In accordance with Article 41 Federal Law dated July 7, 2003 N 126-FZ “On Communications” (Collected Legislation of the Russian Federation, 2003, N 28, Art. 2895; N 52 (Part I), Art. 5038; 2004, N 35, Art. 3607; N 45, Art. 4377; 2005, Art. 1752; 2006, Art. 1069; , Art. 8) and paragraph 4 of the Rules for organizing and carrying out work on mandatory confirmation of the conformity of communications equipment, approved by Decree of the Government of the Russian Federation of April 13, 2005 N 214 (Collection of Legislation of the Russian Federation, 2005, N 16, Art. 1463), I order :
1. Approve the attached Rules for the use of subscriber networks of mobile radio communications.
2. Send this order to state registration to the Ministry of Justice of the Russian Federation.
3. Entrust control over the implementation of this order to the Deputy Minister information technology and communications of the Russian Federation B.D. Antonyuk.
| Minister | L.D. Reiman |
Registration N 9395
Rules for the use of subscriber radio stations with analog modulation of mobile radio networks
(approved by order of the Ministry of Information Technologies and Communications of the Russian Federation
dated April 12, 2007 N 46)
I. General provisions
1. The rules for the use of subscriber radio stations with analog modulation of mobile radio networks (hereinafter referred to as the Rules) were developed in accordance with Article 41 of the Federal Law of July 7, 2003 N 126-FZ “On Communications” (Collected Legislation of the Russian Federation, 2003, N 28, Art. 2895 (Part I), Art. 2004, Art. 3607; Art. 2005, Art. 1752; 10, Art. 1069; No. 31 (Part I), Art. 3452, Art. 8) unified network telecommunications of the Russian Federation.
2. The rules establish mandatory requirements for subscriber radio stations with analog modulation (phase or frequency) in mobile radio networks (hereinafter referred to as subscriber radio stations).
3. Subscriber radio stations are subject to declaration of conformity.
4. Subscriber radio stations are used in radio frequency bands authorized for use by the State Commission on Radio Frequencies.
II. Requirements for subscriber radio stations with analog modulation of mobile radio networks
5. Requirements for the parameters of frequency ranges and duplex frequency spacings used for connecting subscriber radio stations with base stations, are given in Appendix No. 1 to the Rules.
6. The frequency spacing between adjacent channels of subscriber radio stations is 12.5 and (or) 25 kHz.
7. Subscriber radio stations, depending on the information transmitted, are divided into the following types:
1) subscriber radio stations designed to transmit voice information using angular modulation with a constant envelope;
radiation classes - F3E*(1), G3E*(2);
2) subscriber radio stations designed for data transmission using direct carrier modulation or indirect modulation (modulation of a subcarrier in the audio spectrum). Types of modulation - GMSK*(3), MSK*(4), FFSK*(5), multilevel frequency modulation(FM), four- and eight-level phase modulation (PM); radiation classes - F1D*(6), G1D*(7);
3) subscriber radio stations intended for transmission of voice information or data transmission, with mode switching;
4) subscriber radio stations intended for transmitting voice information and transmitting data simultaneously, have a path for transmitting data in the subtone frequency region and transmitting voice information in the tonal region.
8. Subscriber radio stations perform all procedures for sending and receiving calls, establishing, maintaining and releasing connections with subscriber radio stations of mobile radio networks, mobile radio networks telephone communication and terminal equipment of fixed telephone networks and data networks.
9. For subscriber radio transmitters intended to transmit voice information, the following mandatory requirements for parameters are established:
1) deviations of the transmitter frequency from the nominal value in accordance with Appendix No. 2 to the Rules;
4) frequency deviation of transmitters in accordance with Appendix No. 5 to the Rules;
5) the transmitter radiation level in an adjacent channel for a frequency spacing between adjacent channels of 12.5 kHz does not exceed a value equal to minus 60 dBc or 0.2 μW (minus 37 dBm);
6) the transmitter radiation level in an adjacent channel for a frequency spacing between adjacent channels of 25 kHz does not exceed a value equal to minus 70 dBc or 0.2 μW (minus 37 dBm);
7) levels of spurious emissions from transmitters in accordance with Appendix No. 6 to the Rules;
8) frequency deviations of transmitters in transient mode in accordance with Appendix No. 7 to the Rules.
