FTTH (Fiber to the Home), The Ultimate Guide

This paper analyzes several core technologies of FTTH (Fiber to the Home) and expounds the application status of FTTH (Fiber to the Home) optical network. Through the link in this article, you can also find solutions for 4 different types of FTTH (Fiber to the Home) optical networks designed in combination with building types on the market. The core technology of FTTH (Fiber to the Home) mainly includes bending-resistant optical fiber, optical fiber mechanical termination technology, PON technology, etc.

The standard and technical realization of bend-resistant optical fibers are systematically analyzed, especially nano-structured single-mode optical fibers, which have become the mainstream optical fibers for FTTH (Fiber to the Home) applications due to their standard compatibility and good bending-resistant performance;

Optical fiber mechanical termination technology is a challenge to traditional fusion splicing methods, and its transmission performance and service life have been verified through experiments;

As a communication equipment manufacturer established in 1995, Melontel has rich experience in design and production of communication equipment, especially the equipment used in FTTH (Fiber to the Home) construction, and a number of patented products guarantee your FTTH (Fiber to the Home) construction. At the same time, Melontel also provides professional communication accessories for the aerospace engineering field. The perfect product quality is the reason why they choose Melontel.

FTTX Optical Fiber Network Construction Solution

FTTH (Fiber to the Home) refers to extending ONU (Optical Network Unit) to ordinary residential users, and is the optical access network application type closest to users in the FTTx (Fiber to x) series except FTTD (Fiber to the Desktop). FTTH (Fiber to the Home) can provide huge access bandwidth, making the triple play of data, voice and video possible;

And for network operators, FTTH (Fiber to the Home) enhances the transparency of the physical network to data formats, rates, wavelengths and protocols, relaxes requirements for environmental conditions and power supply, and simplifies maintenance and installation.

All Dielectric Self Supporting (ADSS) Cables, The 2022 Complete Guide

From a global perspective, there are two main implementation technologies of FTTH (Fiber to the Home), one is PPP (Point to Point) point-to-point optical access technology, and the other is PON (Passive Optical Network) passive optical network technology.

Point-to-point optical access technology converts electrical signals into optical signals for long-distance transmission, using optical fibers to link end offices and each user, and the uplink and downlink rates can reach 1Gbit/s.

Point-to-point optical access technology has the advantages of mature products, simple structure/technology, and good security. However, this technology needs to lay a large number of optical fibers and optical fiber transceivers, and the overall cost does not drop but rises during large-scale deployment. Therefore, the main problem of adopting the point-to-point optical fiber laying method is that not only the cost is difficult to control, but also the routing of the community is complex, the laying of a large number of optical cables is also very challenging, and the difficulty of management and maintenance on the optical cable line is also greatly increased.

PON technology is recognized by the industry as the best solution for implementing FTTH (Fiber to the Home). PON is a point-to-multipoint fiber access technology. It consists of OLT (Optical Line Terminal) on the central office side, ONU (Optical Network Unit) on the user side, and ODN (Optical Distribution Network). )composition. Generally, the downlink adopts TDM broadcast mode, and the uplink adopts TDMA mode, and can flexibly form topological structures such as tree type, star type, and bus type. The so-called Passive means that the ODN does not contain any active electronic devices and electronic power supplies, and is all composed of passive devices such as optical splitters (Splitter), so its management and maintenance costs are low. PON technology is not easy to be damaged by lightning and radiation interference. Its network structure is flexible and easy to expand, and the shared feeder segment fiber can save laying costs; in addition, PON can achieve business transparency and multi-service support capabilities, so it has received great attention from the industry since its birth. The more popular ones are EPON and GPON.

EPON technology is mature, there are large-scale commercial cases, and the cost is low.

The GPON technical standard is launched according to the concept of telecommunications, and has detailed requirements for the interoperability of equipment. It can provide corresponding QoS guarantees for various service types including TDM, but the current cost is still high.

In the development of FTTH (Fiber to the Home), the technologies adopted by various countries are also different: the broadband access in the United States is mainly developed by cable modem (CM) and ADSL, and Verizon actively promotes the development of FTTP mainly because the telecommunications regulatory policy encourages the adoption of new The pressure of technology building network and the competition and business growth of cable companies decided to implement FTTP directly in some areas in one step.

