Information synchronization method and device and readable storage medium

Abstract

The invention discloses an information synchronization method and device and a readable storage medium, relates to the technical field of communication, and aims to improve the communication efficiency. The method comprises the steps that the terminal context of a first terminal is acquired from core network equipment through a ground station, and satellites in a first satellite group provide services for the first terminal; and sending the terminal context to the satellites in the first satellite group. The embodiment of the invention can improve the communication efficiency.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to an information synchronization method, apparatus, and readable storage medium. Background Art

[0002] In a multi-satellite scenario, a user equipment (UE) registered on one satellite can only communicate with a specific satellite that contains the UE's terminal context. When it is necessary to communicate with a different satellite and the satellite does not have the UE's terminal context, the UE must complete a full attachment process with that satellite. Therefore, every time the UE needs to register with the network, if it connects to a satellite without the UE's terminal context, a full registration process is required, and the interaction process is rather cumbersome, reducing communication efficiency. Summary of the Invention

[0003] Embodiments of this application provide an information synchronization method, apparatus, and readable storage medium to improve communication efficiency.

[0004] In a first aspect, an embodiment of this application provides an information synchronization method, which is applied to a network element disposed on a first satellite. The first satellite is located within a first satellite group, and the first satellite group includes one or more satellites. The method includes:

[0005] Obtaining the terminal context of a first terminal from a core network device through a ground station, where the satellites in the first satellite group provide services for the first terminal;

[0006] Sending the terminal context to the satellites within the first satellite group.

[0007] Optionally, the sending the terminal context to the satellites within the first satellite group includes:

[0008] Encrypting the terminal context using a multicast key;

[0009] Sending the encrypted terminal context to the satellites within the first satellite group in a multicast manner.

[0010] Optionally, the method further includes:

[0011] Obtaining first information from the core network device through the ground station, where the first information is used to indicate the storage time of the terminal context;

[0012] Releasing the terminal context according to the first information.

[0013] Optionally, the releasing the terminal context according to the first information includes:

[0014] If it is determined according to the first information that the time to release the terminal context has arrived, release the terminal context;

[0015] Send a first indication to the satellites in the first satellite group, where the first indication is used to instruct the satellites in the first satellite group to release the terminal context.

[0016] Optionally, releasing the terminal context according to the first information includes:

[0017] If it is determined according to the first information that the time to release the terminal context has arrived, release the terminal context;

[0018] Send the first information to the satellites in the first satellite group, for the satellites in the first satellite group to release the terminal context when it is determined according to the first information that the time to release the terminal context has arrived.

[0019] Optionally, the storage time of the terminal context represents the release time of the terminal context;

[0020] Wherein, the storage time of the terminal context includes one or more time lengths, or includes one or more time points.

[0021] Optionally, the method further includes:

[0022] Obtain an updated multicast key from the ground station;

[0023] Send the updated multicast key to the satellites in the first satellite group.

[0024] In a second aspect, an embodiment of the present application provides an information synchronization method, which is applied to a ground station and includes:

[0025] Obtain the terminal context of a first terminal from a core network device;

[0026] Send the terminal context to a network element disposed on a first satellite;

[0027] Wherein, the first satellite is located in a first satellite group, the first satellite group includes one or more satellites and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is used to send the terminal context to the satellites in the first satellite group.

[0028] Optionally, the method further includes:

[0029] Obtain first information from the core network device, where the first information is used to indicate the storage time of the terminal context;

[0030] Send the first information to the network element disposed on the first satellite.

[0031] Optionally, the method further includes:

[0032] Send an updated multicast key to the network element disposed on the first satellite.

[0033] Optionally, the sending an updated multicast key to the network element disposed on the first satellite includes:

[0034] Encrypt the updated sub-branch key corresponding to the second satellite using the satellite private key of the second satellite within the first satellite group, and encrypt the updated multicast key using the updated sub-branch key corresponding to the second satellite, or encrypt the updated sub-branch key corresponding to the second satellite and the updated multicast key using the satellite private key of the second satellite within the first satellite group, where the second satellite is the updated satellite within the first satellite group;

[0035] Send the encrypted updated key to the network element disposed on the first satellite.

[0036] In a third aspect, an embodiment of the present application provides an information synchronization method, which is applied to a core network device and includes:

[0037] Send the terminal context of the first terminal to the network element disposed on the first satellite through a ground station;

[0038] Wherein, the first satellite is located within a first satellite group, the first satellite group includes one or more satellites and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is used to send the terminal context to the satellites within the first satellite group.

[0039] Optionally, the method further includes:

[0040] Send the first information to the network element disposed on the first satellite through a ground station, where the first information is used to indicate the storage time of the terminal context.

[0041] In a fourth aspect, an embodiment of the present application provides an information synchronization device, which is applied to a network element disposed on a first satellite, the first satellite is located within a first satellite group, and the first satellite group includes one or more satellites, and includes: a memory, a transceiver, and a processor:

[0042] A memory, configured to store a computer program; a transceiver, configured to send and receive data under the control of the processor; a processor, configured to read the computer program in the memory and perform the following operations:

[0043] Obtain the terminal context of the first terminal from the core network device through the ground station, where the satellites in the first satellite group provide services for the first terminal;

[0044] Send the terminal context to the satellites within the first satellite group.

[0045] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0046] Encrypt the terminal context using the multicast key;

[0047] Send the encrypted terminal context to the satellites within the first satellite group in a multicast manner.

[0048] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0049] Obtain first information from the core network device through the ground station, where the first information is used to indicate the storage time of the terminal context;

[0050] Release the terminal context according to the first information.

[0051] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0052] If it is determined according to the first information that the time to release the terminal context has arrived, release the terminal context;

[0053] Send a first indication to the satellites within the first satellite group, where the first indication is used to indicate that the satellites within the first satellite group release the terminal context.

[0054] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0055] If it is determined according to the first information that the time to release the terminal context has arrived, release the terminal context;

[0056] Send the first information to the satellites within the first satellite group, for the satellites within the first satellite group to release the terminal context when it is determined according to the first information that the time to release the terminal context has arrived.

[0057] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0058] Obtain an updated multicast key from the ground station;

[0059] Send the updated multicast key to the satellites in the first satellite group.

