What is a radio relay route?

In amateur radio, a directional radio route is a defined, straight transmission route between two points on which high-frequency signals are transmitted, usually in the microwave range, using directional radio antennas. Microwave links are used to transmit data, voice and images over longer distances without the need for a physical conductor such as cable. They are particularly suitable for bridging obstacles such as bodies of water or rough terrain where a cable connection is difficult or impossible. These point-to-point connections typically rely on a clear line of sight (Fresnel zone) to ensure reliable transmission.