What is the frequency separation between adjacent channels. Telecommunication systems. Requirements for the parameters of the frequency deviation of transmitters in transient mode

The duplex spacing of the transmit and receive channels in the NMT-450 standard is 10 MHz. The frequency separation of adjacent channels is 25 (20) kHz.

Since the total number of radio frequencies available in the system is limited, in order to increase the capacity of the communication system, it is envisaged to form small communication zones ("small cells"). However, as a consequence, the probability of reaching the boundary of the coverage area of the base station to another one controlled by the same radiotelephone switch increases. Moreover, the output power of the transmitters of all mobile stations is automatically reduced by the command of the radiotelephone switch when the station enters the "small cell" area.

The same power down procedure is used to reduce interference when mobile stations are close to base stations with normal coverage areas.

All signaling between the MSC and the mobile station takes place over the communication channel. The call channel, on which all other mobile stations continue to receive, is ready to immediately transmit the next call.

During the call, the base station (on the MSC command) constantly emits a pilot signal (a tone signal with a frequency of about 4000 Hz) and sends it to the side of the mobile station, which receives it and transmits it back 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 it necessary, then the base station decides to connect to another base station or to disconnect the call. The base stations send information about the results of the SNR estimation to the MSC.

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 transmit-receive antennas (BPSS). Each BS has separate antennas for transmitting and receiving, because Diversity is used in cellular networks. The BS controller (computer) provides control of the base station operation, as well as monitoring the operability of all blocks and nodes included in it. All BS are connected to the switching center (CC) of mobile communication via dedicated wire or radio relay communication channels. CC is an automatic station of the cellular communication system, providing all the network management functions. PS - mobile station (subscriber radiotelephones).

Figure 12 - Diagram of a cellular network

S = 39462.6 km2;

The calculation of the radius of the service area R0, km is made according to the formula:

R0 = = = 112.105 km

The number of cells L can be determined by the formula:

L = 1.21 = 1.21 ≈ 18 are

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. One cluster contains C base stations operating directly in non-repeating frequency bands.

The distance D between the centers of the cells in which the same frequency bands are used is calculated by the formula:

D = = = = 39.5 km

radio system antenna telephone connection

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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; N 52 (Part I), Art. 5038; 2004, N 35, article 3607; No. 45, article 4377; 2005, No. 19, article 1752; 2006, No. 6, article 636; No. 10, article 1069; No. 31 (part I), article 3431, article 3452; 2007, N 1, Art.8) and paragraph 4 of the Rules for organizing and carrying out work on mandatory confirmation of the conformity of communication facilities, approved by the Government of the Russian Federation of April 13, 2005 N 214 (Collected Legislation of the Russian Federation, 2005, N 16 , art. 1463), I order:

1. To approve the attached Rules for the Application of Mobile Radio Subscriber Networks.

2. Send this order for state registration to the Ministry of Justice of the Russian Federation.

3. Control over the execution of this order shall be entrusted to the Deputy Minister of Information Technologies and Communications of the Russian Federation B.D. Antonyuk.

The 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) have been 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; N 52 (part I), Art.5038; 2004, N 35, Art.3607; N 45, Art.4377; 2005, N 19, Art. 1752; 2006, N 6, Art. 636; N 10, article 1069; N 31 (part I), article 3431; article 3452; 2007, N 1, article 8) in order to ensure the integrity, stability, functioning and security of the unified telecommunication network of the Russian Federation.

2. The Rules establish mandatory requirements for subscriber radio stations with analogue modulation (phase or frequency) in mobile radio communication 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 permitted 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 separations used for connections of 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 transmitted information, are divided into the following types:

1) subscriber radio stations intended for the transmission of voice information using angular modulation with a constant envelope;

radiation classes - F3E * (1), G3E * (2);

2) subscriber radio stations intended for data transmission using direct carrier modulation or indirect modulation (modulation of a subcarrier in the audio spectrum). Modulation types - 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 the transmission of voice information or data transmission, with mode switching;

4) subscriber radio stations intended for transmission of voice information and data transmission at the same time have a data transmission path in the sub-tone frequency range and transmission of voice information in the tone area.

