Idle UE in high mobility and beam update

Hi folks,
As you know, gNB selects the best Tx beam based on the RACH resources used by UE which correspond to a particular SSB time index.
Suppose there is a high mobility UE in idle condition.
For such UE, for every beam switch in idle mode, UE needs to do a RACH to indicate the updated best beam?
Please let me know if my understanding is correct.

Idle mode only for SA mode.
It’s by beam switching using tci I think.

I think, UE sticks to SSB beams for idle mode.
There is no reason to continue to scan to narrower CSI-RS beams.

Will it not do idle mode reselection in mobility?
If cell change within same cell it should beam switching for idle mode.

If cell change within same cell it should beam switching for idle mode → I understand that UE has to beam switch in idle mode. So, everytime it does a beam switch, gNB to be notified of it through RACH? That’s my question.
Or when paging is done, it is done across all SSBs?

In Idle mode no need to update beam change.
Paging always happen on cell/gNB basis not at beam level.

So, you mean, during paging occasion, gNB will sweep the entire cell with paging info?

Samsung have concept of common beam which always spans entire cell area.
Broadcast messages generally transmitted by common beam.
But your question is interesting…let us see for others opinion.

Good to know… thanks for the info :+1: