The Russian army is armed with dozens of types of satellite communication stations, and all centers differ from each other in their operational and technical structure, which is determined by the specifics of the tasks they solve. How are satellite communication stations and centers equipped with unified equipment complexes?
At the present time, the first and second generation terrestrial means are used to provide the KS. Means of the first generation form the Kristall satellite communications complex, the second - Liven and Legenda. In the Kristall complex, the main (base) stations are R-440-U and R-440-O terminal stations, and in the Liven complex - R-441-U and R-441-O terminal stations.
Space communication station R-440-O, fixed version
Spacecraft with repeaters on board ensure the simultaneous operation of a large number of ESs with each other. The main role is played by a repeater with a set of receiving and transmitting antennas. The simplest repeater is a transceiver device, with the help of which the weak ES signals caught by the receiving antenna are separated from the noise in the receiving device, transferred in frequency to avoid excitation of the repeater, amplified in the transmitting device and transmitted using the transmitting antenna in the direction of the Earth. The rest of the spacecraft equipment is the power supply and life support systems of the repeater. In practice, more complex repeaters are also used, in which the ES signals are demodulated and combined into a common baseband signal transmitted to the ground.
Satellite communication station R-441-UVS
The CS system includes several spacecraft in the geostationary orbit (GSO) of the Gran and Globus-1 types. The Gran-type spacecraft support the operation of the ZS of the Kristall complex, and the Globus-1 spacecraft - the ZS of the Liven and Legend complexes. Each spacecraft serves a certain part of the earth's surface (zone). The spacecraft service area is determined by the position of the vehicle itself relative to the Earth and the antenna used. The points to which the spacecraft data are output are determined by international agreements.
Spacecraft in GSO do not provide operation of ES from high-latitude regions, therefore, to solve this problem, the spacecraft of the "Molniya-3" type in highly elliptical orbits (HEO), from which these regions are clearly "visible", are included in the CS system. Spacecraft on VEO make one orbit around the Earth in 12 hours, and it can be used for communication only for 6 hours. Therefore, to ensure round-the-clock work, 4 devices of this type are needed, forming the so-called "four". The system can include several "fours", which allows for the operation of a large number of stations. Spacecraft of the "Molniya-3" type are intended for operation of earth stations of the "Kristall" complex.
Communication repeater
Communication repeaters are intended for relaying signals from satellite communication stations. They are installed on spacecraft that are launched to geostationary and VEO. In the satellite communication system, repeaters with direct relaying (PR) and signal processing on board (OSB) are used.
In the first case, the repeater provides reception of signals from the ES, their selection, frequency conversion, amplification and transmission. Signals at the input and output of the repeater differ in frequency shift.
The advantage of this type of repeater is its simplicity and the possibility of using any type of earth station for operation, the operating frequency range of which coincides with the frequency range of the repeater.
The disadvantages of these repeaters are due to the need for simultaneous frequency conversion and amplification of a large number of signals (according to the number of stations operating in the shaft). With direct retransmission, the power of the output power amplifier is distributed between all signals received at its input, including interfering ones (such as the receiver's own noise, intentional and unintentional interference), so some of the power is lost. In addition, when several signals are amplified simultaneously, so-called combinational interference occurs, which also consumes part of the power. In addition, this interference can coincide in frequency with the wanted signals, degrading the quality of their reception. Finally, during direct retransmission, noise accumulates: the receiver of the earth station, along with the useful signal, also receives the noise generated by the receiver of the repeater, which, combined with the intrinsic noise of the receiver of the earth station, degrades the quality of the radio link. For normal operation of satellite communication lines using direct relay, it is necessary to reduce the number of stations simultaneously operating in the same trunk. Barrels with signal processing, usually as an emergency or backup, have a direct retransmission mode.
When using direct relay to work with several correspondents, each earth station must have a number of receivers according to the number of correspondents, and each of the receivers must be tuned to its own frequency. This leads to the complication of earth stations and creates certain difficulties when it is necessary to increase the number of directions and communication channels formed by them.
Repeaters with OSB differ in that the signals received from the ES are demodulated and, as a rule, are combined into a group signal (HS) of the trunk. At the same time, the disadvantages inherent in direct retransmission are largely eliminated.
