RU2253946C2 - Satellite communications system for surveillance over moving and stationary objects, transmission of phone messages and data - Google Patents

Abstract

FIELD: communications.

SUBSTANCE: system has satellites, set on circular stationary orbit with antennae mounted on them as well as relay stations, and their ground-based stations. Including central communications control system, satellites control station and subscriber stations, relay station is made in form of serially connected low-noise amplifiers, connected to each receiving narrow-direction antenna, remotely controlled downward converters, amount of which matches number of frequencies bands, and which are separated exclusively for frequencies band zones, intermediate frequency accelerators and remotely controlled upward converters.

EFFECT: not only stationary communications subscribers can access broadband channels, but also mobile subscribers.

2 cl, 10 dwg

Description

The invention relates to the field of communications, and more specifically to radio communication systems using artificial Earth satellites.

The project of the “Regional system of personal satellite communications“ Zerkalo-KR ”” is known, the technical parameters of which are given in the magazine “Connect” No. 50 for 2000.

The project “Regional system of personal satellite communications“ Zerkalo-KR ”” is based on the use of a spacecraft with a multi-beam onboard antenna with a large reflector.

It is assumed that regional systems can be used in those regions where communication infrastructure is not developed and where these services may be in demand. The frequency bands used for the reception and transmission of subscriber terminals of the mobile service selected L (S) with a total band of 29 MHz, and for the feeder line C with a band of 160 MHz.

It is assumed that the system can provide telephone / fax and data transfer when connecting subscribers of this system with each other. In addition, telephone / fax and data transmission when communicating with the subscribers of this system through a central call center with subscribers of the public telephone network, as well as a personal radio call.

To organize direct communication between system subscribers, an on-board processor for processing and switching subscriber signals will be used. As in many multipath systems, it is assumed that the frequency band allocated for the system will be reused. Multiplicity of use is 4-5.

Information transfer rate up to 9.6 kbit / s.

Multi-beam antennas of L (S) - range, equipped with large reflectors deployed in orbit with an equivalent diameter of about 12 m, forming 30-40 beams with narrow radiation patterns. The customer service area is equivalent to the onboard antenna service area with a beam pattern of the order of 10 ° × (4 ÷ 5) °.

The exit of system subscribers to telephone switched networks is provided through gateway stations.

Subscriber terminals will be dual-mode, which will allow them to work also in cellular networks.

It is proposed to use stations with an antenna diameter of at least 6 m as earth gateway stations.

The multi-barrel payload presents new requirements for the service system module, especially for the power supply and thermal control system.

The total power consumption of the payload modules and utility systems is about 6900 watts.

The total mass of the spacecraft is about 2600 kg.

The mass of the payload module is about 700 kg, its power consumption is 5700-6300 watts.

The spacecraft launch to the GSO is carried out by the Proton heavy launch vehicle.

The disadvantages of the system include the fact that it is designed to provide users with voice channels and the exchange of low-speed information.

Essentially, users are offered the same communication services that cellular systems provide. Thus, the presented system is a competitor to rapidly developing cellular communication systems and should take into account their further development.

In any case, the creation of a new system with the same services is associated with great risk. This is confirmed by the bankruptcy of the IRIDIUM satellite communications system, based on a constellation of low-flying satellites and offering the same communications services.

In satellite communication systems designed for mobile communication based on geostationary satellites, it should be possible to increase the energy potential of radio lines and the ability to work in a system of small subscriber terminals, similar to the terminals of cellular systems.

To ensure acceptable energy ratios, it is necessary to install large-diameter antennas on board the geostationary satellite and use them to cover the entire service area from the satellite with narrow beams with high gain.

Technical difficulties in the implementation of such systems arise when it is necessary to organize communication between subscribers located in different ray coverage areas. This requires the installation on a satellite of complex and expensive on-board demodulation and switching devices.

In addition, the satellite requires the installation of a large number of transponders. Such a number of transponders can be installed on heavy satellites and their launch into orbit can be carried out by heavy rocket launchers. All this determines their high cost.

A system with a large initial investment can pay off with developed earth networks and at significant risk.

In recent years, mobile communication systems and especially cellular communications have become widespread. Mass production of cellular communications equipment and a significant number of users made it possible to drastically reduce the cost of the services provided. Nevertheless, the effective use of cellular systems is possible in large cities and densely populated areas. In other areas of low population density, satellite communications systems may be used. Such systems include, first of all, such systems as "IRIDIUM" and "GLOBALSTAR", based on the use of low-flying satellites. The disadvantages of such systems include the need to use a large number of expensive and complex spacecraft. As a result, the cost of the services provided was very high and it was not possible to recruit a sufficient number of users, which would make it possible to ensure the competitiveness and self-sufficiency of the systems. IRIDIUM declared bankruptcy, and GLOBALSTAR has serious economic difficulties. In order to create systems at a lower cost, projects of regional satellite communication systems were developed.

Such systems may include the commissioned regional geostationary mobile satellite communications system ACeS (SC GARUDA-1), the Inform Courier Svyaz magazine No. 11, 2002.

On February 12, 2000, the Russian Proton launch vehicle launched the first satellite of the Indonesian Asia Cellular Satellite System (AceS), designed to provide satellite mobile communications services. The satellite, dubbed Garuda-1, is the heaviest ever produced by LMMS (4,500 kg). It is also the largest commercial cargo launched into the Proton rocket.

The management of the company expected to attract 130-150 thousand subscribers for the first year from the start of operation in August 2000. The system is designed to serve 1 million subscribers and supports up to 11 thousand simultaneous telephone connections.

The compact, dual-mode mobile user terminals were designed and manufactured by Ericsson. However, as the system is mastered, fixed satellite terminals have become increasingly important. The company is developing dynamically, although today it serves only 35 thousand mobile users and 15 thousand fixed terminals.

Currently, the company, with the active support of national and local governments, is implementing the Village Phone program. Already installed 15 thousand fixed telephones.

Along with this, ACeS is actively developing and introducing new services - object tracking systems, data collection / data transfer (up to 300 kbit / s).

A multi-beam antenna was used on the satellite, and to provide communication between subscribers in different beams, an on-board processor for digital processing and switching of subscriber signals was installed on the satellite. When creating the processor, new principles of group processing of a large number of signals were developed and implemented, and a new specialized element base was created.

The disadvantages of the system include the fact that during the design it was focused on the provision of telephone communications and the exchange of low-speed information, that is, essentially the same services that cellular communication systems provide. It is no coincidence that a dynamically developing company has recently tended to provide fixed-line services and the possibility of expanding the circle of users in this regard. Fixed-line users can get new services, such as object tracking systems, data collection / data transfer (up to 300 kbit / s). The company is trying to introduce new services on an existing spacecraft that is not intended for these purposes. Other disadvantages include the specially developed complex signal switching system installed on board and, as a result, the high cost of the spacecraft and, accordingly, the relatively high cost of the services provided. The system is not intended for switching high-speed information flows and cannot be used to work in modern broadband information networks.

