How does a fiber optic cable work. How is the price of an optical cable determined?

Today, optical audio cable is one of the most modern and reliable methods for data transmission via optical fiber using light. As everyone knows, light is one of the fastest phenomena in the world, so it is worth understanding what such a cable is, how it works and what it is for.

Light is a high frequency electromagnetic wave. If it passes through an optical fiber, then at the same time it can carry a very large amount. At the same time, this method of transmission is stable and has a high immunity to electromagnetic radiation. When passing through the optical fiber, the light wave is attenuated - this depends on the transparency, as well as other properties that the optical fiber has, in particular the optical audio cable.

Let's take a closer look at the example of the DAXX R07 optical cable. It is created from glass fibers, which have a high level of transparency. It also has a low dispersion coefficient, which ensures stable data flow and high speed of light propagation. These properties make the R07 optical audio cable one of the best in the interconnect family, making it perfect for high-end home theaters.

The glass fiber of this cable is 280 fine fibers. The thickness of one fiber is 53 microns. Each fiber is varnished with a special reflective layer, which has a high refractive index - this contributes to the formation of a smooth flow of light with the lowest possible attenuation. This design provides high stability when transmitting large amounts of data, which is why for audio signals, the R07 optical cable is one of the best.

To protect it from mechanical damage, the multi-core fiber is filled with a special buffer, and for maximum flexibility of the entire structure, a double layer of PVC is used. An outer nylon shield protects the cable from excessive bending. Metal connectors ensure durability of the application.

Optical audio cable has several advantages over electrical coaxial cable:

Optics has the ability to transmit large amounts of digital information;

Fiber optic can be used to provide ground isolation between the two components. This is especially true when the computer system unit is connected to the receiver.

A quality fiber optic cable is not cheap. Its implementation will also cost a lot (up to $ 40-50). With budget equipment, it is difficult to take advantage of the "optics", so very often users choose a cheaper coaxial digital cable instead of an optical cable.

Often, experts are asked whether it is necessary to buy an expensive cable, because most of them are equipped only with an optical digital output? So, an expensive cable is not really needed. In satellite TV, the sound quality is not the highest (the digital audio data stream has a low bit rate), so for these purposes, you can buy the simplest optical audio cable, which costs about 10-12 dollars.

Optical cable in its action is significantly different from other types of cables. Through it, the signal is transmitted by light fluxes. Optical fibers made of glass are used for this. Such a cable device allows it to transmit data over long distances with minimal loss.

What types of optical cables are there?

Such cables are made in different ways. Therefore, they can transmit signals at different frequencies, have different parameters and perform different kinds of tasks. They are usually classified as singlemode and multimode. Their differences lie in the method of data transmission and the quality of the transmitted signals. Depending on the type of cable, the optical cable prices.

Patch cords and pigtails are produced from optical cables, which are called patch cords and pigtails (for example, pigtail LC). They differ in that the patch cord has connectors on both sides, while the pigtail has connectors on only one side.

What is the structure of the fiber optic cable?

The fiber consists of a core and a cladding. These parameters have different degrees of refraction. The core is made of a denser material than the shell. Each fiber has numbers in its name that indicate the dimensions of the core and cladding. There is a hydrophobic filler inside between the fibers, which protects the fiber from moisture and, consequently, damage. For cables that are used in harsh conditions, additional protection methods are used in the form of armor.

Also, some types of cables can have power elements, which are represented by steel wire or cables made of copper, steel, fiberglass, aluminum. Power elements can be placed either on the side or in the center of the cable. Such elements are necessary to provide the cable with additional flexibility and improve resistance to mechanical stress that can damage the fibers.

It uses a welding method when joining cable lengths. The welded section can be reliably protected from negative environmental factors if used optical bushing.

How are fiber optic cables classified?

These types of cables can be classified according to several criteria: by design, size, laying method, number of fibers, operating conditions. According to their purpose, they can be:

• trunk lines;
• intrazonal;
• local;
• on-site.

According to the method of laying, cables can be located outside or inside objects. Depending on the method of installation, they are suspended on supports, laid in the ground, sewer tunnels, cable pipes, telecommunication wells.

What determines the price of an optical cable?

On optical cable prices will be quite acceptable if you make his choice, taking into account all the features. Even at the design stage of the fiber-optic communication line, it is necessary to determine the exact amount of optical cable and its type. Then the total cost of the product will be added from the account of the materials from which the cable is made and its general purpose. If the cable, for example, will be laid indoors, then you can use a cheaper one. For external laying, you should select cables with higher quality characteristics, which will cost a little more. On server cabinet price also consists of many parameters. For example, these will be the dimensions of the cabinet, its type, purpose and manufacturer. Also, a server cabinet is selected at the design stage of the fiber-optic communication line in order to make the right choice.

