Satellite switching method and device and storage medium

Abstract

The invention provides a satellite switching method and device and a storage medium, and the method comprises the steps that a terminal receives configuration information sent by network equipment through a source satellite, and the configuration information comprises the information of a target satellite and / or the information of a target cell; and performing downlink synchronization with the target satellite based on the configuration information, and accessing the target satellite after the downlink synchronization is completed.

Description

Technical Field

[0001] This application relates to the field of wireless communication technologies, and in particular, to a satellite handover method, apparatus, and storage medium. Background Art

[0002] In the scenario of invariant Physical Cell Identity (PCI) in a Non-Terrestrial Network (NTN), two satellites have overlapping coverage areas and are connected to the same base station (gNB) through feeder links, and are served by different cells with the same PCI.

[0003] For the scenario of invariant PCI in the NTN, a satellite handover method currently discussed by the 3rd Generation Partnership Project (3GPP) is as follows: A terminal (or User Equipment, UE) receives t-Service-r17 (indicating the stop service time of the cell) sent by the source satellite cell through system information. When the current time is equal to or exceeds t-Service-r17, the terminal stops uplink and downlink data transmission, performs downlink synchronization with the target satellite, and after completing the downlink synchronization, accesses the target satellite. Since the PCI of the two cells (source cell and target cell) is the same, and they have the same frequency point and security key, the terminal can obtain the target satellite ephemeris information through System Information Block (SIB) 19 and achieve uplink and downlink synchronization with the target satellite, and access the target cell without handover. However, there will be a data service interruption during the process of disconnecting from the source cell to accessing the target cell in this way. Summary of the Invention

[0004] This application provides a satellite handover method, apparatus, and storage medium to ensure that the uplink and downlink data services are not interrupted during the satellite handover process.

[0005] In a first aspect, this application provides a satellite handover method applied to a terminal, including:

[0006] Receiving configuration information sent by a network device through a source satellite, where the configuration information includes information of a target satellite and / or information of a target cell;

[0007] Based on the configuration information, performing downlink synchronization with the target satellite, and after completing the downlink synchronization, accessing the target satellite.

[0008] In some embodiments, the information of the target satellite includes one or more of the following:

[0009] The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, and the common timing advance information of the target satellite.

[0010] In some embodiments, the information of the target cell includes one or more of the following:

[0011] The cell identifier of the target cell and the synchronization signal block (SSB) configuration information of the target cell.

[0012] In some embodiments, performing downlink synchronization with the target satellite based on the configuration information includes:

[0013] Searching for the SSB of the target satellite based on the configuration information to perform downlink synchronization with the target satellite.

[0014] In some embodiments, searching for the SSB of the target satellite based on the configuration information includes:

[0015] Searching for the SSB of the target satellite based on the configuration information at the stop service moment of the source cell or after the stop service moment of the source cell; or,

[0016] Searching for the SSB of the target satellite based on the configuration information at a first moment before the stop service moment of the source cell.

[0017] In some embodiments, the method further includes:

[0018] If it is determined that the system information received in the downlink synchronization contains the satellite identifier of the target satellite or the cell identifier of the target cell, then complete the downlink synchronization with the target satellite.

[0019] In some embodiments, the method further includes:

[0020] After completing the downlink synchronization with the target satellite, send the information of the second moment to the network device;

[0021] At the second moment, stop data transmission between the source satellite and the network device and start data transmission between the target satellite and the network device.

[0022] In some embodiments, the method further includes:

[0023] Receiving the transmission point information for cooperative transmission with the target cell sent by the source cell or the target cell.

[0024] In some embodiments, receiving the configuration information sent by the network device via the source satellite includes:

[0025] Receiving a broadcast message or a radio resource control (RRC) configuration message sent by the network device via the source satellite, where the broadcast message or the RRC configuration message contains the configuration information.

[0026] In some embodiments, sending information at a second moment to a network device includes:

[0027] Sending a Media Access Control layer Control Element (MAC-CE) or an RRC message to the network device, where the MAC-CE or the RRC message contains the information at the second moment.

[0028] In a second aspect, the present application further provides a satellite handover method applied to a network device, including:

[0029] Sending configuration information to a terminal through a source satellite, where the configuration information contains information about a target satellite and / or information about a target cell.

[0030] In some embodiments, the information about the target satellite includes one or more of the following:

[0031] The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, the common timing advance information of the target satellite.

[0032] In some embodiments, the information about the target cell includes one or more of the following:

[0033] The cell identifier of the target cell, the Synchronization Signal Block (SSB) configuration information of the target cell.

[0034] In some embodiments, the method further includes:

[0035] Sending an SSB through the target satellite and broadcasting system information, where the system information contains the satellite identifier of the target satellite or the cell identifier of the target cell.

[0036] In some embodiments, the method further includes:

[0037] Receiving the information at the second moment sent by the terminal;

[0038] At the second moment, stopping data transmission between the source satellite and the terminal and starting data transmission between the target satellite and the terminal.

