Communication methods, satellite system, electronic device and storage medium

Abstract

The present application relates to the technical field of communications. Disclosed are communication methods, a satellite system, an electronic device and a storage medium. In a communication method disclosed in the present application, when a first server has received a domain name resolution request sent by a terminal device, if the first server stores a first IP address corresponding to a first domain name in the domain name resolution request, the first IP address can be directly returned to the terminal device; and when the first server does not store the first IP address corresponding to the first domain name, the domain name resolution request is forwarded to a local domain name server by means of a second server deployed in a geostationary earth orbit satellite, and the first IP address is acquired from the local domain name server by means of the second server. In this way, satellite communication resources can be effectively saved, and the situation of network access failure of a terminal device can be effectively reduced, thereby improving the user experience.

Description

Communication method, satellite system, electronic device and storage medium

[0001] The present application claims priority from the Chinese patent application No. 202411262375.5 filed on September 10, 2024, and entitled "A communication method, satellite system, electronic device and storage medium", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, and in particular to a communication method, satellite system, electronic device and storage medium. BACKGROUND

[0003] When a terminal device (such as a mobile phone or the like) performs network access, for example, accesses a server corresponding to a domain name, it generally needs to first access a local domain name server (LDNS) to query an Internet Protocol (IP) address corresponding to the domain name, and then access the server corresponding to the domain name according to the IP address. For example, as shown in FIG. 1, when a user inputs a request of Http: / / baab.com / index.abc in a browser application interface 101 of a terminal device 100, the terminal device 100 can send a domain name resolution request carrying a domain name "baab.com" to the LDNS. After receiving the domain name resolution request, the LDNS can obtain an IP address (for example, 202.1.201.1) corresponding to the domain name "baab.com", and returns the IP address to the terminal device 100. The terminal device 100 accesses a server corresponding to the domain name "baab.com" based on the IP address.

[0004] The terminal device can establish a communication connection with the LDNS based on a ground network, such as a wireless local area network (WLAN), a 5th generation mobile communication technology (5G) network, or the like, to query an IP address corresponding to a domain name.

[0005] With the rapid development of spatial information technology, non-terrestrial networks (NTN), such as satellite networks and the like, gradually mature, so that more network services can be implemented through non-terrestrial networks. For example, a terminal device can also obtain an IP address corresponding to a domain name from an LDNS based on a satellite communication mode. When the terminal device accesses a satellite network and needs to query an IP address corresponding to a domain name, a domain name resolution request carrying the domain name can be sent to a forwarding server deployed in a satellite through a satellite communication mode, the forwarding server deployed in the satellite sends the domain name resolution request to the LDNS based on the satellite communication mode, and an IP address returned by the LDNS is obtained. When the forwarding server obtains the IP address corresponding to the domain name, the IP address corresponding to the domain name can be sent to the terminal device. However, in the scheme of obtaining the IP address corresponding to the domain name based on the satellite communication mode, as the network access demand increases, the satellite and the LDNS on the ground will interact frequently, causing serious consumption of satellite communication resources. SUMMARY

[0006] Embodiments of the present application provide a communication method, a satellite system, an electronic device and a storage medium.

[0007] In a first aspect, embodiments of the present application provide a communication method for a satellite system, the satellite system comprising a first server and a second server, the first server being deployed on a first satellite, the first satellite being operated in a first earth orbit, the second server being deployed on a second satellite, the second satellite being operated in a second earth orbit, the second earth orbit being higher than the first earth orbit; the method comprising: the first server receiving a first domain name resolution request sent by a terminal device in a ground system, the first domain name resolution request comprising a first domain name requested by the terminal device to resolve, the first server storing a mapping relationship between domain names and IP addresses; when the first server determines that the first server does not store a first IP address corresponding to the first domain name based on the mapping relationship between domain names and IP addresses, the first server sends the first domain name resolution request to the second server; the second server sending the first domain name resolution request to a local domain name server in the ground system; the second server receiving a first IP address corresponding to the first domain name sent by the local domain name server; the second server sending the first IP address to the first server; and the first server sending the first IP address to the terminal device.

[0008] It can be understood that when the first server receives the domain name resolution request sent by the terminal device, if the first server stores the IP address corresponding to the first domain name carried in the domain name resolution request, the first server can directly return the IP address corresponding to the first domain name to the terminal device, that is, the first server does not need to obtain the IP address corresponding to the first domain name from the local domain name server on the ground every time. In this way, the number of interactions between the server on the satellite and the local domain name server on the ground can be reduced, and satellite communication resources can be saved.

[0009] In addition, when the first server does not store the IP address corresponding to the first domain name carried in the domain name resolution request, the second server deployed in the geosynchronous satellite forwards the domain name resolution request to the local domain name server, and the second server obtains the IP address data from the local domain name server based on a space-ground communication link (or a feeder link) between the geosynchronous satellite and the local domain name server. It can be understood that the network coverage range of the geosynchronous satellite on the ground is much larger than that of the low-orbit satellite, and the geosynchronous satellite operates with the earth, so the space-ground communication link between the geosynchronous satellite and the local domain name server can be basically kept in real-time connection. Therefore, based on the second server, the IP address corresponding to the first domain name can be obtained in real time, and the above-mentioned network access failure of the terminal device can be effectively reduced, and the user experience is improved.

[0010] It can be understood that the first server mentioned in the embodiments of the present application can be the secondary server mentioned in the embodiments of the present application, the second server mentioned in the embodiments of the present application can be the primary server mentioned in the embodiments of the present application, and the first domain name mentioned in the embodiments of the present application can refer to the target domain name mentioned in the embodiments of the present application. The first IP address mentioned in the embodiments of the present application can be the IP address corresponding to the target domain name mentioned in the embodiments of the present application. The first satellite mentioned in the embodiments of the present application can be the satellite 200 mentioned in the embodiments of the present application. The second satellite mentioned in the embodiments of the present application can be the satellite 500 mentioned in the embodiments of the present application.

[0011] In a possible implementation of the first aspect, the first server sends the first domain name resolution request to the second server, including: the first server identifies the first domain name resolution request as a first type of domain name resolution request, and sends the first domain name resolution request to the second server.

[0012] In some embodiments, the first server in the first satellite can also classify the domain name resolution request and perform different operations on different types of domain name resolution requests. For the first type of domain name resolution request (for example, a domain name resolution request that needs to access a server corresponding to the first type of application), if the first server in the first satellite does not have the IP address corresponding to the first domain name in the domain name resolution request, the first server in the first satellite forwards the domain name resolution request to the second server in the geosynchronous satellite. For the second type of domain name resolution request (for example, a domain name resolution request that needs to access a server corresponding to the second type of application), if the first server in the first satellite does not have the IP address corresponding to the first domain name in the domain name resolution request, directly returns the resolution failure information to the terminal device, that is, does not forward the domain name resolution request to the second server. In this way, the data transmission between the satellite and the ground can be reduced, and the consumption of satellite resources can be reduced.

[0013] In a possible implementation of the first aspect, the satellite system further includes a user plane function (UPF); the first server receiving the first domain name resolution request sent by the terminal device in the ground system includes: the UPF receiving the first domain name resolution request sent by the terminal device in the ground system; the UPF determining, based on the first domain name in the first domain name resolution request, that the first domain name resolution request is the first type of domain name resolution request, marking the first domain name resolution request with a first identifier, and sending the first domain name resolution request and the first identifier to the first server.

[0014] In a possible implementation of the first aspect, the UPF determining, based on the first domain name in the first domain name resolution request, that the first domain name resolution request is the first type of domain name resolution request includes: the UPF determining, based on the first domain name in the first domain name resolution request, an application corresponding to the first domain name, obtaining subscription information and / or user plane forwarding rule information corresponding to the application corresponding to the first domain name, and determining, based on the subscription information and / or the user plane forwarding rule information corresponding to the application corresponding to the first domain name, that the first domain name resolution request is the first type of domain name resolution request; or the UPF obtaining, based on the first domain name in the first domain name resolution request, user plane forwarding rule information corresponding to the first domain name, and determining, based on the user plane forwarding rule information corresponding to the first domain name, that the first domain name resolution request is the first type of domain name resolution request.

[0015] In some embodiments, the UPF 202 can communicate with network elements of the ground core network, such as a policy control function (PCF), a session management function (SMF), and the like, to obtain subscription information, user plane forwarding rule information, and the like associated with each application from the network elements of the ground core network, such as the SMF, the PCF, and the like.

[0016] In a possible implementation of the first aspect, the first server identifying that the first domain name resolution request is the first type of domain name resolution request includes: the first server receiving the first domain name resolution request and the first identifier sent by the UPF, and identifying, based on the first identifier, that the first domain name resolution request is the first type of domain name resolution request.

[0017] In a possible implementation of the first aspect, the method further includes: the first server receiving a second domain name resolution request sent by the terminal device, the second domain name resolution request including a second domain name requested by the terminal device to be resolved; when the first server determines, based on the mapping relationship between the domain name and the IP address, that the first server does not store a second IP address corresponding to the second domain name, and identifies that the second domain name resolution request is the second type of domain name resolution request, sending, to the terminal device, resolution failure information.

[0018] In some embodiments, for the second type of domain name resolution request, if the first server in the first satellite does not have the IP address corresponding to the first domain name in the domain name resolution request, the first server directly returns a resolution failure message to the terminal device, i.e., the domain name resolution request will not be forwarded to the second server. In this way, the data transmission between the satellite and the ground can be reduced, and the consumption of satellite resources can be reduced.

[0019] In a possible implementation of the first aspect, the first server receiving the second domain name resolution request sent by the terminal device includes: a user plane function (UPF) receiving the second domain name resolution request sent by the terminal device; the UPF determining, based on a second domain name in the second domain name resolution request, that the second domain name resolution request is a second type of domain name resolution request, marking the second domain name resolution request with a second identifier, and sending the second domain name resolution request and the second identifier to the first server.

[0020] In a possible implementation of the first aspect, the satellite system further includes a third server, the third server being deployed in a third satellite, the third satellite and the first satellite being located in the same constellation, and there being an inter-satellite routing path between the third satellite and the second satellite; the first server sending the first domain name resolution request to the second server includes: the first server determining that there is no inter-satellite routing path between the first satellite and the second satellite, the first server sending the first domain name resolution request to the third server, and the third server sending the first domain name resolution request to the second server.

[0021] It can be understood that the third satellite mentioned in the embodiments of the present application can refer to the satellite 700 mentioned in the embodiments of the present application, and the third server can refer to the first server 701 mentioned in the embodiments of the present application.

[0022] When there is no inter-satellite routing path between the first satellite where the first server is located and the geosynchronous satellite, the first server can send the domain name resolution request to the third server in the third satellite when it is determined that there is an inter-satellite routing path between the third satellite and the second satellite. The third server forwards the domain name resolution request to the second server. This ensures the success rate of the domain name resolution request, reduces the number of user network access failures, and improves user experience.

[0023] In a possible implementation of the first aspect, the second server stores a mapping relationship between domain names and IP addresses, and a period for the second server to update the mapping relationship between domain names and IP addresses from a local domain name server is shorter than a period for the first server to update the mapping relationship between domain names and IP addresses from the local domain name server; the second server sending the first domain name resolution request to the local domain name server includes: the second server determining, based on the mapping relationship between domain names and IP addresses stored in the second server, that the second server does not store the first IP address corresponding to the first domain name, and sending the first domain name resolution request to the local domain name server.

[0024] In some embodiments, the period of updating domain names and IP addresses corresponding to the domain names by the second server in the geosynchronous satellite from the local domain name server on the ground can be less than the period of updating domain names and IP addresses corresponding to the domain names by the first server in the first satellite from the local domain name server on the ground. In this way, the second server can store more domain names and IP addresses than the first server in some time period. When the second server in the geosynchronous satellite receives the domain name resolution request sent by the first server, it can be determined whether the IP address corresponding to the first domain name in the domain name resolution request exists in the second server. If not, the second server establishes a communication connection with the local domain name server on the ground to obtain the IP address corresponding to the first domain name from the local domain name server; if so, the IP address corresponding to the first domain name is directly sent to the first server, and the first server sends the IP address corresponding to the first domain name to the terminal device. In this way, the interaction between the server in the satellite and the local domain name server on the ground can be effectively reduced, and the consumption of satellite resources can be reduced.

[0025] In a possible implementation of the first aspect, the ground system further includes an ephemeris server; the first server sends the first domain name resolution request to the second server, including: the first server sends the first domain name resolution request and the identification information of the first satellite to the second server; the second server receives the first IP address corresponding to the first domain name sent by the local domain name server, including: the ephemeris server receives the identification information of the first satellite sent by the local domain name server, and the ephemeris server is configured to store a mapping relationship between the identification information of the satellite and ephemeris information; the ephemeris server obtains the ephemeris information corresponding to the first satellite based on the identification information of the first satellite; the ephemeris server determines the network coverage ground range information of the first satellite based on the ephemeris information of the first satellite; the ephemeris server sends the network coverage ground range information of the first satellite to the local domain name server; the second server receives the first IP address corresponding to the first domain name sent by the local domain name server, wherein the first IP address is obtained by the local domain name server based on the network coverage ground range information of the first satellite and the mapping relationship between the domain name and the IP address stored by the local domain name server.

