CN109217912B - Multi-mode relay forwarding method based on data security supervision - Google Patents
Multi-mode relay forwarding method based on data security supervision Download PDFInfo
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- CN109217912B CN109217912B CN201811007786.4A CN201811007786A CN109217912B CN 109217912 B CN109217912 B CN 109217912B CN 201811007786 A CN201811007786 A CN 201811007786A CN 109217912 B CN109217912 B CN 109217912B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1851—Systems using a satellite or space-based relay
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/18502—Airborne stations
- H04B7/18506—Communications with or from aircraft, i.e. aeronautical mobile service
- H04B7/18508—Communications with or from aircraft, i.e. aeronautical mobile service with satellite system used as relay, i.e. aeronautical mobile satellite service
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0056—Systems characterized by the type of code used
- H04L1/0061—Error detection codes
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Abstract
A multi-mode relay forwarding method based on data security supervision is disclosed. By using the relay forwarding method, firstly, the safety supervision of the forwarded data can be realized on the relay satellite, and the wrong data is prevented from being forwarded to the target. Secondly, by utilizing a time delay relay forwarding mode, remote control and remote measurement data relay forwarding can be completed under the condition that the ground station and the spacecraft can not be simultaneously visible, and the requirement of high-precision time remote control task can be met. Meanwhile, a data hosting and timing automatic control function can be provided for the spacecraft through a return transmission mode. The relay forwarding mode of the invention can realize the safety supervision of the forwarded data, meet the requirements of various tasks, improve the flexibility of the relay satellite, reduce the time cost of ground maintenance and expand the application mode of the relay satellite.
Description
Technical Field
The invention relates to a multi-mode relay forwarding method based on data security supervision, and belongs to the technical field of satellite relay communication.
Background
The relay satellite is a special communication satellite, can be used for realizing the tracking, measurement and control of the medium and low orbit spacecrafts, and can forward the orbit, remote measurement and other data of the spacecrafts to the earth measurement and control station. The satellite is an important component of a large-scale space system, not only can the coverage rate of a space measurement and control network be greatly improved, but also the real-time performance of spacecraft measurement and control and satellite-ground data transmission can be enhanced, and the problems of foundation measurement and control are well solved. The method has important significance for reducing the operation risk of the spacecraft, improving the efficiency of ground measurement and control command, and particularly timely implementing fault analysis and space rescue under the condition that the spacecraft is abnormal.
The existing relay satellite, such as a space chain first satellite, realizes remote control and remote measurement forwarding between a ground station and a target spacecraft in a radio frequency forwarding mode. The relay mode of direct radio frequency forwarding cannot supervise the safety of forwarding data, only can realize real-time forwarding between the ground station and the target spacecraft, and cannot realize effective relay communication when the spacecraft and the ground station cannot simultaneously see the relay satellite. Therefore, a more secure and flexible relay communication method is required.
Disclosure of Invention
The technical problem solved by the invention is as follows: the defects of the prior art are overcome, and a relay communication mode capable of realizing data safety supervision and delaying forwarding is provided.
The technical solution of the invention is as follows: a multi-mode relay forwarding method based on data security supervision comprises the following steps:
s1, the transmitting terminal sends the data to be forwarded to the relay satellite according to a set relay frame format, wherein the relay frame format comprises a check code for checking the correctness of the data, a forwarding opportunity identifier, a time code for judging the sending time and a target identifier for judging the receiving terminal; the forwarding opportunity identification is divided into a real-time forwarding identification and a delay forwarding identification;
s2, the relay satellite checks the data to be forwarded according to the check code, if the data to be forwarded is wrong, the data to be forwarded is discarded, the corresponding wrong data identification bit is collocated, and the wrong data identification bit is downloaded to the ground station through the telemetering channel and the process is finished; if the verification is correct, the step S3 is entered;
s3, the relay satellite identifies the forwarding opportunity identifier, and if the forwarding opportunity identifier is a real-time forwarding identifier, the relay satellite enters S5; if the time delay forwarding identifier is the time delay forwarding identifier, storing the data to be forwarded to a corresponding position of a memory of the satellite-borne computer according to the time code, and entering S4;
s4, the satellite-borne computer carries out forwarding inquiry at certain time interval, if a certain time code is inquired to be in the range of [ current satellite-hour interval time, current satellite-hour ], the data to be forwarded is extracted from the corresponding position of the memory of the satellite-borne computer, and the S5 is entered;
and S5, the relay satellite identifies the receiving terminal according to the target identifier and sends the data to be forwarded to the receiving terminal.
