Location of base stations mts. Coating Color MTS, Megafon, Yota, Tele2, Beeline, Rostelecom, Sberbank, SkyLink. MTS Coverage Map

There are many ways to determine the location, such as satellite navigation (GPS), location wirelessly wiFi networks and over cellular networks.

In this post, we tried to check how well the technology for determining the location on cell towers in the city of Minsk works (provided that only open bases coordinates of GSM transmitters).

The principle of operation is that cellular telephone (or the cellular communication module) knows which base station transceiver it is being served by and having a database of coordinates of the base station transmitters, you can approximately determine your location.

Now a little about what a transmitter is in the understanding of OpenCellID and how the OpenCellID database is populated. This database is filled different ways, the simplest is to install an application on a smartphone that records the coordinates of the phone and the serving base station, and then sends all measurements to the server. The OpenCellID server calculates the approximate location of the base station based on a large number of measurements (see figure below). So the coordinates wireless network are calculated automatically and are very approximate.

Map OpenStreetMap contributors

Now let's move on to the question of how to use this database. There are two options: use the Cell ID to Coordinate translation service provided by OpenCellID.org, or perform a local search. In our case local way preferable because we are going to drive a 13 km route and web browsing will be slow and inefficient. Accordingly, we need to download the database to the laptop. This can be done by downloading the cell_towers.csv.gz file from downloads.opencellid.org.

The database is a table in CSV format described below:

• - code of the country;
• - operator code;
• - area code;
• - transmitter identifier;
• - transmitter longitude;
• - the latitude of the transmitter.

All cellular modules support the following commands: AT + CREG, AT + COPS (serving base station), AT + CSQ (signal strength from the base station). Some modules make it possible to recognize, in addition to the service transmitter, also neighboring ones, i.e. monitor base stations using AT ^ SMONC for Siemens and AT + CCINFO for Simcom. I had a SIMCom SIM5215E module at my disposal.

Accordingly, we used the AT + CCINFO command, its format is shown below.

We are interested in the following parameters:

• - indicator of the serving transmitter;
• - indicator of the adjacent transmitter;
• - code of the country;
• - operator code;
• - area code;
• - transmitter identifier;
• - received signal power in dBm.

Monitoring works - you can go.

The route ran in the western part of Minsk along the street. Matusevich, Pushkin Ave., st. Ponomarenko, st. Sharangovich, st. Maxim Goretsky, st. Lobanka, st. Kuntsevshchina, st. Matusevich.

Map OpenStreetMap contributors

The log was recorded with an interval of 1 second. Performing the transformation of CellID into coordinates, it turned out that 6498 calls to the OpenCellID database were effective, and 3351 calls did not find matches in the database. Those. hit rate for Minsk is about 66%.

The figure below shows all the transmitters that were encountered in the log and were in the database.

Map OpenStreetMap contributors

The picture below shows all serving transmitters that were found in the log and were in the database. Those. a similar result can be obtained on any cellular module or telephone.

Map OpenStreetMap contributors

As you can see, at one of the moments we were served by a transmitter located behind a traffic intersection at the intersection of ul. Pritytsky and Moscow Ring Road. Most likely, this is a suburban base station serving subscribers at a distance of several kilometers, which leads to significant errors in determining the location by Cell ID.

Since our SIMCom SIM5215Е at every moment of time shows not only the serving transmitter, but also the neighboring ones and the signal levels from them, we will try to calculate the coordinates of the device based on all the data available at a particular moment in time.

Calculation of the subscriber coordinates will be performed as a weighted average of the coordinates of the transmitters:
Latitude \u003d Sum (w [n] * Latitude [n]) / Sum (w [n])
Longitude \u003d Sum (w [n] * Longitude [n]) / Sum (w [n])

As is known from the theory of radio wave propagation, the attenuation of a radio signal in a vacuum is proportional to the square of the distance from the transmitter to the receiver. Those. at a distance of 10 times (for example, from 1 km to 10 km), the signal will become 100 times weaker, i.e. will decrease by 20 dB in power. Accordingly, the weight for each term is determined as:
w [n] \u003d 10 ^ (RSSI_in_dBm [n] / 20)

Here we have assumed that the power of all transmitters is the same, this assumption is erroneous. But due to the lack of information about the power of the base station transmitter, one has to make deliberately rough assumptions.

