Fiber Optic Tech

Pre-terminated Trunk Cable and MTP Cassette Overview

Per-terminated cabling is a popular type of termination method that has been used by the overall network designers. It provides an plug-and-play solution for links between switches, servers, patch panels, and zone distribution areas in the data center. Compared to the Fusion splicing, pre-terminated cabling is apparently more suitable to meet the high-bandwidth, high-density network needs. An article entitled “Understanding Pre-Terminated Cabling and Network Deployment” offers some detailed information about the pre-terminated cabling and its advantages. This article will go further to talk about the elements of the pre-terminated cabling including the pre-terminated trunk cables, and plug and play cassettes.

Pre-terminated Trunk Cables

Pre-terminated trunking cable assemblies provide an easily installed and cost effective alternative to individual field-terminated channels. There are basically pre-terminated fiber cabling and pre-terminated copper cabling, which will be ntroduced in the following part.

  • Pre-terminated MTP/MPO Trunk Cables

Pre-terminated trunk cable usually terminated with MTP/MPO connectors on both ends that provides a quick-to-deploy, scalable solution that improves reliability and reduces installation time and cost. They are capable of supporting multiple users or devices from one point to another while distributing multiple data channels, which is a convenient and economical alternative to running multiple jumpers or fiber cables. Generally 12-fiber MTP/MPO trunk cables and 24-fiber MTP/MPO trunk cables are commonly used separately for 40G applications and 100G applications. The following picture is a 72-fiber female to female MTP trunk cable.

72-fiber-mtp-trunk-cable

There are also high fiber count MTP/MPO trunk cables which have several legs on both ends. The following picture shows a 72-fiber MTP/MPO trunk cable. There are 6 legs on both ends with each leg terminated with a 12-fiber MTP/MPO connectors.

  • Pre-terminated Copper Trunk Cables

Pre-terminated copper cable assemblies including pre-terminated copper trunks and copper patch cords (usually terminated with RJ45 connector), are ideal solutions for data center applications where requires high-efficient deployment. Pre-terminated copper trunk cables are commonly used in point-to-point connections in data centers, such as achieving reliable connectivity between server and switch cabinets. It is a bundle of category cables, built with a choice of 6, 12, or 24 cable bundle and factory terminated with jacks and plugs. The following image shows a jach-to-jack pre-terminated copper trunk cable.

jack-to-jack-pre-terminated-copper-trunk-cables

With factory pre-terminated and tested parts, the pre-terminated copper cable assemblies can help users save time and reduce waste. In addition, they allow fast and easy installation with reduced labor costs in large copper infrastructures with high-density cross-connection and patching systems. FS.COM’s pre-terminated copper cable assemblies are pre-bundled and pre-labeled styles, available in Cat 5e, Cat 6 and Cat 6a UTP and STP cable constructions in jack to jack, plug to plug and jack to plug termination ends.

Pre-terminated MTP Cassette—No Work, No Tools, No Mess

MTP cassettes are used to break out the 12-fiber MTP connectors terminated on trunk cables into simplex or duplex-style connectors. Simplex and duplex style jumpers can then be used to patch into transceiver terminal equipment ports, patch panels or client ports. The cassette features simplex or duplex port adapters across the front and one or two MTP connector adapters across the back. A factory-installed and tested optical fiber assembly inside the module connects the front adapters to the back MTP connector adapter. Alignment pins are pre-installed in the MTP connector located inside the cassette. The below image shows the 12-fiber and 24-fiber MTP cassette.

mtp-cassettes

Using MTP cassettes provides adaptability for the changing data center environment. Facing technology refresh frequencies of 12-18 months, Plug & Play MTP cassettes used in the data center offer a great advantage. When connector requirements change in the future, simply swap the cassettes whilst leaving the existing backbone infrastructure intact. 12-fiber MTP to LC and 24-fiber MTP to LC cassettes provide a quick and efficient way to deploy up to 12 LC or 24 LC fiber ports in a single module respectively. MTP to LC cassettes are a quick and efficient way of deploying MTP connector breakout. These cassettes provide significant installation savings with no field terminations required. Simply plug-and-play!

