What is a gsm module in a tablet and what are its capabilities. GSM module for remote control What is a gsm module in a phone

You can be sure that a gsm alarm system is worth installing on a car. But, before you start describing the benefits, this is actually wonderful view car alarm, I would still like to call for vigilance of car owners. You must be aware that in its pure form, a gsm alarm for a car will not fulfill its function - the safety of a car.

Reliability of GSM signaling

Especially when it comes to prestigious, expensive models that are specially ordered for theft. And they order not to street "punks", but to professional hijackers using professional equipment. Let's face it, and tell ourselves what we already know - any electronic system can be opened by an electronic system.

And therefore, reading about the unique this moment the possibilities of gsm car alarms, it does not interfere with thinking about how to create a comprehensive car security system: electronics + mechanical anti-theft means. Well, now let's move on to the car.

What is a GSM car alarm?

This is, in fact, the same computer that is designed not only to protect your car, but also to monitor its location in real time. In the event of an infringement, the alarm system transmits information about the violation to the owner and to the security console. Control is carried out using mobile phone with GPRS functions. Others are probably out of print now.

The control distance is unlimited, whether you are in a neighboring house or in Tahiti, it does not matter. In addition, the gsm system will completely secure any mechanical actions with your car, without your knowledge, such as loading a car onto a transport for the purpose of kidnapping.

How does GSM alarm system work?

Traditionally, the system consists of a central unit and several (optional) security sensors. There is a remote control key fob in the kit and the alarm system for a car is no different from the classic GSM, except for the principle of operation. Security sensors monitor the perimeter around the car and the interior of the cabin, trunk and hood.

Classification of GSM alarms

price segment. so-called. "budget" - in principle, are classical form car alarms. More expensive ones have the whole set, plus autonomous power supply, and a GPS receiver for monitoring.
Way to inform the owner. These are SMS notifications and auto redial with voice guidance. Plus combined, i.e. both types of notifications.
The way to program a GSM alarm on a car is the holy of holies. It is he who affects the quality and reliability of the system. Programming by sms-messages is still found, but is gradually becoming a thing of the past. The bulk of gsm alarms are programmed and controlled by a DTMF signal (tone dialing through the voice menu)
System power supply. Usually this is a 12V source. More advanced systems have autonomous system power supply, which is included in the event of force majeure. Almost all gsm car alarms are equipped with the function of informing the owner about a power problem.

Without a doubt, gsm alarm system today has no equal in mass use. Thanks to the use of modern technologies, it not only performs security functions, but also greatly facilitates the functionality of the car and the comfort of operation for the car owner.

Gsm alarm can act as a listening device inside the car
In addition to tracking the location using the GPS module, the system controls the speed and fuel level, and conducts video surveillance.
With certain settings of the tilt / movement sensors, the alarm will warn the owner about an attempt to remove the wheels or load the car onto the platform.
Remote control allows you to remotely start the engine for warming up. Those. all the charms that used to be installed separately are now in the hands gsm systems car alarms.

With all the positive characteristics, of course, there is a certain negative. In particular, gsm signaling is very dependent on the existing electronic signals in the city and interference in the form of reinforced concrete structures.

However, today GSM signaling is the most best option ensuring the safety of your car, both in terms of price and in terms of its properties and capabilities.

Good luck to you car lovers.

Lecture Search

Literature

1. Babkov V.Yu., Tsikin I.A. Cellular systems of mobile radio communication.- SP.:

Publishing House of the Polytechnic University, 2011.-426 p.

2. Kuznetsov M.A., Ryzhkov A.E. Modern technologies and standards

mobile communications. - St. Petersburg: Link, 2006.

3. Volkov A.N., Ryzhkov A.E., Sivers M.A. UMTS. Standard cellular communication

third generation. ‒ St. Petersburg, Link, 2008.

4. Standards and 4G radio access networks: LTE, WiMAX / A.E. Ryzhkov,

M.A.Sivers and others - St. Petersburg, Link, 2012 - 226p.

5. Nikitina A.V., Ryzhkov A.E. Radio access networks of the fourth generation.

LTE standard: technologies and procedures. - St. Petersburg, SPbGUT Publishing House, 2012 - 88s.

Answers:

Principles of cellular communication. Cellular technologies. Characteristics of traffic in cellular networks.

cellular, mobile network- one of the types of mobile radio communication, which is based on cellular network. The key feature is 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 composed of them looks like hexagonal cells (honeycombs).

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

The main components of a cellular network are cell phones and base stations, which are usually located on rooftops and towers. When turned on, the cell phone listens to the air, finding a signal from the base station. The 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 go on an analog protocol (AMPS, NAMPS, NMT-450) or digital (DAMPS, CDMA, GSM, UMTS). If the phone goes out of range of the base station (or the quality of the radio signal of the service cell deteriorates), it establishes communication with another (Eng. handover).

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

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

Operators can conclude roaming agreements with each other. Thanks to such contracts, the subscriber, being outside the coverage area of his network, can make and receive calls through the network of another operator.

What is GSM

As a rule, this is carried out at increased rates. The possibility of roaming appeared only in 2G standards and is one of the main differences from 1G networks.

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

The main characteristics of the GSM standard.

GSM(from the name of the group Groupe Special Mobile, later renamed Global System for Mobile Communications) ( Russian SPS-900) is a global standard for digital mobile cellular communication, with time division (TDMA) and frequency division (FDMA). Developed under the auspices of the European Telecommunication Standards Institute (ETSI) in the late 80s.

