• Title/Summary/Keyword: additional retransmission

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Study on Low Delay and Adaptive Video Transmission for a Surveillance System in Visual Sensor Networks (비디오 센서 망에서의 감시 체계를 위한 저지연/적응형 영상전송 기술 연구)

  • Lee, In-Woong;Kim, Hak-Sub;Oh, Tae-Geun;Lee, Sang-Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.5
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    • pp.435-446
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    • 2014
  • Even if it is important to transmit high rate multimedia information without any transmission errors for surveillance systems, it is difficult to achieve error-free transmission due to infra-less adhoc networks. In order to reduce the transmission errors furthermore, additional signal overheads or retransmission of signals should be required, but they may lead to transmission delay. This paper represents a study on low delay and adaptive video transmission for the unmanned surveillance systems by developing system protocols. In addition, we introduce an efficient and adaptive control algorithm using system parameters for exploiting unmanned surveillance system properly over multi-channels.

Effect Analysis of a Authentication Algorithm in IPsec VPN Satellite Communication (IPsec VPN 위성통신에서 인증알고리즘이 미치는 영향 분석)

  • Jeong, Won Ho;Hwang, Lan-Mi;Yeo, Bong-Gu;Kim, Ki-Hong;Park, Sang-Hyun;Yang, Sang-Woon;Lim, Jeong-Seok;Kim, Kyung-Seok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.5
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    • pp.147-154
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    • 2015
  • Satellite broadcasting networks, like if you have if you have just received information that everyone must bring the required security attributes this earth should be done as encryption. In this paper, a satellite communication network AH additional security header in transport mode IPsec VPN by applying the SHA-256 and MD-5 authentication algorithm to authenticate the data portion Error rate and analyze the BER and Throughput. First, to generate a normal IP packet added to IPsec transport mode security header AH were constructed internal authentication data by applying the SHA-256 and MD-5 algorithm. Channel coder was applied to the Rate Compatible Punctured Turbo Codes, packet retransmission scheme Hybrid-ARQ Type-II and Type-III were used. Modulation method was applied to the BPSK, the wireless channel Markov channel (Rician 80%, Rayleigh 20% and Rician 90%, Rayleigh 10%) as an authentication algorithm according to the satellite channel state analyzed how they affect the error rate and Throughput.

UDP with Flow Control for Myrinet (Myrinet을 위한 흐름 제어 기능을 갖는 UDP)

  • Kim, Jin-Ug;Jin, Hyun-Wook;Yoo, Hyuck
    • Journal of KIISE:Information Networking
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    • v.30 no.5
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    • pp.649-655
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    • 2003
  • Network-based computing such as cluster computing requires a reliable high-speed transport protocol. TCP is a representative reliable transport protocol on the Internet, which implements many mechanisms, such as flow control, congestion control, and retransmission, for reliable packet delivery. This paper, however, finds out that Myrinet does not incur any packet losses caused by network congestion. In addition, we ascertain that Myrinet supports reliable and ordered packet delivery. Consequently, most of reliable routines implemented in TCP produce unnecessarily additional overheads on Myrinet. In this paper, we show that we can attain the reliability only by flow control on Myrinet and propose a new reliable protocol based on UDP named RUM (Reliable UDP on Myrinet) that performs a flow control. As a result, RUM achieves a higher throughput by 45% than TCP and shows a similar one-way latency to UDP.