What OSI physical layer term describes the physical medium for microwave transmissions?

• A. air
• B. throughput
• C. goodput
• D. latency

Answer: (A)

Signals at the physical layer travel through a tangible medium. For microwave transmissions, the electromagnetic waves propagate through the air, i.e., free space between the transmitter and receiver. That air is the physical medium the signal uses to travel. The other terms describe performance (how fast data moves, how much useful data is delivered, and the delay), not the medium itself, so they don’t describe what the signal travels through.