Communication method and device

Abstract

The invention discloses a communication method and device, which are used for supporting a terminal to establish connection with satellites under the condition that the terminal cannot access any satellite in a store-and-forward monitoring list due to reasons such as movement. The method comprises: a terminal obtaining first information and a first satellite list, the first information comprising at least one of the following information: information of a first timer; ephemeris information; a third satellite list, wherein the first satellite list is unavailable under the condition of satellite coverage in the third satellite list; the first satellite list corresponds to information of a first area, and the first satellite list is available in the first area; the terminal sends a first message according to the first information, wherein the first message is used for updating the first satellite list; and the terminal receives the second satellite list.

Description

Technical Field

[0001] This application relates to the field of mobile communication technology, and in particular to a communication method and apparatus. Background Technology

[0002] In non-terrestrial networks (NTN) communication scenarios, there is a discontinuous power supply situation under the regenerative relay satellite architecture. In this scenario, the service link between the terminal and the base station and / or the power supply link between the base station and the core network are not always available. In this scenario, network devices send a store-and-forward listener list to the terminal, indicating the satellites the terminal can access. The store-and-forward listener list can contain one or more satellite identifiers. The terminal only needs to attempt to access satellites listed in the store-and-forward listener list, and does not need to attempt to access satellites whose identifiers are not included in the list.

[0003] Currently, in scenarios where the terminal's location changes, the terminal may be unable to access any of the satellites in the store-and-forward listener list. In this case, since the terminal cannot attempt to access satellites outside the store-and-forward listener list, it may be unable to access satellites, resulting in communication failure or increased communication latency. Summary of the Invention

[0004] This application provides a communication method and apparatus that enables a terminal to establish a connection with a satellite when the terminal is unable to access any satellite in the store-and-forward listening list due to reasons such as mobility.

[0005] In a first aspect, embodiments of this application provide a communication method, which can be executed by a first communication device, or in other words, the method can be applied to a first communication device. Unless otherwise specified, the "first communication device" in this application can refer to the terminal device itself, a component within the terminal device, or a logic module or software capable of implementing all or part of the terminal device's functions. The components in this application may include, for example, at least one of a chip, chip system, processor, transceiver, processing unit, transceiver unit, or other functional modules. Taking a terminal as the executing entity as an example, the method includes: the terminal acquiring first information and a first satellite list, wherein the first information includes at least one of the following: information of a first timer; ephemeris information; a third satellite list, wherein the first satellite list is unavailable if satellites in the third satellite list cover the terminal; information of a first region corresponding to the first satellite list, wherein the first satellite list is available within the first region; the terminal sending a first message based on the first information, the first message being used to update the first satellite list; and the terminal receiving a second satellite list.

[0006] Based on the method described in the first aspect, the terminal can send a first message according to the first information. This first message can be used to update the first satellite list. The terminal can also obtain a second satellite list, and therefore, the terminal can access satellites through the updated second satellite list. This method supports the terminal in establishing a connection with satellites even when the terminal is unable to access any satellite in the store-and-forward listening list due to reasons such as mobility.

[0007] It is understood that the satellite list in this application can also be referred to as a store-and-forward monitoring list (S&F monitoring list) or a monitoring list, etc. The satellite list can be used to indicate which satellites a terminal is allowed or authorized to access, or the terminal can determine whether to access a satellite based on the satellite list, or the terminal can determine which satellites are allowed to access based on the satellite list, or the satellite list can be used to assist the terminal in obtaining downlink (DL) data or mobile terminated (MT) data. Alternatively, the terminal can communicate with the core network through satellites in the satellite list, for example, sending uplink (UL) data, mobile originated (MO) data, or signaling to the core network, and / or receiving downlink data, mobile terminated data, or other signaling. The phrase "the first message is used to update the first satellite list" can also be replaced with descriptions such as "the first message is used to update the satellite list," "the first message is used to indicate updating the satellite list," "the first message is used to indicate updating the first satellite list," or "the first message is used to request an update to the satellite list," etc. Optionally, as long as the entity that receives the first message updates the first satellite list or sends a new satellite list to the terminal after receiving the first message, it can be understood that "the first message is used to update the first satellite list".

[0008] In this application, the satellite list may include one or more satellites, specifically information including one or more satellites. The satellite information may include satellite identifiers or other information that can be used to identify the satellite.

[0009] In this application, "satellite identifier" can also be replaced with: "identifier of base station / core network / core network equipment deployed on the satellite", "identifier in broadcast messages sent by base stations deployed on the satellite, such as cell ID", "other information that can identify a satellite", and other information used to identify the satellite.

[0010] It is understood that the satellite list in this application can be determined based on the terminal's location information. For example, the first satellite list can be determined based on the terminal's location when it joins the network, the terminal's location when it is covered by satellites, the terminal's location when the first satellite list is determined, the terminal's location when it obtains the first satellite list, or the terminal's location when the satellites send the first satellite list to the terminal. For example, some or all of the satellites in the first satellite list can cover that location.

[0011] The second satellite list can be understood as an updated first satellite list, or as a new satellite list. Optionally, the updated first satellite list can have the same identifier or name as the original list, but the updated list content overwrites the content of the original list; or, the updated list can only include the parts that are different from the original list, thus updating the list content. The specific implementation method for updating the first satellite list is not limited.

[0012] The second satellite list can be determined based on the terminal's location when the second satellite list is established, the terminal's location when it receives the second satellite list, or the terminal's location when the satellites send the second satellite list to the terminal. For example, some or all of the variants in the second satellite list can cover that location.

[0013] "Information on the first timer" can be replaced with descriptions such as "first timer" or "available timer for the first satellite list." Alternatively, "Information on the first timer" can be replaced with "first time information," where the terminal can obtain the first time information and generate or determine the first timer based on it.

[0014] "Information on the first area" can be replaced with descriptions such as "first area" or "available area of ​​the first satellite list". Optionally, the information on the first area can be an area expressed in latitude and longitude, or an area expressed in one or more tracking areas (TAs).

[0015] In this application, "for indicating" can include both direct and indirect indication.

[0016] In one possible implementation, the terminal may receive the first information and the first satellite list from the first satellite, wherein the first satellite list includes the first satellite.

[0017] Based on this implementation, the first satellite can send the first information and a list of the first satellites to the terminal. Alternatively, the terminal can also obtain the first information from its local configuration. For example, the terminal can obtain information about the first timer and / or ephemeris information from its local configuration.

[0018] In one possible implementation, the first information includes information about the first timer. The terminal can send the first message when or after the first timer expires, or trigger the sending of the first message to the second satellite.

[0019] Based on this implementation, the first timer can represent the validity period of the first satellite list. For example, the first satellite list can be considered available before the first timer expires, meaning that the first satellite list does not need to be updated before the first timer expires. Specifically, the terminal can start the first timer after obtaining the first satellite list, based on the information from the first timer.

[0020] In one possible implementation, the terminal may also receive a broadcast message from a second satellite, the first satellite list of which does not include the second satellite; the terminal may then send the first message to the second satellite.

[0021] Based on this implementation, the terminal can send a first message to the second satellite after receiving a broadcast message from a second satellite not listed in the first satellite list. In conjunction with the requirements of the first timer, the terminal can send a first message to the second satellite, or trigger the sending of a first message to the second satellite, either upon receiving a broadcast message from a second satellite not listed in the first satellite list and when or after the first timer expires.

[0022] In this application, a satellite outside the first satellite list may mean that the first satellite list does not include the satellite, that is, the identifier of the satellite does not belong to the first satellite list.

[0023] In one possible implementation, the second satellite list may include the second satellite.

[0024] In one possible implementation, the terminal may also receive broadcast messages from satellites in the first satellite list and reset the first timer.

[0025] Optionally, "Reset the first timer" can mean setting the timer to 0 and starting the countdown, setting the timer to its maximum and starting the countdown, or restarting the countdown based on the information from the first timer. "Reset the first timer" can also be replaced with "Refresh the first timer," "Restart the first timer," "Set the first timer to zero," or "Set the first timer to its maximum," etc.

[0026] Optionally, the terminal may reset the first timer based on broadcast messages received from satellites in the first satellite list. Alternatively, the terminal may reset the first timer based on the broadcast message itself or information within the broadcast message; for example, the information in the broadcast message may be the identifier of the satellite sending the broadcast message.

[0027] Based on this implementation, in normal scenarios where the terminal remains stationary, if the terminal is still covered by satellites in the first satellite list (i.e., it can receive broadcast messages from these satellites), then the terminal can follow the first satellite list, only accessing or attempting to access satellites in the first satellite list, and not accessing or attempting to access satellites outside the first satellite list. Since there are satellites in the first satellite list that can cover the terminal's location, there is no need to trigger an update to the satellite list.

[0028] In one possible implementation, the first information includes the ephemeris information, and the terminal can determine a fourth satellite list based on the terminal's location information and the ephemeris information. If the coverage area of ​​the satellites in the fourth satellite list includes the terminal's location, and the first satellite list does not include satellites in the fourth satellite list, the terminal can send the first message.

[0029] Optionally, the terminal can obtain ephemeris information from other devices such as core network equipment, access network equipment, satellites, and ephemeris maintenance equipment, or the terminal can configure ephemeris information locally.

[0030] Based on this implementation, the terminal can determine whether to send a first message based on ephemeris information, its location information, and satellites in the first satellite list. Specifically, after obtaining the fourth satellite list, the terminal can determine whether the first satellite list includes satellites from the fourth satellite list. If the first satellite list includes at least one satellite from the fourth satellite list, or if the first satellite list contains at least one satellite that can cover the terminal's location, then the first satellite list is not updated, meaning the first message does not need to be sent. If the first satellite list does not include any satellite from the fourth satellite list, or if the first satellite list does not contain any satellite that can cover the terminal's location, then the first satellite list needs to be updated, meaning the terminal sends the first message.

[0031] It is understood that the fourth satellite list may include one or more satellites that can cover the terminal's current location. In implementation, the fourth satellite list can also be replaced with one or more satellites, meaning the terminal may not be required to obtain a list of satellite identifiers that cover its location. Here, the terminal's current location can be understood as the location when the terminal determines the fourth satellite list. Specifically, the terminal's current location can be the location when the terminal triggers the determination of the fourth satellite list; for example, if the terminal triggers the determination of the fourth satellite list after receiving a broadcast message from a satellite that does not belong to the first satellite list, the terminal's current location could be the location when it received that broadcast message.

[0032] In one possible implementation, the first information also includes time period indication information; accordingly, the terminal can determine the fourth satellite list based on the time period indication information, the terminal's location information, and ephemeris information, wherein the coverage area of ​​the satellites in the fourth satellite list during the time period includes the terminal's location.

[0033] Based on this implementation, the terminal can determine one or more satellites (such as a fourth satellite list) that can cover its location within a given time period, based on its location information, ephemeris information, and time period indication information. If the first satellite list includes at least one satellite from the fourth satellite list, or if the first satellite list contains at least one satellite capable of covering the terminal's location within that time period, the first satellite list does not need to be updated, i.e., the first message does not need to be sent. If the first satellite list does not include any satellite from the fourth satellite list, or if the first satellite list does not contain any satellite capable of covering the terminal's location within that time period, the first satellite list needs to be updated, i.e., the terminal sends the first message.

[0034] In one possible implementation, the first information includes information about the first region; if the first region does not include the location of the terminal, then the terminal sends the first message.

[0035] Based on this implementation, the terminal can send a first message to update the first satellite list if it moves out of the available area of ​​the first satellite list. The phrase "the first area does not include the terminal's location" can also be replaced with "the terminal determines it has moved out of or left the first area".

[0036] In one possible implementation, the first region is determined based on at least one of the following: the terminal's location information; ephemeris information; satellite capability information; the terminal's preference information; and coverage area information of satellites in the first satellite list.

[0037] In this application, the terminal's location information can be used to indicate the terminal's location. Specifically, regarding the determination of the first region, the terminal's location information can be used to indicate whether the terminal sends or does not send the first message; for example, it can be the terminal's geographic coordinates and / or an identifier of the region where the terminal is located. The region identifier can be, for example, a TA identifier, a base station identifier, or a cell identifier, etc., without specific limitations.

[0038] Ephemeris information can be used to indicate the position and / or coverage of a satellite. For example, this ephemeris information can be information about the satellite's motion patterns, such as its orbital parameters, angular velocity, and speed. Based on this information, communication equipment can calculate the satellite's position in its orbit at any given time. Ephemeris information can be found in the detailed implementation section and will not be repeated here.

[0039] Satellite capability information may include the satellite's total storage space and / or remaining storage space. Satellites with small total storage space and / or small remaining storage space may not be included in the satellite list, meaning they will not be considered when determining the first area. Alternatively, if at the edge of the area there is a satellite not on the satellite list with almost no storage space, the area may be expanded to ensure that the terminal can be covered by satellites with available storage space after leaving the first area.

[0040] Terminal preference information may include the terminal's energy-saving requirements (or preferences) and / or latency requirements (or preferences). For example, when four satellites can cover the terminal, as an example, if the terminal's energy-saving requirement is "moderate (or low)," the satellite list may include more satellites, such as three, and the first area may be the coverage area of ​​these three satellites. If the terminal's energy-saving requirement is "strong," the satellite list may include fewer satellites, such as one, and the first area may be the coverage area of ​​this one satellite, thereby helping to reduce terminal power consumption. As another example, if the terminal has low latency requirements and strong energy-saving requirements, the satellite list may include one of the four satellites, and the first area may be the coverage area of ​​this one satellite. If the terminal has high latency requirements and moderate energy-saving requirements, the satellite list may include three of the four satellites, and the first area may be the coverage area of ​​these three satellites, in order to reduce service latency.

[0041] Based on this implementation method, the first region can be determined flexibly and accurately.

[0042] In one possible implementation, the first information includes a list of third satellites. The terminal can receive broadcast messages from third satellites in the third satellite list and send the first message. Alternatively, the terminal can receive broadcast messages from third satellites in the third satellite list and send the first message based on those broadcast messages. Or, the terminal sends the first information after receiving broadcast messages from satellites in the third satellite list.

[0043] Based on this implementation, the terminal can send the first message upon receiving a broadcast message from a satellite in the third satellite list, or in other words, when the satellites in the third satellite list provide coverage. At this time, the first satellite list is unavailable.

[0044] The third satellite list can be determined based on satellites covering the first region. For example, the satellites in the third satellite list may not include those covering the first region. The first region does not include the location of the terminal when it sent the first message. Alternatively, it can be said that the third satellite list does not include satellites in the first satellite list.

[0045] In one possible implementation, the first satellite list does not include satellites in the third satellite list.

[0046] In one possible implementation, the third satellite list is determined based on at least one of the following: the terminal's location information; ephemeris information; satellite capability information; the terminal's preference information; and coverage area information of the satellites in the first satellite list.

[0047] Based on this implementation method, the first region can be determined flexibly and accurately.

[0048] In one possible implementation, the first message is an attach request, a registration request, or a tracking area update (TAU) request.

[0049] Based on this implementation, the terminal device can send a first message to the first network device, and the first network device can update the first satellite list after receiving an attach request, registration request, or tracking area update request. For example, the first network device updates the satellite list every time it receives an attach request, registration request, or tracking area update request.

[0050] In one possible implementation, the first message includes second information that indicates an update to the first satellite list.

[0051] Based on this implementation, the first network device can update the first satellite list according to the second information after obtaining the second information in the first message.

[0052] "Used to instruct the updating of the first satellite list" can refer to the second information directly or indirectly instructing the updating of the first satellite list. "Used to instruct the updating of the first satellite list" can also be replaced with "Used to request an update of the first satellite list".

[0053] In one possible implementation, the coverage area of ​​the satellites in the second satellite list includes the location of the terminal.

[0054] Therefore, by obtaining the second satellite list, the terminal can access or attempt to access satellites that cover its current location. The current location, for example, is the location where the terminal sent the first message.

