Audio/Video Communication: an overview of the state-of-the-art applications and standards

The topic described here refers to real-time communication between two or more partners by way of audio and video streaming over the Internet. Following a preliminary side-condition for a conferencing system, we consider here the state of the art of solutions that do not depend on special encoding hardware or special network connections on the end user’s side, as users are expected to use their off-the-shelf computers for communication. Further, the system should offer user and conference management and should be possibly integratible with alternative audio/video input end points like telephones or even conferencing products of different vendors. Another desirable feature is the availability of application sharing. Audio video communication (AVC) shall be defined here as real-time transmission of audio and video data over public WAN (wide-area networks), namely the current public Internet; including transmission error handling (error concealment and correction) and channel coding of the transmitted signals into compressed streams for bandwith minimization.