[0039] In some embodiments, the method further includes:

[0040] Sending transmission point information for coordinated transmission with the target cell to the terminal through the source cell or the target cell.

[0041] In some embodiments, sending configuration information to the terminal through the source satellite includes:

[0042] Sending a broadcast message or a Radio Resource Control (RRC) configuration message to the terminal through the source satellite, where the broadcast message or the RRC configuration message contains the configuration information.

[0043] In some embodiments, the information at the second moment sent by the receiving terminal includes:

[0044] The media access control layer control element MAC-CE or RRC message sent by the receiving terminal, where the MAC-CE or RRC message contains the information at the second moment.

[0045] In a third aspect, the present application further provides a terminal, including a memory, a transceiver, and a processor;

[0046] The memory is used to store a computer program; the transceiver is used to send and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations:

[0047] Receive the configuration information sent by the network device through the source satellite, where the configuration information contains the information of the target satellite and / or the information of the target cell;

[0048] Based on the configuration information, perform downlink synchronization with the target satellite, and after completing the downlink synchronization, access the target satellite.

[0049] In some embodiments, the information of the target satellite includes one or more of the following:

[0050] The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, the common timing advance information of the target satellite.

[0051] In some embodiments, the information of the target cell includes one or more of the following:

[0052] The cell identifier of the target cell, the synchronization signal block SSB configuration information of the target cell.

[0053] In some embodiments, performing downlink synchronization with the target satellite based on the configuration information includes:

[0054] Search for the SSB of the target satellite based on the configuration information to perform downlink synchronization with the target satellite.

[0055] In some embodiments, searching for the SSB of the target satellite based on the configuration information includes:

[0056] After the stop service moment of the source cell or after the stop service moment of the source cell, search for the SSB of the target satellite based on the configuration information; or,

[0057] At the first moment before the stop service moment of the source cell, search for the SSB of the target satellite based on the configuration information.

[0058] In some embodiments, the operation further includes:

[0059] If it is determined that the system information received in the downlink synchronization includes the satellite identifier of the target satellite or the cell identifier of the target cell, the downlink synchronization with the target satellite is completed.

[0060] In some embodiments, the operation further includes:

[0061] After completing the downlink synchronization with the target satellite, send the information of the second moment to the network device;

[0062] At the second moment, stop data transmission between the source satellite and the network device, and start data transmission between the target satellite and the network device.

[0063] In some embodiments, the operation further includes:

[0064] Receive the transmission point information for cooperative transmission with the target cell sent by the source cell or the target cell.

[0065] In some embodiments, receive the configuration information sent by the network device via the source satellite, including:

[0066] Receive the broadcast message or radio resource control (RRC) configuration message sent by the network device via the source satellite, where the broadcast message or RRC configuration message contains the configuration information.

[0067] In some embodiments, sending the information of the second moment to the network device includes:

[0068] Send a media access control layer control element (MAC-CE) or an RRC message to the network device, where the MAC-CE or RRC message contains the information of the second moment.

[0069] In a fourth aspect, the present application further provides a network device, including a memory, a transceiver, and a processor;

[0070] The memory is used to store a computer program; the transceiver is used to transmit and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations:

[0071] Send configuration information to the terminal via the source satellite, where the configuration information contains the information of the target satellite and / or the information of the target cell.

[0072] In some embodiments, the information of the target satellite includes one or more of the following:

[0073] The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, the common timing advance information of the target satellite.

[0074] In some embodiments, the information of the target cell includes one or more of the following:

[0075] The cell identifier of the target cell, the synchronization signal block (SSB) configuration information of the target cell.

[0076] In some embodiments, this operation further includes:

[0077] Sending the SSB through the target satellite and broadcasting system information, where the system information includes the satellite identifier of the target satellite or the cell identifier of the target cell.

[0078] In some embodiments, this operation further includes:

[0079] Receiving the information at the second moment sent by the terminal;

[0080] At the second moment, stopping data transmission between the source satellite and the terminal and starting data transmission between the target satellite and the terminal.

[0081] In some embodiments, this operation further includes:

[0082] Sending the transmission point information for cooperative transmission with the target cell to the terminal through the source cell or the target cell.

[0083] In some embodiments, sending configuration information to the terminal through the source satellite, including:

[0084] Sending a broadcast message or a radio resource control (RRC) configuration message to the terminal through the source satellite, where the broadcast message or the RRC configuration message includes the configuration information.

[0085] In some embodiments, receiving the information at the second moment sent by the terminal, including:

[0086] Receiving a media access control layer control element (MAC-CE) or an RRC message sent by the terminal, where the MAC-CE or the RRC message includes the information at the second moment.

