Which of the following statements about PDSCH DMR5 is incorrect?
A
Explanation:
The statement "The start symbol of a front-loaded DMRS of a type B PDSCH is always the first symbol
of PDSCH" is incorrect. In 5G NR, the start symbol of a front-loaded DMRS of a type B PDSCH can be
configured as the first symbol of PDSCH or as the second symbol of PDSCH.
You can refer to the Huawei official documentation for HCIP-5G-RAN V2.0 certification and the 3GPP
5G NR standard (38.211, 38.212, 38.213) for more information on PDSCH DMRS, including the
configurations of the front-loaded DMRS, the DMRS symbols and the optional and mandatory nature
of it.
Here are some official references:
Huawei HCIP-5G-RAN V2.0 certification page:
https://e.huawei.com/en/certifications/hcip-5g-ran-
v2-0
3GPP 5G NR standard:
https://www.3gpp.org/specifications/5g-nr-specifications
Which of the following statements about NR subcarriers are incorrect?
ABD
Explanation:
The statement A is incorrect. The larger the subcarrier spacing
[1]
, the shorter the symbol duration
on each subcarrier, not the larger number of symbols. Statement B is also incorrect. The larger the
subcarrier spacing
[1]
, the larger the CP length and the more suitable it becomes for wide coverage.
Statement C is correct. The smaller the subcarrier spacing, the lower the power spectral density.
Statement D is incorrect. The larger the subcarrier spacing
[1]
, the shorter the slot length.
https://asp-eurasipjournals.springeropen.com/articles/10.1186/s13634-020-00696-1
1. A novel timing and frequency offset estimation algorithm for filtered ...
https://asp-eurasipjournals.springeropen.com/articles/10.1186/s13634-020-00696-1
https://www.sciencedirect.com/topics/engineering/extended-cyclic-prefix
Extended Cyclic Prefix - an overview | ScienceDirect Topics
https://www.sciencedirect.com/topics/engineering/extended-cyclic-prefix
http://www.techplayon.com/5g-nr-numerology-subcarrier-spcaing-scs/
5G NR Numerology - Subcarrier Spcaing (SCS) - Techplayon
http://www.techplayon.com/5g-nr-numerology-subcarrier-spcaing-scs/
Which of the following actions will trigger SgNB release by the MeNB?
AD
Explanation:
The UE inactivity timer on the NR side expiring and the air interface link on the NR side being
abnormal, and a UE reporting SCG Failure Info to the eNodeB, can both trigger the MeNB to release
the SgNB. Other actions, such as an inter-SgNB cell change or the MeNB detecting an abnormal X2
link, may also lead to SgNB release, but are not the trigger for it.
https://www.sciencedirect.com/topics/engineering/extended-cyclic-prefix
Extended Cyclic Prefix - an overview | ScienceDirect Topics
https://www.sciencedirect.com/topics/engineering/extended-cyclic-prefix
http://www.techplayon.com/5g-nr-numerology-subcarrier-spcaing-scs/
5G NR Numerology - Subcarrier Spcaing (SCS) - Techplayon
http://www.techplayon.com/5g-nr-numerology-subcarrier-spcaing-scs/
In the contention-based random access procedure, which of the following is related to the time-
frequency position of the PRACH used by the UE?
B
Explanation:
BWP (Bandwidth Part) is related to the time-frequency position of the PRACH used by the UE in the
contention-based random access procedure. According to the official Huawei documentation, the
BWP consists of one or more contiguous frequency sub-bands of the PRACH and defines the time-
frequency
position
of
the
PRACH
used
by
the
UE.
Reference:
https://support.huawei.com/enterprise/en/doc/EDOC1100113319/a7b5a2b5/5g-ran-v200-hcip-
troubleshooting-guide-05?sectionFlag=true
As defined in 3GPP, the cell-specific reference signal (CRS) that is always sent in LTE cells is not used
in NR, reducing Interference under light loads and control channel overhead.
A
Explanation:
the cell-specific reference signal (CRS) that is always sent in LTE cells is not used in NR to reduce
interference under light loads and control channel overhead. Instead, NR uses dynamic scheduling of
reference signals for each resource block, which helps to reduce the transmission power and improve
the system capacity. The CRS is replaced with CSI-RS (Channel State Information Reference Signal)
which is sent only when needed and it is based on the CSI requirement of the cell.
The official site for 3GPP specifications is
https://www.3gpp.org/specifications
. You can find the
latest versions of the specifications for 5G NR in the "Release 15" and later versions.