10. For subscriber radio transmitters intended for data transmission, the following mandatory requirements for parameters are established:
1) deviations in the frequency of transmitters in accordance with Appendix No. 9 to the Rules;
2) the carrier power of transmitters of subscriber radio stations with an external antenna connector (on the antenna equivalent) in accordance with Appendix No. 3 to the Rules;
3) maximum and average effective radiated power (ERP) of subscriber radio transmitters with a built-in antenna in accordance with Appendix No. 4 to the Rules;
4) the duration of transient processes when the transmitter is turned on does not exceed the limit value t_a1 equal to 25 ms.
Graphs of transient processes of changes in carrier power and frequency when transmitters are turned on are given in Appendix No. 10 to the Rules.
5) the duration of transient processes when the transmitter is turned off does not exceed the limit value t_r1 equal to 20 ms.
Graphs of transient processes of changes in carrier power and frequency when transmitters are turned off are given in Appendix No. 11 to the Rules.
6) the transmitter radiation level in an adjacent channel for a frequency spacing between adjacent channels of 12.5 kHz does not exceed a value equal to minus 60 dBc or 0.2 μW (minus 37 dBm);
7) the radiation level in an adjacent channel during transient processes in the transmitter for a frequency spacing between adjacent channels of 12.5 kHz does not exceed a value equal to minus 50 dBc or 2 μW (minus 27 dBm).
The radiation level in an adjacent channel during transient processes in the transmitter for a frequency spacing between adjacent channels of 25 kHz does not exceed a value equal to minus 60 dBc or 2 μW (minus 27 dBm).
8) levels of spurious emissions from the transmitter in accordance with Appendix No. 6 to the Rules.
11. For transmitters of subscriber radio stations intended for the transmission of voice information and data transmission, mandatory requirements for parameters are established in accordance with paragraph 9 and subparagraphs 2) - 6) of paragraph 10 of the Rules.
12. For subscriber radio transmitters intended to transmit voice information and transmit data simultaneously, mandatory requirements for parameters are established in accordance with paragraph 9 of the Rules.
13. For receivers of subscriber radio stations, mandatory requirements for parameters are established:
a) the level of radiation from receivers at the external antenna connector in accordance with Appendix No. 8 to the Rules;
b) the level of radiation from the housing and structural elements of subscriber radio receivers in accordance with Appendix No. 8 to the Rules.
14. The following mandatory requirements for parameters are established for subscriber stations:
1) resistance of subscriber radio stations to climatic influences in accordance with Appendix No. 12 to the Rules;
2) resistance of subscriber radio stations to mechanical influences in accordance with Appendix No. 13 to the Rules.
15. Requirements for power supply of subscriber radio stations. Depending on their purpose, subscriber radios are powered from the following power sources:
a) networks AC rated voltage 220 V and frequency 50 Hz in case of using power supplies for portable subscriber radio stations. Subscriber radio stations ensure operation when the supply voltage changes in the range from minus 15% to plus 10% relative to the rated voltage of 220 V;
b) external source DC(on-board network of a moving object). Subscriber radio stations ensure operability when the supply voltage changes in the range from minus 10% to plus 30% relative to the rated voltage of the on-board network of the moving object;
c) own direct current source ( battery). The type, rated supply voltage of its own direct current source and the limits of voltage change at which the subscriber radio station remains operational are established by the manufacturer.
_____________________________
*(1) Emission class F3E - frequency modulation (F) of one analog telephone channel (3E).
*(2) Emission class G3E - phase modulation (G) of one analog telephone channel (3E).
*(3) In international practice, the abbreviation GMSK (Gaussian Minimum Shift Keying) is used.
*(4) In international practice, the abbreviation MSK (Minimum Shift Keying) is used.
*(5) In international practice, the abbreviation FFSK (Fast Frequency Shift Keying) is used.
*(6) Emission class F1D - frequency modulation (F) of one digital channel data transmission (1D).
*(7) Emission class G1D - phase modulation (G) of one digital data transmission channel (1D).
Appendix No. 1
radio stations with analogue modulation
mobile radio networks
Requirements for the parameters of frequency ranges and duplex frequency spacing for connections between subscriber radio stations and base stations
To connect subscriber radio stations with base stations, they are used frequency ranges and duplex frequency spacings given in the table.
_____________________________
*(1) For duplex subscriber radio stations.
*(2) In international practice, the abbreviation VHF (Very High Frequency) is used.
*(3) In international practice, the abbreviation UHF (Ultrahigh Frequency) is used.
