What Fiber Optic Connectors Are Used for Non Standard Fiber Sizes?

The question I seem to be asked over and over is “What fiber optic connectors are used when I have non-standard size multimode and singlemode fiber”? The frequency of this question led me to write this blog. It can be very frustrating when installers and technicians are faced with this situation, the proper fiber has been identified, but what good is it to me if I cannot install connectors. Fortunately, there are answers and I hope to relieve some of the angst that you may have.

 

Most telecommunications projects utilize standard equipment and fibers that are readily available, but what happens when this is not the case? The standard LC, SC, ST and FC style optical fiber connectors with ferrule holes at or around 126um will suffice 99% of the time but, nonstandard applications such as medical, automotive, high power and others utilize specialty fibers where the standards will not work.

 

Non-Standard (Specialty, Large Core) Fiber

 

As most of us know, standard singlemode optical cable is made with a 9um optical glass core and a 125um cladding (9/125) with multimode standards being 50/125 and the old North American standard of 62.5/125. Many non telecommunication optical applications utilize non-standard fibers. Following is a list of just a few of these fibers:

 

100/140 – This fiber is identifiable by its green jacket color and has a typical attenuation of about 4 dB/km.

 

200/230 - 200/230 will typically have a blue jacket and has a standard attenuation of 6dB/km. You may notice that as the fiber cores increase in size, so does the standard attenuation.

 

960/1000 – This fiber is actually manufactured using plastic instead of the glass we usually find in fiber. Commonly black jacketed, this fiber is popular for optical audio cables; its 300 dB/km attenuation relegates it to short distance transmissions.

 

Large core fibers are also available: 300/330, 400/440, 500/550/ 600/660, 800/880 and many others too numerous to mention.

 

Precision-Drilled Connectors

 

Specialty fibers will not accept the standard 126um fiber connectors, so the technician must search out alternative solutions. Let’s first address the components that make up a fiber connector:

 

The Fiber Connector:

 

Strain Relief Boot

 

The strain relief boot allows the fiber exiting the connector to maintain its bend radius. A connector without a boot would kink the fiber causing attenuation (loss) or possibly a break in the fiber itself. It is important that the boot not be glued into place, gluing the boot will hinder the spring inside the connector, so the boot should be slip fit onto the connector body.

 

Connector Body

 

The body of the connector holds the ferrule in place and allows the connector to be crimped to the fiber and body via the use of a crimp sleeve. Connectors that only crimp to the fiber and not the body (like an ST) will allow the ferrule to piston when force is applied to the fiber, this is why LC, SC and FC connectors are dual crimp and have the advantage of non-optical disconnection.

 

The Ferrule

 

The most important component of any connector is the Ferrule. In the past, ferrules were made from stainless steel but due to performance issues most of today’s ferrules are made from ceramic (Zirconia). The ferrule’s primary function is to hold the fiber precisely to allow for the transmission of optical signal. Most standard ferrules have a hole size of 126um.

 

When specialty/uncommon (large core) fibers are used, many times ferrules with the larger hole sizes are not available. When larger size holes are needed, the ferrule must be drilled to accommodate these sizes.

 

When drilling a ceramic connector ferrule, issues occur that effect the hole tolerance and concentricity. During the drilling process, the ceramic material will chip and flake making the ferrule unusable. Because of these issues, the only ferrule type that can be consistently drilled is stainless alloy.

 

When drilling stainless alloy ferrules, sizes range typically from 250um to as large as 1550um, these sizes step in 10um increments (example 310um, 320um, 330um etc). When manufacturing these drilled ferrules, specifications for hole tolerance, concentricity, length and diameter are all measured and have pass/fail criteria. Some companies offer two options for their drilled ferrules, standard and premium. A standard drilled optical connector has a hole tolerance specification of -10µm/+50µm and a concentricity value of +/- 50µm. Premium drilled connectors will have tighter tolerances; so if higher performance (low attenuation) is required the premium product is the answer. Premium drilled optical ferrules have a hole tolerance specification of -4 µm/+10 µm and a concentricity value of +/- 25 µm. The premium ferrule will allow for better light transmission, which makes this the most popular of all drilled connectors.

 

Understand that the ferrule cannot be drilled while inserted inside of the connector body. All ferrules are drilled before the connecter is manufactured. Once the ferrule is drilled and passes all specifications then it is installed into the finished connector. Many times (like in medical devices) the ferrule is the only thing that is installed onto the fiber, leaving the body and strain relief boot out.

 

It is important to also note that the older SMA905 and SMA906 connectors can be drilled and are commonly used in military, medical, aerospace and research facilities where higher power lasers and heat dissipation are required. The SMA connector uses a larger 3mm ferrule, compared to the typical 2.5mm for SC, FC and ST and the 1.25mm ferrules used for LC connectors.

