RU98659U1 - TWO-LEVEL SATELLITE COMMUNICATION SYSTEM - Google Patents

Abstract

 1. A two-level satellite communications system for telephone communications in the CIS and global data exchange throughout the Earth, including space and ground segments, respectively containing constellations of satellites located in low-altitude and medium-altitude orbits to provide communications, mobile and fixed subscriber stations coordinating communication stations located at the calculated points of the Earth and connected to ground-based transponders, characterized in that the space segment consists of low a satellite-borne satellite constellation containing low-orbit spacecraft located in circular orbits in three evenly spaced planes, and a mid-altitude satellite constellation consisting of spacecraft located on medium-high elliptical orbits in two orbital planes, while both space constellations are equipped with inter-satellite communications, moreover, in the composition of the ground segment includes a control complex, a consumer complex and ground communication channels with a public network. ! 2. The two-level satellite communications system according to claim 1, characterized in that the low-orbit satellite constellation consists of twelve low-orbit spacecraft with four spacecraft in each orbital plane. ! 3. The two-level satellite communication system according to claim 1, characterized in that the medium-altitude satellite constellation consists of six spacecraft with three spacecraft in each orbital plane. ! 4. The two-level satellite communications system according to claim 1, characterized in that the composition of the control

Description

The utility model relates to satellite communication systems having space and terrestrial segments and, in particular, to a two-level satellite system using low-orbit satellite transponders (SR) and satellites in mid-altitude elliptical orbits.

A multifunctional telecommunication space system including a communication subsystem and a monitoring subsystem is known from the prior art. The communication subsystem is built on the basis of satellite repeaters and provides telephone communications, video conferencing, image transmission, machine exchange, Internet access on a global scale with speeds from 1.2 kbit / s to 2948 kbit / s. The operation of the satellite constellations is carried out using ground-based relays included in control stations located at the calculated points of the earth's surface at the intersection of the radio visibility zones of neighboring spacecraft.

The space segment of the system includes three groups of spacecraft for the system of high and low speed communications and monitoring. The first two constellations include 24 satellites in orbits with an altitude of 10,360 km; The monitoring group includes 8-12 spacecraft at an altitude of 600 km.

The Earth segment of the system consists of 12-14 coordinating stations combined with the control stations of the monitoring subsystem and playing the role of regional stations, as well as a fleet of mobile and stationary subscriber stations.

Service signals (call, request, answer, etc.) are transmitted through the nearest spacecraft via feeder lines to the coordinating station, which, having information about all the subscribers of the system and their coordinates, as well as data on the free channels of all spacecraft, makes itineraries of passage signals from one subscriber to another.

The space monitoring system includes spacecraft for optical and radar surveillance. To conduct monitoring of the object, information about the need for monitoring is transmitted to the coordinating station, in the area of which the required spacecraft is located, and after receiving monitoring information, it is reset to the nearest control station and then to the user (see patent No. 2169433, cl. Н04В 7/185 , 1999).

The disadvantage of this system is its complexity and cumbersomeness due to the need for a significant number of spacecraft (minimum 56) and a significant number of ground control stations. At the same time, communication in the system is carried out through several spacecraft and ground stations, which increases the transit time of communication and / or monitoring signals and degrades their quality.

The closest analogue selected for the prototype of the claimed utility model is a satellite communication system between subscribers, which uses two groups of spacecraft, one of which is displayed in low circular orbits, and the other in geostationary circular orbits. In general, this space constellation of satellites includes 36 satellites located in six orbital planes with six satellites in each plane. Satellites are equipped with radio-technical complexes-repeaters. The given orbit of each satellite is supported by its periodic correction. Dispatch stations and subscriber stations are located on Earth. During the operation of the system, the subscriber’s signals, for example, during telephone communications, are relayed through a satellite located in the subscriber’s access area and located in low orbit to the ground control station located in the satellite’s visibility range, and from the control station to the satellite located in the geostationary orbit, and from this satellite to the dispatching station of the receiving subscriber, from which the signals through the satellite in low orbit are relayed to the station of the receiving signal of the subscriber (see awning No. 2107990, class Н04В 7/185, 1998).

