Question: Under which condition, in addition to a requested QoS change beyond initially authorized limits, does the 'Modification of PDP Context' procedure get triggered for a downlink/uplink adjustment?
Option 1: When the maximum bit rate (downlink and uplink) is upgraded to match the device's capabilities.
Option 2: If the network congestion requires temporary reduction in all active PDP contexts' bit rates.
Option 3: When the maximum bit rate (downlink and uplink) is specifically downgraded to 0 kbit/s.
Option 4: During routine network maintenance, affecting all connected User Equipment (UE).
Explanation: The correct answer is Option 3 because one of the specific scenarios that trigger the 'Modification of PDP Context' procedure is when the maximum bit rate for both downlink and uplink is downgraded to 0 kbit/s, indicating a deliberate adjustment to completely halt data transfer on these links, necessitating an update to the PDP context's authorized QoS parameters.