RU2823151C1 - Device for adaptive routing of ip-packets on board of spacecraft in satellite communication networks - Google Patents

Abstract

FIELD: wireless communication equipment.

SUBSTANCE: invention can be used to ensure operation of satellite communication networks based on constellations of spacecraft deployed in geostationary and high-elliptical orbits. Technical result is achieved by the fact that the device for adaptive routing of IP packets on-board a spacecraft in satellite communication networks comprises an intersatellite communication line (ICL) channel, multifunctional on-board digital platform (MODP), comprising a modem and a router, which processes and forms a digital stream, and N user channels, built on the basis of N single-type multi-beam active phased antenna arrays (APAA) with digital formation of directional pattern (DP), wherein the router is configured to perform interchannel switching, switching of multi-beam antenna beams of user channels, as well as control of incoming load from each of N user channels by changing parameters of user channels at the physical level.

EFFECT: providing adaptive routing and traffic control directly on board of the spacecraft, as well as the implementation of the routing procedure control algorithm, aimed at complementing the integrated and differentiated services standard procedures with the possibility of radio link physical layer parameters control, providing dynamic traffic control in communication networks using TCP/IP protocol stack.

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Description

The invention relates to the field of wireless communications and can be used to ensure the functioning of satellite communication networks built on the basis of constellations of spacecraft deployed in geostationary and highly elliptical orbits.

Currently, in the world practice of creating satellite communication systems, there is a tendency to build repeaters based on HTS (High-Throughput Satellite) technology, which makes it possible to increase the throughput of the communication network to 1 Tbit/s [1]. Ensuring optimal use of the high capacity of repeaters requires rational approaches to its distribution, taking into account the spatiotemporal nature of traffic changes. In this regard, intensive scientific research is being carried out on ways and means of organizing routing and managing packet traffic flows, implemented directly in repeaters (RTR) of spacecraft (SC) [2], [3].

The distribution of subscribers (both mobile and fixed) in spacecraft service areas can vary over a wide geographical scale (including polar Arctic regions). At the same time, depending on bandwidth requirements, geographically distributed subscribers generate a non-stationary volume of traffic falling on different satellite communication service areas.

Currently, traffic generated by satellite communication network subscribers is transmitted at the network and transport levels based on the TCP/IP protocol stack. In light of this, the problem of optimal routing and management of information flows becomes especially acute, since the capacity and stability of the satellite communication network depends on this. To solve this problem, a device is proposed that implements adaptive routing of IP (Internet Protocol) packets, taking into account the requirements of subscriber applications for QoS (quality of service) in terms of latency and reliability of transmitted data.

There is a known method and device for routing IP packets in multipath satellite networks [4]. The method comprises: receiving a plurality of signals from an uplink beam; supplying said plurality of signals to a plurality of inputs of a digital channel receiver containing a plurality of outputs; output signals are supplied from at least one of the specified outputs of the digital channel receiver to the regenerative communication subsystem (RCS) and the processed signals from the RCS are supplied to at least one of the specified inputs of the digital channel receiver. In this case, the step of supplying processed signals from the RCS to at least one of the specified inputs of the digital channel receiver includes connecting the processed signals to a switch that selectively supplies signals from the specified uplink beam or processed signals from one of the specified RCS outputs to one of the specified inputs digital channel receiver. The disadvantage of this device is the inability to take into account the requirements of upper-level applications of the OSI model for QoS (Quality of Service) during network interaction based on the TCP/IP protocol stack.

There is also a method of routing in mobile personal satellite communication networks on low-orbit relay satellites [5]. The method of routing in mobile personal satellite communication networks (MPSS) on low-orbit relay satellites (LSR) contains stages in which ballistic information about the current position of the LSR relative to the radio communication zone (ZRS) and radio communication subzone (RSS) on the surface of the globe is periodically sent to all LSRs from flight control center (MCC) and is recorded in each NSR in the database (DB) of ballistic information about the location of the NSR, information about the current location of user terminals (AT) relative to the air defense system and the air defense system is sent to all NSR and to the network control center (NCC), and when When constructing a route, a request is made to the database of registered subscribers in the ADMS and PRS, to the database of NSRs that have established a connection with the gateway station (GS) in the feeder communication line (FLS), and to the database of ballistic information about the location of the NSR in orbit relative to the ADMS and ORS. The disadvantage of this method is the impossibility of dynamic redistribution of non-stationary load (taking into account the required QoS indicators) in adjacent service areas of the spacecraft.

