Satellite telemetry data processing device based on IPv6 protocol

Abstract

The invention discloses a satellite telemetry data processing device based on an IPv6 protocol. The satellite telemetry data processing device comprises an AOS / IP conversion module, an IP routing forwarding module and an IP / AOS conversion module. According to the telemetering processing device, telemetering data AOS frames input by all channels are converted into IP packets through the AOS / IP conversion module, routing output of the telemetering data IP packets is achieved through the IP routing forwarding module, and finally the IP packets routed to the corresponding responder channels are converted into AOS telemetering data frames to be output through the IP / AOS conversion module. According to the telemetry data scheduling realized in the mode, the processing time of software is greatly reduced, the scheduling of the telemetry data is completed by the on-satellite routing processing unit, the IP packet in the downlink telemetry data AOS frame is of a standard structure, the interconnection and intercommunication with the ground IP Internet are easy to realize, and the distribution and analysis of the ground telemetry data are convenient.

Description

Technical Field

[0001] This invention relates to a satellite telemetry data processing device based on the IPv6 protocol, belonging to the technical field of aerospace electronic systems. Background Technology

[0002] Traditional satellite telemetry data is processed in two ways. One method involves transmitting all telemetry data from the entire satellite via a bus to a data management computer (DNC), where its software organizes, schedules, and downloads the data. However, with the increasing downlink telemetry channel speeds and the growing volume of telemetry data, the DNC's telemetry processing time is constantly increasing, impacting the efficiency of other tasks. Therefore, another telemetry data processing method has emerged. In this method, the DNC processes only a portion of the telemetry data. This portion, along with other non-computer-processed telemetry data (such as telemetry data from other satellites transmitted via inter-satellite links), is sent to a telemetry combining device (FPGA or ASIC). This device performs telemetry combining before downloading the data through the telemetry channel. This method alleviates the pressure on the DNC through a dedicated telemetry combining device; however, the design complexity of the telemetry combining device remains significant because the protocols and speeds of telemetry data from different channels vary. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a satellite telemetry data processing device based on the IPv6 protocol. This device uses IP packet routing to receive and route telemetry data, thereby improving the processing capability and flexibility of satellite telemetry data. At the same time, it enables interoperability with the terrestrial Internet, facilitating the distribution, processing, and parsing of telemetry data on the terrestrial network.

[0004] The technical solution of this invention is:

[0005] A telemetry data processing device based on IPv6 protocol routing includes: an AOS / IP conversion module, an IP routing forwarding module, and an IP / AOS conversion module;

[0006] The AOS / IP conversion module is used to receive telemetry data AOS frames from each channel, cache the AOS frames, extract the IP packets, and output them to the IP routing and forwarding module.

[0007] The IP routing and forwarding module is used to receive IP packets from each channel, query the routing table according to the destination IP address in the IP packet, and route each IP packet to the corresponding output channel. Each output channel is configured with an IP / AOS conversion module.

[0008] The IP / AOS conversion module converts IP packets routed to it by the IP routing and forwarding module into corresponding AOS frames for the responder channel and then outputs them to the corresponding responder.

[0009] Furthermore, each channel is configured with an AOS / IP conversion module, and the frame length of the input AOS frames is not necessarily the same.

[0010] Furthermore, the AOS / IP conversion module includes: a frame receive buffer module, an IP packet extraction module, and an IP packet receive buffer module;

[0011] The frame receiving buffer module is used to receive the corresponding channel telemetry data AOS frames and buffer them in a ping-pong manner.

[0012] The IP packet extraction module extracts the corresponding encapsulated packets based on the M_PDU data unit format in the telemetry data AOS frame, and further strips the encapsulated packet header and IPE header to obtain the IP packets;

[0013] The IP packet receiving and caching module performs ping-pong caching on the IP packets obtained by the IP extraction module for the routing and forwarding module to read.

[0014] Furthermore, the M_PDU data unit is a standard CCSDS data unit, and only one M_PDU data unit is contained in an AOS frame. The data in the M_PDU data unit exists in the form of an encapsulated packet.