[0060] In a fifth aspect, an embodiment of the present application provides an information synchronization device, which is applied to a ground station and includes: a memory, a transceiver, and a processor:

[0061] The memory is used to store computer programs; the transceiver is used to send and receive data under the control of the processor; the processor is used to read the computer programs in the memory and perform the following operations:

[0062] Obtain the terminal context of the first terminal from the core network device;

[0063] Send the terminal context to the network element disposed on the first satellite;

[0064] Wherein, the first satellite is located in the first satellite group, the first satellite group includes one or more satellites and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is used to send the terminal context to the satellites in the first satellite group.

[0065] Optionally, the processor is further used to read the computer programs in the memory and perform the following operations:

[0066] Obtain first information from the core network device, where the first information is used to indicate the storage time of the terminal context;

[0067] Send the first information to the network element disposed on the first satellite.

[0068] Optionally, the processor is further used to read the computer programs in the memory and perform the following operations:

[0069] Send the updated multicast key to the network element disposed on the first satellite.

[0070] Optionally, the processor is further used to read the computer programs in the memory and perform the following operations:

[0071] Encrypt the updated sub-branch key corresponding to the second satellite in the first satellite group with the satellite private key of the second satellite, and encrypt the updated multicast key with the updated sub-branch key corresponding to the second satellite, or encrypt the updated sub-branch key corresponding to the second satellite and the updated multicast key in the first satellite group with the satellite private key of the second satellite, where the second satellite is the updated satellite in the first satellite group;

[0072] Send the encrypted updated key to the network element disposed on the first satellite.

[0073] In a sixth aspect, an information synchronization device provided by an embodiment of the present application is applied to a core network device and includes: a memory, a transceiver, and a processor:

[0074] The memory is used to store computer programs; the transceiver is used to transmit and receive data under the control of the processor; the processor is used to read the computer programs in the memory and perform the following operations:

[0075] Send the terminal context of a first terminal to a network element disposed on a first satellite through a ground station;

[0076] Wherein, the first satellite is located in a first satellite group, the first satellite group includes one or more satellites, and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is used to send the terminal context to the satellites in the first satellite group.

[0077] Optionally, the processor is further used to read the computer programs in the memory and perform the following operations:

[0078] Send first information to the network element disposed on the first satellite through a ground station, where the first information is used to indicate the storage time of the terminal context.

[0079] In a seventh aspect, an information synchronization device provided by an embodiment of the present application is applied to a network element disposed on a first satellite, the first satellite is located in a first satellite group, the first satellite group includes one or more satellites, and includes:

[0080] A first acquisition unit, configured to acquire the terminal context of a first terminal from a core network device through a ground station, where the satellites in the first satellite group provide services for the first terminal;

[0081] A first sending unit, configured to send the terminal context to the satellites in the first satellite group.

[0082] In an eighth aspect, an information synchronization device provided by an embodiment of the present application is applied to a ground station and includes:

[0083] A first acquisition unit, configured to acquire the terminal context of a first terminal from a core network device;

[0084] A first sending unit, configured to send the terminal context to a network element disposed on a first satellite;

[0085] Wherein, the first satellite is located in a first satellite group, the first satellite group includes one or more satellites, and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is used to send the terminal context to the satellites in the first satellite group.

[0086] In a ninth aspect, an embodiment of the present application provides an information synchronization device, which is applied to a core network device and includes:

[0087] A first sending unit, configured to send the terminal context of a first terminal to a network element disposed on a first satellite through a ground station;

[0088] Wherein, the first satellite is located in a first satellite group, the first satellite group includes one or more satellites, and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is configured to send the terminal context to the satellites in the first satellite group.

[0089] In a tenth aspect, an embodiment of the present application further provides a processor-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps in the information synchronization method described above are implemented.

[0090] In an embodiment of the present application, the network element disposed on the first satellite obtains the terminal context of the first terminal from the core network device through the ground station, and sends the terminal context to the satellites in the first satellite group. In this way, the satellites in the first satellite group can all achieve synchronization of the terminal context, and the terminal can be registered and connected on any satellite in the group, thereby reducing the number of accesses between the satellite and the ground and improving the communication efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0091] Figure 1 is one of the flowcharts of the information synchronization method provided by an embodiment of the present application;

[0092] Figure 2 is a schematic diagram of an application scenario of an embodiment of the present application;

[0093] Figure 3 is the second flowchart of the information synchronization method provided by an embodiment of the present application;

[0094] Figure 4 is a schematic diagram of an LKH logical key tree;

[0095] Figure 5 is the third flowchart of the information synchronization method provided by an embodiment of the present application;

[0096] Figure 6 is the fourth flowchart of the information synchronization method provided by an embodiment of the present application;

[0097] Figure 7 is the fifth flowchart of the information synchronization method provided by an embodiment of the present application;

[0098] Figure 8One of the structural diagrams of the information synchronization device provided by an embodiment of the present application;

[0099] Figure 9 One of the structural diagrams of the information synchronization device provided by an embodiment of the present application;

[0100] Figure 10 One of the structural diagrams of the information synchronization device provided by an embodiment of the present application;

[0101] Figure 11 One of the structural diagrams of the information synchronization device provided by an embodiment of the present application;

[0102] Figure 12 One of the structural diagrams of the information synchronization device provided by an embodiment of the present application;

[0103] Figure 13 One of the structural diagrams of the information synchronization device provided by an embodiment of the present application; Detailed implementation manners

[0104] In the embodiments of the present application, the term "and / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0105] In the embodiments of the present application, the term "a plurality of" means two or more, and other quantifiers are similar thereto.

[0106] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0107] The embodiments of the present application provide an information synchronization method and device to improve communication efficiency. Among them, the method and the device are based on the same inventive concept. Since the principles for the method and the device to solve problems are similar, the implementation of the device and the method can be referred to each other, and the repeated parts will not be described again.

[0108] See Figure 1 , Figure 1 is the flowchart of the information synchronization method provided by an embodiment of the present application, which is applied to a network element disposed on a first satellite. The first satellite is located in a first satellite group, and the first satellite group includes one or more satellites. As Figure 1 shown, it includes the following steps:

[0109] Step 101: Obtain the terminal context of the first terminal from the core network device through the ground station, where the satellites in the first satellite group provide services for the first terminal.

