Communication method, network element, device, terminal, apparatus, and storage medium

Abstract

The present disclosure relates to a communication method, a network element, a device, a terminal, an apparatus, and a storage medium. The method comprises: receiving a first request sent by a first device, wherein the first request is sent to the first device when a terminal is disconnected from a second device, and then determines to establish a communication connection with a first network element by means of the first device; and sending a first response to the first device on the basis of the received first request, wherein the first device is a terrestrial network device, the second device is a non-terrestrial network device, and the first response is used for indicating that the terminal is allowed to establish a communication connection with the first network element by means of the first device. The present disclosure solves the problem in the prior art that a terminal is not supported to switch from a non-terrestrial network device to a terrestrial network device to access a core network.

Description

Communication method, network element, equipment, terminal, device and storage medium Technical Field

[0001] The present disclosure relates to the field of communication technologies, and in particular to communication methods, network elements, equipment, terminals, devices, and storage media. Background Art

[0002] Currently, terminals can access the core network through non-terrestrial networks (NTN) or terrestrial networks (TN) paths. How terminals switch from non-terrestrial network paths to terrestrial network paths to access the core network requires further research.

[0003] Summary of the Invention

[0004] The embodiments of the present disclosure provide a communication method, a network element, a device, a terminal, an apparatus, and a storage medium.

[0005] In a first aspect, an embodiment of the present disclosure provides a communication method, which is performed by a first network element. The method includes:

[0006] receiving a first request sent by a first device, where the first request is sent to the first device when the terminal determines to establish a communication connection with the first network element through the first device after releasing the connection with the second device;

[0007] Sending a first response to the first device according to the received first request;

[0008] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network;

[0009] The first response is used to indicate acceptance of establishing a communication connection between the terminal and the first network element through the first device.

[0010] In a second aspect, an embodiment of the present disclosure provides a communication method, which is performed by a first device, and the method includes:

[0011] receiving a first request sent by a terminal, where the first request is sent to the first device when the terminal determines to establish a communication connection with the first network element through the first device after releasing a connection with the second device;

[0012] Sending the first request to the first network element;

[0013] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network.

[0014] In a third aspect, an embodiment of the present disclosure provides a communication method, which is executed by a terminal, and the method includes:

[0015] Sending a first request to the first device, where the first request is sent to the first device after the terminal releases the connection with the second device and determines to establish a communication connection with the first network element through the first device;

[0016] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network.

[0017] In a fourth aspect, an embodiment of the present disclosure provides a first network element, including:

[0018] a receiving module, configured to receive a first request sent by a first device, where the first request is sent to the first device when the terminal determines to establish a communication connection with the first network element through the first device after releasing the connection with the second device;

[0019] a sending module, configured to send a first response to the first device according to the received first request;

[0020] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network;

[0021] The first response is used to indicate acceptance of establishing a communication connection between the terminal and the first network element through the first device.

[0022] In a fifth aspect, an embodiment of the present disclosure provides a first device, including:

[0023] a receiving module, configured to receive a first request sent by a terminal, where the first request is sent to the first device when the terminal determines to establish a communication connection with the first network element through the first device after releasing the connection with the second device;

[0024] A sending module, configured to send the first request to the first network element;

[0025] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network.

[0026] In a sixth aspect, an embodiment of the present disclosure provides a terminal, including:

[0027] a sending module, configured to send a first request to the first device, where the first request is sent to the first device when the terminal determines to establish a communication connection with the first network element through the first device after releasing the connection with the second device;

[0028] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network.

[0029] In a seventh aspect, an embodiment of the present disclosure provides a first network element, including:

[0030] one or more processors;

[0031] The first network element is used to execute the communication method described in any one of the first aspects of the embodiments of the present disclosure.

[0032] In an eighth aspect, an embodiment of the present disclosure provides a first device, including:

[0033] one or more processors;

[0034] The first device is used to execute the communication method described in any one of the second aspects of the embodiments of this disclosure.

[0035] In a ninth aspect, an embodiment of the present disclosure provides a terminal, including:

[0036] one or more processors;

[0037] The terminal is used to execute the communication method described in any one of the third aspects of the embodiments of this disclosure.

[0038] In the tenth aspect, an embodiment of the present disclosure proposes a communication system, including a first network element, a first device, and a terminal; wherein the first network element is configured to implement the communication method of any one of the first aspect of the embodiment of the present disclosure; the first device is configured to implement the communication method of any one of the second aspect of the embodiment of the present disclosure; and the terminal is configured to implement the communication method of any one of the third aspect of the embodiment of the present disclosure.

[0039] In an eleventh aspect, an embodiment of the present disclosure proposes a storage medium, which, when an instruction is executed on a communication device, enables the communication device to execute any one of the communication methods of the embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following drawings required for describing the embodiments are introduced. The following drawings are merely some embodiments of the present disclosure and do not impose specific limitations on the protection scope of the present disclosure.

[0041] FIG1A is an exemplary schematic diagram of the architecture of a communication system provided according to an embodiment of the present disclosure;

[0042] FIG1B is an exemplary schematic diagram showing a terminal switching from a device in a non-terrestrial network to a device in a terrestrial network to access a core network according to an embodiment of the present disclosure;

[0043] FIG2 is an interactive schematic diagram of a communication method according to an embodiment of the present disclosure;

[0044] FIG3 is a flow chart of a communication method according to an embodiment of the present disclosure;

[0045] FIG4 is a flow chart of a communication method according to an embodiment of the present disclosure;

[0046] FIG5 is a flow chart of a communication method according to an embodiment of the present disclosure;

[0047] FIG6 is an interactive schematic diagram illustrating a communication method according to an embodiment of the present disclosure;

[0048] FIG7A is a schematic structural diagram of a first network element proposed in an embodiment of the present disclosure;

[0049] FIG7B is a schematic structural diagram of a first device proposed in an embodiment of the present disclosure;

[0050] FIG7C is a schematic diagram of the structure of a terminal proposed in an embodiment of the present disclosure;

[0051] FIG8A is a schematic structural diagram of a communication device proposed in an embodiment of the present disclosure;

[0052] FIG8B is a schematic diagram of the structure of the chip proposed in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0053] The embodiments of the present disclosure provide a communication method, a network element, a device, a terminal, an apparatus, and a storage medium.

[0054] In a first aspect, an embodiment of the present disclosure provides a communication method, which is performed by a first network element. The method includes:

[0055] receiving a first request sent by a first device, where the first request is sent to the first device when the terminal determines to establish a communication connection with the first network element through the first device after releasing the connection with the second device;

[0056] Sending a first response to the first device according to the received first request;

[0057] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network;

[0058] The first response is used to indicate acceptance of establishing a communication connection between the terminal and the first network element through the first device.

[0059] In the above embodiment, the first network element sends a first response to the first device based on the received first request; in this way, the terminal can switch from accessing the first network element from the second device of the non-terrestrial network to accessing the first network element through the first device of the terrestrial network.

[0060] In conjunction with some embodiments of the first aspect, in some embodiments, the receiving a first request sent by the first device further includes:

[0061] When the terminal meets the first condition, using the first non-access stratum count pre-stored in the context information of the terminal as the second non-access stratum count, and additionally storing at least one of the second non-access stratum count and the first cell identifier in the context information of the terminal;

[0062] The first condition includes that the terminal is allowed to perform a store-and-forward operation, or the terminal is allowed to be in a store-and-forward operation;

[0063] The first cell identifier is a cell identifier pre-stored in the context information of the terminal and having a mapping relationship with the second device.

[0064] In the above embodiment, when the terminal meets the first condition, at least one of the second non-access layer count and the first cell identifier is additionally stored in the context information of the terminal; in this way, after the feeder link of the second device is available, when the first network element receives the data temporarily stored by the second device, it can use at least one of the second non-access layer count and the first cell identifier to determine whether the device sending the first message is the second device or to verify the integrity of the first message.

[0065] In conjunction with some embodiments of the first aspect, in some embodiments, the terminal satisfies the first condition, which is determined in the following manner:

[0066] The context information of the terminal includes a first indication;

[0067] The first indication is used to indicate that the terminal is allowed to perform a store-and-forward operation, or that the terminal is allowed to be in a store-and-forward operation.

[0068] In the above embodiment, the first network element indication is used to determine whether the terminal is allowed to perform a store and forward operation, or the terminal is allowed to be in a store and forward operation; in this way, the first indication is stored in the context information of the terminal, and it can be determined that the terminal meets the first condition.

[0069] In conjunction with some embodiments of the first aspect, in some embodiments, the context information of the terminal includes cell information, where the cell information is used to indicate an area covered by the last device having a connection relationship with the terminal;

[0070] The terminal meeting the first condition may also be determined in the following manner:

[0071] Determining, according to the cell information, the last device that has a connection relationship with the terminal;

[0072] The device is a non-terrestrial device, and it is determined that the terminal meets a first condition.

[0073] In the above embodiment, the context information of the terminal includes cell information, and the last device connected to the terminal is determined to be a non-terrestrial device based on the cell information. In this way, the first network element can determine that the terminal meets the first condition based on the cell information.

[0074] In conjunction with some embodiments of the first aspect, in some embodiments, the first request includes a first non-access stratum sequence number;

[0075] The first condition is further determined by at least one of the following:

[0076] The first difference is greater than a preset threshold;

[0077] The feeder link corresponding to the second device is unavailable;

[0078] The first difference is the difference between the first non-access stratum sequence number and the second non-access stratum sequence number;

[0079] The second non-access layer sequence number is determined by counting the first non-access layer.