Appendix No. 2
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for parameters of transmitter frequency deviation from the nominal value
1. The deviation of the transmitter frequency from the nominal value does not exceed the values given in tables NN 1 and 2.
Table N 1. Deviation of transmitter frequency from the nominal value under normal conditions (hereinafter referred to as NU*)
Table No. 2. Deviation of transmitter frequency from the nominal value under extreme conditions (hereinafter - ED**)
_____________________________
* NU are defined in Appendix No. 12 to the Rules.
** EC are defined in Appendix No. 12 to the Rules.
Appendix No. 3
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for carrier power parameters of transmitters (at the antenna equivalent)
1. Maximum values The carrier powers of the transmitters are given in the table.
2. The deviation of the carrier power of the transmitters from the nominal value at NU is within +-1.5 dB.
3. The deviation of the carrier power of the transmitters from the nominal value at EI is in the range from minus 3.0 to plus 2.0 dB.
_____________________________
* For portable subscriber radio stations.
** For portable user radios.
Appendix No. 4
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for the parameters of the maximum and average effective radiated power of transmitters
1. The nominal values of the maximum and average EIM of transmitters are declared by the manufacturer of subscriber radio stations.
2. The deviation of the maximum EIM of transmitters from the nominal value at NU is within +-d_f.
3. The deviation of the average EIM of transmitters from the nominal value at NU is within the limits of +-d_f.
4. The deviation of the maximum (average) EIM of transmitters d_f(dB) from the nominal value at NU is calculated using the formula*:
2 2 d = square root (d + d), (1) f m e
<= +- 6 дБ); d_e - допустимое отклонение параметра (d_e = +- 1,5 дБ).
5. The deviation of the maximum EIM of the transmitters from the nominal value at EI is in the range from minus d_f2 to plus d_f1.
6. The deviation of the average EIM of the transmitters from the nominal value at EI is in the range from minus d_f2 to plus d_f1.
7. The deviation of the maximum (average) EIM of transmitters d_f1 (dB) from the nominal value at EI is calculated using the formula*:
2 2 d = square root (d + d), (2) f1 m e1
where d_m is the measurement error (d_m<= +-6 дБ); d_e1 - допустимое отклонение параметра (d_e1 = + 2 дБ).
8. The deviation of the maximum (average) EIM of transmitters d_f2 (dB) from the nominal value at EI is calculated using the formula*:
2 2 d = square root (d + d), (3) f2 m e2
where d_m is the measurement error (d_m<= +-6 дБ); d_e2 - допустимое отклонение параметра (d_e2 = - 3 дБ).
_____________________________
* When calculating using formulas 1, 2, 3, all values are expressed in linear units.
Appendix No. 5
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for transmitter frequency deviation parameters
1. The maximum permissible deviation of the transmitter frequency (D_max) at modulating signal frequencies in the band from the lower frequency f_1 to the upper frequency f_2 at NU does not exceed the values given in the table.
The lower frequency of the modulating signal f_1 is declared by the manufacturer of subscriber radio stations.
2. The frequency deviation of transmitters at modulating signal frequencies above frequency f_2 at NU satisfies the following requirements:
a) at modulating signal frequencies in the band from f_2 to 6.0 kHz, the deviation of the transmitter frequency does not exceed the value A (Figure 1), measured at frequency f_2. The upper frequency of the modulating signal f_2 is: 2550 Hz (for frequency spacing between adjacent channels 12.5 kHz); 3000 Hz (for frequency spacing between adjacent channels of 25 kHz);
b) at a modulating signal frequency of 6.0 kHz, the deviation of the transmitter frequency does not exceed a value equal to 0.3 D_max;
c) at frequencies of the modulating signal in the frequency band from 6.0 kHz to frequency f_3, equal to the frequency spacing between adjacent channels, the frequency deviation of the transmitters does not exceed the values set by the linear characteristic of the frequency deviation depending on the modulation frequency, which has a limiting value at frequency 6, 0 kHz and a further decline of minus 14 dB per octave.
A graph of the dependence of the transmitter frequency deviation on the modulation frequency is shown in Figure 1.
Figure 1. Graph of transmitter frequency deviation versus modulation frequency
Appendix No. 6
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for the parameters of the level of spurious emissions of transmitters
1. The level of spurious emissions from the transmitter, measured at the external antenna connector at NU, does not exceed the values given in Table No. 1.