A known satellite communications system for monitoring mobile and stationary objects, transmitting telephone messages and data according to the patent of the Russian Federation No. 2118056, MKI N 04 B 7/185.

This satellite communications system consists of artificial satellites launched into circular orbits with a height of 500-900 km, launched artificial satellites placed into a geostationary orbit, artificial satellites launched into intermediate orbits with a height of 2900-3100 km, subscriber stations and control stations, earth stations of the geostationary system. On geostationary satellites suitable for use in the system, global antennas (17 ° x17 °), semi-global (17 ° × 12 °) or various regional antennas (having opened about 5 ° × 6 °, 6 ° × 11 °, etc.) can be installed. ) that cover the entire service area. The frequency band allocated for a satellite communication system is usually divided into individual trunks, the bandwidth of which is 36 MHz or 72 MHz. On satellites, the conversion in the indicated bands of signals received from the receiving antennas into output signals is carried out using transponders consisting of low-noise amplifiers, down converters, intermediate frequency amplifiers, up converters and power amplifiers.

Using this system, the following tasks can be solved:

- monitoring the location and condition of valuable, expensive and dangerous goods at moving objects;

- delivery of messages on the status and functioning of stationary objects;

- Establishment of two-way telephone communications between subscribers;

- data transfer between arbitrary subscribers of the system.

This satellite communications system is based on the use of satellites operating at low altitudes, which provides good radio link energy and favorable conditions for the operation of subscribers' earth stations. Under these conditions, it is possible to make a portable subscriber station weighing no more than 0.5 kg and a life of up to one year without recharging the batteries.

The good energy of communication lines for low-flying satellites makes it possible to use simple light satellites with low power consumption. Satellites can be launched into orbits by low-power missiles, while the creation of a constellation and its maintenance will be of low cost. In this case, strategic missiles withdrawn from service under strategic arms reduction treaties can be used to launch missiles.

As a result, the price of services provided by a specialized system may be significantly lower than that of a universal system.

The specified system is the closest to the claimed object and is selected as a prototype.

The disadvantages of this system include its focus on the transmission of low-speed information and the impossibility of transmitting broadband information, which significantly limits the use of the system as a transmission medium in a single information system.

Earth stations of the geostationary system provide the transmission of broadband information, work together with zone stations, however, they have large-diameter antennas (from 4 m or more) and cannot be installed at stationary objects of observation. Monitoring the operation of stationary objects is carried out using narrow-band communication channels, while monitoring many stationary objects requires the use of broadband channels. Broadband is increasingly required for many advanced individual users, as well as for many mobile subscribers.

The main direction of the global development of society in the new century will be the creation of Information and Communication Technologies (IT), which are one of the most important factors affecting the formation of a twenty-first century society.

Information and communication technologies (a combination of communication channels, switching and control tools) should become the physical basis (foundation, framework) of the Global Information Society and provide transportation services for any type of data transfer with the necessary level of service quality.

In addition to network equipment, transport communication systems occupy an important place in the construction of broadband multiservice networks.

A preliminary study of the creation of a transport system of the required quality showed that it cannot be built on the basis of any one transmission medium and, most likely, several transmission media, such as fiber optic links, digital radio relay lines, cable lines and systems, will participate in the creation of a transport system satellite communications.

Satellite communication systems can be used as transport systems in the case of solving the problem of providing mass users access to broadband networks.

In many cases, using satellite communication systems, it is possible to provide high-quality communication channels at a lower cost and in a shorter time.

For making technical decisions, the cost of creating the system, deployment time, operating costs, the possibility of its further development and modernization are of fundamental importance.

Progress in the development of space technologies and electronics made it possible to optimize the parameters of earth and space stations, as a result of which it was possible to reduce the cost of earth stations, the diameters of their antennas, transmitter capacities, and increase environmental safety, which made it possible to install small stations of a geostationary satellite communication system directly at users and significantly reduce the cost of creating terrestrial networks.

The objective of this proposal is to create a flexible integrated satellite communications system based on geostationary satellites with transformable payload, which could be used as one of the transmission media in a single digital information system and provide transportation services for any type of data transfer with the required level of service quality. The system is designed to support the work of regional, national, local information networks and individual users and provides users with access to broadband multimedia networks, the ability to receive and transmit various streams of information over short and long distances using small subscriber stations.

The solution to this problem is achieved by creating a satellite communications system, consisting of artificial satellites placed in a circular geostationary orbit with antennas, repeaters and their earth stations installed on them, including a central satellite communications system control station, satellite control station and subscriber stations, in which each installed on The satellite antenna is multi-beam in the form of a receiving one, irradiating each zone with one or many narrow beams into which the serviced territory, and transmitting, forming one contour beam per zone, and the repeater is made in the form of series-connected low-noise amplifiers connected to each receiving narrowly directed antenna, remotely controlled down converters, the number of which corresponds to the number of frequency bands into which the bands allocated for the zones are divided frequencies, remotely controlled band-pass filters of intermediate frequency, amplifiers of intermediate frequency and remotely controlled converters up, at The system is equipped with signal-adding devices for each zone, the inputs of which are connected to up-converters that process signals intended for these zones, and the outputs are connected to the inputs of power amplifiers connected by outputs to transmitting zone antennas, as well as to the main zone control and monitoring stations local networks located in zones.

In addition, the repeater is equipped with bandpass filters that transmit signals in the frequency bands specified for subscribers located in the areas of operation of these antennas and are connected to the output of each receiving narrowly directed antenna and to the input of low-noise amplifiers, while the repeaters are equipped with signal addition devices that combine signals coming from two or more controllable band-pass filters and directing combined signals to intermediate-frequency amplifiers.

The authors are not aware of technical solutions with the essential features given in the characterizing part of the claims.

The invention and some possible options for the implementation of satellite communication systems are illustrated by drawings, which show:

Figure 1 - satellite communications system designed to serve regional, national, departmental information networks and individual users.

Figure 2 - satellite communications system based on a light spacecraft, designed to serve regional, national, departmental information networks and individual users in the territory of 3 zones.

Figure 3 - use of the frequency band allocated for a satellite communication system based on a light spacecraft with a transformable payload.

Figure 4 - examples of the distribution of zones in areas served by light, medium or heavy spacecraft.

Figure 5 is a structural diagram of an airborne relay complex with a transformable payload of a satellite communications system designed to serve national, regional, departmental and local information networks, as well as individual users in the territory from 3 zones.

Figure 6 - use of the frequency band allocated for the satellite communications system based on the average spacecraft with transformable payload.

Figure 7 is a structural diagram of an airborne relay complex with a transformable payload of a satellite communications system designed to serve national, regional, departmental and local information networks, as well as individual users on the territory of 5 zones.

On Fig - examples of coverage with narrow beams of territories divided into three zones.

Figure 9 is a structural diagram of an airborne relay complex with a transformable payload of a satellite communications system designed to serve national, regional, departmental information networks and the Internet type in an area of 3 zones with 11 narrow receiving beams in each zone.

