CN114928869A - Satellite-ground cooperative global content distribution routing method, system and electronic equipment - Google Patents

Abstract

The invention provides a satellite-ground cooperative global content distribution routing method, a system and electronic equipment, wherein the method comprises the following steps: the global ground station management center is used for distributing ground stations for users to serve; the system comprises ground stations distributed globally, a satellite-to-ground and inter-satellite path calculation module, a satellite forwarding module and a data transmission module, wherein the ground stations provide content service for users, calculate the satellite-to-ground and inter-satellite paths for data transmission according to load conditions, embed the paths into the header of a message in a segmented routing mode in a segmented coding mode so that the satellite can obtain the forwarding path, and monitor the load in real time so as to provide decision basis for a ground station management center; when the satellite reads the segmented route, the giant low-orbit satellite forwards the data according to the path of the message header, otherwise, the data is forwarded according to the shortest path; and the satellite signal receiver requests the ground station management center to distribute the ground stations to serve the users when the users access the satellite. The method realizes the selection of a path with high bandwidth and low time delay for each data stream, maximizes the system throughput and transmits data with high bandwidth and low time delay.

Description

A satellite-earth coordinated global content distribution and routing method, system and electronic device

technical field

The present invention relates to the technical field of sky-earth fusion network, in particular to a satellite-earth coordinated global content distribution routing method, system and electronic device.

Background technique

Internet content providers typically utilize wide area networks and cloud platforms to transmit data (eg, web content, video, etc.) to globally distributed customers, however, from a global perspective, existing data transmission methods still face two major challenges. First, terrestrial resources are highly concentrated in hotspots and developed areas, making it challenging to provide efficient data transmission for users in remote or rural areas that are underserved by network infrastructure and cloud platforms. Second, due to detours caused by routing strategies of different autonomous systems or terrain factors (eg, mountains, deserts, etc.), the transmission of terrestrial networks, especially for long-distance communication, is more prone to high latency problems.

With the breakthrough of aerospace technology, the emerging megasatellite constellation has developed rapidly. These mega-constellations (e.g., Starlink, OneWeb, Telesat, and Kuiper), consisting of thousands or even tens of thousands of low-orbit satellites, promise low-latency, high-bandwidth communications around the globe, especially for users in remote areas. At the same time, the globally distributed ground station network and ground station infrastructure have also received increasing attention (e.g., AWS Ground Station, Azure Orbital) to enable resilient, flexible, and affordable satellite network services on a global scale. Combining the emerging low-orbit satellite network with terrestrial network infrastructure, content providers can use it to more efficiently serve globally distributed users.

However, there are still difficulties and challenges in realizing high-bandwidth and low-latency data transmission using the integrated sky-earth network. First, in the existing satellite network routing algorithm, there is a problem of incoordination between the satellite path selection on the ground station and the inter-satellite routing. On-satellite path selection strategies that only rely on local information (for example, select the satellite closest to the ground station or with the strongest signal, select the satellite with the longest remaining service time, etc.), do not consider the inter-satellite routing after the data packet is onboard Causes routing detours, resulting in increased delay. At the same time, only using a single up-satellite path selection and inter-satellite routing strategy (eg, shortest path, etc.) will cause traffic to aggregate and cause link congestion. Secondly, the existing terrestrial network traffic engineering algorithms are difficult to adapt to the fusion network. Existing terrestrial network traffic engineering algorithms need to sense traffic information and link status. However, due to the high dynamics of satellites, the topology of the space-ground fusion network is constantly changing, and the scale of satellites in the mega-constellation is large, so it is very difficult to perceive the status of all satellites in real time. Difficult, scalability is difficult to guarantee.

SUMMARY OF THE INVENTION

The present invention provides a satellite-ground coordinated global content distribution routing method, system and electronic equipment, which are used to solve the defects of traffic aggregation and link congestion in the existing space-ground fusion network, so as to realize the selection of high bandwidth and low bandwidth for each data stream. Time-delayed path for efficient data transmission.

The present invention provides a global content distribution and routing method for satellite-ground coordination, which is applied to a global ground station management center, including:

After receiving the ground station service request message sent by the satellite signal receiver, calculate the distance between all ground stations and the user terminal according to the geographic positions of the user terminal and all ground stations, and the ground station service request message is in the user terminal. sent when the terminal accesses the satellite through the satellite signal receiver;

Based on the distances between all ground stations and the user terminal, among the ground stations that meet the distance limit, the ground station with the smallest load is selected as the target ground station;

The information of the target ground station is sent to the user terminal, and the information of the target ground station is used to request a content service.

A satellite-ground coordinated global content distribution and routing method provided by the present invention, applied to a ground station, includes:

After receiving the content service request sent by the user terminal, use the satellite network segment routing method based on the ground station to calculate the data transmission path, and segment the path to encode the path to obtain the encoded data of the path, and the content service request is the described content service request. After the user terminal receives the information of the target ground station sent by the global ground station management center, it is sent according to the information of the target ground station;

The coded data of the path is embedded in the header of the message by using the method of segment routing, and the coded data of the path is used in the satellite, and the satellite parses the path and distributes the content according to the parsed path.

