6.6 OTA transmitted signal quality
38.176-23GPPIntegrated Access and Backhaul (IAB) conformance testingNRPart 2: radiated conformance testingRelease 17TS
6.6.1 General
Unless otherwise stated, the requirements in clause 6.6 apply during the transmitter ON period.
6.6.2 OTA frequency error
6.6.2.1 IAB-DU OTA frequency error
6.6.2.1.1 Definition and applicability
For IAB-DU, OTA frequency error is the measure of the difference between the actual IAB-DU transmit frequency and the assigned frequency. The same source shall be used for RF frequency and data clock generation.
For IAB-DU, OTA frequency error requirement is defined as a directional requirement at the RIB and shall be met within the OTA coverage range.
6.6.2.1.2 Minimum Requirement
The minimum requirements for IAB-DU type 1-O and IAB-DU type 2-O are in TS 38.174 [2], clause 9.6.1.1.
6.6.2.1.3 Test purpose
The test purpose is to verify that OTA frequency error is within the limit specified by the minimum requirement.
6.6.2.1.4 Method of test
Requirement is tested together with OTA modulation quality test, as described in clause 6.6.3.
6.6.2.1.4.1 Initial conditions
Directions to be tested: OTA coverage range reference direction (D.35).
6.6.2.1.5 Test Requirements
For IAB-DU, the modulated carrier frequency of each NR carrier configured by the IAB-DU shall be accurate to within the accuracy range given in table 6.6.2.1.5-1 observed over 1 ms.
Table 6.6.2.1.5-1: OTA frequency error test requirement for IAB-DU type 1-O and IAB-DU type 2-O
|
IAB-DU class |
Accuracy |
|
Wide Area IAB-DU |
±(0.05 ppm + 12 Hz) |
|
Medium Range IAB-DU |
±(0.1 ppm + 12 Hz) |
|
Local Area IAB-DU |
±(0.1 ppm + 12 Hz) |
6.6.2.2 IAB-MT OTA frequency error
6.6.2.2.1 Definition and applicability
For IAB-MT, OTA frequency error is the measure of the difference between actual IAB-MT transmit frequency and the carrier frequency received from the parent node.
For IAB-MT, OTA frequency error requirement is defined as a directional requirement at the RIB and shall be met within the OTA coverage range.
6.6.2.2.2 Minimum Requirement
The minimum requirement for IAB-MT type 1-O and IAB-MT type 2-O are in TS 38.174 [2], clause 9.6.1.2.
6.6.2.2.3 Test purpose
The test purpose is to verify that OTA frequency error is within the limit specified by the minimum requirement.
6.6.2.2.4 Method of test
Requirement is tested together with OTA modulation quality test, as described in clause 6.6.3.
6.6.2.2.4.1 Initial conditions
Directions to be tested: OTA coverage range reference direction (D.35).
6.6.2.2.5 Test Requirements
For IAB-MT type 1-O and IAB-MT type 2-O, the mean value of basic measurements of IAB-MT modulated carrier frequency shall be accurate to within the accuracy range given in table 6.6.2.2.5-1 observed over 1 ms cumulated measurement intervals compared to the carrier frequency received from the parent node.
Table 6.6.2.2.5-1: OTA frequency error test requirement for IAB-MT type 1-O
|
IAB-MT frequency range |
Accuracy |
|
f ≤ 3.0GHz |
±(0.1 ppm + 15 Hz) |
|
3.0GHz< f ≤ 7.125GHz |
±(0.1 ppm + 36 Hz) |
|
24.25GHz < f ≤ 52.6GHz |
±(0.1 ppm + 0.01ppm) |
6.6.3 OTA modulation quality
6.6.3.1 Definition and applicability
OTA modulation quality is defined by the difference between the measured carrier signal and an ideal signal. Modulation quality can e.g. be expressed as Error Vector Magnitude (EVM). The Error Vector Magnitude is a measure of the difference between the ideal symbols and the measured symbols after the equalization. This difference is called the error vector.
