Optical fiber communication is gaining popularity day by day. And, it is worth noting, not in vain. It is based on a special fiber. This approach allows you to achieve excellent performance for transmitting information over long distances. The use of such cables is quite justified. The use of fiber optic elements has many advantages.

The main advantages of fiber optic elements include:

• durability;


• strength;


• reliability;


• resistance to mechanical and external influences;


• broadband;


• minimum price;


• light weight;


• compact dimensions;


• resistance to interference of electromagnetic waves.

This list can be continued for a very long time, since optical fiber is indeed the most advanced medium for transmitting information.

There are two types: single mode and multimode. Both have the most important criteria: dispersion and attenuation. The fiber itself includes a core and a cladding. It is noteworthy that they differ from each other in the refractive index.

As for the propagation of EMW in the fiber, the single-mode one has a fiber core diameter of about 8-10 microns. This indicator is comparable to the wavelength. In multimode, the diameter is 50-60 microns, which makes it possible to propagate a huge number of rays.

History and features of fiber optic communication

Optical fiber communication is a popular and in-demand way of transmitting information.

Despite the fact that this technology has been used on the modern market relatively recently, its principle dates back to 1840, when Daniel Colladon and Jacques Babinette demonstrated their experiment. This principle was that the change in the direction of the light beam was carried out by means of refraction.

However, the method was actively used in this area already in the 20th century.

This type of communication has many advantages, namely:

• low signal attenuation;


• the presence of protection against unauthorized access;


• performing the functions of a dielectric;


• long service life, etc.

Due to the fact that the signal attenuation index is relatively small, it is possible to build a system up to 100 km or more. In turn, the broadband fiber makes it possible to transmit information over such a line at great speed. Usually it can vary up to 1 Tbit per second. Despite the fact that the cost of welding and individual elements of the system is high, the construction of this type of connection is fully justified. Its use is a guarantee of a high-quality signal without interference and distortion.

More benefits of fiber optic communication

Fiber optic communication is widely used to transmit information. Fiber-optic communication has a number of unique characteristics that make it popular.

This type of connection appeared back in 1840 after demonstrating an experiment with changing a light beam through refraction. However, this type has been actively used only recently.

There are a huge number of them. This is directly:

1. Broadband. Through the use of such a fiber, information can be transmitted at high speed. It varies up to 1 Tbit per second. This indicator is due to the extremely high carrier frequency.


2. Affordable cost. Such fibers have an acceptable price, which allows them to be used for many purposes.


3. Low signal attenuation. This criterion makes it possible to construct communication lines of considerable length. It can vary up to 100 km and more.


4. Long period of service. This type of lines, as practice shows, can function perfectly for at least a quarter of a century.


5. Interference resistance. This prevents signal degradation and distortion.


6. Availability of protection against unauthorized unauthorized access. Information that is transmitted through this type of connection is practically impossible to intercept without destroying the main cable.


7. Safety. Optical fiber is the same dielectric. Therefore, it significantly increases the fire and explosion safety of the entire system. This is especially true in enterprises that operate in high-risk environments.

These are the main advantages of such lines. Due to this, high performance and excellent quality of the transmitted signal are achieved.

What is included in fiber optic communication?

Fiber optic lines are a whole system, which includes a number of devices.

The main ones include the following devices:

• receiver;


• transmitter;


• preamp;


• a microcircuit designed to synchronize and restore information;


• a block of the conversion code to parallel and the converter itself;


• laser shaper;


• cable.

Today there are two types of fiber. It is singlemode and multimode. Already from their name the principle of work becomes known.

If only one beam propagates in the first, then many in the second. This is due directly to the refractive index. In a single-mode fiber, it is equal to the wavelength of light, and in a multimode fiber it is somewhat larger.

It is worth noting that both types are characterized by the two most important indicators: dispersion and attenuation.

Maintenance of fiber-optic communication lines

Fiber-optic communication lines are very popular. this is due directly to their capabilities and characteristics.

Maintenance of fiber optic communication lines should be carried out regularly to avoid various errors, distortions in the transmitted signals and breakdowns.

It is noteworthy that this kind of operation should only be trusted by professional craftsmen. This guarantees the complete elimination of inaccuracies. In addition, such operations can significantly extend the service life of both individual elements and the entire system.

The transmission of information is relevant at all times. In order for relaying to be carried out with the highest quality, you should choose powerful and productive devices. Before starting the equipment, it must be configured in accordance with the required parameters.

Today, for such systems, it is important to use fiber-optic communication lines. The use of such elements has many advantages.

Such a system consists of active and passive objects, as well as fiber optic cables, which operate, as a rule, in the infrared range. Mostly close.

It is optical fiber that is by far the most perfect medium for transmitting information.

Among the mass of its advantages, the most important should be highlighted. It:

• affordable price;
• broadband;
• compactness;
• ease;
• low signal attenuation in the fiber;
• resistance to electromagnetic interference.

For information transmission systems, the last criterion is the most important. Thus, the signal arrives without distortion along the entire path of its propagation.

But these elements are not without drawbacks. First of all, the need for powerful active equipment when creating the entire system.

The second drawback is that the installation of the optical fiber is carried out only through the use of precision equipment. Such equipment has a rather high cost.

Another disadvantage is the high cost of repairing breakdowns. However, compared to the huge number of advantages and functional characteristics, these disadvantages fade into the background and are quite insignificant.

It should also be noted that such a fiber can be used in two varieties: single-mode and multimode. This name is due directly to variations in the propagation of radiation in it.

Companies involved in the maintenance of fiber optic communication lines at the exhibition

The Russian complex of international level Expocentre Fairgrounds is traditionally the organizer of a huge number of industry and thematic events. One of them - exhibition "Communication".

Exhibitors are given an excellent opportunity to visit the business program, gain experience, get acquainted with innovations in this area and study the current state of the industry within the framework of the project.

The exhibition is structured by salons, which is a significant convenience for participants. One of the areas is the maintenance of fiber-optic communication lines. Here, representatives of this segment can learn the basic principles and methods, which can improve the situation.