The proposed device is aimed at achieving a technical result, which consists in ensuring the implementation of adaptive routing and traffic control directly on board the spacecraft, as well as the implementation of a routing procedure control algorithm aimed at complementing the standard procedures of integrated services ISA (Integrated Services Architecture) and differentiated services DS (Differentiated Services ) the ability to control the parameters of the physical layer of radio links, providing dynamic traffic control in communication networks using the TCP/IP protocol stack.

Achieving the specified technical result is ensured by the fact that the device, at the IP level, implements the functions of internetworking, routing and congestion control. The router performs inter-trunk switching, as well as switching the beams of a multi-beam antenna of subscriber trunks. Thus, the router, in addition to solving problems of internetworking and managing information flows, controls the parameters of lower levels of the OSI (Open Systems Interconnection) model, implemented in the RTR KA.

Since the objective of the invention is both the routing of IP packets with adaptive load redistribution between service areas of adjacent beams in different subscriber trunks of the RTR spacecraft, and the management of the energy potential of the beams of subscriber trunks, and a system with both of these functions has not been found, the closest prototypes are:

1. In the IP packet routing function - a method and device for routing IP packets in multi-beam satellite networks [4].

2. The routing control function is a method of routing in mobile personal satellite communication networks on low-orbit relay satellites [5].

Unlike prototypes [4] and [5], the proposed device simultaneously solves the problems of adaptive (according to given indicators of ISA and DS services) routing of IP packets and load redistribution in service areas by controlling parameters (radio link energy, multipath beamwidth spacecraft antennas, inter-beam and inter-trunk switching, changes in the total frequency bandwidth in the service areas of multi-beam antennas) of subscriber trunks at the physical level.

The purpose of the invention is to provide a joint solution to routing problems, both according to standard algorithms adopted in the TSRLR protocol stack, and by managing physical layer parameters in subscriber radio links and adaptive routing of IP packets on board a spacecraft in satellite communication networks.

This goal is achieved by the fact that a device for adaptive routing of IP packets on board a spacecraft in satellite communication networks, containing an inter-satellite communication link (MSL) trunk, a multifunctional on-board digital platform (IBP), containing a modem and a router, which processes and generates a digital stream, and N subscriber trunks, built on the basis of N similar multi-beam active phased antenna arrays (AFAR) with digital formation of an array of radiation patterns (AP), characterized in that the active phased antenna array, which provides adaptive changes in the position and shape of the radiation pattern, includes a radiating system , connected to the diplexer of the subscriber trunk (AS), separating the frequencies of the reception and transmission channels, while the output of the AC diplexer is connected to the input of the low noise amplifier (LNA) of the AC, and the input of the AC diplexer is connected to the output of the power amplifier (PA) of the AC, in turn the output The AC LNA is connected to the input of the down AC frequency converter, which ensures the transfer of the spectrum of carrier frequencies of the radio link into the frequency domain of the AC analog-to-digital converter (ADC), while the output of the down AC frequency converter is connected to the input of the AC ADC, where the analog signal is converted into a digital stream , the output of the ADC AC is connected to the input of the modem, which is connected to the router, while the input of the AM AC is connected to the output of the up frequency converter AC, which provides conversion of the frequency spectrum of the signal from a digital stream, connected by its input to the output of the digital-to-analog converter (DAC) AC, in the region of the frequency spectrum of the radio line, while the input of the DAC AC is connected to the output of the modem, and the MBCP is also connected via a modem to the trunk of the inter-satellite communication line (ILS), consisting of an ILS antenna connected to an ILS diplexer that separates the frequencies of the reception and transmission channels, while the output The MLS diplexer is connected to the input of the MLS LNA, and the input of the MLS diplexer is to the output of the MLS PA, in turn, the output of the MLS LNA is connected to the input of the MLS down frequency converter, which ensures the transfer of the radio line carrier frequency spectrum to the frequency domain of the MLS ADC, the output of the MLS down frequency converter connected to the input of the MLS ADC, where the analog signal is converted into a digital stream, the output of the MLS ADC is connected to the input of the modem, while the input of the MLS PA is connected to the output of the MLS up frequency converter, which converts the frequency spectrum of the signal from a digital stream connected by its input to the output DAC MLS, in the frequency spectrum region of the radio line, this input of the DAC MLS is connected to the output of the modem, while the router is configured to perform inter-receiver switching, switching the beams of a multi-beam antenna of subscriber trunks, as well as control the incoming load from each of the N subscriber trunks by changing parameters subscriber trunks at the physical level.

