What is a decrease in amplitude as a signal propagates along a transmission medium best known as?

Attenuation is the technical term for the reduction in signal strength, or amplitude, as a signal travels through a transmission medium. This loss of energy occurs because the medium absorbs or scatters the signal's power as it propagates over a distance. All transmission media, whether guided (like copper wire or fiber optics) or unguided (like wireless), exhibit attenuation. To compensate for this effect, amplifiers or repeaters are often used in communication systems to boost the signal strength at periodic intervals.

A. Crosstalk: This is unwanted interference caused by a signal from one circuit or channel coupling into an adjacent circuit or channel.

B. Noise: This refers to any undesirable random electrical signal that gets added to the primary signal, corrupting its quality, not the inherent loss of the primary signal's strength.

C. Delay distortion: This form of distortion occurs in guided media when different frequency components of a signal travel at different velocities, causing the signal to spread out over time.

1. Stallings

W. (2017). Data and Computer Communications (10th ed.). Pearson. In Chapter 3

"Data Transmission

" Section 3.3

"Transmission Impairments

" it is stated: "Signal strength falls off with distance over any transmission medium. For guided media... this reduction

or attenuation

is generally logarithmic." (p. 78).

2. Gallager

R. G. (2006). Lecture Notes

6.450 Principles of Digital Communications I. MIT OpenCourseWare. Lecture 10

"AWGN Channels and SNR

" discusses how signal power decreases with distance

a fundamental aspect of attenuation. (p. 10-1).

3. International Telecommunication Union (ITU). (2006). Handbook: The NGN as a transport network. In the Glossary of terms

Attenuation is defined as: "Decrease in magnitude of the current

voltage or power of a signal in transmission between points." (p. 239).

4. Kurose

J. F.

& Ross

K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.). Pearson. Chapter 2

"Application Layer

" discusses physical media impairments

noting that as a signal propagates

it becomes weaker due to attenuation. (Section 2.6

p. 70 in the Global Edition).