Research On The Application Of FSO System Base On Broadband Access Network

Today the construction of Chinese telecommunication backbone network has the trends in perfect development, but there still are lots of competitions in different technical proposals of Broadband Access Network. Free Space Optical (FSO) is a kind of new Broadband Access technology. Comparing with optical fiber line, FSO has the advantages of short construction cycle, low cost and is an effective solution to the bottleneck problem of "Last Mile". However, the weather sensitive and the limited transmitting range are obviously shortages of FSO.By analyzing of practical FSO system, the paper describes the constitute and the core technologies of FSO. Through the research on atmospheric channel aspect, the selection principles of FSO operating wavelength are shown.The system optical source of FSO is discussed, and pointed out the Vertical Cavity Surface Emit ting Laser has good application prospect in FSO via analyzing the laser contrastively. Then the paper researches into atmospheric absorption which influences on atmosphere laser transmission, scattering, rapids, thermal blooming effect and the constructs atmospheric channel model. In addition, the other important aspect is that the author has completed the FSO system transmission experiment to telecommunication network in south area of China for the first time and practically tested the influences of system usability which can be caused by FSO. Authors analyzed the empirical datum, and concluded that the weather condition and the distance are primary factors influencing the performance of FSO system. According to the requirements of operation dealer, the paper proposes some corresponding measures to FSO products used in the application situation and the project implementation of the telecommunication network. The research shows that FSO system is suitable for the connection application of short distance in a city. The main application is network application, which includes the last kilometer broadband access, separate regional network bridging among buildings in enterprise and the campus, the metropolis optical fiber net by-pass connection, PHS, 3G, U wireless base depot connects or reserve channel of UMTS, the use of important backup skeleton line, the emergency project and the none- optical cable span environments etc.