The most common type today mobile communications is cellular communication. Services cellular provided to subscribers by operator companies.

Wireless communication to a cell phone is provided by a network of base stations.

Each station provides access to the network in a limited area, the area and configuration of which depends on the terrain and other parameters. Overlapping coverage areas create a honeycomb-like structure; from this image comes the term "cellular communication". When a subscriber moves, his phone is served by one or another base station, and the switching (cell change) occurs in automatic mode, completely invisible to the subscriber, and does not affect the quality of communication in any way. This approach allows, using low-power radio signals, to cover large areas with a mobile communication network, which provides this type of communication, in addition to efficiency, also a high level of environmental friendliness.

The operator company not only provides technical support for mobile communications, but also enters into economic relations with subscribers who acquire from it a certain set of basic and additional services... Since there are a lot of types of services, the prices for them are combined into sets, called tariff plans. The cost of services rendered to each subscriber is calculated by the billing system (software and hardware system that keeps records of the services and services provided to the subscriber).

The operator's billing system interacts with similar systems of other companies, for example, providing a subscriber with roaming services (the ability to use mobile communications in other cities and countries). All settlements for mobile communications, including roaming, are made by the subscriber with his operator, which is a single settlement center for him.

Roaming - access to mobile services outside the coverage area of ​​the "home" operator's network with which the subscriber has a contract.

While in roaming, the subscriber usually keeps his telephone number continues to use his cell phone, making and receiving calls in the same way as on his home network. All the actions necessary for this, including the inter-operator traffic exchange and the attraction of the resources of other communication companies (for example, those providing transcontinental communication) as needed, are performed automatically and do not require additional actions from the subscriber. If the home and guest networks provide communication services in different standards, roaming is still possible: the subscriber can be given another device during the trip, while keeping his phone number and automatically routing calls.

The history of cellular communications.

Work on the creation of civilian mobile communication systems began in the 1970s. By this time, the development of conventional telephone networks in European countries had reached such a level that the next step in the evolution of communications could only be accessibility. telephone connection everywhere and everywhere.

Networks based on the first civilian cellular standard, NMT-450, appeared in 1981. Although the name of the standard is an abbreviation for Nordic Mobile Telephony, the world's first cellular network was deployed in Saudi Arabia. In Sweden, Norway, Finland (and other Nordic countries) NMT networks went live a few months later.

Two years later, in 1983, the first AMPS (Advanced Mobile Phone Service) network, created at the Bell Laboratories research center, was launched in the United States.

The NMT and AMPS standards, which are usually attributed to the first generation of cellular communication systems, provided for the transmission of data in analog form, which did not allow to provide the proper level of noise immunity and protection from unauthorized connections. Subsequently, they have improved modifications through the use of digital technologies, for example, DAMPS (the first letter of the abbreviation owes its appearance to the word Digital - "digital").

The standards of the second generation (the so-called 2G) - GSM, IS-95, IMT-MC-450, etc., originally created on the basis of digital technologies, exceeded the standards of the first generation in sound quality and security, and also, as it turned out later, in terms of to the standard of development potential.

As early as 1982, the European Conference of Post and Telecommunication Administrations (CEPT) set up a group to develop a unified standard for digital cellular communications. The brainchild of this group is GSM (Global System for Mobile Communications).

The first GSM network was launched in Germany in 1992. Today GSM is the dominant cellular standard both in Russia and around the world. In 2004, over 90% of cellular subscribers in our country served GSM networks; in the world GSM was used by 72% of subscribers.

Several frequency ranges are allocated for the operation of equipment of the GSM standard - they are indicated by the numbers in the names. In the European region, GSM 900 and GSM 1800 are mainly used, in America - GSM 950 and GSM 1900 (at the time of the approval of the standard in the United States, “European” frequencies were occupied by other services there).

The popularity of the GSM standard was ensured by its significant features for subscribers:

- immunity from interference, interception and "doubles";

- the presence of a large number of additional services;

- the ability, in the presence of "add-ons" (such as GPRS, EDGE, etc.) to provide data transmission at high speeds;

- presence on the market of a large number of telephones operating in GSM networks;

- simplicity of the procedure for changing one device to another.

In the process of development, cellular networks of the GSM standard have acquired the possibility of expansion due to some "add-ons" over the existing infrastructure, providing high-speed data transmission. GSM networks supporting GPRS (General Packet Radio Service) are called 2.5G, and GSM networks supporting EDGE (Enhanced Data rates for Global Evolution) are sometimes called 2.75G networks.

In the late 1990s in Japan and South Korea third generation networks (3G) appeared. The main difference between the standards on which the 3G networks are built from their predecessors is the expanded capabilities of high-speed data transmission, which makes it possible to implement new services in such networks, in particular, video telephony. In 2002-2003, the first commercial 3G networks began operating in some Western European countries.

Although at present 3G networks exist only in a number of regions of the world, in the engineering laboratories of the largest companies work is already underway to create fourth-generation cellular communication standards. In this case, the focus is not only on further increasing the data transfer rate, but also on increasing the efficiency of use. bandwidth frequency ranges allocated for mobile communications, so that a large number of subscribers located in a limited area could get access to services (which is especially important for megalopolises).

Other mobile communication systems.

In addition to cellular communication, today there are other civil communication systems that also provide mobile communication via radio channels, but built on different technical principles and focused on other subscriber terminals. They are less common than cellular communications, but find use when using cell phones is difficult, impossible, or economically unprofitable.

The DECT microcellular standard is becoming more and more popular, which is used for communications in a limited area. The base station of the DECT standard is capable of providing handsets (up to 8 of them can be served simultaneously) with each other, call forwarding, as well as access to the public telephone network. The potential of the DECT standard makes it possible to provide mobile communications within urban neighborhoods, individual companies or apartments. They turn out to be optimal in regions with low-rise buildings, whose subscribers only need voice communication and can do without mobile transmission data and other additional services.

In satellite telephony, base stations are located on satellites in low-earth orbits. Satellites provide communication where the deployment of a conventional cellular network is impossible or unprofitable (at sea, in vast sparsely populated areas of tundra, deserts, etc.).

Trunking networks that provide subscriber terminals (they are usually called not telephones, but radio stations) communication within a certain territory are systems of base stations (repeaters) that transmit a radio signal from one terminal to another at a significant distance from each other. Since trunking networks usually provide communication to employees of departments (Ministry of Internal Affairs, Ministry of Emergencies, " Ambulance»Etc.) or at large technological sites (along highways, at a construction site, on the territory of factories, etc.), then trunking terminals do not have entertainment opportunities and design delights in their design.

Wearable radios communicate directly with each other without intermediate communication systems. This type of mobile communication is preferred by the state (police, fire brigade etc.) and departmental structures (for communications within the warehouse complex, parking or construction site), and individuals (mushroom pickers, hunter-fishermen or tourists), in situations where it is easier and cheaper to use pocket radio stations to communicate with each other than cell phones (for example, in remote areas without cellular coverage).