Examples of fiber optic communication and its advantages at the exhibition

It is not enough just to know what are the advantages of fiber-optic communication. It is important to be able to apply them correctly in practice, which will ensure the highest quality of the transmitted signal. It is for this purpose that thematic and sectoral events are held.

One of them is exhibition "Communication", which traditionally gathers leading figures and representatives of the industry under one roof of the international complex Expocentre Fairgrounds.

Holding an event on an international scale has a significant impact on the development of the industry as a whole.

International exhibition "Communication" has been attracting the attention of representatives of this industry for many years now.

The exhibition is of great importance, as it contributes to:

• development of the entire industry at the international level;


• bringing new products to the world market;


• introduction of innovations in production;


• exchange of experience and knowledge;


• increasing competitiveness;


• studying the main directions of the market.

Every year, leading figures and representatives of the segment gather within the walls of the Expocentre Fairgrounds to demonstrate the existing developments and achievements. Here you can visit various conferences and symposia, where the most important areas are discussed, in particular, fiber optic communications.

Read our other articles:

Slide Communication

Connection in technology - the transmission of information (signals) over a distance.

Communication types

Depending on what phenomena were used to encode messages, you can highlight the connection using:

• electrons - telecommunications (wire and radio)
• photon radiation - modern optical fiber, some types of signal towers, flashlight signals in Morse code, atmospheric and space laser communications
• sequences of characters from dyes on the material - a letter on paper.
• embossing or changing the shape of the material - optical disc

Depending on the data transmission medium, communication lines are divided into:

• satellite
• air
• ground
• underwater
• underground

Depending on what the message carries, according to the physical principles underlying the communication lines, the following types of communication can be distinguished:

• Wire and cable communication - transmission is carried out along the guiding medium.
• Electrical cable communication
• Fiber optic communication
• Satellite communications - communications using space repeater(s)
• Radio relay communication - communication using terrestrial repeater(s)
• base stations
• Courier communication
• Pigeon mail

Depending on whether the sources / recipients of information are mobile or not, there are stationary (fixed) and mobile connection ( mobile, communication with moving objects- SPO).

According to the type of transmitted signal, analog and digital communications are distinguished.

Signal

Depending on what information is transmitted, there are analog and digital connection. Analog communication is the transmission of continuous messages (such as sound or speech). Digital communication is the transmission of information in a discrete form (digital form). However, discrete messages can be transmitted over analog channels and vice versa. At present, digital communication is replacing analog (digitization is taking place),

Communication line

Communication line(LS) - the physical medium through which information signals of data transmission equipment and intermediate equipment are transmitted.

This is a set of technical devices that ensure the transmission of messages of any kind from the sender to the recipient. It is carried out using electrical signals propagating through wires, or radio signals.

Wired communication lines

Communication circuit- conductors/fiber used to transmit a single signal. In radio communications, the same concept is called trunk. Distinguish cable chain- circuit in the cable and air circuit- hung on supports.

Wired telecommunication lines are divided into cable, air and fiber optic. Cable lines were laid underground. However, due to the imperfection of the design, underground cable communication lines gave way to overhead ones. An ordinary urban telephone cable consists of a bundle of thin copper or aluminum wires, insulated from each other and enclosed in a common sheath. Cables are made up of a different number of pairs of wires, each of which is used to carry telephone signals. The desire to expand the range of transmitted frequencies and increase the capacity of the lines of multichannel systems has led to the creation of new types of cables, the so-called coaxial. They are used to transmit high-frequency television signals, as well as for long-distance and international telephone communications. One wire in a coaxial cable is a copper or aluminum tube (or braid), and the other is a central copper core embedded in it. They are isolated from each other and have one common axis. Such a cable has low losses, almost does not radiate electromagnetic waves and therefore does not create interference. These cables allow the transmission of energy at a frequency of currents up to several million hertz and allow them to transmit television programs over long distances.

Rice. Coaxial cable

Fiber optic communication lines

As wired communication lines, telephone lines and television cables are mainly used. The most developed is telephone wire communication. But it has serious drawbacks: susceptibility to interference, attenuation of signals when they are transmitted over long distances, and low bandwidth. All these shortcomings are deprived of fiber optic lines - a type of communication in which information is transmitted through optical dielectric waveguides ("optical fiber").

Optical fiber is considered the most perfect medium for transmitting large amounts of information over long distances. It is made of quartz, which is based on silicon dioxide, a widely used and inexpensive material, unlike copper. Optical fiber is very compact and lightweight, with a diameter of only about 100 microns.

Optical fiber lines differ from traditional wire lines:

• very high speed of information transfer (for a distance of more than 100 km without repeaters);
• security of transmitted information from unauthorized access;
• high resistance to electromagnetic interference;
• resistance to aggressive environments;
• the ability to transmit simultaneously up to 10 million telephone conversations and one million video signals on one fiber;
• fiber flexibility;
• small size and weight;
• spark, explosion and fire safety;
• ease of installation and installation;
• low cost;
• high durability of optical fibers - up to 25 years.

Rice. Fiber optic cable (cross section)

Currently, the exchange of information between continents is carried out mainly through submarine fiber optic cables, and not through satellite communications. At the same time, the main driving force behind the development of submarine fiber optic communication lines is the Internet.

Rice. Optical fiber network "Transtelecom"

Link may be:

• simplex- that is, allowing data transmission in only one direction, an example is radio broadcasting, television;
• half duplex in turn;
• duplex- that is, allowing data transfer in both directions simultaneously, an example is a phone.

Separation (compaction) of channels:

The creation of several channels on one communication line is ensured by diversifying them by frequency, time, codes, address, wavelength.

• frequency division of channels (FDM, FDM) - division of channels by frequency, each channel is allocated a certain frequency range
• time division of channels (TDM, TDM) - division of channels in time, each channel is allocated a time slice (timeslot)
• code division of channels (CDC, CDMA) - division of channels into codes, each channel has its own code, the imposition of which on the group signal allows you to highlight the information of a particular channel.
• spectral channel separation (SRK, WDM) - separation of channels by wavelength

Wireless communication lines

Radio communication - radio waves in space are used for transmission.