Conclusion

Pre-terminated cabling is the perfect solution to achieve simple and quick installation. Additionally, the transmission testing of pre-terminated cable assemblies is performed by the manufacturer before shipment, and test reports are included with the assemblies. FS.COM offers a full range of high-quality but low-price pre-terminated cable assemblies.  Besides that, we also offer Fiber Taps, J-Hook, Fiber Optic Enclosures, Cable Ties, Fiber Optic Wall Plates, etc. And all of them are tested before shipment. If you have any requirement, please send your request to us.

100G Direct and Breakout Cabling Solutions

With the emerging high-speed network standards and rapidly advancing technology, fiber optic network is driven to meet the growing demand for faster access to larger volumes of data. Although 10G/40G Ethernet becomes the mainstream of telecommunication market nowadays, organizations of all sizes still need to be prepared to integrate speeds of 100G and beyond. For data center networking, users can choose different solutions based on the different transmission distance need. In general, there are two kinds of 100G fiber optic solutions: direct cabling and breakout cabling. It is essential for users to understand the detailed information of each type of solution in order to select the one that meets their current and future connectivity needs.

How 100G Optics Develop

After the IEEE completing the certification of the first 100G standard for Ethernet networks, the transceiver industry launched a new type of form factors for 100G connectivity—CFP (“C” for 100, and FP for Form factor Pluggable). Compared to the most popular 40G QSFP, the size of CFP transceiver is huge. And most CFP implementations doubled the power consumption per bit. Furthermore, the price per bit increased by a factor of ten. These disadvantages becomes the main obstacles of the popularity of 100G CFP transceivers.

The next version of 100G form factors is the CFP2, CFP4, and the CPAK that are improved upon the CFP. But when compared to the popular 10G SFP+ and 40G QSFP+, none of these new members of the CFP family improved density, power consumption, or cost. Fugure 1 shows the size comparison between CFP2, CFP4 and QSFP28 modules.

100g-transceivers

Then here came the 100G QSFP28. The QSFP28 is the exact same footprint as the 40G QSFP+. The 100G QSFP28 is implemented with four 25-Gbps lanes, Just as the 40G QSFP+ is implemented using four 10-Gbps lanes. In all QSFP versions, both the electrical lanes and the optical lanes operate at the same speed, eliminating the costly gearbox found in CFP, CFP2, and the CPAK. The 100G QSFP28 makes it as easy to deploy 100G networks as 10G networks. When compared to any of the other alternatives, 100G QSFP28 increases density and decreases power and price per bit. That’s why it is fast becoming the universal data center form factor. The following part will move on to talk about the 100G optic cabling solutions.

100G Direct Cabling Solutions

QSFP28 transceiver utilizes either fiber or copper media to achieve 100GbE communication in each direction. This transceiver has 4 individual 25GbE lanes which can be used together to achieve 100GbE throughput or separately as 4 individual 25GbE connections (using 4 SFP28 modules).

For 100G short-reach direct cabling within 100m, 100GBASE-SR4 QSFP28 optical module and 100G QSFP28 cable are good choice. Just from the table list of FS.COM 100G optical modules and cables, we know that 100GBASE-SR4 QSFP28 modules can support up to 100 m on OM4 12 fiber multimode MTP cable. And 100G QSFP28 to QSFP28 direct attach copper cable can support up to 5m and 100G QSFP28 to QSFP28 active optical cable can support up to 10m. Figure 2 describes a 100G direct cabling with the use of QSFP28 to QSFP28 DAC and AOC cables.

100g-qsfp28-solution

For 100G long-haul direct cabling, like 10km, both 100GBASE-LR4 QSFP28 optical module and 100GBASE-LR4 CFP4 transceiver can support up to 10km on single-mode LC patch cables. For longer 100G direct cabling above 10km, the 100GBASE-ER4 CFP is the ideal choice as their transmission distances support up to 40 km.