The disadvantage of this system is that for its effective functioning requires a significant number of satellites, which significantly increases the cost of the system and complicates its management. In addition, the principle of communication in this system is excessively complex. So, the communication signals from the subscriber are sent to the satellite in low orbit, from where to the ground control station, then to the satellite in the geostationary orbit, from where to the control station of the receiving subscriber and through the satellite in low orbit, to the station receiving the signal from the subscriber . Given the dynamics of the system, namely, the constant relative change in the position of satellites in low and geostationary orbits, dispatch and subscriber stations, it is necessary to change the position of the transmitting and receiving devices (antennas) of satellites and ground stations, which is very difficult, and in addition, such communication leads to a decrease in the quality of transmitted signals. It should also be noted that the implementation of this system for monitoring the movement of objects, monitoring the functioning of stationary objects, environmental monitoring in specified regions, monitoring the meteorological situation, which are carried out from satellites in low orbits, and the transmission of this information to consumers through control stations leads to the need creating a network of control stations, which increases the already very high cost of the system and further complicates its management. An attempt to improve the operational parameters of the system by introducing into its composition a constellation of satellites placed in a mid-altitude orbit (see RF patent No. 2118056, class Н04В 7/185, 1998), further complicated the system and worsened the quality of the transmitted signals.

The task to which the proposed utility model is aimed is to simplify the satellite communications system, namely, to reduce the number of satellites (spacecraft - SC), while ensuring the transmission and reception of signals from (to) anywhere in the world in almost real time mode high quality and reliability in a wide range of areas of activity.

The solution to this problem is ensured by the fact that the two-level satellite communication system, for telephone communications in the CIS and global data exchange throughout the Earth, including space and ground segments, containing, respectively, constellations of satellites located in low-altitude and medium-altitude orbits to provide communication, mobile and stationary subscriber stations coordinating communication stations located at the calculated points of the Earth and connected to ground-based relays, according to useful of the second model, the space segment consists of a low-orbit satellite constellation containing low-orbit spacecraft located in circular orbits in three evenly spaced planes and a medium-altitude satellite constellation consisting of spacecraft located in medium-altitude elliptical orbits in two orbital planes, both space constellations equipped with inter-satellite communications, and the ground segment includes a control complex, a consumer complex and n Ground-based communication channels with the public network.

In preferred embodiments, the low-orbit satellite constellation consists of twelve low-orbit spacecraft, four spacecraft in each orbital plane; the mid-altitude satellite constellation consists of six spacecraft with three spacecraft in each orbital plane; the control complex of the system includes a system control center; flight control center; communication complex management center; central stations (TsS1, TsS2,); regional stations (PC-1, PC-2); subscriber terminals of consumers; ground control point of communication (NPUS-1, NPUS-2); a complex of measuring instruments, collection and processing of information from the cosmodrome - KSISOI (functionally); the consumer complex includes mobile subscribers, including transport, as well as regional and central control centers.

This solution to the problem, by minimizing the cost of manufacturing, launching and operating the proposed satellite communications system provides it with significant competitive advantages compared to other global satellite communications systems.

The utility model is illustrated by drawings, where:

Fig. 1 shows the structure and composition of the DSSS “Gonets-NE”; Figures 2 and 3 show the structure of the orbital grouping of subsystems, respectively, “Gonets-N” and “Gonets-E”; Fig. 4 shows the radio-technical visibility zones of the NPSA at elevation angles of 15 ° and 30 °; Fig. 5 schematically shows the conditional appearance of the applied spacecraft.

The two-level satellite communications system “Gonets-NE” consists of interconnected ground and space segments. The space segment consists of an orbital grouping of the Gonets-N subsystem, including 12 spacecraft (KA-1), which are low-orbit KA-1 (spacecraft), located in three equally spaced orbital planes of 4 KA-1 in each, as well as a subsystem “Gonets-E”, containing 6 KA-2 in two medium-high elliptical orbits, three KA-2 in each orbital plane. Thus, the “Gonets-NE” system consists of two subsystems:

- Subsystems “Gonets-N” with 12 KA-1 (3 × 4) in circular orbits with an altitude of 1,500 km;

- Subsystems “Gonets-E” with 6 KA-2 (2 × 3) in mid-altitude elliptical orbits with an apogee height of 12,000 km.

