Cell tower power supply. GSM base station and human health

It is hardly possible today to find a person who has never used a cell phone. But does everyone understand how cellular communications work? How does what we have all become accustomed to work and work? Are signals from base stations transmitted through wires or does it all work somehow differently? Or maybe all cellular communications function only through radio waves? We will try to answer these and other questions in our article, leaving a description GSM standard beyond its scope.

At the moment when a person tries to make a call from his mobile phone, or when they start calling him, the phone connects via radio waves to one of the base stations (the most accessible), to one of its antennas. Base stations can be seen here and there, looking at the houses of our cities, at the roofs and facades of industrial buildings, at high-rise buildings, and finally at the red and white masts specially erected for stations (especially along highways).

These stations look like rectangular boxes gray, of which in different sides various antennas stick out (usually up to 12 antennas). The antennas here work for both reception and transmission, and they belong to the operator cellular communications. The base station antennas are directed in all possible directions (sectors) to provide “network coverage” to subscribers from all directions at a distance of up to 35 kilometers.

The antenna of one sector is able to simultaneously service up to 72 calls, and if there are 12 antennas, then imagine: 864 calls can, in principle, be serviced by one large base station at the same time! Although they are usually limited to 432 channels (72*6). Each antenna is connected by cable to the control unit of the base station. And blocks of several base stations (each station serves its own part of the territory) are connected to the controller. Up to 15 base stations are connected to one controller.

The base station is, in principle, capable of operating on three bands: the 900 MHz signal penetrates better inside buildings and structures and spreads further, so this band is often used in villages and fields; a signal at a frequency of 1800 MHz does not travel that far, but more transmitters are installed in one sector, so such stations are installed more often in cities; finally 2100 MHz is a 3G network.

Of course, there may be several controllers in a populated area or region, so the controllers, in turn, are connected by cables to the switch. The purpose of the switch is to connect operator networks mobile communications with each other and with regular city lines telephone communication, long distance communication And international communications. If the network is small, then one switch is enough; if it is large, two or more switches are used. The switches are connected to each other by wires.

In the process of moving a person talking on a mobile phone along the street, for example: he walks, drives public transport, or travels in a personal car - his phone should not lose the network for a moment, you cannot interrupt the conversation.

Continuity of communication is obtained due to the ability of a network of base stations to very quickly switch a subscriber from one antenna to another as he moves from the coverage area of ​​one antenna to the coverage area of ​​another (from cell to cell). The subscriber himself does not notice how he ceases to be connected to one base station and is already connected to another, how he switches from antenna to antenna, from station to station, from controller to controller...

At the same time, the switch provides optimal load distribution across a multi-level network design to reduce the likelihood of equipment failure. A multi-level network is built like this: cell phone- base station - controller - switch.

Let's say we make a call, and the signal has already reached the switchboard. The switch transmits our call towards the destination subscriber - to the city network, to the international or long-distance communication network, or to the network of another mobile operator. All this happens very quickly using high-speed fiber optic cable channels.

Next, our call goes to the switch, which is located on the side of the recipient of the call (the one we called). The “receiving” switch already has data about where the called subscriber is located, in what network coverage area: which controller, which base station. And so, the network polling begins from the base station, the recipient is located, and a call is received on his phone.

The entire chain of events described, from the moment the number is dialed to the moment the call is heard on the receiving end, usually lasts no more than 3 seconds. So today we can call anywhere in the world.

Andrey Povny

Recently, Megafon Volga region gave a technical presentation of a mobile base station. Journalists were invited to this event, and as a result, blog posts also appeared. I found two: I will combine both entries into one. Firstly, they write about the same thing, and secondly, both posts are quite superficial and short, so I don’t see the point of making two entries.
It’s not particularly interesting for those who are in the know, but let it be, maybe you’ll find some interesting details in the photographs.

How does a mobile base station work? cellular network

Original taken from cheger How does a mobile cellular network base station work?

