FTTH Applications of Fiber Splitter

by www.fiber-mart.com

Passive optical network (PON) has been widely applied in the construction of FTTH (fiber to the home). With PON architecture, network service providers can send the signal to multiple users through a single optical fiber, which can help them save great costs. To build the PON architecture, optical fiber splitter is necessary.

 

What Is Fiber Splitter?

The fiber splitter is a passive component specially designed for PON networks. Fiber splitter is generally a two-way passive equipment with one or two input ports and several output ports (from 2 to 64). Fiber splitter is used to split the optical signal into several outputs by a certain ratio. If the ratio of a splitter is 1×8 , then the signal will be divided into 8 fiber optic lights by equal ratio and each beam is 1/8 of the original source. The splitter can be designed for a specific wavelength, or works with wavelengths (from 1260 nm to 1620 nm) commonly used in optical transmission. Since fiber splitter is a passive device, it can provide high reliability for FTTH network. Based on the production principle, fiber splitters include Planar Lightwave Circuit (PLC) and Fused Bionic Taper (FBT).

 

PLC Splitters

PLC splitters are produced by planar technology. PLC splitters use silica optical waveguide technology to distribute optical signals from central office to multiple premise locations. The output ports of PLC splitters can be at most 64. This type of splitters is mainly used for network with more users.

 

The Structure of PLC splitters

Internal Structure

 

The following figure shows a PLC splitter. The optical fiber is splitted into 32 outputs. PLC chip is made of silica glass embedded with optical waveguide. The waveguide has three branches of optical channels. When the light guided through the channels, it is equally divided into multiple lights (up to 64) and transmitted via output ports.

 

Outside Configuration

 

Bare splitter is the basic component of PLC fiber splitter. For better protection of the fragile fiber and optimized use, PLC splitters are often equipped with loose tube, connector and covering box. PLC splitters are made in several different configurations, including ABS, LGX box, Mini Plug-in type, Tray type, 1U Rack mount, etc. For example, 1RU rack mount PLC splitter (as shown in the figure below) is designed for high density fiber optical distribution networks. It can provide super optical performance and fast installation. This splitter is preassembled and fibers are terminated with SC connectors. It’s ready for immediate installation.

 

rack-mount-plc-spllitter

 

FBT Splitters

FBT splitters are made by connecting the optical fibers at high temperature and pressure. When the fiber coats are melted and connected, fiber cores get close to each other. Then two or more optical fibers are bound together and put on a fused taper fiber device. Fibers are drawn out according to the output ratio from one single fiber as the input. FBT splitters are mostly used for passive networks where the split configuration is smaller.

 

PLC Splitters From fiber-mart.COM

Fiberstore offers a wide range of PLC splitters that can be configured with 1xN and 2xN. Our splitters are designed for different applications, configurations including LGX, ABS box with pigtail, bare, blockless, rack mount package and so on.

 

Conclusion

Fiber splitter is an economical solution for PON architecture deployment in FTTH network. It can offer high performance and reliability against the harsh environment conditions. Besides, the small sized splitter is easy for installation and flexible for future network reconfiguration. Therefore, it’s a wise choice to use fiber splitter for building FTTH network.

Fiber Splitter for FTTH Applications

Passive optical network (PON) has been widely applied in the construction of FTTH (fiber to the home). With PON architecture, network service providers can send the signal to multiple users through a single optical fiber, which can help them save great costs. To build the PON architecture, optical fiber splitter is necessary.

 

What Is Fiber Splitter?

The fiber splitter is a passive component specially designed for PON networks. Fiber splitter is generally a two-way passive equipment with one or two input ports and several output ports (from 2 to 64). Fiber splitter is used to split the optical signal into several outputs by a certain ratio. If the ratio of a splitter is 1×8 , then the signal will be divided into 8 fiber optic lights by equal ratio and each beam is 1/8 of the original source. The splitter can be designed for a specific wavelength, or works with wavelengths (from 1260 nm to 1620 nm) commonly used in optical transmission. Since fiber splitter is a passive device, it can provide high reliability for FTTH network. Based on the production principle, fiber splitters include Planar Lightwave Circuit (PLC) and Fused Bionic Taper (FBT).

 

PLC Splitters

PLC splitters are produced by planar technology. PLC splitters use silica optical waveguide technology to distribute optical signals from central office to multiple premise locations. The output ports of PLC splitters can be at most 64. This type of splitters is mainly used for network with more users.

