Journal of KIISE:Information Networking (한국정보과학회논문지:정보통신)

Korean Institute of Information Scientists and Engineers (한국정보과학회)
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An Enhanced TFRC Congestion Control Mechanism for Mobile Environments

무선 이동 환경을 위한 개선된 TFRC 혼잡제어 메커니즘

  • 최미라 (이화여자대학교 컴퓨터학과) ;
  • 이미정 (이화여자대학교 컴퓨터학과)
  • Published : 2003.12.01
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Abstract

TFRC(TCP-Friendly Rate Control) is proposed to satisfy the demands of multimedia applications while being reasonably fair when competing for bandwidth with TCP flows[1-3]. However, TFRC has a shortcoming that the fairness and throughput are degraded when the mobile host using TFRC experiences handoffs. This paper proposes a new control mechanism based on TFRC, which deals with the congestion caused by handoffs as well as the losses caused during the handoffs. The simulation results show that our mechanism achieves better throughput and fairness compared to TFRC for repeated handoffs.

멀티미디어 응용프로그램의 요구 조건을 만족시키면서 TCP 응용프로그램과 공존할 수 있는 혼잡제어 메커니즘으로 TFRC(TCP-friendly Rate Control)가 제안되었는데, TFRC는 TCP 트래픽과 전송 대역폭을 공정하게 공유한다는 기본 특성을 지닌다[1-3]. 그런데, 실험을 통해 살펴본 결과 TFRC 혼잡제어 메커니즘이 무선 이동 환경에 적용될 경우에는 이동호스트가 핸드오프를 거듭할수록 처리율 및 공정성이 저하됨을 알 수 있었다. 이에 본 논문에서는 무선 이동 환경에서의 TFRC 성능 향상을 위해 TFRC가 핸드오프 시 발생한 패킷 손실을 처리하는 방안과 핸드오프 직후 구동하는 혼잡제어 방식을 제안하였다. 시뮬레이션에 의하여 연속적인 핸드오프가 발생하는 무선 이동 환경에서 제안하는 방안이 기존 TFRC에 비해 더 높은 처리율을 유지할 수 있고 공정성도 향상시킴을 볼 수 있었다.

Keywords

References

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