8. Subscriber radio stations perform all procedures for making and receiving a call, establishing, maintaining and releasing connections with subscriber radio stations of mobile radio networks, mobile radiotelephone networks and terminal equipment of fixed telephone networks and data transmission networks.

9. For transmitters of subscriber radio stations intended for the transmission of voice information, the following mandatory requirements for the parameters are established:

1) deviation of the frequency of the transmitters 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 radiation level of the transmitter in the adjacent channel for a frequency separation 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 radiation level of the transmitter in the adjacent channel for a frequency separation between adjacent channels of 25 kHz does not exceed a value equal to minus 70 dBc or 0.2 μW (minus 37 dBm);

7) the levels of spurious emissions of transmitters in accordance with Appendix No. 6 to the Rules;

8) the frequency deviation of the transmitters in the transient mode in accordance with Appendix No. 7 to the Rules.

10. For transmitters of subscriber radio stations intended for data transmission, the following mandatory requirements for parameters are established:

1) frequency deviations of the transmitters in accordance with Appendix N 9 to the Rules;

2) the carrier power of the 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 (EIR) of transmitters of subscriber radio stations with a built-in antenna in accordance with Appendix No. 4 to the Rules;

4) the duration of transients 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 the power and frequency of the carrier when the transmitters are turned on are given in Appendix N 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 the power and frequency of the carrier when the transmitters are turned off are given in Appendix N 11 to the Rules.

6) the emission level of the transmitter in the adjacent channel for a frequency separation 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 level of radiation in the adjacent channel during transient processes in the transmitter for a frequency separation between adjacent channels of 12.5 kHz does not exceed a value equal to minus 50 dBc or 2 μW (minus 27 dBm).

The emission level in the adjacent channel during transient processes in the transmitter for a frequency separation between adjacent channels of 25 kHz does not exceed the value equal to minus 60 dBc or 2 μW (minus 27 dBm).

8) transmitter spurious emission levels in accordance with Appendix 6 to the Regulations.

11. For transmitters of subscriber radio stations intended for the transmission of voice information and data transmission, the mandatory requirements for the parameters are established in accordance with clause 9 and subparagraphs 2) - 6) of clause 10 of the Rules.

12. For transmitters of subscriber radio stations intended for the transmission of voice information and data transmission at the same time, the mandatory requirements for the parameters are established in accordance with paragraph 9 of the Rules.

13. For receivers of subscriber radio stations, mandatory requirements for the parameters are established:

a) the level of radiation of receivers at the external antenna connector in accordance with Appendix No. 8 to the Rules;

b) the level of radiation of the body and structural elements of receivers of subscriber radio stations in accordance with Appendix No. 8 to the Rules.

14. For subscriber stations, the following mandatory requirements for parameters are established:

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 stress in accordance with Appendix No. 13 to the Rules.

15. Requirements for power supply of subscriber radio stations. Power supply of subscriber radio stations, depending on their purpose, is carried out from the following power sources:

a) AC mains with a rated voltage of 220 V and a frequency of 50 Hz in the case of using power supplies for mobile subscriber radio stations. Subscriber radio stations ensure operability when the supply voltage changes in the range from minus 15% to plus 10% relative to the nominal voltage of 220 V;

b) an external source of direct current (on-board network of a mobile object). Subscriber radio stations ensure operability when the supply voltage changes in the range from minus 10% to plus 30% relative to the nominal voltage of the on-board network of the mobile object;

c) own direct current source (battery). The type, nominal supply voltage of its own direct current source and the voltage variation limits at which the subscriber radio remains operational are set by the manufacturer.

_____________________________

* (1) Class of emission F3E - frequency modulation (F) of one analog telephone channel (3E).

* (2) Class of emission 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) Class of emission F1D - frequency modulation (F) of one digital data link (1D).

* (7) Class of emission G1D - phase modulation (G) of one digital data transmission channel (1D).

Appendix N 1

radio stations with analog modulation
mobile radio networks

Requirements for the parameters of frequency ranges and duplex frequency spacing for connections of subscriber radio stations with base stations

For connections of subscriber radio stations with base stations, the frequency ranges and duplex frequency spacing shown in the table are used.

_____________________________

* (1) For duplex subscriber radios.