Most telecom operators in Japan adopt GEPON or Point to Point technology, but another Cable operator (Suo Cable Net) adopts Alcatel-Lucent’s GPON technology. As for WDM-PON technology, due to its advantages of less fiber usage, it has been tested in NTT’s laboratory, but NTT’s actual construction timetable for WDM-PON has not yet been determined.

South Korea’s broadband technology development mainly adopts FTTB+LAN, most of FTTH (Fiber to the Home) adopts EPON technology, and a small part adopts WDM-PON technology and GPON technology.

After the six major telecom operators in China were merged into three major operators (China Telecom, China Unicom, China Mobile), China Telecom was the first operator to build a large-scale optical fiber network, and the technology used was GEPON; In terms of construction, FTTB+LAN and FTTB+ADSL/VDSL are mainly adopted, and the construction of GEPON has only been actively carried out recently; China Mobile has only recently announced its entry into the FTTx market.

Overall, the existing FTTH (Fiber to the Home) technology is dominated by EPON, and GPON technology will also become one of the FTTH (Fiber to the Home) technologies mainly used by the next wave of telecom operators.

FTTX Optical Fiber Network Construction Solution

In FTTH (Fiber to the Home) construction, the loss caused by bending is a major factor affecting FTTH (Fiber to the Home) performance because the optical cable is placed in crowded pipes or fixed in line termination equipment with narrow spaces such as junction boxes and sockets after many bends.

The optical fiber has a certain flexibility. Although it can be bent, when the optical fiber is bent to a certain extent, it will cause a change in the propagation path of the light. Part of the light energy penetrates into the cladding or passes through the cladding as a radiation mode that leaks out and is lost. , resulting in bending loss.

When light travels in a curved section, the closer to the outside of the fiber, the greater the speed of transmission. When transmitted to a certain location, its speed will exceed the speed of light, and the conduction mode will become a radiating mode, resulting in loss.

Fiber bending loss includes macrobending loss and microbending loss. The macrobending loss mainly occurs in the field of optical fiber laying, optical cable splicing and other occasions caused by bending. The microbending loss mainly occurs when the surrounding stability changes during the process of optical fiber sheathing and optical fiber cabling.

 Fiber splice loss is caused by connecting multiple fibers. For example, the shaft center is offset, the end face is not perpendicular to the shaft center, the end face is not flat, the diameter of the butt core does not match, and the quality of welding causes the connection loss. Excessive losses in the construction of these projects will greatly damage the performance of the FTTH (Fiber to the Home) system and reduce the FTTH (Fiber to the Home) Efficiency of engineering construction.

Another major problem in FTTH (Fiber to the Home) construction is the splicing and termination of optical fibers. Traditional optical fiber splicing and termination mainly use fusion splicing technology, which requires professional personnel and expensive equipment, and requires on-site power supply. These are all important to the FTTH (Fiber to the Home) construction site. Higher requirements.

Due to the complex topology structure of traditional FTTH (Fiber to the Home) network, high network technology content, difficult construction, optical cable performance is greatly affected by external forces, and optical fiber splicing and termination have high requirements on the surrounding environment, all of which make the maintenance and management of FTTH (Fiber to the Home) network complicated. This increases costs and reduces efficiency.

FTTH Cables and Their Role in Internet Connectivity

Bending-resistant optical fibers have small bending diameters of optical fibers, which are especially suitable for indoor deployment, which greatly improves the deployment conditions of FTTH (Fiber to the Home) optical cables after entering the house. According to the working wavelength and range of use, G.657 fibers can be divided into two categories: G.657A and G.657B.

There are three main technical approaches to improve the bending resistance of optical fibers:
1. Reducing the fiber core diameter reduces the mode field diameter (MFD) and increases the fiber’s bending resistance.

2. To increase the refractive index difference between the fiber core and the cladding, use high germanium doping in the core or a small amount of P2O5 and more F in the cladding to increase the refractive index difference between the fiber core and the fiber cladding, reduce the mode field diameter, and make the fundamental The optical field of the mode is strictly confined in the fiber core, thereby reducing the bending loss of the fiber.

