How to cross-over Fiber Cables?

Why cross-over Fiber Cables?
Occasionally, there will be instances in which you need to cross over fiber optics cables. The reasons may vary, but at the end of the day, the transmit (TX) and receive (RX) will need to be crossed in order to make a proper connection.
One of these situations is when you have to make a connection, and the cable manufacturers, instead of crossing the cable from end to end, they run them straight through. In other words, when you try to plug in you take the TX from one end but the other end shall also be a TX, which will definitely not work.
That being said, you need to take the TX and plug it into the RX of the other side of the port -this is what’s actually known as a cross-over. You need to make sure to identify the type of connector you are dealing with. If the fibers were reversed, all you need to do is to pull the fibers out, criss-cross them and put them back in, and then the link should be established.
One thing that should be definitely pointed out is that, whenever you are making a cross-over, you should be able to correct both ends properly. That is a good way to prevent subsequent confusions and misfortunes.
For example, you may have done a single cross-over connection within a panel that contains hundreds of them. So this may be not only inconvenient to you, but to the rest of the team in charge of managing those connections.
Another scenario you may have is to have an LC connectors on both sides. To cross over these fibers, all you need to do is to take the fiber connectors out of the holding bracket and criss-cross them manually. The way to do this is, to first pinpoint how the connectors are put together. If they’re split on the bottom, for example, the fibers should come out of the bottom, so you need to figure out a way to pull the fiber out and repeat the procedure for the other one.
Then make sure to handle carefully and not bend any fiber too much so you don’t break it, and then you reattach the bracket to the fiber and make sure it’s sealed properly just by taking a close look at the mechanism of the connector. Sometimes you will hear a click when you lock the bracket. Also, make sure both connectors are put together at the same height so that when you plug them in you can establish a proper connection.
Another scenario that you may come across, it’s the one in which you may have a different type of holding bracket on one of the ends. In this case, you need to pull the fiber out of the bracket. Just to be very careful to identify the orientation so you can keep it after you tear the bracket apart to make a proper cross-over. Once you have the right bracket, insert the fibers into it and make sure to make an appropriate link.
Be advised that every bracket has a particular mechanism, so look at it closely so you can make a good change. If you feel like you’re forcing the fibers too much, or that the mechanism is not loosing up organically, then you may be making a wrong move and you take the risk of breaking the fiber.
Long story short, the reason fiber cables need to be crossed is rather simple: when connecting fiber from one device to another, the fiber strands need to be cross so that TX goes to RX on each end. So if you face a situation like the ones explained above, you don’t need to worry. Fibers can -and must- be crossed-over. Just make sure you’re making the necessary adjustments in a delicate yet competent way to properly establish the connection you need to make.