Table N 1. The level of spurious emissions from the transmitter, measured at the external antenna connector, in the frequency band from 9 kHz to 4 GHz (for subscriber radio stations operating at frequencies up to 470 MHz) or in the frequency band from 9 kHz to 12.75 GHz (for subscriber radio stations operating at frequencies above 470 MHz)
2. The level of spurious radiation from the housing and structural elements of the transmitter of subscriber radio stations at OU does not exceed the values given in Table No. 2.
Table No. 2. Level of spurious emissions from the housing and structural elements of the transmitter of subscriber radio stations in the frequency band from 30 MHz to 4 GHz
Appendix No. 7
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for frequency deviation parameters of transmitters in transient mode
1. The duration of the transient processes of turning on (t_1) and turning off (t_3) transmitters, during which the deviation of the transmitter frequency from the nominal value does not exceed the value of the frequency separation between adjacent channels (+- Delta f) depending on the frequency range, at NU does not exceed the values given in Table No. 1.
Table No. 1
2. The duration of the transient process of switching on the transmitter (t_2), during which the deviation of the transmitter frequency from the nominal value does not exceed half the frequency separation between adjacent channels (+-Delta f/2) depending on the frequency range, with NL does not exceed the values given in Table No. 2.
Table No. 2
3. The time mask of the transient process when turning on a transmitter operating in the frequency range 330 MHz or 450 MHz is shown in Figure 1.
Figure 1. Time mask of the transient process when turning on a transmitter operating in the frequency range 330 MHz or 450 MHz
4. The time mask of the transient process when turning off a transmitter operating in the frequency range of 330 MHz, or 450 MHz, or 800 MHz is shown in Figure 2.
Figure 2. Time mask of the transient process when turning off a transmitter operating in the frequency range 330 MHz or 450 MHz or 800 MHz
_____________________________
* For portable subscriber radio stations, the deviation of the transmitter frequency from the nominal value during t_1 and t_3 is allowed more than one frequency spacing between adjacent channels.
Appendix No. 8
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for receiver emission level parameters
1. The radiation level of receivers, measured at the external antenna connector, at NU does not exceed the values given in Table No. 1.
Table N 1. The level of radiation from receivers, measured at the external antenna connector, in the frequency band from 9 kHz to 4 GHz (for subscriber radio stations operating at frequencies up to 470 MHz) or in the frequency band from 9 kHz to 12.75 GHz (for subscriber radio stations radio stations operating at frequencies above 470 MHz)
2. The level of radiation from the housing and structural elements of subscriber radio receivers at low voltage does not exceed the values given in Table No. 2.
Table No. 2. Level of radiation from the housing and structural elements of the receiver of subscriber radio stations in the frequency band from 30 MHz to 4 GHz
Appendix No. 9
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for frequency deviation parameters of transmitters of a subscriber radio station intended for data transmission
1. The deviation of the transmitter frequency from the nominal value at NL does not exceed the maximum permissible values given in Table No. 1 of Appendix No. 2 to the Rules.
2. The deviation of the transmitter frequency from the nominal value with EC does not exceed the maximum permissible values given in the table.
Appendix No. 10
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for the duration parameters of transient processes when turning on transmitters
Graphs of transient processes of changes in carrier power and frequency when transmitters are turned on are shown in Figures 1 and 2.
At any point in time under NU, when the carrier power of the transmitters is greater than the steady-state transmitter carrier power (P_c) minus 30 dB (P_c - 30 dB), the carrier frequency remains within half the frequency separation between adjacent channels (+-df_c) from the steady-state transmitter carrier frequency (F_c).
The sign of the slope of the section of the graphs “Power as a function of time” shown in Figures 1, 2 between points (P_s - 30 dB) and (P_s - 6 dB) does not change.
For subscriber radio stations with an external antenna connector, the time intervals of transient processes for turning on transmitters t_p at NU are not less than:
For subscriber radio stations that do not have an external antenna connector, the time intervals of transient processes for switching on transmitters t_p at LL are at least 0.20 ms.
Figure 1. Graphs of transient processes of changes in carrier power and frequency when transmitters are turned on, for the case when the duration of the transient process is given from the graph of changes in carrier power
Figure 2. Graphs of transient processes of changes in carrier power and frequency when transmitters are turned on, for the case when the duration of the transient process is given from the graph of changes in carrier frequency
Appendix No. 11
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for the parameters of the duration of transient processes when turning off the transmitters
Graphs of transient processes of changes in carrier power and frequency when the transmitters are turned off are shown in Figure 1.
