What is defined as the maximum distance at which a radio signal can be transmitted or received?

The term that is defined as the maximum distance at which a radio signal can be transmitted or received is known as the radio horizon. This concept refers to the line of sight distance over which radio waves can propagate effectively. The radio horizon is influenced by various factors including the frequency of the signal, the height of the transmitting and receiving antennas, and the surrounding terrain.

In radio communication, the radio horizon helps determine how far signals can be reliably transmitted and received due to the curvature of the Earth and atmospheric conditions. Higher frequency signals typically have a shorter effective range due to increased obstruction from physical barriers, whereas lower frequency signals can propagate further.

Understanding the concept of the radio horizon is crucial for planning effective communication systems, ensuring that the devices are installed at suitable heights, and designing networks that meet coverage requirements.