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Drive test analysis - VoLTE call drop


#1

Hi,

I’m analysing a drive test log using Actix and I’m try to get the cause of VoLTE call drop.

I’m convinced that it was due to poor dl coverage, and the RSRP SINR values support that, but I would like to catch a message that definitely comproves that the poor rf condition was the cause.

I’m checking the RRC messages and I was looking to the n310 parameter which usuallly indicates radio link failures due to bad RSRP values. I’m not sure how to read the information I get about this parameter in the messages since is presented this way:

"

  • . . . . . . . . .rlf-TimersAndConstants-r9:- setup
  • . . . . . . . . . . .t301-r9: 5
  • . . . . . . . . . . .t310-r9: 5
  • . . . . . . . . . . .n310-r9: 6 ( n10)
  • . . . . . . . . . . .t311-r9: 2 ( ms5000)
  • . . . . . . . . . . .n311-r9: 0 ( n1)"

Can someone help me to interpret this?
Should I look for other messages? Which ones?


#2

Hi!
Sorry for the delay!

you can combine between some metrics of actix:

I mean: if you receive the number of : out-of-sync equal to the number of n310 -ie-

if N310 = n10 and we receive 10 messages of out-of-sync : then radio link failure (coverage).

thks

N310