This is interesting! The cartoonist Lewis Baumer was ahead of the scientist-inventors. Punch magazine (1906) published people walking around Hyde Park using portable models phones. The story was titled “Expectations 1907.”

Telephones developed in parallel with broadcasting and communications. The first attempt to create a wireless model was made (1908) by joint efforts:

• Professor Albert Jankla.
• Oakland Transcontinental Telephone Company.
• Power Company.

Railways

Mass production of portable radios failed. Since 1918, the Berlin-Zossen section of the German railways has been testing cordless phones. Six years later the Berlin-Hamburg line provided private passengers with a similar service. 1925 is considered the starting point of industrial manufacturing. Now first class passengers can make calls while enjoying the delights of travel.

The first portable radios of the 40s weighed a fair amount, more like a large backpack. The USA (St. Louis, Missouri) began development of commercial prototypes on June 17, 1946. Soon, AT&T announced Mobile Telephone Service (MTS). Several disparate local operators were born at once.

Moscow speaks!

Soviet engineer Leonid Kupriyanovich (1957-1961) presented the first copies of the devices. The weight of the model was 70 g, allowing the body to be grasped in the palm of your hand. The government, noticing the efforts of the Muscovite, gave priority to the development of the automobile version of the Altai, designed to improve the difficult life of managers. Equipment designed by Voronezh scientific institute communications included MRT-1327, trial version swept the capital (1963). As of 1970, 30 cities received communication opportunities. A type of radio communication exists to this day in Russia.

The capital's exhibition Inforga-65 presented the work of the Bulgarian company Radioelectronics. The idea is still used today: dividing the transceiver equipment. The base station does the heavy lifting; the relatively small handset allows the subscriber to talk within a limited area. The design used Kupriyanovich's ideas. One base served as a support point for a maximum of 15 subscribers. 1966 was marked by the release of a commercial version of RAT-0.5, served by the RATZ-10 access point.

Mobile telephony directly derives from the 0G standard used by the nascent company MTS.

First operator

So, starting in 1949, the Mobile telephone service began operating. Initially (1946), prior to the formation of the division, AT&T began to equip the vast expanses of the United States. A couple of years later, thousands of cities and high-speed highways received the benefits of civilization. However, the number of subscribers was 5000. 30,000 calls were made weekly. There was manual switching of channels by an operator. The weight of the speaker's equipment was 80 pounds.

Initially, the company provided three frequency channels, allowing three subscribers in the city to simultaneously talk. Price:

1. $15 monthly.
2. 30-40 cents per call. Taking into account inflation, a modern subscriber will pay $3.5-4.75.

A similar service in the UK was called the Radiophone Service post offices. In 1959, the web covered the outskirts of Manchester, six years later the web enveloped London. This was followed by the connection of the main cities of the kingdom. The operators gradually increased the speed of stomping on the spot. IMTS added more frequency channels, simultaneously reducing the initial 35 kg of equipment weight. The total number of US subscribers reached 40,000. Two thousand New Yorkers shared 12 channels. Those wishing to make a call had to wait half an hour.

RCC

Radio Common Carrier is considered the main competitor of MTS. The service successfully clogged the airwaves for 20 years (60-80s). The emerging AMPS systems made the company's equipment obsolete. There was no concept of roaming due to incompatible standards:

1. Two-tone sequential pagination of an incoming call.
2. Tone set.
3. Secode 2805 (2.805 kHz calling tone, reminiscent of the operating principle of MTS equipment).

Some phones used half-duplex mode (Motorola LOMO), others were more like walkie-talkies (700 RCA series). Omaha's cell phone was becoming a pile of iron in Arizona. RCC was ignored technical progress, while competitors were developing roaming concepts.

Beginning in 1969, the Penn Central Railroad equipped New York–Washington Line trains with mobile radios. The system received 6 channels of the UHF 450 MHz range. The British Rabbit system developed the concept of Bulgarian scientists. The maximum subscriber-base station range was 300 feet (100 meters). Now a similar technology using 4G has been launched by Apple.

List of significant cellular operators of the second half of the 20th century

1. Norwegian OLT (1966).
2. Finnish ARP (1971). First commercially successful project. Researchers call the company's equipment 0G.
3. Swedish MTD (70s).
4. British Radicoll (July 1971).
5. German A-Netz (1952), B-Netz (1972).

The Swedish automobile MTA (1956), designed by Sture Lauren (Televerket) used pulse dialing. Outgoing calls were direct, the nearest incoming station was selected by the operator. Prefabricated equipment:

• Ericsson switches.
• Devices, base stations Radioaktibolaget (SRA) and Marconi.

The belly of the case is full of relays, vacuum tubes, weight is 40 kg. 1962 brought relief with the introduction of the second generation of B services. Transistors reduced weight, DTMF signaling relieved resources. 1971 marked the advent of MTD. The resource existed for 12 years, leaving 600 subscribers orphaned.

Development of the cellular communication concept

Second World War ended with a complete lack of standards, frequencies, and dedicated channels. In the cold December of 1947, Douglas Ring, Rae Young, and Bell Labs engineers came up with the idea of ​​the cellular cell. Two decades later, Richard Fraenkel, Joel Engel, and Philip Porter developed the concept further by developing a detailed plan. Porter emphasized the need for towers equipped with directional antennas. The dedicated main lobe sharply reduced the level of interference. Porter pioneered the concept of providing resources on demand, reducing collisions.