At any point in time under NU, when the carrier power of the transmitters is greater than the steady-state carrier power of the transmitter (Р_с) minus 30 dB (Р_с - 30 dB), the carrier frequency remains within half the frequency separation between adjacent channels (+-df_c) from the steady-state carrier frequency of the transmitters (F_c).
The sign of the slope of the section of the “Power as a function of time” graphs shown in Figure 1 between points (P_s - 30 dB) and (P_s - 6 dB) does not change.
For subscriber radio stations with an external antenna connector, the time intervals of transient processes for turning off transmitters t_d at NU are not less than:
0.10 ms for frequency spacing between adjacent channels 12.5 kHz;
0.05 ms for frequency spacing between adjacent channels of 25 kHz.
For subscriber radio stations that do not have an external antenna connector, the time intervals of transient turn-off processes t_d at NU are at least 0.20 ms.
Figure 1. Graphs of transient processes of changes in carrier power and frequency when the transmitters are turned off
Appendix No. 12
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for parameters of resistance of subscriber radio stations to climatic influences
1. Classification of subscriber radio stations depending on location conditions in terms of the impact of environmental climatic factors is given in the table.
| Group of subscriber radio stations | Operating temperature, .С | |
|---|---|---|
| Reduced | Increased | |
| Group B3 | -10 | +55 |
| Groups B4, B5 | -25 | +55 |
| Group H6 | +5 | +40 |
| Group H7 | -10 | +50 |
| Note: Designations of groups of subscriber radio stations: 1. B3 - portable, installed in the interior of river vessels; 2. B4 - transportable, installed in cars, motorcycles, agricultural, road and construction equipment; 3. B5 - transportable, installed in mobile railway objects; 4. H6 - wearable, placed during operation in or under the subscriber’s clothing, or in heated above-ground and underground structures; 5. H7 - wearable, used outdoors or in unheated above-ground and underground structures. | ||
2. Subscriber radio stations remain operational when exposed to low and high operating temperatures given in the table.
Normal conditions (NU) - conditions defined as: ambient temperature: from +15 to +35.С; relative humidity: from 45 to 75%; atmospheric pressure from 650 to 800 mmHg; power supply voltage is nominal with a permissible deviation of no more than +- 2%.
Extreme conditions (EC) - conditions of simultaneous exposure to increased (lower) operating temperature of the environment given in the table of Appendix No. 12 to the Rules, and increased (lower) power supply voltage given in paragraph 15 of the Rules.
Appendix No. 13
to the Rules for the use of subscriber
radio stations with analogue modulation
mobile radio networks
Requirements for parameters of resistance of subscriber radio stations to mechanical influences
1. Subscriber radio stations are operational and retain operating parameters after transportation in packaged form under mechanical impacts in the form of shocks, a shock pulse duration of 6 ms with a peak shock acceleration of 250 m/s2 (25g) and the number of shocks in each direction - 4000.
2. User portable radio stations of groups H6 and H7 are operational and retain operating parameters after an impact due to a free fall from a height:
1 m for subscriber radio stations weighing up to 2 kg;
0.5 m for subscriber radio stations weighing up to 5 kg.
3. Subscriber radio stations are operational and maintain operating parameters when exposed to sinusoidal vibration with the characteristics of the influencing factor given in the table.
Table. Characteristics of sinusoidal vibration
Order of the Ministry of Information Technologies and Communications of the Russian Federation dated April 12, 2007 N 46 "On approval of the Rules for the use of subscriber radio stations with analog modulation of mobile radio networks"
Registration N 9395
where is the frequency spacing between the useful and interfering signals;
The level of the useful signal at the receiver input, which is taken equal to = 
;
- dimension matching coefficient.
If the level of the useful signal is not lower than 10 μV (20 dB), then, in accordance with the above empirical formula, the permissible level of the interfering signal can reach 143 dB (73 + 50 + 20 = 143 dB). This value of the permissible level will, in most cases, ensure operation without interfering influences of two neighboring radio stations located within the same office building of the central control center, but operating in different communication networks, and install two stationary antennas in close proximity to each other on the roof of the building.
Thus, using the obtained empirical formula, it is possible to assess the EMC of radio equipment and determine the optimal frequency and territorial separations of radio stations operating in neighboring radio networks.
