• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.301-304
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• 2001

이 논문에서는 미국과 유럽에서 디지털 CATV 전송 방식으로 각각 채택하고 있는 Opencable 시스템과 DVB-C 시스템의 전송성능을 비교하였다. 채널 환경의 신호손상요소는 랜덤잡음과 CTB (Composite Tripple Beats) 잡음을 고려하였다. 전송성능을 비교하기 위하여 각 전송시스템에 대한 모의실험장치를 S/W적으로 구현하여, 각 잡음 값에 따른 BER(Bit Error Rate) 값을 구하였다. 동일한 조건에서 모의실험을 실시한 결과, 64-QAM 모드에서는 Opencable 방식이 우수하고, 256-QAM 모드에서는 두 가지 전송방식의 성능이 비슷하다는 결과를 얻었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2C
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• pp.184-190
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• 2002

This paper compares and analyzes and analyzes the transmission performance of the OpenCable system and the DBD-C system which are adopted as the digital CATV transmission standard in U.S.A. and Europe respectively through computer simulation under the same channel environment. We considered the channel environment including the random noise and the CTB (Composite Tripple Beats) noise as channel impairments in order to compare the two standard fairly. Additionally, we analyzed the transmission performance of the OpenCable system for the various interleaving depths. We implemented each transmission system by software, and we analyzed BER values with respect to the C/N in order to compare their transmission performance. As a result of the computer simulation, to get the BER of ${10}^{-6}$ the OpenCable system requires 1.2 dB kiwer C/N than the DVB-C system in the 64-QAM mode, and the two system require similar C/N in the 256-QAM mode.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11A
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• pp.1253-1262
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• 2004

The Data Over Cable System Interface Specification (DOCSIS) protocol enables the delivery of Internet Protocol(IP) traffic over Cable TV networks with significantly higher data rates. In this paper, we assessed the performance of the DOCSIS protocol using the OPNET. The simulation can be used to predict the upstream system throughput, mean access delay and channel utilization on varying packet size and transmission stream and wid/without concatenation, and it has shown that maximum system throughput is 4.6 Mbps for channel capacity of 5.12 Mbps and packet size of 1500 bytes. The mean access delay varies depending on the offered load, and it is assumed that the offered load does not exceed the capacity of the channel. Excess offered load causes service starvation according to the assigned priority.