Communication method, communication system, device and storage medium

Abstract

The embodiments of the present application relate to the technical field of communications. Provided are a communication method, a communication system, a device, and a storage medium. The method comprises: a first satellite network device receiving a first message, and then sending a rejection message to a terminal device when available storage resources of the first satellite network device are insufficient; and if the first message comprises a first identifier, the rejection message comprising a rejection reason, so that the aggravation of the insufficiency of the available storage resources of the first satellite network device is avoided.

Description

Communication methods, communication systems, equipment and storage media

[0001] This application claims priority to Chinese Patent Application No. 202410667632.7, filed on May 27, 2024, entitled "Communication Method, Communication System, Device and Storage Medium", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to communication methods, communication systems, devices and storage media. Background Technology

[0003] Satellite IoT, as a global form of IoT, has wide applications in many fields. However, due to the limited storage resources of satellite network equipment used to provide satellite IoT, how to design the execution operations of satellite network equipment or terminal devices in scenarios with insufficient storage resources is an urgent problem to be solved. Summary of the Invention

[0004] This application provides a communication method, communication system, device, and storage medium, which are applied in the field of communication technology to avoid exacerbating the problem of insufficient available storage resources in satellite network equipment.

[0005] In a first aspect, embodiments of this application propose a communication method, which can be executed by a first satellite network device, or by a component of the first satellite network device (such as an access network device or a core network device). This application does not limit this.

[0006] For example, the method includes: receiving a first message; sending a rejection message to a terminal device when the available storage resources of the first satellite network device are insufficient; and if the first message includes a first identifier, the rejection message includes a rejection reason.

[0007] It should be understood that "insufficient available storage resources for the first satellite network device" can be interpreted as: the available storage resources of the first satellite network device are less than or equal to a first preset threshold, and / or, the ratio of the available storage resources of the first satellite network device to the total storage resources is less than or equal to a second preset threshold, or other ways reflecting insufficient available storage resources. Therefore, the embodiments of this application do not specifically limit the manifestation of insufficient available storage resources for the first satellite network device.

[0008] In this embodiment, if the first satellite network device still needs to serve the terminal device when its available storage resources are insufficient, it will only exacerbate the insufficient storage resources. Therefore, after receiving the first message, the first satellite network device, when its available storage resources are insufficient, rejects the terminal device's attachment by sending a rejection message. This preserves the available storage resources of the first satellite network device and avoids exacerbating the insufficient storage resources. Furthermore, when the first message includes a first identifier, including a rejection reason in the rejection message allows the terminal device to know that the reason for the rejection is insufficient storage resources, preventing the terminal device from reconnecting and thus also avoiding exacerbating the insufficient storage resources.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, the first message includes at least one of the following:

[0010] (1.1) Request message, which includes attach request message;

[0011] (1.2) Response message for obtaining the contract data corresponding to the terminal device.

[0012] It should be understood that the attach request message may be a non-access stratum (NAS) attach request message or other types of attach request messages, and this embodiment does not specifically limit this. Furthermore, the attach request message may include a first field, which is used to request the terminal device to attach to the first satellite network device.

[0013] It should also be understood that the first identifier is used to indicate that the terminal device is a latency-tolerant type of device. Furthermore, the form in which the first identifier appears in each message is not specifically limited. For example, the first identifier can be a newly added field in the attach request message, or a redefined existing field in the attach request message; this embodiment of the application does not specifically limit this. As another example, the first identifier can be a newly added field in the subscription data retrieval response message, or a redefined existing field in the subscription data retrieval response message; this embodiment of the application does not specifically limit this.

[0014] It should be noted that, since the first message includes at least one of the request message or the response message for obtaining the contracted data corresponding to the terminal device, "the first message includes the first identifier" can be divided into the following cases:

[0015] Case 1: The request message includes a first identifier.

[0016] Scenario 2: The terminal device's response message for acquiring the contracted data includes the first identifier.

[0017] Scenario 3: The request message sent by the terminal device to the first satellite network device includes the first identifier, and the corresponding subscription data acquisition response message of the terminal device also includes the first identifier.

[0018] In Case 1, in one embodiment, the request message includes an attach request message, therefore the first message includes the attach request message, so receiving the first message may include: receiving the attach request message sent by the terminal device.

[0019] In conjunction with the first aspect, in some implementations of the first aspect, the reason for rejection is used to indicate that the reason the terminal device refuses to attach to the first satellite network device is that the first satellite network device has insufficient available storage resources.

[0020] It should be understood that the reason for rejection can be carried in the rejection message. In this embodiment, carrying the reason for rejection in the rejection message can reduce signaling overhead and effectively avoid wasting the available storage resources of the first satellite network device.

[0021] In this embodiment, sending a rejection reason to the terminal device allows the terminal device to clearly understand that the reason for the attachment rejection is insufficient available storage resources of the first satellite network device, thereby suspending the attachment process and reducing unnecessary signaling overhead.

[0022] In another embodiment, the request message includes at least one of the following:

[0023] Attach Request message; Tracking Area Update Request message; Radio Resource Control (RRC) Connection Resumption Request message; Packet Data Protocol (PDP) Context Establishment Request message; Physical Random Access Channel (PRACH) message; Physical Uplink Control Channel (PUCCH) message.

[0024] In scenario 2, if the request message includes an attach request message, and the attach request message does not include a first identifier, then receiving the first message includes:

[0025] Send a terminal device subscription data retrieval request message to the terrestrial network device. The retrieval request message is used to instruct the terrestrial network device to retrieve the terminal device's subscription data from the home subscribe server (HSS).

[0026] Receive a subscription data acquisition response message sent by the terrestrial network equipment. The subscription data acquisition response message includes the subscription data, and the subscription data includes a first identifier.

[0027] It should be understood that the application embodiments do not specifically limit the deployment location of the home user server. For example, the home user server may be deployed on the first satellite network device, or the constellation to which the first satellite network device belongs, or on the ground.

[0028] Accordingly, when available storage resources are insufficient, the first satellite network device sends a rejection message to the terminal device. This rejection message is of the same type as the request message; for example, if the request message includes an attach request message, and the attach request message can be a NAS attach request message, then the rejection message can be a NAS attach rejection message. It should be noted that the rejection message may include a second field indicating "attachment of the terminal device is rejected," and the second field can be in any form indicating "attachment of the terminal device is rejected," such as a number, a field, or other forms; this application does not limit this.

[0029] If the first satellite network device is configured to be strict, it will send a rejection message including a rejection reason to the terminal device when the request message carries the first identifier. Alternatively, if the first satellite network device is configured to be highly tolerant, it can obtain the first identifier from the subscription data acquisition response message when the request message does not carry the first identifier. If the first identifier corresponding to the terminal device is obtained, the first satellite network device will send a rejection message including a rejection reason to the terminal device. Therefore, this embodiment of the application improves the selectivity of the first message and provides selectivity for the first satellite network device to send a rejection message.

[0030] In this embodiment, different situations can all represent "the first message includes the first identifier", which improves the selectivity of the first message.

[0031] In conjunction with the first aspect, in some implementations of the first aspect, while avoiding exacerbating the insufficient available storage resources of the first satellite network device, it is also necessary to consider whether services that have already transmitted data between the terminal device and the first satellite network device will be affected. Therefore, embodiments of this application can configure corresponding sending conditions for rejection messages. In one implementation, sending a rejection message to the terminal device includes:

[0032] If there is no downlink information to be sent to the terminal device, a rejection message is sent to the terminal device.

[0033] It should be understood that downlink information includes pending response information. This pending response information is the response information that the first satellite network device should send back to the terminal device after establishing a connection with the ground network device and sending the relevant data of the terminal device to the ground network device. The relevant data is the data generated by the first satellite network device after its last connection with the terminal device was established.

[0034] In this embodiment, when there is no downlink information to be sent to the terminal device, the first satellite network device sends a rejection message to the terminal device. Conversely, if the first satellite network device determines that it has downlink information that needs to be sent to the terminal device in its local storage, it will send an attach accept message to the terminal device, thereby completing the attachment of the terminal device to the first satellite network device. This allows the first satellite network device to send the corresponding downlink information to the terminal device, which can alleviate the situation of insufficient available storage resources of the first satellite network device and is very likely to make the available storage resources of the first satellite network device sufficient.

[0035] In conjunction with the first aspect, in some implementations of the first aspect, if the first message includes a first identifier, then the rejection message also includes:

[0036] The first timer length is used to instruct the terminal device to retransmit the attach request message after the first timer starts and the first timer length has expired.

[0037] It should be understood that the length of the first timer can be carried in the rejection message. In this embodiment, carrying the length of the first timer in the rejection message can reduce signaling overhead and effectively avoid wasting the available storage resources of the first satellite network device.

[0038] In this embodiment, sending the first timer length to the terminal device allows the terminal device to clearly know the time for retransmitting the attach request message, and ensures that the first satellite network device has left the area covering the terminal device before the terminal device retransmits the attach request message. Therefore, it can ensure that the retransmitted attach request message of the terminal device is sent to other satellite network devices besides the first satellite network device, thus avoiding exacerbating the situation of insufficient available storage resources of the first satellite network device.

[0039] It should be noted that the reason for rejection can be expressed in any form, such as a number, a field, or other form, indicating that "the first satellite network device refuses to attach because the first satellite network device has insufficient available storage resources." This application does not limit this. Similarly, the length of the first timer can be expressed in any form, such as a number, a field, or other form, indicating that "the terminal device will retransmit the attach request message after the first timer starts and the first timer length ends." This application does not limit this.

[0040] In conjunction with the first aspect, in some implementations of the first aspect, the first satellite network device may also be a satellite network device with sufficient available storage resources. For example, the first satellite network device may be a satellite network device with sufficient available storage resources when it enters the area covering the terminal device. Or, for example, the first satellite network device may be a satellite network device with insufficient available storage resources when it enters the area covering the terminal device, but its state changes from insufficient available storage resources to sufficient available storage resources within the area covering the terminal device.

[0041] If the first satellite network device has sufficient available storage resources, receive the first message, including:

[0042] The method further includes receiving an attach request message sent by a terminal device;

[0043] Send an attach accept message to the terminal device;

[0044] Receive the attachment completion message sent by the terminal device;

[0045] Receive the context establishment request message sent by the terminal device and create the context information of the terminal device;

[0046] A second message is sent to the terrestrial network device, the second message including the context information; in response to the second message, the terrestrial network device obtains priority rule configuration information from the home subscriber server;

[0047] Retrieve priority rule configuration information;

[0048] The decision is made based on the priority rule configuration information to obtain the priority information of data transmission corresponding to the service type requested by the terminal device;

[0049] Receive data transmission request messages sent by terminal devices;

[0050] Based on priority information, a data transmission response message is sent to the terminal device.

[0051] It should be understood that the interpretation of the attach request message has been described above and will not be repeated here.

[0052] It should also be understood that the attach accept message and the attach request message are of the same type. For example, when the attach request message is a NAS attach request message, the attach accept message is a NAS attach accept message. It should be noted that the attach accept message may include a third field indicating that "the first satellite network device accepts the attachment of the terminal device." Furthermore, the third field may be presented in any form indicating that "the first satellite network device accepts the attachment of the terminal device," such as a number, a field, or other forms; this application does not limit this.

[0053] Similarly, the attach complete message is of the same type as the attach request message. For example, if the attach request message is a NAS attach request message, the attach complete message is a NAS attach complete message. It should be noted that the attach complete message may include a fourth field, which is used to indicate "the terminal device has completed attaching". The fourth field can be represented in any form that indicates "the terminal device has completed attaching", such as a number, a field, or other forms. This application does not limit this.

[0054] It should be noted that the context establishment request message may include a fifth field, which is used to indicate "requesting the first satellite network device to establish context information". The fifth field may be in any form indicating "requesting the first satellite network device to establish context information", such as a number, a field or other form, and this application does not limit it.

[0055] It should be understood that the context information includes subscription data and may also include connection context information. The interpretation of subscription data has been described above and will not be repeated here. The connection context information is used to indicate that the satellite network device to which the terminal device was previously attached is the first satellite network device. The connection context information can be any form representing "the satellite network device to which the terminal device was previously attached is the first satellite network device," such as numbers, fields, or other forms, and this application does not limit it in this regard.

[0056] In this embodiment, when the first satellite network device has sufficient available storage resources, the terminal device can complete attachment and data transmission. The purpose of the first satellite network device creating context information is to enable other satellite network devices to know the service process that the first satellite network device has been serving based on the context information corresponding to the terminal device created by the first satellite network device when it wants to host the terminal device to other satellite network devices, thereby improving the service efficiency of the entire satellite mobile communication system.

[0057] In conjunction with the first aspect, in some implementations of the first aspect, the attached received message includes:

[0058] The second timer length is used to instruct the terminal device to send a data transmission request message from the start of the second timer until the end of the second timer length.

[0059] It should be understood that the length of the second timer can be expressed in any form, such as a number, a field, or other form, indicating that "the terminal device sends a data transmission request message from the start of the second timer until the end of the second timer length". This application does not limit this.

[0060] In this embodiment, if the terminal device attempts to initiate data transmission on the first satellite network device at any time, the first satellite network device may not have obtained the priority rule configuration information when it receives the data transmission request message. Therefore, without obtaining the priority rule configuration information, the first satellite network device cannot determine how to process the data transmission request message, which can easily cause data transmission interruption. If the terminal device retransmits the data transmission request message, it will also waste the available storage resources of the first satellite network device. Therefore, this embodiment uses the second timer length to indicate the time when the terminal device sends the data transmission request message, which can prevent the terminal device from attempting to initiate data transmission on the first satellite network device before the second timer length expires, thereby ensuring the normal operation of the data transmission process.

[0061] In conjunction with the first aspect, in some implementations of the first aspect, the priority rule configuration information is used to indicate how to configure the priority of data transmission corresponding to the service type requested by the terminal device of the latency-tolerant type and / or the terminal device of the non-latency-tolerant type. Since the priority may be affected by factors such as the first identifier, service type, transmission information length, and transmission information tolerance time length, the priority rule configuration information includes any one of the following:

[0062] First item: Prioritize messages based on whether they include a first identifier;

[0063] The second item: Prioritize the data based on the requested service type, the length of the transmitted information, and / or the tolerable duration of the transmitted information.

[0064] The first item: Prioritizing messages based on whether they include a first identifier, including:

[0065] The first priority is higher than the second priority; the first priority is the priority corresponding to the priority information when the first condition is met, and the second priority is the priority corresponding to the priority information when the second condition is met.

[0066] Among them, satisfying the first condition includes: the first message does not include the first identifier;

[0067] The second condition is met, including: the first message includes the first identifier.

[0068] The second item: Prioritize based on the requested service type, the length of the transmitted information, and / or the tolerable transmission time, including:

[0069] The second priority is greater than the third priority; the second priority is the priority information corresponding to the second condition being met.

[0070] The third priority is the priority corresponding to the priority information when the third condition is met;

[0071] The second condition includes: the first message includes a first identifier and satisfies at least one of the following: the requested service type is a first preset service type; the length of the transmitted information is less than or equal to a first preset length threshold; the tolerable length of the transmitted information is less than or equal to a second preset length threshold.

[0072] The third condition is met, including: the first message includes a first identifier and meets at least one of the following: the requested service type is a second preset service type; the length of the transmitted information is greater than a first preset length threshold; the tolerable length of the transmitted information is greater than a second preset length threshold.

[0073] The first priority, second priority, and third priority are used to indicate the order in which the first satellite network device sorts data transmissions among the terminal devices based on priority.

[0074] It should be understood that the ordering rules for the first, second, and third priorities are sent from the terrestrial network equipment to the first satellite network equipment, and these ordering rules are not affected by whether the first satellite network equipment has sufficient available storage resources.

[0075] It should also be understood that the requested service type includes text transmission, image transmission, or audio transmission, etc. Furthermore, this application embodiment does not specifically limit the source of parameters such as the requested service type, transmission information length, and tolerable transmission time length of the terminal device. These parameters can be carried in the attach request message or other messages sent by the terminal device to the first satellite network device; this application embodiment does not impose specific limitations. Therefore, based on the principle that "first priority is greater than second priority, and second priority is greater than third priority," the first satellite network device can reasonably allocate available storage resources and prioritize providing services to high-priority terminal devices.

[0076] It should be noted that the requested service type can be represented in any form that represents "service type", such as a number, a field, or other forms, and this application does not limit this. Similarly, the transmission information length, the tolerable transmission time length, etc., can be represented in any form that represents "transmission information length", "tolerable transmission time length", etc., such as a number, a field, or other forms, and this application does not limit this.

[0077] In conjunction with the first aspect, in some implementations of the first aspect, to ensure sufficient available storage resources for the first satellite network device, embodiments of this application can achieve this by releasing data to the ground network device. As an optional implementation, before receiving the attach request message sent by the terminal device, the solution further includes:

[0078] Establish communication connections with terrestrial network equipment;

[0079] Data is transmitted to terrestrial network equipment to free up storage resources on the first satellite network equipment.

[0080] In this embodiment, if the first satellite network device successfully connects to the ground network device via a feeder before leaving the area covering the terminal device, it can release data to the ground network device, ensuring sufficient available storage resources for the first satellite network device. Therefore, when the first satellite network device subsequently covers the area of ​​the terminal device with sufficient available storage resources, if the first timer expires, it can receive the attach request message sent by the terminal device, thereby completing the attach process of the terminal device.

[0081] In conjunction with the first aspect, in certain implementations of the first aspect, to ensure that only terminal devices that have undergone authentication and security settings can access the storage resources of the first satellite network device, the method further includes the following before sending the attach accept message to the terminal device:

[0082] Perform authentication and security settings on terminal devices.

[0083] It should be understood that authentication and security settings include at least one of the following: authorization permission for authentication of terminal devices, authorization permission for security establishment of terminal devices, setting of authorization time range for authentication of terminal devices, setting of authorization time range for security establishment of terminal devices, etc.

[0084] Accordingly, the first satellite network device authenticates and sets up security settings for the terminal device. Only when the terminal device passes the authentication and security settings will the first satellite network device send an attach accept message to the terminal device, which can improve the security of the satellite mobile communication system.

