H35-580_V2.0 Sample Questions Answers

According to the 5G NR Downlink CSI Reporting, CSI-RS is the channel/signal that is used by the UE to measure and obtain the CQI. CSI-RS stands for Channel State Information Reference Signal, which is a downlink reference signal transmitted by the gNodeB to enable the UE to estimate the channel quality and feedback the CQI to the gNodeB. The CQI is an indicator of how good or bad the channel quality is, and it can be used by the gNodeB to adjust the modulation and coding scheme for data transmission.

A link budget is an accounting of all the power gains and losses that a communication signal experiences in a telecommunication system 8. A link budget can be used to determine the received signal-to-interference-plus-noise ratio (SINR), which is a measure of the quality of the signal at the receiver. The SINR demodulation threshold is the minimum SINR required to demodulate the signal successfully. The SINR demodulation threshold depends on the modulation and coding scheme (MCS) used by the transmitter, which in turn depends on the service rate or data rate required by the application 9. Generally, the higher the service rate, the higher the MCS level, and therefore the higher the SINR demodulation threshold. Thus, statement A is incorrect. The other statements are correct. The interference margin is relatively small on high frequency bands because there are fewer co-channel interferers due to smaller cell sizes 10. The shadow fading margin is related to the edge coverage rate because it accounts for the variation of signal strength due to obstacles in the propagation path 11. The antenna gain of the 64T64R AAU is approximately 24 dBi according to Huawei’s product specifications 12.

According to the HCIA-5G V2.0 Exam Outline, the statements in options A, B, and C are correct descriptions of throughput-related indicators, which correspond to options A, B, and C. The statement in option D is incorrect because adding the last small packet of each data transmission burst and its transmission duration will reduce the accuracy of throughput measurement.

According to the 5G mmWave Frequency Bands, the maximum bandwidth in mmWave bands as defined in 3GPP Release 16 is 400MHz, which can be achieved without any carrier aggregation method.

In order to achieve ideal coverage, there should be a clearance zone around an antenna of at least d, where d is the Fraunhofer or Rayleigh distance at which the near/far-field transition zone exists 17. This distance depends on the largest dimension of the antenna, D, and the operating wavelength, \uF06C. Ideally, D should be at least a half of a wavelength, which gives a minimum clearance zone of a half-wavelength. For example, at 2.4 GHz, the wavelength is about 0.125 m, so the minimum clearance zone is about 0.0625 m. However, in practical situations, this clearance zone is often compromised and the effects must be determined through simulation or empirical measurement 18. A general guideline is to have a clearance zone of 5-10 m around an antenna to avoid significant degradation of performance 19. Therefore, the best answer is C.

According to the 5G NR Protocol Structure Changes - An Overview, the PCFICH and PHICH channels have been deleted from the physical layer in 5G compared with LTE, because they are no longer needed due to the flexible frame structure and numerology of 5G NR.

 According to the 5G NR Uplink Power Control Procedure, SIB2 is the message that contains the PRACH power control parameters, such as msg3-Alpha, p0-NominalWithoutGrant, and p0-AlphaSets. These parameters are used by the UE to determine the transmit power of the PRACH preamble.

According to the Beamforming techniques for massive MIMO systems in 5G, these statements are correct about downlink beamforming. Beamforming is a technique that uses multiple antennas to steer the transmitted signal toward the intended user or direction. Static beams are used for broadcast channels, such as MIB and SIB, which are transmitted to all UEs in a cell. Dynamic beams are used for traffic channels, such as PDSCH and PDCCH, which are transmitted to specific UEs based on their channel conditions and locations. Both broadcast channels and traffic channels support beamforming, but with different beamforming methods and performance requirements.

According to the NR-ARFCN (NR absolute radio frequency channel number), the NR-ARFCN value consists of two components: the band indicator and the channel number. The band indicator represents the frequency band on which the carrier frequency lies, while the channel number represents the specific carrier frequency within that band. The NR-ARFCN value is calculated by the following formula:

NR-ARFCN = FREF-Offs + NREF-Offs + ΔFGlobal * (Fcarrier - FREF-Offs) / AFGIobal

where FREF-Offs is the reference frequency offset, NREF-Offs is the reference NR-ARFCN offset, ΔFGlobal is the global frequency raster, Fcarrier is the carrier frequency, and AFGIobal is the absolute frequency granularity.

