WO2022002234A1

WO2022002234A1 - Centralized routing method and system applied to satellite network

Info

Publication number: WO2022002234A1
Application number: PCT/CN2021/104184
Authority: WO
Inventors: 冯博昊; 张宏科; 黄云雪; 王洪超; 杨冬; 文国莉; 陆洲
Original assignee: 北京交通大学; 中国电子科技集团公司电子科学研究院
Priority date: 2020-07-03
Filing date: 2021-07-02
Publication date: 2022-01-06
Also published as: CN111884931A; CN111884931B

Abstract

Provided are a centralized routing method and system applied to a satellite network. The method comprises: dividing a plurality of time slices according to topological periodic features of a satellite network; according to the time slices, corresponding satellite network topologies, and a preset requirement, calculating basic forwarding entries from the current routing forwarding end to all other routing forwarding ends; the routing forwarding end loading the basic forwarding entries according to the time slices, encapsulating received user data to obtain an encapsulated data packet, and determining a routing requirement, i.e. basic routing and on-demand routing, according to a user grade and a service type; and determining a corresponding forwarding entry according to the routing requirement, and then performing routing forwarding on the encapsulated data packet according to the corresponding forwarding entry. According to the present application, differentiated routing of user data over a satellite network is realized, and a certain fault recovery capability is achieved.

Description

A centralized routing method and system applied to a satellite network

technical field

The present application relates to the technical field of satellite networks, and in particular to a centralized routing method and system applied to satellite networks.

Background technique

Satellite network plays an irreplaceable role in many aspects such as global communication, navigation and positioning, and deep space exploration due to its wide coverage, broadband broadcast communication and other characteristics. Different from the terrestrial Internet, the satellite network has the characteristics of time-varying topology, which makes the existing routing protocols designed based on a relatively stable networking environment not directly applicable. Therefore, in the prior art, in order to solve the problem that the existing routing protocol cannot be directly applied to the satellite network, the methods of snapshot routing and ad hoc network routing are usually adopted.

SUMMARY OF THE INVENTION

In view of this, the embodiments of the present application provide a centralized routing method and system applied to a satellite network, which solve the problems existing in the prior art that flexibility and signaling overhead are difficult to balance, and on-demand differentiated routing is difficult to achieve.

According to the first aspect, an embodiment of the present application provides a centralized routing method applied to a satellite network, including: dividing a plurality of time slices according to a periodic feature of a satellite network topology, and obtaining a satellite network topology corresponding to each of the time slices; According to each of the time slices, the satellite network topology corresponding to each of the time slices, and the preset requirements, calculate the basic forwarding entries for the current route forwarding end to reach all other route forwarding ends, and deliver each of the basic forwarding entries to the corresponding The current route forwarding end; the route forwarding end loads the basic forwarding entry according to each time slice; the route forwarding end encapsulates the received user data to obtain an encapsulated data packet, in which the encapsulated data packet is Carrying data information, user level and service type sent by the user; the routing forwarding terminal determines routing requirements according to the user level and the service type, and the routing requirements include basic routing requirements and on-demand routing requirements; the The routing and forwarding end determines a corresponding forwarding entry according to the routing requirement, and performs routing and forwarding on the encapsulated data packet according to the corresponding forwarding entry.

Optionally, when the routing requirement is the basic routing requirement, the routing forwarding end determines, according to the basic routing requirement, the basic forwarding entry loaded by the routing forwarding end as the basic routing forwarding entry, and forwards the route according to the basic routing requirement. The entry performs routing and forwarding on the encapsulated data packet.

Optionally, when the routing requirement is the on-demand routing requirement, the routing forwarding terminal determines a corresponding forwarding entry according to the routing requirement, and performs routing and forwarding on the encapsulated data packet according to the corresponding forwarding entry, Including: the routing forwarding terminal sends a path request for querying the forwarding rules to the routing control server according to the on-demand routing requirements; receiving the path request of the routing forwarding terminal, and obtaining the operation of all routing forwarding terminals of the satellite network according to a preset method state; according to the path request, each operating state and the corresponding preset weight, calculate and obtain each link routing cost; according to the satellite network topology corresponding to the current time slice, each link routing cost and preset weight A minimum-cost path algorithm, calculating a minimum-cost path, and generating a path identifier; according to the path identifier, generating an on-demand routing forwarding entry based on the path identifier and delivering it to each routing forwarding terminal included in the minimum-cost path; The routing and forwarding end performs routing and forwarding on the encapsulated data packet according to the on-demand routing and forwarding entry.

Optionally, a centralized routing method applied to a satellite network provided by an embodiment of the present application further includes: acquiring signaling sent by a routing forwarder in a satellite network topology corresponding to a current time slice, where the signaling includes the Route forwarding end state information and link state information corresponding to the route forwarding end; determine whether the route forwarding end is faulty according to the route forwarding end state information and a preset method, when the route forwarding end is determined to be faulty When the fault occurs, the routing forwarding terminal that has failed is eliminated from the satellite network topology to obtain a new topology of the satellite network; according to the link status information and the preset mode, it is judged whether the link is congested. When the link is congested, the congested link is eliminated in the new topology of the satellite network to obtain the final satellite network topology; according to the current time slice and the preset requirement, the current time slice is calculated in the final satellite network topology. The route forwarding end reaches the new basic forwarding entry of all other route forwarding ends, and delivers it to the corresponding route forwarding end, so that the route forwarding end loads the new basic forwarding entry.