[0110] See Figure 2 , Figure 2 is a schematic diagram of the application scenario of the embodiments of the present application. Assume that multiple satellites serving a UE in a certain area are called a satellite group, and the satellites in the satellite group transmit through inter-satellite links or other means. Information such as the satellite group, the UE served by the satellite group, and the leader satellite (primary satellite, for example, the first satellite in the embodiments of the present application) is recorded at the core network. Each time the ground station connects to the leader satellite, the ground station uploads the terminal context to be synchronized to the leader satellite, and the leader satellite then broadcasts the terminal context within the group. Among them, the broadcast message of the leader satellite is encrypted with a multicast key, and the multicast key is preset in each satellite and can also be updated based on the update of the satellite group members.

[0111] Therefore, in this step, the network element disposed on the first satellite can send a request to the ground station for data upload and download. After receiving the request, the ground station forwards the request to the core network device. Then, the core network device sends the terminal context of the first terminal to the network element through the ground station. Among them, the network element disposed on the first satellite can be a base station or the like disposed on the first satellite.

[0112] Step 102: Send the terminal context to the satellites within the first satellite group.

[0113] In this step, the network element disposed on the first satellite encrypts the terminal context with the multicast key and sends the encrypted terminal context to the satellites within the first satellite group in a multicast manner. Among them, the multicast key can be obtained from the ground station or pre-stored in the network element.

[0114] From the above description, it can be seen that in the embodiments of the present application, the network element disposed on the first satellite obtains the terminal context of the first terminal from the core network device through the ground station and sends the terminal context to the satellites within the first satellite group. In this way, the satellites within the first satellite group can all achieve synchronization of the terminal context, and the terminal can be registered and connected on any satellite within the group, thereby reducing the number of accesses between the satellite and the ground and improving the communication efficiency.

[0115] Optionally, the network element disposed on the first satellite may also release the terminal context. Specifically, the network element disposed on the first satellite obtains first information from the core network device through the ground station, where the first information is used to indicate the storage time of the terminal context. Then, the network element disposed on the first satellite releases the terminal context according to the first information.

[0116] The storage time of the terminal context represents the release time of the terminal context. For example, the storage time of the terminal context includes one or more time lengths, or includes one or more time points (such as a specific moment). For example, if the storage time of the terminal context is 10 minutes, it can indicate that the terminal context needs to be released 10 minutes after a certain time point (such as the current time); for example, if the storage time of the terminal context is 15:00, it can indicate that the terminal context needs to be released at 15:00.

[0117] In specific applications, there can be multiple ways to release the terminal context.

[0118] For example, if the network element disposed on the first satellite determines that the time to release the terminal context arrives according to the first information, it releases the terminal context. At the same time, it can also send a first indication to the satellites in the first satellite group, where the first indication is used to indicate the satellites in the first satellite group to release the terminal context. That is, in this way, the network element disposed on the first satellite instructs the other satellites in the group to release the terminal context.

[0119] For another example, if the network element disposed on the first satellite determines that the time to release the terminal context arrives according to the first information, it releases the terminal context. At the same time, it can also send the first information to the satellites in the first satellite group, so that when the satellites in the first satellite group determine that the time to release the terminal context arrives according to the first information, they release the terminal context. That is, in this way, the other satellites in the group obtain the first information from the network element disposed on the first satellite and determine to release the terminal context according to the first information.

[0120] Through the above methods, the satellite can release the terminal context without connecting to the ground station, thus saving on-board storage space and storage efficiency.

[0121] In the embodiments of the present application, to ensure security, the network element disposed on the first satellite can also obtain an updated multicast key from the ground station and send the updated multicast key to the satellites in the first satellite group.

[0122] See Figure 3 , Figure 3The flowchart of the information synchronization method provided by an embodiment of this application is applied to a ground station. As Figure 3 shown, it includes the following steps:

[0123] Step 301, obtain the terminal context of the first terminal from a core network device.

[0124] Among them, the first satellite is located in a first satellite group. The first satellite group includes one or more satellites, and the satellites in the first satellite group provide services for the first terminal. The network element disposed on the first satellite is used to send the terminal context to the satellites in the first satellite group.

[0125] In this step, the network element disposed on the first satellite can send a request to the ground station for data upload and download. After receiving the request, the ground station forwards the request to the core network device. Then, the ground station obtains the terminal context of the first terminal from the core network device. Among them, the network element disposed on the first satellite can be a base station or the like disposed on the first satellite.

[0126] Step 302, send the terminal context to the network element disposed on the first satellite.

[0127] In the embodiment of this application, the network element disposed on the first satellite obtains the terminal context of the first terminal from the core network device through the ground station and sends the terminal context to the satellites in the first satellite group. In this way, the satellites in the first satellite group can all achieve synchronization of the terminal context, and the terminal can be registered and connected on any satellite in the group, thereby reducing the number of accesses between the satellite and the ground and improving the communication efficiency.

[0128] Optionally, the ground station can also obtain the first information from the core network device and send the first information to the network element disposed on the first satellite. Among them, the first information is used to indicate the storage time of the terminal context. The meaning of this first information can refer to the description in the foregoing method embodiment.

[0129] Optionally, the ground station can also send an updated group key to the network element disposed on the first satellite. Specifically, the ground station can encrypt the updated sub-branch key corresponding to the second satellite by using the satellite private key of the second satellite in the first satellite group, and encrypt the updated group key by using the updated sub-branch key corresponding to the second satellite, or encrypt the updated sub-branch key corresponding to the second satellite and the updated group key in the first satellite group by using the satellite private key of the second satellite, where the second satellite is the updated satellite in the first satellite group. Then, the ground station sends the encrypted updated key to the network element disposed on the first satellite.

[0130] In the embodiments of the present application, the multicast key is managed based on the Logical Key Hierarchy (LKH) scheme. The LKH group key management scheme is a centralized management scheme based on a logical key tree. As Figure 4 shown, it is a schematic diagram of the LKH logical key tree. There are two types of nodes in the logical key tree: key nodes and group member nodes. Each key node corresponds to a key k, and according to the different keys it contains, it is divided into three types: root node, intermediate node, and leaf node. The key of the root node (which can correspond to the ground station) is shared by the group members (which can correspond to each satellite U1, U2, U3, etc.), that is, the group key (GK); the intermediate node records the subgroup key shared by some members, which is called the auxiliary key and is used to update the group key and other keys; the leaf node corresponds one-to-one with the group member node and records the private key (Private Key, PK) of each group member.

