Question: What is the criterion for a successful increment of the 'Attempted radio link setups on Iub' measurement, considering the '2 out of 3 approach' for radio link setups on Iub?
Option 1: Transmission of a RADIO LINK SETUP REQUEST message (NBAP) and successful setup of at least one radio link.
Option 2: Successful transmission of a RADIO LINK SETUP REQUEST message (NBAP) by the controlling RNC to the NodeB, regardless of the outcome of the setup.
Option 3: Receipt of a confirmation message from the NodeB for each radio link setup requested in the RADIO LINK SETUP REQUEST message.
Option 4: Completion of the radio link setup within a predefined timeout period after sending the RADIO LINK SETUP REQUEST message.
Explanation: The correct answer is Option 2 because the measurement for 'Attempted radio link setups on Iub' is increased by transmitting a RADIO LINK SETUP REQUEST message (NBAP) from the controlling RNC to the NodeB, regardless of the setup's outcome. The '2 out of 3 approach' suggests broader applicability but doesn't alter the trigger for incrementing this measurement.