Figure 10 is a fragment of the structural diagram of the airborne relay complex for the 2nd zone with a transformable payload and combining the information flows of a satellite communication system designed to serve national regional, departmental information networks and the Internet type in the territory of 3 zones with 11 narrow receiving beams in each zone.

A satellite communications system consists of a communications satellite 1 (FIG. 1), placed in a geostationary orbit; spacecraft control stations 2; central control and monitoring station of satellite communication system 3; national, regional, departmental, local satellite communication networks and control stations for these networks 4; small subscriber stations 5.

Figure 2 shows one example of a territory divided into three zones.

The satellite has multi-beam antennas 6 (Fig. 2) in the form of a receiving one, irradiating with one beam 7, 8, 9 (Fig. 5) each zone into which the served territories are divided (Fig. 2 and Fig. 4).

The repeater is made in the form of series-connected low-noise amplifiers 10, 11, 12 (Fig. 5), the inputs of which are connected to the output of each receiving omnidirectional antenna 7, 8, 9 (Fig. 5), and the outputs are to remote-controlled converters down 13-27 (figure 5), which are connected to remotely controlled band pass filters 28-42 (figure 5). Band-pass filters are connected to amplifiers of intermediate frequency 43-57 (Fig. 5), the outputs of which are connected to remotely controlled converters upward 58-72 (Fig. 5). The upward converters are connected to the inputs of the signal adders 73, 74, 75 (Fig. 5), the outputs of which are connected to the inputs of the on-board power amplifiers 76, 77, 78 (Fig. 5), and the outputs of which are in turn connected to a multipath transmitting antenna forming one contour beam 79, 80, 81 (Fig. 5) for each zone.

In order to reduce the amount of equipment, the repeater is equipped with band-pass filters 363-373 (figure 10), transmitting signals in the frequency bands specified for subscribers located in the areas of operation of these antennas 352-362 (figure 10) and connected to the output of each receiving narrowly directed antenna and to the input of low-noise amplifiers 374-384 (figure 10), while the repeater is equipped with signal addition devices 479-490 (figure 10), combining the signals coming from two or more controlled variable filters 435-478 (figure 10), and guides combined signals to the amplifier and intermediate frequency 479-490 (figure 10).

The entire territory served by satellite is divided into separate zones (some examples are presented in figure 4), the number and size of which are determined on the basis of economic, administrative relations of the regions and technical feasibility. Depending on the size of the served area and the number of zones, the system can be based on the use of light, medium or heavy satellites.

Reception of signals from subscribers is provided by a receiving multi-beam antenna installed on the satellite 7-9 (Fig. 5), 82-86 (Fig. 7), 142-174 (Fig. 9), which, depending on the optimization of the earth-space line, capabilities the spacecraft and the assigned tasks can irradiate each zone with one beam 7, 8, 9 (Fig. 5) or many narrow beams 142-152, 153-163, 164-174 (Fig. 9).

The purpose of optimizing the earth-space lines is to provide such an energy potential for radio links that it is possible to receive, with a given level of quality, weak broadband signals from subscriber stations with small-diameter antennas and low power transmitters, while adhering to the requirements of avoiding interference with neighboring satellites from the existing network of earth stations.

Signal transmission to earth stations is provided by a multi-beam transmit antenna installed on the satellite, each beam of which serves its own zone.

The proposed scheme provides the possibility of functional separation of the lines of the earth - space and space - earth, in which the energy calculation and selection of the parameters of the lines up and down are carried out independently of each other.

The optimization of space-to-earth lines makes it possible to provide such energy for radio lines, at which subscriber stations with small-diameter antennas can be installed at any point in the zone to receive broadband signals.

To service a small-sized territory with a small number of zones, it is possible to use a light spacecraft in the system and a simple payload configuration. In the case of significant size of the territory and the number of zones, the complexity, dimensions and weight of the payload, which can be placed on a spacecraft of medium or heavy classes, increase.

When dividing the served territory into zones and orienting the system to serving mass users, including individual users, it is necessary to ensure the efficient use of the frequency band allocated for the system and the scheme of work in the network system and individual users.

In order to increase the efficiency of the use of the frequency band allocated for the satellite communications system, the entire allocated frequency band is divided into two parts, which, based on the principle of spatial diversity, are used repeatedly and are alternately allocated for zones. Reusable frequency bands form a common effective band in which satellite communications networks can operate.

To reduce the interference of networks operating at the same frequencies, zonal antennas with contour radiation patterns are used on the satellite.

To organize the work of local, regional and national networks, as well as individual users, frequency bands are allocated within the limits of the bands allocated for the zones.

Local networks can operate both within the zones and have connections with networks located in other zones. Regional and national networks usually cover several areas. Operators can order the frequency bands necessary for their networks and organize work in them.

The total amount of information circulating in each zone is estimated by the bandwidth that should be allocated for the zone, provided that a specified level of quality is ensured. Similarly, the total amount of information between the zones is determined by the frequency bands allocated for interband communications.

Transparent channels are formed in the selected bands, in which various types of information can be transmitted and various operating modes can be used.

In these bands, both permanent dedicated communication lines for the transmission of all types of digital information are organized, as well as systems for providing channels on demand. Frequency division multiple access systems and time division multiple access systems are used.

In constantly allocated channels, networks are created with special requirements for communication channels, covering both one and several zones.

The system provides for the possibility of changing, within significant limits, the width of the allocated bands and the formation of frequency spectra for transmitting information from the satellite to the designated areas and to the central station.

Frequency bands can be redistributed according to the analysis results obtained during the operation of the system. This is especially important when offering new communication services, services for providing broadband access, for which there is no reliable data on the schedule.

If the results of marketing research are unreliable and the scientifically sound forecasting of the further development of the needs for the provision of new communication services, such as broadband communications, is impossible and, accordingly, without reliable information on the number of users and their geographical location, it is impossible to design the necessary payload configuration and ensure the loading of the space segment.

The ability to change the allocated frequency bands during the operation of the system to changing user requirements over time increases the efficiency of the system.

The system allows multiple use of the frequency spectrum. The frequency bands allocated for a satellite communications system based on a light spacecraft on the space-to-earth and earth-to-space lines, as well as the effective frequency bands, are shown in FIG.

The frequency band allocated for the system is divided into two parts and two frequency bands are formed, and the territory served by the satellite is divided into 3 zones in which these bands can be used in series.

As some examples, FIG. 4 shows three territories of different sizes, of which the first territory is divided into three zones, the second territory is divided into five zones and the third territory is divided into seven zones. Depending on the size of the territory and the frequency band provided for the system, the choice of the spacecraft and the configuration of its payload are determined. Thus, for a small territory and the three service areas into which it is divided, it is preferable to choose a light spacecraft. For an average territory and a large number of zones, the use of an average satellite may be most effective, and for a large territory and a number of zones, the use of a heavy satellite may be effective.

The service areas shown in FIG. 4 are indicated by a dashed line.

As a result of repeated use of the allocated frequency band, the effective band can significantly exceed the allocated frequency band.

