Content distribution method and system based on satellite multicast, terminal, server and medium

Abstract

The invention relates to the technical field of satellite communication, and discloses a content distribution method and system based on satellite multicast, a terminal, a server and a medium, and the method comprises the steps that a satellite end receives second information sent by the server, and the second information is used for indicating the content subscribed by a user; and the satellite end distributes the second information to user servers in a plurality of multicast groups, so that the user can obtain the required content. According to the invention, through multi-beam satellite multicast, the second information is filled into the corresponding buffer according to the user demand, the local cache hit rate of the user side is maximized, and the ground network occupation and the total network transmission cost are reduced.

Description

Technical Field

[0001] The present application relates to the field of satellite communication technology, and in particular to a content distribution method, system, terminal, server and medium based on satellite multicast. Background Art

[0002] As the demand for video and image transmission continues to grow across fixed and mobile terrestrial networks, optimizing content delivery across the internet is gaining increasing attention. A common solution is to use a dedicated content delivery network (CDN), a network resource that integrates technologies, architectures, and protocols to ensure that key prerequisites for delivering multimedia services over public IP networks (such as quality of experience, efficiency, and scalability) are met. Traditional CDNs have only provided services on the ground, and the large amount of data storage and forwarding that occurs can exacerbate congestion in the terrestrial core network.

[0003] With the introduction of satellite broadcasting capabilities, CDN services have become a current solution due to the satellite system's ability to quickly deploy services, support inexpensive receiving terminals, and reduce congestion in the terrestrial core network by distributing data directly to all edge caches regardless of their location in the coverage area. For example, live linear TV broadcasting is a traditional way of enhancing CDN services by utilizing the broadcasting capabilities of geostationary orbit (GEO) satellites of fixed satellite services (FSS).

[0004] The existing technical solution is to enhance CDN services through satellite broadcasting capabilities, using satellite broadcast channel sets and network coding to push multiple contents (with limited interest) to multiple caches serving multiple users. Generally, one beam is used. As long as the user server is within the beam coverage, it can receive the broadcast message and obtain network content, which can reduce the congestion of the ground core network. However, due to the large broadcast coverage area and the lack of classification of user requests, there is a problem of inefficiency in the distribution of related content in principle. Moreover, the broadcast channel generally uses one beam with limited beam capacity, which is prone to performance limitations in the congested section of the end-to-end transmission path.

[0005] Existing technical solutions also do not consider how to implement and utilize the satellite's multi-beam multicast capabilities by classifying user needs and binding multi-beams to communities with different user needs, taking into account the on-demand distribution of popular content.

[0006] At the same time, due to the highly dynamic nature of network configuration and the need for complex cross-layer protocols to implement data routing and replication, current high-throughput satellite networks rarely support multicast. Furthermore, operators have yet to reach a consensus on the need for multicast-based services, as current high-throughput satellite network platforms are primarily used for point-to-point internet access. Furthermore, the current (low) utilization of satellite transponders has not yet motivated satellite operators to implement network improvements. Consequently, satellite operators have not yet added additional configuration and protocol layers to their infrastructure to support multicast. However, as large satellite constellations are established and the number of users increases dramatically, with user requests differing geographically and in terms of interests, the need for satellite multi-beam multicast will emerge. As the number of users, access volume, and network traffic increase, and the amount of data transmitted in the network becomes excessive, the resource consumption of the ground core network will be significant, leading to increased network transmission costs. Summary of the Invention

[0007] This application proposes a content distribution method, system, terminal, server and medium based on satellite multicast. Through multi-beam satellite multicast, the cache is filled with on-demand content (second information) according to user needs, maximizing the local cache hit rate of the user end, reducing ground network occupancy and overall network transmission costs.

[0008] The present application also discloses a content distribution method based on satellite multicast, which is applied to a satellite terminal and includes:

[0009] receiving second information sent by the server, where the second information is used to indicate content subscribed by the user;

[0010] The second information is distributed to user servers in multiple multicast groups so that users can obtain required content.

[0011] Furthermore, distributing the second information to user servers in multiple multicast groups includes:

[0012] According to the second information served by each user server and the location of each user server, each user server is divided into different multicast groups;

[0013] The second information is distributed to the user servers in the corresponding multicast group in a multi-beam multicast manner, so that the users can obtain their subscribed content from the user servers; each multicast group corresponds to a plurality of user servers.