• LW, MW, HF and VHF communication without the use of repeaters
• Satellite communications - communications using space repeaters
• Radio relay communication - communication using terrestrial repeaters
• Cellular communication - communication using a landline network base stations

Communication system comprises terminal equipment, the source and recipient of the message, and signal conversion devices(UPS) at both ends of the line. Terminal equipment provides primary processing of the message and signal, conversion of messages from the form in which they are provided by the source (speech, image, etc.) into a signal (on the side of the source, sender) and vice versa (on the side of the recipient), amplification, etc. .UPS can provide signal distortion protection.

Types of modern communication

Mail

Mail(Russian Mail (info); from lat. posta) - a type of communication and an institution for transporting news (for example, letters and postcards) and small goods, sometimes people. Carries out regular forwarding of postal items - written correspondence, periodicals, money orders, parcels, parcels - mainly by means of vehicles.

The postal organization in Russia is traditionally a state-owned enterprise. The post office network is the largest organizational network in the country.

Letter- a means of storing information, for example on paper. Before sending a letter on the envelope, you need to put the postal codes of the sender and recipient in accordance with the stencil printed on it.

Rice. Postal envelope with zip code stencil

Rice. Postal envelope of the Russian Federation with a printed postal code

Airmail, or aviation mail(English) airmail), - a type of postal service in which postal items are transported by air using aviation.

Rice. Envelope air mail of the Russian Federation

Pigeon mail- one of the methods of postal communication, in which the delivery of written messages is carried out using carrier pigeons.

Cybermail@

The main advantage of e-mail is the speed of delivery, regardless of the geographical location of the sender of the letter and the recipient. But both the sender and the recipient must have computers and access to e-mail.

And if the sender has these capabilities, but the recipient does not? In the United States, the National Postal Service ensures that an email is delivered to the post office closest to the addressee. There it is printed and delivered in an envelope by the postman to the recipient. Today, air mail delivers a regular letter from Russia to the United States in 3-4 weeks. A new combined (electronic - regular) letter can be delivered within 48 hours. Russia also has a plan to equip post offices with internet and e-mail access. This project is called "Cyberpost@". In all post offices will be opened "Internet salons" - points of collective access to the Internet. In such a salon, it will be possible to send an e-mail containing any text, document, drawing, photograph. This letter will be sent to the nearest post office to the recipient, printed, automatically sealed in an envelope and delivered by the postman to any address within 48 hours. In the online salon, a consultant will help you learn how to use e-mail and take a digital photo. The first such online salon already exists at the Moscow post office. The cost of one page of such a combined letter is 12 rubles, and on a floppy disk - 6 rubles per 2 Kbytes.

A part of the Cyberpost@ project is the so-called "Hybrid mail". This is a hybrid of the modern Internet and the "traditional postman". Now anyone can bring an ordinary letter written on paper to the post office. There it will be entered into a computer and sent by e-mail to the post office closest to the addressee. In it, this letter will be printed on a printer, and the postman will take it to the addressee. Then the letter will reach any city in the country no later than 48 hours, since the longest stage disappears from the delivery process - the transportation of a letter written on paper from city to city. So the letter in terms of delivery speed will be equal to the telegram. But the cost of such a letter is many times less than telegrams. After all, the cost of only one word of a telegram when transmitted across Russia is 80 kopecks, and the cost of one page of a hybrid letter in A4 format and 2000 characters is only 12 rubles. At the same time, several hundred words fit on an A4 page!

The letter can be closed, i.e. the letter is delivered to the recipient in an envelope, or open, i.e. the letter is delivered without an envelope.
You can hand over letters by Hybrid mail, both on paper and on magnetic media.

Later, an addition was added to the Hybrid Mail project for users who own the Internet and e-mail. It allows them to send an email to a recipient who does not own email. This letter goes to the post office nearest to the addressee, it is printed and sealed in an envelope. The postman takes this envelope to the addressee - the recipient of the letter. This significantly reduces the delivery time.

Pneumatic mail, or pneumomail(from the Greek πνευματικός - air), - a system for moving piece goods under the action of compressed or, conversely, rarefied air. Closed passive capsules (containers) move through the pipeline system, carrying light loads and documents inside.

Rice. Pneumomail terminal

It is used in organizations to send original documents, for example, in banks, warehouses and libraries, cash in supermarkets and bank cash desks, analyzes, medical histories, x-rays in medical institutions, as well as samples and samples in industrial enterprises.

Telegraph(from other Greek τῆλε - “far away” + γρᾰ́φω - “I am writing”) - a means for transmitting a signal over wires or other telecommunication channels. Telegraph communications still exist in Russia today. In some countries, the telegraph was considered an obsolete form of communication and curtailed all operations for sending and delivering telegrams. In the Netherlands, telegraph communications ended in 2004. In January 2006, the oldest American national operator, Western Union, announced a complete cessation of services to the population for sending and delivering telegraph messages. At the same time, in Canada, Belgium, Germany, Sweden, Japan, some companies still support the service of sending and delivering traditional telegraph messages.

Telegraph(from other Greek τῆλε - “far away” + γρᾰ́φω - “I am writing”) - a means for transmitting a signal over wires or other telecommunication channels.

Telegram- a message sent by telegraph, one of the first types of communication using electrical transmission of information.

Rice. Telegram

Telephone communications

Telephone(from Greek τῆλε - far and φωνή - voice) - a device for transmitting and receiving sound over a distance by means of electrical signals. Telephone communication is used to transmit and receive human speech.

Fiber optic communication

Fiber optic communication- a type of wired telecommunication that uses electromagnetic radiation of the optical (near infrared) range as an information signal carrier, and fiber optic cables as guide systems. Due to the high carrier frequency and wide multiplexing capabilities, the throughput of fiber-optic lines is many times greater than the throughput of all other communication systems and can be measured in terabits per second. The low attenuation of light in an optical fiber makes it possible to use fiber-optic communication over considerable distances without the use of amplifiers. Fiber-optic communication is free from electromagnetic interference and is difficult to access for unauthorized use - it is technically extremely difficult to intercept a signal transmitted over an optical cable unnoticed.

