5g Ran2.0 Beam Management

5G RAN2.0 Beam Management

www.huawei.com

Date: May 2018

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Objectives 

Upon completion of this course, you will be able to: 

Describe the purpose and basic principles of the Beam Management feature.



Understand basic functions of scenario-based broadcast beams.



Understand the principles of tilt adjustment.



Understand the basic principles of user-level beam management.



Figure out the parameter configuration of the Beam Management feature.

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Page 2

Contents 1. Beam Management Overview 2. Low-Frequency Beam Management 3. High-Frequency Beam Management

4. Feature Activation 5. Related Monitoring Items

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Page 3

Beam Management Overview …

Digital BF (Baseband)

…

… Analog BF (AAU)

Analog beam

Digital beam

Digital beam tracking Get BF matrix from SRS or PMI feedback.

Analog beam tracking Get BF weights from best beam ID feedback.

UE

UE feedback: best beam ID SRS, or PMI

1 PA drives 3 antennas.

Baseband beamforming

64

RF chain

The figure on the left uses an AAU working on the C-band and supporting 64T64R as an example. For static beams, digital weighting is performed on the baseband part.

PA

RF chain

Massive MIMO can use either static weights or the dynamic weights. • Static weights: weights corresponding to static beams ① The UE provides the SSB index or the CSI-RS index. SSB is short for SS/PBCH block and CSI-RS is short for channel state information-reference signal. ② The gNodeB obtains the static beam weight by using the mapping relationship between the index and the beam ID. • Dynamic weights: SRS weights or PMI weights (SRS is short for sounding reference signal and PMI is short for precoding matrix indication.) ① The gNodeB obtains SRS weights based on the channel estimation through SRS measurement and obtains PMI weights through the PMI reported by the UE.

PAs

The Beam Management feature covers only static weights, that is, the management of static beams.

PA

Antenna: (8Hx12Vx2P)

Page 4

Beam Management and Its Subitems Cell-level beam management

SSB beam scanning PRACH beam scanning

Beam management User-level beam management

Beam scanning mode Beam maintenance Beam scheduling

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Page 5

SRS beam measurement CSI-RS beam scanning

Contents 1. Beam Management Overview 2. Low-Frequency Beam Management 3. High-Frequency Beam Management

4. Feature Activation 5. Related Monitoring Items

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Page 6

Contents 2. Low-Frequency Beam Management 2.1 Overview 2.2 Scenario-based Broadcast Beams 2.3 Tilt and Azimuth Adjustment 2.4 User-Level Beam Management

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Page 7

Overview Beam Applicability

Beam Type SSB beam

Beam Quantity

Scanning/ Measurement Mode

User-level

Static beam

Application Scope

≤ 8 scenarioSSB beam scanning based beams

No reporting

PBCH/SS; common PDCCH and PDSCH that send SIBs

8 scenarioBeams received by based beams PRACH

Scenario-based beams for the PRACH Four optimal beams are maintained in each of the left and right polarization directions.

Msg1 to Msg5; PDSCH, PDCCH, PUCCH, and PUSCH before SRS measurement result is reported

Cell-level

PRACH beam

Beam Reporting and Maintenance

32 beams

The polarization sequence is not distinguished for beams measured by maintenance SRS in the uplink. Static beams based on The polarization sequence is PDSCH, PDCCH, SRS measurement or distinguished for beams received by PUCCH, PUSCH, and CSI-RS beam maintenance SRS in the downlink or CSI-RS scanning those measured by CSI-RS. Four optimal beams are maintained in each of the left and right polarization directions.

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Page 8

Overview A main framework of beam management includes: beam configuration, beam

scanning/measurement, beam reporting, beam maintenance, and beam usage. For RAN2.0, this document covers the following contents: • Beam configuration: mainly the beam configuration of SSB

• Beam scanning/measurement: mainly the beam scanning of SSB • Beam reporting and maintenance: Beams from the PRACH and SRS are involved based on the reciprocity. Refer to the preceding table, and details are not described in the following pages. • Beam usage: Based on the result of beam maintenance, each channel (PDSCH, PDCCH, PUCCH, PUSCH, and CSI-RS) selects an optimal beam in each TTI.

