Method for defining low-orbit communication constellation network functions and interfaces based on SysML

Abstract

The present invention provides a method for defining low-orbit communication constellation network functions and interfaces based on SysML, which belongs to the field of satellite communication MBSE modeling. The method first analyzes the stakeholders' needs for the low-orbit communication constellation network based on the SysML use case diagram, sorts out the specific communication indicators and indicator performance, and presents them with a SysML requirement diagram; then analyzes the interface relationship of the constellation network service target and the communication network system used, and presents them with a SysML internal structure diagram; finally, the behavior of each network system during operation is explained, taking the backbone network and the spacecraft network as examples, and using a SysML activity diagram to describe it. The present invention realizes the standardization of the functional interface definition of the low-orbit communication constellation network, and realizes standardized definition based on the model, which is easy to expand; starting from the constellation network requirements, the source and rationality of the functions and interfaces are clarified; and support is provided for executable model construction, demand demonstration, and incremental development.

Description

Technical Field

[0001] The present invention belongs to the field of satellite communication modeling, and specifically relates to a method for defining low-orbit communication constellation network functions and interfaces based on Systems Modeling Language (SysML). Background Art

[0002] The low-orbit communication constellation is a set of communication network systems in China's integrated space-earth information network project, with the space-based network as the core, serving global broadband communications and strategic support. The low-orbit communication constellation includes the inter-satellite network built by space-based satellites, ground stations and mobile terminals, and is currently in the planning stage. To build a low-orbit communication constellation, theoretical proof and experimental verification are required in the planning stage. Generally, a simulation system is used to simulate the constellation system to verify the feasibility of the system.

[0003] At present, the modeling work carried out in the field of low-orbit constellation communications includes the research on the methodology and modeling language of Model-Based Systems Engineering (MBSE), and the research on the meta-model design of equipment systems. Among them, the research on the application of MBSE methodology includes: the application of MBSE, the support of demand analysis and structural design of complex product systems based on SysML, and the research and platform development of unified simulation modeling in multiple fields of complex product systems based on Modelica. However, in the current practice of MBSE in low-orbit constellations, SysML modeling is mainly used for single-machine or system key technologies, and there is a lack of top-level modeling methods at the system level. Summary of the invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, the present invention aims to provide a method for defining low-orbit communication constellation network functions and interfaces based on SysML, which can realize the standardized processing of defining functional interfaces at the top-level functional level of the network, realize standardized definition based on the model, and facilitate expansion; starting from the stakeholders' needs for the constellation network, clarify the source and rationality of the functional interface; and provide support for executable model construction, demand demonstration, and incremental development.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A method for defining low-orbit communication constellation network functions and interfaces based on SysML, characterized by comprising the following steps:

[0007] Step S1, starting from stakeholders’ needs for constellation networks, analyzing participants’ concerns and the functions of each network system;

[0008] Step S2, describing the usage relationship of the constellation network by stakeholders based on the SysML use case diagram;

[0009] Step S3, describing the overall communication indicator requirements for the network based on the SysML requirement diagram;

[0010] Step S4, defining the interface relationship of the constellation network service target and the communication network used based on the SysML internal structure diagram;

[0011] Step S5, describing the backbone network communication process based on the SysML activity diagram;

[0012] Step S6, describing the network communication process between spacecraft based on SysML activity diagram.

[0013] As a preferred embodiment of the present invention, in step S1, the sensors and the task-performing users are not limited to mobile terminals such as remote sensing satellites, reconnaissance satellites, airplanes, and ships.

[0014] As a preferred embodiment of the present invention, according to the different concerns of stakeholders on the low-orbit constellation communication network, the entire network is divided into four network communication behaviors, namely backbone network communication, access control network communication, inter-spacecraft network communication and adjacent network communication.

[0015] As a preferred embodiment of the present invention, the participants include military users, ordinary users, sensors and communication network maintainers.

[0016] As a preferred embodiment of the present invention, stakeholder task requirements are divided into functional requirements and performance requirements; wherein the functional requirements include:

[0017] (1) Multiple data type transmission functions: data, images, commands, voice, and video;

[0018] (2) Random access function: supports random access to network edge nodes;

[0019] (3) Network interconnection function: space-based ring network, space-ground star network and ground-based mesh network are interconnected;

[0020] (4) Fault handling function: capable of fault diagnosis and reconstruction.