According to a satellite-ground coordinated global content distribution and routing method provided by the present invention, after receiving the content service request sent by the user terminal, the satellite network segment routing method based on the ground station is used to calculate the data transmission path, and the path is Perform segment encoding to obtain encoded data of the path, including:

Model the topology, traffic, and routing optimization goals of the world-earth fusion network, discretize the topology of the world-earth fusion network into multiple time slices, filter the data flows that need to be rerouted, and obtain the modeled model;

Select the path to the satellite for each data stream, and select the satellite-to-ground link with the least number of data streams as the path to the satellite among the satellite-to-ground links that satisfy the hop number constraint;

Select the inter-satellite routing path for each data stream, and estimate the maximum bandwidth that can be obtained at each node according to the available bandwidth of each inter-satellite link and the number of data streams at the ground station. The direction of recording the maximum bandwidth is from the inter-orbit or In-orbit, push back from the destination node to construct a complete inter-satellite routing path;

Segment the path, encode the path, determine the split nodes in the path, arrange the star node, all split nodes and destination nodes in order, and store them as the encoded data of the path.

According to a satellite-earth coordinated global content distribution and routing method provided by the present invention, the modeling of the topology, traffic and routing optimization objectives of the sky-earth fusion network specifically includes:

Discrete the topology of the world-earth fusion network into multiple time slices, and the topology in each time slice remains unchanged;

When a satellite-to-ground link between a ground station and a satellite exists in the previous time slot, but does not exist in the current time slot, the data stream passing through the current satellite-to-ground link in the previous time slot needs to be rerouted;

In each time slice, newly established data flows and data flows that need to be rerouted are screened out, new paths are selected for them, and the modeled model is determined.

According to a satellite-ground coordinated global content distribution and routing method provided by the present invention, the selection of a satellite path for each data stream specifically includes:

For each data stream that needs to choose a path, it is determined that the user terminal is connected to the satellite, and the connected satellite is used as the destination satellite;

Select the satellite-to-ground link set of the ground station corresponding to the data stream in the current time slice, calculate the number of hops from the ground station to the destination satellite through the satellite-to-ground link in the set according to the grid-like characteristics of the satellite network, and record the number of hops. The minimum number of hops to reach the destination satellite;

The actual path selection needs to satisfy the constraint that the number of hops is less than or equal to the set multiple of the minimum number of hops. Among all the satellite-to-ground links that satisfy the constraint of the number of hops, the satellite-to-ground link with the least number of data streams is selected as the path to the satellite. , and the corresponding satellite acts as the on-board node to add the data stream to the satellite-ground link.

According to a satellite-ground coordinated global content distribution routing method provided by the present invention, the selection of an inter-satellite routing path for each data stream specifically includes:

According to the distance between the satellites at both ends of each inter-satellite link and the ground station, estimate the available bandwidth of the ground station on each inter-satellite link;

Obtain the direction of data forwarding from the on-board node to the destination node, including the directions between orbits and within orbits;

Within the rectangular range formed by the up-star node to the destination node, starting from the up-satellite node, according to the inter-orbit and intra-orbit directions to the destination node, according to the available bandwidth of each inter-satellite link and the data flow rate of the above-mentioned ground station number, estimate the maximum bandwidth that can be obtained by each satellite passing through the rectangular range, and record whether the direction of the maximum bandwidth is from inter-orbit or intra-orbit;

According to the recorded direction, push backward from the destination node to construct a complete path.

According to a satellite-ground coordinated global content distribution routing method provided by the present invention, segmenting the path and encoding the path specifically includes:

Starting from the up-star node, walk along the inter-orbit link until the next node and the current node are in the same orbit;

Walk along the in-track link until the next node and the current node are on different tracks;

Record the current node, as a split node of the path, repeatedly walk along the direction of the inter-track link and the intra-track link, record the split node, until the destination node is reached;

Arrange the star node, all split nodes and destination nodes in sequence as the encoded data of the path.

The present invention also provides a satellite-ground coordinated global content distribution and routing system, the system comprising: a global ground station management center and a ground station;

The global ground station management center is used to calculate the distance between all ground stations and the user terminal according to the geographic location of the user terminal and all ground stations after receiving the ground station service request message sent by the satellite signal receiver; based on The distance between all ground stations and the user terminal, select the ground station with the least load among the ground stations that meet the distance limit as the target ground station; send the information of the target ground station to the user terminal; the ground station serves The request message is sent when the user terminal accesses the satellite through the satellite signal receiver;

The ground station is configured to calculate the path of data transmission by using the satellite network segment routing method based on the ground station after receiving the content service request sent by the user terminal, and perform segment coding on the path to obtain the encoded data of the path; The encoded data of the path is embedded in the header of the message using the method of segment routing, and the encoded data of the path is used in the satellite, and the satellite parses the path and distributes the content according to the parsed path; the content service request is: After receiving the information of the target ground station sent by the global ground station management center, the user terminal sends the information according to the information of the target ground station.

The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and running on the processor, the processor implementing the above-mentioned satellite-ground cooperation when executing the program global content distribution routing method.

