Indoor optical cable laying:

Indoor optical cable is mainly used for laying horizontal subsystem and vertical trunk subsystem. The laying of the horizontal subsystem cable is very similar to that of the twisted pair, except that the cable is less tensile and therefore should be pulled with more care and a larger radius of curvature. Vertical trunk subsystem optical cable is used to connect equipment to each floor wiring room, generally installed in the cable shaft or elevator. Outdoor optical cable is mainly used for the wiring of subsystems in buildings. In the implementation of building subsystem wiring, should be the first choice of pipeline fiber optic cable, only in the case of the last resort, choose directly buried fiber optic cable or overhead fiber optic cable.

Indoor optical fiber laying:

To prevent sagging or slipping, the cable must be securely secured in the trough, bottom and middle of each floor. Usually, nylon cable ties or steel clips can be used for effective fixation. Finally, the application of oil sesame sealing materials will be in the building each floor cable through all the slots, pipe holes of the gap part of the sealing, and should be taken to block fire materials and other fire prevention measures, in order to achieve the effect of moisture and fire prevention.

The cable should be laid in accordance with the design requirements to reserve the appropriate length, generally at the end of the equipment should be reserved for 5m to 10m, if there are special requirements and appropriate extension.

Outdoor optical fiber laying can be divided into pipeline optical fiber laying and directly buried optical fiber laying

Laying of pipeline and optical cable

1, clean and test. Before laying optical cable, pipe holes should be cleaned and tested one by one. The autocratic cleaning tool should be used during cleaning, and the test rod should be used for test pass inspection after cleaning. The inner diameter of the plastic tube should be 1.5 times the outer diameter of the cable. When more than two subpipes are placed in a cement pipe hole, the equivalent total outside diameter of the subpipe should be less than 85% of the inside diameter of the pipe hole.

2. Lay out plastic tube. When more than two plastic subpipes are put through, such as pipes of different colors, the ends can not be marked. If the tubing is the same color or no color, each end shall be marked separately.

3, cable traction. Cable traction length should be less than 1000m. When this distance is exceeded, segmental traction should be adopted or auxiliary traction should be added in the middle position to reduce cable tension and improve construction efficiency. In order to protect the cable appearance in the traction process from damage, in the cable into the pipe hole, the pipe bend or with other obstacles cross, should be used guide device or bell protection tube and other protective measures.

4. Reserve a margin. After laying the cable, the cable should be placed on the specified pallet one by one in the manhole or hand hole, and there should be an appropriate margin to prevent the cable from being too tight. When the cable in the manhole or hand hole needs to be connected, the reserved length should comply with the minimum value specified in the table.

5. Joint treatment. The cable shall not have a connector in the hole in the middle of the pipeline. When the cable in the manhole no joint, the cable bending placed on the cable tray fixed binding, not in the middle of the manhole directly through, otherwise not only affect the construction and maintenance, and easy to lead to cable damage. When the cable has a joint, it should be protected by the snake hose or soft plastic pipe, and placed on the pallet to be fixed and bundled.

6. Plugging and marking. The outlet end of the cable hole should be sealed tightly to prevent water or debris from entering the tube. The cable and its connection shall be marked with identification number, cable model and specification, etc. Anti-freezing measures should also be taken in severe cold areas to prevent the cable from freezing damage. In case the cable may be damaged, can be set up above or around the insulation plate partition protection.

Laying of directly buried optical cable

1. Embedding depth. Directly buried cable because directly buried under the ground, so, must have a certain distance from the ground, with the help of the tension of the ground, so that the cable is not damaged, at the same time, should also ensure that the cable is not frozen.

2, cable ditch cleaning and backfill. The bottom of the ditch should be smooth, without gravel and hard soil blocks, which hinder the laying of cable debris. If the groove is stone or semi-stone, the bottom of the trench should also be paved with 10cm thick fine soil or sand and copy flat. After cable laying, should backfill 30cm thick fine soil or sand as a protective layer, it is strictly prohibited to gravel, bricks, hard soil, etc., into the protective layer. The protective layer should be gently trodden manually.

3, optical cable laying. When laying optical cable or cable in the same ditch, traction should be laid respectively at the same time. If it is laid in the same ditch as the directly buried cable, the cable should be laid first, then the optical cable should be laid, and arranged in parallel at the bottom of the ditch. As ditch laying cable, should be placed separately at the same time, at the bottom of the ditch shall not cross or overlap. Optical cable should be placed at the bottom of the ditch or natural bending to release the cable stress, such as bending or arch, should try to put flat, but can not use the foot and other tough way.

4. Carry out identification. Mark should be set at the junction, turning point, reserved length or junction with other pipelines for future maintenance and overhaul. Signs can either use autocratic signs or borrow a permanent building near the cable, measure the distance between a part of the building and the cable, and record it for reference.

In addition, there are internal factors and external factors that affect fiber signal attenuation in wiring. Internal factor attenuation is related to the fiber material, this is through the purchase of high quality fiber products. The external factors are related to the construction of optical fiber wiring, because when the construction is laid, the optical fiber is caused by deformation, coupling loss between optical fiber and light source and connection loss between optical fiber, which can be reduced in the construction process. When laying optical fibers, pay attention to the following:

1, bending cable can not exceed the minimum bending radius.

2, laying cable traction should not exceed the maximum laying tension. In addition, the optical fiber must be protected from excessive external forces, such as side pressure, impact, bending, and distortion.

3. Fiber terminating and maintenance should be carried out by highly trained technical personnel. Optical cable used in the trunk, each floor wiring between at least 6 fiber optic cables, advanced applications can best use 12 fiber optic cables. This is from the application, backup and capacity three aspects to consider. As for the optical fiber networking mode is also very flexible. Can achieve:

A. Point to point: A high-speed channel is established between two computers. Transmission rates are several Mbps to several hundred Mbps, and distances can be up to 2 km (multi-mode) to 5 km (single-mode).

B. Star network: A star network topology is established through optical fiber network equipment.

C, ring network: the signal regenerator is connected by optical fiber, forming a loop.