[0055] Secondly, embodiments of this application provide a communication method, which can be executed by a second communication device, or in other words, the method can be applied to a second communication device. Unless otherwise specified, the "second communication device" in this application can refer to the first network device itself, a component within the first network device, or a logic module or software capable of implementing all or part of the functions of the first network device. The components in this application may include, for example, at least one of a chip, chip system, processor, transceiver, processing unit, transceiver unit, or other functional modules. As an example, the first network device can be a mobility management entity (MME), an MME-non-terrestrial (MME-NT), an access and mobility management function (AMF) network element, or an AMF-non-terrestrial (AMF-NT), etc.

[0056] Taking a first network device as the executing entity as an example, the method includes: the first network device deployed on the second satellite receiving a first message from the terminal, the first message being used to update the terminal's first satellite list, the first message being sent by the terminal based on first information; the first network device sending the second satellite list to the terminal; wherein, the first information includes at least one of the following: information of a first timer; ephemeris information; a third satellite list; or, information of a first region corresponding to the first satellite list, the first satellite list being available in the first region.

[0057] In one possible implementation, the first network device is deployed on a second satellite, the coverage area of ​​which includes the location of the terminal; the first network device can also determine that the second satellite is not included in the list of satellites in the first satellite list.

[0058] Based on this implementation, if the first network device can obtain the first satellite list, it can send the second satellite list to the terminal if it determines that the first satellite is not included in the first satellite list, thus avoiding unnecessary updates to the satellite list if the first satellite list includes the second satellite.

[0059] In one possible implementation, the first network device may also send the identifier of the second satellite to the second network device and receive third information indicating that the second satellite is not included in the first satellite list.

[0060] Based on this implementation, if the first network device cannot obtain the first satellite list, and if it determines that the first satellite is not included in the first satellite list, the first network device can send the identifier of the second satellite to the second network device, so that the second network device can determine whether the first satellite list includes the second satellite. If the second network device indicates through third information that the first satellite is not included in the first satellite list, the first network device sends the second satellite list to the terminal, avoiding unnecessary updates to the satellite list if the second satellite is included in the first satellite list.

[0061] The second network device can obtain the first satellite list.

[0062] In one possible implementation, the first network device may also determine the second satellite list based on the location information of the terminal.

[0063] Based on this implementation method, the second satellite list can be determined by the first network device.

[0064] In one possible implementation, the first network device may also send the terminal's location information to the second network device; and receive the second satellite list from the second network device, the second satellite list being determined based on the terminal's location information.

[0065] Based on this implementation, the second network device can determine and send the second satellite list to the first network device.

[0066] Optionally, in addition to determining the second satellite list based on the terminal's location information, the first network device and / or the second network device may also determine the second satellite list based on at least one of ephemeris information, satellite capability information, or terminal preference information. When the second network device determines the second satellite list, the first network device may also send the satellite capability information and / or the terminal's preference information to the second network device.

[0067] In one possible implementation, the first message includes an attach request or a tracking area update request.

[0068] In one possible implementation, the first message includes second information for requesting an update to the first satellite list.

[0069] In one possible implementation, the coverage area of ​​the satellites in the second satellite list includes the location of the terminal.

[0070] The beneficial effects of the second aspect and its various possible implementations can be referred to the effect description of the first aspect and its corresponding implementations, which will be repeated without further elaboration.

[0071] Thirdly, embodiments of this application provide a communication method, which can be executed by a third communication device, or in other words, the method can be applied to a third communication device. Unless otherwise specified, the "third communication device" in this application can refer to the second network device itself, a component within the second network device, or a logic module or software capable of implementing all or part of the functions of the second network device. The components in this application may include, for example, at least one of a chip, chip system, processor, transceiver, processing unit, transceiver unit, or other functional modules. As an example, the second network device may be a home subscriber server (HSS), an MME-terrestrial (MME-T), a user data management (UDM), or an AMF-terrestrial (AMF-T), etc.

[0072] Taking the second network device as the executing entity as an example, the method includes: the second network identifier receiving the identifier of the second satellite from the first network device, and sending third information to the first network device, the third information being used to indicate that the satellites in the first satellite list do not include the second satellite.

[0073] The meanings of the terms "first network equipment," "first satellite list," "third information," and "second satellite" in the third aspect can be found in the introduction in the first aspect, and will not be repeated here.

[0074] Optionally, the second network device can determine whether the first satellite list contains the second satellite based on the identifiers of the first satellite list and the second satellite.

[0075] In one possible implementation, the second network device may also receive location information from a terminal of the first network device and send a second satellite list to the first network device, the second satellite list being determined based on the location information of the terminal.

[0076] Optionally, the second network device can determine the second satellite list based on the terminal's location information.

[0077] Fourthly, embodiments of this application provide a communication method, which can be executed by a fourth communication device, or in other words, the method can be applied to a fourth communication device. Unless otherwise specified, the "fourth communication device" in this application can refer to the third network device itself, a component within the third network device, or a logic module or software capable of implementing all or part of the functions of the third network device. The components in this application may include, for example, at least one of a chip, chip system, processor, transceiver, processing unit, transceiver unit, or other functional modules. As an example, the third network device can be deployed on a first satellite; for example, the third network device is an access network device or core network device on the first satellite. As an example, the third network device can be an MME, MME-NT, AMF, or AMF-NT deployed on the first satellite. The first satellite is included in the list of first satellites.

[0078] Using a fourth network device as the executing entity, the method may include: the fourth network device sending first information and a first satellite list. The first information may include at least one of the following: information about a first timer; ephemeris information; a third satellite list; and information about a first region corresponding to the first satellite list.

[0079] In one possible implementation, the fourth network device can determine the first information.

[0080] Fifthly, a communication device is provided. The device can implement the method described in any possible implementation of any of the first to fourth aspects. The device possesses the functions of the first, second, third, or fourth communication device. The device may be, for example, a terminal device, a first network device, a second network device, or a third network device, or a functional module within a terminal device, a first network device, a second network device, or a third network device.

[0081] In one optional implementation, the device may include modules corresponding one-to-one with the methods / operations / steps / actions performed in any possible implementation of any of the first to fourth aspects. These modules may be hardware circuits, software, or a combination of hardware circuits and software. In another optional implementation, the device includes a processing unit (sometimes also called a processing module) and a communication unit (sometimes also called a transceiver module, communication module, etc.). The transceiver unit is capable of both sending and receiving functions. When the transceiver unit performs the sending function, it may be called a sending unit (sometimes also called a sending module); when it performs the receiving function, it may be called a receiving unit (sometimes also called a receiving module). The sending unit and the receiving unit may be the same functional module, referred to as the transceiver unit, which performs both sending and receiving functions; or, the sending unit and the receiving unit may be different functional modules, with the transceiver unit being a collective term for these functional modules.

[0082] For example, when the apparatus is used to perform the method described in any one of the first to fourth aspects, the apparatus may include a communication unit and a processing unit.

[0083] In a sixth aspect, embodiments of this application also provide a communication device, including a processor for executing a computer program (or computer-executable instructions) stored in a memory, which, when executed, causes the device to perform the method as described in any possible implementation of any of the first to fourth aspects.

[0084] In one possible implementation, the processor and memory are integrated together;

[0085] In another possible implementation, the memory is located outside the communication device.

[0086] The communication device also includes a communication interface for communicating with other devices, such as sending or receiving data and / or signals. Exemplarily, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface.

[0087] A seventh aspect provides a computer-readable storage medium for storing a computer program or instructions that, when executed, enable the implementation of the method described in any possible implementation of any of the first to fourth aspects, and the method shown in any possible implementation of the method described therein.

[0088] Eighthly, a computer program product containing instructions is provided, which, when run on a computer, enables the method described in any possible implementation of any of the first to fourth aspects to be implemented.

[0089] Ninthly, embodiments of this application also provide a communication device for performing the method described in any possible implementation of any of the first to fourth aspects.

[0090] In a tenth aspect, a chip system is provided, comprising logic circuitry (or, as understood, a processor, which may include logic circuitry, etc.), and further comprising input / output interfaces. The input / output interfaces can be used to input messages or to output messages. The input / output interfaces can be the same interface, i.e., the same interface can implement both sending and receiving functions; or, the input / output interface includes an input interface and an output interface, the input interface being used to implement the receiving function, i.e., to receive messages; and the output interface being used to implement the sending function, i.e., to send messages. The logic circuitry can be used to perform operations other than the sending and receiving functions in any possible implementation of any of the first to fourth aspects described above; the logic circuitry can also be used to transmit messages to the input / output interfaces or to receive messages from other communication devices from the input / output interfaces. The chip system can be used to implement the methods described in any possible implementation of any of the first to fourth aspects described above. The chip system can be composed of chips or can include chips and other discrete devices.

[0091] Optionally, the chip system may also include a memory, which can be used to store instructions, and the logic circuits can call the instructions stored in the memory to implement the corresponding functions.

[0092] Eleventhly, a communication method is provided, which may include the method implemented by a first communication device as shown in the first aspect and any possible implementation thereof, and the method implemented by a second communication device as shown in the second aspect and any possible implementation thereof.

[0093] Optionally, the communication method may further include the method implemented by the third communication device as shown in the third aspect and / or the method implemented by the fourth communication device as shown in the fourth aspect and any possible implementation thereof.

[0094] In a twelfth aspect, a communication system is provided, which may include a first communication device and a second communication device. The first communication device may be used to implement the method shown in the first aspect and any possible implementation thereof, and the second communication device may be used to implement the method shown in the second aspect and any possible implementation thereof. Optionally, the communication system may further include a third communication device and / or a fourth communication device, wherein the third communication device may be used to implement the method shown in the third aspect and any possible implementation thereof, and the fourth communication device may be used to implement the method shown in the fourth aspect and any possible implementation thereof.

[0095] The technical effects brought about by the second to twelfth aspects above can be found in the description of the beneficial effects of the corresponding solutions in the first aspect above, and will not be repeated here. Attached Figure Description

[0096] Figure 1 This application provides a schematic diagram of the architecture of a wireless communication system.

[0097] Figure 2 This is a schematic diagram of another wireless communication system architecture provided in an embodiment of this application;

[0098] Figure 3 This is a schematic diagram of another wireless communication system architecture provided in an embodiment of this application;

[0099] Figure 4 This is a schematic diagram of another wireless communication system architecture provided in an embodiment of this application;

[0100] Figure 5 A flowchart illustrating a communication method provided in an embodiment of this application;

[0101] Figure 6 A flowchart illustrating another communication method provided in an embodiment of this application;

[0102] Figure 7 A flowchart illustrating another communication method provided in an embodiment of this application;

[0103] Figure 8 A flowchart illustrating another communication method provided in an embodiment of this application;

[0104] Figure 9 A flowchart illustrating another communication method provided in an embodiment of this application;

[0105] Figure 10 A flowchart illustrating another communication method provided in an embodiment of this application;

[0106] Figure 11 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0107] Figure 12 This is a schematic diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0108] The specific implementation of this application will be described below with reference to the accompanying drawings in the embodiments of this application.

[0109] The embodiments of this application can be applied to various communication systems. For example, communication systems may include cellular systems such as Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), General Packet Radio Service (GPRS), Long Term Evolution (LTE), LTE Frequency Division Duplex (FDD), LTE Time Division Duplex (TDD), Universal Mobile Telecommunications System (UMTS), 5th Generation (5G), or New Radio (NR), or may be applied to future communication systems or other similar communication systems. Alternatively, communication systems may include non-cellular systems such as Ultra Wide Band (UWB), Worldwide Interoperability for Microwave Access (WIMAX), or WiFi.

[0110] Figure 1 A possible, non-limiting system schematic diagram is shown. For example... Figure 1 As shown, the communication system includes a radio access network (RAN) 100 and a core network (CN) 200. The RAN can also be called an access network (AN). Optionally, the communication system may also include the Internet 300. The radio access network 100 may include at least one radio access network device (such as...) Figure 1 110a and 110b in the above), may also include at least one terminal (such as Figure 1(Referring to 120a-120j in the original text). Terminals connect wirelessly to the wireless access network (WLAN) equipment, which in turn connects to the core network via wireless or wired connections. The core network equipment and the WLAN equipment can be independent physical devices, or they can integrate the functions of the core network equipment and the logical functions of the WLAN equipment onto the same physical device. Alternatively, a single physical device can integrate some of the functions of both the core network equipment and the WLAN equipment. Terminals and WLAN equipment can be interconnected via wired or wireless connections. Figure 1 This is just an illustration; the communication system may also include other network devices, such as wireless repeaters and wireless backhaul devices. Figure 1 It is not shown in the middle.

[0111] In this application, unless otherwise specified, access network equipment may be used to represent wireless access network equipment such as base stations.

[0112] Access network equipment can be a device in the RAN that provides priority and / or wireless communication functions for terminal equipment, referred to as RAN equipment or (R)AN equipment. RAN can be an access network in the 3rd generation partnership project (3GPP), such as 4th generation (4G), 5G, or future communication networks. RAN can also be an open RAN (O-RAN or ORAN), a cloud radioaccess network (CRAN), or a communication network combining two or more of the above. RAN equipment can be a base station, evolved NodeB (eNodeB / eNB), or transmission reception point (TRP) in a long term evolution (LTE) or LTE advanced (LTE-A) communication system, a next-generation nodeB (gNB) in a 5G mobile communication system, a base station in a future mobile communication system, a wireless fidelity (WiFi) system, a long range radio (LoRa) system, or an access node in a vehicle-to-everything (V2X) system. RAN equipment can also be a module or unit that performs some of the functions of a base station. For example, it can be a CU, a DU, a CU-user plane (UP), or an RU, etc. For example, a CU is configured to implement the functions of the Packet Data Convergence Protocol (PDCP) layer and above (such as the Radio Resource Control (RRC) layer and / or the Service Data Adaptation Protocol (SDAP) layer); a DU is configured to implement the functions of the protocol layers below the PDCP layer (such as the Radio Link Control (RLC) layer, the Media Access Control (MAC) layer, and / or the Physical (PHY) layer). For specific descriptions of the above protocol layers, please refer to the relevant 3GPP technical specifications. CU and DU can be set up separately or included in the same network element, such as in the baseband unit (BBU).The RU can be included in radio frequency equipment or radio frequency units, such as in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). Any of the units CU, CU-CP, CU-UP, DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. The wireless access network equipment can also be a macro base station (e.g.,...). Figure 1 110a), or micro base stations or indoor stations (such as...) Figure 1 110b) in the text can also be a relay node or a donor node, etc. The embodiments of this application do not limit the specific technology or device form used in the wireless access network equipment. For ease of description, the base station can be used as an example of a wireless access network equipment in this application.

[0113] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0114] In this embodiment, the form of the access network device is not limited. The device used to implement the function of the access network device can be the access network device itself; it can also be a device that supports the access network device in implementing the function, such as a module or chip system. The device can be installed in the access network device or used in conjunction with the access network device.

[0115] In this application, core network equipment can be deployed in core network 200.

[0116] The steps in different embodiments of this application can be used in combination, and no limitation is made herein.

[0117] In this application, network devices can represent access network devices and core network devices.

[0118] It is understood that a network device can be referred to as a communication device. For example, a network device can be understood as a device that has network device functions. For example, the device used to implement the functions of a network device can be the network device itself; or some components within the network device, such as CU, DU, or RU. The device used to implement the functions of a network device can also be a device capable of supporting the network device in implementing those functions, such as a chip system, hardware circuitry, software modules, or a combination of hardware circuitry and software modules. This device can be installed in the network device or can be used in conjunction with the network device. In the embodiments of this application, the chip system can be composed of chips or can include chips and other discrete devices.

[0119] A terminal can also be called a terminal device, user interface (UE), station (STA), mobile station (MS), or mobile terminal. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), the Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, and smart cities. Terminals can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc.

[0120] The embodiments of this application do not limit the specific technology or device form used in the terminal. It is understood that a terminal can be referred to as a communication device. For example, a terminal can be understood as a device with terminal functions. For example, the device used to implement the terminal functions can be a terminal itself; it can also be a device capable of supporting the terminal in implementing those functions, such as a chip system, hardware circuit, software module, or hardware circuit plus software module. This device can be installed in the terminal or can be used in conjunction with the terminal.