The present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, implements the global content distribution and routing method described in any of the above-mentioned satellite-ground coordination.

The present invention provides a satellite-ground coordinated global content distribution and routing method, system and electronic equipment. Through the global ground station management center, ground stations are allocated to users for services; the globally distributed ground stations provide users with content services, and according to load It calculates the satellite-to-satellite and inter-satellite paths of data transmission, and embeds the path into the header of the message in the way of segmented routing by means of segmented coding, so that the satellite can obtain the forwarding path. Through the satellite network segment routing method based on ground stations, with topology, user traffic, and link capacity as input conditions and path length as constraints, a high-bandwidth and low-latency path is selected for each flow to maximize system throughput , realize high-bandwidth and low-latency data transmission, and distribute global Internet content.

Description of drawings

In order to explain the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are of the present invention. For some embodiments of the present invention, for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is the schematic flow chart of the global content distribution routing method applied to the global ground management center provided by the present invention;

2 is a schematic flowchart of a global content distribution and routing method applied to ground station coordination provided by the present invention;

3 is a schematic flowchart of a method for segmented routing of a satellite network based on a ground station provided by the present invention;

Fig. 4 is the schematic flow chart of the path that selects the maximum bandwidth of the destination satellite provided by the present invention;

5 is a schematic diagram of an experimental result of a satellite-ground coordinated global content distribution and routing method provided by the present invention;

6 is a schematic diagram of the composition of a global content distribution routing system provided by the present invention;

FIG. 7 is a schematic structural diagram of an electronic device provided by the present invention.

Reference number:

110: Global Ground Station Management Center; 120: Ground Station; 130: Satellite; 140: Satellite Signal Receiver; 150: Ground Station Selection Module; 160: Path Selection Module; 170: Path Encoding Module; 180: Load Monitoring Module: 190 : segment routing module; 200: shortest path module; 210: request processing module; 810: processor; 820: communication interface; 830: memory; 840: communication bus.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention 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 invention. , not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Below in conjunction with Fig. 1-Fig. 5, describe a kind of satellite-ground coordinated global content distribution routing method of the present invention, applied to the global ground station management center, including:

S100. After receiving the ground station service request message sent by the satellite signal receiver, calculate the distances between all ground stations and the user terminal according to the geographic positions of the user terminal and all ground stations, and the ground station service request message is in the Sent when the user terminal accesses the satellite through the satellite signal receiver;

S200. Based on the distances between all ground stations and the user terminal, among the ground stations meeting the distance limit, select the ground station with the smallest load as the target ground station;

S300. Send the information of the target ground station to the client, where the information of the target ground station is used to request a content service.

As shown in Figure 2, a satellite-ground collaborative global content distribution and routing method, applied to a ground station, includes:

S101. After receiving the content service request sent by the user terminal, use the satellite network segment routing method based on the ground station to calculate the data transmission path, and perform segment coding on the path to obtain the encoded data of the path, and the content service request is After the user terminal receives the information of the target ground station sent by the global ground station management center, it is sent according to the information of the target ground station;

S102: Embed the encoded data of the path into the header of the message by using the segment routing method, the encoded data of the path is used in the satellite, and the satellite parses the path and distributes content according to the parsed path.

The ground station sends the message to the client through the satellite network, and the satellite receives the message, parses it according to the path encoded data in the message header, obtains the next hop of the current satellite, and updates the encoded data and embeds it in the message header. And forward to the next hop until the content is distributed.

When the load of the ground station exceeds the first threshold or is lower than the second threshold, the ground station sends an adjustment signal to the ground station management center to update the load situation; when the load of the ground station exceeds the first threshold th _up , the ground station sends an adjustment signal to the ground station The management center sends an overload signal and updates its load. When the number of users served by the ground station decreases and the load is lower than the second threshold th _low , the ground station sends an overload release signal to the ground station management center and updates its load.

As shown in Figure 3, after the ground station receives the content service request sent by the user terminal, it uses the satellite network segment routing method based on the ground station to calculate the data transmission path, and encodes the path segment to obtain the encoded data of the path. Specifically include:

Model the topology, traffic, and routing optimization goals of the world-earth fusion network;

Model the topology of the sky-earth fusion network, discretize the dynamic topology of the sky-earth fusion network into multiple time slices, and construct a static topology G _t (V _t , E _t ) in each time slice t, where the point set V _t =SAT _t ∪GS, SAT _t is the satellite set, GS is the ground station set, the edge set E _t =ISL _t ∪ GSL _t , ISL _t is the inter-satellite link set, and GSL _t is the satellite-ground link set.