Repeaters of this type are much more complex than repeaters with PR and can only work with a certain fleet of earth stations. Their use can significantly increase the throughput due to the more efficient use of the output power amplifier of the barrel.
As a rule, several sets of receiving and transmitting equipment are installed in one repeater. Each such set of equipment forms a repeater trunk, and in the first case, the trunk provides a direct relay of signals and is called a direct relay trunk, and in the second case, the trunk provides complete signal processing (demodulation) and is called a signal processing trunk. Usually, the receiving and transmitting channels of the trunks are considered separately, calling them, respectively, the receiving and transmitting trunks.
Each trunk has its own operational and technical purpose associated with the need to relay the signals of a certain group of earth stations. For example, for the operation of a central station with several terminal stations, two trunks with direct relaying can be allocated: one for the operation of the central station, the second for a group of terminal stations.
Each repeater trunk operates in its own frequency band of a certain range. At present, the system uses the bands 4/6; 7/8 and 0, 2/0, 4 GHz (the first digit refers to the "ZS-RS" section, the second - to the "RS-ZS" section). The frequency band allocated to one barrel is in the range from hundreds of kilohertz to hundreds of megahertz, depending on the purpose of the barrel.
Signals received in one trunk can be transmitted in another. This makes it possible to organize counter-operation of stations for various purposes when they use different shafts. This possibility is realized in the presence of cross-barrels (cross-links). Inter-barrels are most easily implemented in barrels with on-board signal processing, since in this case low-frequency signals are switched.
Earth stations operating through a common shaft form a definite grouping, usually geographically quite compact. Therefore, each trunk usually operates on its own antennas - receiving and transmitting (sometimes receiving-transmitting antennas are used) with high directivity, which allows them to "illuminate" (serve) certain areas on the earth's surface, called service areas. Thus, a certain service area corresponds to each wellbore. If it is necessary to change the service areas, in some cases, the antennas can be reoriented according to commands from the Earth. The use of highly directional antennas that form the specified service areas makes it possible to reduce mutual interference between communication facilities and the likelihood of radio jamming from the enemy.
If the antenna "illuminates" the entire surface of the Earth visible from the spacecraft, then the formed service area is called global. In this case, the antenna is said to provide global service. Global service is very useful for building a warning system. If the antenna "illuminates" only part of the Earth's surface, then the service is zonal. Zone service allows you to protect the radio link from deliberate interference and improve its performance by concentrating the radiated power of the useful signal in the direction of the correspondent. Area service is useful for a single central earth station or a group of closely spaced stations (located in the same area).
To operate the earth stations of the Kristall complex, the Delta (Gran 'SC in geostationary orbit) and Segment (Molniya-3 SC in a highly elliptical orbit) repeaters are used, and the Liven and Legend "- repeater" Citadel "(SC" Globus-1 "in geostationary orbit).
Mobile earth stations for satellite communications R-440-0, R-441-0, R-439
Satellite communication stations R-440-0, R-441-0 and R-439 are intended for the organization of long-distance multichannel radio communication and notification using repeaters on artificial earth satellites.
For the operation of the stations, repeaters are used that are installed on spacecraft launched into geostationary and elliptical orbits. The stations provide duplex telegraph, telephone, facsimile, telecode communication and data exchange via digital (discrete) channels. The channels formed by the stations have unified input / output parameters (joints), which allows connecting various types of terminal equipment to them.
The stations provide for an anti-jamming (PMZ) mode of operation, which makes it possible to conduct communications in the presence of interference, including deliberate interference.
Satellite communication station R-440-0
The satellite communication station is a single-machine satellite communication station of the "Kristall" complex, operating through repeaters installed on the "Gran" and "Molniya-3" spacecraft, which are injected into geostationary and highly elliptical orbits, respectively.
Counter work with the stations of the "Kristall" complex is provided. The used frequency range is 4/6 GHz. The station provides reception of special signals on a separate carrier and in a common group signal.