[0087] In a fifth aspect, the present application further provides a satellite handover device, including:

[0088] A first receiving unit, configured to receive the configuration information sent by the network device through the source satellite, where the configuration information includes the information of the target satellite and / or the information of the target cell;

[0089] A handover unit, configured to perform downlink synchronization with the target satellite based on the configuration information and access the target satellite after completing the downlink synchronization.

[0090] In some embodiments, the information of the target satellite includes one or more of the following:

[0091] The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, the common timing advance information of the target satellite.

[0092] In some embodiments, the information of the target cell includes one or more of the following:

[0093] The cell identifier of the target cell, the synchronization signal block (SSB) configuration information of the target cell.

[0094] In some embodiments, performing downlink synchronization with the target satellite based on the configuration information includes:

[0095] Searching for the SSB of the target satellite based on the configuration information to perform downlink synchronization with the target satellite.

[0096] In some embodiments, searching for the SSB of the target satellite based on the configuration information includes:

[0097] Searching for the SSB of the target satellite based on the configuration information at or after the stop service moment of the source cell; or,

[0098] Searching for the SSB of the target satellite based on the configuration information at a first moment before the stop service moment of the source cell.

[0099] In some embodiments, the handover unit is further configured to:

[0100] If it is determined that the system information received in the downlink synchronization includes the satellite identifier of the target satellite or the cell identifier of the target cell, then complete the downlink synchronization with the target satellite.

[0101] In some embodiments, the apparatus further includes:

[0102] A first sending unit, configured to send the information of the second moment to the network device after completing the downlink synchronization with the target satellite;

[0103] A first transmission control unit, configured to stop data transmission between the source satellite and the network device at the second moment, and start data transmission between the target satellite and the network device.

[0104] In some embodiments, the apparatus further includes:

[0105] A second receiving unit, configured to receive the transmission point information for cooperative transmission with the target cell sent by the source cell or the target cell.

[0106] In some embodiments, receiving the configuration information sent by the network device via the source satellite includes:

[0107] Receiving a broadcast message or a radio resource control (RRC) configuration message sent by the network device via the source satellite, where the broadcast message or the RRC configuration message includes the configuration information.

[0108] In some embodiments, sending the information of the second moment to the network device includes:

[0109] Send a Media Access Control (MAC) control element (MAC-CE) or an RRC message to a network device, where the MAC-CE or the RRC message contains information about a second time.

[0110] In a sixth aspect, the present application further provides a satellite handover device, including:

[0111] A second sending unit, configured to send configuration information to a terminal via a source satellite, where the configuration information contains information about a target satellite and / or information about a target cell.

[0112] In some embodiments, the information about the target satellite includes one or more of the following:

[0113] The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, the common timing advance information of the target satellite.

[0114] In some embodiments, the information about the target cell includes one or more of the following:

[0115] The cell identifier of the target cell, the Synchronization Signal Block (SSB) configuration information of the target cell.

[0116] In some embodiments, the device further includes:

[0117] A third sending unit, configured to send an SSB and broadcast system information via the target satellite, where the system information contains the satellite identifier of the target satellite or the cell identifier of the target cell.

[0118] In some embodiments, the device further includes:

[0119] A third receiving unit, configured to receive the information about the second time sent by the terminal;

[0120] A second transmission control unit, configured to stop data transmission between the source satellite and the terminal at the second time, and start data transmission between the target satellite and the terminal.

[0121] In some embodiments, the device further includes:

[0122] A fourth sending unit, configured to send transmission point information for coordinated transmission with the target cell to the terminal via the source cell or the target cell.

[0123] In some embodiments, sending the configuration information to the terminal via the source satellite includes:

[0124] Sending a broadcast message or a Radio Resource Control (RRC) configuration message to the terminal via the source satellite, where the broadcast message or the RRC configuration message contains the configuration information.

[0125] In some embodiments, the information at the second moment sent by the receiving terminal includes:

[0126] The media access control layer control element MAC-CE or RRC message sent by the receiving terminal, and the MAC-CE or RRC message contains the information at the second moment.

[0127] In a seventh aspect, the present application further provides a non-transitory readable storage medium storing a computer program for causing a processor to execute the satellite handover method described in the first aspect above, or execute the satellite handover method described in the second aspect above.

[0128] In an eighth aspect, the present application further provides a communication device storing a computer program for causing the communication device to execute the satellite handover method described in the first aspect above, or execute the satellite handover method described in the second aspect above.

[0129] In a ninth aspect, the present application further provides a processor-readable storage medium storing a computer program for causing a processor to execute the satellite handover method described in the first aspect above, or execute the satellite handover method described in the second aspect above.

[0130] In a tenth aspect, the present application further provides a chip product storing a computer program for causing the chip product to execute the satellite handover method described in the first aspect above, or execute the satellite handover method described in the second aspect above.