[0131] When the group members are updated, the group controller (such as the ground station) updates the key tree and sends the new key to the relevant members in a secure form. The update situations include two types: the addition of new members and the deletion of old members.

[0132] For example, in the embodiments of the present application, when there are changes in the satellites within the satellite group, the core network can notify the ground station of the changed information, and the ground station updates the multicast key. Or, the ground station itself can also obtain the information about the changes in the satellites within the satellite group.

[0133] When a user (i.e., a satellite) requests to join the multicast group, the group controller authenticates the user. After successful authentication, the group controller assigns a private key to the group member (for example, through a secure channel), and finds a suitable key node (called the access point) for this member from the logical key tree. Traversing the key tree, the group controller places the key node corresponding to the new member in the key tree. At this time, in order to ensure forward security, that is, to prevent newly added members from decrypting previous historical multicast messages using the current key, it is necessary to update all the keys on the path of the newly added member on the key tree.

[0134] When a member in the multicast group applies to withdraw, the group controller updates the key tree. It not only deletes the member node and leaf node of this member from the key tree, but also updates the keys on the path corresponding to this member to ensure backward security, that is, to ensure that old members cannot decrypt the current multicast messages using historical keys, and sends the updated keys to the required group members.

[0135] Therefore, in the embodiments of the present application, the ground station (root node) maintains the multicast key GK. When the members of a certain satellite group change, the multicast key GK is updated to GK', the sub-branch keys (keys of intermediate nodes) of the group members are updated, and the updated multicast key GK' is encrypted and transmitted using the satellite private key and the sub-branch key.

[0136] For example, in Figure 4 , assuming that the newly added group member is U4 and the corresponding leaf node is K4, the sub-branch key K34 is updated to K35. First, K35 can be encrypted using the satellite private key of K4. After the group member U4 obtains it, K35 can be decrypted using the satellite private key; then, the updated multicast key GK' is encrypted using K35. After the group member U4 obtains it, GK' can be decrypted using K35 to obtain the updated multicast key GK'. Or, K35 and the updated multicast key GK' can also be encrypted using the satellite private key of K4. After the group member U4 obtains it, the updated multicast key GK' can be decrypted using the satellite private key.

[0137] See Figure 5 , Figure 5 is a flowchart of the information synchronization method provided by the embodiments of the present application, which is applied to the ground station. As Figure 5 shown, it includes the following steps:

[0138] Step 501, send the terminal context of the first terminal to the network element disposed on the first satellite through the ground station.

[0139] Among them, the first satellite is located in the first satellite group, the first satellite group includes one or more satellites and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is used to send the terminal context to the satellites in the first satellite group.

[0140] The core network device can store a mapping table, which can be the corresponding relationship between satellites, satellite groups, and the terminals served by the satellite groups, etc. Therefore, after receiving the request of the first satellite, the core network can determine the satellite group of the first satellite and the terminals served by the satellite group, and then obtain the corresponding terminal context.

[0141] In the embodiments of the present application, the network element disposed on the first satellite obtains the terminal context of the first terminal from the core network device through the ground station and sends the terminal context to the satellites in the first satellite group. In this way, the satellites in the first satellite group can all achieve the synchronization of the terminal context, and the terminal can be registered and connected on any satellite in the group, thereby reducing the number of accesses between the satellite and the ground and improving the communication efficiency.

[0142] In an embodiment of the present application, the core network device may also send first information to the network element disposed on the first satellite through a ground station, where the first information is used to indicate the storage time of the terminal context.

[0143] Optionally, the storage time of the terminal context corresponding to the satellite group may also be stored in the above mapping table. For example, the storage time of the terminal context may be a time length or a time point, etc. By setting the storage time of the terminal context, the on-board storage space can be saved.

[0144] In an embodiment of the present application, a solution for UE context synchronization based on multicast is proposed. One satellite in a group of satellites performs UE context synchronization with a ground station, so that the satellite UE contexts within the group are all synchronized.

[0145] See Figure 6 , Figure 6 is the processing flowchart of an embodiment of the present application. It may include:

[0146] Step 601: After leader A (primary satellite A) passes by a ground station containing a UE context database and establishes a Feeder (feedback link) connection, data is uploaded and downloaded.

[0147] For example, leader A may send a request to the ground station for data upload and download. After receiving the request, the ground station forwards the request to the core network.

[0148] Step 602: The core network learns from looking up the mapping table that it is necessary to upload the UE context (terminal context) corresponding to group A, and uploads the UE context to leader A. At the same time, according to the satellite operation time, the core network can also set the storage time of the UE context to obtain the storage time of the UE context.

[0149] Among them, the mapping table may be the corresponding relationship between satellites, satellite groups, and the UEs served by the satellite groups, etc. Therefore, after receiving the request from leader A, the core network can determine the satellite group of leader A and the UEs served by the satellite group, and then obtain the corresponding UE context.

[0150] Step 603: The core network sends the UE context and the storage time of the UE context to leader A through the ground station. The storage time of the UE context may be sent to the terminal simultaneously with the UE context or separately.

[0151] The UE context storage time represents the release time of the UE context. For example, the UE context storage time can be a time duration, a time point, etc. By setting the UE context storage time, the on-board storage space can be saved.

[0152] Among them, the UE context storage time can also be stored in the above mapping table. Thus, when the core network obtains the UE context, it can obtain the UE context storage time.

[0153] Step 604: After receiving the UE context, leader A encrypts the UE context using the multicast key and then performs multicast within the group.

[0154] Step 605: When a certain satellite in group A moves above the UE and the UE needs to make a connection, the satellites in group A use the UE context to establish a connection with the UE for data upload and download.

[0155] Assume that at this time, leader B satellite moves above the ground station and performs the same operations as group A previously.

[0156] Step 606: After group A moves out of the area where the UE is located, group B enters this area. At this time, leader A in group A sends a signaling message to release the storage space of the UE context within the group according to the set UE context storage time.

[0157] In this step, leader A satellite can store the UE context storage time. When it is determined that the UE context needs to be released according to the UE context storage time, leader A satellite performs multicast of the release signaling to notify the satellites within the satellite group to release the UE context.

[0158] Or, leader A satellite can send the UE context storage time to each satellite within the satellite group through multicast, and each satellite can store the UE context storage time. When the satellites within the satellite group determine that the UE context needs to be released according to the UE context storage time, they release the UE context.

