H35-580_V2.0 Exam Dumps : HCIA-5G-RNP&RNO V2.0

According to the 5G-GUTI - 5G Globally Unique Temporary Identity, the NAS layer uses 5G-GUTI to replace IMSI as the temporary ID of a UE for security reasons. The 5G-GUTI is allocated by the AMF (Core Access and Mobility Management Function) at the time of network registration, and it is composed of the GUAMI (Globally Unique AMF ID) and the 5G-TMSI (5G Temporary Mobile Subscriber Identity).

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.

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.