Seven FTTH optical cables that meet differentiated needs are counted

In August 2013, China issued and implemented the "Broadband China" strategy, accelerated the upgrading and transformation of broadband networks, promoted optical fiber into the home, and coordinated to improve the popularization level and access capacity
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 cables used for FTTH have attracted more and more attention, and its structure and manufacturing process are also constantly optimized and
innovated.
Compared with the traditional core trunk network and metropolitan area network, FTTH optical cable needs to be deployed in narrow spaces such as buildings, indoors, and passages, which is not only difficult to construct, but also relatively high construction and maintenance costs
.

FTTH system

In the entire FTTH network, the optical cable network can be divided into three parts, namely the feeder segment, the distribution segment and the home entry segment
.
Due to the different locations and environments of optical cables in the network, optical cables
with different structures are used.

FTTH feeder optical cable refers to the optical cable from the central office to the optical distribution point, and its optical cable products and technologies are not much different from traditional outdoor optical cables, and are consistent
with the choice of conventional metro networks.

FTTH distribution cable refers to the optical cable from the optical distribution point to the network access point, and its optical cable usually needs frequent offline and divergent connection
.
FTTH wiring optical cable usually has several types of stranded loose tube optical cable, loose tube ribbon cable and skeleton ribbon cable, in view of its large number of optical fiber cores, frequent offline and divergent connection, it is advisable to use skeleton fiber strip cable with higher optical fiber assembly density and smaller cable
diameter.

The FTTH cable extends from the network access point to each fiber user, terminates in the user's room or building, and directly connects the 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-purpose optical cable; When the user access point is placed indoors or in the building, the indoor optical cable should be selected for the home optical cable
.

Optical cables for FTTH

FTTH wiring cable

In view of the large number of optical fiber cores, frequent offline and divergent continuation, it is advisable to use a skeleton fiber strip cable
with high optical fiber assembly density and small cable diameter.

Skeleton fiber strip cable with high fiber density, small outer diameter, saving pipeline resources, good anti-side pressure performance, stable structure, convenient connection, no filling ointment, environmental protection and other characteristics, can fully meet the needs
of FTTB, FTTH and other construction and communication capabilities.

The implementation of the skeleton optical fiber strip cable is to connect the optical fiber from the computer room to a number of handover boxes, and then connect to each residential unit, and the optical fiber strip that needs to be connected to the household can be directly extracted by opening a number of divergence windows on the skeleton optical fiber strip cable, without cutting the optical cable in the usual way
.
Because there is no need to connect and only a very small amount of optical cable, coupled with the inherent ointment-free filling characteristics of skeleton fiber optic strip cable, the design and construction
of FTTH is greatly simplified and facilitated.

The skeleton fiber optic strip cable connected to the shaft corridor is separated from the required optical fiber tape at each layer, and converted into pigtail into the indoor through the connector box; The skeleton fiber strip cable connected by the horizontal pipe can be extracted in two sections at each point, which is converted into pigtails into two adjacent households through the connector box, and the head and end of the optical cable are finally collected in the machine room, thus forming a ring-like FTTH solution, so that the optical fiber in the cable can be used
to the maximum.

FTTH introduces fiber optic cables

According to the environment of entering the home, the introduction of optical cables can be outdoor optical cables, indoor optical cables or indoor and outdoor dual-purpose optical cables
.
The optical cable entering the home should adopt optical cable with simple structure, convenient operation, strong tensile resistance and side pressure resistance, so as to facilitate the deployment of overhead and outdoor pipelines and pipe penetration in the building, and ensure the reliability
of optical cable use.

Butterfly lead-in cable

Butterfly introduction optical cable is currently the most used FTTH into the home section optical cable, the optical cable structure is to place the optical fiber or optical fiber tape unit in the middle of the two reinforcements and squeeze a layer of LSZH (can also be PVC) sheath
.
The reinforcement can be copper-plated steel wire, aramid wire or other suitable fiber bundles (FRP or KFRP).