The composition of the station equipment makes it possible to organize 1-2 directions of satellite communication with the maximum speed of the group signal for transmission of 4, 8 or 5, 2 kbit / s. In this case, medium-speed information digital channels are formed with a transmission rate of 1, 2; 2, 4 or 4, 8 kbit / s, as well as low-speed telegraph channels with a transmission rate of up to 100 baud, distributed between the two communication directions as required. The number of formed channels of various types is determined by the capabilities of the "Discrete" time combination / division equipment used in the station. So, at a transmission rate of 4.8 kbit / s, 3 channels of 1, 2 kbit / s and 2 channels of 100 bit / s can be organized, distributed between two communication directions. Other channeling options are also possible. At a group signal rate of 5, 2 kbps, it is possible to work in one direction of communication over a channel with a speed of 4, 8 kbps. The channeling capabilities of the station are discussed in more detail below.
In addition to the listed information communication channels, low-speed telegraph channels of formalized service communication with a speed of 50 baud are organized in each direction of communication.
If necessary, the station can be used in anti-jamming mode using special anti-jamming equipment. In this case, it is possible to organize one single-channel communication direction with an information transmission rate of 100 or 1200 baud. The service channel is preserved.
The main technical and operational characteristics of the station are shown in the table.
The R-440-0 station was mounted on one URAL-375 vehicle. The body is divided into two compartments.
During transportation, the front compartment accommodates the AK-12 antenna device and two autonomous power supplies AB-8-T / 230. The antenna device for operation is lifted with a lifting device from the front compartment and is fixed on the roof of the control room.
Satellite communication station R-441-O
The R-441-O satellite communication station is a mobile station of the Liven complex, mounted on two transport units: a URAL-4320 vehicle and a trailer. The station operates through repeaters installed on spacecraft such as Globus-1 (in geostationary orbit) and Meridian (in high-elliptical orbit).
Counter work is provided with the stations of the Liven and Legend complexes. For operation, the bands 4/6 and 7/8 GHz are used (1st and 2nd bands, respectively). At the same time, the composition of the equipment allows simultaneous reception of signals in both indicated ranges, and transmission - in one (optional).
It is possible to transmit and receive special signals on a separate carrier and in a common group signal.
The station allows organizing 1 … 8 directions of satellite communication at the speed of the group signal for transmission up to 12 kbit / s. In this case, medium-speed channels with a transmission rate of 1, 2 can be formed; 2, 4; 4, 8 and 9, 6 kbps, as well as low-speed channels with bit rates up to 100 bps.
The channelization capabilities of the station are determined by the Agat temporary combining / separating equipment used in it. The number of formed channels and communication directions is related to the speed of the group signal for transmission as follows. The baseband signal is formed from base sequences of 1.5 kbit / s, each of which combines one signal of 1, 2 kbit / s and one - 100 bit / s, as well as service sequences. Thus, at a HS speed of 12 kbit / s, 8 channels of 1, 2 kbit / s and the same number of channels of 100 bit / s are formed, which can be distributed between the communication directions. If it is necessary to organize higher-speed channels, the basic sequences are combined and the number of possible communication directions is reduced.
In each direction of communication, a telegraph channel of formalized service communication is organized, which is allocated from the total number of telegraph communication channels formed by the station.
The station provides operation in anti-jamming mode. The main option is to work for transmission of signals with pseudo-random frequency tuning (PFC), and for reception - FM-SHPS (when working in trunks 4 and 5 of the Citadel repeater). In shafts with direct relaying of signals, the mode with FM-ShPS can be used for transmission and reception.
The equipment of the station provides operation in the radio-automatic telephone exchange mode both along the fixed and non-fixed lines of the repeater. The station provides for automated control, which is implemented using an automated control subsystem (AAC). PAH ensures the implementation of all control functions of the station.
The main technical and operational characteristics of the station are presented in the table.
The station is located on two transport units: a URAL-4320 vehicle (control room U023) and a trailer (control room U022).
The body of the U023 control room is divided into two compartments. The front compartment houses the U100B-U antenna device (in the transport position), the MAD-127/220 dehydrator and power supply elements, the rear compartment houses the AD-30U-T / 400-1V electrical unit. The antenna device is equipped with input devices of the 1st and 2nd ranges (KN-302TE and KU-302LT, respectively). For operation, the antenna device on the machine rises from the compartment and is mounted on the roof of the control room. The station equipment is housed in a trailer. During operation, the control rooms are interconnected by cables from the station kit; a flexible elliptical waveguide serves to transmit a high-power microwave signal to the antenna.
