n-TimingAdvanceOffset in 5G NR SA

Hello Experts,
Anyone has any idea why I have this n-TimingAdvanceOffset in 5G NR SA log?
The same message shown in each sib1 message.
This is in UE log.

Is it the same time advance that we have in LTE?
I doubt that because it is mac report and not sib1 report…

Connected mode timing adjustment are done at MAC level, I think.

Yes, always.

But I see on the mac the TA parameter. Its value different from what I have in sib1.
So what I think it’s the the distance of UE estimation?

Sib1 is open loop TA, less accurate.
MAC level close loop and connected mode, more accurate.
More TA commands.

In TDD, there is a default timing advance of 624 Ts (~20 micro sec).
This 20 micro second is required for UL to DL switching at the eNB end.
In NR it is 25600 Tc (~13 micro second), which depends on SCS and bands.


Now it makes more sense, thanks alot! :wink:

In case of TDD with LTE-NR coexistence, 39936 is used instead of 25600 to match 624 used by LTE TDD

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