[0159] In the embodiments of the present application, the satellites within the multicast can communicate based on the multicast key, and can implement a handover authentication mechanism based on the security context. Among them, for the handover authentication mechanism based on the security context, it is required that the current base station node pre-transmits the security state information, authentication information, service session information, node information, communication state, handover key, etc. related to the mobile user through the secure tunnel between the current base station and the base station to be accessed. Using the solution of the embodiments of the present application, the UE context is transmitted based on the multicast key, reducing the authentication complexity of the UE for the satellite to be accessed, reducing the computational complexity of the handover authentication protocol, and reducing the authentication overhead of the mobile user during handover.

[0160] See Figure 7 , Figure 7 which is the synchronization flowchart of the authentication and authorization vectors in the embodiments of the present application. When the UE connects to the satellite for initial registration, it needs to send an authentication and authorization vector request signaling to the core network through the satellite, and the core network returns the authentication and authorization vector. This process may include:

[0161] Step 701: The UE sends an authentication request to leader A satellite.

[0162] Step 702: Leader A satellite forwards the authentication request to the core network.

[0163] Step 703: After authentication by the core network, it returns the authentication and authorization information.

[0164] Step 704: Leader A satellite forwards the authentication and authorization information to the UE.

[0165] Step 705: Leader A satellite multicasts the authentication and authorization information to the members in the group.

[0166] Through the multicast synchronization mechanism, leader A satellite can synchronize the requested authentication and authorization information (such as authentication and authorization vectors) to multiple satellites for storage. Then, when the UE makes a request for authentication next time, the connected satellite does not need to request the authentication and authorization vector from the core network again, and can directly return the authentication and authorization vector based on the identifier provided by the UE.

[0167] It can be seen from the above embodiments that by using the solution of the embodiments of the present application, the access times between the satellite and the ground are reduced through satellite-to-satellite multicast synchronization, improving the communication efficiency; and by setting the storage time to regularly release the unnecessary UE context, the on-satellite storage space can be saved.

[0168] The technical solutions provided by the embodiments of this application can be applicable to a variety of systems, especially 5G systems. For example, the applicable systems can be the global system of mobile communication (GSM) system, code division multiple access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) general packet radio service (GPRS) system, long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, long term evolution advanced (LTE-A) system, universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) system, 5G New Radio (NR) system, etc. Both terminal devices and network devices are included in these various systems. The system may also include a core network device part, such as the Evolved Packet System (EPS), 5G System (5GS), etc.

[0169] The terminal device involved in the embodiments of the present application can be a device that provides voice and / or data connectivity to users, such as a handheld device with wireless connection capabilities, or other processing devices connected to a wireless modem, etc. In different systems, the name of the terminal device may also be different. For example, in a 5G system, the terminal device can be called a User Equipment (UE). The wireless terminal device can communicate with one or more core network devices (Core Network, CN) via a Radio Access Network (RAN). The wireless terminal device can be a mobile terminal device, such as a mobile phone (or a "cellular" phone) and a computer with a mobile terminal device. For example, it can be a portable, pocket-sized, handheld, computer-integrated, or vehicle-mounted mobile device, which exchanges language and / or data with the wireless access network. For example, devices such as Personal Communication Service (PCS) phones, cordless phones, Session Initiated Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistant (PDA), etc. The wireless terminal device can also be called a system, subscriber unit, subscriber station, mobile station, mobile, remote station, access point, remote terminal, access terminal, user terminal, user agent, user device, which is not limited in the embodiments of the present application.

[0170] As Figure 8 shown, the information synchronization device of the embodiments of the present application is applied to a network element disposed on a first satellite. The first satellite is located in a first satellite group, and the first satellite group includes one or more satellites, and includes: a processor 800, configured to read a program in a memory 820 and execute the following processes:

[0171] Obtain the terminal context of a first terminal from a core network device through a ground station, where the satellites in the first satellite group provide services for the first terminal;

[0172] Send the terminal context to the satellites in the first satellite group.

[0173] A transceiver 810 is configured to receive and transmit data under the control of a processor 800.

[0174] Among them, in Figure 8 The bus architecture may include any number of interconnected buses and bridges, specifically various circuits represented by one or more processors represented by the processor 800 and a memory represented by the memory 820 are linked together. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art, and thus will not be further described herein. The bus interface provides an interface. The transceiver 810 may be multiple components, that is, including a transmitter and a receiver, and provides a unit for communicating with various other devices on the transmission medium. The processor 800 is responsible for managing the bus architecture and general processing, and the memory 820 may store data used by the processor 800 when performing operations.

[0175] The processor 800 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0176] The processor 800 is responsible for managing the bus architecture and general processing, and the memory 820 may store data used by the processor 800 when performing operations.

[0177] The processor 800 is further configured to read the program and perform the following steps:

[0178] Encrypt the terminal context using the multicast key;

[0179] Send the encrypted terminal context to the satellites within the first satellite group in a multicast manner.

[0180] The processor 800 is further configured to read the program and perform the following steps:

[0181] Obtain first information from the core network device through the ground station, where the first information is used to indicate the storage time of the terminal context;

[0182] Release the terminal context according to the first information.

[0183] The processor 800 is further configured to read the program and perform the following steps:

[0184] If it is determined according to the first information that the time to release the terminal context has arrived, release the terminal context;

[0185] Send a first indication to the satellites in the first satellite group, where the first indication is used to instruct the satellites in the first satellite group to release the terminal context.

[0186] The processor 800 is further configured to read the program and perform the following steps:

[0187] If it is determined according to the first information that the time to release the terminal context has arrived, release the terminal context;

[0188] Send the first information to the satellites in the first satellite group for the satellites in the first satellite group to release the terminal context when it is determined according to the first information that the time to release the terminal context has arrived.

[0189] Optionally, the storage time of the terminal context represents the release time of the terminal context;

[0190] Wherein, the storage time of the terminal context includes one or more time lengths, or includes one or more time points.

[0191] The processor 800 is further configured to read the program and perform the following steps:

[0192] Obtain an updated multicast key from the ground station;

[0193] Send the updated multicast key to the satellites in the first satellite group.

[0194] It should be noted here that the above device provided in the embodiment of the present application can implement all the method steps implemented in the above method embodiment and can achieve the same technical effect. Therefore, the same parts and beneficial effects as those in the method embodiment will not be specifically described in this embodiment.