[0014] Furthermore, distributing the second information to the corresponding user server in the multicast group by multi-beam multicasting so that the user can obtain the subscribed content from the user server includes:

[0015] The second information is distributed to the cache in the user server in the corresponding multicast group in a multi-beam multicast manner, so that the user can obtain the subscribed content from the cache.

[0016] The present application also discloses a content distribution method based on satellite multicast, which is applied to a server and includes:

[0017] Receive first information; the first information includes content obtained by the user from the user server;

[0018] Obtaining second information based on the first information, where the second information is used to indicate content subscribed by the user;

[0019] The second information is sent to the satellite end.

[0020] Furthermore, obtaining the second information according to the first information includes:

[0021] Perform user preference analysis on the content received by the user from the cache in the user server to obtain second information.

[0022] Furthermore, the sending the second information to the satellite terminal includes:

[0023] The second information is transmitted to the satellite end through the designated beam, so that the satellite end distributes the second information to the corresponding user service end through the designated beam, so that the user can obtain the subscribed content from the user service end.

[0024] Furthermore, it also includes:

[0025] When the second information or the hot content in the user's area changes, the mapping relationship between the cache, multicast group and beam is updated so that the user can obtain the content he subscribes to; the beam is used to provide the second information to the cache in the user server in its corresponding multicast group.

[0026] The present application also discloses a satellite terminal, which includes at least one processor, the at least one processor is coupled to at least one memory, and the at least one processor is used to read the computer program stored in the at least one memory to execute any of the above-mentioned satellite multicast-based content distribution methods.

[0027] The present application also discloses a server, comprising at least one processor coupled to at least one memory, wherein the at least one processor is configured to read a computer program stored in the at least one memory to execute any of the above-described satellite multicast-based content distribution methods.

[0028] The present application also discloses a content distribution system based on satellite multicast, which includes the satellite terminal and the server mentioned above.

[0029] Furthermore, it also includes a user server; the user server is used to receive second information sent by the satellite end, and the second information is used to indicate the content subscribed by the user.

[0030] Furthermore, the user server includes a cache; the cache is used to cache the received second information so that the user can obtain the subscribed content.

[0031] The present application also discloses a computer-readable storage medium, which stores computer instructions. When the computer instructions are executed on a computer, the computer executes a content distribution method based on satellite multicast corresponding to a satellite terminal, or the computer executes a content distribution method based on satellite multicast corresponding to a server. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a flowchart of a content distribution method based on satellite multicast according to an embodiment of the present application.

[0033] Figure 2 This is a block diagram of a content distribution system based on satellite multicast according to an embodiment of the present application.

[0034] Figure 3 This is a flowchart of another content distribution method based on satellite multicast according to an embodiment of the present application.

[0035] Figure 4 This is a flowchart of a simulated multi-beam multicast implementation in an embodiment of the present application.

[0036] Figure 5 It is a discrete probability distribution diagram of the request content in the embodiment of the present application.

[0037] Figure 6 3 is a graph showing how the cache hit rate and cache miss rate vary with cache capacity in an embodiment of the present application.

[0038] Figure 7 This is a graph showing how the cost of (ground transmission + satellite transmission + storage) varies with cache capacity in an embodiment of the present application.

[0039] Figure 8 This is a comparison chart of the terrestrial network transmission cost and satellite network transmission cost versus cache capacity in an embodiment of the present application.

[0040] Figure 9 This is a graph showing how the average cache hit rate and shared cache hit rate of the multi-beam multicast cache vary with the number of communities under each beam in an embodiment of the present application. DETAILED DESCRIPTION

[0041] In order to have a clearer understanding of the technical features, purposes and effects of the present application, the specific implementation methods of the present application are now described. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. That is, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0042] Unlike traditional methods that only utilize GEO (geostationary orbit, or geosynchronous orbit) broadcast capabilities to achieve enhanced CDN services, the present invention provides a content distribution method based on satellite multicast, which provides high-speed data connections and low latency by utilizing hundreds or thousands of satellites in low Earth orbit. LEO (low Earth orbit satellite) constellations will also significantly increase available capacity by enabling multiple beams on more satellites, see Figure 1 , the embodiments of the present application include:

[0043] Step 101: The server receives first information; the first information includes content obtained by the user from the user server;

[0044] The server may receive user-acquired content cached in a cache in a user server and sent by a network content provider.