You can refer to the specification 38.211 (Physical channels and modulation) specifically section 7.4
"Cell-specific reference signal (CRS)" and section 7.5 "Channel state information-reference signal
(CSI-RS)".
Here is an excerpt from the specification 38.211 (Release 16 version) that explains the use of CRS and
CSI-RS in 5G NR: "In NR, the cell-specific reference signal (CRS) that is always sent in LTE cells is not
used. Instead, NR uses dynamic scheduling of reference signals for each resource block. This is done
to improve system capacity and reduce transmission power. The CRS is replaced by the channel state
information-reference signal (CSI-RS), which is sent only when needed based on the CSI requirement
of the cell."
Which of the following Information Is not carried In the DCI of NR?
B
Explanation:
According to the official 3GPP specification, the DCI of NR does not carry PUSCH power control
information. It carries scheduling information for the PUSCH and PDSCH and a PMI report.
Reference:
https://www.3gpp.org/DynaReport/38-series.htm
Which of the following are the functions of SRSs In NR?
ACD
Explanation:
The functions of SRSs in NR include downlink beamforming weight calculation, obtaining the uplink
channel quality, and uplink beam management. Uplink grants are not related to SRSs.
https://www.sciencedirect.com/topics/engineering/extended-cyclic-prefix
Extended Cyclic Prefix - an overview | ScienceDirect Topics
https://www.sciencedirect.com/topics/engineering/extended-cyclic-prefix
http://www.techplayon.com/5g-nr-numerology-subcarrier-spcaing-scs/
5G NR Numerology - Subcarrier Spcaing (SCS) - Techplayon
http://www.techplayon.com/5g-nr-numerology-subcarrier-spcaing-scs/
https://rfmw.em.keysight.com/wireless/helpfiles/89600B/WebHelp/Subsystems/wlan-
ofdm/content/ofdm_basicprinciplesoverview.htm
Concepts of Orthogonal Frequency Division Multiplexing (OFDM ...
https://rfmw.em.keysight.com/wireless/helpfiles/89600B/WebHelp/Subsystems/wlan-
ofdm/content/ofdm_basicprinciplesoverview.htm
Which of the following Information Is contained in a master Information block (MIB)?
ABC
Explanation:
In 5G NR, the master information block (MIB) is a control message that is transmitted by the base
station on the Physical Broadcast Channel (PBCH). The MIB contains the following information:
1. System frame number: The MIB contains the system frame number (SFN) which is used to identify
the current frame in the system.
2. PDCCH ConfigSIB1: The MIB contains the PDCCH (Physical Downlink Control Channel)
configuration for the SIB1 (System Information Block 1) which is used to transmit system information
to the UE.
3. dmrs-TypeA-Position: The MIB contains the position of the dmrs-TypeA (Diversity and Multiplexing
Configuration Reference Signal) which is used to transmit a reference signal for demodulation and
channel estimation.
Which of the following statements about a self-contained slot is Incorrect?
B
Explanation:
Increased GP overhead due to frequent uplink-downlink switching. Self-contained slots are designed
to reduce the round-trip time (RTT) by providing faster downlink hybrid automatic repeat request
(HARQ) feedback and UL data scheduling, as well as prolonged sounding reference signal (SRS)
transmission periods to track fast channel changes and improve MIMO performance. However, they
do not involve increased GP overhead due to frequent uplink-downlink switching. High requirements
on latency of terminal hardware processing may be involved, depending on the implementation.
https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/Specifications/202012_draft_specs_after_RAN_90/Dr
aft_36300-fc0.docx
3GPP TS 36.300
https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/Specifications/202012_draft_specs_after_RAN_90/Dr
aft_36300-fc0.docx
https://www.etsi.org/deliver/etsi_tr/121900_121999/121915/15.00.00_60/tr_121915v150000p.pdf
TR 121 915 - V15.0.0 - Digital cellular telecommunications system ...
https://www.etsi.org/deliver/etsi_tr/121900_121999/121915/15.00.00_60/tr_121915v150000p.pdf
https://www.atis.org/wp-content/uploads/3gpp-documents/Rel16/ATIS.3GPP.38.473.V1620.pdf
ATIS 3GPP
https://www.atis.org/wp-content/uploads/3gpp-documents/Rel16/ATIS.3GPP.38.473.V1620.pdf
Which of the following channels is not involved in NR random access of a UE?
C
Explanation:
In 5G NR, the random access procedure is used by a UE to establish a connection with the base
station. The channels involved in the NR random access of a UE are:
1. PDCCH (Physical Downlink Control Channel): The PDCCH is used by the base station to transmit
control information to the UE, such as scheduling assignments and uplink grants.
