Research And Design Of Composite PON Of SCM/TDM

With the development of Broadband, there appears an explosive growth of people's demand of network bandwidth, but the traditional access network can't meet such high requirement. PON is proposed to be the key technology to solve this problem.PON is regarded as the next generation broadband access by the world. Recently, due to the dramatic reduction of prices of optical components and the higher requirements of bandwidth, PON has shown its advantages in economy and technology.The standards and the development of PONs are different in different countries. EPON and GPON are the mainly technology of transmitting Ethernet signals, among which, as multi-service broadband access, EPON has excellent characteristics. At present, EPON/GPON is regarded as an effective way to solve the " triple play".EPON synthesizes the advantages of PON and Ethernet:low-cost, high-bandwidth, extensible, flexible and fast service restructuring, good compatibility with Ethernet, large space for upgrading, easy management and so on. However, it is hard to achieve the transmission of HD video and to upgrade the service of video by EPON, which affects the access of whole business. ROF is used to transmit millimeter wave by the technology of subcarrier, which is an effective way to solve high-capacity of bandwidth of optical communication, and this paper presents a composite PON-Super PON, which combines SCM PON, EPON, GPON by using the technology of wavelength division multiplexing, transmitting three different wavelengths of optical wave. This consequently helps to carry different businesses and satisfy the demands of different kinds of customers. Super PON is conducive for the full service access. In Compound PON, we use different optical waves to carry Ethernet signals, GFP signals and RF signals respectively, and then we couple these three optical waves to one optical fiber by the technology of WDM. This program could meet the different needs of users:The users who require low confidentiality of information can choose the service of EPON, while those enterprises which require high degree of confidentiality of information could use the GPON business. This structure is conducive for triple play, and has the following advantages:the most simplified light path, easy maintenance, expansion and upgrading easily. EPON has been applied in some areas in China for many years, the technology is relatively mature. Consequently, the promotion of SCM/Ethernet PON in China is feasible and superior.There is cross-power crosstalk between different waves when they transmit in one optical fiber simultaneously, especially for long-distance transmission, the pulse broadening by dispersion could increase the BER of signals, and then affects the receiving of users'businesses. The paper mainly analyzes the case two different wavelengths of optical waves transmitting in SCM/Ethernet PON by modulating the RF signals on the wavelength of 1550 nm, and using the wavelength of 1490 nm to carry the Ethernet signals. When simulating, Gaussian signals are carried by the wavelength of 1490nm, and we analyze how dispersion and cross-power affect the BER of Gaussian signals when two optical waves transmit long distance in one optical fiber. It can help to improve the system and provide a theoretical basis for reducing BER by analyzing the relationship between all the parameters and BER.At last, the paper looks into the further development of the PON, introduces the FTTH and the tripe play.