How to choose the MPO system for your Fiber Infrastructure

Nowadays, the demand for high connection speeds is increasing at an intimidating pace. People need to send -and receive- more data than ever, and the technology that’s available to them often seems to just not being able to keep up.
Optical fiber seems to represent the best choice when it comes to offering higher speeds -currently required by data center networks. In contrast to multimode and single mode optical networks, which were typically based on duplex fiber links, parallel fiber (MPO-based) connectivity has now become the ideal go-to choice, since it allows the use of pre-terminated systems that can be used in a quick and efficient way.
Nonetheless, this type of connectivity had been used to deliver duplex connectivity combined with duplex modules and breakouts. The selection of multifiber interfaces responds to the demands of increasing applications and density.
This turnover has led to a general consideration of using duplex connectivity, but at the same time, it needs to fill the necessity of including a combination of parallel and duplex interfaces.
Apart from considering these new iterations, it is essential to have a solid grasp on the evolution of network equipment and on the advantages of implementing an infrastructure based on duplex connections.
That being said, let us walk you through the Ethernet Roadmap.
There are several applications housed in data centers, which implies that those applications will demand a diversity in the connectivity topologies. It is commonly known that most networks use duplex links, but the demand for higher speeds requires using duplex links into other groups of links, which is when the term of parallel links enter the debate.
Likewise, this new incorporation asks for certain cabling structures that can handle this new array of options while having the acute vision of what the new results from this structures may provide us with. In other words, what we’re now witnessing it’s a migration from arrangements that involve duplex links into parallel link options that need to cover the requirements of higher speeds.
The great thing about parallel links is that they reduce the operation costs at a significant rate. Since they offer higher connectivity densities, it reduces the power consumption to send that data. This type of connection multiplies the information been transported, so it offers a notable reduction in the time employed in the transmission of information.
The increase of speeds has also developed a certain progress when it comes to the outlining of separate transmission lanes. In the end, the throughput will be augmented due to the incorporation of additional fiber, or the multiplexing over just a single a fiber.
Each one of these parameters will determine the selection of the fiber media and the options for cabling that will become the most appropriate for your data center. The decision of moving from single and duplex links to parallel ones will surely affect your cabling choice. This may traduce to a significant cost at the beginning, but it shall be seen as an investment in the long term.
The first thing you need to do is to determine the desired capacity that your data center will possess in the short-term future. Your team can come in handy forecasting this scenario since it is very well equipped with considering, evaluating and even trying several technologies, platforms and routing strategies.
After coming to terms to answering each one of the specific requirements demanded by your new system, the pre-terminated MPO-based fiber cabling system will enable a quicker utilisation and a certain flexibility of configuration, along with a cabling topology that corresponds appropriately with the new direction and desired performance of your data center direction.
Multimode fiber is definitely the primary media choice for the enterprise data center. Each one of the diverse types of multimode fiber (MMF) will affect the scale and scope of the data center that can be supported when speeds increase, so you need to take that into consideration.
Aside from combining “lanes” to provide for higher and better link speeds, multiplexing several wavelengths on a single pair of fibers offers great results.
The great thing about this new structure of links is that it offers a new set of applications. Depending on the type of configuration, migrations can be enabled between duplex and parallel optics.
This quality is very eloquent when it comes to supporting the notion of the flexibility offered by parallel links. If new needs come up, you should be able to accommodate those necessities by making adjustments to your new structure in your data center.
Every decision that you make towards implementing parallel links will affect your structure -and space- of your cabling, so every single analysis that you can make before adding something to your new structure should be mandatory.
To put it mildly, you need to be aware of the physical space every new configuration is going to occupy. You can have lots of great ideas for new connections, but if you can’t afford the space for it, none of them will work out. But don’t worry, you just need to gain conscience of the dimensions of your cabling configurations so you can design them and implement them properly.
The good thing about duplex cables is that they are very flexible, so not all of these considerations should be thought of as limitations. You can work around them -and, trust us, you should!
By merely thinking about all of this, you could be concerned about the cost it implies, and we hear you. Notwithstanding, this is a cost you need to assume. Not only because the current situation demands it, but also because this decision will stand out as an investment for the near future.
New designs imply adjustments so you can incorporate duplex and parallel connections, meaning that perhaps new racks or more space for your cabling will be needed. This inclusion will also call for changes in the management of your team, which will have to face new ways to handle these devices.
Human beings tend to reject at first all sorts of changes, it’s in our nature, but if you are totally convinced on the benefits that each and single one of these procedures will bring to your data center in the future, you will work through them focused on having the vision aiming at an impending success. The current concerns need to be replaced with a relentless optimism that your work will be enhanced in the long run.
We hope you find this article very useful and that this information can help you increase the speed -and hopefully the quality- of your data center.

Is it OK to bend a Regular Optical Fiber Cable?