[0026] It can be understood that the network coverage ground range information of the satellite can represent the approximate location information of the terminal device. The local domain name server on the ground can select the application server corresponding to the first domain name closest to the location information of the terminal device from the multiple application servers corresponding to the first domain name based on the network coverage ground range information, and send the IP address of the closest application server as the IP address corresponding to the first domain name to the cache server. In this way, the access path and the time delay of the terminal device can be effectively shortened.

[0027] In a possible implementation of the first aspect, the network coverage ground range information of the first satellite includes position information of a ground gateway station currently connected by the first satellite.

[0028] In a possible implementation of the first aspect, the manner in which the local domain name server obtains the first IP address corresponding to the first domain name based on the network coverage position information of the first satellite and the mapping relationship between the domain name and the IP address stored by the local domain name server includes: the local domain name server determines at least one IP address corresponding to the first domain name based on the mapping relationship between the domain name and the IP address stored by the local domain name server; and the local domain name server selects the first IP address from the at least one IP address, the first IP address being an IP address corresponding to an application server closest to the position information of the ground gateway station.

[0029] In a second aspect, the embodiments of the present application provide a communication method for a satellite system, the satellite system including a user plane function UPF and a second server, the second server being deployed on a second satellite, the second satellite operating in a second earth orbit, the second earth orbit being a geosynchronous orbit; the method including: the user plane function UPF receiving a first domain name resolution request sent by a terminal device in a ground system; the first domain name resolution request including a first domain name requested to be resolved by the terminal device; the user plane function UPF determining, based on the first domain name in the first domain name resolution request, that the first domain name resolution request is a first type of domain name resolution request, and sending the first domain name resolution request to the second server; the second server sending the first domain name resolution request to a local domain name server in the ground system; the second server receiving a first IP address corresponding to the first domain name sent by the local domain name server; and the second server sending the first IP address to the terminal device.

[0030] In some embodiments, the domain name resolution request is classified by the UPF, and for a second type of domain name resolution request, the second server can not be sent for processing, so that the data transmission between the geosynchronous satellite and the ground can be reduced, and the consumption of satellite resources can be reduced.

[0031] In a possible implementation of the second aspect, the satellite system further includes a first server, the first server is deployed on a first satellite, the first satellite operates in a first earth orbit, and the second earth orbit is higher than the first earth orbit; and the method further includes: receiving, by a user plane function (UPF), a second domain name resolution request sent by a terminal device; determining, by the UPF, based on a second domain name in the second domain name resolution request, that the second domain name resolution request is a second type of domain name resolution request, and sending the second domain name resolution request to the first server; when the first server determines, based on a mapping relationship between a domain name and an IP address, that the first server does not store a second IP address corresponding to the second domain name, sending, by the first server, resolution failure information to the terminal device; and when the first server determines, based on the mapping relationship between the domain name and the IP address, that the first server stores the second IP address corresponding to the second domain name, sending, by the first server, the second IP address to the terminal device.

[0032] In a possible implementation of the second aspect, the second server sends the first domain name resolution request to the local domain name server, including: when the second server determines that the second server does not store an IP address corresponding to the first domain name, sending, by the second server, the first domain name resolution request to the local domain name server.

[0033] In a third aspect, an embodiment of the present application provides a satellite system, including: a first server and a second server, the first server is deployed on a first satellite, the first satellite operates in a first earth orbit, and the second server is deployed on a second satellite, the second satellite operates in a second earth orbit, and the second earth orbit is higher than the first earth orbit.

[0034] The first server is configured to receive a first domain name resolution request sent by a terminal device in a ground system, the first domain name resolution request includes a first domain name requested to be resolved by the terminal device, and the first server stores a mapping relationship between a domain name and an IP address; the first server is configured to, when it is determined, based on the mapping relationship between the domain name and the IP address, that the first server does not store a first IP address corresponding to the first domain name, send the first domain name resolution request to the second server; the second server is configured to send the first domain name resolution request to a local domain name server in the ground system, the local domain name server is deployed on the ground; the second server is configured to receive a first IP address corresponding to the first domain name sent by the local domain name server; the second server is configured to send the first IP address to the first server; and the first server is configured to send the first IP address to the terminal device, and the first IP address is used for the terminal device to access an application server corresponding to the first domain name.

[0035] In a possible implementation of the third aspect, the first server is configured to, when it is determined that the first domain name resolution request is a first type of domain name resolution request, send the first domain name resolution request to the second server.

[0036] In a possible implementation of the third aspect, the satellite system further includes a user plane function (UPF), and the UPF is configured to receive the first domain name resolution request sent by the terminal device, determine, based on the first domain name in the first domain name resolution request, that the first domain name resolution request is the first type of domain name resolution request, mark the first domain name resolution request with a first identifier, and send the first domain name resolution request and the first identifier to the first server.

[0037] In a possible implementation of the third aspect, the UPF is configured to determine, based on the first domain name in the first domain name resolution request, an application corresponding to the first domain name, acquire subscription information and / or user plane forwarding rule information corresponding to the application corresponding to the first domain name, and determine, based on the subscription information and / or the user plane forwarding rule information corresponding to the application corresponding to the first domain name, that the first domain name resolution request is the first type of domain name resolution request; or the UPF is configured to determine, based on the first domain name in the first domain name resolution request, user plane forwarding rule information corresponding to the first domain name, and determine, based on the user plane forwarding rule information corresponding to the first domain name, that the first domain name resolution request is the first type of domain name resolution request.

[0038] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium storing executable instructions, which, when executed on an electronic device, implement the communication method mentioned in the embodiments of the present application.

[0039] In a fifth aspect, an embodiment of the present application provides an electronic device, including a memory configured to store instructions executed by one or more processors of the electronic device, and the one or more processors configured to execute the communication method mentioned in the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0040] FIG. 1 shows a schematic diagram of a browser interface 101 of a terminal device 100 according to some embodiments of the present application;

[0041] FIG. 2a shows a schematic diagram of a scenario of acquiring an IP address corresponding to a domain name based on a satellite communication mode according to some embodiments of the present application;

[0042] FIG. 2b shows a schematic diagram of a method flow of acquiring an IP address corresponding to a domain name based on a satellite communication mode according to some embodiments of the present application;

[0043] FIG. 3a shows a schematic diagram of a scenario of acquiring an IP address corresponding to a domain name based on a cache server deployed in a satellite according to some embodiments of the present application;

[0044] FIG. 3b shows a schematic diagram of a method flow of acquiring an IP address corresponding to a domain name based on a cache server according to some embodiments of the present application;

[0045] FIG. 4 shows a schematic diagram of an iterative query according to some embodiments of the present application;

[0046] FIG. 5a shows a schematic diagram of a communication method according to some embodiments of the present application;

[0047] FIG. 5b shows a detailed flowchart of a communication method according to some embodiments of the present application;

[0048] FIG. 6 shows a schematic diagram of a communication method for determining IP address based on geographic range according to some embodiments of the present application;

[0049] FIG. 7 shows a flowchart of a communication method for performing different operations on different types of domain name resolution requests according to some embodiments of the present application;

[0050] FIG. 8a shows a schematic diagram of a secondary cache server forwarding a domain name resolution request through a satellite in constellation according to some embodiments of the present application;

[0051] FIG. 8b shows a schematic diagram of a UPF and gNB deployed on different satellites from a secondary cache server according to some embodiments of the present application;

[0052] FIG. 8c shows a flowchart of a communication method based on the schematic diagram shown in FIG. 8a according to some embodiments of the present application;

[0053] FIG. 9 shows a flowchart of a communication method for forwarding a domain name resolution request through a satellite and classifying the domain name resolution request according to some embodiments of the present application;

[0054] FIG. 10 shows a flowchart of a communication method according to some embodiments of the present application;

[0055] FIG. 11 shows a schematic diagram of a terminal device according to some embodiments of the present application;

[0056] FIG. 12 shows a schematic diagram of a server according to some embodiments of the present application. DETAILED DESCRIPTION

[0057] The illustrative embodiments of the present application include, but are not limited to, a communication method, a satellite system, an electronic device, and a storage medium.

[0058] It should be noted that the specific form of the terminal device is not limited in the present application, and the electronic device can be a terminal device such as a mobile phone, a notebook computer, a tablet, a large-screen device, a wearable device (for example, a smart watch, smart glasses, a helmet), a desktop computer, an augmented reality (AR) / virtual reality (VR) device, a personal digital assistant (PDA), and the like, which is not limited herein.

[0059] To more clearly understand the scheme in the embodiments of the present application, first, the terms involved in the present application are explained.

[0060] DNS: a server that stores the mapping relationship between domain names and IP addresses, used to realize the conversion of domain names and IP addresses.

[0061] Uniform Resource Locator (URL): a unique address of any given resource on the Internet, used to indicate the server of the Internet host and the specific web page location. The URL usually contains a protocol (such as HTTP, HTTPS), a domain name (or server name), and a specific path of the resource. For example, for the URL "Http: / / baab.com / index.abc", the protocol is "Http", the domain name is "baab.com", and the specific path of the resource is "index.abc".

[0062] Geostationary Earth Orbit (GEO) satellite: a satellite running in a geostationary orbit, also known as a geostationary satellite. The geostationary satellite runs at an orbital height of about 36000 kilometers, and the geostationary satellite can provide a larger satellite network coverage area, for example, a geostationary satellite can provide a satellite network covering one-third of the global area, which can be approximately considered as synchronous motion with the earth.

[0063] Medium Earth Orbit (MEO) satellite: a satellite running in a medium earth orbit, also known as a medium orbit satellite. The medium earth orbit is a man-made satellite orbit between the low earth orbit and the geostationary orbit. The satellite running in the medium earth orbit has a period of generally between 2 to 24 hours.

[0064] Low Earth Orbit (LEO) satellite: a satellite operating in a low earth orbit, referred to as a low orbit satellite, the orbit height of the low orbit satellite is between 300 kilometers and 2000 kilometers, for example, can be 800 kilometers. The running speed is greater than the earth rotation speed, the network coverage area is small, and the data propagation time delay between the ground equipment is small.

[0065] Next Generation NodeB (gNB): can be referred to as a 5G base station, used to implement the connection between a terminal device and a 5G core network, for example, used to implement routing data sent by a terminal device to a data sending network element in a 5G core network, such as a user plane function (UPF).

[0066] UPF: a network element of a 5G core network, used to implement routing and forwarding of data. For example, used to receive data sent by a gNB and forward the data to a corresponding server.

[0067] Feeder link: used to describe a kind of link in a satellite communication system, the feeder link is used to transmit data between a ground gateway station and a satellite. A terminal device on the ground establishes a connection through a service link and a satellite in space. At the same time, the satellite communicates with the ground gateway through the feeder link. The ground gateway is generally also called a ground station or a ground gateway station. The ground gateway station is responsible for routing data of the terminal device to a telephone, television network or the Internet on the ground.

[0068] FIG. 2a shows a schematic diagram of a scenario for obtaining an IP address corresponding to a domain name based on a satellite communication mode.

[0069] As shown in FIG. 2a, when the terminal device 100 needs to query the IP address corresponding to the target domain name, if the terminal device 100 accesses the satellite network, the domain name resolution request can be sent to the forwarding server 301 in the low-orbit satellite 300 through the gNB 201 and the UPF 202 in the low-orbit satellite 200. The domain name resolution request is sent to the LDNS 400 on the ground based on the ground gateway station 003 by the forwarding server 301, and the IP address corresponding to the target domain name carried in the domain name resolution request is obtained from the LDNS 400, and the IP address corresponding to the target domain name is sent to the terminal device 100 through the gNB 201 and the UPF 202 in the low-orbit satellite 200. After receiving the IP address corresponding to the target domain name, the terminal device 100 initiates a transmission control protocol (TCP) connection to the application server 001 corresponding to the IP address based on the IP address, so as to realize network access. It can be understood that the application server 001 can update its own IP address and domain name to the LDNS 400.

[0070] FIG. 2b shows a method flow diagram for obtaining the IP address corresponding to the domain name based on the satellite communication mode according to the scenario shown in FIG. 2a. As shown in FIG. 2b, the method comprises:

[0071] 1001: The terminal device 100 sends a domain name resolution request to the gNB 201 in the low-orbit satellite 200.

[0072] It can be understood that when the terminal device 100 needs to query the IP address corresponding to the target domain name, if the terminal device 100 accesses the satellite network, the domain name resolution request carrying the target domain name can be sent to the gNB 201 in the low-orbit satellite 200 through the satellite network. In some embodiments, the domain name resolution request can carry the target domain name.

[0073] 1002: The gNB 201 sends the domain name resolution request to the UPF 202 in the low-orbit satellite 200.

[0074] It can be understood that when the gNB 201 receives the domain name resolution request, the gNB 201 can route the domain name resolution request to the UPF 202 in the low-orbit satellite 200 based on the satellite network.

