Basic knowledge of Fiber Optic Cable Jacket & Fire Rating

Fiber optic cable is constructed from the inside core, cladding, coating, strengthen member to the outside cable jacket. As the bare fiber is easily broken, fiber optic cable jacket is needed to provide protection for the shielding and conductors within the cable. The cable jacket is the first line of moisture, mechanical, flame and chemical defense for a fiber cable.

Fiber Optic Cable Jacket Material

Fiber cable jacket is made of various types of materials. It’s important to consider the jacket type when selecting the compatibility with the application’s connectors and environment. The table below contains some of the most common fiber cable jacket material types used both indoor and outdoor cables.

Fiber Optic Cable Jacket Color Code

According to EIA/TIA-598, the fiber optic cable color code defines the jacket color codes for different fiber types (SMF or MMF). For single mode fiber, the jacket color is typically yellow. While for multimode cable, the jacket color can be orange (OM1 & OM2 cable), aqua (OM3 cable) and purple (OM4 cable). For outside plant cables, the standard jacket color is black. For more information about fiber optic cable color code, please refer to How to Identify the Fiber Optic Cable Color Code?

Fiber Optic Cable Fire Rating

Typically, there are eight levels of fire resistance for both non-conductive and conductive cables specified by NEC (National Electrical Code). All indoor fiber optic cables must be marked and installed properly for its intended use: plenums, risers and general purpose areas.

Note:

(1) A Plenum area is a building space used for air flow or air distribution system (drop ceiling and raised floors).

(2) A Riser area is a floor opening, shaft or duct that runs vertically through one or more floors.

(3) A general purpose area is all other area that is not plenum or riser and on the same floor.

OFNP vs. OFNR

As mentioned above, OFNP and OFNR are two types of fiber optic cables that are used in buildings. OFNP cables have fire-resistance and low smoke production characteristics. This is the highest fire rating fiber cable and no other cable types can be used as substitutes. So these cables are mostly installed in plenum areas. Whereas, the fiber-resistance and low smoke of OFNR cables are not good as OFNP. OFNP plenum cables can be used as substitutes for OFNR cables. Through OFNR vs. OFNP, it is worth noticing that OFNR fiber optic cable cannot be used in plenum areas to replace OFNP cables, however, the latter can be used in the riser areas. Both OFNP and OFNR can be used in general purpose areas.

Fiber-Mart Plenum/Riser Fiber Optic Cable Solutions

In the nutshell, plenum rated and riser rated cables are generally deployed within the buildings. Choosing the right type of rated cables can effectively reduce loss when the cables are burning. If your cabling application requires materials that are flame-retardant or compliant with strict safety standards, please always opt for plenum-rated cables. Fiber-mart provides a full line of plenum and riser fiber optic cables, including MTP plenum trunk cables, MTP-LC plenum harness cables, tight-buffered distribution plenum cables, armored tight-buffered plenum cables, and tight-buffered distribution / breakout riser cables. If you have any questions or requirement of Optical Fiber,welcome to contact us: product@fiber-mart.com.

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Very Effective Method of Fiber Optic Cables Selection

After the distribution network plan is developed, the next step we have to do is the selection of the right fiber optic cable. Remember the bulk of the Fiber Optic Cable installed today is for either telephone or office applications. Industrial sites bring some challenges that are not address by many of the common fiber optic cable installation design. Just due to the local telephone company would rather a particular type of fiber optic cable does not mean it is the right one for a facility.

The common rule of thumb for selection optical cable in industrial setting is to use 62.5/125 μm or 50/125 μm Multi-mode fiber cable. The cable should be rated for both indoor and outdoor use and must have an FT-4 flame rating if it is used for indoors. Aluminum interlock armor is preferred over steel tape for all but long, buried runs. Fiber counts should be a minimum of 12, with 24 fibers as the standard for main backbones. More specific selection details depend on the area where the cable will be installed.

Indoor Office Installation

Fiber selection for office applications is relatively simple. The fiber must be flame-rated for either FT-4 general use or FT-6 for plenum. Typically, tight-buffered cable with Kevlar strength members and a light jacket is used. There is little reason to use loose tube as it is more difficult to install and usually does not meet the flame rating standards. As well, fiber optic cables in these environments do not require armor as the chance of crush or pull damage is relatively low. Because jacketed fiber optic cable is more rugged than most coaxial and twisted-pair cables, plan to armor fiber only in the places where coaxial cables would be Armored Fiber Cable.

Indoor Industrial Installations

If fiber optic cable is being installed in plant-floor conditions. It is possible to be installed in existing cable trays and be subjects to more stresses than office cable systems. Thus, some form of armor is recommended, usually aluminum interlocked (TEC style) armor. This armor must be electrically bonded to ground at all distribution cabinets.

Inter-building Installation

Industrial sites often need a combination of indoor and outdoor fiber routing. Telecommunication industry guidelines recommended switching between indoor and outdoor fiber cable types at each transition, a solution than is not practical for most industrial sites. On a typical site, this would require numerous patch boxes or splices and is not worked for both cost and attenuation(signal loss) reasons. Instead, FT-4 flame-rated, tight-buffered cable should be used so that the cable can transmit both indoor and outdoor environment.