Satellite communication station R-439
The R-439 satellite communication station is a mobile station of the Legend complex.
The station operates through repeaters installed on spacecraft such as Globus-1 (in geostationary orbit) and Meridian (in high-elliptical orbit). Counter work is provided with the stations of the Liven and Legend complexes. The operating frequency range is 4/6 GHz. It is possible to receive special signals on a separate carrier and in a common group signal.
The station allows organizing 1 … 4 directions of satellite communication at the speed of the group signal for transmission up to 6 kbps. In this case, medium-speed channels with a transmission rate of 1, 2 can be formed; 2, 4; 4, 8 kbps, as well as low-speed channels with transfer rates up to 100 bps. The channelization capabilities of the station are determined by the Agat temporary combining / separating equipment used in it. The number of formed channels and communication directions is related to the speed of the group signal for transmission as follows.
The baseband signal is formed from base sequences of 1.5 kbit / s, each of which combines one signal of 1, 2 kbit / s and one - 100 bit / s, as well as service sequences. Thus, at a HS speed of 6 kbit / s, 4 channels of 1, 2 kbit / s and the same number of channels of 100 bit / s are formed, which can be distributed between the communication directions. If it is necessary to organize higher-speed channels, the basic sequences are combined and the number of possible communication directions is reduced.
In each direction of communication, it is possible to organize a telegraphic channel of formalized service communication, allocated from the total number of telegraphic communication channels formed by the station.
The station provides operation in anti-jamming mode. The main option is to work for transmission in the frequency hopping mode, and for reception - FM-ShPS (when working in the 4th trunk of the Citadel repeater). In shafts with direct relaying of signals, the mode with FM-ShPS can be used for transmission and reception.
The main variant of the station operation is to work in the radio-automatic telephone exchange mode both in fixed and non-fixed communication directions (repeater lines), implemented in the 4th trunk of the Citadel repeater. When operating in the radio-automatic telephone exchange mode in fixed directions, the station constantly operates at a rate of 6 kbit / s, occupying one of the repeater lines allocated to it. In this case, 4 channels of 1, 2 kbit / s are formed, provided to subscribers at their request for the duration of the negotiations. When working in non-fixed directions (lines), the station is switched on to radiation as needed for the duration of negotiations, providing the subscriber with one channel at a speed of 1.2 kbps, while the transmission rate is 1.5 kbps.
When the station operates in the 1st trunk, it is possible to organize the radio-ATS mode in a fixed direction along 2 channels at a speed of 1, 2 kbit / s out of 4 channels formed by the station at a group signal speed of 6 kbit / s. All 4 channels can be used as fixed channels.
The station includes a set of terminal single-channel equipment, which allows using the formed communication channels directly from the control room.
The station control is automated, it is realized with the help of the control computer of the station.
The main technical and operational characteristics of the station are presented in the table.
The station is located on two transport units: a URAL-4320 vehicle and a two-axle trailer. The control room body is divided into two compartments. The front compartment houses the AK-12ShDL antenna device (in the transport position) and the STS-10/0, 5C stabilizer. The N302TE input device is installed on the antenna device. For operation, the antenna device on the machine rises from the compartment and is mounted on the roof of the control room. A power station ED2x8-T / 400-1VPS ("Toluene") is installed on the trailer. The rear compartment (operator compartment) houses the station equipment. OV-65 heater and FVUA filtering unit are installed outside the control room.
Low-energy satellite communication stations
Satellite communication station R-439P
The R-439P earth transportable satellite communication station is designed to organize satellite communication lines and networks using communication repeaters on the Globus-1 and Yamal satellites located in geostationary orbit.
The directions and networks of satellite communications at the R-439P stations can be deployed in the interests of solving control problems in tactical, operational-tactical and higher levels of command and control, or for solving special tasks. In these networks (directions) over a digital duplex communication channel at a speed of 1, 2; 2, 4; 4, 8 or 9, 6 kbit / s provides the transmission of the following types of messages:
- encrypted telephone communication or data transmission;
- open telephone communication when interfacing with automatic telephone exchange;
- data transmission of machine-to-machine communication;
- transmission and reception of a call, and maintaining an open telephone connection directly between station operators using built-in vocoder speech converting devices (RPU).