Fast, high-quality and secure data transmission is a prerequisite for the modern world. And today, fiber-optic cable is the most perfect and effective material for these purposes. Many people think that this is a unique novelty. In fact, the development of the material and the first fiber optic lines appeared at the end of the 20th century, and work has been carried out to improve this technology for several decades. As a result, today we have received a transmission material that is truly unique in its characteristics, and its use has become widespread and widespread.

Fiber Optic Cable Structure

Outwardly, it has no special differences and resembles a coaxial electric. The main feature and difference is its internal structure. Thin glass fibers are used here as a transmission element. The fiber diameter is 1-10 microns. Each fiber has a glass or plastic sheath that prevents light from escaping. Thus, the light pulses propagate exclusively inside the conductor.

The outer protective layer may differ in its characteristics. The level of its strength and reliability depends on the purpose of the cable. The choice should be guided by the purpose and expected operating conditions.

Types of fiber optic cable

The main division of fiber optic cable is into multimode and singlemode.

Single-mode - has a high data transmission accuracy. The information arrives at the receiver with negligible distortion, since all beams travel along the same path. It should be noted that this type of cable has a rather high cost, therefore it is used in cases with a special level of requirements for the quality and speed of information transfer.

In a multimode product, the light beams travel in different paths, which causes some distortion at the receiver. However, these distortions are not very large and are fully compensated by other advantages of the optical cable. Also, such a cable is quite affordable.

It also has a fiber count. So, for laying internal communications in buildings, an optical cable for 8 fibers is chosen as standard. The range of the amount of fibers is wide enough. You can purchase a 2-fiber product for indoor applications such as IP cameras, or 144 fibers for indoor / outdoor medium-length highways.

According to the method of laying, the cable is divided into:

• intrasite;
• suspended with a remote load-bearing element;
• self-supporting;
• for laying in the ground;
• for cable ducts;
• for laying in pipes.

The choice is made taking into account all parameters and the planned scope of use. It also takes into account the projected requirements for volume and data transfer rate - whether it will be an optical cable of 16 fibers or 96 fibers, for example.

Optical cable advantages

The main advantages of fiber-optic lines are high data transfer rates and low signal attenuation.

Another important advantage is the security of the transmitted data, namely:

• unauthorized connection to a fiber-optic line is impossible - any connection will violate the integrity of the fibers;
• electrical safety - this expands the scope of use of cables. In particular, their use at enterprises is allowed by the presence of explosive production processes;
• a high level of protection against external interference, both created by natural factors (lightning strike), and powerful electrical equipment, high-voltage lines, etc.

High speed internet is best achieved with optical links. Now this technology has come to almost every apartment. The question of how to connect an optical cable is of interest not only to specialists, but also to ordinary users. We will try to expand on the topic in more detail.

We will consider the connection using PON technology (passive optical networks) as the most modern and gaining popularity today, displacing conventional wired lines.

Let's start with the basics in order to understand what we will have to face, because the optical communication technology differs from the usual and usual wires for us, both in terms of the principle of operation and in the way of installation. Of course, this section can be omitted and proceed immediately to solving practical problems, but, nevertheless, knowing the theory it is easier to solve many problems that arise in practice. We will try not to bother you with complicated terms, but to explain everything in a simple and popular way.

How does fiber optic transmission work?

The transmission of a signal through ordinary wires using an electric current runs into two obstacles that limit the speed limit.

1. A signal with a high frequency decays quickly over a long distance.
2. High frequency currents have large losses of energy through radiation into the environment.
3. Nearby wires and equipment are interfering with the signal.

These negative factors are fought by using intermediate amplifiers, screens, twisting wires. But there is a limit to everything. Today, increasing the speed of information transfer is mainly solved by dividing it into parallel streams. For example, USB 3.0 differs from earlier USB 2.0 in that it uses more than one pair of wires to transfer data.

The issue could be fundamentally resolved only with the help of fiber-optic cables. In them, the signal is transmitted using light, more precisely laser radiation, which weakly attenuates at large distances. For communication, glass fibers are used, in which, due to the specially selected properties of the core and the outer layer, the effect of complete reflection of the light beam appears.

Also, due to their small diameter, they are flexible (we also find thin flexible glass fibers in such familiar materials as glass wool and fiberglass).

The system works extremely simply - on one side of the cable, the laser radiation is modulated, encoding information in it, which is decoded by the photodetector at the other end. Multiple streams can be transmitted over one fiber, using lasers with different spectra in parallel.

The transmission speed over optical fiber is orders of magnitude higher than the capabilities of metal conductors and reaches several terabits per second.

