4 General
37.1053GPPActive Antenna System (AAS) Base Station (BS) transmission and receptionRelease 17TS
4.1 Relationship between the AAS BS specification and non‑AAS BS single RAT & MSR specifications
An AAS BS is distinguished from a non-AAS BS by including a dedicated antenna system in its design.
The transceiver to antenna RF interface of the AAS BS (referred to as the transceiver array boundary) comprises one or several TAB connectors. There is no general one-to-one relationship between non-AAS BS antenna connectors and AAS BS TAB connectors, but it can be expected the number of TAB connectors in AAS BS will be greater than or equal to the number of non-AAS BS antenna connectors for respective base stations with corresponding functionality.
For the conducted requirements, the AAS BS requirements are formulated in such a way that the impact of what they are meant to regulate is expected to be "equivalent" to the corresponding non-AAS BS requirements; i.e. the outside world sees the same level of emissions, power levels, or can expect the same demodulation performance at the UE from the AAS BS as it would from a non-AAS BS with equivalent functionality. All non-AAS BS RF requirements (referenced to the non-AAS BS antenna connector) have been adapted to AAS BS conducted requirements. Many requirements are also direct references to the non-AAS BS RF specifications 3GPP TS 25.104 [2], 3GPP TS 25.105 [3], 3GPP TS 36.104 [4] and 3GPP TS 37.104 [5].
NOTE 1: Applying non-AAS BS antenna connector requirements directly to individual TAB connectors renders certain AAS BS requirements excessively strict from a system perspective.
NOTE 2: Both specific references and non-specific references occur.
In addition, some new OTA requirements are introduced. These requirements have no corresponding non-AAS BS requirements.
For a OTA AAS BS there are no conducted requirements. The radiated requirements have been derived based on the principle that they offer the same level of performance and protection as the hybrid AAS BS requirements. The radiated requirements therefore use the same equivalence to the non-AAS requirements. The non-AAS BS RF requirements have therefore been further adapted to apply to OTA metrics in the far field. Some requirements are direct references to the non-AAS BS RF specifications 3GPP TS 25.104 [2], 3GPP TS 25.105 [3], 3GPP TS 36.104 [4] and 3GPP TS 37.104 [5]. Some co-location requirements which have been developed from assumptions on BS-to-BS coupling do not have direct OTA equivalents. The radiated co-location requirements use the same scenarios used to develop the non-AAS RF requirements.
In this specification, the term "requirements for single RAT operation" refers to requirements that are derived from the 3GPP TS 25.104 [2], 3GPP TS 25.105 [3], or 3GPP TS 36.104 [4] specifications baseline, whilst "requirements for MSR operation" refers to requirements derived from the 3GPP TS 37.104 [5] specification baseline (including NR operation as part of MSR).
NB-IoT in-band, NB-IoT guard band, or standalone NB-IoT operation is not supported by AAS BS. When referring to standalone E-UTRA requirements for single RAT operation in 3GPP TS 36.104 [4] or to E-UTRA requirements for MSR operation in 3GPP TS 37.104 [5], any requirements specified in those specifications for E-UTRA with NB-IoT (in-band or guard band) or for standalone NB-IoT, shall not be considered for the AAS BS. Unless otherwise stated, the exclusion of the NB-IoT requirements in this specification applies to all operation modes (i.e. in-band NB-IoT operation, guard band NB-IoT operation and standalone NB-IoT operation).NR requirements for single RAT operation are not specified in the present document because AAS RF requirements for single RAT NR are fully captured in the NR specification 38.104 [27].
Band 46 operation and Band 49 operation is not supported by AAS BS. When referring to standalone E-UTRA requirements for single RAT operation in 3GPP TS 36.104 [4] or to E-UTRA requirements for MSR operation in 3GPP TS 37.104 [5], any requiremetns specified in those specifications for Band 46 or Band 49 operation shall not be considered for the AAS BS with E‑UTRA.