 

The Structure of PLC splitters

Internal Structure

 

The following figure shows a PLC splitter. The optical fiber is splitted into 32 outputs. PLC chip is made of silica glass embedded with optical waveguide. The waveguide has three branches of optical channels. When the light guided through the channels, it is equally divided into multiple lights (up to 64) and transmitted via output ports.

 

Outside Configuration

 

Bare splitter is the basic component of PLC fiber splitter. For better protection of the fragile fiber and optimized use, PLC splitters are often equipped with loose tube, connector and covering box. PLC splitters are made in several different configurations, including ABS, LGX box, Mini Plug-in type, Tray type, 1U Rack mount, etc. For example, 1RU rack mount PLC splitter (as shown in the figure below) is designed for high density fiber optical distribution networks. It can provide super optical performance and fast installation. This splitter is preassembled and fibers are terminated with SC connectors. It’s ready for immediate installation.

 

rack-mount-plc-spllitter

 

FBT Splitters

FBT splitters are made by connecting the optical fibers at high temperature and pressure. When the fiber coats are melted and connected, fiber cores get close to each other. Then two or more optical fibers are bound together and put on a fused taper fiber device. Fibers are drawn out according to the output ratio from one single fiber as the input. FBT splitters are mostly used for passive networks where the split configuration is smaller.

 

PLC Splitters From fiber-mart.COM

Fiberstore offers a wide range of PLC splitters that can be configured with 1xN and 2xN. Our splitters are designed for different applications, configurations including LGX, ABS box with pigtail, bare, blockless, rack mount package and so on.

 

Conclusion

Fiber splitter is an economical solution for PON architecture deployment in FTTH network. It can offer high performance and reliability against the harsh environment conditions. Besides, the small sized splitter is easy for installation and flexible for future network reconfiguration. Therefore, it’s a wise choice to use fiber splitter for building FTTH network.

 

What Can Limit the Data Transmission Distance?

What Can Limit the Data Transmission Distance?

by Fiber-MART.COM

In the optical network, except the speed, data transmission distance is another important thing that we care. What can limit the transmission distance? At first we may think of fiber optic cable. Compared with copper cable, it can support longer transmission distance, high speed, high bandwidth, etc. However, not everything is perfect. Fiber optic cable still has some imperfections that influence the transmission distance. Besides, other transmitting media like transceivers, splices and connectors can also limit the transmission distance. The following will tell more details.

Fiber Optic Cable Type

Fiber optic cable can be divided into single-mode cable and multimode cable. The transmission distance supported by single-mode cable is longer than multimode cable. That’s because of the dispersion. Usually the transmission distance is influenced by dispersion. Dispersion includes chromatic dispersion and modal dispersion (as shown in the following figures). Chromatic dispersion is the the spreading of the signal over time resulting from the different speeds of light rays. Modal dispersion is the spreading of the signal over time resulting from the different propagation mode.

 

For single-mode fiber cable, it is chromatic dispersion that affects the transmission distance. This is because, the core of the single-mode fiber optic is much smaller than that of multimode fiber. So the transmission distance is longer than multimode fiber cable. For multimode fiber cable, modal dispersion is the main cause. Because of the fiber imperfections, these optical signals cannot arrive simultaneously and there is a delay between the fastest and the slowest modes, which causes the dispersion and limits the performance of multimode fiber cable.

 

Optic Transceiver Module

Like most of the terminals, fiber optic transceiver modules are electronic based. Transceiver modules play the role of EOE conversions (electrics-optics-electrics). The conversion of signals is largely depend on an LED (light emitting diode) or a laser diode inside the transceiver, which is the light source of fiber optic transceiver. The light source can also affect the transmission distance of a fiber optic link.

 

LED diode based transceivers can only support short distances and low data rate transmission. Thus, they cannot satisfy the increasing demand for higher data rate and longer transmission distance. For longer transmission distance and higher data rate, laser diode is used in most of the modern transceivers. The most commonly used laser sources in transceivers are Fabry Perot (FP) laser, Distributed Feedback (DFB) laser and Vertical-Cavity Surface-Emitting (VCSEL) laser. The following chart shows the main characteristics of these light sources.

