Optical is a transmission of optical signal terminal equipment, the main transmission monitoring area involved in the signal source. It is responsible for photoelectric conversion and light emission and light reception. In short, the optical machine is the role of a line, in this line can transmit video, data, Ethernet, telephone, etc., and can be any combination of its number. Because the Optical Transceiver is transmitted by means of fiber, so it has a distance: ordinary level can transmit 30KM; no brain: no software support, stable operation; zero attenuation: high fiber purity, minimal attenuation; no interference: Magnetic field interference; construction is simple: can be buried, pipe, overhead, etc. to deploy and so on.
According to different standards, Optical can also be divided into different types. In accordance with the transmission mode, the optical transceiver can be divided into the single-mode optical transceiver and multi-mode optical transceiver; According to the signal processing, can be divided into analog optical and digital Optical transceiver; In accordance with the network, can be divided into point-to-point optical and node-to-point Optical transceiver, and converged transceiver. The following mainly explain the most commonly used digital optical and point-to-point Optical transceiver.
Digital optical transceiver will be multi-channel analog baseband video, audio, data, high-resolution digital, the formation of high-speed digital stream, and then multiplexed the digital stream, through the launch of the optical transceiver, and then through the other end of the receiving transceiver to receive, Demultiplexing, recovery into the digital signal, and then through the digital-analog conversion (A / D analog conversion) to restore the analog video, audio, data. The invention of the digital optical transceiver has solved the shortcomings of the long-term stability of the optical transceiver, such as the influence of the environmental interference, the poor transmission quality and the long-term stability. The main advantages of the transmission distance is long, up to 120km; to use multi-level transmission mode; by the environmental interference is small, high transmission quality; support signal capacity up to 16, or even more (32, 64, 128 Road) and other advantages.
In the selection of optical machine, the user first to decide what kind of data transmission program, that is, using point-to-point, or node or convergence and so on. Point-to-point is the most basic way of transmission, as the name implies, is a little point to another point of transmission, this transmission is more waste of fiber. The principle is to install a transmitter at the front of the monitoring station, the various types of electrical signals into optical signals, through the terminal to receive optical transceiver and then re-converted into electrical signals, between the transmitter and receiver cable connection. Node type is used in hand-handle in series, can be set in a single cable on a number of nodes, can save a lot of fiber. The node-type optical transceiver can also be called bus-type digital optical transceiver, in a 1-core fiber on the multi-point insertion of video signals (non-coding compression, video image loss) and control signals to achieve multi-channel signal cascade transmission. Convergence is the convergence node at the multi-channel remote signal composite, pooled into a core fiber for transmission, can significantly reduce the demand for fiber resources.
At present, the more common is the point of optical and converged Optical transceiver, these two transmission methods to save a lot of fiber resources is a large number of applications such as highways for point-by-point insertion characteristics of the application.
In short, it is no doubt that the optical transceiver plays an irreplaceable role in the transmission of the network, but with the further development of technology, optical will be replaced by other advanced products. Now the application of a wide range of optical transceiver to digital Optical transceiver preferred, the use of advanced digital video and Gigabit fiber high-speed transmission technology, can achieve multi-channel video and multi-channel audio, data, Ethernet, telephone and other signals in single or double Core fiber without distortion, high-quality transmission, basically to meet the needs of network transmission.