摘要 : This report investigates a transmission scheme of NACK (Negative ACKnowledgement) for audio video transmission in multicast communications with RVTR, which was previously proposed by the authors. In order to suppress retransmissio... 展开 This report investigates a transmission scheme of NACK (Negative ACKnowledgement) for audio video transmission in multicast communications with RVTR, which was previously proposed by the authors. In order to suppress retransmission traffic we propose a scheme to control NACK transmission according to the network load and demonstrate the effectiveness of the scheme by experiment. In our experimental system, live audio and video streams captured at a source are multicast to plural destinations. In addition, we confirm that dynamic resolution control of video improves the synchronization quality of audio streams. 收起