 

Installation of the optical connector

 

Once you have identified the correct connector style (ST, FC, SC, LC) and hole drill size the next question is “How to install these connectors?” When considering standard fiber optic connectors (dozens of manufacturers) it really boils down to only three options on how to install the connector on the optical fiber. These options are:

 

Hand/Machine Polishing

 

All fiber optic connectors are manufactured using this epoxy/polish procedure. The move in the fiber industry over the last decade has been to shy away from this process. Labor, consumables, skill level and overall quality is deeming this process obsolete for field connector terminations. The thought process is to let the industry manufacturing professionals handle the task.

 

Mechanical Connectors

 

A mechanical connector is manufactured and machine polished by the connector manufacturer with a small piece of fiber inserted into the connector, this fiber is precision cleaved inside the back of the ferrule and the end is then machine polished. The field installer simply cleaves his fiber and inserts it into the back of the mechanical connector and clamps it into place. Using mechanical connectors drastically reduces labor, and the required skill level of the technician. These connectors are more expensive than epoxy style connectors but the savings in labor costs tend to outweigh the expense.

 

Mechanical Splice

 

Fusion Spliced Connector

 

Most people believe that fusion splicers are used to lengthen and repair fiber optic cables. While this is true, the most common use of a fusion splicer is to attach premade pigtails or the newer Splice on Connectors (SOC). Although the perception is that the investment in the fusion splicer makes this process expensive, the reality is that fusion splicing a connector is the least expensive, lowest labor, highest quality way to install a factory manufactured connector.

 

Now that we have identified the field installation processes for fiber connectors how do we apply this to large core/specialty/Non Standard drilled connectors? Reality is that there are really only two options you have. Fusion splicers cannot splice these specialty fibers and there are no mechanical connectors made today that can be used with these larger core fibers. This leaves us with field installing these connectors using the epoxy/hand polishing procedure or purchasing the cable with the connectors installed by a fiber optic manufacturer. The obvious choice is having your cables manufactured by a company that is a reputable fiber assembly house. These pre-terminated cables will be professionally manufactured and tested; your job is to simply install the cable.

 

Remember that when using specialty/large core fibers there are solutions to your connectorization needs and most of the time the answer is a precision drilled fiber optic connector.

Fiber Optic Patch Cable - (color coding)

Fiber optic patch cable, is also known as fiber optic jumper or fiber optic patch cord which is composed of a fiber optic cable terminated with different connectors on the ends.

 

Fiber optic patch cable is used to cross-connect installed cables and connect communications equipment to the cable plant.It is a very important component of the network.

 

In general, fiber optic patch cables are classified by fiber cable mode or cable structure, by connector construction and by construction of the connector's inserted core cover.

 

Fiber Cable Mode & Structure

 

According to the fiber cable mode, fiber optic patch cables are divided into two common types - Singlemode fiber patch cable and Multimode fiber patch cable. Singlemode fiber patch cables use 9/125 micron bulk single mode fiber cable and single mode fiber optic connectors at both ends. Singlemode fiber patch cable is generally yellow with a blue connector and a longer transmission distance. Multimode fiber patch cables use 62.5/125 micron or 50/125 micron bulk multimode fiber cable and terminated with multimode fiber optic connectors at both ends. It is usually orange or grey, with a cream or black connector, and a shorter transmission distance. According to the fiber optic cable structure, fiber optic patch cables include simplex fiber optic patch cable and duplex fiber optic patch cable. The former has one fiber and one connector on each end while the latter has two fibers and two connectors on each end. Each fiber is marked “A” or “B” or different colored connector boots are used to mark polarity.

 

Connector Construction

 

Connector design standards include FC, SC, ST, LC, MTRJ, MPO, MU, SMA, FDDI, E2000, DIN4, and D4. Fiber optic patch cables are classified by the connectors on either end of themselves. Some of the most common patch cable configurations include FC-FC, FC-SC, FC-LC, FC-ST, ST-LC, SC-SC, and SC-ST.

 

Construction of the Connector's Inserted Core Cover

 

Fiber optic connectors are designed and polished to different shapes to minimize back reflection. This is particularly important in single mode applications. Typical back reflection grades are -30dB, -40dB, -50dB and -60dB. The connector's inserted core cover conforms to APC (Typical back reflection <-60dB), UPC (Typical back reflection <-50dB), or PC (Typical back reflection <-40dB) configuration.

 

The buffer or jacket on patchcords is often color-coded to indicate the type of fiber used. In addition, color-coding of connectors for different fiber standards make it easy to avoid confusion.

 

Fiber Color Codes

 

Similar to the color coding designations of copper cabling, optical fiber has a color code designation for strands of fiber within the larger cable, as well as the cable's jacket. These color codes are set by the EIA/TIA-598 standards guide identification for fiber and fiber related units that determines which color codes are used in which applications. The colors don't only apply for the application though, they also are meant to be of use in determining a cables properties. The differences in colors are based upon different levels of OM and OS fiber (Optical Multimode & Optical Singlemode).

 

Optical fiber cable is separated into strands, which are the individual fibers within the larger piece of cabling. Up to 24 individual strands can be manufactured loosely, and after that point they are usually sectioned into tubes containing 12 each. Each tube containing 12 strands is then given a color.

