Cable (optical fiber cable) is designed to meet the optical, mechanical or environmental performance specifications manufactured, it is the use of the sheath into one or more coated optical fibers as the transmission medium and may be used individually or in a group communication cable assembly. Mainly by the fiber optic cable (glass as thin as a hair) and protective plastic casing and plastic sheath formed, and not within the cable, gold, silver, copper and aluminum and other metals, usually no recycling value. Fiber optic cable is a certain amount of the composition according to a certain way of the cable core, outsourcing jacket, some clad outer sheath to achieve a communication line optical signal transmission. That is: the cable by the optical fiber (light transmitting carrier) after the formation of a certain process. The basic structure of the cable is normally provided by the core, strengthen steel, fillers and jacket several components, can additionally also waterproof layer, a buffer layer, an insulating metal wires and other components. In 1976, the American Institute in Atlanta Bell built the first optical fiber communication experiment system, using a fiber optic cable containing 144 fibers manufactured by Western Electric Company. In 1980, a commercial multi-mode fiber optic cable from the beginning made use on the trunk and a few long-distance lines between local stations. Commercial single-mode fiber optic cable made on long-distance lines began to use in 1983. In 1988, the connection between the United States and Britain and France's first successful transatlantic submarine cable laying, and soon built the first submarine cable across the Pacific. China in 1978, developed its own communications cable, using a multimode optical fiber, cable Stranded core structure. He has worked in Shanghai, Beijing, Wuhan and other places to carry out field tests. Soon after in the local telephone network as interoffice trunks trial, after 1984, gradually for long-distance lines, and began using single-mode fiber. Communications cable than copper cables have greater transmission capacity, long-distance relay, small size, light weight, no electromagnetic interference, has developed into a long haul since 1976, the city relay, coastal and transoceanic submarine communications , as well as local area network, private network wired backbone transmission line, and the city began to field the subscriber loop distribution network development, FTTH, broadband integrated services digital network to provide transmission lines. Cable network is the cornerstone of the information highway is the main transmission cable tool in today's information society various information networks. If the "Internet" called "information superhighway", then, the cable network is the cornerstone of the information highway --- cable network is the physical routing of the Internet. Once a cable destroyed and blocked, "information superhighway" in this direction will come to destruction. Optical transmission of information by, in addition to the usual telephone, telegraph, facsimile and television signals, bank transfer, stock quotes and other bulk transmission of the moment can not be interruptions. Telecommunication cable transmission system developed by the PDH to SDH transmission rate from the original 140MB / S development to 2.5GB / S, 4 × 2.5GB / S, 16 × 2.5GB / S or even higher, that is to say, one pair of cores can open 30,000, 120,000, 480,000 or more, then the road to development. Such a large transmission capacity, the cable once the blockade is not only caused huge losses to the telecommunications sector, and because of poor communication, the masses will cause inconvenience, such as a computer user can not access, the stock market does not know, can not bank remittance, remote deposit Take vanish into thin air, all kinds of information can not be transmitted. In remote mountainous areas, once the cable is lost, so that the county or several counties along the cable in the communication isolation, becoming the island. Damage to military and political authorities and the people caused is immeasurable.