The ground segment (see Fig. 1) includes a control complex, a consumer complex and terrestrial communication channels with a public network.

In the figures and further on, the following conventions are used: AT1 - portable subscriber terminal (telephone); АТ2 - portable subscriber terminal for receiving and transmitting digital photo and video information; AT - subscriber terminal; BS - solar battery; BKU - on-board control complex; BRTK - airborne radio complex; BVK - on-board computer complex; GMDSS - a global multifunctional system of personal satellite communications; DSSS - two-level satellite communications system (“Gonets-NE”); ZRV - radio visibility zone; NIS - ground system infrastructure; OG - orbital grouping; KA - spacecraft; NKA - low orbit spacecraft; KA-1 - low orbit spacecraft; KA-2 - medium altitude spacecraft; PC - regional station; RDP - regional dispatch center; PC - regional station; TsUS - system control center; CA - central station; NPUS - ground control point for communications; KSISOI - a complex of measuring instruments, collection and processing of information from the cosmodrome; LAN - local area network; MLS - inter-satellite communication line; PN - payload; RN - rocket launcher; SEA is a mid-height elliptical orbit.

The subsystem "Gonets-N" is designed to provide data transfer and personal communication for consumers with small-sized subscriber means with non-directional antenna systems with the following characteristics:

- Communication waiting time (at an elevation angle of more than 15 °), min twenty; - The number of consumers, thousand tubes 500; - The number of channels in the sub-satellite zone of one spacecraft fifty.

Information transfer rate in satellite channels using NKA-1:

a) Earth (AT) - KA-1 64 kbps b) Earth (PC) - KA-1 1,024 kbps; c) KA-1 - “Earth” (AT) 256 kbps d) KA-1 - "Earth" (PC) 1,024 kbps; d) KA-1 “Gonets-N” - KA-2 “Gonets-E” (MLS) 256 kbps

The subsystem "Gonets-E" is designed to provide high-speed data transfer and personal communication of consumers with small-sized subscriber means with non-directional antenna systems, while it has the following characteristics:

Communication waiting time (at an elevation angle of more than 15 °), min 0; - The number of consumers, thousand tubes 300; - The number of channels in the sub-satellite zone of one spacecraft 10000;

Information transfer speed in satellite channels using KA-2 subsystem "Gonets-E":

a) "Earth" (AT1) - KA-2 64 kbps b) "Earth" (AT2) - KA-2 10 Mbps; c) "Earth" (CA) - KA-2 300 Mbps; d) KA-2 - “Earth” (AT1) 256 kbps d) KA-2 - “Earth” (AT2) 10 Mbps; f) KA-2 - “Earth” (CA) 300 Mbps; g) KA-2 “Gonets-E” - KA-1 “Gonets-N” (MLS) 256 kbps

It should be noted that for KA-2 subsystem "Gonets-E" provides the ability to work with subscriber terminals of the system "Gonets-N".

The composition of the management complex of the subsystem "Gonets-N" includes:

1. Flight control center;

3. Central stations (TsS1, TsS2);

5. Regional stations (PC1, PC2);

6. Subscriber terminals of consumers;

7. KSISOI - a complex of measuring instruments, collecting and processing information from the cosmodrome (functionally) in terms of the organization of control of the spacecraft during its launch into orbit.

The “Gonets-N” subsystem has the following ballistic structure:

- Type of orbit circular; - height, km 1500; - inclination, hail 82; - number of planes 3; - longitude of orbits, hail 30, 90, 150; - the number of spacecraft in one plane four.

The Gonets-E subsystem uses medium-high elliptical orbits, which is a promising direction in the development of personal satellite communications. The advantage of such orbits is that when KA-2 is in the upper part of the orbit above the northern hemisphere, then the entire territory of Russia, including high-latitude regions, enters the service area. In addition, in comparison with the spacecraft in the high-elec- tric orbit and the geostationary orbit, the attenuation in the radio link is much less.