 

Connector Color Codes

 

Since the earliest days of fiber optics, orange, black or gray was multimode and yellow singlemode. However, the advent of metallic connectors like the FC and ST made connector color coding difficult, so colored strain relief boots were often used.

Deploying Tunable Transceivers: Advantages, Challenges and Solutions

Tunable transceivers represent a cutting-edge technology that allows on-site wavelength adjustment, transcending the fixed-wavelength limitation of traditional static transceivers. The need for tunable devices has become increasingly important as networking technology continues to develop. Dense wavelength division multiplexing (DWDM), which is expected to serve as the central technology in the future of optical networking, allows data of different wavelengths originating from different sources to share a single optical fiber.

 

One drawback of static transceivers is that multiple backups are needed to minimize network downtime in a DWDM environment, given the range of wavelengths present. This can greatly increase operating cost. While it’s true that individual tunable transceivers tend to cost between two to four times more than their static counterparts, they can both minimize cost and maximize flexibility when considered in the context of the system overall. 

 

The flexibility afforded by tunable transceivers is also key to adapting to the needs of a growing network. This aspect will only become more important as transmission rates increase and flexible channel spacing becomes crucial to networking success. 

 

That said, tunable transceiver technology can lead to challenges for operators attempting to interface with legacy equipment. One of the most significant challenges is an inability to tune over the command line interface (CLI); it’s a problem that presents itself for some switches and routers interfacing with tunable XFP transceivers, and is even more common among devices interfacing with tunable SFP+ transceivers.

 

Fortunately there is a solution: a transceiver management module, also known as a tuning box, which features ports designed for hosting tunable transceivers and that works in conjunction with tuning software.

 

Precision Optical Transceivers offers two major transceiver management modules - the TN100-XS and TN100-S-BT.

 

Precision’s TN100-XS tuning module is a USB-powered device capable of hosting both SFP+ and XFP devices. It allows for tuning to any of the standard ITU C-Band 50GHz or 100GHz spaced channels. 

 

The TN100-S-BT is a Bluetooth® powered compact device capable of hosting SFP+ devices, allowing for on-the-go tuning through a proprietary mobile tuning application. The device also allows for tuning to any of the standard ITU C-Band 50GHz or 100GHz spaced channels. 

 

Tuning software is included with both devices and offers the advantage of being web-driven, meaning that the device will stay up-to-date without the need for manual installations of new firmware, or the inherent security compromises that accompany manual network interaction. 

How to Take Care Joy Love Dolls Realistic Sex Doll?

When you own a sexdollrealistic.com, chances are that you would be using it a lot. It’s an investment on your part and needs care as you would for a pet.

The most frequent question is “How do I clean my love doll after use?” For this question, we have collected all you need to know in this detailed guide. While taking care of your sex doll it will extend their lifespan for many years, keeping her fresh, clean and sexy and keep her attractive for future pleasure.

Just a reminder that you need to keep it clean and in hygienic condition for consistent use and need to store it properly to keep safe from pollutants and contaminants. We have conjured some useful sex doll care and storage tips for you here.

Cleaning your doll is easy and it takes only minutes if you have the right tools and techniques. It is actually so easy that sex doll brothels use the same love dolls and they can sanitize the doll for the next customer in no time. Those have become popular as sex dolls help for anxiety and loneliness. Here is how we recommend doing it with safety and ease.

Quick Guide Cleaning Your Sex Doll:
1. You should always clean your doll after any usage or contact with bodily fluid. This is easiest done in the shower or bath with warm water and light soap.  We recommend keeping your doll's head above water level when taking a bath and cleaning it separately.  When showering your doll keep the head upright position.

2. After washing your love doll, dry thoroughly with a clean towel to remove excess moisture. Avoid using too much force and scrubbing back and forth but dry her with a soft pushing move with the towel. Do not use a blow dryer as too hot air can sometimes damage the TPE material made skin.

3. For more delicate care we recommend you can apply baby powder to remove any remaining moisture and keep her skin nice and soft.

4. If you put makeup on her, that can be removed with damp of laundry detergent or mild soap with warm water. You can use a paper towel or dry cloth to pat her face dry.

5. The wigs should be washed separately with a mild shampoo, and let them air dry, if you use a blow dryer you risk damaging the hair and pubic hair.

6. When you buy your doll at Joy Love Dolls you will get some of the most durable and long-lasting dolls on the market. However, we still recommend you take care when moving your doll to avoid any unnecessary bumps, scrapes, or drops.

7. We recommend storing your doll in a cool, dry place away from direct sunlight and extreme heat or cold.

These are the main recommendations for taking care of your TPE Sex Doll.

Following More Detailed Guide will tell you exactly what to do and what to not do with your doll to ensure its maximal lifespan.

More Thorough and Detailed Guide for Taking Care of Your Life Like Sex Doll

TPE Sex Doll Skin Care and Lubricants
Always use water-based lube while having sex with your life-size sex doll. It will help in better vaginal, anal and oral penetration without fear of damaging the doll.