OTA modulation quality requirement is defined as a directional requirement at the RIB and shall be met within the OTA coverage range.
6.6.3.2 Minimum Requirement
The minimum requirement for IAB-DU type 1-O, is in TS 38.174 [2], clause 9.6.2.1.
The minimum requirement for IAB-DU type 2-O, is in TS 38.174 [2], clause 9.6.2.1.
The minimum requirement for IAB-MT type 1-O, is in TS 38.174 [2], clause 9.6.2.2.
The minimum requirement for IAB-MT type 2-O, is in TS 38.174 [2], clause 9.6.2.3.
6.6.3.3 Test purpose
The test purpose is to verify that OTA modulation quality is within the limit specified by the minimum requirement.
6.6.3.4 Method of test
6.6.3.4.1 Initial conditions
Test environment: Normal; see annex B.2.
RF channels to be tested for single carrier:
– B and T; see clause 4.9.1.
IAB RF bandwidth positions to be tested for multi-carrier and/or CA:
– BRFBW and TRFBW in single-band operation, see clause 4.9.1;
– BRFBW_T’RFBW and B’RFBW_TRFBW in multi-band operation, see clause 4.9.1.
Directions to be tested:
– The OTA coverage range reference direction (D.35).
– The OTA coverage range maximum directions (D.36).
Polarizations to be tested: For dual polarized systems the requirement shall be tested and met for both polarizations.
6.6.3.4.2 Procedure for IAB-DU
1) Place the IAB-DU at the positioner.
2) Align the manufacturer declared coordinate system orientation (D.2) of the IAB-DU with the test system.
3) Orient the positioner (and IAB-DU) in order that the direction to be tested aligns with the test antenna.
4) Configure the beamforming settings of the IAB-DU according to the direction to be tested.
5) Set the IAB-DU to output according to the applicable test configuration in clause 4.8 using the corresponding test models or set of physical channels in clause 4.9.2.
For IAB-DU type 1-O declared to be capable of single carrier operation only, set the IAB-DU to transmit a signal according to:
– IAB-DU-FR1-TM3.1a if 256QAM is supported by IAB-DU without power back off
– or IAB-DU-FR1-TM3.1a if 256QAM is supported by IAB-DU with power back off, at manufacturer’s declared rated output power (Prated,c,EIRP) and IAB-DU-FR1-TM3.1 at maximum power
– or IAB-DU-FR1-TM3.1 if highest modulation order supported by IAB-DU is 64QAM
– or IAB-DU-FR1-TM3.2 if highest modulation order supported by IAB-DU is 16QAM
– or IAB-DU-FR1-TM3.3 if highest modulation order supported by IAB-DU is QPSK.
For IAB-DU type 1-O declared to be capable of multi-carrier and/or CA operation, set the IAB-DU to transmit according to the applicable test signal configuration and corresponding power setting specified in clauses 4.7.2 and 4.8 using the corresponding test models on all carriers configured:
– IAB-DU-FR1-TM3.1a if 256QAM is supported by IAB-DU without power back off
– or IAB-DU-FR1-TM3.1a if 256QAM is supported by IAB-DU with power back off, at manufacturer’s declared rated output power (Prated,c,EIRP) and IAB-DU-FR1-TM3.1 at maximum power
– or IAB-DU-FR1-TM3.1 if highest modulation order supported by IAB-DU is 64QAM
– or IAB-DU-FR1-TM3.2 if highest modulation order supported by IAB-DU is 16QAM
– or IAB-DU-FR1-TM3.3 if highest modulation order supported by IAB-DU is QPSK.