* (2) In international practice, the abbreviation VHF (Very High Frequency) is used.

* (3) In international practice, the abbreviation UHF (Ultrahigh Frequency) is used.

Appendix N 2
to the Rules for the Application of Subscriber
radio stations with analog modulation
mobile radio networks

Requirements for the parameters of the frequency deviation of transmitters from the nominal value

1. The deviation of the frequency of the transmitters from the nominal value does not exceed the values given in Tables NN 1 and 2.

Table N 1. Deviation of the frequency of transmitters from the nominal value under normal conditions (hereinafter - NU *)

Table N 2. Deviation of the frequency of transmitters from the nominal value under extreme conditions (hereinafter - EU **)

_____________________________

* NUs are defined in Appendix No. 12 to the Rules.

** ES are defined in Appendix N 12 to the Rules.

Appendix N 3
to the Rules for the Application of Subscriber
radio stations with analog modulation
mobile radio networks

Requirements for the parameters of the carrier power of transmitters (at the dummy antenna)

1. The maximum values of the carrier power of the transmitters are given in the table.

2. The deviation of the carrier power of the transmitters from the nominal value at NL 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 mobile subscriber radio stations.

** For wearable subscriber radios.

Appendix N 4
to the Rules for the Application of Subscriber
radio stations with analog 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 the transmitters are declared by the manufacturer of the subscriber radio stations.

2. The deviation of the maximum EIM of the transmitters from the nominal value at NU is within + -d_f.

3. The deviation of the average EIM of the transmitters from the nominal value at NU is within + -d_f.

4. The deviation of the maximum (average) EIM of transmitters d_f (dB) from the nominal value at NU is calculated by 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. Deviation of the maximum EIM of transmitters from the nominal value at EI is in the range from minus d_f2 to plus d_f1.

6. Deviation of the average EIM of 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 by 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 by 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 according to formulas 1, 2, 3, all values are expressed in linear units.

Appendix N 5
to the Rules for the Application of Subscriber
radio stations with analog modulation
mobile radio networks

Requirements for the parameters of the frequency deviation of transmitters

1. The maximum permissible deviation of the frequency of transmitters (D_max) at frequencies of the modulating signal 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 baseband frequency f_1 is declared by the manufacturer of the subscriber radio stations.

2. The deviation of the frequency of transmitters at frequencies of the modulating signal above the frequency f_2 at NU satisfies the following requirements:

a) at frequencies of the modulating signal in the band from f_2 to 6.0 kHz, the frequency deviation of the transmitters does not exceed the value A (Figure 1), measured at the frequency f_2. The upper frequency of the modulating signal f_2 is: 2550 Hz (for a frequency separation between adjacent channels of 12.5 kHz); 3000 Hz (for a frequency separation between adjacent channels of 25 kHz);

b) at a modulating signal frequency of 6.0 kHz, the frequency deviation of the transmitters 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 the frequency f_3, equal to the frequency spacing between adjacent channels, the frequency deviation of the transmitters does not exceed the values specified by the linear characteristic of the frequency deviation depending on the modulation frequency, which has a limiting value at frequency 6, 0 kHz and further roll-off of minus 14 dB per octave.

The graph of the dependence of the frequency deviation of the transmitters on the modulation frequency is shown in Figure 1.

Figure 1. Graph of the dependence of the frequency deviation of the transmitters on the modulation frequency

Appendix N 6
to the Rules for the Application of Subscriber
radio stations with analog modulation
mobile radio networks

Requirements for the parameters of the level of spurious emissions of transmitters

1. The level of spurious emissions of the transmitter, measured at the external antenna connector at NU, does not exceed the values given in Table N 1.

Table N 1. The level of spurious emissions of the transmitter, measured at the external antenna connector, in the frequency range from 9 kHz to 4 GHz (for subscriber radio stations operating at frequencies up to 470 MHz) or in the frequency range from 9 kHz to 12.75 GHz (for subscriber radio stations operating at frequencies above 470 MHz)

2. The level of spurious emissions of the housing and structural elements of the transmitter of subscriber radio stations at NU does not exceed the values given in Table N 2.