In this case, the station forms a single-channel duplex direction of communication with the frequency (frequency-code) method of multiple access in shafts with PR signals.
The R-439P satellite communication station provides simultaneous operation for reception and transmission without manual search and tuning at any frequency divisible by 500 kHz with a step of 500 kHz in the frequency ranges:
appointment:
3533 ± 8 MHz - in barrel No. 2 of the Globus-1 satellite;
3477, 5 ± 5 MHz - in barrel No. 3 of the Globus-1 satellite;
3473, 75 ± 2, 25 MHz - in barrel No. 2 of the YAMAL satellite;
for transfer:
5858 ± 5 MHz - in barrel No. 2 of the Globus-1 satellite;
5765 ± 5 MHz - in barrel No. 3 of the Globus-1 satellite;
5799, 75 ± 2, 25 MHz - in barrel No. 2 of the YAMAL satellite
The station provides transmission and reception of information signals via a duplex digital channel in the modes of operation at the rates indicated in the table.
Satellite communication station R-438T
Small-sized (portable) satellite communications station R-438 ("Barrier-T (TC)") is designed to provide satellite communications in the interests of frontline and army reconnaissance, as well as airborne and airborne assault formations. Other options for its use are also possible, including for providing separate connections in TZU and RAM.
The main distinguishing features of the station are:
- small dimensions (the station is made in the form of a rectangular package with built-in waveguide-slot antennas, package dimensions are 500x480x180 mm);
- small weight (weight of the station equipment set is about 15 kg.);
- low power consumption (no more than 90 W);
- the ability to work in duplex and simplex networks of information exchange;
- lack of anti-jamming methods of information transmission;
- low bandwidth (channel transmission rate no more than 1200 baud);
- availability of a system for automation of control of the station and control of the functioning of its elements.
The operation of satellite communication networks using R-438 stations is carried out in the trunks with PR signals (trunk No. 4) of the RS on the Globus-1 (Globus) spacecraft in a stationary orbit. In this case, the frequency method of the MD of the stations to the trunk of the retransmission of signals, divided into 10 operating frequencies every 50 kHz, is used, which is 500 kHz (5859, 75 … 5860, 25 MHz). The frequency range of the trunk transmission has the same band and the number of operating frequencies with their nominal value of 3634, 75 … 3635, 25 MHz.
Depending on the OA used in the communication networks (directions) of portable stations, the following types of communication can be provided:
- telephone classified guaranteed durability using equipment of the T-230-1A type ("Flywheel"), "Stability";
- classified data transmission using T-235-1U (V) equipment;
- classified PD using the Olkhon-PC correspondent sensor;
- unclassified service PD with VPU from the station with the possibility of formalized service communication, transmission (reception) of "Receipt" commands, exchange of information between stations using the VPU buffer memory, automatic reading of formalized service information or information from the buffer memory of the correspondent's VPU.
The terminal equipment is interfaced with the R-438 station only at the S1-FL-BN (S1I) interface at a data transfer rate of 1200 Baud in the channel. In shaft No. 4, and RS "Citadel", several networks and communication directions of wearable stations can be organized.
Modernized satellite communication station R-438M
By the nature of information exchange, satellite communication at the R-438 stations can be simplex or duplex. With simplex satellite communication, work between stations is carried out using the same transmit and receive wave number. In case of duplex satellite communication, transmitting and receiving stations working with each other conduct simultaneously on different numbers of transmit and receive waves.
R-438 station provides operation of:
in simplex mode:
- with data transmission equipment (APD) type T-235-1U;
- with a correspondent sensor (CD) "Olkhon-PK";
- with equipment of the T-231-1U type ("Stability");
- from the station's VPU with a preliminary set of information on the keyboard;
in duplex mode:
- telephone communication - with equipment of the T-230-1A type, "Stability";
- telephone communication - with AT-3006 equipment (directly or via T-230-1A);
- with data transmission equipment of the T-235-1U type.
The R-438Ts central station provides operation in the same modes, as well as simplex communication in the OBD mode using the P-115A equipment.
In all modes of operation of the R-438 stations, simultaneous reception of codograms is provided via the second reception channel (control channel) with the recording of information in the memory device and its display on the remote (central) control panel.
