided identifiers (in subclause 5.6.3) for a specific entry in the list, the following conditions 1 and 2 for steering traffic from E-UTRAN to WLAN are satisfied for a time interval TsteeringWLAN:

In the E-UTRAN serving cell:

RSRPmeas < ThreshServingOffloadWLAN, LowP; or

RSRQmeas < ThreshServingOffloadWLAN, LowQ;

In the target WLAN:

ChannelUtilizationWLAN < ThreshChUtilWLAN, Low; and

BackhaulRateDlWLAN > ThreshBackhRateDLWLAN, High; and

BackhaulRateUlWLAN > ThreshBackhRateULWLAN, High; and

BeaconRSSI > ThreshBeaconRSSIWLAN, High;

The UE shall not consider the metrics for which a threshold has not been provided. The UE shall evaluate the E-UTRAN conditions on PCell only. If not all metrics related to the provided thresholds can be acquired for a WLAN BSS, the UE shall exclude that WLAN BSS from the evaluation of the above rule.

The upper layers in the UE shall be notified (see TS 24.302 [28]) when the following conditions 3 or 4 for steering traffic from WLAN to E-UTRAN are satisfied for a time interval TsteeringWLAN:

In the source WLAN:

ChannelUtilizationWLAN > ThreshChUtilWLAN, High; or

BackhaulRateDlWLAN < ThreshBackhRateDLWLAN, Low; or

BackhaulRateUlWLAN < ThreshBackhRateULWLAN, Low; or

BeaconRSSI < ThreshBeaconRSSIWLAN, Low;

In the target E-UTRAN cell:

RSRPmeas > ThreshServingOffloadWLAN, HighP; and

RSRQmeas > ThreshServingOffloadWLAN, HighQ;

[TS 36.331, clause 5.6.12.2]

The UE shall:

1> if the received wlan-OffloadInfo is set to release:

2> release wlan-OffloadConfigDedicated and t350;

2> if the wlan-OffloadConfigCommon corresponding to the RPLMN is broadcast by the cell:

3> apply the wlan-OffloadConfigCommon corresponding to the RPLMN included in SystemInformationBlockType17;

1> else:

2> apply the received wlan-OffloadConfigDedicated:

[TS 36.331, clause 5.6.12.3]

The UE shall:

1> if the UE is configured with either wlan-OffloadConfigCommon or wlan-OffloadDedicated:

2> provide measurement results required for the evaluation of the network selection and traffic steering rules as defined in TS 24.312 [66] to upper layers;

2> evaluate the network selection and traffic steering rules as defined in TS 36.304 [4];

8.4.8.2.3 Test description

8.4.8.2.3.1 Pre-test conditions

System Simulator:

– Cell 1 and WLAN AP 1

– System information combination 22 as defined in TS 36.508 [18] clause 4.4.3.1 is used in E-UTRA cell.

UE:

– The UE supporting ANDSF is pre-provisioned with WLANSP ANDSF MO with at least one WLAN identifier and with ForServiceBased ANDSF MO with RANValidityCondition allowing at least one APN to use both WLAN and LTE and at least one APN to use LTE only.

– The UE supporting RAN rules is configured with at least two PDN connections, one PDN connection offloadable to WLAN and one PDN connection not offloadable to WLAN.

Preamble:

– The UE is in state Generic RB Established (state 3) on Cell 1 according to [18].

8.4.8.2.3.2 Test procedure sequence

Table 8.4.8.2.3.2-1 illustrates the downlink power levels to be applied for Cell 1and WLAN AP 1 at various time instants of the test execution. Row marked "T0" denotes the conditions after the preamble, while rows marked "T1"and "T2" are to be applied subsequently. The exact instants on which these values shall be applied are described in the texts in this clause.

Table 8.4.8.2.3.2-1: Time instances of cell power level and parameter changes

Parameter

Unit

Cell 1

Cell 27

Remark

T0

Cell-specific RS EPRE

dBm/15kHz

-60

–

E-UTRA Cell 1 is a suitable cell and WLAN AP Cell 27 is off.

ChannelUtilizatinWLAN

dBm

–

Off

T1

Cell-specific RS EPRE

dBm/15kHz

-80

–

The power level values are such that conditions for traffic steering from E-UTRA to WLAN are satisfied.

Qrxlevmeas  < ThreshServingOffloadWLAN, LowP and

ChannelUtilizationWLAN < ThreshChUtilWLAN, Low

ChannelUtilizatinWLAN

–

–

120

T2

Cell-specific RS EPRE

dBm/15kHz

-60

–

The power level values are such that conditions for traffic steering from E-UTRA to WLAN are satisfied.

ChannelUtilizationWLAN > ThreshChUtilWLAN, High and Qrxlevmeas  < ThreshServingOffloadWLAN, HighP

ChannelUtilizatinWLAN

dBm

–

Off

Table 8.4.8.2.3.2-2: Main behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The SS transmits an RRCConnectionReconfiguration message to setup WLAN offload configurations on Cell 1 with WLAN offload thresholds.

<–

RRCConnectionReconfiguration

–

–

2

UE transmits RRCConnectionReconfigurationComplete message.

–>

RRCConnectionReconfigurationComplete

–

–

3

SS re-adjusts the cell-specific reference signal levels according to row “T1” in Table 8.4. 8.2.3.2-1.

–

–

–

–

4

Check: Does the UE perform Offload to WLAN procedure in TS 36.508 Table 6.4.3.10-1)?

–

–

1

P

5

The SS changes Cell 1 and WLAN AP 1 parameters according to the row "T2" in table 8.4.8.2.3.2-1.

–

–

–

–

6

Check: Does the UE perform Offload from WLAN procedure in TS 36.508 Table 6.4.3.11-1)?

–

–

2

P

8.4.8.2.3.3 Specific message contents

Table 8.4.8.2.3.3-2: WLAN-OffloadConfig-DEFAULT

Derivation Path: 36.508 table 4.6.3-30 with conditions RSRP and ChannelUtilization

Information Element

Value/remark

Comment

Condition

WLAN-OffloadConfig-r12::= SEQUENCE {

thresholdRSRP-r12::= SEQUENCE {

thresholdRSRP-Low-r12

55

Actual value = Thres+140 => Threshold =-85 dB

thresholdRSRP-High-r12

55

Actual value = Thres+140 => Threshold =-85 dB

}

thresholdRSRQ-r12

Not Present

thresholdRSRQ-OnAllSymbolsWithWB-r12

Not Present

thresholdRSRQ-OnAllSymbols-r12

Not Present

thresholdRSRQ-WB-r12

Not Present

thresholdChannelUtilization-r12

Not Present

thresholdChannelUtilization-r12::= SEQUENCE {

Not Present

thresholdChannelUtilizationLow-r12

50

thresholdChannelUtilizationHigh-r12

80

}

thresholdBackhaul-Bandwidth-r12

Not Present

}

8.4.8.3 WLAN Offload/ Offload Success/ EUTRA RRC_Connected to/from WLAN (Qqualmeas, BeaconRSSI)

8.4.8.3.1 Test Purpose (TP)

(1)

with { UE in EUTRA RRC_CONNECTED state}

ensure that {

when { UE receives RRCConnectionReconfiguration including wlan-OffloadDedicated-r12 to setup WLAN offload configuration }

then { UE sends RRCConnectionReconfigurationComplete }

}

(2)

with { UE in EUTRA RRC_CONNECTED state and configured with thresholdRSRQ-r12 and thresholdBeaconRSSI-r12 in RRCConnectionReconfiguration }

ensure that {

when { UE detects the condition for steering traffic from E-UTRA to WLAN is met for a

time interval TsteeringWLAN }

then { UE performs offload from E-UTRAN to WLAN}

}

(3)

with { UE connected in WLAN and configured with thresholdRSRQ-r12 and thresholdBeaconRSSI-r12 }

ensure that {

when { UE detects the condition for steering traffic from WLAN to E-UTRA is met for a

time interval TsteeringWLAN }

then { UE performs offload from WLAN to E-UTRAN }

}

8.4.8.3.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.331, clause 5.6.12.2 and 5.6.12.3 and TS 36.304 clause 5.6.2.

