FTTH Distribution Section Skeleton Optical Fiber Ribbon Cable Application Detailed Explanation

Author : Yulia

Update time : 2022-08-31 09:14:41

In August 2013, my country announced the implementation of the "Broadband China" strategy, accelerating the upgrading and transformation of broadband networks, promoting fiber-to-the-home, and making overall plans to improve the popularity and access capabilities of urban and rural broadband networks. Carry out the construction of next-generation Internet demonstration cities, and promote the large-scale commercial use of the next-generation Internet. The construction of FTTH has become a development trend, and the optical cable used for FTTH has attracted more and more attention, and its structure and manufacturing process are constantly being optimized and innovated. Compared with the traditional core trunk network and metropolitan area network, FTTH optical cables need to be deployed in narrow spaces such as buildings, indoors, and passages, which is not only difficult to construct, but also relatively expensive to construct and maintain.

FTTH system

In the entire FTTH network, the optical cable network can be divided into three parts, namely the feeder segment, the distribution line segment and the household line segment. Due to the different positions and environments of optical cables in the network, optical cables of different structures are used. FTTH feeder cable refers to the optical cable from the central office to the optical distribution point. Its optical cable products and technologies are not much different from traditional outdoor optical cables, and are consistent with the selection of conventional metropolitan area networks. FTTH distribution optical cable refers to the optical cable from the optical distribution point to the network access point, and the optical cable usually needs to be disconnected frequently and branched. FTTH distribution cables usually have several types of stranded loose tube cables, loose tube ribbon cables and skeleton ribbon cables. In view of the large number of optical fiber cores, frequent disconnection and branch connection, it is advisable to use the optical fiber assembly density. Taller, smaller diameter skeleton fiber optic ribbon cable. The FTTH home segment optical cable extends from the network access point to each fiber user, is terminated in the user's room or building, and directly connects the home fiber optic cable to the ONU. When the user access point is placed outdoors, the outdoor section should use an outdoor optical cable or an indoor and outdoor dual-purpose optical cable; when the user access point is placed indoors or in a building, the home optical cable should be an indoor optical cable.

FTTH distribution cable

In view of the large number of optical fiber cores, frequent offline and branch connections, it is appropriate to use a skeleton-type optical fiber ribbon cable with a high optical fiber assembly density and a small cable diameter. Skeleton fiber optic ribbon cable has the characteristics of high fiber density, small outer diameter, saving pipeline resources, good lateral pressure resistance, stable structure, convenient connection, no filling ointment, and environmental protection. It can fully meet the requirements of FTTB, FTTH, etc. for construction and communication. capacity needs. The implementation of the skeleton fiber optic ribbon cable is to connect the fiber from the computer room to several junction boxes, and then connect to each residential unit. By opening several branch windows on the skeleton fiber optic ribbon cable, the fiber optic ribbon that needs to be connected to the household can be directly pulled out. It is not necessary to cut the fiber optic cable in the usual way. Because there is no need for splicing and only a very small amount of optical cable, and the inherent characteristics of no grease filling of the skeleton optical fiber ribbon cable, it greatly simplifies and facilitates the design and construction of FTTH. The skeleton fiber optic ribbon cable connected to the shaft corridor is separated from the required fiber optic ribbon on each floor, and converted into pigtails through the splice box to enter the room; the skeleton fiber optic ribbon cable connected to the horizontal pipe can be The optical fiber ribbon is divided into two sections, which are respectively converted into pigtails through the splice box and enter into two adjacent households. get maximum use.

FTTH drop cable

The incoming optical cable can be an outdoor optical cable, an indoor optical cable or an indoor and outdoor dual-purpose optical cable according to the environment of the home. The fiber optic cable for the home should use the fiber optic cable with simple structure, convenient operation, strong tensile and lateral pressure resistance, so as to facilitate the layout of overhead, outdoor pipes and pipes in buildings, and to ensure the reliability of the use of the fiber optic cable.