Furthermore, the form of the data to be forwarded is a radio frequency signal, the relay satellite demodulates and decodes the received data to be forwarded into a relay frame format, and the relay satellite checks a check code in the relay frame format; and if and only if the data to be forwarded is verified to be correct, modulating the data to be forwarded into a radio frequency signal for sending.
Furthermore, the transmitting end and the receiving end are the same ground station or the same spacecraft.
Further, the time interval is 100ms to 1 s.
Further, the check code is a CRC check code.
Compared with the prior art, the invention has the advantages that:
(1) the invention can demodulate and decode the radio frequency signal into the data frame on the relay satellite, and then can check the correctness of the forwarded data, so as to realize the safety supervision of the forwarded data, and effectively reduce the probability that the ground station/spacecraft receives the error data.
(2) The invention can realize real-time relay forwarding between the ground station and the spacecraft and can also realize delay relay forwarding between the ground station and the spacecraft. Real-time relay forwarding can only be achieved when the ground station and the spacecraft are simultaneously visible to the relay satellite. The time-delay relay forwarding can realize timely and effective relay communication between the ground station and the spacecraft under the condition that the relay satellite is not visible at the same time, and effectively solves the timeliness problem caused by the fact that the ground station and the spacecraft are not visible at the same time.
(3) The time delay forwarding function of the invention can realize high-precision time forwarding of relay data or remote control instructions. For remote control tasks with high-precision time requirements, if a ground station directly sends instructions, the high-precision time requirements are difficult to meet due to time delay of ground operation and equipment. The time-unifying accuracy of modern spacecraft (also including relay satellites) can be accurate to the microsecond level. The time delay relay forwarding can realize the timing forwarding accurate to hundreds of milliseconds on a relay satellite, so that the remote control task with high precision requirement can be met.
(4) The delay forwarding function can be used for injecting all remote control tasks in a certain time period in the future to the relay satellite at one time, and the relay satellite can forward corresponding data to the target spacecraft at the specified time through the delay forwarding function. The remote control mode can be operated in real time without ground personnel, and the time cost of ground maintenance can be reduced.
(5) The invention can realize the data hosting and timing automatic control functions of the spacecraft through the delay forwarding function. When the spacecraft needs the relay satellite to temporarily store the required data or needs to receive a special remote control command at a certain moment, the data or the remote control command which needs to be stored can be sent to the relay satellite for storage according to an agreed frame format. And the relay satellite transmits the stored data or instruction to the original spacecraft at the corresponding moment when the spacecraft needs to return the data or transmit a remote control instruction. Therefore, the temporary storage function of the spacecraft data can be realized without the intervention of ground personnel, and certain requirements for sending instructions to the spacecraft at set time can be met.
Drawings
FIG. 1 is a schematic diagram of a relay satellite frame format according to the present invention;
FIG. 2 is a schematic diagram of a real-time relay forwarding mode according to the present invention;
fig. 3 is a schematic diagram of a relay forwarding mode of the present invention;
FIG. 4 is a schematic diagram of a timed backhaul forwarding mode according to the present invention;
fig. 5 is a flowchart of the relay satellite forwarding operation of the present invention.
Detailed Description
A multi-path relay forwarding method based on data security supervision, as shown in fig. 5, includes the following steps:
(1) the relay forwarding of the relay satellite is divided into three directions of forward forwarding (ground station- > relay satellite- > spacecraft), reverse forwarding (spacecraft- > relay satellite- > ground station) and return forwarding (spacecraft > relay satellite- > spacecraft), and the data forwarding in the three directions adopts the same relay frame format.