[TS 36.331, clause 5.6.12.2]

The UE shall:

1> if the received wlan-OffloadDedicated is set to release:

…

1> else:

…

2> if the received wlan-OffloadDedicated includes thresholdRSRQ:

3> apply the received thresholdRSRQ;

3> forward the received thresholdRSRQ to upper layers;

…

2> if the received wlan-OffloadDedicated includes thresholdBeaconRSSI:

3> apply the received thresholdBeaconRSSI;

3> forward the received thresholdBeaconRSSI to upper layers;

…

2> if the received wlan-OffloadDedicated includes t-SteeringWLAN:

3> apply the received t-SteeringWLAN;

[TS 36.331, clause 5.6.12.3]

The UE shall:

1> if the UE is configured with either wlan-OffloadConfigCommon or wlan-OffloadDedicated:

2> provide measurement results required for the evaluation of the network selection and traffic steering rules as defined in TS 24.312 [66] to upper layers;

2> evaluate the network selection and traffic steering rules as defined in TS 36.304 [4];

[TS 36.304, clause 5.6.2]

The rules in this sub-clause are only applicable for WLANs for which identifiers has been signalled to the UE by E-UTRAN and the UE is capable of RAN-assisted WLAN interworking based on access network selection and traffic steering rules. Coexistence with ANDSF based WLAN selection and traffic steering methods on the UE is based on mechanism described in TS 23.402 [25]. The rules refer to the following quantities:

ChannelUtilizationWLAN

WLAN channel utilization as defined in subclause 8.4.2.30 in [26].

BackhaulRateDlWLAN

WLAN DLBandwidth as defined in subclause 9.1.2 in [27].

BackhaulRateUlWLAN

WLAN ULBandwidth as defined in subclause 9.1.2 in [27].

BeaconRSSI

WLAN Beacon RSSI as defined in [7].

RSRPmeas

Qrxlevmeas in RRC_IDLE, and PCell RSRP in RRC_CONNECTED as defined in TS 36.331 [3].

RSRQmeas

Qqualmeas in RRC_IDLE, and PCell RSRQ in RRC_CONNECTED as defined in TS 36.331 [3].

The upper layers in the UE shall be notified (see TS 24.302 [28]) when and for which WLAN(s), that matches all the provided identifiers (in subclause 5.6.3) for a specific entry in the list, the following conditions 1 and 2 for steering traffic from E-UTRAN to WLAN are satisfied for a time interval TsteeringWLAN:

In the E-UTRAN serving cell:

RSRPmeas < ThreshServingOffloadWLAN, LowP; or

RSRQmeas < ThreshServingOffloadWLAN, LowQ;

In the target WLAN:

ChannelUtilizationWLAN < ThreshChUtilWLAN, Low; and

BackhaulRateDlWLAN > ThreshBackhRateDLWLAN, High; and

BackhaulRateUlWLAN > ThreshBackhRateULWLAN, High; and

BeaconRSSI > ThreshBeaconRSSIWLAN, High;

The UE shall not consider the metrics for which a threshold has not been provided. The UE shall evaluate the E-UTRAN conditions on PCell only. If not all metrics related to the provided thresholds can be acquired for a WLAN BSS, the UE shall exclude that WLAN BSS from the evaluation of the above rule.

The upper layers in the UE shall be notified (see TS 24.302 [28]) when the following conditions 3 or 4 for steering traffic from WLAN to E-UTRAN are satisfied for a time interval TsteeringWLAN:

In the source WLAN:

ChannelUtilizationWLAN > ThreshChUtilWLAN, High; or

BackhaulRateDlWLAN < ThreshBackhRateDLWLAN, Low; or

BackhaulRateUlWLAN < ThreshBackhRateULWLAN, Low; or

BeaconRSSI < ThreshBeaconRSSIWLAN, Low;

In the target E-UTRAN cell:

RSRPmeas > ThreshServingOffloadWLAN, HighP; and

RSRQmeas > ThreshServingOffloadWLAN, HighQ;

8.4.8.3.3 Test description

8.4.8.3.3.1 Pre-test conditions

System Simulator:

– Cell 1 and Cell 27

– System information combination 22 as defined in TS 36.508 [18] clause 4.4.3.1 is used in E-UTRA cell.

UE:

None.

Preamble:

– The UE is in state Generic RB Established (state 3) on Cell 1 according to [18].

8.4.8.3.3.2 Test procedure sequence

Table 8.4.8.3.3.2-1 illustrates the downlink power levels to be applied for Cell 1and Cell 27 at various time instants of the test execution. Row marked "T0" denotes the conditions after the preamble, while rows marked "T1"and "T2" are to be applied subsequently. The exact instants on which these values shall be applied are described in the texts in this clause.

Table 8.4.8.3.3.2-1: Time instances of cell power level and parameter changes

Parameter

Unit

Cell 1

Cell 27

Remark

T0

Cell-specific RS EPRE

dBm/15kHz

-60

–

E-UTRA Cell 1 is a suitable cell and WLAN Cell 27 is off.

RSRQ

dB

-4.15

–

BeaconRSSI

–

off

Noc

dBm/15kHz

-73

T1

Cell-specific RS EPRE

dBm/15kHz

-75

–

The power level values are such that conditions for traffic steering from E-UTRA to WLAN are satisfied.

– Qqualmeas  < ThreshServingOffloadWLAN, LowQ

– BeaconRSSI > ThreshBeaconRSSIWLAN, High

RSRQ

dB

-13.23

–

BeaconRSSI

–

-60

T2

Cell-specific RS EPRE

dBm/15kHz

-65

–

The power level values are such that conditions for traffic steering from WLAN to E-UTRA are satisfied.

– Qqualmeas  < ThreshServingOffloadWLAN, HighQ

– BeaconRSSI < ThreshBeaconRSSIWLAN, Low

RSRQ

dB

-5

–

BeaconRSSI

–

-86

Table 8.4.8.3.3.2-2: Main behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The SS transmits an RRCConnectionReconfiguration message to setup WLAN offload configurations on Cell 1.

<–

RRCConnectionReconfiguration

–

–

2

Check: Does the UE transmit RRCConnectionReconfigurationComplete message.

–>

RRCConnectionReconfigurationComplete

1

P

3

The SS changes Cell 1 and Cell 27 parameters according to the row "T1" in table 8.4.8.3.3.2-1.