[0075] 1003: The UPF 202 sends the domain name resolution request to the forwarding server 301 in the low-orbit satellite 300.

[0076] In some embodiments, upon receiving the domain name resolution request, the UPF 202 can find the target low-orbit satellite according to a pre-configured selection scheduling strategy, for example, select the low-orbit satellite 300 closest to the low-orbit satellite 200 where the UPF 202 is located as the target low-orbit satellite, and send the domain name resolution request to the forward storage server 301 in the low-orbit satellite 300 based on the satellite network.

[0077] 1004: The forward storage server 301 in the low-orbit satellite 300 sends the domain name resolution request to the LDNS 400 on the ground.

[0078] It can be understood that the forward storage server 301 can forward the domain name resolution request to the LDNS 400 on the ground upon receiving the domain name resolution request, so as to obtain the IP address corresponding to the target domain name from the LDNS 400 on the ground.

[0079] 1005: The LDNS 400 obtains the IP address corresponding to the target domain name based on the domain name resolution request.

[0080] In some embodiments, upon receiving the domain name resolution request, the LDNS 400 can query the IP address corresponding to the target domain name from the data system based on the target domain name carried in the domain name resolution request.

[0081] 1006: The LDNS 400 sends the IP address corresponding to the target domain name to the forward server 301.

[0082] In some embodiments, upon obtaining the IP address corresponding to the target domain name, the LDNS 400 can send the IP address corresponding to the target domain name to the forward server 301.

[0083] 1007: The forward server 301 sends the IP address corresponding to the target domain name to the UPF 202.

[0084] In some embodiments, upon receiving the IP address corresponding to the target domain name, the forward server 301 can send the IP address corresponding to the target domain name to the UPF 202.

[0085] 1008: The UPF 202 sends the IP address corresponding to the target domain name to the gNB 201.

[0086] In some embodiments, upon receiving the IP address corresponding to the target domain name, the UPF 202 can send the IP address corresponding to the target domain name to the gNB 201.

[0087] 1009: The gNB 201 sends the IP address corresponding to the target domain name to the terminal device 100.

[0088] In some embodiments, the gNB 201 receives the IP address corresponding to the target domain name, and can send the IP address corresponding to the target domain name to the terminal device 100.

[0089] 1010: The terminal device 100 accesses the corresponding application server 001 based on the IP address.

[0090] In some embodiments, after receiving the IP address corresponding to the target domain name, the terminal device 100 can access the corresponding application server 001 based on the IP address.

[0091] In some embodiments, the terminal device 100 accesses the corresponding application server 001 based on the IP address in the following manner: the terminal device 100 sends an access request carrying the IP address to the gNB 201, the gNB 201 sends the access request to the UPF 202 after receiving the access request, the UPF 202 sends the access request to the ground gateway station 004 after receiving the access request, and the ground gateway station 004 sends the access request to the corresponding application server 001.

[0092] Access the corresponding application server 001 based on the IP address carried in the access request.

[0093] It can be understood that in the above method, the forwarding server 301 deployed in the satellite 300 needs to forward the domain name resolution request to the ground LDNS 400 each time the terminal device sends a domain name resolution request, and obtain the IP address corresponding to the target domain name from the LDNS 400, and then return the IP address corresponding to the target domain name to the terminal device 100. As a result, due to the increasing demand for network access, the number of domain name resolution requests that the forwarding server 301 needs to forward is relatively large, resulting in frequent interaction between the forwarding server 301 and the ground LDNS 400, and resulting in serious consumption of satellite communication resources.

[0094] To solve the above problem, in some embodiments, a cache server is deployed in the satellite to obtain the IP address corresponding to the domain name. The cache server can update and cache the domain name and the IP address corresponding to the domain name from the ground LDNS 400 at a preset period (for example, every 1 hour). In this way, when the cache server receives a domain name resolution request sent by the terminal device, if the IP address corresponding to the target domain name carried in the domain name resolution request is stored, the cache server can directly return the IP address corresponding to the target domain name to the terminal device, that is, it is not necessary to obtain the IP address corresponding to the target domain name from the ground LDNS each time. In this way, the number of interactions between the cache server and the ground LDNS can be reduced, and satellite communication resources can be saved.

[0095] FIG. 3a shows a scenario diagram of obtaining an IP address corresponding to a domain name based on a cache server deployed in a satellite. As shown in FIG. 3a, when the terminal device 100 needs to query an IP address corresponding to a target domain name, if the terminal device 100 accesses the satellite network, the terminal device 100 can send a domain name resolution request to the cache server 302 in the low-orbit satellite 300 through the gNB 201 and the UPF 202 in the low-orbit satellite 200. When the cache server 302 caches the IP address corresponding to the target domain name, the cache server 302 can send the IP address corresponding to the target domain name to the terminal device 100. When the cache server 302 does not cache the IP address corresponding to the target domain name, the cache server 302 sends a domain name resolution request to the LDNS 400 on the ground based on the ground gateway station 0031, obtains the IP address corresponding to the target domain name returned by the LDNS 400, and sends the obtained IP address corresponding to the target domain name to the terminal device 100. After receiving the IP address corresponding to the target domain name, the terminal device 100 accesses the corresponding application server based on the IP address. It can be understood that the application server 001 can update its own IP address and domain name to the LDNS 400.

[0096] It can be understood that the cache server 302 caches the mapping relationship between the domain name and the IP address, and the cache server 302 can send a domain name resolution request to the LDNS 400 on the ground based on the ground gateway station 0031 when the cache server 302 does not store the IP address corresponding to the target domain name requested by the terminal device to resolve. That is, in addition to the forwarding function of the forwarding server 301 described above, the cache server 302 also has a caching function.

[0097] FIG. 3b shows a method flow diagram of obtaining an IP address corresponding to a domain name based on a cache server based on the scenario shown in FIG. 3a. As shown in FIG. 3b, the method includes:

[0098] 2001: The terminal device 100 sends a domain name resolution request to the gNB 201 in the low-orbit satellite 200.

[0099] It can be understood that when the terminal device 100 needs to query an IP address corresponding to a target domain name, if the terminal device 100 accesses the satellite network, the terminal device 100 can send a domain name resolution request carrying the target domain name to the gNB 201 in the low-orbit satellite 200 through the satellite network. In some embodiments, the domain name resolution request can carry the target domain name.

[0100] 2002: The gNB 201 sends the domain name resolution request to the UPF 202 in the low-orbit satellite 200.

[0101] It can be understood that when the gNB 201 receives the domain name resolution request, the gNB 201 can route the domain name resolution request to the UPF 202 in the low-orbit satellite 200 based on the satellite network.

[0102] 2003: UPF 202 sends a domain name resolution request to the cache server 302 in the low earth orbit satellite 300.

[0103] In some embodiments, upon receiving the domain name resolution request, the UPF 202 can find a target low earth orbit satellite according to a pre-configured satellite selection scheduling strategy, for example, select a low earth orbit satellite 300 closest to the low earth orbit satellite 200 where the UPF 202 is located as the target low earth orbit satellite, and send the domain name resolution request to the cache server 302 in the low earth orbit satellite 300 based on the satellite network.

[0104] 2004: The cache server 302 determines whether the IP address corresponding to the target domain name is cached.

[0105] In some embodiments, upon receiving the domain name resolution request, the cache server 302 can determine whether the IP address corresponding to the target domain name is cached in the cache server 302. When the cache server 302 caches the IP address corresponding to the target domain name, it proceeds to 2005 and sends the IP address corresponding to the target domain name to the UPF 202.

[0106] If the cache server 302 does not cache the IP address corresponding to the target domain name, for example, it has not yet updated the latest domain name and IP address from the LDNS 400, resulting in not caching the IP address corresponding to the target domain name, it proceeds to 2008 and sends the domain name resolution request to the ground LDNS 400 and obtains the IP address corresponding to the target domain name returned by the LDNS 400.

[0107] 2005: The cache server 302 sends the IP address corresponding to the target domain name to the UPF 202.

[0108] In some embodiments, when the cache server 302 caches the IP address corresponding to the target domain name, it can send the IP address corresponding to the target domain name to the UPF 202.

[0109] In some embodiments, when the cache server 302 receives the IP address corresponding to the target domain name sent by the LDNS 400, it can send the IP address corresponding to the target domain name to the UPF 202.

[0110] 2006: The UPF 202 sends the IP address corresponding to the target domain name to the gNB 201.

[0111] In some embodiments, upon receiving the IP address corresponding to the target domain name, the UPF 202 can send the IP address corresponding to the target domain name to the gNB 201.

[0112] 2007: The gNB 201 sends the IP address corresponding to the target domain name to the terminal device 100.

[0113] In some embodiments, the gNB 201 receives the IP address corresponding to the target domain name, and can send the IP address corresponding to the target domain name to the terminal device 100.

[0114] 2008: The terminal device 100 accesses the corresponding application server 001 based on the IP address.

[0115] In some embodiments, after receiving the IP address corresponding to the target domain name, the terminal device 100 can access the corresponding application server 001 based on the IP address. In some embodiments, the terminal device 100 accesses the corresponding application server 001 based on the IP address can be that the terminal device 100 sends an access request carrying the IP address to the gNB 201, the gNB 201 receives the access request, and sends the access request to the UPF 202, the UPF 202 receives the access request, and sends the access request to the ground gateway station 004, and the ground gateway station 004 sends the access request to the corresponding application server 001.

[0116] 2009: The cache server 302 sends a domain name resolution request to the ground LDNS 400.

[0117] In some embodiments, if the cache server 301 does not cache the IP address corresponding to the target domain name, for example, it has not yet updated the latest domain name and IP address from the LDNS 400, resulting in not caching the IP address corresponding to the target domain name, then the domain name resolution request is sent to the ground LDNS 400.

[0118] 2010: The LDNS 400 obtains the IP address corresponding to the target domain name based on the domain name resolution request.

[0119] In some embodiments, when the LDNS 400 receives the domain name resolution request, it can query the IP address corresponding to the target domain name from the data system based on the target domain name carried in the domain name resolution request.

[0120] 2011: The LDNS 400 sends the IP address corresponding to the target domain name to the cache server 302.

[0121] It can be understood that when the LDNS 400 queries the IP address corresponding to the target domain name from the data system, it can send the IP address corresponding to the target domain name to the cache server 302. To achieve that the cache server 302 sends the IP address corresponding to the target domain name to the terminal device 100 based on the steps 2005 to 2007.

[0122] In some embodiments, the LDNS 400 can send the IP address of the target domain name cached in the LDNS 400 to the cache server 302 when determining that the IP address of the target domain name is cached in the LDNS 400.

[0123] In some embodiments, the LDNS 400 can perform an iterative query to obtain the IP address of the target domain name when determining that the IP address of the target domain name is not cached in the LDNS 400.

[0124] An example of the iterative query can be shown in FIG. 4, in which the LDNS 400 sends a domain name resolution request to a root domain name server 401, and the root domain name server 401 returns an IP address of a top-level domain name server 402 corresponding to a suffix of the target domain name (e.g.,.com, etc.) carried in the domain name query request to the LDNS 400. The LDNS 400 sends a domain name resolution request to the corresponding top-level domain name server 402 based on the received IP address of the top-level domain name server 402. When the top-level domain name server 402 stores the IP address of the target domain name, the top-level domain name server 402 sends the IP address of the target domain name to the LDNS 400.

[0125] When the top-level domain name server 402 does not store the IP address of the target domain name, the top-level domain name server 402 sends an IP address of an authoritative domain name server 403 to the LDNS 400. The LDNS 400 sends a domain name resolution request to the authoritative domain name server 403 based on the IP address of the authoritative domain name server 403, and the authoritative domain name server 403 sends the IP address of the target domain name to the LDNS 400.

[0126] It can be understood that the domain name resolution request passed by the terminal device 100 to the LDNS 400 through the cache server 302 can be regarded as a recursive query, and the LDNS 400 can perform the iterative query shown in FIG. 4 when the IP address of the target domain name is not cached, and send the query result, i.e., the IP address corresponding to the target domain name, to the terminal device 100.

[0127] In some embodiments, the UPF 202 can also send identification information of the satellite 200 where the UPF 202 is located when sending the domain name resolution request to the cache server 302. The cache server 302 can carry the identification information of the satellite 200 where the UPF 202 is located when sending the domain name resolution request to the LDNS 400.

[0128] The LDNS 400 on the ground can also send the identification information of the low-orbit satellite 200 to an application server discovery function server (or ephemeris server) to obtain the network coverage ground range information of the low-orbit satellite 200 where the UPF 202 is located at this time when receiving the domain name resolution request and the identification information of the low-orbit satellite 200, wherein the network coverage ground range information of the low-orbit satellite 200 at this time can include the location information of the ground gateway station 004 connected in the low-orbit satellite 200 at this time. The application server discovery function server can be authorized by the operator or controlled by the operator, and the application server discovery function server can be configured with a mapping relationship between ephemeris information (such as satellite orbit information, etc.) and satellite identification information. The application server discovery function server 600 can obtain the ephemeris information of the low-orbit satellite 200 when receiving the satellite identification information of the low-orbit satellite 200, determine the network coverage ground range information of the satellite 200 at this time based on the ephemeris information, such as the location information of the ground gateway station connected in the low-orbit satellite at this time, and send the network coverage ground range information to the LDNS 400 on the ground. It can be understood that the network coverage ground range information of the satellite 200 can represent the approximate location information of the terminal device 100.