[0021] Performance requirements include:

[0022] (5) Access response time: the time from receiving the access request at the network edge to the start of service processing (<1 min);

[0023] (6) Request processing time: the time it takes a node to process a request (in minutes);

[0024] (7) Data processing rate: single node data processing rate (>100 Gbit / s);

[0025] (8) Data transmission rate: Single-channel user transmission rate: 1 Gbps–10 Gbps;

[0026] (9) Number of users: ≥300;

[0027] (10) Resource allocation time: <5min.

[0028] As a preferred embodiment of the present invention, the communication relationship between various network systems is as follows: the sensor equipment / spacecraft formation communicates with the spacecraft responsible for the communication function through the proximity communication network interface; the spacecraft responsible for communication processes the received raw data and communicates with the aerial node or ground node of the backbone network through the sending / receiving modem to form an access network communication interface; the backbone network processes the spacecraft feedback information through the ground station and pushes it to the network maintainer and the user; at the same time, the instructions and data of the user and the network maintainer are sent to the access network interface through the aerial node or the ground node.

[0029] As a preferred embodiment of the present invention, the backbone network communication process described in step S5 based on the SysML activity diagram is as follows:

[0030] By analyzing the backbone network's mission and performance requirements, the backbone network design should include space network interfaces, ground network interfaces, ground station internal networks, virtual private networks, and the Internet; the information provided by the backbone network includes data and mission instructions from other spacecraft, vehicles, sensor networks, operation centers, archive databases, and users. The backbone network enables users to use the Internet or proprietary networks to obtain data information and battlefield situation information for scientific exploration missions, and to command aircraft and executive agencies to perform scientific missions or combat instructions through the backbone network.

[0031] As a preferred embodiment of the present invention, the data path through the backbone network is used to process the data protocol level passing through the network at a 5-layer standard protocol; users connected to the Internet are connected to the space agency's intranet through a secure route, and the space agency's intranet is then connected to the ground station through a VPN. The VPN protocol includes ATM and SONET protocols to adapt to the ground station network protocol type. When the backbone network is connected to the spacecraft and the user is online, the data will be transmitted to the user in real time. If the spacecraft establishes a connection with the backbone network but the user is not connected to the backbone network, the data is temporarily stored in the disk array in the gateway service area. When the user is connected to the backbone network, the data will be obtained from the disk array. The backbone network data acquisition end can be obtained through two methods: ground nodes or air nodes.

[0032] As a preferred embodiment of the present invention, step S6 describes the inter-spacecraft network communication process based on the SysML activity diagram as follows: by analyzing the tasks and performance requirements of the inter-spacecraft communication network, the spacecraft communication network includes a set of radio / optical communication interfaces between spacecraft in a constellation or formation, and the inter-spacecraft network solves the resource coordination problem caused by the need for each spacecraft to connect to the access control network.

[0033] As a preferred embodiment of the present invention, in addition to basic communication between spacecraft, relative position measurement is also included. If the formation or cluster is arranged in a star shape, the central spacecraft is used as the communication medium to connect to the access control network. If the spacecraft are arranged in a mesh shape, any spacecraft can be used as the communication medium for accessing the control network. If the spacecraft are arranged irregularly, one or several spacecraft with the most communication paths are selected as the communication medium for data transmission.

[0034] The present invention has the following beneficial effects:

[0035] 1. The method realizes the standardized processing of defining the functions and interfaces of the communication constellation network, realizes the standardized definition based on the model, and is easy to expand;

[0036] 2. The method starts from the needs of stakeholders of the constellation network and implements forward design from needs to structure (and interface) to function to clarify the source and rationality of the interface;

[0037] 3. The method provides constellation network functions and interfaces based on model definition, which can support the rapid iteration of constellation network models. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 is a use case diagram of the network function layer by stakeholders in the network function layer in an embodiment of the present invention;

[0040] Figure 2 is a diagram of the network function layer task requirements of stakeholders in the network function layer in an embodiment of the present invention;

[0041] Figure 3 It is an internal interface diagram of the network function layer in an embodiment of the present invention;

[0042] Figure 4 is a backbone network data flow diagram in an embodiment of the present invention;

[0043] Figure 5 This is a backbone network function analysis diagram in an embodiment of the present invention;

[0044] Figure 6 is a data flow diagram of the spacecraft communication network in an embodiment of the present invention;

[0045] Figure 7 is a functional analysis diagram of the spacecraft communication network in an embodiment of the present invention;