The result is a more detailed picture of locations.

Map OpenStreetMap contributors

As a result, the route turned out to be well drawn, with the exception of an ejection towards the interchange on the Moscow Ring Road, for the previously described reason. In addition, over time, the coordinate database will be filled, which should also increase the accuracy and availability of positioning technology by Cell ID.

Thank you for attention. Questions and comments are welcome.

The terms "base station" and "cell tower" have long and firmly entered our lexicon. And if the average user remembers these things not so often, then the "cell phone", by habit, is clearly among the ten leaders. Hundreds of millions of people use cellular communications every day, but very few of them think about how this very connection is provided. And of this minority, very few really represent the complexity and subtlety of this communication tool.

From the point of view of most people, setting up a cellular base station is very straightforward. It is enough to hang up a few antennas, connect them to the network - and you're done. But this view is fundamentally wrong. And so we decided to talk about how many subtleties and nuances arise when installing a base station in a metropolis.

To clearly illustrate our story, we documented in detail the process of installing a cell tower on the roof of a building in Moscow, at ul. Krasnodonskaya, 19, building 2. This is a two-storey detached administrative building. We chose this example because this base station not only has a small bracket for hanging antennas, but a 5-section tower 15 m high. But let's start in order.

Preparation and design

The work of installing a base station begins with finding a suitable object. When it is found, a lease is concluded with its owner. The required location of the antennas of the future station, the mass of the payload are determined, and the metal structures are designed based on this. This takes into account the bearing capacity of the structural elements of the building itself.

A set of documentation (almost 5 cm thick) is issued for each installed base station. Among other things, many parameters of the future structure are indicated here: its location on the object, overall dimensions, total weight, location of support points, voltage and power consumption, and so on.

This folder contains comprehensive information:

• project documentation;
• copies of statements, licenses, certificates and conclusions of conformity for all elements, up to nuts and paint;
• working documentation for equipment, metal structures, architectural and construction solutions, lightning protection;
• sanitary and epidemiological conclusion on the safety of the station for residents of surrounding houses.

Let's go back to our tower. After agreement and approval of the project, the platform and five tower segments were manufactured separately at the plant. Since in this case it was a rather heavy structure, it had to be installed on the load-bearing walls of the building. For this, holes were cut in the roof and support beams were installed. They play the role of a pile foundation for the platform, on which the station equipment and a tower with antennas were later mounted. The total weight of the platform was 3857 kg.

The profile, size and number of beams from which the platform is assembled, wall thickness, length of welds, hardware used - all these parameters are calculated based on the payload mass, the bearing capacity of the building walls, as well as possible wind loads in the region. Of course, these are far from the only criteria, first of all, the tower should provide the ability to install transmit-receive antennas at the required height in the visibility range of neighboring base stations. In addition, the structure must be rigid enough so that the relay communication beam does not get lost.

Installation of metal structures

The building is small, it does not have a separate exit to the roof, so a team of installers has to climb the fire escape. Its lower part is cut off so that residents of the surrounding houses do not climb onto the roof. Unfortunately, this does not stop them too much, so something often disappears from the roofs - parts, cables, feeders, etc.

Despite the fact that each station is equipped with an alarm, the security service does not always have time to arrive on time.

The base station of another is already installed on the roof cellular operator, but its size cannot be compared with ours.

After installing the platform, the sites are prepared for the installation of the first section of the tower:

After the section is installed, “tightening the nuts” begins:

Installation of the tower on the studs is done in order to be able to compensate for deviations from the vertical during installation and further operation.

The verticality of the structure is constantly monitored from two points using theodolites. Moreover, measurements are taken separately for each section of the tower, and then the measurement log will be included in the set of documents. Subsequently, periodic measurements of the tower position are carried out, since under its own weight and the weight of the equipment, a slight spiral twisting of the structure can occur (up to 50 mm at 72 m in height).