Paging communication provides receipt of short messages to subscriber terminals - pagers. Currently, paging communications in civil communications are practically not used; due to their limitations, they are pushed into the area of ​​highly specialized solutions (for example, they serve to notify personnel in large medical institutions, transfer data to information electronic displays, etc.).

Since 2004, a new subtype of mobile communication has become more and more widespread, providing the possibility of high-speed data transmission over a radio channel (in most cases, the Wi-Fi protocol is used for this). Areas with Wi-Fi coverage available for public use (paid or free) are called hotspots. In this case, subscriber terminals are computers - both laptops and PDAs. They can also provide two-way voice communication over the Internet, but this feature is used extremely rarely, mainly the connection is used to access the most common Internet services - e-mail, websites, instant messaging systems (for example, ICQ), etc. ...

Where mobile communications are heading.

In developed regions, the main direction of development of mobile communications for the near future is convergence: providing subscriber terminals with automatic switching from one network to another in order to make the most efficient use of the capabilities of all communication systems. Automatic switching, for example, from GSM to DECT (and vice versa), from satellite to "terrestrial" communication, will allow saving subscribers' funds and improving the quality of communication, and when providing wireless data transmission - between GPRS, EDGE, Wi-Fi and other standards, many of which (for example, WiMAX) are just waiting in the wings.

The place of mobile communications in the global economy.

Communications is the most dynamically developing branch of the world economy. But mobile communications, even in comparison with other areas of "telecom", are developing at a faster pace.

Back in 2003, the total mobile phones the planet has exceeded the number of stationary devices connected to wired public networks. In some countries, the number of mobile subscribers already in 2004 exceeded the number of residents. This means that some people have used more than one "mobile" - for example, two cell phones with different carriers, or a voice phone and a wireless modem for mobile access to the Internet. In addition, more and more modules wireless was required to provide technological communications (in these cases, the subscribers are not people, but specialized computers).

Currently, mobile operators provide full coverage of the territory of all economically developed regions of the planet, however, the extensive development of networks continues. New base stations are installed to improve reception in those places where the existing network for some reason cannot provide stable reception (for example, in long tunnels, on the territory of the subway, etc.). In addition, cellular networks are gradually penetrating regions with low incomes of the population. The development of mobile communication technologies, accompanied by a sharp reduction in the cost of equipment and services, makes cellular services available to an increasing number of people on the planet.

Cell phone manufacturing is one of the fastest growing areas of the high technology industry.

The mobile phone service industry is also growing rapidly, offering accessories for personalizing devices: from original bells (ringtones) to key fobs, graphic screensavers, body stickers, interchangeable panels, covers and laces for carrying the device.

Types of telephones.

Cellular (mobile) telephone - a subscriber terminal operating in a cellular network. Essentially, each cellular telephone is a specialized computer that is primarily focused on providing (in the coverage area of ​​a home or guest network) voice communication subscribers, but also supports text and multimedia messaging, is equipped with a modem and a simplified interface. Modern mobile phones provide voice and data transmission in digital form.

The previously existing division of devices into "inexpensive", "functional", "business" and "fashion" models is losing its meaning more and more - business devices acquire the features of fashion models and entertainment functions, as a result of the use of accessories, inexpensive phones become fashion functionality is growing rapidly.

The miniaturization of pipes, which peaked in 1999–2000, was completed for quite objective reasons: the devices reached their optimal size, their further reduction makes it inconvenient to press buttons, read text on the screen, etc. But the cell phone has become a real piece of art: to develop appearance devices attract leading designers, and the owners are given ample opportunities to personalize their devices on their own.

Currently, manufacturers pay special attention to the functionality of mobile phones, moreover, as the main one (the time increases autonomous work, screens are improving, etc.) and their additional capabilities (digital cameras, dictaphones, MP3 players and other "accompanying" devices are built into the devices).

Almost all modern devices, with the exception of some models in the lower price range, allow downloading programs. The majority of devices can run Java applications, the number of phones using operating systems inherited from PDAs or ported from them is increasing: Symbian, Windows Mobile for Smartphones, etc. Phones with built-in operating systems called smartphones (from a combination of the English words "smart" and "phone" - "smart phone").

Communicators - pocket computers equipped with a module supporting GSM / GPRS, and sometimes EDGE and third generation standards - can also be used today as subscriber terminals.

Non-voice services of cellular networks.

A number of non-voice services are available to subscribers of cellular networks, the “assortment” of which depends on the capabilities of a particular phone and on the range of offers of the operator. The list of services in the home network may differ from the list of services available in roaming.

Services can be communication (providing various forms of communication with other people), informational (for example, reporting the weather forecast or market quotes), providing Internet access, commercial (for paying for various goods and services from phones), entertainment (mobile games, quizzes , casinos and lotteries) and others (this includes, for example, mobile positioning). Today, more and more services appear at the interface, for example, most games and lotteries are paid, games that use mobile positioning technologies appear, and so on.

Almost all operators and most modern devices support the following services:

- SMS - Short Message Service - transmission of short text messages;

- MMS - Multimedia Messaging Service - transfer of multimedia messages: photos, videos, etc .;

- automatic roaming;

- determination of the number of the calling subscriber;

- ordering and receiving various means of personification directly through cellular communication channels;

- Internet access and viewing of specialized (WAP) sites;

- download ringtones, pictures, information materials from specialized resources;

- data transmission using the built-in modem (it can be carried out using various protocols, depending on what technologies a particular device supports).

Mobile communication in Russia.

There were no civilian mobile communication systems in the USSR. With some stretch of the imagination, "civil" can be called the "Altai" mobile telephony system, built on the basis of the MRT-1327 standard, which at the turn of the 1970s-1980s was created to provide communication between representatives of the party, state and economic leadership. Altai is successfully operated to this day. Of course, it cannot compete with cellular networks, but it finds application for solving some highly specialized tasks: providing communication for mobile units of city emergency services, telephoning summer cafes, etc.

The first commercial cellular networks built according to the NMT standard were created in Russia in the fall of 1991. The pioneers of mobile telephony in our country were Delta Telecom (St. Petersburg) and Moscow Cellular Communications. The first cell phone call was made on September 9, 1991 in St. Petersburg: Anatoly Sobchak, who was then the mayor of the city, called his colleague, the mayor of New York.

In July 1992, the first calls were made to the Beeline AMPS network.

The first Russian GSM network, created by MTS, began connecting subscribers in July 1994.

In 2005, there are three federal cellular operators in Russia providing services in the GSM standard: MTS, Beeline and MegaFon. The range and quality of telecommunication services offered by them, as well as their prices, are approximately the same. By 2005, the number of base stations in the networks of the leading metropolitan operators in Moscow and the nearest Moscow region was about 3000, and the coverage area exceeded the area of ​​most European countries. In addition to them, there are numerous local operators that operate quite effectively - both subsidiaries of the Big Three and independent companies.

Operators are actively developing the market, increasing the coverage of their networks and popularizing mobile communications among various segments of the population. If in the mid-1990s a cell phone was available only to representatives of the wealthiest strata of the population, today almost everyone can use mobile communications. Russian operators implement the latest services in their networks and offer services built on their basis, often even outstripping most European companies. Currently, all three federal GSM operators are preparing for the deployment of commercial third-generation networks.