 

Transmission Frequency

As the above chart mentioned, different laser sources support different frequencies. The maximum distance a fiber optic transmission system can support is affected by the frequency at which the fiber optic signal will be transmitted. Generally the higher the frequency, the longer distance the optical system can support. Thus, choosing the right frequency to transmit optical signals is necessary. Generally, multimode fiber system uses frequencies of 850 nm and 1300 nm, and 1300nm and 1550 nm are standard for single-mode system.

 

Bandwidth

Bandwidth is another important factor that influences the transmission distance. Usually, as the bandwidth increases, the transmission distance decreases proportionally. For instance, a fiber that can support 500 MHz bandwidth at a distance of one kilometer will only be able to support 250 MHz at 2 kilometers and 100 MHz at 5 kilometers. Due to the way in which light passes through them, single-mode fiber has an inherently higher bandwidth than multimode fiber.

 

Splice and Connector

Splice and connector are also the transmission distance decreasing reasons. Signal loss appears when optical signal passes through each splice or connector. The amount of the loss depends on the types, quality and number of connectors and splices.

 

All in all, the above content introduces so many factors limiting the transmission distance, like fiber optic cable type, transceiver module’s light source, transmission frequency, bandwidth, splice and connector. As to these factors, different methods and choices can be taken to increase the transmission distance. Meanwhile, equipment like repeater and optical amplifiers are also useful to support the long distance transmission. So there must be some ways to help you increase the transmission distance.

A brief introduction of fiber optic splitter?

A brief introduction of fiber optic splitter?

by Fiber-MART.COM

The fiber optic splitter is also referred to as beam splitter, which is an integrated waveguide optical power distribution device. It plays an important role in passive optical network by allowing a single PON interface to be shared among many subscribers. To achieve this, it is designed to split an incident light beam into two or more light beams and couple the light beams to the branch distribution as an optical fiber tandem device, which has the function to maximize the performance of network circuits.

 

The Characteristics of Fiber Optic Splitter

The fiber optic splitter can be terminated with different forms of connectors, and the primary package could be box type or stainless tube type. The first package is usually used with 2mm or 3mm outer diameter cable, the other is normally used in combination with 0.9mm outer diameter cables. Besides, it has variously different split configurations, such as 1×2, 1×8, 2×32, etc. With the development of the splitter manufacturing technology, the fiber optic market can support the high-technical splitter used in the network where the split configurations are 2×64 or larger at present.

 

According to the different transmission medium, there are single-mode fiber optic splitter and multimode fiber optic splitter. For multimode ones, the phrase implies that the fiber is optimized for 850nm and 1310nm operation. For single-mode ones, the phrase means that the fiber is optimized for 1310nm and 1550nm operation. Meanwhile, based on working wavelength difference, there are single window and dual window fiber optic splitters. The single window fiber optic splitter is to use one working wavelength, while the dual window fiber optic splitter is with two working wavelengths.

 

In general, a fiber optic splitter has many input and output terminals to attain the branch of the light beams and maximize the functionality of optical network circuits, which plays an important role in passive optical network (EPON, GPON, BPON, FTTX, FTTH and so on).

 

How Does the Fiber Optic Splitter Work?

 

The fiber optical splitter is a passive optical device that can split, or separate, an incident light beam into several light beams at a certain ratio. As a simple example, Figure 1 shows how splitter with 1×4 split configurations can separate an incident light beam from a single input fiber cable into four light beams and transmit them through four individual output fiber cables. For instance, if the input fiber optic cable carries 1000 Mbps bandwidth, each user in the end of output fiber cables can use the network with 250 Mbps bandwidth.

 

As for the fiber optic splitter with 2×64 split configurations, it is more complicated than the splitter with 1×4 split configurations. There are two input terminals and sixty-four output terminals in the fiber optic splitter with 2×64 split configurations. Its function is to split two incident light beams from two individual input fiber cables into sixty-four light beams and transmit them through sixty-four light individual output fiber cables.

 

What should be noted is that the ejected light beams may or may not have the same optical power as the incident light beam. The designer would better to take it into consideration when designing the passive optical networks.

 

Two Types of Fiber Optic Splitters Classified by Manufacturing Technique

 

On the basis of different manufacturing technique, the fiber optic splitter can be divided into two types, which are popularly used nowadays. One is the traditional fused type optical splitter, fused biconic tapered (FBT) splitter, which features competitive prices; and the other is planar lightwave circuit (PLC) splitter, which has compact size and suits for high-density applications. Both of them have the advantages and can be used in different applications.