[0195] As Figure 9 shown, the information synchronization device in the embodiment of the present application is applied to a network device and includes: a processor 900, configured to read a program in a memory 920 and perform the following processes:

[0196] Obtain the terminal context of a first terminal from a core network device;

[0197] Send the terminal context to a network element disposed on a first satellite;

[0198] Among them, the first satellite is located within a first satellite group. The first satellite group includes one or more satellites, and the satellites in the first satellite group provide services for the first terminal. The network element disposed on the first satellite is used to send the terminal context to the satellites within the first satellite group.

[0199] A transceiver 910, configured to receive and send data under the control of a processor 900.

[0200] Among them, in Figure 9 the bus architecture may include any number of interconnected buses and bridges, specifically, various circuits represented by one or more processors represented by the processor 900 and a memory represented by the memory 920 are linked together. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art. Therefore, they will not be further described herein. The bus interface provides an interface. The transceiver 910 may be multiple elements, that is, including a transmitter and a receiver, and provides a unit for communicating with various other devices on a transmission medium. The processor 900 is responsible for managing the bus architecture and general processing, and the memory 920 may store data used by the processor 900 when performing operations.

[0201] The processor 900 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0202] The processor 900 is responsible for managing the bus architecture and general processing, and the memory 920 may store data used by the processor 900 when performing operations.

[0203] The processor 900 is further configured to read the program and perform the following steps:

[0204] Obtain first information from the core network device, where the first information is used to indicate the storage time of the terminal context;

[0205] Send the first information to the network element disposed on the first satellite.

[0206] The processor 900 is further configured to read the program and perform the following steps:

[0207] Send an updated multicast key to the network element disposed on the first satellite.

[0208] The processor 900 is further configured to read the program and execute the following steps:

[0209] Encrypt the updated sub-branch key corresponding to the second satellite using the satellite private key of the second satellite in the first satellite group, and encrypt the updated multicast key using the updated sub-branch key corresponding to the second satellite, or encrypt the updated sub-branch key and the updated multicast key corresponding to the second satellite using the satellite private key of the second satellite in the first satellite group, where the second satellite is the updated satellite in the first satellite group;

[0210] Send the encrypted updated key to the network element disposed on the first satellite.

[0211] It should be noted here that the above device provided in the embodiment of the present application can implement all the method steps implemented in the above method embodiment and can achieve the same technical effect. The same parts and beneficial effects as those in the method embodiment will not be specifically described in this embodiment.

[0212] As Figure 10 shown, the information synchronization device in the embodiment of the present application is applied to a network device and includes: a processor 1000, configured to read the program in the memory 1020 and execute the following process:

[0213] Send the terminal context of the first terminal to the network element disposed on the first satellite through a ground station;

[0214] wherein the first satellite is located in the first satellite group, the first satellite group includes one or more satellites and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is configured to send the terminal context to the satellites in the first satellite group.

[0215] A transceiver 1010, configured to receive and send data under the control of the processor 1000.

[0216] wherein, in Figure 10Among them, the bus architecture may include any number of interconnected buses and bridges, specifically, various circuits represented by one or more processors represented by processor 1000 and a memory represented by memory 1020 are linked together. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and thus will not be further described herein. The bus interface provides an interface. The transceiver 1010 may be a plurality of components, that is, including a transmitter and a receiver, and provides a unit for communicating with various other devices on the transmission medium. The processor 1000 is responsible for managing the bus architecture and general processing, and the memory 1020 may store data used by the processor 1000 when performing operations.

[0217] The processor 1000 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0218] The processor 1000 is responsible for managing the bus architecture and general processing, and the memory 1020 may store data used by the processor 1000 when performing operations.

[0219] The processor 1000 is further configured to read the program and execute the following steps:

[0220] Send first information to a network element disposed on the first satellite through a ground station, where the first information is used to indicate the storage time of the terminal context.

[0221] It should be noted here that the above device provided in the embodiment of the present application can implement all the method steps implemented in the above method embodiment and can achieve the same technical effects. The same parts and beneficial effects as those in the method embodiment will not be specifically described in this embodiment.

[0222] As Figure 11 shown, the information synchronization device of the embodiment of the present application is applied to a network element disposed on a first satellite. The first satellite is located in a first satellite group, and the first satellite group includes one or more satellites, and includes:

[0223] The first acquisition unit 1101 is configured to acquire the terminal context of the first terminal from the core network device through a ground station, where the satellites in the first satellite group provide services for the first terminal; the first sending unit 1102 is configured to send the terminal context to the satellites in the first satellite group.

[0224] Optionally, the first sending unit includes:

[0225] An encryption subunit, configured to encrypt the terminal context by using a multicast key;

[0226] A sending subunit, configured to send the encrypted terminal context to the satellites in the first satellite group in a multicast manner.

[0227] Optionally, the apparatus further includes:

[0228] A second acquisition unit, configured to acquire first information from the core network device through the ground station, where the first information is used to indicate the storage time of the terminal context;

[0229] A first processing unit, configured to release the terminal context according to the first information.

[0230] Optionally, the first processing unit is further configured to:

[0231] If it is determined according to the first information that the time to release the terminal context arrives, release the terminal context;

[0232] Send a first indication to the satellites in the first satellite group, where the first indication is used to indicate the satellites in the first satellite group to release the terminal context.

[0233] Optionally, the first processing unit is further configured to:

[0234] If it is determined according to the first information that the time to release the terminal context arrives, release the terminal context;

[0235] Send the first information to the satellites in the first satellite group, for the satellites in the first satellite group to release the terminal context when it is determined according to the first information that the time to release the terminal context arrives.

[0236] Optionally, the storage time of the terminal context represents the release time of the terminal context;

[0237] Wherein, the storage time of the terminal context includes one or more time lengths, or includes one or more time points.

[0238] Optionally, the apparatus may further include:

[0239] A third obtaining unit, configured to obtain an updated multicast key from the ground station;

[0240] A second sending unit, configured to send the updated multicast key to satellites within the first satellite group.

[0241] It should be noted here that the above device provided in the embodiment of the present application can implement all the method steps implemented in the above method embodiment, and can achieve the same technical effects. The same parts and beneficial effects as those in the method embodiment will not be specifically described in this embodiment.

