ARRL Technician Practice Exam

What may occur if data signals propagate over multiple paths?

1. Signal strength will increase

2. Error rates are likely to increase

3. Transmission will be faster

4. Communication will become clearer

The correct answer is: Error rates are likely to increase

When data signals propagate over multiple paths, a phenomenon known as multipath propagation occurs. This can lead to constructive and destructive interference, which affects the clarity and consistency of the received signal. One of the main consequences of this interference is an increase in error rates. As signals arrive at the receiving end at slightly different times and phases, they may confuse the receiver, causing inaccuracies in data interpretation. Moreover, the presence of multipath can lead to fading, where the signal strength fluctuates, complicating the task of accurately extracting the intended information. This is particularly crucial in environments with many reflective surfaces, such as urban areas, where signals can take various paths to reach the receiver. While it might seem intuitive that more paths could improve transmission speed or clarity, in practice, the additional complexity introduced by multipath propagation generally contributes to higher error rates rather than enhancing performance.