Long-Run Outdoor Installations

Outdoor fiber cable generally falls into three categories, direct burial, underground conduit, and aerial. These cables are manufactured specifically for outdoor applications and are recommended for any long outdoor cable runs, especially in region subject to cold weather. Most are loose tube designs with high tensile strength, to withstand environmental conditions, and gel filling, to prevent water migration. The jacket materials are specially selected to be abrasion and ultraviolet resistant. If a facility is planning to install long outdoor runs it will need to work closely with the manufacturer ti determine the right cable for its application.

Indoor and Outdoor fiber optic cable delivers outstanding audio, video, telephony and data signal performance for educational, corporate and government campus applications. With a low bending radius and lightweight feature, this cable is suitable for both indoor and outdoor installations. Typical indoor and outdoor cables are loose tube and tight buffer designs, and we also supply ribbon cables, drop cables, distribution cables and breakout cables. These are available in a variety of configurations and jacket types to cover riser and plenum requirements for indoor cables and the ability to be run in duct, direct buried, or aerial/lashed in the outside plant. In addition, Fiber-Mart can supply Indoor and Outdoor fiber optic cable. If you have any questions or requirement of Indoor and Outdoor fiber optic cable,welcome to contact us: product@fiber-mart.com.

What are Polarization-Maintaining Fibers?

This article describes the working principles of PM fibers and their applications. Fiber-Mart can supply PM Fiber Patch Cables. If you have any questions or requirement of PM Fiber Patch Cables, welcome to contact us: product@fiber-mart.com.

What is Polarization?

Light is a type of electromagnetic wave. It consists of oscillating electrical fields, denoted by E, and magnetic fields, denoted by B. Its properties can be described by studying its electrical field E, although we could just as well describe light and its effects in terms of the magnetic field.

Light waves can vibrate in many directions. Those that are vibrating in one direction – in a single plane such as up and down – are called polarized light. Those that are vibrating in more than one direction – in more than one plane such as both up/down and left/right – are called unpolarized light.

Principle of PM Fiber

Provided that the polarization of light launched into the fiber is aligned with one of the birefringent axes, this polarization state will be preserved even if the fiber is bent. The physical principle behind this can be understood in terms of coherent mode coupling. The propagation constants of the two polarization modes are different due to the strong birefringence, so that the relative phase of such copropagating modes rapidly drifts away. Therefore, any disturbance along the fiber can effectively couple both modes only if it has a significant spatial Fourier component with a wavenumber which matches the difference of the propagation constants of the two polarization modes. If this difference is large enough, the usual disturbances in the fiber are too slowly varying to do effective mode coupling. Therefore, the principle of PM fiber is to make the difference large enough.

In the most common optical fiber telecommunications applications, PM fiber is used to guide light in a linearly polarised state from one place to another. To achieve this result, several conditions must be met. Input light must be highly polarised to avoid launching both slow and fast axis modes, a condition in which the output polarization state is unpredictable.

The electric field of the input light must be accurately aligned with a principal axis (the slow axis by industry convention) of the fiber for the same reason. If the PM fiber path cable consists of segments of fiber joined by fiber optic connectors or splices, rotational alignment of the mating fibers is critical. In addition, connectors must have been installed on the PM fibers in such a way that internal stresses do not cause the electric field to be projected onto the unintended axis of the fiber.

Types of PM Fibers

Circular PM Fibers

It is possible to introduce circular-birefringence in a fiber so that the two orthogonally polarized modes of the fiber—the so called Circular PM fiber—are clockwise and counter-clockwise circularly polarized. The most common way to achieve circular-birefringence in a round (axially symmetrical) fiber is to twist it to produce a difference between the propagation constants of the clockwise and counterclockwise circularly polarized fundamental modes. Thus, these two circular polarization modes are decoupled. Also, it is possible to conceive externally applied stress whose direction varies azimuthally along the fiber length causing circular-birefringence in the fiber. If a fiber is twisted, a torsional stress is introduced and leads to optical-activity in proportion to the twist.

Linear PM Fibers

There are manily two types of linear PM fibers which are single-polarization type and birefringent fiber type. The single-polarization type is characterized by a large transmission loss difference between the two polarizations of the fundamental mode. And the birefringent fiber type is such that the propagation constants between the two polarizations of the fundamental mode are significantly different. Linear polarization may be maintained using various fiber designs which are reviewed next.

Linear PM Fibers With Side Pits and Side Tunnels:

Side-pit fibers incorporate two pits of refractive index less than the cladding index, on each side of the central core. This type of fiber has a W-type index profile along the x-axis and a step-index profile along the y-axis. A side-tunnel fiber is a special case of side-pit structure. In these linear PM fibers, a geometrical anisotropy is introduced in the core to obtain a birefringent fibers.

