Space-based heterogeneous multilink networking selection transmission method

Abstract

The invention provides a space-based heterogeneous multi-link networking selection transmission method. The method comprises the following steps: step 1, a user terminal accesses a network; step 2, link quality estimation: the user terminal and the satellite periodically count the receiving and sending data volume of the communication transceiver, and estimate the communication quality of each sending link in combination with the link load and the packet loss rate; step 3, link selection; step 4, link switching: a sending end decides communication link switching by utilizing an accumulation and control chart technology through a link state in service communication so as to ensure that service data is transmitted by an optimal link all the time; and step 5, satellite protocol conversion: a satellite performs protocol conversion from various communication link frames to a unified network layer data packet through address mapping, and hinge communication of multiple heterogeneous links is realized through routing of a unified bearing service data packet by IPv4 (Internet Protocol Version 4). According to the method provided by the invention, heterogeneous terminal networking is realized on a satellite by uniformly bearing data through an IP, link optimization is realized by utilizing a link quality estimation and control chart technology, and the satellite communication flexibility and efficiency are improved.

Description

Technical Field

[0001] The present invention belongs to the field of satellite networking communication technology, relates to space-based heterogeneous multi-link networking, and specifically relates to a space-based heterogeneous multi-link networking transmission selection method. Background Art

[0002] With the iterative development of satellite communication technology and the independent construction of different systems for different users, the types of communication terminals of each system are diverse and complex, and satellites are often equipped with a variety of communication equipment. Due to policy, technology, history and other reasons, there are institutional barriers between systems, and even between subsystems of the same satellite, which cannot be flexibly interconnected, resulting in low communication efficiency and rigid usage. In addition, different links used by various communication equipment have different communication characteristics. For example, high-frequency bands such as Ka and Ku have high communication rates, but are easily affected by environmental interference such as rain and snow; low-frequency bands have a wide coverage range, but the communication rate is low. According to the real-time space electronic environment, how to flexibly and autonomously select and switch the appropriate link on demand is the actual problem faced by users when using satellite communications. Summary of the invention

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a space-based heterogeneous multi-link networking selection transmission method to solve the technical problem that the flexibility and efficiency of space-based heterogeneous multi-link networking in the prior art need to be further improved.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0005] A space-based heterogeneous multi-link networking transmission selection method, the method is performed according to the following steps:

[0006] Step 1: User terminal access to the network:

[0007] The user terminal accesses the satellite network through multiple types of heterogeneous communication transceivers, and the mapping information between the communication transceiver site address and IP address used by the user terminal is stored on the satellite.

[0008] Step 2: Link quality estimation:

[0009] The user terminal and the satellite periodically count the amount of data sent and received by the communication transceiver, and estimate the communication quality of each transmission link based on the link load and packet loss rate.

[0010] The estimation of the communication quality of each transmission link includes the estimation of the quality of the user terminal uplink service communication link and the estimation of the quality of the satellite service transmission downlink link.

[0011] Step 3: Link selection:

[0012] In business communications, the sender selects the optimal link for communication based on the link quality estimate obtained in step 2.

[0013] Step 4: Link switching:

[0014] In business communications, the sender uses the cumulative and control graph technology to decide on communication link switching based on the link status to ensure that business data is always transmitted via the optimal link.

[0015] The communication link switching includes link switching for uplink data transmission of the user terminal and link switching for downlink data transmission of the satellite.

[0016] Step 5: Satellite protocol conversion:

[0017] The satellite performs protocol conversion from various communication link frames to unified network layer data packets through address mapping, and uses IPv4 to uniformly carry the routing of service data packets to achieve hinge communication of multiple heterogeneous links.

[0018] The protocol conversion process includes a frame sealing process and a frame de-framing process, and the frame de-framing process is opposite to the frame sealing process.

[0019] Compared with the prior art, the present invention has the following technical effects:

[0020] (I) The method of the present invention realizes heterogeneous terminal networking by uniformly carrying data with IP on board, realizes link optimization by using link quality estimation and control graph technology, and improves the flexibility and efficiency of satellite communications.