[0080] In the above embodiment, the first condition is further determined by at least one of the first difference being greater than a preset threshold and the feeder link corresponding to the second device being unavailable; in this way, the first network element can determine the first condition more comprehensively.

[0081] In conjunction with some embodiments of the first aspect, in some embodiments, the sending a first response to the first device further includes:

[0082] receiving a first message sent by the second device after the feeder link is available, where the first message includes a second cell identifier and a third non-access stratum sequence number, and the second cell identifier has a mapping relationship with the second device;

[0083] The integrity of the first message is verified using an integrity verification algorithm.

[0084] In the above embodiment, the first network element receives the first message sent by the second device and verifies the integrity of the first message through an integrity verification algorithm; in this way, the first network element can determine whether to accept the first message.

[0085] In conjunction with some embodiments of the first aspect, in some embodiments, verifying the integrity of the first message using an integrity verification algorithm includes:

[0086] The first cell identifier and the second cell identifier are the same, and the integrity of the first message is verified by using an integrity verification algorithm;

[0087] The input of the integrity verification algorithm is determined based on the third non-access stratum sequence number and the second non-access stratum count.

[0088] In the above embodiment, if the first cell identifier is stored in the context information of the terminal, it is possible to determine whether the device sending the first message is the second device by determining whether the first cell identifier and the second cell identifier are the same. If so, the integrity of the first message is verified using an integrity verification algorithm.

[0089] In conjunction with some embodiments of the first aspect, in some embodiments, verifying the integrity of the first message using an integrity verification algorithm includes:

[0090] Verifying the integrity of the first message using an integrity verification algorithm;

[0091] The input of the integrity verification algorithm is determined based on the third non-access stratum sequence number and the second non-access stratum count.

[0092] In the above embodiment, if the first cell identifier is not stored in the context information of the terminal, the integrity of the first message is directly verified using an integrity verification algorithm.

[0093] In conjunction with some embodiments of the first aspect, in some embodiments, the first message further includes first data, where the first data is uplink data sent by the terminal to the second device;

[0094] The step of verifying the integrity of the first message by using an integrity verification algorithm further includes:

[0095] If the integrity verification result of the first message is passed, the first data is accepted;

[0096] The integrity verification result of the first message is failure, and the first data is rejected.

[0097] In the above embodiment, if the integrity verification result of the first message is passed, the first data is accepted; if the integrity verification result of the first message is failed, the first data is rejected; in this way, whether to accept the first message is determined based on the result of the integrity verification and / or the verification result of the second device.

[0098] In conjunction with some embodiments of the first aspect, in some embodiments, the receiving the first data further includes:

[0099] The second non-access stratum count and / or the first cell identifier stored in the context information of the terminal is deleted.

[0100] In the above embodiment, after receiving the first data, the second non-access stratum count and / or the first cell identifier stored in the context information of the terminal is deleted; in this way, the content stored in the terminal context information can be reduced, freeing up more storage space.

[0101] In a second aspect, an embodiment of the present disclosure provides a communication method, which is performed by a first device, and the method includes:

[0102] receiving a first request sent by a terminal, where the first request is sent to the first device when the terminal determines to establish a communication connection with the first network element through the first device after releasing a connection with the second device;

[0103] Sending the first request to the first network element;

[0104] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network.

[0105] In the above embodiment, the first device receives the first request sent by the terminal and sends the first request to the first network element. The first request is sent to the first device after the terminal releases the connection with the second device and determines to establish a communication connection with the first network element through the first device; in this way, the terminal can request to switch from accessing the first network element from the second device of the non-ground network to accessing the first network element through the first device of the ground network.

[0106] In conjunction with some embodiments of the second aspect, in some embodiments, the receiving terminal sends a first request, and then further includes:

[0107] receiving a first response sent by the first network element, where the first response is used to indicate that the first network element accepts establishment of a communication connection between the terminal and the first network element through the first device;

[0108] The first response is sent to the terminal.

[0109] In the above embodiment, the first device receives the first response sent by the first network element and sends the first response to the terminal; in this way, the terminal can switch from accessing the first network element through the second device of the non-terrestrial network to accessing the first network element through the first device of the terrestrial network.

[0110] In a third aspect, an embodiment of the present disclosure provides a communication method, which is executed by a terminal, and the method includes:

[0111] Sending a first request to the first device, where the first request is sent to the first device after the terminal releases the connection with the second device and determines to establish a communication connection with the first network element through the first device;

[0112] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network.

[0113] In the above embodiment, the terminal sends a first request to the first device; thus, the terminal can request to switch from accessing the first network element through the second device of the non-terrestrial network to accessing the first network element through the first device of the terrestrial network.

[0114] In conjunction with some embodiments of the third aspect, in some embodiments, sending the first request to the first device includes:

[0115] Determining that a second condition is met, sending the first request to the first device;

[0116] The second condition is at least one of the following:

[0117] the signal strength of the first device is greater than the signal strength of the second device;

[0118] The feeder link of the second device is unavailable.

[0119] In the above embodiment, when the terminal meets the second condition, it determines to send the first request to the first device; in this way, the terminal can send the first request to the first device when the signal strength of the first device is stronger and / or the feeder link of the second device is unavailable.

[0120] In conjunction with some embodiments of the third aspect, in some embodiments, sending the first request to the first device further includes:

[0121] A first response is received, where the first response is used to indicate acceptance of establishing a communication connection between the terminal and the first network element through the first device.

[0122] In the above embodiment, the terminal receives the first response; thus, the terminal can switch from accessing the first network element through the second device of the non-terrestrial network to accessing the first network element through the first device of the terrestrial network.

[0123] In a fourth aspect, an embodiment of the present disclosure provides a first network element, including:

[0124] a receiving module, configured to receive a first request sent by a first device, where the first request is sent to the first device when the terminal determines to establish a communication connection with the first network element through the first device after releasing the connection with the second device;

[0125] a sending module, configured to send a first response to the first device according to the received first request;

[0126] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network;

[0127] The first response is used to indicate acceptance of establishing a communication connection between the terminal and the first network element through the first device.

[0128] In a fifth aspect, an embodiment of the present disclosure provides a first device, including:

[0129] a receiving module, configured to receive a first request sent by a terminal, where the first request is sent to the first device when the terminal determines to establish a communication connection with the first network element through the first device after releasing the connection with the second device;

[0130] A sending module, configured to send the first request to the first network element;

[0131] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network.

[0132] In a sixth aspect, an embodiment of the present disclosure provides a terminal, including:

[0133] a sending module, configured to send a first request to the first device, where the first request is sent to the first device when the terminal determines to establish a communication connection with the first network element through the first device after releasing the connection with the second device;

[0134] The first device is a device of a terrestrial network; the second device is a device of a non-terrestrial network.

[0135] In a seventh aspect, an embodiment of the present disclosure provides a first network element, including:

[0136] one or more processors;

[0137] The first network element is used to execute the communication method described in any one of the first aspects of the embodiments of the present disclosure.

[0138] In an eighth aspect, an embodiment of the present disclosure provides a first device, including:

[0139] one or more processors;

[0140] The first device is used to execute the communication method described in any one of the second aspects of the embodiments of this disclosure.

[0141] In a ninth aspect, an embodiment of the present disclosure provides a terminal, including:

[0142] one or more processors;

[0143] The terminal is used to execute the communication method described in any one of the third aspects of the embodiments of this disclosure.

[0144] In the tenth aspect, an embodiment of the present disclosure proposes a communication system, including a first network element, a first device, and a terminal; wherein the first network element is configured to implement the communication method of any one of the first aspect of the embodiment of the present disclosure; the first device is configured to implement the communication method of any one of the second aspect of the embodiment of the present disclosure; and the terminal is configured to implement the communication method of any one of the third aspect of the embodiment of the present disclosure.

[0145] In an eleventh aspect, an embodiment of the present disclosure proposes a storage medium, which, when an instruction is executed on a communication device, enables the communication device to execute any one of the communication methods of the embodiments of the present disclosure.

[0146] In the twelfth aspect, an embodiment of the present disclosure proposes a program product. When the program product is executed by a communication device, the communication device executes the method described in the optional implementation of the first aspect, the second aspect, and the third aspect.

[0147] In a thirteenth aspect, an embodiment of the present disclosure proposes a computer program, which, when executed on a computer, enables the computer to execute the method described in the optional implementation of the first, second, and third aspects.

[0148] In a fourteenth aspect, an embodiment of the present disclosure provides a chip or a chip system, which includes a processing circuit configured to execute the method described in the optional implementation of the first, second, and third aspects above.

[0149] It is understandable that the above network elements, devices, terminals, communication systems, storage media, program products, computer programs, chips, or chip systems are all used to perform the methods proposed in the embodiments of the present disclosure. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects of the corresponding methods and will not be repeated here.

[0150] The embodiments of the present disclosure provide communication methods, network elements, devices, terminals, apparatuses, and storage media. In some embodiments, the terms communication method, signal transmission method, wireless frame transmission method, etc. are interchangeable, and the terms information processing system, communication system, etc. are interchangeable.

[0151] The embodiments of the present disclosure are not exhaustive and are merely illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present disclosure. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a certain embodiment can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementation methods in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined. For example, some or all steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementation methods of other embodiments.

