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