[0045] Step 102: The server obtains second information based on the first information;

[0046] The server may classify and summarize the historical content obtained by the user from the cache in the user server to obtain second information, where the second information is used to indicate the content subscribed by the user, and the content subscribed by the user is the content that the user is interested in.

[0047] Optionally, the server can interact with the network connection point and the satellite operator's network manager to determine whether the transport protocol (MPLS) routing and universal stream encapsulation mapping need to be updated, and then determine the mapping relationship between the cache, multicast group and beam; the server's data transmission multicast tree can be continuously adjusted and kept consistent with the required data path; the required data path is the path for users to obtain their subscribed content.

[0048] Optionally, when the second information or the hot content in the user's area changes, the mapping relationship between the cache, multicast group, and beam is updated so that the user can obtain the latest subscribed content after the second information or the hot content in the user's area changes; the beam is used to provide the second information to the cache in the user server in its corresponding multicast group. For example, for a user, after a period of time, his preferred content or the hot content of the nearby cell changes. For example, the user belonging to multicast group A needs to obtain the required content from multicast group C due to changes in preferred content and hot content. At this time, it is necessary to update the mapping relationship between the cache, multicast group, and beam, but the current technology (high-orbit satellite) does not support dynamic configuration of the mapping relationship. Current high-orbit satellites can define beams ranging from global (all beams) to national (multiple beams) to local (a small number or one beam, which may also overlap), but based on geographically related content, one or more multicast groups are associated. It is generally used to push local news or national news. After the deployment of a low-orbit satellite constellation, the mapping relationship will change over time due to the high dynamics of constellation movement or user mobility. Therefore, for multi-beam multicast of a low-orbit satellite constellation, the server needs to interact with the network connection point and the satellite operator's network manager to determine whether the MPLS routing and GSE (Generic Stream Encapsulation) mapping need to be updated to determine the mapping relationship between caches, multicast groups and beams.

[0049] Step 103: The server sends the second information to the satellite terminal;

[0050] The server can send the second information to the satellite via the ground station gateway. The ground station gateway can then send the classified second information to the satellite via a designated beam, allowing the satellite to then send it to the user server in the multicast group via the designated beam, allowing the user to retrieve their subscribed content from the cache in the user server. The server supports user group detection and distributes the most appropriate content to the relevant caches via the appropriate multicast group, allowing users to retrieve the most appropriate subscribed content. In this way, caches that join a specific multicast group will receive a set of content that most users are likely to subscribe to in push mode, thereby increasing the probability of cache hits and reducing the load on the terrestrial network.

[0051] Step 104: The satellite terminal receives the second information sent by the server;

[0052] The satellite end can receive the second information sent by the server through the beam, so as to subsequently accurately push the second information to the cache in the user server corresponding to the user, and then the user obtains the content he needs from the cache.

[0053] Step 105: The satellite end distributes the second information to the user server ends in the plurality of multicast groups so that the users can obtain the required content.

[0054] The satellite divides each user server into different multicast groups based on the second information it serves and the location of each user server. The satellite distributes the second information to the user servers in the corresponding multicast group via multi-beam multicast, allowing users to obtain their subscribed content from the user servers. Each multicast group corresponds to several user servers. Each user server can correspond to multiple multicast groups. For example, if the users served by the user server are interested in multiple types of second information, the user server can join multiple multicast groups corresponding to these multiple types of second information to receive the second information it serves. This allows users to obtain their subscribed content from the satellite, reducing the use of the terrestrial communication network. A cache in the user server stores the second information received by the user server, allowing users to obtain related content.

[0055] This application uses multi-beam satellite multicast to cache on-demand content (second information) based on user needs, maximizing the local cache hit rate of the user server, reducing ground network occupancy and overall network transmission costs. This application uses a combination of terrestrial and satellite networks to effectively distribute content in caches as close to the user as possible, achieving on-demand content distribution based on popularity, providing users with high-quality network content with minimal impact on the core network.