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Page 9

Uplink Beam Selection Uplink Channel

Beam Type and Quantity (Dual Polarization)

Number of Beams Reported by L1 (for L2 Beam Selection)

Number of Used Beams (Static Weight) MSG2/MSG4 uses one beam in each of the left and right polarization directions. MSG3/MSG5 uses all beams for receiving.

PRACH

Scenario-based beam: 16

4 optimal beams in each of the left and right polarization directions

SRS

64 (64 T, 8 x 4 x 2) 32 (32T)

64 (64 T, 8 x 4 x 2) 32 (32T)

8 beams (for TA and 3I measurements)

N/A

According to the beams reported by the SRS/PRACH, L2 selects: PUCCH: 8 narrow beams

N/A

According to the beams reported by the SRS/PRACH, L2 selects: 16 narrow beams (8 beams are used for TA and Doppler measurements.)

PUCCH

PUSCH

16

16

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Page 10

Downlink Beam Selection Downlink Channel

CSI-RS

Beam Type and Quantity

Narrow: 2/4/8

Transmission

Description

CSI-RS beam scanning and CSI-RS 3I measurement are independent processes. CSI-RS beam scanning is enabled only when the SRS static beam measurement is inaccurate or not reported.

According to the beams reported by SRS/CSI-RS, L2 selects: optimal beams in each of the left and right polarization directions. Each port is mapped to a single-polarized beam.

P-SS/S-SS /PBCH/common Narrow or wide: 8 Periodic beam scanning PDCCH/common at most PDSCH/TRS

The PBCH implements beam tracking, optimal beam reporting, beam handover, and cell handover.

User-specific PDCCH

The left and right polarization data is the same.

User-specific PDSCH

Narrow or wide: 2

According to the beams reported by SRS/PRACH/CSI-RS, L2 selects: optimal beams in each of the left and right polarization directions of PRACH/SRS.

Narrow or wide: 2/4/8

According to the beams reported by SRS/PRACH/CSI-RS and the number of streams on PDSCH, L2 selects beams according to the following rules: (1) In PMI weights (the description of transmission beams is the same as that in CSI-RS): The following exists: • 1 beam for each of the left and right polarization directions with 2 antenna ports 1. SRS dynamic weight+RI (8 streams) • 2 beams for each of the left and right polarization directions with 4 antenna ports 2. Static weight (4 streams) • 4 beams for each of the left and right polarization directions with 8 antenna ports 3. PMI+static weight (8 streams) (2) In DFT weights: • 1 beam for each of the left and right polarization directions when the rank is 1 or 2 • 2 beams for each of the left and right polarization directions when the rank is 4

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Page 11

Beams SSB/PRACH Beams

0/8

1/9

2/10 3/11 4/12 5/13 6/14 7/15

Note: Different colors indicate different beam IDs. SSB uses a maximum of eight beams. PRACH uses eight beams. The beam distributions vary with scenarios.

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Static Beams (SRS/CSI-RS)

24/56 25/57 26/58 27/59 28/60 29/61 30/62 31/63 16/48 17/49 18/50 19/51 20/52 21/53 22/54 23/55 8/40

9/41

10/42 11/43 12/44 13/45 14/46 15/47

0/32

1/33

2/34

3/35

Page 12

4/36

5/37

6/38

7/39

Contents 2. Low-Frequency Beam Management 2.1 Overview 2.2 Scenario-based Broadcast Beams 2.3 Tilt and Azimuth Adjustment 2.4 User-Level Beam Management

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Page 13

2. Broadcast Beams 

5G NR improves the broadcast mechanism based on wide beams in the LTE era and uses narrow beam scanning in polling mode to cover the entire cell. The purpose of beam management is to properly design narrow beams and select appropriate time-frequency resources to transmit narrow beams.



Narrow beams can: 

Direct the emitted energy at target users, increasing the demodulation signal-tonoise ratio (SNR) of target users and improving the transmission success rate.

Narrow beams are especially suitable for high frequencies. 

Improve the system coverage and the coverage of control channels, increasing the cell radius.

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Page 14

2.1 Broadcast Channel Narrow Beams NR broadcast beams are N narrow beams with different fixed directions. The broadcast beam coverage of the cell is completed by sending different narrow beams at different moments. By scanning each narrow beam, the UE obtains an optimal beam, and completes synchronization and system message demodulation. #0 #1 #2 . . . #N-3 #N-2 #N-1 Time 

For the initial cell search, the transmission period of the SSB is 20 ms and each transmission is complete within 5 ms.