[0131] The satellite handover method, device and storage medium provided by the present application send configuration information from the network side to the terminal, and the configuration information contains information about the target satellite and / or information about the target cell, so that the terminal can accurately synchronize to the target satellite, thus not only avoiding the problem that the terminal may synchronize to the source satellite resulting in satellite handover failure, but also ensuring that the uplink and downlink data services are not interrupted during the satellite handover process. BRIEF DESCRIPTION OF THE DRAWINGS

[0132] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0133] Figure 1 An example diagram of a multi-connection NTN network provided by related technologies;

[0134] Figure 2 Example diagram of the invariant PCI scenario provided for the related art;

[0135] Figure 3 Schematic diagram of satellite hard handover provided for the related art;

[0136] Figure 4 One of the flow schematic diagrams of the satellite handover method provided by the embodiments of the present application;

[0137] Figure 5 Example diagram of the newly added MAC CE format provided by the embodiments of the present application;

[0138] Figure 6 Another flow schematic diagram of the satellite handover method provided by the embodiments of the present application;

[0139] Figure 7 Example diagram of the multi-point cooperation multi-connection NTN network scenario provided by the embodiments of the present application;

[0140] Figure 8 Example diagram of the multi-connection NTN network satellite change process provided by the embodiments of the present application;

[0141] Figure 9 Schematic diagram of the structure of the terminal provided by the embodiments of the present application;

[0142] Figure 10 Schematic diagram of the structure of the network device provided by the embodiments of the present application;

[0143] Figure 11 One of the structure schematic diagrams of the satellite handover device provided by the embodiments of the present application;

[0144] Figure 12 Another structure schematic diagram of the satellite handover device provided by the embodiments of the present application. Detailed implementation manners

[0145] In the embodiments of the present application, the term "and / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0146] In the embodiments of the present application, the term "plurality" refers to two or more, and other quantifiers are similar thereto.

[0147] In the embodiments of the present application, terms such as "first" and "second" are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first" and "second" are usually of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0148] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0149] To facilitate a clearer understanding of the technical solutions of the embodiments of the present application, some technical contents related to the embodiments of the present application will be introduced first.

[0150] Figure 1 An example diagram of a multi-connected NTN network provided for the related art is as Figure 1 shown. The UE performs dual connection through the NTN network. The NTN network in the figure adopts a transparent transmission network architecture. The base station function is placed at the gateway station. The satellite transparently transmits the physical layer link data of the new air interface (New Radio, NR) between the UE and the gateway station. The link from the UE to the satellite is called the user link, and the link from the satellite to the gateway station is called the feeder link. In the figure, NR-Uu is the protocol interface used between the UE and the satellite and between the satellite and the gateway station, Xn is the protocol interface used between base stations, NG is the protocol interface used between the base station and the core network, and N6 is the protocol interface between the core network and the data network (Data Network, DN).

[0151] Due to the height of the satellite, the latency from the UE to the satellite and from the satellite to the ground gateway station is relatively large, and the latency from different satellites to the UE and from the satellite to the ground gateway station is also different.

[0152] Figure 2 An example diagram of the invariant PCI scenario provided for the related art is as Figure 2 shown. In the scenario of invariant PCI in the NTN network, two satellites have overlapping coverage areas and are connected to the same base station (gNB) through the feeder link. Services are provided by different cells with the same PCI, which is equivalent to co-frequency networking in the terrestrial network (Terrestrial Network, TN), with different transmit-receive points (TRPs) under different cells.

[0153] For the scenario of invariant PCI in the NTN network, one way of satellite handover currently discussed in 3GPP is as follows: The UE receives t-Service-r17 sent by the source satellite cell through the system message. When the current time is equal to or exceeds t-Service-r17, the UE stops the uplink and downlink data transmission, performs the downlink synchronization of the target satellite, and after completing the downlink synchronization, accesses the target satellite. The advantage of this method is that it does not require the traditional handover process, thus optimizing the signaling overhead during the handover process. The disadvantage is that this method belongs to the hard switch of the user link, which will cause the interruption of the data service (the interruption duration is 62 ms), and moreover, if no other optimization scheme is introduced, data loss will also occur. Since the PCI of the two cells is the same, with the same frequency point and security key, and the UE can obtain the ephemeris information of the target satellite through SIB19, the UE can achieve the uplink and downlink synchronization with the target satellite and access the target cell without handover.

[0154] Figure 3 The schematic diagram of satellite hard handover provided by the related technology is as Figure 3 shown. The serving satellite undergoes a handover at time T. For example, before time T, SAT1 is the serving satellite, and after time T, SAT2 is the serving satellite. The UE stops data transmission on SAT1 at time T, starts searching for the Synchronization Signal Block (SSB) of SAT2 for downlink synchronization after time T, performs uplink synchronization after downlink synchronization, and then starts data transmission after completing the uplink and downlink synchronization. In this way, during the period from time T to when the UE completes the uplink and downlink synchronization, the data service is interrupted.

[0155] If satellite soft handover is supported in the existing way (i.e., invariant PCI), since the source satellite and the target satellite use the same PCI, the UE cannot distinguish the SSB, and may synchronize to the source satellite during the soft handover (without stopping the service of the source satellite), resulting in the failure of satellite change.