Early experiments excluded the possibility of promptly changing cells. The principles of frequency reuse, handover, and the foundations of modern communications were laid in the 60s. Bell Labs engineers Amos and Joel Jr. invented three-way networks in 1970, simplifying the handover process. The subscriber switching plan was discussed (1973) by Fluhr and Nussbaum, the signaling system by Hachenburg.

Predecessors mostly flaunted equipment designed to please transport workers. On April 3, 1973, Marty Cooper (Motorola, USA) designed the first manual version, immediately calling competitor Dr. Joel Engel (Bell Labs). The weight of the device, 23 cm long, 13 cm wide, and 4.45 cm thick, was 1.1 kg. The battery took 10 hours to charge, providing 30 minutes of full communication. Cooper's boss played a key role in attracting the attention of Motorola management.

Generations of communication

The development of the industry proceeded in pronounced waves. The term generation caught up with the race at the 3G stage. Now the word is used retrospectively, reviewing past achievements.

1G – analog cells

The concept was launched (1979) by the Japanese Nippon Telegraph and Telephone Company (NTT), covering metropolitan Tokyo. Having fulfilled the five-year plan, the engineers covered the islands of the archipelago with a net. 1981 is considered the year of birth of the Danish, Finnish, Norwegian, Swedish NMT communication systems. A single standard helped implement international roaming. The USA waited 2 years, seeing European successes. Then the Chicago provider Ameritech, using Motorola devices, began to capture the market. Similar steps followed from Mexico, Canada, Great Britain, and Russia.

North America (October 13, 1983 - 2008), Australia (February 28, 1986, Telecom), Canada widely used AMPS; UK – TACS; West Germany, Portugal, South Africa – S-450; France – Radiocom 2000; Spain – TMA; Italy – RTMI. The Japanese produced standards incredibly quickly: TZ-801, TZ-802, TZ-803. Competitor NTT created the JTACS system.

The standard includes a digital call to the station, but the transmission of information is completely analog (modulated UHF signal above 150 MHz). Encryption was completely absent, filling the pockets of private detectives with coins. Frequency division of channels left room for illegal cloning of devices.

On March 6, 1983, the development of the DynaTAC 8000X Ameritech mobile phone was launched, costing the company a fortune. For a whole decade, the device struggled to reach store shelves. The list of people willing to subscribe numbered in the thousands, despite obvious shortcomings:

• Battery life.
• Dimensions.
• Fast discharge.

The phone generation was later successfully upgraded, providing an upgrade to the 2G generation.

2G – digital communication

The emergence of the second stage of development marked the beginning of the 90s. Two main competitors immediately emerged:

1. European GSM.
2. American CDMA.

Key differences:

1. Digital transmission of information.
2. Out-of-band telephone tower calling.

The 2G era is called the era of custom phones. There are too many buyers; the manufacturer collected lists of those interested in advance. Finland was the first to launch the Radioliniya network. European frequencies are historically higher than US frequencies, with some 1G and 2G (900 MHz) bands overlapping. Outdated systems were quickly shut down. The American IS-54 captured the former AMPS resources.

IBM Simon is considered to be the first smartphone: mobile phone, pager, fax, PDA. The software interface provided a calendar, address book, clock, calculator, notepad, email, the option to predict the next symbol like T9. The touchscreen provided control of the QWERTY keyboard. The kit included a stylus. A 1.8 MB PCMCIA memory card expanded the functionality.

There has been a tendency to minimize devices. The bricks began to weigh 100-200 g. SMS messages were first appreciated by the public. The first (automatically generated) GSM text was sent on December 2, 1992, and was tested by people in 1993. The batch prepayment method soon made SMS communication a popular pastime for young people. Later, the passion spread to older generations.

The year 1998 was marked by the appearance of the mobile payment service (Coca-Cola machines, parking lots) and the release of paid media content: the provider Radioliniya (now Eliza) sold the first ringtone. Initially, news subscriptions (2000) were distributed free of charge, the service was paid for by advertising contributions from sponsors. Secure client-bank access appeared (1999, Philippines), supported by Globe and Smart operators. At the same time, the Japanese NTT DoCoMo implemented telephone Internet.

3G

The 2G generation ended in total victory mobile technologies. The daily lives of billions have become filled with challenges. An innovative idea designed to increase data transfer speeds was packet switching (instead of circuit switching). The developers let go of the reins to manufacturers, concentrating entirely on consumer qualities. What was done was a consequence of the introduction of a host of standards. Compatible CDMA introduced several improvements:

1. Reduced connection setup time.
2. Increased packet speed (3.1 Mbps).
3. QoS flags.
4. Simultaneous use of a time slot by several subscribers.

The first 3G WCDMA network (May 2001, commercial use starting October 1) covered Tokyo. South Korean competitors (KTF, SK Telecom) were waiting for 2002. CDMA2000 1xEV-DO technology reached the shores of the United States, and the operator Coin managed to go bankrupt. At the same time, Japan acquired a second set of honeycombs, thanks to Vodafone. Worldwide implementation of the technology followed.

At the same time, intermediate stages of systems formation appeared - 2.5; 2.75G, for example GPRS. These means provided part of the 3G requirements, leaving out others: CDMA2000-1X is theoretically capable of providing 307 kbit/s. Next comes EDGE technology, nominally corresponding to 3G. Almost maximum thresholds are unattainable due to interference.