Table N 2. The level of spurious emissions of the housing and structural elements of the transmitter of subscriber radio stations in the frequency band from 30 MHz to 4 GHz

Appendix N 7
to the Rules for the Application of Subscriber
radio stations with analog modulation
mobile radio networks

Requirements for the parameters of the frequency deviation of transmitters in transient mode

1. The duration of the transient processes of turning on (t_1) and turning off (t_3) the transmitters, during which the deviation of the frequency of the transmitters from the nominal value does not exceed the frequency separation between adjacent channels (+ - Delta f) depending on the frequency range, with NU does not exceed the values given in table N 1.

Table N 1

2. The duration of the transient process of turning on the transmitter (t_2), during which the deviation of the frequency of the transmitters from the nominal value does not exceed half the frequency separation between adjacent channels (+ -Delta f / 2), depending on the frequency range, at NU does not exceed the values given in Table No. 2.

Table N 2

3. The time mask of the transient when the transmitter is turned on, operating in the frequency range of 330 MHz or 450 MHz, is shown in Fig. 1.

Figure 1. Time mask of the transient when the transmitter is turned on, operating in the frequency range of 330 MHz or 450 MHz

4. The time mask of the transient when the transmitter is turned off operating in the frequency range of 330 MHz, or 450 MHz, or 800 MHz, is shown in Fig. 2.

Figure 2. Time mask of the transient when the transmitter is turned off operating in the frequency range of 330 MHz or 450 MHz or 800 MHz

_____________________________

* For wearable subscriber radio stations, the deviation of the transmitter frequency from the nominal value during t_1 and t_3 is allowed for more than one frequency spacing between adjacent channels.

Appendix N 8
to the Rules for the Application of Subscriber
radio stations with analog modulation
mobile radio networks

Requirements for the parameters of the radiation level of receivers

1. The radiation level of the receivers, measured at the external antenna connector, at NU does not exceed the values given in Table N 1.

Table N 1. The radiation level of 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 operating at frequencies above 470 MHz)

2. The level of radiation of the body and structural elements of the receivers of subscriber radio stations at OU does not exceed the values given in Table N 2.

Table N 2. The level of emissions of the housing and structural elements of the receiver of subscriber radio stations in the frequency band from 30 MHz to 4 GHz

Appendix N 9
to the Rules for the Application of Subscriber
radio stations with analog modulation
mobile radio networks

Requirements for the parameters of the frequency deviation of the transmitters of the subscriber radio station intended for data transmission

1. The deviation of the frequency of the transmitters from the nominal value at NU 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 at EI does not exceed the maximum permissible values given in the table.

Appendix N 10
to the Rules for the Application of Subscriber
radio stations with analog modulation
mobile radio networks

Requirements for the parameters of the duration of transients when turning on the transmitters

Graphs of transient processes of changes in power and carrier frequency when the transmitters are turned on are shown in Figures 1 and 2.

At any moment in time with OU, when the carrier power of the transmitters is greater than the steady-state power of the transmitter carrier (P_c) minus 30 dB (P_c - 30 dB), the carrier frequency remains within half the frequency spacing between adjacent channels (+ -df_c) of the steady-state carrier frequency of the transmitter (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 the points (P_c - 30 dB) and (P_c - 6 dB) does not change.

For subscriber radio stations with an external antenna connector, the time intervals of the transient processes of turning on the 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 the transient processes of turning on the transmitters t_p at NU are not less than 0.20 ms.

Figure 1. Graphs of transient processes of changes in the power and frequency of the carrier when the transmitters are turned on, for the case when the duration of the transient is given from the graph of the change in carrier power

Figure 2. Graphs of transient processes of changes in the power and frequency of the carrier when the transmitters are turned on, for the case when the duration of the transient is given from the graph of the change in the frequency of the carrier

Appendix N 11
to the Rules for the Application of Subscriber
radio stations with analog modulation
mobile radio networks

Requirements for the parameters of the duration of transients when turning off the transmitters

Graphs of transient processes of changing the power and frequency of the carrier when the transmitters are turned off are shown in Figure 1.

At any moment in time at OU, when the carrier power of the transmitters is greater than the steady-state power of the transmitter carrier (P_c) minus 30 dB (P_c - 30 dB), the carrier frequency remains within half the frequency spacing between adjacent channels (+ -df_c) of the steady-state carrier frequency of the transmitters (F_c).