[0056] After step 105, the following steps may also be included:

[0057] Step 106: The user service end sends the content obtained by the user to the server.

[0058] After executing steps 101 to 105, the user obtains the content (subscribed content) he / she needs from the cache in the user server, and then the user server sends the content obtained by each user to the server, that is, re-executing steps 101 to 105.

[0059] In the above embodiment, each satellite has multiple beams, with the specific number varying from a few to dozens depending on the technology. Each satellite will activate a certain number of beams, which partially overlap, to provide network coverage in the target area. Beams can be frequency reused, allowing the same frequency band allocation to be reused on non-adjacent beams to increase the total capacity of the satellite. Multi-beams can reuse the same frequency and polarization on non-adjacent beams, maximizing the system's total bandwidth for handling user traffic.

[0060] This application transmits data based on a multi-beam multicast method on the forward link, where the forward link is the data forward path from the ground station gateway to the satellite terminal. In a star-shaped satellite architecture, commonly used broadcast technologies include DVB-S, DVB-S2, or DVB-S2X. Each beam represents a broadcast system in which all satellite terminals can receive the entire forward link traffic. It is also possible to consider combining multi-beam multicast to achieve on-demand distribution of popular content to corresponding users.

[0061] For ease of understanding, the present application embodiment provides a more specific embodiment of a content distribution method based on satellite multicast, such as Figure 3 As shown, it includes the following steps:

[0062] S301: The user terminal activates a virtual network, which is used to connect to the cache closest to the user through the local area network, obtain data collected from the satellite virtual path, and manage content caching and data retrieval related to the CDN service.

[0063] S302: The cache is deployed and enabled through the service orchestration layer close to the satellite end and should be mapped to one or more multicast groups.

[0064] S303: The server considers previous and popular requests related to the cache, which can be analyzed to detect possible preferences of the user group (ie, to detect the preferences of a user group).

[0065] S304: Each buffer joins multiple multicast groups, which are determined based on content preference and user clustering tendency. For example, the satellite end served by beam 1 belongs to multicast group A and multicast group C at the same time.

[0066] S305: The server supports group detection and distributes the most appropriate content to relevant caches via the appropriate multicast group. In this way, caches that join a specific multicast group will receive a set of content that is likely to be of interest to the majority of users in push mode, thereby increasing the probability of cache hits and reducing the load on the terrestrial network.

[0067] S306: The server will interact with the network connection point and the satellite operator's network manager to determine whether the MPLS routing and general flow encapsulation mapping need to be updated to determine the mapping relationship between the buffer, multicast group and beam.

[0068] S307: Develop and include a transport orchestration component in the control and management plane of the satellite operator infrastructure, and formulate and enable a new application programming interface (API) to enable such dynamic configuration as described above.

[0069] S308: The data transmission multicast tree of the server is continuously adjusted and kept consistent with the required data path.

[0070] Because current high-orbit multicast platforms generally do not allow for such dynamic configuration (referring to S305, the cache joining a specific multicast group will be pushed a set of possible majority second information, while the user preferences and search records within the multicast group will be recorded to the server, and then S306 to S308 will be executed to achieve such dynamic configuration). Therefore, in order to fill the current technology gap, it is necessary to reach an agreement with satellite operators who wish to enable the proposed service model to dynamically update the required data path.

[0071] S309: A large number of satellite terminals are used as destinations for multicast traffic and are used to deliver and cache the content of CDN content providers. These satellite terminals provide the cached content to users, thereby avoiding the use of the terrestrial core network for these contents.

[0072] S3010: Performing point-to-point transmission on the ground network when a cache miss occurs.

[0073] In another embodiment of the present application, a simulated multi-beam multicast implementation process is provided, such as Figure 4 As shown, the following steps are included:

[0074] Step S1: Define cache system and request flow parameters

[0075] S11. Define the total content quantity of the system total_contents, for example, a collection of 100 movies and popular videos;

[0076] S12. Define a step size cache_capacity_step for simulating different cache capacities. The simulation will increase the cache capacity by adding one content item at a time.

