Free Practice Questions for Huawei H35-481_V2.0 Exam

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."

In Non-standalone (NSA) networking, X2 self-setup between a gNodeB and an eNodeB requires that the gNodeB and eNodeB be managed by the same OSS. Because gNodeB and eNodeB are managed by the same OSS, the OSS can configure the X2 self-setup parameters, such as the X2 self-setup switch, the X2 interface IP address, and the X2 self-setup trigger conditions. Only when the gNodeB and eNodeB are managed by the same OSS and configured with the same X2 self-setup parameters, the gNodeB and eNodeB can establish an X2 self-setup connection.

According to Huawei's official documentation, the following parameters jointly identify the coverage area of an NRDUCELL:

NRDUCELId

NrDuCellTrpId

NRDUCELUd (Source: Huawei 5G Base Station NR-DU Configuration Guide)

The base station is in a Holdover state when the dock of a base station is locked and the base station fails to obtain clock source signals. Holdover is a state during which the base station uses the last known frequency and time information to maintain synchronization and clock accuracy. According to the Huawei official documentation, "when the clock source is lost, the base station enters the holdover state. In the holdover state, the base station uses the last known frequency and time information to maintain synchronization and clock accuracy. Holdover time is the duration for which the base station can maintain synchronization after the clock source is lost."

When the main control board of a gNodeB is replaced, the Equipment Serial Number (ESN) of the gNodeB also changes. The ESN is a unique identifier of the gNodeB that is programmed into the main control board and is used to identify the specific gNodeB in the network. So when the main control board is replaced, the ESN also changes.

The destination address route configuration is not applicable when multiple IP addresses with different next hop addresses are planned for the gNodeB. Destination address route configuration is used when a single IP address is used by the gNodeB and the next hop address and outgoing interface do not need to be configured. In the case of multiple IP addresses with different next hop addresses, direct route configuration should be used. Direct route configuration requires that the IP address, next hop address, and outgoing interface all be specified for each IP address.

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.

Extended Cyclic Prefix - an overview | ScienceDirect Topics

https://www.sciencedirect.com/topics/engineering/extended-cyclic-prefix

5G NR Numerology - Subcarrier Spcaing (SCS) - Techplayon

http://www.techplayon.com/5g-nr-numerology-subcarrier-spcaing-scs/

Concepts of Orthogonal Frequency Division Multiplexing (OFDM ...

https://rfmw.em.keysight.com/wireless/helpfiles/89600B/WebHelp/Subsystems/wlan-ofdm/content/ofdm_basicprinciplesoverview.htm

According to Huawei official documentation, When the RUN indicator of an AAU is blinking green (on for 1s and off for 1s), it means that the software is being loaded to the board, or the board is not started.

Interconnection through RF modules (A) is also a supported solution for X2 interconnection between LTE and NR base stations. In this solution, the LTE and NR base stations are connected through RF modules, allowing them to share the same frequency band and resources. This solution is particularly useful for scenarios where there is a need for seamless interworking between LTE and NR networks, such as in the early stages of 5G deployment.