Streaming media
Precursors
The Telephone Music Service, a live jukebox service, began in 1929 and continued until 1997. The clientele eventually included 120 bars and restaurants in the Pittsburgh area. A tavern customer would deposit money in the jukebox, use a telephone on top of the jukebox, and ask the operator to play a song. The operator would find the record in the studio library of more than 100,000 records, put it on a turntable, and the music would be piped over the telephone line to play in the tavern. The music media began as 78s, 33s and 45s, played on the six turntables they monitored. CDs and tapes were incorporated in later years.
Precursors
The business had a succession of owners, notably Bill Purse, his daughter Helen Reutzel, and finally Dotti White. The revenue stream for each quarter was split between 60% for the music service and 40% for the tavern owner. This business model eventually became unsustainable due to city permits and the cost of setting up these telephone lines.
Early development
Terminology in the 1970s was at best confusing for applications such as telemetered aircraft or missile test data. By then PCM [Pulse Code Modulation] was the dominant transmission type. This PCM transmission was bit-serial and not packetized so the 'streaming' terminology was often a confusion factor. In 1969 Grumman acquired one of the first telemetry ground stations [Automated Telemetry Station, 'ATS'] which had the capability for reconstructing serial telemetered data which had been recorded on digital computer peripheral tapes. Computer peripheral tapes were inherently recorded in blocks. Reconstruction was required for continuous display purposes without time-base distortion. The Navy implemented similar capability in DoD for the first time in 1973. These implementations are the only known examples of true 'streaming' in the sense of reconstructing distortion-free serial data from packetized or blocked recordings. 'Real-time' terminology has also been confusing in streaming context. The most accepted definition of 'real-time' requires that all associated processing or formatting of the data must take place prior to availability of the next sample of each measurement. In the 1970s the most powerful mainframe computers were not fast enough for this task at significant overall data rates in the range of 50,000 samples per second. For that reason both the Grumman ATS and the Navy Real-time Telemetry Processing System [RTPS] employed unique special purpose digital computers dedicated to real-time processing of raw data samples.
Reading List
Report Issue