Internet Radio Technology


The technological development that has made netcasting possible is "streaming." Through streaming, an audio file can be played as it is downloaded. Before streaming, audio files could not be listened to until the entire file had been downloaded. This technology allows for the simultaneous "live" transmission of an over-the-air radio broadcast on the Internet. The technology behind streaming is called CODEC, or compression-decompression technology. CODEC compresses the signal, forces it into a small envelope, and when it gets to the receiver, it springs out like a jack-in-the-box. This is constantly repeated over and over, creating a stream of information.


There are a number of devices that allow users to receive these audio streams on their computers. RealPlayer by RealNetworks and Microsoft's Media Player are the most popular receivers as both are free downloads.

Sonicbox is a newly developed device that allows users to harness the multitude of Internet radio listening options inside their FM radios. This addresses a problem currently facing netcasting - the personal computer is not often used as an entertainment device. The Sonicbox would combine the best of both worlds: the Internet's wide variety of stations with the radio's compactness and ease of use. Demand will likely be slow for a while because the high-speed connection necessary for use of Sonicbox currently costs around $50 a month.

Well-known among Internet radio listeners are the problems associated with the transmission of Internet radio. A slow connection or too much simultaneous traffic on one site can often cause the signal to break up. A connection speed of 28.8k is needed for decent reception, although a 56k speed is much better for ensuring more continuity in the signal's reception.

Another problem with Internet radio broadcasting, according to Phillip Laven, director of Technical Department for the European Broadcasting Union, is that most servers cannot support more than a few hundred listeners tuning in simultaneously, In order to accommodate a larger listenership, stations have to invest in larger bandwidth, which is very costly. The cost-effective solution, says Levin, is a technology called IP Multicast. When this technology is implemented, servers will no longer have to accommodate each user individually, but instead can send information out once to a large group of users. Figures 1 and 2 illustrate the basic difference in efficiency between the two methods of distribution.