For IAB-DU type 2-O declared to be capable of single carrier operation only, set the IAB-DU to transmit a signal according to the applicable test signal configuration and corresponding power setting specified in clause 4.7.2 and 4.8 using the corresponding test models on all carriers configured:
– IAB-DU-FR2-TM3.1a with 256QAM signal if 256QAM is supported by IAB-DU without power back off, or
– IAB-DU-FR2-TM3.1a at manufacturer’s declared rated output power if 256QAM is supported by IAB-DU with power back off, and IAB-DU-FR2-TM3.1 with highest modulation order supported without power back off, or
– IAB-DU-FR2-TM3.1 with 64QAM signal if 64QAM is supported by IAB-DU without power back off, or
– IAB-DU-FR2-TM 3.1 with highest modulation order without power back off if 64QAM is not supported by IAB-DU, or
– if 64 QAM is supported by IAB-DU with power back off, IAB-DU-FR2-TM 3.1 with 64QAM at manufacturer’s declared rated output power (Prated,c,EIRP) and IAB-DU-FR2-TM3.1 with highest modulation order supported at maximum power.
For IAB-DU type 2-O declared to be capable of multi-carrier and/or CA operation, set the IAB-DU or IAB-MT to transmit according to:
– IAB-DU-FR2-TM3.1a with 256QAM signal if 256QAM is supported by IAB-DU without power back off, or
– IAB-DU-FR2-TM3.1a at manufacturer’s declared rated output power if 256QAM is supported by IAB-DU with power back off, and IAB-DU-FR2-TM3.1 at maximum power, or
– IAB-DU-FR2-TM3.1 with 64QAM signal if 64QAM is supported by IAB-DU without power back off, or
– IAB-DU-FR2-TM3.1 with highest modulation order supported without power back off if 64QAM is not supported by IAB-DU, or
– if 64QAM is supported by IAB-DU with power back off, IAB-DU-FR2-TM3.1 with 64QAM signal at manufacturer’s declared rated output power (Prated,c,EIRP) and IAB-DU-FR2-TM3.1 with highest supported modulation order at maximum power
For IAB-DU-FR1-TM 3.1a and IAB-DU-FR2-TM 3.1, power back-off shall be applied if it is declared.
6) For each carrier, measure the EVM and frequency error as defined in annex L.
7) Repeat steps 5 and 6 for IAB-DU-FR1-TM2 if 256QAM is not supported by IAB-DU type 1-O or for IAB-DU-FR1-TM2a if 256QAM is supported by IAB-DU type 1-O. For IAB-DU-FR1-TM2 and IAB-DU-FR1-TM2a the OFDM symbol power (in the conformance direction) shall be at the lower limit of the dynamic range according to the test procedure in clause 6.4.3.4.2 and test requirements in clause 6.4.3.5.1.
Repeat steps 5 and 6 for IAB-DU-FR2-TM2 if 256QAM is not supported by IAB-DU type 2-O or for IAB-DU-FR2-TM2a if 256QAM is supported by IAB-DU type 2-O. For IAB-DU-FR2-TM2 and IAB-DU-FR1-TM2a the OFDM symbol power (in the conformance direction) shall be at the lower limit of the dynamic range according to the test procedure in clause 6.4.3.4.2 and test requirements in clause 6.4.3.5.2.
In addition, for multi-band RIB, the following steps shall apply:
8) For multi-band RIB and single band tests, repeat the steps above per involved band where single band test configurations and test models shall apply with no carrier activated in the other band.
6.6.3.4.3 Procedure for IAB-MT
1) Place the IAB-MT at the positioner.
2) Align the manufacturer declared coordinate system orientation (D.2) of the IAB-MT with the test system.
3) Orient the positioner (and IAB-MT) in order that the direction to be tested aligns with the test antenna.
4) Configure the beamforming settings of the IAB-MT according to the direction to be tested.
5) Set the IAB-MT to output according to the applicable test configuration in clause 4.8 using the corresponding test models or set of physical channels in clause 4.9.2.