GSM refers to networks of the second generation (2 Generation) (1G - analog cellular communication, 2G - digital cellular communication, 3G - broadband digital cellular communication switched by multi-purpose computer networks, including the Internet).

Cell phones are produced for 4 frequency bands: 850 MHz, 900 MHz, 1800 MHz, 1900 MHz.

In the GSM standard, GMSK modulation is used with a normalized bandwidth of BT - 0.3, where B is the filter bandwidth at a level of minus 3 dB, T is the duration of one bit of a digital message.

GSM is by far the most common communication standard. According to the GSM Association (GSMA), this standard accounts for 82% of the global mobile communications market, 29% of the world's population uses global GSM technologies. The GSMA currently includes operators in over 210 countries and territories.

Construction principle
The principle of building cellular systems in brief is as follows: within the network coverage area, a certain number of relatively low-power stationary transceiver stations (base stations) are installed, each of which has a small coverage area (usually several kilometers). At the same time, the coverage areas of neighboring stations overlap each other somewhat to ensure the possibility of moving a subscriber from one area to another without losing communication. For this overlap to be possible, neighboring stations must use different operating frequencies. A minimum of three different frequencies is required to completely cover a given area so that the triangular stations can have service coverage overlap. The fourth station can again use one of these three frequencies, since it borders only two zones. With this approach, the shape of the coverage area of each base station is a hexagon, and the location of these zones exactly repeats the structure of bee honeycombs, which gave the name to communication systems with a similar construction principle.

Today GSM- the fastest growing cellular communication system. New, somewhat revolutionary technical innovations compatible with GSM, can and will be presented in the near future. All this serves as a solid foundation for the technology to GSM has become the single real standard for digital cellular systems around the world.

Now GSM is developing towards the third generation of cellular systems. The most significant difference between the developed technology GSM and the third generation of systems consists in the requirement for very high data transfer rates, up to 2 Mbps. This means that in order to provide a large network coverage area GSM-900, DCS-1800 And PCS-1900 can be used as components of third generation cellular communication systems. This also means that the high-speed data interface for 3G cellular systems must be designed to be compatible with GSM.

Main characteristics of the standard GSM.

· Frequencies of transmission of a mobile station and reception of a base station, MHz 890-915

· Frequencies of mobile station reception and base station transmission, MHz 935-960

Duplex spacing of receiving and transmitting frequencies, MHz 45

· Message transmission rate in the radio channel, kbps 270, 833

· Speech codec conversion rate, kbps 13

Communication channel bandwidth, kHz 200

· Maximum amount communication channels 124

The maximum number of channels organized in the base station is 16-20

Services provided[edit]

GSM provides support for the following services:

· Data transfer services (synchronous and asynchronous data exchange, including packet data transfer - GPRS). These services do not guarantee the compatibility of terminal devices and only provide the transfer of information to and from them.

· Transmission of speech information.

· Sending short messages (SMS).

· Sending fax messages.

Additional (optional) services:

· Identification of the calling number and restriction of such identification.

· Unconditional and conditional call forwarding to another number.

· Call waiting and holding.

· Conference communication (simultaneous voice communication between three or more mobile stations).

Ban on user-defined services (international calls, roaming calls, etc.)

and many other services.

Advantages and disadvantages[edit]

Advantages of the GSM standard:

· Smaller compared to analog standards (NMT-450, AMPS-800) size and weight of telephones with more time without recharging the battery. This is achieved mainly due to the equipment of the base station, which constantly analyzes the level of the signal received from the subscriber's device. In cases where it is higher than required, a command is automatically sent to the cell phone to reduce the radiated power.

· Good communication quality with a sufficient density of base stations.

· Large network capacity, the possibility of a large number of simultaneous connections.

· Low level industrial interference in these frequency ranges.

· Improved (compared to analog systems) protection against eavesdropping and illegal use, which is achieved through the use of encryption algorithms with a shared key. [ specify]

· Efficient coding (compression) of speech. EFR technology was developed by Nokia and subsequently became the industry standard encoding/decoding for GSM technology (see GSM-FR, GSM-HR and GSM-EFR)

· Wide distribution, especially in Europe, a large selection of equipment.

· Possibility of roaming.

This means that a subscriber of one of the GSM networks can use a cellular phone number not only at home, but also move around the world, moving from one network to another without parting with his subscriber number. The process of switching from network to network occurs automatically, and the user of a GSM phone does not need to notify the operator in advance (in the networks of some operators, there may be restrictions on the provision of roaming to their subscribers, more detailed information can be obtained by contacting your GSM operator directly)

Disadvantages of the GSM standard:

· Speech distortion during digital processing and transmission.

· Communication is possible at a distance of no more than 120 km from the nearest base station, even when using amplifiers and directional antennas. Therefore, to cover a certain area, more transmitters are needed than in the NMT-450 and AMPS.

GSM structure[edit]

Main article: GSM core network

GSM network structure

The GSM system consists of three main subsystems:

base station subsystem (BSS - Base Station Subsystem),

switching subsystem (NSS - Network Switching Subsystem),

· center Maintenance(OMC - Operation and Maintenance Centre).

In a separate class of GSM equipment, terminal devices are allocated - mobile stations (MS - Mobile Station), also known as mobile (cellular) phones.

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GSM (from Groupe Special Mobile, which was later renamed Global System for Mobile Communications) is a digital communication standard developed in the late 80s of the last century.

Income

GSM should be attributed to networks of the second generation, that is, 2G - digital cellular communications.

The standard got its name in honor of the analysis group that created the standard (Groupe Special Mobile). Its development began in 1982. The goal is to build a single cellular system for all European countries in the 900 MHz band. Commercial GSM networks began operating in mid-1991.

