Classroom Companion: Business

parts of the world. The service was mandatory for commercial ships for distress 
communications until 2000 when the International Maritime Organization (a spe-
cialized UN organization) decided that telegraphy was no longer needed since 
 
Chapter 3 ·
Convergence of Technologies and Services

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satellites offered a more reliable service. The world’s oldest telecommunications 
service was terminated after about 150 years of operation. However, the technol-
ogy is still used by radio amateurs. The services offered by the telex network has 
been replaced by email, and the public X.25 packet switched data network has been 
replaced by the Internet.
Audio broadcasts have been sent as analog signals over wireless networks since 
the 1920s (also denoted “over the air audio broadcasting”). From 1993, digitized 
audio broadcasts have also been offered over the Internet (Internet radio, web 
radio, or webcasting). Over the air radio broadcasting is now also shifting from 
analog to digital technology (e.g., digital audio broadcast (DAB)) and are also 
offered as real-time services over the Internet (Internet radio) as well as over wire-
less networks. Television programs have, in addition to over the air transmission, 
been broadcasted over dedicated cable networks since the 1950s and over satellites 
since 1976. From the early 2000s, television programs have also been available over 
the Internet. Some television broadcasters, such as the BBC, offer their television 
programs on web pages in addition to delivering them over cable or satellite net-
works. The Internet allows listening to or viewing broadcast services at any time 
independently of when the program was transmitted over wireless or other media. 
There are also several pay-per-view Internet services such as Netflix and HBO 
offering movies, series, and other video content. Some television companies only 
offer their programs over the Internet.