For IAB-MT type 1-O declared to be capable of single carrier operation only, set the IAB-MT to transmit a signal according to:
– IAB-MT-FR1-TM3.1a if 256QAM is supported by IAB-MT without power back off
– or IAB-MT-FR1-TM3.1a if 256QAM is supported by IAB-MT with power back off, at manufacturer’s declared rated output power (Prated,c,EIRP) and IAB-MT-FR1-TM3.1 at maximum power
– or IAB-MT-FR1-TM3.1 with highest modulation order supported by IAB-MT.
For IAB-MT type 1-O declared to be capable of multi-carrier and/or CA operation, set the IAB-MT to transmit according to the applicable test signal configuration and corresponding power setting specified in clauses 4.7.2 and 4.8 using the corresponding test models on all carriers configured:
– IAB-MT-FR1-TM3.1a if 256QAM is supported by IAB-MT without power back off
– or IAB-MT-FR1-TM3.1a if 256QAM is supported by IAB-MT with power back off, at manufacturer’s declared rated output power (Prated,c,EIRP) and IAB-MT-FR1-TM3.1 at maximum power
– or IAB-MT-FR1-TM3.1 with highest modulation order supported by IAB-MT.
For IAB-MT type 2-O declared to be capable of single carrier operation only, set the IAB-MT to transmit a signal according to the applicable test signal configuration and corresponding power setting specified in clause 4.7.2 and 4.8 using the corresponding test models on all carriers configured:
– IAB-MT-FR2-TM3.1 with 64QAM signal if 64QAM is supported by IAB-MT without power back off, or
– IAB-MT-FR2-TM 3.1 with highest modulation order without power back off if 64QAM is not supported by IAB-MT, or
– if 64 QAM is supported by IAB-MT with power back off, IAB-MT-FR2-TM 3.1 with 64QAM at manufacturer’s declared rated output power (Prated,c,EIRP) and IAB-MT-FR2-TM3.1 with highest modulation order supported at maximum power.
For IAB-MT type 2-O declared to be capable of multi-carrier and/or CA operation, set the IAB-MT to transmit according to:
– IAB-MT-FR2-TM3.1 with 64QAM signal if 64QAM is supported by IAB-MT without power back off, or
– IAB-MT-FR2-TM3.1 with highest modulation order supported without power back off if 64QAM is not supported by IAB-MT, or
– if 64QAM is supported by IAB-MT with power back off, IAB-MT-FR2-TM3.1 with 64QAM signal at manufacturer’s declared rated output power (Prated,c,EIRP) and IAB-MT-FR2-TM3.1 with highest supported modulation order at maximum power
For IAB-MT-FR1-TM 3.1a and IAB-MT-FR2-TM 3.1, power back-off shall be applied if it is declared.
6) For each carrier, measure the EVM and frequency error as defined in annex L.
7) Repeat steps 5 and 6 for IAB-MT-FR1-TM2 if 256QAM is not supported by IAB-MT type 1-O or for IAB-MT-FR1-TM2a if 256QAM is supported by IAB-MT type 1-O. For IAB-MT-FR1-TM2 and IAB-MT-FR1-TM2a the OFDM symbol power (in the conformance direction) shall be at the lower limit of the dynamic range according to the test procedure in clause 6.4.3.4.2 and test requirements in clause 6.4.3.5.1.
In addition, for multi-band RIB, the following steps shall apply:
8) For multi-band RIB and single band tests, repeat the steps above per involved band where single band test configurations and test models shall apply with no carrier activated in the other band.
6.6.3.5 Test requirements
6.6.3.5.1 IAB-DU type 1-O and IAB-MT type 1-O
For IAB-DU type 1-O or IAB-MT type 1-O, the EVM of each NR carrier for different modulation schemes on PDSCH or PUSCH shall be less than the limits in table 6.6.3.5.1-1.
Table 6.6.3.5.1-1: EVM requirements for IAB type 1-O
|
Modulation scheme for PDSCH or PUSCH |
Required EVM (%) |
|
QPSK |
18.5 |
|
16QAM |
13.5 |
|
64QAM |
9 |
|
256QAM |
4.5 |
EVM shall be evaluated for each NR carrier over all allocated resource blocks and downlink slots for IAB-DU or uplink slots for IAB-MT. Different modulation schemes listed in table 6.6.3.5.1-1 shall be considered for rank 1.
