H35-580_V2.0 Practice Exam Questions and Answers

According to the eCPRI Specification V2, eCPRI links have the following characteristics:

• They require clock synchronization: eCPRI links use Ethernet as the transport layer, which does not provide inherent synchronization. Therefore, eCPRI links require external clock synchronization methods, such as IEEE 1588v2 Precision Time Protocol (PTP) or Synchronous Ethernet (SyncE).
• They are based on the IP mechanism: eCPRI links use IP as the network layer, which provides routing and addressing functions for eCPRI messages. eCPRI links can use either IPv4 or IPv6 protocols.
• They require AAU support: eCPRI links connect between Radio Equipment Control (REC) and Radio Equipment (RE) in a base station. AAU (Active Antenna Unit) is a type of RE that integrates RF and antenna functions in one unit. Therefore, eCPRI links require AAU support to enable flexible functional split options and reduce fronthaul bandwidth requirements.

eCPRI links are not based on the TDM mechanism because they do not use fixed time slots to transmit data. Instead, they use variable-length packets to transmit data according to different service requirements.

According to the Career Certification - Huawei Enterprise, CPU usage and transmission interface measurement are counters that can be measured at the board level, which correspond to options A and

B.  

D.  

According to the 5G EN-DC Architecture and Interfaces, there are two methods that can be used to support X2 interconnection between an eNodeB and a gNodeB in NSA networking:

• Interconnection through CI interfaces on the UMPT boards in different subracks: The UMPT is a universal main processing and transmission unit that provides main processing and transmission functions for a subrack. The UMPT has two CI interfaces that can be used for X2 interconnection with other base stations. The CI interfaces support CPRI, OBSAI, and eCPRI protocols and can use optical fibers or electrical cables for transmission. The CI interfaces can be configured as master or slave interfaces depending on the network topology.
• IPRAN interconnection between subracks: IPRAN is an IP-based radio access network that uses IP transport technologies to carry base station traffic over Ethernet or MPLS networks. IPRAN can support X2 interconnection betweendifferent base stations by using IP routers or switches. IPRAN can provide flexible networking, high bandwidth, low latency, and high reliability for X2 interconnection.

The other two methods are not valid for X2 interconnection between an eNodeB and a gNodeB:

• Interconnection via backplane in a subrack: This method is only applicable for X2 interconnection between two eNodeBs or two gNodeBs that are installed in the same subrack. The backplane is the internal bus that connects different boards within a subrack. The backplane supports CPRI, OBSAI, and eCPRI protocols and can provide high-speed data transmission between boards.
• Interconnection through HEI interfaces on the UBBP boards in different subracks: This method is not supported by Huawei base stations. The HEI interface is a high-speed Ethernet interface that is used for data transmission between base stations and core networks or transport networks. The HEI interface supports S1, Xn, F1, E1, and N2 protocols and can use optical fibers or electrical cables for transmission. The HEI interface cannot be used for X2 interconnection between base stations.

Therefore, the correct answer is A and

D.  

According to the 5G NR Channels, the following logical channels can be mapped to different transport channels in the downlink and/or uplink:

• Common Control Channel (CCCH): It can be mapped to Downlink Shared Channel (DL-SCH) or Uplink Shared Channel (UL-SCH).
• Dedicated Control Channel (DCCH): It can be mapped to DL-SCH or UL-SCH.
• Paging Control Channel (PCCH): It can be mapped to Paging Channel (PCH) or DL-SCH.
• Broadcast Control Channel (BCCH): It can be mapped to Broadcast Channel (BCH) or DL-SCH.