Physical basis

Fiber-optic communication is based on the phenomenon of total internal reflection of electromagnetic waves at the interface between dielectrics with different refractive indices. An optical fiber consists of two elements - a core, which is a direct light guide, and a sheath. The refractive index of the core is somewhat higher than the refractive index of the shell, due to which the light beam, experiencing multiple reflections at the core-shell interface, propagates in the core without leaving it.

Application

Fiber-optic communication is increasingly being used in all areas - from computers and on-board space, aircraft and ship systems, to systems for transmitting information over long distances, for example, a fiber-optic communication line Western Europe - Japan, large part of which passes through the territory of Russia. In addition, the total length of submarine fiber-optic communication lines between continents is increasing.

see also

• Information leakage channels transmitted via optical communication lines

Notes

Wikimedia Foundation. 2010 .

• Fiber optic communication lines
• fiber optic cable

See what "Fiber-optic communication" is in other dictionaries:

FIBER OPTICAL COMMUNICATION- A type of wired telecommunication that uses electromagnetic radiation of the optical (near infrared) range as an information signal carrier, and fiber optic cables as guide systems Glossary of business terms. ... ... Glossary of business terms

fiber optic communication- - [L.G. Sumenko. English Russian Dictionary of Information Technologies. M.: GP TsNIIS, 2003.] Topics information technology in general EN fiber optic connectionFOCoptical fiber communication ...

worldwide fiber optic communication- - [L.G. Sumenko. English Russian Dictionary of Information Technologies. M.: GP TsNIIS, 2003.] Topics information technology in general EN fiber optic link around the globeFLAG … Technical Translator's Handbook

OPTICAL COMMUNICATION- transmission of information with the help of light. The simplest (uninformative) types of O. s. used with con. 18th century (e.g. semaphore alphabet). With the advent of lasers, it became possible to transfer to optical. range of means and principles of obtaining, processing ... ... Physical Encyclopedia

Fiber optic transmission line- (FOCL), Fiber optic communication line (FOCL) is a fiber optic system consisting of passive and active elements, designed to transmit information in the optical (usually near infrared) range. Contents 1 ... Wikipedia

Optics opens up a wide range of applications where high-speed, high-bandwidth communications are required. This is a well-proven, understandable and convenient technology. In the Audiovisual domain, it opens up new perspectives and provides solutions not available with other methods. Optics has penetrated all key areas - surveillance systems, dispatching and situational centers, military and medical facilities, and areas with extreme operating conditions. Fiber optics provide a high degree of protection of confidential information, allow the transmission of uncompressed data such as high-resolution graphics and pixel-accurate video. New standards and technologies for FOCL. Fiber - the future of SCS (structured cabling)? We build an enterprise network.

Optical fiber (aka fiber optic) cable- this is a fundamentally different type of cable compared to the two types of electrical or copper cable considered. Information is transmitted through it not by an electrical signal, but by light. Its main element is transparent fiberglass, through which light travels over long distances (up to tens of kilometers) with little attenuation.

The structure of fiber optic cable is very simple and is similar to the structure of a coaxial electrical cable (Fig. 1.). Only instead of a central copper wire, thin (about 1 - 10 microns in diameter) fiberglass is used here, and instead of internal insulation, a glass or plastic sheath is used that does not allow light to go beyond the fiberglass. In this case, we are talking about the regime of the so-called total internal reflection of light from the interface of two substances with different refractive indices (the refractive index of the glass shell is much lower than that of the central fiber). The metal sheath of the cable is usually absent, since shielding from external electromagnetic interference is not required here. However, sometimes it is still used for mechanical protection from the environment (such a cable is sometimes called armored, it can combine several fiber optic cables under one sheath).

Fiber optic cable has exceptional performance on noise immunity and secrecy of transmitted information. No external electromagnetic interference is in principle capable of distorting the light signal, and the signal itself does not generate external electromagnetic radiation. Connecting to this type of cable for unauthorized listening to the network is almost impossible, as this violates the integrity of the cable. The theoretically possible bandwidth of such a cable reaches 1012 Hz, that is, 1000 GHz, which is incomparably higher than that of electric cables. The cost of fiber optic cable is constantly decreasing and is now approximately equal to the cost of a thin coaxial cable.

Typical signal attenuation in fiber optic cables at frequencies used in local networks is from 5 to 20 dB / km, which approximately corresponds to the performance of electric cables at low frequencies. But in the case of a fiber optic cable, with an increase in the frequency of the transmitted signal, the attenuation increases very slightly, and at high frequencies (especially over 200 MHz), its advantages over an electric cable are undeniable, it simply has no competitors.

Fiber-optic communication lines (FOCL) make it possible to transmit analog and digital signals over long distances, in some cases over tens of kilometers. They are also used at shorter, more manageable distances, such as inside buildings. Examples of solutions for building SCS (structured cabling systems) for building an enterprise network are here: Building an enterprise network: Scheme for building SCS - Horizontal optics. , We are building an enterprise network: Scheme for constructing SCS - Centralized optical cable system. , We are building an enterprise network: SCS construction scheme - Zonal optical cable system.

The advantages of optics are well known: immunity to noise and interference, small cable diameter with huge bandwidth, resistance to hacking and interception of information, no need for repeaters and amplifiers, etc.
There were once problems with terminating optical lines, but today they are mostly solved, so working with this technology has become much easier. There are, however, a number of issues that need to be considered solely in the context of application areas. As with copper or radio transmission, the quality of a fiber optic link depends on how well matched the transmitter output signal is to the receiver front end. Incorrect specification of the signal strength leads to an increase in the bit error rate during transmission; the power is too high and the receiver amplifier "saturates", too low and there is a problem with noise as it interferes with the desired signal. Here are the two most critical parameters of FOCL: the output power of the transmitter and transmission losses - attenuation in the optical cable that connects the transmitter and receiver.

There are two different types of fiber optic cable:

* multi-mode or multi-mode cable, cheaper, but of lower quality;
* single-mode cable, more expensive, but has better performance compared to the first one.

The type of cable will determine the number of propagation modes or "paths" that light travels within the cable.

