Question

Wireless Internet networks, including many used in homes, often make use of high-frequency radio waves. High-frequency waves are useful because they can carry a lot of information. However, high-frequency waves are less capable of passing through objects than are low-frequency waves. As a result, waves traveling from a person's wireless laptop computer, for example, could be interrupted by objects between the computer and the modem.

Due to this limitation of high frequency waves, which of the following statements best explains why digital waves are commonly used in high-frequency wireless networks instead of analog waves?
A.
Analog waves cannot reach large enough wavelengths to be used in wireless networks.
B.
Analog waves cannot reach high enough amplitudes to be used in wireless networks.
C.
It is easier to correct small disruptions in digital waves than in analog waves.
D.
Small disruptions in analog waves are more easily corrected than in digital waves.

Answer 1

C.

Digital signals use discrete levels (e.g., 0 and 1), so small distortions/noise are easier to detect and correct (via thresholds, error-detection/correction codes, retransmission) than with continuous analog signals, which degrade gradually and are harder to restore. Choices A and B are incorrect statements about wavelength/amplitude, and D is the opposite of the correct reason.