4.2 Relationship between minimum requirements and test requirements
Conformance to the present specification is demonstrated by fulfilling the test requirements specified in the conformance specifications TS 37.145-1 [29] and TS 37.145-2 [30].
The minimum requirements given in this specification make no allowance for measurement uncertainty. The test specifications TS 37.145-1 [29] and TS 37.145-2 [30] 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 [11].
4.3 Conducted and radiated requirement reference points
AAS BS requirements are defined for two points of reference, signified by radiated requirements and conducted requirements.
Figure 4.3-1: Radiated and conducted points of reference of hybrid AAS BS
Figure 4.3-2: Radiated points of reference of OTA AAS BS
Radiated characteristics are defined over the air (OTA) at the radiated interface boundary (RIB). Radiated requirements are also referred to as OTA requirements. The (spatial) directions in which the OTA requirements apply are detailed for each requirement.
Some OTA requirements are specified as co-location requirements where the requirements are specified at the conducted interface of the co-location reference antenna, co-location requirements are further defined in subclause 4.10.
Conducted characteristics are defined at individual or groups of TAB connectors at the transceiver array boundary, which is the conducted interface between the transceiver unit array and the composite antenna.
The transceiver unit array is part of the composite transceiver functionality generating modulated transmit signal structures and performing receiver combining and demodulation.
The transceiver unit array contains an implementation specific number of transmitter units and an implementation specific number of receiver units. Transmitter units and receiver units may be combined into transceiver units. The transmitter/receiver units have the ability to transmit/receive parallel independent modulated symbol streams.
The composite antenna contains a radio distribution network (RDN) and an antenna array. The RDN is a linear passive network which distributes the RF power generated by the transceiver unit array to the antenna array, and/or distributes the radio signals collected by the antenna array to the transceiver unit array, in an implementation specific way.
How a conducted requirement is applied to the transceiver array boundary is detailed in the respective requirement subclause.
4.4 Base station classes for AAS BS
The requirements in the present document apply to AAS BS of Wide Area BS, Medium Range BS and Local Area BS classes unless otherwise stated. The associated deployment scenarios and definitions of BS classes are exactly the same for AAS BS with and without connectors.
BS classes for OTA AAS BS 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.
BS classes for hybrid AAS BS are defined as indicated below:
– Wide Area BS are characterized by requirements derived from Macro Cell scenarios. For AAS BS of Wide Area BS class, the minimum coupling loss between any TAB connector and the UE is 70 dB.
– Medium Range BS are characterized by requirements derived from Micro Cell scenarios. For AAS BS of Medium Range BS class, the minimum coupling loss between any TAB connector and the UE is 53 dB.
– Local Area BS are characterized by requirements derived from Pico Cell scenarios. For AAS BS of Local Area BS class, the minimum coupling loss between any TAB connector and the UE is 45 dB.
NOTE: Whenever WA BS is referred in this specification, the NB-IoT Wide Area BS and related requirements as defined in 3GPP TS 36.104 [4], are not applicable for OTA AAS BS, nor for hybrid AAS BS.
4.5 Regional requirements
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. Non‑AAS BS requirements are applicable as defined in the present document. In many cases, such requirements include regional requirements that are implicitly referenced from the present specification, and listed in the specification for the specifications concerned 3GPP TS 25.104 [2], 3GPP TS 25.105 [3], 3GPP TS 36.104 [4] and 3GPP TS 37.104 [5].