Gradually, television and radio companies realized the possibilities of wireless digital broadcasting. The first birds to fly were Disney and RealNetworks broadcasts. Evolution introduced the world to HSDPA (High Speed ​​Downstream Packet Access), an improved version of HSPA. The standard was recognized as 3.5G, marketers happily used the abbreviation 3G+. Current version supports data download speeds of 1.8; 3.6; 7.2; 14 Mbit/s. At the end of 2007, a total of 295 million subscribers operated networks everywhere, accounting for 9% of global demand for communications services. Superprofits ($120 billion) forced phone manufacturers to immediately modernize their production pipeline: adapters, PC set-top boxes.

4G

The results of 2009 dispassionately showed: a new generational change is coming, caused by the growing demands of the public. They began to search for technologies that increase transmission speeds tenfold. The first signs are WiMAX and LTE technologies.

The infection spread across Scandinavia with lightning speed, thanks to the efforts of TeliaSoner. Network switching has been permanently removed and replaced with IP addressing. ITU standardizes (March 2008) areas:

1. Gaming applications.
2. IP telephony.
3. Internet.
4. HDTV.
5. Video conferencing.
6. 3D broadcasts.

Set speeds:

1. 100 Mbit/s – mobile objects (transport).
2. 1 Gbps – typical mobile applications.

Considering the above, the belonging of communication types LTE and WiMAX to 4G is doubtful. Experts stated that it is fundamentally impossible for technology to achieve established bar. LTE-A nominally touched the milestone, failing field tests. Engineers are pinning their hopes on the WirelessMAN-Advanced being developed. The situation is the same everywhere: the engineer works, the marketer boasts. This is how the world works.

Operating principle

Cellular networks exploit the ideas of media access control (MAC). Complete analogue of the wired version. Data is multiplexed, saving resources. The physical environment determines the specific protocol design. The radio signal changes due to optical effects, weather conditions, time of day, and year. The reception quality is constantly fluctuating. The obvious solution is to increase the power, but this measure also increases the interference phenomenon. The number of errors is growing. Approximate ratios:

1. Wired network – the number of errors is less than a millionth.
2. Cellular communications - the number of incorrect packets is over a thousandth.

The difference exceeds three orders of magnitude. Terminals have to use half-duplex mode. The energy of the transmitted packet is much higher than the received signal. Features of the circuitry allow interference. The leakage of so much power into the reception path of a full-duplex device interferes with the decryption of packets.

Controlled Access Scheme

An operations controller is appointed to coordinate the distribution of resources. More often the role is played by a tower, an access point. The terminal executes a pre-programmed program for allocating channels, frequencies, time slots, and antennas. No conflicts are guaranteed.

1. TDMA. Time division.
2. FDMA. Division by frequency.
3. OFDMA. Orthogonal frequency access.
4. SDMA. Spatial division.
5. Poll.
6. Token Ring.

Dynamic resource allocation brings undeniable benefits to heavily loaded networks. Because free access protocols spend the lion's share of time preventing collisions. The terminal checks the activity of subscribers one by one, using random number algorithms, providing slots for those wishing to transmit information.

Mobile cellular

cellular- one of the types of mobile radio communications, which is based on cellular network. Key Feature lies in the fact that the total coverage area is divided into cells (cells), determined by the coverage areas of individual base stations (BS). The cells partially overlap and together form a network. On an ideal (flat and undeveloped) surface, the coverage area of ​​one BS is a circle, so the network made up of them looks like a honeycomb with hexagonal cells (honeycombs).

It is noteworthy that in the English version the connection is called “cellular” or “cellular” (cellular), which does not take into account the hexagonal nature of the honeycomb.

The network consists of spatially separated transceivers operating in the same frequency range, and switching equipment that allows you to determine the current location of mobile subscribers and ensure continuity of communication when a subscriber moves from the coverage area of ​​one transceiver to the coverage area of ​​another.

Story

The first use of mobile telephone radio in the United States dates back to 1921: Detroit police used one-way dispatch communications in the 2 MHz band to transmit information from a central transmitter to vehicle-mounted receivers. In 1933, the NYPD began using a two-way mobile telephone radio system, also in the 2 MHz band. In 1934, the US Federal Communications Commission allocated 4 channels for telephone radio communications in the range of 30...40 MHz, and in 1940 about 10 thousand police vehicles were already using telephone radio communications. All of these systems used amplitude modulation. Frequency modulation began to be used in 1940 and by 1946 it had completely replaced amplitude modulation. The first public mobile radiotelephone appeared in 1946 (St. Louis, USA; Bell Telephone Laboratories), it used the 150 MHz band. In 1955, an 11-channel system began operating in the 150 MHz band, and in 1956, a 12-channel system in the 450 MHz band began operating. Both of these systems were simplex and used manual switching. Automatic duplex systems began operating in 1964 (150 MHz) and 1969 (450 MHz), respectively.

In the USSR In 1957, Moscow engineer L.I. Kupriyanovich created a prototype of a portable automatic duplex mobile radiotelephone LK-1 and a base station for it. The mobile radiotelephone weighed about three kilograms and had a range of 20-30 km. In 1958, Kupriyanovich created improved models of the device, weighing 0.5 kg and the size of a cigarette box. In the 60s, Hristo Bochvarov demonstrated his prototype of a pocket mobile radiotelephone in Bulgaria. At the Interorgtekhnika-66 exhibition, Bulgaria is presenting a kit for organizing local mobile communications from pocket mobile phones RAT-0.5 and ATRT-0.5 and a base station RATC-10, providing connection for 10 subscribers.