表示数据流f在时间片t是否经过链路a→b，如果经过则为1，否则为0，则经过链路a→b的数据流的数量为

假设链路a→b在时间片t的链路容量

包含了三种链路：星间链路、地面站和卫星之间的星地链路、用户和卫星之间的星地链路，其容量分别为C_ISL、C_GSL、C_USL。假设每条链路上的数据流都能够公平地共享链路的容量，则数据流f在链路a→b上能获得的带宽为

在路径P_t,f上能获得的带宽为路径上每条链路的带宽最小值

同时，受限于用户和接入卫星的链路容量C_USL，最终f的带宽为

Modeling the flow, for the assignment according to (A2), the data flows served by the ground station gs constitute a data flow set F _gs , and the data flow set served by all the ground stations is F=U _gs∈GS F _gs . For each data stream f in the data stream set, the selected ground station is denoted as SGS _f , the access satellite of the user terminal in time slice t is denoted as UAS _t,f , and the ground station needs to select a path P _t,f for it :SGS _f →a→b→…→UAS _t,f . use

Indicates whether the data flow f passes through the link a→b in the time slice t, if it passes, it is 1, otherwise it is 0, and the number of data flows passing through the link a→b is

Suppose the link capacity of link a→b in time slice t

Three kinds of links are included: the inter-satellite link, the satellite-to-ground link between the ground station and the satellite, and the satellite-to-ground link between the user and the satellite, and their capacities are _CISL , C _GSL , and C _USL , respectively. Assuming that the data flow on each link can share the capacity of the link fairly, the bandwidth that the data flow f can obtain on the link a→b is

The bandwidth that can be obtained on the path P _t,f is the minimum bandwidth of each link on the path

At the same time, limited by the link capacity C _USL of users and access satellites, the final bandwidth of f is

为输入条件，为每条数据流f找到一条路径P_t,f，使得每个时间片内的系统吞吐量最大化，系统吞吐量即所有流量的带宽之和：∑_f∈Fbw_t,f。同时满足路径长度约束条件H(P_t,f)≤αH(SP_t,f)，以满足低时延的需求，其中H函数表示路径的长度，SP_t,f表示从地面站到用户接入卫星的最短路径，α为大于1的定值，表示所选取的路径长度不能超过最短路径的α倍。Model the routing optimization objective with topology G _t , flow F , capacity of each link

For the input condition, find a path P _t,f for each data flow f, so as to maximize the system throughput in each time slice, the system throughput is the sum of the bandwidth of all flows: ∑ _f∈F bw _t,f . At the same time, the path length constraint H(P _t,f )≤αH(SP _t,f ) is satisfied to meet the requirement of low delay, where the H function represents the length of the path, and SP _t,f represents the access from the ground station to the user The shortest path of the satellite, α is a fixed value greater than 1, indicating that the length of the selected path cannot exceed α times the shortest path.

In each time slice, newly established data flows and data flows that need to be rerouted are screened out, and new paths are selected for them. Among them, the data flow that needs to be rerouted is defined as: if a satellite-to-ground link between a satellite and a ground station exists in the previous time slice, but does not exist in the current time slice, the last time slice passes through the satellite-to-ground link. The data flow of the road needs to be rerouted.

For each data stream that needs to choose a path, determine that the user end accesses the satellite as the destination satellite. Select the satellite-ground link set of the ground station corresponding to the data stream in the current time slice. According to the grid-like characteristics of the satellite network, the number of hops from the ground station to the destination satellite through the satellite-ground link in the set is calculated. Among them, the number of hops from the ground station to the destination satellite is calculated according to the following steps: Assuming that the satellite constellation has a total of N orbits, each orbit has M satellites, and a satellite that establishes a connection with the ground station is denoted as src. The position is (η _src , θ _src ), which represents the θ _src satellite in the η _src orbit, the destination satellite is denoted as dst, and the position in the grid is (η _dst , θ _dst ), which represents the η _dst orbit. θ _dst satellites, then the inter-orbital distance from src to dst is Δη=min(|η _dst -η _src |,N-|η _dst -η _src |), and the intra-orbital distance from src to dst is Δθ=min(| θ _dst -θ _src |,N-|θ _dst -θ _src |), the number of hops from src to dst is Δη+Δθ, and the number of hops from the ground station to dst through the satellite-to-ground link connected to src is Δη+Δθ+ 1.

Select the satellite-to-ground link that enables the ground station to reach the destination satellite with a number of hops less than or equal to αH(SP _t,f ) as the candidate set. In the candidate set, the satellite-ground link with the least number of data streams is selected as the path to the satellite, and the corresponding satellite is used as the satellite-mounted node, and then the data stream is added to the satellite-ground link.

天地融合网络的物理位置和逻辑位置是相对应的，当卫星和地面站距离较近时，卫星被地面站使用的概率越大。设地球半径为R，卫星高度为h，则地面站gs在卫星s上的权重可以设置为

进行归一化处理后，地面站gs在卫星s上的流量占比

可以估计为

地面站gs在星间链路a→b上的流量占比

可以估计为两颗卫星流量占比的均值

那么地面站gs在卫星s上获得的总带宽

可以估计为

According to the distance between the satellites at both ends of each inter-satellite link and the ground station and the number of data streams on each inter-satellite link at each ground station, estimate the available bandwidth of the ground station on each inter-satellite link, including the following Step: The position of the satellite can be obtained from the predictability of the satellite movement, and the distance between each satellite s and each ground station gs at time t is calculated according to the positions of the satellite and the ground station

The physical location and logical location of the sky-earth fusion network are corresponding. When the distance between the satellite and the ground station is closer, the probability of the satellite being used by the ground station is greater. Let the radius of the earth be R and the height of the satellite be h, then the weight of the ground station gs on the satellite s can be set as