The sign of the slope of the section of the graphs "Power as a function of time", shown in Figure 1, between the points (P_c - 30 dB) and (P_c - 6 dB) does not change.

For subscriber radio stations with an external antenna connector, the time intervals of the transient processes of turning off the transmitters t_d at NU are not less than:

0.10 ms for 12.5 kHz channel separation;

0.05 ms for a 25 kHz channel separation.

For subscriber radio stations that do not have an external antenna connector, the time intervals of the transient switching off processes t_d at NU are not less than 0.20 ms.

Figure 1. Graphs of transient processes of changing the power and frequency of the carrier when the transmitters are turned off

Appendix N 12
to the Rules for the Application of Subscriber
radio stations with analog modulation
mobile radio networks

Requirements for the parameters of resistance of subscriber radio stations to climatic influences

1. Classification of subscriber radio stations depending on the placement conditions in terms of the impact of climatic factors of the external environment is given in the table.

Group of subscriber radio stations	Working temperature, .С
Group of subscriber radio stations	Decreased	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. В3 - transportable, installed in the internal premises of river vessels; 2. В4 - transportable, installed in cars, motorcycles, agricultural, road and construction equipment; 3. В5 - transportable, installed in mobile railway objects; 4. Н6 - wearable, placed during operation in clothing or under clothing of the subscriber, or in heated ground and underground structures; 5. Н7 - portable, operated outdoors or in unheated ground and underground structures.

2. Subscriber radio stations remain operational when exposed to low and high operating temperatures shown in the table.

Normal conditions (NU) - conditions defined as: ambient temperature: from +15 to + 35.C; relative humidity: 45 to 75%; atmospheric pressure from 650 to 800 mm Hg; power supply voltage - nominal with a permissible deviation of no more than + - 2%.

Extreme conditions (ES) - conditions of simultaneous exposure to increased (lowered) operating temperature of the environment, given in the table of Appendix No. 12 to the Rules, and increased (lowered) power supply voltage, given in paragraph 15 of the Rules.

Appendix N 13
to the Rules for the Application of Subscriber
radio stations with analog modulation
mobile radio networks

Requirements for the parameters of resistance of subscriber radio stations to mechanical stress

1. Subscriber radio stations are operational and retain their operating parameters after transportation in a packed form under mechanical influences 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. Subscriber radio stations of the H6 and H7 groups are operational and retain their operating parameters after a shock due to 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 retain their operating parameters when exposed to sinusoidal vibration with the characteristics of the influencing factor given in the table.

Table. Sinusoidal vibration characteristics

Order of the Ministry of Information Technologies and Communications of the Russian Federation of 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 input of the receiver, which is assumed to be = ;

is the coefficient of dimensionality agreement.

If the level of the useful signal is at least 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). Such a value of the permissible level will in most cases ensure operation without interfering influences of two neighboring radio stations located within the same NCC office building, but operating in different communication networks, and to 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.

EMC calculation of two closely spaced radios

When carrying out a practical choice of operating frequencies of radio stations in the case of installing two stationary antennas on the roof of one office building (NCC or DSP), the permissible level of the interfering signal is mainly determined by the output signal level from the transmitter of the interfering radio station (equal to 148 dB at the transmitter output radiation power of 10 W) and attenuation of the electromagnetic field between stationary antennas.

Specified: Coefficient of linear attenuation 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;

transmitting and receiving antenna gain ;

the distance between 2 fixed antennas installed within the roof of the office building, r = 6m.

It is required to select the nominal operating frequencies of two stationary radio stations located in the same NCC office building.

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 separation of the working channels of radio stations is determined by the formula:

At the final stage of the calculation, the selection of the nominal operating frequencies is carried out.

If one fixed station operates on the frequency , and the frequency separation of the working channels was , then the operating frequency of the second radio station (second radio network) will be equal.

