page_title: Shortwave radio
section_title: Shortwave's future
hierarchical_section_title: Shortwave radio / Shortwave's future
caption_attribution_description: English: HPSDR "Mercury" is a 0-65 MHz Direct Sampling Receiver.
context_page_description: Shortwave radio is radio transmission using shortwave radio frequencies. There is no official definition of the band, but the range always includes all of the high frequency band, which extends from 3–30 MHz; above the medium frequency band, to the bottom of the VHF band.
  Radio waves in the shortwave band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere. Therefore, short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon. This is called skywave or "skip" propagation. Thus shortwave radio can be used for very long distance communication, in contrast to radio waves of higher frequency which travel in straight lines and are limited by the visual horizon, about 64 km. Shortwave radio is used for broadcasting of voice and music to shortwave listeners over very large areas; sometimes entire continents or beyond. Other uses include military over-the-horizon radar, diplomatic communication, amateur radio enthusiasts’ two-way international communication for hobby, education, and emergency service, as well as for long-distance aviation and marine communications.
context_section_description: The development of direct broadcasts from satellites has reduced the demand for shortwave receiver hardware, but there are still a great number of shortwave broadcasters. A new digital radio technology, Digital Radio Mondiale (DRM), is expected to improve the quality of shortwave audio from very poor to standards comparable to the FM broadcast band. The future of shortwave radio is threatened by the rise of power line communication (PLC), also known as Broadband over Power Lines (BPL), which uses a data stream transmitted over unshielded power lines. As the BPL frequencies used overlap with shortwave bands, severe distortions can make listening to analog shortwave radio signals near power lines difficult or impossible.
  According to Andy Sennitt, former editor of the World Radio TV Handbook,
  “shortwave is a legacy technology, which is expensive and environmentally unfriendly. A few countries are hanging on to it, but most have faced up to the fact that the glory days of shortwave have gone. Religious broadcasters will still use it because they are not too concerned with listening figures”.
  However Thomas Witherspoon, editor of shortwave news site SWLingPost.com wrote that
  “shortwave remains the most accessible international communications medium that still provides listeners with the protection of complete anonymity”.
  According to Nigel Fry, head of Distribution for the BBC World Service Group,
  “I still see a place for shortwave in the 21st century, especially for reaching areas of the world that are prone to natural disasters that destroy local broadcasting and Internet infrastructure”.
caption: PC spectrum display of a modern software defined shortwave receiver
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