For all bandwidths, the EVM measurement shall be performed for each NR carrier over all allocated resource blocks and downlink slots for IAB-DU or uplink slots for IAB-MT within 10 ms measurement periods. The boundaries of the EVM measurement periods need not be aligned with radio frame boundaries.
Tables 6.6.3.5.1-2, 6.6.3.5.1-3, 6.6.3.5.1-4 below specify the EVM window length (W) for normal CP for IAB type 1-O.
Table 6.6.3.5.1-2: EVM window length for normal CP, FR1, 15 kHz SCS
|
Channel |
FFT size |
Cyclic prefix length for symbols 1‑6 and 8-13 in FFT samples |
EVM window length W |
Ratio of W to total CP length for symbols 1‑6 and 8-13 (Note) (%) |
|
10 |
1024 |
72 |
28 |
40 |
|
15 |
1536 |
108 |
44 |
40 |
|
20 |
2048 |
144 |
58 |
40 |
|
25 |
2048 |
144 |
72 |
50 |
|
30 |
3072 |
216 |
108 |
50 |
|
40 |
4096 |
288 |
144 |
50 |
|
50 |
4096 |
288 |
144 |
50 |
|
NOTE: These percentages are informative and apply to a slot’s symbols 1 to 6 and 8 to 13. Symbols 0 and 7 have a longer CP and therefore a lower percentage. |
||||
Table 6.6.3.5.1-3: EVM window length for normal CP, FR1, 30 kHz SCS
|
Channel |
FFT size |
Cyclic prefix length for symbols 1‑13 in FFT samples |
EVM window length W |
Ratio of W to total CP length for symbols 1‑13 (Note) (%) |
|
10 |
512 |
36 |
14 |
40 |
|
15 |
768 |
54 |
22 |
40 |
|
20 |
1024 |
72 |
28 |
40 |
|
25 |
1024 |
72 |
36 |
50 |
|
30 |
1536 |
108 |
54 |
50 |
|
40 |
2048 |
144 |
72 |
50 |
|
50 |
2048 |
144 |
72 |
50 |
|
60 |
3072 |
216 |
130 |
60 |
|
70 |
3072 |
216 |
130 |
60 |
|
80 |
4096 |
288 |
172 |
60 |
|
90 |
4096 |
288 |
172 |
60 |
|
100 |
4096 |
288 |
172 |
60 |
|
NOTE: These percentages are informative and apply to a slot’s symbols 1 through 13. Symbol 0 has a longer CP and therefore a lower percentage. |
||||
Table 6.6.3.5.1-4: EVM window length for normal CP for NR, FR1, 60 kHz SCS
|
Channel |
FFT size |
Cyclic prefix length in FFT samples |
EVM window length W |
Ratio of W to total CP (Note) (%) |
|
10 |
256 |
18 |
8 |
40 |
|
15 |
384 |
27 |
11 |
40 |
|
20 |
512 |
36 |
14 |
40 |
|
25 |
512 |
36 |
18 |
50 |
|
30 |
768 |
54 |
26 |
50 |
|
40 |
1024 |
72 |
36 |
50 |
|
50 |
1024 |
72 |
36 |
50 |
|
60 |
1536 |
108 |
64 |
60 |
|
70 |
1536 |
108 |
64 |
60 |
|
80 |
2048 |
144 |
86 |
60 |
|
90 |
2048 |
144 |
86 |
60 |
|
100 |
2048 |
144 |
86 |
60 |
|
NOTE: These percentages are informative and apply to all OFDM symbols within subframe except for symbol 0 of slot 0 and slot 2. Symbol 0 of slot 0 and slot 2 may have a longer CP and therefore a lower percentage. |
||||
6.6.3.5.2 IAB-DU type 2-O and IAB-MT type 2-O
For IAB-DU type 2-O and IAB-MT type 2-O, the EVM of each NR carrier for different modulation schemes on PDSCH or PUSCH shall be less than the limits in table 6.6.3.5.2-1.