Has fiber and other advantages:

1. Absolute protection against external interference, it is impossible to direct an extraneous signal to such a cable.
2. Due to the absence of metallic conductors, such lines cannot be damaged by breakdown of insulation from high voltage, therefore they are also safe for users.
3. Modern fiber optic cable has a small diameter and takes up a lot of space in trays and sewers.
4. It is impossible to read information without damaging the cable, and without disturbing its performance by known methods (for example, fixing electromagnetic radiation).

Another advantage of optical fiber is that it is not of interest to attackers, since it does not contain non-ferrous metals.

But there are also some downsides:

1. such cables cannot be connected with ordinary soldering or twisting, glass must be welded or special connecting elements must be used;
2. fiberglass cables must not be bent in a small radius;
3. the equipment for receiving and transmitting is complex, although with waste and mass production, as with any electronics, its price is constantly decreasing.

How PON Technology Works

At first glance, building a subscriber network can be done in two ways:

1. Run cables from the base station to each user. This is how the standard city network works - a pair of wires go from the PBX to each telephone.
2. Conduct several high-bandwidth trunk lines to which active switches are connected - switches that distribute access between subscribers. This is how the first networks were built using twisted pairs (LAN) and later optical fibers as backbones. For example, there was a fiber-optic line to the house, access to which was distributed among the apartments using twisted pairs connected through switches. These networks were called FTTB (Fiber To Building) - fiber to the building.

PON technology works on a slightly different principle:

1. Active equipment is mounted only by the provider and the client.
2. Up to 128 receivers can be connected per fiber. The network is built according to the principle of a tree, where branches are branches from the line, branches of the second order go from them, and so on.
3. All subscriber devices connected to the same fiber gain access to the time-division network. That is, a packet of information is immediately transmitted to one client, then to the second, and so on in turn. Due to the high bandwidth of the line, this does not in any way reduce the data transfer rate. There is also communication in the opposite direction, but a different laser wavelength is used.

This approach became possible due to the use of special devices - splitters. They split the flow of one fiber into multiple fibers. Radiation losses, of course, are great, but they are compensated for by using high-power lasers, for today the price for them is not so high.

The advantages of splitters are that they are relatively simple, do not require connection to power grids (this is a passive element, hence the name of the technology) and maintenance.

These features of PON technology make it possible to develop networks in any conditions. If for older methods of distributing the Internet, in contrast to the city, where ordinary switches and servers can be placed without problems in any attic or basement and there are no problems with connecting the power supply, in rural areas there were big difficulties, for PON there are no such problems.

The splitter can be hung on any wall or power line support and even placed in a well, the devices are not afraid of moisture.

PON network

To make it more clear how the PON technology works, we will give a diagram of how such a network is organized.

Let's explain the scheme a little:

• The Internet provider or PBX has an OLT (in English - Optical Linear Terminal) from which the distribution is going. Cable lines are connected to it. This is a rather compact device, the photo below shows a rack that can serve several thousand subscribers.

• Several cables extend from each OLT, the diagram shows only one, for four cores. They are bred throughout the entire serviced area in the cable duct, along the supports or in another way.

Due to the high power of lasers, the length of cables can reach up to 60 kilometers, although usually manufacturers guarantee a high-quality signal at a distance of up to 20 km, but this is quite enough for an average city.

• A splitter is hung on each core (on the diagram these are boxes with the Spliter inscription), from them there are branches either to other splitters, or directly to customers. The diagram shows a split into two cables at the top and four at the bottom, but the signal can branch to more cables, although multi-output devices are usually rarely used.

• After the first splitter, several more can be installed.
• At the end of the line, the subscriber has an ONU (in English Optical Network Unit - Optical Network Unit), it can also be called ONT (in English Optical Network Terminal - Optical Network Terminal) to which a LAN cable can be connected. The device is sometimes referred to as an optical modem.

• In addition to LAN connections, ONU almost always has sockets for a telephone, since almost always a PON connection provides a package of services: Internet, telephone, television.

As you can see from the diagram, the network can be easily developed without high costs. For example, in the upper part, instead of the first ONU, install another splitter, to which two subscribers can be connected. You can also replace two-channel splitters with four-channel ones, such as at the bottom of the diagram.

What problems can a regular PON user have?

Our article, as we said above, is not designed for specialists, they already know perfectly well how to connect a fiber-optic cable and set up equipment. When connecting to PON for the first time, providers also usually provide assistance (though more often for a fee, so by doing everything yourself you can save money) with setting up equipment and networks.

How does the connection usually work?

• Contact the provider and write an application, if necessary, make an advance payment.
• After a while, several network installation wizards appear at your entrance. As a rule, these are not employees of the company of the Internet provider, but third-party contractors. They poke holes in the wall in your hallway, run the fiber-optic cable from the switchboard at the entrance to the apartment, weld it and install an optical socket near the entrance.