100G Breakout Cabling Solutions

A breakout cable is a multi-strand cable, typically custom-made, which is divided into multiple duplex cables. For instance, a 40G breakout cable has four individual 10G duplex cables totaling eight strands, while a 100G breakout cable has 10 duplex cables and 20 strands. Figure 3 displays a simple 100G connectivity with 100GBASE-SR4 QSFP28 and QSFP28 to 4SFP28 breakout cables.

gsfp28-to-4sfp28-cable

Between the 100G optical module and 25G optical modules, there always uses the breakout cables connected the two kinds of optical modules, and the common cable solutions are 100G QSFP28 to 4SFP28 Breakout AOC cables or 100G QSFP28 to 4x 25G SFP28 Breakout Direct Attach Passive Copper Cables.

The commonly used 100G breakout cabling solutions is 100G QSFP28 to 4SFP28 DAC. It’s easy to understand how this type of cable function. Just as the QSFP+ breakout cable, the 40GBASE-SR4 QSFP+ optical module at the one end can be connected to 4x10GBASE-SR SFP+ optical modules at the other end.

Conclusion

As IT infrastructures are planning to migrate to 100G data rate, network designers must carefully weigh alternative implementations of such links. With a variety of fibers already deployed, it is important to understand the interoperability of new optics with existing fibers. And for 100G deployment, you are supposed to understand the benefits and challenges of each type of the fiber optic solutions before taking an action. FS.COM’s 100G FHD series covers a full range of 100G optical transceivers and cables, like CFP, CFP2, CFP4, QSFP28, as well as 100G QSFP28 to QSFP28 DAC, 100G QSFP28 to 4SFP28 DAC. Besides the above products, 100G FHD Fiber Enclosures, 100G FHD MTP Modular Cassettes, 100G 160 Fiber 2U Panels and 100G CFP SR10 Cables are also provided. If you want to know more about our products, please contact us directly.

QSFP28 100GBASE-LR4 and 100GBASE-SR4 Optical Modules Overview

Without denying that the market for 100G data center optics is accelerating, and more and more telecommunication vendors are aiming to seize this opportunity to launch cost-effective 100G solutions. FS.COM also offers a series of 100G optical modules and cabling solutions that are compliant to the IEEE standards. Our 100G optical modules support different transmission distance from 100m, 10km and more reach options in CFP and QSFP28 form factors. Before introducing the FS.COM 100G optical modules, let’s firstly talk about the 100 Gigabit Ethernet standard.

IEEE 100GbE Standard Introduction

Defined by the IEEE 802.3ba-2010 standard, 100 Gigabit Ethernet (100GbE) technology was given birth to transmit Ethernet frames at the rates of 100 gigabits per second. The 100G optical modules are not standardized by any official standards body but are in multi-source agreements (MSAs). The major 100Gigabit Ethernet 100GBASE-R optical module standards are briefly listed in the below table.

100g-standards

According to the above table, the 100GBASE-CR4 and 100GBASE-CR10 standards were met by twinax copper cable with a link length of 7m. The 802.3bm standard was approved in 2015, which specifies a lower-cost optical 100GBASE-SR4 PHY for multimode fibers (MMF). The 100GBASE-SR4 standard can operate over OM3 MMF for a link length of 70m, and transmit over OM4 for a link length of 100m. QSFP28-100G-SR4 is one of the common types of the 100G modules, which can be used in 100 Gigabit Ethernet links on up to 100m of OM4 multimode fiber.

For those infrastructure who require a link length longer than 2 km, 100GBASE-LR4 and 100GBASE-ER4 standards were introduced. These two standards are specially designed for use in long haul applications. For example, QSFP28 100GBASE-LR4 optics can support a distance of 10km, and the CFP 100GBASE-ER4 operate over single-mode fiber for a distance of 40km.

As for the 100GBASE-SR10 or 100GBASE-CR10, the 10×10 MSA was intended as a lower cost alternative to 100GBASE-SR4 for applications, which defines an optical Physical Medium Dependent (PMD) sublayer and establish compatible sources of low-cost, low-power, pluggable optical transceivers based on 10 optical lanes at 10 Gbit/s each.