If your love doll’s skin becomes tacky to touch, clean her with a good quality renewal powder to make her skin velvety smooth again. Read more about what is the difference between TPE Sex Doll and Silicone Love Doll.

Bathing Your Love Doll
While bathing your realistic sex doll with a mild soap, never allow her head and neck to submerge deep into the water. Use a soft fabric towel to cleanse and dry her skin. Use of hair dryer is not advised as it can make her skin tough and also degrade the quality.

Bath your doll after a month’s gap using a mild antimicrobial soap.

Cleaning of Vagina, Anus, and Mouth of a Lifelike Sex Doll
Vaginal Irrigator
A “vaginal irrigator” or enema bulb is the right tool for washing your doll vagina thoroughly. The right way to use this irrigator is to fill it with soap and water then use it softly to flush out and clean your doll's vagina from inside. Please do this right after use of your doll to ensure the ease and the best results. We recommend doing the initial flushing with cold water then switch to warm water and mild soap to sanitize. Check here how the sex doll vaginas look like.

Vaginal irrigators or bulbs are very inexpensive and easy to use. We recommend doing this cleaning operation in a shower room where you can let the water run out of her without making a mess. Vaginal irrigators are the best tool for cleaning your sex doll after use.

Luffa on a Stick
If you want to make one extra step cleaning your love dolls inners parts, we recommend a Luffa on a stick.  Luffa helps you to gently scrub inside of your doll’s vagina, anus, and mouth. This is especially helpful if you haven’t been so careful in the first place and over time some fluids have left inside of your doll. Soft scrubbing will help you remove any residue left inside. Be careful not to stick it too hard to the bottom or with any metalcore on the luffa. That might damage your doll penetrating holes. Overtime any residue may begin to smell or compromise the material of your doll so it is important to take good care in the cleansing.

Handheld Shower Head
A handheld showerhead is also a clever option to make it easier clean your real like sex doll. These handheld showerheads allow you to position the stream of water straight inside the penetration holes (but always softly) and clean out the inner parts effectively. If possible us adjustable stream settings so that you can turn it up to high pressure but thicker stream setting.  With enough pressure and right angle for the stream, you’ll be able to quickly flush out your doll in seconds.



Squirt Water Bottle
Last but not least for cleaning your dolls inner parts, any water bottle with a squirting mouthpiece can be used for making a stream of water purged to the vaginal to remove all body fluids similarly as a vaginal irrigator. Simply follow the guides for the vaginal irrigator above.

To Summarize Vaginal Cleaning
Clean your sex doll’s vagina, anus, and mouth after use to prevent the growth of bacteria as TPE material is porous and bacteria can stay in it.

Start by flushing the orifices with mild antimicrobial soap using an irrigator or shower head. Rinse the canals with a vaginal irrigator to ensure deep cleansing. Wipe the canal with a dry clean towel using your fingers, and be very gentle while doing so.

Once your doll is dried, apply renewal power inside and out to keep its subtle, soft and velvety touch alive.

Care for Removable Vagina
Apply renewal powder on the outside of the replaceable vagina and inside of the doll before inserting the replaceable vagina.

Follow the above-mentioned cleaning tips to clean the removable vagina of your love doll. The same guides apply to clean both fixed and removable vagina inside.

Skeleton Care of Your Joy Love Doll
Your realistic sex doll has fixed and moveable joints to provide her more flexibility and multiple positions for sex. It’s quite normal for your love doll to have some modification traces and marks at these parts.

Do not leave the arms and legs of your love doll widely spread for a longer period than needed as the stress may cause tearing. Always bring your doll back to her stress-free position with arms down and legs closed when you are not using her.
Take care not to drop her, knock her on surfaces or drag on the floor as it will bring down her quality and lifespan.
Do not spread her limbs too much and do not apply extreme force on her to prevent damage to her skeleton and skin.
Your doll has enhanced wrists to support her own weight; nevertheless, it is advisable to provide her support by placing pillows or furniture beneath her torso when engaging in doggy style sex with her.
Do not leave her in a bent position for long to prevent body deformation.
Do not leave her standing for long as this may damage her stance.
Like humans, real-life sex dolls can make and hold multiple positions but if you keep the weight too long for small areas or few joints like wrists, it does not make good. The skeleton structure is bendable and flexible but for longer periods always remember to “pack” your doll to safeguard positions limbs collected close to its body and weight distributed to larger areas and back or with a proper hanging hook with always feet on the ground. More about the hanging hooks later in this guide.

Sex Doll Clothing Care
Do not put oil soluble clothing and pigments on your sex doll.

Your doll’s clothing should be color transfer resistant. Avoid darker color clothing as it may bleed and cause discoloration.  Stain cleaner may be used to remove most stains.

Keep your doll away from inks, paints, dark-colored material, newspapers and magazines with colored prints as these items may stain her.