Calculation of EMC of two closely located radio stations
When making a practical selection of operating frequencies of radio stations in the case of installing two stationary antennas on the roof of one office building (TsUS or TsPR), the permissible level of the interfering signal is determined mainly by the output level of the signal from the transmitter of the interfering radio station (equal to 148 dB with a transmitter output power of 10 W) and attenuation of the electromagnetic field between stationary antennas.
Given: Linear attenuation coefficient of the antenna-feeder path of the transmitter and receiver of stationary radio stations;
the length of the antenna-feeder paths of the transmitter and receiver, respectively, and ;
gain of transmitting and receiving antennas 
;
the distance between 2 stationary antennas installed within the roof of a service building is r=6m.
It is required to select the operating frequency ratings of two stationary radio stations located in the same office building of the central control center.
The permissible level of an interfering signal from a nearby transmitter is determined by the formula:
A=148-0.15·6+1.5-0.15·6+1.5-37=112.2.
The frequency spacing of working channels of radio stations is determined by the formula:
At the final stage of calculation, the selection of nominal operating frequencies is carried out.
If one fixed station operates on a frequency 
, and the frequency spacing of the working channels was 
, then the operating frequency of the second radio station (second radio network) will be equal to .
Calculation of EMC of three radio networks
In the case of calculating the permissible level of interfering influence of transmitters of two neighboring radio stations on the receiver of a third, it is necessary to consider third-order intermodulation interference. The results of experimental studies of the frequency dependence of the parameter of three-signal selectivity of receiving devices of radio stations of the "Viola" and "Sapphire" types showed that the assessment of mutual interfering influences between three radio networks organized at intermodulation incompatible frequencies is carried out based on the value of the three-signal selectivity of the receiver equal to 70 dB. The level of the interfering signal at the input of the radio station receiving device is calculated using the formula
where is the attenuation of the feeder path and the antenna gain of one of the two interfering transmitters;
dB - parameter of the three-signal selectivity of the receiver (permissible level of the interfering signal);
VI - correction that takes into account the permissible percentage of time (at the level of 10%) of interference on a combined frequency channel, is taken equal to VI = -5 dB.
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Since the total number of radio frequencies available in the system is limited, in order to increase the capacity of the communication system, the formation of small communication zones ("small cells") is envisaged. However, as a consequence, the probability of reaching the border of the service area of a base station to another one controlled by the same radiotelephone switch increases. Moreover, the transmitter output power of all mobile stations is automatically reduced by command from the radiotelephone switch when the station enters the "small cell" area.
The same power reduction procedure is used to reduce interference when mobile stations are close to base stations with normal service areas.
All signaling between the MSC and the mobile station is carried out over the communication channel. The call channel, on which all other mobile stations continue to receive, is ready for immediate transmission of the next call.
During a call, the base station (on command from the MSC) continuously emits a pilot signal (a tone with a frequency of approximately 4000 Hz) and sends it towards the mobile station, which receives it and transmits it again to the base station. The received return signal is detected and evaluated by the base station. If the transmission quality (signal-to-noise ratio averaged over a certain period of time) makes this necessary, then the base station decides to connect another base station or disconnect the call. The base stations send information about the results of the S/N ratio estimation to the MSC.
A typical set of channels at a base station: -6 communication channels -1 call channel. Repeat channels through two cells, i.e. the same channel can be used by two BSs separated by two cells.
2. BS (base station) equipment consists of a base station controller and transceiver antennas (BTS). Each BS has separate antennas for transmission and reception, because Cellular networks use diversity reception. The BS controller (computer) provides control of the operation of the base station, as well as monitoring the performance of all its constituent blocks and nodes. All BSs are connected to the mobile communications switching center (SC) via dedicated wire or radio relay communication channels. The CC is an automatic station of the cellular communication system that provides all network management functions. PS - mobile station (subscriber radiotelephones).
Figure 12 - Cellular network diagram
S = 39462.6 km2;
The radius of the service area R0, km is calculated using the formula:
R0 = = = 112.105 km
The number of cells L can be determined by the formula:
L = 1.21 = 1.21 
≈ 18 hundred
The number of BSs is equal to the number of cells, since there is one base station for each cell.
Cells are grouped into clusters. In one cluster there are C base stations operating directly in non-repetitive frequency ranges.
The distance D between the centers of cells that use the same frequency bands is calculated by the formula:
D = = 
= = 39.5 km
radio system antenna telephone connection
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