During an intra-gNB DU handover , what is the role of the RRC Reconfiguration message sent by the gNB- CU to the UE?
Correct Answer: A
The correct answer is A . During an intra-gNB DU handover , the UE is moved from one cell/DU resource to another under the same gNB-CU control. The gNB-CU coordinates the handover preparation and sends an RRC Reconfiguration message to the UE. The role of this message is to provide the UE with the required handover command information, such as: Target PCell configuration Radio resource configuration Mobility control information Random access configuration, when needed Measurement or reconfiguration-related information After receiving the RRC Reconfiguration , the UE performs the handover execution procedure toward the target cell and later responds with RRC Reconfiguration Complete . Option B is incorrect because admission control and source-cell scheduling suspension are internal network- side procedures, not the UE-facing role of the RRC Reconfiguration message. Option C is not the best answer because user-plane resource transfer is handled between gNB-CU/gNB-DU functions, while dedicated preamble allocation may be part of the configuration but is not the main purpose of the message. Option D is incorrect because RLC reestablishment and PDCP recovery are lower-layer/user-plane handling actions, not the primary purpose of the RRC Reconfiguration message. Therefore, the correct role is: It instructs the UE to perform handover to the target PCell and provides measurement/configuration information.
In NR SA Option 2, the UE is camped on an SA serving cell. An IRAT handover is triggered for a multi-QCI call, QCI 1 and QCI 6, due to weak coverage of the serving cell. What will happen to both QCIs during the IRAT handover toward LTE?
Correct Answer: D
The correct answer is D. In 5G SA Option 2, NR works independently with the 5G Core, but interworking with LTE/EPC can be supported for mobility continuity. When IRAT handover toward LTE is triggered due to weak NR coverage, the goal is to preserve the active services during mobility. For a multi-QCI service: QCI 1 normally represents the voice bearer, such as VoLTE/IMS voice continuity after movement to LTE. QCI 6 normally represents a non-GBR data bearer. During a supported IRAT handover from NR SA to LTE, both the voice bearer and data bearer can be transferred to LTE, assuming proper interworking, bearer mapping, and LTE coverage availability. Option C is incorrect because IRAT mobility from NR SA to LTE is supported in properly configured networks. Option A is incorrect because the voice bearer is the most critical bearer to preserve. Option B is also not the best answer because the data bearer does not necessarily need to be released during IRAT handover. Therefore, the expected result is: Both QCI 1 voice and QCI 6 data continue on LTE.
Identify the missing network components X, Y, and Z in the architecture diagram.
Correct Answer: B
The correct answer is B . In the 5G Core , component X is connected to: N2 from NG-RAN N11 toward SMF N15 toward PCF N26 toward the EPC mobility entity These are typical interfaces of the AMF , or Access and Mobility Management Function . Therefore, X = AMF . In the EPC , component Z is connected to: S1-MME from eNB S11 toward the gateway N26 toward the 5GC AMF These are typical interfaces of the MME , or Mobility Management Entity . Therefore, Z = MME . Component Y is outside the core user-plane path and represents the external service network connected through N6/SGi , commonly shown as IMS in voice-service architecture diagrams. Therefore, Y = IMS . So the correct mapping is: X: AMF, Y: IMS, Z: MME.
In the context of mmWave deployments , what is the primary benefit of analog beamforming ?
Correct Answer: A
The correct answer is A . In mmWave systems, beamforming is essential because FR2 signals suffer from high path loss and blockage. Analog beamforming uses fewer RF chains than fully digital beamforming, so it is cheaper and less complex in terms of RF hardware, power consumption, and implementation. Research and industry references explain that analog and hybrid beamforming architectures reduce the number of required ADCs/RF chains compared with fully digital beamforming, lowering cost and power complexity. However, analog beamforming has limitations. It usually forms one beam, or a limited number of beams, at a time from a panel. Supporting multiple independent simultaneous beams and more UEs per sector is more associated with digital or hybrid beamforming, not pure analog beamforming. Therefore, the primary benefit is: Low cost and low complexity for coverage at higher mmWave bands.
The correct answer is B . The prachConfigurationIndex defines the PRACH configuration, including the PRACH time-domain occasions and the associated PRACH format according to the PRACH configuration tables. In 5G NR, PRACH configuration is based on 3GPP-defined PRACH tables, where the configuration index maps to the PRACH format and PRACH occasion structure. The other options have different meanings: A). msg1-FrequencyStart defines the frequency-domain starting position of PRACH occasion resources. C). prachRootSequenceIndex defines the root sequence used for PRACH preamble generation. D). totalNumberOfRAPreambles defines how many random access preambles are available. Therefore, the parameter that defines the PRACH format is: prachConfigurationIndex.