As of this writing, GSM is the most widely used communication standard in the world. It accounts for more than 80% of the entire global mobile communications market.

Services provided by GSM

Main services:

Transmission of speech information.

Sending fax messages.

Additional services include:

Definition of incoming numbers.

Voice communication with several subscribers (conferencing).

Prohibition of certain services.

GSM standards

Mobile phones are released with support for 4 frequencies: 850 MHz, 900 MHz, 1800 MHz and 1900 MHz.

Phones are divided into classes depending on the number of bands that devices support. For example, a phone that operates on one frequency is called a single band, and one that operates on three frequencies is called a triband. In some models, you can select a specific frequency.

Advantages and disadvantages of GSM

Let's start with the disadvantages:

Possible speech distortion during digital processing and data transmission.

Ability to communicate at a distance of no more than 120 km from the nearest station.

Now for the benefits:

Smaller size and weight of telephones that use analog standards.

Good protection against eavesdropping and illegal use.

Very widespread throughout the world.

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GSM communication operators in Russia

As of November 2007 in Russia there were about 168 million mobile subscribers. At the same time, 85% of them are clients of the Big Three GSM operators - Mobile Telesystems (MTS), MegaFon and VimpelCom.

Despite the fact that annual growth rates are constantly declining, the level of penetration of cellular services in Russia as a whole is 107%, while in the Moscow licensed zone (MLZ) this figure was 164%.

Leadership in the growth of the subscriber base on a nationwide scale is held by Megafon, and in the MLZ it is inferior to MTS in this indicator. Among federal and regional operators, Tele2, NTK, Baikalwestcom and Yeniseitelecom demonstrate the highest growth rates of subscribers on an annualized basis.

Regional GSM-operators that are not included in the "big cellular three" are looking for a way to compete with the giants of the market. Most of the independent GSM-operators in Russia appeared in the last few years on the basis of operators of the outdated AMPS standard. All of them in 2001-2002. received licenses from the Ministry of Communications, giving them the right to work in the GSM-1800 standard.
Now these companies are launching GSM-networks one after another, but their subscribers, having found themselves in other regions, are forced to pay $1-$1.5 per minute for roaming communications. Now these companies intend to agree on uniform roaming tariffs for each other, which will allow network subscribers to feel as good as MTS, VimpelCom and MegaFon clients when moving around the country, for whom uniform and relatively low intranet roaming tariffs are one of key benefits operators of the Big Three.

Open Joint Stock Company "Mobile TeleSystems" (MTS)- the largest mobile operator in Russia and the CIS countries, serving more than 74 million subscribers. The MTS license portfolio includes most of the regions of Russia, Ukraine, Belarus, Uzbekistan and Turkmenistan, and the population living in the MTS network coverage area is more than 230 million people.
Mobile TeleSystems was founded in October 1993. November 19, 1993 MTS received the first license for the provision of GSM cellular services. On May 15, 1994, the first calls were made in the MTS network, and already on July 7, 1994, MTS began to connect the first subscribers.
In June 2002, MTS launched a network in the Republic of Belarus. In March 2003, MTS acquired a controlling interest in UMC, the leading mobile operator in Ukraine.

JSC "Megafon" is an all-Russian mobile operator of the GSM 900/1800 standard. Formed in May 2002. The licensed territory of OJSC MegaFon covers 100% of the territory of Russia - all 89 constituent entities of the Russian Federation, where 145 million people live. MegaFon is the first all-Russian mobile operator of the GSM 900/1800 standard.

OJSC VimpelCom is a mobile operator in Russia, providing its services under the Beeline trademark. Cellular communications licenses of the VimpelCom group of companies cover the territory where 94% of the Russian population lives, including Moscow, the Moscow Region and St. Petersburg. The Beeline network operates on the territory of 76 constituent entities of the Russian Federation.
VimpelCom was founded on September 15, 1992. In June 1997, the first Russian network of the GSM-1800 standard - BEELINE 1800 was successfully launched. On October 21, 1998, the company successfully launched the first stage of the GSM-900/1800 dual-band network in Moscow.
On March 24, 1999, JSC VimpelCom became a member of the GSM Operators Association, which unites companies operating in the GSM-900 and GSM-1800 standards in Russia and a number of CIS countries.

CJSC "Middle Volga Interregional Association of Radio Telecommunication Systems" (SMARTS) was founded in May 1991 in Samara. The founders of the company are 95% individuals. Now the SMARTS GSM network covers 16 regions of Russia. To date, SMARTS has entered into roaming agreements with almost all Russian networks in 74 regions. The company has global roaming in 78 countries.

OJSC "Uralsvyazinform" is the largest operator of mobile communications and Internet services in the Ural region. The company operates on the territory of seven constituent entities of the Russian Federation with a total area of 1.9 million square meters. km with a population of more than 15 million people

NSS Nizhny Novgorod Cellular Communications- at the end of June 1995, the company began working with subscribers.

GSM-STORE - communication salon, online store

In 1999, the company established communication with the world through international roaming.

Sibirtelecom OJSC is the largest telecommunications operator in the Siberian Federal District. The company operates on an area of about 5 thousand square kilometers with a population of about 21 million people.

TELE2, known as Comviq until 1993, was founded in Sweden in 1981. In Russia, TELE2 is the owner of 12 Russian mobile communication companies. Russia's first mobile communication network TELE2 was launched in Irkutsk on April 1, 2003.