At the beginning of this week, Megafon showed reporters a very interesting thing - a mobile base station, which is equipped on the basis of a Kamaz all-terrain vehicle. I, as a person directly associated with cellular networks and in particular the transmission of data via cellular communication channels, did not hesitate to accept the offer to see how Megafon implemented this, especially since there were few such mobile stations throughout Russia.

This mobile complex provides radio coverage of 2G/3G/4G+ networks, thereby providing subscribers with reliable access to communication and data services. It is independent of fixed communication facilities, which allows it to be deployed in almost any territory and used to create coverage where it is needed. With its help, you can ensure a reliable signal level in a field, forest, or in places where there is no residential infrastructure. Also, using the station you can significantly increase the network capacity, for example, during mass city events, football matches, concerts, etc. By the way, Nizhny Novgorod residents can look at the tower themselves, which is clearly visible when leaving the city in the Shcherbinok area, where this structure is deployed for testing needs.

We were a little unlucky with the weather, but everyone who wanted it was given raincoats, although they weren’t needed there - it never started raining.

Thanks to the operation of the complex, make calls and use mobile internet data can be used by several thousand people. Maximum speed data transfer - 300 Mbit/sec.

The “station on wheels” is equipped with a telescopic antenna mast 30 meters high, which folds and unfolds thanks to hydraulics. It provides a stable signal within a radius of up to 30 kilometers, depending on the terrain and under any climatic conditions. To deploy the entire system it takes from 3 to 6 hours, which is very fast!

By the way, it’s funny, but next to the test site where the system was deployed, there are nice private houses, the local Rublyovka, which is why many decided that it was the owners of these mansions who ordered fast mobile Internet for themselves =)

Jokes aside, let's continue the tour of the station. This whole thing weighs a little more than 20 tons

In addition to the equipment that ensures the operation of mobile communications, the complex is equipped with everything necessary for battery life: fuel for 7 days, electric generator, heating and air conditioning systems, space and equipment for cooking and sleeping places for staff. The crew of the complex consists of five people.

“The crew doesn’t sleep here, don’t worry,” jokes Oleg Abramkin, our guide. Yes, I would immediately like to express my gratitude to him and his colleagues who smartly defended themselves from the flow of our questions. By the way, in free time Andrey works part-time as the head of operation of base stations at the Central Branch of MegaFon.

The power supply is completely autonomous, and if you have access to the central power grid, then connect to it instead of burning diesel fuel.

Diesel generator

Here, when the tower is folded, all the wires are located

The tower is folded and unfolded using hydraulics, after which it is strengthened with metal cables using tubes screwed into the ground

These cables are used to control the locks of each leg of the tower.

The tower can withstand almost any wind

The living compartment and the equipment compartment are located inside the kung.

The interior space is divided approximately in half, the living room has two beds, just like on a train, air conditioning, microwave, laptop, refrigerator - in general, everything an operator needs for an independent existence

Actually, the station equipment. It is located in the far part and is usually fenced off from the living space by a retractable door

In the place where the station is now deployed, with the equipment turned off, there is no LTE, only 3G. This is what Speedtest shows on my phone

And this is what Speedtest shows when the mobile station is turned on.

As you can see, LTE immediately appeared and the speed increased literally 10 times

“MegaFon has several mobile mobile stations in its arsenal. Last year, we launched a complex based on the Ford Transit minibus and actively used it throughout the Central Branch, including in the Nizhny Novgorod region. Thus, with its help, the company provided communications during the Alfa Future People festival. Meanwhile, technical capabilities mobile stations allow us to organize radio coverage of the cellular network as part of larger events, such as the Olympics in Sochi or the upcoming 2018 FIFA World Cup,” added Andrey Abramov, director of infrastructure for the Central Branch of MegaFon.

And here is the second report

Mobile base station. How does this work?