[0046] Figure 8 It is a flow chart of a method for defining low-orbit communication constellation network functions and interfaces based on SysML according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0048] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] The embodiment of the present invention provides a method for defining the network functions and interfaces of a low-orbit communication constellation based on SysML. First, the constellation model is layered, and then the network layer model functions are top-level modeled based on SysML. The modeling types include model flow, behavior, demand analysis, use cases, etc., to build a system meta-model library. Figure 1 and Figure 8 As shown, the method for defining the network functions and interfaces of a low-orbit communication constellation based on SysML comprises the following steps:

[0050] Step S1, starting from stakeholders' demands for constellation networks, analyze participants' concerns and the functions of each network system.

[0051] In this step, the participants include military users, ordinary users, sensors and communication network maintainers.

[0052] Military users refer to the action planners and commanders of various types of troops. Military users need to obtain various types of sensor detection information in the area of ​​concern through the constellation equipment network, judge the detection information to plan combat operations, and distribute combat orders to various executive agencies through the constellation equipment network. The constellation equipment network is required to significantly shorten the response time of space-based information to minutes and provide full-link information guarantee from sensors to shooters; that is, military users are concerned about the real-time and security of data transmission of the constellation equipment network.

[0053] Sensor equipment refers to a collection of various detection equipment used to detect surface areas, such as strategic reconnaissance satellites, navigation satellites, military mapping satellites, military meteorological and oceanographic satellites, etc. Executors refer to various aircraft, ships and other equipment that execute combat orders. Since sensors and actuators are constantly moving relative to the ground, they may need to switch to different access nodes for communication, so the constellation network is required to be able to realize the random access function of various sensors and actuators; that is, sensors and actuators focus on the interactivity of the end devices of the constellation equipment network.

[0054] Ordinary users refer to surface information monitoring agencies such as meteorological stations and ocean bureaus, which require the constellation equipment network to distribute, process and deliver various types of raw data, such as meteorological environment tracking such as thunderstorms and storms, crop and ocean monitoring and pollution monitoring information; that is, ordinary users are concerned about the data processing and push capabilities of the constellation equipment network.

[0055] The communication network maintainer maintains the communication status of the network, including handling the failure of communication nodes, counting information such as network utilization and network load, and can manually intervene in its communication capabilities to ensure the health of the network status of the constellation equipment system.

[0056] According to the different concerns of stakeholders on the low-orbit constellation communication network, the entire network is divided into four types of network communication behaviors, namely backbone network communication, access control network communication, inter-spacecraft network communication and adjacent network communication.

[0057] (1) Backbone Network Communication (BNC): Provides medium-speed, high-speed, and ultra-high-speed broadband transmission to transmit data and mission instructions for spacecraft, vehicles, sensor networks, operation centers, archive databases, and users. It serves military users, ordinary users, and communication network maintainers.

[0058] (2) Access Network Communication (ANC): Provides multi-address random access (distribution) and single-address access (distribution) functions. It includes data transmission through the radio / optical communication interface between the backbone network and mission space devices / sensors / actuators, as well as the local area network communication function on the mission spacecraft. It serves the sensor / actuator equipment and communication network maintainers.

[0059] (3) Inter-spacecraft Communication (IC): Provides radio / optical communication between adjacent spacecraft in a constellation or formation, solving the network overhead problem that each communication node needs to communicate through the access control network and backbone network. It serves sensor / actuator equipment and communication network maintainers.

[0060] (4) Proximity Network Communication (PNC): Provides network communication between vehicles (ships, aircraft, spacecraft) and surface detection sensors. It has the characteristics of low power consumption, low rate, and strong flexibility. It serves sensor / actuator equipment and communication network maintainers.

[0061] Step S2, based on the SysML use case diagram, describes the usage relationship of stakeholders on the constellation network, such as Figure 1 shown.

[0062] Step S3, describing the overall communication indicator requirements for the network based on the SysML requirement diagram.

[0063] like Figure 2 As shown, stakeholder task requirements are divided into functional requirements and performance requirements. Functional requirements include:

[0064] (1) Multiple data type transmission functions: data, images, commands, voice, and video;

[0065] (2) Random access function: supports random access to network edge nodes;

[0066] (3) Network interconnection function: space-based ring network, space-ground star network and ground-based mesh network are interconnected;

[0067] (4) Fault handling function: capable of fault diagnosis and reconstruction.