Table 6.6.3.5.2-1: EVM requirements for IAB type 2-O
|
Modulation scheme for PDSCH or PUSCH |
Required EVM (%) |
|
QPSK |
18.5 |
|
16QAM |
13.5 |
|
64QAM |
9 |
|
256QAM |
4.5 |
|
NOTE: 256QAM is not supported by FR2 IAB-MT PUSCH |
|
EVM requirements shall apply for each NR carrier over all allocated resource blocks and downlink slots for IAB-DU or uplink slots for IAB-MT. PT-RS should be configured for localized setting for every fourth symbol for every second RB for IAB-DU and IAB-MT. Different modulation schemes listed in table 6.6.3.5.2-1 shall be considered for rank 1.
For all bandwidths, the EVM measurement shall be performed for each NR carrier over all allocated resource blocks and downlink slots for IAB-DU or uplink slots for IAB-MT within 10 ms measurement periods. The boundaries of the EVM measurement periods need not be aligned with radio frame boundaries.
Tables 6.6.3.5.2-2 and 6.6.3.5.2-3 below specify the EVM window length (W) for normal CP for IAB-DU type 2-O and IAB-MT type 2-O.
Table 6.6.3.5.2-2: EVM window length for normal CP, FR2, 60 kHz SCS
|
Channel bandwidth (MHz) |
FFT size |
Cyclic prefix lengthen FFT samples |
EVM window length W |
Ratio of W to total CP length (Note) (%) |
|
50 |
1024 |
72 |
36 |
50 |
|
100 |
2048 |
144 |
72 |
50 |
|
200 |
4096 |
288 |
144 |
50 |
|
NOTE: These percentages are informative and apply to all OFDM symbols within subframe except for symbol 0 of slot 0 and slot 2. Symbol 0 of slot 0 and slot 2 may have a longer CP and therefore a lower percentage. |
||||
Table 6.6.3.5.2-3: EVM window length for normal CP, FR2, 120 kHz SCS
|
Channel bandwidth (MHz) |
FFT size |
Cyclic prefix length in FFT samples |
EVM window length W |
Ratio of W to total CP length (Note) (%) |
|
50 |
512 |
36 |
18 |
50 |
|
100 |
1024 |
72 |
36 |
50 |
|
200 |
2048 |
144 |
72 |
50 |
|
400 |
4096 |
288 |
144 |
50 |
|
NOTE: These percentages are informative and apply to all OFDM symbols within subframe except for symbol 0 of slot 0 and slot 4. Symbol 0 of slot 0 and slot 4 may have a longer CP and therefore a lower percentage. |
||||
6.6.4 OTA time alignment error
6.6.4.1 Definition and applicability
For IAB-DU, this requirement shall apply to frame timing in MIMO transmission, carrier aggregation and their combinations. There’s no time alignment error requirement for IAB-MT.
Frames of the NR signals present in the radiated domain are not perfectly aligned in time. In relation to each other, the RF signals present in the radiated domain may experience certain timing differences.
For a specific set of signals/transmitter configuration/transmission mode, the OTA Time Alignment Error (OTA TAE) is defined as the largest timing difference between any two different NR signals. The OTA time alignment error requirement is defined as a directional requirement at the RIB and shall be met within the OTA coverage range.
6.6.4.2 Minimum requirement
The minimum requirement for IAB-DU type 1-O is in TS 38.174 [2], clause 9.6.3.1.
The minimum requirement for IAB-DU type 2-O is in TS 38.174 [2], clause 9.6.3.1.
6.6.4.3 Test purpose
To verify that the OTA time alignment error is within the limit specified by the minimum requirement.
6.6.4.4 Method of test
6.6.4.4.1 Initial conditions
Test environment: Normal; see annex B.2.