Optionally, the obtaining the operating status of all routing forwarding terminals according to a preset method includes: receiving regular sending messages and alarm messages sent by all routing forwarding terminals, where the regular sending messages are the routing and forwarding terminals according to preset. The message sent at time to record the running state of the routing forwarding end and the corresponding link running state, and the alarm message is sent by the routing forwarding end to remind the routing forwarding end of the running state and the corresponding link. The message of whether the link running state exceeds the preset requirement; according to the regular sending message and the alarm message, the running state of all routing forwarding terminals is obtained.

Optionally, acquiring the operating status of all routing forwarding terminals according to a preset method further includes: sending a query message to the routing forwarding terminal, where the query message is used to indicate content options that need to be queried; receiving the routing forwarding terminal The query reporting message is generated by the routing forwarding terminal according to the querying message, and the query reporting message includes information indicating the running status of the routing forwarding terminal.

Optionally, the running state includes: on-off status and average round-trip delay between the route forwarding end and the adjacent route forwarding end, the average throughput on the interface connecting the route forwarding end and the adjacent route forwarding end, and Average packet loss rate;

The link routing cost is calculated by the following formula:

RC=α·PD+β·TH+γ·DP

Among them, RC represents the link routing cost, PD represents the average transmission delay, TH represents the average throughput, DP represents the average packet loss rate, α, β, γ represent the average transmission delay, average throughput, and average packet loss rate, respectively. corresponding preset weights.

According to a second aspect, an embodiment of the present application provides a centralized routing system applied to a satellite network, including: a network status collection module, configured to collect the running status of the routing forwarding terminal, and send the running status of the routing forwarding terminal to a an information reporting module; an information reporting module for reporting the running status of the routing forwarding end to an information collecting module through a communication interface; an information collecting module for monitoring the running status of the routing forwarding terminal through a communication interface; a data processing module for using is used to store the pre-input time slice topology and the operating state of the routing forwarding terminal in the database, and perform topology management on the information stored in the database; the routing calculation module is used for according to the topology information in the data processing module, all The operating status, user level and service type of the routing and forwarding terminal described above calculate the routing path for the data; the forwarding table generation module is used to generate the corresponding forwarding table according to the path calculated by the basic routing and on-demand routing, and send it to the forwarding table management through the communication interface module; the forwarding table management module is used for storing the basic routing forwarding table and the on-demand routing forwarding table generated by the forwarding table generating module; the forwarding module is used for the routing and forwarding terminal to forward the data packets according to the corresponding forwarding table.

Embodiments of the present application provide a non-transitory computer-readable storage medium, where the non-transitory computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, implement the first aspect and any one of the present application The centralized routing method applied to the satellite network described in the optional manner.

An embodiment of the present application provides an electronic device, including: a memory and a processor, the memory and the processor are connected in communication with each other, the memory stores computer instructions, and the processor executes the computer by executing the computer instructions. instruction, so as to execute the centralized routing method applied to a satellite network described in the first aspect and any optional manner of this application.

The technical solution of the present application has the following advantages:

The embodiment of the present application provides a centralized routing method applied to a satellite network. The routing control server generates a series of static topology combinations in advance according to topology changes, and calculates that under each static topology, each route forwarding end reaches any other The basic forwarding entry of the route forwarding end is sent to the corresponding route forwarding end for local storage and loaded in chronological order to form the basic route forwarding entry; in the process of route calculation, low-level users do not need to consider link performance, and use the basic route Realize "best effort" forwarding, which is simple and efficient; for high-level users, the routing control server will implement the calculation method of on-demand routing, that is, according to the collected current network operation status, user level and service type, dynamic planning The forwarding path of the high-level user data is obtained, and the relevant on-demand routing forwarding entry is sent to the relevant routing forwarding terminal in the forwarding path, so as to realize the differentiated routing of the satellite network.

Description of drawings

In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the accompanying drawings that need to be used in the description of the specific embodiments or the prior art will be briefly introduced below. The drawings are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a flowchart of a centralized routing method applied to a satellite network in an embodiment of the present application;

2 is a schematic diagram of basic routing of a centralized routing method applied to a satellite network in an embodiment of the present application;

3 is a schematic diagram of on-demand routing of a centralized routing method applied to a satellite network in an embodiment of the present application;

Fig. 4 is the module composition diagram of the centralized routing system applied to the satellite network in the embodiment of the application;

FIG. 5 is a schematic structural diagram of an electronic device in an embodiment of the present application.

detailed description

The technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict with each other.

The routing method applied to the satellite network provided by the embodiments of the present application is based on the following scenario, that is, the satellite network (including the ground node to which the satellite network belongs) uses logically different address spaces for other networks or users connected to it. Among them, the satellite network routes and forwards data packets based on its own address space (SN-CID, which can be IPv4, IPv6 address, label, etc.), and the address space used by other networks or users (such as IPv4, IPv6 addresses, etc.) will be used as satellite Network Access Identifier (SN-AID). After other network nodes or users access the satellite network, they will register their SN-AID and SN-CID binding relationship with the mapping server of the satellite network through their access routing forwarding terminal. When the data packets of other networks or users enter the satellite network, if the access routing forwarding terminal does not store the binding relationship between the SN-AID and SN-CID of the communication peer corresponding to the destination address of the data packet, the access routing forwarding terminal Will query the mapping server; if the access routing forwarding terminal locally stores the binding relationship between the SN-AID and SN-CID of the communication peer corresponding to the destination address of the data packet or just obtains relevant information from the mapping server, the access routing forwarding The end will encapsulate the data packets of other networks or users based on the SN-CID header, wherein the source address of the encapsulation header is the SN-CID of the forwarding end of the access route, and the destination address of the encapsulation header is the communication pair corresponding to the destination address of the data packet. The SN-CID of the routing and forwarding terminal connected to the terminal; in addition, the information of the user level and service type has been carried in the header based on the SN-CID in a certain way.