This primarily depends on the number of service areas in which frequency bands are used repeatedly.

So, it can be roughly determined that in the territory in which the three zones are defined, it is possible to repeat one of the bands twice, and then the effective band exceeds 1.5 times that actually allocated.

With four zones, the effective band will be twice as high as the one allocated.

With five zones, the effective band will exceed the allotted 2.5 times.

In six zones, the effective frequency band will exceed the real one by 3 times, and in seven zones the effective band will exceed the real one by 3.5 times.

The frequency band allocated to the system can be divided into equal two parts, or into unequal parts. The width of the frequency bands allocated for the zones is determined by the amount of information transmitted.

In information systems, significant amounts of transmitted information are communications between subscribers and the central station. The central station is usually located in the administrative and scientific center, in which the main data banks and offices of state and departmental institutions and major companies are concentrated. The location of the central station in any zone can significantly increase the load of the zone in which it is located, which in turn will require the allocation of a wider frequency band for this zone.

In accordance with the proposed solution, it is possible to implement several options for satellite communications systems.

Option 1

In this embodiment, a satellite communications system based on a light spacecraft is considered. The system can be deployed with the least initial outlay and is best suited for obtaining statistics on the geographical location of users and the distribution of information flows. The spacecraft uses the simplest payload with the possibility of redistributing frequency bands between users.

Consider a territory divided into three zones and a central station located in the second zone. Then, for the first zone, as shown in figure 3, the frequency band F ₁ -F ₅ is allocated, for the second zone, the frequency band F ₅ -F ₁₀ is allocated, consisting of the band F ₅ -F ₆ allocated for the central station and the band F ₆ -F ₁₀ allocated to subscribers of the second zone. In the third zone, the frequency band F ₁ -F _{5 is used} . With a large amount of information exchange between the central station and subscribers of the system, it is necessary to increase the frequency band allocated for the zone in which the central station is located.

When determining the efficiency of using the allocated frequency band and the inequality of the bands allocated for the zones, it is necessary to calculate a coefficient showing the ratio of the effectively used frequency bands to the frequency band allocated for the satellite communication system.

where K is the coefficient of efficiency of use of the allocated frequency band.

The frequency band F ₅ -F _{6 is} designed to supply signals from the central station to the satellite.

In general, when dividing the territory into a larger number of zones, the coefficients in front of the parentheses and showing how many times the left or right frequency band is used in the system will change.

The structural diagram of the airborne relay complex is presented in figure 5. A multi-beam antenna is installed on the spacecraft, each beam of which is directed to its own zone.

In the repeater, the group of elements is repeated many times, and their number depends on the selected circuit, therefore, for brevity, we define this group and give it the name "carrier", which acts as a transfer of the receiving signal to the output signal and consists of a down converter 13 (Fig. 5 ) with a mixer and a remotely controlled frequency synthesizer, a variable remotely controlled bandpass intermediate frequency filter 28 (Fig. 5), an intermediate frequency amplifier 43 (Fig. 5) and an up converter 58 (Fig. 5) with mixer and remotely controlled frequency synthesizer.

The carriers do not include low-noise amplifiers (LNAs), summing devices, and power amplifiers.

Low-noise amplifiers are connected to the outputs of the receiving antennas. Carriers are connected to the LNA outputs, the number of which is determined by a specifically implemented circuit. Carriers are connected to summing devices connected to power amplifiers. The number of summing devices and powerful amplifiers is equal to the number of zones into which the territory is divided.

The signals from the subscribers of the first zone are fed to the receiving on-board antenna 7 (Fig. 5), then amplified by a low-noise amplifier 10 (Fig. 5) and fed to the down converters 13, 16, 18, 20 (Fig. 5). The frequency band F ₁ -F _{5 is} used repeatedly, in this case twice, and is divided into four bands, one of which F ₁ -F _{2 is} designed to serve subscribers of the first zone, the band F ₂ -F _{3 is} designed to establish communications between the subscribers of the first and second zones, the band F ₃ -F _{4 is} intended for organizing communications between subscribers of the first and third zones and the band F ₄ -F _{5 is} intended for communications between subscribers of the first zone and the central station.

In the band F ₁ -F ₂ operate local area networks. The signals of the subscribers of the first zone are fed to the Converter 13 (figure 5), which converts the signals into an intermediate frequency. The converter synthesizer is remotely controlled and can, on commands, move the band across the frequency grid. The main purpose of the converter is to combine the center frequency of the strip F ₁ -F ₂ with the center intermediate frequency. The bandwidth is indicated by the index Δf ₁ . In case of changing the bandwidth defined for the first zone, the combination of the central frequencies can be performed by the synthesizer according to the commands of the main zone station or central station. Next, the signals of the first zone are fed to the bandpass variable filter IF 28 (Fig. 5), which selects the necessary band, and then the signals after the intermediate frequency amplifier 43 (Fig. 5) are fed to the up converter 58 (Fig. 5), which converts the signals to output frequency band. The variable IF bandpass filter, controlled by the commands of the main station, serves to select the necessary intermediate band when changing the frequency band allocated for the first zone. The up converter, in addition to converting the intermediate frequency of the signals to output frequencies, serves to arrange the signals on the frequency scale and form a frequency band for emitting signals to zone I. The signals after the up converter 58 (Fig. 5) are fed to the summing device 73 (Fig. 5) , which also receives signals from the converter 62 (FIG. 5) in the frequency bands Δf _{7 of} zone III, from the converter 66 (FIG. 5), the signals in the band Δf ₉ from the central station and from the converter 70 (FIG. 5) the signals in the band Δf ₁₃ from zone II.

All the signals arriving at the summing device 73 (Fig. 5) are located on the frequency scale using remotely controlled converters upwards and form the frequency spectrum emitted to zone I. After the summing device 73 (Fig. 5), the signals are amplified by a power amplifier 76 (Fig. 5) ) and arrive at the transmitting antenna 79 (Fig. 5), with the help of which they are transmitted to the receiving earth stations of subscribers of zone I.

Similarly, the signals of subscribers of other zones are received, amplified, converted, formed spectra of signals, and then radiated to their zones.

Adjustable synthesizers of down converters 13-27 (Fig. 5), band-pass filters with adjustable passband 28-42 (Fig. 5) and adjustable synthesizers of converters up 58-72 (Fig. 5) allow us to transform the payload and provide the width of communication frequency bands according to needs evolving over time. The same adjustments provide the arrangement of frequencies and the formation of spectra for transmission. Some difference is the communication of subscribers with the central station.