(2) And the ground station/spacecraft (transmitting terminal) transmits the data to be forwarded to the relay satellite through a corresponding channel according to the agreed relay frame format.
(3) After receiving the data to be forwarded, the satellite service center computer of the relay satellite firstly checks the correctness of the data, if the data is found to be wrong in verification, the data is discarded and is collocated with a corresponding identification bit, the identification bit can be downloaded to a ground station telemetering receiving end through telemetering, and the ground can select retransmission or other processing modes (errors occur in the transmitting process); if the data is correct, the next step is entered.
(4) And (4) judging the forwarding time identification of the data by the satellite service center computer, entering the step (6) if the data needs to be forwarded in real time, and storing the effective data to a corresponding position of the memory according to the time code if the data needs to be forwarded in a delayed manner.
(5) The house keeping center computer carries out forwarding task query at intervals of 100 ms-1 s, if the current star time is matched with the time code of a certain stored data in a certain task query, the step (6) is carried out;
(6) when the satellite service center computer executes the relay forwarding task, the target spacecraft (receiving end) is judged according to the target identification words in the effective data, and then the effective data to be forwarded is sent out through the corresponding channel ports.
(7) And the ground station/spacecraft (receiving end) performs subsequent processing after receiving the data forwarded by the relay satellite, so that the relay forwarding task of the relay satellite is completed.
The following detailed description is made with reference to the accompanying drawings.
Fig. 1 is a schematic diagram of a relay satellite frame format according to the present invention. The relay frame format of the relay satellite comprises four parts of an address synchronization word, a mode word, injection data and a CRC check code. The effective data comprises three parts of a main guide head, a data field and an error control field.
The data field content consists of five parts, namely target spacecraft identification characters, time codes, length codes, effective data and filling codes, and is described as follows:
(1) target identification word: the target identification words are spacecraft identification words of a data receiving party and are used for representing target spacecrafts of data to be forwarded;
(2) forwarding opportunity identification: indicating whether the relay satellite needs real-time forwarding or delayed forwarding;
(3) time code: the UTC star time, which is used to represent the delayed forwarding, takes 6 bytes, of which the first four bytes are in seconds(s) and the last 2 bytes are in milliseconds (ms). When the forwarding opportunity is real-time forwarding, the time code is 0;
(4) length code: the method is used for representing the length of actually required forwarding data, and the unit is byte;
(5) valid data: the data to be forwarded comprises address synchronous words, mode words, remote control/remote measuring data and CRC check codes;
(6) filling codes: and when the length of the effective data frame is insufficient, filling AAH for completion.
One, real time relay forwarding mode
(1) Fig. 2 is a schematic diagram of a real-time relay forwarding mode according to the present invention. When the ground station and the spacecraft are visible to the relay satellite at the same time and data needs to be forwarded between the ground station and the spacecraft in real time, the ground station/the spacecraft can send the data needing to be forwarded to the relay satellite according to a relay satellite frame format shown in fig. 1;
(2) after receiving the relay frame, the relay satellite firstly carries out security (correctness) check on the data in a CRC (cyclic redundancy check) mode, if the data are found to be in error, the data are discarded and are juxtaposed with corresponding identification positions, and the data are downloaded to the ground station through remote measurement;
(3) the relay satellite judges the forwarding opportunity identification position of the data, if the data needs to be forwarded in real time, the target identification word in the effective data is compared with the known spacecraft identification word to judge the forwarding target, and then the effective data needing to be forwarded is sent out through a corresponding channel port.
Second, delay relay forwarding mode
(1) Fig. 3 is a schematic diagram of a relay forwarding mode according to the present invention. When the ground station and the spacecraft are not visible to the relay satellite at the same time or have a high-precision requirement on the forwarding time, the ground station/spacecraft can send data to be forwarded to the relay satellite according to a relay satellite frame format shown in fig. 1;
(2) after receiving the relay frame, the relay satellite firstly carries out security check on the data in a CRC (cyclic redundancy check) way, if the data is found to be in error, the data is discarded and is juxtaposed with a corresponding identification bit, and the data is downloaded to the ground station through remote measurement;
(3) the relay satellite judges the forwarding opportunity identification bit of the data, and the relay satellite judges that delayed forwarding is needed. And storing the effective data frames to be forwarded to corresponding positions of the memory according to the forwarding time sequence according to the time codes.
