First of all, we must understand optical fiber communication. Optical fiber is the abbreviation of optical fiber, which is composed of thin glass fiber with a diameter of about 0. 1 mm and is transparent and slender. Although thinner than hair, it has a guided wave structure, which encloses light and propagates along the axis. Optical fiber communication is a communication mode developed because of this magical structure of optical fiber, which takes light wave as carrier frequency and optical fiber as transmission medium.
Its advantages are also obvious: wide transmission frequency bandwidth and large communication capacity; Low loss; Free from electromagnetic interference; Thin wire diameter, light weight and rich resources. However, things can't be 100% perfect, and the optical fiber itself has shortcomings, such as brittle texture and low mechanical strength. If you don't pay attention, it will break at the sheath of the optical cable. When encountering similar problems, the wiring process also needs to master certain skills, mainly how to minimize signal attenuation.
Pay attention to the choice of optical fiber
The choice of optical fiber should be based not only on the number of optical fiber cores and optical fiber types, but also on the use environment of optical cable. For example:
1, multimode fiber can be selected for transmission distance less than 2km, and relay or single-mode fiber can be selected for transmission distance greater than 2km.
2. When choosing optical fiber for building, we should pay attention to its flame retardancy, toxicity and smoke characteristics. Generally, flame retardant but smoky type can be selected in pipelines or forced ventilation places; If it is in an exposed environment, it should be flame retardant, non-toxic and smokeless.
3. When outdoor optical cables are directly buried, armored optical cables should be selected. When overhead, black plastic outer sheath and optical fiber with two or more reinforcing ribs can be selected.
In the construction of optical fiber wiring standards, signal attenuation is also inevitable. There are internal and external reasons: internal attenuation is related to optical fiber materials, and external attenuation is related to construction and installation! So it should be noted that:
The first thing we should do is to terminate and maintain the optical fiber by strictly trained technicians.
Must have a very complete design and construction drawings, so that the construction and subsequent inspection is convenient and reliable. During construction, always be careful not to make the optical cable bear heavy pressure or be stabbed by hard objects; In addition, the traction should not exceed the maximum laying tension.
When the optical fiber wants to turn, its turning radius should be more than 20 times the diameter of the optical fiber itself.
When the optical fiber passes through the wall or floor, a protective plastic pipe with a protective opening should be added, and the pipe should be filled with flame retardant filler. You can also lay a certain amount of plastic pipes in the building in advance.
A laying length should not be too long (generally 2KM), and the wiring should be pulled from the middle to both sides.
When optical fiber is used in the backbone network, at least 6-core optical cable shall be used in each wiring room, and 12-core optical cable shall be used for advanced applications. This is considered from application, backup and expansion.
The most important thing for long-distance optical fiber laying is to choose the appropriate path. The shortest path here is not necessarily the best, but also the right to use the land, the possibility of erection or burial and so on.
When laying in mountainous areas and high-voltage power grid areas, attention should be paid to the reliable grounding of metal objects in optical fibers. Generally, there should be three grounding points per kilometer, or nonmetallic optical fibers should be selected.
Summary: Optical fiber is the medium choice of data network backbone. With the speed entering the range of gigabits and several gigabits, optical fiber will become the dominant building wiring medium. In the future, because optical fiber can be used without wiring cabinets and active hardware, the cost of intermediate links is saved and the total cost is greatly reduced, so the application of optical fiber to desktop will be realized.