On the telecommunications optical fiber communication technology

Abstract: The optical fiber communications can be applied not only to the trunk lines of communication can also be used in electric power communication control system, for industrial monitoring, control and use in the military field but also more and more widely. Optical fiber communication technology as an important support information technology platform for the future information society will play an important role.

Keywords:: optical fiber communication technology advantages
access technology
0 Introduction In recent years, with the transmission and exchange of technology advances, the core network has been largely achieved optical, digital and broadband technology. Meanwhile, with the rapid growth of the business and the increasingly rich multimedia services, enabling users business needs of residential networks is not limited to the original voice, data and multimedia services have become an irresistible trend, the existing voice service access network has increasingly become a bottleneck restricting the construction of information highway, as the development of broadband integrated services digital network barriers.

1
optical fiber communication technology defines the use of optical fiber communication as an information carrier, optical fiber communication as a transmission power of style. In optical fiber communication system, as the carrier of the light frequency is much higher than the frequency of the waves, but as a transmission medium off than coaxial cable or fiber-optic waveguide, the loss is much lower, so that the capacity of optical fiber communication than the microwave communications big several times. Glass fiber is constructed, it is the electrical insulator, so do not worry about ground loops between the optical fiber around the very small, light in optical fiber transmission, optical signals will not worry about the transmission of information leakage is intercepted, fiber core is very small, composed by the multi-core cable diameter is small, so use fiber as a transmission channel, the transmission system footprint is small, crowded underground pipeline to solve the problem.

2 optical fiber communication technology advantages
2.1 frequency band is extremely wide, fiber optic communications capacity than copper wire or cable
a much larger bandwidth, optical fiber communication systems in the light of the modulation, and optical modulation dispersion characteristics. San wavelength window, with dozens of single-mode optical fiber broadband GHz · km. For single-wavelength optical fiber communication systems, due to the electronic bottleneck terminal equipment can not play fiber bandwidth advantage. Usually a variety of complex techniques to increase transmission capacity, especially now that the dense wavelength division multiplexing technology greatly increased the transmission capacity of optical fiber. Patients with dense wave division multiplexing optical fiber transmission capacity can be expanded to several times to several times. Currently, the single-wavelength optical fiber communication systems in general 2.5Gbps transfer rate to 1OGbps, dense wave division multiplexing technique using multi-wavelength transmission system to achieve the transmission rate has reached single-wavelength transmission systems hundreds of times. Huge bandwidth potential of the single-mode fiber as the first choice for Broadband Integrated Services Network media.

2.2 low loss, long-distance relay current, practical optical fiber communication systems using multiple quartz fiber, such fiber loss can be less than 0.20dB/km, so that the transmission loss than any other transmission medium losses are low, therefore, the composition of its relay from the optical fiber communication system than other media to form a system much longer.

If in the future use of non-quartz system, very low-loss optical fiber, the theoretical analysis of the lower loss can be reduced. This means that through the optical fiber communication systems can span greater distances without repeaters; for a long-distance transmission line, due to reduction in the number of relay stations, system cost and complexity can be greatly reduced. At present, the composition of the silica fiber optical communication system has a maximum range of up to 200 relay km, from the non-quartz system composed of very low loss optical fiber communication system to a few kilometers, this communication system for reducing costs, improving reliability and stability of particular importance.

2.3 anti-electromagnetic interference we know that fiber raw materials, insulation made from quartz material, not easily corrode, and insulation. Associated with it an important feature of the optical waveguide for electromagnetic interference immunity, it is not the nature of the lightning interference, ionosphere interference changes and sunspot activity, are not subject to anthropogenic emissions of electromagnetic interference, it can also be used high voltage transmission line parallel to the erection or combined to form composite conductor with the power cable. It is a non-conductive medium, in which the alternating electromagnetic wave does not produce the induced electromotive force, which will not have nothing to do with the signal noise. This is to make it parallel to the power lines and electrical lay near the railway, it will not be electromagnetic interference. This is for the strong electrical fields (such as power transmission lines and electrified railway) communications systems in particular. Fiber diameter
2.4 thin, light weight, soft and easy to lay the fiber core diameter is very small, about 0.1mm, the multi-core optical fiber cable composed of very small diameter, 8-core cable cross-section diameter of about 10mm, the standard coaxial cable to 47mm. This use of fiber optic cable as the transmission channel, the transmission system footprint is small, crowded underground pipeline to solve problems, save the underground pipeline construction investment. In addition, the fiber weight, flexible, fiber optic cable is much lighter than the weight of the aircraft, spacecraft and satellites can reduce the use of optical fiber communications aircraft, ships, spacecraft weight, appears to be more meaningful. Also, the fiber soft and can be around, easy to bundle, to get the high density of small diameter fiber optic cable.

2.5 security performance requirements of communications systems is one of the important security is good. However, with the development of science and technology, electronic means of communication can easily be intercepted, as long as open wire or cable in the vicinity of a special receiver to get open wire or cable can transmit information, not to say the wireless communication. Links to Research Papers Download http://www.hi138.com