–

–

–

–

4

Wait for TsteeringWLAN expiry

–

–

–

–

5

Check: Does the test result of generic procedure in TS 36.508 subclause 6.4.3.10 indicate that the UE has successfully offloaded to WLAN Cell 27 after TsteeringWLAN expiry?

–

–

2

P

6

Wait for 5 seconds

–

–

–

–

7

The SS changes Cell 1 and Cell 27 parameters according to the row "T2" in table 8.4.8.3.3.2-1

–

–

–

–

8

Wait for TsteeringWLAN expiry

–

–

–

–

9

Check: Does the test result of generic procedure in TS 36.508 subclause 6.4.3.11 indicate that the UE has successfully offloaded to EUTRA Cell 1 after TsteeringWLAN expiry?

–

–

3

P

8.4.8.3.3.3 Specific message contents

Table 8.4.8.3.3.3-1: RRCConnectionReconfiguration (step 1, Table 8.4.8.3.3.2-2)

Derivation Path: 36.508, Clause 4.6.1, Table 4.6.1-8, condition WLAN-OffloadSetup

Table 8.4.8.3.3.3-2: wlan-OffloadInfo-r12 (step 1, Table 8.4.8.3.3.2-2)

Derivation Path: 36.508, Clause 4.6.3, Table 4.6.3-29

Information Element

Value/remark

Comment

Condition

wlan-OffloadInfo-r12::= CHOICE {

Setup SEQUENCE {

wlan-OffloadConfigDedicated-r12SEQUENCE {

thresholdRSRP-r12

Not Present

thresholdRSRQ-r12 SEQUENCE {

thresholdRSRQ-Low-r12

17

-11.5dB ≤ RSRQ < -11dB

thresholdRSRQ-High-r12

32

-4 dB ≤ RSRQ < -3.5dB

}

thresholdBeaconRSSI-r12 SEQUENCE {

thresholdBeaconRSSI-Low-r12

50

Value in dBm =-78

thresholdBeaconRSSI-High-r12

60

Value in dBm =-68

}

t-SteeringWLAN-r12

7

7 seconds

}

}

}

8.4.8.4 WLAN Offload / Offload Success / EUTRA RRC_Connected to/from WLAN (Qqualmeas, BackhaulRateDlWLAN) / CA

8.4.8.4.1 Test Purpose (TP)

(1)

with { UE in EUTRA RRC_CONNECTED state with SCell added and configured with thresholdRSRQ-r12 and ThreshBackhRateDLWLAN in RRCConnectionReconfiguration }

ensure that {

when { UE detects the SCell Qqualmeas < ThreshServingOffloadWLAN, LowQ and BackhaulRateDlWL> ThreshBackhRateDLWLAN, High }

then { UE does not performs offload from E-UTRAN to WLAN }

}

(2)

with { UE in EUTRA RRC_CONNECTED state with SCell added and configured with thresholdRSRQ-r12 and ThreshBackhRateDLWLAN in RRCConnectionReconfiguration }

ensure that {

when { UE detects the PCell Qqualmeas < ThreshServingOffloadWLAN, LowQ and BackhaulRateDlWL> ThreshBackhRateDLWLAN, High }

then { UE performs offload from E-UTRAN to WLAN }

}

(3)

with { UE in EUTRA RRC_CONNECTED state with SCell added, a PDN offloaded to WLAN and configured with thresholdRSRQ-r12 and ThreshBackhRateDLWLAN in RRCConnectionReconfiguration }

ensure that {

when { UE detects the SCell Qqualmeas < ThreshServingOffloadWLAN, HighQ for a time interval TsteeringWLAN }

then { UE does not performs offload from WLAN to E-UTRAN }

}

(4)

with { UE in EUTRA RRC_CONNECTED state with SCell added, a PDN offloaded to WLAN and configured with thresholdRSRQ-r12 and ThreshBackhRateDLWLAN in RRCConnectionReconfiguration }

ensure that {

when { UE detects the PCell Qqualmeas < ThreshServingOffloadWLAN, HighQ for a time interval TsteeringWLAN }

then { UE does not performs offload from WLAN to E-UTRAN }

}

8.4.8.4.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.331, clause 5.6.12.2 and 5.6.12.3 and TS 36.304 clause 5.6.2. Unless otherwise stated these are Rel-12 requirements.

[TS 36.331, clause 5.6.12.2]

The UE shall:

1> if the received wlan-OffloadDedicated is set to release:

…

1> else:

…

2> if the received wlan-OffloadDedicated includes thresholdRSRQ:

3> apply the received thresholdRSRQ;

3> forward the received thresholdRSRQ to upper layers;

…

2> if the received wlan-OffloadDedicated includes thresholdBeaconRSSI:

3> apply the received thresholdBeaconRSSI;

3> forward the received thresholdBeaconRSSI to upper layers;

…

2> if the received wlan-OffloadDedicated includes t-SteeringWLAN:

3> apply the received t-SteeringWLAN;

[TS 36.331, clause 5.6.12.3]

The UE shall:

1> if the UE is configured with either wlan-OffloadConfigCommon or wlan-OffloadDedicated:

2> provide measurement results required for the evaluation of the network selection and traffic steering rules as defined in TS 24.312 [66] to upper layers;

2> evaluate the network selection and traffic steering rules as defined in TS 36.304 [4];

[TS 36.304, clause 5.6.2]

The rules in this sub-clause are only applicable for WLANs for which identifiers has been signalled to the UE by E-UTRAN and the UE is capable of RAN-assisted WLAN interworking based on access network selection and traffic steering rules. Coexistence with ANDSF based WLAN selection and traffic steering methods on the UE is based on mechanism described in TS 23.402 [25]. The rules refer to the following quantities:

ChannelUtilizationWLAN

WLAN channel utilization as defined in subclause 8.4.2.30 in [26].

BackhaulRateDlWLAN

WLAN DLBandwidth as defined in subclause 9.1.2 in [27].

BackhaulRateUlWLAN

WLAN ULBandwidth as defined in subclause 9.1.2 in [27].

BeaconRSSI

WLAN Beacon RSSI as defined in [7].

RSRPmeas

Qrxlevmeas in RRC_IDLE, and PCell RSRP in RRC_CONNECTED as defined in TS 36.331 [3].

RSRQmeas

Qqualmeas in RRC_IDLE, and PCell RSRQ in RRC_CONNECTED as defined in TS 36.331 [3].

The upper layers in the UE shall be notified (see TS 24.302 [28]) when and for which WLAN(s), that matches all the provided identifiers (in subclause 5.6.3) for a specific entry in the list, the following conditions 1 and 2 for steering traffic from E-UTRAN to WLAN are satisfied for a time interval TsteeringWLAN:

1. In the E-UTRAN serving cell:

RSRPmeas < ThreshServingOffloadWLAN, LowP; or

RSRQmeas < ThreshServingOffloadWLAN, LowQ;

2. In the target WLAN:

ChannelUtilizationWLAN < ThreshChUtilWLAN, Low; and

BackhaulRateDlWLAN > ThreshBackhRateDLWLAN, High; and

BackhaulRateUlWLAN > ThreshBackhRateULWLAN, High; and

BeaconRSSI > ThreshBeaconRSSIWLAN, High;

The UE shall not consider the metrics for which a threshold has not been provided. The UE shall evaluate the E-UTRAN conditions on PCell only. If not all metrics related to the provided thresholds can be acquired for a WLAN BSS, the UE shall exclude that WLAN BSS from the evaluation of the above rule.