In addition to GSM networks of federal and local cellular operators, networks of other standards continue to operate in Russia: DAMPS, IS-95, NMT-450, DECT and IMT-MC-450. The latter standard has federal status, and networks built on its basis (for example, SkyLink) are developing very actively. However, neither in terms of coverage, nor in terms of the number of subscribers served by networks of all standards other than GSM, they cannot create significant competition for the leading three federal operators.

Literature:

Malyarevsky A., Olevskaya N. Your mobile phone(popular tutorial). M, "Peter", 2004
Zakirov Z.G., Nadeev A.F., Faizullin R.R. Cellular communication of the GSM standard. State of the art, transition to third generation networks("MTS Library"). M., "Eco-Trends", 2004
Popov V.I. GSM Cellular Basics("The Engineering Encyclopedia of the Fuel and Energy Complex"). M., "Eco-Trends", 2005



How radio communication works

Radio (lat.radio- radiate, emit rays, radius- ray) is a type of wireless communication, in which radio waves are used as a signal carrier, freely propagating in space.

Principle of operation
Transmission occurs as follows: on the transmitting side, a signal with the required characteristics (frequency and amplitude of the signal) is generated. The transmitted signal then modulates the higher frequency oscillation (carrier). The received modulated signal is emitted by the antenna into space. On the receiving side, the radio waves induce a modulated signal in the antenna, after which it is demodulated (detected) and filtered by a low-pass filter (thereby getting rid of the high-frequency component - the carrier). The received modulated signal is radiated by the antenna into space.
On the receiving side, the radio waves induce a modulated signal in the antenna, after which it is demodulated (detected) and filtered by a low-pass filter (thereby getting rid of the high-frequency component - the carrier).). Thus, a useful signal is extracted. The received signal may differ slightly from that transmitted by the transmitter (distortion due to interference and interference).

Frequency ranges
The frequency grid used in radio communications is conventionally divided into ranges:

• Long waves (LW) - f = 150-450 kHz (l = 2000-670 m)
• Medium waves (MW) - f = 500-1600 kHz (l = 600-190 m)
• Short waves (HF) - f = 3-30 MHz (l = 100-10 m)
• Ultrashort waves (VHF) - f = 30 MHz- 300 MHz (l = 10-1 m)
• High frequencies (HF-centimeter range) - f = 300 MHz - 3 GHz (l = 1-0.1 m)
• Extremely high frequencies (EHF-millimeter range) - f = 3 GHz - 30 GHz (l = 0.1-0.01 m)
• Hyperhigh frequencies (HHF - micrometer range) - f = 30 GHz - 300 GHz (l = 0.01-0.001 m)

Depending on the range, radio waves have their own characteristics and propagation laws:

• LWs are strongly absorbed by the ionosphere; surface waves, which propagate around the earth, are of primary importance. Their intensity decreases relatively quickly with distance from the transmitter.
• SW are strongly absorbed by the ionosphere during the day, and the area of ​​action is determined by the surface wave, in the evening they are well reflected from the ionosphere and the area of ​​action is determined by the reflected wave.
• HF propagates exclusively through reflection by the ionosphere, so there is a so-called radio silence zone around the transmitter. In the daytime, shorter waves (30 MHz) propagate better, at night, longer ones (3 MHz). Short waves can travel long distances with low transmitter power.
• VHF propagates in a straight line and, as a rule, is not reflected by the ionosphere. They easily bend around obstacles and have a high penetrating power.
• HF does not go around obstacles, spreads within the line of sight. Used in WiFi, cellular, etc.
• EHF does not bend around obstacles, is reflected by most of the obstacles, and spreads within the line of sight. Used for satellite communications.
• Hyper-high frequencies do not bend around obstacles, are reflected like light, and propagate within the line of sight. Limited use.

Propagation of radio waves
Radio waves propagate in emptiness and in the atmosphere; the earthly firmament and water are opaque for them. However, due to the effects of diffraction and reflection, communication is possible between points on the earth's surface that do not have a line of sight (in particular, those located at a great distance).
The propagation of radio waves from a source to a receiver can occur in several ways simultaneously. This spread is called multipath. Due to the multipath and changes in the parameters of the environment, fading occurs - a change in the level of the received signal over time. With multipath, the change in the signal level occurs due to interference, that is, at the point of reception, the electromagnetic field is the sum of time-shifted radio waves of the range.

Radar

Radar- the field of science and technology, combining methods and means of detection, measuring coordinates, as well as determining the properties and characteristics of various objects based on the use of radio waves. A close and somewhat overlapping term is radio navigation, however, in radio navigation, the object whose coordinates are being measured plays a more active role, most often this is the determination of its own coordinates. The main technical device for radar is a radar station.

Distinguish between active, semi-active, active with a passive response and passive RL. They are subdivided according to the used range of radio waves, by the type of the probing signal, the number of channels used, the number and type of measured coordinates, the location of the radar.

Operating principle

Radar is based on the following physical phenomena:

• Radio waves are scattered by electrical inhomogeneities encountered along the path of their propagation (objects with other electrical properties that differ from the properties of the propagation medium). In this case, the reflected wave, as well as the actual radiation of the target, allows you to detect the target.
• At large distances from the radiation source, it can be assumed that radio waves propagate in a straight line and at a constant speed, due to which it is possible to measure the range and angular coordinates of the target (Deviations from these rules, which are valid only in the first approximation, are studied by a special branch of radio engineering - Radio wave propagation. these deviations lead to measurement errors).
• The frequency of the received signal differs from the frequency of the emitted oscillations with the mutual movement of the points of reception and emission (Doppler effect), which allows you to measure the radial speeds of the target relative to the radar.
• Passive radar uses the radiation of electromagnetic waves by the observed objects, it can be thermal radiation inherent to all objects, active radiation generated by the technical means of the object, or spurious radiation created by any objects with working electrical devices.

cellular

cellular, mobile network- one of the types of mobile radio communication, which is based on cellular network. Key feature lies in the fact that the total coverage area is divided into cells (cells), which are determined by the coverage areas of individual base stations (BS). The honeycombs partially overlap and together form a network. On an ideal (even and without building) surface, the coverage area of ​​one BS is a circle, therefore, the network composed of them looks like honeycombs with hexagonal cells (honeycombs).

The network consists of spaced-apart transceivers operating in the same frequency range and switching equipment that allows determining the current location of mobile subscribers and ensuring continuity of communication when a subscriber moves from the coverage area of ​​one transceiver to the coverage area of ​​another.

The principle of cellular communication

The main components of a cellular network are cell phones and base stations, which are usually located on rooftops and towers. When turned on, the cell phone listens to the air, finding a signal from the base station. The telephone then sends its unique identification code to the station. The telephone and the station maintain constant radio contact, periodically exchanging packets. The phone can communicate with the station using an analog protocol (AMPS, NAMPS, NMT-450) or digital (DAMPS, CDMA, GSM, UMTS). If the phone leaves the range of the base station (or the quality of the radio signal of the service cell deteriorates), it establishes communication with another (eng. handover).