[0077] S13. Define the number of caches num_caches in the simulation, that is, the number of cache nodes, which can also be understood as defining the number of terminals;

[0078] S14. Define the number of requests per terminal, requests_per_cache;

[0079] S15. Define the number of beams as 52;

[0080] S16. Define the total number of requests, tot_requests, as the product of the number of requests from each terminal and the number of cache nodes;

[0081] S17. Define the percentage percent_zipf of the Zipf distribution and its exponential parameter alpha. Alpha determines the popularity distribution of content in the Zipf distribution. The value of alpha affects the shape of the Zipf distribution, depending on the size of alpha. A larger alpha indicates a closer uniform distribution, while a smaller alpha indicates a distribution that favors a smaller number of popular content.

[0082] Step S2: Define the cost model

[0083] S21. Define the terrestrial transmission cost terr_cost, which is the cost of transmitting the content from the ground to the user. This cost may include bandwidth costs, data transmission costs, or other related costs.

[0084] S22. Define the satellite transmission cost sat_cost, which is the cost of transmitting the content to the user via satellite. This cost may include satellite bandwidth fees, data transmission fees, etc.

[0085] S23. Define the storage cost arch_cost, which is the cost of storing content in the cache system. This may include hard disk storage costs, cloud storage costs, etc.

[0086] S24. Define the storage cost exponent arch_cost_exp, which affects how the storage cost grows as the cache capacity increases. Specifically, the storage cost is calculated using the formula size^arch_cost_exp, where size is the cache capacity. If arch_cost_exp is greater than 1, the storage cost will rise rapidly as the cache capacity increases; if arch_cost_exp is equal to 1, the storage cost will be proportional to the cache capacity; if arch_cost_exp is less than 1, the storage cost will grow more slowly as the cache capacity increases.

[0087] S25. Determine the correlation of request contents between cells based on the percentage percent_zipf of the Zipf distribution. If percent_zipf is greater than 0.7, it indicates a high-correlation cell; if it is less than 0.3, it indicates a low-correlation cell; and if it is between 0.3 and 0.7, it indicates a medium-correlation cell.

[0088] S26. Define the size of each content item GB_per_content as 2, in gigabytes (GB). This value is used to calculate storage costs and transmission costs, as these costs are usually calculated based on the size of the content.

[0089] Step S3: Request flow generation

[0090] S31. Calculate the number of requests that conform to the Zipf distribution, simul_requests_zipf, and the number of requests that conform to the uniform distribution, simul_requests_uniform, based on the previously defined parameters tot_requests (total number of requests), percent_zipf (percentage of Zipf distributed requests), and percent_uniform (percentage of uniformly distributed requests: 1-percent_zipf).

[0091] S32. Initialize the CH and CM arrays: CH and CM are arrays used to track cache hit and miss rates. They are initialized to 0 and 100, indicating that there are no cache hits and all requests miss the cache at the beginning of the simulation. These arrays will be used to record cache hit and miss rates at different cache capacities.

[0092] S33. Generate a request stream, `request`. First, generate requests that follow a Zipf distribution, numbered `simul_requests_zipf`. Then, generate requests that follow a uniform distribution, numbered `simul_requests_uniform`. Finally, `request` contains all requests in the simulation, some of which follow a Zipf distribution and some follow a uniform distribution. The generated request stream includes content items of varying popularity to simulate a real-world request stream.

[0093] Step S4: Iterate cache capacity, calculate cache hit rate, and calculate request frequency

[0094] S41. Iterate from different cache capacities. Here, it is assumed that the cache capacity of the terminal, cache_capacity, is iterated from 2 GB to 200 GB in sequence, increasing by 2 GB each time. That is, it simulates caching the entire content quantity provided by the content provider from 1 to 100, which can simulate the performance under different cache capacities.

[0095] S42. In each iteration, create an array named occurrence to track the request frequency of the content item; here, initialize it to all zeros to prepare to record the number of requests for each content item;

[0096] S43. Similarly, in each iteration, two variables cache_hit and cache_miss are initialized to record the number of cache hits and misses, respectively, and are initially set to zero.

[0097] S44. Similarly, in each iteration, two variables cache_hit and cache_miss are initialized to record the number of cache hits and misses, respectively, and are initially set to zero.