At the end of the 50s, the development of the Altai car radiotelephone system began in the USSR, which was put into trial operation in 1963. The Altai system initially operated at a frequency of 150 MHz. In 1970, the Altai system operated in 30 cities of the USSR and the 330 MHz range was allocated for it.

In a similar way, with natural differences and on a smaller scale, the situation developed in other countries. Thus, in Norway, public telephone radio has been used for maritime mobile communications since 1931; in 1955 there were 27 coast radio stations in the country. Ground mobile connection began to develop after the Second World War in the form of private networks with manual switching. Thus, by 1970, mobile telephone radio communications, on the one hand, had already become quite widespread, but on the other, it clearly could not keep up with the rapidly growing needs, with a limited number of channels in strictly defined frequency bands. A solution was found in the form of a cellular communication system, which made it possible to dramatically increase capacity by reusing frequencies in a system with a cellular structure.

Of course, as usually happens in life, certain elements of the cellular communication system existed before. In particular, some similarity cellular system used in 1949 in Detroit (USA) by a taxi dispatch service - with the reuse of frequencies in different cells when users manually switch channels at predetermined locations. However, the architecture of the system that is today known as the cellular communications system was outlined only in a technical report from the Bell System, submitted to the US Federal Communications Commission in December 1971. And from that time on, the development of cellular communications itself began, which became truly triumphant in 1985 g., in the last ten years or so.

In 1974, the US Federal Communications Commission decided to allocate a frequency band of 40 MHz in the 800 MHz band for cellular communications; in 1986 another 10 MHz was added in the same range. In 1978, tests of the first experimental cellular communication system for 2 thousand subscribers began in Chicago. Therefore, 1978 can be considered the year of the beginning practical application cellular communications. The first automated commercial cellular telephone system was also introduced in Chicago in October 1983 by American Telephone and Telegraph (AT&T). In Canada, cellular communications have been used since 1978, in Japan - since 1979, in the Scandinavian countries (Denmark, Norway, Sweden, Finland) - since 1981, in Spain and England - since 1982. As of July 1997 cellular communications operated in more than 140 countries on all continents, serving more than 150 million subscribers.

The first commercially successful cellular network was the Finnish Autoradiopuhelin (ARP) network. This name is translated into Russian as “Car radiotelephone”. Launched in the city, it reached 100% coverage of the territory of Finland in. The size of the cell was about 30 km, and there were more than 30 thousand subscribers in the city. It worked at a frequency of 150 MHz.

Operating principle of cellular communication

The main components of a cellular network are cell phones and base stations. Base stations are usually located on the roofs of buildings and towers. When turned on, the cell phone listens to the airwaves, finding a signal from the base station. The phone then sends its unique identification code to the station. The telephone and the station maintain constant radio contact, periodically exchanging packets. Communication between the phone and the station can be via an analog protocol (NMT-450) or digital (DAMPS, GSM, English). handover).

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

The cellular networks of different operators are connected to each other, as well as to the landline 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 in different countries can enter into roaming agreements. Thanks to such agreements, a subscriber, while abroad, can make and receive calls through the network of another operator (albeit at higher rates).

Cellular communications in Russia

In Russia, cellular communications began to be introduced in 1990, commercial use began on September 9, 1991, when the first cellular network in Russia was launched in St. Petersburg by Delta Telecom (operating in the NMT-450 standard) and the first symbolic cell phone call by the mayor of St. Petersburg Anatoly Sobchak. By July 1997, the total number of subscribers in Russia was about 300 thousand. As of 2007, the main cellular communication protocols used in Russia are GSM-900 and GSM-1800. In addition, UMTS also works. In particular, the first fragment of a network of this standard in Russia was put into operation on October 2, 2007 in St. Petersburg by MegaFon. In the Sverdlovsk region, the cellular communication network of the DAMPS standard continues to be used, company-owned Cellular Communications "MOTIV".

In Russia in December 2008, there were 187.8 million cellular users (based on the number of SIM cards sold). The penetration rate of cellular communications (the number of SIM cards per 100 inhabitants) on this date was thus 129.4%. In the regions, excluding Moscow, the penetration level exceeded 119.7%.

The market share of the largest mobile operators as of December 2008 was: 34.4% for MTS, 25.4% for VimpelCom and 23.0% for MegaFon.

In December 2007, the number of cellular users in Russia increased to 172.87 million subscribers, in Moscow - to 29.9, in St. Petersburg - to 9.7 million. Penetration level in Russia - up to 119.1%, Moscow - 176% , St. Petersburg - 153%. The market share of the largest cellular operators as of December 2007 was: MTS 30.9%, VimpelCom 29.2%, MegaFon 19.9%, other operators 20%.

According to data from the British research company Informa Telecoms & Media for 2006, the average cost of a minute of cellular communication for a consumer in Russia was $0.05 - this is the lowest among the G8 countries.

IDC based on research Russian market cellular communications concluded that in 2005, the total duration of calls on a cell phone by residents of the Russian Federation reached 155 billion minutes, and text messages 15 billion units were shipped.