Cellular networks can consist of base stations of different standards, which allows you to optimize network performance and improve its coverage.

Cellular networks of different operators are connected to each other, as well as to the fixed telephone network. This allows subscribers of one operator to make calls to subscribers of another operator, from mobile phones to landlines and from landlines to mobiles.

Operators can conclude roaming agreements with each other. Thanks to such agreements, the subscriber, being outside the coverage area of ​​his network, can make and receive calls through the network of another operator. As a rule, this is done at higher rates. The possibility of roaming appeared only in 2G standards and is one of the main differences from 1G networks.

Operators can share network infrastructure, reducing network deployment and operational costs.

Cellular services

Cellular operators provide the following services:

• Voice call;
• Answering machine in cellular communication (service);
• Roaming;
• Caller ID (Automatic Caller ID) and AntiAON;
• Reception and transmission of short text messages (SMS);
• Reception and transmission of multimedia messages - images, melodies, video (MMS-service);
• Mobile bank (service);
• Access to the Internet;
• Video call and video conferencing

A television

A television(Greek τήλε - far away and lat. video- I see; from Novolatinsky televisio- far-sightedness) - a set of devices for transmitting a moving image and sound over a distance. In everyday life, it is also used to designate organizations involved in the production and distribution of television programs.

Basic principles

Television is based on the principle of sequential transmission of picture elements by radio signal or by wire. The decomposition of the image into elements occurs using a Nipkov disk, a cathode-ray tube or a semiconductor matrix. The number of image elements is selected in accordance with the radio channel bandwidth and physiological criteria. To narrow the bandwidth of transmitted frequencies and reduce the visibility of flickering on the TV screen, interlaced scanning is used. It also allows you to increase the smoothness of the transmission of motion.

The television path in general includes the following devices:

1. TV transmission camera. Serves for converting an image obtained with a lens on a target of a transmitting tube or semiconductor matrix into a television video signal.
2. Video recorder. Records and plays back the video signal at the right time.
3. Video mixer. Allows you to switch between multiple image sources: camcorders, VCRs and others.
4. Transmitter. The RF signal is modulated by a television video signal and transmitted by radio or wire.
5. Receiver - TV. With the help of sync pulses contained in the video signal, the television image is reproduced on the receiver screen (kinescope, LCD, plasma panel).

In addition, an audio path similar to a radio transmission path is used to create a television transmission. Sound is transmitted on a separate frequency, usually using frequency modulation, a technique similar to FM radio stations. In digital television, soundtrack, often multichannel, is transmitted in a common data stream with an image.

It is difficult to imagine a person today who can do without a cellular connection. Every day people call each other, send millions of messages, go online using mobile phones. Responsible for the quality of communication, cost and service package cellular operators.

List of telecom operators in Russia

There is no single operator responsible for mobile communications. In Russia, there are more than a hundred operating mobile operators... Some regional providers are subsidiaries of large cellular operators in Russia.

According to statistics, among the leaders among the companies providing mobile services are 3 - the "big three" providers - MTS, Megafon, Beeline. These companies have the largest number of subscribers, the largest coverage area, and a wide range of services.

1. MTS... The only "cellular", which is included in the top 20 of the world leaders. At the end of 2017, it has the largest number of subscribers in Russia (more than 78 million people), and taking into account the CIS countries, the number of subscribers is more than 100 million. It has the most extensive network of communication salons in the country (over 5700 points).
2. Megaphone... There are more than 76 million subscribers in Russia, there is a great demand for Megafon SIM cards in Abkhazia, Tajikistan, South Ossetia. The company positions itself as an operator with the fastest mobile Internet.
3. Beeline... The VimpelCom OJSC brand is one of the first hundred recognizable brands in the world. The number of subscribers in Russia reaches 59 million people, but Beeline is the leader in the number of roaming countries and partners. This allows you to stay connected while traveling and save on roaming services.

The top popular operators include companies that are not included in the 3 "big three", but are in significant competition in terms of popularity. The rating of mobile operators includes smaller companies, both new and regional. The very notion "big three" is becoming obsolete, because other providers are also conquering the market:

• Tinkoff Mobile is one of the newcomers to the communications market, which offers its users many pleasant bonuses: selection of an individual tariff without unnecessary services and pitfalls, nice rooms available roaming. Also, importantly, the operator provides high-quality communication. And the first time you deposit your account, you will receive.
• Tele2. At the end of 2017, this is the only company that has increased the number of subscribers. It has been operating as a federal Russian operator since 2014 after obtaining a license for communication in the 3G format. The operator's audience is at least 40 million people in 65 regions of the country. Most active subscribers are in Moscow and the Moscow region, in St. Petersburg, the Chelyabinsk and Nizhny Novgorod regions. It takes 3rd place in Russia in terms of the number of base stations, it is distinguished by fast mobile Internet due to low network load, as well as affordable package tariffs with the Internet.
• Yota is a virtual mobile operator. The brand has existed since 2008. Works on the technical infrastructure "Megafon". The subscriber base is about 1.5 million people. Until January 2017, the only operator with unlimited access to the mobile Internet, today the tariff line includes only products with a limited traffic volume for smartphones, and for a tablet and a computer there are offers with unlimited internet, the price of which depends on the speed.
• Rostelecom is an Internet provider and a company providing home wired communications and cable television services. The company offers its subscribers cellular communications in the GSM 900/1800 format and mobile Internet.
• Motiv serves only 4 regions in the Urals Federal District. This trademark has existed since 2002. The company provides communication in the formats GPRS / EDGE, IVR, MMS, SMS, USSD, it is not represented in Moscow.
• SMARTS is a Samara company. Communication in Russia is provided to subscribers from the Volga region and the central regions of the country. The list of services includes GPRS, CSD data transmission, communication in GSM-900, GSM-1800 standards, SMS, MMS transmission.

Before making a choice of a mobile operator, each client should outline his own range of preferences and identify the requirements for mobile communications. Each provider is good in its own way, best operator cellular communication can be of regional status, if the package of services that it provides meets the needs of the client.

A list for communication in Russia, a phone code and a comparison of operators will help you to choose the right provider.

Cellular operators map

Telecommunications companies are sensitive to increasing customer requirements. Now it is not only the major players in the telecommunications market that offer high-quality communication coverage. The emergence of new towers makes it possible to provide communication even to the most remote settlements; it is now possible to use a mobile phone in the metro and in high-rise buildings. Operators provide not only high-quality and uninterrupted telephone coverage, but also fast Internet access via 3G and 4G networks.

Each company is fighting to retain existing subscribers and expand its consumer base, therefore, in almost every city there are salons where customers can not only purchase a starter pack, but also receive qualified assistance or answers to their questions.

Each Russian company there is a database of 11-digit numbers, by which you can determine the operator and the regions of the number connection. The possibility of switching from one operator to another, which appeared after the abolition of "mobile slavery", was not used by all subscribers, therefore the table of codes helps to determine where the unknown incoming "came" from.