[0152] In each embodiment of the present disclosure, unless otherwise specified or provided for by logic, the terms and / or descriptions between the embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form a new embodiment based on their inherent logical relationships.

[0153] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0154] In the embodiments of the present disclosure, “plurality” refers to two or more.

[0155] In some embodiments, the terms "at least one," "one or more," "a plurality of," "multiple," etc. may be used interchangeably.

[0156] In some embodiments, descriptions such as "at least one of A and B," "A and / or B," "A in one case, B in another case," or "in response to one case A, in response to another case B" may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); and in some embodiments, A and B (both A and B are executed). The above is also applicable when there are more branches such as A, B, and C.

[0157] In some embodiments, "A or B" and other descriptions may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). The above is also applicable when there are more branches such as A, B, C, etc.

[0158] The prefixes such as "first" and "second" in the embodiments of the present disclosure are only used to distinguish different description objects and do not constitute any restriction on the position, order, priority, quantity or content of the description objects. For the statement of the description object, please refer to the description in the context of the claims or embodiments, and no unnecessary restriction should be constituted due to the use of prefixes. For example, if the description object is a "field", the ordinal number before the "field" in the "first field" and the "second field" does not limit the position or order between the "fields". "First" and "second" do not limit whether the "fields" they modify are in the same message, nor do they limit the order of the "first field" and the "second field". For another example, if the description object is a "level", the ordinal number before the "level" in the "first level" and the "second level" does not limit the priority between the "levels". For another example, the number of description objects is not limited by the ordinal number and can be one or more. Taking "first device" as an example, the number of "devices" can be one or more. In addition, the objects modified by different prefixes can be the same or different. For example, if the description object is "device", then the "first device" and the "second device" can be the same device or different devices, and their types can be the same or different; for another example, if the description object is "information", then the "first information" and the "second information" can be the same information or different information, and their contents can be the same or different.

[0159] In some embodiments, “including A,” “comprising A,” “used to indicate A,” and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

[0160] In some embodiments, terms such as "in response to...", "in response to determining...", "in the case of...", "at the time of...", "when...", "if...", "if...", etc. can be used interchangeably.

[0161] In some embodiments, terms such as "greater than", "less than or equal to", "not less than", "more than", "more than or equal to", "not less than", "higher than", "higher than or equal to", "not less than", and "above" can be replaced with each other, and terms such as "less than", "less than or equal to", "not greater than", "less than", "less than or equal to", "not more than", "lower than", "lower than or equal to", "not higher than", and "below" can be replaced with each other.

[0162] In some embodiments, devices and equipment can be interpreted as physical or virtual, and their names are not limited to the names recorded in the embodiments. In some cases, they can also be understood as "equipment", "device", "circuit", "device", "node", "function", "unit", "section", "system", "network", "chip", "chip system", "entity", "subject", etc.

[0163] In some embodiments, “access network device (AN device)”, “radio access network device (radio

[0164] The terms access network device (RAN device),” “base station (BS)”, “radio base station”, “fixed station”, “node”, “access point”, “transmission point (TP)”, “reception point (RP)”, “transmission / reception point (TRP)”, “panel”, “antenna panel”, “antenna array”, “cell”, “macro cell”, “small cell”, “femto cell”, “pico cell”, “sector”, “cell group”, “carrier”, “component carrier”, and “bandwidth part (BWP)” are used interchangeably.

[0165] In some embodiments, the terms "terminal", "terminal device", "user equipment (terminal)", "user terminal", "mobile station (MS)", "mobile terminal (MT)", subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, etc. can be used interchangeably.

[0166] In some embodiments, the device may refer to a device on the ground, such as an access network device and / or a core network device on the ground; it may also refer to a device on a satellite, such as an access network device and / or a core network device on a satellite; the embodiments of the present disclosure do not limit whether the device is a device on the ground or a device on a satellite, nor do they limit whether the device refers to an access network device or a core network device.

[0167] In some embodiments, the access network device, the core network device, or the network device can be replaced by a terminal. For example, the various embodiments of the present disclosure can also be applied to a structure in which the communication between the access network device, the core network device, or the network device and the terminal is replaced by communication between multiple terminals (for example, it can also be called device-to-device (D2D), vehicle-to-everything (V2X), etc.). In this case, it can also be set as a structure in which the terminal has all or part of the functions of the access network device. In addition, language such as "uplink" and "downlink" can also be replaced by language corresponding to communication between terminals (for example, "side"). For example, uplink channels, downlink channels, etc. can be replaced by side channels, and uplinks, downlinks, etc. can be replaced by side links.

[0168] In some embodiments, the terminal may be replaced by an access network device, a core network device, or a network device. In this case, the access network device, the core network device, or the network device may have a structure that has all or part of the functions of the terminal.

[0169] In some embodiments, terms such as "uplink", "uplink", "physical uplink" can be interchangeable with each other, and terms such as "downlink", "downlink", "physical downlink" can be interchangeable with each other, and terms such as "side", "sidelink", "side communication", "sidelink communication", "direct connection", "direct link", "direct communication", "direct link communication" can be interchangeable with each other.

[0170] In some embodiments, the terms "downlink control information (DCI)", "downlink (DL) assignment", "DL DCI", "uplink (UL) grant", "UL DCI" and the like may be used interchangeably.

[0171] In some embodiments, terms such as "physical downlink shared channel (PDSCH)" and "DL data" can be used interchangeably, and terms such as "physical uplink shared channel (PUSCH)" and "UL data" can be used interchangeably.

[0172] In some embodiments, "obtain", "get", "obtain", "receive", "transmit", "bidirectional transmission", "send and / or receive" can be interchangeable, and can be interpreted as receiving from other entities, obtaining from a protocol, obtaining by self-processing, autonomous implementation, etc.

[0173] In some embodiments, terms such as "send", "transmit", "report", "download", "transmit", "bidirectional transmission", "send and / or receive" can be used interchangeably.

[0174] In some embodiments, "predetermined" and "preset" can be interpreted as pre-specified in a protocol, etc., or can be interpreted as a pre-set action performed by a device, etc.

[0175] In some embodiments, obtaining data, information, etc. may comply with the laws and regulations of the country where the data is obtained.

[0176] In some embodiments, data, information, etc. may be obtained with the user's consent.

[0177] In addition, each element, each row, or each column in the table of the embodiment of the present disclosure can be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns can also be implemented as an independent embodiment.

[0178] FIG1A is an exemplary schematic diagram showing the architecture of a communication system according to an embodiment of the present disclosure. As shown in FIG1A , a communication system 100 includes a first network element 101 , a first device 102 , and a terminal 103 .

[0179] In some embodiments, the terminal includes, for example, a mobile phone, a wearable device, an Internet of Things device, a car with communication capabilities, a smart car, a tablet computer, a computer with wireless transceiver capabilities, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, and a wireless terminal device in a smart home, but is not limited thereto. It is understood that the communication system described in the embodiment of the present disclosure is for the purpose of more clearly illustrating the technical solution of the embodiment of the present disclosure and does not constitute a limitation on the technical solution proposed in the embodiment of the present disclosure. It is known to those skilled in the art that with the evolution of system architecture and the emergence of new business scenarios, the technical solution proposed in the embodiment of the present disclosure is also applicable to similar technical problems. The following embodiments of the present disclosure may be applied to the communication system 100 shown in FIG1A , or a portion thereof, but are not limited thereto. The entities shown in FIG1A are illustrative only. The communication system may include all or part of the entities shown in FIG1A , or may include other entities other than those shown in FIG1A . The number and form of the entities may be arbitrary. The connection relationship between the entities is illustrative only. The entities may be connected or disconnected, and the connection may be in any manner, including direct or indirect, wired or wireless.

[0180] The embodiments of the present disclosure may be applied to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 5th generation mobile communication system-Advanced (5G-Advanced), 6th generation mobile communication system (6G), 5G New Radio (NR), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New Radio Access (NX), Future Generation Radio Access (FX), Global System for Mobile Communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi) (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark)), Public Land Mobile Network (PLMN) networks, Device-to-Device (D2D) systems, Machine-to-Machine (M2M) systems, Internet of Things (IoT) systems, Vehicle-to-Everything (V2X), systems utilizing other communication methods, and next-generation systems based on and extending these methods. Furthermore, a combination of multiple systems (for example, a combination of LTE or LTE-A with 5G) may also be employed.

[0181] In some embodiments, NAS COUNT is introduced in LTE and 5G systems to defend against replay attacks. The Non Access Stratum Count (NAS COUNT) consists of two parts: an 8-bit Non Access Stratum Sequence Number (NAS SQN) included in the Non Access Stratum (NAS) message, corresponding to the least significant 8 bits of the Non Access Stratum Count; and a 16-bit Non Access Stratum OVERFLOW (NAS OVERFLOW) synchronized between the UE and the network, corresponding to the most significant 16 bits of the Non Access Stratum Count.