Dust the doll’s skin and clothes with renewal powder.

Dust off the remnants to bring back the subtle softness of her skin.

Wig and Hair Care
Remove the wig from her head and clean it with a mild shampoo and conditioner. Let it dry of its own, gently comb it from the bottom up and then put it again on her head. More about taking care of sex doll wigs here.

Realistic Love Doll Hooks and Storing
Proper storage of your sex doll is very important for keeping her in the best condition to perform with you, and also for keeping her usable for long without early wear and tear. So, here we have come up with some useful storage tips for your lovely sex doll.

Cover your doll with a protective soft cloth blanket.
Avoid dark or black color clothes as it may stain her.
Do not hang your doll from the neck freely as the stress and strain may cause deformation over a period of time.

Make sure that your sex doll’s feet are on the floor when you store her vertically. This will help in distributing the forces evenly across your doll’s body, and prevent deformation of her skeleton.

Use 100% natural cotton muslin dust bags to envelop your sex doll, protecting her from dust and dirt, a and also providing a degree of privacy to her.

Different type of hooks, bolts and chains are available to adjust your doll to hang. You can find them at our “Hooks and Storing” section or just ask us to provide to you with your new sex doll and we pick you suitable options.

Use closet bar suspension to keep your doll from structural failures. These closets include protection for your doll’s body to securely suspend her without anything pressing against her soft TPE skin.

If you do not have closet space, we can provide you strong and sturdy hanging rack constructed with heavy-weight plumbing pipe in a gorgeous finish. It also comes with room for her clothing or storing an additional doll.

Wavelength Division Multiplexing (WDM) Increases Network Capacity

by www.fiber-mart.com

WDM is a method of separating or combining multiple wavelengths out of or into a single fiber strand with each wavelength carrying a different signal. Using optical filters lets a certain range of wavelengths pass through, while another range is allowed. Thin-film filter technology (TFF) is often used to achieve this effect. Multiple thin layers are stacked and interference effects are created by sequential reflections on the interface between the layers. This lets light reflect for certain wavelengths and pass through for others.

 

The capacity of a network can be increased cost effectively by using WDM. Two types of WDM are commonly used:

 

Dense Wave Division Multiplexing (DWDM) devices are mainly used when more wavelengths are required between sites and when the network extends over a very long distance. Forty wavelength channels from 1530 nm to 1570 nm are distributed in the C-band. To increase capacity, DWDM can be overlaid on a CWDM infrastructure.

Coarse Wave Division Multiplexing (CWDM) has 18 different wavelength channels standard, spaced 20 nanometers (nm) apart between 1270 nm and 1610 nm. Most systems only use the top eight channels between from 1470 nm and 1610 nm. CWDM systems have the advantage that they can always be upgraded at a later stage. This limits the initial installation costs. The requirements on the lasers is not severe due to the wide channel spacing, allowing less expensive lasers without any temperature control to be used.

The insertion loss of DWDM and CWDM is typically lower than that of optical splitters. This increases the reach of a network from a centralized office substantially. As every customer has wavelength(s) assigned to them, this provides better security and makes eavesdropping virtually impossible.

 

WDMs Can Be Utilized In Different Ways:

Add/Drop Vs Mux/Demux.

A multiplexer, also known as a mux, combines several wavelength channels on one fiber, while a de-multiplexer (demux) separates them at the other side. A mux/demux configuration is very useful to increase a fiber’s end-to-end capacity. A mux is normally located at a central office, while demuxes are placed in either a splice closure or cabinet. From there the fibers are routed in a star-shaped topology to their ultimate destination.

 

An alternative to separating the wavelengths at one side, individual wavelengths can be added or dropped at various points across the line. This process does not affect other wavelengths. This is often preferable when the distance between sites is long or they are grouped in a circular structure.

 

One Or Two Fibers?

An alternative to sending signals at different wavelengths through the same fiber is to use two different fibers. Many CWDM systems use two fibers where one is used for upstream signals and the other for downstream. In this configuration, each customer uses two fibers and one wavelength. Each customer will have two wavelengths if they use a single fiber.

Utilizing the WDM – Increase Fiber Capacity Without Construction

by www.fiber-mart.com

Imagine turning a dirt road into a multilane highway without having to perform any new construction. That is what Wave Division Multiplexing (WDM) allows with an existing fiber network. This technology can greatly reduce the cost of increasing network capacity without having to move a single shovelful of dirt or hang a single new fiber.

 

WHY WDM?

 

It’s no secret that outside-plant (OSP) fiber construction is expensive. Construction costs vary, but they are always hefty, and they increase greatly if cable is buried. In addition to construction, the costs of permitting, zoning, raw materials and splicing are significant. Thus, avoiding installing new fiber is best whenever possible.

 

Many communications providers are experiencing fiber exhaust in their networks. This means that the cable counts initially deployed are not able to handle today’s needs. Now, emerging technologies in cell backhaul, business class services and others are creating a need for yet more fibers. However, in most cases, ever-increasing labor and material prices make new fiber construction too costly to consider for many projects.