Original taken from s1rus c Mobile base station. How does this work?

During emergency situations and mass events that are held in forests, fields or other places remote from residential infrastructure, there may be a problem with cellular communications or the Internet. To solve such problems, there is a mobile base station. It is independent of fixed communication facilities, which allows it to be deployed in almost any territory and used to create communication coverage where it is needed.
The Central Branch of MegaFon has several mobile stations in its inventory: a complex based on a Ford Transit minibus and a KAMAZ-43118. Ford had already proven himself during the Alfa Future People, and with his help the company provided communications throughout the festival. The second complex appeared recently, which made it possible to understand the features of the mobile base station.

1. This is what a mobile base station looks like based on a KAMAZ-43118 off-road truck. The complex provides radio coverage of 2G/3G/4G+ networks. Several thousand people can make calls and use the mobile Internet. The maximum data transfer speed is 300 Mbit/s. The total weight is 20.5 tons.

2. The “station on wheels” is equipped with a telescopic antenna mast 30 meters high, providing a stable signal for 10-20 kilometers, depending on the terrain and climatic conditions. Transceiver antennas are installed on it.

3. For reliable and stable operation complex, it is necessary to level the machine using hydraulic platforms and secure the mast using guy wires, holes for which are drilled with a motor drill, and then meter-long pins are screwed in. It takes from 3 to 6 hours to deploy the station.

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6. The excursion was conducted by Oleg Abramkin, head of operation of base stations of the Central branch of MegaFon.

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8. When possible, the station is connected to the local power grid; when not, it works autonomously. A diesel generator with a power of 19 kW allows you to work autonomously for 7(!) days. Under maximum load fuel consumption is 6 liters per hour.

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11. The station is capable of operating in any weather that occurs in the central region of Russia.

12. If you deploy an MBS in an area where coverage has already reached the theoretical maximum in frequency distribution (the center of a metropolis, for example), only the signal level will improve, but not the number of simultaneously calling subscribers.

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15. In addition to the electric generator, the mobile complex is equipped with everything necessary for autonomous operation: heating and air conditioning systems, cooking equipment and sleeping places for personnel. The crew of the complex consists of five people.

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17. Base station equipment.

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22. What kind of exercises are there without constantly checking the Internet speed? The mobile complex showed a result that surprised me - 70 Mbit/s! My house is smaller, but here there is a forest and a field.

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The basis of each cellular network is a cell (cell) in the central part of which there is a base station (BS). The cell size depends on the type of network, the power of the BS and other factors. The cell radius ranges from 0.5 to 10 kilometers. Thanks to this location, the subscriber, without yet leaving the coverage area of ​​one BS, enters the coverage area of ​​another BS, and so on until the network coverage area is terminated.

Cellular base station power

Everyone knows that the range of the base station is limited, and accordingly the power of the transmitters is relatively low. The power of a base station depends on the size of the cell, the standard used and the location where it is installed. This value is in the range from 5 W to 20 W.

The power of a base station located in a city and covering an area with a radius of 2 kilometers is about 10 W. But this value is only at the output of the transmitters, because due to the directional action of the antennas, the radiation power can reach 100 W. In rural areas the power may be even greater due to the installed amplifiers.

The highest power at the transmitter output can reach up to 30 W, but due to the influence of various obstacles (reinforced concrete buildings, tree crowns), the signal weakens.

Based on the fact that signal propagation conditions are varied, it was decided that the power of the base transmitters will adapt to the conditions (the power can increase and decrease).

Antennas for cellular base station

The antenna is an element of the base station; it is this device that receives and transmits a signal from one subscriber to another. The antenna is an important part of the BS; the quality of communication largely depends on it.

Currently, for GSM/UMTS/4G networks they use panel antennas with cross-polarization and antennas with vertical polarization.

Antennas with cross-polarization are used for open space, and with vertical polarization - indoors.

