However video technology was to be deployed in analog television broadcasting long before it could become practical—or popular—for videophones.
During the first manned space flights, NASA used two radio-frequency (UHF or VHF) video links, one in each direction.
In 1995 the first public videoconference between North America and Africa took place, linking a technofair in San Francisco with a techno-rave and cyberdeli in Cape Town.
Many of these technologies, such as the Media space, are not as widely used today as videoconferencing but were still an important area of research.
The first dedicated systems started to appear as ISDN networks were expanding throughout the world.
The greater 1 MHz bandwidth and 6 Mbit/s bit rate of the AT&T Picturephone in the 1970s also did not achieve commercial success, mostly due to its high cost, but also due to a lack of network effect — with only a few hundred Picturephones in the world, users had extremely few contacts they could actually call to, and interoperability with other videophone systems would not exist for decades.
Videotelephony developed in parallel with conventional voice telephone systems from the mid-to-late 20th century.