What does attenuation mean in data communications?

• A. Loss of signal strength as distance increases
• B. Time for a signal to reach its destination
• C. Leakage of signals from one cable pair to another
• D. Strengthening of a signal by a networking device

Answer: (A)

Attenuation is the loss of signal strength as distance increases. As a signal travels through a medium, energy is spread out and absorbed, so the received signal is weaker. This loss is typically measured in decibels and tends to grow with distance and, in some cases, with frequency. Attenuation matters because when the signal becomes too weak, errors rise and the communication link may fail unless devices like repeaters or better cabling are used to compensate. The other ideas describe different phenomena: the time it takes for a signal to reach its destination is propagation delay, leakage between cables is crosstalk, and strengthening a signal is amplification, not attenuation.