If the number is registered in Moscow and the Moscow region, then the unknown number of the incoming call is easy to determine:

Beeline does not have a clear link to the region, like other large operators. Individual codes the company has installed only for the Far East and Primorsky Krai. And Yota's numbers are not tied to the region, they all start with the code 999.

In the North-West region and St. Petersburg

Southern Federal District, including the North Caucasus

The tables indicate both codes calculated for all regions, and those that apply only in the specified city, area. But large operators have codes for certain areas, that is, cellular services will be cheaper only if they are used in the home region.

The place of registration of numbers with codes 950, 951, 952 at Tele2 can be Irkutsk region, Khanty-Mansiysk region, Lipetsk region, Kursk region, Perm region, Chelyabinsk region, Kemerovo region, Republic of Buryatia, Republic of Mordovia, Tyumen region and Udmurtia.
Large operators have allocated separate codes for the Urals: 922 - Megafon, 982 - MTS.

What numbers are used by Russian operators

The phone number of any Russian operator starts with 8; to dial in the international format, you need to dial +7. However, within Russia, the call will be equally successful when dialing from eight and from +7.

The international code is followed by the prefix digits - this is the DEF code used in mobile networks. Russian operator prefixes start with 9, i.e. general form the code is always like this: 9xx. For companies providing mobile services, one or more of these codes are allocated. This makes it possible to determine the operator and the region of the caller: 926, 916, 977 - Moscow numbers, and 911, 921 or 981 - St. Petersburg.

For the "mobile troika", a series of codes has been allocated in which the second digits also coincide. For example, 91x or 98x are MTS numbers, and 92x or 93x are Megafon numbers.

The next 7 digits are the subscriber's number, by which it is impossible to determine the belonging to the region of residence or provider. The range of Beeline numbers can suggest belonging to the region if the same prefix is ​​used. Code 905 is used in St. Petersburg (range from 250-00-00 to 289-99-99), as well as in the Ulyanovsk region. (range from 183-00-00 to 184-99-99).

But sometimes only the initial digits of the subscriber's number help to identify the operator. For example, DEF-code 958 is used by more than 20 operators, among which there are small companies (covering 1 region and capacity of 10,000 numbers) and large (several tens of regions and hundreds of thousands of numbers).

As an example: the prefix of TransTelecom's numbers is 7958, but since the company serves 30 regions of the country, you need to know the initial digits of the subscriber's number in order to determine the identity of the outgoing call (-00x-xx-xx - Bashkiria, a -03x-xx-xx - Kaliningrad region, etc.).

The same prefix is ​​used by Gazprom Telecom, Business network Irkutsk ", State Unitary Enterprise" Automatic Telephone Station of Smolny "," Interregional TransitTelecom "," Systematics "," T2 Mobile "," Central Telegraph ", etc.

DEF codes are also renumbered as needed. Moscow MTS numbers were transferred from 495 to 985, and Megafon numbers - from 495 to 925.

The telephone code used only by Megafon is 920. The numbering capacity is over 10 million, and numbers with this code are used in 17 regions of the Russian Federation.

The encoding used by Tele2 is 900. But the same code is used by 16 more Russian operators of different calibers in terms of capacity and coverage of regions - Antares, Arkhangelsk Mobile Networks, Yekaterinburg-2000, Kemerovo Mobile Communications, Sky- 1800 ", etc.

Tele2 is the largest of the companies using the 900 prefix: T2 Mobile comprises 17 regions and 3,140,000 numbers (the region is determined by the digits of the subscriber's number), Tele2-Omsk - 3 regions (Jewish Autonomous Region, Omsk Oblast and Chukotka Autonomous Okrug) and 210,000 numbers, Tele2-Saint Petersburg - 1 million numbers for 4 regions (Vologda Oblast, Karelia, Pskov Oblast, Leningrad Oblast and St. Petersburg).

Best rates

The ratings of companies providing cellular services are compiled not only taking into account the number of subscribers and the size of the coverage area, but also the list of services provided by the company and the tariffs established for each position or the entire package.

Advertising campaigns of four leading providers (MTS, Megafon, Tele2, Beeline) are aimed at attracting subscribers, because TV commercials vying with each other prove that the tariffs of this or that company are the most profitable. Telecom operators' tariffs dynamically reflect the company's strategy, consumer preferences and industry trends. At the same time, archive tariffs also operate in parallel until the subscriber switches to a new price offer.

Budget rates

	MTS, Smart	Megaphone, Get involved! Choose	Beeline, The first gigi	Tele 2, "My conversation"
Cost, rub.)	400	450	405	200
Minutes package	200	300	400	200
Internet (GB)	4	6	4	2

It's not hard to get lost in such a variety, but there is no universal tariff plan. It is more convenient and cheaper for subscribers to purchase a range of services - tariff packages that combine, for example, voice communication, SMS and mobile Internet. In addition to the services included in the package, it is necessary to study the limits for them (GB, free minutes, the number of SMS) and determine the needs of the subscriber (mobile Internet, calls in the home network, roaming, etc.).

For many years now I have been following the latest in mobile technology. Previously, it was my hobby, but now it has grown into a professional blog, where I am happy to share the information I have gained with you. All instructions, life hacks, collections best programs and tariff plans I personally checked it myself.

Cellular communication has recently become so firmly established in our daily life that it is difficult to imagine modern society without it. Like many other great inventions, the mobile phone has greatly influenced our lives, and many of its areas. It is difficult to say what the future would be like if it were not for this convenient form of communication. Probably the same as in the movie "Back to the Future-2", where there are flying cars, hoverboards, and much more, but no cellular connection!

But today in a special report for there will be a story not about the future, but about how modern cellular communication is arranged and works.

In order to learn about the work of modern cellular communication in the 3G / 4G format, I asked to visit the new federal operator Tele2 and spent a whole day with their engineers, who explained to me all the subtleties of data transmission through our mobile phones.

But first, I'll tell you a little about the history of the emergence of cellular communications.

The principles of wireless communication were tested almost 70 years ago - the first public mobile radiotelephone appeared in 1946 in St. Louis, USA. In the Soviet Union, a prototype of a mobile radiotelephone was created in 1957, then scientists from other countries created similar devices with different characteristics, and only in the 70s of the last century in America the modern principles of cellular communication were determined, after which its development began.

Martin Cooper - the inventor of the prototype of the portable cell phone Motorola DynaTAC weighing 1.15 kg and dimensions 22.5x12.5x3.75 cm

If in Western countries, by the mid-90s of the last century, cellular communication was widespread and used by most of the population, then in Russia it only began to appear, and became available to everyone a little over 10 years ago.

Bulky brick-like mobile phones that worked in the formats of the first and second generations went down in history, giving way to smartphones with 3G and 4G, better voice communication and high Internet speed.

Why is the connection called cellular? Because the territory in which communication is provided is divided into separate cells or cells, in the center of which base stations (BS) are located. In each "cell" the subscriber receives the same set of services within certain territorial boundaries. This means that moving from one "cell" to another, the subscriber does not feel territorial attachment and can freely use communication services.