 

WDM allows operators to place new equipment at either end of a fiber strand and combine multiple wavelength channels on a single fiber strand. Many existing systems use only a small amount of the spectrum available on single piece of glass. Using either coarse wave-division multiplexing (CWDM) or dense wave-division multiplexing (DWDM), operators can combine many different services on a single fiber by assigning a different color, or wavelength, to each service. Multiplexers are used to combine all these wavelengths onto a single fiber, and demultiplexers are used to separate the colors farther on in the network.

 

Mobile devices, cloud computing, over-the-top video, DOCSIS 3.1 with IPTV, and online gaming are just a few of the drivers for increased bandwidth demand. As demand continues to rise, service providers will need long-term strategies to develop a bigger pipe.

 

Cellular backhaul, FTTx and commercial business services are also creating a need for more fiber capacity. 3G and 4G cellular services require more bandwidth than cellular services needed in years past and therefore require a fiber link to each cell site. A provider may own a fiber sheath that runs right past a cell tower, but all its fibers may currently be used to maximum capacity. Providing lit services or dark fiber to cell towers can be very profitable but not if it requires plowing or hanging new fiber to these cell sites.

 

Business-class services are becoming popular revenue sources for communications companies. Businesses are often willing to sign long-term contracts and pay more than residential customers. In some cases, businesses require fiber to meet their bandwidth needs. The same issue arises here: How is it possible to serve these new customers without having to install new OSP fiber to those sites?

 

WDM TO THE RESCUE

 

Most legacy fiber networks use a single wavelength, or color, on each fiber. Think of it as two people on different mountaintops using white-lens flashlights to communicate via Morse code – not very sophisticated, but it works.

 

All of a sudden, two more people want to start communicating between those two mountaintops. What is the solution? Use different colored lenses on the flashlights to communicate. Senders and receivers will recognize and send only their own colors of light and ignore the others.

 

This is basically what a WDM network does. It uses multiple colors of light over the same medium (fiber). Transmitters tuned to specific wavelengths send light into a passive combiner called a mux (short for multiplexer). All the wavelengths travel down the common fiber and are separated using a passive demultiplexer (also called a demux). Now each receiver at the other end will be able to receive just its own discrete signal.

 

In other words, WDM maps multiple optical signals to individual wavelengths and multiplexes the wavelengths over a single fiber. WDM can carry multiple protocols without having to convert them to a common signal format. A single fiber is able to do virtually anything that’s needed.

 

There are two main types of WDMs. The advantage of CWDM technology is that it is relatively inexpensive compared with DWDM. The transmitters used in CWDM are less expensive, as they do not need to be tuned as precisely as DWDM transmitters. However, CWDM has drawbacks, too: Only 18 channels are available, and fiber amplifiers cannot be used with them. Thus, they are not the ideal choice for long-haul networks.

 

CWDM channels each consume 20 nm of space and together use up most of the single-mode operating range. The wavelengths most commonly used are the eight channels in the 1470 to 1610 nm range. Any transceiver used in CWDM applications operates within one of these channels.

 

DWDM allows many more wavelengths to be combined onto one fiber. It also leverages the capabilities of fiber amplifiers, which can amplify the 1550 nm or C band commonly used in DWDM applications. This makes it ideal for use in long haul and areas of greater customer density. Instead of the 20 nm spacing in CWDM (equivalent to about 15 million GHz), DWDM uses either 50, 100 or 200 GHz spacing in the C and sometimes the L bands. This allows many more wavelengths to be packed onto the same fiber.

 

The downside of DWDM is that the lasers need to be much more accurate and require precise temperature ranges to operate. This makes DWDM applications much more expensive than CWDMs. The introduction of the ITU-T G.694.1 grid in 2002 made integrating DWDM technology easier. It created an industry standard for DWDM.

 

CHOOSING A TYPE OF WDM

 

Before deploying any WDM equipment, it is necessary to ensure that the glass in place will support all the required wavelengths. Low-water-peak or zero-water-peak fiber is more suitable for WDM applications, and older glass types may have water peak issues. If the glass is too old, it may be necessary to bite the bullet and install some new fiber.

 

Assuming the glass is appropriate for WDM, should you use CWDM or DWDM technology to solve fiber exhaust problems? As previously noted, CWDM can support a maximum of 18 channels and is not ideal for long haul. So CWDM would typically be best for applications that do not require the signal to travel great distances and in locations where not many channels are required. The availability of SFP transceivers may also be a limiting factor.

 

For applications that require a high number of channels or for long-haul applications, DWDM is the ideal solution. Though the electronics and passives are not cheap, they are considerably more cost-effective than putting in new fiber.

 

DESIGN CONSIDERATIONS

 

It’s important to ensure that the CWDM and DWDM passives will operate properly in the environment where they will be placed. This becomes especially important when putting CWDM passives in the outside plant. Before buying a mux or demux for use in an unconditioned cabinet or splice case, verify that the operating temperature will fit the application. Many vendors specify the storage temperature but not the operating temperature.