3. Through special processes such as photonic crystal (PCF) and hole-assisted fiber (HAF), the existing G.652 fiber step-type refractive index profile structure is changed to improve the energy confinement capability of the fiber core, thereby reducing the fiber bending loss.

For ordinary optical fibers, when the optical fiber is bent, energy radiation along the bending radius will always occur, and part of the guided wave modes in the original optical waveguide will become leaky modes or radiation modes, and some even become refracting modes (radiation modes). mode), causing bending losses.

This will lose the energy of the transmitted signal, increase the bit error rate of the signal, or even fail to transmit the signal at all. In many environmental conditions, we need a bend-resistant fiber, although only a small bending radius, but the signal can also be transmitted normally.

At present, the main processes for improving the bending resistance of optical fibers are:

• Small Mode Field Diameter Single-Mode Fiber
• Cladding Index Sag Fiber
• Hole-Assisted Fiber (HAF)
• Photonic Crystal Fiber (PCF)

The technology of nanostructured fiber optic cable has also developed greatly.

In particular, the fiber optic drop cable tailored for FTTx has become the standard recommended fiber optic cable for FTTH (Fiber to the Home) households.

Second: the maturity of optical fiber mechanical termination technology and the application of factory pre-terminated optical cables in FTTH (Fiber to the Home). The traditional optical fiber termination mainly adopts the fusion splicing method, and a small amount adopts the grinding splicing method. Both types of terminations require on-site power supply, professional technicians to install, expensive installation equipment, and high requirements for the construction environment. The bending radius is required to be large, which increases the difficulty of FTTH (Fiber to the Home) implementation.

Optical fiber mechanical termination connectors allow us to quickly and easily complete fiber optic terminations in the field with best-in-class optical performance.

Lightweight hand-held installation tools and high-performance cutting knives virtually eliminate the impact of human factors in field installation, ensuring proper termination and stable performance, and each mechanical termination joint installation requires only stripping, cleaning, cutting, rotating and crimping It is so simple, the time can be controlled within one minute, no power supply is required, and 100% pass the factory insertion loss test, etc., which provide convenience and guarantee for the optical fiber termination in our engineering implementation.

Factory pre-terminated optical cables are mainly used in FTTH (Fiber to the Home) construction in North America. Since all products are produced in the factory, the performance of the system can be guaranteed. All of them are plug-and-play and have high flexibility. Factory pre-terminated optical cables have high added value and high initial investment, but do not require on-site termination, low labor costs, flexible networking, and are widely used in places with high labor costs such as the United States.

Third: the continuous development and maturity of PON technology. The research of PON technology originated in 1995. In October 1998, ITU passed the ATM-based PON technology standard-G.983 advocated by the FSAN organization (full service access network). Also known as BPON (Broadband PON), the rate is 155 Mbps, with an option to support 622 Mbps.

EFMA (Ethernet in the First Mile Alliance) proposed the concept of Ethernet-PON (EPON) at the end of 2000, with a transmission rate of 1Gbps, and the link layer is based on simple Ethernet encapsulation.

GPON (Gigabit-Capable PON) was proposed by the FSAN organization in September 2002, and in March 2003, the ITU passed the G.984.1 and G.984.2 protocols.

G.984.1 specifies the overall characteristics of the GPON access system; G.984.2 specifies the ODN (Optical Distribution Network) physical medium-related sublayer of GPON; in June 2004, ITU passed G.984.3, which The relevant requirements for the Transmission Convergence (TC) layer are specified.

For the overall investment cost of FTTH (Fiber to the Home), the cost of optical fiber and cable has been controlled at a fairly good level, and the cost of PON-related products has become very critical. With the active participation of major mainstream communication equipment suppliers, the FTTx market capacity has increased. Amplification, the further development of PON technology, the cost of PON-related products will be more competitive; the last is to reduce the construction and maintenance costs of FTTH (Fiber to the Home).

Fiber Optic Attenuator，The Ultimate Guide

The good bending resistance of G.657 fiber makes it suitable for fiber access networks, including various cabling located in buildings where fiber access network terminals are located. According to the working wavelength and range of use,

G.657 fiber can be divided into two categories: G.657A and G.657B.