[0068] Performance requirements include:

[0069] (5) Access response time: the time from receiving the access request at the network edge to the start of service processing (<1 min);

[0070] (6) Request processing time: the time it takes a node to process a request (in minutes);

[0071] (7) Data processing rate: single node data processing rate (>100 Gbit / s);

[0072] (8) Data transmission rate: Single-channel user transmission rate: 1 Gbps–10 Gbps;

[0073] (9) Number of users: ≥300;

[0074] (10) Resource allocation time: <5min.

[0075] Step S4, defining the interface relationship of the constellation network service target and the communication network used based on the SysML internal structure diagram.

[0076] The communication relationship between each network system is as follows Figure 3As shown, the sensor equipment / spacecraft formation communicates with the spacecraft responsible for the communication function through the proximity communication network interface. The spacecraft responsible for communication processes the received raw data and communicates with the aerial node or ground node of the backbone network through the send / receive modem to form an access network communication interface. The backbone network processes the spacecraft return information through the ground station and pushes it to the network maintainer and the user. At the same time, the instructions and data of the user and the network maintainer are sent to the access network interface through the aerial node or the ground node.

[0077] Step S5, describing the backbone network communication process based on the SysML activity diagram.

[0078] By analyzing the backbone network tasks and performance requirements, the backbone network design should include the space network interface (SNI), the ground network interface (GNI), the ground station internal network, the virtual private network (VPN), and the Internet. Its network hierarchy is as follows: Figure 4 The information provided by the backbone network includes data and mission instructions from other spacecraft, vehicles, sensor networks, operation centers, archive databases and users. The backbone network enables users to obtain data information and battlefield situation information of scientific exploration missions through the Internet or private networks, and command spacecraft and executive agencies to execute scientific missions or combat instructions through the backbone network.

[0079] The data path through the backbone network is as follows Figure 4 As shown in the figure, the protocol level used to process data passing through the network is a 5-layer standard protocol. Users connected to the Internet connect to the space agency's intranet through secure routing, and the space agency's intranet is then connected to the ground station through VPN. The VPN protocol includes ATM and SONET protocols to adapt to the ground station network protocol type. When the backbone network is connected to the spacecraft and the user is online, the data will be transmitted to the user in real time. If the spacecraft establishes a connection with the backbone network, but the user is not connected to the backbone network, the data is temporarily stored in the disk array in the gateway service area. When the user connects to the backbone network, the data will be obtained from the disk array. The backbone network can obtain data through ground nodes or air nodes. The activity diagram during its operation is shown in the following figure. Figure 5 shown.

[0080] Step S6, describing the inter-spacecraft network communication process based on the SysML activity diagram.

[0081] By analyzing the mission and performance requirements of the inter-spacecraft communication network, the spacecraft communication network includes a collection of radio / optical communication interfaces between spacecraft in a constellation and formation. Its network hierarchy is as follows: Figure 6 As shown, the inter-spacecraft network mainly solves the resource coordination problem caused by the need for each spacecraft to connect to the access control network.

[0082] In addition to basic communication between spacecraft, relative position measurement is also included. If the formation or cluster is arranged in a star shape, the central spacecraft is used as the communication medium to connect to the access control network. If the spacecraft are arranged in a mesh shape, any spacecraft can be used as the communication medium to access the control network. If the spacecraft are arranged irregularly, one or more spacecraft with the most communication paths are selected as the communication medium for data transmission. Its functional activity status is as follows: Figure 7 shown.

[0083] The above description is only a preferred embodiment of the present invention and an explanation of the technical principles used. It is not intended to limit the scope of the invention claimed for protection, but only represents the preferred embodiment of the present invention. Those skilled in the art should understand that the scope of the invention involved in the present invention is not limited to the technical solution formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the inventive concept. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

