LTE RRC Layer Interview Questions and Answers

Q1. What is the full form of RRC Layer? In Telecom Protocol Layer where it exist? 
Q2. What are the functionality of RRC layer?
Q3. How many states UE have in LTE?
Q4. What is the 1st message of RRC Layer, UE sent to network while it move from idle to connected state?
Q5. What is the purpose in RRC connection request?
Q6. How many times UE re transmit RRC connection request if RRC connection setup is failed?
Q7. What are the Information Element are present in RRC Connection Request? And the channel name, RLC mode, SRB?
Q8. What is the 2nd message of RRC Layer? What Information Elements are present in this message, channel name, RLC mode, and SRB?
Q9. In RRC connection setup complete what is the channel name, RLC mode and SRB? Name of NAS message present inside there and Information Elements and timer duration?
Q10. What are the reason/causes of RRC connection reject?
Q11. What are the reason/causes of RRC connection release? And release timer?
Q12. What is MIB and which channel carry the MIB, what information UE get after reading MIB? And size of MIB in Lte?
Q13. How many times System Information should be change? And Parameter responsible for count system information changed how many times?
Q14. In connected state UE move from 1st cell to 2nd cell what are the minimum System Information, Q15. UE need to read while move to next cell?
Q16. UE will 1st read which system frame number to decode MIB Information?
Q17. Is UE listening Paging Information in Idle state Yes/No, if yes then which scenario, explain?
Q18. What information paging message carry and how ue identify it’s Paging information?
Q19. How many types of RRC Messages? And what are timers of these messages?
Q20. Which system frame number UE found SIB?
Q21. How many SIBs are using in LTE? Explain?
Q22. What are the information presents in SIB2 & SIB3?
Q23. Which SIB UE will get the information of random access procedure (RAP)?
Q24. Why be need for the RACH procedure in lte and PRACH?
Q25. What are the difference between RACH and SCHEDULING REQUEST?
Q26. How many PLMN can be carry by a cell?
Q27. What is TTI bundling? what is the difference between TTI bundling and SPS scheduling?
Q28. What are radio resource config.dedicated? What kind of information it carry?
Q29. How many timers present in RRC?
Q30. What is difference between Acceptable, Suitable and Reserved Cell.
Q31. How is state “Camped on Any Cell” different from “Any Cell Selection” state?
Q32. What is CSG cell and CSG whitelist?
Q33. Differentiate HPLMN, EHPLMN, RPLMN.
Q34. What is Hybrid Cell?
Q35. What is difference between Serving Cell and Primary Cell? How many Maximum Serving Cell can be there in total?
Q36. Describe what does UE extract from the PBCH? How do we get to know about antenna Configuration from MIB?
Q37. Describe what does UE get from tuning to PSS?
Q38. Describe what does UE get from tuning to SSS?
Q39. In brief describe (main parameters) what does UE get in SIB1?
Q40. In brief describe what does UE get in SIB2?
Q41. In brief describe what does UE get in SIB3?
Q42. In brief describe what does UE get in PCCH?
Q43. Where is MIB and SIB1 mapped in frame?
Q44. After reading SI (System Information), what is the action by UE before Cell Selection? How does it get the input?
Q45. What is Access Class.? What are special provides by AC 11 and 15?
Q46. In which Idle states Emergency call is possible by AC 0 to 9?
Q47. In Order to select a valid candidate PLMN, what is the minimum signal level(RSRP)? What is the minimum quality(RSRQ)?
Q48. What is the “S” criteria. Specify the minimum value for candidate Cell.
Q49. What is “R” Criteria. What is relation Q_hyst, Q_qualmin, & Q_rxlevmin.
Q50. What is Registration? What are the triggers for Registrations?
Q51. What is the difference between Intial and stored Info Cell (Re)Selection?
Q52. What is SIntraSearchP? When will UE choose not to perform measurements in Intra-Frequency cells?
Q53. What is SnonIntraSearchP? When will UE choose not to perform measurement in Inter-RAT/Inter-Freq cells
Q54. What are the mobility states of UE?
Q55. Where do you get T_cr_max, N_cr_H, N_cr_M? When will a mobile go to medium mobility state?
Q56. What are the mobility scaling factors, sf-high and sf-medium? How do you use them?
Q57. In Cell (re)Selection, what is the relation between Squal, ThreshX_HighQ and TreselectionRAT?
Q58. What is Ranking and when will a UE initiate re-relection w.r.t. time, timer and measurement threshold?
Q59. Compared to Non CSG cells, how is the reselection rule for a CSG cell?
Q60. What is special in the re-selection from a CSG/Hybrid cell to non-CSG cell?
Q61. What is the basic criteria to pass to initiate TA Registration?
Q62. What is a PF (Paging Frame) and PO (Paging Occasion)?
Q63. Except SI info, How else does eNB control UE Mobility in Idle Mode?
Q64. When UE reconfigures(deletes earlier value) a field(SRB, DRB etc..), the existing value is released except for during ?.
Q65. Can more than 1 SIB message be included in an SI message? Which ones and in what condition?
Q66. How does the UE get the System Information of Serving Cells other than P Cell?
Q67. How does a Relay Node acquire the System Information? Does it get it like UE Monitoring?
Q68. When are MIB and SIB1 scheduled in a frame?
Q69. How does UE know that there is a change in SI and it needs to monitor and read the SIBx?
Q70. When is Initial security activation initiated?
Q71. What is Radio link failure related actions initiated?
Q72. What are UE actions upon leaving RRC_CONNECTED initiated?
Q73. What are UE actions upon PUCCH/ SRS release request initiated?
Q74. When is Proximity indication initiated?
Q75. What are the 4 different RRC keys which change on every establishment or Handover?
Q76. Describe briefly difference between Handover, Cell Change Order, CS Fallback and SRVCC.
Q77. If a UE in silent mode and it received a paging message of ETWS either CMAS then how user get the information?
Q78. What is Transaction Identifier?
Q79. Parameter name of EPS-Encryption and EPS-Ciphering algorithm?
Q80. What is counter check why it required Lte?
Q81. What is Next Hop chaining count?
Q82. RRC connection release message is one side message and UE never send ACK to ENodeB then Q83. how ENodeB know that the message delivered successfully to UE?
Q84. What is the purpose of RRC re-configuration message?
Q85. What is the purpose of measurement report?
Q86. What are the LTE Handover Events?
Q87. What is UL Information Transfer message?
Q88. What is capability report when UE send this report to network? What are the information elements are present in capability report?
Q89. how enb know to send initial attach request to particular mme (out of 5-6 mme present)?
Q90. What is difference between soft handover and hard handover?
Q91. In Lte how many types of Handover happen?
Q92. while you working on rrc which bug you have find out?
Q93. What do you mean by Resource in Lte? Explain
Q94. Difference between SRB and DRB? How many SRB and DRB a UE can have in Lte?
Q95. Why Handover Required? Define Handover Redirection?
Q96. What are the IRAT-Events?
Q97. What are cell re-selection parameters?
Q98. What are the condition of re-establishment and re-configuration in Lte?
Q99. How many cell you can activate in SS?
Q100. What is the latest bug you have found?
Q101. How do you report a bug?
Q102. Whom you send to bug report? And how?