Do you know that

General characteristics of the GSM standard-Lesson 9 —>> Coding Session 13

Organization of physical and logical communication channels in the GSM standard Frequency plan of the GSM standard. Structure of logical communication channels. The structure of logical control channels. Organization of physical channels. Radio signal modulation

Lesson #11

GSM frequency plan
Physical channel in the GSM standard is a combination of time and frequency division of signals and is defined as a sequence of RF channels (with the possibility of frequency hopping) and time windows of a TDMA frame.
GSM standard designed to create cellular mobile communication systems (MCSS) in the following frequency bands: 890 ... 915 MHz - for transmission by mobile stations (uplink); 935 ... 960 MHz - for transmission by base stations (downlink).
Initially GSM networks will occupy the 10 MHz band in the frequency bands 905 ... 915 MHz (for transmission by mobile stations) and 950 ... 960 MHz (for transmission by base stations) and will operate in parallel with the existing European national networks of analog 900.

MCSS frequency plans, including the GSM standard, are shown in fig. 48.

GSM is a pan-European standard for digital
SSPS AMPS - standard for analog SSPS North
Americas D-AMPS (ADS) - the standard for digital METS North
Americas TACS(ETACS) is the UK standard for analog
JCSS
NMT 900 - Scandinavian standard for analog MCTS HCMTS, NAMTS - Japanese analog CMTS standards
SMPS frequency plans
Each of the lanes dedicated to GSM, is divided into frequency channels. The channel spacing is 200 kHz, which allows organizing 124 frequency channels in GSM, which are distributed in accordance with the placement of cells. The frequencies allocated for the transmission of the mobile station to the base station and in the opposite direction are grouped in pairs, organizing a duplex channel with a spacing of 45 MHz. These pairs of frequencies are also preserved during frequency hops. Each cell is characterized by a fixed assignment of a certain number of pairs of frequencies from 1 to 15 (no more).
If we designate Fl (n) - the number of the carrier frequency in the band 890 ... 915 MHz, Fu (n) - the number of the carrier frequency in the band 955.-.960 MHz, then the channel frequencies are determined by the following formulas:
Fl(n) = 890.2 + 0.2(n - 1), MHz Fu(n) == Fl(n) + 45, MHz 1< n < 124.
Each frequency carrier contains 8 physical channels located in 8 time windows within a TDMA frame and in a sequence of frames. Each physical channel uses the same time window in every TDMA time frame.
Prior to the formation of a physical channel, messages and data presented in digital form are grouped and combined into two types of logical channels: communication channels - for the transmission of coded speech or data (TSN), control channels - for the transmission of control and synchronization signals (CCH).
More than one type of logical channel can be placed on the same physical channel, but only with their appropriate combination.

IN GSM standard There are two main types of logical communication channels:
TCH/F (Full rate traffic channel)
22.8 kbps full rate messaging channel (other designation W)
TCH/H (Half rate traffic channel)
11.4 kbit/s half rate messaging channel (other designation Lm).
One physical channel may be a full rate messaging channel or two half rate channels.

In the first case, the communication channel occupies one time window; in the second, two communication channels occupy the same time window, but interleaved in adjacent frames (i.e., each channel is through a frame).

Structure of logical communication channels
The GSM standard distinguishes two main types of logical communication channels:
TCH / F (Full Rate Traffic Channel) - a message transmission channel with a full speed of 22.8 kbps (another designation is Bm);

TCH / H (Half Rate Traffic Channel) - a message transmission channel with a half speed of 11.4 kbit / s (another designation is m).
One physical channel may be a full rate messaging channel or two half rate channels. In the first case, the communication channel occupies one time window; in the second, two communication channels occupy the same time window, but with interleaving in adjacent frames (i.e., each channel through a frame).

The following types of communication channels are intended for the transmission of coded speech and data:

TCH/FS (Full Rate Traffic Channel for Speech)
—a channel for transmitting voice at full rate;

TCH/HS (Half Rate Traffic Channel for Speech) :
— channel for transmitting voice at half speed;

TCH/F 9.6 (Full Rate Traffic Channel for 9.6 kbit/s User Data)
— data link with a full rate of 9.6 kbps;

TCH/F 4.8 (Full Rate Traffic Channel for 4.8 kbit/s User Data)
— full rate data link 4.8 kbps;

TCH/F 2.4 (Full Rate Traffic Channel for 2.4 kbit/s User Data)
— data link with a full rate of 2.4 kbps;

TSN/N 4.8 (Half Rate Traffic Channel for 9.6 kbit/s User Data)
— 4.8 kbps half rate data link;

CH/H 2.4 (Half Rate Traffic Channel for 9.6 kbit/s User Data)
— 2.4 kbit/s half rate data link.

The digital voice rate on the TCH/FS channel is 13 kbps (increased to 22.8 kbps on the TCH/F channel due to coding).

Channels of connection can transmit a wide range of informational messages, but they are not used to transmit control signals.

In addition, different protocols can be used for data transmission over communication channels, for example, ITU-T X.25.

Structure of logical control channels

Control channels (CCH) provide transmission of control and synchronization signals. There are four types of control channels:

BCCH (Broadcast Control Channels) - channels for transmitting control signals;
CCSN (Common Control Channels) - common control channels;
SDCCH (Standalone Dedicated Control Channels) - individual control channels;
ACCH (Associated Control Channels) - combined control channels.