Hardware cabinet prepared for platform installation:

So, the first section is installed and aligned. Installers are preparing to receive the second section:

Great attention is paid to the safety and comfort of work not only during installation, but also during further maintenance. The work sites are sized so that engineers have enough room to work. Ladder railings have been installed, the openings in the platforms on the tower are closed with hatches to prevent accidental falls. The platform is raised above the roof plane so that in winter time the equipment is not covered with snow and blocked by ice.

Installation of the remaining sections of the tower:

Hardware cabinet queue:

The tower has been mounted, the last measurements have been made using theodolites. Deviations are minimal and strictly within tolerances. The mass of the tower was 2827 kg, and the total weight of all metal structures was 6684 kg.

The colors of the sections are standard: the bottom and top are always red, the intermediate ones alternate with white. At the top, you can see 4 pins, which are a continuation of the edges of the tower - these are lightning protection elements.

Equipment

The next step was the installation of all necessary equipment and cabling. Full list installed equipment:

As a result, the station acquired a rather majestic appearance, especially in comparison with the building itself:

The station is supplied with a voltage of 380 V (3 phases), which is then converted into 48 V. The power is taken with a margin of up to 10 kW. Food is supplied in a separate locker.

Let's open the door of the hardware cabinet. It has built-in air conditioning (top) and heater (bottom).

The cabinet maintains a temperature of 18 ... 20 degrees Celsius throughout the year. This is necessary for the smooth operation of the equipment and the long life of the batteries (they are located at the bottom).

The accumulators are designed to ensure the operation of the station for about a day in the event of a power outage.

Above is the switching unit and voltage converter.

The transfer of information between the system modules and transceivers (about them below) is carried out via fiber optic cables. This is what the connector looks like in the junction box. In no case should you touch it with your hands, the fiber is very sensitive to damage and pollution.

All base stations of cellular communication are connected to a single information fiber optic network, stretched throughout Moscow. The white bay under the equipment cabinet is just the cable through which this station is connected.

To the right of the cabinet are the system gSM modules, CDMA and LTE:

These modules are the heart of the base station; they receive the signal from the antennas and convert and compress it with further transmission. They are not afraid of precipitation, all connectors are sealed, and the operating temperature range is from +60 to -50.

Lightning arresters are located under the system modules, which prevent equipment burnout in the event of a lightning strike:

On the right above the modules, there are fiber-optic cable coils, with which they are connected to the transceivers on the tower.

Let's move on to the tower. It has transceivers installed separately for each band (GSM, CDMA and LTE). They amplify the signal from extremely low values \u200b\u200bup to 115-120 dB. They are powered from the hardware cabinet:

Oblong vertical "boxes" are antennas. They are shielded at the back to protect maintenance personnel from electromagnetic radiation... Let's go up to the site.

Fiber-optic cables are connected to the transceiver at the edges, power supply in the center:

Grounding lead to the tower:

Cable connectors and their plugs on the antenna:

We have already mentioned that designing and building a cellular base station is not at all as easy as it seems to the uninitiated. There are many nuances that are associated with the specific location of the station. For example, radio transmission over a large water surface is deteriorating, although it should be the other way around, because there are no obstacles. But the fact is that an electromagnetic field spreads over the earth's surface, and a large volume of water works as a kind of condenser, over which interference to the radio signal is amplified. And there are many such subtleties, therefore the efficiency of the base station directly depends on the professionalism of the designers and installers.

Yota coverage map is developed using a computer model. Users should study it carefully. It is worth recalling that each region of Russia has its own coverage map. But the common feature for all coverage areas is the same - the computer map cannot reflect the real indicators of the power level and signal speed.

Yota base stations are, of course, indicated on the map, but without taking into account the relief characteristics of the terrain and the situation of radio exchange at the point of connection of the subscriber's equipment.

Yota signal quality measurements are made constantly. Accordingly, the Yota map on the site, displaying the operator's coverage of a particular region, will change all the time (according to the expansion of coverage).

Colors matter

For the Yota coverage map in the Moscow region, special tables are presented with the indication of settlements, the signal power level in dB and the speed of the Internet stream.