An embodiment of the present application provides a centralized routing method applied to a satellite network. As shown in FIG. 1 , the centralized routing method applied to a satellite network specifically includes:

Step S1: Divide a plurality of time slices according to the periodic characteristics of the satellite network topology, and obtain the satellite network topology corresponding to each time slice.

In the embodiment of the present application, since the topology changes of satellites are characterized by periodicity and predictability, at the beginning of the network, the routing control server obtains the topology connection in a cycle according to the satellite trajectory and the link establishment rule, and according to the link The on-off condition of the road is divided into time slices, and the satellite network topology is divided into multiple time slices.

Step S2: According to each time slot, the satellite network topology corresponding to each time slot, and the preset requirements, calculate the basic forwarding entries for the current route forwarding terminal to reach all other routing forwarding terminals, and deliver each basic forwarding entry to the corresponding current route forwarding end.

In this embodiment of the present application, for each time slice, the routing control server takes a preset routing requirement, that is, a certain metric (for example, link transmission delay) as the target, and calculates each route forwarding end in the network to all other routes in the topology For the route of the forwarding end, a series of basic forwarding entries such as (time slice sequence number, destination route forwarding end, forwarding interface, valid time period) are obtained, as shown in Table 1, where SN-CID is the node identifier of the route forwarding end. If the route forwarding end is a satellite node, the forwarding interface is defined as an air port on the satellite; if the route forwarding end is a ground node, the forwarding interface is defined as a device network port.

Table 1 SN-CID _x - basic route forwarding table of route forwarding end

It should be noted that the preset routing requirements in the embodiments of the present application may be set according to actual needs. The embodiments of the present application only take the link transmission delay as an example for description, and the present application is not limited thereto.

Step S3: The routing forwarding end loads the basic forwarding entry according to each time slice.

In the embodiment of the present application, it is assumed that the satellite network includes five routing forwarding terminals with satellite numbers A, B, C, D, and E, then the routing control server can calculate and obtain the basics from A to B, C, D, and E respectively. Forwarding entries, as well as basic forwarding entries from B to A, C, D, E, and so on, until the basic forwarding entries from E to other satellites are obtained, and then the respective basic forwarding entries are delivered to the corresponding routes. The forwarding end, that is, the calculated basic forwarding entries from A to other routing forwarding ends are delivered to A, and the other routing forwarding ends also perform the same operation, which is not repeated here. When each routing forwarding end receives each basic forwarding entry, it will load the basic forwarding entry according to the time sequence of the time slice. For example, one minute is a time period to divide the time slice. After the forwarding entries of the minute and the third minute, each basic forwarding entry of the first minute will be loaded first, and then the basic forwarding entries of the second minute and the third minute will be loaded in turn according to the time slice sequence.

It should be noted that the embodiments of the present application only illustrate the satellite network including five routing forwarding terminals and time periods divided by time slices. In practical applications, they are all set according to the actual satellite network. limited.

Step S4: The routing and forwarding end encapsulates the received user data to obtain an encapsulated data packet, and the encapsulated data packet carries the data information sent by the user, the user level and the service type.

In the embodiment of the present application, it is assumed that user A sends a data packet to user B, and the routing and forwarding terminal 1 to which A is connected encapsulates the data packet sent by user A, wherein the data packet is encapsulated based on the SN-CID header, and the - The source address of the CID header is the SN-CID of the route forwarding end 1, the destination address is the SN-CID of the access route forwarding end of the satellite network connected to the destination end (user B) of the data packet, and at the same time, the user level is filled in the data header. Information and service types, encapsulating data information as data payloads in encapsulated packets. It should be noted that the embodiments of the present application only illustrate that the encapsulated data packet includes the user level and service type, and other user weight information may also be added according to actual needs, which is not limited in the present application.

Step S5: The routing forwarding end determines routing requirements according to the user level and service type, and the routing requirements include basic routing requirements and on-demand routing requirements.

In the embodiment of the present application, the routing and forwarding terminal performs differentiated routing according to the user level and service type, and determines the routing requirements, wherein the routing requirements include basic routing requirements and on-demand routing requirements. When the data packet is waiting in the routing and forwarding terminal queue, According to a certain strategy, high-level data packets can be "queued" and forwarded preferentially. The routing and forwarding end will rearrange the data packets arriving in sequence according to the user level. If the user level is the same, they will be arranged according to the service type (for example, low The delay service is given priority, followed by the low packet loss rate service, and finally the high throughput service). For different service types, routing and forwarding are performed according to their own characteristics.

Step S6: the routing forwarding end determines a corresponding forwarding entry according to the routing requirement, and performs routing and forwarding on the encapsulated data packet according to the corresponding forwarding entry. In the embodiment of the present application, according to different routing requirements, it is selected to perform basic routing forwarding or on-demand routing forwarding on the encapsulated data packet; when the routing requirement is the basic routing requirement, the routing forwarding end determines the loaded basic forwarding entry as the basic forwarding entry. routing and forwarding entries, and routing and forwarding the encapsulated data packets according to the basic routing and forwarding entries.

