The present document is a single-RAT specification for a BS, covering RF characteristics and minimum performance requirements. Conducted and radiated core requirements are defined for the BS architectures and BS types defined in clause 4.3. The applicability of each requirement is described in clause 5.

Conformance to the present specification is demonstrated by fulfilling the test requirements specified in the conformance specification TS 38.141-1 and TS 38.141-2. The minimum requirements given in this specification make no allowance for measurement uncertainty. The test specifications TS 38.141-1 and TS 38.141-2 define test tolerances. These test tolerances are individually calculated for each test. The test tolerances are used to relax the minimum requirements in this specification to create test requirements. For some requirements, including regulatory requirements, the test tolerance is set to zero. The measurement results returned by the test system are compared - without any modification - against the test requirements as defined by the shared risk principle. The shared risk principle is defined in recommendation ITU-R M.1545 [7].

The requirements in this specification apply to Wide Area Base Stations, Medium Range Base Stations and Local Area Base Stations unless otherwise stated. The associated deployment scenarios for each class are exactly the same for BS with and without connectors. For BS type 1-O and 2-O, BS classes are defined as indicated below:

• Wide Area Base Stations are characterised by requirements derived from Macro Cell scenarios with a BS to UE minimum distance along the ground equal to 35 m.
• Medium Range Base Stations are characterised by requirements derived from Micro Cell scenarios with a BS to UE minimum distance along the ground equal to 5 m.
• Local Area Base Stations are characterised by requirements derived from Pico Cell scenarios with a BS to UE minimum distance along the ground equal to 2 m.

For BS type 1-C and 1-H, BS classes are defined as indicated below:

• Wide Area Base Stations are characterised by requirements derived from Macro Cell scenarios with a BS to UE minimum coupling loss equal to 70 dB.
• Medium Range Base Stations are characterised by requirements derived from Micro Cell scenarios with a BS to UE minimum coupling loss equals to 53 dB.
• Local Area Base Stations are characterised by requirements derived from Pico Cell scenarios with a BS to UE minimum coupling loss equal to 45 dB.

For BS type 1-C, 1-H and 1-O, HAPS BS class is defined as indicated below:

• HAPS Base Stations are characterised by requirements derived from High Altitude Platform scenarios with a BS to ground UE minimum distance of typically around 20km.
• Unless otherwise stated, HAPS BS class would refer to Wide Area BS class, which is specified in clause 4.4.

For ATG BS type1-C, 1-H and 1-O, ATG BS class is defined as below:

• ATG Base Stations are characterized by requirements derived from ATG scenarios with a ground BS to air UE with typical vertical altitude of around 10,000m and take-off/landing altitudes down to 3000m.
• Unless otherwise stated, ATG BS class would refer to Wide Area BS class, which is specified in clause 4.4.

Some requirements in the present document may only apply in certain regions either as optional requirements, or as mandatory requirements set by local and regional regulation. It is normally not stated in the 3GPP specifications under what exact circumstances the regional requirements apply, since this is defined by local or regional regulation. Table 4.5-1 lists all requirements in the present specification that may be applied differently in different regions.

In Table 4.6-1, the requirement applicability for each requirement set is defined. For each requirement, the applicable requirement clause in the specification is identified. Requirements not included in a requirement set is marked not applicable (NA).

A spectrum allocation where a BS operates can either be contiguous or non-contiguous. Unless otherwise stated, the requirements in the present specification apply for BS configured for both contiguous spectrum operation and non-contiguous spectrum operation. For BS operation in non-contiguous spectrum, some requirements apply both at the Base Station RF Bandwidth edges and inside the sub-block gaps. For each such requirement, it is stated how the limits apply relative to the Base Station RF Bandwidth edges and the sub-block edges respectively. There are no CA requirements for ATG BS in the present specification.