[0129] The LDNS 400 on the ground can select the application server corresponding to the target domain name closest to the network coverage ground range information of the satellite 200, such as the location information of the ground gateway station 004 connected in the low-orbit satellite 200 at this time, from the multiple application servers corresponding to the target domain name based on the network coverage ground range information, and send the IP address of the closest application server as the IP address corresponding to the target domain name to the cache server 302, so as to effectively shorten the access path and time delay of the terminal device 100.

[0130] It can be understood that the LDNS 400 is used to implement the domain name resolution request of the terminal device within a preset range. For example, the LDNS corresponding to the C city area can be deployed to implement the domain name resolution request sent by the terminal device in the C city area. For example, when the terminal device 100 mentioned in FIGS. 3a and 3b is in the C city area, the cache server 302 will send the domain name resolution request sent by the terminal device 100 to the LDNS in the C city area.

[0131] In summary, in the method for obtaining the IP address corresponding to the target domain name based on the cache server, when the cache server caches the IP address corresponding to the target domain name carried in the domain name resolution request sent by the terminal device, the cache server can directly return the IP address corresponding to the target domain name to the terminal device, i.e., the cache server does not need to obtain the IP address corresponding to the target domain name from the ground LDNS every time. In this way, the number of interactions between the cache server and the ground LDNS can be reduced, and satellite communication resources can be saved.

[0132] However, because the network coverage of the low-orbit satellite is relatively small, and the low-orbit satellite is in continuous operation around the earth, when the LDNS to be accessed by the terminal device is outside the network coverage of the low-orbit satellite, the cache server deployed on the low-orbit satellite cannot communicate with the LDNS, so that in some cases, the cache server will not be able to obtain the IP address corresponding to the target domain name from the LDNS, resulting in network access failure of the terminal device, and affecting user experience.

[0133] For example, if the terminal device 100 sending the domain name resolution request mentioned in FIG. 3b is in the C city area, and the network coverage of the low-orbit satellite 300 is in the D city area far away from the C city area, at this time, the cache server 302 on the low-orbit satellite 300 will not be able to communicate with the LDNS 400 in the C city area. If the cache server 302 does not cache the IP address corresponding to the target domain name in the domain name resolution request sent by the terminal device 100, the cache server 302 will not be able to obtain the IP address corresponding to the target domain name from the LDNS 400, resulting in network access failure of the terminal device 100, and affecting user experience.

[0134] To solve the above problems, the present application provides a communication method, which can deploy servers in both low-orbit satellites and geosynchronous satellites. For example, a secondary server is deployed in a low-orbit satellite, and a primary server is deployed in a geosynchronous satellite. When the secondary server in the low-orbit satellite receives a domain name resolution request sent by a terminal device, if the secondary server in the low-orbit satellite does not have the IP address corresponding to the target domain name in the domain name resolution request, the secondary server in the low-orbit satellite forwards the domain name resolution request to the primary server in the geosynchronous satellite, and the primary server in the geosynchronous satellite establishes a communication connection with the ground LDNS to obtain the IP address corresponding to the target domain name from the LDNS. It can be understood that the network coverage of the geosynchronous satellite on the ground is much larger than the network coverage of the low-orbit satellite on the ground, and the geosynchronous satellite is in continuous operation with the earth, so the satellite-ground communication link between the geosynchronous satellite and the LDNS can be basically kept in real-time connection. Therefore, the IP address data can be obtained from the LDNS in real time through the geosynchronous satellite, so that the network access failure of the terminal device can be effectively reduced, and user experience can be improved.

[0135] It should be noted that when the primary server is deployed on a geosynchronous satellite, the secondary server in the embodiments of the present application can also be deployed on a low-orbit satellite, or on a medium-orbit satellite. In some embodiments, when the secondary server is deployed on a low-orbit satellite, the primary server can also be deployed on a medium-orbit satellite. Hereinafter, the secondary server is deployed on a low-orbit satellite, and the primary server is deployed on a geosynchronous satellite.

[0136] In some embodiments, the secondary server in the low-orbit satellite and the primary server in the geosynchronous satellite can both cache the mapping relationship between the domain name and the IP address.

[0137] In some embodiments, the domain name and IP address information cached by the secondary server in the low-orbit satellite and the primary server in the geosynchronous satellite are consistent. When the primary server in the geosynchronous satellite receives the domain name resolution request sent by the secondary server, the primary server in the geosynchronous satellite forwards the domain name resolution request to the LDNS on the ground to obtain the IP address corresponding to the target domain name from the LDNS.

[0138] In some embodiments, the primary server in the geosynchronous satellite and the secondary server in the low-orbit satellite can both update and cache the domain name and the IP address corresponding to the domain name from the LDNS on the ground at the same preset period (for example, every 1 hour). It can be understood that the preset period can be set according to actual needs, and the present application does not limit the specific value of the preset period.

[0139] In some embodiments, the period for the primary server in the geosynchronous satellite to update and cache the domain name and the IP address corresponding to the domain name from the LDNS on the ground can be less than the period for the secondary server in the low-orbit satellite to update and cache the domain name and the IP address corresponding to the domain name from the LDNS on the ground. In this way, the primary server can store more domain names and IP addresses than the secondary server in some time periods. When the primary server in the geosynchronous satellite receives the domain name resolution request sent by the secondary server, it can be determined whether the IP address corresponding to the target domain name in the domain name resolution request exists in the primary server. If not, the primary server establishes a communication connection with the LDNS on the ground to obtain the IP address corresponding to the target domain name from the LDNS; if so, the IP address corresponding to the target domain name is directly sent to the secondary server, and the secondary server sends the IP address corresponding to the target domain name to the terminal device.

[0140] In some embodiments, the primary server in the geosynchronous satellite can not cache the mapping relationship between the domain name and the IP address. When the primary server in the geosynchronous satellite receives the domain name resolution request sent by the secondary server, the primary server in the geosynchronous satellite forwards the domain name resolution request to the LDNS on the ground to obtain the IP address corresponding to the target domain name from the LDNS.

[0141] It can be understood that when the secondary server receives the domain name resolution request sent by the terminal device, if the IP address corresponding to the target domain name carried in the domain name resolution request is stored, the IP address corresponding to the target domain name can be directly returned to the terminal device, that is, the IP address corresponding to the target domain name does not need to be obtained from the ground LDNS every time. In this way, the number of interactions between the cache server and the ground LDNS can be reduced, and satellite communication resources can be saved.

[0142] In addition, when the secondary server does not store the IP address corresponding to the target domain name carried in the domain name resolution request, the domain name resolution request is forwarded to the LDNS through the primary server deployed in the geosynchronous satellite, and the primary server obtains the IP address data from the LDNS based on the satellite-ground communication link (or called feeder link) between the geosynchronous satellite and the LDNS. It can be understood that the network coverage of the geosynchronous satellite on the ground is much larger than that of the low-orbit satellite, and the geosynchronous satellite runs with the earth, so the satellite-ground communication link between the geosynchronous satellite and the LDNS can be basically kept in real-time connection, and therefore the primary server can obtain the IP address corresponding to the target domain name in real time, which can effectively reduce the above-mentioned network access failure of the terminal device and improve user experience.

[0143] It should be noted that in the embodiments of the present application, the primary server can establish a communication connection with the LDNS on the ground through the ground gateway station when the feeder link between the satellite where the primary server is located and the ground gateway station is effective (that is, can normally communicate).

[0144] The communication method mentioned in the embodiments of the present application will be described in detail below.

[0145] It should be noted that the secondary server 203 mentioned in the embodiments of the present application can be an example of the first server in the embodiments of the present application, the primary server 501 mentioned in the embodiments of the present application can be an example of the second server in the embodiments of the present application, and the secondary server 701 mentioned in the embodiments of the present application can be an example of the third server in the embodiments of the present application.

[0146] FIG. 5a shows a scenario diagram of a communication method. As shown in FIG. 5a, when the terminal device 100 needs to query the IP address corresponding to the target domain name, if the terminal device 100 accesses the satellite network, the domain name resolution request can be sent to the secondary server 203 in the low-orbit satellite 200 through the gNB 201 and the UPF 202 in the low-orbit satellite 200. When the secondary server 203 caches the IP address corresponding to the target domain name, the IP address corresponding to the target domain name can be sent to the terminal device 100. When the secondary server 203 does not cache the IP address corresponding to the target domain name, the domain name resolution request is forwarded to the primary server 501 in the geosynchronous satellite 500, and the primary server 501 in the geosynchronous satellite 500 establishes a communication connection with the LDNS 400 on the ground based on the ground gateway station 0032 to obtain the IP address corresponding to the target domain name from the LDNS 400 on the ground, and sends the obtained IP address corresponding to the target domain name to the terminal device 100. After receiving the IP address corresponding to the target domain name, the terminal device 100 accesses the corresponding application server 001 based on the IP address. It can be understood that the application server 001 can update its own IP address and domain name to the LDNS 400.

[0147] It can be understood that the satellite network of the geosynchronous satellite has a larger coverage area, and runs in synchronization with the earth, so the star-ground communication link between the LDNS and the geosynchronous satellite can basically maintain real-time connection, and therefore the IP address data in the LDNS can be obtained in real time through the geosynchronous satellite, thereby effectively reducing the above-mentioned domain name resolution failure, improving the success rate of domain name resolution, i.e. reducing the user network access failure, and improving the user experience.

[0148] FIG. 5b shows a flow diagram of a communication method based on the scenario shown in FIG. 5a. As shown in FIG. 5b, the method comprises:

[0149] 3001: The terminal device 100 sends a domain name resolution request to the gNB 201 in the low-orbit satellite 200.

[0150] It can be understood that when the terminal device 100 detects the user input network request, it can be determined that the IP address corresponding to the target domain name carried by the network request needs to be queried, and if the terminal device 100 accesses the satellite network, the domain name resolution request carrying the target domain name can be sent to the gNB 201 in the low-orbit satellite 200 through the satellite network.

[0151] In some embodiments, the target domain name can be carried in the domain name resolution request. For example, as shown in the foregoing FIG. 1, when the user inputs a network request of Http: / / baab.com / index.abc in the browser application interface 101 of the terminal device 100, the terminal device can send a domain name resolution request carrying the target domain name "baab.com" to the LDNS.

[0152] In some embodiments, the terminal device 100 can be configured to automatically obtain the IP address of the server on the satellite to be accessed when using the satellite network. For example, the terminal device can be manually configured or configured to automatically obtain the IP address of the secondary server 203 of the low-orbit satellite 200.

[0153] In some embodiments, the terminal device 100 can also send the IP address of the secondary server 203 in the low-orbit satellite 200 to the gNB 201 in the low-orbit satellite 200 when sending the domain name resolution request.

[0154] It should be noted that the domain name resolution request mentioned in the embodiments of the present application can also be referred to as a DNS request, a DNS resolution request, a DNS query request, etc., which is not limited in the present application.

[0155] 3002: The gNB 201 sends the domain name resolution request to the UPF 202 in the low-orbit satellite 200.

[0156] It can be understood that when the gNB 201 receives the domain name resolution request and the IP address of the secondary server 203, the gNB 201 can route the IP address of the secondary server 203 and the domain name resolution request to the UPF 202 in the low-orbit satellite.

[0157] 3003: The UPF 202 sends the domain name resolution request to the secondary server 203.

[0158] In some embodiments, when the UPF 202 receives the domain name resolution request sent by the gNB 201 and the IP address of the secondary server 203, the UPF 202 can send the domain name resolution request to the secondary server 203 based on the IP address of the secondary server 203.

[0159] 3004: The secondary server 203 judges whether the IP address corresponding to the target domain name is cached.

[0160] In some embodiments, when the secondary server 203 receives the domain name resolution request, the secondary server 203 can judge whether the IP address corresponding to the target domain name is cached in the secondary server 203. When the secondary server 203 caches the IP address corresponding to the target domain name, go to 3010, and send the IP address corresponding to the target domain name to the UPF 202.

[0161] If the server 203 does not cache the IP address corresponding to the target domain name, the domain name resolution request can be sent to the target primary server in the geosynchronous satellite. In the embodiments of the present application, the target primary server is taken as the primary server 501 in the geosynchronous satellite 500 for example.

[0162] In some embodiments, the secondary server 203 can be pre-configured with the IP addresses of one or more primary servers. When the secondary server is configured with the IP address of a primary server, the primary server corresponding to the IP address of the primary server is directly taken as the target primary server, and the domain name resolution request is sent to the target primary server based on the IP address of the target primary server. When the secondary server 203 is pre-configured with the IP addresses of multiple primary servers, the target primary server can be selected based on the inter-satellite routing strategy, for example, the primary server in the geosynchronous satellite closest to the current low-orbit satellite 200 is selected as the target primary server. The IP address of the target primary server is obtained, and the domain name resolution request is sent to the target primary server based on the IP address of the target primary server.

