Internet radio (also Webradio) is an Internet-based range of radio broadcasts. The transmission is usually done as streaming audio; Streaming clients are required for use.

story
Already in 1995-1996, the newly founded Info-Radio Berlin-Brandenburg of ORB and SFB organized the streaming service Info-Radio on Demand together with the Technical University Berlin.

The SWF carried out a similar project. Here a part of the SWF broadcast archive was digitized. In the middle of 1995 there were already over 190,000 hours of word and music contributions.

Media publicity was attracted to streaming media around 1998, when the new economy flourished. There was a kind of automatic train forced, for example, many radio stations began to stream parts of their programs simply because others did. Parallel to this, independent webradios were founded. An example of this was youwant.com.

At the end of 2002, in the midst of the crisis of commercial Internet use, America Online launched the exclusive Broadband Radio @ AOL radio program for its broadband customers; AOL did not use the streaming technology of the strategic partner Real Networks, but used a self-developed development called UltraVox, programmed by Nullsoft; Nullsoft was taken over 1999 together with Spinner.com by AOL.

Similar to the US press, there are also cases where radio broadcasters have been established by established, established broadcasters. This is how radio multicult2.0 was created in Berlin in response to the closure of the RBB radio broadcaster.

providers
As with the terrestrial radios, many disciplines and musical styles are served. However, a very wide variety of channels for all kind of music styles and spoken contributions is possible here as a result of the relatively inexpensive possibility of operating an internet radio, as compared to terrestrial broadcasting. The number of web radio transmitters that can be received at an Internet connection is in the tens of thousands, but only a few "transmitters" can be used at the same time. Most terrestrial radios transmit their signal over the Internet. In addition, there are many pure web radio providers. If a provider sends via the Internet, its signal is available to (almost) every Internet connection world-wide.

According to a study conducted by the Bavarian State Center for New Media in April 2010, there were about 2700 German webradios. Of these, 80 per cent are exclusively available on the Internet (Internet only offers), the others are predominantly live streams of the FM radio stations (Simulcast -Streams). Compared to 2009 the number according to the BLM study "Webradiomonitor 2010" rose by over 700 transmitters. Since 2006 (with then 450 Internet users), the number of providers in Germany grew by about 56 percent per year.

The "Webradiomonitor 2016" (publisher: Bavarian State Center for New Media (BLM), Federal Association of the Digital Economy (BVDW) and Association Private Broadcasting and Telemedia eV - VPRT) determined a total of 2,453 webradios. Of these, 73 per cent were exclusively available on the Internet (online-only offers). The live streams of the FM radio stations (simulcast streams) and their online sub-brands were 17% and 10%, respectively. The annual survey also showed that the number of pure webradios has decreased since its high in 2011 (3055 offers) and since 2015 has stuck steady with a little more than 2400 offers, while the number of other online audio offers (User Generated Radiostreams or curated Playlists) in the past years continuously rose.

distribution
According to the ARD / ZDF-Onlinestudie 2010 8% of the Internet surfers weekly webradio listen to Livestream, 26.6% at least rarely. In 2003, the figure was still 5.3% and 17.6% respectively. At the same time, the proportion of DSL / broadband users rose from 24% to 70% between 2003 and 2008. As early as 2006, more than 20 million people in Europe heard Webradio. In the second quarter of 2014, according to the Association of Private Broadcasting and Telemedia e. V. (VPRT) 52 million sessions per month.

First and Second Verifiers
Native internet stations
Internet Broadcaster is an Internet "broadcaster", which either broadcasts only on the Internet or at least carries out its initial use on the Internet and then sells parts of the program later to other stations (content syndication).

Internet broadcasting differs from conventional broadcasters, mainly due to the lower number of listeners compared to traditional stations, as the majority of terrestrial radio stations are still used. An example are university transmitters that provide their programs over the Internet. In these cases, the term Webradio is also used synonymously for the provider or the program.

In addition, there are mostly webradios run by private individuals.

Regular radio stations
The onlineradio is used by numerous radio stations as an alternative transmission technique for a second utilization of their programs. The reception is thus also to be enabled to listeners who can not receive the program either terrestrially or via cable connection or satellite.

Radio on the Internet, for example, is offered by the German public broadcasters who want to reach the audience outside their broadcasting area, such as emigrants or students on a foreign stay.