The upper layers in the UE shall be notified (see TS 24.302 [28]) when the following conditions 3 or 4 for steering traffic from WLAN to E-UTRAN are satisfied for a time interval TsteeringWLAN:

3. In the source WLAN:

ChannelUtilizationWLAN > ThreshChUtilWLAN, High; or

BackhaulRateDlWLAN < ThreshBackhRateDLWLAN, Low; or

BackhaulRateUlWLAN < ThreshBackhRateULWLAN, Low; or

BeaconRSSI < ThreshBeaconRSSIWLAN, Low;

4. In the target E-UTRAN cell:

RSRPmeas > ThreshServingOffloadWLAN, HighP; and

RSRQmeas > ThreshServingOffloadWLAN, HighQ;

The UE shall not consider the metrics for which a threshold has not been provided. The UE shall evaluate the E-UTRAN conditions on PCell only.

8.4.8.4.3 Test description

8.4.8.4.3.1 Pre-test conditions

System Simulator:

– Cell 1 (PCell), if intra band CA Cell 3(SCell) else if inter band CA Cell 10(Scell) and Cell 27

  • Cell 3/Cell 10 is an Inactive SCell according to [18] cl. 6.3.4

– System information combination 22 as defined in TS 36.508 [18] clause 4.4.3.1 is used in E-UTRA cell.

UE:

None.

Preamble:

– The UE is in state Generic RB Established (state 3) on Cell 1 according to TS 36.508 [18].

8.4.8.4.3.2 Test procedure sequence

Table 8.4.8.4.3.2-1 illustrates the downlink power levels to be applied for Cell 1and Cell 27 at various time instants of the test execution. Row marked "T0" denotes the conditions after the preamble, while rows marked "T1", "T2", "T3" and "T4" are to be applied subsequently. The exact instants on which these values shall be applied are described in the texts in this clause.

Table 8.4.8.4.3.2-1: Time instances of cell power level and parameter changes

Parameter

Unit

Cell 1

Cell 3/10

Cell 27

Remark

T0

Cell-specific RS EPRE

dBm/15kHz

-60

-60

–

E-UTRA Cell 1 Cell 3/10 are suitable cell and WLAN Cell 27 is off.

RSRQ

dB

-4.15

-4.15

–

Noc

dBm/15kHz

-73

-73

T1

Cell-specific RS EPRE

dBm/15kHz

-60

-75

–

The power level values are such that conditions SCell Qqualmeas  < ThreshServingOffloadWLAN, LowQ &

BackhaulRateDlWLAN > ThreshBackhRateDLWLAN, High are satisfied. Condition PCell Qqualmeas  < ThreshServingOffloadWLAN, LowQ is not satisfied

RSRQ

dB

-4.15

-13.23

–

BackhaulRateDlWLAN

kbps

–

–

r16384

BackhaulRateUlWLAN

kbps

–

–

r8192

T2

Cell-specific RS EPRE

dBm/15kHz

-75

-75

–

The power level values are such that conditions PCell Qqualmeas  < ThreshServingOffloadWLAN, LowQ &

BackhaulRateDlWLAN > ThreshBackhRateDLWLAN, High are satisfied.

RSRQ

dB

-13.23

-13.23

–

T3

Cell-specific RS EPRE

dBm/15kHz

-75

-65

The power level values are such that condition Qqualmeas  < ThreshServingOffloadWLAN, HighQ for SCell is satisfied and not satisfied for PCell

RSRQ

dB

-13.23

-5

T4

Cell-specific RS EPRE

dBm/15kHz

-65

-75

–

The power level values are such that condition Qqualmeas  < ThreshServingOffloadWLAN, HighQ for PCell is satisfied

RSRQ

dB

-5

-13.23

–

Table 8.4.8.4.3.2-2: Main behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The SS transmits an RRCConnectionReconfiguration message with SCell (Cell 3/10) addition.

<–

RRCConnectionReconfiguration

–

–

2

The UE transmits an RRCConnectionReconfigurationComplete message to confirm SCell (Cell 3/10) addition.

–>

RRCConnectionReconfiguration Complete

–

–

3

The SS transmits an RRCConnectionReconfiguration message to setup WLAN offload configurations on Cell 1.

<–

RRCConnectionReconfiguration

–

–

4

The UE transmit RRCConnectionReconfigurationComplete message.

–>

RRCConnectionReconfigurationComplete

–

–

5

The SS changes Cell 1, Cell 3/10 and Cell 27 parameters according to the row "T1" in table 8.4.8.4.3.2-1.

–

–

–

–

6

Check: Does the test result of generic procedure in TS 36.508 subclause 6.4.3.12 indicate that the UE does not offload to WLAN Cell 27 after TsteeringWLAN expiry?

–

–

1

–

7

The SS changes Cell 1, Cell 3/10 and Cell 27 parameters according to the row "T2" in table 8.4.8.4.3.2-1.

–

–

–

–

8

Check: Does the test result of generic procedure in TS 36.508 subclause 6.4.3.10 indicate that the UE has successfully offloaded to WLAN Cell 27 after TsteeringWLAN expiry?

–

–

2

P

9

The SS changes Cell 1, Cell 3/10 and Cell 27 parameters according to the row "T3" in table 8.4.8.4.3.2-1.

–

–

–

–

10

Check: Does the test result of generic procedure in TS 36.508 subclause 6.4.3.13 indicate that the UE does not offload to EUTRA Cell 1 after TsteeringWLAN expiry?

–

–

3

–

11

The SS changes Cell 1, Cell 3/10 and Cell 27 parameters according to the row "T4" in table 8.4.8.4.3.2-1.

–

–

–

–

12

Check: Does the test result of generic procedure in TS 36.508 subclause 6.4.3.11 indicate that the UE has successfully offloaded to EUTRA Cell 1 after TsteeringWLAN expiry?

–

–

4

P

8.4.8.4.3.3 Specific message contents

Table 8.4.8.4.3.3-1: RRCConnectionReconfiguration (step 3, Table 8.4.8.4.3.2-2)

Derivation Path: 36.508, Clause 4.6.1, Table 4.6.1-8, condition WLAN-OffloadSetup

Table 8.4.8.4.3.3-2: wlan-OffloadInfo-r12 (Table 8.4.8.4.3.3-1)

Derivation Path: 36.508, Clause 4.6.3, Table 4.6.3-29 with condition RSRQ and BackhaulBW

Information Element

Value/remark

Comment

Condition

wlan-OffloadInfo-r12::= CHOICE {

Setup SEQUENCE {

wlan-OffloadConfigDedicated-r12SEQUENCE {

thresholdRSRP-r12

Not Present

thresholdRSRQ-r12 SEQUENCE {

thresholdRSRQ-Low-r12

17

-11.5dB ≤ RSRQ < -11dB

thresholdRSRQ-High-r12

32

-4 dB ≤ RSRQ < -3.5dB

}

thresholdBackhaul-Bandwidth-r12::= SEQUENCE {

thresholdBackhaulDL-BandwidthLow-r12

r4096 kbps

thresholdBackhaulDL-BandwidthHigh-r12

r8192 kbps

thresholdBackhaulUL-BandwidthLow-r12

r0 kbps

Value makes it insignificant for offload

thresholdBackhaulUL-BandwidthHigh-r12

r4294967296 kbps

Value makes it insignificant for offload

}

}

}

}

8.4.8.5 WLAN Offload / T350 expiry

8.4.8.5.1 Test Purpose (TP)

(1)

with { UE in E-UTRA RRC_CONNECTED state receives an RRCConnectionReconfiguration message containing wlan-OffloadConfigDedicated with t350 }

ensure that {

when { UE moves to RRC Idle and in RRC_IDLE state the timer t350 expires }

then { UE offloads to WLAN AP after TsteeringWLAN as per wlan-OffloadConfigCommon not per wlan-OffloadConfigDedicated once the offload conditions are met }

}

8.4.8.5.2 Conformance requirements

References: The conformance requirements covered in the current TC is specified in: TS 36.331, clauses 5.3.5.3, 5.6.12.2, 5.6.12.3, 5.6.12.4, TS 36.304, clause 5.6.2 and TS 24.302, clause 6.10.4.