[0121] Network devices and terminals can be fixed in location or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the network devices and terminals.

[0122] The roles of network devices and terminals can be relative, for example, Figure 1The helicopter or drone 120i in the diagram can be configured as a mobile base station or access point (AP). For terminals 120j accessing the wireless access network 100 via 120i, drone 120i is a network device; however, for network device 110a, 120i is a terminal, meaning that 110a and 120i communicate via a wireless air interface protocol. Alternatively, 110a and 120i can also communicate via a network device-to-network device interface protocol; in this case, 120i is also a network device relative to 110a. Therefore, both network devices and terminals can be collectively referred to as communication devices. Figure 1 110a and 110b can be referred to as communication devices with network equipment functions. Figure 1 The 120a-120j in the text can be referred to as communication devices with terminal functions.

[0123] In this application, network devices and terminals can communicate with each other, and terminals can communicate with each other using licensed spectrum, unlicensed spectrum (or unlicensed spectrum), or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0124] In this application, "send" and "receive" indicate the direction of signal transmission. For example, "send information to XX" can be understood as the destination of the information being XX. "Send information" can include direct transmission or indirect transmission through other communication devices, communication apparatuses, units, or modules. "Receive information from YY" can be understood as the source of the information being YY. "Receive information" can include direct reception from YY or indirect reception from YY through other communication devices, communication apparatuses, units, or modules. Furthermore, "send" can also be understood as the "output" of a chip interface, and "receive" can be understood as the "input" of a chip interface. In other words, "send" or "receive" can occur between devices, such as a base station and a terminal transmitting or receiving data via an air interface. "Send" or "receive" can also occur within a device, such as transmitting or receiving data between components, modules, chips, software modules, or hardware modules within a device via a bus, wiring, or interface.

[0125] In this application, "for indicating" can include both direct and indirect indication. When describing "information" for indicating A, it can include whether the information directly indicates A or indirectly indicates A, but does not necessarily mean that the information carries A.

[0126] The information indicated by a given piece of information is called the information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated, such as, but not limited to, directly indicating the information to be indicated, such as the information to be indicated itself or its index. It can also be indirectly indicated by indicating other information, where there is a relationship between the other information and the information to be indicated. It can also indicate only a part of the information to be indicated, while the other parts are known or pre-agreed upon. For example, the indication of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing the indication overhead to some extent. At the same time, common parts of various pieces of information can be identified and indicated uniformly to reduce the indication overhead caused by individually indicating the same information.

[0127] Furthermore, the specific indication method can also be other methods, such as, but not limited to, the above-mentioned indication methods and their various combinations. The specific details of various indication methods are not elaborated upon herein. As described above, for example, when multiple pieces of information of the same type need to be indicated, the indication methods for different pieces of information may differ. In specific implementation, the required indication method can be selected according to specific needs. This application embodiment does not limit the selected indication method; therefore, the indication methods involved in this application embodiment should be understood to cover various methods that enable the party to be indicated to obtain the information to be indicated.

[0128] The information to be indicated can be sent as a whole or divided into multiple sub-information messages, and the sending period and / or timing of these sub-information messages can be the same or different. This application does not limit the specific sending method. The sending period and / or timing of these sub-information messages can be predefined, for example, according to a protocol, or configured by the transmitting device by sending configuration information to the receiving device. Taking the configuration of the UE by the access network device as an example, the configuration information can include, for example but not limited to, one or a combination of at least two of RRC signaling (or RRC messages), MAC layer signaling, and PHY layer signaling. MAC layer signaling includes, for example, a MAC control element (CE). PHY layer signaling includes, for example, at least one of downlink control information (DCI).

[0129] In the embodiments shown below, the first, second, and various numerical designations are merely distinctions for descriptive convenience and are not intended to limit the scope of the embodiments of this application. For example, they distinguish different indication information.

[0130] "Preset," "predefined," or "preconfigured" can be achieved by pre-storing corresponding codes, tables, or other means of indicating relevant information in the device (e.g., including terminals and network devices), or by pre-defining them in a protocol. This application does not limit the specific implementation method. "Stored" can refer to storing in one or more memories. These memories can be separate installations or integrated into the encoder, decoder, processor, or communication device. Alternatively, some memories can be separate installations, while others are integrated into the decoder, processor, or communication device. The type of memory can be any form of storage medium, and this application does not limit this.

[0131] The embodiments of this application can be applied to communication systems that integrate terrestrial and non-terrestrial communication systems, which can also be called NTN systems. The terrestrial communication system can be, for example, an LTE system, UMTS, a 5G communication system, or various future communication systems, etc., and is not limited here.

[0132] Compared to traditional communication systems, NTN communication systems offer wider coverage and can overcome natural geographical obstacles such as oceans, deserts, and mountains. To overcome the shortcomings of traditional communication systems, NTN systems can serve as an effective supplement. Satellite communication systems can be categorized into three types based on their orbital altitude: geostationary Earth orbit (GEO) satellite communication systems, medium Earth orbit (MEO) satellite communication systems, and low Earth orbit (LEO) satellite communication systems. GEO satellite communication systems can also be called geostationary orbit satellite systems. Generally, compared to terrestrial communication, NTN systems exhibit different channel characteristics (e.g., large transmission delay, Doppler frequency offset, etc.). For example, the round-trip delay of a GEO satellite communication system is 238–270 milliseconds (ms), while that of a LEO satellite communication system is 8 ms–20 ms.

[0133] In NTN communication scenarios, non-terrestrial access network devices such as drones, high altitude platform stations (HAPS), and satellites can provide terminals with services such as data transmission and voice communication. The following discussion primarily focuses on satellite base stations, but is not limited to this.

[0134] In NTN communication, NTN devices can operate in two modes: transparent mode and regenerative mode. Based on these operating modes, the architecture of NTN communication can be divided into two categories:

[0135] One type is the transparent payload architecture, also known as the pass-through architecture. In this architecture, the NTN device can act as a relay or amplifier, performing functions such as RF filtering and amplification to regenerate physical layer signals. The NTN device can be responsible for layer 1 (L1) relay, used for physical layer forwarding, and is not visible to higher layers. For example, in the pass-through architecture, both the RAN device and the core network device are deployed on the ground.

[0136] Another type is the regenerative architecture, in which the NTN device has the processing functions of the access network device. For example, satellites in regenerative operating mode can be further divided into regenerative satellites without inter-satellite links (ISL); or regenerative satellites with inter-satellite links (interfaces between satellites that can directly exchange data), where the inter-satellite link is the Xn port; or regenerative satellites with distributed unit (DU) processing functions of the access network device, in which case the satellite acts as a DU.

[0137] For example, in a regenerative architecture, some or all of the functions of the RAN equipment and / or some or all of the functions of the core network equipment are deployed on satellites.

[0138] For example, the regenerative architecture may have multiple architectural forms, such as shown in Architecture 1 or Architecture 2.

[0139] Architecture 1: Figure 2 This diagram illustrates an NTN communication system architecture applicable to embodiments of this application. This NTN communication architecture can be a regenerative satellite communication architecture with the processing capabilities of access network devices (such as eNBs or gNBs). In this architecture, the access network devices (such as eNBs or gNBs) can be deployed on the satellite. Optionally, core network elements may also be deployed on the satellite. Core network elements can be deployed on the ground; alternatively, all core network elements can be deployed on the satellite. The satellite can communicate with the core network through an NTN gateway. The connection between the NTN gateway and the satellite, or the connection between the core network devices deployed on the ground and the satellite, is called a feeder link. Additionally, the satellite can also provide wireless access services to terminal devices.

[0140] This application's embodiments can also be applied to scenarios with gNB-processed payload based on relay-like architectures, where the satellite can serve as the integrated access and backhaul (IAB). Furthermore, this application's embodiments are also applicable to scenarios with or without inter-satellite links.

[0141] It should be noted that, Figure 2 Only one satellite and one NTN gateway are shown. In actual use, an architecture with multiple satellites and / or multiple NTN gateways can be adopted as needed. Each satellite can provide services to one or more terminal devices, and each NTN gateway can correspond to one or more satellites, or vice versa. This application does not specifically limit the embodiments. Furthermore, Figure 2 This is merely an example of an NTN communication architecture; the NTN communication architecture may also include other specific devices, which are not limited in this application.

[0142] As an example, this application can be used in the 4th generation system (4GS). For instance, a terminal accesses a 4G network through a base station deployed on a satellite, where the satellite base station may include an eNB. Similarly, network elements in the 4G core network (such as MME, service gateway (SGW), public data network / packet data network (PDN) gateway (PGW), or HSS, etc.) can be deployed on a satellite. For details on 4G-related network elements, please refer to 3GPP technical specification (TS) 23.401.

[0143] As another example, this application can be used in the 5th generation system (5GS). For instance, access network equipment in a 5GS architecture can be deployed on a satellite.

[0144] For example, core network equipment in a 5G communication system may include AMF network elements, session management function (SMF) network elements, and user plane function (UPF) elements.

[0145] The AMF (Active Mobility Filter) network element is primarily used for mobility management and access management functions. In 5G communication systems, this AMF network element can be used for mobility management, access authentication, and authorization.

[0146] SMF network elements can be used to manage terminal devices' sessions (including session establishment, modification, and release), select and reselect user plane function network elements, allocate Internet Protocol (IP) addresses for terminal devices, and control quality of service (QoS).

[0147] UPF network elements can be used to forward and receive user data in terminal devices. A session (or connection, link, etc.) for transmitting user data can be established between the UPF network element and the access network device. The UPF network element can receive user data from the data network and transmit the user data to the terminal device through the session between the UPF network element and the access network device. The UPF network element can also receive user data sent by the terminal device through this session and forward the data to the data network. The transmission resources and scheduling functions in the UPF network element that provide services to the terminal device can be managed and controlled by the session management function network element.

[0148] It is understood that AMF can also be replaced by an access management network element. The access management network element in this application can be used to manage the access control and / or mobility of terminal devices. In practical applications, the access management network element can include the mobility management function within the MME in the LTE network framework. That is, in 4G, the access management network element can be the MME. The access management network element can also incorporate access management functions, specifically responsible for terminal device registration, mobility management, tracking area update procedures, reachability detection, selection of session management function network elements, and mobile state transition management. For example, in 5G, the access management network element can be an AMF network element; in future communication systems, the access management network element can still be an AMF network element, or it may have other names; this application does not limit this. When the access management network element is an AMF network element, the AMF can provide Namf services.

[0149] In summary, this application can be applied to at least 4G and / or 5G networks.

[0150] Taking 4G and 5G satellite communication systems as examples, the embodiments of this application may be applicable to, but are not limited to, the following network deployment methods:

[0151] Method 1: The RAN is deployed on a satellite, i.e., RAN onboard. In this architecture, only the RAN is deployed on the satellite, while other network elements are deployed on the ground. For example, the RAN can be an eNB or a gNB.

[0152] Method 2: Some functions of the RAN and MME / AMF are deployed on satellites, while other functions of the MME / AMF and other network elements are deployed on the ground.

[0153] Method 3: The RAN and MME / AMF are deployed on satellites, there is no MME / AMF on the ground, and other network elements are deployed on the ground.

[0154] The above deployment methods describe the deployment methods for RAN and control plane functions. Since these deployment methods also include user plane function network elements, they can be further divided into the following branches:

[0155] (1) No user plane function network elements (such as UPF in 5G, or SGW or PGW in 4G) are deployed on the satellite.

[0156] (2) User plane function network elements (such as UPF in 5G, or SGW or PGW in 4G) are deployed on the satellite.

[0157] As an example, based on the network deployment methods mentioned above, Figure 3 Examples of several network deployment architectures applicable to the embodiments of this application are shown below:

[0158] See Figure 3 The architecture 1 shown in Figure (1) shows the possible deployment scenarios of 4G and 5G network elements on satellites and the ground as follows:

[0159] Deployment on satellites: RAN, such as eNB or gNB.

[0160] Ground-based deployments: MME, SGW, PGW; AMF, SMF, UPF.

[0161] See Figure 3 The architecture shown in (2) 2, 4G and 5G network elements may be deployed on satellite and ground as follows:

[0162] Satellite deployment: 4G network RAN ​​(e.g., eNB) and part of the MME functionality (which may be called MME-NT), with optional deployment of SMG and PGW, etc. 5G network access network equipment (e.g., gNB) and part of the AMF functionality (which may be called AMF-NT). Optional deployment of SMF and UFP, etc.

[0163] Terrestrial deployment: Another part of the MME functionality in 4G networks (which may be called MME-T), with optional deployment of SMG and PGW, etc. Another part of the AMF network element functionality in 5G networks (which may be called AMF-T), with optional deployment of SMF and UFP, etc.

[0164] Understandable. Figure 3The second section of the medium architecture will be introduced using SMG, PGW, SMF, and UPF deployed on the ground as an example.

[0165] See Figure 3 The architecture shown in (3) shows the following possible deployment scenarios for 3G, 4G, and 5G network elements on satellites and ground:

[0166] Satellite deployment: RAN (eNB) and part of the MME functionality (referred to as MME-NT) for 4G networks, with optional deployment of SMG and PGW, etc. Access network equipment (e.g. gNB) and part of the AMF functionality (referred to as AMF-NT) for 5G networks, with optional deployment of SMF and UFP, etc.

[0167] Terrestrial deployment: 4G network uses MME-T and PGW, with optional deployment of SMG and PGW, etc. 5G network uses AMF-T, with optional deployment of SMF and UFP, etc.

[0168] Understandable. Figure 3 The third section of the medium architecture will be introduced using SMG, PGW, SMF, and UPF deployed on the ground as examples.

[0169] See Figure 3 The architecture shown in (4) 4, 4G and 5G network elements may be deployed on satellite and ground as follows:

[0170] Satellite deployment includes: 4G network equipment such as RAN (eNB), MME, SGW, and PGW; and 5G network access network equipment such as gNB, AMF, SMF, and UPF.

[0171] Ground-based deployment: 4G and / or 5G networks can be used to deploy application servers.

[0172] It can be seen that in Figure 3In the architecture shown in number (4), all functions of the core network are deployed on satellites, and this architecture can be called a CN onboard architecture. In this architecture (4), the core network elements deployed on satellites include at least MME, SGW, PGW, and HSS. There are other types of core network elements. As long as the network elements deployed on satellites can complete basic processes, such as attachment processes, it can be called a CN onboard architecture. In the architectures shown in number (2) and number (3), some functions of the MME are deployed on satellites, and some functions are deployed on the ground. This architecture can be called an MME split or AMF split architecture. In addition, in the architectures shown in number (2) and number (3), if some functions of the AMF are deployed on satellites and some functions are deployed on the ground, this architecture can be called an AMF split architecture.

[0173] It is understandable that in the above deployment methods, a satellite may only deploy 4G network equipment or 5G network equipment, or it may deploy both 4G network equipment and 5G network equipment, without specific limitations.

[0174] Figure 3 The architectures shown are merely examples and do not limit the network deployment architecture applicable to the embodiments of this application. For example, the actual application architecture may include more or fewer network elements than any of the above architectures.

[0175] The communication system and business scenarios (or application scenarios) described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios (or new application scenarios), the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0176] In the NTN scenario, a discontinuous power supply scenario exists under the regenerative relay satellite architecture. In this scenario, the service link (or access connection) between the terminal and the base station and / or the power supply link between the base station and the core network are not always available. In this application, the discontinuous power supply scenario can also be described as a satellite store-and-forward (S&F) scenario, a discontinuous power supply state, or a scenario accessed through an access network device with a discontinuous power supply. These descriptions are interchangeable. In this scenario, during satellite operation, neither the service link nor the power supply connection of a network element / device on a satellite is always available; that is, both the service link and the power supply connection will be disconnected for a period of time.