[0182] In some embodiments, the correct security handling of the NAS OVERFLOW and NAS COUNT values ​​of incoming NAS messages by a receiving entity is as follows: If a receiving entity's RECEIVED NAS SQN is higher than the entity's STORED NAS SQN, the entity generates a non-access stratum count for integrity verification of (STORED NAS OVERFLOW)||(RECEIVED NAS SQN) and uses this non-access stratum count to verify the integrity of the NAS message. If the integrity verification succeeds, the receiving entity shall accept the NAS message and update its STORED NAS SQN to be equal to the RECEIVED NAS SQN; otherwise, the receiving entity shall reject the NAS message. If an entity's RECEIVED NAS SQN is less than or equal to its STORED NAS SQN value, it generates a non-access stratum count for integrity verification of (STORED's NAS OVERFLOW + 1)||(RECEIVED NAS SQN) and uses this non-access stratum count to verify the integrity of the NAS message. If the integrity verification succeeds, the receiving entity shall accept the NAS message, update its STORED NAS SQN to RECEIVED NAS SQN, and increase its STORED NAS OVERFLOW; otherwise, the receiving entity shall reject the NAS message.

[0183] In some embodiments, during store-and-forward service operation, the serving link between the terminal and the satellite and the feeder link between the satellite and the non-terrestrial network (NTN) gateway may not be available at the same time. If the serving link is available but the feeder link is not, the satellite may temporarily store uplink (UL) data sent in a NAS message from the terminal and forward the UL data in the NAS message to the core network until the feeder link becomes available.

[0184] In some embodiments, due to satellite mobility, the terminal may detect that the signal strength from a 5G base station or 4G base station (next generation Node B / Evolved NodeB, gNB / eNB) in the terrestrial network (TN) is better, and decide to establish a connection to the core network via the 5G base station or 4G base station in the terrestrial network. In this case, if the terminal successfully connects to the core network via the 5G base station or 4G base station in the terrestrial network, the UL data later forwarded via the satellite will not be accepted by the core network due to integrity verification failure. This is because after the connection establishment process is accepted, the NAS COUNT maintained in the Access and Mobility Management Function / Mobility Management Entity (MME / AMF) will be updated to the latest value. The satellite will later forward the UL data in a NAS message, and because the MME / AMF cannot construct a correct estimated NAS COUNT and the NAS COUNT is out of sync, it will not be able to successfully verify the integrity of the NAS message.

[0185] FIG1B is an exemplary schematic diagram showing a terminal switching from a device in a non-terrestrial network to a device in a terrestrial network to access a core network according to an embodiment of the present disclosure. As shown in Figure 1B, in step 0, the service link between the terminal and the satellite is available, and a store-and-forward operation is performed between the terminal and the satellite. Since the satellite's feeder link is unavailable, the satellite temporarily stores uplink data that has not yet been sent to the core network. In step 1, the terminal detects that the signal strength from the 4G / 5G base station in the terrestrial network is better and decides to establish a connection with the 4G / 5G base station in the terrestrial network. At this time, the terminal sends a connection reestablishment message to the 4G / 5G base station. The 4G / 5G base station forwards the connection reestablishment message to the core network via the S1AP interface. The core network accepts the connection reestablishment, and the terminal and the 4G / 5G base station establish a communication connection. The core network receives the NAS message sent by the terminal and updates its stored NAS COUNT based on the NAS SQN carried in the NAS message. In step 2, when the satellite moves into an available coverage area, the satellite's feeder link becomes available. At this time, the satellite sends the temporarily stored uplink data to the core network. Since the core network's own stored NAS COUNT has been updated, the uplink data sent by the satellite cannot be accepted by the core network due to integrity verification failure.

[0186] FIG2 is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG2 , the embodiment of the present disclosure relates to a communication method for a communication system 100, the method comprising:

[0187] Step S2101: The terminal sends a first request to the first device.

[0188] In some embodiments, the terminal accesses the first network element through a second device from a non-terrestrial network.

[0189] For example, a terminal sends a first message to a second device, where the first message includes uplink data sent by the terminal to a first network element. If a feeder link exists between the second device and a non-terrestrial network gateway (NTN gateway), the second device forwards the uplink data sent by the terminal to the first network element to the non-terrestrial network gateway via the feeder link, and the non-terrestrial network gateway then sends the uplink data to the first network element. If the feeder link corresponding to the second device is unavailable, the second device temporarily stores the uplink data sent by the terminal to the first network element. After the feeder link is restored, the second device forwards the uplink data sent by the terminal to the non-terrestrial network gateway via the feeder link, and the non-terrestrial network gateway then sends the uplink data to the first network element.

[0190] Optionally, in the embodiments of the present disclosure, the first network element may be a core network element, including but not limited to an MME network element and an AMF network element; the first device may be a terrestrial network device, including but not limited to a 4G base station, a 5G base station, and a 6G base station; and the second device may be a non-terrestrial network device, such as a satellite network device. The network device may be an access network device, or both an access network device and a core network device. The embodiments of the present disclosure do not limit the specific types of the first network element, the first device, and the second device.

[0191] Optionally, after the terminal sends the first message to the second device, if the feeder link is disconnected, the second device temporarily stores the uplink data sent by the terminal. Subsequently, due to mobility, the second device disconnects the communication connection with the terminal when it leaves the coverage of the terminal.

[0192] In some embodiments, when the terminal satisfies a second condition, it is determined to establish a communication connection with the first network element through the first device, where the second condition includes at least one of the following:

[0193] A signal from a first device on a terrestrial network is stronger than a signal from a second device on a non-terrestrial network;

[0194] The feeder link corresponding to the second device is unavailable.

[0195] In some embodiments, when the second condition is met, the terminal sends a first request to the first device, where the first request is used to request to establish a communication connection with the first network element through the first device.

[0196] In some embodiments, the first request further includes a first non-access stratum sequence number.

[0197] Step S2102: The first device sends a first request to the first network element.

[0198] In some embodiments, after receiving the first request, the first device sends the first request to the first network element, where the first request is used to request to establish a communication connection with the first network element through the first device.

[0199] Step S2103: The first network element determines a first response.

[0200] In some embodiments, after receiving the first request, the first network element obtains at least one of the cell information and the first indication pre-stored in the terminal context information, and determines whether the terminal meets the first condition based on the cell information and at least one of the first indication. The first condition includes that the terminal is allowed to perform storage and forwarding operations, or the terminal is allowed to be in storage and forwarding operations.

[0201] In some embodiments, the cell information is used to indicate the area covered by the last device having a connection relationship with the terminal; the first indication is used to indicate that the terminal is allowed to perform a store and forward operation, or the terminal is allowed to be in a store and forward operation.

[0202] Optionally, if the first indication exists in the context information of the terminal, it can be determined that the terminal meets the first condition.

[0203] Optionally, the last device connected to the terminal is determined based on the cell information. If the device is a non-terrestrial device, it can also be determined that the terminal meets the first condition.

[0204] For example: based on the cell information, the last device that has a connection relationship with the terminal can be determined; if the device is a non-ground device, such as a base station on a satellite, it can be determined that the terminal meets the first condition; conversely, if the device is a ground device, including but not limited to: ground 4G base stations, 5G base stations, and 6G base stations, it is determined that the terminal does not meet the first condition.

[0205] It should be noted that in the embodiment of the present disclosure, by determining based on cell information that the last device connected to the terminal is a non-terrestrial device and that the terminal's uplink text information stores at least one of the first indications, it can be determined that the terminal meets the first condition.

[0206] In some embodiments, the first condition is further determined by at least one of the following:

[0207] The first difference is greater than a preset threshold, the first difference is the difference between the first non-access stratum sequence number and the second non-access stratum sequence number, and the second non-access stratum sequence number is determined by the first non-access stratum count;

[0208] The feeder link corresponding to the second device is unavailable.

[0209] It should be noted that the first network element pre-stores the first non-access layer count of the terminal, and the first non-access layer count includes the least significant 8-bit non-access layer sequence number and the most significant 16-bit non-access layer overflow; in the embodiment of the present disclosure, the least significant 8-bit non-access layer sequence number of the first non-access layer count is used as the second non-access layer sequence number.

[0210] It should also be noted that, in the embodiment of the present disclosure, if the first difference is less than or equal to the threshold and / or the feeder link corresponding to the second device is available, it means that the terminal does not meet the first condition.

[0211] Optionally, in the embodiments of the present disclosure, the preset threshold value may be set by the device deployer or operator and configured on the first network element to determine whether the first difference is caused by link packet loss due to poor link conditions or by temporary storage of some uplink data on the second device. The embodiments of the present disclosure do not limit the specific value of the preset threshold value.

[0212] Optionally, in the embodiment of the present disclosure, the second non-access stratum count is also referred to as a storage and forwarding non-access stratum count S&F NAS COUNT; in this way, the first non-access stratum count NAS COUNT and the S&F NAS COUNT stored in the context information of the terminal are independent of each other, and when the value of NAS COUNT is updated, the value of S&F NAS COUNT is not affected.

[0213] In some embodiments, when the terminal meets the first condition, at least one of the S&F NAS COUNT and the first cell identifier is additionally stored in the context information of the terminal, and a first response is determined, where the first response is used to instruct the first network element to accept the terminal establishing a communication connection with the first network element through the first device.

[0214] In some embodiments, the first cell identifier is the last cell identifier that has a mapping relationship with the non-terrestrial device that has a connection relationship with the terminal.

[0215] In some optional embodiments, the first cell identifier is a cell identifier with a mapping relationship with the second device.

[0216] Optionally, in an embodiment of the present disclosure, the first cell identifier includes but is not limited to: a 4G base station identifier (eNodeB Identifier, eNB ID), a 5G base station identifier (the next Generation Node B Identifier, gNB ID), a cell identifier (cell ID), and a mapped cell identifier (mapped cell ID).

