Why do we setup multiple A events for a call? Setup for A2 Event, Why?

Question

Hi Folks,

Can you explain me when we will prefer A2 and A3 events for measurement report?
And is there any relation between the events?
What are these Ms,Hys,Thresh,Ofn,Ocn,Mn and how ENb will set these values in the meas config?

Thanks ,

Naveen.

Answer 1

Event A1 and A2 are configured to measure the serving cell and sends the measurement report to eNodeB so that eNodeB take the defined actions. Event A1 is reported when UE measures that serving cell is better than the configured threshold. After receiving this event, eNodeB come to know that current serving cell is better for UE. Event A2 is triggered from UE to eNodeB when the current serving cell measurement goes down than the configured threshold. After receiving event A2, eNodeB can configure UE for reporting other events such as A3, A4, A5 to get the measurement of neighbor cells. Further, eNodeB initiates handover procedure based on the received event (A3/A4/A5).

Comments

Adding few more lines on top of the answer given above.
Event A2: When serving cell becomes worse than configured threshold value.

Entering condition for the event A2:
Ms + Hys < Threshold

Leaving condition for the event A2
Ms - Hys > Threshold