Multimode cable, most commonly used in small industrial, domestic and commercial projects, has the highest attenuation factor and only works over short distances. An older type of cable, 62.5/125 (these figures represent the inner/outer diameters of the fiber in microns), often referred to as "OM1", has limited bandwidth and is used for data transmission at speeds up to 200 Mbps.
Recently, 50/125 "OM2" and "OM3" cables have been introduced, offering speeds of 1Gbps at distances up to 500m and 10Gbps at distances up to 300m.

Single mode cable used in high-speed connections (above 10 Gbps) or over long distances (up to 30 km). For the transmission of audio and video, the most appropriate is the use of OM2 cables.
Reiner Steil, Vice President of Marketing for Extron Europe, notes that fiber optic lines have become more affordable and more widely used for indoor networking, leading to an increase in the use of optical-based AV systems. Steil says: “In terms of integration, FOCLs already have several key advantages today.
Compared to similar copper cabling infrastructure, optics allows both analog and digital video signals to be used simultaneously, providing a single system solution for existing as well as future video formats.
In addition, because optics offer very high bandwidth, the same cable will work with higher resolutions in the future. FOCL easily adapts to new standards and formats emerging in the development of AV technologies.”

Another recognized expert in this field is Jim Hayes, president of the American Fiber Optic Association, which was formed in 1995 and promotes the growth of professionalism in the field of fiber optics and, by the way, has more than 27,000 qualified optical installers and implementers in its ranks. He says the following about the growing popularity of FOCL: “The benefit is in the speed of installation and the cheapness of components. The use of optics in telecommunications is on the rise, especially in Fiber-To-The-Home* (FTTH) systems with wireless access, as well as in the field of security (surveillance cameras).
It seems that the FTTH segment is growing faster than other markets in all developed countries. Here, in the USA, networks of traffic control, municipal services (administration, firemen, police), educational institutions (schools, libraries) are built on optics.
The number of Internet users is growing - and we are rapidly building new data processing centers (DPCs) that use fiber to interconnect. Indeed, when transmitting signals at a speed of 10 Gb / s, the costs are similar to "copper" lines, but the optics consume much less energy. For years, fiber and copper advocates have been battling each other for priority in enterprise networks. Wasted time!
Today, WiFi connectivity has become so good that users of netbooks, laptops, and iPhones have prioritized mobility. And now in corporate local area networks, optics are used to switch with wireless access points.
Indeed, the scope of optics is becoming more and more, mainly due to the above advantages over copper.
Optics has penetrated all key areas - surveillance systems, dispatching and situational centers, military and medical facilities, and areas with extreme operating conditions. Reducing the cost of equipment has allowed the use of optical technologies in traditionally "copper" areas - in conference rooms and stadiums, in retail trade and at transport hubs.
Rainer Steil of Extron comments, “Fiber optic equipment is widely used in healthcare facilities, for example for switching local video signals in operating rooms. Optical signals have nothing to do with electricity, which is ideal for patient safety. FOCLs are also great for medical schools that need to distribute video signals from multiple operating theaters to multiple rooms so that students can watch the operation "live".
Fiber-optic technologies are also preferred by the military, since the transmitted data is difficult or even impossible to "read" from the outside.
Fiber optics provide a high degree of protection of confidential information, allow the transmission of uncompressed data such as high-resolution graphics and pixel-accurate video.
The ability to transmit over long distances makes optics ideal for digital signage systems in large shopping centers, where cable lines can be several kilometers long. If for a twisted pair the distance is limited to 450 meters, then for optics even 30 km is not the limit.
When it comes to the use of fiber in the AV industry, there are two main factors driving progress. Firstly, this is the intensive development of IP-based audio and video transmission systems, which rely on high-capacity networks - FOCLs are ideally suited for them.
Secondly, the widespread requirement to transmit HD video and HR computer images at distances greater than 15 meters - and this is the limit for HDMI transmission over copper.
There are cases when the video signal simply cannot be "distributed" over a copper cable and fiber optics must be used - such situations stimulate the development of new products. Byung Ho Park, Vice President of Marketing at Opticis, explains: “For UXGA 60Hz data bandwidth and 24-bit color, a total speed of 5Gbps, or 1.65Gbps per color channel, is required. HDTV has a slightly lower bandwidth. Manufacturers are pushing the market, but the market is also pushing players to use higher quality images. There are specific applications that require displays capable of displaying 3-5 million pixels or 30-36-bit color depth. In turn, this will require a transfer rate of about 10 Gb / s.
Today, many manufacturers of switching equipment offer versions of video extenders (extenders) for working with optical lines. ATEN International, TRENDnet, Rextron, Gefen and others produce various models for a range of video and computer formats.
In this case, service data - HDCP ** and EDID *** - can be transmitted using an additional optical line, and in some cases - via a separate copper cable connecting the transmitter and receiver.
As a result of HD becoming the standard for the broadcast market, other markets—installation, for example—are also adopting copy protection for DVI and HDMI content,” says Jim Giacetta, senior vice president of engineering at Multidyne. “Using our company's HDMI-ONE device, users can send the video signal from a DVD or Blu-ray player to a monitor or display located up to 1,000 meters away. Previously, no multimode device supported HDCP copy protection.”

Those who work with FOCL should not forget about specific installation problems - cable termination. In this regard, many manufacturers produce both the actual connectors and mounting kits, which include specialized tools, as well as chemicals.
Meanwhile, any FOCL element, whether it is an extension cable, a connector or a cable junction, must be checked with an optical meter for signal attenuation - this is necessary to assess the total power budget (power budget, the main calculated indicator of FOCL). Naturally, it is possible to assemble fiber cable connectors manually, “on the knee”, but really high quality and reliability are guaranteed only when using ready-made, factory-produced “cut” cables subjected to rigorous multi-stage testing.
Despite the huge bandwidth of FOCL, many still have a desire to "shove" more information into one cable.
Here, the development goes in two directions - spectral multiplexing (optical WDM), when several light beams with different wavelengths are sent to one fiber, and the other - data serialization / deserialization (English SerDes), when the parallel code is converted into serial and vice versa.
At the same time, WDM equipment is expensive due to the complex design and use of miniature optical components, but does not increase the transmission rate. The high-speed logic devices used in SerDes equipment also increase the cost of the project.
In addition, equipment is being produced today that allows multiplexing and demultiplexing control data from a common light flux - USB or RS232 / 485. In this case, the light fluxes can be sent along one cable in opposite directions, although the cost of devices performing these "tricks" usually exceeds the cost of an additional fiber to return data.