In the absence of work on the main (operational) channel, it can be used for service communication between the station operators by transmitting formalized commands from the remote (central) control panel.
Main technical characteristics of R-438T
Working frequency range:
- transmission - 5860 MHz;
- reception - 3635 MHz.
The number of working frequencies is 10.
Working frequency grid - 50 kHz.
The transition time to another frequency is no more than 10 s.
Transmitter power - not less than 25 W.
Antenna gain:
- for transmission - not less than 22 dB;
- for reception - not less than 19 dB.
The polarization of the radio signal is circular.
The error probability in the Rum channel is ≤ 10-3 when the ratio of the signal energy to the noise power spectral density E / N0 ≥ 9 dB.
Reception method - quasi-coherent reception of signals from OFT.
The synchronization time of the demodulator in the codogram reception mode at E / N0 ≥ 9dB with a probability of 0.9 - does not exceed 2 s.
Signal manipulation type is relative phase.
The method of pointing antennas to the repeater is manual, using nomograms.
Power supply - AC 220/127 V, DC source - 12 (27) V.
Power consumption from the power supply - no more than 90 W.
Station set weight - no more than 15 kg.
Overall dimensions of the package are 500x480x180 mm.
The number of operators is one.
Station deployment time - no more than 3 minutes.
Mean time between failures - not less than 1000 hours.
The average recovery time of the station under military conditions is no more than 30 minutes.
Formalized service communication between station operators is carried out using the TLU and the control unit. They transmit and receive 512 BCD characters. Entering and reading characters is carried out on the LED display board of the VPU in groups of 5 characters in each group.
Satellite communication at R-438 stations can be simplex or duplex. With simplex communication, the stations operating among themselves transmit and receive alternately on the same frequency (wave). With duplex communication, the stations operating among themselves transmit and receive simultaneously at different frequencies (waves) of transmission and reception.
Transmission (reception) of information at the R-438 station can be provided:
- with preliminary accumulation of information in the memory of the VPU - when working with the correspondent sensor (CD) "Olkhon-PC" or when entering a codogram from the keyboard of the VPU. In the memory of the VPU, up to two codograms of the maximum length of the CD format can be recorded - one for transmission, one for reception. Each codogram contains 510 BCD (102 five-digit groups);
- with direct transmission of information to the channel - when operating the T-230-1A or T-235-1V.
Ways of organizing satellite communications
Satellite communication at the R-438 stations, depending on the tasks to be solved and the available bandwidth resource of the signal relay trunk, can be organized in the direction or in the network. Several networks (directions) of satellite communication of wearable stations can be organized in one RS trunk.
The direction of satellite communication is a way of organizing satellite communication between two stations. The direction of satellite communication can be simplex or duplex, in which secure telephone (T-230-1A) communication, data transmission (T-235-1V, "Olkhon-PC") or unclassified data transmission from the station's VPU are provided.
A satellite communications network is a method of organizing satellite communications between three or more stations. The satellite communication network at the R-438 stations can be organized:
- on the same frequency (wave) of transmission and reception to ensure the transmission of circular messages (formalized commands) from the main station of the network to correspondents of the network or to conduct alternate exchange of information (formalized commands) of the main station with stations of correspondents or between any correspondents of the network. In this case, the station's VPU, the T-235-1V equipment or the Olkhon-PK sensor are used as terminal equipment;
- when using two waves (transmission and reception, respectively) for alternate exchange of information from the main station of the network with the stations of correspondents;
- using three waves (transmission, reception of the first and reception of the second for the service channel) for alternate exchange of information from the main station of the network with stations of correspondents and simultaneous reception of formalized messages on the service channel at the VPU.
Service communication between station operators is carried out with the help of commands typed on the VPU keyboard using the negotiation table of the R-438 station operator and transmitted in the absence of operational information transmission. Reception of service communication commands can be carried out via the second channel of the station reception simultaneously with the reception of operational information via the first channel of reception.
It should be noted that trunk No. 4, and for communication of portable stations, the Globus-1 spacecraft has a limited capacity. To prevent overloading of the repeater amplifier, simultaneous operation of stations is allowed only on eight out of ten operating frequencies.