FS.COM 100G Optical Modules

FS.COM provides 100G QSFP28 optical modules, including 100G QSFP28 SR4, 100G QSFP28 LR4 as well as 100G CFP LR4 optical module. All these 100G transceivers are good choice for today’s high-density data center 100G interconnection and networking.

  • QSFP28 100GBASE-SR4

The QSFP28 100GBASE-SR4 transceiver, based on the QSFP28 from factors, is a parallel 100G optical module designed with optical/electrical connection and digital diagnostic interface. It offers 4 independent transmit and receive channels, each capable of 25Gbps operation for an aggregated data rate of 100Gbps for 100 m on 12-fiber MPO/MTP OM4 multimode fiber.

qsfp28-100gbase-sr4

The QSFP28 SR4 module is a vertically integrated solution that meets IEEE 802.3 standards and MSA requirements with power dissipation well under 3.5W. It supports both 100GBASE-SR4 as well as 4x25G breakout applications, 100G QSFP28 to QSFP28 DAC and 100G QSFP28 SR4 to 4x25G SFP28 break-out cables, meeting the harshest external operating conditions including temperature, humidity and EMI interference.

  • QSFP28 100GBASE-LR4

The 100GBASE-LR4 QSFP28 transceiver, compliant to 100GBASE-LR4 of the IEEE P802.3ba standard, is also a 100Gbps transceiver module designed for long-reach communication applications. This module converts 4 input channels of 25Gbps electrical data to 4 channels of LAN WDM optical signals and then multiplexes them into a single channel for 100Gbps optical transmission. The high performance cooled LAN WDM EA-DFB transmitters and high sensitivity PIN receivers provide superior performance for 100GbE applications up to 10km links over single-mode fibers.

qsfp28-100gbase-lr4

FS.COM 100G Optical Modules

According to the market researchers, the 100G optical transceivers market will be booming in the near future. So what are you waiting for? It is the ideal time for data center designers to prepare for the data center networking and architecture beforehand with 100G transceivers and cables. Contact us for the available 100G optical modules: 100G QSFP28 SR4, 100G QSFP28 LR4, 100G CFP, CFP2 and 100G CFP4 optics. Besides 100G optical modules, FS.COM also provides 100G cable solutions like 100G active optical cable (AOC) and 100G direct attach cable (DAC). You can have what you need here.

Do You Have Any Idea of Water-Resistant Fiber Optic Cable?

There is no doubt that fiber optic cables play an integral role in telecommunication industry. Applications like data centers, local area networks, telecommunication networks, industrial Ethernet, and wireless network are all needing fiber optics to ensure smooth connectivity. Each application requires a specific cable design based on performance requirements, environmental conditions, and installation type. The common fiber optic cables like LC to LC patch cord cannot adapt to the harsh environment (e.g. moisture environment or underground deployment), thus water-resistant fiber optic cables are highly demanded on the market due to their water proof nature. Here is what you should know about the water-resistant fiber optic cable.

Overview of Water-resistant Fiber Optic Cables

Water-resistant fiber optic cable refers to the special type of fiber optic cable that are designed and specified for installations where the cable will come in contact with water or moisture, such as aerial, direct buried, or in conduit. The cables in these applications are exposed to or can be temporarily submerged in water, so they contain either a water-resistant gel-filled or gel-free (dry gel) polymer.

Generally, fiber optic cables can be divided into three types—outside plant cable (OSP), indoor/outdoor, and indoor, which are specified based on the environment and location where they are installed. With the exception of indoor cables, all cables contain water-resistant gel-filled or gel-free material to protect them from water and moisture. Before the use of gel-filled and gel-free materials, flooded core was another water-blocking method that is rarely used today (it has been replaced with gel-filled). The following image shows the gel-filled cables.

water_tolerance

The gel is a gooey substance that must be removed when accessing and installing the cable. Gel-free cables, which are now more widely used, contain a super-absorbent polymer powder that is activated when it comes in contact with water or moisture. This blocks the water from penetrating the cable and allows for some expansion and contraction with temperature changes. Indoor cables do not contain water-resistant material since they are not typically exposed to water. Indoor (and indoor/outdoor) cables must meet additional flammability requirements dictated by local codes, such as the National Electrical Code.

