LTE Training

3G Network Solutions

LTE/IMS/IoT/5G Telecom Centre

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3PCA-NAS (50 Marks)

1. Which protocol carries the NAS messages between eNB and MME?

2. On what conditions MME will send UE the Attach Accept? List top 3 conditions..

3. Is Security Mode command compulsary before Attach Accept? Give reasons for both yes and no.

4. How many bytes is the "command-code" for "Service Request" message. Explain.

5. Which flag is set in Attach Request, if UE wants to send APN only after Security is done. Which message is used to send APN in that case?

6. If UE send Attach Request and receives Detach Request, before Attach Accept/reject, what should be done by the UE?

7.What is difference between GUTI and S-TMSI? Please describe all the bytes of both variables.

8. How does eNB decide, which MME your Attach Request should be forwarded to?

9.Describe which situations UE should execute PLMN Selection.

10. Describe 4 conditions when "Tracking Area Update" will be sent in connected mode.

11.Describe QoS and mention 5 most important constituents of QoS.

12. What are the S1AP messages in which QoS for a user are forwarded to a cell.

13. What is ISR? If UE has this feature, what is the saving in terms of signalling. Which nodes must implement ISR other than UE and MME?