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4 Posts tagged with the fiber_optic_cable tag
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#1. Repurpose unused phone wires for Ethernet.

Campus phone systems are usually built around 25- and 50-pair trunk cable. Most of these wire pairs are redundant and not used as phone lines. These spare pairs can be commandeered for Ethernet through the use of Ethernet extenders, which not only transparently establish a network connection on phone cable, but can also extend links farther than the usual 100-meter limit for Ethernet on copper. Ethernet extenders are an ideal solution for linking isolated workstations without laying new cable.

 

#2. Upgrade to fiber on your existing copper ports.

Fiber optic cable has many advantages, including speed, distance, and resistance to EMI/RFI, plus it’s now usually less expensive to install than the equivalent copper infrastructure. What usually stops the installation of fiber is the prospect of having to replace expensive network switches with fiber switches and having to install fiber NICs in PCs.

 

Media converters are a simple way to convert the RJ-45 ports on existing equipment to fiber. Because media converters are transparent to data, they’re “invisible” to the network—literally plug-and-play. In the data center, modular media converter systems feature powered chassis that house and power multiple media converters—a whole switch’s worth of copper ports can be converted to fiber without cluttering the rack. On the desktop side, tiny USB-powered media converters bring fiber to the desktop without the driver issues and incompatibilities created by fiber NICs.

 

#3. Take advantage of PoE without buying new switches.

Adding power over Ethernet (PoE) devices such as VoIP phones, wireless access points, and security cameras doesn’t have to mean an investment in a new PoE switch. PoE injectors enable you to add power to one or more Ethernet runs using your existing copper-based Ethernet switches. Injectors are particularly useful when adding just one or two PoE devices such as security cameras to a network.

 

#4. Accommodate larger equipment in the cabinets you have now.

Sometimes upgrading servers or switches can lead to a space problem when new, larger equipment restricts cabinet cabling space. These tight squeezes can often be solved by using right-angle patch cables, which can save up to 4" of cabling space over ordinary patch cable, eliminating the expense and difficulty of replacing data cabinets.

 

#5. Bring legacy equipment with serial interfaces into today’s network.

Devices such as machine tools, restaurant equipment, and scientific instrumentation often have a useful life that spans decades. Although newer industrial devices now come equipped with Ethernet, older equipment often has an RS-232, RS-422, or RS-485 serial interface. These serial devices can be brought into the Ethernet network through the use of a device server. Once legacy devices are on Ethernet, they can be accessed from a central location, enabling control, real-time diagnostics, data capture, and alerts.

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Thought you knew your fiber stuff? Check out these four myths:

 

Myth #1: Fiber is too expensive.

Fiber used to be more expensive than copper. Today, however, because manufacturing costs are down and terminations are easier, fiber is often less expensive than the equivalent copper installation. Once installed, fiber optic maintenance costs are significantly less than copper ones.

 

Myth #2: Fiber is difficult to install.

In the old days of grind-and-polish connectors, installing fiber optic cable was a difficult, precise business that required a specialist. But improvements in fiber optic terminations and technologies have made them as easy to terminate as CATx connectors, and now many technicians prefer to install fiber because of its smaller diameter, lighter weight, and ease of testing.

 

Myth #3: Fiber is fragile.

Although terminating fiber cable does require some care to avoid breaking the glass core, in other respects, fiber is actually more robust than copper. Fiber optic cable can withstand a higher pulling tension than copper, is rated for larger temperature ranges, and is immune to EMI/RFI interference. In fact, one of the reasons the military prefers fiber is for its ruggedness and survivability. 

 

Myth #4: Fiber is impossible to hack.

Because a copper cable “leaks” electromagnetic signals, a hacker can read data nearby without actually touching the cable. A fiber cable, on the other hand, uses light that stays within the cable, so a hacker must physically tap into it to gain access to data. So it’s true that fiber cable is more secure than copper cable, but it’s not true that it’s impossible to hack—all that’s needed is a network tap and physical access to the cable. For this reason, it’s important to secure fiber optic cable by protecting it from unauthorized tampering and by encrypting data that must be kept private.

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Multimode, 50- and 62.5-micron cableMultimode cable has a large-diameter core and multiple pathways of light. It comes in two core sizes: 50-micron and 62.5-micron.

Multimode fiber optic cable can be used for most general data and voice fiber applications, such as bringing fiber to the desktop, adding segments to an existing network, and in smaller applications such as alarm systems. Both 50- and 62.5-micron cable feature the same cladding diameter of 125 microns, but 50-micron fiber cable features a smaller core (the light-carrying portion of the fiber).

