Satellite Communication of Real-Time Packet Video Images

摘要

The paper describes major issues and problems in the use of packet satellite channels for real-time video images and suggests some solutions. The DARPA Wide Band Communication Network provides the testbed for this activity. A major idea in this paper is the automatic tradeoff between the quality and the dynamics of the communicated images in order to optimally adapt to the changes of the channel performance and to the changes of the channel performance and to the changes of the scene to be communicated. Extensive work has been performed in the past both on packet-satellite and on real-time digital video. The paper reports work which uses both of these technologies to achieve their marriage in the form of packet satellite real-time video communication. The paper suggests several techniques and describes some new approaches to encoding real-time video communication. Section 2 describes issues which are in the application of packet satellite channels for real-time video communication. Section 3 shows a general approach which addresses these issues. Section 4 describes a general methodology for signal coding and compression, and shows how it may take advantage of time coherence by using time differences while reducing quantization errors at the same time. Section 5 shows a technique for encoding dynamic values, suited for the automatic tradeoff of motion (dynamics) and sharpness. As a 'public service' this paper is accompanied by list of references regarding packet satellite channels.