 

Fused Biconic Tapered (FBT) Splitters

 

The FBT splitter (See Figure 2) is fabricated by the traditional technology with over 20 years history. Its manufacturing technique is relatively mature and the manufacturing cost is lower than PLC splitter, so that the FBT splitter can be deployed in a cost-effective manner in today’s fiber optic market.

 

In the manufacturing process of FBT splitter, there are two or more fibers placed closely together, typically twisted around each other and fused together by applying heat while the assembly is being elongated and tapered. The fused fibers are protected by a glass substrate and then protected by a stainless steel tube. Meanwhile, there is a signal source controls the desired coupling ratio to meet the requirements in applications.

 

Nowadays, FBT splitters are widely used in passive optical networks, especially in the network where the split configuration is not larger than 1×4. In fact, there is a slight drawback of FBT splitter, the split configuration. Detailedly, if more than four splits are required, multiple FBT splitters can be spliced together in concatenation to multiply the amount of splits available, like a tree splitter. By using this design, the package size increases due to multiple FBT splitters and the insertion loss also increases with the additional splitters. Therefore, if high split counts are needed, small package size and low insertion loss are also required, you are suggested to choose a PLC splitter, instead of the FBT splitter.

 

Conclusion

 

With the fast development of optical network, more and more experts attach great importance to the fiber optic splitter, and try to optimize its function as much as possible. As a result, the fiber optic splitters becomes diversiform with different design aims, which can be used in different applications. fiber-mart.com provides a variety of fiber optic splitters which suit for many applications, all of them are tested in-house prior to shipping to guarantee that they will arrive in perfect physical and working condition. We also guarantee the fiber optic splitters to work in your system with a lifetime advance replacement warranty. Your choice is our motivation. Welcome to fiber-mart.com.

The Features of Fiber Optic Cleaver

The Features of Fiber Optic Cleaver

by Fiber-MART.COM

Fiber optic cleaver is used to cut the fiberglass to make a good end face, as we know the quality of the bare fiber end face will determine the quality of the joint of the fibers in the fiber optic fusion process, and the joint point quality means higher or lower attenuation of the fiber connection line.

An optical fiber is cleaved by applying a sufficient high tensile stress in the vicinity of a sufficiently large surface crack, which then rapidly expands across the cross section at the sonic velocity.This idea has many different practical implementations in a variety of commercial cleaving equipment. Some cleavers apply a tensile stress to the fiber while scratching the its surface with a very hard scribing tool, usually a diamond edge.

 

Fiber optic cleavers are used in fusion splicing to make the ready to use optical fiber before putting them into the fusion splicer to melt them together. Some cleavers scratch the surface first, and then apply tensile stress, and some apply a tensile stress that is uniform across the cross section while others bend the fiber through a tight radius, producing high tensile stresses on the outside of the bend.

 

Commercial instruments for simultaneously cleaving all the fibers in a ribbon are also widely available. These ribbon cleavers operate on the same principles as single fiber cleavers. The average cleave quality of a ribbon cleaver is somewhat interior to that of a single fiber cleaver. Scribe-and-break cleaving can be done by hand or by tools that range from relatively inexpensive hand tools to elaborate automated bench tools. Any technique or tools is capable of good cleaves; the trick is consistent finishes time and time again.

What's AON?

What's AON?

by Fiber-MART.COM

Defination

 

AON is a point-to-point network structure (PTP), each subscriber has their own fiber optic line that is terminated on an optical concentrator. AON can be designed differently, depending on specifications. Usually Metro-Ethernet-Switches, IP-Edge routers or Multi-Service Access Nodes (MSANs) with optical Ethernet interfaces. The fiber optics can be terminated by an ONT too, but also by any Ethernet switch or IP router with an optical uplink interface. If the last mile to the subscriber is to be bridged using copper wire, DSLAMs or other MSANs would be used. When MSANs are used, both copper and optical lines can be used for the last mile from the same access node. The following picture shows some basic components of AON.

 

AON

 

AON’s Advantage

AON clearly has the edge because of its flexibility. Due to the static splitting factor and the interfaces on the OLT. AON technology is clearly better regarding to the bandwidth per subscriber. The maximum bandwidth per subscribers is much higher. The flexibility to allocate different bandwidths to individual subscribers is also greater than when PON systems are used. Depending on the splitting factor, a PON connection via fiber optics supplies less bandwidth than a VDSL2 connection via copper wire. The PTP architecture is superior to the PONs PMP architecture. Just by converting boards, subscribers can obtain an upgrade, no network architecture or the service of other subscribers have to change.