Although both can be used in the same way, 50-micron cable is recommended for premise applications (backbone, horizontal, and intrabuilding connections) and should be considered for any new construction and installations. Both also use either LED or laser light sources. The big difference between the two is that 50-micron cable provides longer link lengths and/or higher speeds, particularly in the 850-nm wavelength.

Single-mode, 8–10-micron cable—Single-mode cable has a small 8–10-micron glass core and only one pathway of light. With only a single wavelength of light passing through its core, single-mode cable realigns the light toward the center of the core instead of simply bouncing it off the edge of the core as multimode does.

Single-mode cable provides 50 times more distance than multimode cable. Consequently, single-mode cable is typically used in long-haul network connections spread out over extended areas, including cable television and campus backbone applications. Telcos use it for connections between switching offices. Single-mode cable also provides higher bandwidth, so you can use a pair of single-mode fiber strands full-duplex for up to twice the throughput of multimode fiber.

 

Here is a breakdown of specifications:

50-/125-Micron Multimode Fiber
850-nm Wavelength:
Bandwidth: 500 MHz/km;
Attenuation: 3.5 dB/km;
Distance: 550 m;

1300-nm Wavelength:
Bandwidth: 500 MHz/km;
Attenuation: 1.5 dB/km;
Distance: 550 m

62.5-/125-Miron Multimode Fiber
850-nm Wavelength:
Bandwidth: 160 MHz/km;
Attenuation: 3.5 dB/km;
Distance: 220 m;

1300-nm Wavelength:
Bandwidth: 500 MHz/km;
Attenuation: 1.5 dB/km;
Distance: 500 m

8–10-Micron Single-Mode Fiber
Premise Application:
Wavelength: 1310 nm and 1550 nm;

Attenuation: 1.0 dB/km;

Outside Plant Application:
Wavelength: 1310 nm and 1550 nm;
Attenuation: 0.1 dB/km

 

Want to shop now? Our Fiber cable Selector allows you to quickly find the exact Fiber cable you need. Or you can speak with one of our cable specialist by calling 888-533-1576.

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If you’re accustomed to certifying copper cable, you’ll be pleasantly surprised at how easy it is to certify fiber optic cable because it’s immune to electrical interference. You only need to check a few measurements.

 

Attenuation (or decibel loss)—Measured in decibels/kilometer (dB/km), this is the decrease of signal strength as it travels through the fiber cable. Generally, attenuation problems are more common on multimode fiber optic cables.

 

Return loss—This is the amount of light reflected from the far end of the cable back to the source. The lower the number, the better. For example, a reading of -60 decibels is better than -20 decibels. Like attenuation, return loss is usually greater with multimode cable.

 

Graded refractive index—This measures how the light is sent down the fiber. This is commonly measured at wavelengths of 850 and 1300 nanometers. Compared to other operating frequencies, these two ranges yield the lowest intrinsic power loss (NOTE: This is valid for multimode fiber only.)

 

Propagation delay—This is the time it takes a signal to travel from one point to another over a transmission channel.

 

Optical time-domain reflectometry (OTDR)—This enables you to isolate cable faults by transmitting high-frequency pulses onto a cable and examining their reflections along the cable. With OTDR, you can also determine the length of a fiber optic cable because the OTDR value includes the distance the optic signal travels.

 

There are many fiber testers on the market today. Basic fiber optic testers function by shining a light down on end of the cable. At the other end, there’s a receiver calibrated to the strength of the light source. With this test, you can measure how much light is going to the other end of the cable. Generally these testers give you the results in dB lost, which you can then compare to the loss budget. If the measured loss is less than the number calculated by your loss budget, you installation is good.

 

Newer fiber optic testers have an even broader range of capabilities. They can test both 850- and 1300-nanometer signals at the same time and can even check your cable for compliance with specific standards.

 

Precautions to take when using fiber

 

Intrinsic power loss—As the optic signal travels through the fiber core, the signal inevitably loses some speed through absorption, reflection, and scattering. This problem is easy to manage by making sure your splices are good and your connections are clean.

 

Microbending—These are minute deviations in fiber caused by excessive bends, pinches, and kinks. Using cable with reinforcing fibers and other special manufacturing techniques minimizes this problem.

 

Connector loss—This occurs when two fiber segments are misaligned. This problem is commonly caused by poor splicing. Scratches and dirt introduced during the splicing process can also cause connector loss.

 

Coupling loss—Similar to connector loss, coupling loss results in reduced signal power and is from poorly terminated connector couplings. Remember to be careful and use common sense when installing fiber cable. Use clean components. Keep dirt and dust to a minimum. Don’t pull the cable excessively or bend it too sharply around corners.

 

These properties particular to fiber optic cable can cause problems if you aren’t careful during installation.

 

For more cabling tips visit our resources page.