Optics opens up a wide range of applications where high-speed, high-bandwidth communications are required. This is a well-proven, understandable and convenient technology. In the Audiovisual domain, it opens up new perspectives and provides solutions not available with other methods. At least not without significant labor and monetary costs.

Depending on the main field of application, fiber optic cables are divided into two main types:

Inner cable:
When installing FOCL in enclosed spaces, a fiber-optic cable with a dense buffer (for protection against rodents) is usually used. Used to build SCS as a backbone or horizontal cable. Supports data transmission over short and medium distances. Ideal for horizontal cabling.

External laying cable:
Tight buffered fiber optic cable, armored with steel tape, moisture resistant. It is used for external laying when creating a subsystem of external highways and interconnecting individual buildings. Can be laid in cable channels. Suitable for direct laying in the ground.

External self-supporting fiber optic cable:
The fiber optic cable is self-supporting, with a steel cable. It is used for external laying over long distances within telephone networks. Supports cable TV signal transmission as well as data transmission. Suitable for installation in cable ducts and air installation.

FOCL advantages:

• The transmission of information over FOCL has a number of advantages over transmission over a copper cable. The rapid introduction of fiber into information networks is a consequence of the advantages arising from the characteristics of signal propagation in optical fiber.
• Wide bandwidth - due to the extremely high carrier frequency of 1014Hz. This makes it possible to transmit a data stream of several terabits per second over a single optical fiber. High bandwidth is one of the most important advantages of optical fiber over copper or any other transmission medium.
• Low attenuation of the light signal in the fiber. The industrial optical fiber currently produced by domestic and foreign manufacturers has an attenuation of 0.2-0.3 dB at a wavelength of 1.55 microns per one kilometer. Low attenuation and low dispersion make it possible to build sections of lines without retransmission up to 100 km or more in length.
• The low level of noise in the fiber optic cable allows you to increase the bandwidth by transmitting various signal modulations with low code redundancy.
• High noise immunity. Since the fiber is made of a dielectric material, it is immune to electromagnetic interference from surrounding copper cabling systems and electrical equipment capable of inducing electromagnetic radiation (power lines, motor installations, etc.). Multi-fiber cables also avoid the electromagnetic crosstalk problem that multi-pair copper cables have.
• Small weight and volume. Fiber optic cables (FOCs) are lighter and lighter than copper cables for the same bandwidth. For example, a 900-pair telephone cable with a diameter of 7.5 cm can be replaced by one fiber with a diameter of 0.1 cm. If the fiber is “dressed” in many protective sheaths and covered with steel tape armor, the diameter of such a fiber will be 1.5 cm, several times smaller than the considered telephone cable.
• High security against unauthorized access. Since the FOC practically does not radiate in the radio range, it is difficult to eavesdrop on the information transmitted over it without disturbing the reception and transmission. Monitoring systems (continuous control) of the integrity of the optical communication line, using the high sensitivity properties of the fiber, can instantly turn off the “hacked” communication channel and give an alarm. Sensor systems that use the interference effects of propagated light signals (both along different fibers and different polarizations) have a very high sensitivity to fluctuations, to small pressure drops. Such systems are especially necessary when creating communication lines in government, banking and some other special services that place high demands on data protection.
• Galvanic isolation of network elements. This advantage of optical fiber lies in its insulating property. Fiber helps to avoid electrical ground loops that can occur when two non-isolated computer network network devices connected by copper cable have grounds at different points in a building, such as on different floors. In this case, a large potential difference can occur, which can damage network equipment. For fiber, this problem simply does not exist.
• Explosion and fire safety. Due to the absence of sparking, optical fiber increases network security in chemical, oil refineries, and when servicing high-risk technological processes.
• Economical FOCL. The fiber is made of silica, which is based on silicon dioxide, a widespread and therefore inexpensive material, unlike copper. Currently, the cost of fiber in relation to a copper pair is correlated as 2:5. At the same time, the FOC makes it possible to transmit signals over much longer distances without retransmission. The number of repeaters on extended lines is reduced when using FOC. When using soliton transmission systems, distances of 4000 km have been achieved without regeneration (that is, only with the use of optical amplifiers at intermediate nodes) at a transmission rate above 10 Gbps.
• Long service life. Over time, the fiber will degrade. This means that the attenuation in the installed cable gradually increases. However, due to the improvement of modern technologies for the production of optical fibers, this process is significantly slowed down, and the service life of the FOC is approximately 25 years. During this time, several generations / standards of transceiver systems may change.
• Remote power supply. In some cases, remote power supply of the information network node is required. Optical fiber is not capable of performing the functions of a power cable. However, in these cases, a mixed cable can be used, when, along with optical fibers, the cable is equipped with a copper conductive element. Such a cable is widely used both in Russia and abroad.

However, fiber optic cable also has some disadvantages:

• The most important of them is the high complexity of installation (micron accuracy is required when installing connectors, attenuation in the connector strongly depends on the accuracy of fiberglass cleavage and the degree of its polishing). To install the connectors, welding or gluing is used using a special gel that has the same light refractive index as fiberglass. In any case, this requires highly qualified personnel and special tools. Therefore, most often, fiber optic cable is sold in the form of pre-cut pieces of different lengths, at both ends of which connectors of the desired type are already installed. It should be remembered that poor-quality connector installation drastically reduces the allowable cable length, determined by attenuation.
• It must also be remembered that the use of fiber optic cable requires special optical receivers and transmitters that convert light signals into electrical signals and vice versa, which sometimes significantly increases the cost of the network as a whole.
• Fiber optic cables allow branching of signals (special passive splitters (couplers) for 2-8 channels are produced for this), but, as a rule, they are used to transmit data in only one direction between one transmitter and one receiver. After all, any branching inevitably greatly weakens the light signal, and if there are many branches, then the light may simply not reach the end of the network. In addition, there are internal losses in the splitter, so the total signal power at the output is less than the input power.
• Fiber optic cable is less durable and flexible than electrical cable. A typical allowable bend radius is about 10 - 20 cm, with smaller bend radii the central fiber may break. Poorly tolerates cable and mechanical stretching, as well as crushing effects.
• The fiber optic cable is also sensitive to ionizing radiation, due to which the transparency of the fiberglass decreases, that is, the signal attenuation increases. Sudden changes in temperature also adversely affect it, fiberglass can crack.
• Use fiber optic cable only in networks with a star and ring topology. There are no problems of matching and grounding in this case. The cable provides ideal galvanic isolation of network computers. In the future, this type of cable is likely to supplant electrical cables, or at any rate, to greatly displace them.