 

Active optical technology is more suitable for private network operators,either by laying their own fiber optic infrastructure, or by using debundled fiber optic lines (Fiber Local Loops). AON is perfect for high-profit end customer segments (such as business customers, multi-dwellings, universities, local authorities etc). As in these cases, flexibility, quality and security are demanded. And because of the way they are structured, PON networks struggle to fulfill these requirements. As standardized ONTs are used, the commercial aspects of supplying households on a large scale should be weighed up too and can compete with PON systems. Nevertheless, as PON networks are on the rise, it is likely that some of the disadvantages of PON listed here will gradually eliminate. However, some of the inherent features of a PON will remain. But what is almost certain is that the fiber optic based access network, and end customer products as well, will constantly be upgraded to handle more than 50 Mbps. The whole issue is set to stay an exciting one.

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FIBER-MART(Fiber-Mart.com), based in HongKong & U.S., belongs to SUNMA Group, a worldwide leading supplier in fiber optic network, fttx, fiber cabling & connectivity, fiber testing, fiber splicing, fiber polishing, fiber blowing & integrated network solutions. 

Understand Passive and Active Network Technology

Understand Passive and Active Network Technology

by Fiber-MART.COM

Nowadays, we have access to more information than ever before. We live in a digital world and bandwidth is what makes a digital world happen. There are many types of networks carrying different types of information. However, all these individual networks can be divided into two categories: passive and active. A passive network does not use electrically powered equipment or components to get the signal from one place to another, while an active network uses electrically powered equipment or components to route the signal from one place to another. This article will briefly introduce both passive and active fiber/copper networks.

 

Passive Copper Network

There are many different types of passive copper networks, but the one virtually everyone is familiar with is their home cable TV network. In a copper cable TV network, the cable provider supplies the signal to the home over a coaxial cable. The cable enters the home and is routed to a single television. However, few homes have a single television. For homes with multiple TVs, the signal from the cable provider must be split for each television to receive the signal. The splitting is usually accomplished with a splitter. The splitter requires no electrical power. It will typically have a single input and may have two, three, four, or more outputs. The following picture is an example of a splitter that has a single input and four outputs. An individual cable is routed from the splitter to each television.

 

fiber splitter

With this type of network, loss of signal strength will occur. As the signal from the cable provider is split and routed to multiple televisions, the signal strength to each television is reduced. Adding too many televisions can reduce the signal strength to the point where none of the televisions receives adequate signal strength to operate properly. When this happens, it is time to install an active cable TV network.

 

Active Copper Network

Same with the passive copper networks, there are also many types of active copper networks. The previous section focused on a passive home cable TV network and pointed out that you can only connect a limited number of televisions to this type of network. In order to have adequate signal strength for multiple televisions, for example, one in each room, an active network is required. In an active home cable TV network, one cable enters the home and is routed to a distribution amplifier. The distribution amplifier boosts or amplifies and splits the signal from the cable provider. Each output of the distribution amplifier has a signal strength approximately equal to the signal strength on the input cable from the cable provider. An individual cable is routed from the distribution amplifier to each television.

 

This type of active network overcomes the signal strength problem associated with a passive network. However, it does add a level of complexity and requires power. If the distribution amplifier were to fail, all the televisions would lose their signals. The same would be true if the distribution amplifier were accidentally unplugged: every television in the house would be without a signal.

 

Passive Optical Network

Various types of passive optical networks (PON) are available, and one of the most common types is very similar to the passive cable TV network previously described. However, optical fiber is used instead of coaxial cable. In any PON, couplers are the core. A coupler may combine two or more optical signals into a single output, or the coupler may take a single optical input and distribute it to two or more separate outputs. The following picture is an example of a seven-port coupler. The coupler is splitting a single input signal into six outputs.

 

coupler

Many couplers are designed for bidirectional operation, which enables the same coupler to be used either to combine signals or to split signals. In a bidirectional coupler, each port can be either an input or an output. However, for a PON application, a coupler being used to split a signal may be referred to as a splitter. In a PON, the input to the coupler in the picture above would be split equally between the six outputs. Data going into the coupler would be sent to each output just as the signal from the cable TV provider is sent to each TV in the passive copper network. Although each output will carry the same information as the input, the signal strength will be reduced based on the number of outputs. There is a finite limit on the number of outputs for a PON application; typically, the limit is 32. However, some applications may support more.