Linear PM Fibers With Stress Applied Parts:

An effective method of introducing high birefringence in optical fibers is through introducing an asymmetric stress with two-fold geometrical symmetry in the core of the fiber. The stress changes the refractive index of the core due to photoelastic effect, seen by the modes polarized along the principal axes of the fiber, and results in birefringence. The required stress is obtained by introducing two identical and isolated Stress Applied Parts (SAPs), positioned in the cladding region on opposite sides of the core. Therefore, no spurious mode is propagated through the SAPs, as long as the refractive index of the SAPs is less than or equal to that of the cladding.

The most common shapes used for the SAPs are: bow-tie shape and circular shape. These fibers are respectively referred to as Bow-tie Fiber and PANDA Fiber. The cross sections of these two types of fibers are shown in the figure below. The modal birefringence introduced by these fibers represents both geometrical and stress-induced birefringences. In the case of a circular-core fiber, the geometrical birefringence is negligibly small. It has been shown that placing the SAPs close to the core improves the birefringence of these fibers, but they must be placed sufficiently close to the core so that the fiber loss is not increased especially that SAPs are doped with materials other than silica. The PANDA fiber has been improved further to achieve high modal birefringence, very low-loss and low cross-talk.

PANDA Fiber (left) and Bow-tie Fiber (right). The built-in stress elements made from a different type of glass are shown with a darker gray tone.

Tips: At present the most popular PM fiber in the industry is the circular PANDA fiber. One advantage of PANDA fiber over most other PM fibers is that the fiber core size and numerical aperture is compatible with regular single mode fiber. This ensures minimum losses in devices using both types of fibers.

Linear PM Fibers With Elliptical Structures:

The first proposal on practical low-loss single-polarization fiber was experimentally studied for three fiber structures: elliptical core, elliptical clad, and elliptical jacket fibers. Early research on elliptical-core fibers dealt with the computation of the polarization birefringence. In the first stage, propagation characteristics of rectangular dielectric waveguides were used to estimate birefringence of elliptical-core fibers. In the first experiment with PM fiber, a fiber having a dumbbell-shaped core was fabricated. The beat length can be reduced by increasing the core-cladding refractive index difference. However, the index difference cannot be increased too much due to practical limitations. Increasing the index difference increases the transmission loss, and splicing would become difficult because the core radius must be reduced. Typical values of birefringence for the elliptical core fiber are higher than elliptical clad fiber. However, losses were higher in the elliptical core than losses in the elliptical clad fibers.

Linear PM Fibers With Refractive Index Modulation:

One way to increase the bandwidth of single-polarization fiber, which separates the cutoff wavelength of the two orthogonal fundamental modes, is by selecting a refractive-index profile which allows only one polarization state to be in cutoff. High birefringence was achieved by introducing an azimuthal modulation of the refractive index of the inner cladding in a three-layer elliptical fiber. A perturbation approach was employed to analyze the three-layer elliptical fiber, assuming a rectangular-core waveguide as the reference structure. Examination of birefringence in three-layer elliptical fibers demonstrated that a proper azimuthal modulation of the inner cladding index can increase the birefringence and extend the wavelength range for single-polarization operation.

Applications of PM Fibers

PM fibers are applied in devices where the polarization state cannot be allowed to drift, e.g. as a result of temperature changes. Examples are fiber interferometers and certain fiber lasers. A disadvantage of using such fibers is that usually an exact alignment of the polarization direction is required, which makes production more cumbersome. Also, propagation losses are higher than for standard fiber, and not all kinds of fibers are easily obtained in polarization-preserving form.

PM fibers are used in special applications, such as in fiber optic sensing, interferometry and quantum key distribution. They are also commonly used in telecommunications for the connection between a source laser and a modulator, since the modulator requires polarized light as input. They are rarely used for long-distance transmission, because PM fiber is expensive and has higher attenuation than single mode fiber.

Requirments for Using PM Fibers

Termination: When PM fibers are terminated with fiber connectors, it is very important that the stress rods line up with the connector, usually in line with the connector key.

Splicing: PM fiber also requires a great deal of care when it is spliced. Not only the X, Y and Z alignment have to be perfect when the fiber is melted together, the rotational alignment must also be perfect, so that the stress rods align exactly.

Another requirement is that the launch conditions at the optical fiber end face must be consistent with the direction of the transverse major axis of the fiber cross section.

Picking the right fiber connector – PC, UPC or APC

I wrote a blog post some days ago on the different types of connectors available, which sparked a great deal of feedback and discussion, demonstrating how important the whole topic is to both fiber installers and network planners alike. Thanks again to everyone around the world that contributed, both directly on the PPC’s blog and through various social groups.

To recap, I covered SC, LC, FC, ST and MTP/MPO connectors, and looking through the comments I thought it would be beneficial to focus on one area that the original post deliberately didn’t cover – the differences between Angled Physical Contact (APC) and Ultra Physical Contact (UPC) connectors. Beside one having a green body and the other being colored blue, the different ways they both treat light is crucial in planning a network, as several readers pointed out.