According to a study by J"son & Partners, the number of SIM cards registered in Russia as of the end of November 2008 reached 183.8 million.

see also

Sources

Links

• Information site about generations and standards of cellular communications.
• Cellular communications in Russia 2002-2007, official statistics

cellular in Russia
Cellular operators	Utel Akos Altaisvyaz Baikalwestcom Beeline ETK MegaFon Motive MTS NSS NTK SMARTS Sky Link Sonet Sotel SSB STEC GSM TomskTeleCom UUSS Digital expansion‎
Cell phone sales networks	Divizion Symphony AltTelecom Banzai Betalink Euroset ION Svyaznoy Spectrum Communication Telephone.Ru Teleforum Tochka Ultra Digital City Eldorado
Cellular standards	D-AMPS GSM IMT-MC-450 IS-95

In this article we will tell you about the history of the emergence of mobile communications.

The first radiotelephone communication system appeared in 1946 in the USA - St. Louis. Radiotelephones operated on fixed frequencies and were switched manually. In the Soviet Union, radiotelephone communications appeared in 1959 and were called the Altai system. Naturally, it was not publicly accessible, but was used as government communications and by intelligence agencies. In 1990-1994, during the collapse of the USSR, a large mass of classified developments, including the development of multi-frequency, multi-base radiotelephone communications, were exported “free” from Soviet research institutes outside the cordon. And in 1991 in the USA, and subsequently in Russian Federation appeared new standard radiotelephone – cellular communication NMT-450 (“Sotel”). An analog signal was used. Subsequently, digital standards appeared - GSM-900 and GSM-1800.

With the progressive development of cellular communications, mobile telephones have become widely available. As a rule, a mobile telephone unit (hereinafter referred to as MTA) can operate at a distance of up to 1500 m from the base station.

As you know, each cellular device is assigned its own electronic serial number(ESN), which is encoded into the phone's microchip when the phone is manufactured. By activating the SIM card (Subscriber Identity Module) - a microchip in which the subscriber number is “stitched”, the mobile telephone device receives a mobile identification number (MIN).

Area covered GSM network(Global System for Mobile communications), is divided into separate, adjacent cells (cells) - hence the name “cellular communications”, in the center of which there are transceiver base stations. Typically, such a station has six transmitters, which are located with a 120° radiation pattern and provide uniform area coverage. One average modern station can simultaneously service up to 1000 channels. The area of ​​a “honeycomb” in the city is about 0.5-1 km2; outside the city, depending on the geographical location, it can reach 20 or 50 km2. Telephone traffic in each "cell" is controlled by a base station, which receives and transmits signals over a large range of radio frequencies (dedicated channel - step for each cell phone minimum). The base station is connected to a wired telephone network and is equipped with equipment that converts a high-frequency cell phone signal into a low-frequency signal wired telephone and vice versa, what ensures the pairing of these two systems. Technically modern base station equipment occupies an area of ​​1...3 m2 and is located within one small room, where its work is carried out in automatic mode. For stable operation of such a station, all that is required is the presence wired communication with a telephone exchange (PBX) and mains power 220 V.

In cities and towns with a large concentration of houses, base station transmitters are located directly on the roofs of houses. In suburban and open areas, towers in several sections are used (they can often be seen located along highways).

The coverage area of ​​neighboring stations is contiguous. When a telephone device moves between coverage areas of neighboring stations, it is periodically registered. Periodically, with an interval of 10...60 minutes (depending on the operator), the base station emits a service signal. Having accepted it, the mobile phone automatically adds its MIN and ESN numbers to it and transmits the resulting code combination to the base station. Thus, the identification of a specific mobile cellular telephone device, the account number of its owner and the binding of the device to a specific zone in which it is located are carried out. this moment time. This point is very important - already at this stage it is possible to control the movements of this or that object, but who benefits from this is another question - the main thing is that there is an opportunity...

When a user connects to someone on his phone, the base station allocates him one of the free frequencies of the zone in which he is located, makes appropriate changes to his account (debits funds) and transfers his call to its destination.

If a mobile user moves from one communication zone to another during a conversation, the base station of the zone (cell) he is leaving automatically transfers the communication signal to the free frequency of the zone (cell) adjacent to it.

The most vulnerable from the point of view of the possibility of intercepting ongoing conversations (listening) are analog mobile cell phones. In our region (St. Petersburg), such a standard was present until recently - this is the NMT450 standard (it is also present in the Republic of Belarus). Reliable communication and its distance from the base station in such systems directly depend on the radiation power of the transmitting cell phone.

The analog principle of information transmission is based on the emission of a non-digital radio signal into the air, therefore, by tuning to the appropriate frequency of such a communication channel, it is theoretically possible to listen to the conversation. However, it’s worth “cooling down particularly hot heads” - listening to cellular communications of this standard not so easy, since they are encrypted (distorted) and for accurate speech recognition you need an appropriate decoder. Negotiations of this standard are easier to find than, say, the GSM standard - digital cellular communications, whose mobile phones transmit and receive information in the form digital code. The easiest way to find direction is stationary or stationary objects that provide cellular communications; it is more difficult to find mobile ones, since the movement of the subscriber during a conversation is accompanied by a decrease in signal strength and a transition to other frequencies (when transmitting a signal from one base station to a neighboring one).

Direction Finding Methods

The arrival of cellular communications in every family (today even schoolchildren receive such gifts) is a reality of the times; comfort is already becoming indispensable. The presence of a cell phone allows the user to identify his location, both at the current moment in time, and all his previous movements before that. The current situation can be revealed in two ways.