RF channels to be tested for single carrier: M; see clause 4.9.1.
IAB-DU RF Bandwidth positions to be tested for multi-carrier and/or CA:
– MRFBW in single-band operation, see clause 4.9.1;
– BRFBW_T’RFBW and B’RFBW_TRFBW in multi-band operation, see clause 4.9.1.
Directions to be tested: OTA coverage range reference direction (D.35).
Polarizations to be tested: For dual polarized systems the requirement shall be tested and met considering both polarisations. If the measurement antenna does not support dual polarization, time alignment error shall be measured under the condition that measurement antenna is aligned between the IAB-DU polarisations such that it receives half the power from each polarisation.
6.6.4.4.2 Procedure for IAB-DU
1) Place the IAB-DU at the positioner.
2) Align the manufacturer declared coordinate system orientation (D.2) of the IAB-DU with the test system.
3) Orient the positioner (and IAB-DU) in order that the direction to be tested aligns with the test antenna.
4) Configure the beamforming settings of the IAB-DU according to the direction of the testing.
5) Set the IAB-DU type 1-O to transmit IAB-DU-FR1-TM1.1 or any DL signal using MIMO transmission or carrier aggregation, using the configuration with the minimum number of cells and reference signals.
Set the IAB-DU type 2-O to transmit IAB-DU-FR2-TM 1.1 or any DL signal using MIMO transmission or carrier aggregation, using the configuration with the minimum number of cells and reference signals.
NOTE: For MIMO transmission, different ports may be configured in IAB-DU-FR1-TM1.1 and IAB-DU-FR2-TM 1.1 (using DMRS ports p = 1000 and 1001 with CDM).
For an IAB-DU declared to be capable of single carrier operation only, set the IAB-DU to transmit according to the applicable test configuration in clause 4.8 using the corresponding test model at manufacturer’s declared rated output power, Prated,c,TRP.
If the IAB-DU supports intra band contiguous or non-contiguous Carrier Aggregation set the IAB-DU to transmit using the applicable test configuration and corresponding power setting specified in clauses 4.7.2 and 4.8.
If the IAB-DU supports inter band carrier aggregation set the IAB-DU to transmit, for each band, a single carrier or all carriers, using the applicable test configuration and corresponding power setting specified in clauses 4.7.2 and 4.8.
For IAB-DU type 1-O declared to be capable of multi-carrier operation, set the IAB-DU to transmit according to the applicable test signal configuration and corresponding power setting specified in clauses 4.7.2 and 4.8 using the corresponding test model on all carriers configured.
For IAB-DU type 2-O declared to be capable of multi-carrier operation, set the IAB-DU to transmit according to the applicable test signal configuration and corresponding power setting specified in clauses 4.7.2 and 4.8 using the corresponding test model on all carriers configured.
6) Measure the time alignment error between the different reference symbols on different beams on the carrier(s).
In addition, for a multi-band RIB, the following steps shall apply:
7) For a multi-band RIB and single band tests, repeat the steps above per involved band where single band test configurations and test models shall apply with no carrier activated in the other band.
6.6.4.5 Test Requirement
6.6.4.5.1 IAB-DU type 1-O
For MIMO transmission, at each carrier frequency, OTA TAE shall not exceed 90 ns.
For intra-band contiguous carrier aggregation, with or without MIMO, OTA TAE shall not exceed 285 ns.
For intra-band non-contiguous carrier aggregation, with or without MIMO, OTA TAE shall not exceed 3.025 µs.
For inter-band carrier aggregation, with or without MIMO, OTA TAE shall not exceed 3.025 µs.
6.6.4.5.2 IAB-DU type 2-O
For MIMO transmission, at each carrier frequency, OTA TAE shall not exceed 90 ns.
For intra-band contiguous carrier aggregation, with or without MIMO, OTA TAE shall not exceed 155 ns.
For intra-band non-contiguous carrier aggregation, with or without MIMO, OTA TAE shall not exceed 285 ns.