• Then the servicemen of the provider appear, who hang up the optical modem (usually it is rented), connect it with a cable to the socket, and then configure it. The Internet is already in the house, it remains to distribute it.

The process is approximately the same in a private house, although the distribution boards will either be located on the supports of power lines (telecommunications), in wells, or not at all, and the subscriber cable will be connected from a separate splitter.

These three stages cannot be completed on your own, only if you hire a contract from a provider. In addition, under contracts, networks to the boundaries of the household or even to the outlet are serviced by the Internet provider free of charge (if they are not intentionally damaged), after the boundaries of the division of the line, they are considered the property of the client and all the costs of their operation are borne by him.

ONT connection in the apartment

The figure below shows a typical diagram for connecting devices to an optical terminal. We will immediately analyze its implementation with our own hands, then we will tell you how you can adjust it depending on the capabilities of the equipment, and how to improve it.

Please note that you will have to deal with optics the least, it is enough to know how to connect a fiber-optic cable to a modem, and all other networks are ordinary wired.

Standard service connection

We will describe in detail all the nodes of the circuit, since not everything is clear to a non-specialist.

• The optical socket, as in most cases, is located near the entrance to the hallway. It is connected to the distribution board with a welded optical cable, which was mounted during installation.
• The socket with the terminal is also connected with an optical cable, but it is connected to the connectors. This is a patch cord (this is the name of any fiber-optic and wired connecting cables, we will use this term further), as a rule, purchased.

• A regular telephone cable is used to connect to the telephone. Instead of a telephone socket, it is plugged into the ONT connector, which corresponds to a standard telephone socket, and is laid through the apartment to the place where the device is located.

• To connect to a stationary computer, a twisted pair (LAN cable) is laid throughout the apartment, which is connected to the appropriate ONT and PC connectors. The connection is similar to connecting through a regular switch.
• In order to connect a laptop, Wi Fi is used; for this, a router is placed next to the terminal. In the diagram, it is designated as a PPPoE / Wi-Fi router. It also connects to the ONT using a twisted pair.

• The last connection is a TV, for this a digital TV receiver is placed next to it (in the Set Top Box diagram, this is the English designation of the device). To connect the receiver to the ONT, a twisted pair is used again, with a TV, standard HDMI, SCART or Composite (bells) connectors that connect any video device.

Now let's move on to how to implement this scheme:

• It is best to use a ready-made optical patch cord to connect to the outlet. Such a wire of short length is easy to obtain at any store. You can make it yourself by purchasing a fiber-optic cable and connectors, we will talk about this below when we describe how to move the terminal further from the outlet.
• Then we connect the phone - for this, you can also buy a ready-made wire of the required length with connectors. If it is difficult to choose the length, but you do not want to make a stock, we make it ourselves.

For manufacturing we need:

• special crimping (crimper) for RJ11 - 14 connectors or universal (it will also help when crimping twisted pairs);
• cable of the required length;
• RJ 11 or 14 plug (they cost a penny);
• insulation cleaning tool (nippers knife).

Advice. Do not buy a four-core cable for the RJ14 standard, for standard devices, 2 cores are enough.

• We remove the upper insulation from the wire, for this you can use a knife or nippers or crimper blades (if any).
• We expose the upper insulation by 6-8 millimeters, we do not touch the insulation of individual conductors.
• We push them into the body all the way. Moreover, if we use, as we have already said, a two-core wire, then the conductors must lie in the sockets of the two central contacts. Which side will be red and which side will be green is not important, despite the fact that there is a wiring diagram for these connectors, it is not necessary to follow it, telephones are not sensitive to polarity.

• Then we insert the connector into the crimper, it should fit correctly into the corresponding socket and squeeze its handles. The bar will slide inward, the knives will cut through the insulation of the cores and reliably connect the contacts.

Advice. You can try to crimp the connector without a crimper. To do this, after installing the wires, press the knives separately with a screwdriver with a sharply sharpened tip, and then the bar to fix the wire inside. The work must be done carefully, however, the plugs themselves cost a penny, so you can break a few pieces until you can achieve a normal result.

The phone can also be connected using standard short patch cords. To do this, we install sockets near the phone and ONT.

Conductors in them are usually clamped with terminals. In this case, you need to connect 2 and 3 contacts (red and green wires fit to them, just like in a telephone cable). This approach is even more convenient.

• We connect the computer using a twisted pair. As with the phone, you can try to find a ready-made cable of the required length or purchase a twisted pair cable and plugs. Crimping occurs in exactly the same way, but with one feature, before installing the conductors in the nests, you need to develop the ends of the conductors and arrange them in the correct order, it is shown in the figure below.

