FTTH wiring section skeleton fiber optic cable application details

In August 2013, China issued the “Broadband China” strategy, accelerated the upgrading of broadband networks, promoted fiber-optic access, and coordinated the improvement of urban and rural broadband network access and access capabilities. Carry out the construction of the next-generation Internet demonstration city and promote the large-scale commercialization 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 people's attention, and its structure and manufacturing process are constantly optimized and innovated. Compared with the traditional core trunk network and metropolitan area network, FTTH fiber optic cable needs to be laid in a narrow space such as inside, indoors and inside the tunnel, which is not only difficult to construct, but also relatively high in construction and maintenance costs.

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FTTH system

In the entire FTTH network, the fiber optic cable network can be divided into three parts, namely the feeder segment, the wiring segment and the entry segment. Due to the location of the optical cable in the network and the environment, different optical cables are used.

FTTH feeder cable refers to the cable from the central office to the light distribution point. The cable products and technology are not much different from the traditional outdoor cable, which is consistent with the choice of the conventional metro network.

FTTH distribution cable refers to the fiber optic cable from the light distribution point to the network access point. The cable usually requires frequent offline and divergent connections. FTTH distribution cables usually have several types of stranded loose tube cable, loose tube cable and skeleton cable. In view of the large number of fiber cores, frequent downline and differential connection, fiber assembly density should be adopted. Skeletal fiber optic ribbon cable with a higher cable diameter.

The FTTH home cable extends from the network access point to each fiber user, and is terminated in the user's room or in the building, directly connecting the home optical cable to the ONU. When the user access point is placed outdoors, the outdoor section should use outdoor optical cable or indoor and outdoor dual-use optical cable; when the user access point is placed indoors or in the building, the indoor optical cable should use indoor optical cable.

FTTH fiber optic cable

FTTH wiring cable

In view of the large number of fiber cores and the need for frequent offline and divergent connection, it is preferable to use a fiber-optic ribbon cable with a high density of fiber assembly and a small cable diameter.

Skeleton fiber optic cable has the characteristics of high fiber density, small outer diameter, saving pipeline resources, good lateral pressure resistance, stable structure, convenient connection, no filling grease, environmental protection, etc., which can fully meet the construction and communication of FTTB, FTTH, etc. The need for capacity.

The implementation of the skeleton type optical fiber ribbon cable is to connect the optical fiber from the equipment room to a plurality of transfer boxes, and then to each residential unit, and directly open the optical fiber ribbon that needs to be connected to the household by opening a plurality of divergent windows on the skeleton optical fiber ribbon cable. It is not necessary to cut the cable in the usual way. The need for continuation and the need for a very small number of fiber optic cables, combined with the inherent grease-free filling of the ribbed fiber optic cable, greatly simplifies and facilitates the design and construction of the FTTH.

The skeletal fiber optic ribbon cable connected to the shaft corridor is separated into the required fiber ribbon at each layer, and is converted into pigtails through the joint box to enter the indoor; the skeleton fiber optic ribbon cable that is connected to the horizontal pipeline can be required at each point. The fiber ribbon is divided into two sections and is converted into pigtails through the joint box into two adjacent households. The head and tail of the cable are finally collected in the machine room, thus forming a ring-like FTTH solution, and the fiber in the cable. Get the most out of it.

FTTH introduces optical cable

The introduction of the 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 household. The household optical cable should adopt optical fiber cable with simple structure, convenient operation and strong tensile and lateral pressure resistance, so as to facilitate the laying of overhead, outdoor pipes and pipes in the building, and ensure the reliability of the use of the optical cable.

Butterfly-shaped cable

The butterfly-shaped fiber-optic cable is currently the most widely used FTTH home cable. The cable structure is to place a fiber-optic or fiber-optic ribbon unit in the middle of the two reinforcing members and then squeeze a layer of LSZH (also PVC) sheath. The reinforcement may be a copper plated wire or aramid wire or other suitable fiber bundle (FRP or KFRP). The metal reinforcement butterfly cable has greater tensile strength than the non-metallic reinforcement cable, and is suitable for horizontally laying in a long distance or vertically in a short distance indoor. Non-metallic reinforcing butterfly cable can realize full media entry. It has excellent lightning protection performance and is suitable for outdoor to indoor applications.

