Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
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Access Delay Characteristics of Wi-Fi Network According to User Increase in Subway Section

지하철 구간에서 이용객 증가에 따른 Wi-Fi 접속 지연 특성

  • Koh, Seoung-chon (Department of Railway System, Seoul National University of Science and Technology) ;
  • Choi, Kyu-Hyoung (Department of Railway Electrical/Signaling Engineering, Seoul National University of Science and Technology)
  • 고승천 (서울과학기술대학교 철도시스템학과) ;
  • 최규형 (서울과학기술대학교 철도전기신호공학과)
  • Received : 2015.03.29
  • Accepted : 2015.05.07
  • Published : 2015.05.31
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Abstract

LTE and Wi-Fi networks provide wireless communication services to passengers in subway where the number of network access fluctuates according to passenger movement. While the number of network access increase, LTE can provide stable communication service but Wi-Fi suffers temporal access delay to network. This paper analyzes the increase in access delay of Wi-Fi network according to increasing user in subway section by making mathematical modeling of Wi-Fi network and simulation study. The access delay characteristics of Wi-Fi network is measured along an subway line and the results are compared to the theoretical study. These results can be applied to the connection method to build an efficient network structure between LTE and Wi-Fi interworking network and the future introduction of LTE-R.

지하철에서는 주로 LTE와 Wi-Fi를 통하여 급증하는 무선데이터서비스를 제공하고 있다. 승객의 이동에 따라 이용객 수가 급변하는 특성을 가지고 있으며, LTE는 사용자가 증가해도 안정적인 서비스 제공이 가능한 반면에 Wi-Fi는 이용객이 증가하면 접속시간이 증가하는 등 성능이 크게 저하되는 현상이 발생한다. 본 논문에서는 Wi-Fi 전송망에 대한 수학적 모델링 및 시뮬레이션을 통하여 이용객 증가에 따른 접속지연 증가 특성을 분석하였으며, 영업운영 중인 지하철 10개 역 구간에서 Wi-Fi 망에의 접속지연 및 손실률을 측정하여 비교하였다. 측정 및 분석 결과는 지하철에서의 LTE와 Wi-Fi 간 데이터 오프로딩 구성에 필요한 접속방법 및 향후 LTE-R 도입시 효율적인 망 구성에 적용할 수 있다.

Keywords

References

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