[0098] S45. Traverse each request in the request flow and perform the following operations:

[0099] 1) Count the content items in the request and increase the request frequency count of the corresponding content item occurrence(i);

[0100] 2) Check whether the current request hits the cache by comparing the content item index request(i) in the request to see if it is less than or equal to the current cache capacity cache_capacity;

[0101] 3) If the request hits the cache, the value of cache_hit increases by 1, indicating a cache hit; otherwise, the value of cache_miss increases by 1, indicating a cache miss;

[0102] S46. After the request flow loop is completed, the request frequency array occurrence of the content items is sorted in descending order to obtain the probability density distribution of the request content;

[0103] S47. Add the cache hit rate and miss rate under each cache capacity to the CH and CM arrays, so as to record cache performance data under different cache capacities.

[0104] Step S5: Draw simulation chart

[0105] S51. Normalize the content request frequency occurrence to ensure that the total is equal to 1, and draw a probability density distribution diagram of the request content;

[0106] S52, plotting changes in cache hit rate and miss rate along with cache capacity;

[0107] S53, drawing a cost model to calculate the cost as the cache capacity changes, the cost model including ground transmission cost, satellite transmission cost and storage cost;

[0108] S54. Plot the variation of ground transmission cost and satellite transmission cost with cache capacity.

[0109] The simulation parameter settings are shown in Table 1.

[0110] Table 1 Examples of simulation parameter settings

[0111]

[0112]

[0113] like Figure 5As shown, since the relevance of user request content interests is taken into account, this aspect is modeled through a mixture of request distributions, where 65% of requests use a normal distribution (uniform distribution) and only 35% of requests follow a Zipf distribution. The Zipf distribution is widely used to model interest in multimedia content in homogeneous communities. Simplified, 80% of requests are associated with 20% of the content.

[0114] like Figure 6 As shown in Figure 2, the cache hit rate increases more than linearly from 0 to 20 cached items, which means that increasing the cache size in multibeam multicasting will lead to a larger (and beneficial) increase in cache hit rate. Figure 8 This is also reflected in the 0-20 range, where significant reductions in ground network traffic are experienced. This means that pushing a small portion of content to the corresponding cache via satellite can significantly reduce the load on the ground network, which can be beneficial for alleviating congestion. Beyond 20, increasing cache size leads to a corresponding increase in cache hit rate, and the improvement in cache hit rate is almost linear.

[0115] like Figure 7 As shown in the figure, assuming a single piece of content is 2 GB in size, if no content is delivered via satellite, all traffic is associated with the terrestrial network. The more content delivered via satellite, the higher the cache hit rate, and the smaller the proportion of requests associated with cache misses that occupy the terrestrial network. In the extreme case, if all content is delivered via satellite, no data is transmitted on the terrestrial link. The increase in satellite traffic is linear and, due to broadcasting, independent of the number of requests.

[0116] On the other hand, the reduction in terrestrial network bandwidth is linear, because the cache miss graph is linear but proportional to the number of requests; the unit of measurement of the terrestrial volume graph is actually 10 to the power of 6. Caching everything via satellite seems to be the best option, but it also comes with some disadvantages:

[0117] i) The actual library capacity of a content provider may be very large, not necessarily the 200 GB in the simulation;

[0118] ii) Very rarely requested content is best served in a point-to-point manner over terrestrial links rather than using multicast.

[0119] iii) CDN operators can make trade-off decisions based on the traffic volume graph, deciding how much content to push to alleviate congestion in the terrestrial network according to their internal configuration, the probability density distribution of requested content, and bandwidth costs.

[0120] like Figure 8As shown, the cost model curve shows a slight cost reduction when content begins to be cached. However, in the steady state, satellite costs (assumed to be five times higher than terrestrial costs) and storage costs dominate. CDN operators leveraging both terrestrial and satellite data transmission can use this simple cost model to determine whether and how much content to push via satellite. If the number of requests during the observation period exceeds 32,000, or if satellite costs are low, the advantages of pushing content to caches via satellite multibeam multicast become more pronounced.

