A study of video transmission over explicit rate controlled network

With the emergence of broadband networks, multimedia transmissions are expected to dominate the future network traffic. Recognizing this, researchers have been devoting much effort to the investigation of video transport over broadband communication networks.; To match the characteristics of compressed video, the ideal network for video transmission should support dynamic bandwidth allocation which updates frequently according to video source's bandwidth requirement. The ideal network should also provide minimum bandwidth guarantee to make sure continuous playback with acceptable video quality. Adaptation controller is used in video transmission to adjust the output rate from video encoder to suit the network bandwidth. It is also responsible for finding out the bandwidth requirement of video source and making bandwidth requests accordingly. An outstanding issue in the design of video adaptation controller is how to define the bandwidth demand such that: (1) bounded buffering delays, (2) high quality video delivery and (3) high link utilization can be achieved.; In this thesis, we propose a demand specification framework for transmitting videos over explicit rate-controlled network. We investigate the performance and the behavior of this framework through analytical study and simulations.; The contributions of this thesis are as follows: (1) In previous studies, only the intrinsic data rate of video source is considered in the bandwidth demand calculation with no guarantee of hard delay bound. We show that in order to achieve bounded buffering delay, the smoothing buffer fullness should be included in bandwidth demand calculation. (2) To further increase the multiplexing gain, we suggest a modification to the Minimum Cell Rate (MCR) guarantee defined in the existing ABR service. Instead of assigning no less than the MCR rate to video source, the bandwidth assignment should be allowed to be lower than MCR if that is what the video source requests for. (3) Our study gives an important insight to the key of efficient use of bandwidth and high multiplexing gain, that is to make full use of the delay budget for smoothing and multiplexing. This aspect is overlooked in previous studies.