Specifically, in an embodiment, when the routing requirement is an on-demand routing requirement, the above step S6 specifically includes the following steps:

Step S61: The routing forwarding end sends a path request for inquiring about the forwarding rule to the routing control server according to the on-demand routing requirement.

Step S62: Receive a path request from the routing forwarding terminal, and acquire the operating status of all routing forwarding terminals in the satellite network according to a preset method.

In the embodiment of the present application, after receiving the route request from the route forwarder, the routing control server obtains the route forwarder, user level, and service type information involved in the route request, and obtains the running status of all route forwarders in the current satellite network in a preset manner. .

Specifically, in an embodiment, the above-mentioned step S62 specifically includes the following steps:

Step S621: Receive the regular sending messages and alarm messages sent by all routing forwarding terminals, wherein the regular sending messages are sent by the routing forwarding terminal according to a preset time to record the running state of the routing forwarding terminal itself and the corresponding link running state The alarm message is a message sent by the routing forwarding end to prompt whether the running state of the routing forwarding end and the corresponding link running state exceed the preset requirements.

In the embodiment of the present application, under normal circumstances, the routing forwarding end reports itself and the link operation status to the routing control server, and this interaction is realized by periodically reporting messages, mainly reporting on-off status with neighbors, average delay, average Information such as throughput, average packet loss rate, etc. are shown in Table 2. Among them, the average transmission delay is the average round-trip delay between a route forwarding end and its adjacent route forwarding end, and the average throughput indicates the unit time The average amount of data forwarded by an interface on the forwarding end of a route, and the average packet loss rate refers to the ratio of the number of lost data packets per unit of time to the transmitted data packets.

Table 2 The content of the message regularly reported by the routing forwarder

节点标识Node ID	接口标号Interface label	相邻节点adjacent node	序列号serial number	平均传输时延average transmission delay	平均吞吐量average throughput	平均丢包率Average packet loss rate	……
SN-CIDxSN-CIDx	接口 _a interface _a	SN-CID _y SN-CID _y	时间戳值timestamp value	DelayDelay	ThroughputThroughput	DropRateDropRate	……

In addition, when a certain parameter exceeds a predetermined value, the routing forwarding terminal can actively report the relevant network status to the routing control server. This process is implemented by an alarm message. The content of the alarm message is shown in Table 3. It mainly includes three flag fields, which represent the propagation delay, throughput and packet loss rate respectively. When the flag bit of the flag field is 1, it means that the indicator exceeds the predetermined value.

Table 3 Alarm message content

节点标识Node ID	接口标号Interface label	相邻节点adjacent node	传播时延字段propagation delay field	吞吐量字段Throughput field	丢包率字段Packet loss rate field
SN-CIDxSN-CIDx	接口 _a interface _a	SN-CIDSN-CID	00	11	11

Step S622: Obtain the running status of all routing forwarding terminals according to the regular sending message and the alarm message.

Step S623: Send a query message to the routing forwarder, where the query message is used to indicate content options that need to be queried.

In the embodiment of the present application, at the same time, the routing forwarding terminal also needs to support the routing control server to instantly query its various network status parameters. The query process is implemented by means of query messages and query report messages. The routing control server sends a query message to the routing forwarding terminal, and the routing forwarding terminal sends a query reporting message to the routing control server to respond after receiving the query. Table 4 shows the content of the query message. The sequence number makes a one-to-one correspondence between the query message and the corresponding query report message. The three fields respectively indicate what information the routing control server needs to query from the routing forwarder, and if the field is set to 1, it indicates that this information is to be queried. Table 5 is the content of the query report message. The confirmation number should be equal to the serial number in the corresponding query message content, which represents the response to the query. The corresponding indicator is selected and filled according to the content in the query message. If the indicator is not queried, the item is empty.

It should be noted that the contents included in the periodic reporting message, the query reporting message, the query message and the alarm message in the embodiments of the present application are only examples, and in practical applications, other contents may also be included, which are not limited to With these four types of messages, as long as the network operation status can be completely obtained, the present application is not limited to this.

Table 4 Query message content

Table 5 Query and submit message content

Step S624: Receive a query report message sent by the routing forwarder, wherein the query report message is generated by the routing forwarder according to the query message, and the query report message includes information indicating the running state of the routing forwarder.

In practical applications, through the interaction of the above four types of message messages, the routing control server can summarize the status information of all routing forwarding terminals, and generate a summary table of satellite network status information as shown in Table 6, which provides a basis for calculation and calculation for on-demand routing. After the routing control server calculates the forwarding entry through the on-demand routing mechanism, it delivers the on-demand routing and forwarding entry to the routing forwarding end. During the interaction process, the integrity of the forwarding entry message can be verified by relying on the hash message authentication code field.

Table 6 Summary of Satellite Network Status Information

Step S63: Calculate the route cost of each link according to the path request, each operating state and the corresponding preset weight.

In the embodiment of the present application, in order to provide a relatively good route, the route control server will use different link route costs according to the forwarding requirements of different service types. For example, considering the on-off status and average round-trip delay of the route forwarding end and its adjacent route forwarding ends, the average throughput and average packet loss rate on the interfaces connected to the route forwarding end and its adjacent route forwarding ends , the link routing cost is calculated by the following formula:

RC=α·PD+β·TH+γ·DP

Step S64: According to the satellite network topology corresponding to the current time slice, the route cost of each link, and the preset minimum cost path algorithm, the minimum cost path is obtained by calculation, and the path identifier is generated.