The specificity of UMTS networks is that the coverage area changes depending on the load, and most effective tool Optimizing the coverage area is by adjusting the antenna. In UMTS antennas, you can change the angle of inclination, both mechanical and electrical adjustment.

Placement of cellular base stations

There are several types of base stations: macro, micro, pico.

1. Macro cell is a standard base station that is used mobile networks. The coverage radius of this station is up to 100 kilometers, weight is about 300 kg. Such base stations placed in non-residential premises.
2. A microcell is a compact base station common in operator networks. It differs from a standard station in its emitted power and the number of supported subscribers. The coverage radius reaches up to 5 kilometers, weight – up to 50 kg. The station is placed in a container and attached to a pole.
3. A picocell is a low-power base station that is owned by an operator and used as a network. Such a station is installed in places with the greatest concentration of users. It's the size of a laptop.

Base stations can be located on the roofs of buildings or lamp posts. Picocells are used indoors (shopping centers, entertainment centers).

Construction of cellular base stations

The city's territory is optimally suited for the construction of cellular communication bases, thanks to the dense development of tall buildings. But there are also a number of inconveniences: reinforced concrete buildings interfere with the efficiency of the signal, or the space allocated for the construction of the station is difficult to install the structure.

Outside the city limits, as a rule, there are no objects suitable for installing a station. In this case, it is necessary to erect an antenna mast structure.

Stations are placed not only on cell towers and high-rise buildings, but also on structures such as pipes and elevators. Due to the fact that the areas of high-rise structures are used, there is a significant saving on the construction of the tower, because sometimes the height of the tower reaches 85 meters. And it is not always possible to obtain a building permit in the desired area.

The simpler and more cost-effective option is to place a special design for installing a base station on a finished high-rise building.

Installation and maintenance of cellular base stations

Cellular base stations are the most important stage in building the entire cellular communication system for signal transmission in a given area. To ensure uninterrupted operation, the base station must be correctly positioned and mounted. This process can only be entrusted to true professionals in their field.

Companies serving cellular stations

When choosing a company servicing cellular communication stations, preference should be given to those who have been working in this field for many years.

The Integration company has been in the network construction market since 2012. The company installs and maintains base stations in the city and outside the city. The company installs antenna mast structures, builds radio relay lines communications. When installing the station on residential buildings or high-rise buildings, it carries out coordination with residents and regulatory authorities.

The Advanced Communication Technologies company is a division of Russia's largest telecommunications holding. The company carries out design, installation, service, warranty service and renovation of facilities. The company's customers are MTS, MegaFon, Tele2.

Manufacturers and suppliers of components for cellular communication stations

Some companies producing components for cellular communication stations themselves design and install stations.

The Teleconta company was founded in 2001. It has its own laboratory-measuring complex and production base, where it produces elements of the antenna-feeder path. Holds patents for antennas. Telecont's clients are MTS, Megafon, SMARTS and other companies.

GROUNDTECH LLC - produces and supplies lightning protection systems, devices for uninterrupted transmission of electrical energy.

GROUNDTECH LLC is a distributor of a Slovenian company producing surge protection devices.

Mobile base station on KAMAZ

• VimpelCom company blog (Beeline)

A mobile base station is an almost ordinary cell installed on a vehicle chassis and equipped with a bunch of devices to ensure autonomy. Beeline has several such mobile stations on platforms of varying carrying capacity. They are actively used to create a coating or compact it where it is desperately needed.

What's inside the car?

• Transceiver devices (at 900 MHz, 1800 MHz or 2100 MHz). Simply put, a subscription service.
• Radio relay or satellite equipment for communication with the main Beeline infrastructure.
• Telescopic hydraulic or collapsible antenna support on which transceiver antennas are installed.
• Diesel generator that allows you to work autonomously. When possible, the station is connected to the local power grid; when not, it operates autonomously. Four days for a small station (usually more) and 12 days for KAMAZ in “autonomous” mode is the norm.
• Air conditioners and air heating devices to ensure normal temperature conditions for equipment and personnel (because mobile stations can work both in severe frost and heat).