When preparing a LAN line, do not forget one more feature - twisted pairs have different bandwidth, in order to fully realize the possibilities of optical connection, you need to choose cables of at least category 5, they provide gigabit speed.

• Then we connect the TV receiver and Wi Fi router, everything is exactly the same as for a computer - we stretch a twisted pair cable, which we plug into the appropriate connectors. For the latter, if it is located as in the diagram, it is easier to use a ready-made short patch cord. The router will need to be configured, as this is described in the instructions for its operation.

Simplifying the schema

The standard circuit is designed for components with minimal functionality. But modern devices have advanced capabilities, we will tell you how to use them.

• As a rule, almost all ONT terminals can distribute Wi-Fi, so you can refuse a router.
• TVs with the Smart TV function also most often have a LAN input and do not need a receiver for them.

• If you use a radiotelephone, then its base station can be placed next to the terminal and not run a telephone wire around the house. Moreover, many people already have devices in the hallway where a digital outlet is most often installed.

In general, using a Wi-Fi connection, you can refuse wires, except for the telephone. Many TVs include a module for receiving wireless networks, and for a stationary computer, you can buy a receiver that either plugs into a USB connector or is installed on the motherboard in PCI slots.

However, when connecting via Wi-Fi, you will not be able to achieve the high speeds that an Internet connection via a fiber optic cable implies. Wireless network capabilities are limited and depend on the distance to the router and the presence of obstacles (walls).

Schema improvements

Now let's talk about the possibilities for improving the circuit. There is much more to offer. It is difficult to systematically give options and describe them all, but we will try.

Phone line

Let's start with the simplest thing - a telephone, in a house there may be more than one device in the office, as in the diagram, but several, in the bedroom, in the kitchen, in the living room. An optical modem most often has only one RJ 11 (RJ 14) connector. Therefore, the line from him will have to be branched. This can be done in three ways.

1. Install a telephone splitter - a box with three outputs for RJ connectors in the place required for branching. Alternatively, install a double socket. This option may even be preferable, since later in the event of breakdowns, disconnecting sections, it will be easy to find the damaged line.
2. Install any suitable terminal box at the separation point and split the line with it.
3. Connect another one to the telephone cable using soldering or twisting.

Router

A router installed in the hallway may not provide a clear signal (the weaker it is, the lower the data transfer rate) throughout the apartment or house, especially if the building area is large. It is advisable to move it closer to the center of the housing. True, this option is impossible if the terminal itself distributes Wi-Fi. Alternatively, install the signal amplifier (repeater) closer to the center.

LAN lines

Due to the location of the fiber-optic terminal, the twisted pair lines are long. Although the signal in them does not attenuate much, it is more convenient to lay it all the same from the center, especially if there is a lot of equipment connected to the network in the house. As the best option, of course, it would be to move the ONT terminal itself to the center, but it may not be possible to do this (more on that below).

But there is one more possibility - we move the router to the center, as we said above, and do the rest of the wiring from it. Almost all models of these devices, in addition to distributing Wi-Fi, have four LAN ports per output and work as switches.

Also, in the standard scheme, the laptop is only supposed to be connected via a wireless network. But we have already said that Wi-Fi does not fully implement the high-speed data transfer capabilities that an optical terminal provides. Therefore, it is advisable to stretch a twisted pair cable to connect it to those places (living room, bedroom, kitchen) where you most often use a laptop.

TV

As we have already said, modern TVs with the "smart" function have connectors for connecting a twisted pair (LAN) and a Wi-Fi receiver allows you to abandon the receiver altogether. It is correct to call such devices not even TVs, but monoblock computers with TV functionality.

If the TV supports high definition video or even 3D, it is still better to connect via LAN (due to the possible decrease in speed over the wireless channel). Also for such devices, if a receiver is still used, then it is better to connect it to a TV to ensure video quality not through the SCART or Composite connectors shown in the diagram, but through HDMI or at least DVI.

Another feature today in the house is usually not one TV, but several. How do I connect them?

If you need high quality, then you have to pull a twisted pair to each, if not, then you can get by with Wi-Fi. Even if the TV receiver itself or the receiver to it does not support this technology, the wireless adapter costs less than $ 10.

In this subsection of the article, we will also answer the frequently asked question - how to connect the optical cable of the TV to the receiver?

In principle, there are receivers that are directly connected to an optical network, but they are mainly used for broadcasting in cable networks, that is, for professional use. All home digital television receivers are connected as we described above.

Backup power

The disadvantage of modern high-tech communication lines and not only optical ones is that terminal devices require connection to the electrical network.

If the old telephone could operate on the voltage supplied from the automatic telephone exchange through the wires, then the device connected to the terminal completely depends on its power supply. That is, if the lights in your house go out, you will not be able to receive and receive calls. Therefore, consider a backup power supply for your optical modem.