Nearly all free radios and open channels are broadcasting their entire program on the Internet, since they are generally terrestrial only with very low transmission power and so only in a very limited area could be receivable.

The transmission of current programs is often supplemented by archival and provision of previously sent contributions (audio-on-demand or on-demand streaming).

Numerous German-speaking radio stations offer at least parts of their programs via live streaming over the Internet. In the pursuit of market shares, almost all program providers see themselves as an indispensable to show on the transmission path Internet presence. However, this can lead to a financial dilemma, which is particularly exposed to regular radio with its high basic costs through the transmission networks and by the additional new challenges of transmission on the Internet.

Internet radio versus conventional radio
Internet radio differs in principle from traditional radio:

Distribution and reach
In contrast to conventional broadcasting, which reaches unrestrictedly many receivers within its broadcasting area by means of radio waves, the Internet limits the maximum number of simultaneously possible receivers by the available bandwidth. Solutions are multicast streaming as well as the use of special streaming services or providers. Households that replace several conventional radios with Internet radios can simultaneously receive a DSL connection between seven and 112 radios. Internet connections with a bandwidth less than 128 kb / s do not even allow the reception of a single transmitter that achieves the quality of the conventional broadcast. If the bandwidth is used by radio content, losses can occur in other Internet-specific applications. The load on the networks is, however, less serious than by the video streaming offerings, which with increasing image quality go into the megabit / s range. Conventional broadcasting is increasingly digitized. The transmission infrastructure is constantly being expanded as a result of digitization. This is beneficial not only by the radio, but also by the Internet.

A transmitter having a satellite channel reaches an unlimited number of receivers in the satellite's area, since the receivers need neither a back-channel nor have their own network bandwidth to receive the transmitter.

Broadcasting with return channels via private networks can only reach a limited number of receivers. The communication networks are not suitable for a high number of transmitters which are to reach an unlimited number of receivers at the same time, since an ever-available bandwidth is not assigned to an Internet station. Internet stations often use foreign transmission infrastructure to transport the information to the receiver. The information must be sent by remote server systems, they are received there and retransmitted. Technical faults that occur in this case are often outside the range of influence of the respective transmitters, and to correct interference, is usually more difficult than with conventional broadcasting.

One advantage of Internet radio is the worldwide reception. While FM radio programs are regionally restricted or have satellite access to their content, worldwide access to Internet subscribers is much easier and, in principle, access to a certain internet radio station from anywhere in the world. It is therefore a regular "world receiver". Many thousands of programs from all over the world are accessible via portals, SHOUTcast. In contrast to the traditional shortwave radio receivers, which also receive broadcasters from all over the world, the quality of music in Internet radio is usually very high and the number of stations is significantly higher. Most of the well-known radiostations now also broadcast on the Internet. There are, however, exceptions to availability, if the Internet is partially or completely blocked and / or filtered by national authorities or providers.

The web radio is also a not insignificant distribution medium for independent labels and music styles, which find little space and attention in conventionally receivable radio.

sound quality
The quality of the sound (or the transmission quality) depends essentially on the bit rate and the compression method used (eg Advanced Audio Coding or MP3). In principle everything is possible, from "telephone quality" to CD quality. Most radios offer quite a good, noiseless sound, comparable to the FM radio. When the pieces of music (sound files) are loaded in the same way, there are no losses due to analog conversion. Many stations from overseas offer only bit rates of 32 kbit / s due to bandwidth limitations. For music this is too bad, but language is still very clear. The quality is i. d. R. significantly better than with a short wave receiver. Typically 128 kBit / s is used.

people power
Every PC user with internet connection can become a sender when he sends his own material, such as self-composed or GEMA-free music and own moderation. The potential listener is limited to only a few listeners with a typical DSL connection. During the Serbian revolution in 1997, the regime-critical FM radio B92 dived into the digital underground and broadcast only via the Internet.

Internet-specific differences
Webradio is not limited to secondary processing or archiving of existing programs; Numerous new formats and technologies have been developed; see Webcasting, Netcasting, Narrowcasting and Broadcatch. Also the recording of radios can be facilitated. The Streamripper plugin from Winamp allows the simultaneous recording of MP3 streams.