Signaling channels controls are used only in the direction from the base station to all mobile stations. They carry information that mobile stations need to operate in the system. There are three types of channels for transmitting control signals BCCH:

FCCH (Frequency Correction Channel) - frequency adjustment channel, which is used for carrier synchronization at the mobile station. This channel transmits an unmodulated carrier with a fixed frequency offset relative to the nominal value of the frequency of the communication channel;
SCH (Synchronization Channel) - synchronization channel, through which information is transmitted to the mobile station about the frame (time) synchronization;
BCCH (Broadcast Control Channel) - transmission control channel, provides the transmission of basic transmission control commands (the number of common control channels of those that are combined with other channels, including physical ones, etc.).

Three types of common SSCH control channels are used:
PCH (Paging Channel) - call channel, is used only in the direction from the base station to the mobile to call it;
RACH (Random Access Channel) - parallel access channel, used only in the direction from the mobile station to the base station to request the assignment of an individual control channel;
AGCH (Access Grant Channel) - authorized access channel, is used only for transmission from the base station to the mobile to allocate a special control channel that provides direct access to the communication channel.

Dedicated individual control channels are used in two directions for communication between the base and mobile stations.

There are two types of such channels:

SDCCH / 4 (Stand-alone Dedicated Control Channel) - individual control channel, consists of four subchannels;
SDCCH / 8 (Stand-alone Dedicated Control Channel) - individual control channel, consists of eight subchannels.

These channels are for setting the type of service required by the user. They provide a request to the mobile station about the required type of service, control of the correct response of the base station and allocation of a free communication channel, if possible.

Shared control channels are also used bi-directionally between the base station and the mobile station.

In the forward direction, they transmit a control command from the base station, and in the reverse direction, information about the status of the mobile station. There are two types of ASSN:

FACCH (Fast Associated Control Channel) - a fast associated control channel, is used to transmit commands when a mobile station moves from cell to cell, i.e. when "handover" (handover, handoff) of the mobile station;
SACCH (Slow Associated Control Channel) - slow associated control channel, in the forward direction transmits commands to set the output power level of the transmitter of the mobile station.

What is GSM in a phone?

In the reverse direction, the mobile station sends data regarding the level of the set output power, the level of the radio signal measured by the receiver and its quality.

A shared control channel always contains one of two channels: a communication channel or an individual control channel.

Shared control channels are always combined with communication channels or with individual control channels. There are six types of integrated control channels:

FACCH/F merged with TCH/F;
FACCH/H combined with TCH/H;
SACCH/TF merged with TCH/F;
SACCH/TH combined with TSN/H;
SACCH/C4 merged with SDCCH/4;
SACCH/C8 merged with SDCCH/8.

Organization of physical channels
As a rule, logical channels are combined into groups, which are transmitted by TDMA multiframes.

For example, on the main (zero) frequency in the cell (BCCH carrier) in the zero timeslot, the FCCH + SCH + BCCH + CCCH group is transmitted (in the downlink direction). This group is also called a combined BCCH/CCCH channel. This channel is for all mobile stations served by the cell. Thus, the phone always "knows" where to get system information about the cell in order to gain access to the network.

As can be seen from the figure, the multiframe is divided into 5 groups of 10 frames each, the last frame remains empty. The mobile station determines the frequency of the BCCH carrier by searching for a Frequency correction Burst that is transmitted on the FCCH. It then receives and decodes the current frame number and BSIC identifier over the SCH, which is necessary for correct synchronization with the BTS. The FCCH and SCH channels occupy the first 2 frames in each group. The remaining 8 frames form 2 blocks of four frames. The first block of the first group is for the BCCH channel. Through it, the MS determines the ability to access a given cell and decodes the system information of the cell. The remaining 9 blocks (call signaling blocks) are used to transmit the PCH and AGCH channels that are part of the common control channel CCCH.

Radio signal modulation
Modulation (lat. modulatio - dimension)- the process of changing one or more parameters of a high-frequency carrier oscillation according to the law of a low-frequency information signal.

The transmitted information is embedded in the control signal, and the role of the information carrier is performed by a high-frequency oscillation called the carrier.
Modulation can be carried out by changing the amplitude, phase or frequency of the high-frequency carrier.
This technique provides several important advantages:
Allows you to generate a radio signal that will have properties corresponding to the properties of the carrier frequency. You can read about the properties of waves of different frequency ranges, for example, here.
Allows the use of small antennas, because the size of the antenna must be proportional to the wavelength.
Allows you to avoid interference with other radio signals.

The data stream transmitted in WiMax networks corresponds to a frequency in the region of 11 kHz. If we try to transmit this low frequency signal over the air, we will need an antenna of the following dimensions:

An antenna 24 kilometers long does not seem comfortable enough to use.
If we transmit this signal superimposed on a carrier frequency of 2.5 GHz (the frequency used in Yota WiMax), then we need an antenna 12 cm long.

Modules operating according to the standard of mobile GSM communications, designed to provide communication with StarLine security systems. Their demand is explained by a large number of interferences that occur in urban conditions, as well as by frequent significant remoteness. vehicle from its owner, which has an extremely negative effect on the performance of the alarm.

In such situations, when the signal from a special key fob cannot reach the car, similar GSM modules become the main assistant. Availability this device allows you to establish communication with the security system of the vehicle not using a key fob, but using a mobile phone or smartphone.

Depending on the selected type of GSM device, it becomes possible to perform the following actions:

Enable or disable the security mode of the vehicle.
Turning on or shutting off the engine.
Checking the state in which the vehicle is currently located.
Determining the exact location where given time is the car, as well as its coordinates.

These are just the main features that are included in virtually all similar GSM devices, most of them modern models has an extended list of possible actions. For their implementation, it is enough to make a call to the car or send a text message.