The diagram of the proposed device for adaptive routing of IP packets on board a spacecraft in satellite communication networks is presented in Fig. 1. It contains devices that have the following designations:

1 - subscriber trunk;

2 - trunk of the intersatellite communication line (ILS);

3 - multifunctional on-board digital platform;

4 - multi-beam active phased array antenna (AFAR);

5 - transceiver module;

6 - radiating system;

7 - diplexer of the subscriber trunk (AS);

8 - low noise amplifier (LNA) speaker;

9 - power amplifier (PA) AC;

10 - frequency converter down AC;

11 - frequency converter up AC;

12 - analog-to-digital converter (ADC) AC;

13 - digital-to-analog converter (DAC) AC;

14 - MLS antenna;

15 - MLS diplexer;

16 - MLS LNA;

17 - UM MLS;

18 - MLS frequency converter;

19- frequency converter up MLS;

20 - analog-to-digital converter (ADC) MLS;

21 - DAC MLS;

22 - modem;

23 - router.

The device includes N subscriber trunks 1, built on the basis of N single-type multibeam active phased antenna arrays (AFAR) 4 with digital beamforming, an intersatellite communication link (ISL) trunk 2 and a multifunctional on-board digital platform 3.

In turn, AFAR 4 consists of a radiating system 6 connected to a diplexer of the subscriber trunk (AS) 7, which separates the frequencies of the reception and transmission channels. One of the outputs of the diplexer AC 7 is connected to the input of the low noise amplifier (LNA) AC 8, and the second to the output of the power amplifier (PA) AC 9. The output of the LNA AC 8 is connected to the input of the downward frequency converter AC 10, which ensures the transfer of the spectrum of carrier frequencies of the radio line to the frequency area of operation of the analog-to-digital converter (ADC). From the output of the downconverter, the signal is supplied to the input of the ADC AC 12, where it is converted into a digital stream. The input of the AM AC 9 receives a signal from the up frequency converter AC 11, which ensures the conversion of the frequency spectrum of the signal generated by the DAC AC (from the digital stream) 13 into the frequency spectrum of the radio link.

The digital stream is processed and generated by a multifunctional on-board digital platform (OBDP) 3, containing a modem 22 and a router 23.

The trunk of the intersatellite communication link (ISL) consists of an MLS antenna 14 connected to an MLS diplexer 15, which separates the frequencies of the reception and transmission channels. One of the outputs of the diplexer MLS 15 is connected to the input of the LNA MLS 16, and the second to the output of the PA MLS 17. The output of the LNA MLS 16 is connected to the input of the downconverter MLS 18, which ensures the transfer of the spectrum of carrier frequencies of the radio link to the frequency domain of operation of the analog-to-digital converter (ADC) ). From the output of the downconverter, the signal is supplied to the input of the ADC MLS 12, where it is converted into a digital stream. The input of the MLS 17 PA receives a signal from the up-frequency converter MLS 19, which converts the frequency spectrum of the signal generated by the MLS DAC (from the digital stream) 21 into the frequency spectrum of the radio link.

The proposed device for adaptive routing of IP packets operates as follows.

1. Formation of a multi-beam APAA pattern.

By using N multi-beam APAA 4, each of the N subscriber trunks 1 forms cellular service areas on the earth's surface. Multibeam APAA service areas are formed by synthesizing a pattern array based on digital pattern generation methods [6]. In modem 22, weighting coefficients are formed that form phase shifts between the elements of the radiating system 6 and a given current distribution in the elements of the radiating system 6, which ensures the synthesis of an array of discrete patterns with a given width and bandwidth. The generated weighting coefficients are distributed accordingly between the receiving (diplexer AC 7, LNA AC 8, downward frequency converter AC 10, ADC AC 12) and transmitting (diplexer AC 7, PA AC 9, up frequency converter AC 11, DAC AC 13) pre-mode channels. transmitting modules 5 AFAR 4.

2. Processing of signal-code structures in subscriber radio links and the MLS trunk.

Elements of multi-beam AFAR 4 (diplexer AC 7, LNA AC 8, down frequency converter AC 10, ADC AC 12, DAC AC 13, up frequency converter AC 11, UM AC 9) simultaneously serve as input/output paths for processing signals of subscriber radio lines built using SDR technology (Software Defined Radio - software reconfigurable radio).