The central station is located in zone II and operates on the earth-space line in a dedicated band F ₅ -F ₆ . The specified band is divided into three bands designed to transmit signals to subscribers located in three zones. The signals from the central station arrive at the receiving antenna 9 (Fig. 5) of zone II and, after amplification by the amplifier 12 (Fig. 5), are fed to the down converters 21, 22, 23 (Fig. 5), and after that they are converted to summing devices 73 , 74, 75 (Fig. 5). After amplification by onboard powerful amplifiers 76, 77, 78 (Fig. 5), the signals are transmitted to antenna devices 79, 80, 81 (Fig. 5) and then to zone subscribers. At the central station, signals from zone subscribers enter the antenna devices of their zones 7, 8, 9 (Fig. 5) and after amplification by amplifiers 10, 11, 12 (Fig. 5) in the frequency bands F ₁ -F ₅ defined for I and III zones, and F ₆ -F ₇ , defined for zone II, to the converters down 19, 20, 24 (figure 5) and then after amplification and conversion up go to the addition device 74 (figure 5). After amplification by an onboard power amplifier 77 (Fig. 5), the signals are transmitted to the antenna device 80 (Fig. 5) and are transmitted to zone III, in which the central station is located.

The peculiarity of the proposed scheme is that local networks and individual subscribers work in the bands allocated for local communications. Work is organized using the main zone control and monitoring station. Thus, the main zonal stations provide the work of local zonal networks, and zonal communication organizations themselves determine which systems should be used for operation. When organizing work in the frequency bands allocated for inter-zone communications, work in these bands is also organized by the main zone stations by agreement between themselves, in which case various methods of information transmission and exchange can be used. The role of the central station is reduced to changing the configuration of the payload of the spacecraft at the request of the main zone stations and the organization of information exchange between subscribers and the central station.

It should be noted that when dividing the territory into three zones and ensuring adjustment of the frequency bandwidths, only 15 carriers are required. On-board power amplifiers require only three. Thus, a payload consisting of a specified number of elements can be mounted on a light spacecraft. The system can be recommended with a dedicated band up to 300-500 MHz and with a beam opening of each zone from 2 ° × 3 ° to 2.5 ° × 3.5 °.

Light satellites can be quickly adapted to the changing requirements of users and are most effectively used when it comes to providing new communication services, providing broadband communications.

A light spacecraft, designed for a limited number of users, is able to provide reception of broadband information to terrestrial subscriber stations with antennas with a diameter of 0.9-1.3 m.

Option 2

Given the large size of the territory, in order to maintain the conditions for the reception and transmission of broadband information, it is necessary to divide the territory into a larger number of zones, and accordingly, the volume and weight of the payload will increase. In this case, the payload can be placed on a middle-class or heavy-class spacecraft. Consider the case in which the territory is divided into 5 zones. In the system, the band of allocated frequencies is used repeatedly, for which it is divided into two parts, which are used in turn to transmit signals in the zones.

Effectively used frequency band of received signals and the formation of a frequency spectrum for transmission are presented in Fig.6. As already noted, the utilization factor of the frequency band allocated for the system in this case is about 2.5.

The structural diagram of the airborne relay complex is presented in Fig.7.

A multi-beam antenna is installed on the spacecraft, the rays of which are directed to their zones.

The frequency bands allocated for service areas, in turn, are divided into seven bands for the left half of the spectrum and six bands for the right half of the spectrum.

The frequency bands indicated on the scheme F ₁ -F ₂ and F ₈ -F ₉ are designed to serve local networks and zone subscribers, four bands F ₂ -F ₃ , F ₃ -F ₄ , F ₄ -F ₅ , F ₅ - F _{6 of the} left half of the spectrum and F ₉ -F ₁₀ , F ₁₀ -F ₁₁ , F ₁₁ -F ₁₂ , F ₁₂ -F _{13 of the} right half of the spectrum are defined for interband bonds and the bands F ₆ -F ₇ , F ₁₃ -F ₁₄ for communication of zone subscribers with the central station.

The band F ₇ -F _{8 is} defined for communication between the central station and zone subscribers, and since the central station is located in the third zone, the total band allocated for the third zone is F ₁ -F ₈ . The frequency bands allocated for zones in systems with multiple use of frequencies are sequentially alternated among themselves in the zones and therefore for the zones 1 and 5, the bands F ₁ -F _{8 are} also used. These bands in zones 1 and 5 can be used in the interests of providing communication for zone subscribers.

In the third zone, the band F ₇ -F _{8 is} defined for transmitting signals from the central station to zone subscribers and, in turn, is divided into five bands Δf ₁₉ , Δf ₂₀ , f ₂₁ , Δf ₂₂ , Δf ₂₃ , each of which has a different width depending on passing streams of information.

The frequency bands into which the entire effective band is divided have different widths depending on the passing information flows and are indicated by indices from Δf ₁ to Δf ₃₅ .

As in the first embodiment, the signals coming from the zone subscribers to the zone antennas 82, 83, 84, 85, 86 (Fig. 7) are amplified by low-noise amplifiers 87, 88, 89, 90, 91 (Fig. 7) and are received on carriers with which they are converted to output signals.

The carriers are indicated by serial numbers from 92 to 126, which are indicated at the inputs of the converters.

The carriers are connected to low-noise amplifiers and emit signals in a specific band for them.

In carriers, the signals are converted into output signals and fed to addition devices 127, 128, 129, 130, 131 (Fig. 7), at the inputs of power amplifiers.

All the signals received by the summing device form frequency spectra, which are then amplified by power amplifiers 132, 133, 134, 135, 136 (Fig. 7) and fed to the antenna devices 137, 138, 139, 140, 141 (Fig. 7), s by which they radiate to their zones.

The proposed scheme provides a change in the width of the bands and the formation of these bands into zone bands, the signals in these bands are then amplified and radiated into zones. Thus, the redistribution of frequency bands between users is ensured, and ultimately the most efficient use of the space segment capacity and, in general, the maximum efficiency of the satellite communication system is achieved.

The use of the space segment capacity together with the main zonal stations is controlled by the central control and monitoring station of the communication system and, if necessary, provides the redistribution of frequency bands between users through remotely controlled elements.

It should be noted that when dividing the territory into five zones and ensuring the adjustment of the frequency bandwidths, only 35 carriers are required. Low-noise amplifiers and on-board power amplifiers require only five. Thus, the payload, consisting of a given number of elements, can be installed on the average spacecraft.

The system can be recommended with a dedicated band up to 300-500 MHz and with a beam opening of each zone from 2 ° × 3 ° to 2.5 ° × 3.5 °.

Medium satellites can be quickly adapted to changing user requirements over time.

On a heavy spacecraft, a payload with increased power consumption and more complex configuration can be placed. Such examples include the territory, which is divided into seven zones. In the system, dedicated frequency bands are reused.

When dividing the territory into seven zones and ensuring adjustment of the frequency bandwidth, 63 carriers are required. Low-noise amplifiers and on-board power amplifiers require seven.

The system can be recommended with a dedicated band up to 500-700 MHz and with a beam opening of each zone from 2 ° × 3 ° to 2.5 ° × 3.5 °.

Option 3

The main objective of creating a promising satellite communications system designed for information systems is to provide users with broadband access at affordable prices. This problem is solved by using subscriber terminals with antennas of small size, low radiation power and, accordingly, low cost with the possibility of installing them directly with users and ensuring environmental safety for the environment.