Recommendation G.657 provides minimum limits for fiber characteristics for a basic design structure. Its system design and outdoor equipment network requirements are the same as the G.652D recommendation.

G.657 fiber optic cable focuses on the preferred use in broadband optical access networks, especially its improved bending loss performance, suitable for small capacity fiber optic operating systems and small radius installations in telecommunications offices, apartment buildings and residential buildings.

During the manufacture and installation of the optical cable, the cut-off wavelength and polarization mode performance of the optical fiber in the cable may have a great impact. Install the fiber-optic cables in the installed cables.

Fiber Optic Connector, Everything You Need to Know

There are three main technical approaches to improve the bending resistance of optical fibers:

1. Reducing the fiber core diameter reduces the mode field diameter (MFD) and increases the fiber’s bending resistance.

2. To increase the refractive index difference between the fiber core and the cladding, use high germanium doping in the core or a small amount of P2O5 and more F in the cladding to increase the refractive index difference between the fiber core and the fiber cladding, reduce the mode field diameter, and make the fundamental The optical field of the mode is strictly confined in the fiber core, thereby reducing the bending loss of the fiber.

3. Through special processes such as photonic crystal (PCF) and hole-assisted fiber (HAF), the existing G.652 fiber step-type refractive index profile structure is changed to improve the energy confinement capability of the fiber core, thereby reducing the fiber bending loss.

At present, the main processes for improving the bending resistance of optical fibers are:

Small Mode Field Diameter Single Mode Fiber

Cladding Index Sag Fiber

Hole-Assisted Fiber (HAF)

Photonic Crystal Fiber (PCF)

nanostructured fiber

What is A FAST Connector Fiber Optic? The Ultimate Guide

Hole-assisted fiber (HAF) is formed by arranging a circle of air holes in the cladding around the core of a conventional single-mode fiber.

HAF is also called hole-assisted fiber or hole-assisted fiber. Such fibers rely on the conventional mechanism of total internal reflection.

Because of the many holes around the core of the HAF, adjusting the diameter and arrangement of the holes allows for a more flexible design of the effective refractive index of the fiber than conventional single-mode fibers.

In addition, the holes in the cladding allow the fiber to have a higher refractive index difference and significantly reduce bending losses.

Fiber Optic Patch Panel, The Ultimate Guide

Photonic crystal fiber (PCF), also known as holey fiber or microstructured fiber. PCF fiber is composed of tiny air holes regularly arranged along the axial direction around the core, and light transmission is realized through the confinement of light by these tiny air holes. The unique waveguide structure and flexible fabrication methods make PCF have many exotic properties compared with conventional optical fibers, effectively expanding and increasing the application fields of optical fibers.

According to the light guiding principle, PCF can be divided into two categories: photonic energy gap light guiding and refractive index guiding light.

Photon energy gap light guide uses the cladding to form a photon energy gap for light of a certain wavelength, and the light wave can only exist and propagate in the defects formed by the air core. Although total internal reflection cannot occur in hollow-core PCF, the small hole lattice structure in the cladding acts as a mirror, causing the light to be reflected multiple times at the air and quartz glass interface of many small holes.

Getting to Know Your Fiber Optic Terminal Box

Nanostructured fiber is based on HAF hole-assisted fiber, and the size and position of air holes are improved.

The Nanostructured fiber is formed by arranging a circle of nanostructured air holes in the cladding around the core of conventional single-mode fiber.

Nanostructured fiber Nanostructured air holes are used on a circumference around the core.

The germanium-doped core has a radius similar to that of a conventional single-mode fiber, thus increasing the refractive index difference between the fiber core and the fiber cladding.

A Guide to Cable Tension Clamp

Fiber optic drop cable first appeared in the urban construction of FTTH (Fiber to the Home) in China. Fiber optic drop cable is an FTTH (Fiber to the Home) fiber-to-the-home dedicated optical cable, also known as “8 figure cable”, that is, it contains two parallel non-metallic reinforcement cores in the flat sheath, and 250 microns are sandwiched between the two non-metallic reinforcement cores. At present, the most used optical fibers are 1 to 4 cores, and they can also be made into optical fiber ribbons according to the requirements of the number of cores.