The PBCH period is 80 ms, and the SSB is transmitted by four times within 80 ms.



There are a maximum of eight low-frequency SSBs.

2.2 Scenario-based Broadcast Beams Broadcast beams can be used in various scenarios, such as buildings and squares.

In square scenarios, wide beams are used at the cell center to ensure the access. Narrow beams are used at the cell edge to improve coverage.

For high-rise buildings, beams with wide vertical coverage are used to improve the vertical coverage.

Massive MIMO cell

In business districts, there are both squares and high-rise buildings. Beams providing large horizontal and vertical coverage are used. Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Neighboring cell

In inter-cell interference scenarios, beams with narrow horizontal scanning scope are used to avoid strong interference sources. Page 16

Pattern

Horizontal HPBW

0

Vertical HPBW

Tilt (°)

64T

Azimuth (°)

Default scenario (DEFAULT)

32T (16H2V) 32T (8H4V)

Application Scenario

H105V6 Tilt: –2 to 9 Azimuth: 0

H105V6 Tilt: –2 to 9 Azimuth: 0

H65V12 Tilt: 0 to 6 Azimuth: 0

This scenario is a common and default scenario using typical 3-sector networking, and applies to squares.

1

110°

6°

–2 to 9

0

Y

Y

N

This scenario uses nonstandard 3-sector networking to provide wide horizontal coverage, and applies to squares as well as large and wide buildings. The horizontal coverage area in this scenario is larger than that in scenario 2. The coverage near the cell center in this scenario is slightly poorer than that in scenario 2.

2

90°

6°

–2 to 9

–10 to 10

Y

N

N

This scenario uses nonstandard 3-sector networking. When strong interference sources exist in neighboring cells, the horizontal coverage of a cell can be narrowed down to mitigate the interference from neighboring cells. This scenario applies to low-floor coverage since the vertical coverage scope is small.

3

65°

6°

–2 to 9

–22 to 22

Y

N

Y

This scenario uses nonstandard 3-sector networking. When strong interference sources exist in neighboring cells, the horizontal coverage of a cell can be narrowed down to mitigate the interference from neighboring cells. This scenario applies to low-floor coverage since the vertical coverage scope is small.

4

45°

6°

–2 to 9

–32 to 32

Y

N

N

This scenario applies to low-rise buildings and hotspot coverage.

5

25°

6°

–2 to 9

–42 to 42

Y

N

N

This scenario applies to low-rise buildings and hotspot coverage.

6

110°

12°

0 to 6

0

Y

Y

N

This scenario uses nonstandard 3-sector networking and provides relatively large horizontal coverage and middle-floor coverage

7

90°

12°

0 to 6

–10 to 10

Y

Y

N

This scenario uses nonstandard 3-sector networking. When strong interference sources exist in neighboring cells, the horizontal coverage of a cell can be narrowed down to mitigate the interference from neighboring cells. This scenario applies to middle-floor coverage since the vertical coverage scope is large.

8

65°

12°

0 to 6

–22 to 22

Y

Y

N

This scenario uses nonstandard 3-sector networking. When strong interference sources exist in neighboring cells, the horizontal coverage of a cell can be narrowed down to mitigate the interference from neighboring cells. This scenario applies to middle-floor coverage since the vertical coverage scope is large.

9

45°

12°

0 to 6

–32 to 32

Y

N

N

This scenario applies to middle-rise buildings and hotspot coverage.

10

25°

12°

0 to 6

–42 to 42

Y

N

N

This scenario applies to middle-rise buildings and hotspot coverage.

11

15°

12°

0 to 6

–47 to 47

Y

N

N

This scenario applies to middle-rise buildings and hotspot coverage.

12

110°

25°

6

0

Y

Y

N

This scenario uses nonstandard 3-sector networking and provides relatively large horizontal coverage and high-floor coverage.

13

65°

25°

6

–22 to 22

Y

Y

Y

This scenario uses nonstandard 3-sector networking. When strong interference sources exist in neighboring cells, the horizontal coverage of a cell can be narrowed down to mitigate the interference from neighboring cells. This scenario applies to high-floor coverage since the vertical coverage scope is the largest (among these scenarios).