Prospects for the development of FOCL:

• With the growing demands of new network applications, the use of fiber optic technologies in structured cabling is becoming more and more relevant. What are the advantages and features of using optical technologies in a horizontal cable subsystem, as well as at user workplaces?
• After analyzing the changes in network technologies over the past 5 years, it is easy to see that SCS copper standards have lagged behind the "network arms" race. Not having time to install SCS of the third category, enterprises had to switch to the fifth, now already to the sixth, and the use of the seventh category is not far off.
• Obviously, the development of network technologies will not stop there: gigabit per workplace will soon become the de facto standard, and later de jure, and for LANs (local area networks) of a large or even medium-sized enterprise, 10 Gbit / s Etnernet will not be rare.
• Therefore, it is very important to use a cable system that would easily cope with the increasing speeds of network applications for at least 10 years - this is the minimum service life of SCS defined by international standards.
• Moreover, when changing standards for LAN protocols, it is necessary to avoid the re-laying of new cables, which previously caused significant costs for the operation of SCS and simply is not acceptable in the future.
• Only one transmission medium in SCS satisfies these requirements - optics. Optical cables have been used in telecommunications networks for more than 25 years, and more recently they are also widely used in cable television and LAN.
• In LANs, they are mainly used to build backbone cable channels between buildings and within the buildings themselves. , providing at the same time high speed of data transmission between segments of these networks. However, the development of modern network technologies actualizes the use of optical fiber as the main medium for connecting direct users.

New FOCL standards and technologies:

In recent years, several technologies and products have appeared on the market that make it much easier and cheaper to use fiber in a horizontal cabling system and connect it to user workplaces.

Among these new solutions, first of all, I would like to highlight optical connectors with a small form factor - SFFC (small-form-factor connectors), planar laser diodes with a vertical cavity - VCSEL (vertical cavity surface-emitting lasers) and optical multimode fibers of a new generation.

It should be noted that the recently approved type of multimode optical fiber OM-3 has a bandwidth of more than 2000 MHz/km at a laser radiation length of 850 nm. This type of fiber provides serial transmission of 10 Gigabit Ethernet protocol data streams over a distance of 300 m. The use of new types of multimode fiber and 850-nm VCSEL lasers provides the lowest cost of implementing 10 Gigabit Ethernet solutions.

The development of new standards for fiber optic connectors has made fiber optic systems a serious competitor to copper solutions. Traditionally, fiber optic systems have required twice as many connectors and patch cords as copper - telecom sites require much more floor space to house optical equipment, both passive and active.

Small form factor optical connectors, recently introduced by a number of vendors, offer twice the port density of previous solutions, as each connector contains two optical fibers instead of just one.

At the same time, the size of both optical passive elements - cross-connects, etc., and active network equipment are reduced, which makes it possible to reduce installation costs by four times (compared to traditional optical solutions).

It should be noted that the American standardization bodies EIA and TIA in 1998 decided not to regulate the use of any particular type of optical connectors with a small form factor, which led to the appearance on the market of six types of competing solutions in this area at once: MT-RJ, LC, VF-45, Opti-Jack, LX.5 and SCDC. Also today there are new developments.

The most popular miniature connector is the MT-RJ connector, which has a single polymer ferrule with two optical fibers inside. Its design was developed by a consortium of companies led by AMP Netconnect based on the multi-fiber MT connector developed in Japan. AMP Netconnect has now issued more than 30 licenses for the production of this type of MT-RJ connector.

The MT-RJ connector owes much of its success to its external design, which is similar to that of the 8-pin RJ-45 modular copper connector. The performance of the MT-RJ connector has improved markedly in recent years - AMP Netconnect offers keyed MT-RJ connectors to prevent erroneous or unauthorized connections to the cabling system. In addition, a number of companies are developing single-mode variants of the MT-RJ connector.

Sufficiently high demand in the market of optical cable solutions is used by LC connectors Avaya(http://www.avaya.com). The design of this connector is based on the use of a ceramic tip with a diameter reduced to 1.25 mm and a plastic housing with an external lever-type latch for fixing in the connector socket.

The connector is available in both simplex and duplex versions. The main advantage of the LC connector is the low average loss and its standard deviation, which is only 0.1 dB. This value ensures stable operation of the cable system as a whole. The standard epoxy bonding and polishing procedure is used to install the LC plug. Today, connectors have found their way into manufacturers of 10 Gbps transceivers.

Corning Cable Systems (http://www.corning.com/cablesystems) manufactures both LC and MT-RJ connectors at the same time. In her opinion, the SCS industry has made its choice in favor of MT-RJ and LC connectors. The company recently released the first single-mode MT-RJ connector and UniCam versions of the MT-RJ and LC connectors, which feature fast installation times. At the same time, there is no need to use epoxy glue and polyurethane to install UniCam connectors.

Fiber-optic communication is a new technology for transmitting information over long distances without loss of signal quality. Information is transmitted via a special cable, and electromagnetic field oscillations in the infrared optical range are chosen as the propagation medium. Due to its colossal bandwidth, fiber-optic communication lines are unparalleled among other methods of transmitting large amounts of information.