[0156] In view of the above problems, each embodiment of the present application provides a satellite handover solution, which can ensure that the uplink and downlink data services are not interrupted during the satellite handover process. Moreover, the technical solution provided by the present application is applicable not only to the scenario of invariant PCI in the NTN network, but also to the general satellite handover (or change) scenario.

[0157] Figure 4 One of the flow schematic diagrams of the satellite handover method provided by the embodiment of the present application, this method can be applied to a terminal, as Figure 4 shown. The method includes the following steps:

[0158] Step 400: Receive the configuration information sent by the network device through the source satellite, where the configuration information includes the information of the target satellite and / or the information of the target cell.

[0159] Specifically, in the embodiments of the present application, the network device (e.g., base station) and the terminal are network devices and terminals in the NTN network, and the terminal supports communicating with the network device via satellite.

[0160] Before satellite handover, the network device sends configuration information to the terminal via the source satellite (or source cell, source satellite link), and the configuration information contains information about the target satellite and / or information about the target cell. Among them, the source cell can also be called the source satellite cell, which is the cell served by the source satellite; the target cell can also be called the target satellite cell, which is the cell served by the target satellite. Satellite handover refers to the service satellite of the terminal switching (or changing) from the source satellite to the target satellite.

[0161] In some embodiments, the information about the target satellite includes one or more of the following:

[0162] (1) Satellite identifier of the target satellite.

[0163] (2) Epoch time information of the target satellite.

[0164] The epoch time is in the Universal Time Coordinated (UTC) time format and is jointly defined by utcSecond (UTC second) and utcMicrosecond (UTC microsecond).

[0165] In some embodiments, the epoch time information includes the starting epoch adopted by the target satellite. For example, the starting epoch of the satellite Internet time system is 00:00:00 on January 1, 2006 UTC, the second length uses the International System of Units (SI) second, and it accumulates continuously with the SI second as the basic unit without leap seconds.

[0166] (3) Ephemeris information of the target satellite. For example, the ephemeris information includes a state vector indicating the satellite position and velocity, or information such as satellite orbit parameters.

[0167] (4) Common Timing Advance (Common TA) information of the target satellite. Common TA is used to supplement the transmission delay from the satellite to the uplink synchronization reference point.

[0168] In some embodiments, the information about the target cell includes one or more of the following:

[0169] (1) Cell Identity of the target cell. The cell identity is used to uniquely identify the target cell. For example, the cell identity is the cell identity of Layer 3 (L3).

[0170] (2) SSB configuration information of the target cell. SSB is a synchronization signal block used for the terminal to perform downlink synchronization with the network.

[0171] In some embodiments, the receiving network device receives configuration information sent by the source satellite, including: the receiving network device receives a broadcast message or a Radio Resource Control (RRC) configuration message sent by the source satellite, and the configuration information is included in the broadcast message or the RRC configuration message.

[0172] For example, to carry configuration information through a broadcast message, relevant protocol modifications need to be made to the existing broadcast message. The example code is as follows (the bold font is the newly added part, such as parameters ):

[0173]

[0174]

[0175] If the cell identifier is broadcast, the example code of the configuration information in the broadcast message is as follows:

[0176]

[0177] If the satellite identifier is broadcast, the example code of the configuration information in the broadcast message is as follows:

[0178]

[0179] Again, for example, the example code of carrying configuration information in the RRC configuration message is as follows (the bold font is the newly added part, such as parameters ):

[0180]

[0181]

[0182]

[0183]

[0184] Step 401: Perform downlink synchronization with the target satellite based on the configuration information, and after completing the downlink synchronization, access the target satellite.

[0185] Specifically, after receiving the configuration information sent by the network device, the terminal can perform downlink synchronization with the target satellite based on the information of the target satellite and / or the information of the target cell included in the configuration information. Since the configuration information contains the information of the target satellite and / or the information of the target cell, the terminal can no longer fail to distinguish the SSB, thereby avoiding the problem that the terminal may synchronize to the source satellite and cause satellite handover failure.

[0186] The satellite handover method provided by the embodiments of the present application sends configuration information from the network side to the terminal, and includes the information of the target satellite and / or the information of the target cell in the configuration information, so that the terminal can accurately synchronize to the target satellite, thereby not only avoiding the problem that the terminal may synchronize to the source satellite and cause satellite handover failure, but also ensuring that the uplink and downlink data services are not interrupted during the satellite handover process.

[0187] In some embodiments, performing downlink synchronization with the target satellite based on the configuration information includes:

[0188] Searching for the SSB of the target satellite based on the configuration information and performing downlink synchronization with the target satellite.

[0189] For example, the terminal can use the SSB configuration information of the target cell in the configuration information to search for the SSB of the target satellite, or determine whether the searched SSB is the SSB of the target satellite through information such as the target cell identifier and the target satellite identifier, so as to accurately synchronize to the target satellite.