[0021] (II) The method of the present invention is different from the existing independent use of each communication machine, and the inconsistent protocol system leads to rigid user usage and low resource utilization. The present invention uses on-board address mapping to construct IPv4 datagrams from the link layer to achieve unified bearer for routing exchange, thereby realizing connectivity between heterogeneous satellite communication terminals.

[0022] (III) In traditional networks, network layer parameters such as hop count and delay are used to select routes. Multipath routing research focuses on network layer path selection, and does not pay attention to link layer and physical layer capabilities. The method of the present invention combines the transmission capability of the link layer, interacts with low-overhead data packets, and estimates the link transmission quality by considering link load and packet loss rate. When transmitting multi-link satellite-to-ground data, the link with the best transmission quality is selected, thereby improving transmission efficiency, reducing the probability of satellite-to-ground communication congestion, and improving spectrum utilization.

[0023] (IV) Different from the traditional IP network's processing schemes of packet loss retransmission and waiting, the method of the present invention monitors the communication status by using the accumulation and control diagram method. It can quickly detect the deterioration of the communication link and perform link switching without causing switching oscillation, thereby ensuring the transmission quality and efficiency, while avoiding false detection caused by link quality jitter. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The figure is a schematic diagram of the workflow of the space-based heterogeneous networking multi-link selection transmission method in the embodiment.

[0025] Figure 2 Schematic diagram of the working scenario of selecting transmission methods for multi-link space-based heterogeneous networking in the application example.

[0026] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0027] It should be noted that, unless otherwise specified, all devices and techniques in the present invention are devices and techniques known in the prior art.

[0028] In order to realize hinge communication and multi-link real-time switching of heterogeneous terminals and improve system utilization, the present invention proposes a space-based heterogeneous multi-link networking and transmission selection method. Users configure a variety of communication terminals to access satellites for communication in different systems, and satellite nodes perform protocol conversion. IP is used to uniformly bear exchange routing to realize heterogeneous terminal networking and hinge; considering link load and packet loss rate, the quality of each link is estimated with extremely low overhead to evaluate link transmission performance; the communication quality changes of different links are perceived through control graph technology, and links with good communication quality are selected from the available multi-links for service transmission. The present invention aims at various customized communication systems in the development process of satellite communications and the need for efficient hinge communication of a large number of heterogeneous terminal services. The present invention realizes unified bearer heterogeneous networking through on-board protocol conversion, performs route selection communication based on link quality evaluation, and uses cumulative sum graphs to decide link switching to improve service transmission efficiency. It belongs to the field of satellite communication networking.

[0029] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0030] Example:

[0031] This embodiment provides a space-based heterogeneous multi-link networking transmission selection method, such as Figure 1 As shown, the method is performed according to the following steps:

[0032] Step 1: User terminal access to the network:

[0033] The user terminal accesses the satellite network through multiple types of heterogeneous communication transceivers, and the mapping information between the communication transceiver site address and IP address used by the user terminal is stored on the satellite.

[0034] In step 1, the expression of the communication transceiver is: Tr = {tr n |1≤n≤N}.

[0035] Where:

[0036] Tr represents the set of transceivers;

[0037] N represents the type of transceiver;

[0038] n represents the type number of the transceiver.

[0039] In the communication system used by the nth type of communication transceiver, the design rate of the wireless link from the satellite to the user terminal is The design rate of the wireless link from the user terminal to the satellite is The bit error rate of the wireless link from satellite to user terminal is The bit error rate of the wireless link from the user terminal to the satellite is The specified frame length is l n .

[0040] Then the theoretical packet error rate of uplink communication of the nth type of communication transceiver is The theoretical packet error rate of downlink communication of the nth type of communication transceiver is

[0041] Satellite s i The load configuration is Access Satellites i User terminal u j Configure the communication transceiver as

[0042] In step 1, the process of accessing the satellite network is as follows: user terminal u j Select an available communication transceiver to access the satellite i Send the address of the available communication transceiver site to the ground network management center and Divide Network access application without external identity authentication information.