For multi-band connector or multi-band RIB, the RF requirements in clause 6, 7, 9 and 10 apply separately to each supported operating band unless otherwise stated. For some requirements, it is explicitly stated that specific additions or exclusions to the requirement apply at multi-band connector(s), and multi-band RIB(s) as detailed in the requirement clause. For BS capable of multi-band operation, various structures in terms of combinations of different transmitter and receiver implementations (multi-band or single band) with mapping of transceivers to one or more antenna connectors for BS type 1-C or TAB connectors for BS type 1-H in different ways are possible. For multi-band connector(s) the exclusions or provisions for multi-band apply. For single-band connector(s), the following applies:

• Single-band transmitter spurious emissions, operating band unwanted emissions, ACLR, transmitter intermodulation and receiver spurious emissions requirements apply to this connector that is mapped to single-band. In case there are carrier(s) transmitted simultaneously in another supported operating band in common active RF components, when the RF signals of these antenna connectors cover the same geographical area, the frequency range of the Base Station RF bandwidth in the other supported band to this antenna connector should be excluded from the unwanted emission requirements.
• If the BS is configured for single-band operation, single-band requirements shall apply to this connector configured for single-band operation and no exclusions or provisions for multi-band capable BS are applicable. Single-band requirements are tested separately at the connector configured for single-band operation, with all other antenna connectors terminated.

A BS type 1-H may be capable of supporting operation in multiple operating bands with one of the following implementations of TAB connectors in the transceiver array boundary:

• All TAB connectors are single-band connectors.
  • Different sets of single-band connectors support different operating bands, but each TAB connector supports only operation in one single operating band.
  • Sets of single-band connectors support operation in multiple operating bands with some single-band connectors supporting more than one operating band.
• All TAB connectors are multi-band connectors.
• A combination of single-band sets and multi-band sets of TAB connectors provides support of the type BS type 1-H capability of operation in multiple operating bands.

Unless otherwise stated all requirements specified for an operating band apply only to the set of TAB connectors supporting that operating band. In the case of an operating band being supported only by single-band connectors in a TAB connector TX min cell group or a TAB connector RX min cell group, single-band requirements apply to that set of TAB connectors. In the case of an operating band being supported only by multi-band connectors supporting the same operating band combination in a TAB connector TX min cell group or a TAB connector RX min cell group, multi-band requirements apply to that set of TAB connectors. The case of an operating band being supported by both multi-band connectors and single-band connectors in a TAB connector TX min cell group or a TAB connector RX min cell group is not covered by the present release of this specification. The case of an operating band being supported by multi-band connectors which are not all supporting the same operating band combination in a TAB connector TX min cell group or a TAB connector RX min cell group is not covered by the present release of this specification. BS type 1-O may be capable of supporting operation in multiple operating bands with one of the following implementations at the radiated interface boundary:

• All RIBs are single-band RIBs.
• All RIBs are multi-band RIBs.
• A combination of single-band RIBs and multi-band RIBs provides support of the BS type 1-O capability of operation in multiple operating bands.

For multi-band connectors and multi-band RIBs supporting the bands for TDD, the RF requirements in the present specification assume no simultaneous uplink and downlink occur between the bands. The RF requirements for multi-band connectors and multi-band RIBs supporting bands for both FDD and TDD are not covered by the present release of this specification. There is no multi-band operation requirement for ATG BS.

Co-location requirements are requirements which are based on assuming the BS type 1-O is co-located with another BS of the same base station class, they ensure that both co-located systems can operate with minimal degradation to each other. Unwanted emission and out of band blocking co-location requirements are optional requirements based on declaration. TX OFF and TX IMD are mandatory requirements and have the form of a co-location requirement as it represents the worst-case scenario of all the interference cases. The co-location reference antenna shall be a single column passive antenna which has the same vertical radiating dimension (h), frequency range, polarization, as the composite antenna of the BS type 1-O and nominal 65° horizontal half-power beamwidth (suitable for 3-sector deployment) and is placed at a distance d from the edge of the BS type 1-O, as shown in Figure 4.9-1.

Edge-to-edge separation d between the BS type 1-O and the co-location reference antenna shall be set to 0.1 m. The BS type 1-O and the co-location reference antenna shall be aligned in a common plane perpendicular to the mechanical bore-sight direction, as shown in Figure 4.9-1. The co-location reference antenna and the BS type 1-O can have different width. The vertical radiating regions of the co-location reference antenna and the BS type 1-O composite antenna shall be aligned. For co-location requirements where the frequency range of the signal at the co-location reference antenna is different from the BS type 1-O, a co-location reference antenna suitable for the frequency stated in the requirement is assumed. OTA co-location requirements are based on the power at the conducted interface of a co-location reference antenna, depending on the requirement this interface is either an input or an output. For BS type 1-O with dual polarization the co-location reference antenna has two conducted interfaces each representing one polarization.