[0085] In conjunction with the first aspect, in certain implementations of the first aspect, in case 1, in one embodiment, the request message includes an attach request message, and if the attach request message includes a first identifier, the method further includes:

[0086] In response to the second message, the terrestrial network equipment notifies the home subscriber server to add the first identifier to the subscription data.

[0087] It should be understood that the first identifier may not be included in the subscription data generated during the registration of the terminal device. However, the terminal device may consider including the first identifier later as needed. However, the subscription data of the terminal device in the home user server has not yet been updated. Therefore, the first satellite network device can instruct the ground network device to notify the home user server to add the first identifier to the subscription data. After receiving the notification, the home user server updates the subscription data process according to the context information. The addition of the first identifier by the home user server in the updated subscription data process can ensure the consistency and accuracy of the subscription data.

[0088] Secondly, embodiments of this application propose a communication method, which can be executed by a second satellite network device, or by a component within the second satellite network device (such as an access network device or a core network device). This application does not limit this aspect.

[0089] It should be understood that after the terminal device attaches to the first satellite network device, a satellite takeover may occur. To address this situation, this method includes:

[0090] In the case of satellite takeover, obtain the context information and priority rule configuration information of the terminal device; wherein, the satellite takeover situation is: the first satellite network device has sent a second message to the ground network device before leaving the area covering the terminal device, the second satellite network device enters the area covering the terminal device, and the second satellite network device has insufficient available storage resources;

[0091] Receive data transmission request messages sent by terminal devices;

[0092] Re-establish the connection based on context information;

[0093] The decision is made based on the priority rule configuration information to obtain the priority information of data transmission corresponding to the service type requested by the terminal device;

[0094] If the priority information corresponds to a priority greater than or equal to the second priority, a data transmission response message is sent to the terminal device.

[0095] It should be understood that the interpretation of context information, priority rule configuration information, and data transmission request messages has been described above and will not be repeated here.

[0096] In this embodiment, the terrestrial network device has information forwarding capabilities and can communicate with various satellite network devices. Therefore, it can forward context information and priority rule configuration information, thereby enabling the second satellite network device to take over the data transmission work that the first satellite network device has not completed. Furthermore, this embodiment can re-establish the connection based on context information, reducing unnecessary attachment operations of terminal devices. The priority rule configuration information also provides a basis for whether the second satellite network device, with insufficient available storage resources, should execute the data transmission process.

[0097] Therefore, based on the priority that allows the second satellite network device to transmit data with the terminal device, the second satellite network device transmits data to the terminal device, thereby providing timely data transmission services to the terminal device with the highest priority for data transmission corresponding to the requested service type as much as possible when available storage resources are insufficient, which can meet the latency requirements of the requested service type for data transmission.

[0098] In conjunction with the second aspect, in some implementations of the second aspect, after making a decision based on priority rule configuration information to obtain the priority information of data transmission corresponding to the service type requested by the terminal device, the method further includes:

[0099] If the priority information corresponds to a priority lower than the second priority, then an attachment release message is sent to the terminal device.

[0100] The attachment release message includes:

[0101] The reason for unattaching is indicated to show that the reason for the terminal device unattaching to the second satellite network device is that the second satellite network device has insufficient available storage resources.

[0102] It should be understood that the attach release message and the attach request message are of the same type. For example, if the attach request message can be a NAS attach request message, then the attach release message can be a NAS attach release message.

[0103] It should also be understood that the reason for unattaching the second satellite network device can be in any form indicating that "the reason for unattaching the second satellite network device is that the second satellite network device has insufficient available storage resources," such as numbers, fields or other forms, and this application does not limit this.

[0104] Accordingly, when the priority information corresponds to a priority lower than the second priority, the second satellite network device sends an attach release message to the terminal device, which can disconnect the terminal device from the second satellite network device. This prevents the second satellite network device from providing data transmission services to the terminal device. This satisfies the latency requirements of the low-priority requested service type of the terminal device for data transmission while avoiding the risk of exhausting the resources of the second satellite network device.

[0105] In conjunction with the second aspect, in some implementations of the second aspect, the priority rule configuration information includes any of the following:

[0106] First item: Prioritize messages based on whether they include a first identifier;

[0107] The second item: Prioritize the data based on the requested service type, the length of the transmitted information, and / or the tolerable duration of the transmitted information.

[0108] For the first item: Prioritize messages based on whether they include a first identifier, including:

[0109] The first priority is higher than the second priority; the first priority is the priority corresponding to the priority information when the first condition is met, and the second priority is the priority corresponding to the priority information when the second condition is met.

[0110] Among them, satisfying the first condition includes: the first message does not include the first identifier;

[0111] The second condition is met, including: the first message includes the first identifier.

[0112] Regarding the second item: Prioritize based on the requested service type, the length of the transmitted information, and / or the tolerable transmission time, including:

[0113] The second priority is greater than the third priority; the second priority is the priority information corresponding to the second condition being met.

[0114] The third priority is the priority corresponding to the priority information when the third condition is met;

[0115] The second condition includes: the first message includes a first identifier and satisfies at least one of the following: the requested service type is a first preset service type; the length of the transmitted information is less than or equal to a first preset length threshold; the tolerable length of the transmitted information is less than or equal to a second preset length threshold.

[0116] The third condition is met, including: the first message includes a first identifier and meets at least one of the following: the requested service type is a second preset service type; the length of the transmitted information is greater than a first preset length threshold; the tolerable length of the transmitted information is greater than a second preset length threshold.

[0117] The first and second priorities are the priorities that allow the second satellite network device to transmit data with the terminal device, while the third priority is the priority that does not allow the second satellite network device to transmit data with the terminal device.

[0118] It should be understood that the interpretation of the first identifier, the requested service type, the length of the transmitted information, and the tolerable transmission time in the second aspect is consistent with the interpretation of the first identifier, the requested service type, the length of the transmitted information, and the tolerable transmission time in the first aspect, and will not be repeated here.

[0119] In this embodiment, when the available storage resources of the second satellite network device are insufficient, services are preferentially provided to high-priority terminal devices, and data transmission is rejected by third-priority devices to avoid exacerbating the insufficient available storage resources of the second satellite network device.

[0120] Thirdly, embodiments of this application propose a communication method. This method can be executed by a terminal device, or by a component (e.g., a chip or circuit) configured in the terminal device. This application does not limit the scope of this method.

[0121] For example, the method includes: receiving a rejection message sent by a first satellite network device, the rejection message being sent when the first satellite network device has insufficient available storage resources, and the rejection message including a rejection reason if a first identifier is included in the first message.

[0122] It should be understood that the explanations of "insufficient available storage resources for the first satellite network equipment" and "rejection message" in the third aspect are consistent with the explanations of "insufficient available storage resources for the first satellite network equipment" and "rejection message" in the first aspect, and will not be repeated here.

[0123] In this embodiment, the first satellite network device may be experiencing insufficient available storage resources. In this situation, if the first satellite network device still needs to serve the terminal device, it will only exacerbate the insufficient storage resources. Therefore, considering the insufficient storage resources of the first satellite network device, the terminal device will receive a rejection message from the first satellite network device. This preserves the available storage resources of the first satellite network device and avoids exacerbating the insufficient storage resources. Since the first message includes a first identifier, the reason for rejection is carried in the rejection message, so that the terminal device knows that the reason for rejection is insufficient available storage resources and will not reconnect to the first satellite network device, thereby avoiding exacerbating the insufficient storage resources.

[0124] In conjunction with the third aspect, in some implementations of the third aspect, the first identifier is used to indicate that the terminal device is a latency-tolerant type of device.

[0125] The first message includes at least one of the following:

[0126] (1.1) Request message, which includes attach request message;

[0127] (1.2) Response message for obtaining the contract data corresponding to the terminal device.

[0128] It should be understood that the interpretation of the attach request message, the first identifier, and other information in the third aspect is consistent with the interpretation of the attach request message, the first identifier, and other information in the first aspect, and will not be repeated here.

[0129] It should be noted that since the first message includes at least one of the request message or the response message for obtaining the contracted data corresponding to the terminal device, "the first message includes the first identifier" can be divided into three cases, as described above, and will not be repeated here.

[0130] In this embodiment, different situations can all represent "the first message includes the first identifier", which improves the selectivity of the first message.

[0131] In conjunction with the third aspect, in some implementations of the third aspect, the method further includes, before receiving the rejection message sent by the first satellite network device:

[0132] The terminal device sends an attach request message to the first satellite network device.

[0133] In this embodiment, the attach request message may include both the first field and the first identifier. Therefore, the terminal device can reduce signaling overhead by carrying multiple pieces of information in one attach request message.

[0134] In conjunction with the third aspect, in some implementations of the third aspect, the reason for rejection is used to indicate that the reason the terminal device refuses to attach to the first satellite network device is that the first satellite network device has insufficient available storage resources.

[0135] It should be understood that the explanation of the reasons for rejection in the third aspect is consistent with the explanation of the reasons for rejection in the first aspect, and will not be repeated here.

[0136] In this embodiment, the terminal device receives the rejection reason sent by the first satellite network device, which enables the terminal device to clearly know that the reason for the attachment rejection is that the first satellite network device has insufficient available storage resources, thereby suspending the attachment process and reducing unnecessary signaling overhead.

[0137] In another embodiment, the request message includes at least one of the following:

[0138] Attach Request Message; Tracking Area Update Request Message; Radio Resource Control (RRC) Connection Resumption Request Message; Packet Data Protocol (PDP) Context Establishment Request Message; Physical Random Access Channel (PRACH) Message; Physical Uplink Control Channel (PUCCH) Message.

[0139] In conjunction with the third aspect, in some implementations of the third aspect, the rejection message is sent by the first satellite network device when there is no downlink information to be sent to the terminal device. The downlink information includes a response message to be sent. The response message to be sent is the response information that the first satellite network device needs to provide to the terminal device after sending the relevant data of the terminal device to the ground network device. The relevant data is the data generated by the first satellite network device after establishing a connection with the terminal device last time.

[0140] In this embodiment, the rejection message sent when there is no downlink information to be sent to the terminal device can ensure that the services that the terminal device has already transmitted with the first satellite network device will not be affected.

[0141] In conjunction with the third aspect, in some implementations of the third aspect, if the first message includes a first identifier, then the rejection message also includes:

[0142] The first timer length is used to instruct the terminal device to retransmit the attach request message after the first timer starts and the first timer length has expired.

[0143] It should be understood that the explanation of the first timer length in the third aspect is consistent with the explanation of the first timer length in the first aspect, and will not be repeated here.

[0144] In this embodiment, receiving the first timer length sent by the first satellite network device allows the terminal device to clearly know the time of retransmission of the attach request message, and ensures that the first satellite network device has left the area covering the terminal device when the terminal device retransmits the attach request message. Therefore, it can ensure that the retransmitted attach request message of the terminal device is sent to other satellite network devices besides the first satellite network device, and can avoid aggravating the situation of insufficient available storage resources of the first satellite network device.

[0145] In conjunction with the third aspect, in some implementations of the third aspect, after receiving the first timer length sent by the first satellite network device, the method further includes:

[0146] Start the first timer;

[0147] After the first timer expires, attach request messages are sent to other satellite network devices besides the first satellite network device, or to the first satellite network device with sufficient available storage resources before the first timer expires.

[0148] It should be understood that "other satellite network devices besides the first satellite network device" can be any one of the satellite network devices covering the area of ​​the terminal device after the first timer length has ended. This satellite network device can be another first satellite network device, a second satellite network device, etc., and this embodiment does not specifically limit this. In one example, "other satellite network devices besides the first satellite network device" can be the next satellite network device after the first satellite network device.

[0149] It should be understood that the interpretation of the attach request message in the third aspect is consistent with the interpretation of the attach request message in the first aspect, and will not be repeated here.

[0150] In this embodiment, the terminal device can retransmit the attach request message to the next satellite network device after the first timer expires, thus avoiding exacerbating the insufficient available storage resources of the first satellite network device.

[0151] In conjunction with the third aspect, in some implementations of the third aspect, where the first satellite network device has sufficient available storage resources, the method further includes:

[0152] Send an attach request message to the first satellite network device;

[0153] Receive the attach accept message sent by the first satellite network device;

[0154] Send an attach complete message to the first satellite network device;

[0155] A context establishment request message is sent to the first satellite network device, which instructs the first satellite network device to create context information for the terminal device. A second message, which includes the context information, is sent to the ground network device. In response to the second message, the ground network device obtains priority rule configuration information from the home subscriber server.

[0156] When the first satellite network device has not left the area covering the terminal device, a data transmission request message is sent to the first satellite network device. The data transmission request message is sent by the terminal device after the first satellite network device obtains the priority rule configuration information, makes a decision based on the priority rule configuration information, and obtains the priority information of the data transmission corresponding to the service type requested by the terminal device.

[0157] Based on priority information, receive the data transmission response message sent by the first satellite network device.

[0158] It should be understood that the explanations of the Attach Accept Message, Attach Complete Message, Context Establishment Request Message, Context Information, and Data Transmission Request Message in the third aspect are consistent with the explanations of the Attach Accept Message, Attach Complete Message, Context Establishment Request Message, Context Information, and Data Transmission Request Message in the first aspect, and will not be repeated here.

[0159] In this embodiment, when the first satellite network device has sufficient available storage resources, the terminal device can complete the attachment. The purpose of the first satellite network device creating context information is to enable other satellite network devices to know the service process that the first satellite network device has been serving based on the context information corresponding to the terminal device created by the first satellite network device when it wants to host the terminal device to other satellite network devices, thereby improving the service efficiency of the entire satellite mobile communication system.

[0160] In conjunction with the third aspect, in some implementations of the third aspect, the attached received message includes:

[0161] The second timer length is used to instruct the terminal device to send a data transmission request message from the start of the second timer until the end of the second timer length.

[0162] It should be understood that the explanation of the second timer length in the third aspect is consistent with the explanation of the second timer length in the first aspect, and will not be repeated here.

[0163] Therefore, after receiving the attach accept message sent by the first satellite network device, the method also includes:

[0164] Start the second timer;

[0165] Send a data transmission request message to the first satellite network device, including:

[0166] After the second timer expires, a data transmission request message is sent to the first satellite network device.

[0167] In this embodiment, the terminal device does not send a data transmission request message to any satellite network device before the second timer expires. Therefore, it can effectively avoid executing the data transmission process before the preset steps are completed, thereby ensuring the normal operation of the data transmission process. The preset steps include the ground network device completing the update of the terminal device on the HSS (i.e., the location update process) and the first satellite network device obtaining the priority rule configuration information. It may also include forwarding the newly established context information of the first satellite network device to other satellite network devices in the satellite mobile communication system.

[0168] In conjunction with the third aspect, in some implementations of the third aspect, the method further includes, in the case of satellite takeover:

[0169] Send a data transmission request message to the second satellite network device; wherein, the satellite takeover situation is as follows: the first satellite network device has sent a second message to the ground network device before leaving the area covering the terminal device, the second satellite network device enters the area covering the terminal device, and the second satellite network device has insufficient available storage resources;

[0170] Receive data transmission response messages sent by the second satellite network device. These data transmission response messages are sent by the second satellite network device when the priority corresponding to the priority information is greater than or equal to the second priority.

[0171] It should be understood that in the case of satellite takeover, if the priority information corresponds to a priority greater than or equal to the second priority, it indicates that the terminal device has high latency requirements for data transmission and needs to be processed as soon as possible. Therefore, the second satellite network device with insufficient available storage resources will give priority to providing data transmission services for the terminal device.

[0172] In conjunction with the third aspect, in some implementations of the third aspect, after sending a data transmission request message to the second satellite network device, the method further includes:

[0173] Receive the attachment release message sent by the second satellite network device. The attachment release message is sent by the second satellite network device when the priority corresponding to the priority information is lower than the second priority.

[0174] The attachment release message includes:

[0175] The reason for unattaching is indicated to show that the reason for the terminal device unattaching to the second satellite network device is that the second satellite network device has insufficient available storage resources.

[0176] It should be understood that the explanation of the cause of termination instruction information in the third aspect is consistent with the explanation of the cause of termination instruction information in the second aspect, and will not be repeated here.

[0177] Accordingly, when the priority information corresponds to a priority lower than the second priority, the second satellite network device sends an attach release message to the terminal device, which can disconnect the terminal device from the second satellite network device. This prevents the second satellite network device from providing data transmission services to the terminal device. This satisfies the latency requirements of the low-priority requested service type of the terminal device for data transmission while avoiding the risk of exhausting the resources of the second satellite network device.

[0178] Fourthly, embodiments of this application provide a communication device including various modules or units for performing the methods of the first aspect and any possible implementation thereof.

[0179] Fifthly, embodiments of this application provide a communication device including various modules or units for performing the methods of the second aspect and any possible implementation thereof.

[0180] In a sixth aspect, embodiments of this application provide a communication device, including various modules or units for performing the methods of the third aspect and any possible implementation thereof.

[0181] In a seventh aspect, embodiments of this application provide a communication device including a processor. The processor is coupled to a memory and can be used to execute instructions in the memory to implement the methods described in the first aspect and any possible implementation thereof. Optionally, the device further includes a memory. Optionally, the device further includes a communication interface, and the processor is coupled to the communication interface.

[0182] In one implementation, the communication device is a first satellite network device. When the communication device is a first satellite network device, the communication interface can be a transceiver or an input / output interface.

[0183] In another implementation, the communication device is a chip configured in the first satellite network device. When the communication device is a chip configured in the first satellite network device, the communication interface can be an input / output interface.

[0184] Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0185] Eighthly, embodiments of this application provide a communication device including a processor. The processor is coupled to a memory and can be used to execute instructions in the memory to implement the methods described in the second aspect and any possible implementation thereof. Optionally, the device further includes a memory. Optionally, the device further includes a communication interface, and the processor is coupled to the communication interface.

[0186] In one implementation, the communication device is a second satellite network device. When the communication device is a second satellite network device, the communication interface can be a transceiver or an input / output interface.

[0187] In another implementation, the communication device is a chip configured in a second satellite network device. When the communication device is a chip configured in a second satellite network device, the communication interface can be an input / output interface.