[0043] The satellite forwards the network access application to the ground network management center, which assigns an available IPv4 address. To user terminal u j , and this IPv4 address Reply to the user terminal u in the form of network reply j , indicating that the network access is successful.

[0044] When the satellite forwards the network access reply, it records the current IPv4 address of the user terminal With site address The mapping relationship

[0045] in:

[0046] Indicates user terminal u j Configured communication transceiver The site address;

[0047] Indicates the initial value of the downlink quality, that is, the downlink error-free packet rate when the link is normal.

[0048] Step 2: Link quality estimation:

[0049] The user terminal and the satellite periodically count the amount of data sent and received by the communication transceiver, and estimate the communication quality of each sending link based on the link load and packet loss rate to evaluate the link communication capability.

[0050] In step 2, the communication quality of each transmission link is estimated, including the user terminal uplink service communication link quality estimation and the satellite service transmission downlink quality estimation.

[0051] In step 2, specifically, the method for estimating the quality of the uplink service communication link of the user terminal is:

[0052] User terminal u j By satellite i To the user terminal u j When a user terminal outside sends data, the communication transceiver with the best current communication quality is selected according to the current statistical estimated link quality of the communication transceiver, that is, the one with the largest link quality estimation value. The communication transceiver sends i Send data.

[0053]

[0054] Where:

[0055] For communication transceiver The maximum link quality estimate of the uplink communication quality at time t;

[0056] For communication transceiver Design value of uplink communication rate;

[0057] T is the statistical period;

[0058] For user terminal u j The communication transceiver in the current statistical period obtained at time t Statistics of uplink sent packets;

[0059] For user terminal u jThe communication transceiver in the current statistical period obtained at time t Estimated value of the uplink packet error rate.

[0060] In step 2, further, The statistical methods and The estimation method is: Satellite s i Record the number of messages sent by each communication transceiver to user terminal u in each cycle t j Send and receive from user terminal u j Number of packets received and User terminal u j Record the number of signals sent by each communication transceiver to satellite s in each cycle t i Send to and from satellites i Number of packets received and Satellites i and user terminal u j At the end of each statistical period t, the received statistical value of itself is counted and Sent to the communication peer to inform itself of the number of packets received; user terminal u j Estimate the success rate of uplink data packets sent by each transceiver When there is no uplink data communication At this time

[0061]

[0062] In step 2, specifically, the method for estimating the quality of the satellite service transmission downlink is:

[0063] Satellites i Each transceiver to user terminal u j The estimated downlink packet error rate is When there is no downlink data communication At this time Calculate the satellite downlink quality estimate And modify the user terminal communication transceiver site address corresponding to the satellite downlink quality estimation value Link quality estimates in the onboard address mapping table

[0064] Step 3: Link selection:

[0065] In business communications, the sender selects the optimal link for communication based on the link quality estimate obtained in step 2.

[0066] Link selection includes user terminal uplink service communication link selection and satellite service transmission downlink selection.

[0067] In step 3, specifically, the method for selecting the uplink service communication link of the user terminal is: the user terminal u j By satellite i To the user terminal u j When a user terminal outside sends data, the communication transceiver with the best current communication quality is selected according to the current statistical estimated link quality of the communication transceiver, that is, the one with the largest link quality estimation value. The communication transceiver sends i Send data.

[0068] In step 3, specifically, the method for selecting the downlink for satellite service transmission is as follows: for each IPv4 data message that needs to be forwarded, the routing table is searched for and the next-hop forwarding is performed. According to the next-hop forwarding address, the on-board address mapping table is searched to obtain all available site addresses of the next-hop addruj. And the current link quality estimate corresponding to all available site addresses The transceiver with the largest link quality evaluation value is selected.

[0069] Step 4: Link switching:

[0070] In business communications, the sender uses the cumulative and control graph technology to decide on communication link switching based on the link status to ensure that business data is always transmitted via the optimal link.

[0071] Communication link switching includes link switching for uplink data transmission by user terminals and link switching for downlink data transmission by satellites.

