LTE Layer 3 (RRC Layer) Interview Questions
- What is difference between Acceptable, Suitable and Reserved Cell.
- How is state “Camped on Any Cell” different from “Any Cell Selection” state?
- What is CSG cell and CSG whitelist?
- Differentiate HPLMN, EHPLMN, RPLMN.
- What is Hybrid Cell?
- What is difference between Serving Cell and Primary Cell? How many Maximum Serving Cell can be there in total?
- Describe what does UE extract from the PBCH? How do we get to know about antenna Configuration from MIB?
- Describe what does UE get from tuning to PSS?
- Describe what does UE get from tuning to SSS?
- In brief describe (main parameters) what does UE get in SIB1?
- In brief describe what does UE get in SIB2?
- In brief describe what does UE get in SIB3?
- In brief describe what does UE get in PCCH?
- Where is MIB and SIB1 mapped in frame?
- Describe how do you get SIB2 to SIB13 info and periodicity?
- What is SI Modification Period? How do you get notified?
- After reading SI (System Information), what is the action by UE before Cell Selection? How does it get the input?
- What is Access Class.? What are special provides by AC 11 and 15?
- In which Idle states Emergency call is possible by AC 0 to 9?
- In Order to select a valid candidate PLMN, what is the minimum signal level(RSRP)? What is the minimum quality(RSRQ)?
- What is the “S” criteria. Specify the minimum value for candidate Cell.
- What is “R” Criteria. What is relation Q_hyst, Q_qualmin, & Q_rxlevmin.
- What are the triggers to make UE go from Idle to Connected mode?
- What is Registration? What are the triggers for Registrations?
- What is the difference between Intial and stored Info Cell (Re)Selection?
- What is SIntraSearchP? When will UE choose not to perform measurements in Intra-Frequency cells?
- What is SnonIntraSearchP? When will UE choose not to perform measurement in Inter-RAT/Inter-Freq cells
- What are the mobility states of UE?
- Where do you get T_cr_max, N_cr_H, N_cr_M? When will a mobile go to medium mobility state?
- What are the mobility scaling factors, sf-high and sf-medium? How do you use them?
- In Cell (re)Selection, what is the relation between Squal, ThreshX_HighQ and TreselectionRAT?
- What is Ranking and when will a UE initiate re-relection w.r.t. time, timer and measurement threshold?
- Compared to Non CSG cells, how is the reselection rule for a CSG cell?
- What is special in the re-selection from a CSG/Hybrid cell to non-CSG cell?
- What is the basic criteria to pass to initiate TA Registration?
- What is a PF (Paging Frame) and PO (Paging Occasion)?
- Except SI info, How else does eNB control UE Mobility in Idle Mode?
- What are the logical channels/Message types associated with SRB0, SRB1, SRB2, DRB and MRB?
- When UE reconfigures(deletes earlier value) a field(SRB, DRB etc..), the existing value is released except for during ?.
- What are the two (types of) messages there for BCCH in the DL-SCH?
- Can more than 1 SIB message be included in an SI message? Which ones and in what condition?
- How does the UE get the System Information of Serving Cells other than P Cell?
- How does an Relay Node acquire the System Information? Does it get it like UE Monitoring?
- When is MIB and SIB1 scheduled in a frame?
- How does UE know that there is a change in SI and it needs to monitor and read the SIBx?
- What are the triggers for UE to again Monitor the SI and read/update the values.
- When is Paging initiated?
- When is RRC connection establishment initiated?
- When is Initial security activation initiated?
- When is RRC connection reconfiguration initiated?
- When is Counter check initiated?
- When is RRC connection re-establishment initiated?
- When is RRC connection release initiated?
- When is RRC connection release requested by upper layers initiated?
- When is Radio resource configuration initiated?
- What are Radio link failure related actions initiated?
- What are UE actions upon leaving RRC_CONNECTED initiated?
- What are UE actions upon PUCCH/ SRS release request initiated?
- When is Proximity indication initiated?
- What are the 4 different RRC keys which change on every establishment or Handover?
- Describe briefly difference between Handover, Cell Change Order, CSFallBack and SRVCC.
- What are the entities added/deleted on SRB add/delete?
- What are the entities added/deleted on DRB add/delete?
- What are the entities added/deleted on SCell add/delete?
- In ASN.1, what is the difference between SEQUENCE, SET and CHOICE? Illustrate.
- Form a BCCH-MIB Binary Message with following Info:
BCCH-BCH-Message ::= SEQUENCE { message BCCH-BCH-MessageType }
BCCH-BCH-MessageType ::= MasterInformationBlock
MasterInformationBlock ::= SEQUENCE { dl-Bandwidth ENUMERATED { n6, n15, n25, n50, n75, n100},
phich-Config PHICH-Config,
systemFrameNumber BIT STRING (SIZE (8)), “assume 10101010”
spare BIT STRING (SIZE (10)) }
PHICH-Config ::= SEQUENCE { phich-Duration ENUMERATED {normal, extended},
phich-Resource ENUMERATED {oneSixth, half, one, two} }
Related Posts:
- LTE Layer 1 (Physical Layer) Interview Questions
- LTE Layer 2 (MAC,RLC,PDCP) Interview Questions
- LTE Layer 3 (RRC Layer) Interview Questions