FAQ

The interruption of optical cable lines due to external factors or the optical fiber itself, which affects communication services, is called optical cable line failure. Optical cable line failures cause business interruption for a long time and affect a wide range of business areas. They are a key link in safe broadcasting work. In order for the optical cable communication system to work normally, in addition to careful design, careful construction, and normal maintenance, once an optical cable failure occurs, it must be dealt with in a timely manner to ensure that the line is smooth and the failure time is shortened as much as possible. This is an important part of improving communication quality.

1. Distance judgment When the computer room determines that the fault is an optical cable line fault, the line maintenance department should test the faulty optical cable line in the computer room as soon as possible, and use the OTDR test to determine the location of the line fault point.

1.1 The optical cable is completely broken If there are reservations on both sides of the site, take centralized reservations and add a joint to deal with them; There are joints near the fault point and there are enough reservations on site, use the method of pulling reservations and using the original joints; There is neither reservation nor joint near the fault point, so it should be solved by cable extension.

Fiber optic cables are indispensable for modern power supply and communication. Once there is a problem with the fiber optic cable, it will block the communication business and bring great changes to our life. To solve this problem, we should understand the fiber optic cable failure.

Optical fiber connectors are suitable for high-speed optical fiber links. High-loss optical fiber connectors may cause network failures. Do troubleshooting.

The first category is the optical attenuation caused by the too small bending radius of the optical cable.

When bending the optical cable, the minimum bending radius cannot be exceeded.

1. Burial depth. Since the direct buried optical cable is directly buried under the ground, there must be a certain distance from the ground. With the help of the tension of the ground, the optical cable will not be damaged. At the same time, the optical cable should also be protected from freezing.

Before laying the optical cable, the construction and related personnel should be properly trained on the matters that should be paid attention to in the construction, such as the essentials of laying out methods and safety, and ensure that the construction personnel obey the command.

1. The solution to environmental factors. First of all, it is necessary to determine whether hydrogen loss occurs in the outgoing optical cable. If hydrogen loss occurs, the attenuation degree can be judged by calculation, and compared with the margin reserved in the previous optical cable design. If the attenuation degree exceeds the margin, it needs to be replaced. If it is within the margin range, it can be maintained by formulating a plan. If the attenuation is caused by the physical characteristics of the optical cable itself, that is, the change of its own parameters with temperature increases, it is necessary to perform a window test, calculate according to the curve, and compare it with the design margin. If it exceeds the margin, it needs to be replaced.

Optical fiber is widely used in the field of communication because of its specific performance. Although the construction level of optical fiber cable has been significantly improved with the improvement of construction technology, there are still natural and artificial problems. This paper mainly expounds the common problems and countermeasures of optical cable construction for reference.

1. What are the causes of noise in optical fiber communication systems? There are noise caused by unqualified extinction ratio, noise caused by random variation of light intensity, noise caused by time jitter, point noise and thermal noise at the receiving end, mode noise of optical fiber, noise caused by pulse broadening caused by dispersion, and mode distribution noise of LD. , the noise generated by the frequency chirp of the semiconductor laser and the noise generated by the reflection.

1. What is the birefringence of a single-mode fiber? There are two orthogonal polarization modes in a single-mode fiber. When the fiber is not perfectly cylindrically symmetric, the two orthogonal polarization modes do not degenerate. The absolute value of the difference between two orthogonal polarization modes is birefringence.

1. What is the blind spot of OTDR? What is the impact on testing? How to deal with the dead zone in the actual test? Typically, a series of blind spots caused by saturation of an OTDR receiver is called a blind spot.

Optical fiber is the abbreviation of optical fiber. It is a fiber made of glass or plastic. It can transmit optical signals to thousands of kilometers away. Hundreds of thousands of optical fibers are combined together to make a cable-like optical cable. , so the optical cable is composed of a certain number of optical fibers, and the outer sheath is wrapped with a protective layer, which not only improves the strength of the optical fiber, but also greatly increases the communication capacity.