EMC calculation of three radio networks

In the case of calculating the permissible level of interfering influence of the transmitters of two neighboring radio stations on the receiver of a third one, it is necessary to consider intermodulation interference of the third order. The results of experimental studies of the frequency dependence of the three-signal selectivity parameter of the receiving devices of the Viola and Sapfir radio stations showed that the assessment of mutual interfering influences between three radio networks organized at intermodulation incompatible frequencies is based on the three-signal selectivity of the receiver equal to 70 dB. The level of the interfering signal at the input of the receiving device of the radio station is calculated by the formula

where is the attenuation of the feeder path and the antenna gain of one of the two interfering transmitters;

dB - parameter of three-signal selectivity of the receiver (permissible level of the interfering signal);

VI - the amendment, taking into account the permissible percentage of time (at the level of 10%) of the manifestation of interference on the co-frequency channel, is taken equal to VI = -5 dB.

What is the frequency separation between adjacent channels. Telecommunication systems. Requirements for the parameters of the frequency deviation of transmitters in transient mode

Best articles on computer science

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

II. Requirements for subscriber radio stations with analog modulation of mobile radio networks

Requirements for the parameters of frequency ranges and duplex frequency spacing for connections of subscriber radio stations with base stations

Requirements for the parameters of the frequency deviation of transmitters from the nominal value

Table N 1. Deviation of the frequency of transmitters from the nominal value under normal conditions (hereinafter - NU *)

Table N 2. Deviation of the frequency of transmitters from the nominal value under extreme conditions (hereinafter - EU **)

Requirements for the parameters of the carrier power of transmitters (at the dummy antenna)

Requirements for the parameters of the maximum and average effective radiated power of transmitters

Requirements for the parameters of the frequency deviation of transmitters

Requirements for the parameters of the level of spurious emissions of transmitters

Table N 2. The level of spurious emissions of the housing and structural elements of the transmitter of subscriber radio stations in the frequency band from 30 MHz to 4 GHz

Requirements for the parameters of the frequency deviation of transmitters in transient mode

Requirements for the parameters of the radiation level of receivers

Table N 2. The level of emissions of the housing and structural elements of the receiver of subscriber radio stations in the frequency band from 30 MHz to 4 GHz

Requirements for the parameters of the frequency deviation of the transmitters of the subscriber radio station intended for data transmission

Requirements for the parameters of the duration of transients when turning on the transmitters

Requirements for the parameters of the duration of transients when turning off the transmitters

Requirements for the parameters of resistance of subscriber radio stations to climatic influences

Requirements for the parameters of resistance of subscriber radio stations to mechanical stress

Table. Sinusoidal vibration characteristics

More related articles

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You need to know

What is the frequency separation between adjacent channels. Telecommunication systems. Requirements for the parameters of the frequency deviation of transmitters in transient mode

Best articles on computer science

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

II. Requirements for subscriber radio stations with analog modulation of mobile radio networks

Requirements for the parameters of frequency ranges and duplex frequency spacing for connections of subscriber radio stations with base stations

Requirements for the parameters of the frequency deviation of transmitters from the nominal value

Table N 1. Deviation of the frequency of transmitters from the nominal value under normal conditions (hereinafter - NU *)

Table N 2. Deviation of the frequency of transmitters from the nominal value under extreme conditions (hereinafter - EU **)

Requirements for the parameters of the carrier power of transmitters (at the dummy antenna)

Requirements for the parameters of the maximum and average effective radiated power of transmitters

Requirements for the parameters of the frequency deviation of transmitters

Requirements for the parameters of the level of spurious emissions of transmitters

Table N 2. The level of spurious emissions of the housing and structural elements of the transmitter of subscriber radio stations in the frequency band from 30 MHz to 4 GHz

Requirements for the parameters of the frequency deviation of transmitters in transient mode

Requirements for the parameters of the radiation level of receivers

Table N 2. The level of emissions of the housing and structural elements of the receiver of subscriber radio stations in the frequency band from 30 MHz to 4 GHz

Requirements for the parameters of the frequency deviation of the transmitters of the subscriber radio station intended for data transmission

Requirements for the parameters of the duration of transients when turning on the transmitters

Requirements for the parameters of the duration of transients when turning off the transmitters

Requirements for the parameters of resistance of subscriber radio stations to climatic influences

Requirements for the parameters of resistance of subscriber radio stations to mechanical stress

Table. Sinusoidal vibration characteristics

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You need to know

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)