Web radio - also known by a number of names including internet radio, internet streaming, or audio streaming - is where radio programmes are broadcast via the internet.
Advantages of web broadcasting
The obvious advantage of web radio is that it is not illegal, so anyone can broadcast legally over the internet. As a result, there are literally thousands of radio stations broadcasting over the internet.
In addition, as the web is international, so a web radio station can gain listeners from all over the world.
Disadvantages of web broadcasting
A disadvantage of web radio is that, although it is ideal for listening on a home computer, mobile litening may be difficult and/or expensive for the listener.
Also, although the number of potential listeners is no longer limited by a transmitter's range, the actual number of listeners may well be limited by internet bandwidth.
The main downside of web broadcasting, however, is that limitation on the number of listeners is defined by the web connection's "bandwidth".
In the case of an internet connection, bandwidth is measured not in Hz or KHz, but in bits per second (b/s), or in kb/s or Mb/s.
For large web stations such as Radio Caroline or the Voice Of Peace, who may have dedicated web servers, this is rarely a serious issue. But for a home broadband connection, only about 20 listeners may be able to listen at a time. This can be increased by reducing the audio bitrate, but this comes at a cost of lower audio quality.
For pre-recorded programmed, an alternative is to have downloadable audio files, such as with Podcasting.
Ex-pirates now broadcasting online
A number of ex-pirates have now returned as web radio stations.
Radio Caroline - also via the Sky satellite and occasional RSL's
Radio Jackie (SW London) - also 107.8 FM as an ILR
Solar Radio (London) - also via the Sky satellite
Starforce Radio International - live streaming
Web radio and actual radio
Most licenced stations broadcast both by transmitter, serving their target area, and also have a web stream for listening outside of their transmitter's range.
In addition, a few web-only stations are re-broadcast by very naughty boys who feed their streamed audio through a transmitter. Web radio stations which have been re-broadcast by pirate transmitters include Unknown FM.net, which is often heard across a wide area of London on various different frequencies.