 

Active Optical Network

An active optical network is very similar to the active home cable TV network previously described. One optical fiber connects to a switch instead of a distribution amplifier. The switch rebroadcasts the data to each individual user. A separate cable is routed from the switch to each individual user. This type of active network overcomes the signal strength problem associated with a passive network. However, it does add a level of complexity and requires power. If the switch were to fail, all the users would lose access to incoming data. The same would be true if the switch lost power: data would stop flowing.

 

Conclusion

Some basic information about passive copper network, active copper network, passive optical network and active optical network has been described in this article. And each kind of network has their own features. Before choosing a certain one, please make clear all the related information and then install it.

Tips In Splicing Your Fiber Optic Cable

Tips In Splicing Your Fiber Optic Cable

by Fiber-MART.COM

Fiber Optic Fusion splicer is a must in the process of properly joining two bare optical fiber together. Since splicing fiber optic cables together is a much more complex process than splicing metal wires, it works together with the fiber cleaver to meet the end need. Before using the fusion splicer, we need to cut the fiber optic cable and take away all the fiber cable jacket, then use fiber optic cleaver to make the fiberglass end face ready, after finishing these work we can use the fiber fusion splicer to melt the two fiberglass together.

Talking about splicing fiber optic cable, you will find two different types of splicing processes. Here are some tips in splicing your cable by using this certain method. You have to notice first that fusion splicing is generally a bond of two or more optical fibers that joined together permanently by welding. You need to provide splice cleaver if you want to have less problems of light loss or reflection. Making such a poor spice causes the ends of the fiber could not melt together properly, and surely it could cause problems.

 

First, you can start to prepare the fiber. Strip all coatings. tubes, as well as jackets of your cable and make sure that you have only bare fiber left. Clean all of the filing gel from the fiber by using gel cleaner. Ensuring that you are cleaning it well since clean environment will be great to support better connection.

Second, you can cleave the fiber. You need to provide a good cleaver to get an excellent splice. You can align the fibers either automatically or manually when you fusing the fibers together. It will be depended on the type of your machine.

 

Third, you can take heat shrink tubing to protect the fiber. It will be perfect to keep the optical fiber of your cable safe from any elements that might create breakage.

 

Now your cable has been spliced successfully. In order to get maximum splicing result, it will be better for you to provide some supporting tools in great quality. Therefore, you will not feel disappointed with the splicing result of the cable.

 

This fusion splicer is a well performed automated fusion-splicing machines. fiber-mart.com offer a range of fiber Fusion splicers,such as Fujikura fusion splicer and Sumitomo fusion splicer,Fitel Furukawa fusion splicer.

How to test the FTTx PON

How to test the FTTx PON

by Fiber-MART.COM

With the demand of ever growing bandwidth, FTTx PON (passive optical network) is being deployed to provide optical fiber’s advantages at a lower cost than point-to-point architecture affords. But there are some unique test challenges when installing and maintaining the FTTx PON network. How to solve it? This article will provide some information about FTTx PON testing for your reference.

 

Basic Information About FTTx PON Testing

Proper testing is a critical part of installing, activating and maintaining a PON. Most components are tested again after splicing, and installation of splitters and access terminals although they are tested during manufacturing process. Field testing is required to ensure no excess loss or reflectance has been introduced due to micro-bends in installed fiber, poor splices, macro-bends in splice closures or access terminals, or dirty, damaged, or improperly seated connectors. If not detected and corrected, excess loss or reflectance often results in poor network performance. Initially, performance may seem acceptable, but over time, transmission errors may begin to increase long before the need for any maintenance activity would normally be expected. Usually, four tests are taken to verify optical links, which are connector inspection, insertion loss test, optical return loss test and OTDR (optical time domain reflectometry) test.

 

Connector Inspection

 

Connector inspection and cleaning during installation and maintenance are one of the most effective methods to ensure expected performance of an optical network. Typically, an optical microscope is used to inspect the connectors as shown in the following picture. To prevent accidental eye damage when inspecting fibers potentially carrying live traffic, a video microscope images the connector end-face and displays the magnified image on a handheld display. Thus it’s easy to detect the dirt, debris or damage. Images may be captured before and after cleaning, then compared for any variation. Connector contamination and damage are the most common causes of poor optical network performance.

