Fiber optic communication has the advantage of large information capacity and strong anti-interference ability, its superior performance has been confirmed, and gradually replace the previous electronic circuit in modern communication system as the main communication network, and become an important way for modern communication. And electronic circuits of the communication system is short of development of fiber optic communication system advantages, which becomes a bottleneck.
In fiber optic transmission, only scientific and reasonable communications architecture can play the advantages of optical fiber system, composed of ideal high speed, large capacity, good quality fiber optic network. The original electronic circuits of communication in all optical network is a huge obstacle. Existing in traditional telecommunication networks and fiber optic networks coexist the photoelectric conversion process, and the combination is limited by electronic devices, optoelectronic information exchange capacity depends on the working speed of electronic parts, was larger in photoelectric switching optical network bandwidth becomes narrow, and the network bandwidth is limited.
So it needs to exchange nodes in fiber optic communication network directly in optical switching Mulitmode Singlemode Media Converter Technology and eliminate photoelectric conversion process, so as to release the bandwidth of optical fiber communication, realize the advantages of its communications capacity and high communication rate. So high-profile optical switching technology, is considered to be a new generation of broadband technology.
1.The way of Mulitmode Singlemode Media Converter switching
Optical signal multiplexing generally have space division multiplex(SDM) and time division multiplexing(TDM) and wavelength division multiplexing(WDM). The corresponding also have space division in exchange, and to complete three wavelength division multiplexing channel switching.
TDM multiplexing method is commonly used in communication network signal, a channel can be divided into several different time slot, each light path signal distribution takes different time slot, will be a fitting for the baseband channel high speed data flow transmitted light. Time division switching time slot will be used to implement. Time slot switching device to write input signal sequence into the light cache, and then read out according to the established order, and the implementation is a frame of any time slot switching to another a time slot, complete the temporal exchange program. General bistable laser light can be used as a cache, but it can only according to the output, cannot meet the needs of high speed switching and high capacity.
And optical fiber delay line is a kind of division switching equipment, time-division multiplexing of optical path signal input to the optical divider, its only a the same time slot on each output channel of light signal, and then these signals through different optical delay line, through the different delay line signals obtained at different time delays, the final combination fits the signal before reusing the original signal, thereby completing time division switching.
WDM technology in optical transmission system, they are widely used in optical WDM system, the source and destination end you need to use the same wavelengths of light to transmit signals, such as not multiplexing when reuse each multiplexing terminal you need to use additional multiplexing equipment, thus increasing the cost and complexity for the system. So if in the WDM system, using wavelength division optical switching on intermediate transport nodes, can meet for an additional device implements the source end of the WDM system with the purpose, and can save system resources, improve resource utilization.
Wavelength division first optical switching systems will light signal with the resolver is divided into multiple channels to meet the need of wavelength division optical wavelengths, finally will receive signals after reuse of a dense wavelength division multiplexing signal, output by a fiber optic cable, it is using the characteristics of the optical fiber broadband and low dissipation in wavelength multiplexing multiple optical signals, greatly improving the optical fiber channel utilization and improve the capacity of communication system.