However, the use of small subscriber stations encounters serious technical difficulties associated with the fact that small antennas have a wide radiation pattern and the emission of signals can lead to interference with neighboring communication satellites located in a geostationary orbit. This problem is sharply aggravated due to a decrease in the diameter of earth station antennas.

Improving the parameters of the earth-space line is possible using the proposed scheme, which provides functional separation of the earth-space and space-to-earth lines, in which the calculation and optimization of lines can be carried out independently of each other.

The aim of optimizing the earth-space lines is to enable the transmission of broadband information to the satellite using earth stations with small antennas and low power transmitters while fulfilling the requirements for observing the level of permissible interference to neighboring satellites. When coordinating satellites in orbit, an acceptable level of interference is set, the excess of which is not allowed by earth stations.

The best conditions can be created by installing a large-diameter multi-beam receiving on-board antenna on the satellite, covering the served territory with narrow beams with high gain and providing low-level signals from small subscriber stations.

The diameter of the antenna mounted on the spacecraft depends on the type of spacecraft and can vary significantly. Accordingly, this will affect the parameters of earth stations.

The optimization of the space-to-earth line, in which it is possible to receive broadband signals to small earth stations, has already been considered in options 1 and 2 and can be used in this option.

Therefore, in the proposed embodiment, the same principle of distribution of frequency bands in the system for users is used and the same scheme on the space-to-earth line is used as in the first embodiment. The difference lies in constructing a circuit on the earth-space line, since several receiving antennas operate in the zones. The simplest solution would be to add in the adder the signals received with the help of highly directional antennas and extract the bands determined for them from the total signal by the transponders. The disadvantage of this method is the addition of noise in the adder and the resulting degradation of the signal-to-noise ratio at the transponder inputs. The elimination of this drawback is possible by allocating the required bands at the outputs of low-noise amplifiers of highly directional antennas and processing the signals in the selected bands in separate carriers. To carry out this operation requires a significantly larger number of carriers.

Consider one of the possible options for a satellite communications system, built on the use of the proposed principles.

In the system, the territory served by the satellite is divided into three zones, and using a multi-beam antenna, each zone is covered by eleven narrow beams, then the total number of narrow beams in the system will be 33 beams. For a particular system, the number of narrow beams providing a continuous coverage of each zone can be different. The number of users in the rays can also vary significantly. The proposed version of the system is designed to achieve the maximum possible technical parameters when creating small-sized and cheap earth stations and, accordingly, earth satellite communications networks. The system is designed for the most efficient use of space segment capacity. Examples of coverage with narrow beams of a territory divided into three zones are shown in Fig. 8.

The structural diagram of the airborne relay complex is presented in Fig.9.

The entire frequency band allocated for the satellite communication system is divided into two bands, one of which F ₁ -F _{15 is} used repeatedly, as in the first version of the system, and one band F ₁₅ -F ₃₀ , intended for the second zone and the central station, used once. The frequency bands defined for the zones are in turn divided into four parts.

The first zone is considered as an example. In the first zone, the band F ₁ -F _{12 is} used to organize the operation of intra-zone local communication networks, two bands F ₁₂ -F ₁₃ and F ₁₃ -F ₁₄ are used for inter-zone communications and one F ₁₄ -F ₁₅ for communication with the central station. Each of these bands is divided in turn into eleven bands. Eleven narrowly directed antennas of the first zone receive signals from their subscribers in the frequency band F ₁ -F ₁₅ . Four carriers are connected to each narrowly directed antenna of the first zone, one of which is designed to process the signals of the first zone, the second for processing signals intended for communication with subscribers of the second zone, the third for processing signals intended for communication with subscribers of the third zone, and the fourth for processing signals intended for communication with the central station.

Consider the organization of the system in the frequency band F ₁ -F ₁₂ allocated for local communication networks of the first zone.

The bands are allocated for subscribers in the first ray, second, third and so on rays indicated in the scheme F ₁ -F ₂ , F ₂ -F ₃ , F ₃ -F ₄ , F ₄ -F ₅ , F ₅ -F ₆ F ₆ -F ₇ , F ₇ -F ₈ , F ₈ -F ₉ , F ₉ -F ₁₀ , F ₁₀ -F ₁₁ , F ₁₁ -F ₁₂ .

The center frequencies of each band are indicated by the indices f ₁ , f ₂ , f ₃ , f ₄ , f ₅ , f ₆ , f ₇ , f ₈ , f ₉ , f ₁₀ , f _11, respectively. The signals from the subscribers in the first beam and occupying the frequency band F ₁ -F ₂ intended for the receiving subscribers of the first zone are fed to the antenna 142 (Fig. 9), a low-noise amplifier 175 (Fig. 9), and then the carrier 208 (Fig. .9), in which they are converted to intermediate frequency signals, pass through a tunable band-pass filter, amplified and then converted to output frequency signals. The output signals with the help of a tunable up-converter take a predetermined position on the frequency scale and go to the summing device 343 (Fig. 9), at the input of a powerful amplifier 346 (Fig. 9). Similarly, the signals of beams 143-152 (Fig. 9) in the other ten frequency bands F ₂ -F ₁₂ are fed to their low-noise beam amplifiers 176-185 (Fig. 9) and then carriers 209-218 (Fig. 9), using which are converted and received on the device of the summation of the rays 343 (Fig.9) at the input of the power amplifier 346 (Fig.9) of the first zone.

The signals coming from the subscribers of the first zone in the frequency band F ₁₂ -F ₁₃ pass through the antenna-feeder device of the rays 142-152 (Fig.9) and LNA 175-185 (Fig.9) and then fed to the carriers 230-240 ( Fig.9). In carriers, the signals are converted and sent to the summation device 345 (Fig.9) of the third zone.

The signals received from the subscribers of the first zone through the antenna-feeder device of the rays 142-152 (Fig.9) and LNA 175-185 (Fig.9) in the frequency band F ₁₃ -F ₁₄ are transmitted to carriers 263-273 (Fig.9 ) In carriers, the signals are converted and sent to the summation device 344 (Fig.9) of the second zone.

The signals from the subscribers of the first zone in the frequency band F ₁₄ -F ₁₅ to the antenna-feeder devices of the rays 142-152 (Fig.9) and LNA 175-185 (Fig.9) and intended for the central station, are fed to the carriers 285- 295 (Fig. 11), in which they are converted and sent to the summation device 344 (Fig. 9) of the second zone. In the second zone is the central station.

In addition to these signals, signals from the carriers 321-331 (Fig. 9) of the second zone, carriers 252-262 (Fig. 9) of the third zone, and from the carrier 296 (Fig. 9) of the central station are supplied to the summation device of the first zone.

After the summing device 343 (Fig. 9), the signals are fed to a power amplifier 346 (Fig. 9) and then to the antenna of the first zone 349 (Fig. 9).

In the same way, signals are received from subscribers of the second and third zones, processing of these signals and transmission to the zones.