[0242] Such as Figure 12 shown, the information synchronization device in the embodiment of the present application is applied to a ground station and includes:

[0243] A first obtaining unit 1201, configured to obtain a terminal context of a first terminal from a core network device;

[0244] A first sending unit 1202, configured to send the terminal context to a network element disposed on a first satellite;

[0245] Wherein, the first satellite is within a first satellite group, the first satellite group includes one or more satellites, and the satellites in the first satellite group provide services for the first terminal. The network element disposed on the first satellite is configured to send the terminal context to satellites within the first satellite group.

[0246] Optionally, the device may further include:

[0247] A second obtaining unit, configured to obtain first information from the core network device, where the first information is used to indicate a storage time of the terminal context;

[0248] A second sending unit, configured to send the first information to the network element disposed on the first satellite.

[0249] Optionally, the device may further include:

[0250] A third sending unit, configured to send an updated multicast key to the network element disposed on the first satellite.

[0251] Optionally, the third sending unit is further configured to:

[0252] Encrypt the updated sub-branch key corresponding to the second satellite within the first satellite group using the satellite private key of the second satellite, and encrypt the updated multicast key using the updated sub-branch key corresponding to the second satellite, or encrypt the updated sub-branch key and the updated multicast key corresponding to the second satellite using the satellite private key of the second satellite within the first satellite group, where the second satellite is the updated satellite within the first satellite group;

[0253] Send the encrypted updated key to the network element disposed on the first satellite.

[0254] It should be noted here that the above device provided in the embodiments of the present application can implement all the method steps implemented in the above method embodiments and can achieve the same technical effects. The same parts and beneficial effects as those in the method embodiments in this embodiment will not be specifically described herein again.

[0255] As Figure 13 shown, the information synchronization device of the embodiments of the present application is applied to a core network device and includes:

[0256] A first sending unit 1301, configured to send the terminal context of the first terminal to the network element disposed on the first satellite through a ground station;

[0257] Wherein, the first satellite is within a first satellite group, the first satellite group includes one or more satellites and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is configured to send the terminal context to the satellites within the first satellite group.

[0258] Optionally, the device may further include:

[0259] A second sending unit, configured to send first information to the network element disposed on the first satellite through a ground station, where the first information is used to indicate the storage time of the terminal context.

[0260] It should be noted here that the above device provided in the embodiments of the present application can implement all the method steps implemented in the above method embodiments and can achieve the same technical effects. The same parts and beneficial effects as those in the method embodiments in this embodiment will not be specifically described herein again.

[0261] It should be noted that the division of units in the embodiments of the present application is illustrative, merely a logical function division, and there may be other division methods in actual implementation. In addition, in each embodiment of the present application, the various functional units may be integrated in a processing unit, may exist separately physically for each unit, or two or more units may be integrated in one unit. The above-mentioned integrated units may be implemented in the form of hardware or in the form of software functional units.

[0262] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a processor-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks, or optical discs.

[0263] The embodiments of the present application further provide a communication device, including: a memory, a processor, and a program stored on the memory and executable on the processor. When the processor executes the program, the steps in the information synchronization method described above are implemented.

[0264] The embodiments of the present application further provide a processor-readable storage medium. A program is stored on the readable storage medium. When the program is executed by the processor, all the processes of the above-mentioned information synchronization method embodiments are implemented, and the same technical effects can be achieved. To avoid repetition, it will not be elaborated here. Among them, the aforementioned readable storage medium can be any available medium or data storage device accessible by the processor, including but not limited to magnetic memories (such as floppy disks, hard disks, magnetic tapes, magneto-optical discs (MO), etc.), optical memories (such as CDs, DVDs, BDs, HVDs, etc.), and semiconductor memories (such as ROM, EPROM, EEPROM, non-volatile memories (NAND FLASH), solid-state drives (SSD)).

[0265] It should be noted that in this document, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising such element.

[0266] From the description of the above embodiments, those skilled in the art can clearly understand that the above-described embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such understanding, the technical solution of the present application, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, disk, optical disc) and includes several instructions for causing a terminal (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in various embodiments of the present application.

[0267] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them fall within the protection scope of the present application.

Claims

1. An information synchronization method, characterized in that, Applied to a network element disposed on a first satellite, the first satellite being within a first satellite group, the first satellite group including one or more satellites, the method includes: Obtaining, by a ground station, a terminal context of a first terminal from a core network device, wherein a satellite in the first satellite group provides services for the first terminal; Sending the terminal context to satellites within the first satellite group.

2. The method according to claim 1, wherein The sending the terminal context to satellites within the first satellite group includes: Encrypting the terminal context using a multicast key; Sending the encrypted terminal context to satellites within the first satellite group in a multicast manner.

3. The method according to claim 1, wherein The method further includes: Obtaining, by the ground station, first information from the core network device, wherein the first information is used to indicate a storage time of the terminal context; Releasing the terminal context according to the first information.

4. The method according to claim 3, characterized in that, The releasing the terminal context according to the first information includes: Releasing the terminal context if it is determined according to the first information that the time to release the terminal context has arrived; Sending a first indication to satellites within the first satellite group, wherein the first indication is used to indicate that satellites within the first satellite group release the terminal context.

5. The method according to claim 3, characterized in that The releasing the terminal context according to the first information includes: Releasing the terminal context if it is determined according to the first information that the time to release the terminal context has arrived; Sending the first information to satellites within the first satellite group for the satellites within the first satellite group to release the terminal context when it is determined according to the first information that the time to release the terminal context has arrived.

6. The method according to claim 3, characterized in that The storage time of the terminal context represents the release time of the terminal context; wherein the storage time of the terminal context includes one or more time lengths, or includes one or more time points.

7. The method according to claim 1, characterized in that The method further includes: Obtaining an updated multicast key from the ground station; Sending the updated multicast key to satellites within the first satellite group.

8. An information synchronization method, characterized in that, Applied to a ground station, includes: Obtaining a terminal context of a first terminal from a core network device; Sending the terminal context to a network element disposed on a first satellite; wherein the first satellite is within a first satellite group, the first satellite group includes one or more satellites and satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is used to send the terminal context to satellites within the first satellite group.

9. The method according to claim 8, wherein The method further includes: Obtaining first information from the core network device, wherein the first information is used to indicate a storage time of the terminal context; Sending the first information to the network element disposed on the first satellite.

