Transmission frame structure for IOverCCSDS fast routing forwarding

Abstract

The embodiment of the invention provides a transmission frame structure for IOverCCSDS fast routing forwarding, and relates to the technical field of transmission frame structure design, and the transmission frame structure comprises a physical layer, a data link layer and a network layer which are sequentially superposed from bottom to top; wherein an EPP head and an IPE head which are used for bearing CCSDS data are sequentially arranged between the data link layer and the network layer. According to the technical scheme provided by the invention, the technical problems of limited routing query capability, insufficient routing forwarding performance and the like of the existing air-space network are solved, the routing forwarding performance is improved, the network performance of air-based and space-based IP networks is improved, and a technical framework of the air-space-ground integrated high-performance IP network is powerfully constructed.

Description

Technical Field

[0001] This application relates to the technical field of transmission frame structure design. Specifically, it relates to a transmission frame structure for fast routing and forwarding of IP over CCSDS. Background Art

[0002] The integrated space-air-ground network aims to achieve seamless coverage and efficient communication globally by integrating space-based networks (such as high, medium, and low Earth orbit satellite networks), air-based networks (such as unmanned aerial vehicle networks, high-altitude aircraft networks, and aviation Internet), and ground-based networks (such as fiber optic networks and terrestrial mobile communication networks).

[0003] The IP over CCSDS protocol in the space communication network protocol family of the Consultative Committee for Space Data Systems (CCSDS) standardizes the transmission of IP (Internet Protocol) packets (including IPv4 and IPv6) in the data link layer of air-based and space-based networks, realizing seamless connection with ground-based IP networks and providing an infrastructure for building an integrated space-air-ground all-IP network.

[0004] Since air-based and space-based networks have characteristics such as high dynamic changes, high latency, and high latency jitter compared with ground-based networks, the design of IP routing and switching in space-air networks faces greater challenges. At the same time, due to factors such as power consumption, heat dissipation, and structural size of space-air platforms, the performance of chips such as processors selected is not high, resulting in low routing lookup and switching forwarding rates in space-air networks, insufficient network performance, and the inability to build a unified and coordinated integrated space-air-ground network.

[0005] Therefore, there is an urgent need for a transmission frame structure that can improve the routing and forwarding performance of air-based and space-based IP over CCSDS networks. Summary of the Invention

[0006] Embodiments of this application provide a transmission frame structure for fast routing and forwarding of IP over CCSDS to improve routing and forwarding performance and further enhance the network performance of air-based and space-based IP networks.

[0007] Other features and advantages of this application will become apparent through the following detailed description, or be learned in part through the practice of this application.

[0008] According to the first aspect of the embodiments of this application, a transmission frame structure for fast routing and forwarding of IP over CCSDS is provided, including: a physical layer, a data link layer, and a network layer stacked in sequence from bottom to top;

[0009] Among them, an EPP header and an IPE header for carrying CCSDS data are sequentially arranged between the data link layer and the network layer.

[0010] In some embodiments of the present application, based on the foregoing solution, the data link layer is composed of the header and tail of USLP, the header and tail of AOS, the header and tail of TC, the header and tail of TM, or the header and tail of Prox-1.

[0011] In some embodiments of the present application, based on the foregoing solution, the last bit of the last byte segment of the IPE header is "1", and the last bits of the remaining byte segments are "0", and each byte segment is provided with 7-bit valid bits.

[0012] In some embodiments of the present application, based on the foregoing solution, the IPE header includes: an IPE header length byte segment, a frame type byte segment, a frame priority byte segment, a maximum hop number byte segment, a label nesting number byte segment, a label value byte segment, a source satellite label value byte segment, a destination satellite label value byte segment, a source satellite input interface number byte segment, a destination satellite output interface number byte segment, and a message type byte segment;

[0013] Among them, the IPE header length byte segment is used to represent the length value calculated by bytes from the frame type to the end of the IPE header;

[0014] The frame type byte segment is used to represent the type of the data link layer transmission frame;

[0015] The frame priority byte segment is used to represent the priority of the transmission frame;

[0016] The maximum hop number byte segment is used to represent the maximum hop number value allowed for the transmission frame forwarding;

[0017] The label nesting number byte segment is used to represent the number of label nestings;

[0018] The label value byte segment is used to represent the label value of the next-hop satellite;

[0019] The source satellite label value byte segment is used to represent the label value of the space-air network access satellite;

[0020] The destination satellite label value byte segment is used to represent the label value of the space-air network landing satellite;

[0021] The source satellite input interface number byte segment is used to represent the input interface number for the access satellite to connect to the ground station through the air interface link;

[0022] The destination satellite output interface number byte segment is used to represent the output interface number for the landing satellite to connect to the ground station through the air interface link;

[0023] The message type byte segment is used to represent the type of the network layer message carried.