Table 4.5-1: List of regional requirements
|
Clause number |
Requirement |
Comments |
|---|---|---|
|
4.6 |
Operating bands and Band Categories |
Some operating bands may be applied regionally. |
|
6.6.2, 9.7.2 |
Occupied bandwidth and OTA Occupied bandwidth |
The requirement may be applied regionally. There may also be regional requirements to declare the Occupied bandwidth according to the definition. |
|
6.6.4, 9.7.4 |
Spectrum emission mask and OTA Spectrum emission mask |
The mask specified may be mandatory in certain regions. In other regions this mask may not be applied. Additional spectrum protection requirements may apply regionally. |
|
6.6.5, 9.7.5 |
Operating band unwanted emissions and OTA Operating band unwanted emissions |
Category A or Category B operating band unwanted emissions limits may be applied regionally. |
|
6.6.5, 9.7.5 |
Operating band unwanted emissions and OTA Operating band unwanted emissions |
The BS may have to comply with the applicable emission limits established by FCC Title 47 [15], when deployed in regions where those limits are applied and under the conditions declared by the manufacturer. |
|
6.6.5, 9.7.5 |
Operating band unwanted emissions and OTA Operating band unwanted emissions |
The requirements for protection of DTT may apply regionally. |
|
6.6.5, 9.7.5 |
Operating band unwanted emissions and OTA Operating band unwanted emissions |
Regional requirement as defined in 3GPP TS 37.104, subclause 6.6.2.4.4 [9] may be applied for the protection of systems operating in frequency bands adjacent to band 1 as defined in 3GPP TS 37.104, subclause 4.5, [9] in geographic areas in which both an adjacent band service and UTRA and/or E‑UTRA are deployed. |
|
6.6.5, 9.7.5 |
Operating band unwanted emissions and OTA Operating band unwanted emissions |
Additional requirements defined for Band 24 in 3GPP TS 37.104, subclause 6.6.2.4.5 may apply in regions where FCC regulation applies. |
|
6.6.5, 9.7.5 |
Operating band unwanted emissions and OTA Operating band unwanted emissions |
Additional band 32 unwanted emissions requirements may apply in certain regions |
|
6.6.6, 9.7.6 |
Spurious emissions and OTA Spurious emissions |
Category A limits are mandatory for regions where Category A limits for spurious emissions, as defined in Recommendation ITU-R SM.329 [14] apply. Category B limits are mandatory for regions where Category B limits for spurious emissions, as defined in Recommendation ITU-R SM.329 [14] apply. |
|
6.6.6, 9.7.6 |
Spurious emissions and OTA Spurious emissions |
Additional spurious emissions requirements may be applied for the protection of system operating in frequency ranges other than the AAS BS operating band as described in 3GPP TS 37.104 [9] subclause 6.6.1.3 (NOTE). |
|
6.6.6, 9.7.6 |
Spurious emissions and OTA Spurious emissions |
In addition to 3GPP requirements, the BS may have to comply with the applicable emission limits established by FCC Title 47 [15], when deployed in regions where those limits are applied, and under the conditions declared by the manufacturer. |
|
6.6.6, 9.7.6 |
Spurious emissions and OTA Spurious emissions |
The emission limits specified as the basic limit + X (dB) are applicable, unless stated differently in regional regulation. |
|
6.7, 9.8 |
Transmitter intermodulation and OTA Transmitter intermodulation |
Additional requirements may apply in certain regions. |
|
7.5, 10.6 |
Blocking and OTA Blocking |
For the Public Safety LTE BS in Korea from 718 to 728 MHz in Band 28, regional blocking requirement is specified in TS 36.104 [8], subclause 7.6.3. |
|
7.6, 10.7.4 |
Rx spurious emissions and OTA Rx Spurious emissions |
The emission limits specified as the basic limit + X (dB) are applicable, unless stated differently in regional regulation. |
4.6 Operating Bands and Band Categories
The operating bands and band categories for AAS BS are the same as for non-AAS BS, as described in 3GPP TS 37.104 [5].
NOTE 1: AAS BS does not support GSM, but BC2 is still applicable for protection of and against GSM operation in BC2 operating bands.
NOTE 2: AAS BS does not support Band 46 (and all its sub-bands defined in 3GPP TS 36.104 [8], subclause 5.5) operation nor Band 49 operation, but Band 46 or Band 49 requirements are still applicable for AAS BS for protection of and against Band 46 or Band 49 operation.