14

45°

25°

6

–32 to 32

Y

Y

N

This scenario applies to high-rise buildings and hotspot coverage.

–42 to 42

Y

Y

N

This scenario applies to high-rise buildings and hotspot coverage.

–47 to 47

Y

N

N

This scenario applies to high-rise buildings and hotspot coverage.

15

25°

25°

6

16

15°

25°

6

Note: It is recommended that the cell be deactivated before modifying the coverage scenario of broadcast beams. Otherwise, the cell will be reestablished after the modification. Three patterns of 8H4V products do not support azimuth adjustment.

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Page 17

 Generally, the default scenario is recommended and is applicable to typical 3sector networking.  If the requirements for horizontal coverage are high, it is recommended that scenario 1, 6, or 12 be used. In this case, cell edge UEs can obtain higher beam gains and the coverage at the cell edge is improved.  If a fixed interference source exists at the cell edge, scenario 2, 3, 7, 8, 9, or 13 can be used to narrow the horizontal coverage area and avoid the interference.  When only isolated buildings exist, scenario 4, 5, 9, 10, 11, 14, 15, or 16 is recommended to provide small horizontal coverage. These scenarios are not suitable for continuous networks.  When only low-rise buildings exist, you can select a scenario from scenarios 1 to 5.  When middle-rise buildings exist, you can select a scenario from scenarios 6 to 11.  When high-rise buildings exist, you can select a scenario from scenarios 12 to 16.

The following key parameters are used to select a scenario: • h: site height • d: distance between the UE and the base station • α: beam scanning range • Direction of the normal line For example, the 64T 10 dB beamwidth is 45°, and the normal direction of the beams is horizontal. Assuming that the distance between the building and the base station is 70 m and the base station height is 25 m, the beams can cover floors below 54 m vertically. The horizontal coverage range can be calculated similarly. In actual networking, both horizontal and vertical ranges must be considered. Height of covered floors = 25 + 70 x tan(22.5°) ≈ 54 m

≈ 30 m

25 m

α = 45°

Horizontal normal line 25 m

h = 25 m

d = 70 m

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Page 18

Contents 2. Low-Frequency Beam Management 2.1 Overview 2.2 Scenario-based Broadcast Beams 2.3 Tilt and Azimuth Adjustment 2.4 User-Level Beam Management

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Page 19

2.3 Tilt and Azimuth Adjustment To reduce the difficulty in site selection planning and site optimization and to save optimization and coordination costs, remote downtilt adjustment is required. The tilts and azimuths of broadcast channel narrow beams can be entirely adjusted in the unit of 1°through the parameter setting. In scenarios where the interference from neighboring cells is severe, users can adjust the tilt and azimuth to make the beams target at users in the local cell. This reduces the overlapped coverage in neighboring cells. In addition, more beam directions can be achieved by adjusting the tilt and azimuth, meeting different coverage

requirements and implementing flexible networking.

The beam gain is the greatest when the preset downtilt is used.

The beam gain decreases when the preset downtilt is not used.

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The beam gain is the greatest when the preset azimuth is used.

Page 20

Part of the beam gain decreases when the preset azimuth is not used.

2.3 Tilt and Azimuth Adjustment Tilt adjustment is not supported (in scenarios 12 to 16) because the vertical scanning range has reached the upper limit. Azimuth adjustment is not supported (in scenarios 0, 1, 6, and 12) because the horizontal scanning range has reached the upper limit. The adjustment range is based on the parameter setting. Then, the parameter is substituted into the steering vector. The steering vector is multiplied by the initial weight matrix to obtain the final steering vector, which is then sent to the baseband part. Note: Only the maximum adjustment capability is provided here. In actual situations, when the tilt is adjusted to a certain degree, the side lobe suppression may not be sufficient. The adjustment range varies according to the specific requirements. If the upper side lobe meets the suppression requirement of 12 dB, the preset downtilt (6°) is used as the reference. For digital RET, the increase range is 8° and the decrease range is 3°. 

The tilt adjustment range in scenarios 1 to 5 (with a vertical 3 dB beamwidth of 6°) is –2°to 9°.



The tilt adjustment range in scenarios 6 to 11 (with a vertical 3 dB beamwidth of 12°) is 0° to 6°.