Are there other things like this?

Why do you need MBS?

What about more details?

July 6-7, 2011 In the Uchalinsky district of the Republic of Bashkortostan, a spring festival (Sabantuy) is being held in the village of Kalkanovo on the shore of Lake Kalkan. Cellular communications in the celebration area are not available from all operators. The population of the village is 395 people, the estimated number of people who attended the holiday is 2000 people. Two weeks before the holiday, approvals begin, then the station goes to the site and within an hour is deployed and goes into fully functional mode. The crew is two people: a driver-mechanic and an engineer. They live directly in the car, where there are two sleeping places. They eat food and rations “from home”, bought with “travel allowances”, plus they have the means to buy hot food directly at the holiday. Phase centers The antennas are located at a height of 10-15 meters above the ground, so at the machine level the radiation density is hundreds of times lower than permissible according to the standard, and inside it decreases even hundreds of times, and there is no need to wear it. During the operation of the BS, the total traffic amounted to 385.14 Erlang, and there were overloads a couple of times (1 Erlang is one hour of a subscriber’s conversation on the network, taking into account the dialing time, that is, in total, the subscribers spoke for about 16 days in 2 days: of course, this the distribution was uneven).

How many papers do you need to sign to move out of the garage?

What about specific TX?

For example, we have KamAZ-53229, where an antenna with a support 17 meters high is located in an isothermal van body. The chassis is designed to move only on hard surfaces (roads, fields, etc.), and deploys without braces. On the support there are 3 sector antennas with a height of 1.3 meters, an RRS antenna with a diameter of 0.6 meters. The support is equipped with a device for remote adjustment of the RRS antenna; an additional pipe support for mounting the RRS antenna is installed on the roof of the body. The isothermal body has three compartments - the BS hardware compartment, the antenna support equipment compartment and the diesel-electric generator compartment. The hardware compartment of the body houses 8 racks of technological equipment up to 1.9 m high (BS racks, ECU racks with batteries, transmission systems). Compartment height
hardware BS 2.5 meters. It includes a transportable earth satellite communication station (PZSSS) with an antenna with a diameter of 1.2 meters with an automatic guidance system on board the satellite repeater. PZSSS provides binding of the MBS to the switching network through four digital streams of 2 Mb/s.

The hardware compartment of the body is equipped with air conditioning, heating and supply and exhaust ventilation systems. It includes an autonomous power supply system - a 16 kW diesel-electric generator with fuel tanks. Battery life in normal mode at least 12 days. Plus cables 140 meters long for connecting MBS to three-phase network external
electricity supply The BS hardware room is equipped with an operator's workstation, as well as two sleeping places (in the BS hardware room and in the car cabin). MBS crew – 2 people. It is possible to use atmospheric lasers for connection, but they are not installed in the current configuration. The station is adapted for Russian conditions: resistant to heat, cold, bears and vandals.

Does the network capacity increase when a mobile BS is deployed nearby?

What's next?

Cellular towers are installed in open areas so that base stations can be mounted on them. Base stations are a set of devices responsible for receiving, transmitting and processing a cellular signal.

Despite the fact that the spread mobile methods Communication in Russia is intensive; many cities and villages find themselves without this type of communication.

Cell phone towers

Cell phone towers are used away from urban areas. In megacities, base stations are placed on the roofs of houses. Their range of action reaches 3-5 kilometers. And around roads, near rural settlements, special towers are installed. As a rule, these are white and red pillars, towers, on top of which a base station is mounted. When there are no forests or reinforced concrete structures in the signal path, towers can be placed at a distance of 10-15 km from each other.

As the mast rental market grows, the landscape is changing rapidly.