To help us understand all this jargon, let’s look back at why the original Flat Fiber Connector evolved into the Physical Contact (PC) connector and then onto UPC and APC.

The primary issue with Flat Fiber connectors is that when two of them are mated it naturally leaves a small air gap between the two ferrules; this is partly because the relatively large end-face of the connector allows for numerous slight but significant imperfections to gather on the surface. This is not much use for single mode fiber cables with a core size of just 8-9 µm, hence the necessary evolution to Physical Contact (PC) Connectors.

The PC is similar to the Flat Fiber connector but is polished with a slight spherical (cone) design to reduce the overall size of the end-face. This helps to decrease the air gap issue faced by regular Flat Fiber connectors, resulting in lower Optical Return Loss (ORL), with less light being sent back towards the power source.

Building on the convex end-face attributes of the PC, but utilizing an extended polishing method creates an even finer fiber surface finish: bringing us the Ultra Physical Contact (UPC) connector. This results in a lower back reflection (ORL) than a standard PC connector, allowing more reliable signals in digital TV, telephony and data systems, where UPC today dominates the market. Most engineers and installers believe that any poor performance attributed to UPC connectors is not caused by the design, but rather poor cleaving and polishing techniques. UPC connectors do have a low insertion loss, but the back reflection (ORL) will depend on the quality of the fiber surface and, following repeat matings/unmatings, it will begin to deteriorate.

So what the industry needed was a connector with low back reflection, that could sustain repeated matings/unmatings without ORL degradation. Step forward the Angled Physical Contact (APC) connector.

Although PC and UPC connectors have a wide range of applications, some instances require return losses in the region of one-in-a-million (60dB). Only APC connectors can consistently achieve such performance. This is because adding a small 8° angle to the end-face allows for even tighter connections and smaller end-face radii. Combined with that, any light that is redirected back towards the source is actually reflected out into the fiber cladding, again by virtue of the 8° angled end-face.

It is true that this slight angle on each connector brings with it rotation issues that Flat, PC and UPC connectors simply don’t have. It is also the case that the three aforementioned connectors are all inter-mateable, whereas the APC isn’t. So, why then is the APC connector so important in fiber optics?

 

The uses of APC connectors

The best feedback examples from my previous blog came from people experienced with Fttxand Radio Frequency (RF) applications. The advance in analogue fiber optic technology has driven demand for it to replace more traditional coaxial cable (copper). Unlike digital signals (which are either ON or OFF), the analogue equipment used in applications such as DAS, FTTH and CCTV is highly sensitive to changes in signal, and therefore requires minimal back reflection (ORL).

 

APC ferrules offer return losses of -65dB. In comparison a UPC ferrule is typically not more than -55dB. This may not sound like a major difference, but you have to remember that the decibel scale is not linear. To put that into context a -20dB loss equates to 1% of the light being reflected back, -50dB leads to nominal reflectance of 0.001%, and -60dB (typical of an APC ferrule) equates to just 0.0001% being reflected back. This means that whilst a UPC polished connector will be okay for a variety of optical fiber applications, only an APC will cope with the demands of complex and multi-play services.

 

The choice is even more important where connector ports in the distribution network might be left unused, as is often the case in FTTx PON network architectures. Here, optical splitters are used to connect multiple subscriber Optical Network Units (ONUs) or Optical Network Terminals (ONTs). This is not a problem with unmated APC connections where the signal is reflected into the fiber cladding, resulting in typical reflectance loss of -65dB or less. The signal from an unmated UPC connector however, will be sent straight back towards the light source, resulting in disastrously high loss (more than 14dB), massively impeding the splitter module performance.

Picking the right physical contact connector

Looking at current technology, it’s clear that all of the connector end-face options mentioned in this blog post have a place in the market. Indeed, if we take a sidestep across to Plastic Optical Fiber (POF) applications, this can be terminated with a sharp craft knife and performance is still deemed good enough for use in the high-end automotive industry. When your specification also needs to consider cost and simplicity, not just optical performance, it’s hard to claim that one connector beats the others. Therefore whether you choose UPC or APC will depend on your particular need. With those applications that call for high precision optical fiber signaling, APC should be the first consideration, but less sensitive digital systems will perform equally well using UPC. Fiber-Mart can supply many kinds fiber connectors. If you have any questions or requirement of fiber connectors,welcome to contact us: product@fiber-mart.com.

The Advantages and Disadvantages of Optical Fiber

Driven by the rising demand for higher bandwidth and faster speed connections for a variety of industrial and residential purposes, fiber optic transmission is becoming more and more common in modern society. In this tutorial, the advantages and disadvantages of fiber optic transmission will be explored in details.

