220-801 · Question #178
Which of the following wireless transmission methods requires line of sight?
The correct answer is A. Infrared. Infrared (IR) wireless transmission requires an unobstructed direct line of sight between the transmitter and receiver because IR signals cannot pass through solid objects.
Question
Which of the following wireless transmission methods requires line of sight?
Options
- AInfrared
- BRFID
- C802.11a
- DBluetooth
How the community answered
(39 responses)- A90% (35)
- B5% (2)
- C3% (1)
- D3% (1)
Why each option
Infrared (IR) wireless transmission requires an unobstructed direct line of sight between the transmitter and receiver because IR signals cannot pass through solid objects.
Infrared transmission uses light waves in the near-infrared spectrum, which are blocked by any opaque physical barrier. This means the transmitting and receiving devices must be directly facing each other with no obstacles between them, a fundamental physical constraint of the technology.
RFID uses radio frequency waves that can penetrate non-metallic materials and does not require line of sight between the tag and reader.
802.11a uses radio waves in the 5 GHz band that can pass through walls and other obstacles, though signal strength is reduced.
Bluetooth uses radio waves in the 2.4 GHz band and can transmit through walls and around obstacles without requiring line of sight.
Concept tested: Infrared wireless - line of sight requirement
Source: https://learn.microsoft.com/en-us/windows/win32/irda/about-windows-sockets-irda
Topics
Community Discussion
No community discussion yet for this question.