[0163] 3005: The secondary server 203 sends the domain name resolution request to the primary server 501.

[0164] In some embodiments, when the secondary server 203 determines that the server 301 does not cache the IP address corresponding to the target domain name, the secondary server 203 sends the domain name resolution request to the primary server 501 in the geosynchronous satellite 500.

[0165] 3006: The primary server 501 sends the domain name resolution request to the LDNS 400 on the ground.

[0166] In some embodiments, after receiving the domain name resolution request, the primary server 501 can send the domain name resolution request to the LDNS 400 on the ground.

[0167] In some embodiments, the secondary server 203 and the primary server 501 can both cache the mapping relationship between the domain name and the IP address.

[0168] In some embodiments, the secondary server 203 and the primary server 501 cache the same domain name and IP address information. When the primary server 501 receives the domain name resolution request sent by the secondary server 203, the primary server 501 forwards the domain name resolution request to the LDNS 400 on the ground to obtain the IP address corresponding to the target domain name from the LDNS 400.

[0169] In some embodiments, the primary server 501 and the secondary server 203 can both update and cache the domain name and the IP address corresponding to the domain name from the ground LDNS 400 at the same preset period (e.g., every 1 hour). It can be understood that the preset period can be set according to actual needs, and the specific value of the preset period is not limited in the present application.

[0170] In some embodiments, the period of updating the domain name and the IP address corresponding to the domain name from the ground LDNS 400 by the primary server 501 can be shorter than the period of updating the domain name and the IP address corresponding to the domain name from the ground LDNS 400 by the secondary server 203. In this way, the primary server 501 can store more domain names and IP addresses than the secondary server 203. When the primary server 501 receives the domain name resolution request sent by the secondary server 203, it can be determined whether the IP address corresponding to the target domain name in the domain name resolution request exists in the primary server 501. If not, the primary server 501 establishes a communication connection with the ground LDNS 400 to obtain the IP address corresponding to the target domain name from the LDNS 400; if so, the IP address corresponding to the target domain name is directly sent to the secondary server 203, and the secondary server 203 sends the IP address corresponding to the target domain name to the terminal device.

[0171] In some embodiments, the primary server 501 can not cache the mapping relationship between the domain name and the IP address. When the primary server 501 receives the domain name resolution request sent by the secondary server 203, the primary server 501 forwards the domain name resolution request to the ground LDNS 400 to obtain the IP address corresponding to the target domain name from the LDNS 400.

[0172] It can be understood that the range of the satellite network coverage of the satellite 500 on the ground is greater than the range of the satellite network coverage of the satellite 200 on the ground.

[0173] 3007: The LDNS 400 obtains the IP address corresponding to the target domain name based on the domain name resolution request.

[0174] In some embodiments, when the LDNS 400 obtains the domain name resolution request, it can query the IP address of the target domain name carried in the domain name resolution request.

[0175] In some embodiments, when the LDNS 400 determines that the IP address of the target domain name is cached in the LDNS 400, the LDNS 400 can send the IP address of the target domain name cached in the LDNS 400 to the primary server 501.

[0176] In some embodiments, when the LDNS 400 determines that the IP address of the target domain name is not cached in the LDNS 400, the LDNS 400 can perform the iterative query mentioned in the foregoing FIG. 4 to obtain the IP address of the target domain name.

[0177] It can be understood that in some embodiments, there can be multiple IP addresses of the server corresponding to the target domain name. For example, when the terminal device 100 detects that the user opens the application A or opens a certain page in the application A, it can be detected that the network request for accessing the server of the application A, and there can be multiple servers corresponding to the application A, for example, multiple servers corresponding to the application A are deployed in the C urban area. Therefore, there will be multiple IP addresses of the servers corresponding to the application A.

[0178] Therefore, in some embodiments, when the UPF 202 sends the domain name resolution request to the secondary server 203, the UPF 202 can also send the identification information of the satellite 200 where the UPF 202 is located. The secondary server 203 carries the identification information of the satellite 200 where the UPF 202 is located when sending the domain name resolution request to the primary server 501, and the primary server 203 carries the identification information of the satellite 200 where the UPF 202 is located when sending the domain name resolution request to the LDNS 400.

[0179] As shown in FIG. 6, when the LDNS 400 on the ground receives the domain name resolution request and the identification information of the low-orbit satellite 200, the LDNS 400 can also send the identification information of the low-orbit satellite 200 to an application server discovery function server (or ephemeris server) 600 to obtain the network coverage ground range information of the low-orbit satellite 200 where the UPF 202 is located at this time, wherein the network coverage ground range information of the low-orbit satellite 200 at this time can include the position information of the ground gateway station 004 connected in the low-orbit satellite 200 at this time. The application server discovery function server 600 can be authorized by the operator or controlled by the operator, and the application server discovery function server 600 can be configured with a mapping relationship between ephemeris information (such as satellite orbit information, etc.) and satellite identification information. When the application server discovery function server 600 receives the satellite identification information of the low-orbit satellite 200, the application server discovery function server 600 can obtain the ephemeris information of the low-orbit satellite 200, determine the network coverage ground range information of the satellite 200 at this time based on the ephemeris information, for example, the position information of the ground gateway station connected in the low-orbit satellite at this time, and send the network coverage ground range information to the LDNS 400 on the ground. It can be understood that the network coverage ground range information of the satellite 200 can represent the approximate position information of the terminal device 100.

[0180] The LDNS 400 on the ground can select an application server corresponding to the target domain name with network coverage ground range information closest to the location information of the ground gateway station 004 currently connected in the low-orbit satellite 200 from a plurality of application servers corresponding to the target domain name based on the network coverage ground range information, and send the IP address of the closest application server as the IP address corresponding to the target domain name to the primary server 501, so that the access path and latency of the terminal device 100 can be effectively shortened.

[0181] 3008: The LDNS 400 sends the IP address corresponding to the target domain name to the primary server 501.

[0182] In some embodiments, the LDNS 400 can send the IP address corresponding to the target domain name to the primary server 501 when receiving the IP address corresponding to the target domain name.

[0183] 3009: The primary server 501 sends the IP address corresponding to the target domain name to the secondary server 203.

[0184] In some embodiments, the primary server 501 can send the IP address corresponding to the target domain name to the secondary server 203 when receiving the IP address corresponding to the target domain name.

[0185] 3010: The secondary server 203 sends the IP address corresponding to the target domain name to the UPF 202.

[0186] In some embodiments, when the secondary server 203 caches the IP address corresponding to the target domain name, the IP address corresponding to the target domain name can be sent to the UPF 202.

[0187] In some embodiments, when the secondary server 203 receives the IP address corresponding to the target domain name sent by the primary server 501, the IP address corresponding to the target domain name can be sent to the UPF 202.

[0188] 3011: The UPF 202 sends the IP address corresponding to the target domain name to the gNB 201.

[0189] In some embodiments, the UPF 202 can send the IP address corresponding to the target domain name to the gNB 201 when receiving the IP address corresponding to the target domain name.

[0190] 3012: The gNB 201 sends the IP address corresponding to the target domain name to the terminal device 100.

[0191] In some embodiments, the gNB 201 can send the IP address corresponding to the target domain name to the terminal device 100 when receiving the IP address corresponding to the target domain name.

[0192] 3013: The terminal device 100 accesses the corresponding application server 001 based on the IP address.

[0193] In some embodiments, after receiving the IP address corresponding to the target domain name, the terminal device 100 can access the corresponding application server (AS) 001 based on the IP address. It should be noted that the application server mentioned in the embodiments of the present application can also be referred to as an application function (AF).

[0194] In some embodiments, the terminal device 100 can access the corresponding application server 001 based on the IP address in the following manner: the terminal device 100 sends an access request carrying the IP address to the gNB 201, the gNB 201 sends the access request to the UPF 202 after receiving the access request, the UPF 202 sends the access request to the ground gateway station 004 after receiving the access request, and the ground gateway station 004 sends the access request to the corresponding application server 001.

[0195] In summary, based on the communication method shown in FIGS. 5a and 5b, if the secondary server in the low-orbit satellite does not have the IP address corresponding to the target domain name in the domain name resolution request, the secondary server in the low-orbit satellite forwards the domain name resolution request to the primary server in the geosynchronous satellite, and the primary server in the geosynchronous satellite establishes a communication connection with the LDNS on the ground to obtain the IP address corresponding to the target domain name from the LDNS. It can be understood that the satellite network coverage area of the geosynchronous satellite is large, and the geosynchronous satellite runs with the earth, so the star-ground communication link between the geosynchronous satellite and the LDNS can basically maintain real-time power supply connection. Therefore, the IP address data in the LDNS can be obtained in real time through the geosynchronous satellite, so as to effectively improve the success rate and reliability of the domain name resolution request, reduce the network access failure of the terminal device, and improve the user experience.

[0196] In addition, based on the communication method shown in FIGS. 5a and 5b, the application server corresponding to the target domain name closest to the coverage geographical range of the low-orbit satellite 200 can be selected based on the network coverage position information of the terminal device accessing the satellite, such as the low-orbit satellite 200, and the IP address of the closest application server is sent to the terminal device as the IP address corresponding to the target domain name. In this way, the access path and the time delay of the terminal device can be effectively shortened.

[0197] In some embodiments, the secondary server in the low-orbit satellite can also classify the domain name resolution request and perform different operations on different types of domain name resolution requests. For a first type of domain name resolution request (for example, a domain name resolution request that needs to access a server corresponding to the first type of application), if the secondary server in the low-orbit satellite does not have the IP address corresponding to the target domain name in the domain name resolution request, the secondary server in the low-orbit satellite forwards the domain name resolution request to the primary server in the geosynchronous satellite. For a second type of domain name resolution request (for example, a domain name resolution request that needs to access a server corresponding to the second type of application), if the secondary server in the low-orbit satellite does not have the IP address corresponding to the target domain name in the domain name resolution request, directly returns the resolution failure information to the terminal device, that is, will not forward the domain name resolution request to the primary server in the geosynchronous satellite. In this way, the data transmission between the geosynchronous satellite and the ground can be reduced, and the consumption of satellite resources can be reduced.

[0198] FIG. 7 takes the secondary server in the low-orbit satellite performing different operations on different types of domain name resolution requests as an example. A flowchart of a communication method is shown, as shown in FIG. 7, the method comprises:

[0199] 4001: The terminal device 100 sends a domain name resolution request to the gNB 201 in the low-orbit satellite 200.

[0200] 4002: The gNB 201 sends the domain name resolution request to the UPF 202 in the low-orbit satellite 200.

[0201] It should be noted that the contents of 4001-4002 are similar to those in 3001-3002, and the embodiments of the present application will not be repeated here.

[0202] 4003: The UPF 202 sends the domain name resolution request to the secondary server 203.

[0203] In some embodiments, when the UPF 202 receives the domain name resolution request sent by the gNB 201 and the IP address of the secondary server 203, the UPF 202 can send the domain name resolution request to the secondary server 203 based on the IP address of the secondary server 203.

[0204] In some embodiments, when the UPF 202 receives the domain name resolution request of the terminal device 100, it can also determine the application that sends the domain name resolution request based on the target domain name. It can be understood that the server name corresponding to the domain name is the name of the application server corresponding to the application. Therefore, based on the server name corresponding to the domain name, the application that sends the domain name resolution request, or the application corresponding to the target domain name, can be determined.

[0205] Then, the UPF 202 determines the category of the application based on the application-associated subscription information and / or the user plane offloading rule, and marks different identifiers for the domain name resolution request based on the category of the application. The UPF 202 can send the domain name resolution request and the corresponding identifier to the secondary server 203.

[0206] For example, when the UPF 202 receives the domain name resolution request sent by the gNB 201, the domain name in the domain name resolution request is identified, the user plane offloading rule / N4 session rule is matched and executed, and it can also be understood that the rule detection is performed on the domain name resolution request data packet, that is, the UPF 202 obtains the application subscription information and / or the user plane forwarding rule information. The UPF 202 can determine the category of the application according to the application subscription data and / or the user plane forwarding rule information, and mark different identifiers for the domain name resolution request.

[0207] For example, when the application is determined to be a first type of application based on the application-associated subscription information and / or the user plane forwarding rule information, the domain name resolution request is determined to be a first type of domain name resolution request, and the domain name resolution request is marked with a first identifier. When the application is determined to be a second type of application based on the application-associated subscription information and / or the user plane forwarding rule information, the domain name resolution request is determined to be a second type of domain name resolution request, and the domain name resolution request is marked with a second identifier. When the application is determined to be a third type of application based on the application-associated subscription information and / or the user plane forwarding rule information, the domain name resolution request is determined to be a third type of domain name resolution request, and the domain name resolution request is not subjected to domain name resolution, and a resolution failure information is directly returned to the terminal device 100.