Tight-Buffered & Loose Tube Cable Construction Provides Excellent Moisture Resistance

Water-resistant materials and cables are included in many industry specifications and standards. Generally, there are two basic water-resistant cable designs: Tight-buffer cables (primarily used inside buildings), Loose tube cables (used for OSP and indoor/outdoor).

It is known to all that most tight-buffered cable designs (seen in image below) are specified for indoor use, but some of them are designed with water-resistant powder and yarn, making them suitable for some indoor/outdoor applications. This tight-buffered cable utilizes an different design approach to deal with the moisture issue. Buffer materials are low-porosity plastics with excellent moisture resistance. This construction very effectively minimises the water molecule and OH-ion concentration level at the glass surface and virtually eliminates the stress corrosion phenomenon.

tight-buffered-cable

In loose tube cables (seen in image below), in order to prevent the water from reaching the 250μm coated fibers, the tubes surrounding the fibers must be filled with water-absorbent powder or gel that withstands high-moisture conditions, making them excellent for outside plant applications. This approach is especially made to waterproof the cable by filling the empty spaces in the cable with gel. The gel-filled tubes can also expand and contract with temperature changes, which makes loose-tube cable great for harsh, high-humidity environments where water or condensation can be a problem. However, gels can move, flow, and settle, leaves an uncertainty of the filled level of any particular point of a loose-tube gel-filled cable. Because loose-tube cable is typically 250 microns, you’ll need a fan-out kit to build up the individual fiber strands to 900 microns when making the transition at the entrance point from outdoor loose-tube to indoor to tight-buffered cable.

loose-tube-cable

The same level of protection remains in place all along the fiber, regardless of installation conditions, environment, or time. The balance of the tight-buffered, tight bound cable designs is such that it minimizes the open spaces available in the cable structure in which water can reside. Even if an outer cable jacket is cut, or water otherwise enters the cable structure, only a very small percentage of the cross-sectional area is open to water.

Conclusion

When selecting the suitable fiber optic cables, one must consider the application, the installation location, and the appropriate cable design and type according to specifications and standards. The water-resistant optic cable is specially made for moisture environment to insure the smooth connectivity. However, whether to have the loose tube fiber optic cable or tight buffered cable, it depends on the installation location. FS.COM offers a full range of fiber optic cables at very economical rates. These cables are widely used and are highly demanded on the market due to their water proof nature. In addition to this, we offer these cables in various fiber optic cable specifications, such as duplex/simplex fiber cable, single-mode/multimode fiber optic cable, LC/FC/SC/ST fiber optic cable and so on. LC to FC patch cord is absolutely high quality and low price, just as the other fiber optic cables. If you want to know more about our products, please contact us directly.

Understanding Pre-Terminated Cabling and Network Deployment

Data center nowadays are migrating to high-bandwidth, high-density network infrastructure. This increased network speeds have tighter link budget requirements that can be challenging to achieve with field terminations. Pre-terminated cabling includes a variety of trunk cables, array cables, and plug and play cassettes that gives data center managers options that suit specific needs. Besides this, there are several reasons to consider pre-terminated optical fiber in data center solution. The following image shows the pre-terminated UTP cassettes.

pre-terminated-utp-cassette

No Need to Test the Network Performance

With pre-terminated cable assemblies, transmission testing of assemblies is performed by the manufacturer before shipment, and test reports are included with the assemblies. This leaves only continuity testing for copper and 10% insertion loss and continuity testing for fiber, which reduces the time spent testing on-site.

Reduce Downtime

With pre-terminated solutions, data center managers can make changes quickly based on network growth, business decisions, or shifting requirements. In disaster recovery situations that call for fast, temporary data communications set-up, pre-terminated cabling can minimize business downtime and establish communications quickly. It can also be disassembled quickly when the situation is resolved. The components are reusable for more efficient moves, adds, and changes (MACs).