Model range

In fact, all available models of Starline GSM modules have common similar advantages that are common to all devices of this manufacturer, among them are:

Introduction of modern innovative technologies into the alarm system allows you to increase the level of car safety and the quality of its protection.
A combined combination of guaranteed reliability and promptness of the information provided or actions taken.
The range of goods is presented in various price categories, which ensures its availability to all car owners.
Instant notification of possible attempts to break into the car or steal it.
Ease of installation and ease of operation.
Starline is a Russian manufacturer of security systems and related products, therefore specifications and other nuances of the proposed range of models are focused on the peculiarities of the domestic climate.

There were no significant shortcomings in the Starline GSM modules.

Most of the negative customer reviews about such devices in general are caused by the purchase and use of Chinese-made devices that were not designed for Russian climatic conditions and are rarely repairable in case of failure.

For a more accurate understanding of what these modules are, it is proposed to consider some models in detail.

The first to be analyzed in detail is the Starline 2CAN 35 model, which belongs to the class of economy class devices:

The built-in mode called "Immobilizer" helps protect the vehicle from possible theft. If the module system does not identify the person starting the engine as the owner of the car, then the attacker will not be able to drive away in a stolen car.
Another mode of operation called "Anti-robbery" provides protection not only road transport but also its owner. If the owner of the car becomes a victim of an attack and subsequent theft, then the attacker will be able to drive off a certain distance, which will ensure the safety of the true owner, and then the engine will be automatically turned off.
The GSM module of this model can be installed on virtually any car that was produced from 2009 to 2014.
The device is capable of operating temperature conditions-40°C to +85°C.
Dimensions differ in their compactness: 5x3.5x1 cm.
The module can be guaranteed to perform all its functions in humidity environment up to 95%.
The basic package includes instructions for both mounting the module and its use, a signal cable and a document that allows you to use the warranty repair service if necessary.
This system will cost car owners approximately at 1800-2000 rubles excluding shipping costs.

Another model for consideration is the M32 CAN T, which has the following features:

The multifunctionality of the module, as an innovation, the possibility of insurance Telematics has appeared. Thanks to it, the device collects statistical data on mileage, and also analyzes the driving style, allowing you to significantly reduce the cost of CASCO insurance.
New iCAN function responsible for blocking the engine if necessary. The connection is carried out by ordinary wiring, so this additional system car security is inconspicuous and will not be noticed by intruders.
Another innovation called iKey makes it possible to automatically start the engine without the need to spend one of the regular vehicle keys. Switching on will occur via the CAN bus, which will significantly reduce the cost of automatic start.
The presence of a 2CAN interface allows you to easily install the module on all vehicles with the corresponding bus.
The set parameters of the settings allow you to automatically start the engine of the machine with the appropriate command on the smartphone, the set time, or when a certain temperature regime is reached.
Determining the coordinates of the location of the vehicle can be implemented not only using the installed application, but also using the online service on the official Starline website.
The built-in microphone allows you to listen to what is happening inside your own car at any time.
In addition to the standard basic package, along with the module, the buyer will also receive an LED indicator, a SIM card, a microphone, wires, a GPS receiver, all necessary adapters and a power module.
The price for this model is approximately 13,000-13,500 rubles, excluding shipping costs. If you plan to install the system by a qualified master, then the total expense will be about 18,000 rubles. The installation process takes about 5-6 hours.

The last model considered will be the M31+iDatalink Start CAN module, which is one of the most expensive and multifunctional models of devices in this class.

Among its features are:

Availability of redesigned Telematics of the new generation.
The device has a built-in microphone and an additional GPS module.
The ability to control the vehicle by using a smartphone, as well as determining the exact coordinates of the car at any convenient time.
You can control the GSM module using a special application, as well as by sending text messages or making phone calls.
The proposed module is compatible with virtually all vehicles present on the modern Russian car market. However, if incompatibility is detected, the manufacturer undertakes to replace the device with a compatible analogue without any additional payments from the client.
The package additionally includes an immobilizer crawler, which does not require the use of keys.
The module is fully compatible with SIM-cards of any mobile operators and any selected tariffs. In total, four different phone numbers can be written to the device at once.
By connecting the limit switches of all car doors, as well as the hood and trunk, the owner of the vehicle will receive an autonomous security system that will notify him of any suspicions related to violation of security boundaries.
Notification about violations of the speed limit has been added to the functions, which will be issued in the form of SMS messages.
The cost of such a GSM module is 14000-14500 rubles, however, if the installation by the master is chosen, the price will be increased to 25,000 rubles.

Which model to choose

All Starline GSM modules meet high quality standards, undergo preliminary testing and have a significant warranty period. Therefore, no matter what specific model is selected, there is no doubt about the quality of the equipment of this manufacturer.

It is necessary to build on the selection process only from the available budget, since different models are in absolutely different price ranges, and from the necessary functionality of the module. At the same time, it is important to remember that the more additional security features that operate on various principles, offers the device - the higher will be the degree of safety of the car.

Buying a vehicle is a process important to many. And sooner or later we think about how to ensure the safety of the operation of our car. A modern and reliable GPS / GSM car alarm helps in this, thanks to which constant control over the car will be ensured at any time of the day or night.

What is specific?

Satellite signaling is modern device, working on the basis of two built-in and GSM. The first is needed in order to determine the location of the car relative to the world coordinate system, since this is a global network consisting of 24 satellites in orbit. The module is supplemented with special receivers, through which communication with satellites is established. Good GPS/GSM car alarm recognizes a large number of satellites.