For inter-band carrier aggregation, with or without MIMO, OTA TAE shall not exceed 3.025 µs.
6.6.5 Timing error between IAB-DU and IAB-MT
6.6.5.1 Definition and applicability
This requirement shall apply to IAB-DU DL and IAB-MT UL simultaneous transmission.
The timing error between IAB-DU and IAB-MT is specified for a specific set of simultaneous signals/transmitter configuration/transmission mode.
6.6.5.2 Minimum requirement
The minimum requirement for IAB type 1-O is in TS 38.174 [2], clause 6.5.4.
The minimum requirement for IAB type 2-O is in TS 38.174 [2], clause 9.6.4.
6.6.5.3 Test purpose
To verify that the OTA timing error between IAB-DU and IAB-MT simultaneous transmission is within the limit specified by the minimum requirement.
6.6.5.4 Method of test
6.6.5.4.1 Initial conditions
Test environment: Normal; see annex B.2.
RF channels to be tested for single carrier: M; see clause 4.9.1.
IAB-DU RF Bandwidth positions to be tested for multi-carrier and/or CA:
– MRFBW in single-band operation, see clause 4.9.1;
– BRFBW_T’RFBW and B’RFBW_TRFBW in multi-band operation, see clause 4.9.1.
Directions to be tested: OTA coverage range reference direction (D.35).
Polarizations to be tested: For dual polarized systems the requirement shall be tested and met considering both polarisations. If the measurement antenna does not support dual polarization, time alignment error shall be measured under the condition that measurement antenna is aligned between the IAB-DU polarisations such that it receives half the power from each polarisation.
6.6.5.4.2 Procedure
1) Place the IAB-DU and IAB-MT at the positioner.
2) Align the manufacturer declared coordinate system orientation (D.2) of the IAB-DU and IAB-MT with the test system.
3) Orient the positioner (and IAB-DU and IAB-MT) in order that the direction to be tested aligns with the test antenna.
4) Configure the beamforming settings of the IAB-DU and IAB-MT according to the direction of the testing.
5) Set the IAB type 1-O to transmit IAB-DU-FR1-TM1.1 or IAB-MT-FR1-TM1.1. using the configuration with the minimum number of cells and reference signals.
– Set the IAB type 2-O to transmit IAB-DU-FR2-TM 1.1 or IAB-MT-FR1-TM1.1 using the configuration with the minimum number of cells and reference signals.
– For an IAB-DU declared to be capable of single carrier operation only, set the IAB-DU to transmit according to the applicable test configuration in clause 4.8 using the corresponding test model at manufacturer’s declared rated output power, Prated,c,TRP.
– For IAB type 1-O declared to be capable of multi-carrier operation, set the IAB-DU and IAB-MT to transmit according to the applicable test signal configuration and corresponding power setting specified in clauses 4.7.2 and 4.8 using the corresponding test model on all carriers configured.
– For IAB type 2-O declared to be capable of multi-carrier operation, set the IAB-DU and IAB-MT to transmit according to the applicable test signal configuration and corresponding power setting specified in clauses 4.7.2 and 4.8 using the corresponding test model on all carriers configured.
6) Measure the timing error between the DM-RS symbols on the IAB-DU and IAB-MT beams. Note that the possible difference in DM-RS symbol position and slot number shall be compensated for in the measured timing error.
In addition, for a multi-band RIB, the following steps shall apply:
7) For a multi-band RIB and single band tests, repeat the steps above per involved band where single band test configurations and test models shall apply with no carrier activated in the other band.
6.6.5.5 Test Requirement
6.6.5.5.1 IAB type 1-O
The timing error between IAB-DU and IAB-MT shall not exceed minimum requirement plus measurement uncertainty defined in Table 4.1.2.2-1.
6.6.5.5.2 IAB type 2-O
The timing error between IAB-DU and IAB-MT shall not exceed minimum requirement plus measurement uncertainty defined in Table 4.1.2.2-2.