Question: What action does the MAC entity take upon receiving a PUSCH Pathloss Reference RS Update MAC CE on a Serving Cell in a 5G NR network?
Option 1: Ignore the update and continue using the previous pathloss reference RS for PUSCH.
Option 2: Automatically apply the update to all serving cells without notifying lower layers.
Option 3: Indicate to lower layers the information regarding the PUSCH Pathloss Reference RS Update MAC CE.
Option 4: Request confirmation from the network before applying the pathloss reference RS update.
Explanation: In a 5G NR network, when the MAC entity receives an update for the pathloss reference signal (RS) used for PUSCH on a serving cell, it informs lower layers about this change. This ensures all relevant UE components are aware of and can apply the updated pathloss reference for efficient uplink transmission power control.