[0121] like Figure 9 As shown in the figure, when there are 52 beams, the cache capacity of each beam is set to 16, there are a total of 32,000 requests, 320 terminals, each terminal initiates 100 requests, and each beam processes an average of 615 requests. In this case, considering multi-beam multicast, by increasing the number of cells under each beam, the average cache hit rate and shared cache hit rate of the multi-beam multicast cache are obtained as the number of communities under each beam increases. The shared cache hit rate is determined by judging whether the content item index request(i) of the current request content is less than or equal to the current beam capacity (16) divided by the current number of cells when the number of cells covered in the beam increases.

[0122] This application considers the use of user groups' preferred content requests when simulating satellite communication to enhance CDN services. Compared with the pure broadcast mode, the multi-beam multicast method has better performance. This application not only considers the on-demand distribution of popular traffic, but also combines satellite networks and terrestrial networks. By analyzing the requested content and simulating the multi-beam multicast cache hit rate, it can provide a reference for satellite network operators to decide whether to push content via satellite and how much to push.

[0123] This application designs an enhanced CDN architecture by hybrid modeling of user-side requested content, leveraging the satellite system's multicast capabilities, and jointly utilizing terrestrial and satellite networks. This architecture leverages the satellite's wide coverage area to support a cache for on-demand content, and defines a mechanism for pushing popular content to the cache via the satellite's multibeam multicast capabilities. This application considers the use of user groups with preferred content requests, and simulation results show that when content push is enabled via satellite multibeam multicast, terrestrial network traffic is significantly reduced, which helps reduce the load and congestion on the core network, thereby saving costs in terms of overall service provision.

[0124] An embodiment of the present application also provides a satellite terminal, which includes at least one processor, the at least one processor is coupled to at least one memory, and the at least one processor is used to read a computer program stored in the at least one memory to execute steps 104 and 105 described in the above embodiment.

[0125] An embodiment of the present application also provides a server, which includes at least one processor, the at least one processor is coupled to at least one memory, and the at least one processor is used to read a computer program stored in the at least one memory to execute steps 101 to 103 described in the above embodiment.

[0126] An embodiment of the present application further provides a content distribution system based on satellite multicast, which includes the satellite terminal described in the above embodiment and the server described in the above embodiment.

[0127] In one embodiment of the present application, the satellite multicast-based content distribution system further includes a user server configured to receive second information sent by the satellite terminal, the second information indicating the content subscribed by the user. The user server also includes a buffer configured to cache the received second information so that the user can retrieve the subscribed content.

[0128] Optionally, the embodiment of the present application further includes a ground station gateway, and the server sends the second information to the user service end in the multicast group via satellite through the ground station gateway. Optionally, multiple ground station gateways can be set up, and the multiple ground station gateways can be geographically separated from each other and interconnected through a ground data network; each user link (uplink and downlink) is associated with the feeder link (downlink and uplink) of the gateway. The ground station gateway can establish a network connection with the network content provider through a network connection point; the network content provider can send the content cached in the cache in the user service end to the server, so that the server can classify and summarize the second information based on the user's preference for historical content.

[0129] In this embodiment, the cache can be deployed and enabled by the service orchestration layer close to the satellite end, and mapped to one or more multicast groups. The mapping path is determined by content preference and user clustering tendency (geographic distribution of users). For example, the satellite end served by beam 1 belongs to both multicast group A and multicast group C. Figure 2 shown.

[0130] Optionally, at any given time, a satellite is associated with only one ground station gateway and one beam, determined by the beam and frequency mapping on the satellite. In the event of mobility or failure, it can also switch to another ground station gateway, resulting in the presence of multiple ground station gateways. Multiple ground station gateways are geographically separated, and data connectivity between them needs to be managed using terrestrial broadband connections. For performance and security reasons, this network should be isolated from other networks and operated directly by the satellite service operator. The ground station gateway network is typically a high-speed IP network that utilizes fiber optic links and implements virtual paths with guaranteed transmission quality through a proprietary protocol. This proprietary protocol can be Multi-Protocol Label Switching (MPLS). Additionally, there is at least one network connection point (NCP) to the public terrestrial network, through which the internal ground station gateway network connects to the public network and Internet Service Providers (ISPs).

[0131] Optionally, users can enable a virtual network to connect to the cache closest to the user through a local area network, obtain data collected from the satellite virtual path, and manage content caching and data retrieval related to CDN services.