Considering that the power consumption of the ONT is usually within the range of 15-20 watts, any uninterruptible power supply unit is suitable for this purpose (it is accepted to abbreviate UPS - uninterruptible power supply).

For example, if an uninterruptible power supply has a 9 A / h battery, then it will be able to provide you with communication for 6-7 hours. During this time, the mains are usually repaired. For rural areas where power outages are longer, you can choose a unit with a larger battery capacity.

It is advisable to connect a Wi-Fi router in addition to an optical modem to the UPS. Then, in the event of a power outage, you will have not only a telephone connection, but also the Internet, provided that the batteries of a laptop, tablet or smartphone are charged.

ONT terminal transfer

As we already said, the location of the modem at the front door is not optimal; it is advisable to place it closer to the center of the apartment in order to improve Wi-Fi communication and reduce the length of wired lines.

Of course, porting a device can be problematic:

• the provider may not allow the modem to be moved independently;
• the subscriber optical cable is quite picky about the laying conditions, does not like bending under a small radius, it needs to be additionally protected.

But sometimes it is still desirable to rearrange the modem, especially in large apartments with several levels. Let's consider how this can be done, or rather, how to lengthen the optical cable.

There are several options:

• Use an optical cable with connectors corresponding to the connectors in the socket and the modem (a kind of patch cord) of long length. The most acceptable option, however, such cables are not found on sale, but you can make it yourself. Moreover, with this approach, there are no problems with the provider.
• Extend fiber optic using connectors... Below is a look at how this can be done. But note that the signal loss with this method will be greater than with the first option.
• Weld fiber cable... It's actually not that hard, and we'll look at how it's done too. The only problem is that a welding machine costs several thousand dollars and is not worth buying for one or two joints. Although if you are going to continue building optical networks on a professional level ...

You can also borrow equipment from a friend or rent for a day.

By the way, sometimes they ask if it is possible to install two ONTs in one apartment. In principle, it is possible, but unlike telephones, they cannot work in parallel, you will have to pay for two personal accounts. So this choice makes sense only if you need uninterrupted internet and it is possible to connect to the internet via fiber optic cable from different providers.

By the way, a similar scheme, though wired, is implemented at my home. Through a DSL modem, I am connected to the republican provider Beltelecom, from which I have chosen a tariff without a monthly fee. The second connection using a twisted pair cable to the server of the local provider (director of the enterprise is a neighbor and friend), where the Internet is obtained for free. If someone has a breakdown, then I easily switch to reserve.

To help, we also offer video connection of an optical cable:

Connecting and connecting optical cables

All the works that are described below are usually done by craftsmen for a decent fee, although as you can see, they are quite simple with the equipment and tools. In my opinion, mastering the connection of optics is also not difficult, as well as the correct soldering of the usual copper wires.

True, such a need rarely arises, but we will look with an eye to the future, perhaps soon optical fiber will replace copper everywhere, and terminal devices will connect to it directly, and not through ONT.

Installing optical connectors

Let's look at how the most common SC connectors are mounted. The vast majority of modems and sockets use this type. For installation, we need a set of special tools and materials.

Although it costs decently, it is still cheaper than a fiber-optic splicer. Such kits are usually supplied with detailed instructions, so we will give an approximate order of operations for review.

The steps for installing the connector on the cable are as follows:

1. We remove the insulation with special pliers - a stripper. This tool has calibrated gaps between the cutting edges allowing you to remove layers one by one without damaging the fiber itself.
2. Then the Kevlar fiber is cut, which reinforces the wire sheath. To do this with ordinary scissors will not work because of its great strength. You will need stronger blades, which are most commonly available from a stripper.
3. Then a part of the connector is put on, which will fix it on the cable.
4. Then the hydrophobic coating on the glass fiber itself is removed with a special composition or simply with alcohol wipes.
5. Next, glue is prepared and typed into a syringe, which will fix the fiber in the connector. A strictly metered amount is introduced into the channel, into which the exposed fiber is then passed.
6. After the glue has hardened, the optical fiber is chipped off with a special tool.
7. Then its butt end is sanded.
8. In conclusion, the rest of the connector is put on, and it is crimped with a special crimp.

Fiber optic connection with a mechanical connector

This method is simpler than the previous one: pieces of fiber-optic cable are taken, with connectors (pigtails) mounted in an industrial environment, and are joined with a mechanical connector. The disadvantage of this method is the signal loss at the connections, it is comparable to a decrease in the light intensity in the connectors themselves (it is clear that you cannot refuse connectors). So it is better to either weld or mount the fiber in the connector.

Interesting. Pig-tail is translated from English as "pig's tail", a rather apt comparison.