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Page 21

Contents 2. Low-Frequency Beam Management 2.1 Overview 2.2 Scenario-based Broadcast Beams 2.3 Tilt and Azimuth Adjustment 2.4 User-Level Beam Management

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Page 23

2.3 User-Level Beam Management SRS-based Static Beam Measurement •

•

Obtain an optimal beam through SRS static beam measurement on the base station side.

It is applicable to reciprocal channels when SRS channel quality near or at the cell center is good.

•

•

SRS static beam measurement The SRS beam quality of UEs at the cell edge is poor.

CSI-RS Beam Scanning Obtain an optimal beam through the scanning on the UE side and feedback of CSI-RS beams. It is used when the SINR of the SRS at the cell edge is low.

Aperiodic

Periodic

SRS

√

√ (40 ms)

CSI-RS

√

N/A

CSI-RS scanning

Aperiodic: priority-based scheduling

√

CSI-RS 10 ms: four times SRS 10 ms: four times

Proper beams cannot be selected for UEs at the cell edge due to poor SRS channel quality. √ Proper beams are selected for UEs at the cell center.

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Proper beams are selected for UEs at the cell edge.

Page 24

Contents 1. Beam Management Overview 2. Low-Frequency Beam Management 3. High-Frequency Beam Management

4. Feature Activation 5. Related Monitoring Items

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Page 25

Contents 3. High-Frequency Beam Management 3.1 Overview 3.2 Broadcast Beams 3.3 Tilt Adjustment 3.4 User-Level Beam Management

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Page 26

Overview Beam Applicability

Beam Type

SSB beam

Beam Scanning/ Quantity Measurement Mode

CSI-RS beam

21

SSB beam scanning

21

Beams received by PRACH

One-to-one mapping is performed between the beams received by PRACH and SSB beams and the beams are received by PRACH at fixed positions.

Msg3 and Msg5; PUCCH and PUSCH before the SRS measurement is reported

60

CSI-RS beam scanning

Aperiodic beam scanning: Several beams near the optimal beam are selected for scanning. After DCI scheduling is performed, the beam is reported along with the PUSCH. A maximum of four CSIs and RSRPs can be reported. Each TRX maintains a set of four optimal beams.

PDSCH, PDCCH, and CSI-RS

60

Beams received by SRS

The optimal beam set maintained in the downlink is used as an input, and is scanned again by using an SRS, and is sorted again.

PUCCH and PUSCH

User-level

SRS beam

Application Scope

Initial access phase: One optimal beam is maintained in both the left and right polarization directions. Connected mode: Periodic scanning is implemented. After DCI scheduling is performed, only one optimal beam is reported along with the PUSCH. Filtering is performed for the beam together with the optimal beam set maintained by user-level CSI-RS.

Cell-level

PRACH beam

Beam Reporting and Maintenance

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Page 27

SSB, common PDCCH and PDSCH sending SIB, Msg2, and Msg4 After a UE accesses the network, the optimal beam for periodic level-1 scanning can also be used by the PDCCH, PDSCH, or CSI-RS.

Beam Management Process

SSB beam scanning

PRACH beam scanning

P1: Periodic SSB beam scanning is implemented on the base station side. At the same time, wide beam scanning is implemented on the UE side.

CSI-RS beam measurement

SRS beam measurement

Beam maintenance

P2: Precise CSI-RS beam scanning is implemented on the base station side.

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Beam recovery

P3: Narrow beam scanning is implemented on the UE side.

Page 28

Beam Management Process Step 1

Step 3

Step 2

The base station sends celllevel narrow beams through SSB polling.

Step 15 The base station sends downlink beams according to information reported by the UE, and delivers specific DCI to the UE.

The UE uses wide beam scanning to determine the optimal receive wide beam.

PRACH scanning is used to obtain the optimal PRACH beam and the optimal SSB beam is implicitly carried.

Step 14

Step 13

The UE sends a beam recovery request (similar to PRACH) to the base station according to the candidate beams.

The upper layer instructs the UE to perform the latest available beam measurement, and selects candidate beams.

Step 4

Step 5

RAR and MSG4 use the optimal SSB beam.

MSG3 and MSG5 use the same PRACH beam.

