LTTS-Batch 2_Week1 LTTS-Batch 2_Week1 The number of attempts remaining is 1 1 / 30 1. In the gNB CU/DU functional split, which layers does the CU (Centralized Unit) terminate? a. MAC and PHY b. PHY and RLC c. RRC and PDCP d. RLC and MAC 2 / 30 2. In FDD (Frequency Division Duplex), how are uplink and downlink separated? a. Same frequency, different time slots b. Uplink is disabled entirely c. Same frequency and same time, separated by coding d. Different, paired frequency bands used at the same time 3 / 30 3. What does NSA (Non-Standalone) 5G deployment rely on for control-plane signaling? a. An anchoring LTE eNB, with the NR gNB added as a secondary node (EN-DC) b. A dedicated satellite backhaul link c. A standalone 5G core with no LTE involvement d. Only the NR gNB with no core network 4 / 30 4. What is SRS (Sounding Reference Signal) used for? a. Downlink synchronization only b. Carrying the UE's NAS signaling c. Transmitted by the UE in uplink so the gNB can estimate the uplink channel d. Broadcasting system information 5 / 30 5. What is the main interface between a UE and the RAN called, in both LTE and NR? a. X2 interface b. Uu interface c. S1 interface d. N2 interface 6 / 30 6. In NR numerology, how is subcarrier spacing (SCS) calculated for numerology μ? a. μ × 100 kHz b. 15 × 2^μ kHz c. 15 / 2^μ kHz d. 15 + μ kHz 7 / 30 7. In LTE's E-UTRAN architecture (3GPP TS 36.300), what is the radio base station called? a. eNodeB (eNB) b. gNodeB (gNB) c. NodeB d. Base Transceiver Station (BTS) 8 / 30 8. What is the primary purpose of the PSS (Primary Synchronization Signal) and SSS (Secondary Synchronization Signal)? a. To carry user data b. To carry system information c. To let the UE detect the cell and derive its Physical Cell Identity (PCI) d. To measure uplink interference 9 / 30 9. What does RSRP (Reference Signal Received Power) measure? a. The uplink transmit power of the UE b. The ratio of signal power to total received power including interference c. The number of resource blocks allocated d. The power level of a specific downlink reference signal, used to assess signal strength 10 / 30 10. Which fading model applies when a dominant line-of-sight path exists alongside scattered reflections? a. Rayleigh fading b. AWGN-only channel c. Doppler fading d. Rician fading 11 / 30 11. Which of the following best summarizes the relationship between RAN architecture, frame structure, and link performance? a. They are unrelated and studied independently in real deployments b. Architecture defines how the network is organized, frame structure defines how time/frequency resources are organized, and channel/noise conditions determine how reliably those resources can actually be used c. Frame structure alone determines a network's entire capacity d. Architecture is only relevant to core network engineers, not RAN engineers 12 / 30 12. Which 3GPP specification defines the 5G NR and NG-RAN architecture? a. TS 38.300 b. TS 36.300 c. TS 38.211 d. TS 23.501 13 / 30 13. What is the duration of one subframe in both LTE and NR? a. 10 ms b. 0.5 ms c. 1 ms d. 2 ms 14 / 30 14. What is CSI-RS (Channel State Information Reference Signal) primarily used for? a. To replace the PSS/SSS entirely b. To synchronize UE timing at initial access c. To carry the PBCH payload d. To let the UE measure and report channel quality/state for scheduling and beamforming decisions 15 / 30 15. Which 5GC network function handles user-plane data forwarding? a. AUSF b. AMF c. UPF d. SMF 16 / 30 16. What does SA (Standalone) 5G deployment use for both RAN and core? a. eNB and 5GC b. eNB and EPC only c. gNB and EPC d. gNB and 5GC, with no LTE dependency 17 / 30 17. What does SINR (Signal-to-Interference-plus-Noise Ratio) capture that RSRP alone does not? a. Only the transmit power of the serving cell b. The UE's battery level c. The impact of both interference and noise relative to the desired signal, not just raw signal strength d. The number of active bearers 18 / 30 18. In a modulation scheme comparison, why is QPSK generally more robust to noise than 64QAM? a. QPSK does not use any reference signals b. QPSK's constellation points are farther apart, making it less likely that noise causes a decoding error c. QPSK uses more bits per symbol d. QPSK requires a wider bandwidth 19 / 30 19. What is the primary purpose of the cyclic prefix (CP) in an OFDM symbol? a. To increase transmission power b. To reduce the number of subcarriers c. To combat inter-symbol interference caused by multipath delay spread d. To encrypt the payload 20 / 30 20. What does the SSB (SS/PBCH Block) consist of? a. PSS, DMRS, and CSI-RS b. SRS, PBCH, and PDCCH c. PSS, SSS, and PBCH d. PDSCH, PDCCH, and PBCH 21 / 30 21. What causes multipath fading in a wireless channel? a. Excessive transmit power b. Multiple reflected/scattered copies of the same signal arriving at different times and combining constructively or destructively c. Using too many subcarriers d. A single, unobstructed line-of-sight path 22 / 30 22. Which fading model applies when there is no dominant line-of-sight path, only scattered reflections? a. Rician fading b. Free-space path loss c. Rayleigh fading d. Log-normal shadowing 23 / 30 23. Why does a link experiencing Rayleigh fading typically need a higher SNR than an AWGN-only link to achieve the same BER? a. Rayleigh fading only affects the transmitter, not the receiver b. AWGN channels always have lower bandwidth c. Fading adds additional error events beyond thermal noise alone, requiring extra margin to reach the same BER d. Rayleigh fading eliminates thermal noise entirely 24 / 30 24. Which 5GC network function is primarily responsible for UE mobility and registration management? a. UPF b. SMF c. AMF d. UDM 25 / 30 25. Which core network architecture does LTE use? a. IMS only b. NGC (Next Generation Core) c. EPC (Evolved Packet Core) d. 5GC (5G Core) 26 / 30 26. What is one key architectural motivation for moving from LTE to 5G NR? a. Supporting significantly higher data rates, lower latency, and massive device density b. Removing the need for mobility management c. Using only licensed spectrum below 1 GHz d. Eliminating the need for a core network entirely 27 / 30 27. What is a modulated waveform's constellation diagram primarily used to visualize? a. The frequency spectrum only b. The amplitude and phase state of each transmitted symbol c. The core network topology d. The physical antenna layout 28 / 30 28. How many subframes make up one LTE radio frame? a. 20 b. 10 c. 14 d. 5 29 / 30 29. Which frequency range does FR2 cover in 5G NR? a. 1-2 GHz only b. Below 1 GHz c. Below 6 GHz d. Roughly 24.25-52.6 GHz 30 / 30 30. Which interface connects the gNB-CU to the gNB-DU? a. X2 b. F1 c. Xn d. NG Your score is
