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How to Choose the Right Fiber Optic Cables?

Are you looking to buy fiber optic cables? As with all types of wire and cable, there are many options when it comes to choosing the ideal type of fiber optic cable for your intended use and environment. The fiber optic cable has become the go-to choice when designing a high-speed, low-latency broadband network for both residential and commercial uses. In this article, we will walk you through the basics of fiber optic cabling and help you figure out the best option for your networks.

What’s the Fiber Optic Cable?

The fiber optic cable is specially designed for high-performance data transfer in long-distance applications. It contains countless microfiber strands wrapped in a protective outer sheath. It can carry data signals in the form of light, which can travel significantly faster and farther than the traditional copper cabling. With the fiber optic network, the deployment distance can be easily extended to 60-80 kilometers with no obvious signal degradation. It offers improved performance in terms of bandwidth, speed, signal strength and more. Fiber optic cables can be found in a huge variety of applications, from today’s high-end Internet, small office LANs, and many other applications that require a broadband connection, such as computer networking, video surveillance, online conferencing, etc.

• Pre-terminated Fiber Optic Cable

The per-terminated fiber cable arrives on-site with the connector attached and ready to install. It’s normally made at a pre-determined length, and it’s undeniable of higher quality than its counterpart. The pre-terminate cable helps eliminate rework, transmission testing, etc. And it comes in a plug-and-play design, which can be easily connected and disconnected, cutting off the deployment time by at least 70%. It is manufactured and assembled in a well-controlled environment to ensure the best possible network performance, and signal loss can be highly restrained with thorough inspections. The pre-terminated cable can be used in mission-critical applications that demand the highest level of accuracy, like video surveillance systems.

Structure of the Fiber Optic Cable

The fiber optic cable consists of five components: core, cladding, coating, strengthen member and outer jacket. The core is a strand of high-purity glass or plastic whose diameter is measured in microns, varying from 8 to 63 microns, where light pulses generated by a laser or LED can pass through. The core is surrounded by a less refractive indexed cladding that reflects light back to the core to avoid light leakage to the surroundings, which reduces cross-talk between fibers. And there is a plastic coating over the cladding to reinforce the fiber core and provide extra protection against pinching, shocks, bends, etc. Optical fibers are extremely fragile during pulling. To absorb excessive tension from the tensile force, strengthen member is often added to provide additional support to the cable, and the material can range from Kevlar to gel-filled sleeves. For extra physical protection, the cable is shielded in an outer jacket, the purpose of which is to protect the cable from environmental hazards.

How Fiber Optic Cable Works?

Simply put, light (laser or LED) travels down a fiber optic cable by repeatedly bouncing off the ‘walls’ of the cable with continued internal mirror-like reflection. The size of the fiber core is critical in determining how far a signal can travel. In general, the smaller the core, the farther the light will travel before it needs to be regenerated. Since most fiber networks cannot directly blend into the network infrastructure your home or office can use, the stretch between the main fiber network line and the end-user, also known as the ‘last mile’, is often completed by the old-fashioned coaxial cable, copper cable, etc.

Differences between Fiber Optic Cables and Ethernet Cables

The biggest difference between these two types of cables is that the Ethernet cable can deliver power while the fiber optic cable cannot. The Ethernet cable is a tried-and-tested form of cabling often used in a copper-based network to transmit both power and data simultaneously to the powered device. However, the major drawback is that it will experience severe signal degradation at long distances since it can only support a maximum transmission range of 100 meters. And the signal loss will also increase as the DC resistance rises. And because it uses electrical signals for data transmission, it is susceptible to electromagnetic interference, and data sent in this way can be intercepted by third parties.

On the contrary, the fiber optic cable is able to transmit more information at a much faster speed (100 times faster) than the copper wire in the same amount of time over a greater distance. Its bandwidth is much higher than what you would expect from an Ethernet connection. It can support ultra-high-speed data transmission rates of up to 10 Gbps and more. Moreover, It doesn’t carry any electricity, so it’s inherently safer to operate in high-voltage locations. Additionally, the fiber optic cable is impervious to EMI and power fluctuation, making it ideal for business uses in demanding environments where lightning and power surges are often present.

Advantages and Disadvantages of Fiber Optic Cables

The advantages you can expect from fiber optic cabling are:

1. Impeccable Network Speed

In data networking, no current technology is better than fiber cabling. The fiber optic network is significantly faster than even the highest-speed copper-based network connection since it transmits data at 2/3 the speed of light (slightly slower than that in the vacuum due to the refractive index). And it’s fairly easy to get 10 Gigabit with fiber, while most copper cables like the Cat5 cables (10/100 Mbps) can only support Fast Ethernet. Some copper cables can transfer data at Gigabit speeds, but they support significantly lower bandwidth than fiber optic cables. The amount of information that the fiber cable can transmit per unit of time will also exceed that of the copper cabling.