[TS 36.331, clause 5.3.5.3]

If the RRCConnectionReconfiguration message does not include the mobilityControlInfo and the UE is able to comply with the configuration included in this message, the UE shall:

…

1> if the RRCConnectionReconfiguration message includes wlan-OffloadInfo:

2> perform the dedicated WLAN offload configuration procedure as specified in 5.6.12.2;

1> submit the RRCConnectionReconfigurationComplete message to lower layers for transmission using the new configuration, upon which the procedure ends;

[TS 36.331, clause 5.6.12.2]

The UE shall:

1> if the received wlan-OffloadInfo is set to release:

2> release wlan-OffloadConfigDedicated and t350;

2> if the wlan-OffloadConfigCommon corresponding to the RPLMN is broadcast by the cell:

3> apply the wlan-OffloadConfigCommon corresponding to the RPLMN included in SystemInformationBlockType17;

1> else:

2> apply the received wlan-OffloadConfigDedicated:

[TS 36.331, clause 5.6.12.3]

The UE shall:

1> if the UE is configured with either wlan-OffloadConfigCommon or wlan-OffloadConfigDedicated:

2> provide measurement results required for the evaluation of the network selection and traffic steering rules as defined in TS 24.312 to upper layers;

2> evaluate the network selection and traffic steering rules as defined in TS 36.304;

[TS 36.331, clause 5.6.12.4]

The UE shall:

1> if T350 expires or is stopped:

2> release the wlan-OffloadConfigDedicated and t350;

2> if the wlan-OffloadConfigCommon corresponding to the RPLMN is broadcast by the cell:

3> apply the wlan-OffloadConfigCommon corresponding to the RPLMN included in SystemInformationBlockType17;

[TS 36.304, clause 5.6.2]

The rules in this sub-clause are only applicable for WLANs for which identifiers has been signalled to the UE by E-UTRAN and the UE is capable of RAN-assisted WLAN interworking based on access network selection and traffic steering rules. Coexistence with ANDSF based WLAN selection and traffic steering methods on the UE is based on mechanism described in TS 23.402. The rules refer to the following quantities:

ChannelUtilizationWLAN

WLAN channel utilization as defined in subclause 8.4.2.30 in [26].

BackhaulRateDlWLAN

WLAN DLBandwidth as defined in subclause 9.1.2 in [27].

BackhaulRateUlWLAN

WLAN ULBandwidth as defined in subclause 9.1.2 in [27].

BeaconRSSI

WLAN Beacon RSSI as defined in [7].

RSRPmeas

Qrxlevmeas in RRC_IDLE, and PCell RSRP in RRC_CONNECTED as defined in TS 36.331 [3].

RSRQmeas

Qqualmeas in RRC_IDLE, and PCell RSRQ in RRC_CONNECTED as defined in TS 36.331 [3].

The upper layers in the UE shall be notified (see TS 24.302) when and for which WLAN(s), that matches all the provided identifiers (in subclause 5.6.3) for a specific entry in the list, the following conditions 1 and 2 for steering traffic from E-UTRAN to WLAN are satisfied for a time interval TsteeringWLAN:

In the E-UTRAN serving cell:

RSRPmeas < ThreshServingOffloadWLAN, LowP; or

RSRQmeas < ThreshServingOffloadWLAN, LowQ;

In the target WLAN:

ChannelUtilizationWLAN < ThreshChUtilWLAN, Low; and

BackhaulRateDlWLAN > ThreshBackhRateDLWLAN, High; and

BackhaulRateUlWLAN > ThreshBackhRateULWLAN, High; and

BeaconRSSI > ThreshBeaconRSSIWLAN, High;

The UE shall not consider the metrics for which a threshold has not been provided. The UE shall evaluate the E-UTRAN conditions on PCell only. If not all metrics related to the provided thresholds can be acquired for a WLAN BSS, the UE shall exclude that WLAN BSS from the evaluation of the above rule.

The upper layers in the UE shall be notified (see TS 24.302) when the following conditions 3 or 4 for steering traffic from WLAN to E-UTRAN are satisfied for a time interval TsteeringWLAN:

In the source WLAN:

ChannelUtilizationWLAN > ThreshChUtilWLAN, High; or

BackhaulRateDlWLAN < ThreshBackhRateDLWLAN, Low; or

BackhaulRateUlWLAN < ThreshBackhRateULWLAN, Low; or

BeaconRSSI < ThreshBeaconRSSIWLAN, Low;

In the target E-UTRAN cell:

RSRPmeas > ThreshServingOffloadWLAN, HighP; and

RSRQmeas > ThreshServingOffloadWLAN, HighQ;

The UE shall not consider the metrics for which a threshold has not been provided. The UE shall evaluate the E-UTRAN conditions on PCell only.

[TS 24.302, clause 6.10.4]

This subclause applies if the RAN rules control the WLAN access selection and traffic routing as described in subclause 6.10.2.

The access stratum layer of the 3GPP access can provide:

1) move-traffic-to-WLAN indication, along with list of WLAN identifiers. An entry in the list of the WLAN identifiers consists of SSID, BSSID, HESSID, or any combination of them; and

2) move-traffic-from-WLAN indication.

The user preferences take precedence over the indications provided by the access stratum layer of the 3GPP access.

Upon:

– receiving move-traffic-to-WLAN indication, along with the list of the WLAN identifiers, if the user preferences are not present; or

– establishment of a new PDN connection in 3GPP access, if the PDN connection is an offloadable PDN connection, the access stratum indicated move-traffic-to-WLAN, the access stratum has not indicated the move-traffic-from-WLAN indication after indicating of the move-traffic-to-WLAN indication and the user preferences are not present;

and:

– the UE is capable to simultaneously route IP traffic to both 3GPP access and WLAN; or

– the UE is not capable to simultaneously route IP traffic to both 3GPP access and WLAN, and all the PDN connections of the UE in 3GPP access are offloadable PDN connections;

the UE:

a) shall perform the procedure in subclause 5.1.3.2.3 and in subclause 5.2.3.2 to select the selected WLAN and the NAI for authentication;

b) if not authenticated yet with the selected WLAN using the NAI for authentication in subclause 6.4, shall authenticate with the selected WLAN using the NAI for authentication in subclause 6.4. During authentication, if the selected WLAN is a trusted WLAN, SCM is supported by both UE and network, MCM is not supported by UE, network or both, and if:

