In the 21st century, because of the rich video and image content on the Internet, the demand for bandwidth has grown rapidly, and the current wired broadband access methods mainly include technologies such as XDSL, HFC, FTTX+LAN and so on. The most commonly used in XDSL technology is ADSL, which uses a pair of existing telephone lines to theoretically provide users with an asymmetric transmission rate of 1.5 Mbps to 8 Mbps downstream and 640 Kbps to 1 Mbps upstream.
However, when ADSL encounters wide-bandwidth services such as distance education, online games, on-demand TV, telemedicine, and e-government services, its ability to withstand is limited and its service quality will be reduced. HFC utilizes CableModem for data transmission, after bidirectional transformation of the existing broadcast television network, it also takes into account IP services on the basis of transmitting broadcast television. HFC upstream can provide 40MHz bandwidth, but bandwidth sharing is also difficult to meet the future development of a large number of upstream services.
FTTx+LAN access is a way of using Gigabit Ethernet switching technology, using optical fiber plus 5 types of wiring, and using computer LAN to access end users to achieve high-speed user information access. It can meet the needs of current broadband multimedia services , But cannot broadcast radio and television. XDSL, HFC, FTTX+LAN are not the ultimate access methods. The interactive high-definition viewing revolution launched by HDTV has made fiber with high bandwidth, large capacity, low loss and other excellent characteristics become the data transmission to the client The inevitable choice of media. FTTH is a recognized long-term goal and final solution for the development of access networks. There are three main solutions for FTTH: point-to-point FTTH solution, point-to-multipoint EPON FTTH solution and GPON FTTH solution.