2. Improved Reliability & Security

The fiber optic cable is less susceptible to environmental factors than other network media. It’s immune to temperature fluctuations, moisture, shocks and vibration, lightning surges, etc. And given that the fiber optic cable doesn’t carry electrical currents, it is unaffected against electromagnetic interference, which can otherwise impede the performance of connections. Additionally, it features a higher security level and is very secure for transmitting data. Since it doesn’t work with RF signals, there is no chance for intruders to break into your packets. The signal traveling through the cable is trapped in the individual strand and can only be accessed physically from the end of the cable, so any attempts to tap the information will be immediately acknowledged.

3. Long-Term Cost Effectiveness

The upfront cost of fiber optic networks is higher, but the capacity for long-term deployment has outweighed the initial investment. In addition, with the evolvement of technology, in terms of the cables themselves, fiber optic cables can be made less expensive than equivalent lengths of copper wire. Because fiber is made from glass material while copper is metal, fiber is much more resistant to corrosion, while copper will degrade much faster. They can last for up to 20-50 years for years of continuous operation (and they could also last for 60 years or more if properly installed and well-maintained), while their copper counterparts have to be replaced every 3-5 years. Moreover, the fiber optic cables can support a higher bandwidth capacity that can not only meet the users’ current needs but also meet their future needs as well. The Gigabit speeds offered by fiber make sure that no matter how fast the speed will be in the future, the fiber optic network will always be at the forefront of Internet technology.

The disadvantages that should be avoided in fiber optic cabling are:

1. Vulnerable to Physical Damage

The fiber optic cables are much thinner and lighter than the copper wires, but they’re not as robust as their counterparts. Since these cables are delicate, they can easily be severed by accident during renovations and rewiring. Twisting and pulling of fiber optic cables can affect their functionality, and once the cables are bent, they will no longer work, making laying cables around corners a tricky business. If the cable breaks in the middle, there’s no way for it to be repaired. And worse still, all the network devices connected to it will also go down. And the fiber optic cables are also susceptible to radiation damage or chemical exposure.

2. Unidirectional Light Propagation

One of the major drawbacks of fiber optic cables is that they can only propagate light in a unidirectional fashion, which means data can only travel in one direction. So, if you want your communication to be bidirectional, two concurrent fiber cables must be laid out in a parallel manner, which will highly increase the upfront cost.

How to Choose Fiber Optic Cables?

The fiber optic cable is the key to a successful fiber optic network and it helps you to retrofit your network infrastructure, but sorting through different types of cables can be a frustrating experience. Here, we have summarized a list of factors you should consider when buying fiber optic cables:

Single-mode vs Multi-mode Fiber

One of the very first things to consider when choosing fiber optic cables is the core diameter. The single-mode fiber has 125μm of cladding around a very tine core of 9μm and allows the transmission of only one spread of light beam (laser) to pass through, making it more suitable for long-haul installations. Single-mode fiber gives you a higher transmission rate and up to 50 times more distance than multi-mode fiber (can support a distance up to 100 kilometers), but with a higher cost. The single-mode fiber has very low propagation loss and merely no dispersion. Its extremely thin core allows the laser to travel in it with virtually no reflection, which highly lowers the attenuation rate. The single-mode fiber optic cable is often coated with a yellow sheath. It can be applied in fast-speed point-to-point links, metropolitan and access networks, small-to-mid-sized businesses, campuses, etc.

The multi-mode fiber has the same cladding but a large core (typically 50μm or 62.5μm). It is designed to carry multiple light rays and is usually preferred for data transmission at relatively short distances, for example, within a building. More information can pass through the multi-mode fiber at a given time without any interference and keep unchanged. The multi-mode fiber supports multiple data transfer protocols, such as Ethernet and Internet protocols. Due to the larger core diameter, the fiber end is more easily aligned during fiber termination. And the multi-mode fiber and connector are more economical and easier to work with other optical equipment, while the single-mode connections require greater care and skill to terminate, which is why their components are often pre-terminated at the factory. In addition, multi-mode connections can be easily performed in the field, providing installation flexibility, cost savings and peace of mind. Moreover, multi-mode transceivers are almost two to three times cheaper than single-mode transceivers. The multi-mode fiber optic cable is usually coated with an orange or aqua jacket, used in short-distance applications like data centers, intelligent sensing systems, radio telecommunications, etc.

Simplex vs Duplex

Simplex and duplex fiber optic cables feature two different types of communication channels in the fiber optic network. In the simplex fiber, information can only travel in one direction at a time. It only contains a strand of glass or plastic fiber and a single outer jacket, in which one end is the transmitter, while the other end is the receiver, and these two ends are not reversible. Simplex fiber can be useful for single fiber (BiDi) transceivers. It’s a great option for setting up a network that will require data to travel long distances in one direction, as the cable can only carry one beam of light at a time. The simplex fiber optic cable is mostly used for one-way data transfer. It’s a good choice for applications like oil line monitors, interstate trucking scales, automated speed and boundary sensors, etc.