[0177] In this scenario, the service link and power supply connection may not be available simultaneously. Therefore, network elements or devices deployed on the satellite need to receive and store uplink data from the terminal when the service link is available; when the power supply connection is available, the network elements or devices deployed on the satellite forward the stored uplink data to network elements or devices deployed on the ground, and / or receive and store downlink data sent to the terminal from network elements or devices deployed on the ground. When the service link becomes available again, the network elements or devices deployed on the satellite forward the stored downlink data to the terminal. For example, the network elements deployed on the ground may be core network elements deployed on the ground; the network devices deployed on the ground may include application servers or functional modules deployed on the ground.

[0178] For example Figure 4 As shown, with the satellite's position changing, at some times the service link is available while the feeder link is unavailable, at other times the service link is unavailable while the feeder link is available, and at still other times both the service link and the feeder link are unavailable. The satellite in the regenerative relay satellite architecture supports processing of received signals, including demodulation, decoding, encoding, modulation, and information processing; that is, the satellite has the functions of all access network equipment (such as gNB or eNB), and may also have some or all of the core network equipment functions (e.g., at least one of AMF, SMF, or UDM). In this application, the discontinuous feeder scenario can also be described as a satellite store-and-forward scenario, a discontinuous feeder state, or a scenario accessed through access network equipment with a discontinuous feeder; these descriptions are interchangeable.

[0179] Specifically, when a terminal accesses a regenerator-and-forward satellite, if the feed link is unavailable, the satellite needs to store uplink information from the terminal. When the feed link becomes available, the satellite forwards the stored uplink information to the ground core network equipment or data network. For downlink, the ground network equipment sends downlink information to the regenerator-and-forward satellite. If the service link is unavailable, the regenerator-and-forward satellite needs to store downlink information from the ground core network equipment or data network (e.g., PDN, data network (DN), or server). When the service link between the terminal and the satellite becomes available, the satellite forwards the stored downlink information to the terminal. This satellite operating mode in this scenario can be called the S&F satellite operating mode. The ground network equipment can be located in a core network deployed on the ground.

[0180] Specifically, the S&F satellite operating mode is an operating mode in which the S&F satellite provides communication services (store and forward information) to terminals when the serving satellite cannot simultaneously connect to the terrestrial network via feed link or inter-satellite link (ISL) for a certain period of time and / or geographical area. For uplink, storage refers to the onboard storage of uplink information from the terminal, and forwarding refers to forwarding the stored uplink information to the terrestrial network. For downlink, storage refers to the onboard storage of downlink information from the terrestrial network, and forwarding refers to forwarding the stored downlink information to the terminal. The S&F satellite operating mode can be used to transmit latency-tolerant or non-real-time services, such as short message service (SMS), cellular internet of things (CIoT), or MTC data.

[0181] In this application, a serving satellite is a satellite that provides satellite access to a terminal (e.g., a service cell). Depending on its orbit, a serving satellite covers a specific geographical area for a limited period of time.

[0182] In scenarios with discontinuous power supply, if the service link between the terminal and the base station changes from unavailable to available, an RRC connection needs to be established between the terminal and the access network equipment. The terminal can also register (or attach) and establish a session with the core network (such as MME, AMF or SMF) on the satellite.

[0183] Furthermore, in this application, some or all of the network elements in the core network can be deployed on a satellite. For example, at least one network element such as AMF, SMF, UPF, or UDM can be deployed on a satellite. When some or all of the network elements in the core network can be deployed on a satellite, this architecture can be simply referred to as a core network satellite architecture, and the some or all network elements deployed on the satellite can be called an on-board core network.

[0184] In scenarios with discontinuous power supply, the store-and-forward listener list is a concept proposed for terminal energy saving. In this application, the store-and-forward listener list may also be referred to as a satellite list or monitoring list, which may contain identifiers (satellite IDs) of one or more satellites. In S&F scenarios, the terminal only needs to attempt to access satellites in the satellite list, and does not need to attempt to access satellites whose identifiers are not included in the satellite list.

[0185] For example, if a terminal is not registered (or not attached to) the core network, and the terminal receives a broadcast message from a satellite whose identifier is in the satellite list, the terminal can initiate registration (or attachment) with or through that satellite. Specifically, the terminal can establish an RRC connection with the base station on that satellite and send a registration request (or attachment request) to the base station. Alternatively, if the terminal is already registered, and the terminal receives a broadcast message from a satellite whose identifier is in the satellite list, the terminal can attempt to execute a TAU procedure or send uplink data. Uplink data can also be referred to as terminal-initiated data.

[0186] In this application, "satellite identifier" can also be replaced with: "identifier of base station / core network / core network equipment deployed on the satellite", "identifier in broadcast messages sent by base stations deployed on the satellite, such as cell ID", "other information that can identify a satellite", and other information used to identify the satellite.

[0187] It is understandable that the satellite list can be generated and sent to the terminal by core network elements. For example, the satellite list can be generated by MME / MME-T (i.e., the MME function or part of the function deployed on the ground). Core network elements can generate the satellite list based on the terminal's location information and ephemeris information (optionally, as well as the terminal's energy-saving preferences). The ephemeris information can determine the satellite's location and coverage area at each moment. Therefore, based on the ephemeris information and the terminal's location information, satellites covering the terminal's current location at different time periods can be determined. The satellite list is for the purpose of saving energy for the terminal. The terminal's current location mentioned here can be the location when the terminal sends messages such as attach requests, registration requests, or TAU requests to the satellite. For example, based on the ephemeris information and the terminal's location information, it can be determined that within a certain time period (e.g., 12 hours), satellites 1, 2, and 3 cover the terminal's current location. However, the terminal does not want to access all satellites but rather wants to save energy. Therefore, core network elements can select satellites 1 and 3 as satellites in the satellite list, meaning the satellite list includes the identifiers of satellite 1 and satellite 3. Subsequently, the core network element can send the satellite list to the terminal. Optionally, the core network element can indirectly send the satellite list to the terminal through other devices, such as through core network elements and base stations deployed on satellites.

[0188] Currently, even when a satellite list is configured on the terminal, if the terminal's location changes due to movement or other reasons, the terminal will still only attempt to connect to satellites in the satellite list. However, the satellites in the satellite list may never or in the short term be able to cover the terminal's changed location, causing the terminal to be unable to connect to satellites in the satellite list and unable to attempt to connect to satellites outside the satellite list, resulting in the failure to establish a connection between the terminal and the satellite.

[0189] To prevent satellites in the satellite list from failing to cover the terminal's location, and to prevent the terminal from accessing other satellites outside the satellite list, this application provides a communication method. In this application, the terminal can send a first message based on first information to trigger an update of the satellite list, thereby enabling the terminal to access satellites in the updated satellite list.

[0190] The communication method may be implemented by one or more of a terminal (or terminal equipment, etc.), a first network device (or first network element) or a second network device (or second network element), or by a device or component in one or more of the above network elements or devices.

[0191] In this application, the implementation is described using a terminal, a first network device, and a second network device as examples. The actions performed by the terminal can be replaced by modules or chips within the terminal; the actions performed by the first network device can be replaced by modules or chips within the first network device; the actions performed by the second network device can be replaced by modules or chips within the second network device; and the actions performed by the first computing node can be replaced by modules or chips within the first computing node.

[0192] It is understandable that the first network device can be deployed on a satellite. Taking a 4G network as an example, the first network device can be an MME or an MME-NT. Similarly, taking a 5G network as an example, the first network device can be an AMF or an AMF-NT.

[0193] The second network device can be deployed on the ground. For example, in a 4G network, the second network device could be an HSS or an MME-T. Similarly, in a 5G network, the first network device could be a UDM or an AMF-T.

[0194] In this application, the satellite on which the first network device is located is not among the satellites in the terminal's list of satellites to be updated.

[0195] The following will combine Figure 5 The process shown in S101-S103 describes the technical solution in this application.

[0196] S101: The terminal obtains the first information and the first satellite list.

[0197] The first satellite list may include information about one or more satellites. In other words, the first satellite list includes one or more satellites. The satellite information may include satellite identifiers or other information that can be used to identify the satellite. The satellite list can be used to indicate which satellites the terminal is allowed or authorized to access, or the terminal can determine whether to access a satellite based on the satellite list, or the terminal can determine which satellites are allowed to access based on the satellite list, or the satellite list can be used to assist the terminal in obtaining downlink data or terminal termination data. Alternatively, the terminal can communicate with the core network through satellites in the satellite list, for example, by sending uplink data to the core network, initiating data or signaling, and / or receiving downlink data, terminal termination data, or other signaling.

[0198] The terminal only needs to attempt to access a satellite in the first satellite list after receiving a broadcast message from a satellite in that first list. For example, the broadcast message may contain a satellite identifier. When the terminal determines that the satellite identifier in the broadcast message is included in the first satellite list, it can attempt to access that satellite. The first satellite list may be, for example, a store-and-forward listener list.

[0199] As an example, the terminal obtains the first satellite list by receiving the first satellite list from the first satellite. The satellites in the first satellite list may include the first satellite itself.

[0200] It is understandable that the first satellite list is a list of satellites to be updated.

[0201] In this application, the first information can be used to determine whether to update the first satellite list. Determining whether to update the first satellite list can be understood as the terminal determining whether to send the first message in S102. If it determines to update the satellite list, the terminal sends the first message; otherwise, if it determines not to update the satellite list, it does not need to send the first message. The method by which the terminal determines whether to update the satellite list is described in S102. The terminal's determination of whether to update the first satellite list can also be described as: determining to update the satellite list, or determining whether to update the satellite list, or determining to trigger an update of the satellite list (or the first satellite list), or determining whether to trigger an update of the satellite list (or the first satellite list).

[0202] In this application, the first information can be used by the terminal to determine whether to update the first satellite list.

[0203] As one possible implementation, the terminal can receive first information from the first satellite. As previously explained, the first satellite can be a satellite in a first satellite list. For example, the terminal can receive the first information and / or the first satellite list from the first satellite (or a third network device, such as a network device deployed on the first satellite) during or after accessing the first satellite. For instance, the terminal can receive the first satellite list from the first satellite, as well as the first information. As another possible implementation, the first information can be preset or pre-configured.

[0204] The first information includes at least one of the following: information from the first timer, ephemeris information, information from the first region, or information from the third satellite list. That is, the first information can determine whether to update the satellite list based on information from the first timer, ephemeris information, information from the first region, or information from the third satellite list.

[0205] The information for the first timer, ephemeris information, information for the first region, and the third satellite list are explained below.

[0206] (1) Information about the first timer. The first satellite list can be considered available before the first timer expires. The first timer can also be called the availability timer for the first satellite list. It can be understood that the terminal will not trigger an update to the first satellite list before the first timer expires. Alternatively, it can be said that the terminal can trigger an update to the first satellite list after the first timer expires.

[0207] The information for the first timer can indicate its duration, such as seconds (s), hours, or days, without specific limitation. If the first information includes the first timer information, the terminal can start the first timer after receiving the first satellite list. Starting the first timer can mean that the terminal starts counting down from 0, or it can mean that the terminal counts down according to the duration, without specific limitation.

[0208] It is understandable that "information on the first timer" can be replaced with descriptions such as "first timer" or "available timers in the first satellite list." Alternatively, "information on the first timer" can be replaced with "first time information," allowing the terminal to obtain the first time information and generate or determine the first timer based on it.

[0209] In this application, timer timeout can also be referred to as timer expiration or timeout. It can mean that the timer, starting from its maximum value, counts down to its minimum value (e.g., 0); or it can mean that the timer, starting from its minimum value (e.g., 0), counts down to its maximum value. The maximum value can be a value determined based on the timing duration and the timer's timing unit. For example, if the timing duration is 10 seconds and the timer's timing unit is seconds, then the maximum value can be 10.

[0210] Optionally, the information for the first timer can come from network devices, such as from the first satellite or core network devices. The information for the first timer can also be pre-configured or preset by the terminal; there are no specific limitations.

[0211] The following section, in conjunction with method 1, explains in detail how the terminal determines whether to update the satellite list based on the information from the first timer; this will not be elaborated upon here.

[0212] (2) Ephemeris Information. The ephemeris information mentioned in this application is used to indicate the position and / or coverage of a satellite. For example, the ephemeris information can be information about the satellite's motion patterns, such as its orbital parameters, angular velocity, and speed. Based on this information, communication equipment can calculate the satellite's position on its orbit at each moment. Ephemeris information can be represented as a simple correspondence, such as the satellite position information corresponding to each moment / time period. Ephemeris information can also be represented as a satellite coverage map, such as satellite coverage availability information. A satellite coverage map can divide the Earth's surface into multiple grid points and show the grid points covered and uncovered by the satellite at each moment. For example, the satellite's orbital period around the Earth is one hour, with an accuracy of minutes. Each minute, the satellite corresponds to a satellite coverage map. Some grid points on the map are lit, and some are dark. The lit grid points represent the grid points that the satellite will cover at that corresponding moment in each cycle.

[0213] It should be noted that the ephemeris information involved in this application includes, but is not limited to, traditional ephemeris information, satellite map information, and gateway station deployment information. Traditional ephemeris information includes, but is not limited to, orbital parameters, or parameters such as the satellite's azimuth calculated based on orbital parameters. It is understood that traditional ephemeris information can be used to calculate, predict, depict, or track the satellite's flight time, position, velocity, and other states. For example, traditional ephemeris information can be 17 bytes of information to represent position (78 bits) and velocity (54 bits), or traditional ephemeris information can be 18 bytes of information to represent orbital parameters (e.g., semi-major axis, range, eccentricity, perigee distance, etc.). Satellite map information can be the area covered by the satellite on a map at each moment. This application does not limit the specific form, content, and name of the ephemeris information; please refer to the definition of ephemeris information in the protocol. For example, in this application, ephemeris information can also be referred to as satellite coverage availability information.

[0214] In one possible embodiment, the terminal can determine whether satellites in the first satellite list will cover the terminal's location in the future based on ephemeris information. If satellites in the first satellite list will not cover, or will not cover, the terminal's location for a period of time, the terminal can determine to update the satellite list.

[0215] Optionally, the ephemeris information may originate from network devices, such as from the first satellite, from other satellites, from core network elements, or from devices used for managing, maintaining, storing, or configuring ephemeris information; there are no specific restrictions. The ephemeris information may also be pre-configured or predefined, but this application does not specifically require this.

[0216] The following section, in conjunction with method 2, explains in detail how the terminal determines whether to update the satellite list based on ephemeris information; this will not be elaborated upon here.

[0217] (3) Information about the first area corresponding to the first satellite list, wherein the first satellite list is available within the first area. The first area can also be referred to as the available area of ​​the first satellite list. When the terminal moves out of this first area, the satellites in the first satellite list cannot cover the terminal, or the satellites in the first satellite list cannot cover the terminal within a tolerable time.

[0218] As an example, the information for the first area can be an area identifier, which the terminal can use to determine the location of the first area. For instance, the first area can be a TA (Target Area) or a combination of multiple TAs, in which case the area identifier can be a TA identifier or index. The first area can also be the coverage area of ​​one or more base stations, and correspondingly, the area identifier can be a base station identifier. The first area can also be the coverage area of ​​one or more cells, and correspondingly, the area identifier can be a cell identifier, etc.

[0219] As another example, the first region can be a region identified by geographic coordinates, and correspondingly, the information of the first region can be the range of geographic coordinates. For example, the geographic coordinates can be in the form of latitude and longitude, and this application does not make specific requirements on the form of geographic coordinates and coordinate ranges.

[0220] It is understood that the scope of the first area may be the same as or different from the scope of the terminal's registration area (RA). The RA may include one or more TAs. It can be configured by network devices; for example, the RA information can be sent to the terminal by the first satellite or an access network device within the first satellite. The RA information may include, for example, identifiers of one or more TAs. When the terminal's location leaves or exceeds the RA's scope, the terminal can send a TAU request. In this application, assuming the scope of the first area is different from the RA's scope, when the terminal leaves or exceeds the scope of the first area, a first message can be sent to update the first satellite list. Optionally, the terminal's location leaving or exceeding the first area may also mean that the first area does not include the terminal's location.