When working for reception, subscriber radio link signals are received by one of the subscriber trunks 1 using APAA 4 in one of the array of formed beams. Next, the received signals through the diplexer AC 7, LNA AC 8, down frequency converter AC 10 enter the ADC AC 12. Digital signals from the output of the ADC AC 12 enter the modem 22, where demodulation and noise-resistant decoding of these signals occurs, followed by sending target information, necessary for the functioning of the TCP/IP protocol stack, in router 23.

When working for transmission, target information generated in accordance with the TCP/IP protocol stack in router 23 enters modem 22, where the subscriber radio link structure is formed by noise-resistant coding and modulation of the received target information. From the output of modem 22, the formed structure of the subscriber radio line in the form of a digital stream is supplied to the DAC AC 13, from where, in the form of an analog signal, it is sent to the input of the up frequency converter AC 11 and then to the PA AC 9. From the output of the PA AC 9, the signal of the subscriber radio line through the diplexer AC 7 enters the radiating system 6 of the APAA 4 and is emitted in one of the N subscriber trunks 1.

The target information intended for relaying between spacecraft is generated in the router 23 and then enters the modem 22, where the structure of the inter-satellite communication radio link for reception and transmission is formed. In reception mode, signals relayed via MLS are received by the MLS antenna 14 of the MLS 2 trunk and then through the MLS 15 diplexer, MLS 16 LNA, MLS 18 down frequency converter, and arrive at the MLS 20 ADC. From the output of the MLS 20 ADC, the digital stream enters the modem 22, where demodulation and noise-resistant decoding of MLS signals occurs, followed by sending the target information necessary for the operation of the TCP/IP protocol stack to router 23. In transmission mode, the signals relayed over the MLS are generated in accordance with the TCP/IP protocol stack in router 23, from where they then enter modem 22, where the structure of the MLS radio link is formed by noise-resistant coding and modulation of the received target information. From the output of modem 22, the formed structure of the MLS radio line, in the form of a digital stream, is supplied to the DAC MLS 21, from where, in the form of an analog signal, it is sent to the input of the frequency converter up MLS 19 and then to the MLS 77 UM. From the output of the MLS 77 UM, the MLS radio line signal through The MLS 75 diplexer enters the MLS 14 antenna.

3. Formation of an adaptation mechanism in the router and subscriber trunks.

The router 23 of the spacecraft stores the routing tables of subscribers served by both this spacecraft and the routing tables of adjacent spacecraft. During operation, routers of 23 different satellites exchange routing tables to organize the interaction of satellite communication network subscribers, as well as to redistribute the load between service areas of adjacent satellites.

Packets of target information received by router 23 from modem 22, generated by subscribers of the satellite communication network based on the TCP/IP protocol stack, are analyzed in router 23 in order to determine the recipient address and requirements for the parameters of packet delivery (operation in accordance with a given type of ISA or DS service ) taking into account the type of traffic (elastic or inelastic traffic) [7].

In the case when subscribers exchanging packets of target information are in the service area of N subscriber trunks 7 of one spacecraft, these packets are relayed by one of the multi-beam APAA 4 over subscriber radio links. In the case when subscribers are in the service areas of different satellites, packets of target information in accordance with the addresses of the routing tables are redirected between different satellites by using the MLS trunk 5.

Router 23 monitors the incoming load from each of the N subscriber trunks 7. If the load in one of the subscriber trunks 7 increases, router 23 initiates a procedure to ensure that the QoS level required for subscriber applications is maintained. To do this, router 23, by software reconfiguring the subscriber trunk 7 path, changes the following parameters:

- position of TV beams of multi-beam APAA 4 for the purpose of redirecting adjacent beams of subscriber trunks 1 from service areas with less load;

- increasing the width of the beam pattern of multi-beam APAA 4 in those service areas from which part of its beams were redirected;

- energy potential of subscriber radio links in subscriber trunks 1 with an increase in energy in those trunks that serve areas with a large volume of traffic;

- distribution of the frequency bandwidth of subscriber radio links between the beams of one multi-beam APAA 4 of the subscriber trunk 1, depending on the load on each beam.