[0208] The first type of application can be an application associated with first type of subscription information and / or first type of user plane forwarding rule information, and the first type of subscription information and / or the first type of user plane forwarding rule information indicates that the service provider of the first type of application has signed a first agreement information with the network operator. The second type of application can be an application associated with second type of subscription information and / or second type of user plane forwarding rule information, and the second type of subscription information and / or the second type of user plane forwarding rule information indicates that the service provider of the application has signed a second agreement information with the network operator. The third type of application can be an application that is not associated with subscription information and / or user plane forwarding rule information, for example, the service provider of the application has not signed an agreement information with the network operator, and at this time, the application is not allowed to use the DNS resolution service.

[0209] In some embodiments, the UPF 202 can also determine the category of the domain name resolution request based on the domain name corresponding user plane forwarding rule information based on the domain name in the domain name resolution request. That is, the domain name and the user plane forwarding rule information have corresponding associations. For example, when it is determined that the domain name corresponding user plane forwarding rule information is first category user plane forwarding rule information, it is determined that the domain name resolution request is a first category domain name resolution request, and when it is determined that the domain name corresponding user plane forwarding rule information is second category user plane forwarding rule information, it is determined that the domain name resolution request is a second category domain name resolution request.

[0210] In some embodiments, the UPF 202 can be used to communicate with network elements of the ground core network, such as a policy control function (PCF), a session management function (SMF), and the like, to obtain subscription information, user plane forwarding rule information, and the like associated with each application from the network elements of the ground core network, such as the SMF, the PCF, and the like.

[0211] It should be noted that the above classification method is only exemplary, and the classification method of the domain name resolution request is not limited in the present application.

[0212] 4004: The secondary server 203 determines whether the IP address corresponding to the target domain name is cached.

[0213] In some embodiments, when the secondary server 203 receives the domain name resolution request, it can determine whether the IP address corresponding to the target domain name is cached in the secondary server 203. When the secondary server 203 caches the IP address corresponding to the target domain name, it can proceed to 4010 and send the IP address corresponding to the target domain name to the UPF 202.

[0214] In some embodiments, if the secondary server 203 does not cache the IP address corresponding to the target domain name, it can proceed to 40051 and determine whether the domain name resolution request is a first category domain name resolution request.

[0215] In some embodiments, the secondary server 203 and the primary server 501 can update and cache the domain name and the IP address corresponding to the domain name from the ground LDNS 400 at a preset period (e.g., every 1 hour).

[0216] 40051: The secondary server 203 determines whether the domain name resolution request is a first category domain name resolution request.

[0217] If the secondary server 203 determines that the domain name resolution request is a first-class domain name resolution request, it means that a domain name resolution request needs to be sent to the primary server 501. Then, it is transferred to 4005, and the secondary server 203 sends the domain name resolution request to the primary server 501 in the geostationary satellite 500.

[0218] If the secondary server 203 determines that the domain name resolution request is a type II domain name resolution request, it means that it does not need to send a domain name resolution request to the primary server 501. Therefore, it forwards the request to 40052 and sends a resolution failure message to UPF 202, so that UPF 202 can send the resolution failure message to the terminal device. The resolution failure message may include the reason for the resolution failure, such as the secondary server 203 being unable to resolve the request. In some embodiments, the reason for the resolution failure may also be in the form of an identifier, characters, or numbers.

[0219] For example, when the identifier corresponding to the domain name resolution request is a type 1 identifier, the secondary server 203 determines whether the domain name resolution request is a type 1 domain name resolution request and, if so, forwards it to the primary server 501 in the geostationary satellite 500. When the identifier corresponding to the domain name resolution request is a type 2 identifier, it is determined to be a type 2 domain name resolution request. For type 2 domain name resolution requests, a resolution failure message is directly returned to the terminal device 100, meaning the domain name resolution request is not forwarded to the primary server 501 in the geostationary satellite 500. This reduces data transmission between the geostationary satellite and the ground, thus reducing the consumption of satellite resources.

[0220] It should be noted that the resolution failure information mentioned in the embodiments of this application may also be referred to as DNS resolution failure response, DNS query failure response, DNS resolution response, DNS query response, etc., and the embodiments of this application do not limit it.

[0221] 40052: Secondary server 203 sent a parsing failure message to UPF 202.

[0222] 40053: UPF 202 sends a parsing failure message to gNB 201.

[0223] In some embodiments, when UPF 202 receives a parsing failure message, it can send the parsing failure message to gNB 201.

[0224] 40054: gNB 201 sends a parsing failure message to terminal device 100.

[0225] In some embodiments, when gNB 201 receives a parsing failure message, it can send the parsing failure message to terminal device 100.

[0226] It should be noted that the steps of 4005-4013 are similar to the steps of 3005-3013, and the following will not be described again.

[0227] 4005: The secondary server 203 sends a domain name resolution request to the primary server 501 in the geosynchronous satellite 500.

[0228] 4006: The primary server 501 sends a domain name resolution request to the LDNS on the ground.

[0229] 4007: The LDNS obtains the IP address corresponding to the target domain name based on the domain name resolution request.

[0230] 4008: The LDNS sends the IP address corresponding to the target domain name to the primary server 501.

[0231] 4009: The primary server 501 sends the IP address corresponding to the target domain name to the secondary server 203.

[0232] 4010: The secondary server 203 sends the IP address corresponding to the target domain name to the UPF 202.

[0233] 4011: The UPF 202 sends the IP address corresponding to the target domain name to the gNB 201.

[0234] 4012: The gNB 201 sends the IP address corresponding to the target domain name to the terminal device 100.

[0235] 4013: The terminal device 100 accesses the server 001 corresponding to the application based on the IP address.

[0236] In summary, based on the communication method shown in FIG. 7, by classifying the domain name resolution request, the data transmission between the geosynchronous satellite and the ground can be reduced, and the consumption of satellite resources can be reduced.

[0237] It can be understood that the communication method shown in FIG. 7 is to determine whether the domain name resolution request is sent to the primary server 501 by the secondary server 203. In some embodiments, the determination of whether the domain name resolution request is sent to the primary server 501 can also be determined by the UPF 202.

[0238] That is, the UPF 202 can determine, when receiving the domain name resolution request, that the domain name resolution request is a first type of domain name resolution request based on the manner of classifying the domain name resolution request in step 4003, and directly send the domain name resolution request to the first-level server 501, and when the domain name resolution request is a second type of domain name resolution request, send the domain name resolution request to the second-level server 203. When receiving the domain name resolution request, the second-level server 203 determines whether the second-level server 203 does not exist the IP address corresponding to the target domain name in the domain name resolution request, and directly returns the information of the resolution failure to the terminal device 100 based on the UPF 202 and the gNB 201, or determines that the second-level server 203 exists the IP address corresponding to the target domain name in the domain name resolution request, and directly returns the IP address corresponding to the target domain name to the terminal device 100 based on the UPF 202 and the gNB 201.

[0239] It can be understood that the first-level server 501 can store the domain name and the IP address. When the first-level server 501 receives the domain name resolution request sent by the UPF 202, it can be determined whether the first-level server 501 exists the IP address corresponding to the target domain name in the domain name resolution request, and if not, the first-level server 203 establishes a communication connection with the ground LDNS 400 to realize the acquisition of the IP address corresponding to the target domain name from the LDNS 400; if it exists, the IP address corresponding to the target domain name is directly sent to the terminal device 100 based on the UPF 202 and the gNB 201.

[0240] In some embodiments, the first-level server 501 can not cache the mapping relationship between the domain name and the IP address. When the first-level server 501 receives the domain name resolution request, the domain name resolution request is forwarded to the ground LDNS 400 to realize the acquisition of the IP address corresponding to the target domain name from the LDNS 400, and the IP address corresponding to the target domain name is sent to the terminal device 100 based on the UPF 202 and the gNB 201.

[0241] In some embodiments, when the low-orbit satellite 200 where the second-level server 203 is located does not exist an inter-satellite routing path with the geosynchronous satellite 500, that is, the second-level server 203 cannot directly establish a communication connection with the first-level server. The second-level server 203 can query an auxiliary satellite in the constellation where the low-orbit satellite 200 is located and which exists an inter-satellite path with the geosynchronous satellite 500, and forward the domain name resolution request to the first-level server 501 in the geosynchronous satellite 500 through the auxiliary satellite.

[0242] FIG. 8a shows a scenario diagram in which a secondary server 203 forwards a domain name resolution request to a primary server 501 through an auxiliary satellite 700 in the constellation 002. As shown in FIG. 8a, when the low-orbit satellite 200 where the secondary server 203 is located does not have an inter-satellite routing path with the geosynchronous satellite 300, the secondary server 203 can send the domain name resolution request to a secondary server 701 in the satellite 700 (auxiliary satellite) when it determines that the satellite 700 has an inter-satellite routing path with the geosynchronous satellite 300. The secondary server 701 forwards the domain name resolution request to the primary server 501 in the geosynchronous satellite 500.

[0243] In some embodiments, as shown in FIG. 8b, the UPF 202 and the gNB 201 can also be deployed in different satellites as the secondary server 203. For example, the UPF 202 and the gNB 201 are deployed in the low-orbit satellite 200, and the secondary server 203 is deployed in the low-orbit satellite 200-1. The present application does not make any limitation.

[0244] FIG. 8c shows a flow diagram of a communication method based on the scenario shown in FIG. 8a. As shown in FIG. 8c, the method includes:

[0245] 5001: The terminal device 100 sends a domain name resolution request to the gNB 201 in the low-orbit satellite 200.

[0246] 5002: The gNB 201 sends the domain name resolution request to the UPF 202 in the low-orbit satellite 200.

[0247] 5003: The UPF 202 sends the domain name resolution request to the secondary server 203.

[0248] 5004: The secondary server 203 determines whether the IP address corresponding to the target domain name is cached.

[0249] It should be noted that the steps 5001-5004 can refer to the steps 3001-3004, or can refer to the steps 4001-4005, which will not be described here.

[0250] 50051: The secondary server 203 determines whether there is a routing path between the secondary server 203 and the primary server 501 in the geosynchronous satellite 500.

[0251] In some embodiments, if the secondary server 203 determines that there is a routing path between the secondary server 203 and the primary server 501 in the geosynchronous satellite 500, it goes to 5005, and the secondary server 203 sends the domain name resolution request to the primary server 501 in the geosynchronous satellite 500.

[0252] In some embodiments, if the secondary server 203 determines that there is no routing path between the secondary server 203 and the primary server 501 in the geosynchronous satellite 500, the secondary server 203 goes to 50052, and the secondary server 203 acquires the secondary server 701 that has a routing path with the primary server 501 in the geosynchronous satellite 500.

[0253] It can be understood that when the secondary server 203 determines that there is an inter-satellite routing path between the satellite 200 and the satellite 500, it is determined that there is a routing path between the secondary server 203 in the satellite 200 and the primary server 501 in the satellite 500, i.e., the secondary server 203 and the primary server 501 can communicate. When the secondary server 203 determines that there is no inter-satellite routing path between the satellite 200 and the satellite 500, it is determined that there is no routing path between the secondary server 203 in the satellite 200 and the primary server 501 in the satellite 500, i.e., the secondary server 203 and the primary server 501 cannot communicate.

[0254] 50052: The secondary server 203 acquires the secondary server 701 that has a routing path with the primary server 501 in the geosynchronous satellite 500.

[0255] In some embodiments, the secondary server 203 can successively send a link query request to other satellites (e.g., processors in other satellites) in the constellation 002, and the link query request can carry identification information of the satellite 500. The satellite receiving the link query request can query whether there is an inter-satellite routing path with the satellite 500, and when there is, it returns a presence response to the secondary server 203. When there is not, it returns an absence response to the secondary server 203. When the secondary server 203 first receives the presence response, for example, receives the presence response sent by the satellite 700, it stops sending the link query request to other satellites. And send a domain name resolution request to the secondary server 203 in the satellite 700.

[0256] It can be understood that there is an inter-satellite link (ISL) between satellites belonging to the same constellation, i.e., an inter-satellite routing path. There is at least one inter-satellite link between different constellations, ensuring that satellites in different constellations can communicate.

[0257] 50053: The secondary server 203 sends a domain name resolution request to the secondary server 701.

[0258] 50054: The secondary server 701 sends a domain name resolution request to the primary server 501 in the geosynchronous satellite 500.

[0259] In some embodiments, the secondary server 701 sends the domain name resolution request to the primary server 501 in the geosynchronous satellite 500 upon receiving the domain name resolution request.

[0260] It should be noted that the steps 5005-5013 can refer to the steps 3005-3013, and will not be described here.

[0261] 5005: The secondary server 203 sends the domain name resolution request to the primary server 501 in the geosynchronous satellite 500.

[0262] 5006: The primary server 501 sends the domain name resolution request to the LDNS on the ground.

[0263] 5007: The LDNS obtains the IP address corresponding to the target domain name based on the domain name resolution request.

[0264] 5008: The LDNS sends the IP address corresponding to the target domain name to the primary server 501.

[0265] 5009: The primary server 501 sends the IP address corresponding to the target domain name to the secondary server 203.

