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Link Availability of Terrestrial Free-space Optical Communication Systems in Korea

우리나라 옥외 무선광통신 시스템의 링크 가용성

  • Mai, Vuong V. (School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Ha, Dung T. (School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Kim, Hoon (School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST))
  • ;
  • ;
  • 김훈 (한국과학기술원 전기및전자공학부)
  • Received : 2018.01.12
  • Accepted : 2018.02.14
  • Published : 2018.04.25

Abstract

We analyze the link availability of terrestrial free-space optical (FSO) communication systems in Korea. For this purpose, we utilize several theoretical models to calculate the power losses induced by absorption and scattering in the atmospheric channel, using five-year meteorological data for three major cities in Korea (Seoul, Busan, and Daejeon). Also, we estimate the power variations at the receiver caused by scintillation in the data. Those power losses and variations are used to estimate the availability of FSO links in the three cities. The results show that link availability is estimated to be over 95% in Daejeon for a 3.5-km FSO link, when the transmitter power and receiver diameter are greater than 10 dBm and 7 cm respectively. Slightly worse link availabilities are obtained for Busan and Seoul.

본 연구에서 서울, 부산, 대전의 5년치 날씨 정보를 활용하여 우리나라 옥외 무선 광통신 시스템의 링크 가용성을 이론적으로 분석하였다. 이를 위하여 기상 상태와 시계(visibility)를 이용하여 대기의 흡수와 산란이 유발하는 광전력 감쇠를 계산하였다. 또한 날씨 정보를 활용하여 신틸레이션에 의한 수신 광전력 변화를 예측하였다. 대기의 흡수 및 산란에 의한 광전력 손실과 신틸레이션에 의한 광전력 변화가 서로 무관하다는 가정 하에 수신 광전력과 수신 감도를 비교하여 링크 가용성을 도출하였다. 분석결과 10 dBm 송신기 출력과 7 cm 수광 직경을 가진 수신기를 사용한 3.5 km 시스템의 링크 가용성은 대전에서 95% 이상으로 예측되었다. 부산과 서울의 경우 대전보다 열악한 시계로 인하여 낮은 링크 가용성을 보였다.

Keywords

References

  1. M. A. Khalighi and M. Uysal, "Survey on free space optical communication: a communication theory perspective," IEEE Commun. Sur. Tut. 4, 2231-2258 (2014).
  2. H. Kaushal and G. Kaddoum, "Optical communication in space: challenges and mitigation techniques," IEEE Commun. Sur. 19, 57-96 (2017). https://doi.org/10.1109/COMST.2016.2603518
  3. H. Kim, Long-term evaluation and analysis of short-reach free-space optical link, Master Degree Thesis, Seogang University, Seoul (2004).
  4. E. Leitgeb, M. Gebhart, U. Birnbacher, W. Kogler, and P. Schrotter, "High availability of hybrid wireless networks," Proc. SPIE 5465 (2004).
  5. I. Kim and E. Korevaar, "Availability of free-space optics (FSO) and hybrid FSO/RF systems," Proc. SPIE 4530, 84-95 (2001).
  6. A. Prokes, "Atmospheric effects on availability of free space optics systems," Opt. Eng. 48, 066001 1-10 (2009). https://doi.org/10.1117/1.3155431
  7. F. Nadeem, V. Kvicera, M. S. Awan, E. Leitgeb, S. S. Muhammad, and G. Kandus, "Weather effects on hybrid FSO/RF communication link," IEEE J. Sel. Areas Commun. 27, 1687-1697 (2009). https://doi.org/10.1109/JSAC.2009.091218
  8. J. Turan and Ľ. Ovseník, "Experimental FSO network availability estimation using interactive fog condition monitoring," Proc. SPIE 10142, 1014223 1-16 (2016).
  9. A. J. Kshatriya, Y. B. Acharya, A. K. Aggarwal, and A. K. Majumdar, "Estimation of FSO link availability using climatic data," J. Opt. 45, 324-330 (2016). https://doi.org/10.1007/s12596-016-0327-4
  10. A. A. Basahel, M. R. Islam, S. A. Zabidi, and M. H. Habaebi, "Availability assessment of free-space-optics links with rain data from tropical climates," J. Lightwave Technol. 35, 4282-4288 (2017). https://doi.org/10.1109/JLT.2017.2732459
  11. I. Kim, B. McArthur, and E. Korevaar, "Comparison of laser beam propagation at 785 nm and 1550 nm in fog and haze for optical wireless communications," Proc. SPIE 4214, 26-37 (2001).
  12. M. Ijaz, Z. Ghassemlooy, J. Pesek, O. Fiser, H. Le Minh, and E. Bentley, "Modeling of fog and smoke attenuation in free space optical communications link under controlled laboratory conditions," J. Lightwave Technol. 31, 1720-1726 (2013). https://doi.org/10.1109/JLT.2013.2257683
  13. M. A. Esmail, H. Fathallah, and M. S. Alouini, "Outdoor FSO communications under fog: attenuation modeling and performance evaluation," IEEE Photon. J. 8, 1-22 (2016).
  14. S. Bendersky, N. S. Kopeika, and N. Blaunstein, "Atmospheric optical turbulence over land in Middle East coastal environments: prediction modeling and measurements," Appl. Opt. 43, 4070-4079 (2004). https://doi.org/10.1364/AO.43.004070
  15. A. A. Farid and S. Hranilovic, "Outage capacity optimization for free-space optical links with pointing errors," J. Lightwave Technol. 25, 1702-1710 (2007). https://doi.org/10.1109/JLT.2007.899174
  16. H. Yuksel, S. Milner, and C. Davis, "Aperture averaging for optimizing receiver design and system performance on free-space optical communication links," J. Opt. Netw. 4, 462-475 (2005). https://doi.org/10.1364/JON.4.000462