Step S65: According to the path identifier, an on-demand routing forwarding entry based on the path identifier is generated and delivered to each routing forwarding terminal included in the minimum cost path.

Step S66: The routing and forwarding end performs routing and forwarding on the encapsulated data packet according to the on-demand routing and forwarding entry.

In the embodiment of the present application, the routing control server selects the corresponding weights according to different service types, and obtains the path with the minimum cost according to the Dijkstra algorithm, and generates an on-demand path indexed by the path identifier (PID, which is the length of two SN-CIDs). The routing forwarding entry is sent to the corresponding routing forwarding end on the generated path to logically maintain a high-quality link, as shown in Table 7. The data can be forwarded after the routing and forwarding end is loaded locally. In addition, the origin route forwarding end on the path first needs to rewrite the source SN-CID and destination SN-CID addresses of the encapsulated data packets into PIDs, and then forward the data according to the PID-based on-demand route forwarding entry; the destination route forwarding The end needs to remove the PID-based data header, and then forward the data according to the destination address of the user data packet.

Table 7 On-demand routing forwarding entries

It should be noted that the Dijkstra algorithm is used in the embodiments of the present application to calculate the minimum cost path. In practical applications, other algorithms may also be selected for the preset minimum cost path algorithm, and the present application is not limited to this.

Specifically, the centralized routing method applied to a satellite network provided by the embodiment of the present application further includes:

Step S01: Acquire signaling sent by a routing forwarding end in a satellite network topology corresponding to a current time slice, where the signaling includes routing and forwarding end state information and link state information corresponding to the routing and forwarding end.

In the embodiment of the present application, the routing control server monitors the running status of the satellite network in real time, and the routing control server first obtains the signaling sent by the routing forwarding terminal in the satellite network topology corresponding to the current time slice, which is used to determine the status and the status of the routing forwarding terminal. Link up and down status.

Step S02: Judge whether the route forwarder is faulty according to the status information of the route forwarder and the preset mode, when the route forwarder is determined to be faulty, remove the faulty route forwarder from the satellite network topology to obtain a new satellite network. topology. In the embodiment of the present application, if the signaling from the routing forwarding terminal is not received for three consecutive times, it is determined that the routing forwarding terminal is faulty; when all the routing forwarding terminals are not faulty, the original satellite network topology is determined as the above-mentioned The new topology of the satellite network, that is, the topology of the satellite network has not changed, and the link failure is judged on this basis. It should be noted that this application only exemplifies the preset method of fault judgment, and other methods may be used in practical applications, such as monitoring by time, which is not limited in this application.

Step S03: Determine whether the link is congested according to the link state information and the preset mode, and when the link is congested, remove the congested link from the new topology of the satellite network to obtain the final satellite network topology. In the embodiment of the present application, after the new topology of the satellite network is obtained, it is determined whether all links in the new topology of the satellite network are congested, and when no congestion occurs in all links, the new topology of the satellite network is determined. is the final satellite network topology; if all routing forwarding ports and links are not faulty, the final satellite network topology will be the initial satellite network topology.

Step S04: According to the current time slice and preset requirements, in the final satellite network topology, calculate the new basic forwarding entry of the current routing forwarding terminal to all other routing forwarding terminals, and deliver it to the corresponding routing forwarding terminal so that the routing forwarding terminal can be updated to the new forwarding terminal. The base forwarding entry is loaded and the relevant base forwarding entry previously calculated based on the topology containing the forwarding end of the faulty route or/and the congested link is withdrawn.

Specifically, as shown in FIG. 2 , an example of basic route distribution and data packets traversing the satellite network in encapsulated form is given. At the beginning of the network, the routing control server obtains the topological connection within a period according to the satellite trajectory and constellation (a period refers to the restoration of the topology of the sky-earth network to a certain state, in which the relative positions of nodes, link status, channel quality, etc. are basically the same). , and divide the time slice. When the connection relationship between the satellite (routing forwarding end) and the adjacent node is changed due to the movement, a new time slice will be generated. After that, the route calculation is performed for each route forwarding end in each time slice to all other route forwarding ends in the topology, and finally a series of basic forwarding entries are obtained. The routing control server issues the forwarding table used by each routing forwarding terminal, and the corresponding routing forwarding terminal loads the basic forwarding entry locally according to the time period indicated by the time slice after receiving its own forwarding table to form the basic routing forwarding. entry. When the data packets of other network nodes SN-AID1 (low-level users) pass through the satellite network, the access routing forwarding end SN-CID1 encapsulates the data packets and forwards them according to the basic routing forwarding entries until it reaches the satellite network routing forwarding end SN-CID4 decapsulates and finally sends the data packet to other network node SN-AID2.

As shown in Figure 3, an example of on-demand routing is given. After receiving the data packets encapsulated by other network nodes SN-AID1 (high-level users) based on SN-CID, the satellite network routing forwarding end SN-CID1 makes a path request to the routing control server. The routing control server calculates a new transmission path according to the service type of other network nodes and the current network state, and identifies it with a PID. Thereafter, the routing control server delivers the on-demand routing forwarding entry to the corresponding routing forwarding end. After the relevant routing and forwarding entries are configured locally on the involved routing and forwarding ends, the SN-CID1 replaces the source SN-CID and destination SN-CID in the original encapsulation header with PIDs, and then routes and forwards the data based on the on-demand routing and forwarding entries. The intermediate routing forwarding end uses the PID as an index to forward to SN-CID4. The latter decapsulates the data packet and sends it to the other network node SN-AID2.

