Question: What is the primary purpose of the Broadcast Common Transport Bearer Indication Information Element (IE) in UTRAN's Iub interface Node B Application Part (NBAP) signalling?
Option 1: To establish a new transport bearer for each Common Transport Channel.
Option 2: To request the CRNC to modify the existing transport bearer's QoS settings.
Option 3: To indicate to the CRNC that a specific Common Transport Channel is no longer in use.
Option 4: To inform the CRNC to utilize an existing transport bearer for a specified Common Transport Channel instead of creating a new one.
Explanation: This option correctly reflects the purpose of the Broadcast Common Transport Bearer Indication IE, as it allows Node B to signal to the CRNC that an existing transport bearer should be reused for a particular Common Transport Channel, rather than setting up a new transport bearer, optimizing resource utilization in the network.