Question: Under what condition is the Downlink Power Timeslot Control procedure not allowed to be initiated by the Serving Radio Network Controller (SRNC) in a UTRAN Iur interface context?
Option 1: When the UE (User Equipment) is in idle mode.
Option 2: If the signalling bearer connection for the relevant UE Context is not established.
Option 3: After a handover to a different DRNS (Destination Radio Network Subsystem).
Option 4: Once the SRNC has initiated deletion of the last Radio Link in the concerned DRNS.
Explanation: This is correct because, according to the specifications, if the SRNC has initiated the deletion of the last Radio Link in the DRNS (Destination Radio Network Subsystem), the Downlink Power Timeslot Control procedure cannot be initiated. This ensures that once the process of removing the final radio link is underway, no new power control procedures are started, likely to maintain consistency and prevent conflicts in the network configuration.