Fiber Optic Transmission Technology

Usually, a fiber optic communication system consists of three main components: optical transmitter, fiber optic cable and an optical receiver. The optical transmitter converts electrical signal to optical signal; the fiber optic cable carries the optical signal from the optical transmitter to the optical receiver; and the optical receiver reconverts the optical signal to electrical signal. The most commonly used optical transmitter is semiconductor devices like LEDs (light-emitting diodes) and laser diodes. Photodetector is the key part of an optical receiver. It converts light into electricity using photodetector effect. As for the fiber optic cable, there is too much to say. As the use and demand for speed and bandwidth, the development of optical cables is amazing. Now in the optical cable market, there are OS2 fIber, OM1 fIber, OM2 fIber, OM3 fIber, OM4 fiber and OM5 fiber cable for different optical applications. Optical fibers are used as a medium for telecommunication and networking because it is flexible and can be bundled as cables. It is especially advantageous for long-distance communications, because light propagates through the fiber with little attenuation compared to electrical copper cables. The figure below shows that all fiber optic transmission systems use modulated light to convey information from a transmitter to a companion receiver.

Advantages and Disadvantages of Optical Fiber

Given the speed and bandwidth advantages optical fiber has over copper cable, it also contains some drawbacks. Here are advantages and disadvantages of optical fiber cable.

Advantages of Optical Fiber

Greater Bandwidth & Faster Speed—Optical fiber cable supports extremely high bandwidth and speed. The amount of information that can be transmitted per unit of optical fiber cable is its most significant advantage.

Cheap—Several miles of optical fiber cable can be made cheaper than equivalent lengths of copper wire. With numerous vendors swarm to compete for the market share, optical cable price would sure to drop.

Thinner and Light-weighted—Optical fiber is thinner, and can be drawn to smaller diameters than copper wire. They are of smaller size and light weight than a comparable copper wire cable, offering a better fit for places where space is a concern.

Higher carrying capacity—Because optical fibers are much thinner than copper wires, more fibers can be bundled into a given-diameter cable. This allows more phone lines to go over the same cable or more channels to come through the cable into your cable TV box.

Less signal degradation—The loss of signal in optical fiber is less than that in copper wire.

Light signals—Unlike electrical signals transmitted in copper wires, light signals from one fiber do not interfere with those of other fibers in the same fiber cable. This means clearer phone conversations or TV reception.

Long Lifespan—Optical fibers usually have a longer life cycle for over 100 years.

Disadvantages of Optical Fiber

Limited Application—Fiber optic cable can only be used on ground, and it cannot leave the ground or work with the mobile communication.

Low Power—Light emitting sources are limited to low power. Although high power emitters are available to improve power supply, it would add extra cost.

Fragility—Optical fiber is rather fragile and more vulnerable to damage compared to copper wires. You’d better not to twist or bend fiber optic cables.

Distance—The distance between the transmitter and receiver should keep short or repeaters are needed to boost the signal.

How to Select the Right Optical Fiber Cable?

Optical fiber has gained much momentum in communication networks, and there emerges a dazzling array of vendors competing to manufacture and supply fiber optic cables. When selecting optical fiber, you’d better start with a reliable vendor. Here’s a guide to clarify some of the confusions about choosing fiber optic cable.

Check manufacturer qualification

The major optical cable manufacturers should be granted ISO9001 quality system certification, ISO4001 international environment system certification, the ROHS, the relevant national and international institutions certification such as the Ministry of Information Industry, UL certification and etc.

Choose cable jacket

The standard jacket type of optical cable is OFNR, which stands for “Optical Fiber Non-conductive Riser”. Besides, optical fibers are also available with OFNP, or plenum jackets, which are suitable for use in plenum environments such as drop-ceilings or raised floors. Another jacket option is LSZH. Short for “Low Smoke Zero Halogen”, it is made from special compounds which give off very little smoke and no toxic when put on fire. So always refer to the local fire code authority to clarify the installation requirement before choosing the jacket type.

Indoor vs. Outdoor

The choice greatly depends on your application. The major difference between indoor and outdoor fiber cable is water blocking feature. Outdoor cables are designed to protect the fibers from years of exposure to moisture. In a campus environment, you can get cables with two jackets: an outer PE jacket that withstands moisture and an inner PVC  jacket that is UL-rated for fire retardancy. You can bring the cable into a building, strip off the PE jacket and run it anywhere, while normal outdoor cables are limited to 50 feet inside the building.

Fiber count

Both indoor and outdoor fiber cable have a vast option of fiber count ranging from 4-144 fibers. If your fiber demand exceeds this range, you can custom the fiber count for indoor or outdoor optical cable. Unless you are making fiber patch cords or hooking up a simple link with two fibers, it is highly recommended to get some spare fibers.

Conclusion

Obviously, advantages of optical fiber communication in various aspects contribute to the rapid development of optical fiber communication. Although it’s still with some disadvantages, and it will be improved with the future development of tech. Let’s expect it together.Fiber-mart is a renowned vendor that committed to develop and supply optical fiber of all types, including fiber patch cable, indoor/outdoor optical cable and FTTH fiber optical cable, etc. Each of our fiber optic cable is tested in strict environment to deliver excellence in performance and reliability. Optical fiber custom service is also available in Fiber-mart, so you can make your unique fiber optic cable in according to your specific needs. Moreover, our global inventory system enables fast same-day shipping that will greatly shorten your waiting time. If you have any questions or requirement of Optical Fiber, welcome to contact us: product@fiber-mart.com.