[0024] In some embodiments of the present application, based on the foregoing solution, the EPP header includes: a protocol identifier byte segment, a high-level protocol identifier byte segment, a header length byte segment, a header checksum byte segment, and a frame length byte segment;

[0025] Among them, the protocol identifier byte segment is used to identify the protocol of this layer;

[0026] The high-level protocol identifier byte segment is used to identify the protocol of the upper layer;

[0027] The header length byte segment is used to represent the length value of the EPP header calculated in bytes;

[0028] The header checksum byte segment is used for CRC-8 / ITU check of the header ranges of both the EPP of this layer and the IPE of the upper layer;

[0029] The frame length byte segment is used to represent the length values of the EPP header, the IPE header, and the IP packet calculated in bytes.

[0030] In some embodiments of the present application, based on the foregoing solution, the effective bit of the protocol identifier byte segment is 3 bits.

[0031] In some embodiments of the present application, based on the foregoing solution, the effective bit of the high-level protocol identifier byte segment is 3 bits.

[0032] In some embodiments of the present application, based on the foregoing solution, the effective bit of the header length byte segment is 2 bits.

[0033] In some embodiments of the present application, based on the foregoing solution, the effective bit of the header checksum byte segment is 8 bits.

[0034] In some embodiments of the present application, based on the foregoing solution, the effective bit of the frame length byte segment is 16 bits.

[0035] The technical solution of the present application solves the technical problems such as limited routing query ability and insufficient routing forwarding performance in the current space-air network, improves the routing forwarding performance, enhances the network performance of space-based and space-based IP networks, and effectively constructs the technical framework of an integrated high-performance IP network for space-air-ground.

[0036] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. In the accompanying drawings:

[0038] Figure 1 It shows a schematic structural diagram of a transmission frame structure for IP over CCSDS fast routing and forwarding according to an embodiment of the present application;

[0039] Figure 2 It shows a schematic structural diagram of an IPE header according to an embodiment of the present application;

[0040] Figure 3 It shows a schematic structural diagram of an EPP header according to an embodiment of the present application. Detailed implementation manners

[0041] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art.

[0042] In addition, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of the present application. However, those skilled in the art will realize that the technical solutions of the present application can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, well-known methods, devices, implementations, or operations are not shown or described in detail to avoid obscuring aspects of the present application.

[0043] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0044] Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0045] To solve the technical problems existing in the prior art, the present application provides a transmission frame structure for IP over CCSDS fast routing and forwarding.

[0046] See Figure 1 , which shows a schematic structural diagram of a transmission frame structure for IP over CCSDS fast routing and forwarding according to an embodiment of the present application.

[0047] As Figure 1 shown, the transmission frame structure includes: a physical layer, a data link layer, and a network layer that are stacked in sequence from bottom to top;

[0048] Among them, an EPP header and an IPE header for carrying CCSDS data are sequentially arranged between the data link layer and the network layer.

[0049] It can be understood that by adding the EPP header and the IPE header, the transmission frame can carry CCSDS data, and thus the transmission frame can be applicable to the air-based and space-based data link layers.

[0050] It should be noted that EPP refers to Encapsulation Packet Protocol, the encapsulation data packet protocol.

[0051] IPE refers to Internet Protocol Extension, the Internet protocol extension.

[0052] In some feasible embodiments, based on the foregoing solution, the data link layer is composed of the header and tail of USLP, the header and tail of AOS, the header and tail of TC, the header and tail of TM, or the header and tail of Prox-1.

[0053] As Figure 1 shown, the data link layer can be composed of any one of the header and tail of USLP, the header and tail of AOS, the header and tail of TC, the header and tail of TM, and the header and tail of Prox-1.

[0054] It should be noted that USLP refers to Unified Space Data Link Protocol, the unified space data link protocol.

[0055] AOS refers to Advanced Orbiting Systems, the advanced orbital system.

[0056] TM refers to TeleCommand, the telemetry and telecontrol.

[0057] Prox-1 refers to Proximity-1, the proximity communication protocol.

[0058] In some feasible embodiments, based on the foregoing solution, the last bit of the last byte segment of the IPE header is "1", and the last bits of the remaining byte segments are "0", and each byte segment is provided with 7-bit valid bits.