The fiber optic drop cable is small in size, especially suitable for passing through various pipes in the building, adapting to various complex laying and application environments in the building, and has good soft performance, which can be easily constructed like a telephone line. When wiring, it can be cut on site and installed with “quick connectors” and “cold connectors”. On-site construction does not require fiber fusion, which greatly improves construction efficiency.

In addition, the ultra-small bending radius of the fiber optic drop cable is also suitable for indoor wiring. Depending on the application, the fiber optic drop cable can also be made into a self-supporting fiber optic drop cable with a steel core structure to increase its tensile performance.

No matter what type of fiber optic drop cable, you can peel off the outer skin to 250μm coating layer by hand without tools, which brings great convenience to the construction of the optical cable and greatly reduces the cost of optical cable wiring. The processing time of the optical cable and the requirements for the construction personnel during the construction process. In terms of performance, many properties such as compressive tensile strength and bending resistance are superior to the loose or tight optical cables currently widely used in the field of integrated wiring.

1. The optical cable product is small in size, light in weight and compact in structure. It adopts a figure-of-8 structure and a unique groove design, which can provide excellent stripping performance. The optical cable can be stripped without tools. Construction is very convenient.

2. The optical fiber adopts G.657 small bending radius optical fiber, and the reinforcing element adopts non-metallic material. The optical cable has excellent bending performance, which is suitable for FTTH (Fiber to the Home) indoor bending and small space deployment, and can be laid like a telephone line.

3. The optical fiber is placed in the middle of the two non-metallic reinforcing cores, which has excellent resistance to lateral pressure and tensile strength. Since the diameter of the non-metallic reinforcing core is much larger than that of the optical fiber, when the optical cable is subjected to lateral pressure and impact, the optical fiber will get Effective protection, so it can withstand a lot of pressure.

4. The sheath is made of environmentally friendly low-smoke halogen-free flame-retardant polyolefin material, which has excellent flame-retardant properties and is suitable for indoor wiring. HDPE outer sheath can also be used according to user requirements, so that the optical cable has good abrasion resistance and UV resistance, or PVC sheath and other suitable materials can be used.

5. The optical cable can be matched with a variety of connectors on site, and can be cold-spliced ​​at the end on site, without the need for fusion operation, and the permanent connection of single-core or multi-core optical fibers can be realized by simple tools and mechanical connection technology. Continuation is very convenient. Moreover, the introduction of pigtails is eliminated, the construction efficiency is improved, and the project cost is reduced.

6. The optical cable has good elasticity and is suitable for the situation where the optical cable is often required to be bent, such as indoor and terminal installation.

7. The structure is simple and compact, which is convenient for pipe placement in the building.

The application of fiber optic drop cable has greatly improved the laying conditions of FTTH (Fiber to the Home) optical cable after entering the home, and it is currently used in more and more applications in the market.

Structured Cabling Design for Network Upgrade and Reconstruction

The pre-terminated fiber optic cable system is a scheme widely adopted by the Verizon operator in the United States in the implementation of FTTH (Fiber to the Home) in the United States. The scheme has been deployed in more than 10 million households in the United States. The pre-connected fiber optic cable system refers to our installation in a large area. An Optisheath outdoor splice with factory pre-terminated Multiports multiport enclosures connecting the enclosure to multiple smaller areas, which are ultimately connected to each home via factory pre-installed OptiTap splice and adapters . Enables fast, safe, and flexible FTTH (Fiber to the Home) fiber optic cable routing.

Key benefits of pre-terminated fiber optic cable systems include:

Easy and fast installation: Compared with traditional solutions, the installation time is reduced by more than half.

Training is simple and easy: with a little training, you can master how to install and implement.

Save capital investment: reduce the number of splicing points by 2/3 and reduce equipment loss.

No weather restrictions: The outdoor installation part is extremely simple and easy, and the outdoor construction in rainy days is equally convenient.

Excellent product performance: factory prefabrication, strict quality control and stable production process ensure excellent product performance and reliability.

Fiber Optic Drop Cable，Everthing You Need Know