О. В. Фёдорова е. В. Мезина е. В. Хамис английский язык в сфере информационных технологий и коммуникаций учебное пособие

Today, radio takes many forms, including wireless networks, mobile communications of all types, as well as radio broadcasting.

Before the advent of television, commercial radio broadcasts included not only news and music, but dramas, comedies, variety shows, and many other forms of entertainment. Radio was unique among dramatic presentation that it used only sound.

Aviation voice radios use VHFAM. Aircraft fly high enough that their transmitters can be received hundreds of miles away, even though they are using VHF.

Marine voice radios can use AM in the shortwave High Frequency—3 MHz to 30 MHz. Government, police, fire and commercial voice services use narrowband FM on special frequencies. Civil and military HF (high frequency) voice services use shortwave radio to contact ships at sea, aircraft and isolated settlements.

Mobile phones transmit to a local cell site that ultimately connects to the public switched telephone network through an optic fiber or microwave radio and other network elements. When the mobile phone nears the edge of the cell site's radio coverage area, the central computer switches the phone to a new cell. Cell phones originally used FM, but now most use various digital modulation schemes. Satellite phones come in two types: INMARSAT and Iridium. Both types provide world-wide coverage. INMARSAT uses geosynchronous satellites, with aimed high-gain antennas on the vehicles. Iridium uses 66 Low Earth Orbit satellites as the cells.

Television sends the picture as AM and the sound as FM, with the sound carrier at fixed frequency (4.5 MHz in the NTSC system) away from the video carrier. Analog television also uses a vestigial sideband on the video carrier to reduce the bandwidth required.

Radio-frequency energy can be used for heating of objects. Microwave ovens use intense radio waves to heat food. Diathermy equipment is used in surgery for sealing of blood vessels. Induction furnaces are used for melting metal for casting.

Tractor beams can use radio waves which exert small electrostatic and magnetic forces. These are enough to perform station-keeping in microgravity environments.

Radiation pressure from intense radio waves has been proposed as a propulsion method for an interstellar probe called Starwisp. Since the waves are long, the probe could be a very light metal mesh, and thus achieve higher accelerations than if it were a solar sail.

Radio remote control use radio waves to transmit control data to a remote object as in some early forms of guided missile, some early TV remotes and a range of model boats, cars and airplanes. Large industrial remote-controlled equipment such as cranes and switching locomotives now usually use digital radio techniques to ensure safety and reliability.

Energy autarkic radio technology consists of a small radio transmitter powered by environmental energy (push of a button, temperature differences, light, vibrations, etc.). This technology includes, for example, solar powerstations in orbit beaming energy down to terrestrial users.