One of the most common concerns amongst the installation of fiber cables is related to the possibility of bending a fiber cable or not. Worrying about this issue comes off rather naturally: if one does bend a fiber cable, let’s say around a corner, would that harm the cable? Or even more importantly, would it affect the quality of the transmission?
I’m sorry to share this news, but the answer is… yes. However, you do not need to let this concern grow out of proportion. You just need to take under consideration the following bits of information we’re about to show you, and you will be able to get over any issue you may have in regards to the bending -or not- of your fiber cables.
Under ideal conditions, there should be no loss of light within the fiber cable, which is one of the greatest features of fiber cables in the first place. Nonetheless, the scenario surrounding our actual installations are very far from that dreamy or utopian setting.
Depending on the way we install our systems, from the way we configure the connections through the actual alignment of cables, the inevitable losses of operating within the real world can be reduced or increased -and in this gap, it’s exactly where your control plays an essential role!
That control should be based on solid information. That being said, you should be aware of a parameter called “Bend Radius”, which is the minimum radius a cable can be bent without suffering any sort of damage. In other words, the smaller the bend radius, the larger the flexibility of the cable. Some manufacturers indicate the Bend Radius of fiber cables (Beyondtech surely does, is in its packaging and in their datasheets), but if you don’t have that information, you should know that the typical Bend Radius for fiber patch cables is around 30 mm.
Remember that you should be able to take any action that reduces those inevitable losses, that’s why it’s so important that you know this factor: bend loss starts happening only when the fiber cable is being bent at a higher measure than the cable’s maximum bend tolerance.
When installing your systems, you also need to be careful that the jackets have not only been perfectly built but that they’re also perfectly connected, since flaws in either one of these instances will result in losses in dB across time.
Another factor you need to take into consideration is pressure: if you tight your cables one against the other too tightly, that excess will generate leaks in the long term. Another eventuality you must avoid is when you have heavy objects pressed against the cables, just because that will definitely provoke an increase in losses. (This of course only applies to indoor cables)
As the supervisor of your network, you should develop the habit of constantly taking a thorough look at your installations: sometimes objects move after unforeseeable displacements, or get bigger thanks to high temperatures, so that object that originally didn’t disturb the rest of your installation may actually do it after a while.
Long story short: it is OK to bend your fiber cable, but you just need to be careful. You now know some facts that can lead you to properly design and implement strategies to reduce the losses that will inevitably come your way when using your fiber cables for installing your networks.