[0190] In some embodiments, searching for the SSB of the target satellite based on the configuration information includes:

[0191] Searching for the SSB of the target satellite based on the configuration information at or after the stop service time of the source cell; or,

[0192] Searching for the SSB of the target satellite based on the configuration information at a first time before the stop service time of the source cell.

[0193] Specifically, the terminal can start searching for the SSB of the target satellite at different times according to the stop service time of the source cell (such as t-Service-r17 configured in the broadcast message of the source cell).

[0194] For example, the terminal can determine whether the current time is the stop service time of the source cell or after the stop service time of the source cell before each data transmission. If the current time is the stop service time of the source cell or has exceeded the stop service time of the source cell, it immediately starts searching for the SSB of the target satellite and performs downlink synchronization with the target satellite.

[0195] For another example, the terminal may start searching for the SSB of the target satellite at a first moment before the service stop moment of the source cell. The first moment refers to a certain moment before the service stop moment of the source cell. The first moment or the duration from the first moment to the service stop moment of the source cell may be agreed upon by the protocol, indicated by the network side, or determined by the terminal through other means, which is not limited herein.

[0196] In some embodiments, the method further includes:

[0197] If it is determined that the system information received in the downlink synchronization contains the satellite identifier of the target satellite or the cell identifier of the target cell, the downlink synchronization with the target satellite is completed.

[0198] Specifically, when the terminal performs downlink synchronization, if the cell identifier obtained in the system information received in the downlink synchronization (such as SIB1 or SIB19 in the broadcast message) is the same as the cell identifier of the target cell, or the satellite identifier obtained is the same as the satellite identifier of the target satellite, it indicates that the terminal has been downlink synchronized to the target satellite, and thus the downlink synchronization with the target satellite is completed. Otherwise, if the system information received in the downlink synchronization does not contain the satellite identifier of the target satellite or the cell identifier of the target cell, the terminal continues to search for the SSB of the target satellite until the downlink synchronization with the target satellite is completed.

[0199] If the target cell broadcasts the satellite identifier, the satellite identifier can be added to SIB19. The example code is as follows (where the bold font is the added part, such as the parameter ):

[0200]

[0201]

[0202] In some embodiments, the method further includes:

[0203] After completing the downlink synchronization with the target satellite, send the information of the second moment to the network device;

[0204] At the second moment, stop data transmission between the source satellite and the network device, and start data transmission between the target satellite and the network device.

[0205] Specifically, after the terminal completes downlink synchronization with the target satellite, it can send information about the second moment (such as absolute time or relative offset, etc.) to the network device. This second moment is the moment when both the network side and the terminal side change to the target satellite. Changing to the target satellite means that the terminal conducts uplink and downlink data transmission with the network side through the target satellite, and the network side also conducts uplink and downlink data transmission with the terminal through the target satellite, that is, the serving satellite of the terminal changes to the target satellite. The second moment can be determined by the terminal and then notified to the network side to ensure that both the terminal and the network side change to the target satellite simultaneously and ensure uninterrupted data transmission.

[0206] At this second moment, the terminal stops data transmission with the network device through the source satellite and starts data transmission with the network device through the target satellite. The network device also changes to the target satellite at this second moment, that is, it stops data transmission with the terminal through the source satellite and starts data transmission with the terminal through the target satellite.

[0207] It should be noted that there are various ways to ensure that both the terminal and the network side change to the target satellite simultaneously. For example, in addition to the terminal notifying the network side of the information about the second moment, it can also be the network side notifying the terminal of the information about the second moment, or the protocol stipulating the time offset of the second moment relative to a reference moment (such as t-Service-r17), and so on.

[0208] In some embodiments, when the terminal sends the information about the second moment to the network device, it can be through the target satellite (or target cell, target satellite link) to send the information about the second moment to the network device.

[0209] In some embodiments, when the terminal sends the information about the second moment to the network device, it can be through the source satellite (or source cell, source satellite link) to send the information about the second moment to the network device. In this case, the timing for the terminal to send the information about the second moment is before the stop service moment of the source cell.

[0210] In some embodiments, sending the information about the second moment to the network device includes:

[0211] Sending a Media Access Control-Control Element (MAC-CE) or an RRC message to the network device, where the MAC-CE or the RRC message contains the information about the second moment.

[0212] For example, when the terminal notifies the network side of the time to change the satellite through the MAC CE, it can send the information about the second moment through a newly added MAC CE (the MAC CE for primary satellite change). An example of the format of the newly added MAC CE is Figure 5As shown in the figure, in the figure, SFN represents System Frame Number, and Slot represents time slot. In some embodiments, a certain one (such as LCID37) of the reserved LCIDs 37 - 42 in the Logical Channel Identifier (LCID) can be used for the newly added MAC CE.

[0213] For another example, when the terminal notifies the network side of the time change of the satellite through an RRC message, the information of the second moment can be sent by adding UE Assistance Information. The example code is as follows:

[0214]

[0215]

[0216] In some embodiments, the method further includes:

[0217] Receiving the transmission point information for coordinated transmission with the target cell sent by the source cell or the target cell.

[0218] Specifically, for the case of multi - point cooperative transmission, since the change of the target satellite may cause the change of the cooperative transmission point, the source cell or the target cell can perform the corresponding multi - point cooperative transmission configuration, and the source cell or the target cell notifies the transmission point information for coordinated transmission with the target cell.

[0219] For example, when the target cell changes, the target cell notifies the terminal of other cells or TRPs for coordinated transmission. Or, when the source cell notifies the information of the target cell, it simultaneously notifies the terminal of the available cooperative cells or TRPs.

[0220] Figure 6 This is the second flow diagram of the satellite handover method provided by the embodiments of the present application. This method can be applied to network devices, such as Figure 6 As shown, the method includes the following steps:

[0221] Step 600: Sending configuration information to the terminal through the source satellite, where the configuration information includes the information of the target satellite and / or the information of the target cell.

[0222] Specifically, in the embodiments of the present application, the network device (for example: base station) and the terminal are network devices and terminals in the NTN network, and the terminal supports communicating with the network device through the satellite.

[0223] Before satellite handover, the network device sends configuration information to the terminal via the source satellite (or source cell, source satellite link), and the configuration information contains information about the target satellite and / or information about the target cell. Among them, the source cell can also be referred to as the source satellite cell, which is the cell served by the source satellite; the target cell can also be referred to as the target satellite cell, which is the cell served by the target satellite. Satellite handover refers to the handover (or change) of the serving satellite of the terminal from the source satellite to the target satellite.

[0224] In some embodiments, the information about the target satellite includes one or more of the following:

[0225] (1) The satellite identifier of the target satellite.

[0226] (2) The Epoch time information of the target satellite.

[0227] The Epoch time is in the Universal Time Coordinated (UTC) time format and is jointly defined by utcSecond (UTC seconds) and utcMicrosecond (UTC microseconds).

[0228] In some embodiments, the Epoch time information includes the starting Epoch adopted by the target satellite. For example, the starting Epoch of the satellite Internet time system is 00:00:00 UTC on January 1, 2006, the second length uses the SI second, and continuous accumulation is carried out with the SI second as the basic unit without leap seconds.

[0229] (3) The Ephemeris information of the target satellite. For example, the Ephemeris information includes a state vector indicating the satellite position and speed, or information such as satellite orbit parameters.

[0230] (4) The Common TA information of the target satellite. Common TA is used to supplement the transmission delay from the satellite to the uplink synchronization reference point.

[0231] In some embodiments, the information about the target cell includes one or more of the following:

[0232] (1) The Cell Identity of the target cell. The cell identity is used to uniquely identify the target cell. For example, the cell identity is the cell identity of Layer 3 (L3).

[0233] (2) The SSB configuration information of the target cell. SSB is the synchronization signal block and is used for the terminal to perform downlink synchronization with the network.

[0234] In some embodiments, sending configuration information to the terminal via the source satellite includes:

[0235] The source satellite sends a broadcast message or an RRC configuration message to the terminal, and the configuration information is included in the broadcast message or the RRC configuration message.

[0236] After receiving the configuration information sent by the network device, the terminal can perform downlink synchronization with the target satellite based on the information of the target satellite and / or the information of the target cell included in the configuration information. For example, the terminal searches for the SSB of the target satellite based on the configuration information. Since the configuration information includes the information of the target satellite and / or the information of the target cell, the terminal can no longer fail to distinguish the SSB, thus avoiding the problem that the terminal may synchronize to the source satellite and cause satellite handover failure.

[0237] The satellite handover method provided by the embodiments of the present application sends configuration information from the network side to the terminal, and the information of the target satellite and / or the information of the target cell is included in the configuration information, so that the terminal can accurately synchronize to the target satellite. Thus, not only can the problem that the terminal may synchronize to the source satellite and cause satellite handover failure be avoided, but also the uplink and downlink data services during the satellite handover process can be ensured not to be interrupted.

[0238] In some embodiments, the method further includes:

[0239] The target satellite sends an SSB and broadcasts system information, and the satellite identifier of the target satellite or the cell identifier of the target cell is included in the system information.

[0240] Specifically, the satellite identifier of the target satellite or the cell identifier of the target cell is included in the system information broadcast by the target satellite (or the target cell). When the terminal performs downlink synchronization, it can determine whether it is synchronized to the target satellite according to whether the satellite identifier of the target satellite or the cell identifier of the target cell is included in the system information received during downlink synchronization.