MTS cell towers

The MTS company ranks second in the number of base stations among large cellular operators in Russia. In 2016, about 137 thousand units were installed. This company was the first to lease out its towers to competitors and other enterprises, offering rather preferential conditions in the form of no penalties for early termination of the contract and no hidden or additional payments.

Beeline cell towers

In 2016, Beeline had about 96 thousand installed base stations. The dynamics of their increase is relatively modest: 4.5 thousand new stations appear per year. Although it was the installation of new towers that allowed the company to offer 4G Internet in many regions of Russia.

Megafon cell towers

As of 2016, Megafon had the most base stations installed: about 164 thousand. This company increases their number by 14-15 thousand per year.

Cellular tower Tele2

The Tele 2 operator is growing dynamically. In 2016, it had about 96 thousand base stations, which is comparable in coverage to Beeline. This company installs or leases 12 thousand new towers and stations per year. There is reason to believe that at this rate of development, this operator will soon take a stronger position in the top four.

How to install cell towers, and what is the price?

Cellular towers are used where there are no other options for placing base stations. Even around villages you can find tall structures on which it will be cheaper to mount antennas than to install a tower. These could be pipes, elevators and other types of high-type buildings.

The requirements for installing a tower are quite complicated:

• the height of the original tower should be from 72 to 100 meters;
• It is advisable to choose the highest place in the area; any hill or hill will do;
• access to electricity is required. If it is not there, you need to install a separate transformer;
• The tower should be installed near populated areas or roads with high traffic capacity.

The intensity of construction of towers is high; for example, in the Moscow region, several dozen of them are installed during the warm season.

The cost of building one cell tower is about 5 million rubles. IN lately It is customary to rent land for such structures not only from legal entities, but also from individuals. True, the rates for private landowners are purely symbolic - several hundred rubles per year.

What is the cost to rent a cell tower?

The big four cell phone operators own only 70% of the towers. Even companies such as MTS, Beeline, Tele 2 and Megafon rent part of the capacity from companies that specialize in the construction of towers. These include players such as:

• “Russian Tower” (1.7 thousand towers);
• "Vertical" (1.6 thousand towers).

Renting a cell tower is relatively inexpensive. U different companies the price can range from 15 to 30 thousand rubles per month.

Cell Tower Manufacturers and Suppliers

Most tasks related to the construction of cell towers can be solved by Russian companies and suppliers.

There are several companies that have proven themselves in this area:

• Metal-System LLC: the company produces towers, masts, and pipe stands for mounting base stations on the roofs of buildings.
• Altaystroydiagnostika LLC helps to build a tower based on a mast or tower in compliance with all technical and legal requirements. The company's experts know how to properly install supports and ensure uninterrupted operation of the equipment.
• The metal structures plant "Spetsstroykomplekt" can produce a tower according to standard drawings or taking into account the wishes of the customer. You can order here additional options for the tower: lightning rod, platform for technical personnel.
• MKTEK company is considered one of the cheapest manufacturers of cell towers. The towers installed by this company have a sectional structure. Depending on the required height of the mast or tower, you can choose different quantities sections. This saves money for those customers who plan to install a tower on a hill and who do not need the maximum height of the structure.

The total number of enterprises in Russia that produce and supply equipment for the installation of cellular towers is several dozen companies. The market is so developed that consumers have the opportunity to choose a company that will suit them in terms of the time frame for manufacturing and installation of the tower, the cost of the work, and the features of the technical equipment of the tower.

Tower maintenance

Maintaining towers is not cheap. Equipment must be changed at an uncertain frequency. Some towers work longer in an unchanged condition, others quickly fail. It depends on the type of equipment, average load honeycomb

Sometimes tower owners replace the equipment with more modern ones. 4G networks are gradually spreading throughout Russia. Behind this simple phrase there is a huge amount of work involved in upgrading equipment.

Simple maintenance of towers without modernization costs approximately 5% of the cost per year, that is, 250 thousand rubles.