Which set of technologies are used to deliver ALD signals?

Which set of technologies are used to deliver ALD signals?

• A. Amplitude Modulation/Infrared/Wireless
• B. Bluetooth/Infrared/Induction Loop
• C. Frequency Modulation/Induction Loop
• D. Frequency Modulation/Infrared/Induction Loop

Answer: (D)

This item tests how ALD signals are delivered across different media to stay reliable in various environments. Using frequency modulation provides a stable radio-frequency carrier that encodes data effectively even when there’s noise, so the signal can travel through air. Infrared adds a line-of-sight optical channel, which is immune to RF interference and useful when wireless radio channels are crowded or restricted. An induction loop offers near-field magnetic coupling for close-range communication, which can work where optical or RF paths aren’t practical. Combining these three methods—FM for RF transmission, infrared for optical delivery, and induction loop for near-field signaling—covers multiple scenarios and enhances reliability. The other options mix in technologies that don’t deliver the same broad, multi-media capability, such as relying on a single medium or using modulation schemes that are less robust in certain conditions.

This item tests how ALD signals are delivered across different media to stay reliable in various environments. Using frequency modulation provides a stable radio-frequency carrier that encodes data effectively even when there’s noise, so the signal can travel through air. Infrared adds a line-of-sight optical channel, which is immune to RF interference and useful when wireless radio channels are crowded or restricted. An induction loop offers near-field magnetic coupling for close-range communication, which can work where optical or RF paths aren’t practical.

Combining these three methods—FM for RF transmission, infrared for optical delivery, and induction loop for near-field signaling—covers multiple scenarios and enhances reliability. The other options mix in technologies that don’t deliver the same broad, multi-media capability, such as relying on a single medium or using modulation schemes that are less robust in certain conditions.