Beijing Optical Terminal Manufacturer Raytrans Introduces Optical Terminal Selection Considerations
Optical terminal selection considerations: Classified by the signal transmitted over fiber, optical terminals can be divided into analog optical terminals based on analog technology and digital optical terminals based on digital technology. The working principle of analog optical terminals is essentially modulation/demodulation, filtering, and signal mixing. Whether LED or LD, their electro-optical modulation characteristics are not linear, and issues such as distortion and interference that are unavoidable in analog processing may occur during signal transmission. Moreover, there are difficult technical challenges in large-capacity transmission and multi-service mixed transmission.
The situation for digital optical terminals is different. In fiber, there are only two states: "light" and "no light." Therefore, the linearity requirement for the light source is low or almost nonexistent, avoiding signal loss during processing. In addition, digital optical terminals can more easily achieve multi-channel and multi-signal mixed transmission. Since all signals are converted to digital signals, multi-channel and multi-signal transmission can be easily realized with TDM (Time Division Multiplexing) technology. Some optical terminal manufacturers can now transmit 10 channels of uncompressed real-time video images over a single wavelength channel at once.
Fiber network topology determines the type of video optical terminal. Based on the fiber transmission network topology, in addition to traditional point-to-point optical terminals, node-type and ring-network optical terminals are also available. Node-type video optical terminals form the front-end nodes into a chain or tree network. At each node, the node unit first receives the signal, converts it to an electrical signal, exchanges and multiplexes it with the local node signal, and after electro-optical conversion, uses WDM technology to multiplex it onto a single fiber for transmission. No analog-to-digital conversion is performed at each node, reducing signal attenuation.
Ring-network optical terminals connect the main nodes into a ring network, and can also have star branches through optical branching, enabling flexible network topology and unique functions such as full-network information sharing. Multimode or single-mode fiber cables: The fiber network is composed of multimode or single-mode cables, which determines whether to select multimode or single-mode terminals. For new projects, it is recommended to prioritize the use of Shiguang Optical Network integrated service optical terminals with single-mode fiber and single-mode optical terminals. Compared with multimode fiber, single-mode fiber offers longer transmission distance, larger information capacity, and higher speed.