As in the first embodiment, the transmitters provide for the commands of the central or main zone stations to control over a wide range the bandwidth of the amplified signals and the ability to change the location of the signals on the frequency scale when forming a spectrum for the emission of signals into the zones.

Thanks to this, the satellite communication system can be tuned to the current real schedule.

A special place is occupied by communication with the central station. Depending on the place where the central station is located, and in which zone and in which beam it is located, an appropriate frequency band must be provided for this beam to receive signals from the central station.

In this embodiment, the central station is located in beam 168 (FIG. 9) of the second zone. The signals from the central station in the frequency band F ₁₅ -F ₁₆ are fed to the antenna 168 (Fig. 9), then to the LNA 201 (Fig. 9) and, finally, to three carriers 296, 297, 298 (Fig. 9), in which they are processed and sent to the summation devices 343, 344, 345 (Fig.9) at the inputs of the power amplifiers of each zone. The considered option is limiting in its technical capabilities due to the optimization of the system in all basic parameters. However, with an increase in the number of zones in the case of preserving the limiting parameters, the number of carriers and information flow control elements will rapidly increase. So, with three zones and eleven beams in each zone, 135 carriers and 405 elements that are adjustable in them will be required. With five zones and eleven beams in each zone, 335 transporters and 1,005 adjustable elements will be required. With seven zones and eleven beams in each zone, 623 carriers and 1869 adjustable elements will be required.

Option 4

In the third version, a system is optimized for the main parameters and, therefore, provides the most favorable conditions for users. However, these conditions are created due to a significant complication of the spacecraft, which is expressed in an increase in the volume and weight of the payload, an increase in the number of adjustable elements and a more complex control system. This mainly depends on the number of zones into which the served territory is divided, and the number of sharply directed receiving antennas providing continuous coverage of the zones.

Under these conditions, the ability to reduce the number of remotely controlled elements and equipment of the repeater is essential.

A significant reduction in the number of equipment of the repeater and, accordingly, the volume and weight of the payload can be ensured by combining several streams into one stream and further amplification and conversion of the total signals using single relay elements. This proposal is a further development of the system described in the third version. As in the third version, a system is considered in which the territory is divided into three zones and 11 highly directional antennas serve each zone.

The essence of the proposal is set forth in Fig. 10, which shows a fragment of the structural diagram of an onboard relay complex for the second zone, with a transformable payload and combining information flows of a satellite communication system designed to serve national, regional, departmental information networks and the Internet type. For the first and third zones, the scheme can be represented in a similar way. At the same time, the presentation of part of the scheme makes it possible to consider the scheme in close-up more clearly.

It is assumed that the frequency band allocated for the satellite communication system is used in the same way as in the third embodiment.

The central station is located in the coverage area of the receiving narrowly directed antenna 355 (figure 10).

The signals from the subscribers of the second zone are fed to the receiving narrowly directed antennas 352-362 (figure 10), then to the bandpass filters 363-373 (figure 10), transmitting signals in the frequency bands defined for subscribers located in the areas of operation of these antennas and further on low-noise amplifiers 374-384 (figure 10). For each low-noise amplifier, four down converters 388-391, 392-395, 396-399, 400-403, 404-407, 408-411, 412-415, 416-419, 420-423, 424-427, 428 are connected -431 (figure 10), connected in series with controlled bandpass filters of intermediate frequency 435-478 (figure 10). The signals pass through the converters down and enter the remotely adjustable bandpass filters of the intermediate frequency and then to the adders of the intermediate frequency signals, in which the information flows are combined. Specifically, we consider the combination of signals from subscribers of highly directional antennas 360, 361, 362 (figure 10). The signals from these pointed antennas in the frequency bands F ₄₈ -F ₄₉ , F ₅₂ -F ₅₃ and F ₅₆ -F ₅₇ are sent from the bandpass filters to the addition device 487 (Fig. 10) and after the addition device are fed to the intermediate frequency amplifier 502 (Fig. 10) and further to the up converter 517 (Fig. 10) connected to the summing device 522 (Fig. 10), to which all signals intended for zone 2 are received. Further, the signals pass in exactly the same way as scheme of option 3. The signals arriving in the frequency bands F ₄₉ -F ₅₀ , F ₅₃ -F ₅₄ and F ₅₇ -F ₅₈ are sent from the strip x filters to the addition device 488 (Fig. 10) and after the addition device are supplied to the intermediate frequency amplifier 503 (Fig. 10) and then to the up converter 518 (Fig. 10) connected to the summation device 521 (Fig. 10), which receives all the signals intended for zone 1. The signals coming in the frequency bands F ₅₀ -F ₅₁ , F ₅₄ -F ₅₅ and F ₅₈ -F ₅₉ are sent from the bandpass filters to the addition device 489 (figure 10) and after the device addition goes to the intermediate frequency amplifier 504 (figure 10) and then to the up converter 519 (figure 10), connected a summing device 523 (Figure 10), which receives all signals intended for zone 3. The signals coming in the frequency F ₅₁ -F _52, lanes F ₅₅ -F ₅₆ and F ₅₉ -F ₆₀ are routed by bandpass filters the addition device 490 (Fig. 10) and after the addition device are supplied to an intermediate frequency amplifier 505 (Fig. 10) and then to an up converter 520 (Fig. 10) connected to the summation device 522 (Fig. 10), to which all signals intended for zone 2, including signals intended for the central station.

In the same way, there is a combination of streams from receiving highly directional antennas 352-355 (Fig. 10) and 356-359 (Fig. 10), four streams from each antenna group. In addition, from the omnidirectional antenna 355 (Fig. 10) in the frequency band F ₁₅ -F ₁₆ defined for transmitting signals from the central station, the signals are sequentially fed to down converters 385, 386, 387 (Fig. 10), to remotely adjustable band-pass filters intermediate frequency 432, 433, 434 (figure 10), intermediate frequency amplifiers 491, 492, 493 (figure 10), up converters 506, 507, 508 (figure 10) and adders 521, 522, 523 (figure .10), to which other signals specific to these zones come, and then the signals go to power amplifiers 524, 525, 526 (Fig. 10) and to new antennas 527, 528, 529 (Figure 10).

The choice of threads for combining can be done arbitrarily. When grouping flows, a significant role can be played by the use of data on the distribution of information flows obtained during the operation of the system or as a result of marketing research. You can select high-speed streams and convert them using a single carrier, or combine several streams with relatively low speeds, which can be amplified using a single amplifier of an intermediate frequency. Thus, it is possible to maintain the flexibility of the system, providing the possibility of redistributing frequency bands for transmitting information streams. The combination of three streams makes it possible to reduce the number of intermediate frequency amplifiers and up-converters by three times. Combining the four threads makes it possible to reduce the number of these elements by four times. In the general case, it is possible to combine an arbitrary number of streams and such a combination should be carried out in accordance with the technical capabilities of the spacecraft and the intended purpose of the combination.

The combination of streams can give a particularly positive result when building a satellite communication system based on medium or heavy satellites.

The system provides for the possibility of using earth stations for various purposes. Depending on the tasks performed, the stations have several versions that differ in design features, equipment, complexity and, accordingly, cost.