[0072] In step 4, specifically, the method for link switching for uplink data transmission of the user terminal is as follows: the user terminal u j To satellites i During the data transmission process, the status of the currently used link is monitored in real time. When the packet error rate increases and exceeds the normal level, the communication service is switched to the communication transceiver with the largest link quality estimation value other than the currently used communication transceiver for transmission.

[0073] In step 4, further, the method for link switching of uplink data transmission of the user terminal is: at the end time t of each packet error rate statistical estimation period, the user terminal u j Calculate the current and satellite s i Uplink communication transceiver used for communication The corresponding control chart cumulative sum in, For communication transceiver The allowable deviation of uplink packet error rate jitter under normal circumstances; if Greater than the set judgment threshold H n , then the link packet error rate is determined to exceed the threshold, Set to 0, switch the communication service to the communication transceiver with the largest link quality estimation value except the currently used communication transceiver, otherwise continue to use the current communication transceiver for service communication.

[0074] In step 4, specifically, the link switching method for satellite downlink data transmission is: satellite s i Real-time monitoring of the current link status, calculation of the control graph cumulative sum of the current communication downlink It is determined whether to switch the downlink by judging whether the value exceeds a predetermined threshold. If switching is required, the communication service is switched to the communication transceiver with the largest link quality estimation value other than the currently used communication transceiver.

[0075] Step 5: Satellite protocol conversion:

[0076] The satellite performs protocol conversion from various communication link frames to unified network layer data packets through address mapping, and uses IPv4 to uniformly carry the routing of service data packets to achieve hinge communication of multiple heterogeneous links.

[0077] The protocol conversion process includes a framing process and a deframing process, and the deframing process is the opposite of the framing process.

[0078] In step five, the frame sealing process is as follows: for the uplink signal received by the satellite payload, the communication transceiver demodulates and processes it to obtain a link frame, identifies the frame type through the frame header, and directly extracts the IPv4 message in the frame payload if the frame payload is an IPv4 message; for the frame payload in other data formats, the corresponding IPv4 information is obtained through the site address information in the link frame header and the on-board address mapping table, and an IPv4 message header is constructed, and the frame payload and IPv4 header are packaged to form an IPv4 message; the IPv4 message is routed and the link is selected, and then the frame is sealed and handed over to the communication transceiver for modulation and transmission.

[0079] Application examples:

[0080] This application example provides a method for selecting transmission in a space-based heterogeneous multi-link network based on the above embodiment. The working scenario of the method in this application example is as follows: Figure 2 As shown, it includes: satellite, user terminal and ground network management.

[0081] The satellite is a high-orbit satellite, responsible for receiving uplink signals from user terminals and sending them to target users after processing. The processing process includes wireless signal reception and demodulation, protocol deframing, routing and link selection, protocol framing, modulation and transmission, and the on-board network parameters are configured according to the ground network management instructions.

[0082] The user terminal is responsible for sending the user's network layer service data to the satellite using a suitable transceiver, receiving the signal sent downlink by the satellite to itself, and sending the parsed network layer data to the user.

[0083] The ground network management is the ground management center of the entire network, responsible for the satellite network function configuration and the maintenance of the entire network status.

[0084] Specifically:

[0085] First, the satellite S1 contains two types of communication transceivers, a link estimation and routing module, a protocol conversion module, and an onboard network management agent:

[0086] The two types of communication transceivers are S low-speed communication transceiver Ka high-speed communication transceiver Used to modulate baseband data and demodulate intermediate frequency signals; respectively run the S low-speed communication system protocol and the Ka high-speed communication system protocol, where the S link frame contains payload data and does not support the IPv4 protocol, and the Ka frame contains the network layer IPv4 protocol and has an IPv4 message header; the design rates of the satellite-to-user and user-to-satellite wireless links in the above two communication systems are downlink

[0087] Upper behavior The bit error rate is The frame lengths are l1 = 500 bytes and l2 = 1000 bytes respectively. The theoretical packet error rate of uplink and downlink communication of S and Ka transceivers is User terminal u1 is also equipped with S and Ka communication transceivers.

