Category Archives: FTTH

FTTX PON – the Replacement of Copper Network

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Introduction

FTTX (Fiber-To-The-X) is know as different Passive Optical Network (PON) configurations which can be used to describe any optical fiber network that replaces all or part of a copper network. It is different from the traditional fiber optic network used for Local Area Network (LAN) applications.

A key difference between FTTX and the traditional fiber optic network is the number of optical fibers required for each user. In most FTTX applications, only one optical fiber is used. The single optical fiber passes data in both directions (bidirectional, or BiDi). This is very different from a LAN application where the transmit optical fiber sends data in one direction and the receive optical fiber sends data in the other direction. In a LAN application, both optical fibers can have data passing through them at the same time.

1000BASE-T SFPA transceiver, or converter, is typically a device that has two receptacles or ports. One mates with the transmit optical fiber and the other mates with the receive optical fiber. This allows the device to be transmitting and receiving simultaneously. This is known as full-duplex operation, e.g., a 1000BASE-T SFP transceiver with a RJ45 port can take advantage of this operation. In an FTTX single optical fiber application, full-duplex operation is typically not possible; usually only half-duplex operation takes place. This means that part of the time the optical fiber is carrying a signal in one direction, and the rest of the time, it is carrying a signal in the other direction. The key to making this system work is timing. Data is sent downstream for a predetermined amount of time and then data is sent upstream for a predetermined amount of time. This process is also known as Time Division Multiplexing (TDM).

FTTX systems typically use multiple wavelengths. The downstream laser is always a different wavelength than the upstream laser. The downstream laser is typically the longer wavelength, such as 1480 nm or 1550 nm (or both), and the upstream laser is typically 1310 nm. FTTX is possible with optical fiber distances up to 20 km because optical fiber is capable of transmitting information with a very low level of loss. The typical loss for an FTTX optical fiber at 1550 nm is 0.25 dB/km and 0.35 dB/km at 1310 nm.

Types of FTTX

According to the X, there are Fiber-To-The-Home (FTTH), Fiber-To-The-Building (FTTB), Fiber-To-The-Curb (FTTC), Fiber-To-The-Node (FTTN), Fiber-To-The-Desk (FTTD), etc.

FTTH

Fiber to Copper Media ConverterAn FTTH PON uses optical fiber from the central office to the home; there are no active electronics helping with the transmission of data in between the two locations. The central office is a communications switching facility. It houses a large number of complex switches that establish temporary connections between subscriber lines that terminate at the central office. At the home, a converter box (e.g., a Fiber to Copper Media Converter with SFP and RJ45 ports) changes the optical signal from the optical fiber into electrical signals. The converter box interfaces with existing home cabling such as coaxial cabling for cable TV, twisted-pair cabling for telephone, and Category 5e or 6 cabling for Internet connectivity.

FTTB

An FTTB PON is very similar to an FTTH PON. It uses optical fiber from the central office to the building and there are no electronics helping with transmission in between. The optical signal from the optical fiber is converted into electrical signals in a converter box at the building. The converter box interfaces with existing cabling such as coaxial cabling for cable TV, twisted-pair cabling for telephone, and Category 5e or 6 cabling for Internet coonectivity.

FTTC

In an FTTC PON, optical fiber runs from the central office and stops at the curb. The “curb” may be right in front of the house or some distance down the block. The converter box is located where the optical fiber stops, and it changes the optical signal from the optical fiber into electrical signals. These electrical signals are typically brought into the home through some existing copper cabling. The electrical signals may need to be processed by another converter box inside the house to interface with existing cabling such as coaxial cabling for cable TV, twisted-pair cabling for telephone, and Category 5e or 6 cabling for Internet coonectivity.

FTTN

FTTN is sometimes referred to as fiber to the neighborhood. An FTTN PON only has optical fiber from the central office to the node. The node is typically a telecommunications cabinet that serves a neighborhood or section of a neighborhood. The optical signal from the optical fiber is converted into electrical signals inside the telecommunications cabinet. These electrical signals are distributed throughout the neighborhood through existing copper cables to the houses.