Using the SNR-Link connector as an example, we will describe the execution of the work.

• The cable is stripped of insulation and cleaved.
• The ends of the stripped cable are inserted into the connector.

• Then the latch fixing the joint is simply pressed.

This is where the work ends. As you can see in the photo below, the test of this connection shows a loss of 0.028 dB, which is comparable to the loss in the connector, although according to the passport data, the connector allows losses of up to 0.04 dB. By the way, the device is reusable.

Wire welding

As we already said, it is best to weld wires or pigtails, this is also not difficult, the whole problem is only in the cost of the device. Let's show how welding takes place in stages.

• The device turns on and self-test takes place.

• Next, we introduce the type of cable to be welded. And for this you do not need to professionally understand all types of fiber-optic conductors, we simply enter the marking indicated either on the packaging or on the very surface of the insulation.

• Then, removing the outer protective layer with any suitable tool, we install the wire in a special holder. Before that, do not forget to put on the KDZS sleeve (a set of parts for protecting the welded joint), which will then close the welding place.

• Then the holder is placed in the thermostat of the apparatus, and it turns on. The insulation is removed by heat, while the risk of damage to the fiber is much less than with conventional mechanical stripping.

• The lid closes and the thermostat starts. He cleans the wire himself.

• Then, without removing the wire from the holder, we wipe it with alcohol (a round container with a swab is on the top cover of the device) to remove the hydrophobic coating and install it in the cleaver. The holder in it, as in the stripper, is attached to the magnet. Chipping takes place when the lid is closed. Scraps of fiber fall into a special container so as not to get lost (it is easy to drive a thin fiber almost invisible to the eye under the skin, but it is difficult to extract it later).

Attention. Be very careful about fiber optic waste, they should not be lost, as it can be harmful to health. It is especially dangerous if pieces of glass wire enter the respiratory tract.

• When the two wires are prepared, without removing them from the holders, we install them directly under the welding electrodes.

• We start the welding process. The machine aligns and centers the fibers and splices them in less than ten seconds.

At the end of welding, the device shows the result - what losses will be at this joint. In the image below, they are highlighted with an oval, only 0.01 dB.

• It remains to plant the KZDS sleeve, for this it is put on the joint (we first remove the holders) and the wire is placed in the oven.

The process also takes a few seconds. We remove the finished welded fiber optic cable from the oven (be careful, it will be hot).

As you can see, everything is pretty simple, if you do not have crooked hands, you can quickly learn how to weld fiber optics just by reading the manual for the welding machine (our article is also suitable) or get a 10-minute instruction. I note that it is much more difficult to acquire the skills of connecting ordinary wires with a soldering iron and solder so quickly.

We hope that our article has told everything about an optical cable, how to connect it, connect, coordinate the operation of a fiber-optic modem with other devices. Even if you are not going to assemble networks or connectors yourself, knowing how to do it, you can find the cause of the breakdowns and ways to fix them. Let the Internet in your home always be fast and uninterrupted.

Multifiber cable is often used in domestic and industrial environments. We propose to consider what a single-house and multimode optical cable is, what this cable is for, where to buy it, and how to connect it.

General information

Fiber optic cable (OGD, OGTs, OKB, OKG, OKKM, OKL, OKLZH OPTs, OSD, OKS, OKSTM, OMZKGM, OPD, OPS, MGTS) is a cord containing one or more optical fibers. The elements are individually coated with layers of plastic, which are contained in a protective tube suitable for the environment in which the cable will be used.

Application area the wire has a very wide:

• transmission of signals between buildings over long distances at high speed;
• creation of long-distance telephone communication;
• creation of Internet networks, etc.

Optical Time Domain Reflectometers (OTDRs), which are optoelectronic devices used to characterize optical fiber, test cable performance. OTDR is the optical equivalent of an electronic time domain reflectometer. It introduces a series of optical pulses into the fiber, due to which testing is carried out, after the result of the reaction, reflectograms are displayed, the measurement is carried out by comparing the results. It also extracts light from the same end of the fiber that is scattered (backscattered) or reflected from points along the fiber. The reflected strength is measured as an integrated value that is dependent on time and fiber length.

You can buy testers at the Incab factory, as well as tools that are used to fasten and dismantle wires, cut them or modernize them in a domestic environment.

Optical cable types and their design

An optical fiber consists of a core and a cladding selected for total internal reflection of the signals due to the difference in refraction between them. In practice, the shell is usually coated with a layer of acrylate or polyimide polymer. These substances protect the fiber from damage, but do not contribute to its optical waveguide properties.