[0266] In some embodiments, when there is no routing path between the primary server 501 and the secondary server 203, the primary server 501 sends the IP address corresponding to the target domain name to the secondary server 701, and the secondary server 701 sends the IP address corresponding to the target domain name to the secondary server 203.

[0267] In some embodiments, when there is a routing path between the primary server 501 and the secondary server 203, the primary server 501 sends the IP address corresponding to the target domain name to the secondary server 203 through the routing path.

[0268] 5010: The secondary server 203 sends the IP address corresponding to the target domain name to the UPF 202.

[0269] 5011: The UPF 202 sends the IP address corresponding to the target domain name to the gNB 201.

[0270] 5012: The gNB 201 sends the IP address corresponding to the target domain name to the terminal device 100.

[0271] 5013: The terminal device 100 accesses the server 001 corresponding to the application based on the IP address.

[0272] In summary, based on the communication method shown in FIGS. 8a and 8b, when there is no inter-satellite routing path between the low-orbit satellite 200 where the secondary server 203 is located and the geosynchronous satellite 500, the secondary server 203 can send the domain name resolution request to the server 701 in the satellite 700 when it is determined that there is an inter-satellite routing path between the satellite 700 and the geosynchronous satellite 500. The server 701 forwards the domain name resolution request to the primary server 501 in the geosynchronous satellite 500. This ensures the success rate of the domain name resolution request and reduces the number of network access failures of the user, thereby improving the user experience.

[0273] In summary, based on the communication method in the embodiments of the present application, if the secondary server in the low-orbit satellite does not have the IP address corresponding to the target domain name in the domain name resolution request, the secondary server in the low-orbit satellite forwards the domain name resolution request to the primary server in the geosynchronous satellite, and the primary server in the geosynchronous satellite establishes a communication connection with the LDNS on the ground to obtain the IP address corresponding to the target domain name from the LDNS. It can be understood that the satellite network coverage area of the geosynchronous satellite is relatively large, and the geosynchronous satellite operates with the earth, so the star-ground communication link between the geosynchronous satellite and the LDNS can basically maintain real-time power supply connection. Therefore, the IP address data in the LDNS can be obtained in real time through the geosynchronous satellite, thereby effectively improving the success rate and reliability of the domain name resolution request, reducing the network access failure of the terminal device, and improving the user experience.

[0274] In addition, based on the communication method in the embodiments of the present application, the application server corresponding to the target domain name closest to the coverage geographical range of the low-orbit satellite 200 can be selected based on the network coverage location information of the access satellite of the terminal device, such as the low-orbit satellite 200, and the IP address of the closest application server is sent to the terminal device as the IP address corresponding to the target domain name. In this way, the access path and latency of the terminal device can be effectively shortened.

[0275] In addition, based on the communication method in the embodiments of the present application, by classifying the domain name resolution request, the data transmission between the geosynchronous satellite and the ground can be reduced, and the consumption of satellite resources can be reduced.

[0276] FIG. 9 shows a flowchart of a communication method based on the scenario of needing to forward the domain name resolution request through the auxiliary satellite shown in FIG. 8a and the scenario of classifying the domain name resolution request. As shown in FIG. 9, the method includes:

[0277] 6001: The terminal device 100 sends a domain name resolution request to the gNB 201 in the low-orbit satellite 200.

[0278] 6002: The gNB 201 sends the domain name resolution request to the UPF 202 in the low-orbit satellite 200.

[0279] 6003: The UPF 202 sends a domain name resolution request to the secondary server 203.

[0280] 6004: The secondary server 203 determines whether the IP address corresponding to the target domain name is cached.

[0281] 60051: The secondary server 203 determines whether the domain name resolution request is a first type of domain name resolution request.

[0282] 60052: The secondary server 203 sends resolution failure information to the UPF 202.

[0283] 60053: The UPF 202 sends the resolution failure information to the gNB 201.

[0284] 60054: The gNB 201 sends the resolution failure information to the terminal device 100.

[0285] 60055: The secondary server 203 determines whether a routing path exists between the secondary server 203 and the primary server 501 in the geosynchronous satellite 500.

[0286] It should be noted that the steps 4001-40055 of the steps 6001-60033 are not repeated here.

[0287] 60056: The secondary server 203 acquires a secondary server 701 that has a routing path with the primary server 501 in the geosynchronous satellite 500.

[0288] 60057: The secondary server 203 sends a domain name resolution request to the secondary server 701.

[0289] 60058: The secondary server 701 sends a domain name resolution request to the primary server 501 in the geosynchronous satellite 500.

[0290] 6005: The secondary server 203 sends a domain name resolution request to the primary server 501 in the geosynchronous satellite 500.

[0291] 6006: The primary server 501 sends a domain name resolution request to the LDNS on the ground.

[0292] 6007: The LDNS acquires an IP address corresponding to the target domain name based on the domain name resolution request.

[0293] 6008: The LDNS sends the IP address corresponding to the target domain name to the primary server 501.

[0294] 6009: The primary server 501 sends the IP address corresponding to the target domain name to the secondary server 203.

[0295] 6010: The secondary server 203 sends the IP address corresponding to the target domain name to the UPF 202.

[0296] 6011: The UPF 202 sends the IP address corresponding to the target domain name to the gNB 201.

[0297] 6012: The gNB 201 sends the IP address corresponding to the target domain name to the terminal device 100.

[0298] 6013: The terminal device 100 accesses the server 001 corresponding to the application based on the IP address.

[0299] It should be noted that the steps 50051-5013 of the steps 60056-6013 are not repeated here.

[0300] FIG. 10 shows a flowchart of a communication method according to an embodiment of the present application. As shown in FIG. 10, the communication method comprises:

[0301] 7001: The terminal device sends a domain name resolution request corresponding to a first domain name to a first server.

[0302] In some embodiments, the first server is deployed on a first satellite, the first satellite is operated in a first earth orbit, the domain name resolution request comprises the first domain name, and the first server stores a mapping relationship between a domain name and an IP address.

[0303] The first server can be the secondary server 203 mentioned in the embodiments of the present application. The first satellite can refer to the low earth orbit satellite 200 mentioned in the embodiments of the present application, or the low earth orbit satellite 200-1.

[0304] In some embodiments, the terminal device can send the domain name resolution request corresponding to the first domain name to the first server in the manner of steps 3001-3003 or steps 5001-5003.

[0305] 7002: The first server determines whether the IP address corresponding to the first domain name is stored.

[0306] In some embodiments, the first server can determine whether the IP address corresponding to the first domain name is stored based on the corresponding relationship between the domain name and the IP address stored by the first server. The first server can determine whether the IP address corresponding to the first domain name is stored in the manner of step 3004.

[0307] If the first server determines that the IP address corresponding to the target domain name is stored, go to 7008, and the second server sends the first IP address to the terminal device.

[0308] If the first server determines that the IP address corresponding to the target domain name is not stored, go to 7003, and the first server sends a domain name resolution request to the second server.

[0309] In some embodiments, the second server can be the secondary server 203 mentioned in the embodiments of the application.

[0310] 7003: The first server sends a domain name resolution request to the second server.

[0311] The second server is deployed on a second satellite, and the second satellite operates in a second earth orbit, which is higher than the first earth orbit.

[0312] In some embodiments, the second satellite can be the satellite 500 mentioned in the embodiments of the application, and the second earth orbit can be the high earth orbit mentioned in the embodiments of the application. The satellite network coverage range of the second satellite is greater than that of the first satellite.

[0313] In some embodiments, the manner in which the first server sends a domain name resolution request to the second server can refer to steps 3005, 50051-5005, 40051-4005.

[0314] 7004: The second server sends a domain name resolution request to the local domain name server.

[0315] In some embodiments, the manner in which the second server sends a domain name resolution request to the local domain name server can refer to step 3006.

[0316] In some embodiments, the local domain name server can be the LDNS 500 mentioned in the embodiments of the application.

[0317] 7005: The local domain name server obtains a first IP address corresponding to the first domain name based on the domain name resolution request.

[0318] In some embodiments, the manner in which the local domain name server obtains a first IP address corresponding to the first domain name based on the domain name resolution request can refer to step 3007.

[0319] 7006: The local domain name server sends the first IP address to the second server.

[0320] In some embodiments, the manner in which the local domain name server sends the first IP address to the second server can refer to 3008.

[0321] 7007: The second server sends the first IP address to the first server.

[0322] 7008: The first server sends the first IP address to the terminal device.

[0323] In some embodiments, the manner in which the second server sends the first IP address to the terminal device can refer to 3009-3012 and 5008-5012.

[0324] In summary, based on the communication method in the embodiments of the present application, if the second server in the low-orbit satellite does not have the IP address corresponding to the target domain name in the domain name resolution request, the second server in the low-orbit satellite forwards the domain name resolution request to the first server in the geosynchronous satellite, and the first server in the geosynchronous satellite establishes a communication connection with the LDNS on the ground to obtain the IP address corresponding to the target domain name from the LDNS. It can be understood that the satellite network coverage area of the geosynchronous satellite is relatively large, and the geosynchronous satellite runs with the earth, so the star-ground communication link between the geosynchronous satellite and the LDNS can basically maintain a real-time feeder connection. Therefore, the IP address data in the LDNS can be obtained in real time through the geosynchronous satellite, so as to effectively improve the success rate and reliability of the domain name resolution request, reduce the network access failure of the terminal device, and improve the user experience.

[0325] In addition, based on the communication method in the embodiments of the present application, the application server corresponding to the target domain name closest to the coverage geographical range of the low-orbit satellite 200 can be selected based on the network coverage position information of the access satellite of the terminal device, such as the low-orbit satellite 200, and the IP address of the closest application server is sent to the terminal device as the IP address corresponding to the target domain name. In this way, the access path and the time delay of the terminal device can be effectively shortened.

[0326] In addition, based on the communication method in the embodiments of the present application, by classifying the domain name resolution request, the data transmission between the geosynchronous satellite and the ground can be reduced, and the consumption of satellite resources can be reduced.

[0327] In some embodiments, the communication method mentioned in the embodiments of the present application can be used in a communication system, and the communication system includes a ground system and a satellite system. The ground system includes a terminal device, a local domain name server, a ground gateway station and the like. The satellite system includes a first server, a second server, a UPF, a gNB and the like. The first server is deployed in a first satellite, and the first satellite runs in a first earth orbit. The second server is deployed in a second satellite, and the second satellite runs in a second earth orbit. The second earth orbit is higher than the first earth orbit.

[0328] The embodiments of the present application provide a satellite system, which includes the first server and the second server, the UPF, the gNB and the like mentioned in the embodiments of the present application. The satellite system provided by the embodiments of the present application can perform the communication method performed by each device in the satellite system.

[0329] It should be noted that the methods and features in the embodiments of the present application can be combined in any form, that is, the embodiments formed by combining the methods and features in the embodiments of the present application in any form are within the protection scope of the embodiments of the present application.

[0330] The structure of the terminal device 100 and the primary server 203, the secondary server 501 and the LDNS 400 mentioned in the embodiments of the present application will be introduced below.

[0331] FIG. 11 shows a structural schematic diagram of a terminal device 100. As shown in FIG. 11, the terminal device 100 can include a processor 110, a power module 140, a memory 180, a mobile communication module 130, a wireless communication module 120, a sensor module 190, an audio module 150, a camera 170, an interface module 160, a key 101 and a display screen 102.

[0332] FIG. 12 shows a structural schematic diagram of a server. The server shown in FIG. 12 can be the structure of the primary server 501, the secondary server 203 or the LDNS 400 mentioned in the embodiments of the present application.

[0333] In an embodiment, the server 1200 can include one or more processors 1204, system control logic 1208 connected with at least one of the processors 1204, system memory 1212 connected with the system control logic 1208, non-volatile memory (NVM) 1216 connected with the system control logic 1208, and a network interface 1220 connected with the system control logic 1208.

[0334] In some embodiments, the processor 1204 can include one or more single-core or multi-core processors. In some embodiments, the processor 1204 can include any combination of general-purpose processors and special-purpose processors (for example, graphics processors, application processors, baseband processors, etc.). In the embodiments in which the server 1200 adopts the eNB (Evolved Node B) 101 or the RAN (Radio Access Network) controller 102, the processor 1204 can be configured to perform various embodiments, for example, can be used to perform the methods required to be performed by the primary server 501, the secondary server 203 or the LDNS 400 in the embodiments of the present application.

[0335] The embodiments of the present application provide a computer readable storage medium, which stores executable instructions, and the instructions are executed on an electronic device to implement the communication method provided in the embodiments of the present application.

[0336] An electronic device includes a memory to store instructions for execution by one or more processors of the electronic device and one or more processors to execute a communication method provided in embodiments of the present application.

[0337] Embodiments of the mechanisms disclosed herein can be implemented in hardware, software, firmware, or any combination thereof. Embodiments of the application can be implemented as computer programs or program code executing on programmable systems comprising at least one processor, a storage system (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device.

[0338] Program code can be applied to input instructions to perform the functions described herein and generate output information. The output information can be applied to one or more output devices, in known fashion. For purposes of this application, a processing system includes any system that has a processor, such as a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), or a microprocessor.