How To Choose The Right Fiber Patch Cable ?

There are many different types of fiber optic cable. Fiber-Mart stocks hundreds of varieties and we can custom build thousands of other types. The sheer number of options can be overwhelming to people that don’t work with fiber optic cable regularly. So here are some common questions.

Do you need singlemode or multimode fiber optic cable?

If you already have a cable and you need more of it, you can usually tell the type of cable by the color of it. Single-mode cable is typically yellow.  Multi-mode cable (either 62.5 micron or 50 micron) is usually orange. And 10GB multi-mode cable is usually aqua.If you don’t know the color, you have to find some sort of documentation that describes the type of cable you need. Below are some terms and the type of cable they are usually associated with.

·OS1, OS2, 9 micron, 9µm, 9/125 = Singlemode

·OM1, 62.5 micron, 62.5µm, 62.5/125 = Multi-mode 62.5

·OM2, 50 micron, 50µ, 50/125 = Multi-mode 50

·OM3, 10GB, 10gig, 50 micron, 50µm, 50/125 = 10GB Multi-mode

As you can see, it can be a bit confusing since both 50 micron and 62.5 micron are multi-mode and are orange. It’s also confusing because 50 micron cable can also be 10GB aqua cable. In cases where it isn’t clear, you may have to find documentation for the hardware you are using to figure out what you really need.The different cables all have strengths and weaknesses.  Single-mode cable is frequently used for very long distance cable runs. It’s not unusual to use a 20KM piece of single-mode cable. But, the hardware to support single-mode cable is traditionally more expensive.

Multi-mode fiber doesn’t work over such long distances, but the hardware for it is traditionally less expensive. Multi-mode 62.5 and multi-mode 50 are commonly used with LED based communications hardware. 10GB multi-mode, which is also 50 micron, is faster than the other types of multi-mode, mainly because its been designed to work with faster, laser based communications hardware.

What is Return Loss?

When light hits the end of a fiber optic cable, a portion of it can bounce back towards the source. This is known as Back Reflection and it can cause a few different problems. Return Loss is the term for how much the end of a cable cuts down on Back Reflection. You want as much Return Loss as possible.

What is Insertion Loss?

When light travels out of the port on your hardware into the fiber optic cable, some of it is lost in the transition. The amount that is lost is referred to as Insertion Loss. You want as little Insertion Loss as possible

Do you need UPC?

Most of our customers are simply looking to minimize Insertion Loss and maximize Return Loss. This means they want as much light as possible to pass through the fiber to its destination and as little light as possible to bounce back to its source. For most applications, UPC will provide this for you. However, in some circumstances, you need more Return Loss than UPC can offer. That is when you use APC. If you have green connectors on your fiber or devices, you may need APC.

Do you need APC?

APC is designed specifically to maximize return loss. APC ends are actually polished to have an ~8° angle on the end of the fiber. An APC end will almost always have a green connector to make it clear that the fiber is APC. The part that is actually polished to an angle is so small that you won’t be able to tell it is angled from looking at it.

If you mix APC and UPC, the result can be tremendous insertion loss (meaning a lot of light will be lost at the point where you connect the APC to the UPC). So, if you have a port on your device that specifies it needs APC, you will need to use a cable with an APC end on it. If you have a cable with a green connector and you want to attach an adapter cable to the end, you will need to make sure an APC end connects to it.

Do you need simplex, duplex, or more?

Simplex cable has a single fiber optic cable and usually one connector on each end. Fiber optic communication equipment typically sends data in one direction on a cable. So, for bi-directional communication, hardware typically uses duplex cable.

Duplex cable has two fiber optic cables and it usually has two connectors on each end. LC and SC connectors can be joined together with a clip that spaces them the correct distance apart to plug both connectors into equipment at the same time. If there is equipment that requires the ends be plugged in closer or farther apart, you can simply remove the clips.

You can also get cable that has many more strands of fiber in it.

What jacket do you need?

Our duplex cable typically comes in a basic zip-cord style where the two fibers are in their own jackets and those two jackets are seamed together. You can also get round jacket cable where multiple cables are run inside a single round jacket, often with reinforcers running through it.

If you are going to be running the cable outdoors or in a conduit where it may be exposed to moisture you will need an Outdoor rated cable.

If the cable is going to be abused in any way, including running along the ground where it might be stepped on or used in a way where it’ll be unwound and wound back up repeatedly, armored cable may be required.

If you want a cable that can be run over by a tank, just mention it, we have something that can handle tanks.

If the cable is in a plenum space, you may need a cable that is plenum rated. Plenum is an air space above multiple rooms. For instance, in office buildings, it’s not unusual for the walls of rooms to only go up as high as the drop ceiling. If you pop your head above the ceiling, you’ll see across many walls and see the ceilings of many rooms. That area is a plenum area where multiple rooms share a common overhead air space. The rules for using plenum vary based on local building codes.