It is very important that there is continuity of the connection when moving. This is ensured by the so-called handover, in which the connection established by the subscriber is, as it were, picked up by neighboring cells on the relay, and the subscriber continues to talk or dig in social networks.

The entire network is divided into two subsystems: a base station subsystem and a switching subsystem. Schematically, it looks like this:

In the middle of the "honeycomb", as mentioned above, there is base station, which usually serves three "cells". The radio signal from the base station is radiated through 3 sector antennas, each of which is directed to its own "cell". It so happens that several antennas of one base station are directed to one "cell" at once. This is due to the fact that the cellular network operates in several bands (900 and 1800 MHz). In addition, this base station may have equipment of several generations of communication (2G and 3G) at once.

But on the towers of BS Tele2 there is only equipment of the third and fourth generation - 3G / 4G, since the company decided to abandon old formats in favor of new ones, which help to avoid interruptions in voice communication and provide more stable internet. Regulars of social networks will support me in the fact that nowadays Internet speed is very important, 100-200 kb / s is no longer enough, as it was a couple of years ago.

The most common location for the BS is a tower or mast built specifically for it. Surely you could see the red and white BS towers somewhere far from residential buildings (in a field, on a hill), or where there are no tall buildings nearby. Like this one that is visible from my window.

However, in urban areas it is difficult to find a place for a massive structure. Therefore, in large cities, base stations are located on buildings. Each station picks up a signal from mobile phones at a distance of up to 35 km.

These are antennas, the BS equipment itself is located in the attic, or in a container on the roof, which is a pair of iron cabinets.

Some base stations are located where you wouldn't even guess. Like on the roof of this parking lot.

The BS antenna consists of several sectors, each of which receives / sends a signal in its own direction. If the vertical antenna communicates with telephones, then the round antenna connects the BS to the controller.

Depending on the characteristics, each sector can handle up to 72 calls simultaneously. The BS can consist of 6 sectors, and serve up to 432 calls, but usually fewer transmitters and sectors are installed at the stations. Cellular operators, such as Tele2, prefer to install more base stations to improve the quality of communication. As I was told, the most modern equipment is used here: Ericsson base stations, transport network - Alcatel Lucent.

From the base station subsystem, the signal is transmitted towards the switching subsystem, where the connection is established with the direction desired by the subscriber. The switching subsystem has a number of databases that store information about subscribers. In addition, this subsystem is responsible for security. To put it simply, the switch performs It has the same functions as the female operators who used to connect you with the subscriber by hand, only now all this happens automatically.

The equipment for this base station is hidden in this iron cabinet.

In addition to conventional towers, there are also mobile versions of base stations placed on trucks. They are very convenient to use during natural disasters or in crowded places (football stadiums, central squares) during holidays, concerts and various events. But, unfortunately, due to problems in the legislation, they have not yet found wide application.

To ensure optimal radio coverage at ground level, base stations are designed in a special way, therefore, despite the range of 35 km. the signal does not apply to aircraft altitude. However, some airlines have already begun installing small base stations on their aircraft to provide cellular communications inside the aircraft. Such a BS connects to a terrestrial cellular network using a satellite link. The system is complemented by a control panel that allows the crew to turn the system on and off, as well as certain types of services, for example, turning off the voice on night flights.

I also looked into the Tele2 office to see how specialists control the quality of cellular communication. If a few years ago such a room would have been hung up to the ceiling with monitors showing network data (congestion, network failures, etc.), then over time the need for such a number of monitors has disappeared.

Technologies have developed greatly over time, and such a small room with several specialists is enough to monitor the operation of the entire network in Moscow.

Few views from the Tele2 office.

At a meeting of the company's employees, plans to capture the capital are discussed) From the beginning of construction until today, Tele2 has managed to cover the whole of Moscow with its network, and is gradually conquering the Moscow region, launching more than 100 base stations weekly. Since I now live in the region, it is very important to me. so that this network comes to my town as quickly as possible.

The company plans for 2016 to provide high-speed communication in the metro at all stations, at the beginning of 2016 Tele2 communication is present at 11 stations: 3G / 4G communication at the Borisovo metro, Delovoy Tsentr, Kotelniki, Lermontovsky Prospekt , Troparevo, Shipilovskaya, Zyablikovo, 3G: Belorusskaya (Koltsevaya), Spartak, Pyatnitskoe shosse, Zhulebino.

As I said above, Tele2 abandoned the GSM format in favor of the third and fourth generation standards - 3G / 4G. This allows the installation of 3G / 4G base stations with a higher frequency (for example, inside the Moscow Ring Road, BSs stand at a distance of about 500 meters from each other) in order to provide more stable communication and high speed mobile internet, which was not in the networks of previous formats.

From the company's office, I, in the company of engineers Nikifor and Vladimir, go to one of the points where they need to measure the communication speed. Nikifor stands opposite one of the masts on which communications equipment is installed. If you look closely, you will notice another such mast a little further on the left, with equipment from other cellular operators.

Oddly enough, but cellular operators often allow their competitors to use their tower structures to accommodate antennas (of course, on mutually beneficial terms). This is because building a tower or mast is expensive and can save you a lot of money!

While we were measuring the speed of communication, Nikifor several times passers-by grandmothers and uncles asked if he was a spy)) "Yes, we are jamming Radio Liberty!).

The equipment actually looks unusual, from its appearance you can assume anything.

The company's specialists have a lot of work, considering that in Moscow and the region the company has more than 7 thousand. base stations: of which about 5 thousand. 3G and about 2 thousand. base stations LTE, and recently the number of BS has increased by about a thousand more.
In just three months, 55% of the total number of new base stations of the operator in the region were put on the air in the Moscow region. At the moment, the company provides high-quality coverage of the territory where more than 90% of the population of Moscow and the Moscow region live.
By the way, in December the 3G Tele2 network was recognized as the best in quality among all metropolitan operators.

But I decided to personally check how good Tele2's connection is, so I bought a SIM card in the nearest shopping center on Voykovskaya metro station, with the simplest "Very black" tariff for 299 rubles (400 sms / minutes and 4 GB). By the way, I had a similar Beeline tariff, which is 100 rubles more expensive.

I checked the speed on the spot. Reception - 6.13 Mbps, transmission - 2.57 Mbps. Considering that I am standing in the center of a shopping center, this is a good result, Tele2 communication penetrates well through the walls of a large shopping center.

At metro Tretyakovskaya. Signal reception - 5.82 Mbps, transmission - 3.22 Mbps.

And at the Krasnogvardeyskaya metro station. Reception - 6.22 Mbps, transmission - 3.77 Mbps. I measured it at the exit from the subway. If you take into account that this is the outskirts of Moscow, it is very decent. I think that the connection is quite acceptable, we can confidently say that it is stable, considering that Tele2 appeared in Moscow just a couple of months ago.

Tele2 has a stable connection in the capital, which is good. I really hope that they will come to the region as soon as possible and I will be able to take full advantage of their connection.

Now you know how cellular communication works!