[0188] Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0189] Ninthly, embodiments of this application provide a communication device including a processor. The processor is coupled to a memory and can be used to execute instructions in the memory to implement the methods in the third aspect and any possible implementation thereof. Optionally, the device further includes a memory. Optionally, the device further includes a communication interface, and the processor is coupled to the communication interface.

[0190] In one implementation, the communication device is a terminal device. When the communication device is a terminal device, the communication interface can be a transceiver or an input / output interface.

[0191] In another implementation, the communication device is a chip configured in a terminal device. When the communication device is a chip configured in a terminal device, the communication interface can be an input / output interface.

[0192] Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0193] In a tenth aspect, embodiments of this application provide a processor, including: an input circuit, an output circuit, and a processing circuit. The processing circuit is configured to receive signals through the input circuit and transmit signals through the output circuit, causing the processor to execute the methods of the first to third aspects and any possible implementation thereof.

[0194] In specific implementation, the processor can be one or more chips, the input circuit can be input pins, the output circuit can be output pins, and the processing circuit can be transistors, gate circuits, flip-flops, and various logic circuits. The input signal received by the input circuit can be received and input by, for example, but not limited to, a receiver, and the signal output by the output circuit can be output to, for example, but not limited to, a transmitter and transmitted by the transmitter. Furthermore, the input circuit and the output circuit can be the same circuit, which is used as the input circuit and the output circuit at different times. This application does not limit the specific implementation of the processor and various circuits.

[0195] Eleventhly, embodiments of this application provide a communication device, including a processor and a memory. The processor is used to read instructions stored in the memory, receive signals via a receiver, and transmit signals via a transmitter to execute the methods of the first to third aspects and any possible implementation thereof.

[0196] Optionally, the processor may be one or more, and the memory may be one or more.

[0197] Optionally, the memory may be integrated with the processor, or the memory may be separated from the processor.

[0198] In specific implementation, the memory can be a non-transitory memory, such as read-only memory (ROM), which can be integrated on the same chip as the processor or set on different chips. The embodiments of this application do not limit the type of memory or the way the memory and processor are set.

[0199] It should be understood that the relevant data interaction process, such as sending indication information, can be the process of the processor outputting indication information, and receiving capability information can be the process of the processor receiving input capability information. Specifically, the data output by the processor can be sent to the transmitter, and the input data received by the processor can come from the receiver. Here, the transmitter and receiver can be collectively referred to as a transceiver.

[0200] The communication device mentioned in the eleventh aspect above can be one or more chips. The processor in the communication device can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, integrated circuit, etc.; when implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. This memory can be integrated into the processor or located outside the processor and exist independently.

[0201] In a twelfth aspect, embodiments of this application provide a first satellite network device, including a processor, a memory, and a transceiver. The memory is used to store computer-executed instructions, the transceiver is used to send and receive data, and the processor is used to run the computer-executed instructions. When the processor executes the computer-executed instructions stored in the memory, it instructs the first satellite network device to perform the methods described in the first aspect and any possible implementation of the first aspect.

[0202] In a thirteenth aspect, embodiments of this application provide a second satellite network device, including a processor, a memory, and a transceiver. The memory is used to store computer-executed instructions, the transceiver is used to send and receive data, and the processor is used to run the computer-executed instructions. When the processor executes the computer-executed instructions stored in the memory, it instructs the second satellite network device to perform the methods described in the second aspect and any possible implementation of the second aspect.

[0203] In a fourteenth aspect, embodiments of this application provide a terminal device, including a processor, a memory, and a transceiver. The memory is used to store computer execution instructions, the transceiver is used to send and receive data, and the processor is used to execute the computer execution instructions stored in the memory. When executing the computer execution instructions stored in the memory, the processor is used to instruct the terminal device to execute the methods described in the third aspect and any possible implementation of the third aspect.

[0204] In a fifteenth aspect, embodiments of this application provide a computer-readable storage medium storing a computer program or instructions that, when executed on a computer, cause the computer to perform the methods described in the first to third aspects and any possible implementation thereof.

[0205] In a sixteenth aspect, this application provides a chip or chip system including at least one processor and a communication interface. The communication interface and the at least one processor are interconnected via a circuit. The at least one processor is used to run computer programs or instructions to perform the methods described in the first to third aspects or any possible implementations of the first to third aspects. The communication interface in the chip can be an input / output interface, a pin, or a circuit, etc.

[0206] In a seventeenth aspect, this application provides a communication system, which includes terminal equipment and satellite network equipment;

[0207] The terminal device is used to execute the method described in any possible implementation of the third aspect, and the satellite network device is used to execute the method described in any possible implementation of the first or second aspect.

[0208] In an eighteenth aspect, embodiments of this application provide a computer program product including a computer program, which, when run on a computer, causes the computer to perform the methods described in the first to third aspects and any possible implementation of the first to third aspects.

[0209] In one possible implementation, the chip or chip system described above in this application further includes at least one memory storing instructions. The memory can be an internal storage unit of the chip, such as a register or cache, or it can be a storage unit of the chip itself (e.g., read-only memory, random access memory, etc.).

[0210] It should be understood that the fourth, seventh, and twelfth aspects of this application correspond to the technical solutions of the first aspect of this application; the fifth, eighth, and thirteenth aspects of this application correspond to the technical solutions of the second aspect of this application; the sixth, ninth, and fourteenth aspects of this application correspond to the technical solutions of the third aspect of this application; and the tenth, eleventh, and fifteenth to eighteenth aspects of this application correspond to the technical solutions of the first to third aspects of this application. The beneficial effects obtained by each aspect and the corresponding feasible implementation are similar, and will not be described again. Attached Figure Description

[0211] Figure 1 is a schematic diagram showing the availability of service links in the satellite mobile communication system 100 at time T0, as applied in an embodiment of this application.

[0212] Figure 2 is a schematic diagram showing that the feeder link of the satellite mobile communication system 200 used in the embodiments of this application is available at time T1;

[0213] Figure 3 is a schematic diagram of the architecture of another satellite mobile communication system 300 applied in an embodiment of this application;

[0214] Figure 4 is a schematic diagram of the architecture of another satellite mobile communication system 400 applied in an embodiment of this application;

[0215] Figure 5 is an exemplary signaling interaction diagram of the related technology execution terminal device attachment;

[0216] Figure 6 is a schematic flowchart of the communication method 600 provided in the embodiment of this application, shown from the perspective of device interaction;

[0217] Figure 7 illustrates the signaling interaction between the terminal device and the first satellite network device in Case 1 of the communication method 700 provided in this embodiment of the application from the perspective of device interaction.

[0218] Figure 8 illustrates the signaling interaction between the terminal device and the first satellite network device in case 2 of the communication method 800 provided in this embodiment of the application from the perspective of device interaction.

[0219] Figure 9(a) is a signaling interaction diagram between a terminal device and multiple network devices in case 1 of the communication method 900 provided in the embodiment of this application, from the perspective of device interaction.

[0220] Figure 9(b) illustrates the signaling interaction between a terminal device and multiple network devices in the satellite takeover situation of the communication method 900 provided in the embodiments of this application from the perspective of device interaction.

[0221] Figure 10 is a schematic block diagram of a communication device 1000 provided in an embodiment of this application;

[0222] Figure 11 is a possible structural schematic diagram of the terminal device 1100 provided in an embodiment of this application;

[0223] Figure 12 is a possible structural diagram of a satellite network device provided in an embodiment of this application, such as a structural diagram of a base station 1200. Detailed Implementation

[0224] To facilitate a clear description of the technical solutions in the embodiments of this application, some terms and technologies involved in the embodiments of this application will be briefly introduced below:

[0225] 1. Satellite Internet of Things

[0226] Satellite Internet of Things (IoT) is a new type of network that uses satellite network devices for communication. It forms a large-scale network with a certain number of satellite network devices, covering the globe and providing broadband internet access and other communication services to ground-based and / or airborne terminal devices. IoT is an important component of future information technology development. Its main technical feature is connecting objects to satellite IoT via communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection. For example, Narrow Band Internet of Things (NB-IoT) is an emerging technology in the IoT field that supports low-power devices in wide-area cellular data connections, also known as Low Power Wide Area Network (LPWAN). NB-IoT uses licensed frequency bands and can be deployed in three ways: in-band, guard band, or standalone carrier, coexisting with existing networks. Another example is Cellular Internet of Things (CIoT), a communication technology with wide coverage that provides seamless connectivity services. It utilizes existing cellular networks to achieve interconnection between objects. Cellular IoT supports multiple connectivity technologies, including second-generation (2G), third-generation (3G), fourth-generation (4G), and fifth-generation (5G), as well as low-power wide-area network technologies specifically designed for IoT, such as NB-IoT. The choice of connectivity technology depends on the specific needs of the application scenario, such as data transmission speed, power consumption, coverage, and cost. Compared to traditional terrestrial networks that rely solely on ground base stations for communication, satellite IoT moves the base stations to outer space; each satellite network device essentially functions as a mobile base station.

[0227] 2. Store and forward (S&F)

[0228] Store-and-forward mode, also known as S&F satellite mode or S&F mode, is an operating mode in which satellite network equipment communicates with terrestrial network equipment via feeder link (FL) or inter-satellite link (ISL) to provide communication services (e.g., storing and forwarding information) to terminal equipment.

[0229] It should be understood that the store-and-forward mode has corresponding manifestations for satellite network devices in different time periods and / or geographical areas. For example, for the uplink (UL), "store" means that the satellite network device receives the UL information from the terminal device and writes it locally on the satellite network device to complete the local storage of the UL information; "forward" means that the satellite network device forwards the locally stored UL information to the terrestrial network device. For the downlink (DL), "store" means that the satellite network device receives the DL information from the terrestrial network device and writes it locally on the satellite network device to complete the local storage of the DL information; "forward" means that the satellite network device forwards the locally stored DL information to the terminal device.

[0230] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0231] To facilitate understanding of the embodiments of this application, the following description is provided first:

[0232] First, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with essentially the same function and effect. For example, the length of the first timer and the length of the second timer are only used to distinguish different timer lengths and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0233] Second, in the embodiments of this application, the words "exemplary" or "for example" are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design options. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0234] Third, in the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, a--c, bc, or abc, where a, b, and c can be single or multiple.

[0235] Fourth, in the embodiments of this application, "when," "if," and "if" all refer to the device making corresponding processing under certain objective circumstances, and are not limited to a time, nor do they require the device to make a judgment action when it is implemented, nor do they mean that there are other limitations.

[0236] Fifth, the term "simultaneously" in the embodiments of this application can be understood as at the same point in time, within a period of time, or within the same cycle. The specific meaning can be understood in conjunction with the context.

[0237] Sixth, in the embodiments of this application, "B corresponding to A" means that B is associated with A. "Execute B according to A" does not mean that B is executed only according to A, but also that B is executed according to A and / or other information.

[0238] Seventh, "predefined" or "preconfigured" can be achieved by pre-storing corresponding codes, tables, or other means of indicating relevant information in the device (e.g., including terminal devices and network devices), and this application does not limit the specific implementation method. "Storing" can refer to storing in one or more memories. The one or more memories can be separate installations or integrated into the encoder or decoder, processor, or communication device. Alternatively, some memories can be separate installations, while others are integrated into the decoder, processor, or communication device. The type of memory can be any form of storage medium, and this application does not limit this.

[0239] The term "predefined" in this application can be understood as definition, pre-defined, stored, pre-stored, pre-negotiated, pre-configured, solidified, or pre-burned.

[0240] Eighth, in the embodiments of this application, "for indicating" can include both direct and indirect indication, as well as explicit and implicit indication. The information indicated by a certain piece of information is called the information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated, such as, but not limited to, directly indicating the information to be indicated, such as the information to be indicated itself or its index. It can also indirectly indicate the information to be indicated by indicating other information, where there is a correlation between the other information and the information to be indicated. It can also indicate only a part of the information to be indicated, while the other parts are known or pre-agreed upon. For example, the indication of the information to be indicated can be achieved by pre-agreed upon (e.g., by a protocol specifying) the existence of a certain information element, thereby reducing the indication overhead to some extent.

[0241] Ninth, several embodiments are described in detail below with reference to multiple flowcharts. However, it should be understood that these flowcharts and their corresponding descriptions are for illustrative purposes only and should not constitute any limitation on this application. Not every step in each flowchart is necessarily required; for example, some steps can be skipped. Furthermore, the execution order of each step is not fixed and is not limited to what is shown in the figures. The execution order of each step should be determined by its function and internal logic.

[0242] To facilitate understanding of the communication methods, communication systems, devices, and storage media provided in the embodiments of this application, the communication methods, system architecture, and application scenarios provided in the embodiments of this application will be described below. It is understood that the system architecture and application scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application and do not constitute a limitation on the technical solutions provided in the embodiments of this application.

[0243] The technical solutions of this application can be applied to communication scenarios in various satellite mobile communication systems, such as: cellular IoT systems, satellite mobile communication systems compatible with long term evolution (LTE), satellite mobile communication systems compatible with LTE frequency division duplex (FDD), satellite mobile communication systems integrated with 5G, satellite mobile communication systems combined with new radio access technology (NR), and satellite mobile communication systems combined with vehicle-to-X (V2X), etc. V2X can include vehicle-to-network (V2N), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), long-term evolution of vehicle-to-vehicle communication (LTE-V), vehicle-to-everything (V2X), machine-type communication (MTC), the Internet of Things (IoT), long-term evolution of machine-to-machine communication (LTE-M), and machine-to-machine (M2M). It should be noted that the specific communication application scenarios mentioned above are merely examples and do not constitute limitations.

[0244] To facilitate understanding of the embodiments of this application, the satellite mobile communication system applicable to the embodiments of this application will be described in detail first with reference to FIG1. ​​FIG1 is a schematic diagram of the architecture of the satellite mobile communication system 100 used in the embodiments of this application. As shown in FIG1, the satellite mobile communication system 100 may include at least one terminal device, such as the terminal device 110 shown in FIG1. ​​The satellite mobile communication system 100 may also include at least one satellite network device, such as the satellite network device 120 shown in FIG1. ​​The terminal device 110 may be mobile or fixed. The satellite network device 120 is a device that can communicate with the terminal device 110 through a service link, such as an aircraft including an airborne base station. The embodiments of this application do not specifically limit the coverage area of ​​the satellite network device 120. For example, it can cover more than 300 square kilometers and can simultaneously provide services to hundreds of thousands or millions of terminal devices (such as water meter devices, agricultural equipment, etc.).

[0245] Figure 1 illustrates an exemplary terminal device and a satellite network device, and the satellite mobile communication system 100 may include other numbers of terminal devices or other numbers of satellite network devices, which are not limited in this application embodiment.

[0246] It should be understood that satellite network device 120 can provide communication coverage for a specific geographical area at different time periods and can communicate with terminal devices located within that coverage area (cell). It should also be understood that satellite network device 120 can communicate with different devices at different time periods and / or geographical areas. For example, as shown in Figure 1, at time T0, satellite network device 120 communicates with terminal device 110 via a service link and receives data sent by satellite network device 120; at this time, the service link is available. Satellite network device 120 will travel in the direction of travel shown in Figure 1. When it leaves the area covering terminal device 110, the service link becomes unavailable. As shown in Figure 2, in satellite mobile communication system 200, at time T1, satellite network device 120 has left the area covering terminal device 110 and entered the area covering ground network device 130. Satellite network device 120 communicates with ground network device 130 via a feeder link and forwards data sent by terminal device 110 to the ground network device; at this time, the feeder link is available, but the service link is unavailable.

[0247] It should be understood that the satellite mobile communication system 200 in Figure 2 is the same in architecture as the satellite mobile communication system 200 in Figure 1, both including terminal equipment 110, satellite network equipment 120 and terrestrial network equipment 130.

[0248] The aforementioned communication devices, such as terminal device 110, satellite network device 120, or terrestrial network device 130 in Figure 2, can be configured with multiple antennas. These multiple antennas may include at least one transmitting antenna for transmitting signals and at least one receiving antenna for receiving signals. Additionally, each communication device also includes a transmitter chain and a receiver chain, which, as will be understood by those skilled in the art, may include multiple components related to signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, or antennas). Therefore, satellite network device 120 and terminal device 110 can communicate via multi-antenna technology, or satellite network device 120 and terrestrial network device 130 can also communicate via antenna technology.

[0249] Optionally, the satellite mobile communication system 100 or satellite mobile communication system 200 may also include other network entities such as a network controller and a mobility management entity, and the embodiments of this application are not limited thereto.

[0250] In this embodiment of the application, the satellite network device can be any device with wireless transceiver capabilities. This equipment includes, but is not limited to: evolved node B (eNB), radio network controller (RNC), node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved node B, or home node B, HNB), baseband unit (BBU), access point (AP), wireless relay node, wireless backhaul node, transmission point (TP), or transmission and reception point (TRP) in a wireless fidelity (WIFI) system. It can also be a next-generation node B (gNB) in a 5G system, such as NR, or a transmission point (TRP or TP), one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a network node constituting a gNB or transmission point, such as a baseband unit (BBU) or a distributed unit (DU).

[0251] In some deployments, a gNB may include a centralized unit (CU) and a dedicated unit (DU). The gNB may also include an active antenna unit (AAU). The CU implements some of the gNB's functions, and the DU implements others. For example, the CU handles non-real-time protocols and services, implementing radio resource control (RRC) and packet data convergence protocol (PDCP) layer functions. The DU handles physical layer protocols and real-time services, implementing radio link control (RLC), media access control (MAC), and physical (PHY) layer functions. The AAU implements some physical layer processing functions, radio frequency processing, and active antenna-related functions. Since RRC layer information ultimately becomes PHY layer information, or is derived from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can be considered to be sent by the DU, or by the DU+AAU. It is understood that satellite network equipment can be devices that include one or more of the following: CU nodes, DU nodes, and AAU nodes. In addition, the CU can be classified as a satellite network device in the radio access network (RAN) or as a satellite network device in the core network (CN), and this application does not limit this.