The recent state of Optical Fiber Connectors

We have already covered the fundamentals of the optics connectors in a previous post. We explained the differences in polishing, RL and IL and choosing the right one. Nonetheless, technology keeps moving forward, and we need to be aware of the latest advancements so we can properly take advantage of the resources at our disposal.
In this post, we’ll take a look at the most recent developments in the field of connectors. So feel free to join the ride, and explore what the next generation of connectors is all about!
Nowadays, physical space has become an important issue. With the advent of more connection needs, size has gotten increasingly valuable when it comes to adopting new connections for the future. This is where splice-on connectors come in handy since they have expanded the catalog of resources for companies that need to establish new connections in their plants.
New connectors, ranging from fiber-to-the-x (FTTx) to no-epoxy/no-polish (NENP), for example, are now being used to augment speed and diminishes expenses. These new modules allow to decrease the size required for a “splice tray” and diminish the cost of space needed. This shall be the trend followed by the new developments in optic fiber connectors.
The increasing demand for access networks and the increased value of rack space has originated the inclusion of small form connectors or multi-fiber connectors with high-bandwidth features. This need is represented by repair, need to improve fiber routing, fiber system upgrades and installation of space to temporary connections.
The current needs of the optic fiber scene have aimed towards a technology and equipment-cost perspective. The demand and the technology and have made a notorious impact on the cost and performance of the next generation of connectors.
The other area that has been dramatically changed in field termination, is represented by the need for an angled polished connector (APC) end face as the interface. APC interface has become the industry standard for FTTx and other outside plant equipment. That being said, the cost of material per termination has been reduced considerably as the new generation of connectors has become commonly utilized.
Anaerobic (epoxy/polish):
These connectors have been made by taking the existing field fiber and adhering it inside the ferrule. These anaerobic terminations are low-cost connectors that offer a robust performance over time and throughout changes in temperature. Anaerobic connectors have now been justifiably accepted in the optic fiber industry. Perhaps the only limitation of these terminations it that their efficiency is highly determined by the expertise of the technicians who install them and handle them.
No-epoxy no-polish (NENP):
These connectors posses a physical way of retaining the field fiber by compression and meet the fiber retention qualities while offering/providing a factory-polished end face for mating in the adapter. The only conditions for a proper performance of this type of terminations are represented by location and stability. The retention technology that these terminations offer is established by its manufacturers. The only foreseeable limitation is the impact of temperature in these terminations, which can cause unwanted margins of loss.
NENP angled polished connectors: The introduction of consistent APC terminations has filled the necessity of field-installed APC connectors in FTTx-type projects. However, the incorporation and alignment of these connectors are both time-consuming and extremely craft-sensitive. The consequence is a considerable need for a higher maintenance, which may add cost to the termination.
The variables of field deployment range from temperature change, performance variation due to factory fiber characteristics, quality of field fiber with regards to quality of fiber, tools and termination process. Taking into consideration all of these variables when defining a mechanical connector, the manufacturers have been able to consistently meet the insertion of loss requirements. The individual optical performance requirements have to be addressed with the specific mechanical connector manufacturer to guarantee a flawless optical plant is being put together.
Fusion splice-on connectors:
These connectors remove some variables and add strength. The vast majority of splice-on connectors are now available for use in the field and they are able to retain a consistent splice loss and return loss over temperature and time. These connectors can keep the performance of a splice-on pigtail without having to store a splice sleeve and they stand for being the most robust and consistent option for field-installable fiber connectors.
MPO/MTP® connector:
These terminations provide offers strength in numbers. Holding the strength from the fusion splice type connector and expanding its flexibility for field deployment generates a field-installable multi-fiber connector known as the MPO (multi-fiber push on). This connector offers the same benefits as a single fiber fusion splice-on connector but terminates up to 12 fibers per connection. This type of connector helps with restoration, repair and upgrade projects of existing MPO networks. The factory end face and fusion spliced optical path produce a solid alternative for field termination. The MPO termination has been growing and will continue to grow with fiber consolidation and high-speed bandwidth connections.
Self-contained patch and splice modules:
This is a variation of field-installable termination that goes into a self-contained field-installable patch and splice module. Field-installable modules employ a traditional pigtail splice to an adapter; fortunately, the need for factory pre-termination is removed. This is very convenient to those cases where space is limited or when you need a small footprint fiber termination. Because this module is self-contained, patch and splice, this option constitutes a cost-effective solution when adding a circuit to an existing fiber rack system or colocation type deployment.
Taking a decision towards which one of these options are the best for your needs is certainly not easy, but that doesn’t mean that you won’t be able to make a proper decision. You just need to gather a good amount of solid information based on what your system really needs.
It is mandatory then to have a good sense of the space available for potential adjustments. That being said, you then need to take a close look at the available options offered by trustworthy manufacturers. If you do a thorough research, rest assured that you will find the resources that will accommodate your needs.
So don’t despair if you suspect that you’re not able to find a perfect solution to your problem because more often than not, that seems to be the case. Just make sure to focus on having a solid understanding on the demands, study proficiently the resources at your disposal and then get prepared to make the ultimate decision that will help you satisfy what you most urgently need for.
We really hope you can find all of this information very useful for your projects.

