In the early 1980s, the 2Mbps color digital video conferencing system developed by Japan and the United States formed a non-standard domestic video conference network. In the mid-1980s, the rapid development of large-scale integrated circuit technology, breakthroughs in image encoding and decoding technology, and reduced channel costs provided good development conditions for video conferencing to become practical. However, the digital video conference system of this period has always used dedicated codec hardware and software. The codecs used by the interoperable conference terminals must be from the same manufacturer, otherwise they can not work properly, which greatly hinders the extendibility of the video conferencing system and interoperability between systems.
Since the 1990s, the scale, number of users, and business volume of the Internet based on the TCP/IP protocol have increased exponentially. Especially in the mid-1990s, the rapid development of the computer Internet has had a huge and profound impact on the telecommunications industry. Multimedia communication systems based on packet switching networks have gradually become the focus of attention of researchers and telecommunications, network and computer manufacturers.
Video conferencing has gone through two stages: analog video conferencing and digital video conferencing. Analog video conferencing is an early video conferencing, and this kind of communication service was available in the 1970s. At that time, black-and-white images were transmitted, and it was limited to holding meetings between two locations. Nevertheless, the video conferencing still needs to occupy a very wide frequency band, the cost is very high, so this kind of video conference has not been developed.