Step 6

The UE in the connected mode actively triggers SSB reporting. Then, periodic SSB measurement is performed.

Step 7

Step 8

Configure CSIRS secondary beam scanning to indicate the optimal beams of the PDCCH and PDSCH.

The UE side uses the corresponding wide beam to receive signals, and measures and reports the CRI and RSRP corresponding to the optimal beam on the base station side.

Step 12

Step 11

Step 10

Step 9

The UE fails to detect the beams and sends an indication to the upper layer.

The base station sends cell-level narrow beams through SSB polling. (Repeat step 1.)

The UE selects the optimal narrow beams, the base station maintains the optimal beam set, and the uplink and downlink beam sets are maintained separately.

The base station uses the SRS to measure the optimal beam set maintained in the downlink and selects the optimal beams for the PUCCH and PUSCH.

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Page 29

Contents 3. High-Frequency Beam Management 3.1 Overview 3.2 Broadcast Beams 3.3 Tilt Adjustment 3.4 User-Level Beam Management

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Page 30

Broadcast Channel Narrow Beams Broadcast beams are N narrow beams with different fixed directions. The broadcast beam coverage of the cell is completed by sending different narrow beams at different moments. By scanning each narrow beam, the UE obtains an optimal beam, and completes synchronization and system message demodulation. #0 #1 #2 . . . #N-3 #N-2 #N-1 Time 

 

For the initial cell search, the transmission period of the SSB is 20 ms and each transmission is complete within 5 ms. The PBCH period is 80 ms, and the SSB is transmitted by four times within 80 ms. There are a maximum of 64 high-frequency SSBs.

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Page 31

Contents 3. High-Frequency Beam Management 3.1 Overview 3.2 Broadcast Beams 3.3 Tilt Adjustment 3.4 User-Level Beam Management

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Page 32

Tilt Adjustment in High Frequency Bands Due to architecture factors, the 19A version does not support dynamic weights. Therefore, approximate downtilt adjustment can be implemented by deleting beams. The tilt adjustment range supported by high frequency bands is 0° to 30°. • • • • •

For downtilt from 26.25° to 30°: Delete four layers of beams. For downtilt from 18.75° to 26.25°: Maintain one layer of beams at the cell center. For downtilt 18.75° to 11.25°: Delete two layers of beams at the cell edge. For downtilt 11.25° to 3.75°: Delete one layer of beams at the cell edge. For downtilt from 0° to 3.75°: No beams are deleted.

As shown in the preceding figures, if the downtilt adjustment range is 3.75°, beams of the outmost layer are deleted. Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Page 33

Contents 3. High-Frequency Beam Management 3.1 Overview 3.2 Broadcast Beams 3.3 Tilt Adjustment 3.4 User-Level Beam Management

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Page 34

User-Level Beam Management gBS/UE rough sweeping (Step-1):

gNodeB uses SSB for celllevel wide beam sweeping, and UE receives signals using different wide beams.

gBS precise sweeping (Step-2):

gNodeB uses CSI-RS for narrow beam sweeping, and UE receives signals using the optimal wide beam.

UE precise sweeping (Step-3):

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Page 35

gNodeB uses precise CSIRS beam, and UE receives signals using several narrow beams.

Contents 1. Beam Management Overview 2. Low-Frequency Beam Management 3. High-Frequency Beam Management

4. Feature Activation 5. Related Monitoring Items

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

Page 36

Feature Activation 1. Basic 3D coverage (scenario-based broadcast beams) Parameter Meaning

Parameter ID

Setting Notes

Scenario

By default, only the default scenario is supported. Licenses are required for the configuration of other scenarios. NRDUCellTrpBeam.Coverage Before the configuration, run the DSP NRDUCELLTRP command to Scenario query the scenarios supported by the AAU. Changing the scenario will cause the cell to reset. For low frequencies, it is recommended that this parameter be set to the preset tilt (6°) to obtain the maximum beam gains. For high frequencies, it is recommended that this parameter be set to 0°. Changing the tilt will cause the cell to reset.

Tilt

NRDUCellTrpBeam.Tilt

Azimuth

NRLoCellRsvdParam.Azimuth It is recommended that this parameter be set to 0°.