The duplex fiber optic cable consists of two simplex cables. In the duplex fiber cable, the transmission is bidirectional for it uses 2 fibers to communicate. The fibers are arranged in a zipcode construction. One strand transmits data from point A to point B and the other from B to A. Both ends have a transmitter and a receiver. The duplex fiber optic cable can also be further categorized into half-duplex and full-duplex. Half-duplex means that information can be transmitted in both directions but not simultaneously, while full-duplex means that data transfer can occur in both directions at the same time. It can be utilized in applications, such as telecommunications, workstations, Ethernet/fiber switches, large modems and network servers, and backbone ports.

Indoor vs Outdoor

There are certain cables distinguished as indoor and outdoor based on the applications and intended uses. And the major difference between the indoor and outdoor fiber optic cables is the water protection. The indoor cables are usually convenient and easy to use. They are not waterproof but are fire-resistant, which makes them ideal for home and office uses. Indoor fiber optic cables feature a tight buffered lined with Kevlar strength members to increase the tensile strength. The outdoor cables are designed specially to protect fibers from years of water exposure and other environmental elements. Most outdoor cables are made with loose tubes that are filled with gel or water absorbent powder. And since these cables are often deployed under the ground, they are greatly improved with tensile strength for greater pulling distances. Ribbon, loose tube, aerial, direct-buried and armored fiber optic cables are a few popular types of cables in this category. And for underground fiber laying, armored cables are the best choice to prevent rodent penetration.

Connector Type

The connector plays a key role in establishing a secure fiber network. Numerous types of connectors have been developed, such as ST, SC, LC and MU connectors, to offer easier fiber termination. The Straight Tip (ST) connector is the most popular fiber connector in multi-mode networks that utilizes a bayonet-style socket and has a long cylindrical ferrule to hold the fiber. It’s spring-loaded, which means it can be easily connected and removed. The subscriber connector, SC connector, is a snap-in connector that latches with a simple push-pull motion. It normally comes with a square plastic housing. It’s mainly designed for the single-mode and duplex networks, often utilized in optical network applications, such as cable TV, media converters and FTTX. The Lucent Connector is a standard ceramic ferrule connector that can be easily terminated with any adhesive, nearly half the size of the SC connector (smaller ferrule-1.25mm). This type of connector is mainly used for single-mode systems and high-density network applications, like data centers, local networks, FTTH, CATV, etc. The MU connector is a miniature SC connector with a square shape and push-pull mating mechanism, ideal for both single-mode and multi-mode fibers. It is also applicable to high-density applications like data centers, telecommunications, etc.

Jacket Material

The jacket of the fiber optic cable is made of various types of materials, like PVC, and PE. Each is designed for use in different scenarios. The PVC is usually a low-cost, flexible material, and it cannot tolerate high temperatures, hydrogen chloride gas, etc., so the PVC jacket is more suitable for applications like low-voltage devices and computer networking. On the other hand, PE has excellent resistance to water and moisture and it can work under a wide range of temperatures. So it’s a good option for making outdoor fiber optic cables. Another type of jacket is made of LSZH. This material does not give off halogenic compounds when it is burned, which reduces the chances of toxicity in combustible atmospheres.

Installation Tips

1. How to Manage Fiber Optic Cables?

As the number of connected devices increases, the distribution and management of fiber cables become more and more difficult. To address this problem, the fiber termination box was created to manage the incoming and outgoing cables. It offers a cost-effective method to organize multiple strands of fiber cables in a budget-friendly way. Considering fiber optic cables are more susceptible to physical damages caused by bending, folding or pinching than copper cables, extra protection is needed.

1)Mark the cable at a pre-determined length (say 150 cm) and stripe the cable sheath. Cut off the white cable and mark the remaining cable at 17 cm. Stripe the protective sheath and splice the cable into multiple pigtails. After striping the coating, insert the fibers into a protective tube and wrap up the fiber terminal with the insulating tape to fix the tube (feeder cable).

2)Pass the feeder cable through the metal cable gland. Place the protective tube or sleeve around the cable into the metallic saddle and fix the cable on the fiber tray with the fixtures (use cable ties if necessary) and arrange the pigtails around the curvature.

3)Install the fiber adapters/couplers on the fiber tray (some are pre-installed). Number the patch cords and plug the patch cords into the adapters one by one. Splice and fuse the patch cord terminals with the pigtails and arrange them in the splice tray.

4)Take a protective sleeve and wrap it around the pre-terminated cable. Remove the plug from the entry slot, insert the cable into the termination box and re-install the plug. Fix the cable with cable ties if necessary. Arrange the pre-terminated cable in the fiber tray and connect the terminal to the other end of the adapter.

2. How to Run the Fiber Optic Cables?

There are mainly two ways to run the fiber cables: aerial and underground. For aerial building, you’ll need to wire the aerial fiber optic cables (specially designed for outside plant installation) between poles by being lashed to a wire rope messenger strand with a small gauge wire. But building new poles is costly and geographically challenging, which is only recommended for professional, large-scale network deployments. On the other hand, conduit cabling is often used both indoors and outdoors, especially for underground cables. But as is mentioned above, if you’re gonna run the power cable along with the fiber optic cables, they should be arranged in different conduits.

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