optic communications
1.Lead as impurity in RIG (rare earth iron garnet) Faraday rotators used for fibre optic communications systems.
2.Forward error correcting techniques (FEC) has become one of the key techniques in high-speed and long distance optic-fiber communications.
3.The principles, characteristics of fiber Raman amplifier(FRA) are introduced. And the functions of distributed fiber Raman amplifier(DFRA)in extending transmission distance and increasing gain are described. The application of DFRA in repeaterless submarine fiber optic cable communications is also described.
4.RoF (radio over fiber) technique uses analogue fiber optic links to transmit and distribute microwave/millimeter wave signals. It integrates the techniques of optical communications and wireless communications, and will act as a more important role in military and wireless communications. RoF has been a hot research field in the world.
5.The municipality has an advanced modern communications system, with an optic-fiber transmission network of 3,000 kilometers of large capacity and high efficiency, a long-distance automatic exchange capacity of 20,000 terminals, electric lines of 30,000 and a basic multimedia and high-speed broad-band communications network.
6.Communications between the MOSHIP and the SRV will be much improved through the use of a lightweight fibre-optic umbilical allowing for their transmission of vital navigation and command information.
7.A joint venture of French communications companies has broken new ground by stringing fiber-optic cables to the homes of 1,500 telephone customers in the northern town of Biarrits and setting up an experimental two-way video system in which customers see one another while they chat.
8.The Chinese armed forces regard the participation in the construction of transportation, energy, water con-servancy and communications projects as the focal points in supporting the development of the western region. They have engaged in the expansion or reconstruction of 8 airports, 3 national highways and 4 expressways; the construction of 9 energy facilities such as pipelines, natural gas fields and oil-and-gas fields; the construction of 7 hydropower stations and 19 trunk diversion channels; and the laying of 8 optic telecommunications cables totaling more than 20,000 km.