Through the above steps S1 to S6, the embodiment of the present application provides a centralized routing method applied to a satellite network. The routing control server generates a series of static topology combinations in advance according to topology changes, and calculates the arrival of each routing forwarding end. The basic forwarding entries of any other route forwarding end are delivered to the corresponding route forwarding end for local storage and loaded in chronological order to form basic route forwarding entries; in the process of route calculation, low-level users do not need to consider link performance, use The basic routing implements "best effort" forwarding, which is simple and efficient; for high-level users, the routing control server will implement the calculation method of on-demand routing, that is, according to the collected current network operation status, user level and service type, The forwarding path of the high-level user data is dynamically planned, and the relevant on-demand routing forwarding entry is sent to the relevant routing forwarding terminal in the forwarding path, so as to realize the differentiated routing of the satellite network. The embodiment of the present application also provides a centralized routing system applied to a satellite network, as shown in FIG. 4 , including:

The network status collection module 1 is used to collect the running status of the routing and forwarding terminal, and send the running status of the routing and forwarding terminal to the information reporting module 2; some of the information can be collected directly from the routing and forwarding terminal, and other information needs to send and receive signaling independently Packet collection.

The information reporting module 2 is used to report the running status of the routing forwarding terminal to the information collecting module 3 through the communication interface; it includes an active reporting component and a passive reporting component, and the routing forwarding terminal uses the active reporting component to actively report the network status to the routing control server; the passive component It is used to respond to the query message of the routing control server.

The information collection module 3 is used to monitor the running state of the routing forwarding end through the communication interface; it mainly includes an active query component and a passive receiving component. The routing control server uses the active query component to send query messages to the routing forwarding end to obtain the current network running status; the passive receiving component is used to continuously monitor the routing forwarding end and receive network status messages periodically reported by the routing forwarding end.

The data processing module 4 is used to store the pre-input time slice topology and the running state of the routing forwarding terminal in the database, and perform topology management on the information stored in the database; it mainly includes a database component, a time slice optimization component, a topology management component and a Network state information management component. In practical applications, in order to ensure smooth switching between time slices, for the original time slice topology, the time slice optimization component takes T time before and after adjacent time slices, and fills in the original time slice topology as an intermediate time slice, such as time slices 1[a,b), time slice 2[b,c), optimized time slice 1'[a,bT), intermediate time slice [bT,b+T), and time slice 2'[b+T ,c); the database component is used to store the topology after adding the intermediate time slice and the network status information reported by the routing forwarder; the topology management component, reads the time slice topology in the database to calculate the route, and based on the collected network status information Real-time update of the current time slice topology.

The routing calculation module 5 is used to calculate the routing path for the data according to the topology information in the data processing module, the running state of the routing forwarding terminal, the user level and the service type; it mainly includes a basic routing calculation component and an on-demand routing calculation component. The basic routing calculation component calculates the path from each node in the network to all other nodes in the topology with a certain metric (for example, the link transmission delay) as the goal; the on-demand routing component calculates the path according to the user level and service type carried by the user data packet. The network states are weighted and the path of least cost is derived according to Dijkstra's algorithm.

The forwarding table generation module 6 is used to generate a corresponding forwarding table according to the path calculated by the basic route and the on-demand route, and send it to the forwarding table management module 7 through the communication interface; including the basic routing forwarding table and the on-demand routing forwarding table.

The forwarding table management module 7 is used to store the basic routing forwarding table and the on-demand routing forwarding table generated by the forwarding table generating module; including the basic routing forwarding table component and the on-demand routing forwarding table component

The forwarding module 8 is used for the routing forwarding end to forward the data packets according to the corresponding forwarding table.

Through the cooperation of the above components, the embodiment of the present application provides a routing system applied to a satellite network. The routing control server generates a series of static topology combinations in advance according to topology changes, and calculates that each routing forwarding end reaches other The basic forwarding entry of any route forwarding end is delivered to the corresponding route forwarding end for local storage and loaded in chronological order to form the basic route forwarding entry; in the process of route calculation, low-level users do not need to consider link performance, and use the basic Routing implements "best effort" forwarding, which is simple and efficient; for high-level users, the routing control server will implement the calculation method of on-demand routing, that is, on the basis of time slice routing, the routing control server will collect the current network Based on the running status, user level and service type, the forwarding path of user data is dynamically planned, and the relevant on-demand routing forwarding entries are sent to the relevant routing forwarding terminals in the forwarding path to realize the differentiated routing of the satellite network.

The embodiment of the present application first provides an example of basic route calculation and distribution. At the beginning of the network, for the time slice topology within one cycle of input (a cycle refers to the restoration of the topology of the world-earth network to a certain state, where the relative positions of nodes, link status, channel quality, etc. are basically the same), the data in the routing control server The processing module 4 calls the time slice optimization component to take an intermediate time slice for adjacent time slices and store them in the database. The topology management component reads the time slice topology in the database, the basic routing component in the routing calculation module 5 performs routing calculation for each node in each time slice to all other nodes in the topology, and the forwarding table generates the basic routing in module 6. The routing forwarding table component generates a series of routing forwarding terminal forwarding entries according to the basic routing entries in the format of the basic routing forwarding table. The routing control server issues a periodic forwarding table to each routing forwarding terminal. After the forwarding table management module 7 of the corresponding routing forwarding terminal receives its own forwarding table, the basic routing forwarding table component first stores all the basic routing forwarding tables. Then determine which time slice it is in according to the current system time, and finally load the forwarding entry locally according to the time period indicated by the time slice.