Main Components

Satellite signaling consists of basic and additional equipment. Of the basic components, each security system equipped with:

processing unit;
interface software;
antenna;
sensors;
GPS module.

Each alarm has its own design features and programmed for a specific algorithm of work. As additional components of a satellite line, a GSM module for car alarms, an immobilizer, a listening device and

Why is GSM needed?

The GSM network is an important element of car alarms, since through this module an alarm text message is sent to the car owner's mobile phone, which allows you to respond in a timely manner, for example, to an attempted theft. The alarm must be equipped with an antenna, the task of which is to establish communication with the satellite. It is installed so that there are as few obstacles as possible to the transmission of a signal or data packet.

How does the security system work?

GPS/GSM car alarm consists of two electronic units that are mounted inside the car. The first block is needed to determine the geoposition of the car in relation to satellites, the second - to ensure communication with the driver of the car. The advantage of its use is that they are connected to the dispatcher control panel, and therefore all important information will go directly to the security company. True, these services are paid.

Regardless of who the equipment manufacturer is, each system has its own characteristics and functional differences. The efficiency of its work is ensured by the quality of area coverage by a specific mobile operator. The advantage of satellite security complexes in that multifunctional two-way communication between the car and the owner will be provided. All information is provided to him on a mobile phone.

Types and features

Modern GSM car alarms are paging, duplicating or performing GPS monitoring. Paging is the cheapest and allows you to determine the location of the vehicle from a distance. A feature of GPS monitoring is the ability to determine the exact location of the machine and remote control the main systems of a car - ignition or engine. To alarms elite class include duplicating, which not only carry out GPS monitoring, but also have a number of additional features. Modern GSM car alarms are characterized by a number of advantages:

Large network coverage.
Multifunctionality.
The ability to track the movement of the car.
Hidden installation.

But the reviews note that satellite security lines also have disadvantages, the most important of which is the ability to read the GPS code signal. In addition, if the car is underground, then it is impossible to pick up the signal from the sensor.

Selection rules

Modern manufacturers offer a huge selection of car alarms. But experts and owners of equipment of different brands are advised to pay attention to a number of details when choosing:

if there is an immobilizer, then if necessary, you can block the engine;
built-in motion blocking systems block the fuel supply to the engine if the immobilizers break the power supply circuits during operation;
remote start - important advantage modern security lines;
The GPS module is a guarantee that the driver's key fob will receive information about where the stolen car is located.

How to do it yourself?

Of course, there are a huge number of modern models of car alarms. But not everyone has the opportunity to purchase products of a particular brand. Note that the simplest do-it-yourself GSM car alarm can be made from a phone.

Those who have already made such equipment with their own hands say that this process is simple, the main thing is to choose diagrams and descriptions. As components you need to prepare:

old mobile phone on buttons;
magnet;
reed switch;
wires;
switch.

The assembly process is quite simple. First, the subscriber's call is configured, that is, the current number of the owner on one button. Then the front panel of the phone is removed, since you need access to the board where the contacts are connected. On this stage It is important to solder the wires correctly. So, if the functions of turning off the phone and hanging up fall on one button, then one wire is soldered to the button itself, and the second to the key that will be responsible for the call. If the end and end buttons of the mobile device are different, then the wires are soldered to each of them.

After the circuit is completed, a magnet is placed on the door, and then the reed switch is adjusted. As you can see, this one is easy to create. But the essence of its work differs from the principle of operation of conventional signaling systems: when you try to open the door, the contacts of the reed switch close, and a call will come from the phone to the number that is programmed. Using an additional switch, the alarm is armed and disarmed. Such a system will promptly warn the owner of the car about unauthorized access. In addition, the systems are distinguished by low cost of creation, almost complete autonomy, while the phone will be periodically charged.

Pandora DXL 3910

Consider the most popular security systems that deserve a lot of different reviews. So, the model attracts attention with innovation, since GPS / GSM car alarms do not require the use of a key fob. The whole system works on the basis of labels, that is, key fobs with two buttons that do not display any information. The car alarm is controlled via a smartphone, but you can set up a GSM voice interface or install a mobile application.

Thanks to the flexibility of customization, the system can be easily adapted to the requirements of a particular owner. And yet, as users note, the Pandora DXL 3910 will look harmoniously in the standard system of any car. Among the shortcomings, users note that the system is too complicated, it has a huge number of settings, which are very difficult to deal with even for experienced owners of automotive electronics.

StarLine: B64 Dialog CAN and D94 2CAN GSM/GPS Slave

GSM-module for car alarm StarLine is a modern device that provides full control over the car. This brand offers to evaluate wide choose security lines with a variety of functionalities. So, the StarLine B64 Dialog CAN model, in addition to security functions, allows you to control the service functions of a car - interior lighting, temperature control in it and many other important little things.

The device comes with two key fobs - one has an LCD display, and the second is simple and compact, but both provide two-way communication with the central unit at a distance of up to 2 km. Fans of compact but powerful systems note that this car alarm model is distinguished by its affordable cost and additional features. Of the minuses, the lack of auto-start of the engine is distinguished.

Car alarm GSM GPS, according to many users, is the best in this series. This is a whole security system, the possibilities of which are unlimited. The device is controlled via a smartphone, and the alarm can detect the car with great accuracy when it is stolen. It is no coincidence that this model has been repeatedly recognized as the most reliable in terms of protection against scanning and hacking. The advantage of the device is in the three-axis shock and tilt sensor, which is supplied in the kit. It is triggered by any attempt to move the car from its place. Among the minuses, users note the difficulty of setting up and the expensive cost, but in terms of performance and reliability, this car alarm is worthy of attention.