[0015] Furthermore, a complete encapsulation packet may reside in only one M_PDU data unit or multiple M_PDU data units. The starting position of a spatial packet is obtained based on the first header pointer in the M_PDU header, and the complete encapsulation packet is obtained from this frame or subsequent frames based on the packet length in the encapsulation packet header. The IP packet is obtained by removing the header bytes from the encapsulation packet.

[0016] Furthermore, the IP routing and forwarding module includes: a routing table lookup module, a routing splitting module, a splitting cache module, and a rendezvous module;

[0017] The routing table lookup module is used to compare the destination IP address of the IP packet in the receiving cache module with the entries in the routing table one by one. If the comparison is successful, the routing is successful; if the comparison fails, the packet is discarded. Each input channel corresponds to one routing table lookup module, and there are m routing table lookup modules for m input channels.

[0018] The routing splitting module stores successfully routed IP packets in the corresponding splitting cache module. Each input channel corresponds to one routing splitting module, and there are m routing splitting modules for m input channels. The splitting cache module adopts a ping-pong caching method.

[0019] The combiner module is used to combine all IP packets that have been split into different channels into this channel before outputting them.

[0020] Furthermore, the routing cache module adopts a ping-pong architecture with a cache size of 1280 bytes, which is used to store IP packets after successful routing. Each input channel corresponds to n routing caches, where n is the number of output channels, and there are a total of (m×n) routing caches for m input channels.

[0021] Furthermore, the IP / AOS conversion module includes: an IP packet sending buffer module, an IP packet framing module, and a frame sending buffer module;

[0022] The IP packet sending buffer module is used to buffer the combined IP packets. The number of buffers for each output channel depends on the priority of the channel data.

[0023] The IP packet framing module is used to transform IP packets into AOS data frames and send them out.

[0024] The frame transmission buffer module is used to ping-pong buffer the converted AOS data frames to enable continuous data stream output to the transponder.

[0025] Furthermore, the priority number of the telemetry output channel is 3. If priority is not distinguished, the number of combiner buffers is 1.

[0026] The beneficial effects of this invention compared to the prior art are:

[0027] The satellite telemetry processing device based on the IPv6 protocol proposed in this invention converts AOS frames of telemetry data input from each channel into IP packets through an AOS / IP conversion module, routes these IP packets through an IP routing and forwarding module, and finally converts the IP packets routed to the corresponding transponder channels back into AOS telemetry data frames for output through an IP / AOS conversion module. This telemetry data scheduling mechanism significantly reduces software processing time. The onboard routing processing unit handles the telemetry data scheduling, and the IP packets in the downlink telemetry data AOS frames have a standard structure, facilitating interconnection with the terrestrial IP Internet and simplifying the distribution and parsing of terrestrial telemetry data. Attached Figure Description

[0028] Figure 1 This is a system block diagram of the satellite telemetry data processing device based on the IPv6 protocol of the present invention;

[0029] Figure 2 This is a schematic diagram of the satellite telemetry data processing device based on the IPv6 protocol of the present invention.

[0030] Figure 3 This is a schematic diagram of the data structure of the satellite telemetry data processing device based on the IPv6 protocol of the present invention;

[0031] Figure 4This is a schematic diagram of the IP routing and forwarding module of the satellite telemetry data processing device based on the IPv6 protocol of the present invention. Detailed Implementation

[0032] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0033] Figure 1 This is a system block diagram of the satellite telemetry data processing device based on the IPv6 protocol of this invention. The invention relates to a telemetry data processing device (i.e., an IPv6 router). The sources of telemetry data mainly include two aspects: First, telemetry data from the local satellite is collected by the data management computer. Each lower-level data management computer on the satellite collects various telemetry information and transmits it to the data management computer via the 1553B bus or CAN bus. The data management computer collects and schedules the data before outputting it to the telemetry data processing device. Second, telemetry data from other satellites is received through the inter-satellite links. The telemetry data processing device is essentially an IPv6 router. Both local and other satellite telemetry data are routed and forwarded in the form of IP packets within this device. After forwarding to the transponder interface, the telemetry data is organized, scheduled, and transmitted out.

