Final answer:
Airport radio (APRT RDO) is typically provided by an air traffic control tower or a Flight Service Station, which manage air traffic and provide information services. At non-towered airports, UNICOM stations may offer similar communication services.
Step-by-step explanation:
Airport radio (APRT RDO), in most cases, is provided by an air traffic control tower (ATC tower) or a Flight Service Station (FSS). These are facilities within the air traffic control system tasked with the responsibility of managing the flow of air traffic around an airport. Specifically, the ATC tower handles the clearance and control of aircraft within the airport's immediate airspace, while the FSS provides information services such as weather briefings and emergency assistance to pilots.
For airports without a control tower, airport radio services might also be provided by a UNICOM (Universal Communications) station which is more commonly found at smaller, non-towered airports. UNICOM is used for non-controlled airport communications to assist aircraft in coordinating arrivals and departures among themselves.