FTTD

FTTD is a ideal of FTTX solution. Fiber connection is installed from the main computer room to a terminal or fiber media converter near the user’s desktop. FTTD is a high-bandwidth solution that expands the traditional fiber backbone system by running fiber directly to desktops. It is a horizontal wiring option that pushes the available bandwidth beyond 10G. It is an intriguing, underestimated and overlooked way to create a beneficial system that is expandable and performance-driven.

Fiberstore’s FTTX Solutions

As more bandwidth is needed for digital voice, high-speed data and high-definition video, service providers can count on Fiberstore’s innovative optical infrastructure solutions to meet today’s challenges and prepare for tomorrow’s demands. Fiberstore offers a variety of options to achieve “end-to-end” FTTX architectures that can transmit voice, data and video through the PON technologies. Fiberstore’s FTTX solutions include CWDM & DWDM multiplexers/demultiplexers, transceivers (e.g., SFP, SFP+, XFP), media converters, cables etc.

Article Source: http://www.fiberopticshare.com/passive-and-active-network-fundamentals.html

Guide To Choose The Best Fiber Optic Cable Suits Your Application

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Fiber optic cable is favored for today’s high-speed data communications because it eliminates the problems of twisted-pair cable, such as near-end crosstalk (NEXT), electromagnetic interference (EMI), and security breaches. Fibre Optic Cable is the preferred option in the interconnecting links between floors or buildings, is the backbone of any structured cabling solution. While, making the right decisions when it comes to Data Network cabling is difficult as it can make a huge difference in the ability of your network to reliably support current and future requirements. There are many factors to consider and today I will guide you through the many options available and find the best one suits your application.

1. Multimode Fiber Cable Or Single-mode Fiber Cable

There are two basic types of fiber: mulitimode and single-mode. Both types consist of two basic components: the core and the cladding which traps the light in the core.

Multimode fiber cable

Multimode fiber, as the name suggests, permits the signal to travel in multiple modes, or pathways, along the inside of the glass strand or core. It is available with fiber core diameters of 62.5 and a slightly smaller 50 microns. The problem with multimode fiber optics is that long cable runs in multiple paths may lead to signal distortion. This can result in incomplete and unclear data transmission.

Applications covering short distances can use multimode fiber optic network cable. Ideal uses for such kinds of cables are within data center connections. Multimode cables are economical choices for such applications. There are various performance levels within the multimode fiber optic cable such as OM3 cable for distances within 300 m, OM4 cable supports Gigabit Ethernet distances within 550m and 10G applications.

Single-mode fiber cable

Single-mode fiber cables offer a higher transmission rate. These cables contain a tiny core that measures about five to ten microns. These tiny cores have the capacity to eliminate distortion and produce the highest transmission speeds. Single-mode fiber generally has a core that is 8.3 microns in diameter. Singlemode fiber requires laser technology for sending and receiving data. Although a laser is used, light in a single-mode fiber also refracts off the fiber cladding. The presence of high intensity lasers helps transfer data across large distances. Singlemode has the ability to carry a signal for miles.

Single mode is used for long haul or extreme bandwidth applications, gives you a higher transmission rate and up to 50 times more distance than multimode, but it also costs more. The small core and its single lightwave virtually eliminate any distortion that could result from overlapping light pulses, providing the least signal attenuation and highest transmission speeds of any fiber cable type.

The best choice to choose multimode optical cable when the transmission distance is less than 2km. In the other sides, use single-mode optical cable when the transmission is more than 2km. Although the core sizes of multimode and singlemode fiber differ, after the cladding and another layer for durability are applied, both fiber types end up with an outer diameter of about 250 microns. This makes it both more robust and easier to work with.

2. Indoor Cable Or Outdoor Cable

The major difference between indoor and outdoor cables is water blocking. Any conduit is someday likely to get moisture in it. Outdoor cables are designed to protect the fibers from years of exposure to moisture.

