4.12 Co-location requirements
38.176-23GPPIntegrated Access and Backhaul (IAB) conformance testingNRPart 2: radiated conformance testingRelease 17TS
4.12.1 General
Co-location requirements are requirements which are based on assuming the IAB type 1-O is co-located with another BS or IAB of the same base station class. They ensure that both co-located systems can operate with minimal degradation to each other.
The co-location requirements in table 4.12.1-1 rely on a co-location reference antenna used to mimic an IAB to base station or IAB co-location scenario.
Table 4.12.1-1: Co-location requirements
Clause number |
Requirement |
Co-location reference antenna operation |
Type |
---|---|---|---|
6.5 |
OTA transmit ON/OFF power for FR1 |
Measure emission |
Mandatory |
6.7.5.3 6.7.5.5 |
OTA spurious emission: Protection of the IAB receiver of own or different BS and IAB |
Measure emission |
Optional based on declaration |
OTA spurious emission: Co-location with other base stations and IAB-Nodes |
|||
6.8 |
OTA transmitter intermodulation |
Inject the interferer signal |
Mandatory |
7.6 |
OTA out-of-band blocking: Co-location with other base stations or IAB-Nodes |
Inject the interferer signal |
Optional based on declaration |
The OTA transmit ON/OFF power requirement and OTA transmitter intermodulation requirement are mandatory requirements where the test requirement is derived using the co-location reference antenna, which represents the worst-case scenario.
The co-location reference antenna is defined in TS 38.174 [2].
4.12.2 Co-location test antenna
4.12.2.1 General
Co-location requirements are specified as power levels into or out of the conducted interface of the co-location reference antenna. For conformance testing the requirements are translated to the input or output of a co-location test antenna (CLTA).
A CLTA is a practical antenna which can be used to test conformance to the co-location requirements.
4.12.2.2 Co-location test antenna characteristics
A co-location test antenna is a practical passive antenna that is used for conformance testing of the co-location requirements and is based on the definition of the co-location reference antenna. A CLTA shall comply with the requirements specified in table 4.12.2.2-1.
Translation of the requirements to other test antennas are not precluded but suitable translations between the co-location reference antenna and test antenna must be provided to demonstrate that the method is within the specified MU.
NOTE: The currently defined CLTAs are suitable for testing IAB type 1-O implemented with a planar antenna array. The method for testing IAB with other antenna array implementations is not covered by the present release of the present document.
Table 4.12.2.2-1: CLTA characteristics
Parameter |
In-band CLTA |
Out-of-band CLTAs |
Vertical radiating dimension (h) |
Test object vertical radiating length ±30% |
N/A |
Horizontal beam width |
65° ± 10° |
65° ± 10° |
Vertical beam width |
N/A |
The half-power vertical beam width of the CLTA equals the narrowest declared (D.3) vertical beamwidth ±3° |
Polarization |
Match |
Match to in-band |
Conducted interface return loss |
> 10 dB |
> 10 dB |
NOTE: If a multi-column or multi-band antenna is used the column closest to the NR IAB shall be selected while other columns are terminated during testing. |
4.12.2.3 Co-location test antenna alignment
The alignment between the NR IAB under test and the co-location test antenna is described in table 4.12.2.3-1 and figure 4.12.2.3-1. The same physical alignment applies to in-band and out-of-band co-location requirements.
Table 4.12.2.3-1: CLTA alignment tolerances
Parameter |
|
Edge-to-edge separation between the NR IAB and the CLTA, d |
0.1 m ± 0.01 m |
Vertical alignment |
Centre ± 0.01 m |
Front alignment |
Radome front ± 0.01 m |
NR IAB type 1
–
O
CLTA
Horizontal View
Vertical View
d
M
echanical
bore
–
sight
direction
M
echanical
bore
–
sight
direction
Side View
Back
sid
e
Front
sid
e
Figure 4.12.2.3-1: Alignment of NR IAB and CLTA