The first is a method of targeted direction finding of a cell phone, which determines the direction to a working transmitter from three to six points and gives a pinpoint location of the radio signal source. The peculiarity of this method is that it can be applied by order of someone, for example, authorities authorized by law.

The second method is through a cellular operator, which automatically constantly records where a particular subscriber is at a given moment in time, even when he is not conducting any conversations. This registration occurs automatically using identifying service signals automatically transmitted by the cell phone to the base station (this was discussed earlier). The accuracy of determining the subscriber's location depends on a number of factors: the topography of the area, the presence of interference and signal reflection from buildings, the position of base stations and their workload (the number of active operator mobile phones in a given cell), and the size of the cell. Hence, the accuracy of determining the location of a cellular subscriber in the city is noticeably higher than in open areas, and can reach a spot of several hundred meters. Analysis of data on the subscriber's communication sessions with various base stations (from which station the call was made and to which one, time of the call, etc.) allows us to reconstruct a picture of all the subscriber's movements in the past. The data is automatically registered with the mobile operator (for billing and more...), since payment for such services is based on the duration of use of the communication system. This data can be stored for several years, and this time is not yet regulated by federal law, only by departmental acts.
You can conclude that confidentiality is ensured, but not for everyone. If it is necessary to listen to your communications, or determine your location, almost any “equipped” intelligence service or criminal community is able to do this without any effort.

It is more difficult to intercept a conversation if it is being conducted from a moving car, because... The distance between the cell phone user and the direction-finding equipment (if we are talking about analog communications) is constantly changing and if these objects move away from each other, especially in rough terrain among houses, the signal weakens. When moving quickly, the signal is transferred from one base station to another, with a simultaneous change in operating frequency - this makes it difficult to intercept the entire conversation (unless it is conducted purposefully with the participation of a telecom operator), since it takes time to find a new frequency.

You can draw conclusions from this yourself. Turn off your cell phone if you do not want your location to be known.

Hidden features of cell phones

A modern MTA can switch into voice recorder mode (recording sounds from the built-in microphone) automatically according to a signal, or a given program, without the permission of its owner. It is not a fact that every MTA records the owner’s speech and voice and then transmits the information, but such a possibility is technically provided in every modern MTA. It's like having a gun hanging on the wall. And if the action takes place during a performance in a theater, then it is almost obvious that before the end of the performance the gun will fire. So in this case, the MTA has the ability to record and transmit information, and this factor must be taken into account when using your “mobile phone”.

The information is received by the station closest to the MTA - the cell. How is information transmitted over the air? The MTA communicates with the station in bursts of digital pulse signals, which are called time slots. The duration of one service communication session can last from a fraction of a second to several seconds.

The MTA carries out such service communication sessions with the base station constantly when the cell phone is turned on. Initially, this occurs after the MTA is turned on, then the phone, communicating with the nearest communication station of its operator (according to the installed SIM card), positions its position on the ground, broadcasts its data (for example, the identification number of the cell phone on the network, etc.) , i.e. it is registered on the network. Based on this registration in subsequent negotiations to this subscriber payment is charged for connections, communication services, call tariffs and roaming. In addition to time slots in a communication session when the power is turned on, the MTA periodically, approximately once an hour (and during active movement constantly) communicates with a nearby base station, positioning its position and, if necessary (going beyond the cell) registering in the zone responsibility of another neighboring base station. The duration and frequency of service communication sessions (time slots) for different MTAs is different and ranges (frequency) from 10 to 35 times a day. In this case, the duration of time slots varies in the range of 2-25 milliseconds.

Many modern MTAs automatically include functions for various types of service informing the owner, for example, about the weather forecast or news, so the time slots for such a phone will be more frequent and longer. In this case, it is impossible to determine exactly what signals your mobile phone sends to the base station without special equipment. One can only record the very fact of a short communication session that occurred without the participation of the MTA owner. In any case, if you receive an SMS message, then time slots have been exchanged.

Every cell phone owner needs to know this feature of “their” MTA, despite the fact that manufacturing companies are in no hurry to either share this information with buyers of their products or explain these functions and their purpose. As they say, forewarned is protected... An indirect sign of the MTA operating at high power transmission is a rapidly discharging battery.

How to check a cell phone

At the dawn of the mass popularization of cell phones (and this was not so long ago), the population was dominated by mobile telephone devices (MTAs), purchased abroad and requiring Russification. In addition, some cell phones brought from abroad to the CIS (purchased on the secondary market because they are cheap), when connecting a SIM card local operator turned out to be blocked (they did not implement some of the functions stated in the MTA menu and in its operation manual). People took the MTA to the appropriate service (according to the name of the MTA) and sometimes received the answer: your phone will not work in Russia. Since then, MTAs, brought privately from abroad, began to be secretly divided into “white” and “gray”. "White" can be revived and used in the CIS "by full program“, and the “gray” ones are practically hopeless, or require such investments that they outweigh their very cost. Therefore, for some time now, “gray” mobile devices come to Russia only in single copies, or in batches imported by small “shuttles”, or after Russians vacation abroad, due to their ignorance. In this regard, a test method for checking MTA was born.

To test, you need to press the keys on the keyboard in sequence: *#06#. As a result, the series and model number indicated in the passport data will be displayed. The same data is printed on the MTA body under battery. How will they help?