The ability to control the parameters of the physical layer of subscriber radio links allows router 23, in addition to the standard routing and congestion control procedures used in the TCP/IP protocol stack, to provide adaptation on board the spacecraft to changes in load in the service areas of subscriber trunks 1.

The analysis of the level of technology made it possible to establish that analogues, characterized by a set of features identical to all the features of the claimed technical solution, are absent in known sources of information, which indicates that the claimed method complies with the patentability condition of “novelty”.

The purpose of the present invention is to provide a joint solution to routing problems, both according to standard algorithms adopted in the TCP/IP protocol stack, and by managing physical layer parameters in subscriber radio links and adaptive routing of IP packets on board a spacecraft in satellite communication networks achieved.

Literature

1. Chechin G.V. Satellite communication systems based on geostationary repeaters. - M.: Hotline - Telecom, 2020.

2. Kamnev V.E., Cherkasov V.V., Chechin G.V. Satellite communication networks. - M.: Military Parade, 2010.

3. Shinichi T., Masato T., Hashimoto Y. An Experimental Mobile Satellite Communication Network with an Onboard Packet Switch System // Proceedings IEEE 56th Vehicular Technology Conference. Vancouver, BC, Canada. 24-28 Sept. 2002.

4. Patent 2643455 (RF). Method and device for routing IP packets in multipath satellite networks / Scott James P. - Publ. 02/01/2018-Н04Н 60/97.

5. Patent 2714220 (RF). A method of routing in mobile personal satellite communication networks on low-orbit relay satellites with zonal registration of subscribers and a router of a low-orbit relay satellite with integrated services for implementing the specified method / Panteleimonov I.N. - Publ. 02/13/2020-H04W 40/20.

6. Grigoriev L. N. Digital formation of radiation patterns in phased antenna arrays. - M.: Radio engineering, 2010.

7. Stallings V. Modern computer networks. - M.: Peter, 2003.

Claims (1)

A device for adaptive routing of IP packets on board a spacecraft in satellite communication networks, containing an intersatellite communication link (ISL) trunk, a multifunctional on-board digital platform (MBDP) containing a modem and a router that processes and generates a digital stream, and N subscriber trunks built based on N similar multi-beam active phased antenna arrays (APAA) with digital formation of an array of radiation patterns (AP), characterized in that the active phased antenna array, which provides adaptive changes in the position and shape of the radiation pattern, includes a radiating system connected to the diplexer of the subscriber trunk (AS), separating the frequencies of the reception and transmission channels, while the output of the AC diplexer is connected to the input of the low noise amplifier (LNA) of the AC, and the input of the AC diplexer is connected to the output of the power amplifier (PA) of the AC, in turn, the output of the AC LNA is connected to the input of the converter frequency down AC, which ensures the transfer of the spectrum of carrier frequencies of the radio link into the frequency domain of the analog-to-digital converter (ADC) AC, while the output of the frequency converter down AC is connected to the input of the ADC AC, where the analog signal is converted into a digital stream, the output of the ADC AC is connected to the input of the modem, which is connected to the router, while the input of the AM AC is connected to the output of the up-frequency converter AC, which provides conversion of the frequency spectrum of the signal from a digital stream connected by its input to the output of the digital-to-analog converter (DAC) AC, into the frequency spectrum of the radio link, while the input of the AC DAC is connected to the output of the modem, and the MBDC is also connected via a modem to the trunk of the intersatellite communication line (ISL), consisting of an MLS antenna connected to an MLS diplexer that separates the frequencies of the reception and transmission channels, while the output of the MLS diplexer is connected to the input of the MLS LNA, and the input of the MLS diplexer is to the output of the MLS PA, in turn, the output of the MLS LNA is connected to the input of the MLS down frequency converter, which ensures the transfer of the radio line carrier frequency spectrum to the frequency domain of the MLS ADC operation, the output of the MLS down frequency converter is connected to the input of the MLS ADC, where conversion of an analog signal into a digital stream, the output of the MLS ADC is connected to the input of the modem, while the input of the MLS PA is connected to the output of the MLS up frequency converter, which ensures the conversion of the frequency spectrum of the signal from the digital stream, connected by its input to the output of the MLS DAC, into the frequency spectrum of the radio link , while the input of the MLS DAC is connected to the output of the modem, and the router is configured to perform inter-trunk switching, switching beams of a multi-beam antenna of subscriber trunks, as well as control the incoming load from each of the N subscriber trunks by changing the parameters of the subscriber trunks at the physical level.

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