[0252] Satellite network equipment provides services to cells. Terminal devices communicate with cells through transmission resources (e.g., frequency domain resources, or spectrum resources) allocated by the satellite network equipment. These cells can belong to macro base stations (e.g., macro eNB or macro gNB) or to base stations corresponding to small cells. Small cells can include: metro cells, micro cells, pico cells, femto cells, etc. These small cells have the characteristics of small coverage area and low transmission power, and are suitable for providing high-speed data transmission services.

[0253] The terrestrial network device 130 is also a device with unlimited transmission and reception capabilities. The specific form of this device is as described above and will not be repeated here.

[0254] In the embodiments of this application, the terminal device may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user apparatus. The terminal devices in the embodiments of this application may be mobile phones, tablets, computers with wireless transceiver capabilities, virtual reality (VR) terminal devices, augmented reality (AR) terminal devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical care, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, wearable devices, terminal devices in 5G networks, or terminal devices in future evolved public land mobile networks (PLMNs), etc.

[0255] Wearable devices, also known as wearable smart devices, are a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not merely hardware devices; they achieve powerful functions through software support, data interaction, and cloud interaction. Broadly defined, wearable smart devices include those with comprehensive functions, large sizes, and the ability to perform complete or partial functions without relying on a smartphone, such as smartwatches or smart glasses. They also include devices focused on a specific application function that require the use of other devices, such as smart bracelets and smart jewelry for vital sign monitoring.

[0256] Furthermore, terminal devices can also be terminal devices within an IoT system. For example, when the satellite mobile communication system is a cellular IoT (CIoT) system, the terminal device is a device that communicates with satellite network equipment using cellular IoT, and can also be called an IoT terminal, CIoT UE, etc.

[0257] This application does not limit the specific form of the terminal device.

[0258] For example, as shown in Figure 3, a satellite mobile communication system 300 includes a terminal device 110, a base station (E-UTRAN, or eNB) 310, a core-service gateway node (C-SGN) 320, a home subscriber server 330, etc.

[0259] It should be understood that in actual network deployment, in order to reduce the number of physical network elements, some core network elements can be deployed uniformly, referred to as C-SGN. Since core network elements include mobility management entity (MME), serving gateway (S-GW), packet data network gateway (P-GW), etc., C-SGN can include MME, S-GW, or P-GW. It should also be understood that terminal device 110 can be CIoT UE. Moreover, for the convenience of communication management, the embodiment of this application can split the core serving gateway node 320 into at least two parts: the first part is the C-SGN located on satellite (SAT) network equipment, or referred to as C-SGN-SAT equipment; the second part is the C-SGN located on ground (GND) network equipment, or referred to as C-SGN-GND equipment. For example, as shown in FIG3, the core serving gateway node 320 includes one C-SGN-SAT equipment and one C-SGN-GND equipment. It should be understood that since the C-SGN-SAT device and base station 310 can be deployed on the satellite network device 120 in the air, the satellite network device 120 includes the C-SGN-SAT device and base station 310. Furthermore, the C-SGN-GND device in Figure 3 is equivalent to the terrestrial network device 130 in Figure 2, and the C-SGN-GND device and home subscriber server 330 can be deployed on the ground.

[0260] It should be noted that the satellite mobile communication system 300 may also include other nodes, such as service capability exposure function (SCEF), etc., wherein the SCEF is deployed on the ground, and this application embodiment does not specifically limit it.

[0261] Figure 3 shows a schematic diagram of the system architecture of another satellite mobile communication system 300, which includes a satellite network device 120. However, there can be one or more satellite network devices 120. For example, as shown in Figure 4, another satellite mobile communication system 400 may include satellite network device 120 and another satellite network device 140. The core service gateway node 320 in Figure 4 includes two C-SGN-SAT devices and one C-SGN-GND device. Similarly, in other satellite mobile communication systems, the core service gateway node 320 may include two or more C-SGN-SAT devices and one or more C-SGN-GND devices. This application embodiment does not specifically limit this.

[0262] Similar to the description of another satellite mobile communication system 300, another satellite mobile communication system 400 may also include other nodes, such as Service Capability Open Element (SCEF), etc., wherein the SCEF is deployed on the ground, and this application embodiment does not specifically limit this.

[0263] Satellite IoT, as a global form of IoT, has wide applications in many fields. However, due to the limited storage resources of satellite network equipment used to provide satellite IoT, there is a possibility of overload operation.

[0264] Specifically, from a macro perspective, in application scenarios combining IoT services and store-and-forward models, the uplink and downlink data from terminal devices are stored on satellite network equipment for extended periods. Furthermore, based on ephemeris deployment calculations, the average access interval between terminal devices and satellite network equipment reaches several hours. In addition, satellite network equipment serves a large number of terminal devices, potentially reaching hundreds of millions. Therefore, given the long data storage time and the large number of terminal devices connected to satellite network equipment, the demand for on-board storage resources is substantial. However, due to the limited payload capacity of satellite network equipment, there is a constraint on on-board storage resources.

[0265] From a micro perspective, satellite network equipment with insufficient storage resources cannot provide normal services to terminal devices. For example, as shown in Figure 5, the signaling interaction process between a satellite network device with insufficient storage resources and a terminal device is illustrated below:

[0266] S510, The terminal device sends an attach request message to the satellite network device.

[0267] S520 satellite network equipment allocates storage resources.

[0268] S530, Terminal device retransmits attach request message.

[0269] It should be understood that after a terminal device sends an attach request message to a satellite network device, the satellite network device needs to allocate storage resources in response to the attach request message. However, allocating storage resources does not guarantee that storage resources will be allocated. Therefore, if the satellite network device cannot allocate the corresponding storage resources to the terminal device, it may remain in the allocation state, preventing the terminal device from attaching to the satellite network device. For the terminal device, if it does not receive an attach accept message for a period of time, it cannot determine the reason for not receiving the accept message. In this case, to improve the attach success rate, the terminal device can only consider retransmitting the attach request message to complete the attach.

[0270] In other words, in related technologies, even if the satellite network device has insufficient storage resources, it still intends to provide services to the terminal device. However, when the terminal device cannot attach to the satellite network device normally, it will retransmit the attach request message. This exacerbates the storage resource shortage situation for the satellite network device. Therefore, how to design the execution operation of the satellite network device in the scenario of insufficient storage resources is an urgent problem to be solved. In this regard, the embodiments of this application propose a communication method, the main inventive idea of ​​which is as follows:

[0271] When the first satellite network device has insufficient available storage resources, it sends a rejection message to the terminal device. If the first message includes a first identifier, the rejection message includes a rejection reason. Sending a rejection message can reasonably preserve available storage resources and stop providing services to the terminal device, thus avoiding exacerbating the situation of insufficient available storage resources of the first satellite network device. The rejection reason can let the terminal device know that the reason for the rejection by the first satellite network device is insufficient available storage resources, thus avoiding the terminal device from reconnecting and further preventing the situation of insufficient available storage resources of the first satellite network device from being aggravated.

[0272] The technical solutions shown in this application will be described in detail below through specific embodiments. It should be noted that the following embodiments may exist independently or in combination. For the same or similar content, such as explanations of terms or nouns, and explanations of steps, reference can be made to each other in different embodiments, and will not be repeated.

[0273] In a satellite mobile communication system comprising multiple satellite network devices and one terminal device, for ease of description, the satellite network device that first communicates with the terminal device is referred to as the first satellite network device. Subsequent satellite network devices that communicate with the terminal device after the first satellite network device leaves the area covering the terminal device are referred to as the second satellite network device. During the initialization phase, the terminal device powers on and executes the registration process. After registration, the terminal device searches for a terrestrial network PLMN. If no terrestrial network PLMN is found, it searches for the PLMNs of the satellite network devices. When the first satellite network device enters the area covering the terminal device, it indicates that the first satellite network device has entered the terminal device's communication range. The terminal device can detect the satellite cell provided by the first satellite network device. Since other satellite network devices also simultaneously enter the terminal device's communication range, the terminal device can obtain information such as the PLMN and translation lookaside buffer (TLB) of each satellite network device that has entered its communication range via SIB32. Terminal devices can also obtain information about whether a satellite network device is operating in store-and-forward mode from SIB31 or SIB32 sent by each satellite network device. SIB31 or SIB32 is a system information block (SIB). Both SIB31 and SIB32 have information forwarding capabilities, enabling terminal devices to obtain information about whether a satellite network device is operating in store-and-forward mode.

[0274] After a satellite network device enters the communication range of a terminal device, if there is only one satellite network device, the terminal device will trigger the initial attachment process. If there are multiple satellite network devices, the terminal device will first determine which satellite network device to attach to before triggering the initial attachment process.

[0275] The following describes a communication method for interaction between a terminal device and a first satellite network device. Specifically, Figure 6 is a schematic flowchart of a communication method 600 provided in this application embodiment, shown from the perspective of device interaction. This communication method 600 includes:

[0276] S610, the first satellite network device receives the first message.

[0277] It should be understood that the first satellite network device may refer to a satellite network device with insufficient available storage resources or a satellite network device with sufficient available storage resources. The specific form of the first satellite network device can be referred to the relevant description of the satellite network device mentioned above, and will not be repeated here.

[0278] It should also be understood that the available storage resources of the first satellite network device can change in real time. For example, at the first moment, the available storage resources of the first satellite network device are insufficient; at the second moment, the available storage resources of the first satellite network device are sufficient.

[0279] The first message is obtained by the first satellite network device. As for the source of the first message, this application embodiment does not limit it. For example, the source may include terminal device and / or terrestrial network device.

[0280] S620. If the available storage resources of the first satellite network device are insufficient, a rejection message is sent to the terminal device; if the first message includes a first identifier, the rejection message includes a rejection reason.

[0281] The phrase "insufficient available storage resources for the first satellite network device" can be understood as: the available storage resources of the first satellite network device are less than or equal to a first preset threshold, and / or, the ratio of the available storage resources of the first satellite network device to the total storage resources is less than or equal to a second preset threshold, or other ways reflecting insufficient available storage resources. Therefore, this application embodiment does not specifically limit the manifestation of insufficient available storage resources for the first satellite network device.

[0282] It should be understood that the specific form of the terminal device can be referred to the above-mentioned relevant descriptions, and will not be repeated here.

[0283] In this embodiment, if the first satellite network device still needs to serve the terminal device when its available storage resources are insufficient, it will only exacerbate the insufficient storage resources. Therefore, after receiving the first message, the first satellite network device, when its available storage resources are insufficient, rejects the terminal device's attachment by sending a rejection message. This preserves the available storage resources of the first satellite network device and avoids exacerbating the insufficient storage resources. Furthermore, when the first message includes a first identifier, including a rejection reason in the rejection message allows the terminal device to know that the reason for the rejection is insufficient storage resources, preventing the terminal device from reconnecting and thus also avoiding exacerbating the insufficient storage resources.

[0284] It should be understood that the first identifier is used to indicate that the terminal device is a latency-tolerant type of device.

[0285] In the phrase "the first message includes a first identifier," the first identifier, also known as the "S&F function support" flag, indicates that the terminal device is a latency-tolerant device. In other words, the terminal device has the capability to handle "S&F operations," which can be understood as accepting delayed processing of the requested service. Therefore, including the first identifier in the first message informs the first satellite network device that the requested service does not require immediate processing and that it can accept processing and transmission delays during the processing of the requested service. It should be understood that in this embodiment, latency includes not only processing latency and propagation latency but also other types of latency; therefore, this embodiment does not specifically limit the type of latency.

[0286] It should be noted that the first identifier in the message can be in any form that indicates "the terminal device is a latency-tolerant type of device", such as a number, a field, or other form, and this application does not limit it. For example, the first identifier is "S&F".

[0287] To improve the selectivity of the first message, the following explanation is provided regarding the first message:

[0288] The first message includes at least one of the following:

[0289] (1.1) Request message, which includes an attached request message.

[0290] (1.2) Response message for obtaining the contract data corresponding to the terminal device.

[0291] The following is an explanation of the attach request message.

[0292] The attach request message may be a NAS attach request message or other types of attach request messages; this embodiment does not specifically limit this. Furthermore, the attach request message may include a first field, which is used to request the terminal device to attach to the first satellite network device.

[0293] It should be understood that the first field in the attach request message can be in any form that represents "requesting the terminal device to attach to the first satellite network device", such as a number, a field, or other form, and this application does not limit this. For example, the first field is "attach Request".

[0294] It should be noted that, since the first message includes at least one of the request message or the response message for obtaining the subscription data corresponding to the terminal device, "the first message includes the first identifier" can be divided into the following cases:

[0295] Case 1: The request message sent by the terminal device to the first satellite network device includes a first identifier.

[0296] Scenario 2: The terminal device's response message for acquiring the contracted data includes the first identifier.

[0297] Scenario 3: The request message sent by the terminal device to the first satellite network device includes the first identifier, and the corresponding subscription data acquisition response message of the terminal device also includes the first identifier.

[0298] It should be understood that the representation of the first identifier in each message is not specifically limited. Specifically, for Case 1: the request message includes an attach request message, and the attach request message includes a first identifier. This first identifier can be a newly added field in the attach request message, which improves the scalability of the attach request message while maintaining its original functionality. The first identifier can also be a redefined field in the attach request message, which helps reduce signaling overhead. Furthermore, the first identifier can be obtained by the first satellite network device from the terminal device. Therefore, in Case 1, this embodiment can improve the convenience and timeliness of the first satellite network device obtaining the first identifier.

[0299] For scenario 2: The subscription data acquisition response message corresponding to the terminal device includes a first identifier. This first identifier can be a newly added field in the subscription data acquisition response message, thus improving the scalability of the subscription data acquisition response message while maintaining its original functionality. The first identifier can also be a redefined field in the subscription data acquisition response message, which reduces signaling overhead. Furthermore, the first identifier can be obtained by the first satellite network device from the ground network device. Therefore, in scenario 2, this embodiment can reduce the storage resources required for the first satellite network device to parse the attach request message sent by the terminal device.

[0300] Regarding scenario 3: the attach request message includes a first identifier and the corresponding subscription data acquisition response message of the terminal device also includes a first identifier. The specific representation of the first identifier in scenario 3 is similar to the description in scenario 1, and the specific representation of the corresponding subscription data acquisition response message of the terminal device including the first identifier in scenario 3 is similar to the description in scenario 2, so it will not be repeated here. Furthermore, in scenario 3, this embodiment can improve the accuracy of the first satellite network device in determining whether the terminal device is of a latency-tolerant type.

[0301] It should also be understood that the information included in the first message differs under different circumstances, thus corresponding to different procedures for receiving the first message. In circumstance 1, the first message includes a request message, and the request message includes an attach request message. Therefore, the first satellite network device receiving the first message may include: the first satellite network device receiving the attach request message sent by the terminal device.

[0302] In other words, the terminal device sends an attach request message to the first satellite network device.

[0303] It should be understood that sending an attach request message to the first satellite network device is an exemplary implementation of the terminal device triggering the initial attach process. This application does not specifically limit the implementation of the terminal device triggering the initial attach process.

[0304] Furthermore, this embodiment does not specifically limit the information contained in the request message. For example, in another embodiment, in addition to the attach request message, the message sent by the UE to the first satellite network device may also be a tracking area update request message. The tracking area update request message sent by the UE to the first satellite network device includes a first identifier. If the available storage resources of the first satellite network device are insufficient, a tracking area update rejection message is sent through the first identifier. The tracking area update rejection message may contain a rejection reason.

[0305] In another embodiment, the message sent by the UE to the first satellite network device may be one or more of the following: RRC connection recovery request message, PDP context establishment request message, attach request message, PRACH message, PUCCH message, etc. The above message includes a first identifier. If the first satellite network device has insufficient available storage resources, a rejection message is sent through the first identifier. The rejection message corresponds to one or more of the following: RRC connection recovery rejection message, PDP context establishment rejection message, attach rejection message, PRACH rejection message, PUCCH rejection message, etc.

[0306] In scenario 1, a specific embodiment of this solution can be shown in Figure 7. Specifically, the communication method 700 includes:

[0307] S710, the UE sends an attach request message to SAT#i, the attach request message carrying a first identifier.

[0308] S720. If there is insufficient available storage resources in SAT#i, a rejection message is sent to the UE. The rejection message includes the reason for rejection.

[0309] It should be understood that the specific form of SAT#i is similar to the specific form of the first satellite network device, and will not be repeated here. The specific form of the UE is similar to the specific form of the terminal device, and will not be repeated here. In this embodiment, in S710, the message sent by the UE to SAT#i is not limited to the attach request message, but can also be extended to one or more of the following messages: RRC connection recovery request message, PDP context establishment request message, attach request message, PRACH message, PUCCH message, etc.

[0310] It should be noted that the communication method 700 executed in this embodiment is similar to the communication method including the above steps S610 to S620, and will not be described again here.

[0311] All of the above situations demonstrate that "the first message includes the first identifier", which improves the diversity and selectivity of the first message.

[0312] Furthermore, in the case where the request message sent by the terminal device to the first satellite network device includes the first identifier, this embodiment does not specifically limit whether the corresponding subscription data acquisition response message of the terminal device includes the first identifier. Similarly, in the case where the corresponding subscription data acquisition response message of the terminal device includes the first identifier, this embodiment does not specifically limit whether the request message includes the first identifier.

[0313] Therefore, in an optional implementation, the embodiments of this application can enable the first satellite network device to know first whether the request message sent by the terminal device to the first satellite network device includes the first identifier. Specifically: if it is known that the request message sent by the terminal device to the first satellite network device includes the first identifier, then the first satellite network device no longer needs to determine whether the corresponding subscription data acquisition response message of the terminal device includes the first identifier; if it is known that the attach request message does not include the first identifier, then the first satellite network device determines whether the corresponding subscription data acquisition response message of the terminal device includes the first identifier.

[0314] In other words, in case 2, if the request message sent by the terminal device to the first satellite network device does not include the first identifier, in order for the first satellite network device to know whether the terminal device is a latency-tolerant type of device, S610 further includes the following process:

[0315] Step 630: The first satellite network device sends a terminal device subscription data retrieval request message to the ground network device. The retrieval request message is used to instruct the ground network device to retrieve the terminal device subscription data from the home user server.