If you have a production or service that you want to tell our readers about, write to me - Aslan ( [email protected] ) and we will make the best report that will be seen not only by the readers of the community, but also by the site http://ikaketosdelano.ru

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Communication is called mobile if the source of information or its recipient (or both) move in space. Since its inception, radio communication has been mobile. Above, in the third chapter, it is shown that the first radio stations were intended for communication with mobile objects - ships. After all, one of the first radio communication devices A.S. Popov was installed on the battleship "Admiral Apraksin". And it was thanks to radio communication with him that in the winter of 1899-1900 this ship, lost in the ice of the Baltic Sea, was saved. However, in those years, this "mobile communication" required bulky radio transceivers, which did not contribute to the development of much-needed individual radio communication even in the Armed Forces, let alone private clients.

On June 17, 1946, in St. Louis, USA, telephone business leaders AT&T and Southwestern Bell launch the first private radio telephone network. The elementary base of the equipment was tube electronic devices, so the equipment was very bulky and was intended only for installation in cars. The weight of the equipment without power supplies was 40 kg. Despite this, the popularity of mobile communications began to grow rapidly. This created a new, more serious problem than weight and dimensions. An increase in the number of radio facilities, with a limited frequency resource, led to strong mutual interference for radio stations operating on channels close in frequency, which significantly deteriorated the quality of communication. To eliminate mutual interference at repeating frequencies, it was necessary to ensure a minimum of a hundred-kilometer spacing in space between the two groups of radio systems. That is why mobile communications were basically used for the needs of special services. For mass implementation, it was required to change not only the weight and dimensions, but also the very principle of organizing communication.

As noted above, in 1947, a transistor was invented, performing the functions of electronic tubes, but having a much smaller size. It was the appearance of transistors that was of great importance for the further development of radiotelephone communication. The replacement of electronic tubes with transistors created the prerequisites for the widespread introduction of a mobile phone. The main deterrent was the principle of communication organization, which would eliminate or at least reduce the influence of mutual interference.

Studies of the ultrashort wavelength range of waves, carried out in the 40s of the last century, made it possible to reveal its main advantage over short waves- broadband, that is, high frequency capacity and the main disadvantage - strong absorption of radio waves by the propagation medium. Radio waves in this range are not able to bend around the earth's surface, therefore, the communication range was provided only on the line of sight, and, depending on the transmitter power, a maximum of 40 km was provided. This disadvantage soon turned into an advantage that gave impetus to the active mass adoption of cellular telephony.

In 1947, D. Ring, an employee of the American company Bell Laboratories, proposed a new idea for organizing communications. It consisted in dividing space (territory) into small sections - cells (or cells) with a radius of 1–5 kilometers and in separating radio communication within one cell (by rational repetition of the communication frequencies used) from communication between cells. Frequency repetition has significantly reduced frequency resource utilization problems. This made it possible to use the same frequencies in different cells distributed in space. In the center of each cell, it was proposed to locate a base receiving and transmitting radio station, which provided radio communication within the cell with all subscribers. The dimensions of the cell were determined by the maximum communication range of the radiotelephone apparatus with the base station. This maximum range is called the cell radius. During the conversation, the cellular radiotelephone is connected to the base station by a radio channel, through which the telephone conversation is transmitted. Each subscriber must have his own micro-radio station - "mobile phone" - a combination of a telephone, a transceiver and a mini-computer. Subscribers communicate with each other through base stations that are connected to each other and to the public telephone network.

To ensure uninterrupted communication when a subscriber moves from one zone to another, it was necessary to use computer control over the telephone signal emitted by the subscriber. It was computer control that made it possible to switch a mobile phone from one intermediate transmitter to another within just a thousandth of a second. Everything happens so quickly that the subscriber simply does not notice it. Thus, computers are the central part of a mobile communication system. They search for a subscriber in any of the cells and connect him to the telephone network. When a subscriber moves from one cell (cell) to another, computers seem to transfer the subscriber from one base station to another and connect the subscriber of the "foreign" cellular network to "their" network. This happens at the moment when the "stranger" subscriber is in the coverage area of ​​the new base station. Thus, roaming is carried out (which in English means "wandering" or "vagrancy").

As noted above, the principles of modern mobile communications were an achievement already at the end of the 40s. However, in those days, computer technology was still at such a level that its commercial use in telephone communication systems was difficult. Therefore, the practical application of cellular communication became possible only after the invention of microprocessors and integrated semiconductor microcircuits.

First cell telephone set the prototype of the modern device was designed by Martin Cooper (Motorola, USA).

1973 in New York, on top of a 50-story building by Motorola, under his leadership, the world's first cellular base station was installed. She could serve no more than 30 subscribers and connect them to land lines.

On April 3, 1973, Martin Cooper dialed his boss's number and said the following words: “Imagine, Joel, that I call you from the world's first cell phone. I have it in my hands, and I am walking along New York Street. "

The phone Martin called from was called Dyna-Tac. Its dimensions were 225 × 125 × 375 mm, and its weight was a little no less than 1.15 kg, which, however, is much less than the 30 kilogram devices of the late forties. With the help of the device it was possible to call and receive a signal, to negotiate with a subscriber. This phone had 12 keys, of which 10 were digital for dialing the subscriber's number, and the other two provided the start of a conversation and interrupted the call. Dyna-Tac batteries allowed for about half an hour of talk time, and it took 10 hours to charge them.

Although most of the development took place in the United States, the first commercial cellular network was launched in May 1978 in Bahrain. Two cells with 20 channels in the 400 MHz band served 250 subscribers.

A little later, cellular communication began its triumphant march around the world. More and more countries understood the benefits and convenience that it could bring. However, the lack of a single international standard for the use of the frequency range, over time, led to the fact that the owner of a cell phone, moving from one state to another, could not use a mobile phone.

In order to eliminate this major deficiency, since the late seventies Sweden, Finland, Iceland, Denmark and Norway have started joint research to develop a single standard. The result of the research was the NMT-450 (Nordic Mobile Telephone) communication standard, which was intended to operate in the 450 MHz range. This standard was first used in 1981 in Saudi Arabia, and only a month later in Europe. Various versions of the NMT-450 have been adopted in Austria, Switzerland, Holland, Belgium, Southeast Asia and the Middle East.

In 1983, the AMPS (Advanced Mobile Phone Service) network was launched in Chicago, which was developed by Bell Laboratories. In 1985, in England, the TACS (Total Access Communications System) standard was adopted, which was a kind of American AMPS. Two years later, due to a sharp increase in the number of subscribers, the HTACS (Enhanced TACS) standard was adopted, adding new frequencies and partially correcting the shortcomings of its predecessor. France, on the other hand, stood apart from everyone else and began using its own Radiocom-2000 standard since 1985.

The next was the NMT-900 standard, using the frequencies of the 900 MHz range. A new version began to be applied in 1986. It allowed to increase the number of subscribers and improve the stability of the system.

However, all of these standards are analog and belong to the first generation of cellular communication systems. They use an analog method of transmitting information using frequency (FM) or phase (PM) modulation - as in conventional radio stations. This method has a number of significant disadvantages, the main of which are the ability to listen to conversations by other subscribers and the impossibility of combating signal fading when the subscriber moves, as well as under the influence of the terrain and buildings. The congestion of the frequency bands caused interference in conversations. Therefore, by the end of the 1980s, the creation of the second generation of cellular communication systems based on digital signal processing methods began.