How much do you need?

This is a pretty simple question, but if you need a cable fast, it can be very helpful to know the effect that length has on fiber optic cable.  10GB Multi-mode cable will do up to 10GB/s up to 330M. But, if you need a 20M 50 micron cable that can do 10GB/s then you can often use Multi-mode 50 cable available instead. Here’s a quick chart to show bandwidth vs speed:

Fiber optic patch cord is available in OM1, OM2, OM3, OM4 multimode and OS2 single-mode types. Both ends of the cable are terminated with a high performance hybrid or single type connector comprising of a SC, ST, FC, LC, MTRJ, E2000 connector in simplex and duplex. These are typically not ruggedized, depending on the application, making them suitable for internal use. How to choose right patch cables for your network?

Just follow these 6 steps:

Step 1: Choose the Right Connector Type (LC/SC/ST/FC/MPO/MTP)

On both ends of the fiber optic patch cord are terminated with a fiber optic connector (LC/SC/ST/FC/MPO/MTP). Different connector is used to plug into different device. If ports in the both ends devices are the same, we can use such as LC-LC/SC-SC/MPO-MPO patch cables. If you want to connect different ports type devices, LC-SC/LC-ST/LC-FC patch cables may suit you.

Step 2: Choose Single-mode or Multimode Cable Type?

Single-mode fiber patch cord uses 9/125um glass fiber, Multimode fiber patch cord uses 50/125um or 62.5/125um glass fiber. Single-mode fiber optic patch cord is used in long distance data transmission. multimode fiber optic patch cord is use in short distance transmission. Typical single-mode fiber optic patch cord used yellow fiber cable and multi mode fiber optic patch cord used orange or aqua fiber cable.

Step 3: Choose Simplex or Duplex Cable Type?

Simplex means this fiber patch cable is with one cord, at each end is only one fiber connector, which is used for Bidirectional (BIDI) fiber optic transceivers. Duplex can be regarded as two fiber patch cable put side by side, which is used for common transceivers.

Step 4: Choose the Right Cable Length (1m/5m/10m/20m/30m/50m)

Fiber optic patch cables are made in different lengths, usually from 0.5m to 50m. You should choose an appropriate cable length according to the distance between the devices you want to connect.

Step 5: Choose the Right Connector Polish Type (UPC/APC)

Since the loss of the APC connector is lower than UPC connectors, usually, the optical performance of APC connectors is better than UPC connectors. In the current market, the APC connectors are widely used in applications such as FTTx, passive optical network (PON) and wavelength-division multiplexing (WDM) that are more sensitive to return loss. But APC connector is usually expensive than UPC connector, so you should weigh the pros and cons. With those applications that call for high precision optical fiber signaling, APC should be the first consideration, but less sensitive digital systems will perform equally well using UPC. Usually, connector color of APC patch cable is green, and of UPC patch cable is blue.

Step6: Choose the Right Cable Jacket Type (PVC/LSZH/OFNP/Armored)

Usually, there are three cable jacket types: Polyvinyl Chloride (PVC), Low Smoke Zero Halogen (LSZH) and Optical Fiber Nonconductive Plenum (OFNP). You can see there features in figure below and choose the right one for your network.

Besides the three cables mentioned above, there is another common cable—Armored Cable. The double tubing and steel sleeve construction make these patch cables completely light tight, even when bent. These cables can withstand high crushing pressures, making them suitable for running along floors and other areas where they may be stepped on. The tubing also provides excellent cutting resistance, abrasion resistance, and high tensile strength. Fiber-Mart provides all kinds of fiber optic patch cables to meet demands of various customers!Any questions feel free contact us: product@fiber-mart.com

Difference Between Media Converter and Network Switch

Media converter and network switch are both widely used in today’s high speed network applications. In some scenes, one can used to replace another one. Then, which one should I choose for my network? What is the difference between media converter and network switch? This post will cover the knowledge of media converter and network switch, and explain the difference between.

 What does Media Converter mean?

 A media converter, in the context of network hardware, is a cost-effective and flexible device intended to implement and optimize fiber links in every kind of network. Among media converters, the most often used type is a device that works as a transceiver, which converts the electrical signal utilized in copper unshielded twisted pair (UTP) network cabling to light waves used for fiber optic cabling. It is essential to have the fiber optic connectivity if the distance between two network devices is greater than the copper cabling’s transmission distance.The copper-to-fiber conversion carried out by a media converter allows two network devices having copper ports to be connected across long distances by means of fiber optic cabling.

Techopedia explains Media Converter

A media converter offers fiber-to-fiber conversion as well, from multi-mode fiber into single-mode fiber. It also converts a dual fiber link to single fiber with the help of bi-directional (BIDI) data flow. In addition, media converters have the capability to convert between wavelengths for applications that use wavelength division multiplexing (WDM).