[0221] In this application, the location of the terminal outside a certain area can be understood as the terminal leaving or moving out of the area, or the area not including the location of the terminal.

[0222] In one possible embodiment, the first region can be determined based on at least one of the following: the terminal's location information, ephemeris information, satellite capability information, terminal preference information, or coverage area information of satellites in the first satellite list.

[0223] The satellite's capability information may include the satellite's total storage space and / or remaining storage space. Satellites with small total storage space and / or small remaining storage space may not be included in the satellite list, meaning they will not be considered when determining the first area. Alternatively, if a satellite outside the satellite list has almost no storage space at the edge of the area, the area may be expanded to ensure that the terminal can be covered by satellites with available storage space after leaving the first area.

[0224] Terminal preference information may include the terminal's energy-saving requirements (or energy-saving needs) and / or latency requirements (or latency needs). This preference information can be stored as subscription information in network devices, such as in network elements like HSS or UDM. For example, when four satellites can cover the terminal, as an example, if the terminal's energy-saving needs are "moderate (or low)," the satellite list can include more satellites, such as three, and the first area can be the coverage area of ​​these three satellites. If the terminal's energy-saving needs are "strong," the satellite list can include fewer satellites, such as one, and the first area can be the coverage area of ​​this one satellite, thus helping to reduce terminal power consumption. As another example, if the terminal has low latency requirements and strong energy-saving needs, the satellite list includes one of the four satellites, and the first area can be the coverage area of ​​this one satellite. If the terminal has high latency requirements and moderate energy-saving needs, the satellite list includes three of the four satellites, and the first area can be the coverage area of ​​these three satellites, to reduce service latency.

[0225] Optionally, the information for the first region may come from network devices, such as from the first satellite. The first satellite list and / or the information for the first region may be determined by network elements or network devices deployed on the first satellite, or by ground-based network elements or network devices connected to the first satellite; this application does not specifically limit this.

[0226] (4) Third satellite list.

[0227] In this application, when a satellite in the third satellite list covers the terminal, the first satellite list is unavailable.

[0228] Optionally, the coverage area of ​​the satellites in the third satellite list may not include the first region, or the coverage area of ​​the satellites in the third satellite list may include unavailable areas of the first satellite list. As described above, the first region may be an available area of ​​the first satellite list. And / or, the first satellite list may not include satellites in the third satellite list, or the third satellite list may not include satellites in the first satellite list.

[0229] In other words, a terminal can determine that the first satellite list is unavailable when it receives a broadcast message from a satellite in the third satellite list, or when the terminal is covered by satellites in the third satellite list. In this case, it can either send the first message or update the first satellite list. Conversely, if it does not receive a broadcast message from a satellite in the third satellite list, or if satellites in the third satellite list do not cover the terminal, it may choose not to send the first message or update the first satellite list.

[0230] It is understood that the third satellite list can be determined based on at least one of the following: terminal location information, ephemeris information, satellite capability information, terminal preference information, or coverage area information of satellites in the first satellite list. For example, one or more satellites whose coverage area does not include the terminal's location can be identified as satellites in the third satellite list based on the terminal's location information and ephemeris information. Optionally, if the satellite capability information indicates that the satellite's total storage space is small and / or the satellite's remaining storage space is small, then the satellite cannot cover the first area, meaning that satellite can be included in the third satellite list. Optionally, if the terminal's preference information indicates that the terminal has high energy-saving requirements and / or low latency requirements, then the number of satellites in the third satellite list can be less to improve energy efficiency; if the terminal's preference information indicates that the terminal has low energy-saving requirements and / or high latency requirements, then the number of satellites in the third satellite list can be more to efficiently update the first satellite list.

[0231] It can also be understood that the third satellite list is related to the first region. For example, the coverage area of ​​satellites in the third satellite list does not include the first region.

[0232] In one possible embodiment, a first satellite list and a third satellite list can be sent to the terminal by a first satellite or an access network device within the first satellite. The first satellite list and / or the third satellite list can be determined by a network element or network device deployed on the first satellite, or by a ground-based network element or network device connected to the network element or network device of the first satellite; this application does not specifically limit this. It is understood that the third satellite list can be determined by a third network device deployed on the first satellite, or by other network devices connected to the third network device.

[0233] S102: The terminal sends a first message based on the first information, which is used to update the first satellite list.

[0234] Accordingly, the first network device receives the first message. Optionally, in the S&F scenario, the first network device can be an access network device deployed on the second satellite. The second satellite is not among the satellites listed in the first satellite list.

[0235] S102 can also be described as follows: after determining to update the first satellite list based on the first information, the terminal can send a first message, which is used to update the first satellite list. Alternatively, the first message can be said to be used to update the satellite list.

[0236] In this application, the first message may include a registration request, an attachment request, or a TAU request, etc.

[0237] Among these, a registration request, also known as a registration message, can be used by a terminal to request registration to a 5G network. This access network device can be deployed on a second satellite; for example, the access network device may be the first network device. An attach request, also known as an attach message, can be used by a terminal to request attach to a 4G network. This access network device can also be deployed on a second satellite; for example, the access network device may be the first network device. A TAU request can be used by a terminal to request a TA update. Additionally, the first message can also be other messages sent by the terminal to the first network device during the access process or after accessing the first network device.

[0238] It is understood that, in addition to their original functions, registration requests, attach requests, or TAU requests, as the first message, can also be used in this application to update the first satellite list. For example, in this application, the attach request can be used not only for a terminal to request attaching to a 4G network, but also to update the first satellite list.

[0239] In this application, the first message is used to update the first satellite list, which may mean that the first message is used to directly or indirectly instruct the updating of the first satellite list.

[0240] In this context, "direct instruction" can refer to the first message containing information indicating an update to the first satellite list. This information may be referred to as "second information" below. Accordingly, the first network device can update, trigger an update, or determine to update the first satellite list based on the second information in the first message.

[0241] As an example, a field can be added to the first message to carry second information. For instance, this field could contain 1 bit. When this bit has the first value, it indicates that the first message carries second information; when the bit has the second value, it indicates that the first message does not carry second information. The first and second values ​​can be different; for example, the first value can be 0 and the second value can be 1, or the first value can be 1 and the second value can be 0.

[0242] The second piece of information may be an indication for updating the satellite list, or an indication for updating the store-and-forward monitoring list. The second piece of information may also have other names, and this application does not specifically limit its name.

[0243] Indirect instruction can mean that the first message itself does not contain information indicating the updating of the first satellite list, but rather the first network device decides to update the first satellite list based on the first message after receiving it. For example, the first network device can be configured to always update the terminal's satellite list after receiving the terminal's first message. Alternatively, the first network device can be configured to determine whether to update the terminal's satellite list after receiving the terminal's first message. If it determines that updating the terminal's satellite list is necessary, the first network device can update, trigger an update, or confirm the update of the first satellite list; if it determines that updating the terminal's satellite list is not necessary, then the first network device does not need to update, trigger an update, or confirm the update of the first satellite list. The method of updating the satellite list is described in S103 below and will not be elaborated here.

[0244] In one possible embodiment, before sending the first message to the first network device, the terminal may receive a broadcast message from the first network device (or the second satellite). This broadcast message may include the identifier of the second satellite, and the terminal may also determine that the second satellite is not in the first satellite list, meaning the identifier of the second satellite is not included in the first satellite list. Specifically, if the satellite identifier is included in the first satellite list, it means the satellite belongs to the first satellite list; if the satellite identifier is not included in the first satellite list, it means the satellite does not belong to the first satellite list.

[0245] This can also be understood as the terminal, upon receiving a broadcast message from the first network device (or the second satellite), determining whether to send the first message based on the first information. Alternatively, the broadcast message can be used to trigger the terminal to determine whether to send the first message based on the first information.

[0246] For example, after receiving a broadcast message from the second satellite, the terminal may determine whether to send a first message based on one or more of methods 1 to 3 described below. If it determines to send the first message, the terminal may access or attempt to access the second satellite, and during or after accessing the second satellite, send the first message to the first network device on the second satellite. For example, the first message may be a registration request, attach request, or TAU request sent by the terminal after accessing a base station deployed on the second satellite.

[0247] As described in S101, the first information includes at least one of the following: information of the first timer, ephemeris information, information of the first region, or the third satellite list. The following describes, in conjunction with methods 1 to 4, how the terminal determines to send the first message (or determines to update the first satellite list) based on the information of the first timer, ephemeris information, information of the first region, or the third satellite list.

[0248] Method 1: The terminal can determine whether to send the first message based on whether the first timer has expired. Specifically, if the first timer expires, the terminal can send the first message; or, in other words, if the first timer expires, the terminal determines to update the first satellite list. Conversely, if the first timer does not expire, the terminal does not send the first message; or, in other words, if the first timer does not expire, the terminal determines not to update the first satellite list. As described in S101 regarding the information of the first timer, the terminal can start the first timer based on the information after obtaining the first satellite list.

[0249] It is understandable that if the terminal receives a broadcast message from a second satellite that does not belong to the first satellite list before the first timer expires, the terminal will not send the first message.

[0250] It can also be understood that if the terminal determines that the satellite belongs to the first satellite list based on the satellite identifier carried in the received satellite broadcast message, the terminal can reset the first timer. For example, the terminal can reset the first timer by starting it from 0 or by restarting the countdown from its maximum value.

[0251] In another possible embodiment, the terminal may reset the first timer after accessing or attempting to access a satellite in the first satellite list.

[0252] It is understood that in the above embodiments, resetting the first timer can prevent the terminal from updating the satellite list without moving or accessing any satellites in the first satellite list, thus avoiding unnecessary overhead. In other words, the first timer will only time out and trigger an update of the satellite list if the terminal moves or is unable to be covered by any satellite in the first satellite list before the first timer expires.

[0253] For example, in a normal scenario where the terminal remains stationary, the terminal will be covered by satellites in the first satellite list periodically. In this case, the terminal adheres to the first satellite list, only accessing or attempting to access satellites within the list, and not accessing or attempting to access satellites outside the list. Since there are satellites in the first satellite list that can cover the terminal's location, there is no need to trigger an update to the satellite list.

[0254] Based on Method 1, when the first timer expires, the terminal can disregard the first satellite list, allowing it to access or attempt to access satellites outside the first satellite list. This is because after the first timer expires, the satellites in the first satellite list are considered no longer suitable for terminal access. The terminal can update the first satellite list using satellites outside the list. Alternatively, each time the terminal accesses a satellite in the first satellite list, or receives a broadcast message from a satellite in the first satellite list, it indicates that the terminal is still under normal coverage, and therefore does not need to update the first satellite list. Thus, the terminal needs to reset the first timer to prevent unnecessary satellite list updates due to the first timer expiring.

[0255] Method 2: The terminal determines whether satellites in the first satellite list can cover its location based on its location information and ephemeris information, and decides whether to send the first message based on the determination result. The location information can be used to indicate the terminal's location. As an example, after receiving a broadcast message from a satellite not in the first satellite list, the terminal triggers Method 2 to determine whether to send the first message. The location information can indicate the terminal's location at the time of receiving the broadcast message; that is, the terminal's location can be the location at the time of receiving the broadcast message. If satellites in the first satellite list cannot cover the terminal's location, the terminal can send the first message, or update the first satellite list. If satellites in the first satellite list can cover the terminal's location, the terminal does not send the first message, or does not update the first satellite list. The inability of a satellite to cover the terminal's location includes: the satellite never covering the terminal's location, or the satellite not covering the terminal's location for a period of time. The inability of a satellite to cover the terminal's location could be due to reasons such as the satellite being no longer in use, changes in satellite services, or changes in satellite capabilities.

[0256] Optionally, after receiving the broadcast message from the second satellite, the terminal can determine whether the satellites in the first satellite list can cover its current location based on its location information and ephemeris information. In this case, the terminal's current location can be its location at the time it received the broadcast message from the second satellite. Optionally, the terminal can obtain ephemeris information and / or its location information from the broadcast message from the second satellite; for example, the terminal's location information can be the tracking area or cell specified in the broadcast message from the second satellite.

[0257] In one possible embodiment, when determining whether satellites in the first satellite list can cover the terminal's current location, the terminal can determine satellites whose coverage area includes the terminal's location based on its location information and ephemeris information, obtain a fourth satellite list, and determine whether to send a first message or update the first satellite list based on the fourth satellite list and the first satellite list. The coverage area of ​​the satellites in the fourth satellite list includes the terminal's location; that is, the satellites in the fourth satellite list can be satellites capable of covering the terminal's location. The fourth satellite list includes the identifiers of one or more satellites; in other words, the fourth satellite list includes one or more satellites.

[0258] Specifically, the terminal can determine whether the first satellite list includes satellites in the fourth satellite list, and based on the determination result, decide whether to send the first message or update the first satellite list. If the first satellite list does not include satellites in the fourth satellite list, or the fourth satellite list does not contain satellites that can cover the terminal's location, the terminal can decide to send the first message and / or update the first satellite list; conversely, if the first satellite list includes satellites in the fourth satellite list, or the fourth satellite list contains satellites that can cover the terminal's location, the terminal can decide not to send the first message and / or not to update the first satellite list.

[0259] As one possible implementation for determining the fourth satellite list, the terminal can determine, based on location information and ephemeris information, which satellites can cover the terminal's location as satellites in the fourth satellite list. For example, the terminal can determine one or more satellites that can cover its location based on location information and ephemeris information, and these one or more satellites can be included in the fourth satellite list. Specifically, determining which satellites can cover the terminal's location can involve determining which satellites can cover the terminal's location at least at any given time.

[0260] Based on this implementation, the terminal can determine the satellites that can cover its location, obtain a fourth satellite list, and determine whether there is a satellite in the first satellite list that can cover the terminal's location based on the intersection of the fourth satellite list and the first satellite list. If the fourth satellite list and the first satellite list do not intersect, the terminal can determine to send a first message and / or determine to update the first satellite list; if they intersect, the terminal can determine not to send the first message and / or determine not to update the first satellite list. It is understood that since the satellites in the fourth satellite list can cover the terminal's location at least at any given time, when there is at least one intersecting satellite between the first and fourth satellite lists, the terminal can access at least one satellite at that location, thus avoiding the terminal failing to successfully access a satellite. As described above, in method 2, the terminal's location can be the location where the terminal receives a broadcast message from a satellite not belonging to the first satellite list (such as a second satellite).

[0261] As another possible implementation for determining the fourth satellite list, the terminal can determine, based on location information and ephemeris information, which satellites can cover its location within a certain period of time, and include them in the fourth satellite list. For example, the terminal can determine, based on location information and ephemeris information, which satellites can cover its location, and the time during which the satellites cover its location, and then determine, based on that time, one or more satellites that can cover its location within a certain period of time, which can be included in the fourth satellite list. In this application, "covering the terminal's location" can also be described as "the coverage area includes the terminal's location."

[0262] The term "a period of time" can also be described as a "time interval," which can be sent to the terminal by the network device or can be preset or pre-configured. The first satellite list is considered to be effective after the end of this time interval; therefore, the end time of this time interval can also serve as the effective or invalidation time of the first satellite list. This time interval can be related to the terminal's latency requirements and / or energy-saving requirements. For example, if the terminal's energy-saving requirement is "strong," the time interval can be set to a longer period to help reduce power consumption; if the terminal's energy-saving requirement is "moderate (or low)," the time interval can be set to a shorter period to help reduce latency. Similarly, if the terminal has low latency requirements, the time interval can be set to a longer period; if the terminal has high latency requirements, the time interval can be set to a shorter period.

[0263] As an example, the terminal can obtain indication information for the aforementioned time period. For instance, the indication information for the time period is duration information, also known as auxiliary duration, such as indicating one or more hours, one day, or multiple days. In this example, the terminal can determine the fourth satellite list based on the time period indication information, the terminal's location information, and ephemeris information. The satellites in the fourth satellite list must be able to cover the terminal's location within that time period.