– the UE is capable to simultaneously route IP traffic to both 3GPP access and WLAN; or

– the UE is not capable to simultaneously route IP traffic to both 3GPP access and WLAN, and the UE has only one PDN connection;

shall handover one offloadable PDN connection from 3GPP access to the WLAN access using procedures in subclause 6.4.2.6.2;

NOTE: When the UE already has one PDN connection established via WLAN in SCM, and if move-traffic-to-WLAN indication is received, it is up to the UE implementation to determine whether to offload a PDN connection from 3GPP access to WLAN. In that case, it is also up to the UE implementation to determine which one of the offloadable PDN connections will be offloaded.

c) if the selected WLAN is a trusted WLAN, and MCM is supported by both UE and network, shall handover all the offloadable PDN connections from 3GPP access to the WLAN access using procedures of 3GPP TS 24.244];

d) if the selected WLAN is an untrusted WLAN, and if the UE supports access to EPC via untrusted WLAN, shall handover all the offloadable PDN connections from 3GPP access to the WLAN access using procedures in subclause 7.2.1 and subclause 7.2.2; and

e) if the UE has a valid IARP rule for APN, shall use the IARP for APN using the procedures in subclause 6.8.2.2.4.5.

Upon receiving move-traffic-from-WLAN indication, and if the user preferences are not present, the UE shall handover all the PDN connections established in (or previously handed over to) WLAN access to the 3GPP access using procedures in 3GPP TS 24.301.

8.4.8.5.3 Test Description

8.4.8.5.3.1 Pre-test conditions

System Simulator:

– Cell 1 and WLAN AP 1.

– System information combination 22 as defined in TS 36.508 [18] clause 4.4.3.1 is used in E-UTRA cell.

UE:

– The UE supporting ANDSF is pre-provisioned with WLANSP ANDSF MO with at least one WLAN identifier and with ForServiceBased ANDSF MO with RANValidityCondition allowing at least one APN to use both WLAN and LTE and at least one APN to use LTE only.

– The UE supporting RAN rules is configured with at least two PDN connections, one PDN connection offloadable to WLAN and one PDN connection not offloadable to WLAN.

Preamble:

– The UE is in state Generic RB Established (state 3) on Cell 1 according to [18].

8.4.8.5.3.2 Test procedure sequence

Table 8.4.8.5.3.2-1 illustrates the downlink power levels and other changing parameters to be applied for the cells at various time instants of the test execution. Row marked "T0" denotes the initial conditions after preamble, while the configuration marked "T1" and "T2" are applied at the point indicated in the Main behaviour description in Table 8.4.8.5.3.2-2.

Table 8.4.8.5.3.2-1: Time instances of cell power level and parameter changes

Parameter

Unit

Cell 1

Cell 27

Remark

T0

Cell-specific RS EPRE

dBm/15kHz

-60

–

E-UTRA Cell 1 is a suitable cell and WLAN AP Cell 27 is off.

BeaconRSSI

dBm

–

Off

T1

Cell-specific RS EPRE

dBm/15kHz

-80

–

The power level values are such that conditions for traffic steering from E-UTRA to WLAN are satisfied.

Qrxlevmeas  < ThreshServingOffloadWLAN, LowP and

ChannelUtilizationWLAN < ThreshChUtilWLAN, Low

ChannelUtilizationWLAN

–

–

55

–

T2

Cell-specific RS EPRE

dBm/15kHz

-60

The power level values are such that conditions for traffic steering from WLAN to E-UTRA are satisfied

ChannelUtilizationWLAN

–

–

100

Table 8.4.8.5.3.2-2: Main behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The SS transmits an RRCConnectionReconfiguration message to setup WLAN offload configurations on Cell 1 with WLAN offload thresholds and t350.

<–

RRCConnectionReconfiguration

–

–

2

The UE transmits an RRCConnectionReconfigurationComplete message on Cell 1.

–>

RRCConnectionReconfigurationComplete

–

–

3

The SS transmits an RRCConnectionRelease message on Cell 1.

<–

RRCConnectionRelease

–

–

4

The SS changes WLAN parameters according to the row "T1" in table 8.4.8.5.3.2-1.

–

–

–

–

5

The UE transitions to state RRC_IDLE which starts timer t350.

–

–

–

–

6

Wait for 300 seconds to allow t350 expiry.

–

–

–

–

7

Check: Does the test result of generic test procedure in TS 36.508 subclause 6.4.3.10 indicate that the PDN connections are offloaded from 3GPP access to the WLAN with offload parameters as per wlan-OffloadConfigCommon?

–

–

1

P

8

The SS changes WLAN parameters according to the row "T2" in table 8.4.8.5.3.2-1.

–

–

–

–

9

The test result of generic test procedure in TS 36.508 Table 6.4.3.11-1 indicates that the PDN connection is offloaded from the WLAN access to E-UTRAN

–

–

–

–

8.4.8.5.3.3 Specific message contents

Table 8.4.8.5.3.3-1: SystemInformationBlockType17 (Preamble and all steps of table 8.4.8.5.2.2-2)

Derivation Path: 36.508 table 4.4.3.3-15

Information Element

Value/remark

Comment

Condition

SystemInformationBlockType17-r12 ::= SEQUENCE {

wlan-OffloadInfoPerPLMN-List-r12 [1] SEQUENCE (SIZE (1..maxPLMN-r11)) OF {

1 Entry

wlan-OffloadConfigCommon-r12

WLAN-OffloadConfig-DEFAULT

as per Table 8.4.8.5.3.3-2

}

lateNonCriticalExtension

Not present

}

Table 8.4.8.5.3.3-2: WLAN-OffloadConfig-DEFAULT(Preamble and all steps of table 8.4.8.5.2.2-2)

Derivation Path: 36.508, Clause 4.6.3, Table 4.6.3-30, condition RSRP and ChanUtilization

Information Element

Value/remark

Comment

Condition

WLAN-OffloadConfig-r12::= SEQUENCE {

thresholdRSRP-r12::= SEQUENCE {

thresholdRSRP-Low-r12

75

thresholdRSRP-High-r12

85

}

thresholdChannelUtilization-r12::= SEQUENCE {

thresholdChannelUtilizationLow-r12

65

thresholdChannelUtilizationHigh-r12

75

}

}

Table 8.4.8.5.3.3-3: RRCConnectionReconfiguration (step 1, Table 8.4.8.5.3.2-2)

Derivation Path: 36.508, Clause 4.6.1, Table 4.6.1-8, condition WLAN-OffloadSetup

Information Element

Value/remark

Comment

Condition

wlan-OffloadInfo-r12 CHOICE {

setup SEQUENCE {

wlan-OffloadConfigDedicated-r12

WLAN-OffloadConfig-DEFAULT

as per Table 8.4.8.5.3.3-4

t350-r12

min5

}

}

Table 8.4.8.5.3.3-4: WLAN-OffloadConfig-DEFAULT (step 1, Table 8.4.8.5.3.2-2)

Derivation Path: 36.508, Clause 4.6.3, Table 4.6.3-30, condition RSRP and ChanUtilization