Given that AFGIobal is 15 kHz, FREF-Offs is 3000 MHz, and NREF-Offs is 600000, we can plug in these values and Fcarrier = 3300 MHz into the formula and get:

NR-ARFCN = 3000 + 600000 + 5 * (3300 - 3000) / 0.015 NR-ARFCN = 633000

Therefore, the correct answer is A.

To find the number of RBs in a 5G cell, we need to know the bandwidth and the subcarrier spacing of the cell. The bandwidth is the total frequency range allocated for the cell, while the subcarrier spacing is the frequency separation between adjacent subcarriers in the cell. A RB is a group of 12 consecutive subcarriers in the frequency domain 12. Therefore, the number of RBs in a 5G cell can be calculated by dividing the bandwidth by the product of the subcarrier spacing and 12.

Given that the bandwidth is 100 MHz and the subcarrier spacing is 60 kHz, we can use the following formula to find the number of RBs:

Number of RBs = Bandwidth / (Subcarrier spacing * 12) Number of RBs = 100 MHz / (60 kHz * 12) Number of RBs = 100000 kHz / 720 kHz Number of RBs = 138.888…

However, since the number of RBs must be an integer, we need to round it down to the nearest multiple of 3 3. This is because the NR standard defines different frequency ranges for different subcarrier spacings, and each frequency range has a minimum and maximum number of RBs that are multiples of 3 4. For example, for subcarrier spacing of 60 kHz, the frequency range is from 24250.08 MHz to 52600.08 MHz, and the minimum and maximum number of RBs are 66 and 273, respectively.

Therefore, the closest multiple of 3 to 138.888… is 135. However, this number is not valid because it is lower than the minimum number of RBs for subcarrier spacing of 60 kHz. The next valid multiple of 3 is 273, which is also the maximum number of RBs for subcarrier spacing of 60 kHz. Therefore, the correct answer is C. 273.

According to the 5G SA Cell Search & Network Entry Matrix, a UE completes frame synchronization after reading the MIB, not the SS. The SS (Synchronization Signal) is used for initial detection and coarse timing synchronization, but it does not provide enough information for frame synchronization. The MIB (Master Information Block) is part of the SSB (Synchronization Signal Block) and contains essential system information, such as system frame number and subcarrier spacing, which are needed for frame synchronization.

According to the Huawei 5G Base Station Product Description, the following boards support CPU usage query:

• UPEU (Universal Power and Environment Interface Unit): It provides power supply and environment monitoring functions for other boards in a subrack. It supports CPU usage query through commands or web pages.
• UMPT (Universal Main Processing and Transmission Unit): It provides main processing and transmission functions for a subrack. It supports CPU usage query through commands or web pages.
• UBBP (Universal Baseband Processing Unit): It provides baseband processing functions for a subrack. It supports CPU usage query through commands or web pages.

The FAN (Fan Unit) does not support CPU usage query because it does not have a CPU.

According to the Radio Resource Control, the maximum number of RRC_CONNECTED UEs depends on the number of available C-RNTIs (Cell Radio Network Temporary Identifiers) in a cell. The number of C-RNTIs is limited by the size of the RNTI field in the DCI (Downlink Control Information) format. For NR TDD cells, the RNTI field size is 16 bits, which allows up to 65,536 C-RNTIs. For NR FDD cells, the RNTI field size is 14 bits, which allows up to 16,384 C-RNTIs. Therefore, an NR TDD cell can support more RRC_CONNECTED UEs than an NR FDD cell under the same gNodeB.

According to the HCIA-5G V2.0 Exam Outline, in the NSA DC architecture, when a UE moves to a neighboring gNodeB, the SgNB change procedure is triggered, which corresponds to option D.

According to the 5G NR Physical Layer Specifications, demodulation reference signals (DMRSs) are required for the following channels/signals in the downlink and uplink:

• Downlink Physical Broadcast Channel (DPBCH)
• Downlink Physical Downlink Control Channel (DPDCCH)
• Downlink Physical Shared Channel (DPOSCH)
• Uplink Physical Random Access Channel (PRACH)
• Uplink Physical Uplink Control Channel (PUCCH)
• Uplink Physical Uplink Shared Channel (PUSCH)