[0088] The link estimation and routing module is responsible for regularly collecting and counting the downlink packet error rate of the S communication transceiver and the Ka high-speed communication transceiver for each terminal accessing the satellite, which is used to calculate the quality of the downlink channel from the satellite to the communication transceiver of each terminal, and record it in the routing table item corresponding to the terminal; when routing data messages, if the target node has multiple matching links, the path with good link quality is selected for transmission; at the same time, when the communication quality of the current transmission link deteriorates, other optimal communication paths are switched in time.

[0089] The protocol conversion module is responsible for receiving link frames from S and Ka communication transceivers, de-framing them according to the corresponding S low-speed communication system protocol or Ka high-speed communication system protocol to obtain frame payload data, converting them into IPv4 messages as needed and marking the communication transceiver number to send them to the routing decision module; the IPv4 messages sent by the routing decision module are marked with the corresponding S or Ka transceiver system according to the routing decision result, and the payload in the IP data message is framed according to the S low-speed communication system protocol or Ka high-speed communication system protocol, encapsulated into the S link frame or Ka link frame format, and then sent to the corresponding transceiver for modulation and transmission.

[0090] Onboard network management agent: responsible for receiving command information sent by the ground network management, including address mapping information, link selection control information, routing table operation information, protocol conversion management, etc.

[0091] Second, the user terminal contains two types of communication transceivers and routing decision modules:

[0092] User terminal 1 is equipped with S low-speed communication transceiver and Ka high-speed communication transceiver to access satellite s1; network data communication is performed with user equipment through the network port on the user side.

[0093] When a user needs to communicate via satellite, the routing decision module is responsible for regularly estimating the uplink packet error rate of the S / Ka transmitter and selecting the communication transceiver with the best link quality for transmission.

[0094] Third, ground network management: The ground network management is the management center of the satellite network. It is responsible for the network registration, authentication, address allocation, mobility management of transceivers, management of satellite system global address mapping information, configuration of network parameters, etc., and interacts with the satellite through the feeder link.

[0095] Specifically, the method of this application example is performed according to the following steps:

[0096] Step 1: User terminal access to the network:

[0097] The user terminal accesses the satellite network through multiple types of heterogeneous communication transceivers, and the mapping information between the communication transceiver site address and IP address used by the user terminal is stored on the satellite.

[0098] In this embodiment, the process of accessing the satellite network is as follows: through the configured S or Ka communication transceiver, the satellite s1 sends a message with its own site address to the ground network management center. The satellite forwards the application data packet to the ground network management center, which assigns an available IPv4 address addr to the normal user after authentication. u1The satellite sends the network access success response message containing this address to u1, and replies to the network access terminal to inform it of the successful network access; when the satellite forwards the network access response, it records the site address of the user terminal As well as the corresponding initialized link quality estimate and the IPv4 address addr assigned by the ground network management center u1 , the mapping relationship Added to the on-board address mapping table.

[0099] Step 2: Link quality estimation:

[0100] The user terminal and the satellite periodically count the amount of data sent and received by the communication transceiver, and estimate the communication quality of each transmission link based on the link load and packet loss rate.

[0101] The communication quality of each transmission link is estimated, including the user terminal uplink service communication link quality estimation and the satellite service transmission downlink quality estimation.

[0102] Specifically, in this application example, the method for estimating the quality of the uplink service communication link of the user terminal is as follows: S and Ka communication transceivers and The estimated uplink communication quality at the current time t is

[0103] in and are the communication transceivers S and Ka obtained by user u1 at time t in the current statistical period. and The statistical value of the uplink data volume and the estimated value of the uplink packet error rate.