[0217] In some embodiments, when the terminal does not meet the first condition, at least one of the S&F NAS COUNT and the first cell identifier is not stored in the context information of the terminal, and the first response is directly determined. The first response is used to instruct the first network element to accept the terminal to establish a communication connection with the first network element through the first device.

[0218] In some embodiments, after determining the first response, the first network element sends the first response to the first device, where the first response is used to instruct the first network element to accept the terminal establishing a communication connection with the first network element through the first device.

[0219] In an embodiment of the present disclosure, when the terminal meets the first condition, the S&F NAS COUNT is stored in the context information of the terminal so that the NAS COUNT and the S&F NAS COUNT stored in the terminal context information are independent of each other; in this way, after the corresponding feeder link is available, when the second device sends the temporarily stored uplink data to the first network element through the first message, the first network element can use the stored S&F NAS COUNT to verify the integrity of the first message.

[0220] Step S2104: The first network element sends a first response to the first device.

[0221] In some embodiments, the first network element sends a first response to the first device, where the first response is used to instruct the first network element to accept the establishment of a communication connection between the terminal and the first network element through the first device.

[0222] Step S2105: The first device sends a first response to the terminal.

[0223] In some embodiments, after receiving the first response sent by the first network element, the first device sends a first response to the terminal, where the first response is used to instruct the first network element to accept the communication connection established between the terminal and the first network element through the first device.

[0224] In some optional embodiments, after receiving the first response, the terminal establishes a communication connection with the first network element through the first device.

[0225] Step S2106: The second device sends a first message to the first network element.

[0226] In some embodiments, after the corresponding feeder link is available, the second device sends a first message to the first network element, where the first message includes a second cell identifier and a third non-access layer sequence number, wherein the second cell identifier has a mapping relationship with the second device.

[0227] In some embodiments, the first message also includes uplink data sent by the terminal of the second device temporarily stored when the feeder link corresponding to the second device is unavailable. In the embodiment of the present disclosure, the uplink data sent by the terminal is also referred to as first data.

[0228] Step S2107: The first network element verifies the integrity of the first message.

[0229] In some optional embodiments, after the first network element receives the first message sent by the second device, if the identifier of the first cell is stored in the context information of the terminal, it is also necessary to determine whether the first cell identifier and the second cell identifier are the same. If they are the same, the integrity of the first message is further verified through an integrity verification algorithm; if they are not the same, it means that the device sending the first message is not the second device, and there is no need to verify the integrity of the first message through the integrity verification algorithm, and the first message is directly discarded.

[0230] In some optional embodiments, when the terminal does not meet the first condition, the identifier of the first cell is not stored in the context information of the terminal; after the first network element receives the first message sent by the second device, it obtains the cell identifier in the terminal context information that has a mapping relationship with the non-ground device last accessed by the terminal; if the cell identifier and the second cell identifier are the same, the integrity of the first message is further verified through an integrity verification algorithm; if the cell identifier and the second cell identifier are different, there is no need to verify the integrity of the first message through the integrity verification algorithm, and the first message is directly discarded.

[0231] In some embodiments, an integrity verification algorithm is input based on the third non-access stratum sequence number and the S&F NAS COUNT stored in the context information of the terminal to verify the integrity of the first message. If the integrity verification of the first message succeeds, the first network element accepts the first message; if the integrity verification of the first message fails, the first network element rejects the first message.

[0232] In some optional embodiments, the integrity of the first message may be verified in the following manners, including:

[0233] Obtain the S&F NAS COUNT stored in the context information of the terminal, wherein the least significant 8 bits of the S&F NAS COUNT are used as the stored NAS SQN, the most significant 16 bits are used as the stored NAS OVERFLOW, and the third non-access stratum sequence number is used as the received NAS SQN.

[0234] If the value of the RECEIVED NAS SQN is greater than the value of the STORED NAS SQN, the first network element generates a non-access stratum count of (STORED NAS OVERFLOW)||(RECEIVED NAS SQN) for integrity verification and verifies the integrity of the first message. If the integrity verification of the first message passes, the first network element accepts the first message and updates the value of the STORED NAS SQN to the value of the RECEIVED NAS SQN. Otherwise, the first network element rejects the first message.

[0235] If the value of the RECEIVED NAS SQN is less than or equal to the STORED NAS SQN, the first network element generates a non-access stratum count of (STORED NASOVERFLOW + 1) || (RECEIVED NAS SQN) for integrity verification and verifies the integrity of the first message. If the integrity verification of the first message passes, the first network element accepts the first message, updates the value of the STORED NAS SQN to the value of the RECEIVED NAS SQN, and increases the value of the STORED NAS OVERFLOW by 1. Otherwise, the first network element rejects the first message.

[0236] In some optional embodiments, if at least one of the S&F NAS COUNT and the first cell identifier is separately stored in the terminal context information, after the first network element receives the first data stored by the second device, it also includes deleting at least one of the S&F NAS COUNT and the first cell identifier separately stored in the context information of the terminal.

[0237] It should be noted that if the S&F NAS COUNT and the first cell identifier are stored in the context information of the terminal at the same time, the first network element shall delete both of them after receiving the first data stored by the second device; if only one of the S&F NAS COUNT and the first cell identifier is stored, the first network element shall delete the stored one after receiving the first data stored by the second device.

[0238] In the embodiment of the present disclosure, after the first network element receives the first request sent by the first device, it sends a first response to the first device, and the first response is used to instruct the first network element to accept the terminal to establish a communication connection with the first network element through the first device; after receiving the first response, the terminal can establish a communication connection with the first network element through the first device. In the embodiment of the present disclosure, when the terminal meets the second condition, the terminal determines to establish a communication connection with the core network through the device of the ground network, and sends a first request to the core network to request to establish a communication connection with the core network through the device of the ground network. The core network determines the first response to instruct the receiving terminal to access the core network through the device of the non-ground network, which solves the technical problem that the terminal cannot switch from the device of the non-ground network to the device of the ground network to access the core network.

[0239] In some embodiments, reference may be made to other optional implementations described before or after the description corresponding to FIG. 2 .

[0240] FIG3 is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3 , the embodiment of the present disclosure involves a first network element 101, and the method includes:

[0241] Step S3101: A first network element receives a first request sent by a first device.

[0242] For optional implementations of step S3101, reference may be made to the optional implementations of step 2102 in FIG2 and other related parts in the embodiment involved in FIG2 , which will not be described in detail here.

[0243] In some embodiments, the first device sends a first request to the first network element. The first request is sent to the first device when the terminal releases the connection with the second device and determines to establish a communication connection with the first network element through the first device. The first request is used to request to establish a communication connection with the first network element through the first device.

[0244] Optionally, in the embodiments of the present disclosure, the first network element may be a core network element, including but not limited to an MME network element and an AMF network element; the first device may be a terrestrial network device, including but not limited to a 4G base station, a 5G base station, and a 6G base station; and the second device may be a non-terrestrial network device, such as a satellite network device. The network device may be an access network device, or both an access network device and a core network device. The embodiments of the present disclosure do not limit the specific types of the first network element, the first device, and the second device.

[0245] In some embodiments, the first request further includes a first non-access stratum sequence number.

[0246] Step S3102: The first network element determines a first response.

[0247] The optional implementation of step S3102 can refer to the optional implementation of step S2103 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0248] In some embodiments, when the terminal meets the first condition, at least one of the S&F NAS COUNT and the first cell identifier is stored in the context information of the terminal, and a first response is determined, where the first response is used to instruct the first network element to accept the terminal establishing a communication connection with the first network element through the first device.

[0249] In some embodiments, when the terminal does not meet the first condition, at least one of the S&F NAS COUNT and the first cell identifier is not stored in the context information of the terminal, and the first response is directly determined, and the first response is used to instruct the first network element to accept the terminal to establish a communication connection with the first network element through the first device.

[0250] It should be understood that in the embodiment of the present disclosure, after receiving the first request, the first network element determines a first response, and the first response is used to instruct the first network element to accept the terminal to establish a communication connection with the first network element through the first device; it should be noted that when the terminal meets the first condition, the first network element stores at least one of the S&F NAS COUNT and the first cell identifier in the context information of the terminal; when the terminal does not meet the first condition, the first response is directly determined without storing at least one of the S&F NAS COUNT and the first cell identifier in the context information of the terminal.

[0251] Step S3103: The first network element sends a first response to the first device.

[0252] The optional implementation of step S3103 can refer to the optional implementation of step S2104 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0253] In some embodiments, the first network element sends a first response to the first device, where the first response is used to instruct the first network element to accept the establishment of a communication connection between the terminal and the first network element through the first device.

[0254] Step S3104: The first network element receives a first message sent by the second device.

[0255] The optional implementation of step S3104 can refer to the optional implementation of step S2106 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0256] In some embodiments, a first message sent by a second device is received.

[0257] Optionally, the first message includes a second cell identifier and a third non-access layer sequence number, and the second cell identifier has a mapping relationship with the second device.

[0258] Optionally, the first message further includes uplink data sent by the terminal of the second device and temporarily stored when the feeder link of the second device is unavailable.

[0259] Step S3105: The first network element verifies the integrity of the first message.