Ballistic construction of an orbital grouping on a mid-height ellipse has the following advantages:

A single continuous coverage of the territory of the Russian Federation from 40 ° to 80 ° N and from 20 ° to 170 ° east areas of radio-technical visibility of the spacecraft at an angle of the place of work of subscribers of at least 30 ° and an angle of the place of work of ground control points of the communication station of the communication center of at least 15 ° and the minimum number of spacecraft in the orbital group

The composition of the management complex of the subsystem "Gonets-E" includes:

1 Terrestrial communications control points (Western NPUS-1, Eastern NPUS-2);

2. Central stations (TsS-1, TsS-2);

3. Subscriber terminals of consumers;

4. KSISOI - a complex of measuring instruments, collecting and processing information from the cosmodrome (functionally) in terms of the organization of control of the KA-2 when it is placed in a medium-high elliptical orbit.

The “Gonets-E” subsystem has a 2x3 orbital structure with orbit parameters shown in Table 1. Orbital planes are 180 ° apart in absolute space.

Table 1 Main elements Value Semi-major axis of the orbit 12793 km Eccentricity 0.46 Mood 63.4 ° Argument of latitude perigee 270 ° Draconic period of circulation 3 ^h 58 ^m 55.5 ^s Subscriber work angle 25 ÷ 30 ° The angle of the place of work of the ground-based communications control center (NPUS) 10 ÷ 15 ° Served area 30 ÷ 80 °

This ballistic construction of the orbital grouping is based on the use of four-hour medium-high elliptical orbits. The orbital grouping is located in 2 orbital planes, in each of which there are three KA-2. The orbital period of KA-2 in such an orbit is about 4 hours, while the device is in the service area (CIS territory) for at least 2 hours. The service area created on the surface of the Earth allows for continuous coverage of the CIS.

The management complex of the “Gonets-NE” system includes:

1. System Management Center (NCC);

2. Mission Control Center (MCC);

3. The control center of the connected complex (TsUSK);

4. Central stations (TsS1, TsS2);

5. Regional stations (PC-1, PC-2);

6. Subscriber consumer terminals (ATP);

7. Ground control point of communication (NPUS-1, NPUS-2);

8. KSISOI - a complex of measuring instruments, collection and processing of information from the cosmodrome (functionally).

Each KA-1, which is part of the Gonets-N subsystem, operates within its radio visibility zone. For data transmission to places outside the radio visibility zone of this KA-1, terrestrial data lines and inter-satellite communication lines can be used.

The subsystem “Gonets-N” uses the following frequency ranges:

- 0.3 / 0.4 GHz - for working with personal users equipped with low-power terminals, including the existing communication system;

- 2.2 / 2.6 GHz - for data transfer between regional stations and users equipped with high-speed and fairly powerful terminals;

- 50/60 GHz - for the inter-satellite communication link between the spacecraft "Gonets-N" and the spacecraft "Gonets-E".

The composition of the payload (PN) of each KA-1 includes:

- on-board radio complex (BRTK) of the range 0.3 / 0.4 GHz;

- BRTK main line of communication with the PC;

- BRTC inter-satellite communication line.

For the functioning of the DSSS, BRTK for subscribers of the subsystems “Gonets-N” and “Gonets-E” in the territory south of 40 ° N in the frequency range 0.3 / 0.4 GHz, it provides telephone communications and the transfer of small amounts of information, as well as the implementation of self-determination of the location of mobile subscribers (aircraft, ships, etc.);

The BRTC in the frequency range 2.2 / 2.6 GHz provides communication between the spacecraft and regional stations.

The BRTK in the 50/60 GHz band provides communication with the KA-2 from the Gonets-E subsystem, which are in the visible range at a speed of 256 kbit / s.

The indicated BRTC are built on the principle of complete processing of information on board, including decoding, demodulation, and route-address relaying to specified sub-satellite zones, while the following relay modes are provided:

- in real time in the radio visibility zone of one KA-1.2 (5000 km) - up to 85% of subscriber traffic;

- via inter-satellite communication lines (MLS) or via ground-based regional relay stations (PC) when transmitting information between different zones - up to 10% of traffic;

- in the "mailbox" mode with transfer on board the KA-1,2 - up to 5% of the traffic.

