Question: Which layers of the OSI seven-layer reference model are utilized in the three-layer protocol model for the Iuant interface, specifically for RET antenna control?
Option 1: Layers 1, 2, and 7 (Physical, Data Link, and Application Layers)
Option 2: Layers 3, 4, and 5 (Network, Transport, and Session Layers)
Option 3: Layers 5, 6, and 7 (Session, Presentation, and Application Layers)
Option 4: Layers 1, 3, and 6 (Physical, Network, and Presentation Layers)
Explanation: The Iuant interface for RET antenna control uses a compact three-layer protocol model derived from the OSI seven-layer reference model. This model incorporates Layer 1 (Physical) for signaling and data characteristics, Layer 2 (Data Link) utilizing a specific HDLC standard, and Layer 7 (Application) defining the payload format and command set, known as the 'Iuant: Application Part', ensuring streamlined implementation.