[0132] An embodiment of the present application further provides a computer-readable storage medium, in which computer instructions are stored. When the computer instructions are executed on a computer, the computer executes the method corresponding to the satellite end described in the above embodiment, or the computer executes the method corresponding to the server described in the above embodiment.

[0133] It should be noted that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0134] Those skilled in the art should clearly understand that, for the convenience and brevity of description, the specific working processes of the satellite multicast-based content distribution system, satellite terminal, server and computer-readable storage medium described in the above embodiments can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0135] Those skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or may be accomplished by instructing the relevant hardware through a program, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk, or an optical disk, etc.

[0136] The above are only optional embodiments of the present application, which are only used to illustrate the technical solution of the present application rather than to limit it. Without departing from the spirit and scope of the present application, modifications, equivalent replacements, improvements, etc. to the specific implementation methods of the present application should be included in the scope of protection of the present application.

Claims

1. A content distribution method based on satellite multicast, applied to a satellite terminal, characterized in that: include: receiving second information sent by the server, where the second information is used to indicate content subscribed by the user; The second information is distributed to user servers in multiple multicast groups so that users can obtain required content.

2. The content distribution method based on satellite multicast according to claim 1, characterized in that: The distributing the second information to user servers in multiple multicast groups includes: According to the second information served by each user server and the location of each user server, each user server is divided into different multicast groups; The second information is distributed to the user servers in the corresponding multicast group in a multi-beam multicast manner, so that the users can obtain their subscribed content from the user servers; each multicast group corresponds to a plurality of user servers.

3. The content distribution method based on satellite multicast according to claim 2, characterized in that: The distributing the second information to the corresponding user server in the multicast group by multi-beam multicasting, so that the user can obtain the subscribed content from the user server, includes: The second information is distributed to the cache in the user server in the corresponding multicast group in a multi-beam multicast manner, so that the user can obtain the subscribed content from the cache.

4. A content distribution method based on satellite multicast, applied to a server, characterized in that: include: receiving a first message; The first information includes content obtained by the user from the user server; Obtaining second information based on the first information, where the second information is used to indicate content subscribed by the user; The second information is sent to the satellite end.

5. The content distribution method based on satellite multicast according to claim 4, characterized in that: The obtaining of the second information according to the first information includes: Perform user preference analysis on the content received by the user from the cache in the user server to obtain second information.

6. The content distribution method based on satellite multicast according to claim 4, characterized in that: The sending the second information to the satellite terminal includes: The second information is transmitted to the satellite end through the designated beam, so that the satellite end distributes the second information to the corresponding user service end through the designated beam, so that the user can obtain the subscribed content from the user service end.

7. The content distribution method based on satellite multicast according to any one of claims 4 to 6, characterized in that: Also includes: When the second information or the hot content in the user's area changes, the mapping relationship between the cache, multicast group and beam is updated so that the user can obtain the content he subscribes to; the beam is used to provide the second information to the cache in the user server in its corresponding multicast group.

8. A satellite terminal, characterized in that: The system comprises at least one processor coupled to at least one memory, and configured to read a computer program stored in the at least one memory to execute the content distribution method based on satellite multicast according to any one of claims 1 to 3.

9. A server, characterized in that: The system comprises at least one processor coupled to at least one memory, and configured to read a computer program stored in the at least one memory to execute the satellite multicast-based content distribution method according to any one of claims 4 to 7.

10. A content distribution system based on satellite multicast, characterized in that: It comprises the satellite terminal as claimed in claim 8 and the server as claimed in claim 9.

11. The satellite multicast-based content distribution system according to claim 10, characterized in that: It also includes a user server; the user server is used to receive second information sent by the satellite, and the second information is used to indicate the content subscribed by the user.

12. The satellite multicast-based content distribution system according to claim 11, characterized in that: The user server includes a cache; the cache is used to cache the received second information so that the user can obtain the subscribed content.

13. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions. When the computer instructions are executed on a computer, the computer executes the satellite multicast-based content distribution method according to any one of claims 1 to 3, or the computer executes the satellite multicast-based content distribution method according to any one of claims 4 to 7.

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