[0316] It should be understood that after receiving the subscription data acquisition request message, the terrestrial network device sends a notification message to the Home Subscriber Server (HSS). The HSS performs a local lookup based on the notification message. After finding the subscription data corresponding to the terminal device, the HSS sends a notification response message to the terrestrial network device. The notification response message carries the subscription data, which includes a first identifier.

[0317] It should be noted that the notification message may be the same as or similar to the contract data acquisition request message. This application embodiment does not specifically limit the specific form of the message. Furthermore, the notification response message may be the same as or similar to the contract data acquisition response message. This application embodiment does not specifically limit this either.

[0318] Step 631: The ground network device sends a subscription data acquisition response message to the first satellite network device. The subscription data acquisition response message includes the subscription data, which includes the first identifier.

[0319] It should be understood that before the terminal device engages in business transactions with the first satellite network device, the terminal device can power on and execute a registration process, that is, the terminal device needs to register its subscription data with the Home Subscriber Server (HSS). This subscription data, also known as registration data, includes a first identifier indicating that the terminal device is a latency-tolerant type of device. The subscription data may also include other types of identifiers or fields; however, this application embodiment does not specifically limit the information included in the subscription data.

[0320] It should also be understood that, in case 2, step 630 can be understood as the authentication phase of the terminal device.

[0321] In scenario 2, a specific embodiment of this solution can be shown in Figure 8. Specifically, the communication method 800 includes:

[0322] S810, the UE sends an attach request message to SAT#i, the attach request message does not carry the first identifier.

[0323] It should be understood that in S810 above, the request message sent by the UE to SAT#i is not limited to the attach request message. For example, in another embodiment, the message sent by the UE to the first satellite network device, in addition to the attach request message, can also be a tracking area update request message.

[0324] In another embodiment, the message sent by the UE to the first satellite network device may also be one or more of the following: RRC connection restoration request message, PDP context establishment request message, attach request message, PRACH message, PUCCH message, etc.

[0325] S820 and SAT#i send a UE subscription data acquisition request message to the C-SGN-GND device.

[0326] The specific form of the C-SGN-GND device is similar to that of the terrestrial network device, and will not be described again here.

[0327] The S830 and C-SGN-GND devices send notification messages to the HSS.

[0328] S840 and HSS send a notification response message to the C-SGN-GND device, which includes a first identifier.

[0329] It should be understood that the notification response message contains contract data, which includes a first identifier.

[0330] It should also be understood that the application embodiments do not specifically limit the deployment location of the HSS. For example, the HSS can be deployed on SAT#i, or the constellation to which SAT#i belongs, or on the ground.

[0331] The S850 and C-SGN-GND devices send a subscription data retrieval response message to SAT#i. The subscription data retrieval response message includes the subscription data obtained from the HSS, and the subscription data includes a first identifier.

[0332] S860. If there is insufficient available storage resources in SAT#i, SAT#i sends a rejection message to the UE, which includes the reason for rejection.

[0333] For example, in another embodiment, if the notification response message includes a first identifier and the first satellite network device has insufficient available storage resources, a tracking area update rejection message is sent via the first identifier, and the tracking area update rejection message may include a rejection reason.

[0334] In another embodiment, if the notification response message includes a first identifier and the first satellite network device has insufficient available storage resources, a rejection message is sent through the first identifier. The rejection message corresponds to one or more of the following messages: RRC connection recovery rejection message, PDP context establishment rejection message, attach rejection message, PRACH rejection message, PUCCH rejection message, etc.

[0335] It should be noted that the communication method 800 executed in this embodiment is similar to the communication method including steps 630 to 631 described above, and will not be repeated here. In this scenario, the first satellite network device can determine whether the terminal device is of a latency-tolerant type.

[0336] Correspondingly, if the first satellite network device is configured strictly when available storage resources are insufficient, it will refuse the attachment of the terminal device if the request message does not carry the first identifier. Alternatively, if the first satellite network device is configured with high tolerance, it can obtain the first identifier from the subscription data acquisition response message if the request message does not carry the first identifier. If the first identifier corresponding to the terminal device is obtained, the first satellite network device will send a rejection message including the rejection reason to the terminal device. Therefore, this embodiment improves the selectivity of the first message and provides selectivity for the first satellite network device to send a rejection message.

[0337] The above are exemplary descriptions of different cases, including the first message, the first identifier, and "the first message includes the first identifier". Below, in the case where "the first message includes the first identifier", the following descriptions will explain the information contained in the rejection message, the conditions under which the first satellite network device sends the rejection message to the terminal device, and the operations performed by the terminal device based on the rejection message:

[0338] It should be understood that after the terminal device sends an attach request message to the first satellite network device, the first satellite network device will send a rejection message to the terminal device if its available storage resources are insufficient. Furthermore, the first satellite network device will also send rejection messages to the terminal device in other situations where attaching is not permitted. If the terminal device receives rejection messages containing the same information under different circumstances, it cannot determine the reason for the attachment rejection and will retransmit the attach request message. This repeated attach process will cause signaling overhead to the first satellite network device, causing it to constantly process the retransmitted attach request message from the terminal device, consuming local resources. However, the first satellite network device already has no storage resources to provide services to the terminal device, thus only exacerbating the insufficient available storage resources of the first satellite network device.

[0339] Therefore, to avoid exacerbating the shortage of available storage resources in the first satellite network device by retransmitting the attach request message when the terminal device has insufficient storage resources, in this embodiment, the rejection message may include:

[0340] The reason for rejection is used to indicate that the terminal device refuses to attach because the first satellite network device has insufficient available storage resources.

[0341] The reason for rejection can also be used to indicate that the attach process needs to be paused. Furthermore, the reason for rejection can be expressed in any form, such as a number, field, or other form, indicating that "the first satellite network device refuses to attach because the first satellite network device has insufficient available storage resources," and this application does not limit this. For example, the reason for rejection could be "reason: insufficient available storage resources."

[0342] It should be understood that the reason for rejection can be carried in the rejection message. In this embodiment, carrying the reason for rejection in the rejection message can reduce signaling overhead and effectively avoid wasting the available storage resources of the first satellite network device.

[0343] In this embodiment, sending a rejection reason to the terminal device allows the terminal device to clearly understand that the reason for the attachment rejection is insufficient available storage resources of the first satellite network device, thereby suspending the attachment process and reducing unnecessary signaling overhead.

[0344] Accordingly, when available storage resources are insufficient, the first satellite network device sends a rejection message to the terminal device. This rejection message is of the same type as the request message; for example, if the request message includes an attach request message, and the attach request message can be a NAS attach request message, then the rejection message can be a NAS attach rejection message. It should be noted that the rejection message may include a second field indicating "attachment of the terminal device is rejected," and the second field can be in any form indicating "attachment of the terminal device is rejected," such as a number, a field, or other forms; this application does not limit this.

[0345] If the first satellite network device is configured to be strict, it will send a rejection message including a rejection reason to the terminal device when the request message carries the first identifier. Alternatively, if the first satellite network device is configured to be highly tolerant, it can obtain the first identifier from the subscription data acquisition response message when the request message does not carry the first identifier. If the first identifier corresponding to the terminal device is obtained, the first satellite network device will send a rejection message including a rejection reason to the terminal device. Therefore, this embodiment of the application improves the selectivity of the first message and provides selectivity for the first satellite network device to send a rejection message.

[0346] In another embodiment, the rejection message may further include:

[0347] The first timer length is used to instruct the terminal device to retransmit the attach request message after the first timer starts and the first timer length has expired.

[0348] It should be noted that when the rejection message only includes the rejection reason, the terminal device can pre-store a first timer length. After the terminal device parses the rejection message and finds that it includes the aforementioned rejection reason, the first timer is started. The attach request message is not retransmitted before the first timer length expires. Therefore, for the terminal device, this embodiment can improve the parsing speed of the rejection message; for the first satellite network device, it can save transmission resources.

[0349] The first timer length can be understood as a backoff value, used to indicate when the terminal device can retry the attach process. During the duration before the first timer length expires, the terminal device should not initiate a new attach attempt with any satellite network device operating in store-and-forward mode within the same PLMN.

[0350] It should be understood that the length of the first timer can be expressed in any form, such as a number, a field, or other form, representing "the terminal device starts the first timer (or timer #1) until the first timer length ends and then retransmits the attach request message". This application does not limit this. For example, the length of the first timer is 15 minutes.

[0351] It should also be understood that this embodiment does not specifically limit the value of the first timer length. In one optional embodiment, the value of the first timer length is greater than or equal to the duration for which the first satellite network device covers the area where the terminal device is located once. For example, if the duration for which the first satellite network device covers the area where the terminal device is located once is 15 minutes, the first timer length is 15 minutes or 20 minutes, etc. In another optional embodiment, the value of the first timer length is greater than or equal to the duration required for the first satellite network device to leave the area where the terminal device is located. For example, if the duration required for the first satellite network device to leave the area where the terminal device is located is 1 minute, the first timer length is 2 minutes, etc.

[0352] It should also be understood that the length of the first timer can be carried in the rejection message. In this embodiment, carrying the length of the first timer in the rejection message can reduce signaling overhead and effectively avoid wasting the available storage resources of the first satellite network device.

[0353] In this embodiment, the rejection message includes a first timer length, which allows the terminal device to clearly know the time for retransmitting the attach request message. The terminal device will only retransmit the attach request message after the first timer length has expired, ensuring that the first satellite network device has left the area covering the terminal device before the terminal device retransmits the attach request message. Therefore, it can be ensured that the retransmitted attach request message of the terminal device is sent to other satellite network devices besides the first satellite network device, which can avoid aggravating the situation of insufficient available storage resources of the first satellite network device.

[0354] It should be noted that the rejection message may also include a rejection reason and a first timer length. Furthermore, this application embodiment does not specifically limit the method of carrying the rejection reason and the first timer length. For example, some or all of the rejection reason and the first timer length can be carried in newly added fields in the rejection message, which can improve the scalability of the rejection message while maintaining its original functionality. Alternatively, some or all of the rejection reason and the first timer length can be redefined original fields in the rejection message, which helps reduce signaling overhead.

[0355] In this embodiment, the rejection message includes both the rejection reason and the length of the first timer, enabling the terminal device to know that the reason for the first satellite network device's refusal to attach is that the first satellite network device has insufficient available storage resources. Furthermore, the terminal device starts the first timer and retransmits the attach request message after the first timer length expires. This allows for a better understanding of the available storage resources and flight status of the first satellite network device.

[0356] Furthermore, in this embodiment, the rejection message may include a rejection reason and a first timer length, or a rejection reason and a first timer length, which improves the flexibility of the rejection message configuration.

[0357] In the above embodiments, when faced with a request message sent by a latency-tolerant terminal device to the first satellite network device, the consideration is how to avoid exacerbating the insufficient available storage resources of the first satellite network device. However, while avoiding exacerbating the insufficient available storage resources of the first satellite network device, it is also necessary to consider whether services that have already transmitted data between the terminal device and the first satellite network device will be affected. Therefore, embodiments of this application can configure corresponding sending conditions for rejection messages. In one embodiment, in S620, the first satellite network device sends a rejection message to the terminal device, including:

[0358] Step 621: If there is no downlink information to be sent to the terminal device, send a rejection message to the terminal device.

[0359] It should be understood that downlink information includes pending response information. This pending response information is the response information that the first satellite network device should send back to the terminal device after establishing a connection with the ground network device and sending the relevant data of the terminal device to the ground network device. The relevant data is the data generated by the first satellite network device after its last connection with the terminal device was established.

[0360] It should be noted that the downlink information can be numbers, fields, or other forms, and this application does not limit this.

[0361] Specifically, if the first satellite network device determines that it does not have downlink information that needs to be sent to the terminal device locally, and the downlink information only includes downlink information to be sent to other terminals, the first satellite network device will refuse the initial attach process because it lacks available storage resources.

[0362] When the first satellite network device determines whether it has stored downlink information that needs to be sent to the terminal device, the process specifically includes: the first satellite network device performing an authentication process for the terminal device and identifying a second identifier of the terminal device. If the first satellite network device finds, based on the second identifier, that it does not store downlink information belonging to the terminal device, it indicates that it does not store downlink information that needs to be sent to the terminal device.

[0363] The second identifier mentioned above can be a globally unique temporary UE identity (GUTI), an international mobile subscriber identity (IMSI), a provisional-international mobile subscriber identity (P-IMSI), etc. This application does not limit the specific form of the second identifier that uniquely identifies the terminal device, such as a number, a field, or other forms.

[0364] Conversely, if the first satellite network device determines that its local storage contains downlink information that needs to be sent to the terminal device, it will send an attach accept message to the terminal device, thereby completing the attachment of the terminal device to the first satellite network device. This allows the first satellite network device to send (i.e., release) the corresponding downlink information to the terminal device. This can alleviate the situation of insufficient available storage resources on the first satellite network device and is very likely to ensure that the available storage resources of the first satellite network device are sufficient. At the same time, it can also ensure that the services that the terminal device has already transmitted data with the first satellite network device will not be affected. Here, "sufficient available storage resources" can be understood as: available storage resources are greater than a first preset threshold, and / or, the ratio of available storage resources to total storage resources is greater than a second preset threshold, or other ways that reflect sufficient available storage resources.

[0365] Therefore, in real-world scenarios, when faced with a first satellite network device that supports terminal device access, if the available storage resources of the first satellite network device are insufficient, then when a terminal device of the latency-tolerant type accesses the device, the first satellite network device can decide whether to allow the terminal device to access based on whether its own available storage resources are insufficient and whether downlink information is released to the terminal device. In the case of refusing access, it can provide the terminal device with a clear reason for refusal, thereby avoiding the terminal device repeatedly reconnecting to the first satellite network device with insufficient available storage resources and causing communication burden on the first satellite network device.

[0366] It should be understood that the terminal device will retransmit the attach request message after learning that it cannot attach to a first satellite network device with insufficient available storage resources. Furthermore, the available storage resources of the retransmitted satellite network device are uncertain. For example, the retransmitted satellite network device may be another first satellite network device with insufficient available storage resources, or it may be a second satellite network device with either insufficient or sufficient available storage resources. Therefore, this embodiment can execute different procedures depending on the availability of storage resources on the retransmitted satellite network device.

[0367] For example, when the first satellite network device leaves the area covering the terminal device and another first satellite network device enters the area covering the terminal device, the first timer length ends (or the first timer length expires, the first timer length is outdated, etc.). Since the other first satellite network device does not have enough available storage resources, after the first satellite network device sends a rejection message to the terminal device, this embodiment can repeat S610 to S620.

[0368] In another example, when the first satellite network device leaves the area covering the terminal device and the second satellite network device enters the area covering the terminal device, the first timer ends. Since the second satellite network device has sufficient available storage resources, the terminal device can attach to the second satellite network device.

[0369] The above describes the communication scheme when the available storage resources of the first satellite network device are insufficient. It should be understood that the available storage resources of the first satellite network device vary at different times, so the first satellite network device can also be a satellite network device with sufficient available storage resources.

[0370] Specifically, after the first satellite network device sends a rejection message to the terminal device, the method further includes:

[0371] Step 640: The terminal device starts the first timer.

[0372] Step 641: After the first timer expires, the terminal device sends an attach request message to other satellite network devices besides the first satellite network device, or switches to the first satellite network device with sufficient available storage resources before the first timer expires. Other satellite network devices besides the first satellite network device include the second satellite network device.

[0373] It should be understood that "other satellite network devices besides the first satellite network device" can be any satellite network device covering the area of ​​the terminal device from the start of the first timer to the end of the first timer length. This satellite network device can be another first satellite network device, a second satellite network device, etc., and this embodiment does not specifically limit this. In one example, "other satellite network devices besides the first satellite network device" can be the next satellite network device after the first satellite network device.

[0374] If, after the first timer expires, the first satellite network device has sufficient available storage resources and has not left the area covering the terminal device, then the first satellite network device performs the attach completion process. Specifically, the method further includes:

[0375] Step 642: If the first satellite network device has sufficient available storage resources, the terminal device sends an attach request message to the first satellite network device.

[0376] It should be understood that the explanation of the attach request message has been described above, and for the sake of brevity, it will not be repeated here.

[0377] Step 643: The first satellite network device sends an attach accept message to the terminal device.

[0378] It should be understood that the attach accept message may include a third field, which indicates that "the first satellite network device accepts the attachment of the terminal device." The third field can be in any form indicating that "the first satellite network device accepts the attachment of the terminal device," such as a number, a field, or other forms; this application does not limit this. For example, the third field could be "accept." Furthermore, the attach accept message is a message sent by the first satellite network device to the terminal device when sufficient storage resources are available; embodiments of this application do not specifically limit the information carried by this message.

[0379] It should also be understood that the attach accept message and the attach request message are of the same type. For example, when the attach request message is a NAS attach request message, the attach accept message is a NAS attach accept message.

[0380] Step 644: The terminal device sends an attach complete message to the first satellite network device.

[0381] It should be understood that the attachment completion message may include a fourth field indicating "the terminal device has completed attachment," and the fourth field may be in any form indicating "the terminal device has completed attachment," such as a number, a field, or other form, which is not limited in this application. For example, the fourth field may be "complete."

[0382] It should also be understood that the attach complete message and the attach request message are of the same type. For example, when the attach request message is a NAS attach request message, the attach complete message is a NAS attach complete message.

[0383] Step 645: The terminal device sends a context establishment request message to the first satellite network device.

[0384] It should be understood that the context establishment request message instructs the first satellite network device to create context information for the terminal device and send a second message to the ground network device, the second message including the context information; in response to the second message, the ground network device obtains priority rule configuration information from the home subscriber server.

[0385] It should be noted that the context establishment request message may include a fifth field, which is used to indicate "requesting the first satellite network device to establish context information". The fifth field may be in any form indicating "requesting the first satellite network device to establish context information", such as a number, a field or other form, and this application does not limit it.

[0386] Step 646: The first satellite network device creates context information for the terminal device.

[0387] After the first satellite network device sends an attach accept message to the terminal device, the creation of context information specifically involves the first satellite network device creating context information corresponding to the terminal device based on the terminal device's subscription data.