Next, an example of on-demand routing is given. After receiving the data packets encapsulated by other network nodes SN-AID1 (high-level users) based on SN-CID, the satellite network routing forwarding end SN-CID1 makes a path request to the routing control server. The topology processing component reads the current time slice topology in the database and the network state information reported by the information reporting module, and the on-demand routing calculation component in the routing control server calculates a new transmission path according to the service types of other network nodes and the current network state, and identified by PID. Thereafter, the on-demand routing and forwarding table generating component of the routing control server generates the on-demand routing and forwarding entry and sends it to the corresponding routing and forwarding terminal. The on-demand routing and forwarding table management component of the routing and forwarding end performs storage and local configuration. After that, SN-CID1 replaces the source SN-CID and destination SN-CID in the original encapsulation header with PID, and then forwards the data based on the on-demand routing and forwarding entry. CID4. The latter decapsulates the data packet and sends it to the other network node SN-AID2. Wherein, the network state is obtained by the routing service controller from the routing forwarding end through a period (query). The network state collection module 1 at the routing and forwarding end also periodically collects the network state of the satellite and stores it in the information reporting module 2. The active reporting component periodically reports the current network status to the routing service controller. The passive receiving component continues to monitor. After receiving the data packet, it determines that it is the network status message reported by the information by judging the flag bit, and then stores the network status message reported by each routing forwarding end in the database. When there is no current network status in the calculation-on-demand routing read database, the active query component of the routing service controller sends a query message to the routing forwarder. After the routing forwarder receives it, the passive reporting component reads the storage status and replies to the query report message. , and the active collection component stores it in the database after receiving it for subsequent routing calculation.

Finally, an example of topology update is given. The topology management component periodically queries the network status table in the database. When a node occurs or fails/the parallel link is congested, the faulty node recovers, or/the parallel link is no longer congested, the topology management component triggers the update of the original topology, and Recalculate and deliver the basic route forwarding entry for the affected time slice.

This embodiment of the present application also provides an electronic device. As shown in FIG. 5 , the electronic device may include a processor 901 and a memory 902, where the processor 901 and the memory 902 may be connected through a bus or in other ways. Take bus connection as an example.

The processor 901 may be a central processing unit (Central Processing Unit, CPU). The processor 901 may also be other general-purpose processors, digital signal processors (Digital Signal Processors, DSPs), application specific integrated circuits (Application Specific Integrated Circuits, ASICs), Field-Programmable Gate Arrays (Field-Programmable Gate Arrays, FPGAs) or Other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components and other chips, or a combination of the above types of chips.

As a non-transitory computer-readable storage medium, the memory 902 can be used to store non-transitory software programs, non-transitory computer-executable programs and modules, such as program instructions/modules corresponding to the methods in the embodiments of the present application. The processor 901 executes various functional applications and data processing of the processor by running the non-transitory software programs, instructions and modules stored in the memory 902, that is, to implement the above method.

The memory 902 may include a storage program area and a storage data area, wherein the storage program area may store an operating system and an application program required by at least one function; the storage data area may store data created by the processor 901 and the like. Additionally, memory 902 may include high-speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, flash memory device, or other non-transitory solid state storage device. In some embodiments, memory 902 may optionally include memory located remotely from processor 901, which may be connected to processor 901 via a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

One or more modules are stored in the memory 902, and when executed by the processor 901, perform the above-described methods.

The specific details of the above electronic device can be understood by referring to the corresponding related descriptions and effects in the above method embodiments, and details are not repeated here.

Those skilled in the art can understand that the realization of all or part of the processes in the methods of the above embodiments can be accomplished by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and the program can be executed when the program is executed. , may include the flow of the above-mentioned method embodiments. Wherein, the storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a flash memory (Flash Memory), a hard disk (Hard Disk Drive) , abbreviation: HDD) or solid-state hard disk (Solid-State Drive, SSD), etc.; the storage medium may also include a combination of the above-mentioned types of memories.

The above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the specific embodiments of the present application can still be modified. Or equivalent replacements, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present application, shall all be included in the scope of the claims of the present application.

Claims

A centralized routing method applied to a satellite network, comprising:

Divide a plurality of time slices according to the periodic characteristics of the satellite network topology, and obtain the satellite network topology corresponding to each of the time slices;

According to each of the time slices, the satellite network topology corresponding to each of the time slices, and the preset requirements, calculate the basic forwarding entries for the current route forwarding end to reach all other route forwarding ends, and deliver each of the basic forwarding entries to the corresponding The current route forwarding end of ;

The routing and forwarding terminal loads the basic forwarding entry according to each of the time slices;

The routing and forwarding terminal encapsulates the received user data to obtain an encapsulated data packet, wherein the encapsulated data packet carries the data information sent by the user, the user level and the service type;

The routing forwarding terminal determines routing requirements according to the user level and the service type, and the routing requirements include basic routing requirements and on-demand routing requirements;

