Question: What is a key principle for the Iub interface specification regarding Node B's internal structure and protocols?
Option 1: Node B's physical structure and internal protocols are fully visible over Iub to ensure backward compatibility.
Option 2: Neither the physical structure nor any internal protocols of Node B shall be visible over Iub, allowing for future technology introductions.
Option 3: The Iub interface requires a detailed understanding of Node B's internal protocols for efficient resource allocation.
Option 4: Node B's logical model, but not its physical structure, influences the specification of the Iub interface.
Explanation: This question assesses understanding of the Iub interface's design principles, specifically concerning Node B's architecture. The correct answer reflects a crucial aspect of the Iub interface's general principles: that neither the physical structure nor internal protocols of Node B are visible over Iub, ensuring flexibility and future-proofing for seamless upgrades and innovations.