A bit of history or how it all began

The rapid development of information technologies could not satisfy the existing methods of communication, our society gradually integrated into the information field, which required new approaches to the choice of methods and methods of communication. A little time has passed since the invention of the first radio stations, but innovative technological solutions were required that could provide not for the momentary needs of mankind, but would work for the future. Theoretical developments of scientists and the first experiments proved that the possibility of broadcasting an information flow using light is much more efficient than signal transmission via radio waves in various ranges.

The first working developments were proposed in 1966 - scientists showed a cable made of ordinary glass, in the hope that it would become a replacement for coaxial wire. The first fiber-optic communication cable had a very high attenuation factor, which was unacceptable. Research continued, but two main problems remained - what to use as a signal carrier and what kind of light source should be for the most efficient transmission of a large amount of information with minimal losses. The solution was found only in the 70s of the last century, when new lasers were invented and new materials appeared as the basis for the cable. Over the next half century, the construction of fiber-optic communication lines experienced a real boom:

• in 1988, the laying of the first large-scale communication line between Japan and the United States was completed;
• in 2003, for the first time, a signal transmission rate of about 11 Tbps was achieved;
• In 2009, tests in the field of high-speed data transmission crossed a new frontier - scientists managed to broadcast a stream of 15.5 Tbps without loss of speed over a distance of about 7000 km.

Research continues, fiber-optic communication lines are being laid all over the world, which make it possible to transmit large amounts of information over considerable distances. This method has become the basis of high-speed access to the Internet, significantly overtaking other popular connection methods in terms of key parameters.

Features of design and installation

The design of fiber-optic communication lines is a complex and time-consuming process that must take into account a number of features, from the technical feasibility of a route to the number of main and auxiliary equipment that will be connected within the network.

The process of designing and developing a communication line can be divided into several stages:

• determination of the technical feasibility of the installation;
• choice of cable type and length;
• carrying out technical calculations to identify the value of the signal attenuation coefficient, and other important indicators;
• selection of the necessary equipment and auxiliary means to ensure the uninterrupted operation of the network and compliance with information transmission standards;
• route design and construction. The installation of fiber-optic communication lines can be carried out in two ways - suspended (the cable is laid over the air on existing or new technical supports) or underground (for this it is necessary to do special ground work). The choice of route laying method depends on the climatic zone, atmospheric conditions (degree of soil freezing, solar or wind activity), terrain and other factors;
• preparation of the necessary technical documentation indicating the number of connection points, various branches and general routing (the so-called skeletal diagram);
• a list of specific technical and hardware tools involved in creating a workable communication line (fixed terminals, amplifiers, transceivers, branch couplings and other equipment);
• coordination of the project with the customer and installation work.

One of the main features of the installation is that the fiber-optic communication channel within the project can reach several tens of kilometers, while the standard wire length is much less. This provides for connections within the same communication line between cable segments. You can connect two wire segments in several ways:

• detachable connection (using optical connectors). This method has one advantage - the work takes place quickly enough and does not require special equipment. The main disadvantage is that this significantly increases the cost of the communication line and contributes to an increase in signal loss when using a large number of connecting elements;
• inseparable way. There are several options here, including gluing and splicing fiber optic communication lines. These processes are quite laborious and require special equipment and practical skills, but the result is the almost complete absence of transmission speed losses and monolithic cable connection.

Fiber-optic communication lines, the equipment used for which meets international standards, can serve for half a century without any visible loss of signal quality.

Key aspects of maintenance

Maintenance of fiber-optic communication lines is a whole complex of various activities that are aimed at maintaining the stable performance of all elements of the system. This includes preventive and repair activities that are carried out at different intervals. Regular maintenance of a fiber-optic communication line provides for the following activities:

• visual inspection of the integrity of the communication line without climbing to the technical support (with the air mounting method). Schedule of holding at least once every six months;
• selective check of the condition of the cables in the clamps with lifting onto the technological support - during the first year of operation, the regularity of checks every 6 months, in the future - as needed;
• arbitrary inspections of the entire network or its individual sections (work is carried out by specialists) - annually;
• measurement of the attenuation coefficient in the network and comparison with the initial indicators - twice a year or in case of a noticeable decrease in the quality of receiving and transmitting information;
• control of icing of the optical cable - depending on the specific climatic conditions;
• check of couplings and grounding of supports - annually.

If problems are found, it is necessary to call specialists who will find the cause, establish the specific location of the breakdown (cable breakage or damage, malfunction in the system hardware, etc.) and eliminate it. Carrying out regular maintenance and repair work is a guarantee that the fiber-optic communication line (FOCL) will be in working condition throughout the entire service life.

Features and main advantages of FOCL

Fiber-optic communication systems are now widely used around the world, gradually replacing other wired data transmission methods due to their features and unique characteristics. Let's take a closer look at some of the key points to understand the benefits of fiber optic communication:

• throughput. This is one of the main characteristics that is important for a communication line. The potential of one channel allows reaching a volume of several terabits per second;
• versatility. An optical cable can transmit signals of various modulations;
• minimum attenuation factor. Due to this quality, the length of the network section without the use of additional repeaters or amplifiers can reach up to 100 kilometers;
• data security. It is almost impossible for an attacker to connect to a fiber-optic line - in the event of a physical violation of the integrity of the channel, the signal will stop passing through the cable, and reliable coding will protect against interception of information using software tools. Additionally, the security system will warn of an attempted entry and hacking. It is thanks to this feature that optical cables are used by various organizations (law enforcement agencies, banks, research companies) that work with classified data;
• Fire safety. Due to their structure and the materials used, fiber optic cables do not support combustion and do not generate sparks. This allows them to be used in chemical, oil refining and other enterprises with a high level of fire hazard;
• economic benefit. Despite the fact that the cost of laying the line is quite high, it will still be cheaper and better than a traditional connection using copper cable. Additionally, it is worth considering the minimum costs for signal amplifiers, especially when it comes to large sections of highways. For comparison, repeaters should be installed every 5-7 kilometers with a standard connection, and every 100 kilometers with a fiber optic cable;
• reliability and durability. When using the connection in standard climatic conditions, the service life of the cable and connecting equipment will be approximately twice as long as when operating a copper cable.

Due to these advantages, communication lines based on fiber-optic connections are very popular in our time around the world.