Individual coated fibers (or groups of fibers assembled into ribbons or bundles) have rigid resins as a buffer in the main tube and form the core of the cable. Several layers of protective sheathing, depending on the application, are added to form the cable. Rigid fiber assemblies sometimes supply light-absorbing ("dark") glass between the fibers to prevent light from leaking from one fiber and being injected into the other. This reduces cross-talk between filaments, reduces light glare. All four connectors have white caps that cover the lugs.

There are such wire types according to the principle of production and operation:

1. angular;
2. waterproof armored (field of use soil - TOC, water, air);
3. on-site industrial (uses a plant to transmit signals between workshops, etc.).

Onsite cable(CSN, DPL, DPM, DPO, DPS, DPT, DROP) usually closed, has a flexible fiber with a bundle of elastic fibrous polymer reinforcing elements, such as aramid (for example Belkin, Luxmann, Gpon, Twaron or Kevlar), with a light plastic cover, to form a simple cord. Each end of the cable can be equipped with a dedicated optical fiber connector that allows it to easily connect to or disconnect from the network.

For use in more stressful conditions, a more powerful cable is much more often used, for which more serious requirements are - armored... It uses a special tube with a special design, the fiber is laid in a spiral in semi-rigid shells, which allows you to stretch the cable without stretching the fibers themselves. This protects the yarns from stress during styling due to temperature changes or physical stress. The strands themselves, with copper veins, help to conduct signals at the highest level in any environment.

The combined armored cable is widely used for underwater or high-air nets where it can be damaged by fish, high winds and precipitation. This cord is non-flammable, moisture, acid does not affect it in any way, and even physically it is quite difficult to break it. It is used as a main overhead wire, underwater, for sewerage, single-fiber (special type cable), which helps to carry a signal between cities, etc. This extension block can be dry or gel coated for protection and better conductive properties.

A dry block offers less fiber protection than a gel filled block, which is also more expensive. Instead of a loose tube, the fibers can be embedded in heavy polymer insulation, commonly referred to as "hard buffer" wires. The dense adapter is used as a splitter or wiring panel, or a self-supporting wire that helps to conduct signals in extreme situations. A cable conduit is a device that already comes with a pull cable (two-fiber dielectric cable, usually made of epoxy glass), aramid yarn, 3 mm protective tube with an additional layer of Kevlar surrounding each fiber. The wire has a high capacitance, signal attenuation is almost impossible even in extreme conditions (50 150 C / W).

The cargo rope looks approximately the same, except that it is also equipped with reinforced steel conductors, which is why its characteristics allow powerful machine structures, vehicles, tankers and other cargo to be moved with this rope. Such wires can be connected to any construction equipment (pipe stand, welding, concrete mixer, etc.), most often they are mounted on supports (reinforcement is used).

Distribution cables have a common Kevlar insulation, a pull rope, and 900 micrometers of special hardened coating, which is used to process each fiber. Basically, such wires are also reinforced with special steel threads, which increase the transfer capacity, in addition, it is easier to connect the wire to the power supply or the device.

Optical cable for audio devices

Optical subscriber cable TOSLINK (marking stands for Toshiba Link) for the receiver, is a standardized wire with optical fiber, the termination is connected using SPDIF, DNS, MINI, ODT, USB audio output. It is most commonly used in consumer audio devices (using a special "socket"), where it carries the digital audio stream from devices such as CD and DVD players, DAT recorders, computers, and modern xbox game consoles to a receiver that can decode. two audio channels. These wires are used by brands such as Samsung, Apple and others.

Home theater and TV cable

Although TOSLINK supports several different media formats and physical standards, digital video connections use the EIAJ / JEITA RC-5720 rectangular connector (also CP-1201 and JIS C5974-1993 F05), this connector is the most common today.

Due to the use of synchronization recovery, audio or digital optical TOSLINK cable for lg, samsung TVs transmits interference, jitter, communication may be interrupted. Cord resistance often plays a disservice. But in most cases, the bandwidth is very high, a person without training and special devices will not notice any communication problems.

A certain structure and technology of work, forces the cable of television and acoustics to be no longer than 5 meters, otherwise the input signal will be transmitted poorly, the sound will start to make noise, "the picture will float." In most cases, an optical cable for sound or communication is initially built into the device, but if it is not available, it can be bought in electrical stores.

Principle of operation audio wires are based on the work of a simple optical cable:

1. Both single-core and multi-strand cables can be used;
2. To check their performance, you need to use reflectors, they also control the quality of the connection and bending;
3. For the operation of any communication cable, the Internet, an audio device, a normal temperature is required within the range of -10 to +40 degrees;
4. The termination is equipped with a special cable that looks like a microplug;
5. It is connected to the desired connector or it comes pre-built.

It is not difficult to connect such cables using a special connector and plug (plug). It is mainly used infrared soldering or cutting (welding).