The specified data is the IMEI (International Mobile Equipment Identifier) ​​of your MTA. After this notification procedure to the cellular company, your MTA, along with the SIM card (or even the newly inserted one), will be under the control of your cellular operator. It is better to find out this number in advance (when purchasing or operating the MTA) and write it down somewhere away from prying eyes. If the device is lost or stolen, this data must be transferred to your cellular operator. This is necessary so that your MTA can be accurately found, or at least, would be blocked from service by the operator you were using before you lost your phone.

Cellular communications have recently become so firmly established in our daily lives 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 areas of it. It is difficult to say what the future would be like if it were not for this convenient type of communication. Probably the same as in the movie "Back to the Future 2", where there are flying cars, hoverboards, and much more, but there is no cellular communication!

But today, in a special report for, there will be a story not about the future, but about how modern cellular communications are structured and work.

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

But first I’ll tell you a little about the history 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 in other countries created similar devices with different characteristics, and only in the 70s of the last century in America were the modern principles of cellular communications determined, after which its development began.

Martin Cooper - inventor of the portable cell phone prototype Motorola phone DynaTAC weighs 1.15 kg and measures 22.5 x 12.5 x 3.75 cm

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

Bulky, brick-shaped mobile phones that worked in the first and second generation formats have become history, giving way to smartphones with 3G and 4G, better voice communications and high Internet speeds.

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 connection when moving. This is ensured thanks to the so-called handover, in which the connection established by the subscriber is, as it were, picked up by neighboring cells in a relay race, and the subscriber continues to talk or delve into social networks.

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

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

But on Tele2 BS towers there is equipment only of the third and fourth generation- 3G/4G, since the company decided to abandon old formats in favor of new ones, which help avoid interruptions in voice communication and provide a 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 a BS is a tower or mast built specifically for it. Surely you could see 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, which is visible from my window.

However, in urban areas it is difficult to find a place to place a massive structure. Therefore, in large cities, base stations are located on buildings. Each station picks up signals 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 in places you wouldn't even guess. Like, for example, 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 phones, then the round antenna connects the BS to the controller.

Depending on the characteristics, each sector can handle up to 72 calls simultaneously. A BS can consist of 6 sectors and serve up to 432 calls, but usually fewer transmitters and sectors are installed at stations. Cellular operators such as Tele2 prefer to install more BS 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 a connection is established in the direction desired by the subscriber. The switching subsystem has a number of databases that store subscriber information. In addition, this subsystem is responsible for security. To put it simply, the switch is complete It has the same functions as the female operators who used to connect you with the subscriber with their hands, only now all this happens automatically.

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

In addition to the usual towers, there are also mobile options base stations located 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 legislation, they have not yet found wide application.

To ensure optimal radio signal coverage at ground level, base stations are designed in a special way, therefore, despite the range of 35 km. the signal does not extend to aircraft flight altitude. However, some airlines have already begun installing small base stations on their boards that provide cellular communications inside the aircraft. Such a BS is connected to a terrestrial cellular network using satellite channel. 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 monitor the quality of cellular communications. If a few years ago such a room would have been hung to the ceiling with monitors showing network data (load, network failures, etc.), then over time the need for so many monitors has disappeared.

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

Some views from the Tele2 office.

At a meeting of company employees, plans to capture the capital are discussed) From the beginning of construction until today, Tele2 has managed to cover all 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's plans for 2016 include providing high-speed communications in the metro at all stations; at the beginning of 2016, Tele2 communications are present at 11 stations: 3G/4G communications at the Borisovo, Delovoy Tsentr, Kotelniki, and Lermontovsky Prospekt metro stations. , “Troparevo”, “Shipilovskaya”, “Zyablikovo”, 3G: “Belorusskaya” (Ring), “Spartak”, “Pyatnitskoye Shosse”, “Zhulebino”.

As I said above, Tele2 abandoned the GSM format in favor of third and fourth generation standards - 3G/4G. This allows you to install 3G/4G base stations with a higher frequency (for example, inside the Moscow Ring Road, BSs are located at a distance of about 500 meters from each other) to provide more stable communications and high speed mobile Internet, which was not the case in 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 in front of one of the masts on which communication equipment is installed. If you look closely, you will notice a little further to the left another such mast, with equipment from other cellular operators.

Oddly enough, cellular operators often allow their competitors to use their tower structures to place antennas (naturally on mutually beneficial terms). This is because building a tower or mast is an expensive proposition, and such an exchange can save a lot of money!

While we were measuring the communication speed, Nikifor was asked several times by passing grandmothers and uncles if he was a spy)) “Yes, we are jamming Radio Liberty!”

The equipment actually looks unusual; from its appearance one can assume anything.

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

But I decided to personally check how good Tele2’s connection is, so I bought a SIM card in the shopping center closest to me on Voykovskaya metro station, with the most simple tariff“Very black” for 299 rubles (400 SMS/minutes and 4 GB). By the way, I had a similar Beeline tariff, which was 100 rubles more expensive.

I checked the speed without going far from the cash register. 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 on metro station Krasnogvardeyskaya. Reception - 6.22 Mbps, transmission - 3.77 Mbps. I measured it at the exit of the subway. If you take into account that this is the outskirts of Moscow, it’s 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.

