Messages in NR like TAU update in LTE

Hi NR Experts.

For Idle mode procedure:

  1. What messages seen like we have TAU update in LTE if UE move from cell 1 to cell 2 having different TAC.
  2. Is there any message like mobility registration update?

Do you mean Layer 3 messages?

Yes, L3 messages.

Registration Request with cause mobility update in 5G SA in that scenario.

There is no TAU update in 5G SA as far as I know in terms of signallng (NAS).


Do you mean UE need to indicate support of mobility registration update?

If UE move in 5G SA in idle mode between 2 cells having different TAC then what will happen?

Registration areas consist of different TACs, so for the scenario you mention above, yes UE needs to send registration request with mobility update to perform a registration success on new TAC.

For more info, check out TS 24.501 and 5G Standalone Access Registration Signaling Messages.

Ok, so it means mobility update is not OTA message seen in L3 it’s part of registration request.

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