[0260] The optional implementation of step S3105 can refer to the optional implementation of step S2107 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0261] In some optional embodiments, after the first network element receives the first message sent by the second device, if the identifier of the first cell is stored in the context information of the terminal, it is also necessary to determine whether the first cell identifier and the second cell identifier are the same. If they are the same, the integrity of the first message is further verified through an integrity verification algorithm; if they are not the same, it means that the device sending the first message is not the second device, and the first message is discarded.

[0262] In some optional embodiments, when the terminal does not meet the first condition, the identifier of the first cell is not stored in the context information of the terminal; after the first network element receives the first message sent by the second device, it obtains the cell identifier in the terminal context information that has a mapping relationship with the non-ground device last accessed by the terminal; if the cell identifier and the second cell identifier are the same, the integrity of the first message is further verified through an integrity verification algorithm; if the cell identifier and the second cell identifier are different, there is no need to verify the integrity of the first message through the integrity verification algorithm, and the first message is directly discarded.

[0263] In some embodiments, an integrity verification algorithm is input based on the third non-access stratum sequence number and the S&F NAS COUNT stored in the context information of the terminal to verify the integrity of the first message. If the integrity verification of the first message succeeds, the first network element accepts the first message; if the integrity verification of the first message fails, the first network element rejects the first message.

[0264] In some optional embodiments, if at least one of the S&F NAS COUNT and the first cell identifier is separately stored in the terminal context information, after the first network element receives the first data stored by the second device, it also includes deleting at least one of the S&F NAS COUNT and the first cell identifier separately stored in the context information of the terminal.

[0265] FIG4 is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG4 , the embodiment of the present disclosure involves a first device 102, and the method includes:

[0266] Step S4101: The first device receives a first request sent by a terminal.

[0267] The optional implementation of step S4101 can refer to the optional implementation of step S2101 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0268] In some embodiments, the first device receives a first request sent by the terminal. The first request is sent to the first device after the terminal releases the connection with the second device and determines to establish a communication connection with the first network element through the first device; the first request is used to request to establish a communication connection with the first network element through the first device.

[0269] In some embodiments, the first request further includes a first non-access stratum sequence number.

[0270] Step S4102: The first device sends a first request to the first network element.

[0271] The optional implementation of step S4102 can refer to the optional implementation of step S2102 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0272] In some embodiments, after receiving the first request, the first device sends the first request to the first network element, where the first request is used to request to establish a communication connection with the first network element through the first device.

[0273] Step S4103: The first device receives a first response sent by the first network element.

[0274] The optional implementation of step S4103 can refer to the optional implementation of step S2104 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0275] In some embodiments, a first response sent by the first network element is received, where the first response is used to instruct the first network element to accept the establishment of a communication connection between the terminal and the first network element through the first device.

[0276] Step S4104: The first device sends a first response to the terminal.

[0277] The optional implementation of step S4104 can refer to the optional implementation of step S2105 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0278] In some embodiments, the first device sends a first response to the terminal, where the first response is used to instruct the first network element to accept the communication connection established between the terminal and the first network element through the first device.

[0279] In some optional embodiments, after receiving the first response, the terminal establishes a communication connection with the first network element through the first device.

[0280] FIG5 is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG5 , the embodiment of the present disclosure involves a terminal 103, and the method includes:

[0281] Step S5101: The terminal sends a first message to the second device.

[0282] The optional implementation of step S5101 can refer to the optional implementation of step S2101 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0283] In some embodiments, the terminal accesses the first network element through a second device of the non-terrestrial network, and the terminal sends a first message to the second device, wherein the first message includes uplink data; there is a feeder link between the second device and the non-terrestrial network gateway, and the second device forwards the uplink data sent by the terminal to the non-terrestrial network gateway through the feeder link, and the non-terrestrial network gateway then sends the received uplink data to the first network element.

[0284] Optionally, after the terminal sends the first message to the second device, if the feeder link is disconnected, the second device temporarily stores the uplink data sent by the terminal. Subsequently, due to mobility, the second device disconnects the communication connection with the terminal when it leaves the coverage of the terminal.

[0285] Step S5102: The terminal sends a first request to the first device.

[0286] The optional implementation of step S5102 can refer to the optional implementation of step S2101 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0287] In some embodiments, the terminal satisfies a second condition and determines to establish a communication connection with the first network element through the first device, where the second condition includes at least one of the following:

[0288] A signal from a first device on a terrestrial network is stronger than a signal from a second device on a non-terrestrial network;

[0289] The feeder link corresponding to the second device is unavailable.

[0290] In some embodiments, when the second condition is met, the terminal sends a first request to the first device, where the first request is used to request to establish a communication connection with the first network element through the first device.

[0291] In some embodiments, the first request further includes a first non-access stratum sequence number.

[0292] Step S5103: The terminal receives a first response sent by the first device.

[0293] The optional implementation of step S5103 can refer to the optional implementation of step S2105 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0294] In some embodiments, a first response sent by the first device is received, where the first response is used to instruct the first network element to accept the establishment of a communication connection between the terminal and the first network element through the first device.

[0295] In some optional embodiments, after receiving the first response, the terminal establishes a communication connection with the first network element through the first device.

[0296] FIG6 is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG6 , the embodiment of the present disclosure relates to a communication method for a communication system 100, the method comprising:

[0297] Step S6101: The terminal sends a first message to the second device.

[0298] The optional implementation of step S6101 can refer to the optional implementation of step S2101 in Figure 2, step S5101 in Figure 5, and other related parts in the embodiments involved in Figures 2 and 5, which will not be repeated here.

[0299] In some embodiments, the terminal accesses the first network element through a second device of the non-terrestrial network, and the terminal sends a first message to the second device, wherein the first message includes uplink data; there is a feeder link between the second device and the non-terrestrial network gateway, and the second device forwards the uplink data sent by the terminal to the non-terrestrial network gateway through the feeder link, and the non-terrestrial network gateway then sends the received uplink data to the first network element.

[0300] In some embodiments, when the feeder link between the second device and the non-terrestrial network gateway is unavailable, the second device temporarily stores the uplink data sent by the terminal.

[0301] Step S6102: The terminal sends a first request to the first device.

[0302] Optional implementations of step S6102 may refer to step S2101 in FIG. 2 , step S4101 in FIG. 4 , step S5102 in FIG. 5 and other related parts in the embodiments involved in FIG. 2 , FIG. 4 and FIG. 5 , which will not be described in detail here.

[0303] In some embodiments, when the terminal satisfies a second condition, it is determined to establish a communication connection with the first network element through the first device, where the second condition includes at least one of the following:

[0304] A signal from a first device on a terrestrial network is stronger than a signal from a second device on a non-terrestrial network;

[0305] The feeder link to the second device is not available.

[0306] In some embodiments, when the second condition is met, the terminal sends a first request to the first device, where the first request is used to request to establish a communication connection with the first network element through the first device.

[0307] In some embodiments, the first request further includes a first non-access stratum sequence number.

[0308] Step S6103: The first device sends a first request to the first network element.

[0309] The optional implementation of step S6103 can refer to the optional implementation of step S2102 in Figure 2, step S3101 in Figure 3, step S4102 in Figure 4, and other related parts in the embodiments involved in Figures 2, 3, and 4, which will not be repeated here.

[0310] In some embodiments, after receiving the first request, the first device sends the first request to the first network element, where the first request is used to request to establish a communication connection with the first network element through the first device.

[0311] Step S6104: The first network element determines a first response.

[0312] The optional implementation of step S6104 can refer to the optional implementation of step S2103 in Figure 2, step S3102 in Figure 3, and other related parts in the embodiments involved in Figures 2 and 3, which will not be repeated here.

[0313] In some embodiments, when the terminal meets the first condition, at least one of the S&F NAS COUNT and the first cell identifier is stored in the context information of the terminal, and a first response is determined, where the first response is used to instruct the first network element to accept the terminal establishing a communication connection with the first network element through the first device.

[0314] In some embodiments, when the terminal does not meet the first condition, at least one of the S&F NAS COUNT and the first cell identifier is not stored in the context information of the terminal, and the first response is directly determined, and the first response is used to instruct the first network element to accept the terminal to establish a communication connection with the first network element through the first device.

[0315] Step S6105: The first network element sends a first response to the first device.

[0316] The optional implementation of step S6105 can refer to the optional implementation of step S2104 in Figure 2, step S3103 in Figure 3, step S4103 in Figure 4, and other related parts in the embodiments involved in Figures 2, 3, and 4, which will not be repeated here.

[0317] In some embodiments, the first network element sends a first response to the first device, where the first response is used to instruct the first network element to accept the establishment of a communication connection between the terminal and the first network element through the first device.

[0318] Step S6106: The first device sends a first response to the terminal.

[0319] The optional implementation of step S6106 can refer to the optional implementation of step S2105 in Figure 2, step S4104 in Figure 4, step S5103 in Figure 5, and other related parts in the embodiments involved in Figures 2, 4 and 5, which will not be repeated here.

[0320] In some embodiments, the first device sends a first response to the terminal, where the first response is used to instruct the first network element to accept the communication connection established between the terminal and the first network element through the first device.

[0321] In some optional embodiments, after receiving the first response, the terminal establishes a communication connection with the first network element through the first device.

[0322] Step S6107: The second device sends a first message to the first network element.

[0323] The optional implementation of step S6107 can refer to the optional implementation of step S2106 in Figure 2, step S3104 in Figure 3, and other related parts in the embodiments involved in Figures 2 and 3, which will not be repeated here.