Claims

1. A method for defining low-orbit communication constellation network functions and interfaces based on SysML, characterized in that: The steps include: Step S1, starting from the stakeholders' needs for the constellation network, analyzing the concerns of each participant and the functions of each network system; Step S2, describing the usage relationship of the constellation network by stakeholders based on the SysML use case diagram; Step S3, describing the overall communication indicator requirements for the network based on the SysML requirement diagram; Step S4, defining the interface relationship of the constellation network service target and the communication network used based on the SysML internal structure diagram; Step S5, describing the backbone network communication process based on the SysML activity diagram; The backbone network communication process is described based on SysML activity diagram as follows: By analyzing the backbone network's mission and performance requirements, the backbone network design should include space network interfaces, ground network interfaces, ground station internal networks, virtual private networks, and the Internet; the information provided by the backbone network includes data and mission instructions from other spacecraft, vehicles, sensor networks, operation centers, archive databases, and users. The backbone network enables users to use the Internet or proprietary networks to obtain data information and battlefield situation information for scientific exploration missions, and to command spacecraft and executive agencies to execute scientific missions or combat instructions through the backbone network; Step S6, describing the network communication process between spacecraft based on SysML activity diagram; The inter-spacecraft network communication process described based on the SysML activity diagram is as follows: by analyzing the tasks and performance requirements of the inter-spacecraft communication network, the spacecraft communication network includes a set of radio / optical communication interfaces between spacecraft in a constellation and formation, and the inter-spacecraft network solves the resource coordination problem caused by the need for each spacecraft to connect to the access control network; The communication relationship between each network system is as follows: the sensor equipment / spacecraft formation communicates with the spacecraft responsible for the communication function through the adjacent communication network interface. The spacecraft responsible for communication processes the received raw data and communicates with the aerial node or ground node of the backbone network through the send / receive modem to form an access network communication interface. The backbone network processes the spacecraft feedback information through the ground station and pushes it to the network maintainer and user. At the same time, the instructions and data of the user and network maintainer are sent to the access network interface through the aerial node or ground node.

2. According to claim 1, a method for defining low-orbit communication constellation network functions and interfaces based on SysML, characterized in that: In step S1, sensors and users performing tasks include remote sensing satellites, reconnaissance satellites, aircraft, and ships.

3. According to claim 1, a method for defining low-orbit communication constellation network functions and interfaces based on SysML, characterized in that: According to the different concerns of stakeholders on the low-orbit constellation communication network, the entire network is divided into four types of network communication behaviors, namely backbone network communication, access control network communication, inter-spacecraft network communication and adjacent network communication.

4. According to claim 1, a method for defining low-orbit communication constellation network functions and interfaces based on SysML, characterized in that: The participants include military users, civilian users, sensors, and communication network maintainers.

5. According to claim 1, a method for defining low-orbit communication constellation network functions and interfaces based on SysML, characterized in that: Stakeholder task requirements are divided into functional requirements and performance requirements; among them, functional requirements include: (1) Transmission function of various data types: data, images, commands, voice, and video; (2) Random access function: supports random access to network edge nodes; (3) Network interconnection function: space-based ring network, space-ground star network and ground-based mesh network are interconnected; (4) Fault handling function: capable of fault diagnosis and reconstruction; Performance requirements include: (5) Access response time: The time from receiving the access request at the network edge to the start of service processing is less than 1 minute; (6) Request processing time: The time it takes a node to process a request is in minutes. (7) Data processing rate: single node data processing rate> 100 Gbit / s; (8) Data transmission rate: single-channel user transmission rate: 1Gbps – 10Gbps; (9) Number of users: ≥300; (10) Resource allocation time: <5min.

6. According to claim 1, a method for defining low-orbit communication constellation network functions and interfaces based on SysML, characterized in that: The data path through the backbone network is used to process data passing through the network at a standard Layer 5 protocol. Users connecting to the Internet connect to the space agency's intranet through secure routing, and the space agency's intranet is then connected to the ground station through VPN. The VPN protocol includes ATM and SONET protocols to adapt to the ground station network protocol type. When the backbone network is connected to the spacecraft and the user is online, the data will be transmitted to the user in real time. If the spacecraft establishes a connection with the backbone network but the user is not connected to the backbone network, the data is temporarily stored in the disk array in the gateway service area. When the user connects to the backbone network, the data will be obtained from the disk array. The backbone network can obtain data through two methods: ground nodes or air nodes.

7. According to claim 1, a method for defining low-orbit communication constellation network functions and interfaces based on SysML, characterized in that: In addition to basic communications between spacecraft, relative position measurement is also included. If the formation or cluster is arranged in a star shape, the central spacecraft will be used as the communication medium to connect to the access control network. If the spacecraft are arranged in a mesh shape, any spacecraft can be used as the communication medium to access the control network. If the spacecraft are arranged irregularly, one or several spacecraft with the most communication paths will be selected as the communication medium for data transmission.

Images