Metal reinforcement butterfly optical cable has greater tensile strength than non-metal reinforced optical cable, suitable for long-distance indoor horizontal deployment or short-distance indoor vertical deployment, non-metallic reinforced butterfly optical cable can achieve full media into the home, superior lightning protection performance, suitable for outdoor to indoor applications
.

The structure of the self-supporting butterfly optical cable is to place the optical fiber (or optical fiber tape) in the middle of two parallel reinforcements, and at the same time place a metal hanging wire parallel at one end and squeeze a layer of LSZH (can also be PVC) sheath
.
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, can meet the flying span pulling equipment below 50 meters, and is suitable for introducing indoor application environment
from outdoor overhead.

The pipe into the home butterfly optical cable, add two more reinforcements for the butterfly optical cable, and then block the longitudinal package of the water barrier, and squeeze a layer of PE sheath
.
Because of its tensile strength and waterproof performance, it is suitable for outdoor pipe entry applications
.

Circular entry cable

Circular introduction optical cable is directly covered with high bonding strength tight sleeve material made of tight sleeve optical fiber outside single-mode or multimode optical fiber, using high-strength aramid as a strengthening element, and extruding a layer of LSZH sheath outside, the structure of self-supporting circular introduction optical cable is to increase metal steel strand hanging wire
.
The tight sleeve optical cable has a simple structure, a thin outer diameter and a soft outer diameter, which is convenient for connection, which is very suitable for indoor application environments
.
Self-supporting circular entry-in cables are suitable for applications where outdoor overhead is introduced indoors
.
The circular introduction optical cable can be terminated on site to meet the requirements of rapid construction of
access network construction.

Small central bundle tube entry cable

Small central tube lead-in cables have obvious advantages
over ordinary optical cables in terms of outer diameter and weight.
The small central bundle tube introduction optical cable adopts aramid as the strengthening component 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, 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 the weight is 65%
less.
Because of its small outer diameter, light weight, and tensile and bending performance requirements, it is suitable for indoor applications from outdoor overhead and introduction
.

Layered twisted inlet cable

The layered twisted lead-in cable introduced here is a one-core incoming optical cable
per tube.

Optical cable is a core singlemode or multimode optical fiber sleeve made of high-modulus plastic filled waterproof compound loose tube, the center of the cable core is a metal reinforcement extruded with a layer of polyethylene, loose tube around the center reinforcement twisted into a compact and round cable core, at the same time in the center reinforcement a wrap has been put two strands of water-blocking yarn, the cable core aramid yarn armor after longitudinal wrapping water-blocking belt extruded a layer of aluminum-polyethylene sheathed cable
.
The optical cable structure is semi-dry, with only one optical fiber in each bushing, and the use of aramid increases its tensile force, which is suitable for applications that are introduced from outdoor overhead into the indoor environment
.

Flat all-media introduction optical cable

The cross-sectional contour of the flat all-medium introduction optical cable adopts an oblong shape, the waterstop belt is set parallel to the upper and lower sides of the optical fiber belt, the use of non-metallic reinforcements, with superior directional bending performance and good resistance to side pressure, the oblong section of the optical cable can effectively reduce the destructive caused by wind load, so that the optical cable can adapt to a variety of harsh construction conditions and complex environments, which is conducive to the realization of long-span overhead laying, suitable for introducing indoor application environment
from outdoor overhead.
Can be used
with outdoor distribution box.

Due to the large number of FTTH users and the differentiation of their needs, under the continuous improvement of user requirements, construction costs, convenient and fast construction and the reliability of the line, there are many types of FTTH optical cables, and it is necessary to choose the appropriate optical fiber cable type scientifically and
reasonably.

This paper introduces the FTTH distribution segment skeleton fiber strip cable and FTTH entry section optical cable
.
With the continuous expansion of the application range of optical cables and the continuous development of optical cable technology, optical fiber communication network replacing copper communication network continues to extend to the terminal, the structure of optical cables is also constantly improving, new varieties of optical cables will continue to be launched, optical cables have been transformed from traditional structural forms to traditional structures as the main structure of a variety of structures as auxiliary forms, but the structural changes of optical cables are always inseparable from the requirements suitable for users and laying environment, convenient and fast construction and line reliability requirements, cost reduction and resource saving requirements
.