[0324] In some embodiments, after the feeder link is available, the second device sends a first message to the first network element, the first message includes a second cell identifier and a third non-access layer sequence number, and the second cell identifier has a mapping relationship with the second device.

[0325] In some embodiments, the first message also includes uplink data sent by the terminal that is temporarily stored by the second device.

[0326] Step S6108: The first network element verifies the integrity of the first message.

[0327] The optional implementation of step S6108 can refer to the optional implementation of step S2107 in Figure 2, step S3105 in Figure 3, and other related parts in the embodiments involved in Figures 2 and 3, which will not be repeated here.

[0328] In some optional embodiments, after the first network element receives the first message sent by the second device, if the identifier of the first cell is stored in the context information of the terminal, it is also necessary to determine whether the first cell identifier and the second cell identifier are the same. If they are the same, the integrity of the first message is verified through an integrity verification algorithm; if they are not the same, it means that the device sending the first message is not the second device, and there is no need to verify the integrity of the first message through the integrity verification algorithm, and the first message is directly discarded.

[0329] In some optional embodiments, when the terminal does not meet the first condition, the identifier of the first cell is not stored in the context information of the terminal; after the first network element receives the first message sent by the second device, it obtains the cell identifier in the terminal context information that has a mapping relationship with the non-ground device last accessed by the terminal; if the cell identifier and the second cell identifier are the same, the integrity of the first message is further verified through an integrity verification algorithm; if the cell identifier and the second cell identifier are different, there is no need to verify the integrity of the first message through the integrity verification algorithm, and the first message is directly discarded.

[0330] In some embodiments, an integrity verification algorithm is input based on the third non-access stratum sequence number and the S&F NAS COUNT stored in the context information of the terminal to verify the integrity of the first message. If the integrity verification of the first message succeeds, the first network element accepts the first message; if the integrity verification of the first message fails, the first network element rejects the first message.

[0331] In some optional embodiments, if at least one of the S&F NAS COUNT and the first cell identifier is separately stored in the terminal context information, after the first network element receives the first data stored by the second device, it also includes deleting at least one of the S&F NAS COUNT and the first cell identifier separately stored in the context information of the terminal.

[0332] The embodiments of the present disclosure further provide an apparatus for implementing any of the above methods. For example, an apparatus is provided, comprising units or modules for implementing each step performed by the first network element 101 in any of the above methods. For another example, another apparatus is provided, comprising units or modules for implementing each step performed by the first device 102 in any of the above methods.

[0333] It should be understood that the division of the various units or modules in the above device is merely a division of logical functions. In actual implementation, they may be fully or partially integrated into a physical entity, or they may be physically separated. In addition, the units or modules in the device may be implemented in the form of a processor calling software: for example, the device includes a processor, the processor is connected to a memory, and the memory stores instructions. The processor calls the instructions stored in the memory to implement any of the above methods or implement the functions of the various units or modules of the above device, wherein the processor is, for example, a general-purpose processor, such as a central processing unit (CPU) or a microprocessor, and the memory is a memory within the device or a memory outside the device. Alternatively, the units or modules in the device can be implemented in the form of hardware circuits, and the functions of some or all of the units or modules can be realized by designing the hardware circuits. The above-mentioned hardware circuits can be understood as one or more processors; for example, in one implementation, the above-mentioned hardware circuit is an application-specific integrated circuit (ASIC), which realizes the functions of some or all of the above units or modules by designing the logical relationship of the components in the circuit; for example, in another implementation, the above-mentioned hardware circuit can be realized by a programmable logic device (PLD). Taking a field programmable gate array (FPGA) as an example, it can include a large number of logic gate circuits, and the connection relationship between the logic gate circuits is configured by configuring the configuration file, thereby realizing the functions of some or all of the above units or modules. All units or modules of the above devices can be realized in the form of software called by the processor, or in the form of hardware circuits, or in part by the form of software called by the processor, and the rest by hardware circuits.

[0334] In the embodiments of the present disclosure, the processor is a circuit with signal processing capabilities. In one implementation, the processor can be a circuit with instruction reading and execution capabilities, such as a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU) (which can be understood as a microprocessor), or a digital signal processor (DSP). In another implementation, the processor can implement certain functions through the logical relationship of the hardware circuit. The logical relationship of the above-mentioned hardware circuit is fixed or reconfigurable. For example, the processor is a hardware circuit implemented by an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as an FPGA. In a reconfigurable hardware circuit, the process of the processor loading a configuration document and implementing the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units or modules. In addition, it can also be a hardware circuit designed for artificial intelligence, which can be understood as an ASIC, such as a neural network processing unit (NPU), a tensor processing unit (TPU), a deep learning processing unit (DPU), etc.

[0335] FIG7A is a schematic diagram of the structure of a first network element proposed in an embodiment of the present disclosure. As shown in FIG7A , the first network element may include: a receiving module 7101 and a sending module 7102 .

[0336] In some embodiments, the receiving module is used to receive a first request sent by a first device, where the first request is sent to the first device after the terminal releases the connection with the second device and determines to establish a communication connection with the first network element through the first device.

[0337] In some embodiments, the sending module is used to send a first response to the first device based on the received first request; wherein, the first device is a device of a ground network; the second device is a device of a non-ground network; the first response is used to indicate that the terminal is accepted to establish a communication connection with the first network element through the first device.

[0338] Optionally, the above-mentioned receiving module is used to execute the communication steps such as sending and / or receiving performed by the terminal in any of the above methods, such as step S3101, which will not be repeated here.

[0339] FIG7B is a schematic diagram of the structure of a first device according to an embodiment of the present disclosure. As shown in FIG7B , the first device may include: a receiving module 7201 and a sending module 7202 .

[0340] In some embodiments, the receiving module is used to receive a first request sent by the terminal, where the first request is sent to the first device after the terminal releases the connection with the second device and determines to establish a communication connection with the first network element through the first device.

[0341] In some embodiments, the sending module is used to send the first request to the first network element; wherein, the first device is a device of a terrestrial network; and the second device is a device of a non-terrestrial network.

[0342] Optionally, the above-mentioned receiving module is used to execute the communication steps such as sending and / or receiving performed by the terminal in any of the above methods, such as step S4101, which will not be repeated here.

[0343] FIG7C is a schematic diagram of the structure of a terminal proposed in an embodiment of the present disclosure. As shown in FIG7C , the terminal may include: a sending module 7301 .

[0344] In some embodiments, the sending module is used to send a first request to a first device, and the first request is sent to the first device after the terminal releases the connection with the second device and determines to establish a communication connection with the first network element through the first device; wherein, the first device is a device of a ground network; and the second device is a device of a non-ground network.

[0345] Optionally, the sending module is used to execute the communication steps such as sending and / or receiving performed by the terminal in any of the above methods, such as step S5101, which will not be repeated here.

[0346] Figure 8A is a schematic diagram of the structure of a communication device 8100 proposed in an embodiment of the present disclosure. Communication device 8100 can be a device (e.g., an access network device, a core network device, etc.), or an IoT device, or a chip, chip system, or processor that supports the device in implementing any of the above methods. Communication device 8100 can be used to implement the methods described in the above method embodiments. For details, please refer to the description of the above method embodiments.

[0347] As shown in Figure 8A, the communication device 8100 includes one or more processors 8101. The processor 8101 can be a general-purpose processor or a dedicated processor, for example, a baseband processor or a central processing unit. The baseband processor can be used to process the communication protocol and communication data, and the central processing unit can be used to control the communication device (such as a base station, a baseband chip, a terminal device, a terminal device chip, a DU or a CU, etc.), execute programs, and process program data. Optionally, the communication device 8100 is used to perform any of the above methods. Optionally, one or more processors 8101 are used to call instructions to enable the communication device 8100 to perform any of the above methods.

[0348] In some embodiments, the communication device 8100 further includes one or more transceivers 8102. When the communication device 8100 includes one or more transceivers 8102, the transceiver 8102 performs at least one of the communication steps such as sending and / or receiving in the above method (for example, step S2101, but not limited thereto), and the processor 8101 performs at least one of the other steps (for example, step S2102, but not limited thereto). In an optional embodiment, the transceiver may include a receiver and / or a transmitter, and the receiver and transmitter may be separate or integrated. Optionally, the terms transceiver, transceiver unit, transceiver, transceiver circuit, interface circuit, and interface may be interchangeable, the terms transmitter, transmitting unit, transmitter, and transmitting circuit may be interchangeable, and the terms receiver, receiving unit, receiver, and receiving circuit may be interchangeable.

[0349] In some embodiments, the communication device 8100 further includes one or more memories 8103 for storing data. Alternatively, all or part of the memories 8103 may be located outside the communication device 8100. In alternative embodiments, the communication device 8100 may include one or more interface circuits 8104. Optionally, the interface circuits 8104 are connected to the memories 8103 and may be configured to receive data from the memories 8103 or other devices, or to send data to the memories 8103 or other devices. For example, the interface circuits 8104 may read data stored in the memories 8103 and send the data to the processor 8101.