 

Insertion Loss Test

 

Insertion loss test measures the end-to-end loss of the installed link by injecting light with a known power level and wavelength at one end, and measuring the received power level output from the other end. The measured difference between the transmitted and received power levels indicates the optical loss through the network. Insertion loss is considered acceptable when the measured loss level is lower than the budgeted loss level.

 

Optical Return Loss Test

Optical return loss test injects light with known wavelength and power level into one end and measures the power level returned to that same end. The difference between the injected power level and the measured return level is the return loss. Return loss is considered acceptable when it is higher than the budgeted return loss target. A low return loss value (below 35 dB) is often an indication of one or more sources of excess reflection in the network under test, typically due to dirty or damaged connectors or a fiber break.

 

As optical network loss is wavelength dependent, insertion and return loss testing is typically performed using wavelengths at or near those which will be used during network operation. Regarding FTTx PON, upstream wavelength of 1310 nm may be used, while 1490 nm and 1550 nm are used in the downstream direction. Consequently, insertion and return loss testing at 1310 nm, 1490 nm and 1550 nm may be required. If the insertion and return loss measured at each wavelength are within the levels budgeted for the link, then the optical network may be considered ready for activation. But in many cases, the network operators require the network to be more fully documented using an OTDR.

 

Which Test, When and Where?

 

Optical testing is typically performed at various points in a network’s lifetime. Installation verification testing occurs as the network is being constructed or after network installation is complete, but before the network is activated. This is usually when the most complete testing is performed, and may include insertion and return loss testing as well as OTDR testing. Maintenance troubleshooting is performed when service outages occur, and typically requires rapid response to restore service as quickly as possible.

 

Insertion loss tests are primarily used to test FTTx PON during installation. Insertion loss testing may be performed on individual fiber segments as they are installed. An end-to-end insertion loss test may also be performed on the FTTx PON after is partially or fully installed. A stable optical light source and an optical power meter are required to measure insertion loss. Access to both ends of the fiber-under-test is required. Consequently, this is typically an out-of-service test.

 

OTDR testing is typically completed as the FTTx PON is being deployed. Using an OTDR, distribution fibers are typically tested after installation and connection to the splitter. Once attached to the splitter, these fibers may only be tested from the downstream access point or subscriber premise. OTDR testing during FTTx PON installation testing is usually performed only at 1310 and 1550 nm. During operation, the FTTx PON always utilizes 1490 nm in the downstream direction and 1310 nm in the upstream direction. It may additionally utilize 1550 nm as a second downstream wavelength. Fiber loss is highest at 1310 nm and lowest at 1550 nm, while bending-induced loss is highest at 1550 nm.

 

Conclusion

 

PON is being deployed worldwide to more cost-effectively deliver higher bandwidth broadband services to subscribers. FTTx PON presents some unique testing challenges. The testing methods mentioned in this article are recommended to verify or troubleshoot FTTx PON. Hope it can help when needed.

News for Tuesday 02 May, 2017

• EPON OLT with 4-EPON Interfaces Module brief introduction
• EPON ONU with 1-PON Port and 24 10/100M ports

MTP/MPO SOLUTIONS

MTP/MPO SOLUTIONS

by Fiber-MART.COM

Data centers and ever-expanding server clusters have created a huge demand for more bandwidth and more space efficiency. Multifiber Push-On (MPO) connectors have answered the call and provide up to 24 or more fibers in a single connector pushing up to and beyond 100Gbps data transmission. The best part is that the connector takes roughly the same space as a single simplex SC connector. MPOs are paving the way for increased data transmission speeds and rack density.

 

MTP® is a registered trademark of US Conec, marketed as a “high performance MPO connector with multiple engineered product enhancements to improve optical and mechanical performance when compared to generic MPO connectors.” MTP and MPO are often used interchangeably and MTP is considered a generalized trademark. Both MTP and MPO are available with standard or elite / low loss options. fiber-mart.com terminates our cables with both MPO and MTP connectors, so please be sure to specify with our sales staff if you need genuine US Conec MTP connectors.

 

MPO and MTP in Data Centers and Beyond

 

Many switches, servers and other network hardware come with fiber optic ports built in. More and more hardware is being shipped with QSFP/QSFP+/SR4/CFP/CXP ports and MPO fiber cables are becoming a requirement in these fields. However, data centers don’t have a monopoly on the technology!