Preferably, in the frequency ranges 0.3 / 0.4 GHz and 2.2 / 2.6 GHz, 7-element antenna systems are used, which is due to the required transmission speeds and the necessary characteristics of the communication lines. Transmission antennas are used in all frequency ranges. The inter-satellite channel is implemented at V-band frequencies.

In the body of KA-1,2 (see Fig. 5), a unit for turning the panels of the solar battery (BS) is installed for its orientation to the Sun. Also, a propulsion system (not shown conditionally) is located in the KA-1.2 case for correcting the position of the KA-1.2. The housing also contains BRTK blocks and devices of service systems (not shown conditionally). KA-1 used BS with photoconverters based on three-stage gallium arsenide and rechargeable batteries (AB) on lithium-ion cells (not shown conditionally). The mass of KA-1 is about 800 kg.

The composition of the payload (PN) KA-2 subsystem "Gonets-E" includes the following:

- BRTK range 0.3 / 0.4 GHz (PN-AT1);

- BRTK range 11/14 GHz (PN-AT2);

- BRTK range 40 GHz (PN-TsS);

- BRTC inter-satellite communication line (MLS) 50/60 GHz (PN MLS);

- Equipment for resource management of communications PN (AURS).

PN-AT1 is designed to provide continuous telephone communications and the transfer of small amounts of information for subscribers of the Gonets-NE system in the CIS.

PN-AT2 is designed to provide operational, secure, high-speed data transmission (up to 10 Mbit / s) in the CIS, including the transmission of photos and video images in close-to-real time mode.

PN-TsS is designed to provide communication with central stations and transfer large amounts of information (up to 300 Mbit / s).

PN-MLS is designed to provide communication between spacecraft from the subsystems “Gonets-N” and “Gonets-E” located in the field of visibility with a speed of 256 kbit / s.

AURS is designed to provide interaction between the BRTC different frequency ranges, as well as directional routing of data packets.

KA-2 of the subsystem “Gonets-E” is made with the ability to work with subscriber terminals of the “Gonets-NE” system.

The mass-energy characteristics of PN determine the weight of KA-2 about 2000 kg and the total energy consumption of about 3 kW.

Airborne relay complexes are built on the principle of complete processing of information on board, including decoding, demodulation, and route-address relaying to specified sub-satellite zones.

Enlarged SC “Gonets-E” has the following components (not shown conditionally):

- mirror hybrid mirror antenna (GZA);

- central unit;

- BS panels on the rods.

The central unit (not shown conditionally) includes:

- the base on which the irradiators of the GZA are placed;

- blocks of repeaters;

- Ku-band antennas on the drives for their retargeting in the required angles - ± 10 °;

- V-band antennas (for the inter-satellite communication line (MLS)) on the drives, for their retargeting at the required angles - ± 25 °;

- V-band antennas (for trunk lines) on the drives, for their retargeting at the required angles - ± 11 °;

- sensors of the orientation and stabilization system (SOS);

- at the bottom of the block are service systems.

For communication with the ground-based communications control point - NPUS KA-2 of the subsystem "Gonets-E" is equipped with two antennas (not shown conventionally). Each such antenna has its own guidance system to enable the simultaneous operation of the KA-2 with two NPUS.

The work of the proposed DSSS is as follows.

A communication session begins from the moment when the subscriber and the NSTL simultaneously fall into the radio visibility zone of one of the KA-1,2. At the same time, the angle of the place of work of the NPUS is 15 °, and the subscriber is 30 °. This condition leads to the fact that the number of NPPS, due to the large length of the Russian Federation from east to west, should be at least two. The choice of the position of the NTSC in latitude is determined by the interval 50 ÷ 60 °. As a result of this, it is advisable that the NPUS be located in Moscow and Khabarovsk. This provides a large common area of visibility, which provides convenience in organizing communications. Figure 4 shows the radio-technical visibility zones of the non-criminal inspection system located in these cities, as well as their general radio-visibility zone. In the framework of the proposed ballistic structure of the orbital grouping under two NPUS: Western NPUS-1 and Eastern NPUS-2, the following communication arrangements are possible without involving regional communication lines:

subscriber 1 - KA1 - NPUS - KA1 - subscriber 2;

subscriber 1 - KA1 - NPUS - KA2 - subscriber 2;

subscriber 1 - КА1 - НПУС1 - НПУС2 - КА2 - subscriber 2.