[0059] In some feasible embodiments, based on the foregoing solution, the IPE header includes: an IPE header length byte segment, a frame type byte segment, a frame priority byte segment, a maximum hop number byte segment, a label nesting number byte segment, a label value byte segment, a source satellite label value byte segment, a destination satellite label value byte segment, a source satellite incoming interface number byte segment, a destination satellite outgoing interface number byte segment, and a message type byte segment;

[0060] Among them, the IPE header length byte segment is used to represent the length value calculated by bytes from the frame type to the end of the IPE header;

[0061] The frame type byte segment is used to represent the type of the data link layer transmission frame;

[0062] The frame priority byte segment is used to represent the priority of the transmission frame;

[0063] The maximum hop number byte segment is used to represent the maximum hop number value allowed for the transmission frame forwarding;

[0064] The label nesting number byte segment is used to represent the number of label nestings;

[0065] The label value byte segment is used to represent the label value of the next-hop satellite;

[0066] The source satellite label value byte segment is used to represent the label value of the space-air network access satellite;

[0067] The destination satellite label value byte segment is used to represent the label value of the space-air network landing satellite;

[0068] The source satellite incoming interface number byte segment is used to represent the input interface number by which the access satellite is connected to the ground station through the air interface link;

[0069] The destination satellite outgoing interface number byte segment is used to represent the output interface number by which the landing satellite is connected to the ground station through the air interface link;

[0070] The message type byte segment is used to represent the type of the network layer message carried.

[0071] It should be noted that in this embodiment, the label nesting number byte segment, the label value byte segment, the source satellite label value byte segment, and the destination satellite label value byte segment designed in the IPE header can enable the routing and forwarding of the transmission frame to no longer need to query the routing forwarding table, and only need to quickly forward the frame to the outgoing interface according to the label in the frame.

[0072] Exemplarily, refer to Figure 2, showing an IPE header.

[0073] As Figure 2 shown, the last bit of the last byte segment of the IPE header is "1", and the last bits of the other byte segments are "0". Therefore, only 7 bits of each byte segment are valid bits to carry information. The design of each information field is as follows:

[0074] 1) IPE header length, 7 bits, representing the length value in bytes from the frame type to the end of the IPE header, supporting an IPE header with a maximum length of 128 bytes.

[0075] 2) Frame type, 3 bits, representing the type of the data link layer transmission frame. Among them, 0b001 represents USLP; 0b010 represents AOS; 0b011 represents TM; 0b100 represents TC; 0b101 represents Prox-1; other values are reserved for future use.

[0076] 3) Frame priority, 4 bits, representing the priority of the transmission frame. The maximum support is 16 priorities, 0b0000 represents the highest priority; 0b1111 represents the lowest priority.

[0077] 4) Maximum hop count, 7 bits, representing the maximum hop value allowed for the transmission frame forwarding. The broadcast frame is set to 0b1111111; the unicast frame is set to the maximum hop value allowed by the routing.

[0078] 5) Label nesting count, 7 bits, representing the number of label nestings, with a maximum support of 120 label nesting stacks, and this value does not exceed the maximum hop count at most. When this value is 0, it means there is no label nesting; when this value is 120, it means there are 120 label nestings. Each time the frame is forwarded in the network (i.e., each time it passes through a hop), this value is decremented by one.

[0079] 6) Label value, 7 bits, representing the label value of the next-hop satellite. When the transmission frame is forwarded, there is no need to look up the routing forwarding table, and only the label value of the outermost layer (the top of the stack) (i.e., the label value of the next-hop satellite) is read. Each time it passes through a hop, the label value of the outermost layer (the top of the stack) is stripped off. The label value can be nested, representing the adjacent next-hop to the last-hop successively from the top of the stack to the bottom of the stack.

[0080] 7) Source satellite label value, 7 bits, representing the label value of the space-air network access satellite.

[0081] 8) Destination satellite label value, 7 bits, representing the label value of the space-air network landing satellite.

[0082] 9) Input interface number of the source satellite, 7 bits, representing the input interface number by which the access satellite is connected to the ground station through the air interface link.

[0083] 10) Outlet interface number of the host satellite, 7 bits, indicating the output interface number through which the landing satellite is connected to the ground station via the air interface link.

[0084] 11) Message type, 7 bits, indicating the type of the network layer message carried. Among them, 0x20 indicates IPv4; 0x56 indicates IPv6; other values are reserved for future use.

[0085] In some feasible embodiments, based on the foregoing solution, the EPP header includes: a protocol identifier byte segment, a high-level protocol identifier byte segment, a header length byte segment, a header checksum byte segment, and a frame length byte segment;

[0086] Among them, the protocol identifier byte segment is used to identify the protocol of this layer;

[0087] The high-level protocol identifier byte segment is used to identify the protocol of the upper layer;

[0088] The header length byte segment is used to represent the length value of the EPP header calculated in bytes;

[0089] The header checksum byte segment is used for CRC-8 / ITU check of the header ranges of both the EPP of this layer and the high-level IPE;

[0090] The frame length byte segment is used to represent the length value of the EPP header, the IPE header, and the IP message calculated in bytes.

[0091] In some feasible embodiments, based on the foregoing solution, the valid bits of the protocol identifier byte segment are 3 bits.