Previously, in 1982, the European Conference of the Administrations of Posts and Telecommunications (CEPT), uniting 26 countries, decided to create a special group Groupe Special Mobile. Its goal was to develop a single European standard for digital cellular communications. The new communication standard took eight years to develop, and was first announced only in 1990, when the specifications of the standard were proposed. The special group initially decided to use the 900 MHz band as a single standard, and then, taking into account the prospects for the development of cellular communications in Europe and around the world, it was decided to allocate the 1800 MHz band for the new standard.

The new standard was named GSM - Global System for Mobile Communications. GSM 1800 MHz is also called DCS-1800 (Digital Cellular System 1800). The GSM standard is a digital standard for cellular communications. It implements time division multiplexing (TDMA - time division multiple access, message encryption, block coding, and GMSK modulation) (Gaussian Minimum Shift Keying).

The first state to launch a GSM network is Finland, which launched this standard into commercial operation in 1992. The following year, the first DCS-1800 One-2-One network was launched in the UK. From this moment on, the global spread of the GSM standard all over the world begins.

The next step after GSM is the CDMA standard, which provides faster and more reliable communication due to the use of code division. This standard began to emerge in the United States in 1990. In 1993, the United States began to use CDMA (or IS-95) in the 800 MHz frequency range. At the same time, the DCS-1800 One-2-One network was launched in England.

In general, there were many communication standards, and by the mid-nineties most of the civilized countries were smoothly moving to digital specifications. Whereas the first generation networks allowed only voice to be transmitted, the second generation of cellular communication systems, which is GSM, allow providing other non-voice services as well. In addition to the SMS service, the first GSM phones allowed for the transmission of other non-voice data. For this, a data transfer protocol was developed, called CSD (Circuit Switched Data). However, this standard had very modest characteristics - the maximum data transfer rate was only 9600 bits per second, and then on condition of stable communication. However, such speeds were quite enough for the transmission of a facsimile message.

The rapid development of the Internet in the late 90s led to the fact that many cellular users wanted to use their handsets as modems, and the existing speeds were clearly not enough for this.
In order to somehow satisfy the need of their customers for access to the Internet, engineers invent the WAP protocol. WAP is an abbreviation for Wireless Application Protocol, which translates to wireless application access protocol. In principle, WAP can be called a simplified version of the standard Internet protocol HTTP, only adapted for the limited resources of mobile phones, such as small display sizes, low performance of telephone processors and low data transfer rates in mobile networks... However, this protocol did not allow standard Internet pages to be viewed; they had to be written in WML, which was adapted for cell phones. As a result, although subscribers of cellular networks got access to the Internet, it turned out to be very "cut down" and of little interest. Plus, to access WAP sites, the same communication channel was used as for voice transmission, that is, while you are downloading or viewing the page, the communication channel is busy, and the same money is debited from the personal account as during the conversation. As a result, quite an interesting technology was practically buried for some time and was used by subscribers of cellular networks. different operators very rare.
Cellular equipment manufacturers urgently had to look for ways to increase the data transfer rate, and as a result, HSCSD (High-Speed ​​Circuit Switched Data) technology was born, which provided quite acceptable speed - up to 43 kilobits per second. This technology was popular with a certain circle of users. But still, this technology did not lose the main drawback of its predecessor - data was still transmitted via a voice channel. The developers again had to do painstaking research. The efforts of engineers were not in vain, and quite recently a technology called GPRS (General Packed Radio Services) appeared - this name can be translated as a packet radio data transmission system. This technology uses the principle of channel separation for voice and data transmission. As a result, the subscriber pays not for the duration of the connection, but only for the amount of transmitted and received data. In addition, GPRS has another advantage over earlier technologies for mobile data transmission - during the GPRS connection, the phone is still able to receive calls and SMS messages. On the this moment modern phone models on the market, when making a call, suspend the GPRS connection, which is automatically resumed at the end of the call. Such devices are classified as a class B GPRS terminal. It is planned to manufacture class A terminals, which will simultaneously download data and conduct a conversation with an interlocutor. There are also special devices that are designed only for data transmission, and they are called GPRS modems or class C terminals. In theory, GPRS is capable of transmitting data at a speed of 115 kilobits per second, but at the moment most telecom operators provide a communication channel that allows you to develop speed up to 48 kilobits per second. This is primarily due to the equipment of the operators themselves and, as a consequence, the lack of cell phones on the market that support higher speeds.

With the advent of GPRS, they again remembered the WAP protocol, since now, with the help of new technology, access to small-volume WAP-pages becomes many times cheaper than in the days of CSD and HSCSD. Moreover, many telecom operators provide unlimited access to WAP network resources for a small monthly subscription fee.
With the advent of GPRS, cellular networks have ceased to be called second generation networks - 2G. We are currently in the 2.5G era. Non-voice services are becoming more and more in demand, the cell phone, computer and the Internet are merging. Developers and operators are offering us more and more different value-added services.
So, using the capabilities of GPRS, a new messaging format was created, which was called MMS (Multimedia Messaging Service), which, unlike SMS, allows you to send from a cell phone not only text, but also various multimedia information, for example, sound recordings, photos and even video clips. Moreover, an MMS message can be sent either to another phone that supports this format, or to an e-mail box.
Increased processor power of phones now allows you to download and run on it various programs... To write them, the Java2ME language is most often used. Owners of most modern phones now have no difficulty in connecting to the Java2ME application developers site and downloading to their phone, for example, new game or another required program. Also, no one will be surprised by the ability to connect the phone to personal computer, in order to use a special software most often supplied with the handset, save or edit on a PC address book or organizer; while on the road, using a combination of mobile phone + laptop, go to the full Internet and view your email... However, our needs are constantly growing, the volume of transmitted information is growing almost daily. And more and more demands are being made on cell phones, as a result of which the resources of current technologies are becoming insufficient to meet our growing demands.

It is to address these requests that the fairly recently created third-generation 3G networks, in which data transmission dominates over voice services, are intended. 3G is not a communication standard, but a general name for all high-speed cellular networks that will grow and are already growing out of the existing ones. Huge data transfer rates allow you to transfer high-quality video images directly to your phone, maintain a constant connection to the Internet and local networks. The use of new, improved security systems allows today to use the phone for various financial transactions - a mobile phone is quite capable of replacing a credit card.

It is quite natural that third-generation networks will not become the final stage in the development of cellular communications - as they say, progress is inexorable. The ongoing integration of various types of communication (cellular, satellite, television, etc.), the emergence of hybrid devices, including a cell phone, PDA, video camera, will certainly lead to the emergence of 4G, 5G networks. And today, even science fiction writers are unlikely to be able to tell about how this evolutionary development will end.

Globally, about 2 billion mobile phones are currently in use, of which more than two thirds are connected to the GSM standard. CDMA is the second most popular, while the rest represent specific standards used mainly in Asia. Now in developed countries there is a situation of "satiety" when demand stops growing.