5G SA timeAlignmentTimer timer

5G NR
1

Hello Experts,

Anyone has any idea why I have this timeAlignmentTimercommon=500 in SIB1 and timeAlignmentTimer=750 in RRCsetup in 5G NR SA log?

can anyone explain when timeAlignmentTimercommon will start and expire
and when UE Dedicated timeAlignmentTimer will start and expire

My understanding ,
UE will start timeAlignmentTimerCommon=500ms timer when it received RAR.
since RRCsetup also configured , timeAlignmentTimer =750ms it will be updated to 750ms
UE will restart timeAlignmentTimer once UE received the first TA MAC CE

Question : TA MAC CE should be send within 750ms or not ?

2

Yes your understanding is correct, yes network has to send TA Mac CE before 750 ms timer got expired if it’s expired then ue think , it’s loss the dL sync

This is my understanding. Based on experience. Please correct me :blush: