Data transmission method and apparatus, and device

Abstract

The present disclosure relates to the technical field of communications, and provides a data transmission method and apparatus, and a device. The data transmission method comprises: receiving first information of a first session sent by a satellite device; and receiving downlink data by means of the first session on the basis of the first information, wherein the first session refers to a session that continuously occupies allocated resources, and the first information comprises fixed session identification information and time information of the session continuously occupying the allocated resources.

Description

Data transmission method, device and equipment

[0001] This disclosure claims priority to the Chinese patent application filed with the China Patent Office on June 13, 2023, with application number 202310697642.0 and application name “A Data Transmission Method, Device and Equipment,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to the field of communication technology, and in particular to a data transmission method, apparatus, and device. Background Art

[0003] In related technologies, data exchange between terminals and application servers relies on an end-to-end connection. When the network enables onboard store-and-forward operations from terminals to servers, the end-to-end connection between the terminals and application servers disappears, and data cannot be exchanged in real time using this end-to-end connection. However, how terminals can access downlink data from remote application servers using non-end-to-end connections remains unclear.

[0004] As mentioned above, there is currently no clear definition of how a terminal obtains downlink data from an application server based on a non-end-to-end connection after enabling on-board store-and-forwarding. Based on this, in the case of such a non-end-to-end connection in the related art, the network cannot accurately determine the target terminal corresponding to the downlink data, which makes it impossible to ensure that the target terminal accurately receives the downlink data.

[0005] Summary of the Invention

[0006] The purpose of the present disclosure is to provide a data transmission method, apparatus and device to solve the problem in the related art that in the case of non-end-to-end connection, the target terminal cannot be guaranteed to accurately receive downlink data.

[0007] In order to solve the above technical problems, an embodiment of the present disclosure provides a data transmission method, which is applied to a terminal, including:

[0008] receiving first information of a first session sent by a satellite device;

[0009] receiving downlink data through the first session according to the first information;

[0010] The first session refers to a session that continuously occupies the allocated resources;

[0011] The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

[0012] In some embodiments, the first information further includes at least one of the following:

[0013] Response method for receiving downlink data;

[0014] Paging time window;

[0015] Periodic registration timer;

[0016] Satellite identification.

[0017] In some embodiments, before receiving the first information of the first session sent by the satellite device, the method further includes:

[0018] receiving demand information based on the downlink data, and sending a first request to the satellite device;

[0019] The receiving first information of the first session sent by the satellite device includes:

[0020] receiving a first response fed back by the satellite device, where the first response carries first information of a first session;

[0021] The first request carries at least one of the following:

[0022] Receive uplink data delivery confirmation;

[0023] Waiting to receive downlink data;

[0024] Receiving priority of downlink data;

[0025] Service type corresponding to the session.

[0026] In some embodiments, the method further comprises:

[0027] Reserving, according to the first response, air interface resources and session information corresponding to the session;

[0028] The air interface resources are used to receive downlink data.

[0029] In some embodiments, before receiving downlink data through the first session according to the first information, the method further includes:

[0030] accessing the satellite device according to the first parameter, and sending a second request to the satellite device, where the second request is used to obtain information of a downlink data buffer component on the satellite device or to indicate receiving downlink data or to request registration or to request sending uplink data;

[0031] receiving a second response fed back by the satellite device, where the second response carries information of the downlink data buffer component or carries instruction information instructing the terminal to use resources corresponding to the first session to receive downlink data;

[0032] The receiving downlink data through the first session according to the first information includes:

[0033] receiving, through the first session, downlink data sent by the downlink data buffer component on the satellite device according to the first information and the information of the downlink data buffer component or the indication information;

[0034] The first parameter includes at least one of: uplink data transmission status, candidate response methods for receiving downlink data, locally stored first session information, network paging reason, and relevant identification of the satellite device.

[0035] In some embodiments, the second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception mode for downlink data supported by the terminal;

[0036] And / or, the second response carries the downlink data receiving mode allowed by the satellite device.

[0037] In some embodiments, further comprising:

[0038] The receiving mode for downlink data supported by the terminal is sent to the satellite device.

[0039] In some embodiments, the receiving, through the first session, downlink data sent by the downlink data buffer component on the satellite device includes:

[0040] The downlink data sent by the satellite device according to the receiving mode and using the downlink data buffer component on the satellite device is received through the first session.

[0041] In some embodiments, further comprising:

[0042] Determining a first mapping relationship between the session identification information of the first session and air interface resources;

[0043] The accessing the satellite device according to the first parameter includes:

[0044] Access the satellite device according to the first parameter and the first mapping relationship.

[0045] In some embodiments, the first session is a protocol data unit (PDU) session or a non-PDU session.

[0046] The present disclosure also provides a data transmission method, which is applied to a satellite device and includes:

[0047] Sending first information of a first session to the terminal;

[0048] Sending downlink data to the terminal through the first session according to the first information;

[0049] The first session refers to a session that continuously occupies the allocated resources;

[0050] The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

[0051] In some embodiments, the first information further includes at least one of the following:

[0052] Response method for receiving downlink data;

[0053] Paging time window;

[0054] Periodic registration timer;

[0055] Satellite identification.

[0056] In some embodiments, further comprising:

[0057] Determining the response mode for receiving downlink data according to reference information; wherein the reference information includes: the time information, and at least one of the downlink reception priority;

[0058] And / or, determining a paging time window or a periodic registration timer corresponding to the terminal according to the ephemeris information of the satellite device.

[0059] In some embodiments, further comprising:

[0060] Determining, according to the response mode for receiving downlink data, to initiate paging or wait for the terminal to access;

[0061] Wherein, when it is determined to initiate paging, the terminal is instructed to receive downlink data in the paging reason.

[0062] In some embodiments, before sending the first information of the first session to the terminal, the method further includes:

[0063] receiving a first request sent by the terminal;

[0064] The sending the first information of the first session to the terminal includes:

[0065] Feedback a first response to the terminal according to the first request, where the first response carries first information of the first session;

[0066] The first request carries at least one of the following:

[0067] Receive uplink data delivery confirmation;

[0068] Waiting to receive downlink data;

[0069] Receiving priority of downlink data;

[0070] Service type corresponding to the session.

[0071] In some embodiments, further comprising:

[0072] Reserving system resources and session information of the session corresponding to the first response;

[0073] The system resources are used to send downlink data.

[0074] In some embodiments, feeding back a first response to the terminal according to the first request includes:

[0075] In a case where the first request indicates a request to activate the on-board store-and-forward operation or the terminal has already activated the on-board store-and-forward operation, allocating resources and establishing a first session or updating an existing session to the first session according to the first request;

[0076] A first response is fed back to the terminal according to the first session.

[0077] In some embodiments, before sending downlink data to the terminal through the first session according to the first information, the method further includes:

[0078] receiving a second request sent by the terminal, where the second request is used to obtain information of a downlink data buffer component on the satellite device or to indicate receiving downlink data or to request registration or to request sending uplink data;

[0079] Feedback a second response to the terminal according to the second request, where the second response carries information about the downlink data buffer component or carries instruction information instructing the terminal to use resources corresponding to the first session to receive downlink data;

[0080] The sending downlink data to the terminal through the first session according to the first information includes:

[0081] According to the first information and the information of the downlink data buffer component or the instruction information, the downlink data buffer component on the satellite device is used to send downlink data to the terminal through the first session.

[0082] In some embodiments, the second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception mode for downlink data supported by the terminal;

[0083] And / or, the second response carries the downlink data receiving mode allowed by the satellite device.

[0084] In some embodiments, further comprising:

[0085] Receive the receiving mode for downlink data supported by the terminal and sent by the terminal.

[0086] In some embodiments, the sending downlink data to the terminal through the first session by using a downlink data buffer component on the satellite device includes:

[0087] According to the first information and the downlink data receiving mode supported by the terminal, the downlink data is sent to the terminal through the first session by utilizing the downlink data buffer component on the satellite device.

[0088] In some embodiments, the first session is a protocol data unit (PDU) session or a non-PDU session.

[0089] In some embodiments, further comprising:

[0090] caching a notification for the terminal, the notification being used to indicate that the terminal has activated an on-board store-and-forward operation;

[0091] The notification carries downlink data storage and forwarding information, and the downlink data storage and forwarding information includes: downlink data sending mode, the terminal identifier, PDU session identifier, on-board storage configuration, candidate user address identifier, and at least one of the candidate user IP address.

[0092] In some embodiments, further comprising:

[0093] The notification is sent to a server.

[0094] In some embodiments, before sending downlink data to the terminal through the first session according to the first information, the method further includes:

[0095] determining a downlink data sending mode according to the second information;

[0096] The second information includes: at least one of intersatellite link status information and a downlink data storage and forwarding request from the server; the downlink data storage and forwarding request includes: at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

[0097] In some embodiments, further comprising:

[0098] Feedback a downlink data storage and forwarding response to the server according to the downlink data sending mode;

[0099] Among them, the downlink data storage forwarding response carries downlink data storage forwarding information, and the downlink data storage forwarding information includes: the downlink data sending method, the terminal identifier, the PDU session identifier, the on-board storage configuration, the expected time of delivery of the downlink data, the candidate user address identifier, and at least one of the candidate user IP addresses.

[0100] In some embodiments, the on-board storage configuration includes at least one of: cache space, and retention time of cached data;

[0101] Alternatively, the on-board storage configuration does not include: cache space and cache data retention time, and the downlink data storage and forwarding information further includes: cache space and cache data retention time.

[0102] In some embodiments, the downlink data storage and forwarding information further includes: relevant information for monitoring the satellite equipment.

[0103] In some embodiments, further comprising:

[0104] Determine a second mapping relationship between the identifier of the terminal, the identifier of the first session, and a related identifier of the server.

[0105] The present disclosure also provides a data transmission method, which is applied to a server and includes:

[0106] Receive downlink data storage and forwarding information sent by satellite equipment;

[0107] Sending downlink data to the satellite device according to the downlink data storage and forwarding information;

[0108] The downlink data storage and forwarding information includes at least one of: a downlink data transmission mode, a terminal identifier, a PDU session identifier, an on-board storage configuration, an estimated time of downlink data delivery, a candidate user address identifier, and a candidate user IP address;

[0109] The downlink data storage and forwarding information is carried in a notification to the terminal, where the notification is used to indicate that the terminal has activated the on-board store-and-forward operation, or is carried in a downlink data storage and forwarding response.

[0110] In some embodiments, sending downlink data to a satellite device according to the downlink data storage and forwarding information includes any one of the following:

[0111] In the process of receiving the uplink buffer data, sending the downlink data to the satellite device according to the downlink data storage and forwarding information;

[0112] The downlink data is sent to the satellite device according to the downlink data storage and forwarding information and the downlink data sending requirement information.

[0113] In some embodiments, before receiving the downlink data storage and forwarding information sent by the satellite device, the method further includes:

[0114] Sending a downlink data storage and forwarding request of the server to the satellite device;

[0115] The downlink data storage and forwarding request includes at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

[0116] The present disclosure also provides a data transmission device, which is a terminal and includes a memory, a transceiver, and a processor.

[0117] A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0118] receiving, by the transceiver, first information of a first session sent by a satellite device;

[0119] receiving downlink data through the first session according to the first information;

[0120] The first session refers to a session that continuously occupies the allocated resources;

[0121] The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

[0122] In some embodiments, the first information further includes at least one of the following:

[0123] Response method for receiving downlink data;

[0124] Paging time window;

[0125] Periodic registration timer;

[0126] Satellite identification.

[0127] In some embodiments, the operations further include:

[0128] Before receiving the first information of the first session sent by the satellite device, sending a first request to the satellite device through the transceiver according to the downlink data reception demand information;

[0129] The receiving first information of the first session sent by the satellite device includes:

[0130] receiving a first response fed back by the satellite device, where the first response carries first information of a first session;

[0131] The first request carries at least one of the following:

[0132] Receive uplink data delivery confirmation;

[0133] Waiting to receive downlink data;

[0134] Receiving priority of downlink data;

[0135] Service type corresponding to the session.

[0136] In some embodiments, the operations further include:

[0137] Reserving, according to the first response, air interface resources and session information corresponding to the session;

[0138] The air interface resources are used to receive downlink data.

[0139] In some embodiments, the operations further include:

[0140] Before receiving downlink data through the first session according to the first information, accessing the satellite device according to the first parameter, and sending a second request to the satellite device through the transceiver, wherein the second request is used to obtain information of a downlink data buffer component on the satellite device, or to indicate receiving downlink data, or to request registration, or to request sending uplink data;

[0141] receiving, by the transceiver, a second response fed back by the satellite device, where the second response carries information about the downlink data buffer component or carries instruction information instructing the terminal to use resources corresponding to the first session to receive downlink data;

[0142] The receiving downlink data through the first session according to the first information includes:

[0143] receiving, through the first session, downlink data sent by the downlink data buffer component on the satellite device according to the first information and the information of the downlink data buffer component or the instruction information;

[0144] The first parameter includes at least one of: uplink data transmission status, candidate response methods for receiving downlink data, locally stored first session information, network paging reason, and relevant identification of the satellite device.

[0145] In some embodiments, the second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception mode for downlink data supported by the terminal;

[0146] And / or, the second response carries the downlink data receiving mode allowed by the satellite device.

[0147] In some embodiments, the operations further include:

[0148] The receiving mode for downlink data supported by the terminal is sent to the satellite device via the transceiver.

[0149] In some embodiments, the receiving, through the first session, downlink data sent by the downlink data buffer component on the satellite device includes:

[0150] The downlink data sent by the satellite device according to the receiving mode and using the downlink data buffer component on the satellite device is received through the first session.

[0151] In some embodiments, the operations further include:

[0152] Determining a first mapping relationship between the session identification information of the first session and air interface resources;

[0153] The accessing the satellite device according to the first parameter includes:

[0154] Access the satellite device according to the first parameter and the first mapping relationship.

[0155] In some embodiments, the first session is a protocol data unit (PDU) session or a non-PDU session.

[0156] The present disclosure also provides a data transmission device, which is a satellite device and includes a memory, a transceiver, and a processor.

[0157] A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0158] Sending, via the transceiver, first information of a first session to a terminal;

[0159] Sending downlink data to the terminal through the first session according to the first information;

[0160] The first session refers to a session that continuously occupies the allocated resources;

[0161] The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

[0162] In some embodiments, the first information further includes at least one of the following:

[0163] Response method for receiving downlink data;

[0164] Paging time window;

[0165] Periodic registration timer;

[0166] Satellite identification.

[0167] In some embodiments, the operations further include:

[0168] Determining the response mode for receiving downlink data according to reference information; wherein the reference information includes: the time information, and at least one of the downlink reception priority;

[0169] And / or, determining a paging time window or a periodic registration timer corresponding to the terminal according to the ephemeris information of the satellite device.

[0170] In some embodiments, the operations further include:

[0171] Determining, according to the response mode for receiving downlink data, to initiate paging or wait for the terminal to access;

[0172] Wherein, when it is determined to initiate paging, the terminal is instructed to receive downlink data in the paging reason.

[0173] In some embodiments, the operations further include:

[0174] Before sending first information of a first session to a terminal, receiving, by the transceiver, a first request sent by the terminal;

[0175] The sending the first information of the first session to the terminal includes:

[0176] Feedback a first response to the terminal according to the first request, where the first response carries first information of the first session;

[0177] The first request carries at least one of the following:

[0178] Receive uplink data delivery confirmation;

[0179] Waiting to receive downlink data;

[0180] Receiving priority of downlink data;

[0181] Service type corresponding to the session.

[0182] In some embodiments, the operations further include:

[0183] Reserving system resources and session information of the session corresponding to the first response;

[0184] The system resources are used to send downlink data.

[0185] In some embodiments, feeding back a first response to the terminal according to the first request includes:

[0186] In a case where the first request indicates a request to activate the on-board store-and-forward operation or the terminal has already activated the on-board store-and-forward operation, allocating resources and establishing a first session or updating an existing session to the first session according to the first request;

[0187] A first response is fed back to the terminal according to the first session.

[0188] In some embodiments, the operations further include:

[0189] Before sending downlink data to the terminal through the first session according to the first information, receiving, by the transceiver, a second request sent by the terminal, wherein the second request is used to obtain information of a downlink data buffer component on the satellite device, or to indicate receiving downlink data, or to request registration, or to request sending uplink data;

[0190] Feedback a second response to the terminal according to the second request, where the second response carries information about the downlink data buffer component or carries instruction information instructing the terminal to use resources corresponding to the first session to receive downlink data;

[0191] The sending downlink data to the terminal through the first session according to the first information includes:

[0192] According to the first information and the information of the downlink data buffer component or the instruction information, the downlink data buffer component on the satellite device is used to send downlink data to the terminal through the first session.

[0193] In some embodiments, the second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception mode for downlink data supported by the terminal;

[0194] And / or, the second response carries the downlink data receiving mode allowed by the satellite device.

[0195] In some embodiments, the operations further include:

[0196] The transceiver receives, from the terminal, a reception mode for downlink data supported by the terminal.

[0197] In some embodiments, the sending downlink data to the terminal through the first session by using a downlink data buffer component on the satellite device includes:

[0198] According to the first information and the downlink data receiving mode supported by the terminal, the downlink data is sent to the terminal through the first session by utilizing the downlink data buffer component on the satellite device.

[0199] In some embodiments, the first session is a protocol data unit (PDU) session or a non-PDU session.

[0200] In some embodiments, the operations further include:

[0201] caching a notification for the terminal, the notification being used to indicate that the terminal has activated an on-board store-and-forward operation;

[0202] The notification carries downlink data storage and forwarding information, and the downlink data storage and forwarding information includes: downlink data sending mode, the terminal identifier, PDU session identifier, on-board storage configuration, candidate user address identifier, and at least one of the candidate user IP address.

[0203] In some embodiments, the operations further include:

[0204] The notification is sent to a server via the transceiver.

[0205] In some embodiments, the operations further include:

[0206] Before sending downlink data to the terminal through the first session according to the first information, determining a downlink data sending mode according to the second information;

[0207] The second information includes: at least one of intersatellite link status information and a downlink data storage and forwarding request from the server; the downlink data storage and forwarding request includes: at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

[0208] In some embodiments, the operations further include:

[0209] Feedback a downlink data storage and forwarding response to the server according to the downlink data sending mode;

[0210] Among them, the downlink data storage forwarding response carries downlink data storage forwarding information, and the downlink data storage forwarding information includes: the downlink data sending method, the terminal identifier, the PDU session identifier, the on-board storage configuration, the expected time of delivery of the downlink data, the candidate user address identifier, and at least one of the candidate user IP addresses.

[0211] In some embodiments, the on-board storage configuration includes at least one of: cache space, and retention time of cached data;

[0212] Alternatively, the on-board storage configuration does not include: cache space and cache data retention time, and the downlink data storage and forwarding information further includes: cache space and cache data retention time.

[0213] In some embodiments, the downlink data storage and forwarding information further includes: relevant information for monitoring the satellite equipment.

[0214] In some embodiments, the operations further include:

[0215] Determine a second mapping relationship between the identifier of the terminal, the identifier of the first session, and a related identifier of the server.

[0216] The present disclosure also provides a data transmission device, which is a server and includes a memory, a transceiver, and a processor.

[0217] A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0218] Receiving downlink data storage and forwarding information sent by the satellite equipment through the transceiver;

[0219] Sending downlink data to the satellite device through the transceiver according to the downlink data storage and forwarding information;

[0220] The downlink data storage and forwarding information includes at least one of: a downlink data transmission mode, a terminal identifier, a PDU session identifier, an on-board storage configuration, an estimated time of downlink data delivery, a candidate user address identifier, and a candidate user IP address;

[0221] The downlink data storage and forwarding information is carried in a notification to the terminal, where the notification is used to indicate that the terminal has activated the on-board store-and-forward operation, or is carried in a downlink data storage and forwarding response.

[0222] In some embodiments, sending downlink data to a satellite device according to the downlink data storage and forwarding information includes any one of the following:

[0223] In the process of receiving the uplink buffer data, sending the downlink data to the satellite device according to the downlink data storage and forwarding information;

[0224] The downlink data is sent to the satellite device according to the downlink data storage and forwarding information and the downlink data sending requirement information.

[0225] In some embodiments, the operations further include:

[0226] Before receiving the downlink data storage and forwarding information sent by the satellite device, sending a downlink data storage and forwarding request of the server to the satellite device through the transceiver;

[0227] The downlink data storage and forwarding request includes at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

[0228] The present disclosure also provides a data transmission device, which is applied to a terminal and includes:

[0229] A first receiving unit, configured to receive first information of a first session sent by a satellite device;

[0230] a second receiving unit, configured to receive downlink data through the first session according to the first information;

[0231] The first session refers to a session that continuously occupies the allocated resources;

[0232] The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

[0233] In some embodiments, the first information further includes at least one of the following:

[0234] Response method for receiving downlink data;

[0235] Paging time window;

[0236] Periodic registration timer;

[0237] Satellite identification.

[0238] In some embodiments, further comprising:

[0239] A first sending unit is configured to send a first request to the satellite device according to the downlink data reception requirement information before receiving the first information of the first session sent by the satellite device;

[0240] The receiving first information of the first session sent by the satellite device includes:

[0241] receiving a first response fed back by the satellite device, where the first response carries first information of a first session;

[0242] The first request carries at least one of the following:

[0243] Receive uplink data delivery confirmation;

[0244] Waiting to receive downlink data;

[0245] Receiving priority of downlink data;

[0246] Service type corresponding to the session.

[0247] In some embodiments, further comprising:

[0248] a first processing unit, configured to reserve air interface resources and session information corresponding to the session according to the first response;

[0249] The air interface resources are used to receive downlink data.

[0250] In some embodiments, further comprising:

[0251] a second processing unit, configured to, before receiving downlink data through the first session according to the first information, access the satellite device according to the first parameter and send a second request to the satellite device, where the second request is used to obtain information of a downlink data buffer component on the satellite device, or to indicate receiving downlink data, or to request registration, or to request sending uplink data;

[0252] a third receiving unit, configured to receive a second response fed back by the satellite device, where the second response carries information about the downlink data buffer component or carries instruction information instructing the terminal to use resources corresponding to the first session to receive downlink data;

[0253] The receiving downlink data through the first session according to the first information includes:

[0254] receiving, through the first session, downlink data sent by the downlink data buffer component on the satellite device according to the first information and the information of the downlink data buffer component or the indication information;

[0255] The first parameter includes at least one of: uplink data transmission status, candidate response methods for receiving downlink data, locally stored first session information, network paging reason, and relevant identification of the satellite device.

[0256] In some embodiments, the second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception mode for downlink data supported by the terminal;

[0257] And / or, the second response carries the downlink data receiving mode allowed by the satellite device.

[0258] In some embodiments, further comprising:

[0259] The second sending unit is configured to send a receiving mode for downlink data supported by the terminal to the satellite device.

[0260] In some embodiments, the receiving, through the first session, downlink data sent by the downlink data buffer component on the satellite device includes:

[0261] The downlink data sent by the satellite device according to the receiving mode and using the downlink data buffer component on the satellite device is received through the first session.

[0262] In some embodiments, further comprising:

[0263] A first determining unit, configured to determine a first mapping relationship between the session identification information of the first session and air interface resources;

[0264] The accessing the satellite device according to the first parameter includes:

[0265] Access the satellite device according to the first parameter and the first mapping relationship.

[0266] In some embodiments, the first session is a protocol data unit (PDU) session or a non-PDU session.

[0267] The present disclosure also provides a data transmission device, which is applied to satellite equipment and includes:

[0268] A third sending unit, configured to send first information of the first session to the terminal;

[0269] a fourth receiving unit, configured to send downlink data to the terminal through the first session according to the first information;

[0270] The first session refers to a session that continuously occupies the allocated resources;

[0271] The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

[0272] In some embodiments, the first information further includes at least one of the following:

[0273] Response method for receiving downlink data;

[0274] Paging time window;

[0275] Periodic registration timer;

[0276] Satellite identification.

[0277] In some embodiments, further comprising:

[0278] A second determining unit is configured to determine the response mode for receiving downlink data according to reference information; wherein the reference information includes: the time information, and at least one of a downlink reception priority;

[0279] And / or, determining a paging time window or a periodic registration timer corresponding to the terminal according to the ephemeris information of the satellite device.

[0280] In some embodiments, further comprising:

[0281] a third determining unit, configured to determine, according to the response mode for receiving downlink data, whether to initiate paging or wait for the terminal to access;

[0282] Wherein, when it is determined to initiate paging, the terminal is instructed to receive downlink data in the paging reason.

[0283] In some embodiments, further comprising:

[0284] a fourth receiving unit, configured to receive a first request sent by the terminal before sending the first information of the first session to the terminal;

[0285] The sending the first information of the first session to the terminal includes:

[0286] Feedback a first response to the terminal according to the first request, where the first response carries first information of the first session;

[0287] The first request carries at least one of the following:

[0288] Receive uplink data delivery confirmation;

[0289] Waiting to receive downlink data;

[0290] Receiving priority of downlink data;

[0291] Service type corresponding to the session.

[0292] In some embodiments, further comprising:

[0293] a third processing unit, configured to retain system resources and session information of a session corresponding to the first response;

[0294] The system resources are used to send downlink data.

[0295] In some embodiments, feeding back a first response to the terminal according to the first request includes:

[0296] In a case where the first request indicates a request to activate the on-board store-and-forward operation or the terminal has already activated the on-board store-and-forward operation, allocating resources and establishing a first session or updating an existing session to the first session according to the first request;

[0297] A first response is fed back to the terminal according to the first session.

[0298] In some embodiments, further comprising:

[0299] a fifth receiving unit, configured to receive a second request sent by the terminal before sending downlink data to the terminal through the first session according to the first information, wherein the second request is used to obtain information of a downlink data cache component on the satellite device, or to indicate receiving downlink data, or to request registration, or to request sending uplink data;

[0300] a first feedback unit, configured to feed back a second response to the terminal according to the second request, where the second response carries information about the downlink data buffer component or carries instruction information instructing the terminal to use resources corresponding to the first session to receive downlink data;

[0301] The sending downlink data to the terminal through the first session according to the first information includes:

[0302] According to the first information and the information of the downlink data buffer component or the instruction information, the downlink data buffer component on the satellite device is used to send downlink data to the terminal through the first session.

[0303] In some embodiments, the second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception mode for downlink data supported by the terminal;

[0304] And / or, the second response carries the downlink data receiving mode allowed by the satellite device.

[0305] In some embodiments, further comprising:

[0306] A sixth receiving unit is configured to receive a receiving mode for downlink data supported by the terminal and sent by the terminal.

[0307] In some embodiments, the sending downlink data to the terminal through the first session by using a downlink data buffer component on the satellite device includes:

[0308] According to the first information and the downlink data receiving mode supported by the terminal, the downlink data is sent to the terminal through the first session by utilizing the downlink data buffer component on the satellite device.

[0309] In some embodiments, the first session is a protocol data unit (PDU) session or a non-PDU session.

[0310] In some embodiments, further comprising:

[0311] a first cache unit, configured to cache a notification for the terminal, the notification being used to indicate that the terminal has activated an on-board store-and-forward operation;

[0312] The notification carries downlink data storage and forwarding information, and the downlink data storage and forwarding information includes: downlink data sending mode, the terminal identifier, PDU session identifier, on-board storage configuration, candidate user address identifier, and at least one of the candidate user IP address.

[0313] In some embodiments, further comprising:

[0314] The fifth sending unit is used to send the notification to the server.

[0315] In some embodiments, further comprising:

[0316] a fourth determining unit, configured to determine a downlink data sending mode according to the second information before sending the downlink data to the terminal through the first session according to the first information;

[0317] The second information includes: at least one of intersatellite link status information and a downlink data storage and forwarding request from the server; the downlink data storage and forwarding request includes: at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

[0318] In some embodiments, further comprising:

[0319] A second feedback unit is configured to feed back a downlink data storage and forwarding response to the server according to the downlink data sending mode;

[0320] Among them, the downlink data storage forwarding response carries downlink data storage forwarding information, and the downlink data storage forwarding information includes: the downlink data sending method, the terminal identifier, the PDU session identifier, the on-board storage configuration, the expected time of delivery of the downlink data, the candidate user address identifier, and at least one of the candidate user IP addresses.

[0321] In some embodiments, the on-board storage configuration includes at least one of: cache space, and retention time of cached data;

[0322] Alternatively, the on-board storage configuration does not include: cache space and cache data retention time, and the downlink data storage and forwarding information further includes: cache space and cache data retention time.

[0323] In some embodiments, the downlink data storage and forwarding information further includes: relevant information for monitoring the satellite equipment.

[0324] In some embodiments, further comprising:

[0325] The fifth determining unit is configured to determine a second mapping relationship between the identifier of the terminal, the identifier of the first session, and a related identifier of the server.

[0326] The present disclosure also provides a data transmission device, which is applied to a server and includes:

[0327] A seventh receiving unit, configured to receive downlink data storage and forwarding information sent by the satellite device;

[0328] a sixth sending unit, configured to send downlink data to the satellite device according to the downlink data storage and forwarding information;

[0329] The downlink data storage and forwarding information includes at least one of: a downlink data transmission mode, a terminal identifier, a PDU session identifier, an on-board storage configuration, an estimated time of downlink data delivery, a candidate user address identifier, and a candidate user IP address;

[0330] The downlink data storage and forwarding information is carried in a notification to the terminal, where the notification is used to indicate that the terminal has activated the on-board store-and-forward operation, or is carried in a downlink data storage and forwarding response.

[0331] In some embodiments, sending downlink data to a satellite device according to the downlink data storage and forwarding information includes any one of the following:

[0332] In the process of receiving the uplink buffer data, sending the downlink data to the satellite device according to the downlink data storage and forwarding information;

[0333] The downlink data is sent to the satellite device according to the downlink data storage and forwarding information and the downlink data sending requirement information.

[0334] In some embodiments, further comprising:

[0335] a seventh sending unit, configured to send a downlink data storage and forwarding request of the server to the satellite device before receiving the downlink data storage and forwarding information sent by the satellite device;

[0336] The downlink data storage and forwarding request includes at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

[0337] An embodiment of the present disclosure also provides a non-transitory readable storage medium, which stores a computer program, and the computer program is used to enable a processor to execute the above-mentioned terminal side, satellite device side or server side method.

[0338] The beneficial effects of the above technical solution disclosed in the present invention are as follows:

[0339] In the above scheme, the data transmission method receives the first information of the first session sent by the satellite device; based on the first information, receives downlink data through the first session; wherein, the first session refers to a session that continuously occupies the allocated resources; the first information includes: fixed session identification information, and time information during which the session continuously occupies the allocated resources; it can enable the terminal to accurately receive the corresponding downlink data through the maintained first session; in the case of non-end-to-end connection, through the maintained first session, the network can accurately determine the terminal corresponding to the downlink data, thereby ensuring that the target terminal accurately receives the downlink data; it well solves the problem in the related technology that in the case of non-end-to-end connection, the target terminal cannot be guaranteed to accurately receive the downlink data. BRIEF DESCRIPTION OF THE DRAWINGS

[0340] FIG1 is a schematic diagram of a wireless communication system architecture according to an embodiment of the present disclosure;

[0341] FIG2 is a schematic diagram of a tracking scenario in a remote area according to an embodiment of the present disclosure;

[0342] FIG3 is a schematic diagram of an on-board store-and-forward model according to an embodiment of the present disclosure;

[0343] FIG4 is a flowchart of a data transmission method according to an embodiment of the present disclosure;

[0344] FIG5 is a second flow chart of a data transmission method according to an embodiment of the present disclosure;

[0345] FIG6 is a third flowchart of a data transmission method according to an embodiment of the present disclosure;

[0346] FIG7 is a schematic diagram of a first embodiment of a data transmission method according to an embodiment of the present disclosure;

[0347] FIG8 is a second schematic diagram of a specific implementation flow of the data transmission method according to an embodiment of the present disclosure;

[0348] FIG9 is a third schematic diagram of a specific implementation flow of the data transmission method according to an embodiment of the present disclosure;

[0349] FIG10 is a fourth flowchart of a specific implementation of the data transmission method according to an embodiment of the present disclosure;

[0350] FIG11 is a fifth flowchart of a specific implementation of the data transmission method according to an embodiment of the present disclosure;

[0351] FIG12 is a sixth schematic diagram of a specific implementation flow of the data transmission method according to an embodiment of the present disclosure;

[0352] FIG13 is a first structural diagram of a data transmission device according to an embodiment of the present disclosure;

[0353] FIG14 is a second structural diagram of a data transmission device according to an embodiment of the present disclosure;

[0354] FIG15 is a third structural diagram of a data transmission device according to an embodiment of the present disclosure;

[0355] FIG16 is a first structural diagram of a data transmission device according to an embodiment of the present disclosure;

[0356] FIG17 is a second structural diagram of a data transmission device according to an embodiment of the present disclosure;

[0357] FIG18 is a third structural diagram of the data transmission device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0358] The following will be combined with the accompanying drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the embodiments described are only part of the embodiments of the present disclosure and not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0359] In the embodiments of the present disclosure, the term "and / or" describes the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0360] In the embodiments of the present disclosure, the term "plurality" refers to two or more than two, and other quantifiers are similar thereto.

[0361] It is explained here that the technical solutions provided by the embodiments of the present disclosure can be applicable to a variety of systems, especially 5G systems. For example, applicable systems can be global system of mobile communication (GSM) systems, code division multiple access (CDMA) systems, wideband code division multiple access (WCDMA) general packet radio service (GPRS) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, long term evolution advanced (LTE-A) systems, universal mobile telecommunication systems (UMTS), worldwide interoperability for microwave access (WiMAX) systems, 5G new air interface (NR) systems, etc. These various systems include terminal devices and network devices. The system can also include a core network part, such as an evolved packet system (EPS), a 5G system (5G System, 5GS), etc.

[0362] Figure 1 shows a block diagram of a wireless communication system to which embodiments of the present disclosure may be applied. The wireless communication system includes a terminal device (also referred to as a terminal) and a network device.

[0363] The terminal device involved in the embodiments of the present disclosure may be a device that provides voice and / or data connectivity to a user, a handheld device with wireless connection function, or other processing device connected to a wireless modem. In different systems, the name of the terminal device may also be different. For example, in a 5G system, the terminal device may be called User Equipment (UE). A wireless terminal device can communicate with one or more core networks (CN) via a radio access network (RAN). The wireless terminal device may be a mobile terminal device, such as a mobile phone (or "cellular" phone) and a computer with a mobile terminal device. For example, it may be a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device that exchanges voice and / or data with a radio access network. For example, personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), and other devices. The wireless terminal device may also be referred to as a system, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, an access point, a remote terminal device, an access terminal device, a user terminal device, a user agent, or a user device, but is not limited in the embodiments of the present disclosure.

[0364] The network device involved in the embodiments of the present disclosure may be a base station, which may include multiple cells providing services to terminals. Depending on the specific application scenario, the base station may also be called an access point, or may be a device in an access network that communicates with a wireless terminal device through one or more sectors on an air interface, or may be named by another name. The network device may be used to interchange received air frames with Internet Protocol (IP) packets, acting as a router between the wireless terminal device and the rest of the access network, wherein the rest of the access network may include an Internet Protocol (IP) communication network. The network device may also coordinate the attribute management of the air interface. For example, the network device involved in the embodiments of the present disclosure may be a base transceiver station (BTS) in the Global System for Mobile communications (GSM) or code division multiple access (CDMA), a network device (NodeB) in wide-band code division multiple access (WCDMA), an evolutionary Node B (eNB or e-NodeB) in the long term evolution (LTE) system, a 5G base station (gNB) in the next generation 5G network architecture, a home evolved Node B (HeNB), a relay node, a femto, a pico, etc., and is not limited in the embodiments of the present disclosure. In some network structures, the network device may include a centralized unit (CU) node and a distributed unit (DU) node, and the centralized unit and the distributed unit may also be geographically separated.

[0365] Network devices and terminal devices can each use one or more antennas for Multiple Input Multiple Output (MIMO) transmission. MIMO transmission can be single-user MIMO (SU-MIMO) or multi-user MIMO (MU-MIMO). Depending on the configuration and number of antenna combinations, MIMO transmission can be two-dimensional MIMO (2D-MIMO), three-dimensional MIMO (3D-MIMO), full-dimensional MIMO (FD-MIMO), or massive MIMO. It can also use diversity transmission, precoding, or beamforming.

[0366] The following first introduces the contents involved in the solution provided by the embodiment of the present disclosure.

[0367] In remote areas or disaster zones where ground base stations are difficult to deploy, mobile communication networks can provide terminals with communication services via satellite to access the terrestrial network. However, in actual deployment, due to the limited number of gateways or restricted site locations, some areas (such as offshore and polar regions) may have satellite base station coverage but no local gateway to provide real-time connection to the terrestrial network. In addition, non-geostationary satellites (such as low-orbit satellites) move rapidly relative to the ground, and the feeder link from the satellite base station to the terrestrial network may become intermittent or temporarily unavailable. In this case, the mobile communication network will be unable to provide the terminal with an end-to-end connection to the ground server via satellite to transmit the terminal's business data to the terrestrial network or obtain data from the ground server in real time.

[0368] In response to the above situation, when the terminal does not have high requirements for data transmission latency, the mobile communication network can cache the terminal's uplink data in the onboard device and forward it to the ground network when the satellite and the gateway establish an available link. Alternatively, the received ground server data can be cached in the onboard device and sent to the terminal after the satellite and the terminal establish a connection. This provides a non-real-time communication service between the terminal and the application server, which can be called a communication service based on on-board storage and forwarding.

[0369] The following is a detailed introduction to the relevant content.

[0370] 1. Scenarios where on-board store-and-forwarding is required;

[0371] Current research has highlighted scenarios where remotely deployed Internet of Things (IoT) devices are used for data collection. For example, research institutions collect data on polar animals to study their habits or movements, as shown in Figure 2; government agencies conduct remote measurements for disaster warning (e.g., submarine cable monitoring). These IoT devices primarily operate in remote locations or environments with challenging environments, making it difficult to obtain support from ground-based base stations. Consequently, they often rely on satellites for remote data transmission. Because these devices have low latency requirements and the location may lack a gateway or lack a stable connection to a local gateway for various reasons, data can be uploaded and cached onboard a satellite device, which can then be forwarded when the satellite can connect to a gateway or terminal.

[0372] 2. On-board store-and-forward model;

[0373] To support these scenarios, the study proposes an onboard store-and-forward model, as shown in Figure 3. Terminals send data to the satellite for caching or retrieve cached data. When the satellite connects to a gateway or another gateway via an intersatellite link, it sends the cached data to the terrestrial network or retrieves data from the terrestrial network. Regarding network architecture, it is possible to consider deploying base stations and possibly some core network elements on the satellite.

[0374] 3. 5G architecture;

[0375] In the 5G core network reference point architecture, N6 is the interface between the User Plane Function (UPF) and the Data Network (DN). N33 is the direct interface between the Network Exposure Function (NEF) and the Application Function (AF), used to expose core network capabilities. The DN and AF can be deployed together or separately.

[0376] 4. Internet of Things Non-IP Data Delivery (NIDD);

[0377] Currently, the control plane optimization features of the Cellular Internet of Things (CIoT) 5G System (5GS) are defined:

[0378] The control plane CIoT 5GS is optimized for exchanging user data between the terminal (User Equipment, UE) and the session management function (Session Management Function, SMF) as the payload of the non-access stratum (Non-Access-Stratum, NAS) message in the uplink and downlink directions, avoiding the establishment of the user plane connection of the protocol data unit (Protocol Data Unit, PDU) session. The UE and the access and mobility management function (Access and Mobility Management Function, AMF) perform integrity protection and encryption on the user data by using NAS PDU integrity protection and encryption. For IP (Internet Protocol Association) and Ethernet data, the UE and SMF can negotiate and perform header compression.

[0379] Specifically, the UE and AMF negotiate to support and use the control plane cellular Internet of Things (CIoT) 5GS optimization. When the control plane CIoT 5GS optimization function is used and the PDU session type is unstructured, the SMF selects the NEF or UPF based on the UE subscription information.

[0380] During the PDU session establishment procedure, AMF indicates to SMF that the control plane CIoT 5GS optimization is available for data transmission.

[0381] In addition, the Non-IP Data Delivery (NIDD) feature is currently defined.

[0382] The core network establishes an unstructured PDU session between the UE and the AF to complete the transmission of uplink and downlink data. Typically, this can be delivered using the Application Programming Interface (API) provided by the NEF to the AF, or using the UPF using a point-to-point N6 tunnel.

[0383] Based on the above, the embodiments of the present disclosure provide a data transmission method, apparatus, and device to address the related art issue of being unable to ensure that a target terminal accurately receives downlink data in a non-end-to-end connection. The method, apparatus, and device are based on the same patent application concept. Since the principles for solving the problems in the method, apparatus, and device are similar, their implementation can refer to each other, and any repetitions will not be repeated.

[0384] The data transmission method provided in the embodiment of the present disclosure is applied to a terminal, as shown in FIG4 , and includes:

[0385] Step 41: Receive first information of a first session sent by a satellite device;

[0386] Step 42: Receive downlink data through the first session according to the first information; wherein the first session refers to a session that continuously occupies the allocated resources; the first information includes: fixed session identification information, and time information for which the session continuously occupies the allocated resources.

[0387] The time information may include: term type, such as permanent (ie always) or limited term. For a limited term, it may also include the specific time of the limited term, but is not limited thereto.

[0388] The "downlink data" may include application or user-related data sent by an application server, which can be used for communication between the terminal and a remote user, or for updating the configuration of applications within the terminal, indicating subsequent operations, etc. This downlink data may be application data. Specifically, "receiving downlink data through the first session" may include, but is not limited to, establishing a link for information exchange through the first session and using the link to carry the downlink data for transmission.

[0389] The data transmission method provided by the embodiment of the present disclosure receives first information of a first session sent by a satellite device; receives downlink data through the first session based on the first information; wherein the first session refers to a session that continuously occupies allocated resources; the first information includes: fixed session identification information, and time information during which the session continuously occupies allocated resources; enables the terminal to accurately receive corresponding downlink data through the maintained first session; supports the network to accurately determine the terminal corresponding to the downlink data through the maintained first session in the case of non-end-to-end connection, thereby ensuring that the target terminal accurately receives the downlink data; and effectively solves the problem in the related art that in the case of non-end-to-end connection, it is impossible to ensure that the target terminal accurately receives the downlink data.

[0390] The first information further includes at least one of the following: a response method for receiving downlink data; a paging time window; a periodic registration timer; and a satellite identifier.

[0391] This can support resource management. The response mode may correspond to paging or active access, but is not limited thereto.

[0392] Furthermore, before receiving the first information of the first session sent by the satellite device, it also includes: sending a first request to the satellite device according to the downlink data receiving demand information; the receiving of the first information of the first session sent by the satellite device includes: receiving a first response fed back by the satellite device, the first response carrying the first information of the first session; wherein the first request carries at least one of the following: receiving uplink data delivery confirmation; waiting for receiving downlink data; receiving priority of downlink data; service type corresponding to the session.

[0393] This also supports resource management. After receiving the first response, the terminal can complete the establishment or update of the session, save the satellite identifier (and / or base station identifier and / or cell identifier), session information, and allocated air interface resources, and establish a mapping relationship between the configuration and the air interface resources (see the first mapping relationship below). Subsequently, when the terminal needs to initiate a registration process or needs to access the network to send uplink data, it can give priority to the satellite access network for establishing the session, but is not limited to this.

[0394] In the embodiment of the present disclosure, the data transmission method further includes: reserving air interface resources and session information corresponding to the session according to the first response; wherein the air interface resources are used to receive downlink data.

[0395] This also supports resource management to ensure the transmission of subsequent downlink data. "Reserving the air interface resources for the corresponding session" can omit the renegotiation process and trigger new resource negotiation only when the resource cannot complete the reception operation, but this is not limited to this.

[0396] Furthermore, the data transmission method, before receiving downlink data through the first session according to the first information, further includes: accessing the satellite device according to a first parameter and sending a second request to the satellite device, the second request being used to obtain information of a downlink data cache component on the satellite device or indicating reception of downlink data or requesting registration or sending uplink data; receiving a second response fed back by the satellite device, the second response carrying information of the downlink data cache component or carrying indication information instructing the terminal to use resources corresponding to the first session to receive downlink data; receiving downlink data through the first session according to the first information includes: receiving downlink data sent by the downlink data cache component on the satellite device through the first session according to the first information and the information of the downlink data cache component or the indication information; wherein the first parameter includes at least one of: uplink data transmission status, candidate response methods for receiving downlink data, locally stored first session information, a reason for network paging, and a related identifier of the satellite device.

[0397] This can support the accurate implementation of the downlink data reception process.

[0398] The second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception method for downlink data supported by the terminal; and / or the second response carries a reception method for downlink data allowed by the satellite device.

[0399] This can also support the process of accurately receiving downlink data.

[0400] Furthermore, the data transmission method further includes: sending a receiving mode for downlink data supported by the terminal to the satellite device.

[0401] This makes it easier for the satellite device to accurately obtain the receiving mode.

[0402] The receiving of the downlink data sent by the downlink data cache component on the satellite device through the first session includes: receiving the downlink data sent by the satellite device according to the receiving mode and using the downlink data cache component on the satellite device through the first session.

[0403] This makes it easier to accurately receive downlink data.

[0404] Furthermore, the data transmission method also includes: determining a first mapping relationship between the session identification information of the first session and the air interface resources; accessing the satellite device according to the first parameter includes: accessing the satellite device according to the first parameter and the first mapping relationship.

[0405] This allows for accurate access to satellite equipment.

[0406] The first session is a protocol data unit (PDU) session or a non-PDU session.

[0407] This can ensure the diversity of the implementation of this solution.

[0408] The present disclosure also provides a data transmission method, which is applied to a satellite device, as shown in FIG5 , and includes:

[0409] Step 51: Sending first information of a first session to a terminal;

[0410] Step 52: Send downlink data to the terminal through the first session according to the first information; wherein the first session refers to a session that continuously occupies the allocated resources; the first information includes: fixed session identification information, and time information for which the session continuously occupies the allocated resources.

[0411] The data transmission method provided by the embodiment of the present disclosure is through sending first information of a first session to a terminal; sending downlink data to the terminal through the first session according to the first information; wherein the first session refers to a session that continuously occupies the allocated resources; the first information includes: fixed session identification information, and time information during which the session continuously occupies the allocated resources; it is possible to enable the terminal to accurately receive the corresponding downlink data through the maintained first session; in the case of a non-end-to-end connection, the network can accurately determine the terminal corresponding to the downlink data through the maintained first session, thereby ensuring that the target terminal accurately receives the downlink data; it is a good solution to the problem in the related art that in the case of a non-end-to-end connection, the target terminal cannot be guaranteed to accurately receive the downlink data.

[0412] The first information further includes at least one of the following: a response method for receiving downlink data; a paging time window; a periodic registration timer; and a satellite identifier.

[0413] This can support resource management. The response mode may correspond to paging or active access, but is not limited thereto.

[0414] Furthermore, the data transmission method also includes: determining the response method for receiving downlink data based on reference information; wherein the reference information includes: the time information, and at least one of the downlink reception priorities; and / or, determining the paging time window or periodic registration timer corresponding to the terminal based on the ephemeris information of the satellite device.

[0415] In this way, the above-mentioned response mode and / or the paging time window or periodic registration timer corresponding to the terminal can be accurately obtained.

[0416] In an embodiment of the present disclosure, the data transmission method further includes: determining whether to initiate paging or wait for the terminal to access based on the response method for receiving downlink data; wherein, when it is determined to initiate paging, the terminal is instructed to receive downlink data in the paging reason.

[0417] This ensures that the terminal receives downlink data accurately. Specifically, the satellite device decides whether to initiate paging or wait for the terminal to access based on the response method. When initiating a paging call, the paging reason instructs the terminal to receive downlink buffered data.

[0418] Furthermore, before sending the first information of the first session to the terminal, it also includes: receiving a first request sent by the terminal; sending the first information of the first session to the terminal includes: based on the first request, feeding back a first response to the terminal, and the first response carries the first information of the first session; wherein, the first request carries at least one of the following: receiving an uplink data delivery confirmation; waiting for receiving downlink data; the receiving priority of downlink data; the service type corresponding to the session.

[0419] This can support resource management. "Feeding back a first response to the terminal according to the first request" may include, but is not limited to, feeding back a first response to the terminal according to the first request and ephemeris information.

[0420] In an embodiment of the present disclosure, the data transmission method further includes: reserving system resources and session information of a session corresponding to the first response; wherein the system resources are used to send downlink data.

[0421] This can also support resource management to ensure the transmission of subsequent downlink data. Specifically, the session information and allocated resource configuration can be retained during the session keep alive period, but the present invention is not limited thereto.

[0422] Among them, the feeding back a first response to the terminal based on the first request includes: when the first request indicates a request to activate the on-board store-and-forward operation or the terminal has activated the on-board store-and-forward operation, according to the first request, allocating resources and establishing a first session or updating the existing session to a first session; and feeding back a first response to the terminal based on the first session.

[0423] This allows for accurate feedback of the first response.

[0424] Furthermore, before sending downlink data to the terminal through the first session according to the first information, it also includes: receiving a second request sent by the terminal, the second request is used to obtain information of the downlink data cache component on the satellite device or indicate receiving downlink data or for requesting registration or for requesting sending uplink data; according to the second request, a second response is fed back to the terminal, the second response carries information of the downlink data cache component or carries indication information instructing the terminal to use the resources corresponding to the first session to receive downlink data; sending downlink data to the terminal through the first session according to the first information includes: according to the first information and the information of the downlink data cache component or the indication information, using the downlink data cache component on the satellite device to send downlink data to the terminal through the first session.

[0425] This can support the accurate implementation of the downlink data reception process.

[0426] The second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception method for downlink data supported by the terminal; and / or the second response carries a reception method for downlink data allowed by the satellite device.

[0427] This can also support the process of accurately receiving downlink data.

[0428] Furthermore, the data transmission method further includes: receiving a receiving mode for downlink data supported by the terminal and sent by the terminal.

[0429] In this way, the receiving mode can be accurately obtained.

[0430] The step of sending downlink data to the terminal through the first session by using the downlink data caching component on the satellite device includes sending downlink data to the terminal through the first session by using the downlink data caching component on the satellite device according to the first information and the reception method for downlink data supported by the terminal.

[0431] This allows downlink data to be sent accurately.

[0432] In the embodiment of the present disclosure, the first session is a protocol data unit (PDU) session or a non-PDU session.

[0433] This can ensure the diversity of the implementation of this solution.

[0434] Furthermore, the data transmission method also includes: caching a notification for the terminal, the notification being used to indicate that the terminal has activated the on-board storage and forwarding operation; wherein the notification carries downlink data storage and forwarding information, and the downlink data storage and forwarding information includes: downlink data sending mode, the terminal identifier, the PDU session identifier, the on-board storage configuration, the candidate user address identifier, and at least one of the candidate user IP addresses.

[0435] This can support the accurate implementation of the downlink data caching process.

[0436] In the embodiment of the present disclosure, the data transmission method further includes: sending the notification to the server.

[0437] This can support triggering related operations on the server side.

[0438] Furthermore, before sending downlink data to the terminal through the first session according to the first information, it also includes: determining the downlink data sending method according to the second information; wherein, the second information includes: at least one of the inter-satellite link status information and the server's downlink data storage and forwarding request; the downlink data storage forwarding request includes: at least one of the downlink forwarding strategy, forwarding priority and downlink data delivery confirmation method.

[0439] This can further support the process of accurately implementing downlink data caching.

[0440] In an embodiment of the present disclosure, the data transmission method further includes: feeding back a downlink data storage forwarding response to the server based on the downlink data sending method; wherein the downlink data storage forwarding response carries downlink data storage forwarding information, and the downlink data storage forwarding information includes: the downlink data sending method, the terminal identifier, the PDU session identifier, the on-board storage configuration, the expected time of delivery of the downlink data, the candidate user address identifier, and at least one of the candidate user IP addresses.

[0441] This can also further support the process of accurately implementing downlink data caching.

[0442] In which, the on-board storage configuration includes: cache space, and at least one of the retention time of cached data; or, the on-board storage configuration does not include: cache space and the retention time of cached data, and the downlink data storage forwarding information also includes: cache space, and at least one of the retention time of cached data.

[0443] This ensures that the on-board storage configuration includes at least one of the cache space and the retention time of the cached data.

[0444] Furthermore, the downlink data storage and forwarding information also includes: relevant information for monitoring the satellite equipment.

[0445] This makes it easier for the server to accurately monitor the target satellite. The relevant information of the satellite device may include at least one of the satellite identifier, the transmission time window, and the like.

[0446] In the embodiment of the present disclosure, the data transmission method further includes: determining a second mapping relationship between the identifier of the terminal, the identifier of the first session, and a related identifier of the server.

[0447] This can also further support the accurate implementation of the downlink data caching process. The second mapping relationship can be used to manage data or notifications, for example, it can be used to process cached "notifications for the terminal", but is not limited thereto.

[0448] The present disclosure also provides a data transmission method, which is applied to a server, as shown in FIG6 , and includes:

[0449] Step 61: Receive downlink data storage and forwarding information sent by the satellite device;

[0450] Step 62: Send downlink data to the satellite device according to the downlink data storage and forwarding information; wherein the downlink data storage and forwarding information includes: downlink data sending mode, terminal identifier, PDU session identifier, on-board storage configuration, expected time of delivery of downlink data, candidate user address identifier, and at least one of the candidate user IP addresses; the downlink data storage and forwarding information is carried in a notification to the terminal, the notification is used to indicate that the terminal has activated the on-board storage and forwarding operation, or is carried in a downlink data storage and forwarding response.

[0451] The data transmission method provided by the embodiment of the present disclosure receives downlink data storage and forwarding information sent by a satellite device; sends downlink data to the satellite device according to the downlink data storage and forwarding information; wherein the downlink data storage and forwarding information includes: downlink data sending mode, terminal identifier, PDU session identifier, on-board storage configuration, expected time of delivery of downlink data, candidate user address identifier, and at least one of the candidate user IP addresses; the downlink data storage and forwarding information is carried in a notification to the terminal, and the notification is used to indicate that the terminal has activated the on-board storage and forwarding operation, or is carried in a downlink data storage and forwarding response; it can support the terminal to accurately receive the corresponding downlink data through the maintained first session; it supports that in the case of non-end-to-end connection, the network can accurately determine the terminal corresponding to the downlink data through the maintained first session, thereby ensuring that the target terminal accurately receives the downlink data; it well solves the problem in the related art that in the case of non-end-to-end connection, the target terminal cannot be guaranteed to accurately receive the downlink data.

[0452] Among them, sending downlink data to the satellite device according to the downlink data storage and forwarding information includes any one of the following items: sending downlink data to the satellite device according to the downlink data storage and forwarding information during the process of receiving uplink cache data; sending downlink data to the satellite device according to the downlink data storage and forwarding information and downlink data sending demand information.

[0453] This allows for diversified downlink data transmission. The phrase "sending downlink data to the satellite device based on the downlink data storage and forwarding information and the downlink data transmission requirement information" can be understood as meaning that, when downlink data needs to be sent, the downlink data is sent to the satellite device based on the downlink data storage and forwarding information, but the present invention is not limited thereto.

[0454] Furthermore, before receiving the downlink data storage and forwarding information sent by the satellite device, it also includes: sending a downlink data storage and forwarding request of the server to the satellite device; wherein the downlink data storage and forwarding request includes: at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

[0455] This allows the server to accurately obtain the corresponding downlink data storage and forwarding response.

[0456] The data transmission method provided in the embodiment of the present disclosure is described below with an example, where the server takes an application server as an example, and the first session takes a PDU session as an example.

[0457] In response to the above technical problems, an embodiment of the present disclosure provides a data transmission method, which can be specifically implemented as a method for a terminal to obtain downlink data from a server (it can also be called a method for a terminal to obtain downlink data under an onboard store-and-forward operation) to achieve end-to-end (i.e., application server to terminal) transmission of downlink data. This solution mainly involves: for a UE with activated store-and-forward, if the UE indicates the network (i.e., indicates to the network) that there is expected downlink data (such as end-to-end confirmation information for uplink data, information that the UE has been pre-configured to receive downlink data, etc.), then the network reserves the allocated network resources for the UE until the UE completes the reception of the downlink data. If the UE is unaware of whether there is downlink data, but the application server has data (such as UE configuration information) to send, then the network (corresponding to the above-mentioned satellite equipment) instructs the application server to prioritize the reuse of the uplink data storage and forwarding resources allocated to the UE in accordance with a certain principle.

[0458] The following is a specific example to illustrate this solution.

[0459] Example 1: The UE has activated on-board store-and-forward or requested to activate store-and-forward, or the network activated the store-and-forward operation based on the power supply situation, and the UE expects to receive downlink data, and the network establishes a keep-alive PDU session (corresponding to the first session above);

[0460] Architecture 1: Base stations + lightweight core network (AMF + SMF + Unified Data Management (UDM) function + UPF + NEF) deployed on the same satellite;

[0461] Architecture 2: Base stations + UPF are deployed on low-orbit satellites, and lightweight core networks (AMF + SMF + UDM) are deployed on high-orbit satellites;

[0462] As shown in Figure 7, the solution in this example includes the following steps:

[0463] 1-2. In one or more of the following situations, the terminal carries information indicating the reception of downlink data in the request to establish or update a PDU session (i.e., a PDU session establishment / update request; corresponding to the above-mentioned first request), such as an "uplink data delivery confirmation" indication or an "expectation to receive downlink data" indication, and the reception priority of the downlink data.

[0464] Case (1): The terminal needs to receive confirmation information from the server for uplink data;

[0465] Case (2): The terminal needs to receive the server's response information for uplink data;

[0466] Case (3): According to pre-configuration, the terminal needs to receive downlink data from the application server.

[0467] 3.AMF forwards the PDU session establishment / update request to SMF, specifically:

[0468] 3a. The PDU session establishment / update request carries information for activating on-board store-and-forward (and may also carry the information carried in the first request);

[0469] Or, 3b.AMF determines that the terminal has activated on-board store-and-forward or activates on-board store-and-forward based on the power supply situation, and notifies SMF when forwarding the PDU session establishment / update request;

[0470] Or, 3c.SMF queries AMF or UDM whether the terminal has activated on-board store-and-forward.

[0471] 4. Based on the information that the terminal has activated or requested to activate on-board storage and forwarding and receiving downlink data requests, such as the "uplink data delivery confirmation" indication or the "expectation to receive downlink data" indication, the SMF determines to establish a keep-alive PDU session in the UPF or NEF or update the existing PDU session to a keep-alive PDU session (that is, a PDU session that retains resources, that is, continues to occupy the allocated resources and does not release them, and each network element will store the relevant context); corresponding to the above-mentioned allocation of resources and establishment of the first session or updating the existing session to the first session according to the first request. The SMF determines one or more parameters of the PDU session, such as always keeping alive, keeping alive for a limited period, and the validity period of keeping alive (corresponding to the time information of the above-mentioned session continuously occupying the allocated resources) based on the UE's subscription information, PDU session type (such as IP session, unstructured session, etc.), downlink data reception priority (such as high priority, low priority, etc.) and ephemeris information. Specifically:

[0472] 4a. If the PDU session is an IP session, the UPF on the same satellite as the base station is used as the anchor point, and the network keeps the UE IP address unchanged (ie, the selected UPF is located on the same satellite as the base station, and the IP address assigned to the terminal remains unchanged);

[0473] Or 4b. [Applicable to Architecture 1] If the PDU session is an unstructured session, the NEF on the same satellite as the base station is used as the anchor point, and the network maintains the mapping relationship between the UE identifier (such as the Generic Public Subscription Identifier (GPSI)), the PDU session identifier, and the AF (server) identifier (corresponding to the second mapping relationship between the identifier of the above-mentioned terminal, the identifier of the first session, and the relevant identifier of the server). If the NEF cannot obtain the NIDD (non-IP data transmission) information in the UE subscription information or configuration, because the N33 interface between the NEF and the AF is unavailable, the NEF or SMF requests the UE to report the target server identifier or the target server address identifier; or allocates a temporary AF identifier and establishes a mapping between the UE identifier, the PDU session identifier, the DN information, and the temporary AF identifier.

[0474] 5a.SMF sends a PDU session establishment or update response message to AMF, including information such as keep-alive session identifier (corresponding to the keep-alive PDU session in the figure), always keep-alive, limited keep-alive, keep-alive validity period, allowed downlink reception priority, etc.

[0475] In some embodiments, it may also include: 5b. SMF has an event subscription to notify AF, triggering NEF to notify AF that the UE activates storage and forwarding and establishes PDU session information; specifically, the event that triggers notification to AF (UE identity, activation of storage and forwarding, PDU session information, etc.).

[0476] 6. The AMF determines the recommended or preferred response mode of the UE (such as waiting for paging or UE active access, both of which are possible) based on the downlink reception priority based on one or more information of whether the PDU session is a keep-alive session and always keep-alive, keep-alive for a limited period, and the validity period of the keep-alive, and determines the UE-specific paging time window or UE periodic registration timer based on the ephemeris information; corresponding to the above-mentioned determination of the response mode for receiving downlink data based on the reference information; wherein the reference information includes: the time information, and at least one of the downlink reception priorities; and / or, determining the paging time window or periodic registration timer corresponding to the terminal based on the ephemeris information of the satellite device.

[0477] 7.AMF sends the PDU session establishment or update response and PDU session information (keep-alive PDU session, always keep-alive, limited keep-alive, keep-alive validity period) to the UE through a NAS message; and sends one or more of the "recommended or preferred response method" indication, UE-specific paging time window, and periodic registration timer to the UE through the same NAS message or by initiating the UE configuration update procedure.

[0478] 8. The UE saves the mapping relationship between the satellite identifier, base station identifier and / or cell identifier (corresponding to the relevant identifiers of the above-mentioned satellite equipment) and the PDU session and (UE) configuration information (corresponding to the above-mentioned first mapping relationship).

[0479] It is explained here that Example 1 involves establishing a keep-alive session and allocating resources, which can be combined with any of the following examples to complete downlink data transmission, but is not limited thereto.

[0480] Example 2: A base station + lightweight core network (AMF+SMF+UDM+UPF+NEF) is deployed on the same satellite, and downlink data is transmitted through the user plane and stored on the UPF.

[0481] In this scenario, when the UE accesses serving satellite 1, there is no power feed between satellite 1 and the ground gateway, and neither control plane information nor user plane data can reach the ground in a timely manner. By the time the satellite moves to connect to the gateway, the UE may no longer be within the satellite's coverage area, meaning the air interface connection between the UE and the base station has been disconnected.

[0482] As shown in Figure 8, the solution in this example includes the following steps:

[0483] 0. The UE has activated store-and-forward, and the network establishes a PDU session for the UE. As the satellite moves, the feeder link between the satellite and the gateway becomes available, establishing N6 and N33 connections. Further:

[0484] [Scenario A] 0a. The UE has uplink data cached in the UPF. At this time, the network maintains the UE's registration status and PDU session information.

[0485] 0b. After the N6 interface is established, the UPF forwards the uplink data to the ground server. The server obtains the UE identifier, UE IP address, and PDU session information.

[0486] [Scenario B] The UE has no uplink data cache, but establishes a keep-alive PDU session anchored at the UPF. The network retains the UE's registration status and PDU session information.

[0487] 0c-0e. When the UE registers, based on the UE's subscription information or UE policy, the AMF or UDM subscribes to the SMF to notify the target AF of the event of activating store-and-forward UE. Alternatively, the NEF subscribes to the SMF to notify the target AF of the event of activating store-and-forward UE. When the notification is triggered, the target AF's information (such as AF ID, server IP address, data network name DNN, data network access identifier DNAI) can be transmitted. When the network activates store-and-forward for the UE and establishes a keep-alive PDU session, the SMF notifies the NEF to trigger the "event of notifying the AF (i.e., notifying the target AF of the event of activating store-and-forward UE)", and carries the UE ID, activation store-and-forward ID, target AF information, and PDU session information (such as PDU session ID, PDU session type, UE IP address, etc.). The NEF caches the notification (also called the activation store-and-forward notification; corresponding to the above-mentioned cached notification for the terminal, the notification is used to indicate that the terminal has activated the on-board store-and-forward operation) and forwards the notification to the AF or a third-party server after the feeder link is available to establish the N33 interface.

[0488] 1. The AF or a third-party server has downlink data to send to the UE (e.g., delivery confirmation of uplink data, other data (e.g., notification information)) and selects a satellite that can provide store-and-forward services. It can reuse the PDU session and serving satellite recorded when receiving uplink data (Scenario A, 0b) or receiving the store-and-forward activation notification (Scenario B, 0c-0e). If no record exists, an active query can be initiated, see 2a below.

[0489] 2a. In some embodiments, when the feeder link is available, the AF queries the UE through the NEF based on the UE identity and AF information whether an available PDU session supporting store-and-forward has been established (ie, queries whether the UE has activated store-and-forward and PDU session information).

[0490] 3. When feed is available, the AF obtains the allocated buffer size, buffered data retention time, and supported forwarding strategies (e.g., timely forwarding or delay-tolerant forwarding, either of which is acceptable) from the NEF or SMF. This means querying the stored forwarding information. Based on one or more of these pieces of information and the ephemeris information, the AF decides whether to select the current satellite. If the requirements are not met, the AF abandons the current satellite and waits for connection to the next satellite, repeating steps 1-3 of this example.

[0491] 4. Select the satellite, AF sends a request for downlink data storage and forwarding to NEF or SMF (such as the expected downlink forwarding strategy, forwarding priority, downlink data delivery confirmation, etc.). NEF or SMF feeds back a response for downlink data storage and forwarding. Specifically:

[0492] 4a. The SMF determines the downlink forwarding method (i.e., forwarding via ISL relay or retaining it on the local satellite) based on the desired forwarding strategy (e.g., timely forwarding or delay-tolerant forwarding), one or more forwarding priorities (high priority or low priority), and the availability of the ISL. For example, for data with a forwarding strategy of "immediate forwarding," ISL relay can be selected; for data with a forwarding strategy of "delay-tolerant forwarding," retaining it on the local satellite can be selected.

[0493] 4b. After receiving the confirmation (i.e., the response of the downlink data storage and forwarding), the AF sends the downlink data to the UPF cache.

[0494] 5-7. Satellites use different forwarding methods:

[0495] [Method A] Relay forwarding via intersatellite links;

[0496] 5a. The SMF finds the UE's current serving satellite, Satellite 2, or selects Satellite 2, which can provide faster service to the UE, based on information such as the arrival time of other satellites and the UPF cache space. The SMF forwards the data to the corresponding UPF (this can be done using existing mechanisms and is not detailed here). Satellite 2 can then use [Method B] or [Method C] described below.

[0497] [Mode B] Forwarding by this satellite, the allowed downlink reception priority = high priority;

[0498] 5b. The UPF or SMF notifies the AMF that there is downlink data retention (i.e. notifies the AMF to establish a user plane connection with the UE). The UE's preferred response method is paging or both (i.e. paging and active access). The AMF determines that the UE is reachable as soon as possible.

[0499] 6. The AMF determines the reachable time of the UE based on the ephemeris information and the UE location, and initiates paging before the paging time window is reached, or notifies the RAN of the reachable time of the UE, which then determines the paging time.

[0500] 7. The UE restores the user plane tunnel and possible N3 tunnel from the UE to the RAN (i.e., restores the user plane connection) through the service request process; this may correspond to the above-mentioned second request for indicating the reception of downlink data.

[0501] 8.AMF notifies SMF that "UE is reachable" and UPF forwards the downlink cache data (i.e. cached downlink data) to the UE.

[0502] [Mode C] Forwarding by this satellite, the allowed downlink reception priority = low priority;

[0503] 5c. The UPF or SMF notifies the AMF that there is downlink data retention. The UE's preferred response mode is UE-initiated access. The AMF does not initiate paging but waits for UE-initiated access.

[0504] 6-7. The UE initiates a registration request (or service request, carrying PDU session information; which may correspond to the second request mentioned above for registration request) to the AMF based on the periodic registration timer configured by the network. The AMF determines that the current UE is the target UE for retained data based on the UE identifier, and carries the identifier of "activating the user plane connection of this PDU session" or the identifier of "downlink data arrival" and the PDU session information in the registration request response (or request response). The UE activates the user plane connection based on the response;

[0505] When the UE has uplink data to send, it can preferentially access the current satellite based on the locally stored keep-alive PDU session information and satellite identifier (and / or base station identifier and / or cell identifier; corresponding to the relevant identifier of the above-mentioned satellite device), initiate a service request (corresponding to the above-mentioned access to the satellite device based on the first parameter, and send a second request to the satellite device; the second request is used to request to send uplink data), and carry PDU session information (such as PDU session identifier). Based on the UE identifier and PDU session identifier, the AMF determines that the current UE is the target UE for retained data, and executes the service request response process to activate the user plane connection.

[0506] 8.AMF notifies SMF that "UE is reachable", and UPF forwards the downlink cache data to the UE (corresponding to the above-mentioned terminal receiving downlink data through the first session based on the first information).

[0507] Example 3: Base stations + UPF are deployed on low-orbit satellites, and lightweight core networks (AMF + SMF + UDM) are deployed on high-orbit satellites. NEF is deployed on high-orbit satellites or on the ground, and is transmitted through the user plane. Downlink data is stored on the UPF.

[0508] In this scenario, a high-orbit satellite connects to a ground gateway via a continuously or intermittently available feed, sending control plane information to the ground. When a low-orbit satellite serves a user interface (UE), there is no feed to the ground gateway, and user plane data cannot reach the ground in a timely manner. By the time the low-orbit satellite reaches the gateway, the UE may no longer be within the satellite's coverage area, meaning the air interface connection between the UE and the base station has been lost.

[0509] As shown in Figure 9, the solution in this example includes the following steps:

[0510] 0a-c. The AF or a third-party server subscribes to NEF or other Network Functions (NF) to notify the AF of events (which may carry the AF identifier, information about the UE that activated the store-and-forward service, etc.): When a UE activates the store-and-forward service, the AF is notified. When the network activates the store-and-forward operation for the UE or establishes a keep-alive PDU session, the NEF or other NF is triggered to send a notification to the AF, which carries the UE identifier and the serving satellite identifier. In some embodiments, it may also carry one or more information such as PDU session information, an indication of the presence of uplink buffered data, and an indication of uplink data delivery confirmation.

[0511] The "activation of the store-and-forward operation" indicates that the UE has an established keep-alive or non-keep-alive PDU session.

[0512] 1. When the server (including AF or third-party server) has downlink data, it sends a "downlink data storage and forwarding request" message to the NEF or other NF, carrying one or more information such as UE identification, data service type, downlink data volume, expected retention time, expected downlink data sending method, forwarding priority, and downlink data delivery confirmation.

[0513] 2.NEF or other NF (such as SMF or network storage function NRF or UDM or network data analysis function (NWDAF)) determines the downlink data sending mode (such as simultaneous sending and receiving, immediate sending, etc.; corresponding to the above-mentioned determination of the downlink data sending mode based on the second information) according to the information in the "downlink data storage and forwarding request" message (such as data service type, downlink data volume, expected retention time, expected downlink data sending mode, forwarding priority, and downlink data delivery confirmation), at least one of the information such as the PDU session available to the UE, the indication of the existence of uplink cached data, and the indication of uplink data delivery confirmation, as well as the ephemeris information, selects the UPF for caching the downlink data, and determines the transmission time window for the server to connect to the network.

[0514] 3-7.SMF or NEF executes different processes according to different sending methods:

[0515] [A, sending and receiving at the same time: select the UPF with uplink cache data retention]

[0516] 3a. The NEF or other NF sends a response message to the AF or a third-party server for the downlink data storage and forwarding request. The message contains information (e.g., instructions sent while waiting to receive uplink data, confirmed downlink transmission method, etc.) to notify the AF to send downlink data while waiting to receive uplink data, and provides information required to monitor the target satellite (e.g., satellite identifier, transmission time window; corresponding to the downlink data storage and forwarding information, it also includes relevant information for monitoring the satellite equipment). Specifically, the response message may carry downlink data storage and forwarding information, which includes at least one of the downlink data transmission method, the terminal identifier, the PDU session identifier, the onboard storage configuration, the estimated time of downlink data delivery, the candidate user address identifier, and the candidate user IP address.

[0517] 4a. When the feeder link to the LEO satellite is available, the N6 connection is established and the UPF forwards the uplink data to the ground server. The server obtains the UE identifier, UE IP address, and PDU session information.

[0518] 5a. AF queries NEF or SMF for PDU session information, allowed buffer space, and buffer data retention time (i.e., queries store-and-forward information).

[0519] [B, receive immediately: select the most recently arrived UPF that meets the store-and-forward requirements]

[0520] 3b. The UPF selected by the SMF can be the UPF anchor for the keep-alive PDU session or the UPF anchor for the unreleased non-keep-alive PDU session. The SMF notifies the selected UPF via the inter-satellite link to establish or update the N4 session and provides information such as the UE identity, PDU session identity, allocated buffer space, and data retention time.

[0521] 4b. The SMF sends a PDU session update command to the AMF, updating the PDU session to a keep-alive PDU session or modifying session parameters (which may correspond to allocating resources and establishing a first session or updating an existing session to a first session according to the first request). The message may carry one or more of the following information: UE identifier, PDU session identifier, always keep-alive indication, limited keep-alive indication, and keep-alive validity period. At the same time, the AMF is informed of the selected UPF identifier or the satellite identifier.

[0522] 5b. The AMF determines the paging time window of the UE or the periodic registration timer of the UE according to the ephemeris information based on the information that the PDU session is a keep-alive session and one or more of the information of always keep-alive, limited keep-alive, and the validity period of the keep-alive, and the forwarding priority given in the "Downlink Data Storage and Forwarding Request" message (corresponding to the above-mentioned determination of the paging time window or periodic registration timer corresponding to the terminal according to the ephemeris information of the satellite device).

[0523] 6.AMF sends the PDU session update instruction and UE configuration update information through the UE's current serving satellite (which may be different from the satellite where the selected UPF is located). Similar to steps 7-8 of Example 1: Step 7 of Example 1.AMF sends the PDU session establishment or update response and PDU session information (keep-alive PDU session, always keep-alive, limited-time keep-alive, keep-alive validity period) to the UE through a NAS message; and sends one or more of the "recommended or preferred response method" indication, UE-specific paging time window, and periodic registration timer to the UE through the same NAS message or by initiating the UE configuration update process. Step 8 of Example 1.UE saves the mapping relationship between satellite identifier, base station identifier and / or cell identifier and PDU session and configuration information.

[0524] 7.SMF or NEF or other NF sends a response message to the downlink data storage and forwarding request to AF, notifies AF through the information in the message (such as the confirmed downlink sending method) that the data can be sent immediately, and provides the UPF information providing the service (such as UE identifier, confirmed downlink data sending method, PDU session identifier, UE IP address, UPF identifier, UPF address identifier, allowed cache space, cache data retention time) and the information required to monitor the target satellite (such as satellite identifier, transmission time window).

[0525] 8. The server monitors the target satellite and sends the downlink data to the UPF cache when the feeder link from the satellite to the ground is available.

[0526] 9. UPF notifies SMF that downlink data has arrived. SMF queries AMF for UE reachability and notifies that downlink data is retained (establishes a user plane connection with the UE). Similar to 5b or 5c in Example 2: Step 5b of Example 2. UPF or SMF notifies AMF that downlink data is retained. The UE's preferred response method is paging or both (i.e., paging and active access). AMF determines that the UE is reachable as soon as possible. Step 5c of Example 2. UPF or SMF notifies AMF that downlink data is retained. The UE's preferred response method is UE active access. AMF does not initiate paging but waits for UE to actively access.

[0527] 10. Data forwarding process: The satellite pages the UE or the UE actively accesses the satellite to obtain the downlink data cached by the UPF. Similar to steps 6-8 in Example 2:

[0528] [Method B] In Example 2, step 6: The AMF determines the UE's reachable time based on the ephemeris information and UE location, initiates paging before the paging time window, or notifies the RAN of the UE's reachable time, which then determines the paging time. In Example 2, step 7: The UE restores the user plane tunnel and possible N3 tunnel to the RAN (i.e., restores the user plane connection) through the service request process. In Example 2, step 8: The AMF notifies the SMF that the UE is reachable, and the UPF forwards the downlink buffered data (i.e., the buffered downlink data) to the UE.

[0529] [Method C] In steps 6-7 of Example 2, the UE initiates a registration request (or service request, carrying PDU session information) to the AMF based on the periodic registration timer configured by the network. The AMF determines that the current UE is the target UE for the retained data based on the UE identifier, and carries the identifier of "activate the user plane connection of this PDU session" or the identifier of "downlink data arrival" and the PDU session information in the registration request response (or request response). The UE activates the user plane connection based on the response; when the UE has uplink data to send, it can preferentially access the current satellite based on the locally stored keep-alive PDU session information and satellite identifier (and / or base station identifier and / or cell identifier; corresponding to the relevant identifiers of the above-mentioned satellite equipment), initiate a service request, and carry the PDU session information (such as the PDU session identifier). The AMF determines that the current UE is the target UE for the retained data based on the UE identifier and PDU session identifier, and executes the service request response process to activate the user plane connection. In step 8 of Example 2, the AMF notifies the SMF that "the UE is reachable", and the UPF forwards the downlink buffered data to the UE.

[0530] Example 4: A base station + lightweight core network (AMF+SMF+UDM+UPF+NEF) is deployed on the same satellite. Downlink data is transmitted through the control plane and stored on the UPF or AMF.

[0531] As shown in Figure 10, the solution in this example includes the following steps:

[0532] 0-4. Same as steps 0-4 in Example 2, specifically:

[0533] 0. The UE has activated store-and-forward, and the network establishes a PDU session for the UE. As the satellite moves, the feeder link between the satellite and the gateway becomes available, establishing N6 and N33 connections. Further:

[0534] [Scenario A] 0a. The UE has uplink data cached in the UPF. At this time, the network maintains the UE's registration status and PDU session information.

[0535] 0b. After the N6 interface is established, the UPF forwards the uplink data to the ground server. The server obtains the UE identifier, UE IP address, and PDU session information.

[0536] [Scenario B] The UE has no uplink data cache, but establishes a keep-alive PDU session anchored at the UPF. The network retains the UE's registration status and PDU session information.

[0537] 0c-0e. When the UE registers, based on the UE's subscription information or UE Policy, the AMF or UDM subscribes to the SMF to notify the target AF of the event of activating store-and-forward UE; alternatively, the NEF subscribes to the SMF to notify the target AF of the event of activating store-and-forward UE; when the notification is triggered, the target AF's information (such as AF ID, server IP address, data network name DNN, data network access identifier (DN Access Identifier, DNAI)) can be transmitted. When the network activates store-and-forward for the UE and establishes a keep-alive PDU session, the SMF notifies the NEF to trigger the "event of notifying the AF (i.e., notifying the target AF of the event of activating store-and-forward UE)", and carries the UE ID, activation store-and-forward ID, target AF information, and PDU session information (such as PDU session ID, PDU session type, UE IP address, etc.). The NEF caches the notification (also called the activation store-and-forward notification; corresponding to the above-mentioned cached notification for the terminal, the notification is used to indicate that the terminal has activated the on-board store-and-forward operation) and forwards the notification to the AF or a third-party server after the feeder link is available to establish the N33 interface.

[0538] 1. The AF or a third-party server has downlink data to send to the UE (e.g., delivery confirmation of uplink data, other data (e.g., notification information)) and selects a satellite that can provide store-and-forward services. It can reuse the PDU session and serving satellite recorded when receiving uplink data (Scenario A, 0b) or receiving the store-and-forward activation notification (Scenario B, 0c-0e). If no record exists, an active query can be initiated, see 2a below.

[0539] 2a. In some embodiments, when the feeder link is available, the AF queries the UE through the NEF based on the UE identity and AF information whether an available PDU session supporting store-and-forward has been established (ie, queries whether the UE has activated store-and-forward and PDU session information).

[0540] 3. When feed is available, the AF obtains the allocated buffer size, buffered data retention time, and supported forwarding strategies (e.g., timely forwarding or delay-tolerant forwarding, either of which is acceptable) from the NEF or SMF. This means querying the stored forwarding information. Based on one or more of these pieces of information and the ephemeris information, the AF decides whether to select the current satellite. If the requirements are not met, the AF abandons the current satellite and waits for connection to the next satellite, repeating steps 1-3 of this example.

[0541] 4. Select the satellite, AF sends a request for downlink data storage and forwarding to NEF or SMF (such as the expected downlink forwarding strategy, forwarding priority, downlink data delivery confirmation, etc.). NEF or SMF feeds back a response for downlink data storage and forwarding. Specifically:

[0542] 4a. The SMF determines the downlink forwarding method (i.e., forwarding via ISL relay or retaining it on the local satellite) based on the desired forwarding strategy (e.g., timely forwarding or delay-tolerant forwarding), one or more forwarding priorities (high priority or low priority), and the availability of the ISL. For example, for data with a forwarding strategy of "immediate forwarding," ISL relay can be selected; for data with a forwarding strategy of "delay-tolerant forwarding," retaining it on the local satellite can be selected.

[0543] 4b. After receiving the confirmation (i.e., the response of the downlink data storage and forwarding), the AF sends the downlink data to the UPF cache.

[0544] 5-9. Satellites use different forwarding methods:

[0545] [Method A] Relay forwarding via intersatellite links;

[0546] 5a. The SMF finds the UE's current serving satellite, Satellite 2, or selects Satellite 2, which can provide faster service to the UE, based on information such as the arrival time of other satellites and the UPF cache space. The SMF forwards the data to the corresponding UPF (this can be done using existing mechanisms and will not be detailed here). Satellite 2 can then use the following [Method B] or [Method C]:

[0547] Alternatively, 5b. The UPF forwards the data to the AMF on the same satellite. The AMF finds the UE's current serving satellite, Satellite 2, or selects Satellite 2 that can provide faster service to the UE based on information such as the arrival time of other satellites at the terminal and the AMF cache space, and forwards the data to the corresponding AMF. (Specific mechanisms can be used and are not described here.) Then, steps 6-9 of [Method B] or steps 6-8 of [Method C] can be used on Satellite 2.

[0548] [Method B] This satellite forwards and the configuration is cached in UPF.

[0549] 5c. The UPF or SMF notifies the AMF: Enable UE reachability (downlink data is retained by the UPF). This notification may carry the PDU session identifier and the following cases 1 or 2 may be executed:

[0550] Case 1: [Allowed downlink reception priority = high priority] The AMF determines that the UE is reachable as soon as possible and pages the UE. Specifically:

[0551] 6a-7. The AMF determines the UE's reachable time based on the ephemeris information and the UE's location. It initiates paging before the paging window arrives, or it notifies the RAN of the UE's reachable time, which then determines the paging time. The UE responds to the paging and establishes a Radio Resource Control (RRC) connection. Steps 8-9 of this method are then executed.

[0552] Case 2: [Allowed downlink reception priority = low priority] AMF does not initiate a call and waits for the UE to actively access. Specifically:

[0553] 6b. The UE initiates a registration request (carrying a PDU session identifier) ​​to the AMF based on the periodic registration timer configured by the network; or when the UE has uplink data to send, it preferentially accesses the current satellite and establishes an RRC connection based on the locally stored keep-alive PDU session information and satellite identifier (and / or base station identifier and / or cell identifier; corresponding to the relevant identifiers of the above-mentioned satellite equipment), and the message carries the PDU session identifier. The AMF determines that the current UE is the target UE for the retained data based on the UE identifier, and carries the "activate this PDU session" identifier or the "downlink data arrival" identifier and the PDU session information in the response message. Subsequently, steps 8-9 under this method are executed.

[0554] 8-9.AMF notifies SMF that "UE is reachable (corresponding to the Enable UE reachable response in the figure)". UPF forwards the downlink buffered data to AMF via SMF and sends it to the UE via a downlink NAS message.

[0555] [Method C] This satellite forwards and the configuration is cached in AMF.

[0556] 5d.UPF forwards the data to AMF. The specific forwarding message may carry the PDU session identifier and downlink data.

[0557] 6a / 6b / 7. Same as [Method B], specifically:

[0558] Case 1: [Allowed downlink reception priority = high priority] AMF pages the UE. Specifically:

[0559] 6a-7. The AMF determines the UE's reachable time based on the ephemeris information and UE location, and initiates paging before the paging window arrives, or notifies the RAN of the UE's reachable time, which then determines the paging time. The UE responds to the paging and establishes an RRC connection. Then, proceed to step 8 of this method.

[0560] Case 2: [Allowed downlink reception priority = low priority] AMF does not initiate a call and waits for the UE to actively access. Specifically:

[0561] 6b. The UE initiates a registration request (carrying a PDU session identifier) ​​to the AMF based on the periodic registration timer configured by the network; or when the UE has uplink data to send, it preferentially accesses the current satellite and establishes an RRC connection based on the locally stored keep-alive PDU session information and satellite identifier (and / or base station identifier and / or cell identifier; corresponding to the relevant identifiers of the above-mentioned satellite equipment), and the message carries the PDU session identifier. The AMF determines that the current UE is the target UE for the retained data based on the UE identifier, and carries the "activate the PDU session" identifier or the "downlink data arrival" identifier and the PDU session information in the response message. Subsequently, step 8 under this method is executed.

[0562] 8. The AMF sends the buffered data (i.e., the buffered downlink data) to the UE via a downlink NAS message.

[0563] Example 5: A base station + lightweight core network (AMF+SMF+UDM+UPF+NEF) is deployed on the same satellite, non-IP data is transmitted through the control plane, and downlink data is stored on the SMF or NEF.

[0564] As shown in Figure 11, the solution in this example includes the following steps:

[0565] 0. The UE has activated store-and-forward, and the network establishes an unstructured PDU session for the UE. As the satellite moves, the feeder link between the satellite and the gateway becomes available, establishing an N33 connection. Further:

[0566] [Scenario A] 0a. The UE has uplink data cached in the NEF. At this time, the network maintains the UE's registration status and PDU session information.

[0567] 0b. After the N33 interface is established, the NEF sends a message (e.g., Nnef_NIDD_DeliveryNotify Request) to the ground server and forwards the uplink data. The AF (or a third-party server) obtains the UE identifier and PDU session information. If the "store and forward" flag is present, it determines that the UE has activated the store and forward function.

[0568] [Scenario B] The UE has no uplink data cache, but establishes a PDU session anchored at the NEF. The network retains the UE's registration status and PDU session information.

[0569] 0c-0e. When the UE registers, based on the UE's subscription information or UE Policy, the AMF or UDM subscribes to the SMF or NEF to notify the target AF of the event of activating storage and forwarding of the UE. When the notification is triggered, the information of the target AF (such as AF identifier, server IP address, DNN, DNAI) can be transmitted. When the network activates storage and forwarding for the UE and establishes an unstructured PDU session, the SMF or NEF triggers the "event of notifying AF" and carries the UE identifier, activation storage and forwarding identifier, target AF information and PDU session information (such as PDU session identifier, unstructured PDU session indication (i.e., unstructured indication), allocated cache space, and cache data retention time). The NEF caches the notification and forwards it to the AF or third-party server after the feeder link is available to establish the N33 interface.

[0570] 1. The AF or a third-party server has downlink data to send to the UE (e.g., confirmation of uplink data delivery, other data (e.g., notifications), etc.) and selects a satellite that provides store-and-forward services. This can reuse satellites that received uplink data (Scenario A, 0b) or received store-and-forward activation notifications (Scenario B, 0c-0e). If no record exists, an active query can be initiated (see step 2a below).

[0571] 2a. In some embodiments, when power is available, the AF queries the UE through the NEF based on the UE identity and AF information whether the UE has activated store-and-forward and an unstructured PDU session supporting store-and-forward (corresponding to PDU session information).

[0572] 3. The AF knows that the UE has activated the store-and-forward function and obtains the allocated buffer size, buffered data retention time, and supported forwarding policies (e.g., timely forwarding or delay-tolerant forwarding, either of which is acceptable) from the NEF or SMF. This means querying the store-and-forward information. Based on one or more of these pieces of information and the ephemeris information, the AF decides whether to select the current satellite. If the requirements are not met, the AF abandons the current satellite and waits for connection to the next satellite, repeating steps 1-3 of this example.

[0573] 4. Select the satellite, and the AF sends a message (such as a delivery request) to the NEF or SMF, carrying information related to storage and forwarding (such as the expected downlink forwarding strategy, forwarding priority, and delivery confirmation of downlink data).

[0574] 4a. The NEF or SMF determines the downlink forwarding method (i.e., forwarding via ISL relay or retaining it on the local satellite) based on the desired downlink forwarding strategy (e.g., timely forwarding or delay-tolerant forwarding), one or more forwarding priorities (high priority or low priority), and information such as ISL availability. For example, for data with a forwarding strategy of "immediate forwarding," ISL relay can be selected; for data with a forwarding strategy of "delay-tolerant forwarding," retaining it on the local satellite can be selected.

[0575] 4b. After receiving the confirmation (i.e., the Delivery Response), the AF sends the downlink data to the NEF buffer. This response may include a confirmation to send or receive indication (indicating that the server data is being sent to the satellite), a downlink forwarding strategy, and an estimated time of arrival for the downlink data.

[0576] 5-9. Satellites use different forwarding methods. Similar to steps 5c / 5d-9 in Example 4, the main difference is that the network element involved in forwarding data is the SMF or NEF. For details, please refer to the following:

[0577] [Method B] This satellite forwards and the configuration is cached in NEF.

[0578] 5c.NEF or SMF notifies AMF: Enable UE reachability (downlink data is stuck in NEF). This notification may carry the PDU session identifier. The following cases 1 or 2 may be executed later:

[0579] Case 1: [Allowed downlink reception priority = high priority] The AMF determines that the UE is reachable as soon as possible and pages the UE. Specifically:

[0580] 6a-7. The AMF determines the UE's reachable time based on the ephemeris information and the UE's location. It initiates paging before the paging window arrives, or it notifies the RAN of the UE's reachable time, which it then determines the paging time. The UE responds to the paging request and establishes an RRC connection. Steps 8-9 of this method are then executed.

[0581] Case 2: [Allowed downlink reception priority = low priority] AMF does not initiate a call and waits for the UE to actively access. Specifically:

[0582] 6b. The UE initiates a registration request (carrying a PDU session identifier) ​​to the AMF based on the periodic registration timer configured by the network; or when the UE has uplink data to send, it preferentially accesses the current satellite and establishes an RRC connection based on the locally stored keep-alive PDU session information and satellite identifier (and / or base station identifier and / or cell identifier; corresponding to the relevant identifiers of the above-mentioned satellite equipment), and the message carries the PDU session identifier. The AMF determines that the current UE is the target UE for the retained data based on the UE identifier, and carries the "activate this PDU session" identifier or the "downlink data arrival" identifier and the PDU session information in the response message. Subsequently, steps 8-9 under this method are executed.

[0583] 8-9.AMF notifies SMF that "UE is reachable (corresponding to the Enable UE reachable response in the figure)". NEF forwards the downlink buffered data to AMF via SMF and sends it to the UE via a downlink NAS message.

[0584] [Method C] This satellite forwards and configures the cache in the SMF.

[0585] 5d.NEF forwards the data to SMF. The specific forwarding message may carry the PDU session identifier and downlink data.

[0586] 6a / 6b / 7. Same as [Method B], specifically:

[0587] Case 1: [Allowed downlink reception priority = high priority] AMF pages the UE. Specifically:

[0588] 6a-7. The AMF determines the UE's reachable time based on the ephemeris information and UE location, and initiates paging before the paging window arrives, or notifies the RAN of the UE's reachable time, which then determines the paging time. The UE responds to the paging and establishes an RRC connection. Then, proceed to step 8 of this method.

[0589] Case 2: [Allowed downlink reception priority = low priority] AMF does not initiate a call and waits for the UE to actively access. Specifically:

[0590] 6b. The UE initiates a registration request (carrying a PDU session identifier) ​​to the AMF based on the periodic registration timer configured by the network; or when the UE has uplink data to send, it preferentially accesses the current satellite and establishes an RRC connection based on the locally stored keep-alive PDU session information and satellite identifier (and / or base station identifier and / or cell identifier; corresponding to the relevant identifiers of the above-mentioned satellite equipment), and the message carries the PDU session identifier. The AMF determines that the current UE is the target UE for the retained data based on the UE identifier, and carries the "activate the PDU session" identifier or the "downlink data arrival" identifier and the PDU session information in the response message. Subsequently, step 8 under this method is executed.

[0591] 8. The AMF sends the buffered data (i.e., the buffered downlink data) to the UE via a downlink NAS message.

[0592] Example 6: A base station and edge computing server are deployed on the same satellite, and downlink data is stored on the satellite's edge computing server.

[0593] As shown in Figure 12, the solution in this example includes the following steps:

[0594] 1. The UE accesses the base station to prepare to send uplink data or pre-configure resources for receiving downlink data; the first RRC message (e.g., RRC establishment request, re-establishment request, recovery request) sent to base station 1 on satellite 1 may carry security parameters, service type (e.g., reliability service), target server parameters (e.g., address identifier, server identifier), "uplink data delivery confirmation" or "expectation to receive downlink data" indication, priority for receiving downlink data, and other information, such as: UE identifier, service type, target server parameters, uplink data delivery confirmation, expectation to receive downlink data, downlink data reception priority, etc.

[0595] 2-4. The base station activates the store-and-forward operation based on the UE request or the feeder link situation. Specifically, it completes RRC authentication based on the subscription information, UE identity, and security parameters; determines the allocated UE cache space and data retention time; and determines the air interface resource configuration, preferred response method, dedicated paging time window, and UE periodic access timer. The recommended or preferred response method can be determined based on ephemeris information, service type, priority of received downlink data, etc. If the service is a reliability service and requires uplink data delivery confirmation, a dedicated paging time window is configured for the UE; otherwise, a periodic access timer can be configured for the UE.

[0596] 5. The UE receives a first RRC response message sent by the base station, which may include: an allocated UE address identifier, a UE identifier, activation of store and forwarding, on-board edge server parameters (such as edge server address, address identifier), allocated cache space, air interface resource configuration parameters, UE configuration parameters (such as UE-specific paging time window, periodic access timer), satellite identifier, base station identifier, cell identifier, and one or more of the preferred response method.

[0597] 6 The base station forwards the data sent by the UE to the edge server cache (specifically: the UE sends uplink data to the base station, and the base station forwards it).

[0598] 7. When the application server (i.e., AF or third-party server) has downlink data to send and waits for the feeder link between the satellite and the gateway to become available, the onboard edge server (i.e., edge computing server 1 in the figure) establishes a connection with the third-party application server and completes security authentication (i.e., server authentication).

[0599] 8. After the security authentication is passed, the uplink data and related information (such as UE ID and "store and forward activated" ID) are sent to the application server. The application server determines whether there is downlink data that needs to be sent to the UE based on the UE ID.

[0600] 9. In some embodiments, the application server queries the base station for allocated cache space, cache data retention time, etc.; that is, queries for store-and-forward information.

[0601] 10. If satellite 1 is selected, a request message for downlink data storage and forwarding is sent to satellite 1, which may carry one or more information including UE identification, service type, cached data volume, expected downlink forwarding strategy, forwarding priority, and downlink data delivery confirmation.

[0602] 11. Based on the subscription information and the service type, expected downlink forwarding strategy, forwarding priority, downlink data delivery confirmation, and other information in the request message, the base station authorizes the application server to use the store-and-forward operation to send data to the UE, and determines the forwarding method for the downlink data (such as relaying through the inter-satellite link, retaining it on the satellite, etc.).

[0603] 12. The base station sends a response to the application server for downlink data storage and forwarding, which carries the data cache space, cache retention time, estimated downlink data delivery time, and / or edge server address.

[0604] 13. The base station performs the following corresponding processes according to different forwarding methods:

[0605] Intersatellite Link Relay

[0606] 13a. The application server sends the downlink data to the base station buffer.

[0607] 14. The base station determines the current UE's serving satellite or the satellite that will soon reach the UE based on the ephemeris information, and forwards the downlink data and configuration information (such as UE identification, service type, service priority, downlink data delivery confirmation, server address, etc.) to the selected satellite base station (such as forwarding downlink data and configuration information to other satellites) or edge server through the inter-satellite link.

[0608]

This satellite forwards

[0609] 13b. The application server sends the downlink data to the onboard edge server cache.

[0610] 14. The edge server notifies base station 1 of the data arrival. The base station (i.e., base station 1) determines whether to initiate paging to the UE or wait for the UE to actively access based on the ephemeris information, stored UE context, downlink data reception priority, etc.

[0611] 15. In some embodiments, after the base station reaches the coverage area of ​​the UE, the base station initiates paging to the UE, carrying a "downlink data retained" indication or the paging reason is data or retained data.

[0612] 16. The UE responds to the paging message of downlink retained data, or arrives at the time window of periodic access, or has uplink data to send, and gives priority to accessing the base station, and sends a second RRC message, which may carry the UE identifier, UE address identifier, indication of allowing reception of offline data, and supported reception methods (such as pull and push).

[0613] Then execute 17a-18a or 17b-19:

[0614] 17a-18a: The base station sends a second RRC message response, which carries the UE identifier, the allowed receiving mode (such as pull, push), and the edge server address. If the receiving mode is pull, the UE establishes a connection with the edge server and retrieves the cached downlink data.

[0615] 17b-19: The base station sends a second RRC message response, which carries the UE identifier and the allowed reception mode. If the reception mode is push, the UE maintains the RRC connection, and the base station notifies the edge server to send data to the UE.

[0616] Based on the above, the solutions provided by the embodiments of the present disclosure involve the following contents:

[0617] 1. The terminal negotiates and manages the resources for receiving downlink data with the base station or core network;

[0618] Terminal side:

[0619] (1) The UE carries one or more information related to receiving downlink data, including an "uplink data delivery confirmation" indication, an "expectation to receive downlink data" indication, a downlink data reception priority, and a service type (such as reliability service) in an RRC or NAS message according to the need to receive downlink data (corresponding to the above-mentioned downlink data reception requirement information); sends a first request to the satellite device according to the above-mentioned downlink data reception requirement information; receives a first response fed back by the satellite device, the first response carrying first information of the first session; wherein the first request carries at least one of the following: receiving uplink data delivery confirmation; waiting to receive downlink data; downlink data reception priority; and service type corresponding to the session.

[0620] (2) The UE selectively monitors the wireless signal of the target satellite according to the "recommended or preferred response method (corresponding to the above-mentioned response method for receiving downlink data)" indicated by the base station or core network, the UE-specific paging time window, the periodic registration timer, and the satellite identifier, and responds to the network's paging message or actively accesses the network to receive downlink data.

[0621] (3) The UE retains the network-preconfigured air interface resources and PDU session information, which are preferentially used for receiving downlink data; corresponding to the above-mentioned retaining the air interface resources and session information of the corresponding session according to the first response; wherein the air interface resources are used for receiving downlink data.

[0622] Core network side:

[0623] (1) The SMF determines to establish or update an existing PDU session in the UPF or NEF as a PDU session with reserved resources (a keep-alive PDU session) based on the activation of on-board store-and-forward information, the information on the received downlink data request (such as an "uplink data delivery confirmation" indication or an "expectation to receive downlink data" indication), the UE subscription, the downlink data reception priority, and the ephemeris information, and determines one or more parameters of the PDU session, such as always keep-alive, keep-alive for a limited period, or the validity period of keep-alive. This corresponds to the above-mentioned receiving the first request sent by the terminal; and feeding back a first response to the terminal based on the first request.

[0624] (2) The AMF determines the UE's recommended or preferred response mode (e.g., waiting for paging, UE active access, or both) based on whether the PDU session is a keep-alive session, keep-alive parameters (e.g., always keep-alive, limited keep-alive, keep-alive validity period), downlink reception priority, etc., and determines one or more of the UE-specific paging time window, UE periodic registration timer, and UE periodic access timer based on the ephemeris information. This corresponds to the above determination of the response mode for receiving downlink data based on the reference information; and / or, the determination of the paging time window or periodic registration timer corresponding to the terminal based on the ephemeris information of the satellite device.

[0625] (3) For the PDU session that is kept alive, each NF in the core network retains the session information and allocated resource configuration during the PDU session keepalive period and gives priority to using the configured resources when resuming data transmission. This corresponds to retaining the system resources and session information for the session corresponding to the first response; wherein the system resources are used to send downlink data.

[0626] 2. Downlink data caching process (core network side);

[0627] (1) When each NF in the core network activates store-and-forward for the UE and establishes a PDU session, the NEF caches the notification of the UE activated store-and-forward sent to the AF (corresponding to the notification cached above for the terminal, the notification is used to indicate that the terminal has activated the on-board store-and-forward operation), including the UE identifier, PDU session identifier, on-board storage configuration (such as storage space size, retention validity period), and in some embodiments, the UE IP address (optional); and forwards it to the AF after the connection with the AF is established.

[0628] (2) The SMF processes the server's downlink data storage and forwarding request message and information (such as the expected downlink forwarding strategy (such as timely forwarding or delay-tolerant forwarding, both are acceptable), forwarding priority, and downlink data delivery confirmation); and determines the downlink data forwarding method (such as intersatellite link relay forwarding, or retaining forwarding on this satellite) based on the downlink forwarding strategy, forwarding priority, intersatellite link status and other information; corresponding to the above-mentioned determination of the downlink data sending method based on the second information.

[0629] (3) The SMF determines the downlink data receiving mode, generates and sends a downlink data storage and forwarding response message, which carries the confirmed downlink transmission mode (such as simultaneous transmission and reception, or immediate transmission) and the UPF information providing the service (such as PDU session identifier, UE IP address, UPF identifier, UPF address identifier, allowed buffer space, buffer data retention time), and the information required for monitoring the target satellite (such as satellite identifier, transmission time window). Corresponding to the above, based on the downlink data transmission mode, the downlink data storage and forwarding response is fed back to the server; the downlink data storage and forwarding information also includes: relevant information for monitoring the satellite equipment.

[0630] (4) NEF or SMF allocates a temporary AF identifier, establishes a mapping between the UE identifier, PDU session identifier, DN information and the temporary AF identifier (corresponding to the second mapping relationship between the identifier of the terminal, the identifier of the first session and the relevant identifier of the server), and manages cached data.

[0631] 3. The process of receiving downlink data;

[0632] Terminal side:

[0633] (1) The UE preferentially selects the base station deployed by the satellite to access the network based on the current uplink data transmission status, the response mode configured by the AMF or base station, the locally stored keep-alive PDU information, and the satellite identifier (and / or base station identifier and / or cell identifier), initiates a NAS message or an RRC message to the network, and obtains the device information (such as device identifier and address identifier) ​​of the downlink data cache; corresponding to the above-mentioned first parameter, accesses the satellite device and sends a second request to the satellite device, the second request is used to obtain information of the downlink data cache component on the satellite device or to indicate receiving downlink data or to request registration or to request sending uplink data; receives a second response fed back by the satellite device, the second response carries information of the downlink data cache component or carries indication information instructing the terminal to use the resources corresponding to the first session for downlink data reception; wherein the first parameter includes: uplink data transmission status, candidate response modes for receiving downlink data, locally stored first session information, reason for network paging, and relevant identifier of the satellite device.

[0634] (2) When the UE sends a NAS or RRC message to access the network, it carries an indication of allowing downlink data reception and a supported reception mode (such as pull or push); corresponding to the above-mentioned second request, it carries an indication that the terminal allows downlink data reception and / or a reception mode for downlink data supported by the terminal.

[0635] Base station or network side:

[0636] (1) The base station or AMF determines whether and when to initiate paging to the UE or wait for the UE to actively access the network based on the downlink reception priority, preferred response mode, and ephemeris information.

[0637] (2) The base station confirms and informs the UE of the downlink data reception mode. When the reception mode is push, the base station notifies the edge server to send data to the UE. (1) + (2) on this side corresponds to the above-mentioned downlink data caching component on the satellite device sending downlink data to the terminal through the first session based on the first information and the downlink data reception mode supported by the terminal.

[0638] In summary, the embodiments of the present disclosure provide a method for a terminal to obtain data from a remote application server based on on-board storage and forwarding operations. For scenarios where a real-time connection between the terminal and the server cannot be established via satellite, the method tries to meet the terminal's needs for timely and efficient acquisition of downlink data sent by the application server, thereby realizing end-to-end downlink data transmission.

[0639] It is to be noted here that the relevant contents between the above examples and between the execution entities (such as UE, base station, etc.) can refer to each other, and the repeated contents will not be repeated.

[0640] The embodiment of the present disclosure further provides a data transmission device, which is a terminal, as shown in FIG13 , including a memory 131 , a transceiver 132 , and a processor 133 :

[0641] The memory 131 is used to store computer programs; the transceiver 132 is used to send and receive data under the control of the processor 133; the processor 133 is used to read the computer program in the memory 131 and perform the following operations:

[0642] receiving, via the transceiver 132, first information of a first session sent by a satellite device;

[0643] receiving downlink data through the first session according to the first information;

[0644] The first session refers to a session that continuously occupies the allocated resources;

[0645] The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

[0646] The data transmission device provided by the embodiment of the present disclosure receives first information of a first session sent by a satellite device; receives downlink data through the first session based on the first information; wherein the first session refers to a session that continuously occupies the allocated resources; the first information includes: fixed session identification information, and time information during which the session continuously occupies the allocated resources; it can enable the terminal to accurately receive the corresponding downlink data through the maintained first session; in the case of a non-end-to-end connection, the network can accurately determine the terminal corresponding to the downlink data through the maintained first session, thereby ensuring that the target terminal accurately receives the downlink data; it well solves the problem in the related art that in the case of a non-end-to-end connection, it cannot be guaranteed that the target terminal accurately receives the downlink data.

[0647] Specifically, the transceiver 132 is configured to receive and send data under the control of the processor 133 .

[0648] In FIG13 , the bus architecture may include any number of interconnected buses and bridges, specifically linking together various circuits of one or more processors represented by processor 133 and memory represented by memory 131. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, all of which are well known in the art and, therefore, will not be further described herein. The bus interface provides an interface. The transceiver 132 may be a plurality of components, including a transmitter and a receiver, providing a unit for communicating with various other devices over a transmission medium, such as a wireless channel, a wired channel, an optical cable, and the like. For different user devices, the user interface 134 may also be an interface capable of connecting to required external or internal devices, including but not limited to a keypad, a display, a speaker, a microphone, a joystick, and the like.

[0649] The processor 133 is responsible for managing the bus architecture and general processing, and the memory 131 can store data used by the processor 133 when performing operations.

[0650] In some embodiments, the processor 133 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0651] The processor calls the computer program stored in the memory to execute any of the methods provided by the embodiments of the present disclosure according to the obtained executable instructions. The processor and the memory can also be arranged physically separately.

[0652] The first information further includes at least one of the following: a response method for receiving downlink data; a paging time window; a periodic registration timer; and a satellite identifier.

[0653] Furthermore, the operation also includes: before receiving the first information of the first session sent by the satellite device, sending a first request to the satellite device through the transceiver according to the downlink data reception demand information; the receiving of the first information of the first session sent by the satellite device includes: receiving a first response fed back by the satellite device, the first response carrying the first information of the first session; wherein the first request carries at least one of the following: receiving uplink data delivery confirmation; waiting for receiving downlink data; receiving priority of downlink data; service type corresponding to the session.

[0654] In the embodiment of the present disclosure, the operation further includes: reserving air interface resources and session information corresponding to the session according to the first response; wherein the air interface resources are used to receive downlink data.

[0655] Furthermore, the operation also includes: before receiving downlink data through the first session according to the first information, accessing the satellite device according to a first parameter, and sending a second request to the satellite device through the transceiver, the second request being used to obtain information of a downlink data cache component on the satellite device or to indicate receiving downlink data or to request registration or to request sending uplink data; receiving a second response fed back by the satellite device through the transceiver, the second response carrying information of the downlink data cache component or carrying indication information instructing the terminal to use resources corresponding to the first session to receive downlink data; receiving downlink data through the first session according to the first information includes: receiving downlink data sent by the downlink data cache component on the satellite device through the first session according to the first information and the information of the downlink data cache component or the indication information; wherein the first parameter includes at least one of: uplink data transmission status, candidate response methods for receiving downlink data, locally stored first session information, a reason for network paging, and a related identifier of the satellite device.

[0656] The second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception method for downlink data supported by the terminal; and / or the second response carries a reception method for downlink data allowed by the satellite device.

[0657] Furthermore, the operation also includes: sending, through the transceiver, a receiving mode for downlink data supported by the terminal to the satellite device.

[0658] The receiving of the downlink data sent by the downlink data cache component on the satellite device through the first session includes: receiving the downlink data sent by the satellite device according to the receiving mode and using the downlink data cache component on the satellite device through the first session.

[0659] Furthermore, the operation also includes: determining a first mapping relationship between the session identification information of the first session and the air interface resource; and accessing the satellite device according to the first parameter includes: accessing the satellite device according to the first parameter and the first mapping relationship.

[0660] The first session is a protocol data unit (PDU) session or a non-PDU session.

[0661] It should be noted here that the above-mentioned device provided by the embodiment of the present disclosure can implement all the method steps implemented by the method embodiment on the above-mentioned terminal side, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0662] The present disclosure also provides a data transmission device, which is a satellite device, as shown in FIG14 , including a memory 141 , a transceiver 142 , and a processor 143 :

[0663] The memory 141 is used to store computer programs; the transceiver 142 is used to send and receive data under the control of the processor 143; the processor 143 is used to read the computer program in the memory 141 and perform the following operations:

[0664] Sending first information of the first session to the terminal through the transceiver 142;

[0665] Sending downlink data to the terminal through the first session according to the first information;

[0666] The first session refers to a session that continuously occupies the allocated resources;

[0667] The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

[0668] The data transmission device provided by the embodiment of the present disclosure sends first information of a first session to the terminal; according to the first information, sends downlink data to the terminal through the first session; wherein the first session refers to a session that continuously occupies the allocated resources; the first information includes: fixed session identification information, and time information during which the session continuously occupies the allocated resources; it is possible for the terminal to accurately receive the corresponding downlink data through the maintained first session; in the case of a non-end-to-end connection, the network can accurately determine the terminal corresponding to the downlink data through the maintained first session, thereby ensuring that the target terminal accurately receives the downlink data; it well solves the problem in the related art that in the case of a non-end-to-end connection, it is impossible to ensure that the target terminal accurately receives the downlink data.

[0669] Specifically, the transceiver 142 is configured to receive and send data under the control of the processor 143 .

[0670] In FIG14 , the bus architecture may include any number of interconnected buses and bridges, specifically various circuits linking together one or more processors represented by processor 143 and memory represented by memory 141. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 142 may be a plurality of components, i.e., a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium, such as a wireless channel, a wired channel, an optical cable, and the like. The processor 143 is responsible for managing the bus architecture and general processing, and the memory 141 may store data used by the processor 143 when performing operations.

[0671] The processor 143 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0672] The first information further includes at least one of the following: a response method for receiving downlink data; a paging time window; a periodic registration timer; and a satellite identifier.

[0673] Furthermore, the operation also includes: determining the response method for receiving downlink data based on reference information; wherein the reference information includes: the time information, and at least one of the downlink reception priorities; and / or, determining the paging time window or periodic registration timer corresponding to the terminal based on the ephemeris information of the satellite device.

[0674] In an embodiment of the present disclosure, the operation further includes: determining whether to initiate paging or wait for the terminal to access based on the response method for receiving downlink data; wherein, when it is determined to initiate paging, instructing the terminal to receive downlink data in the paging reason.

[0675] Furthermore, the operation also includes: before sending the first information of the first session to the terminal, receiving a first request sent by the terminal through the transceiver; sending the first information of the first session to the terminal includes: according to the first request, feeding back a first response to the terminal, and the first response carries the first information of the first session; wherein, the first request carries at least one of the following: receiving an uplink data delivery confirmation; waiting for receiving downlink data; receiving priority of downlink data; service type corresponding to the session.

[0676] In the embodiment of the present disclosure, the operation further includes: reserving system resources and session information of a session corresponding to the first response; wherein the system resources are used to send downlink data.

[0677] Among them, the feeding back a first response to the terminal based on the first request includes: when the first request indicates a request to activate the on-board store-and-forward operation or the terminal has activated the on-board store-and-forward operation, according to the first request, allocating resources and establishing a first session or updating the existing session to a first session; and feeding back a first response to the terminal based on the first session.

[0678] Furthermore, the operation also includes: before sending downlink data to the terminal through the first session according to the first information, receiving a second request sent by the terminal through the transceiver, the second request is used to obtain information of the downlink data cache component on the satellite device or indicate receiving downlink data or for requesting registration or for requesting sending uplink data; according to the second request, feeding back a second response to the terminal, the second response carries information of the downlink data cache component or carries indication information instructing the terminal to use the resources corresponding to the first session to receive downlink data; sending downlink data to the terminal through the first session according to the first information includes: according to the first information and the information of the downlink data cache component or the indication information, using the downlink data cache component on the satellite device to send downlink data to the terminal through the first session.

[0679] The second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception method for downlink data supported by the terminal; and / or the second response carries a reception method for downlink data allowed by the satellite device.

[0680] Furthermore, the operation also includes: receiving, through the transceiver, a receiving mode for downlink data supported by the terminal and sent by the terminal.

[0681] The step of sending downlink data to the terminal through the first session by using the downlink data caching component on the satellite device includes sending downlink data to the terminal through the first session by using the downlink data caching component on the satellite device according to the first information and the reception method for downlink data supported by the terminal.

[0682] In the embodiment of the present disclosure, the first session is a protocol data unit (PDU) session or a non-PDU session.

[0683] Furthermore, the operation also includes: caching a notification for the terminal, the notification being used to indicate that the terminal has activated the on-board storage and forwarding operation; wherein the notification carries downlink data storage and forwarding information, and the downlink data storage and forwarding information includes: downlink data sending mode, the terminal identifier, the PDU session identifier, the on-board storage configuration, the candidate user address identifier, and at least one of the candidate user IP addresses.

[0684] In the embodiment of the present disclosure, the operation further includes: sending the notification to the server via the transceiver.

[0685] Furthermore, the operation also includes: before sending downlink data to the terminal through the first session according to the first information, determining the downlink data sending method according to the second information; wherein the second information includes: at least one of the inter-satellite link status information and the server's downlink data storage and forwarding request; the downlink data storage and forwarding request includes: at least one of the downlink forwarding strategy, forwarding priority and downlink data delivery confirmation method.

[0686] In an embodiment of the present disclosure, the operation also includes: feeding back a downlink data storage forwarding response to the server based on the downlink data sending method; wherein the downlink data storage forwarding response carries downlink data storage forwarding information, and the downlink data storage forwarding information includes: the downlink data sending method, the terminal identifier, the PDU session identifier, the on-board storage configuration, the expected time of delivery of the downlink data, the candidate user address identifier, and at least one of the candidate user IP addresses.

[0687] In which, the on-board storage configuration includes: cache space, and at least one of the retention time of cached data; or, the on-board storage configuration does not include: cache space and the retention time of cached data, and the downlink data storage forwarding information also includes: cache space, and at least one of the retention time of cached data.

[0688] In the embodiment of the present disclosure, the downlink data storage and forwarding information further includes: relevant information for monitoring the satellite equipment.

[0689] Furthermore, the operation further includes: determining a second mapping relationship between the identifier of the terminal, the identifier of the first session, and a related identifier of the server.

[0690] It should be noted here that the above-mentioned device provided in the embodiment of the present disclosure can implement all the method steps implemented in the method embodiment on the satellite equipment side and can achieve the same technical effect. The parts and beneficial effects that are the same as the method embodiment in this embodiment will not be described in detail here.

[0691] The embodiment of the present disclosure further provides a data transmission device, which is a server, as shown in FIG15 , including a memory 151 , a transceiver 152 , and a processor 153 :

[0692] The memory 151 is used to store computer programs; the transceiver 152 is used to send and receive data under the control of the processor 153; the processor 153 is used to read the computer program in the memory 151 and perform the following operations:

[0693] Receiving downlink data storage and forwarding information sent by the satellite equipment through the transceiver 152;

[0694] Sending downlink data to the satellite device via the transceiver 152 according to the downlink data storage and forwarding information;

[0695] The downlink data storage and forwarding information includes at least one of: a downlink data transmission mode, a terminal identifier, a PDU session identifier, an on-board storage configuration, an estimated time of downlink data delivery, a candidate user address identifier, and a candidate user IP address;

[0696] The downlink data storage and forwarding information is carried in a notification to the terminal, where the notification is used to indicate that the terminal has activated the on-board store-and-forward operation, or is carried in a downlink data storage and forwarding response.

[0697] The data transmission device provided by the embodiment of the present disclosure receives downlink data storage and forwarding information sent by a satellite device; sends downlink data to the satellite device according to the downlink data storage and forwarding information; wherein the downlink data storage and forwarding information includes: downlink data sending mode, terminal identifier, PDU session identifier, on-board storage configuration, expected time of delivery of downlink data, candidate user address identifier, and at least one of the candidate user IP addresses; the downlink data storage and forwarding information is carried in a notification to the terminal, and the notification is used to indicate that the terminal has activated the on-board storage and forwarding operation, or is carried in a downlink data storage and forwarding response; it can support the terminal to accurately receive the corresponding downlink data through the maintained first session; it supports that in the case of non-end-to-end connection, the network can accurately determine the terminal corresponding to the downlink data through the maintained first session, thereby ensuring that the target terminal accurately receives the downlink data; it well solves the problem in the related art that in the case of non-end-to-end connection, the target terminal cannot be guaranteed to accurately receive the downlink data.

[0698] Specifically, the transceiver 152 is configured to receive and send data under the control of the processor 153 .

[0699] In FIG15 , the bus architecture may include any number of interconnected buses and bridges, specifically various circuits linking together one or more processors represented by processor 153 and memory represented by memory 151. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 152 may be a plurality of components, i.e., a transmitter and a receiver, providing a unit for communicating with various other devices over a transmission medium, such as a wireless channel, a wired channel, an optical cable, or the like. The processor 153 is responsible for managing the bus architecture and general processing, and the memory 151 may store data used by the processor 153 when performing operations.

[0700] The processor 153 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0701] Among them, sending downlink data to the satellite device according to the downlink data storage and forwarding information includes any one of the following items: sending downlink data to the satellite device according to the downlink data storage and forwarding information during the process of receiving uplink cache data; sending downlink data to the satellite device according to the downlink data storage and forwarding information and downlink data sending demand information.

[0702] Furthermore, the operation also includes: before receiving the downlink data storage and forwarding information sent by the satellite device, sending a downlink data storage and forwarding request of the server to the satellite device through the transceiver; wherein the downlink data storage and forwarding request includes: at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

[0703] It should be noted here that the above-mentioned device provided in the embodiment of the present disclosure can implement all the method steps implemented in the above-mentioned server-side method embodiment, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0704] The present disclosure also provides a data transmission device, which is applied to a terminal, as shown in FIG16 , and includes:

[0705] The first receiving unit 161 is configured to receive first information of a first session sent by a satellite device;

[0706] A second receiving unit 162 is configured to receive downlink data through the first session according to the first information;

[0707] The first session refers to a session that continuously occupies the allocated resources;

[0708] The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

[0709] The data transmission device provided by the embodiment of the present disclosure receives first information of a first session sent by a satellite device; receives downlink data through the first session based on the first information; wherein the first session refers to a session that continuously occupies the allocated resources; the first information includes: fixed session identification information, and time information during which the session continuously occupies the allocated resources; it can enable the terminal to accurately receive the corresponding downlink data through the maintained first session; it supports that in the case of non-end-to-end connection, the network can accurately determine the terminal corresponding to the downlink data through the maintained first session, thereby ensuring that the target terminal accurately receives the downlink data; it well solves the problem in the related art that in the case of non-end-to-end connection, it cannot be guaranteed that the target terminal accurately receives the downlink data.

[0710] The first information further includes at least one of the following: a response method for receiving downlink data; a paging time window; a periodic registration timer; and a satellite identifier.

[0711] Furthermore, the data transmission device also includes: a first sending unit, used to send a first request to the satellite device according to the downlink data reception demand information before receiving the first information of the first session sent by the satellite device; the receiving of the first information of the first session sent by the satellite device includes: receiving a first response fed back by the satellite device, the first response carrying the first information of the first session; wherein the first request carries at least one of the following: receiving uplink data delivery confirmation; waiting for receiving downlink data; receiving priority of downlink data; service type corresponding to the session.

[0712] In the embodiment of the present disclosure, the data transmission device further includes: a first processing unit, configured to reserve air interface resources and session information corresponding to a session according to the first response; wherein the air interface resources are used to receive downlink data.

[0713] Furthermore, the data transmission apparatus further includes: a second processing unit, configured to, before receiving downlink data through the first session according to the first information, access the satellite device according to a first parameter and send a second request to the satellite device, the second request being used to obtain information about a downlink data cache component on the satellite device or to indicate receiving downlink data, or to request registration, or to request sending uplink data; and a third receiving unit, configured to receive a second response fed back by the satellite device, the second response carrying information about the downlink data cache component or carrying indication information instructing the terminal to use resources corresponding to the first session to receive downlink data. The receiving downlink data through the first session according to the first information includes: receiving downlink data sent by the downlink data cache component on the satellite device through the first session according to the first information and the information about the downlink data cache component or the indication information; wherein the first parameter includes at least one of: uplink data transmission status, candidate response methods for receiving downlink data, locally stored first session information, a reason for network paging, and a related identifier of the satellite device.

[0714] The second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception method for downlink data supported by the terminal; and / or the second response carries a reception method for downlink data allowed by the satellite device.

[0715] Furthermore, the data transmission device further includes: a second sending unit, configured to send a receiving mode for downlink data supported by the terminal to the satellite device.

[0716] The receiving of the downlink data sent by the downlink data cache component on the satellite device through the first session includes: receiving the downlink data sent by the satellite device according to the receiving mode and using the downlink data cache component on the satellite device through the first session.

[0717] Furthermore, the data transmission device also includes: a first determination unit, used to determine a first mapping relationship between the session identification information of the first session and the air interface resources; accessing the satellite device according to the first parameter includes: accessing the satellite device according to the first parameter and the first mapping relationship.

[0718] The first session is a protocol data unit (PDU) session or a non-PDU session.

[0719] It should be noted here that the above-mentioned device provided by the embodiment of the present disclosure can implement all the method steps implemented by the method embodiment on the above-mentioned terminal side, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0720] The present disclosure also provides a data transmission device, which is applied to satellite equipment, as shown in FIG17 , and includes:

[0721] The third sending unit 171 is configured to send first information of the first session to the terminal;

[0722] A fourth receiving unit 172, configured to send downlink data to the terminal through the first session according to the first information;

[0723] The first session refers to a session that continuously occupies the allocated resources;

[0724] The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

[0725] The data transmission device provided by the embodiment of the present disclosure sends first information of a first session to the terminal; according to the first information, sends downlink data to the terminal through the first session; wherein the first session refers to a session that continuously occupies the allocated resources; the first information includes: fixed session identification information, and time information during which the session continuously occupies the allocated resources; it can enable the terminal to accurately receive the corresponding downlink data through the maintained first session; it supports that in the case of non-end-to-end connection, the network can accurately determine the terminal corresponding to the downlink data through the maintained first session, thereby ensuring that the target terminal accurately receives the downlink data; it well solves the problem in the related art that in the case of non-end-to-end connection, it cannot be guaranteed that the target terminal accurately receives the downlink data.

[0726] The first information further includes at least one of the following: a response method for receiving downlink data; a paging time window; a periodic registration timer; and a satellite identifier.

[0727] Furthermore, the data transmission device also includes: a second determination unit, used to determine the response method for receiving downlink data based on reference information; wherein the reference information includes: the time information, and at least one of the downlink reception priorities; and / or, based on the ephemeris information of the satellite device, determine the paging time window or periodic registration timer corresponding to the terminal.

[0728] In an embodiment of the present disclosure, the data transmission device further includes: a third determination unit, used to determine whether to initiate paging or wait for the terminal to access based on the response method for receiving downlink data; wherein, when it is determined to initiate paging, the terminal is instructed to receive downlink data in the paging reason.

[0729] Furthermore, the data transmission device also includes: a fourth receiving unit, used to receive a first request sent by the terminal before sending the first information of the first session to the terminal; sending the first information of the first session to the terminal includes: based on the first request, feeding back a first response to the terminal, the first response carrying the first information of the first session; wherein the first request carries at least one of the following: receiving uplink data delivery confirmation; waiting for receiving downlink data; receiving priority of downlink data; service type corresponding to the session.

[0730] In the embodiment of the present disclosure, the data transmission device further includes: a third processing unit, configured to retain system resources and session information of a session corresponding to the first response; wherein the system resources are used to send downlink data.

[0731] Among them, the feeding back a first response to the terminal based on the first request includes: when the first request indicates a request to activate the on-board store-and-forward operation or the terminal has activated the on-board store-and-forward operation, according to the first request, allocating resources and establishing a first session or updating the existing session to a first session; and feeding back a first response to the terminal based on the first session.

[0732] Furthermore, the data transmission device also includes: a fifth receiving unit, used to receive a second request sent by the terminal before sending downlink data to the terminal through the first session according to the first information, the second request being used to obtain information of the downlink data cache component on the satellite device or to indicate receiving downlink data or to request registration or to request sending uplink data; a first feedback unit, used to feed back a second response to the terminal according to the second request, the second response carrying information of the downlink data cache component or carrying indication information instructing the terminal to use the resources corresponding to the first session to receive downlink data; sending downlink data to the terminal through the first session according to the first information includes: sending downlink data to the terminal through the first session using the downlink data cache component on the satellite device according to the first information and the information of the downlink data cache component or the indication information.

[0733] The second request carries an indication that the terminal is allowed to receive downlink data, and / or a reception method for downlink data supported by the terminal; and / or the second response carries a reception method for downlink data allowed by the satellite device.

[0734] Furthermore, the data transmission device further includes: a sixth receiving unit, configured to receive a receiving mode for downlink data supported by the terminal and sent by the terminal.

[0735] The step of sending downlink data to the terminal through the first session by using the downlink data caching component on the satellite device includes sending downlink data to the terminal through the first session by using the downlink data caching component on the satellite device according to the first information and the reception method for downlink data supported by the terminal.

[0736] In the embodiment of the present disclosure, the first session is a protocol data unit (PDU) session or a non-PDU session.

[0737] Furthermore, the data transmission device also includes: a first cache unit, used to cache notifications for the terminal, the notification is used to indicate that the terminal has activated the on-board storage and forwarding operation; wherein, the notification carries downlink data storage and forwarding information, and the downlink data storage and forwarding information includes: downlink data sending mode, the terminal identifier, PDU session identifier, on-board storage configuration, candidate user address identifier, and at least one of the candidate user IP addresses.

[0738] In the embodiment of the present disclosure, the data transmission device further includes: a fifth sending unit, configured to send the notification to the server.

[0739] Furthermore, the data transmission device also includes: a fourth determination unit, which is used to determine the downlink data sending method based on second information before sending downlink data to the terminal through the first session based on the first information; wherein, the second information includes: at least one of the inter-satellite link status information and the server's downlink data storage and forwarding request; the downlink data storage forwarding request includes: at least one of the downlink forwarding strategy, forwarding priority and downlink data delivery confirmation method.

[0740] In an embodiment of the present disclosure, the data transmission device further includes: a second feedback unit, configured to feed back a downlink data storage forwarding response to the server based on the downlink data sending method; wherein the downlink data storage forwarding response carries downlink data storage forwarding information, and the downlink data storage forwarding information includes: the downlink data sending method, the terminal identifier, the PDU session identifier, the on-board storage configuration, the expected time of delivery of the downlink data, the candidate user address identifier, and at least one of the candidate user IP addresses.

[0741] In which, the on-board storage configuration includes: cache space, and at least one of the retention time of cached data; or, the on-board storage configuration does not include: cache space and the retention time of cached data, and the downlink data storage forwarding information also includes: cache space, and at least one of the retention time of cached data.

[0742] In the embodiment of the present disclosure, the downlink data storage and forwarding information further includes: relevant information for monitoring the satellite equipment.

[0743] Furthermore, the data transmission device further includes: a fifth determining unit, configured to determine a second mapping relationship between the identifier of the terminal, the identifier of the first session, and a related identifier of the server.

[0744] It should be noted here that the above-mentioned device provided by the embodiment of the present disclosure can implement all the method steps implemented by the method embodiment on the satellite equipment side, and can achieve the same technical effect. The parts and beneficial effects that are the same as the method embodiment in this embodiment will not be described in detail here.

[0745] The present disclosure also provides a data transmission device, which is applied to a server, as shown in FIG18 , and includes:

[0746] The seventh receiving unit 181 is configured to receive downlink data storage and forwarding information sent by the satellite device;

[0747] A sixth sending unit 182 is configured to send downlink data to a satellite device according to the downlink data storage and forwarding information;

[0748] The downlink data storage and forwarding information includes at least one of: a downlink data transmission mode, a terminal identifier, a PDU session identifier, an on-board storage configuration, an estimated time of downlink data delivery, a candidate user address identifier, and a candidate user IP address;

[0749] The downlink data storage and forwarding information is carried in a notification to the terminal, where the notification is used to indicate that the terminal has activated the on-board store-and-forward operation, or is carried in a downlink data storage and forwarding response.

[0750] The data transmission device provided by the embodiment of the present disclosure receives downlink data storage and forwarding information sent by a satellite device; sends downlink data to the satellite device according to the downlink data storage and forwarding information; wherein the downlink data storage and forwarding information includes: downlink data sending mode, terminal identifier, PDU session identifier, on-board storage configuration, expected time of delivery of downlink data, candidate user address identifier, and at least one of the candidate user IP addresses; the downlink data storage and forwarding information is carried in a notification to the terminal, and the notification is used to indicate that the terminal has activated the on-board storage and forwarding operation, or is carried in a downlink data storage and forwarding response; it can support the terminal to accurately receive the corresponding downlink data through the maintained first session; it supports that in the case of non-end-to-end connection, the network can accurately determine the terminal corresponding to the downlink data through the maintained first session, thereby ensuring that the target terminal accurately receives the downlink data; it well solves the problem in the related art that in the case of non-end-to-end connection, the target terminal cannot be guaranteed to accurately receive the downlink data.

[0751] Among them, sending downlink data to the satellite device according to the downlink data storage and forwarding information includes any one of the following items: sending downlink data to the satellite device according to the downlink data storage and forwarding information during the process of receiving uplink cache data; sending downlink data to the satellite device according to the downlink data storage and forwarding information and downlink data sending demand information.

[0752] Furthermore, the data transmission device also includes: a seventh sending unit, which is used to send a downlink data storage forwarding request of the server to the satellite device before receiving the downlink data storage forwarding information sent by the satellite device; wherein the downlink data storage forwarding request includes: at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

[0753] It should be noted here that the above-mentioned device provided by the embodiment of the present disclosure can implement all the method steps implemented by the above-mentioned server-side method embodiment, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0754] It should be noted that the division of units in the embodiments of the present disclosure is schematic and is merely a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional units in the various embodiments of the present disclosure may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0755] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a processor-readable storage medium. Based on this understanding, the technical solution of the present disclosure is essentially or the part that contributes to the relevant technology or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the present disclosure. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0756] An embodiment of the present disclosure further provides a non-transitory readable storage medium storing a computer program, wherein the computer program is used to enable a processor to execute the above-mentioned terminal side, satellite device side or server side method.

[0757] The non-transitory readable storage medium can be any available medium or data storage device that can be accessed by the processor, including but not limited to magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO)), optical storage (such as compact disks (CD), digital video discs (DVD), Blu-ray discs (BD), high-definition versatile discs (HVD), etc.), and semiconductor memory (such as read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), non-volatile memory (NAND (Non-volatile Memory Device) FLASH), solid-state drive (Solid State Disk or Solid State Drive, SSD)), etc.

[0758] Among them, the implementation embodiments of the methods on the above-mentioned terminal side, satellite device side or server side are all applicable to the embodiments of the non-transitory readable storage medium, and can also achieve the same technical effects.

[0759] Those skilled in the art will appreciate that the embodiments of the present disclosure may be provided as methods, systems, or computer program products. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) containing computer-usable program code.

[0760] The present disclosure is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present disclosure. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer-executable instructions. These computer-executable instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0761] These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the processor-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0762] These processor-executable instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0763] It should be noted that it should be understood that the division of the above modules is merely a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. Moreover, these modules can all be implemented in the form of software called by a processing element; or they can all be implemented in the form of hardware; or some modules can be implemented in the form of software called by a processing element, and some modules can be implemented in the form of hardware. For example, the determination module can be a separately established processing element, or it can be integrated into a chip of the above-mentioned device. In addition, it can also be stored in the memory of the above-mentioned device in the form of program code, and called by a processing element of the above-mentioned device to perform the functions of the above-mentioned determination module. The implementation of other modules is similar. In addition, these modules can all or partly be integrated together, or they can be implemented independently. The processing element described here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above modules can be completed by the hardware integrated logic circuit in the processor element or by instructions in the form of software.

[0764] For example, each module, unit, sub-unit or sub-module may be one or more integrated circuits configured to implement the above method, such as one or more application-specific integrated circuits (ASICs), one or more digital signal processors (DSPs), or one or more field programmable gate arrays (FPGAs). For another example, when a module is implemented by scheduling program code through a processing element, the processing element may be a general-purpose processor, such as a central processing unit (CPU) or other processor that can call program code. For another example, these modules may be integrated together and implemented in the form of a system-on-a-chip (SOC).

[0765] The terms "first," "second," and the like in the specification and claims of the present disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present disclosure described herein may be implemented in a sequence other than that illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units need not be limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or devices. In addition, the use of "and / or" in the specification and claims to indicate at least one of the connected objects, for example, A and / or B and / or C, means that seven situations are included: A alone, B alone, C alone, both A and B present, both B and C present, both A and C present, and all A, B, and C present. Similarly, the use of "at least one of A and B" in the specification and claims should be understood to mean "A alone, B alone, or both A and B present."

[0766] Obviously, those skilled in the art may make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is intended to include these modifications and variations.

Claims

1. A data transmission method, applied to a terminal, comprising: receiving first information of a first session sent by a satellite device; receiving downlink data through the first session according to the first information; The first session refers to a session that continuously occupies the allocated resources; The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

2. The data transmission method according to claim 1, wherein: The first information also includes at least one of the following: A response method for receiving downlink data; Paging time window; Periodic registration timer; Satellite identification.

3. The data transmission method according to claim 1, wherein: Before receiving the first information of the first session sent by the satellite device, the method further includes: Sending a first request to the satellite device according to the downlink data receiving demand information; The receiving first information of the first session sent by the satellite device includes: receiving a first response fed back by the satellite device, where the first response carries first information of a first session; The first request carries at least one of the following: Receive uplink data delivery confirmation; Waiting to receive downlink data; Receiving priority of downlink data; Service type corresponding to the session.

4. The data transmission method according to claim 3, further comprising: According to the first response, retaining air interface resources and session information corresponding to the session; The air interface resources are used to receive downlink data.

5. The data transmission method according to claim 1, wherein: Before receiving downlink data through the first session according to the first information, the method further includes: Accessing the satellite device according to the first parameter, and sending a second request to the satellite device, wherein the second request is used to obtain information of a downlink data buffer component on the satellite device or to indicate receiving downlink data or to request registration or to request sending uplink data; receiving a second response fed back by the satellite device, where the second response carries information of the downlink data buffer component or carries indication information instructing the terminal to use resources corresponding to the first session to receive downlink data; The receiving downlink data through the first session according to the first information includes: receiving, through the first session, downlink data sent by the downlink data buffer component on the satellite device according to the first information and the information of the downlink data buffer component or the indication information; The first parameter includes at least one of: uplink data transmission status, candidate response modes for receiving downlink data, locally stored first session information, reasons for network paging, and relevant identifiers of the satellite device.

6. The data transmission method according to claim 5, wherein: The second request carries an indication that the terminal is allowed to receive downlink data, and / or a receiving mode for downlink data supported by the terminal; And / or, the second response carries a downlink data receiving mode allowed by the satellite device.

7. The data transmission method according to claim 5, further comprising: A receiving mode for downlink data supported by the terminal is sent to the satellite device.

8. The data transmission method according to claim 6 or 7, wherein: The receiving, through the first session, the downlink data sent by the downlink data buffer component on the satellite device comprises: The downlink data sent by the satellite device according to the receiving mode and using the downlink data buffer component on the satellite device is received through the first session.

9. The data transmission method according to claim 5, further comprising: Determine a first mapping relationship between the session identification information of the first session and the air interface resources; The step of accessing the satellite device according to the first parameter includes: The satellite device is accessed according to the first parameter and the first mapping relationship.

10. The data transmission method according to claim 1, wherein: The first session is a protocol data unit (PDU) session or a non-PDU session.

11. A data transmission method, applied to satellite equipment, comprising: Sending first information of a first session to a terminal; Sending downlink data to the terminal through the first session according to the first information; The first session refers to a session that continuously occupies the allocated resources; The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

12. The data transmission method according to claim 11, wherein: The first information also includes at least one of the following: A response method for receiving downlink data; Paging time window; Periodic registration timer; Satellite identification.

13. The data transmission method according to claim 12, further comprising: Determine the response mode for receiving downlink data according to the reference information; wherein the reference information includes: the time information, and at least one of the downlink receiving priority; And / or, determining a paging time window or a periodic registration timer corresponding to the terminal according to the ephemeris information of the satellite device.

14. The data transmission method according to claim 12, further comprising: Determining, according to the response mode for receiving downlink data, to initiate paging or wait for the terminal to access; Wherein, when it is determined to initiate paging, the terminal is instructed to receive downlink data in the paging reason.

15. The data transmission method according to claim 11, wherein: Before sending the first information of the first session to the terminal, the method further includes: receiving a first request sent by the terminal; The sending the first information of the first session to the terminal includes: Feedback a first response to the terminal according to the first request, where the first response carries first information of the first session; The first request carries at least one of the following: Receive uplink data delivery confirmation; Waiting to receive downlink data; Receiving priority of downlink data; Service type corresponding to the session.

16. The data transmission method according to claim 15, further comprising: Reserving system resources and session information of the session corresponding to the first response; The system resources are used to send downlink data.

17. The data transmission method according to claim 15, wherein: The feeding back a first response to the terminal according to the first request includes: In a case where the first request indicates a request to activate the on-board store-and-forward operation or the terminal has activated the on-board store-and-forward operation, allocating resources and establishing a first session or updating an existing session to the first session according to the first request; According to the first session, a first response is fed back to the terminal.

18. The data transmission method according to claim 11, wherein: Before sending downlink data to the terminal through the first session according to the first information, the method further includes: receiving a second request sent by the terminal, where the second request is used to obtain information of a downlink data buffer component on the satellite device or to indicate receiving downlink data or to request registration or to request sending uplink data; Feedback a second response to the terminal according to the second request, where the second response carries information of the downlink data buffer component or carries indication information instructing the terminal to use the resources corresponding to the first session to receive downlink data; The sending downlink data to the terminal through the first session according to the first information includes: According to the first information and the information of the downlink data buffer component or the indication information, the downlink data is sent to the terminal through the first session by utilizing the downlink data buffer component on the satellite device.

19. The data transmission method according to claim 18, wherein: The second request carries an indication that the terminal is allowed to receive downlink data, and / or a receiving mode for downlink data supported by the terminal; And / or, the second response carries a downlink data receiving mode allowed by the satellite device.

20. The data transmission method according to claim 18, further comprising: A receiving mode for downlink data supported by the terminal is received and sent by the terminal.

21. The data transmission method according to claim 19 or 20, wherein: The sending downlink data to the terminal through the first session by using the downlink data buffer component on the satellite device includes: According to the first information and the receiving mode for downlink data supported by the terminal, the downlink data is sent to the terminal through the first session by utilizing the downlink data buffer component on the satellite device.

22. The data transmission method according to claim 11, wherein: The first session is a protocol data unit (PDU) session or a non-PDU session.

23. The data transmission method according to claim 11, further comprising: caching a notification for the terminal, the notification being used to indicate that the terminal has activated an on-board store-and-forward operation; The notification carries downlink data storage and forwarding information, and the downlink data storage and forwarding information includes: downlink data sending mode, the terminal identifier, PDU session identifier, on-board storage configuration, candidate user address identifier, and at least one of the candidate user IP addresses.

24. The data transmission method according to claim 23, further comprising: The notification is sent to a server.

25. The data transmission method according to claim 11, wherein: Before sending downlink data to the terminal through the first session according to the first information, the method further includes: Determining a downlink data sending mode according to the second information; The second information includes: at least one of the intersatellite link status information and the server's downlink data storage and forwarding request; the downlink data storage and forwarding request includes: at least one of the downlink forwarding strategy, forwarding priority and downlink data delivery confirmation method.

26. The data transmission method according to claim 25, further comprising: Feedback a downlink data storage and forwarding response to the server according to the downlink data sending mode; The downlink data storage forwarding response carries downlink data storage forwarding information, and the downlink data storage forwarding information includes: the downlink data sending mode, the terminal identifier, the PDU session identifier, the on-board storage configuration, the estimated time of delivery of the downlink data, the candidate user address identifier, and the candidate user address identifier. Select at least one of the following: User IP address.

27. The data transmission method according to claim 23 or 26, wherein: The on-board storage configuration includes: cache space, and at least one of the retention time of cache data; Alternatively, the on-board storage configuration does not include: cache space and retention time of cache data, and the downlink data storage and forwarding information also includes: cache space, and at least one of retention time of cache data.

28. The data transmission method according to claim 23 or 26, wherein: The downlink data storage and forwarding information also includes: relevant information for monitoring the satellite equipment.

29. The data transmission method according to claim 11, further comprising: Determine a second mapping relationship between the identifier of the terminal, the identifier of the first session, and a related identifier of the server.

30. A data transmission method, applied to a server, comprising: Receiving downlink data storage and forwarding information sent by satellite equipment; Sending downlink data to the satellite device according to the downlink data storage and forwarding information; The downlink data storage and forwarding information includes: downlink data sending mode, terminal identifier, PDU session identifier, on-board storage configuration, estimated time of downlink data delivery, candidate user address identifier, and at least one of the candidate user IP address; The downlink data storage and forwarding information is carried in a notification to the terminal, where the notification is used to indicate that the terminal has activated the on-board storage and forwarding operation, or is carried in a downlink data storage and forwarding response.

31. The data transmission method according to claim 30, wherein: The sending of downlink data to the satellite device according to the downlink data storage and forwarding information includes any one of the following: In the process of receiving the uplink buffer data, sending the downlink data to the satellite device according to the downlink data storage and forwarding information; The downlink data is sent to the satellite device according to the downlink data storage and forwarding information and the downlink data sending requirement information.

32. The data transmission method according to claim 30, wherein: Before receiving the downlink data storage and forwarding information sent by the satellite device, it also includes: Sending a downlink data storage and forwarding request of the server to the satellite device; The downlink data storage and forwarding request includes: downlink forwarding strategy, forwarding priority and At least one of the downlink data delivery confirmation methods.

33. A data transmission device, the data transmission device being a terminal, comprising a memory, a transceiver, and a processor: A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations: Receiving, by the transceiver, first information of a first session sent by a satellite device; receiving downlink data through the first session according to the first information; in, The first session refers to a session that continuously occupies the allocated resources; The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

34. The data transmission device according to claim 33, wherein: The first information also includes at least one of the following: A response method for receiving downlink data; Paging time window; Periodic registration timer; Satellite identification.

35. The data transmission device according to claim 33, wherein: The operations also include: Before receiving the first information of the first session sent by the satellite device, sending a first request to the satellite device through the transceiver according to the downlink data reception requirement information; The receiving first information of the first session sent by the satellite device includes: receiving a first response fed back by the satellite device, where the first response carries first information of a first session; The first request carries at least one of the following: Receive uplink data delivery confirmation; Waiting to receive downlink data; Receiving priority of downlink data; Service type corresponding to the session.

36. The data transmission device according to claim 35, wherein: The operations also include: According to the first response, retaining air interface resources and session information corresponding to the session; The air interface resources are used to receive downlink data.

37. The data transmission device according to claim 33, wherein: The operations also include: Before receiving downlink data through the first session according to the first information, accessing the satellite device according to the first parameter, and sending a second request to the satellite device through the transceiver, the second request being used to obtain information of a downlink data buffer component on the satellite device or to indicate receiving downlink data or to request registration or to request sending uplink data; receiving, by the transceiver, a second response fed back by the satellite device, where the second response carries information of the downlink data buffer component or carries indication information instructing the terminal to use resources corresponding to the first session to receive downlink data; The receiving downlink data through the first session according to the first information includes: receiving, through the first session, downlink data sent by the downlink data buffer component on the satellite device according to the first information and the information of the downlink data buffer component or the indication information; The first parameter includes at least one of: uplink data transmission status, candidate response modes for receiving downlink data, locally stored first session information, reasons for network paging, and relevant identifiers of the satellite device.

38. The data transmission device according to claim 37, wherein: The second request carries an indication that the terminal is allowed to receive downlink data, and / or a receiving mode for downlink data supported by the terminal; And / or, the second response carries a downlink data receiving mode allowed by the satellite device.

39. The data transmission device according to claim 37, wherein: The operations also include: The receiving mode for downlink data supported by the terminal is sent to the satellite device through the transceiver.

40. The data transmission device according to claim 38 or 39, wherein: The receiving, through the first session, the downlink data sent by the downlink data buffer component on the satellite device comprises: The downlink data sent by the satellite device according to the receiving mode and using the downlink data buffer component on the satellite device is received through the first session.

41. The data transmission device according to claim 37, wherein: The operations also include: Determine a first mapping relationship between the session identification information of the first session and the air interface resources; The step of accessing the satellite device according to the first parameter includes: The satellite device is accessed according to the first parameter and the first mapping relationship.

42. The data transmission device according to claim 33, wherein: The first session is a protocol data unit (PDU) session or a non-PDU session.

43. A data transmission device, the data transmission device being a satellite device, comprising a memory, a transceiver, and a processor: a memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; A processor is configured to read the computer program in the memory and perform the following operations: Sending, via the transceiver, first information of a first session to a terminal; Sending downlink data to the terminal through the first session according to the first information; The first session refers to a session that continuously occupies the allocated resources; The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

44. The data transmission device according to claim 43, wherein: The first information also includes at least one of the following: A response method for receiving downlink data; Paging time window; Periodic registration timer; Satellite identification.

45. The data transmission device according to claim 44, wherein: The operations also include: Determine the response mode for receiving downlink data according to the reference information; wherein the reference information includes: the time information, and at least one of the downlink receiving priority; And / or, determining a paging time window or a periodic registration timer corresponding to the terminal according to the ephemeris information of the satellite device.

46. ​​The data transmission device according to claim 44, wherein: The operations also include: Determining, according to the response mode for receiving downlink data, to initiate paging or wait for the terminal to access; Wherein, when it is determined to initiate paging, the terminal is instructed to receive downlink data in the paging reason.

47. The data transmission device according to claim 43, wherein: The operations also include: Before sending first information of a first session to a terminal, receiving, by the transceiver, a first request sent by the terminal; The sending the first information of the first session to the terminal includes: Feedback a first response to the terminal according to the first request, where the first response carries first information of the first session; The first request carries at least one of the following: Receive uplink data delivery confirmation; Waiting to receive downlink data; Receiving priority of downlink data; Service type corresponding to the session.

48. The data transmission device according to claim 47, wherein: The operations also include: Reserving system resources and session information of the session corresponding to the first response; The system resources are used to send downlink data.

49. The data transmission device according to claim 47, wherein: The feeding back a first response to the terminal according to the first request includes: In a case where the first request indicates a request to activate the on-board store-and-forward operation or the terminal has activated the on-board store-and-forward operation, allocating resources and establishing a first session or updating an existing session to the first session according to the first request; According to the first session, a first response is fed back to the terminal.

50. The data transmission device according to claim 43, wherein: The operations also include: Before sending downlink data to the terminal through the first session according to the first information, receiving a second request sent by the terminal through the transceiver, the second request being used to obtain information of a downlink data buffer component on the satellite device or to indicate receiving downlink data or to request registration or to request sending uplink data; Feedback a second response to the terminal according to the second request, where the second response carries information of the downlink data buffer component or carries indication information instructing the terminal to use the resources corresponding to the first session to receive downlink data; The sending downlink data to the terminal through the first session according to the first information includes: According to the first information and the information of the downlink data buffer component or the indication information, the downlink data is sent to the terminal through the first session by utilizing the downlink data buffer component on the satellite device.

51. The data transmission device according to claim 50, wherein: The second request carries an indication that the terminal is allowed to receive downlink data, and / or a receiving mode for downlink data supported by the terminal; And / or, the second response carries a downlink data receiving mode allowed by the satellite device.

52. The data transmission device according to claim 50, wherein: The operations also include: A receiving mode for downlink data supported by the terminal and sent by the terminal is received through the transceiver.

53. The data transmission device according to claim 51 or 52, wherein: The sending downlink data to the terminal through the first session by using the downlink data buffer component on the satellite device includes: According to the first information and the receiving mode for downlink data supported by the terminal, the downlink data is sent to the terminal through the first session by utilizing the downlink data buffer component on the satellite device.

54. The data transmission device according to claim 43, wherein: The first session is a protocol data unit (PDU) session or a non-PDU session.

55. The data transmission device according to claim 43, wherein: The operations also include: caching a notification for the terminal, the notification being used to indicate that the terminal has activated an on-board store-and-forward operation; The notification carries downlink data storage and forwarding information, and the downlink data storage and forwarding information includes: downlink data sending mode, the terminal identifier, PDU session identifier, on-board storage configuration, candidate user address identifier, and at least one of the candidate user IP addresses.

56. The data transmission device according to claim 55, wherein: The operations also include: The notification is sent to a server via the transceiver.

57. The data transmission device according to claim 43, wherein: The operations also include: Before sending downlink data to the terminal through the first session according to the first information, determining a downlink data sending mode according to the second information; The second information includes: intersatellite link status information and server downlink data storage conversion The downlink data storage and forwarding request includes at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

58. The data transmission device according to claim 57, wherein: The operations also include: Feedback a downlink data storage and forwarding response to the server according to the downlink data sending mode; Among them, the downlink data storage forwarding response carries downlink data storage forwarding information, and the downlink data storage forwarding information includes: the downlink data sending method, the terminal identifier, the PDU session identifier, the on-board storage configuration, the expected time of delivery of the downlink data, the candidate user address identifier, and at least one of the candidate user IP addresses.

59. The data transmission device according to claim 55 or 58, wherein: The on-board storage configuration includes: cache space, and at least one of the retention time of cache data; Alternatively, the on-board storage configuration does not include: cache space and retention time of cache data, and the downlink data storage and forwarding information also includes: cache space, and at least one of retention time of cache data.

60. The data transmission device according to claim 55 or 58, wherein: The downlink data storage and forwarding information also includes: relevant information for monitoring the satellite equipment.

61. The data transmission device according to claim 43, wherein: The operations also include: Determine a second mapping relationship between the identifier of the terminal, the identifier of the first session, and a related identifier of the server.

62. A data transmission device, the data transmission device being a server, comprising a memory, a transceiver, and a processor: A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations: Receiving downlink data storage and forwarding information sent by satellite equipment through the transceiver; Sending downlink data to the satellite device through the transceiver according to the downlink data storage and forwarding information; in, The downlink data storage and forwarding information includes: downlink data sending mode, terminal identifier, PDU session identifier, on-board storage configuration, estimated time of downlink data delivery, candidate user address identifier, and at least one of the candidate user IP address; The downlink data storage and forwarding information is carried in a notification to the terminal, and the notification is used to indicate The terminal has activated the on-board store-and-forward operation, or carried it in the downlink data store-and-forward response.

63. The data transmission device according to claim 62, wherein: The sending of downlink data to the satellite device according to the downlink data storage and forwarding information includes any one of the following: In the process of receiving the uplink buffer data, sending the downlink data to the satellite device according to the downlink data storage and forwarding information; The downlink data is sent to the satellite device according to the downlink data storage and forwarding information and the downlink data sending requirement information.

64. The data transmission device according to claim 62, wherein: The operations also include: Before receiving the downlink data storage and forwarding information sent by the satellite device, sending a downlink data storage and forwarding request of the server to the satellite device through the transceiver; The downlink data storage and forwarding request includes: at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

65. A data transmission device, applied to a terminal, comprising: A first receiving unit, configured to receive first information of a first session sent by a satellite device; A second receiving unit, configured to receive downlink data through the first session according to the first information; The first session refers to a session that continuously occupies the allocated resources; The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

66. The data transmission device according to claim 65, wherein: The first information also includes at least one of the following: A response method for receiving downlink data; Paging time window; Periodic registration timer; Satellite identification.

67. The data transmission device according to claim 65, wherein: Also includes: A first sending unit is configured to send a first request to the satellite device according to the downlink data reception requirement information before receiving the first information of the first session sent by the satellite device; The first receiving unit is specifically configured to: Receive a first response fed back by the satellite device, wherein the first response carries a first message of the first session. interest; The first request carries at least one of the following: Receive uplink data delivery confirmation; Waiting to receive downlink data; Receiving priority of downlink data; Service type corresponding to the session.

68. The data transmission device according to claim 67, wherein: Also includes: A first processing unit, configured to reserve air interface resources and session information corresponding to a session according to the first response; The air interface resources are used to receive downlink data.

69. The data transmission device according to claim 65, wherein: Also includes: a second processing unit, configured to access the satellite device according to a first parameter and send a second request to the satellite device before receiving downlink data through the first session according to the first information, wherein the second request is used to obtain information of a downlink data buffer component on the satellite device or to indicate receiving downlink data or to request registration or to request sending uplink data; A third receiving unit is configured to receive a second response fed back by the satellite device, where the second response carries information of the downlink data buffer component or carries indication information instructing the terminal to use the resources corresponding to the first session to receive downlink data; The second receiving unit is specifically configured to: receiving, through the first session, downlink data sent by the downlink data buffer component on the satellite device according to the first information and the information of the downlink data buffer component or the indication information; The first parameter includes at least one of: uplink data transmission status, candidate response modes for receiving downlink data, locally stored first session information, reasons for network paging, and relevant identifiers of the satellite device.

70. The data transmission device according to claim 69, wherein: The second request carries an indication that the terminal is allowed to receive downlink data, and / or a receiving mode for downlink data supported by the terminal; And / or, the second response carries a downlink data receiving mode allowed by the satellite device.

71. The data transmission device according to claim 69, wherein: Also includes: The second sending unit is used to send the receiving mode for downlink data supported by the terminal to the satellite device.

72. The data transmission device according to claim 70 or 71, wherein: The receiving, through the first session, the downlink data sent by the downlink data buffer component on the satellite device comprises: The downlink data sent by the satellite device according to the receiving mode and using the downlink data buffer component on the satellite device is received through the first session.

73. The data transmission device according to claim 69, wherein: Also includes: A first determining unit, configured to determine a first mapping relationship between the session identification information of the first session and air interface resources; The step of accessing the satellite device according to the first parameter includes: The satellite device is accessed according to the first parameter and the first mapping relationship.

74. The data transmission device according to claim 65, wherein: The first session is a protocol data unit (PDU) session or a non-PDU session.

75. A data transmission device, applied to satellite equipment, comprising: A third sending unit, configured to send first information of a first session to a terminal; a fourth receiving unit, configured to send downlink data to the terminal through the first session according to the first information; The first session refers to a session that continuously occupies the allocated resources; The first information includes: fixed session identification information and time information of the session continuously occupying the allocated resources.

76. The data transmission device according to claim 75, wherein: The first information also includes at least one of the following: A response method for receiving downlink data; Paging time window; Periodic registration timer; Satellite identification.

77. The data transmission device according to claim 76, wherein: Also includes: A second determining unit, configured to determine the response mode for receiving downlink data according to reference information; wherein the reference information includes: the time information, and at least one of the downlink receiving priority; And / or, determining a paging time window or a periodic registration timer corresponding to the terminal according to the ephemeris information of the satellite device.

78. The data transmission device according to claim 76, wherein: The data transmission device further comprises: A third determining unit, configured to determine, according to the response mode for receiving downlink data, whether to initiate paging or wait for the terminal to access; Wherein, when it is determined to initiate paging, the terminal is instructed to receive downlink data in the paging reason.

79. The data transmission device according to claim 75, wherein: Also includes: a fourth receiving unit, configured to receive a first request sent by the terminal before sending the first information of the first session to the terminal; The sending the first information of the first session to the terminal includes: Feedback a first response to the terminal according to the first request, where the first response carries first information of the first session; The first request carries at least one of the following: Receive uplink data delivery confirmation; Waiting to receive downlink data; Receiving priority of downlink data; Service type corresponding to the session.

80. The data transmission device according to claim 79, wherein: Also includes: a third processing unit, configured to retain system resources and session information of a session corresponding to the first response; The system resources are used to send downlink data.

81. The data transmission device according to claim 79, wherein: The feeding back a first response to the terminal according to the first request includes: In a case where the first request indicates a request to activate the on-board store-and-forward operation or the terminal has activated the on-board store-and-forward operation, allocating resources and establishing a first session or updating an existing session to the first session according to the first request; According to the first session, a first response is fed back to the terminal.

82. The data transmission device according to claim 75, wherein: Also includes: a fifth receiving unit, configured to receive a second request sent by the terminal before sending downlink data to the terminal through the first session according to the first information, wherein the second request is used to obtain information of a downlink data buffer component on the satellite device or to indicate receiving downlink data or to request registration or to request sending uplink data; A first feedback unit is configured to feed back a second response to the terminal according to the second request, where the second response carries information about the downlink data buffer component or carries indication information instructing the terminal to use resources corresponding to the first session to receive downlink data; The sending downlink data to the terminal through the first session according to the first information includes: According to the first information and the information of the downlink data buffer component or the indication information, the downlink data is sent to the terminal through the first session by utilizing the downlink data buffer component on the satellite device.

83. The data transmission device according to claim 82, wherein: The second request carries an indication that the terminal is allowed to receive downlink data, and / or a receiving mode for downlink data supported by the terminal; And / or, the second response carries a downlink data receiving mode allowed by the satellite device.

84. The data transmission device according to claim 82, wherein: The data transmission device further comprises: A sixth receiving unit is used to receive a receiving mode for downlink data supported by the terminal and sent by the terminal.

85. The data transmission device according to claim 82 or 83, wherein: The sending downlink data to the terminal through the first session by using the downlink data buffer component on the satellite device includes: According to the first information and the receiving mode for downlink data supported by the terminal, the downlink data is sent to the terminal through the first session by utilizing the downlink data buffer component on the satellite device.

86. The data transmission device according to claim 75, wherein: The first session is a protocol data unit (PDU) session or a non-PDU session.

87. The data transmission device according to claim 75, wherein: Also includes: The first cache unit is used to cache a notification for the terminal, wherein the notification is used to indicate that the terminal The terminal has activated the on-board store-and-forward operation; The notification carries downlink data storage and forwarding information, and the downlink data storage and forwarding information includes: downlink data sending mode, the terminal identifier, PDU session identifier, on-board storage configuration, candidate user address identifier, and at least one of the candidate user IP addresses.

88. The data transmission device according to claim 87, wherein: Also includes: The fifth sending unit is used to send the notification to the server.

89. The data transmission device according to claim 75, wherein: Also includes: a fourth determining unit, configured to determine a downlink data sending mode according to second information before sending downlink data to the terminal through the first session according to the first information; The second information includes: at least one of the intersatellite link status information and the server's downlink data storage and forwarding request; the downlink data storage and forwarding request includes: at least one of the downlink forwarding strategy, forwarding priority and downlink data delivery confirmation method.

90. The data transmission device according to claim 89, wherein: Also includes: A second feedback unit, configured to feed back a downlink data storage and forwarding response to the server according to the downlink data sending mode; Among them, the downlink data storage forwarding response carries downlink data storage forwarding information, and the downlink data storage forwarding information includes: the downlink data sending method, the terminal identifier, the PDU session identifier, the on-board storage configuration, the expected time of delivery of the downlink data, the candidate user address identifier, and at least one of the candidate user IP addresses.

91. The data transmission device according to claim 87 or 90, wherein: The on-board storage configuration includes: cache space, and at least one of the retention time of cache data; Alternatively, the on-board storage configuration does not include: cache space and retention time of cache data, and the downlink data storage and forwarding information also includes: cache space, and at least one of retention time of cache data.

92. The data transmission device according to claim 87 or 90, wherein: The downlink data storage and forwarding information also includes: relevant information for monitoring the satellite equipment.

93. The data transmission device according to claim 75, wherein: Also includes: The fifth determining unit is used to determine a second mapping relationship between the identifier of the terminal, the identifier of the first session, and a related identifier of the server.

94. A data transmission device, applied to a server, comprising: A seventh receiving unit, used for receiving downlink data storage and forwarding information sent by the satellite device; A sixth sending unit, configured to send downlink data to a satellite device according to the downlink data storage and forwarding information; The downlink data storage and forwarding information includes: downlink data sending mode, terminal identifier, PDU session identifier, on-board storage configuration, estimated time of downlink data delivery, candidate user address identifier, and at least one of the candidate user IP address; The downlink data storage and forwarding information is carried in a notification to the terminal, where the notification is used to indicate that the terminal has activated the on-board storage and forwarding operation, or is carried in a downlink data storage and forwarding response.

95. The data transmission device according to claim 94, wherein: The sixth sending unit is specifically used for any of the following: In the process of receiving the uplink buffer data, sending the downlink data to the satellite device according to the downlink data storage and forwarding information; The downlink data is sent to the satellite device according to the downlink data storage and forwarding information and the downlink data sending requirement information.

96. The data transmission device according to claim 94, wherein: Also includes: A seventh sending unit, configured to send a downlink data storage and forwarding request of the server to the satellite device before receiving the downlink data storage and forwarding information sent by the satellite device; The downlink data storage and forwarding request includes: at least one of a downlink forwarding strategy, a forwarding priority, and a downlink data delivery confirmation method.

97. A non-transitory readable storage medium storing a computer program for causing a processor to execute the method of any one of claims 1 to 32.

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