[0034] Figure 2 This is a block diagram of the satellite telemetry data processing device based on the IPv6 protocol of the present invention, mainly including an AOS / IP conversion module, an IP routing and forwarding module, and an IP / AOS conversion module. The IP routing and forwarding module has m input ports and n output ports, so the satellite telemetry data processing device has m AOS / IP conversion modules and n IP / AOS conversion modules. If each port is a bidirectional input / output port, then n = m. The function of the AOS / IP conversion module is to convert AOS frames into IP packets for routing and forwarding. The function of the IP routing and forwarding module is to realize the addressing and forwarding of IP packets from the source to the destination. The function of the IP / AOS conversion module is to convert IP packets routed to the output end into AOS frames for output to the corresponding channel.

[0035] Specifically, the AOS / IP conversion module receives telemetry data AOS frames from each channel, buffers the AOS frames, extracts IP packets, and outputs them to the IP routing and forwarding module. Each channel is configured with one AOS / IP conversion module, and the frame length of the input AOS frames may vary. The IP routing and forwarding module receives IP packets from each channel, queries the routing table based on the destination IP address in the IP packet, and routes each IP packet to the corresponding output channel. Each output channel is configured with one IP / AOS conversion module. The IP / AOS conversion module converts the IP packets routed to it by the IP routing and forwarding module into AOS frames for the corresponding transponder channel and then outputs them to the corresponding transponder.

[0036] like Figure 2As shown, the AOS / IP conversion module includes: a frame receive buffer module, an IP packet extraction module, and an IP packet receive buffer module. The frame receive buffer module receives AOS frames of telemetry data for the corresponding channel and buffers them in a ping-pong manner. The IP packet extraction module extracts the corresponding encapsulated packets according to the M_PDU data unit format in the telemetry data AOS frame, and further removes the encapsulated packet header and IPE header to obtain IP packets. The IP packet receive buffer module buffers the IP packets obtained by the IP extraction module in a ping-pong manner for the routing and forwarding module to read. The M_PDU data unit is a standard CCSDS data unit. An AOS frame contains only one M_PDU data unit, and the data in the M_PDU data unit exists in the form of encapsulated packets. A complete encapsulated packet may be located in only one M_PDU data unit or multiple M_PDU data units. The starting position of a spatial packet is obtained according to the first header pointer in the M_PDU header, and the complete encapsulated packet is obtained from this frame or subsequent frames according to the packet length in the encapsulated packet header. The IP packet is obtained by removing the header bytes from the encapsulated packet.

[0037] like Figure 3 This is a schematic diagram of the data structure of the satellite telemetry data processing device based on the IPv6 protocol of the present invention, which is helpful to explain the mutual conversion process between AOS frames and IP packets.

[0038] Each channel receives telemetry data AOS frames. The length of AOS frames varies from channel to channel, but the frame length for a specific channel is fixed, typically 512 bytes, 896 bytes, or 1024 bytes. Upon receiving an AOS frame, it is first buffered in a ping-pong manner, with each buffer's size matching the frame length. Each AOS frame contains an M_PDU unit. Based on the header pointer of the M_PDU unit and the size of the encapsulated packet in the packet header, each encapsulated packet is extracted sequentially. The size of the encapsulated packet is not fixed, with a maximum length of 1288 bytes. An M_PDU unit may contain multiple encapsulated packets, and an encapsulated packet may also be divided into multiple parts placed in multiple consecutive M_PDU units. After removing the first 8 bytes of the encapsulated packet, the IP packet is obtained. The maximum length of the IP packet is 1280 bytes. The extracted IP packet is sent to the IP packet receive buffer, which uses a ping-pong structure, with each buffer being 1280 bytes in size.