Indoor Cables

Indoor cables are what we call “tight-buffered” cables, where the glass fiber has a primary coating and secondary buffer coatings that enlarge each fiber to 900 microns—about 1mm or 1/25-inch—to make the fiber easier to work with. Indoor cables are flexible, and tough, containing multiple Tight Buffered or Unit Cord fibers.

Types Of Indoor cables available

indoor cables

Simplex and Zip Cord: Simplex Fiber Optic Cables are one fiber, tight-buffered (coated with a 900 micron buffer over the primary buffer coating) with Kevlar (aramid fiber) strength members and jacketed for indoor use. The jacket is usually 3mm (1/8 in.) diameter. Zipcord is simply two of these joined with a thin web. It’s used mostly for patch cord and backplane applications, but zipcord can also be used for desktop connections. They are commonly used in patch cord and backplane applications. Additionally, they can be utilized for desktop connections. These cables only have one fiber and are generally used indoors.

Distribution cables: They contain several tight-buffered fibers bundled under the same jacket with Kevlar strength members and sometimes fiberglass rod reinforcement to stiffen the cable and prevent kinking. These cables are small in size, and used for short, dry conduit runs, riser and plenum applications. The fibers are double buffered and can be directly terminated, but because their fibers are not individually reinforced, these cables need to be broken out with a “breakout box” or terminated inside a patch panel or junction box. The distribution cable is smaller and used in dry and short conduit runs, plenum and riser applications, is the most popular cable for indoor use.

Breakout cables: They are made of several simplex cables bundled together inside a common jacket for convenience in pulling and ruggedness. This is a strong, rugged design, but is larger and more expensive than the distribution cables. It is suitable for conduit runs, riser and plenum applications, is ideal for industrial applications where ruggedness is important or in a location where only one or two pieces of equipment (such as local hubs) need to be connected.

Outdoor Cables

Optical fiber in outdoor applications requires more protection from water ingress, vermin, and other conditions encountered underground. Outdoor cables also need increased strength for greater pulling distances. Buyers should know the potential hazards that the cables will face, for example, if the cables will be exposed to chemicals or extreme temperatures.

Loose Tube cables: These cables are composed of several fibers together inside a small plastic tube, which are in turn wound around a central strength member and jacketed, providing a small, high fiber count cable. This type of cable is ideal for outside plant trunking applications, as it can be made with loose tubes filled with gel or water absorbent powder to prevent harm to the fibers from water. Since the fibers have only a thin buffer coating, they must be carefully handled and protected to prevent damage. It can be used in conduits, strung overhead or buried directly into the ground.

Ribbon Cable: This cable offers the highest packing density, since all the fibers are laid out in rows, typically of 12 fibers, and laid on top of each other. This way 144 fibers only has a cross section of about 1/4 inch or 6mm! Some cable designs use a “slotted core” with up to 6 of these 144 fiber ribbon assemblies for 864 fibers in one cable! Since it’s outside plant cable, it’s gel-filled for water blocking.

Armored Cable: Cable installed by direct burial in areas where rodents are a problem usually have metal armored between two jackets to prevent rodent penetration. This means the cable is conductive, so it must be grounded properly. You’d better choose armored fiber cable when use cable directly buried outdoor.

Aerial Cable: They can be lashed to a messenger or another cable (common in CATV) or have metal or aramid strength members to make them self supporting. Aerial cables are for outside installation on poles.

The table below summarizes the choices, applications and advantages of each.

