O-RAN Interview Questions – Expert Scenario Based (20 Q&A)
This page provides expert-level O-RAN (Open RAN) interview questions covering architecture, SMO, RIC, CU/DU/RU split, open interfaces, real-field integration issues and lab troubleshooting. These questions are designed for RAN Engineers, O-RAN Integration Engineers, System Testers and Telecom Architects.
Conceptual & Architecture Questions
Q1. What is O-RAN and why was it introduced?
O-RAN introduces open, interoperable RAN architecture to break vendor lock-in, enable multi-vendor deployments and accelerate innovation.
Q2. Difference between traditional RAN and O-RAN?
Traditional RAN is vendor-locked with proprietary interfaces, while O-RAN uses open interfaces and disaggregated components.
Q3. What are the main O-RAN components?
SMO, Near-RT RIC, Non-RT RIC, O-CU, O-DU and O-RU are the core O-RAN components.
Q4. Why is disaggregation important in O-RAN?
Disaggregation enables independent scaling, vendor diversity and flexible deployment across cloud and edge.
CU / DU / RU Split Scenarios
Q5. What functional splits are used in O-RAN?
O-RAN supports multiple splits such as 7-2x between O-DU and O-RU and higher-layer splits between O-CU and O-DU.
Q6. Why is fronthaul critical in O-RAN?
Fronthaul carries time-sensitive data between O-DU and O-RU, requiring low latency and strict synchronization.
Q7. What happens if fronthaul latency increases?
Increased latency can cause HARQ failures, throughput degradation and radio instability.
Q8. How is synchronization handled in O-RAN?
Using IEEE 1588v2 (PTP) and Sync-E to meet tight timing requirements.
RIC & SMO Scenarios
Q9. What is the role of Near-RT RIC?
Near-RT RIC enables real-time optimization using xApps for scheduling, mobility and interference management.
Q10. Difference between Near-RT RIC and Non-RT RIC?
Near-RT RIC handles near-real-time control, while Non-RT RIC performs policy management and AI/ML training.
Q11. What is an xApp?
An xApp is a microservice application running on Near-RT RIC to optimize RAN behavior.
Q12. What is the role of SMO?
SMO manages lifecycle, configuration, fault and performance management across O-RAN components.
Real Field & Integration Scenarios
Q13. Multi-vendor O-RAN deployment fails – why?
Interface incompatibility, timing mismatch or configuration inconsistency between vendors.
Q14. How do you troubleshoot E2 interface issues?
Analyze E2 setup messages, latency, subscription failures and RIC logs.
Q15. Throughput drops after xApp deployment – cause?
Incorrect optimization logic, policy conflict or excessive control signaling.
Q16. How do you monitor O-RAN performance?
Using KPIs, telemetry, PM counters and SMO dashboards.
LAB & Hands-On Scenarios
Q17. O-DU starts but O-RU not detected – debug steps?
Check fronthaul configuration, VLANs, timing sync and interface compatibility.
Q18. How do you test xApp functionality in lab?
Simulate traffic scenarios and observe RAN behavior changes via KPIs.
Q19. Lab shows frequent radio link failures – O-RAN angle?
Check fronthaul latency, synchronization drift and DU scheduling behavior.
Q20. How do you design an O-RAN stress test?
Introduce high traffic, multi-vendor load, xApp actions and monitor stability, latency and throughput.
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