Bandwidth characteristics of multimedia data traffic on a local area network

Limited spacecraft communication links call for users to investigate the potential use of video compression to optimize bandwidth allocations for multimedia interaction. The objective of the study is to determine the transmission characteristics of data types independently and then in a multimedia mode over Ethernet. Commercial desktop video teleconferencing video compression hardware and software were used and typical task scenarios selected. The data packet size, number of packets, and the network utilization were recorded. Each data type-compressed motion video, text and/or bit mapped graphics, and a compressed image file-was transmitted independently and characterized. Then transmission of a multimedia combination was characterized. The multimedia data used transmission bandwidths of 365 kbps or less, according to the frame rate of the motion video. These characteristics are found to be compatible with Space Station Freedom capabilities. Even uplink imagery to SSF may be performed at minimal frame rates and/or within seconds of delay depending on the user´s allocated bandwidth