[0339] The program code can be implemented in a high level procedural or object oriented programming language to communicate with a processing system. The program code can be implemented in assembly or machine language, if desired. In fact, the mechanisms described herein are not limited in scope to any particular programming language. In any case, the language can be a compiled or interpreted language.

[0340] In some cases, the disclosed embodiments can be implemented in hardware, firmware, software, or any combination thereof. The disclosed embodiments can also be implemented as instructions carried by or stored on a transitory or non-transitory machine-readable (e.g., computer-readable) medium, which can be read and executed by one or more processors. For example, the instructions can be distributed over the network or by other computer readable media. Thus, a machine-readable medium can include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer), including without limitation, recordable non-transitory media, floppy disks, optical disks, optical, CD-ROMs, read-only memories (ROMs), random access memories (RAMs), erasable programmable ROMs (EPROMs), electrically erasable programmable ROMs (EEPROMs), magnetic or optical cards, flash memory, and the like. The machine-readable media can further include a tangible, machine-readable storage or transmission medium encoded with one or more machine-readable instructions stored thereon. The machine-readable instructions can be any set of instructions that can be executed by one or more processors to cause the machine to perform a machine-readable medium.

[0341] In the drawings, some of the structures or method features can be shown in particular arrangements and / or orders. However, it should be understood that such specific arrangements and / or orders can not be required. Instead, these features can be arranged in a different manner and / or order than shown in the illustrative drawings, in some embodiments. Additionally, inclusion of a structural or method feature in a particular figure is not meant to imply that such feature is required in all embodiments, and in some embodiments, such feature can not be included or can be combined with other features.

[0342] It should be noted that each unit / module mentioned in the embodiments of the devices of the present application is a logical unit / module, and in physical form, one logical unit / module can be a physical unit / module, or a part of a physical unit / module, or a combination of multiple physical unit / modules, and the physical implementation form of the logical unit / module itself is not the most important, and the combination of the functions implemented by these logical units / modules is the key to solving the technical problems proposed in the present application. In addition, in order to highlight the innovative part of the present application, the above-mentioned embodiments of the devices of the present application do not introduce units / modules that are not closely related to solving the technical problems proposed in the present application, which does not mean that the above-mentioned device embodiments do not have other units / modules.

[0343] It should be noted that in the examples and descriptions of the present patent, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including one" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0344] Although the present application has been illustrated and described with reference to certain preferred embodiments thereof, it should be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit and scope of the present application.

Claims

A communication method characterized by comprising: A satellite system, comprising a first server and a second server, the first server is deployed on a first satellite, the first satellite runs on a first earth orbit, the second server is deployed on a second satellite, the second satellite runs on a second earth orbit, the second earth orbit is higher than the first earth orbit; The method comprises: The first server receives a first domain name resolution request sent by a terminal device in a ground system, the first domain name resolution request comprising a first domain name requested to be resolved by the terminal device, and the first server stores a mapping relationship between domain names and IP addresses; When the first server determines that the first server does not store a first IP address corresponding to the first domain name based on the mapping relationship between domain names and IP addresses, the first server sends the first domain name resolution request to the second server, wherein the first server sending the first domain name resolution request to the second server comprises: the first server identifying the first domain name resolution request as a first type of domain name resolution request, and sending the first domain name resolution request to the second server, the classification of the first domain name resolution request being determined based on subscription information and / or user plane forwarding rule information corresponding to an application corresponding to the first domain name; The second server determines that the second server does not store the first IP address corresponding to the first domain name based on the mapping relationship between domain names and IP addresses stored in the second server, and sends the first domain name resolution request to a local domain name server in the ground system, wherein a period for the second server to update the mapping relationship between domain names and IP addresses from the local domain name server is less than or equal to a period for the first server to update the mapping relationship between domain names and IP addresses from the local domain name server; The second server receives the first IP address corresponding to the first domain name sent by the local domain name server; The second server sends the first IP address to the first server; The first server sends the first IP address to the terminal device. The communication method according to claim 1, characterized in that The satellite system further comprises a user plane function UPF; The first server receives a first domain name resolution request sent by a terminal device in a ground system, comprising: The user plane function UPF receives the first domain name resolution request sent by the terminal device in the ground system; The user plane function UPF determines that the first domain name resolution request is a first type of domain name resolution request based on the first domain name in the first domain name resolution request, marks the first domain name resolution request with a first identifier, and sends the first domain name resolution request and the first identifier to the first server. The communication method according to claim 2, characterized in that The user plane function UPF determines that the first domain name resolution request is the first type of domain name resolution request based on the first domain name in the first domain name resolution request, comprising: The user plane function UPF determines an application corresponding to the first domain name based on the first domain name in the first domain name resolution request, and obtains subscription information and / or user plane forwarding rule information corresponding to the application corresponding to the first domain name, and determines that the first domain name resolution request is a first type of domain name resolution request based on the subscription information and / or user plane forwarding rule information corresponding to the application corresponding to the first domain name; or The user plane function UPF obtains user plane forwarding rule information corresponding to the first domain name based on the first domain name in the first domain name resolution request, and determines that the first domain name resolution request is the first type of domain name resolution request based on the user plane forwarding rule information corresponding to the first domain name. The communication method according to claim 1, wherein The first server identifying that the first domain name resolution request is a first type of domain name resolution request comprises: The first server receives the first domain name resolution request and a first identifier sent by the user plane function UPF, and identifies that the first domain name resolution request is the first type of domain name resolution request based on the first identifier. The communication method according to any one of claims 1-4, wherein The method further comprises: The first server receives a second domain name resolution request sent by the terminal device, the second domain name resolution request comprising a second domain name requested to be resolved by the terminal device; When the first server determines that the first server does not store a second IP address corresponding to the second domain name based on the mapping relationship between the domain name and the IP address, and identifies that the second domain name resolution request is a second type of domain name resolution request, the first server sends resolution failure information to the terminal device. The communication method according to claim 5, characterized in that The first server receiving the second domain name resolution request sent by the terminal device comprises: The user plane function UPF receives the second domain name resolution request sent by the terminal device; The user plane function UPF determines that the second domain name resolution request is the second type of domain name resolution request based on the second domain name in the second domain name resolution request, marks a second identifier for the second domain name resolution request, and sends the second domain name resolution request and the second identifier to the first server. The communication method according to any one of claims 1 to 4, characterized in that The satellite system further comprises a third server, the third server being deployed on a third satellite, the third satellite and the first satellite being located in the same constellation, and there being an inter-satellite routing path between the third satellite and the second satellite; The first server sending the first domain name resolution request to the second server comprises: The first server determines that there is no inter-satellite routing path between the first satellite and the second satellite, the first server sends the first domain name resolution request to the third server, and the third server sends the first domain name resolution request to the second server. The communication method according to any one of claims 1 to 4, characterized in that The ground system further comprises an ephemeris server; The first server sending the first domain name resolution request to the second server comprises: the first server sending the first domain name resolution request and identification information of the first satellite to the second server. The second server receives the first IP address corresponding to the first domain name sent by the local domain name server, including: The ephemeris server receives the identification information of the first satellite sent by the local domain name server, and the ephemeris server is configured to store a mapping relationship between identification information of a satellite and ephemeris information; The ephemeris server acquires ephemeris information corresponding to the first satellite based on the identification information of the first satellite; The ephemeris server determines network coverage ground range information of the first satellite based on the ephemeris information of the first satellite; The ephemeris server sends the network coverage ground range information of the first satellite to the local domain name server; The second server receives the first IP address corresponding to the first domain name sent by the local domain name server, wherein the first IP address is acquired by the local domain name server based on the network coverage ground range information of the first satellite and a mapping relationship between domain names and IP addresses stored by the local domain name server. The communication method according to claim 8, characterized in that The network coverage ground range information of the first satellite includes position information of a ground gateway station currently connected by the first satellite. The communication method according to claim 9, characterized in that The manner in which the local domain name server acquires the first IP address based on the network coverage position information of the first satellite and the mapping relationship between domain names and IP addresses stored by the local domain name server includes: The local domain name server determines at least one IP address corresponding to the first domain name based on the mapping relationship between domain names and IP addresses stored by the local domain name server; The local domain name server selects the first IP address from the at least one IP address, and the first IP address is an IP address corresponding to an application server closest to the position information of the ground gateway station. A communication method characterized by comprising: For a satellite system, the satellite system includes a user plane function (UPF), a first server, and a second server, the first server is deployed on a first satellite, the first satellite runs in a first earth orbit, the second server is deployed on a second satellite, the second satellite runs in a second earth orbit, the second earth orbit is a geosynchronous orbit, and the second earth orbit is higher than the first earth orbit; The method includes: The user plane function (UPF) receives a first domain name resolution request sent by a terminal device in a ground system; the first domain name resolution request includes a first domain name requested to be resolved by the terminal device; The user plane function (UPF) determines, based on the first domain name in the first domain name resolution request, that the first domain name resolution request is a first type of domain name resolution request, sends the first domain name resolution request to the second server, and the classification of the first domain name resolution request is determined based on subscription information and / or user plane forwarding rule information corresponding to an application corresponding to the first domain name. The second server determines that the first IP address corresponding to the first domain name is not stored in the second server based on a mapping relationship between domain names and IP addresses stored in the second server, and sends the first domain name resolution request to a local domain name server in the ground system, and a period for the second server to update the mapping relationship between domain names and IP addresses from the local domain name server is less than or equal to a period for the first server to update the mapping relationship between domain names and IP addresses from the local domain name server; The second server receives the first IP address corresponding to the first domain name sent by the local domain name server; The second server sends the first IP address to the terminal device; The user plane function UPF receives a second domain name resolution request sent by the terminal device; The user plane function UPF determines that the second domain name resolution request is a second type of domain name resolution request based on a second domain name in the second domain name resolution request, and sends the second domain name resolution request to the first server. The communication method according to claim 11, characterized in that The method further comprises: When the first server determines that the second IP address corresponding to the second domain name is not stored in the first server based on the mapping relationship between domain names and IP addresses, the first server sends resolution failure information to the terminal device; When the first server determines that the second IP address corresponding to the second domain name is stored in the first server based on the mapping relationship between domain names and IP addresses, the first server sends the second IP address to the terminal device. A satellite system, characterized in that Comprise: A first server and a second server, the first server is deployed on a first satellite, the first satellite runs in a first earth orbit, the second server is deployed on a second satellite, the second satellite runs in a second earth orbit, the second earth orbit is higher than the first earth orbit; The first server is configured to receive a first domain name resolution request sent by a terminal device in a ground system, the first domain name resolution request comprising a first domain name requested to be resolved by the terminal device, and the first server stores a mapping relationship between domain names and IP addresses; The first server is configured to send the first domain name resolution request to the second server when it is determined that the first IP address corresponding to the first domain name is not stored in the first server based on the mapping relationship between domain names and IP addresses, and the sending of the first domain name resolution request to the second server comprises: identifying the first domain name resolution request as a first type of domain name resolution request, and sending the first domain name resolution request to the second server, the classification of the first domain name resolution request being determined based on subscription information and / or user plane forwarding rule information corresponding to an application corresponding to the first domain name. The second server is configured to determine, based on a mapping relationship between domain names and IP addresses stored in the second server, that the first IP address corresponding to the first domain name is not stored in the second server, and send the first domain name resolution request to a local domain name server in the ground system, and the second server updates the mapping relationship between domain names and IP addresses from the local domain name server at a period less than or equal to a period at which the first server updates the mapping relationship between domain names and IP addresses from the local domain name server. The second server is configured to receive the first IP address corresponding to the first domain name sent by the local domain name server. The second server is configured to send the first IP address to the first server. The first server is configured to send the first IP address to the terminal device. The satellite system of claim 13, wherein The satellite system further includes a user plane function (UPF). The UPF is configured to receive the first domain name resolution request sent by the terminal device. The UPF is configured to determine, based on the first domain name in the first domain name resolution request, that the first domain name resolution request is a first type of domain name resolution request, mark the first domain name resolution request with a first identifier, and send the first domain name resolution request and the first identifier to the first server. According to the satellite system of claim 14, The UPF is configured to determine, based on the first domain name in the first domain name resolution request, an application corresponding to the first domain name, obtain subscription information and / or user plane forwarding rule information corresponding to the application corresponding to the first domain name, and determine, based on the subscription information and / or the user plane forwarding rule information corresponding to the application corresponding to the first domain name, that the first domain name resolution request is the first type of domain name resolution request; or The UPF is configured to determine, based on the first domain name in the first domain name resolution request, user plane forwarding rule information corresponding to the first domain name, and determine, based on the user plane forwarding rule information corresponding to the first domain name, that the first domain name resolution request is the first type of domain name resolution request. A computer-readable storage medium, characterized by Executable instructions are stored, and the instructions are executed on an electronic device to implement the communication method of any one of claims 1 to 12. An electronic device, characterized by comprising: The electronic device comprises: a memory configured to store instructions executed by one or more processors of the electronic device, and the one or more processors configured to execute the communication method of any one of claims 1 to 12.

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