인터넷에서 고품질 오디오 스티리밍 서비스를 위한 복합적 QoS 보장기법

Abstract

This paper describes a hybrid QoS guarantee scheme for high quality audio streaming services on the Internet. One of the continuous multimedia data, digital audio, has the timing restrictions on transmission and playback over the packet switching networks. The continuous playback of the audio data requires the isochronous transmission of the audio data packet through the Internet. In order to retain the QoS at the ultimate destination (client) as the same as servers provide, the transmission protocols should consider the error conditions such as packet loss, and out of order delivery. Generally, the protocols supporting the transmission of continuous multimedia data do not recover the errors due to the packet loss, and out of order delivery. These are working good for the audio and video streaming services with the toll quality, but not for the high quality streaming services, such as the surround hi-fi sound/music playback. The hybrid QoS guarantee scheme includes the three mechanisms to overcome the problem. First, the selective retransmission is adopted to recover the packet loss with the minimal

overhead. Second, the adaptive buffering at client-side is designed to prevent from the starvation of audio data during the retransmission. Finally, the adaptive transmission rate at server-side is also used to maintain the isochronous transmission even after the retransmission due to packet loss. The experiments haven good results of the hybrid QoS guarantee scheme for the high quality audio streaming services on the Internet.