 

Anybody working with a large count of fiber that likes to save space is a good candidate for MPO technology. Large bundles of hundreds of fibers, trunk cables, are spliced into pigtails. The old method would be to use a distribution fan-out cable or duplex cables to patch the trunk cable into your infrastructure. With MPO technology, you can connect your single fiber cables once, then route the rest of the way with MPO fanouts and trunk cables, minimizing the number of connectors and cables you’re working with.

 

Multimode Fiber Variants

 

 

While singlemode is optimized for long range data transfer, multimodes are designed with high-bandwidth short range optimization in mind (Single-mode and Multimode Explained).

 

OM1 is a 62.5/125µm fiber core, with the jacket usually cladded in orange. This is typically found in older applications where high bandwidth isn’t a priority.

OM2 is the first variant of 50/125µm, usually also orange, but widely unused. OM2 offers modest improvement over OM1, however OM3 is leaps and bounds ahead with not much more cost.

OM3 is a laser optimized variant of 50/125µm multimode, and is the first fiber mode that supports 10Gb/40Gb/100Gb Ethernet.

OM4 is a recent addition to the lineup which offers a longer range than OM3. It should be noted that OM3 and OM4 are cross-compatible, and while OM4 is only needed for distances that exceed OM3 capabilities, it can still be used for shorter connections.

 

MPO Gender Interface

 

MPO Genders can be counter-intuitive to newcomers to the technology. MPO cables are a plug, so they must be male, and transceivers have a port so they must be female, right? Wrong on both counts!

 

MPOs are classified by the guide pins on the end of the connector, and require 1 male and 1 female to mate properly. MPO connectors use a “barrel sleeve” adapter that simply holds one male and one female MPO “plug” together. The male guide pins fit into the female holes to ensure precise fiber alignment. Attempting to mate two female connectors will result in a seemingly secure connection, but with extremely high loss, and attempting to mate two male connectors will most likely damage one or both connectors due to the guide pins clashing.

 

Transceivers and cassettes come with the sleeve adapter built in, and the industry standard is a male connection on the inside. Therefore, the standard for cables is female to female. This changes, however, when you need to extend a cable or connect two cables. You will then need a male to female cable plus adapter. If you’re designing a multi-ferrule MPO trunk backbone cable, you might consider making this male to male, then patching to your hardware with female to female cables. We offer all combinations of genders, so contact us with your needs and we will be able to customize these for you.

What should I do to maintain my fiber?

What should I do to maintain my fiber?

by Fiber-MART.COM

There are many ways of being proactive when it comes to fiber plant. However, because of the durability and low maintenance requirements fiber stewards are frequently rolling the dice and taking a wait and see attitude.

 

Here are a few ways you can get in front of problems.

 

Third Party Testing Services:

My wife's a teacher, and she doesn't let her kids grade their own tests. However, we IT professionals think little about separating the conflict of interest in having the same individual install and test installations or performance. I have been in way to many closets to think this is a waste of effort. The craftsmanship of some fiber installations leaves much to be desired.

 

Fiber Optic Testing and Documentation (OTDR, PM & LS)

1.Require a bi-directional OTDR trace

2.Require a PM & LS test to verify core power levels

3.Require an image of the connector endface prior to testing (ensures the contractor cleans the endface prior to testing)

4.If testing Multimode fiber, ensure your contractor is using a mandrel

5.When testing with an OTDR, ensure a launch box is being used (1km - SM, 150m - MM)

 

Network configuration and maintenance

1.Consult a certified RCDD before making any adds moves and changes, especially when upgrading speed on Multimode fiber

2.Consider a performance contract with a company to ensure they are recommending the appropriate equipment (If performance is low or equipment is faulty, the integrator will replace the hardware)

3.Schedule annual maintenance with a third party to ensure schedules are kept.

 

Description:

Services designed to support the IT professional in maintenance, documentation, installation and testing.

 

OTDR Trace Analysis & Off-site Storage 

OTDR Trace Analysis

Interpretation Services

File Storage (Off-site Backup)

Comparison Analysis (Compare benchmark to current trace)

Report Generation

 

Description:

OTDR analysis and storage services for IT professionals interested in a second opinion or off-site storage of network trace files. If traced are completed and stored for future reference, emergency restoration, annual maintenance and management, prevention of degradation are all made easier.

 

 

Consulting and Project Management Services:

The following is a list of consulting services offered through fiber-mart.com:

Design Consulting Services

Project Management Services

 

Description:

 

Consulting and project management services for IT professionals interested in leveraging the experience of fiber optic professionals.