LTE Attach Procedure Interview Questions

Q01. Which layer carry Attach Request Message in up-link direction?
Q02. What are the information elements are presents in attach request message?
Q03. How UE get PDN connectivity request?
Q04. What is the timer of Attach message? And it duration?
Q05. What is the meaning of EPS Mobility Management(EMM) and what kind of information it carry?
Q06. In which case UE carry IMSI or GUTI? Elaborate them?
Q07. What are the Information Element are present in Authentication Request Message?
Q08. What are the Information Element are present in Security Mode Command?
Q09. Suppose IMSI and GUTI both are not available, then what UE will do?
Q10. How UE calculate Authentication Token and Random Value?
Q11. Why Security Mode Command are using 2 times in Attach Procedure?
Q12. What is the difference between Attach Request, Attach Accept and Attach Complete? And in which messages these information's is present?
Q13. What is difference between Radio Bearer and EPS Bearer?
Q14. How many Radio Bearers are uses in LTE?
Q15. How many EPS Bearers are uses in LTE?
Q16. Which type of Attach Procedure UE will do to utilize IMS Services?
Q17. What are the information elements present in Initial Context Setup and which message is using?
Q18. Once UE send Attach Request toward EnodeB then how EnodeB identified the particular MME?
Q19. Attach Failure Causes?
Q20. Detach call flow(Procedure)?
Q21. Who generate IP address for UE? In which message UE get this IP address?
Q22. How many maximum IP addresses a UE can have in lte?
Q23. How MME select S-Gw and P-Gw in LTE?
Q24. How MME get the PDN address of a specific UE in attach procedure?
Q25. What are the Information Element present in Create Session Request?
Q26. What are the causes of Authentication Failure?
Q27. What are the causes of Security Mode Command Failure?
Q28. What is Service Request?
Q29. What is the difference between Service Request and Extended Service Request?
Q30. The RRC-Connection Re-configuration message receive by UE and send by UE in Attach procedure in Which Signalling Radio Bearer(SRB)?
Q31. What is UE Capability Request,What are the Information Elements present in UE Capability Request?
Q32. Who send Capability Request message to UE, Why Capability Request is transmission in Attach Procedure 2 times?
Q33. How many Default and Dedicated Bearer a UE can establish in LTE?
Q34. What happen to default bearer which is present earlier if UE don’t have DL/UL data?
Q35. Suppose UE have only partial Default Bearer present and suddenly P-Gw receive Downlink Data then how MME re-activate default bearer?

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