[0388] In this embodiment, the purpose of creating context information is to enable other satellite network devices (e.g., a second satellite network device) to know the service process that the first satellite network device has been serving when the terminal device is to be hosted by the first satellite network device, based on the context information corresponding to the terminal device created by the first satellite network device, thereby improving the service efficiency of the entire satellite mobile communication system.

[0389] The context information includes contract data, etc. This application embodiment does not specifically limit the information included in the context information.

[0390] Step 647: After creating the context information of the terminal device, the first satellite network device sends a second message to the ground network device. The second message includes the context information.

[0391] It should be understood that, in response to the second message, the terrestrial network device obtains priority rule configuration information from the Home Subscriber Server (HSS).

[0392] Optionally, in step 647, in response to the second message, the terrestrial network device can also trigger the Home Subscriber Server (HSS) to update the subscription data of the terminal device. The terrestrial network device can trigger the HSS update of the terminal device's subscription data through the subscriber to authentication server interface (S6A) used for authentication and authorization in the Internet of Things, thereby improving the convenience of satellite mobile communication system management. After the HSS update is successful, all satellite network devices can obtain all subscription data related to the terminal device through the terrestrial network device, ensuring the real-time update and accuracy of the subscription data.

[0393] It should be understood that the priority rule configuration information is used to indicate how to configure the priority of this service for terminal devices of the latency-tolerant type, and the priority may be affected by factors such as the first identifier, service type, transmission information length, and transmission information tolerance time length.

[0394] Step 648: The first satellite network device obtains the priority rule configuration information of the terminal device.

[0395] It should be understood that the explanation of priority rule configuration information can be found in the relevant description, and will not be repeated here for the sake of brevity.

[0396] The source of priority rule configuration information can be terrestrial network equipment or second satellite network equipment, so this application embodiment does not specifically limit the source of priority rule configuration information.

[0397] Therefore, in an optional implementation, step 648, whereby the first satellite network device obtains the priority rule configuration information of the terminal device, includes: the first satellite network device receiving priority rule configuration information sent by the terrestrial network device. The priority rule configuration information is obtained by the terrestrial network device from its home subscriber server. This acquisition method, based on the information forwarding capability of the terrestrial network device, improves the convenience for the first satellite network device to obtain the priority rule configuration information.

[0398] It should also be understood that this embodiment does not specifically limit the way the above information is carried. For example, priority rule configuration information can be carried in a link layer negotiation message.

[0399] Step 649: Make a decision based on the priority rule configuration information to obtain the priority information of data transmission corresponding to the service type requested by the terminal device.

[0400] It should be noted that, in one optional implementation, if the first satellite network device obtains the priority rule configuration information of the terminal device, and the second timer expires during the coverage of the terminal device's area by the first satellite network device, then the terminal device can execute the data transmission process. Therefore, the data transmission process is analyzed below:

[0401] Step 650: The terminal device sends a data transmission request message to the first satellite network device.

[0402] It should be understood that the data transmission request message may include a sixth field, which indicates that the terminal device requests data transmission. Furthermore, the format of this sixth field can be any form representing "the terminal device requests data transmission," such as a number, a field, or other forms; this application does not limit this. For example, the sixth field could be "request data transmission."

[0403] Step 651: Send a data transmission response message to the terminal device according to the priority information.

[0404] In this embodiment, when the first satellite network device has sufficient available storage resources, the terminal device can complete attachment and data transmission. The purpose of the first satellite network device creating context information is to enable other satellite network devices to know the service process that the first satellite network device has been serving based on the context information corresponding to the terminal device created by the first satellite network device when it wants to host the terminal device to other satellite network devices, thereby improving the service efficiency of the entire satellite mobile communication system.

[0405] In step 643 above, the attached accept message includes:

[0406] The second timer length is used to instruct the terminal device to send a data transmission request message from the start of the second timer until the end of the second timer length.

[0407] It should be understood that the length of the second timer can be expressed in any form, such as a number, a field, or other form, indicating that "the terminal device sends a data transmission request message from the start of the second timer until the end of the second timer length". This application does not limit this.

[0408] It should also be understood that the attached receive message is a type of message, and the second timer length can be expressed in any form, such as a number, field, or other form, indicating that "the terminal device starts the second timer (or timer #2) and sends a data transmission request message after the second timer length ends." This application does not limit this. For example, the second timer length is 1 minute.

[0409] It should be noted that this embodiment does not specifically limit the value of the second timer length. In an optional implementation, since the function of the second timer length is to prevent the terminal device from initiating data transmission before the second timer length expires, and before the second timer length expires, the ground network device needs to complete the location update of the terminal device on the HSS, or forward the newly established context information of the first satellite network device to other satellite network devices in the satellite mobile communication system. Therefore, in an exemplary embodiment, the value of the second timer length is greater than or equal to the sum of the first duration and the second duration; wherein, the first duration is the duration required for the HSS to perform the location update, and the second duration is the duration required for the ground network device to forward the priority rule configuration information.

[0410] In this embodiment, if the terminal device attempts to initiate data transmission on the first satellite network device at any time, the first satellite network device may not have obtained the priority rule configuration information when it receives the data transmission request message. Therefore, without obtaining the priority rule configuration information, the first satellite network device cannot determine how to process the data transmission request message, which can easily cause data transmission interruption. If the terminal device retransmits the data transmission request message, it will also waste the available storage resources of the first satellite network device. Therefore, this embodiment uses the second timer length to indicate the time when the terminal device sends the data transmission request message, which can prevent the terminal device from attempting to initiate data transmission on the first satellite network device before the second timer length expires, thereby ensuring the normal operation of the data transmission process.

[0411] The priority rule configuration information in steps 648 to 649 above is explained below, that is, the priority rule configuration information includes any one of the following:

[0412] First item: Prioritize messages based on whether they include the first identifier.

[0413] The second item: Prioritize the data based on the requested service type, the length of the transmitted information, and / or the tolerable duration of the transmitted information.

[0414] For the first item: Prioritize messages based on whether they include a first identifier, including:

[0415] The first priority is greater than the second priority; the first priority is the priority information corresponding to the first condition, and the second priority is the priority information corresponding to the second condition.

[0416] The first condition includes: the first message does not include the first identifier; the second condition includes: the first message includes the first identifier.

[0417] Regarding the second item: Prioritize based on the requested service type, the length of the transmitted information, and / or the tolerable transmission time, including:

[0418] The second priority is greater than the third priority; the second priority is the priority information corresponding to the second condition; the third priority is the priority information corresponding to the third condition.

[0419] The second condition includes: the first message includes a first identifier and satisfies at least one of the following: the requested service type is a first preset service type; the length of the transmitted information is less than or equal to a first preset length threshold; the tolerable length of the transmitted information is less than or equal to a second preset length threshold; the third condition includes: the first message includes a first identifier and satisfies at least one of the following: the requested service type is a second preset service type; the length of the transmitted information is greater than a first preset length threshold; the tolerable length of the transmitted information is greater than a second preset length threshold.

[0420] Furthermore, the first priority, the second priority, and the third priority are used to indicate the order in which the first satellite network device performs data transmission on each terminal device based on the priority order.

[0421] It should be understood that the ordering rules for the first, second, and third priorities are sent from the terrestrial network equipment to the first satellite network equipment, and these ordering rules are not affected by whether the first satellite network equipment has sufficient available storage resources.

[0422] It should also be understood that the requested service type includes text transmission, image transmission, or audio transmission, etc.

[0423] Furthermore, the requested service type can be another newly added field in the attach request message, which improves the scalability of the attach request message while maintaining its original functionality. The requested service type can also be a redefined field in the attach request message, which helps reduce signaling overhead.

[0424] It should be noted that the requested service type can be represented in any form that represents the "service type," such as a number, field, or other form, and this application does not limit this. For example, the service type can be "01," "02," "03," etc., where "01" represents text transmission, "02" represents image transmission, and "03" represents audio transmission.

[0425] Similarly, the transmission information length, the tolerable transmission time, etc., can be expressed in any form that represents the "transmission information length" or "tolerable transmission time", such as numbers, fields, or other forms. This application does not limit this.

[0426] In this embodiment, the type of service requested by the terminal device enables the first satellite network device to provide accurate services.

[0427] Furthermore, this application embodiment does not specifically limit the source of parameters such as the type of service requested by the terminal device, the length of the transmitted information, and the tolerable duration of the transmitted information. These parameters can be carried in the attach request message or other messages sent by the terminal device to the first satellite network device, and this application embodiment does not make specific limitations. Therefore, based on the principle that "the first priority is greater than the second priority, and the second priority is greater than the third priority," the first satellite network device can reasonably allocate available storage resources and prioritize providing services to high-priority terminal devices.

[0428] To ensure sufficient available storage resources for the first satellite network device, this embodiment can achieve this by releasing data to a ground network device. In an optional implementation, in step 641, after the first timer expires, the terminal device can send an attach request message to other satellite network devices besides the first satellite network device, or switch to the first satellite network device with sufficient available storage resources before the first timer expires. Before the first satellite network device receives the attach request message sent by the terminal device, the method further includes:

[0429] Step 1: The first satellite network device establishes a communication connection with the ground network device.

[0430] Step 2: The first satellite network device transmits data to the ground network device to release storage resources on the first satellite network device.

[0431] It should be understood that if the first satellite network device successfully connects to the ground network device via a feeder before leaving the area covering the terminal device, then data can be released to the ground network device, ensuring sufficient available storage resources for the first satellite network device.

[0432] To ensure that only authenticated and secure terminal devices can access the storage resources of the satellite network device, the method further includes the following steps before the first satellite network device sends an attach accept message to the terminal device:

[0433] Step 3: The first satellite network device authenticates and sets up security for the terminal device.

[0434] It should be understood that authentication and security settings include at least one of the following: authorization permission for authentication of terminal devices, authorization permission for security establishment of terminal devices, setting of authorization time range for authentication of terminal devices, setting of authorization time range for security establishment of terminal devices, etc.

[0435] Accordingly, the first satellite network device authenticates and sets up security settings for the terminal device. Only when the terminal device passes the authentication and security settings will the first satellite network device send an attach accept message to the terminal device, which can improve the security of the satellite mobile communication system.

[0436] Optionally, in Case 1, since the attach request message sent by the terminal device to the first satellite network device may or may not include the first identifier, and there may be inconsistencies between whether the attach request message includes the first identifier and whether the subscription data includes the first identifier, the method further includes, in response to the second message, the terrestrial network device notifying the home subscriber server to add the first identifier to the subscription data.

[0437] It should be understood that the first identifier may not be included in the subscription data generated during the registration of the terminal device. However, the terminal device may carry the first identifier later as needed. However, the subscription data of the terminal device in the HSS has not yet been updated. Therefore, the first satellite network device can instruct the ground network device to notify the HSS to add the first identifier to the subscription data. After receiving the notification, the HSS updates the subscription data process according to the context information. The addition of the first identifier by the HSS in the updated subscription data process can ensure the consistency and accuracy of the subscription data.

[0438] The above describes the communication scheme between the terminal device and the first satellite network device. However, in practical applications, a satellite takeover situation may occur. That is, the first satellite network device sends a second message to the ground network device before leaving the area covering the terminal device, and the second satellite network device enters the area covering the terminal device, but the second satellite network device has insufficient available storage resources.

[0439] In other words, the terminal device can attach using a first satellite network device with sufficient available storage resources. However, after attaching, there is a possibility that the first satellite network device may leave the area covering the terminal device. Therefore, the following explains the next satellite network device to enter the area covering the terminal device and the corresponding operation:

[0440] In the event of satellite takeover, the methods also include:

[0441] Step 660: The second satellite network device obtains the context information and priority rule configuration information of the terminal device.

[0442] The explanations of the context information and the priority rule configuration information have been described above. For the sake of brevity, they will not be repeated here.

[0443] The context information of the terminal device can be obtained from terrestrial network devices, first satellite network devices, or other devices with information forwarding capabilities. Similarly, the priority rule configuration information can be obtained from terrestrial network devices or first satellite network devices, etc. Therefore, this application embodiment does not specifically limit the source of the terminal device's context information or the source of the priority rule configuration information.

[0444] Therefore, in an optional implementation, step 660, whereby the second satellite network device obtains the context information and priority rule configuration information of the terminal device, includes: the second satellite network device receiving the context information and priority rule configuration information sent by the ground network device. The context information is sent to the ground network device by the first satellite network device, which has sufficient storage resources, after communicating with the terminal device and completing the terminal device's attachment. The priority rule configuration information is obtained by the ground network device from the home subscriber server. This acquisition method, based on the information forwarding capability of the ground network device, improves the convenience for the second satellite network device to obtain the context information and priority rule configuration information.

[0445] It should also be understood that this embodiment does not specifically limit the way the above information is carried. For example, at least one of the context information or priority rule configuration information can be carried in the link layer negotiation message.

[0446] Step 661: The terminal device sends a data transmission request message to the second satellite network device.

[0447] It should be understood that the data transmission request message may include a sixth field, which indicates that the terminal device requests data transmission. Furthermore, the format of this sixth field can be any form representing "the terminal device requests data transmission," such as a number, a field, or other form; this application does not limit this. For example, the sixth field could be "request data transmission."

[0448] The terminal device starts a second timer. Based on the terminal device starting the second timer, step 661 above includes: after the second timer expires, the terminal device sends a data transmission request message to the second satellite network device.

[0449] Therefore, the terminal device does not send a data transmission request message to the second satellite network device before the second timer expires. This effectively avoids the data transmission process from being executed before the ground network device completes the terminal device's update on the HSS (i.e., the location update process) and forwards the newly established context information of the first satellite network device to other satellite network devices in the satellite mobile communication system.

[0450] Step 662: The second satellite network device re-establishes the connection based on the context information.

[0451] It should be understood that the context information includes subscription data and may also include connection context information. The interpretation of subscription data has been described above and will not be repeated here. The connection context information is used to indicate that the satellite network device to which the terminal device was previously attached was the first satellite network device. The connection context information can be any form representing "the satellite network device to which the terminal device was previously attached was the first satellite network device," such as numbers, fields, or other forms, and this application does not limit this. For example, "UE1, SAT#k" indicates that the satellite network device to which UE1 was connected before the connection was lost was SAT#k.

[0452] It should also be understood that, based on the context information of the connection corresponding to the terminal device, the second satellite network device can determine that the satellite network device to which the terminal device was previously attached is the first satellite network device, and then take over the service of the first satellite network device to re-establish the connection.

[0453] In this embodiment, the attachment of the terminal device to the first satellite network device is a prerequisite for the second satellite network device to take over the corresponding services. If the terminal device re-executes the attachment process, it increases the signaling consumption of the terminal device and degrades the user experience. Therefore, in order to reduce the repeated attachment operations of the terminal device, this embodiment can re-establish the connection based on context information to realize the connection between the terminal device and the second satellite network device.

[0454] Step 663: The second satellite network device makes a decision based on the priority rule configuration information to obtain the priority information of data transmission corresponding to the service type requested by the terminal device.

[0455] Step 664: If the priority information corresponds to a priority greater than or equal to the second priority, then send a data transmission response message to the terminal device.

[0456] It should be understood that the second satellite network device may consider different priority information and respond accordingly to data transmission request messages sent by different terminal devices. In other words, the priority information may correspond to a priority that is greater than, equal to, or less than the second priority, and the second satellite network device will execute different steps depending on the priority information. For example, when the priority information corresponds to a priority that is greater than or equal to the second priority, the second satellite network device will execute step 664 as described above. As another example, when the priority information corresponds to a priority that is less than the second priority, the second satellite network device will send an attach release message to the terminal device.

[0457] The attachment release message includes: release reason indication information, which indicates that the reason for the terminal device to release attachment to the second satellite network device is that the second satellite network device has insufficient available storage resources.

[0458] It should be understood that the termination indication information can be presented in any form indicating that "the reason for the termination of attachment of the second satellite network device is insufficient available storage resources of the second satellite network device," such as numbers, fields, or other forms, and this application does not limit this. For example, the termination indication information may be "reason for termination indication information."

[0459] Accordingly, after the second satellite network device enters the area covering the terminal device, it needs to take over the unfinished services of the first satellite network device that left the area covering the terminal device. However, the second satellite network device has insufficient available storage resources. Therefore, in this case, the second satellite network device cannot take over all the unfinished services of the first satellite network device, and some of the services taken over may contain services awaiting data transmission. Specifically, for each terminal device attached to the first satellite network device that has not yet had time to transmit data, the second satellite network device needs to perform data transmission. However, due to insufficient available storage resources, it cannot support data transmission operations for all terminal devices. Therefore, this embodiment of the application considers the priority information of data transmission corresponding to the service type requested by the terminal device. Based on the priority that allows the second satellite network device to transmit data with the terminal device, the second satellite network device performs data transmission. Thus, in the case of insufficient available storage resources, it provides services to terminal devices with high data transmission priority corresponding to the requested service type as much as possible, which can reduce the data transmission latency of terminal devices with high data transmission priority corresponding to the requested service type.

[0460] Generally, the first satellite network device can provide services for the data transmission of the terminal device. However, when the first satellite network device is about to leave the area covering the terminal device, it will be taken over by the satellite network device that is about to enter the area covering the terminal device. For example, the satellite network device that is about to enter the area covering the terminal device can be a second satellite network device, another first satellite network device, another second satellite network device, etc. This embodiment does not make specific limitations on this.

[0461] In the event of insufficient available storage resources in the second satellite network, priority rule configuration information includes any of the following:

[0462] First item: Prioritize messages based on whether they include the first identifier.

[0463] The second item: Prioritize the data based on the requested service type, the length of the transmitted information, and / or the tolerable duration of the transmitted information.

[0464] For the first item: Prioritize messages based on whether they include a first identifier, including:

[0465] The first priority is greater than the second priority; the first priority is the priority information corresponding to the first condition, and the second priority is the priority information corresponding to the second condition.

[0466] The first condition includes: the first message does not include the first identifier; the second condition includes: the first message includes the first identifier.

[0467] Regarding the second item: Prioritize based on the requested service type, the length of the transmitted information, and / or the tolerable transmission time, including:

[0468] The second priority is greater than the third priority; the second priority is the priority information corresponding to the second condition; the third priority is the priority information corresponding to the third condition.