StarLine M 30 (Messenger GPS)

GSM/GPS modules Starline Messenger are devices that allow you to control the car security system. A huge number of such modules are supplied in the StarLine series. So, StarLine M21 is a module that is controlled by the phone and allows you to determine the coordinates of the car. The peculiarity of the module is the ability to work with any GSM-communication operators. The owner of the car can give commands in several ways:

through a mobile application on iOS/Android platforms;
sending a text message with a command code;
phone call to the security system number.

This novelty can also be used as an independent security system, as there are three line outputs on the case, through which the module can be connected to those located on the door, hood and trunk. This module is powerful - you will be in touch with your car, wherever you are.

Pantera Cl-550

There are a variety of reviews about this GSM car alarm, but among the pluses are the affordable price of the device and the ease of setting it up. For a mid-range security system, the Pantera Cl-550 can be considered a reliable anti-theft device that emits a siren when triggered. The model is equipped with simple, but quite reliable sensors, so the car will be protected from break-ins. The advantage of the model is the ability to program and configure, which is quite rare for this price category. Some users note that the level of the security system is not very high.

Jaguar Ez-ultra

This is a one-way GPS / GSM car alarm that attracts attention at a low price effective protection from interference and speed. The system can be configured to use separate radio channels, especially if additional service functions are required. Among the advantages of the model, users note the expansion of autorun control and the ability to arm the alarm when the system is running. Idling engine. According to users, the Jaguar Ez-ultra is easy to install and configure, but it is not easy to hack it.

Tomahawk 7.1

This GPS / GSM car alarm attracts attention with the silent arming function, which is not available in all premium models. An undeniable bonus of the system can be considered non-volatile memory, which even when the power is turned off will save all data on the state of the device. The dual dialogue code with a modern coding algorithm is the key to the high security of the system. But the model also has a drawback - there are no additional channels so that you can control external devices.

Alligator C-500

Of the economical, but high-quality car alarms, this one can be noted. It works at a distance of 2.5 km, has six independent security zones, is equipped with intelligent autorun and has the function of controlling additional devices. In addition, the two-way GSM module for car alarm "Alligator" received a lot of good reviews. Installing the line in the car is simple and convenient, you don’t even need to go to a service center for this. Users say that the missing immobilizer can be filled with an additional module.

Thus, in order for the security system on the car to be effective and reliable, choose a model in which the speed of alerting the driver is higher. It is for this indicator that GSM systems are in high demand among those who want to protect their car from theft and unauthorized entry.

Any module is a functionally completed unit for solving certain tasks.

For GSM modules it is:

remote control of home equipment (heating boiler, gate, barrier);
transmission of information for security systems fire alarm;
expanding the possibilities of car alarms (autostart).

In addition, GSM modules are used as part of equipment for wireless connection to the Internet for tablets and laptops. These are various modems and routers.

They include a transceiver operating in the GSM standard, an interface for communication with other devices. For engineering management technical systems by switching on/off the supply voltage, relay switching units are used.

The exchange of information and the formation of control signals can be carried out in different ways:

SMS messages;
via internet protocol (GPRS, 3G, 4G).

Each has pros and cons. The first option is less demanding on the quality of communication (signal level). It does not require any special equipment to operate. software- a mobile phone is enough. The disadvantage is the relative complexity of monitoring the communication channel. As a rule, acknowledgment is used for this - confirmation by a response SMS of the receipt or execution of a command.

If the module is used to detect emergency situations (alarm, power outage, gas boiler failure), then the owner may not receive information about this event or see it with a long delay.

Solutions exist in the form of periodic sending by the block installed on the test message object. You can also make a manual request for the module status, but all this is quite complicated, slow and, as a result, inefficient.

Below are the main areas of application of GSM technologies in remote control and monitoring systems for houses, cottages and apartments.

ALARM SYSTEM FOR HOME WITH GSM MODULE

The advantage of this method of organizing security is mobility. The disadvantage is the already considered difficulties in monitoring the state of the alarm system. When working with the centralized security console (RCS), you can use blocks with signal transmission over the Internet channel. In this case, it is possible to implement permanent control.

To work with cell phone this method will not work, so you need to take care of organizing a stable connection. Even in the area of stable reception and transmission of the GSM signal, there is a possibility of losing SMS messages. In case of an uncertain connection, you can use one of the following methods:

connection of an external antenna;
installation of a cell phone booster.

In any case, you will need to install a mast to accommodate the antenna. Its height depends on the terrain. Since the antenna must be used directional, it will not be superfluous to find out the location of the nearest base stations and their belonging to a particular operator.

To organize GSM signaling, devices are produced that combine a control panel and a transceiver module. Thus, the device simultaneously monitors home alarm sensors and transmits information about their status to the user's phone.

To increase the reliability of the security fire system, it is worth purchasing a module with two SIM card slots. Using SIM cards from two different operators, you reduce the risk of missing SMS messages.

In addition, there are solutions that allow you to find out in a timely manner about the problems of the cellular network at the location of the house. For example, Xital has implemented a solution in which two units installed in different places control each other. In case of problems with one, the other reports it to predetermined phones.

Of course, not everyone will decide to purchase two modules to control one object, but if you have friends who have a private house or dacha, you can team up with them. Each module will protect its object, plus control the "partner" wherever he is.

GSM MODULE FOR REMOTE CONTROL

The most popular remote control:

heating - boiler;
access control system (ACS) - gates, barriers, etc.

GSM modules for heating boiler.

For heating boilers, two tasks are relevant:

work management;
remote control modes and parameters.

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