[0104] The statistical methods and The estimation method is as follows: the satellite S1 link estimation and routing module records the number of packets sent by the S and Ka communication transceivers in each cycle. and the number of packets received The link decision module of user u1 records the number of data packets sent by the S and Ka communication transceivers in each cycle t and the number of packets received At the end of each statistical period t, satellite s1 will Send it to user u1, and user u1 will Sent to satellite s1. User u1 estimates the uplink packet error rate of S and Ka transceivers When a communication transceiver has no uplink data communication, its corresponding

[0105] Specifically, in this application example, the satellite service transmission downlink quality estimation method is as follows:

[0106] This application example uses the communication between the satellite and user terminal u1 as an example, and the methods for other users are the same. i The method for estimating downlink quality is the same as the method used by users to estimate uplink quality. Satellite S1 estimates the downlink packet error rate of S and Ka transceivers. When the S or Ka communication transceiver has no data communication or is 0, at this time Then the satellite downlink quality is calculated

[0107] And record it in real time to the corresponding user communication transceiver site address In the entry in the on-board address mapping table

[0108]

[0109] Step 3: Link selection:

[0110] In business communications, the sender selects the optimal link for communication based on the link quality estimate obtained in step 2.

[0111] Link selection includes user terminal uplink service communication link selection and satellite service transmission downlink selection.

[0112] Specifically in this application example, the method for selecting the uplink service communication link of the user terminal is: when the user terminal starts to send data via the satellite, the routing decision module selects the communication transceiver with the best current communication quality, that is, the communication transceiver with the largest link quality estimation value, to send data information to the satellite based on the current statistical estimated link quality of the communication transceiver.

[0113] In this application example, the method for selecting the downlink link for satellite service transmission is as follows: for each IPv4 data message that needs to be sent downlink, the routing table is searched for the next hop forwarding, and the on-board address mapping table is searched according to the next hop forwarding address to obtain the next hop All site addresses available and its current link quality Select the transceiver with the largest current link quality evaluation value.

[0114] Step 4: Link switching:

[0115] In business communications, the sender uses the cumulative and control graph technology to decide on communication link switching based on the link status to ensure that business data is always transmitted via the optimal link.

[0116] Communication link switching includes link switching for uplink data transmission by user terminals and link switching for downlink data transmission by satellites.

[0117] Specifically in this application example, the method for link switching for uplink data transmission of the user terminal is as follows: when user u1 is sending data via the satellite, the routing decision module monitors the status of the currently used link in real time. When the packet error rate increases and exceeds the normal level, it switches to other communication transceivers with the largest link quality estimation value for transmission.

[0118] The specific decision-making process is as follows: at the end time t of each packet error rate statistical estimation cycle, user u1 calculates the uplink communication transceiver currently used for satellite communication The corresponding control chart cumulative sum in is the standard deviation of the theoretical packet error rate of the nth type of communication transceiver in the normal environment. Greater than the set judgment threshold The link packet error rate is determined to exceed the threshold, Set to 0 and switch the communication service to other available communication transceivers with the largest link quality estimation value.

[0119] Specifically, the link switching method for satellite downlink data transmission in this application example is as follows: the path selection and routing module monitors the current link status in real time, and uses a similar method to the terminal link switching method to calculate the control graph cumulative sum corresponding to the downlink used by the current communication in is the standard deviation of the theoretical packet error rate of the nth type of communication transceiver in the downlink under normal conditions. Greater than the set judgment threshold The link packet error rate is determined to exceed the threshold, Set to 0 and switch the communication service to other available communication transceivers with the largest link quality estimation value.

[0120] Step 5: Satellite protocol conversion:

[0121] The satellite performs protocol conversion from various communication link frames to unified network layer data packets through address mapping, and uses IPv4 to uniformly carry the routing of service data packets to achieve hinge communication of multiple heterogeneous links.

[0122] The protocol conversion process includes a framing process and a deframing process, and the deframing process is the opposite of the framing process.

[0123] Specifically in this application example, the de-framing process is: uniformly convert the network layer and link layer data of different system protocols of S and Ka, so that multiple systems can realize routing exchange under the unified IP bearer. Here, the S link frame contains payload data and does not support the IPv4 protocol. The Ka frame contains the network layer IPv4 protocol and has an IPv4 message header. The specific protocol conversion process is: for the S or Ka uplink signal received by the satellite payload, the S or Ka communication transceiver delivers the demodulated link frame to the protocol conversion module. The protocol conversion module identifies the frame type through the frame header. For the S data frame, the source and destination site address information in the link frame header is combined with the on-board address mapping table to obtain the source and destination node corresponding IPv4 addresses, construct the IPv4 message header, and package the S frame payload and IPv4 header to form an IPv4 message; for the Ka data frame, directly extract the IPv4 message in the frame payload. Then the IPv4 message is handed over to the link perception and routing module for routing and link selection, and then the frame is sealed and handed over to the communication transceiver for modulation and transmission.