 

The operating temperature of an optical component is the actual temperature range in which the component will work. Usually, a component must remain within a specified temperature range to perform at a specified optical performance level.

 

The storage temperature of an optical component is the temperature at which an optical component can be stored without causing any degradation or component failure when it is used in the component’s specified operating temperature limits. Some storage temperatures can exceed the actual operating temperature of the components. When sourcing WDM filters, ensure that they will be able to operate within the temperatures in which they will be deployed.

 

Another design consideration with any WDM network is insertion loss. Though WDM creates a huge increase in capacity, it also creates insertion loss in a network. Using the maximum insertion loss values in the link budget is a good idea; keep in mind that some manufacturers do not include the connector loss if the device is terminated.

 

Calculate the loss for both the mux and demux components. The maximum insertion loss on a typical eight-channel CWDM is 3 dB, so for a mux/demux solution, add 6 dB of insertion loss.

 

WDM filters can be designed to drop individual colors at a specific location and keep sending the rest down the fiber path. In some applications, combining several wavelengths at a certain location and then dropping individual channels to customers along the same route may be desirable. This is the most common type of design used in fiber-to-the business and cell tower applications.

 

SUMMARY

 

WDM technology is a very effective method for overcoming fiber exhaust. Placing passive filters and WDM transceivers at each end of a fiber optic network can greatly increase bandwidth without having to spend capital on new fiber construction projects. Most current fiber technologies use only a small sliver of the available bandwidth capacity of single-mode glass, so a properly designed WDM network can unlock a floodgate of available power in a network. Using many channels on the same piece of optical fiber enables operators to serve businesses, cell towers and residential customers with the same fiber. Fiber counts are no longer a constraint.

AN INTRODUCTION TO WDM TECHNOLOGY

by www.fiber-mart.com

WDM technology can be a reliable, cost-effective method of solving fiber exhaust problems and expanding bandwidth across campuses, municipalities, school districts, and other networks. In our first installment, we covered the basics behind the technology and how it works. In this installment, we will discuss how to begin deciding which WDM is right for you, as well as addressing some common misconceptions about this incredibly valuable technology.

 

CWDM or DWDM?

Deciding between CWDM and DWDM is a complex issue, with many network- and application-specific variables that need to be considered. While we recommend a consultation with an expert to get a definitive answer, here are some preliminary considerations:

 

Common Misconception 1: WDM is extremely expensive to install.

For many network operators, the concept of “WDM” is inextricably linked with large, complex active line systems that cost hundreds of thousands of dollars. For most applications, this is a case of upselling by their OEMs. In fact, you can reap many of the benefits much more cost-effectively with a passive filter system. Passive CWDM and DWDM systems can be monitored via a tap port on the faceplate of most mux/demuxes.

 

Common Misconception 2: WDM can only cover long distances.

Network operators are often discouraged from adopting passive WDM system because the rated distances of the transceivers are much longer than required. For example, the shortest rated distance for CWDM transceivers is 40km, and 80km for DWDM transceivers. Is it still possible to use these optics if your campus is only, say, 8km, or even 100m apart?

 

The answer is yes! With the proper level of attenuation on the transmitting side of your transceivers, you can still deploy a passive WDM solution to add services and conserve fiber.

 

Further Reading

For more information about different WDM strategies and how to use them, you can check out our coverage on our ZS line of standard passives, this application note on some simple passive architectures, and an overview WDM strategies using a single strand of common fiber.

 

You can also schedule a consultation with our experts, who will walk you through your options step by step and find the perfect solution for your network.

How Many Cables Can You Pull Through A Hole?

by www.fiber-mart.com

A guide to help figure out how many cables you can pull through a hole to help you plan your structured wiring project.

 

I'd like to run new cables for TV, phone and network and I came up with this little chart that might help you figure out how many telecom cables you can pull through a hole. It includes Cat3 2-pair, Cat3 4-pair, Cat5 4-pair, Cat5e 4-pair, Cat6 4-pair, RG59 and RG6 Quad Shield in various sized holes.

 

Dimensions of cables vary so please double check the actual cables you're going to use.

 

For the holes I selected sizes that match the auger sizes of Greenlee D'Versibit Flexible Drill Bits which are a popular type of installation bit used when pulling cables in existing walls. The bits come in 3/8", 1/2", 9/16", 3/4" and 1" diameters.

 

There are 2 values in the chart. In black is the maximum number of cables I think I can jam through the hole and in green is the number of cables based on a 40% fill.

 

The NEC (National Electric Code) specifies conduits for power cables should not exceed 40% fill. This allows for some room to run extra cable in the future or change to larger cable as well as heat and providing enough room to minimize chances of damaging cables while pulling.