After normalization, the traffic proportion of ground station gs on satellite s

can be estimated as

The traffic proportion of the ground station gs on the inter-satellite link a→b

It can be estimated as the average of the traffic proportions of the two satellites

Then the total bandwidth obtained by the ground station gs on the satellite s

can be estimated as

可以估计为地面站可获得的总带宽除以数据流的数量：

Estimate the bandwidth available on each inter-satellite link for each data stream. Assuming that the position of satellite a in the grid is (η _a , θ _a ), it represents the θ _a satellite of the η _a -th orbit, and the position of satellite b in the grid is (η _b , θ _b ), which represents the η th satellite The theta _b -th satellite in the _b orbit. Then the bandwidth of link a→b

It can be estimated as the total bandwidth available to the ground station divided by the number of data streams:

如果通过轨内链路到达卫星(i,j)，前一个节点为(i,j-θ_dir)，可获得的带宽intra_i,j为上述轨内链路的估计带宽和前一个节点可获得带宽的较小值：

D_i,j可以通过以下状态转移方程计算得到：Select the path with the largest bandwidth to the destination satellite. As shown in Figure 4, the direction of data forwarding from the on-board node to the destination node is obtained, including the inter-orbit and intra-orbit directions. Within the rectangular range formed from the on-board node to the destination node, according to the inter-orbit direction and the intra-orbit direction from the on-board node to the destination node, estimate the maximum bandwidth that can be obtained by the satellites reaching the rectangular range in turn, and record the maximum bandwidth. Whether the direction is from inter-orbital or intra-orbital. According to the direction recorded above, push backwards from the destination node to construct a complete path. Specifically, the maximum bandwidth that can be obtained by the jth satellite (i,j) of the ith orbit is denoted as D _i,j . Starting from the on-board node, other satellites can be reached through inter-orbit links or intra-orbit links. The direction of the inter-orbit link from the on-board node to the destination satellite is denoted as η _dir , and the direction of the intra-orbit link is denoted as θ _dir . The value is 1 or -1, indicating the direction in which the satellite number increases or decreases (1 in the case of the same orbital plane). If the satellite (i,j) is reached through the inter-orbit link, the previous node is (i-η _dir ,j), the available bandwidth inter _i,j is the estimated bandwidth of the above-mentioned inter-orbit link and the previous node can obtain Smaller value of bandwidth:

If the satellite (i,j) is reached through the in-orbit link, and the previous node is (i,j-θ _dir ), the available bandwidth intra _i,j is the estimated bandwidth of the above-mentioned in-orbit link and the available bandwidth of the previous node Smaller value of bandwidth:

D _i,j can be calculated by the following state transition equation:

和用户与卫星之间的星地链路容量C_USL的较小值。对于和上星节点处于不同轨道但具有相同轨内位置的卫星，即i≠η_src且j＝θ_src，从上星节点出发的最短路径只能通过轨间链路到达，其带宽为上述通过轨间链路到达可获得的带宽：D_i,j＝inter_i,j；对于和上星节点处于同一轨道的卫星，即i＝η_src且j≠θ_src，从上星节点出发的最短路径只能通过轨内链路到达，其带宽为上述通过轨内链路到达可获得的带宽：D_i,j＝intra_i,j；对于其余矩形范围内的卫星，可以通过轨内链路到达，也可以通过轨间链路到达，选择并记录可获得带宽较大的链路，其带宽为inter_i,j和intra_i,j的较大值：D_i,j＝max(inter_i,j,intra_i,j)。The maximum bandwidth of the up-star node src is initialized to the bandwidth of the ground station's up-star link equally distributed to each data stream

and the smaller value of the satellite-ground link capacity C _USL between the user and the satellite. For satellites that are in different orbits but have the same intraorbital position with the on-board node, i.e. i≠η _src and j=θ _src , the shortest path from the on-satellite node can only be reached through the inter-orbit link, and its bandwidth is the above-mentioned pass The available bandwidth of the inter-orbit link: D _i,j =inter _i,j ; for satellites in the same orbit as the on-board node, i.e. i=η _src and j≠θ _src , the shortest path from the on-board node It can only be reached through the in-orbit link, and its bandwidth is the above-mentioned available bandwidth through the in-orbit link: D _i,j =intra _i,j ; for the rest of the satellites within the rectangular range, it can be reached through the in-orbit link, It can also be reached through the inter-track link, select and record the link with a larger bandwidth, and its bandwidth is the larger value of inter _i,j and intra _i,j : D _i,j =max(inter _i,j , intra _i,j ).

Segment the path and encode the path, including the following steps: starting from the up-star node, walking along the inter-orbit link until the next node and the current node are in the same orbit; then walking along the intra-orbit link until The next node and the current node are in different orbits. Record the current node as a split node of the path. Repeatedly walking in the direction of the inter-track link and the intra-track link, recording the split nodes, until reaching the destination node. Arrange the star node, all split nodes and destination nodes in order, which is the encoded path. Until all data flows that need to be routed have made decisions and enter the next time slice.