[0469] The second condition includes: the first message includes a first identifier and satisfies at least one of the following: the requested service type is a first preset service type; the length of the transmitted information is less than or equal to a first preset length threshold; the tolerable transmission time is less than or equal to a second preset length threshold. The third condition includes: the first message includes a first identifier and satisfies at least one of the following: the requested service type is a second preset service type; the length of the transmitted information is greater than a first preset length threshold; the tolerable transmission time is greater than a second preset length threshold.

[0470] The first and second priorities are the priorities that allow the second satellite network device to transmit data with the terminal device, while the third priority is the priority that does not allow the second satellite network device to transmit data with the terminal device.

[0471] It should be noted that the embodiments of this application do not specifically limit the values ​​of the first preset length threshold and the second preset length threshold. For example, the first preset length threshold is 140 bytes, and the second preset length threshold is 3 hours.

[0472] In one exemplary implementation, when the priority rule configuration information is "priority sorting based on the length of the transmitted information", if the length of the information transmitted by the terminal device is 30 bytes, the second satellite network device can configure the priority information of the terminal device as the second priority according to the priority rule configuration information; if the length of the information transmitted by the terminal device is 1400 bytes, the second satellite network device can configure the priority information of the terminal device as the third priority according to the priority rule configuration information.

[0473] In another exemplary implementation, when the priority rule configuration information is "prioritize according to the tolerable transmission time of the information", if the tolerable transmission time of the terminal device is 1 hour, the second satellite network device can configure the priority information of the terminal device as the second priority according to the priority rule configuration information; if the tolerable transmission time of the terminal device is 10 hours, the second satellite network device can configure the priority information of the terminal device as the third priority according to the priority rule configuration information.

[0474] In another exemplary embodiment, the value of the second timer length is greater than or equal to the sum of the first duration and the second duration; wherein, the first duration is the duration required for the ground network device to receive context information and perform location updates, and the second duration is the duration required for the ground network device to forward context information to other satellite network devices other than the second satellite network device.

[0475] In this embodiment, the attached receive message includes a second timer length, which can prevent the terminal device from performing the data transmission process before the ground network device completes the update of the terminal device on the HSS (i.e., the location update process) and forwards the newly established context information of the first satellite network device to other satellite network devices in the satellite mobile communication system.

[0476] Therefore, the second satellite network device does not need to communicate with the terminal device. It can achieve attachment by sending the context information of the terminal device created by the first satellite network device through the ground network device. It can also obtain priority rule configuration information, thus providing a basis for the second satellite network device with insufficient available storage resources to execute the data transmission process.

[0477] Accordingly, the second satellite network device can respond according to the priority of the decision. Specifically, when the priority of the data transmission corresponding to the service type requested by the terminal device is greater than or equal to the second priority, the second satellite network device sends a data transmission response message to the terminal device. When the priority of the priority information is less than the second priority, the second satellite network device sends an attach release message to the terminal device, which can disconnect the terminal device from the second satellite network device. This prevents the second satellite network device from providing data transmission services to the terminal device. This satisfies the latency requirements of the low-priority service type requested by the terminal device while avoiding the risk of exhausting the resources of the second satellite network device.

[0478] It should be understood that after the second satellite network device leaves the area covering the terminal device, other satellite network devices enter the area covering the terminal device. These other satellite network devices can be those with sufficient available storage resources or those with insufficient available storage resources. As an optional implementation, if the satellite network device entering the area covering the terminal device is one with insufficient available storage resources, then in this embodiment, the terminal device can detect this other satellite network device.

[0479] In scenario 1, another specific embodiment of this solution can be as shown in Figure 9(a). Specifically, the communication method 900 includes:

[0480] S901, the UE sends an attach request message to SAT#i, the attach request message carrying a first identifier.

[0481] S902. If there is insufficient available storage resources in SAT#i, a rejection message is sent to the UE. The rejection message includes the reason for rejection and the length of the first timer.

[0482] In one alternative implementation, before the first timer length ends, SAT#i drives out of the area covering the UE, SAT#j drives into the area covering the UE, and SAT#j drives out of the area covering the UE, while SAT#k drives into the area covering the UE.

[0483] S903, the first timer length ends.

[0484] It should be understood that after the first timer length ends, the UE executes the following S904.

[0485] S904, the UE sends an attach request message to SAT#k, the attach request message including a first identifier.

[0486] It should be understood that the specific form of SAT#k is similar to that of the first satellite network equipment, and will not be described in detail here.

[0487] S905. If there is sufficient available storage resources in SAT#k, send an attach accept message to the UE, which carries the second timer length.

[0488] S906, the UE sends an attach complete message to SAT#k.

[0489] S907, the UE sends a context establishment request message to SAT#k.

[0490] S908 and SAT#k create the UE's context information.

[0491] S909 and SAT#k send a second message to the C-SGN-GND device, which includes the UE's context information.

[0492] The S910 and C-SGN-GND devices send a third message to the HSS.

[0493] S911 and HSS perform local lookups based on third messages to find priority rule configuration information.

[0494] S912 and HSS send a fourth message to the SGN-GND device, which carries priority rule configuration information.

[0495] It should be understood that S912-S914 is a location update procedure triggered by the C-SGN-GND device so that the HSS can obtain updates about the registration. After registration is completed, any device in the communication system (such as terrestrial network equipment) can obtain user subscription data (i.e., subscription data) from the HSS.

[0496] The S913a and C-SGN-GND devices send priority rule configuration information to SAT#k.

[0497] S914a and SAT#k make decisions based on priority rule configuration information to obtain the priority information for data transmission corresponding to the service type.

[0498] S915, UE determines the end of the second timer length.

[0499] It should be understood that after the second timer length ends, the UE executes S916(a).

[0500] S916a, the UE sends a data transmission request message to SAT#k.

[0501] S917a and SAT#k send data transmission response messages to the UE based on priority information.

[0502] The description and effects of this solution are similar to those of the aforementioned solutions, and will not be repeated here.

[0503] In scenario 1, another specific embodiment of this solution can be as shown in Figure 9(b). Specifically, the communication method 900 includes:

[0504] S901, the UE sends an attach request message to SAT#i, the attach request message carrying a first identifier.

[0505] S902. If there is insufficient available storage resources in SAT#i, a rejection message is sent to the UE. The rejection message includes the reason for rejection and the length of the first timer.

[0506] In one alternative implementation, before the first timer length ends, SAT#i drives out of the area covering the UE, SAT#j drives into the area covering the UE, and SAT#j drives out of the area covering the UE, while SAT#k drives into the area covering the UE.

[0507] S903, the first timer length ends.

[0508] It should be understood that after the first timer length ends, the UE executes the following S904.

[0509] S904, the UE sends an attach request message to SAT#k, the attach request message including a first identifier.

[0510] It should be understood that the specific form of SAT#k is similar to that of the first satellite network equipment, and will not be described in detail here.

[0511] S905. If there is sufficient available storage resources in SAT#k, send an attach accept message to the UE, which carries the second timer length.

[0512] S906, the UE sends an attach complete message to SAT#k.

[0513] S907, the UE sends a context establishment request message to SAT#k.

[0514] S908 and SAT#k create the UE's context information.

[0515] S909 and SAT#k send a second message to the C-SGN-GND device, which includes the UE's context information.

[0516] The S910 and C-SGN-GND devices send a third message to the HSS.

[0517] S911 and HSS perform local lookups based on third messages to find priority rule configuration information.

[0518] S912 and HSS send a fourth message to the SGN-GND device, which carries priority rule configuration information.

[0519] The S913b and C-SGN-GND devices send the UE's context information and priority rule configuration information to SAT#j.

[0520] Specifically, SAT#i passes through the area covering the UE before the second timer length ends. SAT#j covers the area covering the UE after the second timer length ends.

[0521] S914b and SAT#j re-establish the connection based on the context information and make decisions based on the priority rule configuration information to obtain the priority information of data transmission corresponding to the service type.

[0522] S915, UE determines the end of the second timer length.

[0523] It should be understood that after the second timer length ends, the UE executes S916b.

[0524] S916b, the UE sends a data transmission request message to SAT#j.

[0525] S917b: When the priority of the data transmission priority information corresponding to the service type is greater than or equal to the second priority, a data transmission response message is sent.

[0526] The description and effects of this solution are similar to those of the aforementioned solutions, and will not be repeated here.

[0527] Wherein, SAT#i is the first satellite network device or another satellite network device, SAT#j is the second satellite network device, and SAT#k is the first satellite network device.

[0528] It should be understood that the communication method performed in this embodiment is similar to the communication method including the second satellite network device performing the above-described data transmission process and the first satellite network device performing the data transmission process, and will not be described again here.

[0529] Therefore, in the communication method 900 provided in Figure 9(b), the second satellite network device can determine the priority information of the data transmission corresponding to the service type requested by the terminal device based on the obtained priority rule configuration information. Based on the comparison between the priority information and the second priority, it decides whether to allow the terminal device to transmit data. This avoids aggravating the insufficient available storage resources and improves the operational autonomy of the second satellite network device.

[0530] It should be noted that in this embodiment, the satellite network equipment used to provide satellite IoT suffers from insufficient available storage resources. Similarly, in other scenarios, terrestrial cellular network equipment also faces insufficient available storage resources. Therefore, the communication method provided in this embodiment can be extended to scenarios where terrestrial cellular network equipment supports terminal device access.

[0531] The above description refers to the satellite network device that enters the area covering the terminal device as the second satellite network device. However, after the first satellite network device leaves the area covering the terminal device, other satellite network devices enter the area covering the terminal device, and these other satellite network devices may be another second satellite network device with sufficient or insufficient available storage resources.

[0532] Therefore, in another optional implementation, if the second satellite network device obtains the context information and priority rule configuration information of the terminal device, and the second timer expires when the second satellite network device leaves the area covering the terminal device, and the second timer expires when another second satellite network device enters the area covering the terminal device, then the terminal device will execute the data transmission process if the other second satellite network device has sufficient available storage resources. This data transmission process is similar to the process described above, except that the satellite network device being taken over is another second satellite network device. For the sake of brevity, this embodiment will not elaborate on this. Therefore, since the second timer length allows the terminal device to know which satellite network device is about to attempt to transmit or receive data, the normal operation of the data transmission process can be guaranteed whether either the second satellite network device takes over the data transmission process or another second satellite network device takes over the data transmission process.

[0533] It should be understood that the above description pertains to a terminal device that is of the latency-tolerant type, as described in the embodiments of this application. However, the first message may include a third identifier, which indicates that the terminal device is not of the latency-tolerant type. The inclusion of a third identifier in the first message includes the following three cases: the attach request message includes the third identifier, the contract data acquisition response message corresponding to the terminal device includes the third identifier, or the attach request message and the contract data acquisition response message corresponding to the terminal device are both present.

[0534] In the event that the first satellite network device has insufficient available storage resources and the first message may include a third identifier, the first satellite network device may set a corresponding decision, such as sending a rejection message including a fourth identifier to the terminal device, wherein the fourth identifier is used to indicate that the satellite network device running store-and-forward mode does not serve this type of terminal device.

[0535] The method provided by the embodiments of this application has been described in detail above with reference to Figures 7 to 9(a) and 9(b). The apparatus provided by the embodiments of this application will be described in detail below with reference to Figure 10.

[0536] Figure 10 is a schematic block diagram of a communication device 1000 provided in an embodiment of this application. As shown in Figure 10, the communication device 1000 may include a processing unit 1010 and a transceiver unit 1020.

[0537] In one possible design, the communication device 1000 can implement the operations corresponding to the terminal device in the above method embodiments. For example, the communication device can be the terminal device, or a component configured in the terminal device, such as a chip or circuit.

[0538] The communication device 1000 can implement the corresponding operations of the terminal device in the method embodiments shown in Figures 7 to 9(a) and 9(b). For example, the transceiver unit 1020 can be used to execute S710 in method 700. Furthermore, each unit in the communication device 1000 and the other operations and / or functions described above are respectively for implementing the corresponding processes in the method embodiment shown in Figure 7.

[0539] Specifically, when the communication device 1000 is used to execute the method 700 in FIG7, the transceiver unit 1020 can be used to send an attach request message to SAT#i, the attach request message carrying a first identifier.

[0540] In another possible design, the communication device 1000 can perform the operation corresponding to the first satellite network device in the above method embodiments. For example, the communication device can be the first satellite network device, or a component configured in the first satellite network device, such as a chip or circuit.

[0541] The communication device 1000 can implement the corresponding operations of the first satellite network device in the method embodiments shown in Figures 7 to 9(a) and 9(b). For example, the transceiver unit 1020 can be used to execute S720 in method 700, etc. Furthermore, each unit in the communication device 1000 and the other operations and / or functions described above are respectively for implementing the corresponding processes in the method embodiment shown in Figure 7.

[0542] Specifically, when the communication device 1000 is used to execute method 700 in FIG7, the transceiver unit 1020 can be used to send a rejection message to the UE when there is insufficient available storage resources in SAT#i, the rejection message including a rejection reason.

[0543] In another possible design, the communication device 1000 can perform the operation corresponding to the second satellite network device in the above method embodiments. For example, the communication device can be the second satellite network device, or a component configured in the second satellite network device, such as a chip or circuit.

[0544] The communication device 1000 can implement the corresponding operations of the second satellite network device in the method embodiment shown in FIG9(b). For example, the transceiver unit 1020 can be used to execute S916b, S917b, etc. in method 900. Furthermore, each unit in the communication device 1000 and the other operations and / or functions described above are respectively for implementing the corresponding processes in the method embodiment shown in FIG7.

[0545] Specifically, when the communication device 1000 is used to execute method 917b in FIG9(b), the transceiver unit 1020 can be used to send a data transmission response message to the terminal device when the priority of the data transmission priority information corresponding to the service type is greater than or equal to the second priority.

[0546] It should be understood that the specific process of each unit performing the above-mentioned corresponding steps has been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

[0547] It should also be understood that the module division in the embodiments of this application is illustrative and only represents a logical functional division. In actual implementation, there may be other division methods. Furthermore, the functional modules in the various embodiments of this application can be integrated into a processor, exist as separate physical entities, or have two or more modules integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0548] It should be understood that the communication device 1000 may correspond to the terminal device 110 or satellite network device 120 in the satellite mobile communication system 100 shown in FIG. 1, or another satellite network device 140 in FIG. 3. The terminal device 110 may be an example of a terminal device, and the satellite network device 120 may be an example of a first satellite network device. The other satellite network device 140 may be an example of a second satellite network device. The processing unit 1010 in the communication device 1000 may correspond to the processor in the terminal device 110, satellite network device 120, or another satellite network device 140. It can call instructions stored in the memory through the processor in the terminal device 110, satellite network device 120, or another satellite network device 140 to implement the above-mentioned functions, such as network encoding and acquiring raw packets. The transceiver unit 1020 may correspond to the interface in the terminal device 110, satellite network device 120, or another satellite network device 140. It can respond to the instructions of the processor to implement the above-mentioned functions of receiving and / or sending data.

[0549] Specifically, the transceiver unit 1020 in the communication device 1000 can be implemented using a transceiver or a communication interface, for example, corresponding to the transceiver 1120 in the terminal device 1100 shown in FIG. 11 and the remote radio unit (RRU) 1220 in the satellite network device shown in FIG. 12. The processing unit 1010 in the communication device 1000 can be implemented using at least one processor, for example, corresponding to the processor 1110 in the terminal device 1100 shown in FIG. 11 and the processor 1260 in the satellite network device shown in FIG. 12.

[0550] It should be understood that the specific process of each unit performing the above-mentioned corresponding steps has been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

[0551] Figure 11 is a possible structural schematic diagram of a terminal device 1100 provided in an embodiment of this application. The terminal device 1100 can be applied to the system shown in Figure 1 to perform the functions of the terminal device in the above method embodiment. As shown in Figure 11, the terminal device 1100 includes a processor 1110 and a transceiver 1120. Optionally, the terminal device 1100 also includes a memory 1130. The processor 1110, transceiver 1120, and memory 1130 can communicate with each other through internal connection channels to transmit control and / or data signals. The memory 1130 is used to store computer programs, and the processor 1110 is used to call and run the computer programs from the memory 1130 to control the transceiver 1120 to transmit and receive signals. Optionally, the terminal device 1100 may also include an antenna 1140 for transmitting uplink data or uplink control signaling output by the transceiver 1120 via wireless signals.

[0552] The processor 1110 and the memory 1130 can be combined into a communication device. The processor 1110 is used to execute the program code stored in the memory 1130 to achieve the above functions. In specific implementation, the memory 1130 can be integrated into the processor 1110 or independent of the processor 1110. The processor 1110 can correspond to the processing unit 1010 in FIG10.

[0553] The transceiver 1120 described above can correspond to the transceiver unit 1020 in Figure 10. The transceiver 1120 may include a receiver (or receiver circuit) and a transmitter (or transmitter circuit). The receiver is used to receive signals, and the transmitter is used to transmit signals.

[0554] It should be understood that the terminal device 1100 shown in FIG11 can implement the various processes involving the terminal device in the method embodiments shown in FIG7 to FIG9(a) and FIG9(b). The operation and / or function of each module in the terminal device 1100 are respectively for implementing the corresponding processes in the above method embodiments. For details, please refer to the description in the above method embodiments. To avoid repetition, detailed descriptions are appropriately omitted here.

[0555] The processor 1110 described above can be used to execute the actions implemented internally by the terminal device as described in the preceding method embodiments, while the transceiver 1120 can be used to execute the actions described in the preceding method embodiments of the terminal device sending to or receiving from the satellite network device. For details, please refer to the descriptions in the preceding method embodiments; they will not be repeated here.

[0556] Optionally, the terminal device 1100 may also include a power supply 1150 for providing power to various devices or circuits in the terminal device.

[0557] In addition, to make the terminal device more functional, the terminal device 1100 may also include one or more of the following: an input unit 1160, a display unit 1170, an audio circuit 1180, a camera 1190, and a sensor 1191. The audio circuit 1180 may also include a speaker 1181, a microphone 1182, etc.