(5) And the house service center computer performs forwarding task query every 100 ms. If the current UTC satellite time is inquired in a certain task inquiry and the time code of the effective data to be forwarded is consistent, the target identification words in the effective data are compared with the known spacecraft identification words to judge the target spacecraft/ground station, and then the effective data to be forwarded is sent out through the corresponding channel port.
Three, timing backhaul forwarding mode
As shown in fig. 4, the data hosting and timing auto-control function is a special form of the delay relay forwarding mode, and is characterized in that the transmitting end and the receiving end of the relay frame are the same spacecraft. Therefore, the target identification word of the valid data in the frame format is a receiving-end (also a transmitting-end) spacecraft identification word.
Those skilled in the art will appreciate that those matters not described in detail in the present specification are well known in the art.
Claims (4)
1. A multi-mode relay forwarding method based on data security supervision is characterized in that relay forwarding of a relay satellite is divided into three directions of forward forwarding, reverse forwarding and return forwarding, and data forwarding in the three directions adopts the same relay frame format, and the method comprises the following steps:
s1, the transmitting terminal sends the data to be forwarded to the relay satellite according to a set relay frame format, wherein the relay frame format comprises a check code for checking the correctness of the data, a forwarding opportunity identifier, a time code for judging the sending time and a target identifier for judging the receiving terminal; the forwarding opportunity identification is divided into a real-time forwarding identification and a delay forwarding identification;
s2, the relay satellite checks the data to be forwarded according to the check code, if the data to be forwarded is wrong, the data to be forwarded is discarded, the corresponding wrong data identification bit is collocated, and the wrong data identification bit is downloaded to the ground station through the telemetering channel and the process is finished; if the verification is correct, the step S3 is entered;
s3, the relay satellite identifies the forwarding opportunity identifier, and if the forwarding opportunity identifier is a real-time forwarding identifier, the relay satellite enters S5; if the time delay forwarding identifier is the time delay forwarding identifier, storing the data to be forwarded to a corresponding position of a memory of the satellite-borne computer according to the time code, and entering S4;
s4, the on-board computer transmits and inquires at preset time intervals, if a certain time code is inquired to be in the range of [ current satellite-hour interval, current satellite-hour ], the data to be transmitted is extracted from the corresponding position of the on-board computer memory, and the process enters S5;
s5, the relay satellite identifies the receiving terminal according to the target identifier and sends the data to be forwarded to the receiving terminal;
the form of the data to be forwarded is a radio frequency signal, the relay satellite demodulates and decodes the received data to be forwarded into a relay frame format, and the relay satellite verifies a verification code in the relay frame format; and if and only if the data to be forwarded is verified to be correct, modulating the data to be forwarded into a radio frequency signal for sending.
2. The multi-mode relay forwarding method based on data security supervision according to claim 1, characterized in that: the transmitting end and the receiving end are the same ground station or the same spacecraft.
3. The multi-mode relay forwarding method based on data security supervision according to claim 1, characterized in that: the time interval is 100 ms-1 s.
4. The multi-mode relay forwarding method based on data security supervision according to claim 1, characterized in that: the check code is a CRC check code.
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| CN110224740B (en) * | 2019-06-06 | 2022-03-25 | 上海航天测控通信研究所 | Intermediate frequency processor of relay terminal |
| CN112441259B (en) * | 2020-12-02 | 2023-02-03 | 中国人民解放军63920部队 | Method and device for judging delay transmission control effect of multiple spacecrafts |
| CN114153191B (en) * | 2021-11-23 | 2024-05-03 | 中国人民解放军63920部队 | Spacecraft control method, device and system |
| CN114257292B (en) * | 2021-12-15 | 2024-04-05 | 北京航天飞行控制中心 | Spacecraft relay substituted transmission remote control instruction comparison judging method and device |
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