An experimental platform is built to verify the satellite-ground coordinated global content distribution routing system and the satellite network segment routing method based on the ground station proposed by the present invention. The main attributes of the experimental verification machine are: CPU E5-2630v4, operating system Ubuntu 20.04. 1LTS. The shortest path algorithm (SP), the satellite network-oriented ELB algorithm, the NCMCR algorithm and the algorithm of the present invention (AEROPATH) are used for comparison. FIG. 5 is a schematic diagram showing the comparison of throughput and various algorithms of the ground station-based satellite network segment routing method of the present invention. The system throughput is the sum of the bandwidths of all data streams, and the higher the value, the better; the system throughput changes with time, and the system throughput of the method proposed in the present invention is always better than other algorithms. Realize high-bandwidth and low-latency data transmission for global Internet content distribution.

Referring to FIG. 6 , the present invention also discloses a satellite-ground coordinated global content distribution and routing system, including: a global ground station management center 110 and a ground station 120;

The global ground station management center 110 is configured to, after receiving the ground station service request message sent by the satellite signal receiver, calculate the distance between all ground stations and the user terminal according to the geographic positions of the user terminal and all ground stations; The distance between the ground station 120 and the user terminal, select the ground station with the smallest load among the ground stations that meet the distance limit as the target ground station; send the information of the target ground station to the user terminal; the ground station serves The request message is sent when the user terminal accesses the satellite through the satellite signal receiver;

The global ground station management center 110 includes: a ground station selection module 150, the ground station selection module 150 collects the information of all ground stations, including: geographic location and load; when a user applies for ground service, a ground station is selected for each user serve it.

The ground station 120 is used to calculate the path of data transmission by using the satellite network segment routing method based on the ground station 120 after receiving the content service request sent by the user terminal, and to perform segment coding on the path to obtain the encoded data of the path; The encoded data of the path is embedded in the header of the message using the method of segment routing, and the encoded data of the path is used in the satellite, and the satellite parses the path and distributes the content according to the parsed path; the content service request is: After the user terminal receives the information of the target ground station sent by the global ground station management center, it is sent according to the information of the target ground station;

The ground station 120 includes: a path selection module 160, a path encoding module 170, and a load monitoring module 180. The path selection module 160 runs a routing algorithm and calculates a data transmission path; the path encoding module 170 divides the calculated path into A plurality of segments are encoded to form encoded data, and the encoded data is embedded in the header of the message by using the method of segment routing; the load monitoring module 180 monitors the load of the ground station in real time, and when the load of the ground station 120 is higher than the set first When the threshold is lower than the set second threshold, the ground station 120 will send the current load to the global ground station management center 110 to reduce or increase the users assigned by the global ground station management center.

A satellite-ground coordinated global content distribution and routing system, further comprising: a satellite 130 and a satellite signal receiver 140;

The satellite 130 includes: a segment routing module 190 and a shortest path module 200. For a packet containing a segment routing header, the segment routing module 190 parses the packet segment routing header and decodes the path to obtain the next hop. , and re-encode the path into the message header; for messages without segment routing headers, the satellite uses the shortest path module to calculate the routing table and forward the message;

The satellite signal receiver 140 is connected to the user terminal and includes a user request processing module. If the user has not been assigned a ground station serving it, then when the user initiates a ground station service request, the user request processing module applies to the ground station management center for a ground station. Station service, wait for the ground station management center to assign the user a ground station that provides services, and then forward the user request to the assigned ground station.

Through the global ground station management center 110, the ground stations 120 are allocated to users to serve them; the globally distributed ground stations 120 provide users with content services, calculate the satellite-to-ground and inter-satellite paths for data transmission according to the load situation, and use segment coding The path is embedded in the header of the message in the way of segment routing, so that the satellite can obtain the forwarding path. At the same time, the real-time monitoring load provides a decision basis for the ground station management center; when the satellite 130 reads the segment route, according to the message The data is forwarded by the path of the head, otherwise, it is forwarded according to the shortest path; the satellite signal receiver 140 requests the global ground station management center 110 to allocate the ground station 120 to serve the user when the user accesses the satellite. Through the satellite network segment routing method based on ground stations, with topology, user traffic, and link capacity as input conditions, and path length as constraints, a high-bandwidth and low-latency path is selected for each data stream to maximize system throughput It can realize high-bandwidth and low-latency data transmission for global Internet content distribution.

FIG. 7 illustrates a schematic diagram of the physical structure of an electronic device. As shown in FIG. 7 , the electronic device may include: a processor (processor) 810, a communication interface (Communications Interface) 820, a memory (memory) 830, and a communication bus 840, The processor 810 , the communication interface 820 , and the memory 830 communicate with each other through the communication bus 840 . The processor 810 can invoke the logic instructions in the memory 830 to execute a satellite-ground coordination method for global content distribution and routing, which is applied to the global ground station management center, including:

After receiving the ground station service request message sent by the satellite signal receiver, calculate the distance between all ground stations and the user terminal according to the geographic positions of the user terminal and all ground stations, and the ground station service request message is in the user terminal. sent when the terminal accesses the satellite through the satellite signal receiver;

Based on the distances between all ground stations and the user terminal, among the ground stations that meet the distance limit, the ground station with the smallest load is selected as the target ground station;

The information of the target ground station is sent to the user terminal, and the information of the target ground station is used to request a content service.