New Fiber Optics transmission record reported at OFC2018

The NICT (Network System Research Institute )and Fujikura Ltd. (Fujikura, President: Masahiko Ito) developed a 3-mode optical fiber, capable of wide-band wavelength multiplexing transmission with a standard outer diameter (0.125 mm) that can be cabled with existing equipment.
The researchers have successfully demonstrated a transmission experiment over +1000 km with a data-rate of 159 Tb/s. Multimode fibers have different propagation delays between optical signals in different modes that make it difficult to simultaneously satisfy large data-rates and long-distance transmission. This achievement shows that such limitations may be overcome.
Converting the results to the product of data-rate and distance, which is a general indicator of transmission capability, results in 166 Pb/s×km. This is the world record in a standard outer diameter few-mode optical fiber and the largest data-rate over 1000 km for any kind of standard-diameter fiber. In order to achieve the transmission capacity of 159 Tb/s, mode multiplexing is used in combination with 16-QAM (quadrature amplitude modulation), which is a practical high-density multilevel modulation optical signal, for all 348 wavelengths and MIMO (multiple-input and multiple-output) enables unscrambling of mixed modal signals even after transmission over more than 1000 km. This shows that standard outer diameter multimode fibers can be used for communication of high capacity optical backbone transmission systems.
The results of this demonstration were selected for presentation as a post-deadline paper at the 41st Optical Fiber Communication Conference and Exhibition (OFC2018).
In order to cope with ever-increasing communication traffic, research on large-scale optical transmission using new types of optical fiber exceeding the limit of conventional optical fiber and its application is actively conducted all over the world. The main new types of optical fibers studied are multicore fibers in which multiple passages (cores) are arranged in an optical fiber and multimode fibers that support multiple propagation modes in a single core with a larger core diameter. Up to now, successful transmission experiments of large capacity and long distance have been reported for multicore fiber, but it was considered that transmission which satisfied both large capacity and long distance simultaneously was difficult in multimode fiber.
In this work, NICT constructed a transmission system using an optical fiber developed by Fujikura and successfully transmitted over 1045 km with a data-rate of 159 Tb/s (Fig. 1). Converting the results to the product of transmission data-rate and distance, which is a general indicator of transmission capability, is 166 Pb/s×km. This is about twice the world record so far in the few-mode fibers.
The transmission system consists of the following element technologies.
3-mode optical fiber with standard outer diameter 0.125 mm
348 wavelength optical comb light source
16-QAM multi-level modulation technology equivalent to 4 bits / single polarization symbol
Separation technology of multimode optical signals with different propagation speeds in fiber (MIMO processing)
The researchers succeeded in transmitting over 1045 km using a standard 3-mode optical fiber. When laying of standard outer diameter optical fibers takes place, the existing equipment can be used and the practical use at an early stage is promising. Also, the ultimate large-capacity transmission will become possible in the future if combined with multicore technology, which is researched by NICT in cooperation with industry, university, and government in Japan.
The researchers will continue to research and develop future optical communication infrastructure technologies which can smoothly accommodate traffic such as big data and 5G network services.

Why you should care about better fiber optics?

Doing some research online we found this article in the Fhys.org Website, The original article was delivered by the Norwegian University of Science and Technology.
Fiber optic research can give us better medical equipment, improved environmental monitoring, more media channels—and maybe better solar panels.
“Optical fibres are remarkably good at transmitting signals without much loss in the transfer,” says Professor Ursula Gibson at NTNU’s Department of Physics.
However: “Glass fibres are good up to a wavelength of about 3 microns. More than that, and they’re not so good,” she says.
And that is sometimes problematic. Telecom uses the near-infrared part of the wave spectrum because it has the least loss of energy when passing through the glass.
But if we could utilize even longer wavelengths, the benefits would include better medical diagnoses and more precise environmental monitoring of airborne gas particles. Longer wavelengths could also mean more space for media channels since the competition is fierce for the wavelengths where free space transmission normally takes place now.
Optical glass fibres are not made of pure glass, but require a core with a bit of some other material to transmit signals.
This is clearly quite complicated to achieve, and the methods have gradually been perfected over the last 50 years.At NTNU, various research groups have been experimenting with optical fibres using a semiconductor core of silicon (Si) and gallium antimonide (GaSb) instead of small amounts of germanium oxide, which is used in silica fibres now. Some of the researchers’ latest research findings have now been presented in Nature Communications.
Ph.D. candidate Seunghan Song is the first author of the article in the prestigious journal. The article “describes a method for making optical fibers were part of the core that is gallium antimonide, which can emit infrared light. Then the fiber is laser treated to concentrate the antimonide,” says Gibson.
This process is carried at room temperature. The laser processing affects the properties of the core.
Silicon is well known as the most commonly used material in solar panels. Along with oxygen, silicon is the most common material in glass and glass fiber cables as well.
Gallium antimonide is less typical, although others have also used the same composition in optical instruments. But not in the same way.
With the new method, the gallium antimonide is initially distributed throughout the silicon. This is a simpler and cheaper method than others to grow crystals, and the technology offers many possible applications.
“Our results are first and foremost a step towards opening up a larger portion of the electromagnetic wave spectrum for optical fiber transmission,” Gibson says.
Learning about the fundamental properties of the semiconductor materials in glass fibers allows us to make more efficient use of rare resources like gallium.