Fast and Simple Deployment

Field termination is the most time-consuming, labor-intensive part of the cable installation process. Once pre-terminated cabling is delivered, it can be unpacked, readied for deployment, and connected quickly. In many cases pre-terminated cabling can cut installation time by up to 80% over field terminations.

Additionally, precision factory-termination processes take place in a clean, well-lit environment, unlike termination in uncontrolled field conditions. This increases the likelihood of clean and uncontaminated optical fiber ports, enables lower loss budgets, and provides overall better electrical transmission. Factory terminations are also guaranteed under warranty, which offer data center managers peace of mind.

Easy Maintenance

Pre-terminated solutions allow for quick clean-up due to minimal leftover materials and scrap. Also, because there is less waste and material to clean up, pre-terminated solutions also help meet green design, waste reduction, and material reuse goals. Additionally, pre-terminated solutions provide an easy way for network managers to proceed a routine check.

If you are making up your mind to deploy a pre-terminated system, one thing you shouldn’t miss is that the planning process typically requires more time upfront and more detailed analysis to determine specific cabling and termination routes along the cable trays and within the cabinets. Once the detailed plan is formulated and approved, the system’s cabling and connectivity components are manufactured and tested at the factory to ensure they meet all applicable industry standards prior to delivery. The next part will go on to talk about the how to select the suitable pre-terminated solution.

pre-terminated-cabling-solution

How to Choose the Pre-terminated Cable

Pre-terminated cabling solutions are ideally suited for data center environments where the cable routes are well defined and where the time for deployment, ease of installation, network reliability and manageability are paramount. When selecting pre-terminated cable assemblies, be sure to use a reliable provider that can offer services such as guaranteed cabling performance, design assistance, certified contractor training, and the ability to support large quantities of assemblies in the required delivery window. Make sure the pre-terminated copper or optical fiber purchased through a manufacturer uses components that have been tested and verified by a third party to exceed TIA and IEEE standards. The manufacturer should also provide 100% testing in a quality-controlled environment before the cabling is shipped out to the worksite.

Conclusion

Pre-terminated cables are the plug-and-play solution for links between switches, servers, and patch panels in the data center. As the computing environments and business needs of organizations differ widely, not every enterprise will find the benefits of pre-terminated systems outweigh the investment. Field-terminated copper and fiber cabling and connectivity systems are generally less costly to purchase in terms of the various components. Just to find a suitable solution system for your own network. Providing reliable quality, advanced testing system and favorable price, progress of FS.COM has never stopped. We offer a variety of pre-terminated optics including the breakout patch cable, pre-terminated trunk cable and adapter panels. Fiber optic cables like SC fiber patch cable and LC to LC patch cord are also needed. If you have any requirement of our products, please send your request to us.

Alien Crosstalk: Do You Mind It or Not?

Alien crosstalk refers to the noise that may occur in a cable that runs alongside one or more other signal-carrying cables. It is the combination of alien near-end crosstalk (NEXT) and alien far-end crosstalk (FEXT). The alien acrosstalk between fiber jumper cables reduces the operational bandwidth of a cabling solution due to an increased level of crosstalk noise decreasing the overall signal-to-noise ratio (SNR). This additional reduction in operational bandwidth are posing threat for the performance of network infrastructure, especially for the higher-bandwidth applications. Therefore the ANSI/TIA/EIA standard committees are proposing that new NEXT and attenuation limits be considered. This pose briefly introduce some things about alien crosstalk (AXT), and the way to measure it.

