Awareness-driven media stream transmitting framework of virtual tele-conferencing

In this paper, we propose. an awareness-driven media stream transmitting framework of virtual tele-conferencing. First we introduce a space model of awareness and Interaction, which define the awareness and interaction between objects and determine the media streams transmitting at run time. Based on the space model of awareness, we design a multicast middleware above the socket layer; participants of a multicast session are connected via a virtual multicast tree that consists of unicast connections between end hosts where the cost of each link is the awareness degree between sender and receiver. According to different awareness degree, different type of data such as status, live audio and video will be transmitted to different objects composing dynamic multicast group. This framework supports flexible dynamic multicast, which effectively reduces the total bandwidth and has high scalability for system extension.