Cable Type Application Advantages
Distribution Premises Small size for lots of fibers, inexpensive
Breakout Premises Rugged, easy to terminate, no hardware needed
Loose Tube Outside Plant Rugged, gel or dry water-blocking
Armored Outside Plant Prevents rodent damage
Ribbon Outside Plant Highest fiber count for small size

All cables share some common characteristics. For example, they all include various plastic coatings to protect the fiber, from the buffer coating on the fiber itself to the outside jacket. All also include some strength members for pulling the cable without harming the fibers. Outdoor fiber optic cable has moisture protection, either a gel filling or a dry powder or tape. Direct-buried cables may have a layer of metal armor to prevent damage from rodents. It is advisable that you should customize your cable to make it suitable to your application when the quantity of fiber optic cables is large and also for the cost-effective reasons. Knowing basic information about fiber optic cables make choosing the right one for the project a lot easier. It is always beneficial to konw more about fiber optic cables.

The Process Of FTTH Network From 2011 To 2013

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FiberStore news, the Chinese traditional fiber optic connector manufacturers not fared well in 2013, according to statistics, in the first quarter shipments of fiber optic connectors for FTTH “cold junction” decreased nearly 80% compared to 2012, which is regarded as technical magic for rapid deployment of FTTH by operators, gradually fell out of favor.

In the FTTH project, inevitably need to connect 5-7 fiber breakpoint. Before the advent of FTTH, fiber is mainly used for the backbone network, the breakpoints are using fusion splicer to connect, but because of its fusion splicer bulky, expensive, difficult to master the technology, these characteristics make it does not apply to FTTH project fast, low cost, convenience requirements.

Therefore, a few years ago, the industry developed fast connector, simple, convenient and low cost of FTTH splice junction, called the cold welding technology. United States, Japan, South Korea, which are the earliest development scale of FFTH, all have used the cold welding technology, verify the maturity of this technology.

“Hot melt” Return

In 2011, China Telecom launched the “city network” strategy, start the FTTH large-scale construction of China, and follow the international operators used cold welding technology. For a time, Chinese fast connector market raised quickly.

In the second half of 2011, cold welding technology began a large-scale unsuitable. The cold welding industrial chain which lacked details exposed its shortcomings: Although the same shape, but the heart technology of slot technology and matching fluid were unable to mark the international technology, below standard connectors entered into the network, caused massive FTTH quality problems.

In 2012, the three big operators reflected on this, Wei Leping, China Telecom Science and Technology Committee, noted: “FTTH network with serious quality problems, the network Splice, splitters and other products need to strengthen quality inspection.” But the problem was not changed with the operator’s attention. At present, in addition to Shanghai and Jiangsu, FTTH from other provinces still have serious quality problems.

However, it also provides an opportunity for some vendors. Fusion Splicers with “Miniaturization, long battery life, low cost, easy to operate” characters became hot topics in research and development.

FTTH Promote The Surge In Demand For Optical Network Testing

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Testing is an important means to enhance network quality, network construction, an important means of operators. Test on the one hand, to ensure the consistency and stability of the business, at the same time can be effectively promoted the maturity of the industry.

Currently, the test is not only limited to test network equipment, more and more important for the business and user perception test. Therefore, testing techniques, testing tools developed laboratory environment to build all aspects of test quality assurance will affect the results of the entire test.

In the field of fiber optic communications, with China Mobile completed 100G network test now, “Broadband China” strategy forthcoming FTTH being the country vigorously. Fiber optic communication testing methods and techniques are changed with the change of network.

FTTH test can be roughly divided into the construction, maintenance, fault diagnosis phases. FTTH three wavelengths (1310nm, 1490 nm and 1550 nm) loss during the construction phase, the test focus. The optical splitter in a PON will bring a larger loss (such as a 1:32 optical splitter loss will be greater than 15dB), not only makes the light generating loss downlink, the uplink of the light will produce substantially the same loss. Splitter implementation techniques vary, making each optical path loss may exist differences, in order to strictly limit each optical path loss within the budget is a challenge.

Optical return loss is one of the difficulties of the current test. Optical return loss is not only a loss of energy, but also lead to the originator laser instability. Recommendations based on the ITU-TG.983 and G.984 series, optical return loss values should be in both directions. PON-based FTTH OTDR put forward new demands, requires not only support the 1490nm wavelength testing, but also with penetrating optical splitter. In addition, FTTH network transmission distance is shorter, but the introduction of the high loss of optical splitter requirements OTDR dynamic range wide enough selection of shorter OTDR dead; joints more requirements, high linearity.

