Efficient Video Streaming Based on the TCP-Friendly Rate Control Scheme

TCP 친화적인 전송률 제어기법 기반의 효율적인 비디오 스트리밍

  • Lee, Jungmin (Department of Electronics Engineering, Kwangwoon University) ;
  • Lee, Sunhun (Department of Electronics Engineering, Kwangwoon University) ;
  • Chung, Kwangsue (Department of Electronics Engineering, Kwangwoon University)
  • Published : 2005.09.01

Abstract

The multimedia traffic of continuous video and audio data via streaming service accounts for a significant and expanding portion of the Internet traffic. This streaming data delivery is mostly based on RTP with UDP. However, UDP does not support congestion control. For this reason, UDP causes the starvation of congestion controlled TCP traffic which reduces its bandwidth share during overload situation. In this paper, we propose a new TCP-friendly rate control scheme called 'TF-RTP(TCP-Friendly RTP)'. In the congested network state, the TF-RTP exactly estimates the competing TCP's throughput by using the modified parameters. Then, it controls the sending rate of the video streams. Therefore, the TF-RTP adjusts its sending rate to TCP-friendly and fair share with competing TCP traffics. Through the simulation, we prove that the TF-RTP correctly estimates the TCP's throughput and improves the TCP-friendliness and fairness.

최근 비디오나 오디오 스트리밍 서비스와 같은 멀티미디어 트래픽이 증가하고 있다. 이러한 트래픽들은 패킷을 전달하는데 대부분 UDP(User Datagram Protocol)기반의 RTP(Realtime Transport Protocol)를 사용한다. 하지만 UDP기반의 RTP는 기본적으로 혼잡 제어 메커니즘이 없으며 현재 인터넷의 주요 트래픽인 TCP(Transmission Control Protocol)와의 형평성을 보장하지 않는다는 문제점을 갖는다. 본 논문에서는 비디오 스트림의 TCP 친화적인 전송률 조절 기법으로 TF-RTP(TCP-Friendly RTP)를 제안하였다. TF-RTP는 네트워크 상태가 혼잡하여 패킷 손실이 발생할 경우, 개선된 파라미터 산출 방법을 사용하여 경쟁하는 TCP의 전송률을 보다 정확하게 계산하여 전송되는 비디오 스트림의 전송률을 조절함으로써 경쟁하는 TCP 트래픽과 친화적으로 동작하며 네트워크 대역폭을 보다 공평하게 사용하게 된다. 실험을 통해 제안하는 TF-RTP가 TCP의 전송률을 보다 정화하게 계산하며 TCP 트래픽과의 친화성, 형평성 측면에서도 성능 개선을 보임을 확인할 수 있었다.

Keywords

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