An electronic device is also applied to the ground station, including:

After receiving the content service request sent by the user terminal, use the satellite network segment routing method based on the ground station to calculate the data transmission path, and segment the path to encode the path to obtain the encoded data of the path, and the content service request is the described content service request. After the user terminal receives the information of the target ground station sent by the global ground station management center, it is sent according to the information of the target ground station;

The coded data of the path is embedded in the header of the message by using the method of segment routing, and the coded data of the path is used in the satellite, and the satellite parses the path and distributes the content according to the parsed path.

In addition, the above-mentioned logic instructions in the memory 830 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, Read-Only Memory (ROM, Read-Only Memory), Random Access Memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program codes .

In another aspect, the present invention also provides a computer program product, the computer program product includes a computer program, the computer program can be stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer can Execute a satellite-ground coordinated global content distribution routing method provided by the above methods, applied to the global ground station management center, including:

After receiving the ground station service request message sent by the satellite signal receiver, calculate the distance between all ground stations and the user terminal according to the geographic positions of the user terminal and all ground stations, and the ground station service request message is in the user terminal. sent when the terminal accesses the satellite through the satellite signal receiver;

Based on the distances between all ground stations and the user terminal, among the ground stations that meet the distance limit, the ground station with the smallest load is selected as the target ground station;

The information of the target ground station is sent to the user terminal, and the information of the target ground station is used to request a content service.

A computer program product is also applied to the ground station, comprising:

After receiving the content service request sent by the user terminal, use the satellite network segment routing method based on the ground station to calculate the data transmission path, and segment the path to encode the path to obtain the encoded data of the path, and the content service request is the described content service request. After the user terminal receives the information of the target ground station sent by the global ground station management center, it is sent according to the information of the target ground station;

The coded data of the path is embedded in the header of the message by using the method of segment routing, and the coded data of the path is used in the satellite, and the satellite parses the path and distributes the content according to the parsed path.

In yet another aspect, the present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored, and the computer program is implemented when executed by a processor to execute a satellite-earth coordinated global content provided by the above methods Distribution routing method, applied to the global ground station management center, including:

After receiving the ground station service request message sent by the satellite signal receiver, calculate the distance between all ground stations and the user terminal according to the geographic positions of the user terminal and all ground stations, and the ground station service request message is in the user terminal. sent when the terminal accesses the satellite through the satellite signal receiver;

Based on the distances between all ground stations and the user terminal, among the ground stations that meet the distance limit, the ground station with the smallest load is selected as the target ground station;

The information of the target ground station is sent to the user terminal, and the information of the target ground station is used to request a content service.

A non-transitory computer-readable storage medium is also applied to a ground station, comprising:

After receiving the content service request sent by the user terminal, use the satellite network segment routing method based on the ground station to calculate the data transmission path, and segment the path to encode the path to obtain the encoded data of the path, and the content service request is the described content service request. After the user terminal receives the information of the target ground station sent by the global ground station management center, it is sent according to the information of the target ground station;

The coded data of the path is embedded in the header of the message by using the method of segment routing, and the coded data of the path is used in the satellite, and the satellite parses the path and distributes the content according to the parsed path.

The device embodiments described above are only illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in One place, or it can be distributed over multiple network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution in this embodiment. Those of ordinary skill in the art can understand and implement it without creative effort.

From the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and certainly can also be implemented by hardware. Based on this understanding, the above-mentioned technical solutions can be embodied in the form of software products in essence or the parts that make contributions to the prior art, and the computer software products can be stored in computer-readable storage media, such as ROM/RAM, magnetic A disc, an optical disc, etc., includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods described in various embodiments or some parts of the embodiments.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A global content distribution routing method based on satellite-ground coordination is characterized by being applied to a global ground station management center and comprising the following steps:

after receiving a ground station service request message sent by a satellite signal receiver, calculating the distances between all ground stations and a user side according to the geographical positions of the user side and all ground stations, wherein the ground station service request message is sent when the user side is accessed to a satellite through the satellite signal receiver;

selecting the ground station with the minimum load as a target ground station from the ground stations meeting the distance limit based on the distances between all the ground stations and the user side;

and sending the information of the target ground station to the user side, wherein the information of the target ground station is used for requesting content services.

2. A satellite-ground cooperative global content distribution routing method is applied to a ground station and comprises the following steps:

after receiving a content service request sent by a user side, calculating a data transmission path by using a satellite network segmented routing method based on a ground station, and carrying out segmented coding on the path to obtain coded data of the path, wherein the content service request is sent by the user side according to information of a target ground station after receiving the information of the target ground station sent by a global ground station management center;

and embedding the encoded data of the path into the header of the message by using a segmented routing method, wherein the encoded data of the path is used in a satellite, and the satellite analyzes the path and distributes contents according to the analyzed path.