The original solution was proposed by the branch in Sochi, where Yota towers are marked on the map with multi-colored marks:

The Yota tower map provides a variety of information. Thanks to it, you can get data on the conversion of stations for the transmission of LTE Internet. The option to search for your base station for subscribers is extremely simple: press CTRL + F and type the final 4 digits of the BSID number in the search window.

Wider step

The Yota repeater map suggests that the operator's coverage area is steadily growing. This year, the number of LTE network stations increased by more than half (60%). The main indicators for the operator were made by representative offices in Irkutsk and Khabarovsk (where there are more than 2 times 4G repeaters). Good results were recorded in the North-West of the country: the Leningrad and Vologda regions - an overall figure of 50%.

The launch of new base stations of the LTE network significantly increased the Yota 4G coverage area and reduced the load on the towers already in operation. The operator is steadily increasing its presence in the high-speed Internet market.

Some details

Operator Yota, whose tower map was drawn up without regard to external realities, warns its subscribers that:

Maximum fluctuations

Changes in Yota power, maximum db signal measured by test programs or instruments, may lead to disconnection. According to the information http://www.yota77.ru/map.htm, the signal level in the Moscow region fluctuates in the range of 18-22 dB. The maximum value is marked at 29 dB.

In areas with a low level of signal power (0-2 dB), for its qualitative increase (up to 20 dB), you can purchase a gain antenna with the corresponding indicators and a built-in Yota modem.

Published 22.04.2015 by Johhny

The telecom operator MTS will sell personal base stations to its subscribers - individuals. MTS has been installing such devices for corporate clients since 2010. These miniature base stations (BS) are called femtocells and are used to create high-quality indoor network reception (indoor coverage). First, the company will sell femtocells in Moscow, and in the future the whole of Russia will be considered.

In the photo - MTS femtocell:

This project was implemented due to the claims of state regulatory bodies to the quality of mobile communications in the megalopolis (after dissatisfaction with the quality of communications in Moscow D. Medvedev). At the same time, as you can see, MTS is going partially solve the problem at the expense of your subscribers... After all, it will be very useful in response to the client's claim to offer him to buy a personal base station.

The sale of portable "home" BS in Moscow should begin this fall. Then, already in December, the operator will analyze the profitability of the project and decide on the feasibility of selling them throughout the country.

Femtocell is comparable in size to our usual router, and will cost the subscriber about RUB 6,000 (by the way, this is more than 3 times more expensive than an average Wi-Wi-router). Connecting an indoor base station is quite simple, so the subscriber can do it himself. However, for this purpose you will need high-quality Internet access, because the mini BS transmits voice traffic and data transmission from mobile phones to the “general cellular network of MTS” via broadband Internet. Otherwise it won't work.

Femtocell supports the third generation (3G) network and is able to serve the area up to 300-400 sq. M. These BS will be especially in demand in buildings with thick walls, basements, new buildings and in all those rooms where, for one reason or another, there are problems with the coating cellular network MTS. At the same time, the femtocell directly affects the volume of voice and Internet traffic generated by subscribers - it increases by at least 20%. Unfortunately, it is not known how harmful such a "home" base station can be to human health, because it is a high-frequency emitter that is in close proximity to you.

Taking into account the experience of MegaFon, which has already tried to sell femtocells to private clients in a number of regions of Russia, these mini-base stations can become an extremely niche product. Very, very few people are ready to part with 6,000 rubles in order to do his work for the operator and, thus, also additionally bind yourself to him (not a bad marketing idea in light of the start of number portability from one operator to another). It would be much more logical to offer femtocells as an additional service of fixed Internet providers. In Moscow, this could be done by the same MGTS, which, by the way, is now modernizing its network, switching houses to fiber. It would be worth including such an indorka in the kit with a "free" MGTS router, and cellular from MTS could earn full in all Moscow apartments.

I just want to add that I am more for this project than against. After all, no one forces you to pay for an indoor BS, but there is always a quick, albeit not cheap, option to solve your communication problem. sometimes it takes years to expect such justice from MTS.