The self-supporting butterfly cable has a structure in which an optical fiber (or a fiber ribbon) is placed between two parallel reinforcing members, and a metal suspension wire is placed in parallel at one end, and a LSZH (also PVC) sheath is extruded. The self-supporting butterfly fiber optic cable is an indoor and outdoor dual-purpose optical cable. Because it has a hanging wire unit, it has stronger tensile performance and can meet the flying span of 50 meters or less. It is suitable for the indoor environment to be introduced from the outdoor overhead.

The pipeline enters the butterfly-shaped optical cable, and the butterfly-shaped optical cable is further provided with two reinforcing members, and then the water-blocking belt is longitudinally wrapped, and then a PE sheath is extruded. Due to its increased tensile strength and waterproof performance, it is suitable for outdoor pipelines to the application environment.

Round lead cable

The circular lead-in cable is a tight-fitting fiber made of a high-strength tight-fitting material directly on a single-mode or multi-mode fiber. The high-strength aramid is used as a reinforcing member, and a LSZH sheath is extruded on the outside. The structure of the self-supporting circular introduction cable is to increase the metal steel stranded wire. The compact cable has a simple structure, a thin outer diameter, a soft and convenient connection, and is very suitable for indoor application environments. The self-supporting circular drop cable is suitable for applications that are introduced into the room from an outdoor overhead. The circular introduction cable can be used in the field to meet the requirements of rapid construction of the access network.

Small center bundle tube introduction cable

Small center bundle tube drop cables have significant advantages over conventional cables in terms of outer diameter and weight. The small center bundle tube type introduction cable adopts aramid as the reinforcing member of the optical cable to meet the tensile strength requirement 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 common central tubular cable and 65% less. Due to its small outer diameter, light weight, and the requirements for tension and bending performance, it is suitable for the indoor environment from the outdoor overhead.

The layer twisted drop cable introduced here is a one-core fiber-optic cable per tube.

The optical cable is a kind of inner-filled waterproof compound loose tube made of high-modulus plastic by inserting a single-core single-mode or multi-mode optical fiber. The core of the core is extruded with a layer of polyethylene outside the metal reinforcement, and the loose sleeve is strengthened around the center. The pieces are twisted into a compact and round core, and at the same time, two water-blocking yarns are placed in the center reinforcement, and the core aramid yarn is wrapped in a longitudinal water-blocking strip to extrude a layer of aluminum-polyethylene. Set the cable. The cable structure is semi-dry, and there is only one fiber in each bushing. The use of aramid to increase its tensile force is suitable for the application environment that is introduced into the room from the outdoor overhead.

Flat full medium introduction cable

The cross-sectional profile of the flat all-media introduction cable adopts an oblong shape, and the water blocking strips are arranged in parallel on the upper and lower sides of the optical fiber ribbon. The non-metallic reinforcing members are used, which have superior directional bending performance and good lateral pressure resistance, and an oblong cross section. The optical cable can effectively reduce the destructiveness caused by the wind load, so that the optical cable can adapt to various harsh construction conditions and complex environments, and is advantageous for the large-span overhead laying, which is suitable for the indoor environment introduced from the outdoor overhead. Can be used with outdoor distribution boxes.

Due to the variety of FTTH users and the difference in their requirements, there are many types of FTTH fiber optic cables, which require a scientific and reasonable selection, under the various requirements of continuous improvement of users' requirements, construction cost, convenient construction and reliability of the line. Fiber optic cable type.

This paper introduces the FTTH wiring section skeleton type optical fiber ribbon cable, and the FTTH introduction section cable. With the continuous expansion of optical cable applications and the continuous development of optical cable technology, optical fiber communication networks have replaced copper wire communication networks to extend to terminals, and the structure of optical cables has been continuously improved. New types of optical cables will be continuously introduced, and optical cables have been constructed from traditional structures. It is transformed into a traditional structure with multiple structures as the auxiliary form, but the structural changes of the optical cable are always inseparable from the requirements of the user and the laying environment, the convenience of construction and the reliability of the line, the cost reduction and the resource saving.