In the capital stable connection Tele2 is there, that's 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, which will be seen not only by readers of the community, but also by the website http://ikaketosdelano.ru

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It is difficult to imagine a person today who can live without cellular communications. Every day people call each other, send millions of messages, go online using mobile phones. Mobile operators are responsible for the quality of communication, cost and package of services.

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 Russian mobile operators.

According to statistics, the leaders among companies providing mobile communication services include 3 - “ 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 “cell phone” that is among the 20 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 stores in the country (more than 5,700 points).
2. Megaphone. There are more than 76 million subscribers in Russia, and there is great demand for Megafon SIM cards in Abkhazia, Tajikistan, and South Ossetia. The company positions itself as the operator with the fastest mobile Internet.
3. Beeline. The Vimpelcom OJSC brand is among the top hundred recognizable brands in the world. The number of subscribers in Russia reaches 59 million people, but Beeline leads 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 “big three”, but in terms of popularity they constitute significant competition. The rating of cellular operators includes smaller companies, new ones, and regional ones. The very concept of the “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, beautiful rooms, affordable roaming. Also, importantly, the operator provides high-quality communication. And when you replenish your account for the first time, you will receive.
• Tele2. At the end of 2017, this is the only company that increased the number of subscribers. It has been operating as a federal Russian operator since 2014 after receiving a license for communications in 3G format. The operator's audience is at least 40 million people in 65 regions of the country. The most active subscribers are in Moscow and the Moscow region, in St. Petersburg, Chelyabinsk and Nizhny Novgorod regions. It ranks 3rd in Russia in terms of the number of base stations, is distinguished by fast mobile Internet due to low network load, as well as affordable package rates with the Internet.
• Yota - virtual mobile operator. The brand has existed since 2008. Powered by Megafon technical infrastructure. The subscriber base is about 1.5 million people. Until January 2017, the only operator with unlimited access to mobile Internet, today tariff line includes only products with limited data for smartphones, and for tablet and computer there are offers with unlimited internet, the price of which depends on the speed.
• Rostelecom is an Internet provider and company providing home wireline services, cable television. The company offers its subscribers cellular communications in GSM 900/1800 and Mobile Internet.
• "Motiv" serves only 4 regions in the Ural Federal District. This brand has existed since 2002. The company provides communications in GPRS / EDGE, IVR, MMS, SMS, USSD formats, but is not represented in Moscow.
• "SMARTS" is a Samara company. Communications in Russia are provided to subscribers from the Volga region and 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 choosing a cellular operator, each client must outline his own range of preferences and outline the requirements for mobile communications. Each provider is good in its own way, best operator cellular communications can also have regional status if the package of services it provides meets the client’s needs.

A list of communications within Russia, a telephone code and a comparison of operators will help you choose a suitable provider.

Map of mobile operators

Communications companies are sensitive to increasing customer demands. Now it is no longer only major players in the telecommunications market that offer high-quality communication coverage. The emergence of new towers makes it possible to provide communications to even the most remote settlements, to use mobile phone Now you can do it in the subway and in high-rise buildings. Operators provide not only high-quality and uninterrupted telephone coverage, but also fast access to the Internet via 3G and 4G networks.

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

Each Russian company has a database of 11-digit numbers, which can be used to determine the operator and regions of connection of the number. Not all subscribers took advantage of the opportunity to switch from one operator to another, which appeared after the abolition of “mobile slavery,” so the table of codes helps determine where the unknown incoming “came” from.

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

Beeline does not have a clear connection to the region, like other large operators. The company has separate codes only for the Far East and Primorsky Territory. And Yota numbers not tied to the region, all start with code 999.

In the North-West region and St. Petersburg

Southern Federal District, including the North Caucasus

The tables indicate both codes designed for all regions, and those that apply only to the specified city or region. But large operators have codes for individual areas, i.e. cellular services will be cheaper only when used in your home region.

The place of registration of numbers with codes 950, 951, 952 with Tele2 can be the 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 do Russian operators use?

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

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

For the “mobile three” there are a series of codes in which the second digits also match. For example, 91x or 98x are MTS numbers, and 92x or 93x are Megafon numbers.

The next 7 digits are the subscriber number, by which it is impossible to determine belonging to the region of residence or provider. The range of Beeline numbers can indicate region membership 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 number help determine the operator. For example, DEF code 958 is used by more than 20 operators, including small companies (covering 1 region and a capacity of 10,000 numbers) and large ones (several dozen regions and hundreds of thousands of numbers).

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

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

The numbering of DEF codes also changes 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 number capacity is more than 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 other Russian operators of different calibers in terms of capacity and regional coverage - Antares, Arkhangelsk Mobile Networks", "Ekaterinburg-2000", "Kemerovo Mobile Communications", "Sky-1800", etc.

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

Best rates

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

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

Budget rates

	MTS, Smart	Megaphone, Get involved! Choose	Beeline, First gigs	Tele 2, "My Conversation"
Cost, rub.)	400	450	405	200
Package of minutes	200	300	400	200
Internet (GB)	4	6	4	2

It’s not difficult to get lost in such 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 communications, SMS and mobile Internet. In addition to the services included in the package, you need to study the limits on them (GB, free minutes, number of SMS) and determine the needs of the subscriber (mobile Internet, calls on the home network, roaming, etc.).

I have been following new developments in the field of mobile technologies for many years. Previously, this was my hobby, but now it has grown into a professional blog, where I am happy to share the information I have accumulated with you. All instructions, life hacks, selections best programs And tariff plans I checked it personally on myself.