[0264] In this example, the fourth satellite list is determined as follows: the terminal can determine one or more satellites that can cover the terminal based on ephemeris information and the terminal's location information, as well as the duration for which these satellites will cover the terminal. The terminal can also determine the effective expiration time of the first satellite list based on time period indication information and the time the first satellite list was received. Furthermore, based on this expiration time and the duration for which these satellites will cover the terminal, the terminal can filter out one or more satellites that can cover the terminal before the expiration time and include them in the fourth satellite list. Satellites capable of covering the terminal can be those that are currently capable of covering the terminal or those that will be capable of covering the terminal in the future.

[0265] Optionally, the time period indication information can come from network devices, such as from the first satellite. For example, the terminal can receive the time period indication information from the first satellite (or the access network device of the first satellite) during or after accessing the first satellite. Furthermore, the time period indication information can also be pre-configured or preset, without specific limitations.

[0266] It is understandable that, since the satellites in the fourth satellite list can cover the terminal's location for a period of time, when there is at least one overlapping satellite between the first and fourth satellite lists, the terminal can access or attempt to access at least one satellite within that period of time, thus avoiding the terminal being unable to successfully access a satellite for an extended period of time.

[0267] Method 3: The terminal determines whether to send the first message based on whether it has moved out of the first area. Specifically, the terminal can determine whether its location is within the first area based on its location information and the information of the first area. If the terminal's location is not within the first area, it means the terminal has moved out of the first area; if the terminal's location is within the first area, it means the terminal has not moved out of the first area. As an example, after receiving a broadcast message from a satellite that does not belong to the first satellite list, the terminal triggers Method 3 to determine whether to send the first message. The location information can indicate the terminal's location when it received the broadcast message; that is, the terminal's location can be the location when it received the broadcast message.

[0268] If the terminal moves out of the first area, the terminal can determine whether to send the first message, or in other words, the terminal can determine whether to update the first satellite list. If the terminal does not move out of the first area, the terminal can determine whether to not send the first message, or in other words, the terminal can determine whether to not update the first satellite list.

[0269] Method 4: The terminal determines whether to send the first message or update the first satellite list based on whether it has received a broadcast message from a satellite in the third satellite list, or whether a satellite in the third satellite list covers the terminal's location. Specifically, if the terminal receives a broadcast message from a satellite in the third satellite list, or if a satellite in the third satellite list covers the terminal's location, the terminal sends the first message or updates the first satellite list. Here, the terminal's location can be the location at the time the first message is sent.

[0270] The third satellite list can be determined by the first satellite and / or sent to the terminal.

[0271] It is understood that methods 1 to 4 above are examples of how the terminal determines whether to update the first satellite list based on the information of the first timer, ephemeris information, and information of the first region. This should not be interpreted as meaning that S102 can only be implemented in the above ways. For example, in some cases, two or more methods from methods 1 to 4 can be combined. For instance, by combining methods 1 and 4, the first satellite can provide the terminal with information about the first timer and the first region. The terminal can determine to update the first satellite list after the first timer expires and / or after the terminal moves out of the first region, or send the first message after the first timer expires and / or the terminal moves out of the first region. Furthermore, in some cases, the implementation methods in methods 1 to 4 above can be adaptively extended.

[0272] S103: The first network device sends the second satellite list to the terminal.

[0273] Accordingly, the terminal receives the second list of satellites.

[0274] It is understood that the second satellite list is obtained by the first network device after receiving the first message in S102. As described in S102, the first message may directly or indirectly instruct the updating of the first satellite list. Optionally, the first message may contain second information.

[0275] The second satellite list can be an updated or revised version of the first satellite list. For example, the second satellite list may include information about differences between it and the first satellite list. This difference information may include, for example, identifiers of satellites added or removed from the first satellite list. Alternatively, the second satellite list can be obtained by updating the first satellite list. Furthermore, the second satellite list can also be a completely new satellite list. That is, the second satellite list may be unrelated to the first satellite list or not based on it.

[0276] Optionally, the first satellite list and the second satellite list have no overlap, that is, the first satellite list does not include satellites in the second satellite list, and / or the second satellite list does not include satellites in the first satellite list.

[0277] Optionally, the second satellite list includes the second satellite, or in other words, the second satellite list includes the identifier of the second satellite.

[0278] In one possible embodiment, after receiving the first message, if the first satellite list of the terminal does not contain the satellite that the terminal has accessed or attempted to access (i.e., the second satellite), the first network device may obtain the second satellite list and send the second satellite list to the terminal.

[0279] Specifically, the first network device can obtain the terminal's first satellite list and determine whether the second satellite belongs to the first satellite list based on the identifiers of the satellites in the first satellite list and the identifiers of the second satellite.

[0280] The following describes how the first network device obtains the first satellite list of the terminal.

[0281] One way for the first network device to obtain the terminal's first satellite list is by obtaining it locally. For example, the first network device may store or configure a correspondence between the terminal's satellite list and the terminal's identifier. Therefore, after receiving a first message, the first network device can query the corresponding first satellite list based on the terminal's identifier. The first network device can obtain the terminal's identifier based on the first message; for example, the first message may carry the terminal's identifier, or the first message may be transmitted through a connection associated with the terminal's identifier. Furthermore, if the first network device determines from the terminal's satellite list that a second satellite does not belong to the first satellite list, it can obtain the second satellite list.

[0282] A second way for the first network device to obtain the first satellite list of the terminals is that the first network device can obtain the first satellite list from other network devices (such as referred to as the second network device). For example, the second network device can store the first satellite list of the terminals, such as storing the correspondence between the first satellite list of the terminals and the terminal identifiers.

[0283] As an example, the first network device can send the terminal's identifier to the second network device and receive a first satellite list sent by the second network device based on the terminal's identifier. Furthermore, if the first network device determines from the terminal's satellite list that a second satellite does not belong to the first satellite list, it can obtain the second satellite list.

[0284] It is understandable that the second network device can communicate directly or indirectly with the first network device. For example, for a 4G network, if a CN onboard architecture is used, the first network device can be an MME and the second network device can be an HSS; if an MME-separated architecture is used, the first network device can be an MME-NT and the second network device can be an MME-T. Similarly, for a 5G network, if a CN onboard architecture is used, the first network device can be an AMF and the second network device can be a UDM; if an AMF-separated architecture is used, the first network device can be an AMF-NT and the second network device can be an AMF-T.

[0285] The third way for the first network device to obtain the first satellite list of the terminal is that the terminal can carry the first satellite list in the first message.

[0286] In this application, the second satellite list can be determined based on at least one of the following: terminal location information, ephemeris information, satellite capability information, or terminal preference information. Specifically, the second satellite list can be determined by a first network device or other network devices based on at least one of the following: terminal location information, ephemeris information, satellite capability information, or terminal preference information.

[0287] As described in S101, satellite capability information may include the satellite’s total storage space and / or the satellite’s remaining storage space.

[0288] The terminal's preference information may include its energy-saving requirements and / or latency requirements. For example, if the terminal's energy-saving requirement is "moderate (or low)," the second satellite list may include more satellites; if the terminal's energy-saving requirement is "strong," the satellite list may include fewer satellites. Similarly, if the terminal's latency requirement is "strong," the second satellite list may include more satellites; if the terminal's latency requirement is "moderate (or low)," the satellite list may include fewer satellites.

[0289] The following describes how the first network device obtains the second satellite list of the terminal.

[0290] In this application, the first network device obtains the second satellite list by generating or determining the second satellite list after receiving the first message. For example, the first network device may determine the second satellite list based on at least one of the following after receiving the first message: the terminal's location information, ephemeris information, satellite capability information, or the terminal's preference information.

[0291] The second satellite list can also be determined or generated by a network device other than the first network device. This network device can be a second network device or any other network device. For example, the first network device can send the terminal's identifier and location information to this network device. Correspondingly, after obtaining the terminal's identifier, the network device can obtain the terminal's preference information based on the identifier. Additionally, this network device can store ephemeris information and / or satellite capability information. Therefore, this network device can determine the second satellite list based on at least one of the terminal's location information, ephemeris information, satellite capability information, or terminal preference information, and after determining the second satellite list, the second network device can send the second satellite list to the first network device.

[0292] The following is combined with Figure 6 The process shown illustrates how the first network device obtains the second satellite list.

[0293] like Figure 6As shown, taking a 4G network as an example, in the CN uplink architecture, the MME can determine the second satellite list, where the MME can act as the first network device. This process may include the following steps:

[0294] S201: The terminal sends a first message to the MME. The MME receives the first message accordingly. The MME is deployed on a second satellite, which is not part of the first satellite list.

[0295] As shown in S201, the first message can be an attach request or a TAU request. Optionally, the first message may carry second information and / or a first list of satellites.

[0296] It can be understood that S201 can be used as an exemplary implementation of S102.

[0297] S202: Optional, MME determines that the second satellite is not included in the first satellite list.

[0298] As one implementation, the MME needs to determine whether the second satellite is present in the first satellite list before determining the second satellite list. In other words, the MME determines the second satellite list only if the second satellite is not present in the first satellite list. Alternatively, the MME can update the first satellite list even if the second satellite is not present in the first satellite list.

[0299] As an alternative implementation, the MME can determine the second satellite list upon receiving the first message, without needing to check whether the first satellite list contains the second satellite; that is, S202 does not need to be executed at this time. Therefore, in this implementation, the MME can execute S205 after receiving the first message, skipping S202 to S204.

[0300] In this implementation, the MME needs to determine that the second satellite is not included in the first satellite list before determining the second satellite list (i.e., before executing S202).

[0301] If the first message carries a first satellite list, the MME can determine whether the first satellite list contains a second satellite based on the first satellite list carried in the first message. In this case, it is not necessary to execute S203-S204. That is, the MME can execute S202 based on the terminal's first satellite list carried in the first message.

[0302] If the first message does not carry the first satellite list, the MME can search its local data based on the terminal's identifier to determine whether the terminal's first satellite list is stored. If the MME has stored the first satellite list, S203-S204 does not need to be executed; that is, the MME can execute S202 based on the locally stored first satellite list. Alternatively, if the MME does not store the first satellite list locally, it can execute S203-S204 to obtain the first satellite list.

[0303] In S203-S204, if the first message does not carry the terminal's first satellite list, and / or the MME does not store the first satellite list locally, the MME can obtain the first satellite list from the HSS. That is, S203-S204 can still be executed before S202. It can be understood that the HSS can also be replaced by other network devices that store the terminal's first satellite list.

[0304] S203: The MME sends a query request to the HSS to request the terminal's first list of satellites, which may include the terminal's identifier. The terminal's identifier may be, for example, the terminal's International Mobile Subscriber Identity (IMSI). The query request may be an update location request, or it may have other names; there are no specific requirements.

[0305] The HSS can store a list of the terminal's first satellites. For example, the first satellite can send the HSS a mapping between the terminal's first satellite list and the terminal's identifier. The terminal's first satellite list can originate from that first satellite.

[0306] S204: The HSS provides the MME with the terminal's first list of satellites based on the terminal's identifier.

[0307] The first satellite list can be included in the updatelocation ACK response sent by the HSS to the MME.

[0308] S205: MME determines the second satellite list.

[0309] In S205, the MME can determine a second satellite list based on at least one of the terminal's location information, ephemeris information, satellite capability information, or terminal preference information.

[0310] Among them, at least one of ephemeris information, satellite capability information, or terminal preference information can be stored in the HSS, and the MME can obtain at least one of the ephemeris information, satellite capability information, or terminal preference information from the HSS.

[0311] S206: The MME sends a second satellite list to the terminal. This second satellite list can be carried in the response message corresponding to the first message. For example, if the first message is an attach request, the response message can be an attach confirmation message. Similarly, if the first message is a TAU request, the response message can be a TAU acceptance message.

[0312] It is understandable that S205 and S206 can serve as examples of one implementation of S103. In this example, S202-S204 do not need to be executed, and the MME does not need to determine whether the first satellite list contains the second satellite before generating the second satellite list. Alternatively, S202, S205, and S206 can serve as examples of another implementation of S103. In this example, before generating the second satellite list, the MME needs to determine that the first satellite list does not contain the second satellite. The first satellite list can be carried in the first message or stored locally on the MME. Furthermore, S202 to S206 can serve as examples of another implementation of S103. In this example, before generating the second satellite list, the MME needs to determine that the first satellite list does not contain the second satellite. The first satellite list can come from the HSS.

[0313] Additionally, in the CN satellite architecture, S204 can also be executed by the HSS, meaning the HSS can determine the second satellite list. In this case, S205 can be replaced by S207-S208; that is, only one of S205 and S207-S208 needs to be executed.

[0314] S207: The MME sends a satellite list update request to the HSS, requesting the HSS to determine a second satellite list. Optionally, the request may carry the terminal's location information. Optionally, the request may also include satellite capability information and / or terminal preference information. Additionally, at least one of the following—ephemeris information, satellite capability information, or terminal preference information—may be stored in the HSS.

[0315] Therefore, upon receiving the request, the HSS can determine a second list of satellites based on the terminal's location information and at least one of ephemeris information, satellite capability information, or terminal preference information.

[0316] S208: The HSS sends a second list of satellites to the MME.

[0317] In the MME-separated architecture, Figure 6 In S201 to S208, the actions performed by the MME can be replaced by those performed by the MME-NT. Additionally, in S201 to S208, the actions of the HSS can be replaced by those performed by the MME-T.

[0318] It's understandable. Figure 6The illustrated process can be adapted to suit 5G networks. For example, for 5G networks, Figure 6 Actions performed by the MME can be replaced by actions performed by the AMF, and actions performed by the HSS can be replaced by network elements such as the UDM. Figure 6 The IMSI of the terminal can also be replaced with an identifier in the 5G network, such as the subscriber confidentiality identifier (SUCI) or the subscription permanent identity (SUPI). Figure 6 The word "attach" in this context can be replaced with "register".

[0319] In one possible embodiment, the terminal may also obtain fourth information, which can be used to determine whether to update the second satellite list. The fourth information may include information from a third timer, ephemeris information, or information from a second region, as described in the description of the first information.

[0320] As an example, the terminal can also obtain information about a third timer corresponding to the second satellite list. The third timer can be understood as an available timer for the second satellite list, used to determine whether to update the second satellite list. The function and determination method of the third timer information can refer to the information of the first timer. For example, the terminal can obtain the third timer information from its local configuration. Alternatively, the first network device can send the first timer information to the terminal.

[0321] As an example, the terminal can also obtain ephemeris information. Referring to the description of ephemeris information in the first information section, this ephemeris information can be used to determine whether to update the second satellite list. For example, the terminal can obtain ephemeris information from its local configuration. Alternatively, the ephemeris information can be sent to the terminal by the first network device.

[0322] As an example, the terminal can also obtain information about a second region. The second region can be understood as the available area of ​​a second satellite list, used to determine whether to update the second satellite list. The function and determination method of the information in the second region can refer to the information in the first region. For example, the terminal can receive information about the second region from a first network device.

[0323] It is understood that the type of the first information used to determine whether to update the first satellite list may be the same as or different from the type of the fourth information used to determine whether to update the second satellite list. For example, in S102, the terminal determines to update the first satellite list based on the information of the first timer. Subsequently, after obtaining the second satellite list, it can determine whether to update the second satellite list based on the information of the third timer, or it can determine whether to update the second satellite list based on other fourth information. This application does not make specific requirements.

[0324] The following is combined with Figures 7 to 10 Taking 4G networks as an example, the implementation process of methods 1 to 4 will be introduced respectively.

[0325] like Figure 7 As shown, when the first information is the information of the first timer, the process by which the terminal obtains the first satellite list and updates the first satellite list may include the following steps:

[0326] S301: The terminal sends an attach request or TAU request to the MME (or MME-T) deployed on the first satellite.

[0327] S302: The MME (or MME-T) deployed on the first satellite sends an attach confirmation message or TAU acceptance message to the first terminal, which carries a list of the first satellites.