10. The method according to claim 8, wherein The method further includes: Sending an updated multicast key to the network element disposed on the first satellite.

11. The method according to claim 10, wherein The sending the updated multicast key to the network element disposed on the first satellite includes: Encrypt the updated sub-branch key corresponding to the second satellite within the first satellite group using the satellite private key of the second satellite, and encrypt the updated multicast key using the updated sub-branch key corresponding to the second satellite, or encrypt the updated sub-branch key and the updated multicast key corresponding to the second satellite using the satellite private key of the second satellite within the first satellite group, where the second satellite is the updated satellite within the first satellite group; Send the encrypted updated key to the network element disposed on the first satellite.

12. An information synchronization method, characterized in that, Applied to a core network device, including: Send the terminal context of the first terminal to the network element disposed on the first satellite through a ground station; Wherein, the first satellite is located within a first satellite group, the first satellite group includes one or more satellites and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is configured to send the terminal context to the satellites within the first satellite group.

13. The method according to claim 12, wherein The method further includes: Send first information to the network element disposed on the first satellite through a ground station, where the first information is used to indicate the storage time of the terminal context.

14. An information synchronization device, characterized in that, Applied to a network element disposed on a first satellite, the first satellite is located within a first satellite group, the first satellite group includes one or more satellites, including: a memory, a transceiver, a processor: The memory is configured to store a computer program; the transceiver is configured to send and receive data under the control of the processor; the processor is configured to read the computer program in the memory and perform the following operations: Obtain the terminal context of the first terminal from a core network device through a ground station, where the satellites in the first satellite group provide services for the first terminal; Send the terminal context to the satellites within the first satellite group.

15. The device according to claim 14, characterized in that, The processor is further configured to read the computer program in the memory and perform the following operations: Encrypt the terminal context using a multicast key; Send the encrypted terminal context to the satellites within the first satellite group in a multicast manner.

16. The device according to claim 14, characterized in that, The processor is further configured to read the computer program in the memory and perform the following operations: Obtain first information from the core network device through the ground station, where the first information is used to indicate the storage time of the terminal context; Release the terminal context according to the first information.

17. The device according to claim 16, characterized in that, The processor is further configured to read the computer program in the memory and perform the following operations: If it is determined according to the first information that the time to release the terminal context has arrived, release the terminal context; Send a first indication to the satellites within the first satellite group, where the first indication is used to indicate that the satellites within the first satellite group release the terminal context.

18. The device according to claim 16, characterized in that, The processor is further configured to read the computer program in the memory and perform the following operations: If it is determined according to the first information that the time to release the terminal context has arrived, release the terminal context; Send the first information to the satellites in the first satellite group for the satellites in the first satellite group to release the terminal context at the time determined according to the first information when reaching the time to release the terminal context.

19. The device according to claim 14, characterized in that, The processor is further configured to read the computer program in the memory and perform the following operations: Obtain an updated multicast key from the ground station; Send the updated multicast key to the satellites in the first satellite group.

20. An information synchronization device, characterized in that, Applied to the ground station, including: a memory, a transceiver, a processor: The memory is used to store a computer program; the transceiver is used to transmit and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations: Obtain the terminal context of the first terminal from the core network device; Send the terminal context to the network element disposed on the first satellite; Wherein, the first satellite is located in the first satellite group, the first satellite group includes one or more satellites and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is used to send the terminal context to the satellites in the first satellite group.

21. The device according to claim 20, wherein, The processor is further configured to read the computer program in the memory and perform the following operations: Obtain the first information from the core network device, wherein the first information is used to indicate the storage time of the terminal context; Send the first information to the network element disposed on the first satellite.

22. The device according to claim 20, wherein, The processor is further configured to read the computer program in the memory and perform the following operations: Send the updated multicast key to the network element disposed on the first satellite.

23. The device according to claim 22, characterized in that, The processor is further configured to read the computer program in the memory and perform the following operations: Encrypt the updated sub-branch key corresponding to the second satellite by using the satellite private key of the second satellite in the first satellite group, and encrypt the updated multicast key by using the updated sub-branch key corresponding to the second satellite, or encrypt the updated sub-branch key corresponding to the second satellite and the updated multicast key by using the satellite private key of the second satellite in the first satellite group, wherein the second satellite is the updated satellite in the first satellite group; Send the encrypted updated key to the network element disposed on the first satellite.

24. An information synchronization device, characterized in that, Applied to the core network device, including: a memory, a transceiver, a processor: The memory is used to store a computer program; the transceiver is used to transmit and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations: Send the terminal context of the first terminal to the network element disposed on the first satellite through the ground station; Wherein, the first satellite is located in the first satellite group, the first satellite group includes one or more satellites and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is used to send the terminal context to the satellites in the first satellite group.

25. The device according to claim 24, characterized in that, The processor is further configured to read the computer program in the memory and perform the following operations: Send a first piece of information to the network element disposed on the first satellite via a ground station, where the first piece of information is used to indicate the storage time of the terminal context.

26. An information synchronization device, characterized in that, Applied to a network element disposed on a first satellite, the first satellite being within a first satellite group, the first satellite group including one or more satellites, including: A first acquisition unit, configured to acquire, via a ground station, the terminal context of a first terminal from a core network device, where the satellites in the first satellite group provide services for the first terminal; A first sending unit, configured to send the terminal context to the satellites within the first satellite group.

27. An information synchronization device, characterized in that, Applied to a ground station, including: A first acquisition unit, configured to acquire the terminal context of a first terminal from a core network device; A first sending unit, configured to send the terminal context to a network element disposed on a first satellite; where the first satellite is within a first satellite group, the first satellite group including one or more satellites and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is configured to send the terminal context to the satellites within the first satellite group.

28. An information synchronization device, characterized in that, Applied to a core network device, including: A first sending unit, configured to send, via a ground station, the terminal context of a first terminal to a network element disposed on a first satellite; where the first satellite is within a first satellite group, the first satellite group including one or more satellites and the satellites in the first satellite group provide services for the first terminal, and the network element disposed on the first satellite is configured to send the terminal context to the satellites within the first satellite group.

29. A processor-readable storage medium, characterized in that, The processor-readable storage medium stores a computer program, and the computer program is used to cause the processor to execute the method according to any one of claims 1 to 13.

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