Licensing and costs
Whoever broadcasts radio programs exclusively on the Internet does not require an authorization in Germany (§ 20b of the Rundfunkstaatsvertrag - RStV). However, an offer, which is distributed by a server in Germany, must be displayed to the competent Landesmedienanstalt. The ad is free of charge via the Internet portals of all 14 Landesmedienanstalten in Germany; the omission of the advertisement or an incorrect advertisement may be subject to a fine of up to EUR 500,000 (§ 49 (1) sentence 1 No. 18 RStV). However, the Bavarian regional center for new media (BLM) calls a capacity threshold of 500 simultaneous listeners, from which only an advertisement is required. This reflects the legal situation correctly. § 20b and § 49, para. 1, sentence 1, No. 18 RStV only speak of "radio programs" exclusively distributed on the Internet. However, it must be noted that, according to the exemption provision in § 2 para. 3 no. 1 RStV, such offers are not broadcasting, which are offered "at least less than 500 potential users at the same time reception". Electronic information and communication services which are neither broadcasting, P. Of the Broadcasting Treaty or telecommunication services i. S of the Telecommunications Act, telemedia i. P. Of § 2 para. 1 sentence 3 RStV and as such pursuant to Art. Section 54 (1) sentence 1 of the German Interstate Broadcasting Corporation (RStV).

In Germany, for example, charges are charged for GEMA (minimum remuneration 30 Euro / month) and GVL (minimum remuneration non-commercial: 500 Euro / year, commercial: 1500 Euro / year) if the web radio plays royalty-releasing music. Additional costs arise through the "traffic" (the transmitted data volume): The more people listen, the more expensive it becomes for the sender. Classic broadcasters, which simulate their broadcasts over the Internet ("simulcasten"), have generally concluded flat-rate contracts with their streaming providers.

technology
Streaming Server
In order to reduce the amount of data to be transmitted over the Internet, lossy audio compression processes such as MP3, Ogg Vorbis or Real Audio are normally used (see streaming formats); for the encoding are various highly specialized streaming codecs available. The main requirement for such special streaming codecs is the highest possible data compression, while the streaming data formats must also contain additional information (eg metadata, advertising, control information, etc.).

As a streaming server, programs such as Icecast, SHOUTcast, Nicecast or the QuickTime Streaming Server can be used.

The transmission is performed by means of special streaming protocols (live streaming) or via the file transmission protocols HTTP and FTP (on-demand streaming). The main requirement for special streaming protocols is a high error tolerance, so that as far as possible at least five percent of packet losses can be compensated for without visible or audible quality losses.

Streaming clients
In addition to an Internet connection, so-called streaming clients are required to receive webradios. As a streaming client, computer programs can be used on PCs or smartphones. But also special hardware solutions such as MediaCenter or Player are possible. These are often referred to as Internet or Webradio in trade. Some streams work only with a few proprietary clients, Flash or only in the browser of the radio web page. Many MP3 / AAC stream offers, Such as those from the Shoutcast portal, are standardized to the extent that they are compatible with most popular media player programs (eg Winamp, VLC media player, Windows Media Player, etc.). This makes zapping through various transmitters considerably easier.

radio equipment
Especially since the proliferation of wireless internet connections via WLAN (WiFi) or mobile telephony, the receipt of radio transmitters via the Internet is no longer essentially limited to the PC. There are now more independent web radio receivers, for example for the living room, which can be connected to the Internet via the (WLAN) router. The devices can be searched for stations all over the world, as far as these are listed in the extensive lists of manufacturers' portals. According to the selection criteria Land (location) and musical direction (genre), the navigation opens a quick access. Since there are very few manufacturers for the built-in chipsets, the menu management is often identical across all brands. Most devices also offer the possibility to manage the station selection via the web portals of the manufacturers on the PC. Some of these devices offer good sound characteristics and can also be connected to the stereo system. Other devices feed the signal from the router into the TV. Webradio over the mobile phone is standard in smartphones. Latest game consoles can also play web radio. In addition, different radios also have additional reception options for DAB and / or FM stations.

televisions
Modern TV sets with an Internet connection and HDMI sticks with a corresponding software can also play Internet radio.

distribution
The distribution of the streams can be done centrally or decentrally via P2P technology. While the technical or financial requirements are high in the central distribution, the P2P technology offers a simple and cost-effective way to produce web radio due to the low bandwidth requirements of the transmitter. A disadvantage of the P2P technology is the unstable data flow. The most popular software producers in this area are peercast and flatcast.