Claims

1. A space-based heterogeneous multi-link networking selection transmission method, characterized in that: The method proceeds as follows: Step 1: User terminal access to the network: The user terminal accesses the satellite network through multiple types of heterogeneous communication transceivers, and the mapping information between the communication transceiver site address and the IP address used by the user terminal is stored on the satellite; Step 2: Link quality estimation: The user terminal and the satellite periodically count the amount of data sent and received by the communication transceiver, and estimate the communication quality of each transmission link based on the link load and packet loss rate; The communication quality estimation of each transmission link includes the user terminal uplink service communication link quality estimation and the satellite service transmission downlink quality estimation; Step 3: Link selection: In the service communication, the sending end selects the best link for communication according to the link quality estimation obtained in step 2; The link selection includes user terminal uplink service communication link selection and satellite service transmission downlink selection; Step 4: Link switching: In business communications, the sender uses the cumulative sum control graph technology to decide on the communication link switching based on the link status to ensure that the business data is always transmitted via the optimal link; The communication link switching includes link switching for uplink data transmission of the user terminal and link switching for downlink data transmission of the satellite; Step 5: Satellite protocol conversion: The satellite performs protocol conversion from various communication link frames to unified network layer data packets through address mapping, and uses IPv4 to unify the routing of service data packets to achieve hinge communication of multiple heterogeneous links; The protocol conversion process includes a frame sealing process and a frame de-framing process, and the frame de-framing process is opposite to the frame sealing process.

2. The space-based heterogeneous multi-link networking transmission selection method according to claim 1, characterized in that: In step 1, the expression of the communication transceiver is: Tr = {tr n |1≤n≤N}; Where: Tr represents the set of transceivers; N represents the type of transceiver; n represents the type number of the transceiver; In the communication system used by the nth type of communication transceiver, the design rate of the wireless link from the satellite to the user terminal is The design rate of the wireless link from the user terminal to the satellite is The bit error rate of the wireless link from satellite to user terminal is The bit error rate of the wireless link from the user terminal to the satellite is The specified frame length is l n ; Then the theoretical packet error rate of uplink communication of the nth type of communication transceiver is The theoretical packet error rate of downlink communication of the nth type of communication transceiver is Satellite s i The load configuration is Access Satellites i User terminal u j Configure the communication transceiver as 3. The space-based heterogeneous multi-link networking transmission selection method according to claim 2, characterized in that: In step 1, the process of accessing the satellite network is as follows: user terminal u j Select an available communication transceiver to access the satellite i Send the address of the available communication transceiver site to the ground network management center and Divide Network access application with external identity authentication information; The satellite forwards the network access application to the ground network management center, which assigns an available IPv4 address. To user terminal u j , and this IPv4 address Reply to the user terminal u in the form of network reply j , indicating that the network access is successful; When the satellite forwards the network access reply, it records the current IPv4 address of the user terminal With site address The mapping relationship in: Indicates user terminal u j Configured communication transceiver The site address; Indicates the initial value of the downlink quality, that is, the downlink error-free packet rate when the link is normal.

4. The space-based heterogeneous multi-link networking transmission selection method according to claim 1, characterized in that: In step 2, the method for estimating the quality of the uplink service communication link of the user terminal is: Where: For communication transceiver The maximum link quality estimate of the uplink communication quality at time t; For communication transceiver Design value of uplink communication rate; T is the statistical period; For user terminal u j The communication transceiver in the current statistical period obtained at time t Statistics of uplink sent packets; For user terminal u j The communication transceiver in the current statistical period obtained at time t Estimated value of the uplink packet error rate.