[0039] Conversely, IP packets output by the IP packet routing and forwarding module are combined and buffered. To ensure routing and forwarding speed and prevent frame loss, the combining buffer should be large enough. The specific size is determined based on the instantaneous routing rate from each port to that port and the instantaneous outgoing rate. In this implementation, the buffer size is 8192 * 1280 bytes, or a total of 10 MB, implemented using external SDRAM memory. Each transponder has three combining buffers to store IP packets of different priorities. The priority of each IP packet is distinguished by the communication type field in the packet header. By differentiating the priorities of different telemetry signals on the satellite, priority scheduling of telemetry signals can be achieved, ensuring that higher-priority telemetry signals are prioritized for transmission. During each frame assembly, the IP packet combining buffer is polled sequentially according to high and low priority. When an IP packet is ready for output, an 8-byte IPE header and an encapsulation header are added to the IP packet to form an encapsulation packet. Then, based on the size of the encapsulation packet and the remaining space in the current M_PDU unit, it is decided whether to split the encapsulation packet. If the encapsulation packet is less than or equal to the remaining space in the current M_PDU unit, it is placed directly into the current M_PDU unit without splitting. If it is greater than the remaining space in the current M_PDU unit, it needs to be split into multiple parts and placed in the current M_PDU unit and subsequent M_PDU units. After assembly, the M_PDU unit is augmented with an AOS frame header, synchronization header, and error control field to form an AOS frame, which is then sent to the corresponding frame transmission buffer. The frame transmission buffer structure is a ping-pong architecture, with each buffer's size equal to the length of the corresponding channel's AOS frame.

[0040] Figure 4 This is a schematic diagram of the IP packet routing and forwarding module of the satellite telemetry data processing device based on the IPv6 protocol of the present invention. The function of the IP packet routing and forwarding module is to look up the routing table based on the destination IP address in the IP packets received in each channel, and route each IP packet to the corresponding output channel. This module includes a routing table lookup module, a route splitting module, a splitting buffer module, and a recombining module.

[0041] The routing table lookup module reads IP packets from the IP packet receive buffer and determines the destination of the IP packet based on the destination address and the routing table. For a router with m receive channels, there are m routing table lookup modules. Each module copies the latest routing table from the router's main routing table and stores it internally. This allows the m routing table lookup modules to work independently and in parallel, improving the speed of route lookup. The route lookup process involves comparing the destination IP address of the IP packet with each IP address in the routing table until a match is found. After obtaining the output channel identifier, the packet is then passed to the routing module for further processing.

[0042] Based on the routing lookup results, the routing module routes the IP packet to the corresponding routing cache.

[0043] The routing cache module stores IP packets routed from each channel. There are (m×n) routing caches. The routing cache from the i-th input (1≤i≤m) to the j-th output (1≤j≤n) is denoted as "routing cache ij". The routing caches that can be distributed from the i-th input are "routing cache i1", "routing cache i2", and so on up to "routing cache in", for a total of n caches. The routing caches that need to be merged from the j-th output are "routing cache 1j", "routing cache 2j", and so on up to "routing cache mj", for a total of m caches. Each routing cache uses a ping-pong architecture and has a size of 1280 bytes.

[0044] The combining module reads and combines IP packets from all the split buffers output from a single channel. The speed at which the split buffers are read must be greater than the speed at which IP packets are read from all input channels to prevent IP packets from being lost due to congestion in the split buffers. The quickly read IP packets are buffered in the large output buffers of each channel and are scheduled for output by the IP / AOS conversion module.

[0045] The IP / AOS conversion module includes an IP packet transmission buffer module, an IP packet framing module, and a frame transmission buffer module. The IP packet transmission buffer module buffers the combined IP packets; the number of buffers for each output channel depends on the channel's data priority. The IP packet framing module converts IP packets into AOS data frames and transmits them. The frame transmission buffer module performs ping-pong buffering on the converted AOS data frames to achieve continuous data stream output to the transponder. For example, if the telemetry output channel has a priority of 3, and priority is not differentiated, the number of combiner buffers is 1.

[0046] The parts of this invention not described in detail are common knowledge to those skilled in the art.

Claims

1. A telemetry data processing device based on IPv6 protocol routing, characterized in that, include: AOS / IP conversion module, IP routing forwarding module, and IP / AOS conversion module; The AOS / IP conversion module is used to receive telemetry data AOS frames from each channel, cache the AOS frames, extract the IP packets, and output them to the IP routing and forwarding module. The IP routing and forwarding module is used to receive IP packets from each channel, query the routing table according to the destination IP address in the IP packet, and route each IP packet to the corresponding output channel. Each output channel is configured with an IP / AOS conversion module. The IP / AOS conversion module converts IP packets routed to it by the IP routing and forwarding module into corresponding AOS frames for the responder channel and then outputs them to the corresponding responder.