4.7 Channel arrangements
The channel arrangements for AAS BS are the same as those for UTRA non-AAS BS, E-UTRA non-AAS BS and NR non-AAS BS as described in 3GPP TS 37.104 [5].
NOTE: Requirements for nominal carrier spacing of 19.8 MHz and 20.1 MHz for carriers in Band 46 as specified in 36.104 [8] subclause 5.7.1, are not applicable for AAS BS.
4.8 Requirements for contiguous and non-contiguous spectrum
A spectrum allocation where an AAS BS operates can be either contiguous or non-contiguous. Unless otherwise stated, the requirements in the present specification apply for AAS BS configured for both contiguous spectrum operation and non-contiguous spectrum operation.
For AAS 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.
4.9 Requirements for AAS BS capable of operation in multiple operating bands
For AAS BS capable of operation in multiple operating bands, the RF requirements in clause 6, 7, 9, and 10 apply separately to each supported operating band unless otherwise stated.
A hybrid AAS BS 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 TAB connectors.
– Different sets of single band TAB connectors support different operating bands, but each TAB connector supports only operation in one single operating band.
– Sets of single band TAB connectors support operation in multiple operating bands with some single band TAB connectors supporting more than one operating band.
– All TAB connectors are multiband TAB connectors.
– A combination of single band sets and multi-band sets of TAB connectors provides support of the hybrid AAS BS 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 certain requirements it is explicitly stated that specific additions or exclusions to the requirement apply at multi-band TAB connectors as detailed in the requirement subclause. When referencing the NR specification 3GPP TS 38.104 [27] for a BS type 1-H the multi-band connector term is equivalent to a multi-band TAB connector in this specification.
In the case of an operating band being supported only by single band TAB 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.
NOTE: Each supported operating band needs to be operated separately during conformance testing on single band TAB connectors.
For a band supported by a TAB connector where the transmitted carriers are not processed in active RF components together with carriers in any other band, TX single band requirements shall apply. For a band supported by a TAB connector where the received carriers are not processed in active RF components together with carriers in any other band, RX single band requirements shall apply.
In the case of an operating band being supported only by multi-band TAB 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 TAB connectors and single band TAB 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 TAB 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.
An OTA AAS BS 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 multiband RIBs.
– A combination of single band RIBs and multi-band RIBs provides support of the OTA AAS BS capability of operation in multiple operating bands.
In certain requirements it is explicitly stated that specific additions or exclusions to the requirement apply at multi-band RIBs as detailed in the requirement subclause.
NOTE: Each supported operating band needs to be operated separately during conformance testing for single RIBs.
For multi-band TAB 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 TAB connectors and multi-band RIBs supporting bands for both FDD and TDD are not covered by the present release of this specification.
A RIB may operate multi-RAT where the individual RATs are operated in different RAT specific bands that partially or fully overlap; ΔfOBUE and ΔfOOB are according to the combined frequency range occupied by the overlapping bands.
4.10 OTA Co-location with other base stations
Co-location requirements are requirements which are based on assuming the AAS BS 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 emissions 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.
NOTE: Due to the low level of the unwanted emissions for the spurious emissions and TX OFF level, co-location is the most suitable method to show conformance.
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 AAS BS and nominal 65° horizontal half-power beamwidth (suitable for 3-sector deployments) and is placed at a distance d from the edge of the AAS BS, as shown in Figure 4.10-1.
Figure 4.10-1 Illustration of AAS BS enclosure and co-location reference antenna
Edge-to-edge separation d, between the AAS BS and the co-location reference antenna shall be set to 0.1 m.
The AAS BS and the co-location reference antenna shall be aligned in a common plane perpendicular to the mechanical bore-sight direction, as shown in figure 4.10-1.
The co-location reference antenna and the AAS can have different width.
The vertical radiating regions of the co-location reference antenna and the AAS 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 AAS BS, 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 AAS BS with dual polarization the co-location reference antenna has two conducted interfaces each representing one polarization.