Butterfly drop cable

Butterfly drop optical cable is the most widely used FTTH in-home segment optical cable. The optical cable structure is to place the optical fiber or optical fiber ribbon unit in the middle of the two strength members and then extrude a layer of LSZH (or PVC) sheath. The reinforcement can be copper plated steel wire, or aramid wire or other suitable fiber bundles (FRP or KFRP). The metal-strengthened butterfly optical cable has greater tensile strength than the non-metallic strengthened optical cable, and is suitable for long-distance indoor horizontal layout or short-distance indoor vertical layout. , Superior lightning protection performance, suitable for applications from outdoor to indoor. The structure of the self-supporting butterfly optical cable is to place the optical fiber (or optical fiber ribbon) in the middle of two parallel strength members, and at the same time place a metal suspension wire in parallel at one end and then extrude a layer of LSZH (or PVC) sheath. The self-supporting butterfly optical cable is an indoor and outdoor dual-purpose optical cable. Because of the hanging wire unit, it has stronger tensile performance and can meet the flying span of less than 50 meters. Pipeline-into-house butterfly optical cable, add two reinforcements for the butterfly optical cable, wrap it vertically with water blocking tape, and then extrude a layer of PE sheath. Because of its increased tensile strength and waterproof performance, it is suitable for the application environment of outdoor pipeline entry.

Bound drop cable

The round drop optical fiber cable is made of a single-mode or multi-mode optical fiber directly covered with a high-bond strength tight-buffered fiber, using high-strength aramid as a reinforcing element, and extruding a layer of LSZH jacket on the outside. , The structure of the self-supporting circular drop cable is to increase the metal stranded wire. The tight-sleeve optical cable has a simple structure, a thin and soft outer diameter, and is easy to connect. It is very suitable for indoor applications. The self-supporting circular drop cable is suitable for the application environment where it is introduced into the room from the outdoor overhead. The circular drop optical cable can be terminated on site to meet the requirements of rapid construction of the access network.

Small central bundled drop cable

Compared with ordinary optical cables, small central bundled drop optical cables have obvious advantages in outer diameter and weight. The small central bundle type drop-in cable adopts aramid fiber as the strengthening member of the optical cable, which can meet the tensile strength requirements of the optical cable; the optical fiber is generally 1-4 core G657A optical fiber; the outer sheath is LSZH sheath, and the outer diameter of the optical cable is not more than 5mm , the weight is not heavier than 25kg/km, which is 42% smaller than the outer diameter of the smallest ordinary central tube optical cable, and 65% less in weight. Because of its small outer diameter, light weight, and meeting the requirements of tensile force and bending performance, it is suitable for the application environment introduced from the outdoor overhead to the indoor. The layer-twisted drop cable introduced here is a home optical cable with one core per tube. The optical cable is a single-mode or multi-mode optical fiber sheathed into a loose tube made of high-modulus plastic and filled with waterproof compound. The pieces are twisted into a compact and round cable core, and at the same time, two strands of water-blocking yarn are placed around the central reinforcing piece. Set into cable. The structure of the optical cable is semi-dry, and there is only one optical fiber in each sleeve. Aramid fiber is used to increase its tensile force, which is suitable for the application environment where it is introduced from the outdoor overhead into the room.

Flat all-dielectric drop cable

The cross-sectional profile of the flat all-dielectric drop-in cable adopts an oval shape, and the water blocking strips are arranged parallel to the upper and lower sides of the optical fiber ribbon. Non-metallic reinforcements are used, which has excellent directional bending performance and good lateral pressure resistance. The oval cross-section The optical fiber cable can effectively reduce the damage caused by wind load, so that the optical fiber cable can adapt to various harsh construction conditions and complex environments, which is conducive to the realization of long-span overhead laying, and is suitable for the application environment that is introduced from the outdoor overhead into the indoor environment. Can be used with outdoor distribution box.

Due to the numerous types of FTTH users and the differentiation of their needs, under the continuous improvement of user requirements, construction costs, convenience and speed of construction and reliability of lines, there are many types of optical cables for FTTH. Fiber optic cable type.

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