[0092] In some feasible embodiments, based on the foregoing solution, the valid bits of the high-level protocol identifier byte segment are 3 bits.

[0093] In some feasible embodiments, based on the foregoing solution, the valid bits of the header length byte segment are 2 bits.

[0094] In some feasible embodiments, based on the foregoing solution, the valid bits of the header checksum byte segment are 8 bits.

[0095] In some feasible embodiments, based on the foregoing solution, the valid bits of the frame length byte segment are 16 bits.

[0096] Exemplarily, referring to Figure 3 , a kind of EPP header is shown.

[0097] As Figure 3 shown, the design of each information field of the EPP header is as follows:

[0098] 1) Protocol identifier, 3 bits, identifying the protocol at this layer. 0b001 represents EPP, and other values are reserved for future use.

[0099] 2) Upper-layer protocol identifier, 3 bits, identifying the protocol of the upper layer. 0b101 represents IPE, and other values are reserved for future use.

[0100] 3) Header length, 2 bits, representing the length value of the EPP header in bytes; set to 0b10, indicating that the EPP header length is 4 bytes.

[0101] 4) Header checksum, 8 bits, used for CRC-8 / ITU checksum of the header ranges of both the EPP and upper-layer IPE at this layer, with the generating polynomial X^8+X^2+X^1+1.

[0102] 5) Frame length, 16 bits, representing the length value of the EPP header, IPE header, and IP packet in bytes, and can carry an IP packet with a maximum length of 65403 bytes.

[0103] Those skilled in the art will readily conceive of other embodiments of the present application after considering the specification and practicing the disclosed embodiments herein. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include common general knowledge or conventional technical means in the technical field not disclosed in the present application. It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. A transmission frame structure for IP over CCSDS fast routing and forwarding, characterized in that Including: A physical layer, a data link layer, and a network layer sequentially stacked from bottom to top; Wherein, an EPP header and an IPE header for carrying CCSDS data are sequentially arranged between the data link layer and the network layer.

2. The method according to claim 1, wherein The data link layer is composed of the header and tail of USLP, the header and tail of AOS, the header and tail of TC, the header and tail of TM, or the header and tail of Prox-1.

3. The method according to claim 1, characterized in that The last bit of the last byte segment of the IPE header is "1", and the last bits of the remaining byte segments are "0", and each byte segment is provided with 7-bit valid bits.

4. The method according to any one of claims 1 to 3, characterized in that The IPE header includes: an IPE header length byte segment, a frame type byte segment, a frame priority byte segment, a maximum hop number byte segment, a label nesting number byte segment, a label value byte segment, a source satellite label value byte segment, a destination satellite label value byte segment, a source satellite input interface number byte segment, a destination satellite output interface number byte segment, and a message type byte segment; Among them, the IPE header length byte segment is used to represent the length value calculated by bytes from the frame type to the end of the IPE header; The frame type byte segment is used to represent the type of the data link layer transmission frame; The frame priority byte segment is used to represent the priority of the transmission frame; The maximum hop number byte segment is used to represent the maximum hop number value allowed for the transmission frame forwarding; The label nesting number byte segment is used to represent the number of label nestings; The label value byte segment is used to represent the label value of the next-hop satellite; The source satellite label value byte segment is used to represent the label value of the space-air network access satellite; The destination satellite label value byte segment is used to represent the label value of the space-air network landing satellite; The source satellite input interface number byte segment is used to represent the input interface number of the access satellite connected to the ground station through the air interface link; The destination satellite output interface number byte segment is used to represent the output interface number of the landing satellite connected to the ground station through the air interface link; The message type byte segment is used to represent the type of the network layer message carried.

5. The method according to claim 1, wherein The EPP header includes: a protocol identifier byte segment, a high-level protocol identifier byte segment, a header length byte segment, a header check byte segment, and a frame length byte segment; Among them, the protocol identifier byte segment is used to identify the protocol of this layer; The high-level protocol identifier byte segment is used to identify the protocol of the upper layer; The header length byte segment is used to represent the length value of the EPP header calculated by bytes; The header check byte segment is used for CRC-8 / ITU check of the header ranges of both the EPP of this layer and the high-level IPE; The frame length byte segment is used to represent the length value of the EPP header, the IPE header, and the IP message calculated by bytes.

6. The method according to claim 5, characterized in that, The valid bits of the protocol identifier byte segment are 3 bits.

7. The method according to claim 5, characterized in that The valid bits of the high-level protocol identifier byte segment are 3 bits.

8. The method according to claim 5, characterized in that, The valid bits of the header length byte segment are 2 bits.

9. The method according to claim 5, wherein The valid bits of the header check byte segment are 8 bits.

10. The method according to claim 5, characterized in that The valid bits of the frame length byte segment are 16 bits.

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