5. The space-based heterogeneous multi-link networking transmission selection method according to claim 4, characterized in that: In step 2, the The statistical methods and The estimation method is: Satellite s i Record the number of messages sent by each communication transceiver to user terminal u in each cycle t j Send and receive from user terminal u j Number of packets received and User terminal u j Record the number of signals sent by each communication transceiver to satellite s in each cycle t i Send to and from satellites i Number of packets received and Satellites i and user terminal u j At the end of each statistical period t, the received statistical value of itself is counted and Sent to the communication peer to inform itself of the number of packets received; user terminal u j Estimate the success rate of uplink data packets sent by each transceiver When there is no uplink data communication At this time 6. The space-based heterogeneous multi-link networking transmission selection method according to claim 4, characterized in that: In step 3, the method for selecting the uplink service communication link of the user terminal is as follows: j By satellite i To the user terminal u j When a user terminal outside sends data, the communication transceiver with the best current communication quality is selected according to the current statistical estimated link quality of the communication transceiver, that is, the one with the largest link quality estimation value. The communication transceiver sends i Send data.

7. The space-based heterogeneous multi-link networking transmission selection method according to claim 6, characterized in that: In step 4, the method for link switching of uplink data transmission of the user terminal is as follows: the user terminal u j To satellites i During the data transmission process, the status of the currently used link is monitored in real time. When the packet error rate increases and exceeds the normal level, the communication service is switched to the communication transceiver with the largest link quality estimation value other than the currently used communication transceiver for transmission.

8. The space-based heterogeneous multi-link networking transmission selection method according to claim 7, characterized in that: In step 4, the method for link switching of uplink data transmission of the user terminal is as follows: at the end time t of each packet error rate statistical estimation period, the user terminal u j Calculate the current and satellite s i Uplink communication transceiver used for communication The corresponding control chart cumulative sum in, For communication transceiver The allowable deviation of uplink packet error rate jitter under normal circumstances; if Greater than the set judgment threshold H n , then the link packet error rate is determined to exceed the threshold, Set to 0, switch the communication service to the communication transceiver with the largest link quality estimation value except the currently used communication transceiver, otherwise continue to use the current communication transceiver for service communication.

9. The space-based heterogeneous multi-link networking transmission selection method according to claim 8, characterized in that: In step 2, the method for estimating the quality of the satellite service transmission downlink is: Satellites i Each transceiver to user terminal u j The estimated downlink packet error rate is When there is no downlink data communication At this time Calculate the satellite downlink quality estimate And modify the user terminal communication transceiver site address corresponding to the satellite downlink quality estimation value Link quality estimates in the onboard address mapping table In step 3, the method for selecting the downlink for satellite service transmission is as follows: for each IPv4 data message that needs to be forwarded, the routing table is searched for the next hop forwarding, and the on-board address mapping table is searched according to the next hop forwarding address to obtain all available site addresses of the next hop addruj. And the current link quality estimates corresponding to all available site addresses Selecting the transceiver with the largest link quality evaluation value; In step 4, the link switching method for sending satellite downlink data is as follows: satellite s i Real-time monitoring of the current link status, calculation of the control graph cumulative sum of the current communication downlink It is determined whether to switch the downlink by judging whether the value exceeds a predetermined threshold. If switching is required, the communication service is switched to the communication transceiver with the largest link quality estimation value other than the currently used communication transceiver.

10. The space-based heterogeneous multi-link networking transmission selection method according to claim 1, characterized in that: In step 5, the frame sealing process is as follows: for the uplink signal received by the satellite payload, the communication transceiver demodulates and processes to obtain a link frame, identifies the frame type through the frame header, and directly extracts the IPv4 message in the frame payload if the frame payload is an IPv4 message; for the frame payload is in other types of data formats, obtains the corresponding IPv4 information through the site address information in the link frame header and the on-board address mapping table, constructs the IPv4 message header, and packages the frame payload and the IPv4 header to form an IPv4 message; The IPv4 message is routed and the link is selected, and then framed and handed over to the communication transceiver for modulation and transmission.

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