3. The global content distribution routing method for satellite-ground collaboration as claimed in claim 2, wherein after receiving the content service request sent by the user, the method calculates a data transmission path by using a satellite network segment routing method based on a ground station, and performs segment coding on the path to obtain coded data of the path, specifically comprising:

modeling the topology, the flow and the route optimization target of the heaven and earth fusion network, dispersing the topology of the heaven and earth fusion network into a plurality of time slices, and screening data streams needing to be rerouted to obtain a modeled model;

selecting a staring path for each data stream, and selecting a staring link with the least data stream quantity as the staring path from the staring links meeting the hop count constraint;

selecting an inter-satellite routing path for each data stream, estimating the maximum bandwidth which can be obtained at each node according to the available bandwidth of the ground station at each inter-satellite link and the number of the data streams, recording that the direction of the maximum bandwidth comes from inter-orbit or intra-orbit, and reversely pushing from a target node to construct a complete inter-satellite routing path;

and segmenting the path, encoding the path, determining segmentation nodes in the path, and arranging the staring node, all the segmentation nodes and the destination node in sequence to store as the encoded data of the path.

4. The global content distribution routing method for satellite-ground collaboration as claimed in claim 3, wherein the modeling of topology, traffic and route optimization objectives of the world-ground converged network specifically comprises:

dispersing the topology of the heaven and earth converged network into a plurality of time slices, wherein the topology in each time slice is kept unchanged;

when a satellite-ground link between a ground station and a satellite exists in the last time slice but does not exist in the current time slice, the data flow of the last time slice passing through the current satellite-ground link needs to be rerouted;

and screening out newly established data flows and data flows needing to be rerouted in each time slice, selecting a new path for the newly established data flows and determining a modeled model.

5. The global content distribution routing method for satellite-to-ground collaboration as claimed in claim 3, wherein the selecting a path of a satellite for each data stream specifically comprises:

determining a user side access satellite for each data stream needing path selection, wherein the access satellite is used as a target satellite;

selecting a satellite-ground link set of a ground station corresponding to the data stream in the current time slice, calculating the hop counts of the ground station to a target satellite through satellite-ground links in the set according to the latticed characteristic of a satellite network, and recording the least hop counts of the target satellite;

the actual selected path needs to meet the constraint condition that the hop count is less than or equal to the set multiple of the minimum hop count, and the satellite-ground link with the minimum number of data streams is selected from all the satellite-ground links meeting the hop count constraint condition to serve as the last-star path, the corresponding satellite serves as a last-star node, and the data streams are added to the satellite-ground links.

6. The global content distribution routing method for satellite-to-ground collaboration as claimed in claim 3, wherein the selecting an inter-satellite routing path for each data stream specifically comprises:

estimating the available bandwidth of the ground station on each intersatellite link according to the distance between the satellites at the two ends of each intersatellite link and the ground station;

acquiring the data forwarding direction from the staring node to the destination node, including the direction between the rails and the direction in the rails;

in a rectangular range formed by a staring node and a destination node, starting from the staring node, estimating the maximum bandwidth which can be obtained by each satellite in the rectangular range according to the inter-orbit and intra-orbit directions to the destination node and the available bandwidth of each inter-satellite link of the ground station and the quantity of data streams, and recording whether the direction of the maximum bandwidth comes from the inter-orbit or the intra-orbit;

and according to the recorded direction, backward pushing from the destination node to construct a complete path.

7. The global content distribution routing method for satellite-to-ground collaboration as claimed in claim 3, wherein the segmenting the path and encoding the path comprises:

starting from the upper star node, walking along the inter-rail link until the next node and the current node are in the same orbit;

walking along the intra-rail link until the next node and the current node are in different rails;

recording a current node as a segmentation node of a path, repeatedly walking along the direction of an inter-rail link and an intra-rail link, and recording the segmentation node until a target node is reached;

and arranging the staring node, all the segmentation nodes and the destination node in sequence to be used as the encoded data of the path.

8. A satellite-to-ground coordinated global content distribution routing system, the system comprising: a global ground station management center and ground stations;

the global ground station management center is used for calculating the distances between all ground stations and the user side according to the geographical positions of the user side and all ground stations after receiving the ground station service request message sent by the satellite signal receiver; selecting a ground station with the minimum load from the ground stations meeting the distance limit as a target ground station based on the distances between all the ground stations and the user side; sending the information of the target ground station to the user side; the ground station service request message is sent when the user terminal accesses a satellite through the satellite signal receiver;

the ground station is used for calculating a data transmission path by using a satellite network segmented routing method based on the ground station after receiving a content service request sent by the user side, and carrying out segmented coding on the path to obtain coded data of the path; the coded data of the path is embedded into the header of the message by using a segmented routing method, the coded data of the path is used in a satellite, and the satellite analyzes the path and distributes content according to the analyzed path; and the content service request is sent according to the information of the target ground station after the user side receives the information of the target ground station sent by the global ground station management center.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor when executing the program implements a satellite-to-ground coordinated global content distribution routing method according to any one of claims 1 to 7.

10. A non-transitory computer readable storage medium having stored thereon a computer program, wherein the computer program when executed by a processor implements the satellite-to-ground collaborative global content distribution routing method according to any one of claims 1 to 7.

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