Question: Under what condition can a UE (User Equipment) determine that a gNB (gNodeB) has initiated channel occupancy in a shared spectrum channel access period?
Option 1: Upon receiving a Random Access Response from the gNB.
Option 2: By detecting a DL (DownLink) transmission burst(s) in that period or through an indication by a DCI (Downlink Control Information).
Option 3: After a successful handover to the gNB.
Option 4: When the UE is in RRC (Radio Resource Control) Connected state.
Explanation: This option is correct because, according to the principles of shared spectrum channel access, a UE can ascertain that a gNB has initiated channel occupancy either by directly observing a DL transmission burst within the specified period, which actively indicates the gNB's use of the channel, or through explicit signaling via DCI, which informs the UE of the gNB's intention to occupy the channel. This method ensures the UE is aware of and can adapt to the gNB's channel usage for efficient shared spectrum management.