2. Configuration for user-level beam scanning //Configuring SINR threshold for beam scanning transition from SRS to CSI-RS MOD NRDUCELLRSVDPARAM: NrLocalCellId=1, Rsvd8Param50=-15dB; //Configuring the distance between the beam and the optimal beam for CSI-RS beam scanning MOD NRDUCELLRSVDPARAM: NrLocalCellId=1, Rsvd8Param51=2;

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Page 37

Contents 1. Beam Management Overview 2. Low-Frequency Beam Management 3. High-Frequency Beam Management

4. Feature Activation 5. Related Monitoring Items

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Page 38

Basic 3D Coverage Feature Observation This feature is enabled by default. You can run LST NRDUCELLTRPBEAM command to query the configured beam scenario and tilt. Trace the UE and observe the RSRP corresponding to the optimal beam. Then, determine whether the beam scenario takes effect. For example, if the UE locates at the normal direction of the vertical beam as shown in the following figure, when the H105V6 scenario is changed to the H110V25 scenario, you can observe that the RSRP reported by the UE after the change is higher than the RSRP reported by the UE before the change. The beam ID is also changed from 4 to 3.

2

3

4

5 6

1

2 7

1

0

3

4

5 6

0

H105V6 Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

7

H110V25 Page 39

Beam Management External CHR Cell Tracing Event ID

Recording Mode

0x01008002

Private event | PERIOD_PRIVATE_B Fixed period: 15 real-time stream EAM_TRAFFIC CELL minutes | SIG log

Statistics on downlink service traffic at the MAC layer collected based on beams (including initial transmission and retransmission service traffic, which is calculated based on cell-level beams) (TDD only) For unused beams, this field is set to an invalid value.

0x01008003

Private event | BEAM_NOISE_TRAC Fixed period: 15 real-time stream KING minutes | SIG log

Average and maximum values of beam-based interference (cell-level) (TDD only)

0x01008005

Private event | PERIOD_PRIVATE_B Fixed period: 15 real-time stream EAM_SYN_UE_NUM minutes | SIG log

Number of synchronized UEs using the static beams ID0 to ID127. Each UE is counted only in the optimal beam.

Private period | PERIOD_PRIVATE_U real-time stream E_MEASUREMENT | SIG log

User-defined periodic L2 measurement event in a gNodeB After the event is subscribed, the measurement results of the following will be recorded based on the L2 user instance period. BeamSwitchNum: optimal beam handover times (The optimal beams obtained through TRX sorting are selected on high frequency bands.) CsiRs_Beam1_ID: ID of the first beam reported by the UE (four in total) CsiRs_Beam1_Rsrp: RSRP of the first beam reported by the UE (four in total) Ssb_Beam_ID: ID of the SSB beam reported by the UE Ssb_Rsrp: RSRP of the SSB beam reported by the UE

0x01000003

Event Name

Event Description Event & Parameter Meaning and Parameters

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

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Beam Management-related Monitoring Items (Performance Monitoring) Optimal beam ID and RSRP of each TRX on high frequency bands

Monitoring Item

English Name

Description

TRX0DlOptBeamID

TRX0_DlOptBeamID

Indicates the ID of the optimal downlink beam at the detection reporting time.

TRX0DlOptBeamRsrp

TRX0_DlOptBeamRsrp

Indicates the RSRP corresponding to the optimal downlink beam at the detection reporting time.

TRX0UlOptBeamID

TRX0_UlOptBeamID

Indicates the ID of the optimal uplink beam at the detection reporting time.

TRX0UlOptBeamRsrp

TRX0_UlOptBeamRsrp

Indicates the RSRP corresponding to the optimal uplink beam at the detection reporting time.

Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

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Thinking Question: What's the specific impact of a faulty AAU dipole? Are there any disaster recovery measures? Is it

necessary to replace the entire AAU? Answer: A few faulty channels (64T64R) have limited negative impacts on the performance. The AAU can still be used.

This issue can be handled using an algorithm and setting the weight of damaged channels to zero. However, the orthogonality of the MU must be protected from being affected. An alarm will be generated if the number of faulty channels reaches a specified threshold. In this case, you need to replace the AAU.

If the number of faulty high-frequency channels reaches a specified threshold, an alarm is reported, and 4T is rolled back to 2T. Copyright © 2018 Huawei Technologies Co., Ltd. All rights reserved.

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