2. The telemetry data processing device based on IPv6 protocol routing according to claim 1, characterized in that: Each channel is configured with an AOS / IP conversion module, and the frame length of the input AOS frames may not be the same.

3. The telemetry data processing device based on IPv6 protocol routing according to claim 1, characterized in that: The AOS / IP conversion module includes: a frame receive buffer module, an IP packet extraction module, and an IP packet receive buffer module; The frame receiving buffer module is used to receive the corresponding channel telemetry data AOS frames and buffer them in a ping-pong manner. The IP packet extraction module extracts the corresponding encapsulated packets based on the M_PDU data unit format in the telemetry data AOS frame, and further strips the encapsulated packet header and IPE header to obtain the IP packets; The IP packet receiving and caching module performs ping-pong caching on the IP packets obtained by the IP extraction module for the routing and forwarding module to read.

4. The telemetry data processing device based on IPv6 protocol routing according to claim 3, characterized in that: The M_PDU data unit is a standard CCSDS data unit. Only one M_PDU data unit is contained in an AOS frame, and the data in the M_PDU data unit exists in the form of an encapsulated packet.

5. The telemetry data processing device based on IPv6 protocol routing according to claim 4, characterized in that: A complete encapsulation packet may be located in only one M_PDU data unit or multiple M_PDU data units. The starting position of a spatial packet is obtained based on the first header pointer in the M_PDU header, and the complete encapsulation packet is obtained from this frame or subsequent frames based on the packet length in the encapsulation packet header. The IP packet is obtained by removing the header bytes from the encapsulated packet.

6. The telemetry data processing device based on IPv6 protocol routing according to claim 1, characterized in that: The IP routing and forwarding module includes: a routing table lookup module, a routing splitting module, a splitting cache module, and a merging module; The routing table lookup module is used to compare the destination IP address of the IP packet in the receiving cache module with the entries in the routing table one by one. If the comparison is successful, the routing is successful; if the comparison fails, the packet is discarded. Each input channel corresponds to one routing table lookup module, and there are m routing table lookup modules for m input channels. The routing splitting module stores successfully routed IP packets in the corresponding splitting cache module. Each input channel corresponds to one routing splitting module, and there are m routing splitting modules for m input channels. The splitting cache module adopts a ping-pong caching method. The combiner module is used to combine all IP packets that have been split into different channels into this channel before outputting them.

7. The telemetry data processing device based on IPv6 protocol routing according to claim 6, characterized in that: The routing buffer module adopts a ping-pong architecture with a buffer size of 1280 bytes. It is used to store IP packets after successful routing. Each input channel corresponds to n routing buffers, where n is the number of output channels. There are a total of (m×n) routing buffers for m input channels.

8. The telemetry data processing device based on IPv6 protocol routing according to claim 1, characterized in that: The IP / AOS conversion module includes: an IP packet sending buffer module, an IP packet framing module, and a frame sending buffer module; The IP packet sending buffer module is used to buffer the combined IP packets. The number of buffers for each output channel depends on the priority of the channel data. The IP packet framing module is used to transform IP packets into AOS data frames and send them out. The frame transmission buffer module is used to ping-pong buffer the converted AOS data frames to enable continuous data stream output to the transponder.

9. A telemetry data processing device based on IPv6 protocol routing according to claim 8, characterized in that: The priority number of the telemetry output channel is 3. If priority is not distinguished, the number of combiner buffers is 1.

10. A telemetry data processing device based on IPv6 protocol routing according to any one of claims 1-9, characterized in that: The telemetry data processed by the telemetry data processing device comes from two sources: first, the telemetry data of the satellite itself collected by the data management computer. Each data management lower-level computer on the satellite collects various telemetry information on the satellite and transmits it to the data management computer via the 1553B bus or CAN bus. The data management computer collects and schedules the data before outputting it to the telemetry data processing device; second, the telemetry data of other satellites received through the inter-satellite link of the satellite itself.

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