[0328] Accordingly, the terminal obtains the first satellite list and executes the timing of the first timer according to the information of the first timer.

[0329] As an example of a terminal obtaining information about the first timer, the terminal can obtain this information from its local configuration. For instance, the terminal determines the information about the first timer based on a preset or pre-configured setting. In this case, the attach confirmation message or TAU accept message in S302 may not carry the information about the first timer.

[0330] As another example of a terminal obtaining the first timer, the information of the first timer can be determined by the MME (or MME-T), therefore the attach confirmation message or TAU accept message in S302 can also carry the information of the first timer. Accordingly, the terminal can obtain the information of the first timer.

[0331] It is understandable that the way the terminal obtains the information of the first timer and the first satellite list in S302 can be used as an example of S101 when the first information is the information of the first timer.

[0332] S303: After a period of time, the terminal receives a broadcast message from the first satellite (or the eNB of the first satellite), which includes the identifier of the first satellite.

[0333] For example, if the terminal does not move, or if the terminal moves only a small range, the terminal may receive a broadcast message from the first satellite after a period of time.

[0334] S304: If the terminal determines that the first satellite is included in the first satellite list, it resets the first timer to avoid updating the satellite list when the terminal can still access satellites in the first satellite list, thus avoiding unnecessary overhead.

[0335] The list of first satellites may include the identifier of the first satellite.

[0336] Subsequent terminals can send attach requests, TAU requests, or uplink data to the first satellite (such as to the eNB of the first satellite).

[0337] The first satellite (such as the eNB to the first satellite) can also send a detach message or an access network release message to the terminal to disconnect the terminal from the first satellite.

[0338] Understandably, in S303 and S304, the first satellite can also be any other satellite in the first satellite list. That is, the terminal can reset the first timer after receiving a broadcast message from a satellite in the first satellite list; in other words, the terminal does not need to update the first satellite list after receiving a broadcast message from a satellite in the first satellite list, and it is not required that the satellite is a previously accessed satellite.

[0339] S305: After a period of time, the terminal receives a broadcast message from the second satellite (or the eNB of the second satellite), which includes the identifier of the second satellite.

[0340] S306: The terminal determines that the second satellite is not included in the first satellite list and the first timer has not expired, so the terminal does not access or attempt to access the second satellite.

[0341] The first satellite list does not include the identifier for the second satellite.

[0342] S307: The terminal determines that the second satellite is not included in the first satellite list and the first timer expires. The terminal sends an attach request or TAU request to the MME (or MME-T) deployed on the second satellite.

[0343] Optionally, the attach request or TAU request may carry second information and / or a first satellite list. The second information can be used to instruct the updating of the first satellite list. The first satellite list can be used by network equipment such as the MME (or MME-T) to determine that the second satellite is not included in the first satellite list.

[0344] It is understood that S307 can be considered an example of S102 where the first message includes information about the first timer. The first message in S102 can be an attach request or a TAU request. An MME (or MME-T) deployed on a second satellite can be considered an example of a first network device. S307 can be implemented with reference to the description of Method 1 in S102, and will not be repeated here.

[0345] Following S307, you can refer to Figure 6The process and related steps are explained below, and the list of second satellites is obtained by the MME (or MME-T) deployed on the second satellite.

[0346] S308: The MME (or MME-T) deployed on the second satellite sends a list of the second satellites to the terminal.

[0347] It is understandable that S308 can be used as an example of S103.

[0348] like Figure 8 As shown, when the first information is ephemeris information, the process by which the terminal obtains and updates the first satellite list may include the following steps:

[0349] S401: The terminal sends an attach request or TAU request to the MME (or MME-T) deployed on the first satellite.

[0350] S402: The MME (or MME-T) deployed on the first satellite sends an attach confirmation message or TAU acceptance message to the first terminal, which carries a list of the first satellites.

[0351] Accordingly, the terminal obtains the first list of satellites. In addition, the terminal can also obtain ephemeris information.

[0352] As an example of a terminal obtaining ephemeris information, the terminal can obtain ephemeris information from its local configuration. For example, the terminal determines the ephemeris information based on a preset or pre-configured setting. In this case, the attach confirmation message or TAU accept message in S302 may not carry information about the first timer.

[0353] As another example of the terminal acquiring the first timer, ephemeris information can be sent to the terminal by the MME (or MME-T). For example, ephemeris information can also be carried in the attach confirmation message or TAU accept message in S402. Accordingly, the terminal can obtain the ephemeris information.

[0354] Optionally, the terminal can also obtain the time period indication information from the local configuration, or the attachment confirmation message or TAU acceptance message in S302 can carry the time period indication information.

[0355] It is understandable that the way the terminal obtains ephemeris information and the first satellite list in S402 can be used as an example of S101 when the first information is ephemeris information.

[0356] S403: After a period of time, the terminal receives a broadcast message from the first satellite, which includes the identifier of the first satellite.

[0357] Optionally, the broadcast message may include ephemeris information.

[0358] For example, if the terminal does not move, or if the terminal moves only a small range, the terminal may receive a broadcast message from the first satellite after a period of time.

[0359] S404: The terminal determines that the first satellite is included in the first satellite list. The terminal may send an attach request, a TAU request, or send uplink data or terminal-initiated data to the first satellite (e.g., to the eNB of the first satellite). Alternatively, the terminal may choose not to send an attach request, a TAU request, or send uplink data or terminal-initiated data.

[0360] The first satellite (such as the eNB to the first satellite) can also send a disconnect message or access network release message to the terminal to disconnect the terminal from the first satellite.

[0361] Understandably, in S403 and S404, the first satellite can also be any other satellite in the first satellite list. That is, a terminal can access or attempt to access a satellite after receiving a broadcast message from one of the satellites in the first satellite list, without needing to update the first satellite list or verify that the satellite is one it has previously accessed.

[0362] S405: After a period of time, the terminal receives a broadcast message from the second satellite, which includes the identifier of the second satellite.

[0363] Optionally, the broadcast message may include ephemeris information.

[0364] S406: If the terminal determines that the second satellite is not included in the first satellite list, and determines that the satellites in the first satellite list can cover the terminal's current location based on the ephemeris information and the terminal's location information, then the terminal will not access or attempt to access the second satellite.

[0365] The statement that "the satellites in the first satellite list can cover the current location of the terminal" can mean that at least one satellite in the first satellite list can cover the location of the terminal at at least one moment in any future time period; or it can mean that at least one satellite in the first satellite list can cover the location of the terminal at at least one moment in the time period indicated by the time period indication information.

[0366] The terminal's current location can refer to its location when it receives a broadcast message from the second satellite.

[0367] S407: If the terminal determines that the second satellite is not included in the first satellite list, and determines that the satellites in the first satellite list cannot cover the terminal's current location based on the ephemeris information and the terminal's location information, then the terminal sends an attach request or TAU request to the MME (or MME-T) deployed on the second satellite.

[0368] The statement that "the satellites in the first satellite list cannot cover the terminal's current location" can mean that at least one satellite in the first satellite list will not be able to cover the terminal's location at any time in the future; or it can mean that at least one satellite in the first satellite list will not be able to cover the terminal's location for a period of time.

[0369] It is understandable that in S406 and S407, the way the terminal determines whether the satellites in the first satellite list can cover the terminal's current location based on the ephemeris information and the terminal's location information can be referred to the explanation of method 2 in S102.

[0370] Following S407, you can refer to Figure 6 The process and related steps are explained below, and the list of second satellites is obtained by the MME (or MME-T) deployed on the second satellite.

[0371] S408: The MME (or MME-T) deployed on the second satellite sends a list of the second satellites to the terminal.

[0372] It is understandable that S408 can be used as an example of S103.

[0373] like Figure 9 As shown, when the first information is information about the first region, the process by which the terminal obtains and updates the first satellite list may include the following steps:

[0374] S501: The terminal sends an attach request or TAU request to the MME (or MME-T) deployed on the first satellite.

[0375] S502: The MME (or MME-T) deployed on the first satellite sends an attach confirmation message or TAU acceptance message to the first terminal, which carries the first satellite list and first area information. The first area information indicates the available areas of the first satellite list.

[0376] Accordingly, the terminal obtains information about the first satellite list and the first region.

[0377] The first region can be determined based on the terminal's location information, ephemeris information, satellite capability information, and terminal preferences. For details, please refer to the description of the first region in S101.

[0378] It is understandable that the way the terminal obtains the information of the first region and the first satellite list in S502 can be used as an example of S101 when the first information is the information of the first region.

[0379] S503: After a period of time, the terminal receives a broadcast message from the first satellite, which includes the identifier of the first satellite.

[0380] For example, if the terminal does not move, or if the terminal moves only a small range, the terminal may receive a broadcast message from the first satellite after a period of time.

[0381] S504: The terminal determines that the first satellite is included in the first satellite list. The terminal may send an attach request, a TAU request, or send uplink data or initiate data to the first satellite (such as to the eNB of the first satellite).

[0382] The first satellite (such as the eNB to the first satellite) can also send a disconnect message or access network release message to the terminal to disconnect the terminal from the first satellite.

[0383] Understandably, in S503 and S504, the first satellite can also be any other satellite in the first satellite list. That is, a terminal can access or attempt to access a satellite after receiving a broadcast message from a satellite in the first satellite list, without needing to update the first satellite list or verify that the satellite is one it has previously accessed.

[0384] Optionally, the first satellite can also send updated information about the first region to the terminal after receiving information from the terminal. That is, each time the terminal connects to a satellite in the first satellite list, the network device can update the information about the first region on the terminal.

[0385] The updated area can be determined based on the terminal's location information, ephemeris information, satellite capability information, and terminal preferences. The terminal's location information can be the same as or different from the location information of the terminal used to determine the first area in S502. If the terminal's location information is different, i.e., the terminal's location changes, the updated first area may differ from the previous first area.

[0386] S505: After a period of time, the terminal receives a broadcast message from the second satellite, which includes the identifier of the second satellite.

[0387] S506: If the terminal determines that the second satellite is not included in the first satellite list, and determines that the terminal has not moved out of the first area based on the information of the first area and the terminal's location information, then the terminal will not access or attempt to access the second satellite.

[0388] S507: If the terminal determines that the second satellite is not included in the first satellite list, and determines that the terminal has not moved out of the first area based on the information of the first area and the terminal's location information, then the terminal sends an attach request or TAU request to the MME (or MME-T) deployed on the second satellite.

[0389] It is understandable that in S506 and S507, the way the terminal determines whether it has moved out of the first area based on the information of the first area and the terminal's location information can be referred to the description of method 3 in S102.

[0390] Following S507, you can refer to Figure 6 The process and related steps are explained below, and the list of second satellites is obtained by the MME (or MME-T) deployed on the second satellite.

[0391] S508: The MME (or MME-T) deployed on the second satellite sends a list of the second satellites to the terminal.

[0392] It is understandable that S508 can be used as an example of S103.

[0393] like Figure 10 As shown, when the first information is the third satellite list, the process by which the terminal obtains and updates the first satellite list may include the following steps:

[0394] S601: The terminal sends an attach request or TAU request to the MME (or MME-T) deployed on the first satellite.

[0395] S602: The MME (or MME-T) deployed on the first satellite sends an attach confirmation message or TAU acceptance message to the first terminal, carrying a first satellite list and a third satellite list. The first satellite list is unavailable when a satellite in the third satellite list covers the terminal.

[0396] Accordingly, the terminal obtains the first satellite list and the third satellite list.

[0397] The third satellite list can be determined based on the terminal's location information, ephemeris information, satellite capability information, and terminal preferences. For details, please refer to the explanation of the third satellite list in S101. Alternatively, the third satellite list can be determined based on the first region, and / or the first satellite list may not include satellites in the third satellite list, and the first region may be the available area of ​​the first satellite list.

[0398] It is understandable that the way the terminal obtains the third satellite list and the first satellite list in S602 can be used as an example of S101 when the first information is the third satellite list.

[0399] S603: After a period of time, the terminal receives a broadcast message from the first satellite, which includes the identifier of the first satellite.

[0400] For example, if the terminal does not move, or if the terminal moves only a small range, the terminal may receive a broadcast message from the first satellite after a period of time.

[0401] S604: The terminal determines that the first satellite is included in the first satellite list. The terminal may send an attach request, a TAU request, or send uplink data or initiate data to the first satellite (such as to the eNB of the first satellite).

[0402] The first satellite (such as the eNB to the first satellite) can also send a disconnect message or access network release message to the terminal to disconnect the terminal from the first satellite.

[0403] Understandably, in S603 and S604, the first satellite can also be any other satellite in the first satellite list. That is, a terminal can access or attempt to access a satellite after receiving a broadcast message from a satellite in the first satellite list, without needing to update the first satellite list or verify that the satellite is one it has previously accessed.

[0404] Optionally, the first satellite can also send an updated list of third satellites to the terminal after receiving information from the terminal. That is, the network device can update the list of third satellites every time the terminal accesses a satellite in the first satellite list.

[0405] The third satellite list can be determined based on the terminal's location information, ephemeris information, satellite capability information, and terminal preferences. The terminal's location information may be the same as or different from the location information used to determine the third satellite list in step S502. If the terminal's location information is different, i.e., the terminal's location changes, the updated third satellite list may differ from the previous one.

[0406] S605: After a period of time, the terminal receives a broadcast message from the second satellite, which includes the identifier of the second satellite.

[0407] S606: Optionally, if the terminal determines that the second satellite is not included in the first satellite list and the second satellite is not included in the third satellite list, then the terminal will not access or attempt to access the second satellite.

[0408] S607: If the terminal determines that the second satellite is not included in the first satellite list and the second satellite is included in the third satellite list, then the terminal sends an attach request or TAU request to the MME (or MME-T) deployed on the second satellite.

[0409] It is understandable that in S606 and S607, the method by which the terminal determines whether the third satellite list contains the second satellite can be referred to the description of method 4 in S102.

[0410] After S607, you can refer to Figure 6 The process and related steps are explained below, and the list of second satellites is obtained by the MME (or MME-T) deployed on the second satellite.

[0411] S608: The MME (or MME-T) deployed on the second satellite sends a list of the second satellites to the terminal.

[0412] It is understandable that S608 can be used as an example of S103.

[0413] Figures 7 to 10 In the diagram, dashed arrows and dashed boxes represent optional steps, but this does not exclude the possibility that other steps may also be optional.

[0414] It's understandable. Figures 7 to 10 The illustrated process can be adapted to suit 5G networks. For example, for 5G networks, Figures 7 to 10 Actions performed by the MME can be replaced by actions performed by the AMF, and actions performed by the MME-NT can be replaced by actions performed by the AMF-NT. Figures 7 to 10 The word "attach" in this context can be replaced with "register".

[0415] Based on the same technical concept, this application provides a communication device, which includes modules, units, or means that perform the method steps in the above method embodiments. The functions, units, or means can be implemented by software, hardware, or hardware executing corresponding software.

[0416] For example, see Figure 11 The device 1100 may include a processing module 1101 and a transceiver module 1102.

[0417] Optionally, the transceiver module 1102 may include a sending module and / or a receiving module. The sending module is used to perform the sending operation in the above method embodiments. The receiving module is used to perform the receiving operation in the above method embodiments.

[0418] It should be noted that the communication device 1100 may include a transmitting module but not a receiving module. Alternatively, the communication device 1100 may include a receiving module but not a transmitting module. Specifically, it depends on whether the above-described scheme executed by the communication device 1100 includes both transmitting and receiving actions.

[0419] The processing module 1101 is used for data processing. The transceiver module 1102 can realize the corresponding communication functions.

[0420] Optionally, the communication device 1100 may further include a storage module, which can be used to store instructions and / or data. The processing module 1101 can read the instructions and / or data in the storage module so that the communication device 1100 can implement the aforementioned method embodiments.

[0421] For example, the communication device 1100 may be a first communication device or a component configurable on the first communication device. The first communication device may be, for example, a terminal (such as...). Figures 5 to 10 (The terminal in the above method embodiment). The processing module 1101 is used to perform terminal processing-related operations in the above method embodiment. The transceiver module 1102 is used to perform terminal sending and / or receiving-related operations in the above method embodiment.