Generally, media converters are protocol specific and they support an extensive array of data rates and network types. They are presented as physical layer or Layer 2 switching systems. Media converters that include Layer 2 switching functionality offer rate-switching as well as other innovative features.

Network intricacy, challenging applications and the increasing range of network devices drive network bandwidth and speed requirements to new extents and push longer distance requirements inside the local area network (LAN). The answer to these issues is media converters.Media converters permit fiber usage when required and integrate new devices into existing cabling infrastructure. Media converters provide flawless incorporation of fiber and copper, and various fiber forms in LAN networks. They support a multitude of protocols, media types and data rates to build a more trustworthy and cost-effective network.

Media converter characteristics:

·Expands network distances with the conversion of UTP to fiber and the extension of fiber links

·Retains investments in pre-existing devices

·Boosts the potential of present fiber with WDM wavelengths

New applications for media converters:

·Remotely handled converters and multi-port switch configurations

·Conversion of DM wavelengths to enhance the bandwidth capacity

·Facilitate fiber-to-the-desktop

What is Network Switch?

A network switch is a computer networking device that connects devices together on a computer network by using packet switching to receive, process, and forward data to the destination device. Usually, a switch serves as a controller, enabling networked devices to talk to each other efficiently. Through information sharing and resource allocation, switches save businesses money and increase employee productivity. And the network switch operates at the data link layer (Layer 2) of the Open Systems Interconnection (OSI) model called layer 2 switch, which operates at the network layer (layer 3) of the OSI model called layer 3 switch.

The relationship between switches, media converters, and OSI layers

Today’s media converters are often switches, and switches often act as media converters. Plus, both switches and media converters are frequently described in terms of layers—Layer 2, Layer 3. How can you tell what the heck you’re looking at?

Most of the confusion happens around OSI Layer 2 where Layer 1 media converters have evolved to meet basic switches. And today’s switches are rapidly advancing into Layer 3 and 4, territory formerly held by routers, muddying the waters still more.

A clear understanding of what OSI layers do, and what the differences between devices operating at different layers are, will help you select the right device.

OSI is a layered network design framework. The layers are referenced in the Open Systems Interconnection (OSI) Reference Model (which provides a layered network design framework that establishes a standard so that devices from different vendors work together). The OSI model is hierarchical. The layer at which a switch or a media converter operates determines which addressing detail it reads as data passes through.

Layer 1: media converters

Layer 1 is the Physical Layer. Media converters operating at Layer 1 only convert electrical signals and physical media without doing anything to data coming through the link.

These media converters only have two ports—one in, one out—and convert the incoming electrical signal from one cable type and then transmit it over another type—UTP to fiber, thick coax to Thin, and so on.

Layer 2: switches and media converters

Layer 2 is the Data-Link Layer. Devices operating at Layer 2 sort packets using physical network addresses, also known as MAC addresses. All network hardware is permanently assigned this number during its manufacture.

Both switches and media converters can be Layer 2 devices. Usually the only difference between a Layer 2 switch and a Layer 2 media converter is the number of ports—a device with two or three ports is called a media converter; four or more ports is called a switch. A media converter operating at Layer 2 may have more than two ports and may have ports operating at different speeds.

Devices operating at Layer 2 are very fast, but aren’t very smart because they don’t look at data packets closely. A Layer 2 media converter is considered to be fairly advanced for a media converter, but a Layer 2 switch is a basic switch. You follow?

Layer 3: switches

Layer 3 is the Network Layer. Layer 3 switches use network or IP addresses that identify locations on the network. Because they read packets more closely than Layer 2 switches do, they identify network locations as well as physical devices. A location can be a LAN workstation, an address in a computer’s memory, or even a different packet of data traveling through a network.

Switches operating at Layer 3 are smarter than Layer 2 devices and incorporate routing functions to actively calculate the best way to send a packet to its destination.

Layer 4: switches

Layer 4—the Transport Layer of the OSI model—coordinates communications between systems. Layer 4 switches are capable of identifying which application protocols (HTTP, SNTP, FTP, and so forth) are included with each packet, and use this information to hand off the packet to the appropriate higher-layer software.

Because Layer 4 devices enable you to establish priorities for network traffic based on application, you can assign a high priority to packets belonging to your vital in-house applications, with different forwarding rules for low-priority packets.

Layer 4 switches also provide an effective wire-speed security shield for a network because any company- or industry-specific protocols can be confined to only authorized switched ports or users. This security feature is often reinforced with traffic filtering and forwarding features.

High-end vs. low-end switches

Switches can also be considered low end or high end. A low-end switch operates in Layer 2 of the OSI model and can also operate in a combination of Layers 2 and 3. High-end switches operate in Layer 3, Layer 4, or a combination of the two.

Conclusion

Media converters can be used anywhere in the network to integrate newer technology with existing equipment to support new applications, technologies and future growth. Layer 2 and layer 3 network switches are also widely deployed in enterprise and data center for higher speed and more capacity. Fiber-Mart provides both media converters and managed network switches for your option. You can choose the most suitable one according to your specific needs:product@fiber-mart.com