 

For some reason TIA/EIT and most LAN installers have adopted the 40% fill rule even though these are very lower power cables. When running cable through conduit the NEC says that the same conduit fill rules apply for low power cables as I understand it. I'm not 100% sure what the rule is when just running cable through holes and not conduit. What I've seen installers do is measure the size of their cable bundle and choose a drill bit slightly larger so that the bundle pulls easily without damaging the cable. The hole size needs to conform with building codes regarding making holes in structural members (generally no more than 1/3rd the width of the member.) Check with your local codes before starting. This is used mainly as a guide to help in planning and determining which size bits to buy. They aren't cheap!

 

 

As you can see the Cat6 cable is a lot thicker than Cat5e cable. The whole reason I made this chart was to determine which cable to buy as I have a limited amount of space to run the cables.

 

They both support Gigabit Ethernet 1000Base-T. Even the older Cat5 cable was able to run at gigabit speeds. The issue comes with transmission problems that may cause errors and slow down the network. Cat5e is better than Cat5 and Cat 6 is better than Cat5e in that regard.

 

Most Cat6 cable has a plastic center spline that helps prevent crosstalk and other signal issues. That's the main reason the Cat6 cable is thicker. Some manufacturers have found ways to make cable that meets that Cat6 spec without the need for the center spline.

 

Most of the splineless cat6 cable I've seen is plenum rated. (see Cat6, Splineless, UTP, 23AWG, 8C Solid Bare Copper, Plenum, 1000ft, Blue, Bulk Ethernet Cable (Made in USA)) which is about 3 times the cost of regular riser cat 6 with a spline. The plenum rating means it's made with a different jacket material that doesn't release toxic fumes if it burns. I did however find this Riser rated ICC CMR CAT6 UTP 500 MHz (NO SPLINE) / ICC-ICCABR6VWH  which is only 2x the cost of regular Cat6 cable.

 

If I use Cat5e or splineless Cat6 the installation will be easier as I'd have to drill less holes or I could make smaller holes. Still trying to figure out if it's worth the expense of the more expensive splineless Cat6 instead of regular Cat5e.

Ethernet Patch Cable Colour Codes & Bestpractices

by www.fiber-mart.com

Keeping data from getting crossed in a data center can be a pain. Below are some of the standards followed in Data Centers

blue - most common so workstations or generic servers.

red - critical systems. Sometimes used for building fire systems

yellow - less critical system.

orange - cabels that go off to other racks

green - where the money flows for e-commerce systems.

black - VoIP systems since the phones came with blakc patch leads

white - video camera network

pink - used for rs-232 serial cables

purple - used of isdn type links

tan - telephone lines  

This is the current list of colors of ethernet cables that can find be found in general ind DC or have seen:

 

blue

light blue (rare but commonly used on cisco cables)

fluorescent blue (even rarer)

red (many of these are cross over cables)

yellow (this was a standards approved color for cross over cables)

cisco cable yellow

orange

pink

fluorescent pink

green

fluorescent green (never seen this buts its in catalogs)

black (easy to confused with power cords)

white (sort of rare)

light gray

dark gray (rare)

silver (rare)

tan/beige (common in cat 3 patch cables)

purple/violet (they are different but when you order one you get the other)

fluorescent violet (very rare)

 

 

One thing to consider is about 15% of all males are slighly color blind and only about 10% think they are. Many colors look the same but often times a color blind person can easliy tell the difference between say tan cables and beige cables but can't tell the red from the green.

 

 

Color codes for fiber (fibre?)

 

  

Orange - multimode

Yellow- Single mode

gray - could be either but tends to be single mode

light blue - could be either

Color codes for fiber jackets

Blue - Stright cut - fiber joint is perpeneducalr at 90 degrees

Green - Angled cut - fiber joint is angled slightly

 

Note that buildings will often have these colors:

 

 

red - fire alarm cables

white - cheaper fire alarm cables

blue - who knows? Could be alarm, fire, hvac, or data

tan - same as blue but older

 

For -48 volt systems you can get:

 

 

red - ground.

black - negitive 48V but can routinely be -56V

blue - could be the same as red or black but tends to be the same as red on a differenc circut

 

 

Note that -48 Volt systems tend to be able to provide massive amounts of unfused current. These system will often have enough capacity to boil the metal in tools.

 

 

That describes the outer jackets. Inside cables like power you can have:

 

 

Live power from selected places around the world:

  

red (power Au/UK)

brown (old for AU/NZ/UK)

yellow (old phase 2 UK)

blue (old phase 3 UK)

blue (phase 3 in AU)

blue neutral in Europe

black (power in Europe)

Gray (old IEC phase 3)

gray (power Europe)

gray (neural in US/Japan)

white (neutral in US)

white (pahse 2 in Au)

white (swtich return in AU/UK)

green/yellow - Ground most places

green or yellow but not both (power IEC 60446 and a bad idea)

green (ground in the US according to parts of the Elec code)

green (Never ground in the US according to parts of the Elec code)

bare copper (ground in the US or death)

 

 

The color codes for ships make much more sense and are about as uniform. For example blue is used for compressed air on US registered ships yet blue is for water on UK registered ships.