[0422] For example, in the implementation Figure 5 When the terminal shown is in operation: the transceiver module 1102 can be used to acquire first information and a first satellite list, and can also send a first message based on the first information. Additionally, the transceiver module 1102 can receive a second satellite list from the first network device.

[0423] In one possible implementation, the transceiver module 1102 can be used to receive first information and a first satellite list from the first satellite, wherein the first satellite list includes the first satellite.

[0424] In one possible implementation, the transceiver module 1102 can be used to send the first message when or after the first timer times out. The processing module 1101 can be used to start the timing of the first timer.

[0425] In one possible implementation, the transceiver module 1102 can also be used to receive broadcast messages from the second satellite and send the first message to the second satellite.

[0426] In one possible implementation, the transceiver module 1102 can also be used to receive broadcast messages from satellites in the first satellite list, and the processing module 1101 can also reset the first timer.

[0427] In one possible implementation, the first information includes the ephemeris information, and the processing module 1101 can determine the fourth satellite list based on the terminal's location information and the ephemeris information. The transceiver module 1102 can send the first message if the coverage area of ​​the satellites in the fourth satellite list includes the terminal's location, and the first satellite list does not include the satellites in the fourth satellite list.

[0428] In one possible implementation, the first information also includes time period indication information. The processing module 1101 can determine the fourth satellite list based on the time period indication information, the terminal's location information, and ephemeris information. The coverage area of ​​the satellites in the fourth satellite list during the time period includes the terminal's location.

[0429] In one possible implementation, the first information includes information about a first region, but the first region does not include the location of the terminal, then the transceiver module 1102 sends the first message.

[0430] In one possible implementation, the first information includes a list of third satellites. The transceiver module 1102 can receive broadcast messages from third satellites in the third satellite list and send the first message.

[0431] Furthermore, the communication device 1100 can be a second communication device or a component configurable on the second communication device. The second communication device is, for example, a first network device (such as...). Figures 5 to 10 The first network device in the above method embodiment). The processing module 1101 is used to perform processing-related operations of the first network device in the above method embodiment. The transceiver module 1102 is used to perform sending and / or receiving-related operations of the first network device in the above method embodiment.

[0432] For example, in the implementation Figure 5 When the first network device shown is in operation: the transceiver module 1102 can be used to receive the first message from the terminal; the transceiver module 1102 can also send the second satellite list to the terminal.

[0433] In one possible implementation, the processing module 1101 may also determine that the satellites in the first satellite list do not include the second satellite.

[0434] In one possible implementation, the transceiver module 1102 can also be used to send the identifier of the second satellite to the second network device; and receive third information, which is used to indicate that the satellites in the first satellite list do not include the second satellite.

[0435] In one possible implementation, the processing module 1101 can also be used to determine the second satellite list based on the location information of the terminal.

[0436] In one possible implementation, the transceiver module 1102 can also be used to send the location information of the terminal to the second network device; and receive the second satellite list from the second network device, the second satellite list being determined based on the location information of the terminal.

[0437] Furthermore, the communication device 1100 can be a third communication device or a component configurable on a third communication device. The third communication device is, for example, a second network device (such as...). Figure 6 (The HSS / MME-T in the above method embodiment, or it could be UDM, AMF-T, etc.). The processing module 1101 is used to perform processing-related operations of the second network device in the above method embodiment. The transceiver module 1102 is used to perform sending and / or receiving-related operations of the second network device in the above method embodiment.

[0438] In one possible implementation, the transceiver module 1102 can be used to receive the identifier of the second satellite from the first network device and send third information to the first network device.

[0439] In one possible implementation, the processing module 1101 can determine whether the first satellite list contains the second satellite based on the identifiers of the first satellite list and the second satellite.

[0440] In one possible implementation, the transceiver module 1102 may also receive location information from the terminal of the first network device and send a second satellite list to the first network device.

[0441] In one possible implementation, the processing module 1101 can determine the second satellite list based on the terminal's location information.

[0442] Furthermore, the communication device 1100 can be a fourth communication device or a component configurable on a fourth communication device. The fourth communication device is, for example, a third network device (such as a network device deployed on the first satellite). The processing module 1101 is used to perform processing-related operations of the third network device in the above method embodiments. The transceiver module 1102 is used to perform transmission and / or reception-related operations of the third network device in the above method embodiments.

[0443] In one possible implementation, transceiver module 1102 can be used to send first information and a first list of satellites.

[0444] In one possible implementation, the processing module 1101 can determine the first information.

[0445] It should be understood that all relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0446] The processing module 1101 in the above embodiments can be implemented by at least one processor or processor-related circuitry. The transceiver module 1102 can be implemented by a transceiver or transceiver-related circuitry. The transceiver module 1102 can also be referred to as a communication module or communication interface.

[0447] The following is another structural schematic diagram of the communication device according to an embodiment of this application. For example... Figure 12 As shown, this application embodiment also provides a communication device 1200, including:

[0448] At least one processor 1201; and a communication interface 1203 communicatively connected to the at least one processor 1201; the at least one processor 1201 causes the device to perform the method steps in the above method embodiments through the communication interface 1203 by executing instructions stored in at least one memory 1202.

[0449] Optionally, the at least one memory 1202 is located outside the device 1200.

[0450] Optionally, the device 1200 includes at least one memory 1202, which is connected to at least one processor 1201, and stores instructions that can be executed by the at least one processor 1201. Figure 12 The dashed line indicates that memory 1202 is optional for device 1200.

[0451] The processor 1201 and the memory 1202 can be coupled through an interface circuit or integrated together; no restriction is imposed here.

[0452] This application embodiment does not limit the specific connection medium between the processor 1201, memory 1202, and communication interface 1203. This application embodiment... Figure 12 The processor 1201, memory 1202, and communication interface 1203 are connected via a bus 1204. Figure 12 The connections between other components are shown in bold and are for illustrative purposes only, not as limiting information. The bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, Figure 12 The bus is represented by a thick line, but this does not mean that there is only one bus or one type of bus.

[0453] When the communication device 1200 is a first communication device, the first communication device may include a processor, a memory, and a transceiver. The memory may store computer program code, and the transceiver includes a transmitter and a receiver.

[0454] The processor is primarily used for processing communication protocols and data; for example, controlling the first communication device, executing software programs, and processing the data from those programs. The memory is mainly used to store software programs and data. The transmitter is used to send signals to other communication devices or equipment, and the receiver is used to receive signals from other communication devices or equipment.

[0455] When the communication device 1200 is a chip in the first communication device, the chip may include a processor, a memory, and a transceiver. The transceiver may be an input / output circuit or a communication interface. The processor may be a processing module integrated on the chip, a microprocessor, or an integrated circuit. In the above method embodiments, the transmitting operation of the first communication device can be understood as the output of the chip, and the receiving operation of the first communication device in the above method embodiments can be understood as the input of the chip.

[0456] Similarly, when the communication device 1200 is a second communication device, the second communication device may include a processor, a memory, and a transceiver. The memory may store computer program code, and the transceiver includes a transmitter and a receiver.

[0457] The processor is primarily used for processing communication protocols and data; controlling the secondary communication device; executing software programs; and processing the data from those programs. The memory is mainly used for storing software programs and data. The transmitter is used to send signals to other communication devices or equipment, and the receiver is used to receive signals from other communication devices or equipment.

[0458] When the communication device 1200 is a chip in the second communication device, the chip may include a processor, a memory, and a transceiver. The transceiver may be an input / output circuit or a communication interface. The processor may be a processing module integrated on the chip, a microprocessor, or an integrated circuit. In the above method embodiments, the transmitting operation of the second communication device can be understood as the output of the chip, and the receiving operation of the second communication device in the above method embodiments can be understood as the input of the chip.

[0459] It should be understood that the processor mentioned in the embodiments of this application can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, integrated circuit, etc. When implemented in software, the processor can be a general-purpose processor, implemented by reading software code stored in memory.

[0460] For example, the processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0461] It should be understood that the memory mentioned in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0462] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory (storage module) can be integrated into the processor.

[0463] It should be noted that the memories described herein are intended to include, but are not limited to, these and any other suitable types of memories.

[0464] Based on the same technical concept, embodiments of this application also provide a computer-readable storage medium, including a program or instructions, which, when run on a computer, cause the methods in the above method embodiments to be executed.

[0465] This application also provides a chip or chip system, including circuitry (such as analog circuitry and / or logic circuitry; or understood as the chip system including one or more processors, the one or more processors including circuitry, etc.), or understood as the chip including a processor. The circuitry or processor is coupled to a memory for executing computer programs or instructions stored in the memory, such that... Figures 5 to 10Alternatively, the methods shown in the various embodiments of this application may be implemented. The chip or chip system may also include input / output interfaces. For example, taking the chip as an example of implementing the functions of a terminal, the chip can receive information from other modules of the terminal (such as radio frequency or antenna) through the input / output interface, and this information may be sent to the terminal by other communication devices such as network devices. Alternatively, the chip can send information to other modules in the terminal (such as radio frequency or antenna) through the input / output interface, and this information may be sent by the terminal to other communication devices such as network devices.

[0466] Based on the same technical concept, embodiments of this application also provide a computer program product, including instructions that, when run on a computer, cause the methods in the above method embodiments to be executed.

[0467] Based on the same technical concept, embodiments of this application also provide a communication system, which may include a first communication device and a second communication device. Optionally, the communication system may further include a third communication device and / or a fourth communication device.

[0468] The first communication device can be used to implement the method implemented by the terminal in the above method embodiments; the second communication device can be used to implement the method implemented by the first network device in the above method embodiments; the third communication device can be used to implement the method implemented by the second network device in the above method embodiments; and the fourth communication device can be used to implement the method implemented by the third network device in the above method embodiments. For example, this communication system can be used to execute... Figures 5 to 10 The actions performed by the network device in the process shown.

[0469] Based on the same technical concept, embodiments of this application also provide a communication system, which may include a first communication device and a second communication device. For example, the first communication device is a terminal, and the second communication device is a network device.

[0470] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0471] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0472] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0473] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0474] In the description of this application, terms such as "first" and "second" are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order. It should be noted that this application does not limit the order in which "first," "second," etc., appear; for example, "second" may appear first, followed by "first," and this application does not impose such a limitation.

[0475] In the description of this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple. In the description of this application, " / " means "or," for example, a / b means a or b.

Claims

1. A communication method, characterized in that, include: Obtain first information and a first satellite list, wherein the first satellite list includes information about one or more satellites; A first message is sent based on the first information, and the first message is used to update the first satellite list; Receive a second satellite list, which is an updated version of the first satellite list; The first information includes at least one of the following: Information from the first timer; ephemeris information; A third satellite list, comprising information on one or more satellites, excludes satellites from the first satellite list. If satellites in the third satellite list cover the terminal, the first satellite list is unavailable; or... Information about the first region corresponding to the first satellite list, wherein the first satellite list is available within the first region.

2. The method as described in claim 1, characterized in that, The acquisition of the first information and the first satellite list includes: Receive the first information and the first satellite list from the first satellite, wherein the satellites in the first satellite list include the first satellite.

3. The method as described in claim 1, characterized in that, The first information includes information about the first timer, and sending the first message based on the first information includes: After the first timer expires, the first message is sent.

4. The method according to any one of claims 1-3, characterized in that, The method further includes: Receive a broadcast message from a second satellite, where the first satellite list does not include the second satellite; Sending the first message includes: The first message is sent to the second satellite.

5. The method according to any one of claims 1-4, characterized in that, The method further includes: Receive broadcast messages from satellites in the first satellite list; Reset the first timer.

6. The method as described in claim 1, characterized in that, The first information includes the ephemeris information, and sending the first message based on the first information includes: Based on the terminal's location information and ephemeris information, a fourth satellite list is determined. The coverage area of ​​the satellites in the fourth satellite list includes the location of the terminal, and the first satellite list does not include the satellites in the fourth satellite list. Send the first message.

7. The method as described in claim 6, characterized in that, The first information also includes indications of the time period; The step of determining the fourth satellite list based on the terminal's location information and ephemeris information includes: Based on the information from the second timer, the location information of the terminal, and the ephemeris information, the fourth satellite list is determined, and the coverage area of ​​the satellites in the fourth satellite list during the time period includes the location of the terminal.

8. The method as described in claim 1, characterized in that, The first information includes the third satellite list, including: Receive broadcast messages from third satellites, the list of third satellites including the third satellites; Send the first message.

9. The method as described in claim 1 or 8, characterized in that, The first satellite list does not include the satellites in the third satellite list.

10. The method as described in claim 1, characterized in that, The method is applied to a terminal, the first information includes information about the first region, and the step of sending a first message based on the first information includes: If the first area does not include the location of the terminal, send the first message.

11. The method as described in claim 10, characterized in that, The method is applied to a terminal, wherein the first region is determined based on at least one of the following: The location information of the terminal; ephemeris information; Satellite capability information; The terminal's preference information; or, Coverage area information of the satellites in the first satellite list.

12. The method according to any one of claims 1-11, characterized in that, The first message is an attach request, a registration request, or a tracking area update request.

13. The method as described in claim 12, characterized in that, The first message includes second information, which is used to instruct the updating of the first satellite list.

14. The method according to any one of claims 1-13, characterized in that, The method is applied to a terminal, and the coverage area of ​​the satellites in the second satellite list includes the location of the terminal.

15. A communication method, characterized in that, The methods shown include: The terminal receives a first message, which is used to update the terminal's first satellite list. The first message is sent by the terminal based on first information, and the first satellite list includes information about one or more satellites. Send a second satellite list to the terminal, the second satellite list being an updated version of the first satellite list; The first information includes at least one of the following: Information from the first timer; ephemeris information; A third satellite list, comprising information on one or more satellites, excluding satellites from the first satellite list, is unavailable if satellites in the third satellite list cover the terminal; or... Information about the first region corresponding to the first satellite list, wherein the first satellite list is available within the first region.

16. The method as described in claim 15, characterized in that, The method is applied to a first network device, which is deployed on a second satellite, and the coverage area of ​​the second satellite includes the location of the terminal. The method further includes: It was determined that the second satellite is not included in the first satellite list.

17. The method as described in claim 15, characterized in that, The method is applied to a first network device, which is deployed on a second satellite. The coverage area of ​​the second satellite includes the location of the terminal. The method further includes: Send the identifier of the second satellite to the second network device; Receive third information, which indicates that the second satellite is not included in the first satellite list.

18. The method according to any one of claims 15-17, characterized in that, The method further includes: The second satellite list is determined based on the location information of the terminal.

19. The method according to any one of claims 15-17, characterized in that, The method further includes: Send the terminal's location information to the second network device; The terminal receives a second satellite list from the second network device, the second satellite list being determined based on the terminal's location information.

20. The method according to any one of claims 1-19, characterized in that, The first message includes an attachment request or a tracking area update request.

21. The method as described in claim 20, characterized in that, The first message includes second information, which is used to request an update to the first satellite list.

22. The method according to any one of claims 15-21, characterized in that, The coverage area of ​​the satellites in the second satellite list includes the location of the terminal.

23. A communication device, characterized in that, Includes methods for performing the method as described in any one of claims 1-14, or methods for performing the method as described in any one of claims 15-22.

24. A communication device, characterized in that, It includes at least one processor, said at least one processor being configured to execute a computer program or instructions to implement the method as described in any one of claims 1-14, or to implement the method as described in any one of claims 15-22.

25. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions, which, when executed by a communication device, implement the method as described in any one of claims 1-14, or the method as described in any one of claims 15-22.

26. A computer program product, characterized in that, When the computer program product is executed by a computer, the computer executes the method as described in any one of claims 1-14, or executes the method as described in any one of claims 15-22.

27. A chip or chip system, characterized in that, It includes at least one processor for performing the method as described in any one of claims 1-14, or includes methods for performing the method as described in any one of claims 15-22.

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