Plain English Meaning

Radio relay stations spread across a large area of airspace so the controller in the center building can talk to aircraft no matter where they are in that sector.

Full Definition

Unmanned communication facilities, distributed throughout an Air Route Traffic Control Center's airspace, that relay voice transmissions between pilots and the controller working the sector. They extend the controller's radio coverage so aircraft at varying altitudes and locations can stay in contact across the full sector.

Context Anchor

Seen when the handbook describes FAA ground-based communication, , or equipment used to support aircraft large .