In large-scale FTTH deployment phase, testing will be very heavy instrument automation has become one of the factors to be considered. FiberStore’s FOT-930 test instrument developed for this demand, the user simply one-button operation can be completed in the 10s three wavelengths (1310nm, 1490 nm and 1550 nm) bi-directional loss, optical return loss and fiber length test and automatically store test results.

Activation and maintenance, fault diagnosis stage, the most commonly used test instruments PON power meter. EPON or GPON system using time division multiple access technology, OLT and ONT need to activate in order to work, PON power meter has to trigger tests optical power capacity and support meter needs different optimization. FTTH construction early will also face business opened the challenges, many links need to manually construction service activation, as well as the opening of a long cycle, poor customer perception. Troubleshooting link, the failure rate and the declaration of DSL-more than twice the proportion of regional centers for processing, the door-to-door high.

FiberStore, EXFO, JDSU and other enterprises to provide FTTH is simple, fast, and a variety of intelligent solutions, provide strong support for FTTH construction.

The Rapid Development of FTTH Borrow PON Promote Triple Play

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The arrival of the triple play, will greatly promote the video business, such as high-definition television, as well as the future of 3D TV business rapid development of broadband services, but also broadband access network is another new challenge. FTTH can not only provide massive bandwidth support business, and low operating costs, therefore, FTTH mode will gradually become the mainstream of triple play network construction in 2010 years to achieve scale deployment.

Significant advantages of FTTH

In the past few years, carriers generally adopted EPON technology, by the large-scale depolyment of FTTB/FTTN original access network of optical fibers and speed to achieve from the original 512K “narrow” broadband to 4M/8M/12M high bandwidth upgrade but with the growing popularity of high-definition television and other the severe erosion bandwith video class of business in the next few years, due to the limited bandwidth of EPON can prodive effective, as well as the number of users more brought under a single PON port existing mode will lead to the present FTTB-based access network to turn highlights powerless in the next era of full-service, bandwidth bottlenecks. Continues to mature as the whole industry chain, the end-to-end cost of each line of FTTH has dropped to about 1,000 yuan, has reached the scale deployment costs level, especially in the new area, FTTH FTTB cost disadvantage compared to the gradual narrow, basically reached the same level. Taking into account the FTTH can provide massive bandwidth, business support, and teh operating costs are vey low, FTTH mode will gradually become the mainstream, and achieve economies of scale deployments in 2010.

High quality FTTH

Shanghai Bell as leading technology PON equipment manufacturers, has launched GPON/EPON/10GPON mixed interpolation solutions based on the original 7342 platform, together with a light terminal series to meet operators under different scenarios and business needs FTTH deployment. The Shanghai Bell and Verizon the asymmetric 10G GPON current network pilot. Shanghai Bell will strive to promote 10GPON mature early realization of its commercial deployment.

GPON for FTTH deployment

In FTTH scenario, because GPON splitting ration can be achieved 1:128, with better network planning flexibility, mobility and bandwidth scheduling, can effectively reduce the sunk cost. GPON offers higher effective downlink bandwidth and better QoS guarantee. In addition, in the process of upgrading to the next generation 10G PON compared to EPON, GPON can achieve a smoother evolution.

Completely isolated 10G GPON GPON up and down the line wavelength, wavelength division superposition can be used, in the case does not change the current network deployment OLT / ONT / ODN smooth upgrade. Upstream wavelength and 10GEPON and EPON overlap, so using time division multiplexing manner compatible with the existing network deployment EPON ONU, which will lead to all central office OLT line card with new the line of 10GEPON card to replace this deployment of existing network services and devices serious. Therefore, GPON technology is more suitable for the construction of the FTTH network.