Alien Crosstalk

Alien crosstalk is the coupling of noise from one cable link to another. This happens if one cable is surrounded by many other cables in a bundle. Alien crosstalk can be particularly troublesome because, unlike the simple crosstalk caused by a single interfering signal, it cannot be eliminated by phase cancellation. As noted before, alien crosstalk in high-speed application is far more severer than in lower-bandwidth infrastructure. The following image shows the Alien crosstalk coupling between pairs of wires of the same color in a UTP (unshielded twisted pair) cable.

alien-crosstalk

Gigabit Ethernet (GbE) technology uses an encoding method of transmitting data on all four cable pairs simultaneously and in both directions. This method is demanding on the cabling infrastructure, which might be resulted in alien crosstalk being generating within adjacent, parallel, unshielded twisted-pair (UTP) cables. People usually have the misconception that if they use shielded cables, then alien crosstalk would not be a problem. However, if the shield is not terminated correctly even a shielded system can fall foul of alien crosstalk.

How Do We Measure AXT?

Since the alien crosstalk had really bad influence in network performance, attempting to control alien crosstalk through cable design and cable installation would be a great changer to guarantee the installed network performance. In all, there are three methods that can help to control the alien crosstalk:

  • Through cable design by decreasing the combined sources of noise (NEXT, FEXT, and return loss) within the system, effectively increasing the overall SNR.
  • Through installation control by ensuring cables are not installed in such a way as to exacerbate the problem. This approach would preclude the use of bundled UTP cables, overfilling of conduits and trunking, or close-proximity parallel cable runs.
  • Through the use of screened, balanced, twisted-pair cables.

Thanks to the above methods, we might have a chance to minimize the alien crosstalk. But we still have the need to know how to test alien crosstalk. Typically we test alien crosstalk between each pair of each disturber to each pair of the disturbed in a cable bundle. Two solutions in use today are based on test devices connecting the victim and disturber cables under test, respectively a communication channel between the devices. The following example uses the Fluke DSX-5000 testers to measure the alien crosstalk.

For near-end alien crosstalk testing, the main unit is connected to the victim channel, and the remote unit is connected to a disturber channel. we identify the potential Disturbed cable that is surrounded by Disturbers, not including cables’ connectors that are adjacent to gaps. For Disturbers, we pick cables in the same bundle that surround the Disturbed cable. These are the cables where the connectors are likely to cause the majority of the ANEXT. The connector shown in green identifies a potential good disturbed cable connector.

near-end-axt

We make an ANEXT measurement with the Master unit of the DSX-5000 connected to the Disturbed (victim) at the near-end with a terminator at the far. The DSX-5000 remote unit is connected to the near-end of the Disturber with a terminator attached at the far end. The Master unit and remote are then connected together via the RJ45 communication ports to enable them to synchronise the tests being made. The measurements are then made on the Disturbed (Victim) as above for each Disturber.

Alien Crosstalk also requires a measurement to be made from the far-end. This is the PS AACR-F (Power Sum Alien Attenuation Crosstalk Ratio Far End) measurement. This is performed in the same way as PS ANEXT but the setup is different. The Main unit is connected to the Disturbed cable connector as before. However, the remote unit is connected at the far end and the terminator at the near end as in the diagram below. In addition, the communication cable between the master and remote unit is connected through one of the horizontal RJ45 links.

far-end-axt

During the whole testing no matter the ANEXT or the far-end AXT measurement, the Main unit of the DSX-5000 tester remains connected to the Disturbed (Victim) cable. Each time a measurement of Disturbed (Victim) is completed for one Disturber, the remote unit and the terminator are moved to the next Disturber to make the next test, this is continued until all the Disturbers in the bundle have been measured for that Disturbed cable.

Summary

Alien crosstalk measurement setup is more complex than that of general crosstalk testing. Because the alien crosstalk should be executed for a bundle of cables (at least six cables). Furthermore, more test instruments are needed for alien crosstalk, except for the Fluke DSX-5000 tester. Therefore, whether to go for a PSANEXT or ANEXT measurements, this might be a time-consuming and troublesome process. FS.COM is a professional telecom manufacturer. We not only supply plenty of optical products,  such as fiber patch cables (ST-LC patch cord), transceiver modules, or DAC/AOC cables, etc, but the best services to all of our customers. If you have any doubt about today’s topic, you are always welcomed to contact us.


Page 5 of 17« First...
5
......Last »