Question: What is the valid range for the value of the SCellIndex Information Element, as used to identify a Secondary Cell (SCell) in Radio Resource Control (RRC) protocol?
Option 1: INTEGER (0..15)
Option 2: INTEGER (1..16)
Option 3: INTEGER (0..31)
Option 4: INTEGER (1..31)
Explanation: The correct answer, INTEGER (1..31), reflects the specified value range for SCellIndex as defined in the RRC protocol. This range is crucial for identifying SCells within Cell Groups, ensuring uniqueness and avoiding conflicts. The other options are incorrect because they either start from 0 or end at a value less than 31, which would limit the potential number of identifiable SCells.