Information Element

Value/remark

Comment

Condition

WLAN-OffloadConfig-r12::= SEQUENCE {

thresholdRSRP-r12::= SEQUENCE {

thresholdRSRP-Low-r12

75

thresholdRSRP-High-r12

85

}

thresholdChannelUtilization-r12::= SEQUENCE {

thresholdChannelUtilizationLow-r12

50

thresholdChannelUtilizationHigh-r12

75

}

}

8.4.8.6 WLAN Offload / Offload Success / EUTRA RRC_Connected to/from WLAN (ANDSF and RAN rules co-existence)

8.4.8.6.1 Test Purpose (TP)

(1)

with { UE in E-UTRA RRC_CONNECTED state, with valid ISRP ANDSF rule using RAN thresholds }

ensure that {

when { Offload based on RAN rules is satisfied but based on stored ISRP ANDSF rule is not }

then { UE does not offload PDN connections to WLAN }

}

(2)

with { UE in E-UTRA RRC_CONNECTED state, with valid ISRP ANDSF rule using RAN thresholds }

ensure that {

when { Offload based on stored ISRP ANDSF rule is satisfied }

then { UE offload PDN connections to WLAN }

}

(3)

with { UE in E-UTRA RRC_CONNECTED state and A PDN offloaded to WLAN, with valid ISRP ANDSF rule using RAN thresholds }

ensure that {

when { Offload based on RAN rules is satisfied but based on stored ISRP ANDSF rule is not }

then { UE does not offload PDN connections to EUTRAN }

}

(4)

with { UE in E-UTRA RRC_CONNECTED state and A PDN offloaded to WLAN, with valid ISRP ANDSF rule using RAN thresholds }

ensure that {

when { Offload based on stored ISRP ANDSF rule is satisfied }

then { UE offload PDN connections to EUTRAN }

}

8.4.8.6.2 Conformance requirements

References: The conformance requirements covered in the current TC is specified in: TS 36.331, clauses 5.3.5.3, 5.6.12.2, 5.6.12.3, TS 36.304, clause 5.6.2 and TS 24.302, clause 6.10.4.

[TS 36.331, clause 5.3.5.3]

If the RRCConnectionReconfiguration message does not include the mobilityControlInfo and the UE is able to comply with the configuration included in this message, the UE shall:

…

1> if the RRCConnectionReconfiguration message includes wlan-OffloadInfo:

2> perform the dedicated WLAN offload configuration procedure as specified in 5.6.12.2;

1> submit the RRCConnectionReconfigurationComplete message to lower layers for transmission using the new configuration, upon which the procedure ends;

[TS 36.331, clause 5.6.12.2]

The UE shall:

1> if the received wlan-OffloadInfo is set to release:

2> release wlan-OffloadConfigDedicated and t350;

2> if the wlan-OffloadConfigCommon corresponding to the RPLMN is broadcast by the cell:

3> apply the wlan-OffloadConfigCommon corresponding to the RPLMN included in SystemInformationBlockType17;

1> else:

2> apply the received wlan-OffloadConfigDedicated:

[TS 36.331, clause 5.6.12.3]

The UE shall:

1> if the UE is configured with either wlan-OffloadConfigCommon or wlan-OffloadConfigDedicated:

2> provide measurement results required for the evaluation of the network selection and traffic steering rules as defined in TS 24.312 to upper layers;

2> evaluate the network selection and traffic steering rules as defined in TS 36.304;

[TS 36.304, clause 5.6.2]

The rules in this sub-clause are only applicable for WLANs for which identifiers has been signalled to the UE by E-UTRAN and the UE is capable of RAN-assisted WLAN interworking based on access network selection and traffic steering rules. Coexistence with ANDSF based WLAN selection and traffic steering methods on the UE is based on mechanism described in TS 23.402. The rules refer to the following quantities:

ChannelUtilizationWLAN

WLAN channel utilization as defined in subclause 8.4.2.30 in [26].

BackhaulRateDlWLAN

WLAN DLBandwidth as defined in subclause 9.1.2 in [27].

BackhaulRateUlWLAN

WLAN ULBandwidth as defined in subclause 9.1.2 in [27].

BeaconRSSI

WLAN Beacon RSSI as defined in [7].

RSRPmeas

Qrxlevmeas in RRC_IDLE, and PCell RSRP in RRC_CONNECTED as defined in TS 36.331 [3].

RSRQmeas

Qqualmeas in RRC_IDLE, and PCell RSRQ in RRC_CONNECTED as defined in TS 36.331 [3].

The upper layers in the UE shall be notified (see TS 24.302) when and for which WLAN(s), that matches all the provided identifiers (in subclause 5.6.3) for a specific entry in the list, the following conditions 1 and 2 for steering traffic from E-UTRAN to WLAN are satisfied for a time interval TsteeringWLAN:

In the E-UTRAN serving cell:

RSRPmeas < ThreshServingOffloadWLAN, LowP; or

RSRQmeas < ThreshServingOffloadWLAN, LowQ;

In the target WLAN:

ChannelUtilizationWLAN < ThreshChUtilWLAN, Low; and

BackhaulRateDlWLAN > ThreshBackhRateDLWLAN, High; and

BackhaulRateUlWLAN > ThreshBackhRateULWLAN, High; and

BeaconRSSI > ThreshBeaconRSSIWLAN, High;

The UE shall not consider the metrics for which a threshold has not been provided. The UE shall evaluate the E-UTRAN conditions on PCell only. If not all metrics related to the provided thresholds can be acquired for a WLAN BSS, the UE shall exclude that WLAN BSS from the evaluation of the above rule.

The upper layers in the UE shall be notified (see TS 24.302) when the following conditions 3 or 4 for steering traffic from WLAN to E-UTRAN are satisfied for a time interval TsteeringWLAN:

In the source WLAN:

ChannelUtilizationWLAN > ThreshChUtilWLAN, High; or

BackhaulRateDlWLAN < ThreshBackhRateDLWLAN, Low; or

BackhaulRateUlWLAN < ThreshBackhRateULWLAN, Low; or

BeaconRSSI < ThreshBeaconRSSIWLAN, Low;

In the target E-UTRAN cell:

RSRPmeas > ThreshServingOffloadWLAN, HighP; and

RSRQmeas > ThreshServingOffloadWLAN, HighQ;

The UE shall not consider the metrics for which a threshold has not been provided. The UE shall evaluate the E-UTRAN conditions on PCell only.

[TS 24.302, clause 6.10.4]

This subclause applies if the RAN rules control the WLAN access selection and traffic routing as described in subclause 6.10.2.

The access stratum layer of the 3GPP access can provide:

1) move-traffic-to-WLAN indication, along with list of WLAN identifiers. An entry in the list of the WLAN identifiers consists of SSID, BSSID, HESSID, or any combination of them; and

2) move-traffic-from-WLAN indication.

The user preferences take precedence over the indications provided by the access stratum layer of the 3GPP access.