The routing and forwarding end determines a corresponding forwarding entry according to the routing requirement, and performs routing and forwarding on the encapsulated data packet according to the corresponding forwarding entry.
The centralized routing method applied to a satellite network according to claim 1, wherein when the routing requirement is the basic routing requirement, the routing forwarding terminal sends the routing forwarding terminal to the routing terminal according to the basic routing requirement. The loaded basic forwarding entry is determined as a basic routing and forwarding entry, and the encapsulated data packet is routed and forwarded according to the basic routing and forwarding entry.
The centralized routing method applied to a satellite network according to claim 1, wherein when the routing requirement is the on-demand routing requirement, the routing forwarding terminal determines a corresponding forwarding entry according to the routing requirement , and route and forward the encapsulated data packet according to the corresponding forwarding entry, including:

The routing forwarding terminal sends a path request for querying the forwarding rule to the routing control server according to the on-demand routing requirement;

Receive the path request of the routing forwarding terminal, and obtain the operating status of all routing forwarding terminals of the satellite network according to a preset method;

Calculate the route cost of each link according to the path request, each of the running states and the corresponding preset weights;

According to the satellite network topology corresponding to the current time slice, the route cost of each link and the preset minimum cost path algorithm, the minimum cost path is calculated and obtained, and the path identifier is generated;

According to the path identifier, an on-demand routing forwarding entry based on the path identifier is generated and delivered to each routing forwarding terminal included in the minimum cost path;

The routing and forwarding end performs routing and forwarding on the encapsulated data packet according to the on-demand routing and forwarding entry.
The centralized routing method applied to a satellite network according to claim 1, further comprising:

Obtaining signaling sent by the routing forwarding terminal in the satellite network topology corresponding to the current time slice, where the signaling includes the routing forwarding terminal state information and the link state information corresponding to the routing forwarding terminal;

Determine whether the route forwarder is faulty according to the status information of the route forwarder and the preset mode, and when the route forwarder is determined to be faulty, place the faulty route forwarder in the satellite network topology Eliminate to obtain a new topology of the satellite network;

Judging whether the link is congested according to the link state information and the preset method, and when the link is congested, the congested link is eliminated from the new topology of the satellite network to obtain the final satellite network topology;

According to the current time slice and the preset requirement, calculate the new basic forwarding entry from the current route forwarding end to all other route forwarding ends in the final satellite network topology, and deliver it to the corresponding route forwarding end to enable the route forwarding The end loads the new base forwarding entry.
The centralized routing method applied to a satellite network according to claim 3, wherein the obtaining the operating states of all routing forwarding terminals according to a preset method includes:

Receive the regular sending messages and alarm messages sent by all routing forwarding terminals, where the regular sending messages are sent by the routing forwarding terminal according to the preset time to record the running status of the routing forwarding terminal itself and the corresponding link operation. Status message, the alarm message is a message sent by the routing forwarding terminal to prompt the routing forwarding terminal itself and whether the corresponding link running status exceeds the preset requirement;

According to the regular sending message and the alarm message, the running status of all routing forwarding terminals is obtained.
The centralized routing method applied to a satellite network according to claim 3, wherein the obtaining the operating states of all routing forwarding terminals according to a preset method further comprises:

sending a query message to the routing forwarding terminal, where the query message is used to indicate content options that need to be queried;

Receive a query report message sent by the routing forwarding terminal, the query reporting message is generated by the routing forwarding terminal according to the query message, and the query reporting message includes a message indicating the running status of the routing forwarding terminal. information.
The centralized routing method applied to a satellite network according to claim 3, wherein the running state includes: the on-off status of the routing forwarding terminal and the adjacent routing forwarding terminal and the average round-trip delay, the routing Average throughput and average packet loss rate on the interface connecting the forwarding end to the adjacent routing forwarding end;

The link routing cost is calculated by the following formula:

RC=α·PD+β·TH+γ·DP

Among them, RC represents the link routing cost, PD represents the average transmission delay, TH represents the average throughput, DP represents the average packet loss rate, α, β, γ represent the average transmission delay, average throughput, and average packet loss rate, respectively. corresponding preset weights.
A centralized routing system applied to a satellite network, comprising:

a network status collection module, used for collecting the running status of the routing forwarding terminal, and sending the running status of the routing forwarding terminal to the information reporting module;

an information reporting module, configured to report the running status of the routing forwarding terminal to the information collecting module through a communication interface;

an information collection module, used for monitoring the running state of the routing forwarding terminal through the communication interface;

The data processing module is used for storing the pre-input time slice topology and the running state of the routing forwarding terminal in the database, and performing topology management on the information stored in the database;

a routing calculation module, configured to calculate a routing path for the data according to the topology information in the data processing module, the running state of the routing forwarding terminal, the user level and the service type;

The forwarding table generation module is used to generate the corresponding forwarding table according to the path calculated by the basic route and the on-demand route, and send it to the forwarding table management module through the communication interface;

The forwarding table management module is used to store the basic routing forwarding table and the on-demand routing forwarding table generated by the forwarding table generation module;

The forwarding module is used for the routing forwarding end to forward the data packets according to the corresponding forwarding table.
A computer-readable storage medium, characterized in that, the computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the application to a satellite network according to any one of claims 1 to 7 is realized. centralized routing method.
An electronic device, comprising:

A memory and a processor, wherein the memory and the processor are connected in communication with each other, the memory stores computer instructions, and the processor executes any one of claims 1 to 7 by executing the computer instructions The centralized routing method described in Item 1 is applied to a satellite network.