[0350] The communication device 8100 described in the above embodiments may be a device or a terminal, but the scope of the communication device 8100 described in the present disclosure is not limited thereto, and the structure of the communication device 8100 may not be limited by FIG. 8A. The communication device may be an independent device or may be part of a larger device. For example, the communication device may be: 1) an independent integrated circuit IC, or a chip, or a chip system or subsystem; (2) a collection of one or more ICs, optionally, the above IC collection may also include a storage component for storing data or programs; (3) an ASIC, such as a modem; (4) a module that can be embedded in other devices; (5) a receiver, a terminal device, an intelligent terminal device, a cellular phone, a wireless device, a handheld device, a mobile unit, an in-vehicle device, a device, a cloud device, an artificial intelligence device, etc.; (6) others, etc.

[0351] FIG8B is a schematic diagram of the structure of a chip 8200 according to an embodiment of the present disclosure. If the communication device 8100 can be a chip or a chip system, please refer to the schematic diagram of the structure of the chip 8200 shown in FIG8B , but the present disclosure is not limited thereto.

[0352] The chip 8200 includes one or more processors 8201. The chip 8200 is configured to execute any of the above methods.

[0353] In some embodiments, chip 8200 further includes one or more interface circuits 8202. Terms such as interface circuit, interface, and transceiver pins may be used interchangeably. In some embodiments, chip 8200 further includes one or more memories 8203 for storing data. Alternatively, all or part of memory 8203 may be located external to chip 8200. Optionally, interface circuit 8202 is connected to memory 8203 and may be used to receive data from memory 8203 or other devices, or may be used to send data to memory 8203 or other devices. For example, interface circuit 8202 may read data stored in memory 8203 and send the data to processor 8201.

[0354] In some embodiments, the interface circuit 8202 performs at least one of the communication steps (e.g., step S2101, but not limited thereto) in the above method, such as sending and / or receiving. The interface circuit 8202 performing the communication steps (e.g., sending and / or receiving) in the above method, for example, means that the interface circuit 8202 performs data exchange between the processor 8201, chip 8200, memory 8203, or a transceiver device. In some embodiments, the processor 8201 performs at least one of the other steps (e.g., step S2102, but not limited thereto).

[0355] The present disclosure also proposes a storage medium having instructions stored thereon, which, when executed on the communication device 8100, causes the communication device 8100 to execute any of the above methods. Optionally, the storage medium is an electronic storage medium. Optionally, the storage medium is a computer-readable storage medium, but is not limited thereto, and may also be a storage medium readable by other devices. Optionally, the storage medium may be a non-transitory storage medium, but is not limited thereto, and may also be a temporary storage medium.

[0356] The present disclosure also provides a program product, which, when executed by the communication device 8100, enables the communication device 8100 to perform any of the above methods. Optionally, the program product is a computer program product.

[0357] The present disclosure also proposes a computer program, which, when executed on a computer, causes the computer to perform any one of the above methods.

Claims

1. A communication method, characterized in that, The method is executed by a first network element, and the method includes: Receiving a first request sent by a first device, where the first request is sent by the first device when it is determined to establish a communication connection with the first network element through the first device after the terminal releases the connection with a second device; Sending a first response to the first device according to the received first request; Wherein, the first device is a device of the terrestrial network; the second device is a device of the non-terrestrial network; The first response is used to indicate acceptance of the terminal establishing a communication connection with the first network element through the first device.

2. The method according to claim 1, wherein After receiving the first request sent by the first device, it further includes: When the terminal meets a first condition, using a first non-access stratum count pre-stored in the context information of the terminal as a second non-access stratum count, and storing at least one of the second non-access stratum count and a first cell identifier in the context information of the terminal separately; Wherein, the first condition includes that the terminal allows execution of a store-and-forward operation, or the terminal allows to be under a store-and-forward operation; The first cell identifier is a cell identifier pre-stored in the context information of the terminal and having a mapping relationship with the second device.

3. The method according to claim 2, wherein The terminal meets the first condition and is determined in the following manner: The context information of the terminal includes a first indication; Wherein, the first indication is used to indicate that the terminal allows execution of a store-and-forward operation, or the terminal allows to be under a store-and-forward operation.

4. The method according to claim 2 or 3, characterized in that The context information of the terminal includes cell information, and the cell information is used to indicate the area covered by the last device having a connection relationship with the terminal; The terminal meets the first condition and can also be determined in the following manner: Determining the last device having a connection relationship with the terminal according to the cell information; The device is a non-terrestrial device, and it is determined that the terminal meets the first condition.

5. The method according to any one of claims 2-4, characterized in that The first request includes a first non-access stratum sequence number; The first condition is also determined by at least one of the following: A first difference is greater than a preset threshold; The feeder link corresponding to the second device is unavailable; Wherein, the first difference is the difference between the first non-access stratum sequence number and a second non-access stratum sequence number; The second non-access stratum sequence number is determined by the first non-access stratum count.

6. The method according to any one of claims 2-5, characterized in that, After sending the first response to the first device, it further includes: Receiving a first message sent by the second device after the feeder link is available, where the first message includes a second cell identifier and a third non-access stratum sequence number, and the second cell identifier has a mapping relationship with the second device; Verifying the integrity of the first message through an integrity verification algorithm.

7. The method according to claim 6, characterized in that, Verifying the integrity of the first message through the integrity verification algorithm includes: When the first cell identifier and the second cell identifier are the same, verifying the integrity of the first message through the integrity verification algorithm; Wherein, the input of the integrity verification algorithm is determined based on the third non-access stratum sequence number and the second non-access stratum count.

8. The method according to claim 6, characterized in that, Verifying the integrity of the first message through the integrity verification algorithm includes: Verifying the integrity of the first message through the integrity verification algorithm; Among them, the input of the integrity verification algorithm is determined based on the third non-access stratum sequence number and the second non-access stratum count.

9. The method according to any one of claims 6-8, characterized in that, The first message further includes first data, and the first data is uplink data sent by the terminal to the second device; After verifying the integrity of the first message through the integrity verification algorithm, it further includes: If the integrity verification result of the first message passes, accept the first data; If the integrity verification result of the first message fails, reject accepting the first data.

10. The method according to claim 9, characterized in that After accepting the first data, it further includes: Delete the second non-access stratum count and / or the first cell identifier stored in the context information of the terminal.

11. A communication method, characterized in that, The method is executed by a first device, and the method includes: Receive a first request sent by a terminal, where the first request is sent by the terminal to the first device after the terminal releases the connection with the second device and determines to establish a communication connection with a first network element through the first device; Send the first request to the first network element; Among them, the first device is a device of the terrestrial network; the second device is a device of the non-terrestrial network.

12. The method according to claim 11, characterized in that After receiving the first request sent by the terminal, it further includes: Receive a first response sent by the first network element, where the first response is used to indicate that the first network element accepts the terminal to establish a communication connection with the first network element through the first device; Send the first response to the terminal.

13. A communication method, characterized in that, The method is executed by a terminal, and the method includes: Send a first request to a first device, where the first request is sent by the terminal to the first device after the terminal releases the connection with the second device and determines to establish a communication connection with a first network element through the first device; Among them, the first device is a device of the terrestrial network; the second device is a device of the non-terrestrial network.

14. The method according to claim 13, wherein Sending the first request to the first device includes: Determine that the second condition is met and send the first request to the first device; The second condition is at least one of the following: The signal strength of the first device is better than the signal strength of the second device; The feeder link of the second device is unavailable.

15. The method according to any one of claims 13-14, characterized in that After sending the first request to the first device, it further includes: Receive a first response, where the first response is used to indicate accepting the terminal to establish a communication connection with the first network element through the first device.

16. A first network element, characterized in that, It includes: A receiving module, configured to receive a first request sent by a first device, where the first request is sent by the terminal to the first device after the terminal releases the connection with the second device and determines to establish a communication connection with a first network element through the first device; A sending module, configured to send a first response to the first device according to the received first request; Among them, the first device is a device of the terrestrial network; The second device is a device of the non-terrestrial network; The first response is used to indicate accepting the terminal to establish a communication connection with the first network element through the first device.

17. A first device, characterized in that, It includes: A receiving module, configured to receive a first request sent by a terminal, where the first request is sent by the terminal to the first device after the terminal releases the connection with the second device and determines to establish a communication connection with a first network element through the first device; A sending module, configured to send the first request to the first network element; Wherein, the first device is a device of the terrestrial network; The second device is a device of the non-terrestrial network.

18. A terminal, characterized in that, Comprising: A sending module, configured to send a first request to a first device, where the first request is sent to the first device when it is determined to establish a communication connection with a first network element through the first device after the terminal releases the connection with a second device; Wherein, the first device is a device of the terrestrial network; the second device is a device of the non-terrestrial network.

19. A first network element, characterized in that, Comprising: One or more processors; Wherein, the processor is configured to execute the communication method according to any one of claims 1 to 10.

20. A first device, characterized in that, Comprising: One or more processors; Wherein, the processor is configured to execute the communication method according to any one of claims 11 to 12.

21. A terminal, characterized in that, Comprising: One or more processors; Wherein, the processor is configured to execute the communication method according to any one of claims 13 to 15.

22. A communication system, characterized in that, Comprising: A first network element, configured to implement the communication method according to any one of claims 1-10; A first device, configured to implement the communication method according to any one of claims 11-12; A terminal, configured to implement the communication method according to any one of claims 13-15.

23. A storage medium, the storage medium stores instructions, characterized in that, When the instruction runs on a communication device, the communication device is caused to execute the communication method according to any one of claims 1-10, 11-12, 13-15.

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