Upon:

– receiving move-traffic-to-WLAN indication, along with the list of the WLAN identifiers, if the user preferences are not present; or

– establishment of a new PDN connection in 3GPP access, if the PDN connection is an offloadable PDN connection, the access stratum indicated move-traffic-to-WLAN, the access stratum has not indicated the move-traffic-from-WLAN indication after indicating of the move-traffic-to-WLAN indication and the user preferences are not present;

and:

– the UE is capable to simultaneously route IP traffic to both 3GPP access and WLAN; or

– the UE is not capable to simultaneously route IP traffic to both 3GPP access and WLAN, and all the PDN connections of the UE in 3GPP access are offloadable PDN connections;

the UE:

a) shall perform the procedure in subclause 5.1.3.2.3 and in subclause 5.2.3.2 to select the selected WLAN and the NAI for authentication;

b) if not authenticated yet with the selected WLAN using the NAI for authentication in subclause 6.4, shall authenticate with the selected WLAN using the NAI for authentication in subclause 6.4. During authentication, if the selected WLAN is a trusted WLAN, SCM is supported by both UE and network, MCM is not supported by UE, network or both, and if:

– the UE is capable to simultaneously route IP traffic to both 3GPP access and WLAN; or

– the UE is not capable to simultaneously route IP traffic to both 3GPP access and WLAN, and the UE has only one PDN connection;

shall handover one offloadable PDN connection from 3GPP access to the WLAN access using procedures in subclause 6.4.2.6.2;

NOTE: When the UE already has one PDN connection established via WLAN in SCM, and if move-traffic-to-WLAN indication is received, it is up to the UE implementation to determine whether to offload a PDN connection from 3GPP access to WLAN. In that case, it is also up to the UE implementation to determine which one of the offloadable PDN connections will be offloaded.

c) if the selected WLAN is a trusted WLAN, and MCM is supported by both UE and network, shall handover all the offloadable PDN connections from 3GPP access to the WLAN access using procedures of 3GPP TS 24.244];

d) if the selected WLAN is an untrusted WLAN, and if the UE supports access to EPC via untrusted WLAN, shall handover all the offloadable PDN connections from 3GPP access to the WLAN access using procedures in subclause 7.2.1 and subclause 7.2.2; and

e) if the UE has a valid IARP rule for APN, shall use the IARP for APN using the procedures in subclause 6.8.2.2.4.5.

Upon receiving move-traffic-from-WLAN indication, and if the user preferences are not present, the UE shall handover all the PDN connections established in (or previously handed over to) WLAN access to the 3GPP access using procedures in 3GPP TS 24.301.

8.4.8.6.3 Test Description

8.4.8.6.3.1 Pre-test conditions

System Simulator:

– Cell 1 and WLAN AP 1.

– System information combination 22 as defined in TS 36.508 [18] clause 4.4.3.1 is used in E-UTRA cell.

UE:

– The UE supporting ANDSF is pre-provisioned with WLANSP ANDSF MO with at least one WLAN identifier and with ForServiceBased ANDSF MO with RANValidityCondition allowing at least one APN to use both WLAN and LTE and at least one APN to use LTE only.

– The UE supporting RAN rules is configured with at least two PDN connections, one PDN connection offloadable to WLAN and one PDN connection not offloadable to WLAN.

– The UE has a ISRP ANDSF rule using RAN thresholds of BackhaulRateDlWLAN.

Preamble:

– The UE is in state Generic RB Established (state 3) on Cell 1 according to [18].

8.4.8.6.3.2 Test procedure sequence

Table 8.4.8.6.3.2-1 illustrates the downlink power levels and other changing parameters to be applied for the cells at various time instants of the test execution. Row marked "T0" denotes the initial conditions after preamble, while the configuration marked "T1", "T2", “T3” and “T4” are applied at the point indicated in the Main behaviour description in Table 8.4.8.6.3.2-2.

Table 8.4.8.6.3.2-1: Time instances of cell power level and parameter changes

Parameter

Unit

Cell 1

WLAN

Remark

T0

Cell-specific RS EPRE

dBm/15kHz

-79

–

E-UTRA Cell 1 is a suitable cell and WLAN is switched off.

T1

Cell-specific RS EPRE

dBm/15kHz

-91

–

The power level values are such that conditions for traffic steering from E-UTRA to WLAN are satisfied for RSRP and UL Backhaul BW (RAN) and not satisfied for DL Backhaul BW(ANDSF).

BackhaulDL-Bandwidth

kbps

–

r2048

BackhaulUL-Bandwidth

kbps

–

r16384

T2

Cell-specific RS EPRE

dBm/15kHz

-79

–

The power level values are such that conditions for traffic steering from E-UTRA to WLAN are not satisfied for RSRP and UL Backhaul BW (RAN) and satisfied for DL Backhaul BW(ANDSF).

BackhaulDL-Bandwidth

kbps

–

r16384

BackhaulUL-Bandwidth

kbps

–

r2048

T3

Cell-specific RS EPRE

dBm/15kHz

-91

–

The power level values are such that conditions for traffic steering from WLAN to E-UTRA are satisfied for UL Backhaul BW(RAN) and not satisfied for DL Backhaul BW(ANDSF).

BackhaulDL-Bandwidth

kbps

–

r16384

BackhaulUL-Bandwidth

kbps

–

r2048

T4

Cell-specific RS EPRE

dBm/15kHz

-91

–

The power level values are such that conditions for traffic steering from WLAN to E-UTRA satisfied for DL Backhaul BW(ANDSF/RAN).

BackhaulDL-Bandwidth

kbps

–

r1024

BackhaulUL-Bandwidth

kbps

–

r16384

Table 8.4.8.6.3.2-2: Main behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The SS changes Cell 1 and WLAN parameters according to the row "T1" in table 8.4.8.6.3.2-1.

–

–

–

–

2

Check: Does the test result of generic test procedure in TS 36.508 Table 6.4.3.10-1 indicate that the PDN connection is offloaded from E-UTRAN to the WLAN?

–

1

F

3

The SS changes Cell 1 and WLAN parameters according to the row "T2" in table8.4.8.6.3.2-1.

–

–

–

–

4

Check: Does the test result of generic test procedure in TS 36.508 Table 6.4.3.10-1 indicate that the PDN connection is offloaded from E-UTRAN to the WLAN?

–

–

2

P

5

The SS changes Cell 1 and WLAN parameters according to the row "T3" in table 8.4.8.6.3.2-1

–

–

–

–

6

Check: Does the test result of generic test procedure in TS 36.508 Table 6.4.3.11-1 indicate that the PDN connection is offloaded from the WLAN access to E-UTRAN?

–

–

3

F

7

The SS changes Cell 1 and WLAN parameters according to the row "T4" in table 8.4.8.6.3.2-1

–

–

–

–

8

Check: Does the test result of generic test procedure in TS 36.508 Table 6.4.3.11-1 indicate that the PDN connection is offloaded from the WLAN access to E-UTRAN?

–

–

4

P

8.4.8.6.3.3 Specific message contents

Table 8.4.8.6.3.3-1: WLAN-OffloadConfig-DEFAULT

Derivation Path: 36.508, Clause 4.6.1, Table 4.6.3-30, condition RSRP and BackhaulBW

Information Element

Value/remark

Comment

Condition

WLAN-OffloadConfig-r12::= SEQUENCE {

thresholdRSRP-r12::= SEQUENCE {

thresholdRSRP-Low-r12

75

thresholdRSRP-High-r12

85

}

thresholdBackhaul-Bandwidth-r12::= SEQUENCE {

thresholdBackhaulDL-BandwidthLow-r12

r2048

thresholdBackhaulDL-BandwidthHigh-r12

r4096

thresholdBackhaulUL-BandwidthLow-r12

r2048

thresholdBackhaulUL-BandwidthHigh-r12

r4096

}

t-SteeringWLAN-r12

7

Typical value in real networks

}