[0558] Figure 12 is a possible structural diagram of a satellite network device provided in an embodiment of this application, such as a structural diagram of a base station 1200. Furthermore, both the first and second satellite network devices can adopt this possible structure. The base station 1200 can be applied to the system shown in Figure 1 to perform the functions of the satellite network device in the above method embodiment. As shown in Figure 12, the base station 1200 may include one or more RRUs 1220 and one or more BBUs 1210. The RRU 1220 can be called a transceiver unit, corresponding to the transceiver unit 1020 in Figure 10. Optionally, the transceiver unit may also be called a transceiver, transceiver circuit, or transceiver, etc., and may include at least one antenna 1230 and a radio frequency unit 1240. Optionally, the transceiver unit may include a receiving unit and a transmitting unit. The receiving unit may correspond to a receiver (or receiver circuit), and the transmitting unit may correspond to a transmitter (or transmitter circuit). The RRU 1220 is mainly used for the transmission and reception of radio frequency signals and the conversion between radio frequency signals and baseband signals. The BBU1210 is mainly used for baseband processing and base station control. The RRU 1220 and BBU1210 can be physically installed together or physically separated, i.e., a distributed base station.

[0559] BBU1210 is the control center of the base station, also known as a processing unit, which corresponds to processing unit 1010 in Figure 10. It is mainly used to perform baseband processing functions, such as channel coding, multiplexing, modulation, and spreading. For example, the BBU (processing unit) can be used to control the base station to execute the operation procedures of the satellite network equipment described in the above method embodiments, such as generating the aforementioned instruction information.

[0560] In one example, the BBU1210 can consist of one or more boards. These boards can collectively support a single access standard wireless access network (such as an LTE network), or they can each support different access standards wireless access networks (such as LTE, 5G, or other networks). The BBU1210 also includes a memory 1250 and a processor 1260. The memory 1250 stores necessary instructions and data. The processor 1260 controls the base station to perform necessary actions, such as controlling the base station to execute the operational procedures for the satellite network equipment described in the above method embodiments. The memory 1250 and processor 1260 can serve one or more boards. That is, each board can have its own memory and processor, or multiple boards can share the same memory and processor. Furthermore, each board can also have necessary circuitry.

[0561] It should be understood that the base station 1200 shown in Figure 12 can implement the various processes involving the satellite network equipment in the method embodiment shown in Figure 7. The operation and / or function of each module in the base station 1200 are respectively for implementing the corresponding processes in the above method embodiment. For details, please refer to the description in the above method embodiment; to avoid repetition, detailed descriptions are appropriately omitted here.

[0562] The BBU1210 described above can be used to perform the actions implemented internally by the satellite network device as described in the preceding method embodiments, while the RRU 1220 can be used to perform the actions described in the preceding method embodiments whereby the satellite network device sends data to or receives data from the terminal device. Please refer to the descriptions in the preceding method embodiments for details, which will not be repeated here.

[0563] It should be understood that the base station 1200 shown in Figure 12 is only one possible architecture for satellite network equipment and should not be construed as limiting this application in any way. The method provided in this application can be applied to satellite network equipment with other architectures, such as satellite network equipment including CU, DU, and active antenna unit (AAU). This application does not limit the specific architecture of the satellite network equipment.

[0564] This application also provides a communication device, including a processor and an interface; the processor is used to execute the method in any of the above method embodiments.

[0565] It should be understood that the aforementioned communication device can be one or more chips. For example, the communication device can be a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a central processing unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0566] This embodiment provides a communication system, which includes, but is not limited to, terminal devices (such as terminal device 110 as shown in Figure 1 or Figure 2) and satellite network devices (such as satellite network device 120 as shown in Figure 1 or Figure 2). This application embodiment does not specifically limit the architecture of the communication system.

[0567] In implementation, each step of the above method can be completed by integrated logic circuits in the processor's hardware or by instructions in software. The steps of the method disclosed in the embodiments of this application can be directly implemented by a hardware processor, or by a combination of hardware and software modules in the processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, detailed descriptions are omitted here.

[0568] It should be noted that the processor in the embodiments of this application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by the integrated logic circuitry in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above methods.

[0569] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0570] According to the method provided in the embodiments of this application, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the computer to perform the method of any of the embodiments shown in FIG7 to FIG9(a) and FIG9(b).

[0571] According to the method provided in the embodiments of this application, this application also provides a chip system including at least one processor and a communication interface, the communication interface and at least one processor being interconnected via a line, the at least one processor being used to run a computer program or instructions, causing the computer to perform the method of any of the embodiments shown in FIG7 to FIG9(a) and FIG9(b).

[0572] According to the method provided in the embodiments of this application, this application also provides a computer program product, including a computer program that, when run, causes the computer to perform the method of any of the embodiments shown in FIG7 to FIG9(a) and FIG9(b).

[0573] In the above-described device embodiments, each satellite network device corresponds completely to a terminal device, and in the method embodiments, each satellite network device or terminal device performs a corresponding step. For example, the communication unit (transceiver) performs the receiving or transmitting steps in the method embodiments, while other steps besides transmitting and receiving can be performed by the processing unit (processor). The specific functions of each unit can be found in the corresponding method embodiments. There can be one or more processors.

[0574] As used in this specification, the terms "component," "module," "system," etc., are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process and / or an execution thread, and components may be located on a single computer and / or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable media on which various data structures are stored. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0575] Those skilled in the art will recognize that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0576] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0577] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0578] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0579] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0580] In the above embodiments, the functions of each functional unit can be implemented entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. A computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. Computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., high-density digital video discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0581] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the 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 cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.

[0582] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, Applied to first satellite network equipment, including: Receive the first message; If the first satellite network device has insufficient available storage resources, a rejection message is sent to the terminal device; if the first message includes a first identifier, the rejection message includes a rejection reason.

2. The method according to claim 1, characterized in that, The first identifier is used to indicate that the terminal device is a latency-tolerant type of device.

3. The method according to claim 2, characterized in that, The first message includes at least one of the following: Request message, the request message including attach request message; The terminal device receives a response message for acquiring the contracted data.

4. The method according to claim 3, characterized in that, The receiving of the first message includes: Receive attach request messages sent by terminal devices.

5. The method according to claim 1, characterized in that, The reason for rejection is used to indicate that the reason the terminal device refuses to attach to the first satellite network device is that the first satellite network device has insufficient available storage resources.

6. The method according to claim 3, characterized in that, The request message includes at least one of the following: Tracking Area Update Request Message; Radio Resource Control (RRC) Connection Resumption Request Message; Packet Data Protocol (PDP) Context Establishment Request Message; Physical Random Access Channel (PRACH) Message; Physical Uplink Control Channel (PUCCH) Message.

7. The method according to claim 3, characterized in that, If the attach request message does not include a first identifier, then receiving the first message includes: Send a subscription data acquisition request message of the terminal device to the terrestrial network device, wherein the acquisition request message is used to instruct the terrestrial network device to acquire the subscription data of the terminal device from the home subscriber server; The system receives a subscription data acquisition response message sent by the terrestrial network device. The subscription data acquisition response message includes the subscription data, and the subscription data includes the first identifier.

8. The method according to claim 1, characterized in that, Sending a rejection message to the terminal device includes: If there is no downlink information to be sent to the terminal device, a rejection message is sent to the terminal device. The downlink information includes pending response information. The pending response information is the response information that the first satellite network device needs to provide feedback to the terminal device after sending the relevant data of the terminal device to the ground network device. The relevant data is the data generated by the first satellite network device after establishing a connection with the terminal device last time.

9. The method according to claim 3, characterized in that, If the first message includes a first identifier, then the rejection message further includes: The first timer length is used to instruct the terminal device to start the first timer and wait until the first timer length expires before retransmitting the attach request message.

10. The method according to claim 1, characterized in that, When the first satellite network device has sufficient available storage resources, receiving the first message includes: Receive attach request messages sent by terminal devices; The method further includes: Send an attach accept message to the terminal device; Receive the attachment completion message sent by the terminal device; Receive the context establishment request message sent by the terminal device and create the context information of the terminal device; A second message is sent to the terrestrial network device, the second message including the context information; in response to the second message, the terrestrial network device obtains priority rule configuration information from the home subscriber server; Retrieve priority rule configuration information; The decision is made based on the priority rule configuration information to obtain the priority information of data transmission corresponding to the service type requested by the terminal device; Receive data transmission request messages sent by terminal devices; Based on the priority information, a data transmission response message is sent to the terminal device.

11. The method according to claim 10, characterized in that, The attach accept message includes: The second timer length is used to instruct the terminal device to send a data transmission request message from the start of the second timer until the end of the second timer length.

12. The method according to claim 10, characterized in that, The priority rule configuration information includes any one of the following: Prioritize messages based on whether the first message includes a first identifier; Prioritize based on the requested service type, the length of the transmitted information, and / or the tolerable duration of the transmitted information.

13. The method according to claim 12, characterized in that, The priority sorting based on whether the first message includes a first identifier includes: The first priority is greater than the second priority; the first priority is the priority corresponding to the priority information when the first condition is met, and the second priority is the priority corresponding to the priority information when the second condition is met. The first condition being met includes: the first message does not include the first identifier; The second condition being met includes: the first message including a first identifier.

14. The method according to claim 12, characterized in that, The prioritization based on the requested service type, the length of the transmitted information, and / or the tolerable duration of the transmitted information includes: The second priority is greater than the third priority; the second priority is the priority corresponding to the priority information when the second condition is met; The third priority is the priority corresponding to the priority information when the third condition is met; The second condition includes: the first message includes a first identifier and satisfies at least one of the following: the requested service type is a first preset service type; the length of the transmitted information is less than or equal to a first preset length threshold; the tolerable length of the transmitted information is less than or equal to a second preset length threshold. The third condition is met, including: the first message includes a first identifier and meets at least one of the following: the requested service type is a second preset service type; the length of the transmitted information is greater than a first preset length threshold; the tolerable length of the transmitted information is greater than a second preset length threshold. The first priority, the second priority, and the third priority are used to indicate the sorting order in which the first satellite network device performs data transmission on each terminal device based on the priority order.

15. The method according to claim 10, characterized in that, Before receiving the attach request message sent by the receiving terminal device, the method further includes: Establish communication connections with terrestrial network equipment; Data is transmitted to the terrestrial network equipment to free up storage resources on the first satellite network equipment.

16. The method according to claim 10, characterized in that, Before sending the attach accept message to the terminal device, the method further includes: Perform authentication and security settings on the terminal device.

17. The method according to claim 10, characterized in that, If the attach request message includes a first identifier, the method further includes: In response to the second message, the terrestrial network device notifies the home subscriber server to add the first identifier to the subscription data.

18. A communication method, characterized in that, Applications to second satellite network equipment include: In the case of satellite takeover, obtain the context information and priority rule configuration information of the terminal device; wherein, the satellite takeover situation is: the first satellite network device has sent a second message to the ground network device before leaving the area covering the terminal device, the second satellite network device enters the area covering the terminal device, and the second satellite network device has insufficient available storage resources; Receive the data transmission request message sent by the terminal device; Re-establish the connection based on the context information; The decision is made based on the priority rule configuration information to obtain the priority information of data transmission corresponding to the service type requested by the terminal device; If the priority information corresponds to a priority greater than or equal to the second priority, a data transmission response message is sent to the terminal device.

19. The method according to claim 18, characterized in that, After making a decision based on the priority rule configuration information to obtain the priority information of data transmission corresponding to the service type requested by the terminal device, the method further includes: If the priority information corresponds to a priority that is less than the second priority, then an attachment release message is sent to the terminal device.

20. The method according to claim 19, characterized in that, The attachment release message includes: The reason for unattaching is indicated to the terminal device, which states that the reason for unattaching from the second satellite network device is that the second satellite network device has insufficient available storage resources.

21. The method according to claim 18, characterized in that, The priority rule configuration information includes any one of the following: Prioritize messages based on whether the first message includes a first identifier; Prioritize based on the requested service type, the length of the transmitted information, and / or the tolerable duration of the transmitted information.

22. The method according to claim 21, characterized in that, The priority sorting based on whether the first message includes a first identifier includes: The first priority is greater than the second priority; the first priority is the priority corresponding to the priority information when the first condition is met, and the second priority is the priority corresponding to the priority information when the second condition is met. The first condition being met includes: the first message does not include the first identifier; The second condition being met includes: the first message including a first identifier.

23. The method according to claim 21, characterized in that, The prioritization based on the requested service type, the length of the transmitted information, and / or the tolerable duration of the transmitted information includes: The second priority is greater than the third priority; the second priority is the priority corresponding to the priority information when the second condition is met; The third priority is the priority corresponding to the priority information when the third condition is met; The second condition includes: the first message includes a first identifier and satisfies at least one of the following: the requested service type is a first preset service type; the length of the transmitted information is less than or equal to a first preset length threshold; the tolerable length of the transmitted information is less than or equal to a second preset length threshold. The third condition is met, including: the first message includes a first identifier and meets at least one of the following: the requested service type is a second preset service type; the length of the transmitted information is greater than a first preset length threshold; the tolerable length of the transmitted information is greater than a second preset length threshold. The first priority and the second priority are priorities that allow the second satellite network device to transmit data with the terminal device, and the third priority is a priority that disallows the second satellite network device from transmitting data with the terminal device.

24. A communication method, characterized in that, Applied to terminal devices, including: The system receives a rejection message sent by a first satellite network device. The rejection message is sent when the first satellite network device has insufficient available storage resources, and if the first message includes a first identifier, the rejection message includes a rejection reason.

25. The method according to claim 24, characterized in that, The first identifier is used to indicate that the terminal device is a latency-tolerant type of device.

26. The method according to claim 25, characterized in that, The first message includes at least one of the following: Request message, the request message including attach request message; The terminal device receives a response message for acquiring the contracted data.

27. The method according to claim 24, characterized in that, Before receiving the rejection message sent by the first satellite network device, the method further includes: Send an attach request message to the first satellite network device.

28. The method according to claim 24, characterized in that, The reason for rejection is used to indicate that the reason the terminal device refuses to attach to the first satellite network device is that the first satellite network device has insufficient available storage resources.

29. The method according to claim 26, characterized in that, The request message includes at least one of the following: Tracking Area Update Request Message; Radio Resource Control (RRC) Connection Resumption Request Message; Packet Data Protocol (PDP) Context Establishment Request Message; Physical Random Access Channel (PRACH) Message; Physical Uplink Control Channel (PUCCH) Message.

30. The method according to claim 24, characterized in that, The rejection message is sent by the first satellite network device when there is no downlink information to be sent to the terminal device. The downlink information includes a response information to be sent. The response information to be sent is the response information that the first satellite network device needs to provide to the terminal device after sending relevant data of the terminal device to the ground network device. The relevant data is the data generated by the first satellite network device after establishing a connection with the terminal device last time.

31. The method according to claim 26, characterized in that, If the first message includes a first identifier, then the rejection message further includes: The first timer length is used to instruct the terminal device to start the first timer and wait until the first timer length expires before retransmitting the attach request message.

32. The method according to claim 31, characterized in that, After receiving the rejection message sent by the first satellite network device, the method further includes: Start the first timer; After the first timer expires, attach request messages are sent to other satellite network devices besides the first satellite network device, or to the first satellite network device with sufficient available storage resources before the first timer expires.

33. The method according to claim 24, characterized in that, If the first satellite network device has sufficient available storage resources, the method further includes: Send an attach request message to the first satellite network device; Receive the attach accept message sent by the first satellite network device; Send an attach complete message to the first satellite network device; A context establishment request message is sent to the first satellite network device, the context establishment request message instructing the first satellite network device to create context information for the terminal device; a second message is sent to the ground network device, the second message including the context information; in response to the second message, the ground network device obtains priority rule configuration information from the home subscriber server; When the first satellite network device has not left the area covering the terminal device, a data transmission request message is sent to the first satellite network device. The data transmission request message is a message sent by the terminal device after obtaining priority rule configuration information from the first satellite network device, making a decision based on the priority rule configuration information, and obtaining the priority information of the data transmission corresponding to the service type requested by the terminal device. Based on the priority information, the data transmission response message sent by the first satellite network device is received.

34. The method according to claim 33, characterized in that, The attach accept message includes: The second timer length is used to instruct the terminal device to send a data transmission request message from the start of the second timer until the end of the second timer length.

35. The method according to claim 34, characterized in that, After receiving the attach accept message sent by the first satellite network device, the method further includes: Start the second timer; Sending a data transmission request message to the first satellite network device includes: After the second timer expires, a data transmission request message is sent to the first satellite network device.

36. The method according to claim 33, characterized in that, In the event of satellite takeover, the method further includes: Send a data transmission request message to the second satellite network device; wherein, the satellite takeover situation is as follows: the first satellite network device has sent a second message to the ground network device before leaving the area covering the terminal device, the second satellite network device enters the area covering the terminal device, and the second satellite network device has insufficient available storage resources; The system receives a data transmission response message sent by a second satellite network device, wherein the data transmission response message is sent by the second satellite network device when the priority corresponding to the priority information is greater than or equal to the second priority.

37. The method according to claim 36, characterized in that, After sending a data transmission request message to the second satellite network device, the method further includes: Receive an attachment release message sent by a second satellite network device, wherein the attachment release message is sent by the second satellite network device when the priority corresponding to the priority information is lower than the second priority.

38. The method according to claim 37, characterized in that, The attachment release message includes: The reason for unattaching is indicated to the terminal device, which states that the reason for unattaching from the second satellite network device is that the second satellite network device has insufficient available storage resources.

39. A satellite network device, characterized in that, include: Processor and memory; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the satellite network device to perform the method as claimed in any one of claims 1-17 or any one of claims 18-23.

40. A terminal device, characterized in that, include: Processor and memory; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the terminal device to perform the method as described in any one of claims 24-38.

41. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-38.

42. A chip system, characterized in that, It includes at least one processor and a communication interface, the communication interface and the at least one processor being interconnected via a line, the at least one processor being configured to run a computer program or instructions to perform the method as described in any one of claims 1-38.

43. A communication system, characterized in that, The communication system includes terminal equipment and satellite network equipment; The terminal device is used to perform the method as described in any one of claims 24 to 38, and the satellite network device is used to perform the method as described in any one of claims 1 to 17 or the method as described in any one of claims 18 to 23.

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