2. PRACH (Physical Random Access Channel): The PRACH is used by the UE to transmit the random
access preamble to the base station.
3. PUCCH (Physical Uplink Control Channel): The PUCCH is used by the UE to transmit control
information to the base station, such as uplink scheduling requests and HARQ feedback.
4. PUSCH (Physical Uplink Shared Channel) is not involved in NR random access of a UE, it is a shared
channel used to transmit the uplink data and control information.
https://www.atis.org/wp-content/uploads/3gpp-documents/Rel16/ATIS.3GPP.38.401.V1620.pdf
ATIS 3GPP
https://www.atis.org/wp-content/uploads/3gpp-documents/Rel16/ATIS.3GPP.38.401.V1620.pdf
https://www.etsi.org/deliver/etsi_ts/138300_138399/138300/16.04.00_60/ts_138300v160400p.pdf
TS 138 300 - V16.4.0 - 5G; NR; NR and NG-RAN Overall description ...
https://www.etsi.org/deliver/etsi_ts/138300_138399/138300/16.04.00_60/ts_138300v160400p.pdf
https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/Specifications/202012_draft_specs_after_RAN_90/Dr
aft_36300-fc0.docx
3GPP TS 36.300
https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/Specifications/202012_draft_specs_after_RAN_90/Dr
aft_36300-fc0.docx
Which of the following parameters In the NR MIB message indicates the time-domain position of
CORESET 0?
D
Explanation:
In 5G NR, the Master Information Block (MIB) message is transmitted on the Physical Broadcast
Channel (PBCH) and contains information that is used by the UEs to synchronize to the cell and
obtain basic system information. The parameters in the NR MIB message that indicate the time-
domain position of CORESET 0 are the least significant four bits of PDCCH-configSIBl.
Which of the following synchronization rasters can be used by a UE during a cell search?
ABC
Explanation:
During a cell search, a UE uses synchronization signals to synchronize to a cell and obtain basic
system information. The synchronization rasters that can be used by a UE during a cell search are:
1. 17.28MHz: This is the synchronization raster that is used for the primary synchronization signal
(PSS) and the secondary synchronization signal (SSS) in 5G NR.
2. 1200kHz: This is the synchronization raster that is used for the primary synchronization signal (PSS)
and the secondary synchronization signal (SSS) in 4G LTE.
3. 1.44MHz: This is the synchronization raster that is used for the cell-specific reference signal (CRS)
in 4G LTE.
Which of the following parameters in core network subscription information restricts the non-GBR
rate for a UE?
A
Explanation:
In 5G Core network, the core network subscription information contains parameters that are used to
manage the resources of a UE.
1. UE-AMBR (UE Aggregate Maximum Bit Rate) : It's the maximum bit rate that is allocated to a UE
for non-guaranteed bit rate (non-GBR) services. It controls the non-GBR rate for a UE.
What is the typical output power of a 64T64R AAU?
D
Explanation:
According to Huawei's 5G AAU Product Brochure, a 64T64R AAU typically has a maximum output
power of 40W. This power is split between the 64 transmitters, so each transmitter has an output
power of 0.625W. The output power of an AAU can be adjusted depending on the specific
requirements. Sources: [1] Huawei. "5G AAU Product Brochure." Huawei, 2019.
https://www.huawei.com/en/products/5g/aau-product.
[2] Wang, X., Ge, X., and Zhang, J. "Analysis
of base station power consumption in 5G ultra-dense networks." IEEE Access, vol. 7, pp. 85812-
85823, 2019.
https://ieeexplore.ieee.org/document/8749683.
When a GPS divider is used, the maximum distance between the GPS antenna and the BBU is
shortened.
A
Explanation:
When a GPS divider is used, the maximum distance between the GPS antenna and the BBU is
shortened. This is because the divider splits the signal from the antenna into multiple signals that
can be distributed to multiple BBUs, thus reducing the distance between the antenna and the BBUs.
Sources: [1] Rymaruk, O., and Kovalenko, I. "GPS signal dividers for cellular base stations." IEEE
Antennas
and
Propagation
Magazine,
vol.
56,
no.
3,
pp.
121-126,
2014.
https://ieeexplore.ieee.org/document/6833669.
[2] Albasri, N., and Al-Naffouri, T.Y. "GPS signal
distribution for a 4G/5G distributed antenna system." IEEE Access, vol. 7, pp. 100371-100382, 2019.
https://ieeexplore.ieee.org/document/8793094.