For the continuity of the communication session provides a flexible transition from one option to organize communication to another. In particular, it is possible to change the spacecraft and the NPS during a communication session between two subscribers.

For each orbital structure, the requirement of continuity of communication, in conjunction with other system parameters, determines the requirements for the number of spacecraft with which the NPUS should simultaneously work. For example, for a 2x3 orbital structure, an NPUS should be able to work simultaneously with three spacecraft.

The characteristics of the inter-satellite communication lines (MLS) between the KA-2 in the mid-elliptical orbit and the spacecraft (KA-1), as well as an estimate of the maximum length of the radio lines and the ranges of variation of the declination angle from the moment the connection was established at the boundary of the visibility zone to the sub-satellite position, are given in Table 2.

table 2 Time from apogee, min Spacecraft altitude at SEA, km Latitude of spacecraft at SEA, degrees KA-KA range, km B-H Declination, degrees HB Declination, degrees 0 12370 63.4 22100 -70.0 -35.4 thirty 11500 57.5 20800 -68.3 -34.7 40 10850 53.5 20100 -67.3 -32.6

The range of variation of the declination angle, after the establishment of communication along the B-H line (top-bottom) at the border of the visibility zone from minus 68.3 ° to minus 90 °.

The range of variation of the declination angle, after the establishment of communication along the HB line (bottom-top) at the border of the visibility zone, from minus 37 ° to plus 90 °.

The launch of KA-1,2 (the proposed system) into orbit is carried out by group launches.

The proposed DSSS is the Gonets-NE global multi-functional personal satellite communication system based on a two-level orbital grouping with six KA-2 in a medium-high elliptical orbit and twelve spacecraft (KA-1), which will allow for the exchange of large amounts of data, telephone communications up to 300 thousand subscribers located in the Russian Federation from 41 ° to 80 ° N and from 20 ° to 170 ° east (including circumpolar regions), as well as provide data transmission anywhere in the world.

The technology existing in the Russian Federation allows manufacturing and launching up to 8 spacecraft per year for the Gonets-N subsystem, as well as 2-3 spacecraft per year for the Gonets-E subsystem. Flight tests of the proposed system begin with the launch of one spacecraft at SEA and one block of 4 spacecraft into low-circular orbit in 2014.

Claims (5)

1. A two-level satellite communications system for telephone communications in the CIS and global data exchange throughout the Earth, including space and ground segments, respectively containing constellations of satellites located in low-altitude and medium-altitude orbits to provide communications, mobile and fixed subscriber stations coordinating communication stations located at the calculated points of the Earth and connected to ground-based transponders, characterized in that the space segment consists of low a satellite-borne satellite constellation containing low-orbit spacecraft located in circular orbits in three evenly spaced planes, and a mid-altitude satellite constellation consisting of spacecraft located on medium-high elliptical orbits in two orbital planes, while both space constellations are equipped with inter-satellite communications, moreover, in the composition of the ground segment includes a control complex, a consumer complex and ground communication channels with a public network. 2. The two-level satellite communications system according to claim 1, characterized in that the low-orbit satellite constellation consists of twelve low-orbit spacecraft with four spacecraft in each orbital plane. 3. The two-level satellite communications system according to claim 1, characterized in that the medium-altitude satellite constellation consists of six spacecraft with three spacecraft in each orbital plane. 4. The two-level satellite communication system according to claim 1, characterized in that the control complex of the system includes a system control center; flight control center; communication complex management center; central stations (TsS1, TsS2,); regional stations (PC-1, PC-2); subscriber terminals of consumers; ground control point of communication (NPUS-1, NPUS-2); complex of measuring instruments, collection and processing of information from the cosmodrome - KSISOI (functionally). 5. The two-level satellite communication system according to claim 1, characterized in that the consumer complex includes mobile subscribers, including transport, as well as regional and central control centers.