Receiving earth stations in the system can provide reception of both narrowband and broadband information. The request channel with the control station in this case is carried out via the landline telephone channels of the general switched network. The antenna diameter of such stations is about 0.4-0.6 m. The stations are designed to operate in the entire frequency range allocated for the satellite communication system, and the stations are tuned to a given specific frequency by the command signals of the communication system control station. To realize this possibility, the receiving devices are equipped with frequency synthesizers controlled remotely by commands of the control station. In addition, intermediate frequency amplifiers also have remotely controlled variable bandpass filters for receiving signals in a given frequency band.

There is the possibility of using transceiver stations in the system.

Each transceiver earth station provides operation in the entire frequency range allocated to the system. The occupied bandwidth and the radiation power of the subscriber station is set by the communication network management station. For this, remotely controlled frequency synthesizers are installed at the stations and remotely controlled bandpass filters in the amplifiers of the intermediate frequency.

To organize the interaction of the control station and subscriber stations, control channels are allocated.

At the stations, depending on the requirements, antenna-feeder devices can be installed to operate in two polarizations.

If it is necessary to transmit broadband information, stations must have an appropriate antenna diameter (up to 3.6 m), so as not to interfere with the operation of neighboring satellites and to ensure the standards for radiated power established for the earth network.

In the proposed communication system, the entire service area is divided into separate zones that are irradiated with their own antennas, and local communication networks are concentrated in these zones.

With such a construction of the system, one central control station cannot control the operation of the system in the zones, since the antennas of the zone networks are directed to their zones and do not illuminate the zone in which the central control station is located.

Therefore, each zone should have its own main control station.

From these stations, local communication networks are managed and channels are provided on demand or communication lines are established for a longer period of time. For each physically established communication line at the request of the transmitting subscriber, the necessary bandwidth is provided to ensure the required level of quality. Zone control stations of local communication networks control the use of the frequency band allocated for the zones and transmit data to the central control station of the communication system. The central station determines the use of the frequency bands allocated to the zones for the organization of inter-zone communications and at the same time ensures, if necessary, the redistribution of the allocated bands in order to use them most efficiently.

The central and main zone control stations continuously monitor the radiated power of subscriber stations and provide for the adjustment of the power level of earth transmitting stations in order to ensure the operation of the airborne transmitter in linear mode.

Thus, the proposed system allows us to solve the problem of providing broadband communication services to mass users at the lowest cost for creating the system and its further operation in comparison with the proposed foreign and domestic projects.

High economic indicators were obtained due to the use of this proposal, optimization of the system according to technical parameters and economic indicators.

The system provides conditions for the development of regional, local communication networks and the work of individual users. The work of local communication network operators and individual users is organized through the main zone station, which distributes the space segment allocated for the zone between the local communication networks operating in the zone and individual users and monitors their work. Thus, the frequency bands are completely at the disposal of local telecom operators and local authorities.

The system can be used small cheap earth stations for receiving and transmitting broadband information, installed directly by users. In addition, it is possible to use more complex earth stations intended for the simultaneous reception and transmission of broadband information when working with multiple subscribers located in one or in different zones.

The possibility of creating a system without undue initial costs. For the full loading of the space segment, it is necessary to have a developed earth network, and only in this case is it possible to load the capacity of the space segment. According to the experience gained in the development of satellite communications systems, it is known that the development of the Earth’s network is slow, especially the development of the Earth’s mass network and the provision of new communication services. Proceeding from this, to study the needs for new communication services, the geographical location of users and the dynamics of the development of the earth network, it is necessary to use a spacecraft designed for a relatively small number of users and the ability to adjust information flows during the operation of a communication satellite.

Therefore, the deployment of a satellite communications system and the creation of terrestrial networks is advisable to start on the basis of a light satellite, designed for a relatively small number of users, and during its operation, analyze statistical data on information flows, and then prepare a proposal for further development of the system by launching new satellites with installed they have the payload of the required configuration and the possibility of transforming it during operation. A scientific forecast for the further development of the system will help prepare the launch of technically simple in design efficient and cheap spacecraft.

Here are some known data for comparison.

The estimated cost of creating a regional system of satellite mobile communications Zerkalo-KR, including marketing and advertising costs, will be $ 360 million.

The system can serve up to 350-400 thousand subscribers.

The cost of 1 minute of communication is within $ 0.4-06.

The total cost of the AceS system was initially planned for the project at $ 750 million, but in reality it was required to implement the system to increase the total amount of attracted financing to $ 820 million, of which the cost of creating the system itself was $ 561 million.

In the proposed system, the cost of manufacturing and launching into orbit of a light satellite is about $ 35-45 million. The cost of manufacturing and launching an average satellite into orbit is about $ 55-65 million.

The cost of manufacturing and launching a heavy satellite into orbit is about $ 105-115 million.

The proposed satellite communication system based on a geostationary satellite can be used in conjunction with satellite based systems in low and medium orbits in the same way as in the prototype. The difference will be that with such an application, a system created on the basis of satellites in geostationary, low and medium orbits can provide access to broadband channels not only to fixed-line subscribers, but also to mobile subscribers.

Using this offer, mobile subscribers of the system can receive and transmit information in such a volume that it can be processed and transferred to the receiving subscriber in mobile conditions. Naturally, a mobile subscriber needs a slightly smaller amount of information than a fixed subscriber.

Claims (2)

1. A satellite communication system for monitoring mobile and stationary objects, transmitting telephone messages and data, consisting of artificial satellites launched into a circular geostationary orbit with antennas, repeaters and their earth stations installed on them, including a central control station for the satellite communications system and a control station satellites, and subscriber stations, characterized in that each antenna installed on the satellite is multi-beam in the form of a receiving one, irradiating one or many nodes beams of each zone into which the serving territory is divided, and a transmitting one, forming one contour beam for each zone, and the repeater is made in the form of low-noise amplifiers connected to each receiving narrowly directed antenna, to each of which carriers are connected, the number of which corresponds to the number of bands frequencies into which the frequency bands allocated for the zones are divided, consisting of serially connected remotely controlled by commands of the central control station downward developers remotely controlled by the commands of the central control station of intermediate frequency bandpass filters, amplifiers of the intermediate band and remotely controlled by the commands of the central control station of upstream converters, while the system is equipped with signal addition devices installed for each zone, the inputs of which are connected to upstream converters that process signals intended for the respective zones, and the outputs are connected to the inputs of the power amplifiers connected to the outputs with Pass the zonal antennas, the system is also provided with a main control station and control local networks located in zones. 2. The satellite communications system according to claim 1, characterized in that the repeater is equipped with bandpass filters that transmit signals in the frequency bands defined for subscribers located in the areas of operation of these antennas and connected to the output of each receiving narrowly directed antenna and to the input of low-noise amplifiers, at the same time, the repeaters are equipped with signal addition devices combining signals coming from two or more controlled band-pass filters and directing the combined signals to intermediate frequency amplifiers.

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