[0241] If the cell identifier obtained by the terminal in the system information received during downlink synchronization is the same as the cell identifier of the target cell, or the satellite identifier obtained is the same as the satellite identifier of the target satellite, it indicates that the terminal has been downlink synchronized to the target satellite, thus completing the downlink synchronization with the target satellite. Otherwise, if the satellite identifier of the target satellite or the cell identifier of the target cell is not included in the system information received during downlink synchronization, the terminal continues to search for the SSB of the target satellite until the downlink synchronization with the target satellite is completed.

[0242] In some embodiments, the method further includes:

[0243] Receiving the information at the second moment sent by the terminal;

[0244] At the second moment, stop data transmission between the source satellite and the terminal, and start data transmission between the target satellite and the terminal.

[0245] Specifically, after the terminal completes downlink synchronization with the target satellite, it can send information about the second moment (such as absolute time or relative offset, etc.) to the network device. The second moment is the moment when both the network side and the terminal side change to the target satellite. Changing to the target satellite means that the terminal performs uplink and downlink data transmission with the network side through the target satellite, and the network side also performs uplink and downlink data transmission with the terminal through the target satellite, that is, the serving satellite of the terminal changes to the target satellite. The second moment can be determined by the terminal and then notified to the network side to ensure that both the terminal and the network side change to the target satellite simultaneously and ensure that data transmission is not interrupted.

[0246] At this second moment, the terminal stops data transmission with the network device through the source satellite and starts data transmission with the network device through the target satellite. The network device also changes to the target satellite at this second moment, that is, it stops data transmission with the terminal through the source satellite and starts data transmission with the terminal through the target satellite.

[0247] In some embodiments, when the terminal sends the information about the second moment to the network device, it can be sent through the target satellite (or target cell, target satellite link) to the network device.

[0248] In some embodiments, when the terminal sends the information about the second moment to the network device, it can be sent through the source satellite (or source cell, source satellite link) to the network device. In this case, the timing of the terminal sending the information about the second moment is before the stop service moment of the source cell.

[0249] In some embodiments, receiving the information about the second moment sent by the terminal includes:

[0250] Receiving the MAC-CE or RRC message sent by the terminal, where the MAC-CE or RRC message contains the information about the second moment.

[0251] In some embodiments, the method further includes:

[0252] Sending the transmission point information for coordinated transmission with the target cell to the terminal through the source cell or the target cell.

[0253] Specifically, for the case of multi-point cooperative transmission, since the change of the target satellite may cause changes in the cooperative transmission points, the source cell or the target cell can perform corresponding multi-point cooperative transmission configuration and notify the transmission point information for coordinated transmission with the target cell.

[0254] For example, when the target cell changes, the target cell notifies other cells or TRPs for coordinated transmission to the terminal. Alternatively, when the source cell notifies the target cell of information, it simultaneously notifies the terminal of available coordinated cells or TRPs.

[0255] The methods provided in the embodiments of the present application are based on the same inventive concept. Therefore, the implementation of each method can be referred to each other, and the repeated parts will not be elaborated.

[0256] The following uses examples of specific application scenarios to illustrate the methods provided in the above-mentioned embodiments of the present application.

[0257] Figure 7 This is an example diagram of a multi-point cooperative multi-connection NTN network scenario provided for the embodiments of the present application. The figure illustrates an uplink joint reception scenario of two low-earth orbit satellites. The primary and secondary satellites are connected to the same base station, and the coverage areas of the primary and secondary satellites overlap. The primary and secondary satellites, as TRPs of different cells, jointly provide services for the terminal. Among them, the base station (or primary cell) adjusts the fast Fourier transform (FFT) window time offset of the secondary cell connected to the secondary satellite based on the latency of the primary satellite link, ensuring the time alignment of the uplink signals received from the primary satellite link (such as the Physical Uplink Shared Channel (PUSCH)) and the uplink signals received from the secondary satellite link, and realizing joint reception.

[0258] Figure 8 This is an example diagram of the satellite change process of a multi-connection NTN network provided for the embodiments of the present application. As Figure 8 shown, it mainly includes the following processes:

[0259] 1. The network side (primary cell / source cell) configures the target cell identifier and auxiliary information related to the target satellite (epoch time, ephemeris, common TA) through a broadcast message or an RRC configuration message via the primary (source) satellite link. The terminal receives the broadcast message or RRC configuration message from the network side (primary cell / source cell) and obtains the cell identifier and related auxiliary information (epoch time, ephemeris, common TA) of the target satellite.

[0260] 2. The network side (secondary cell / target cell) sends SSB information on the secondary (target) satellite link and carries the secondary (target) cell identifier in the broadcast message.

[0261] 3. After receiving the information configured by the network side, the terminal starts a timer according to t-Service-r17 in the broadcast message of the primary cell / source cell. At the first moment before the timer times out, the terminal starts to search for the SSB of the secondary cell or target cell for downlink synchronization.

[0262] 4. If the broadcast message received by the terminal for downlink synchronization contains the target cell identifier, the terminal completes the downlink synchronization with the target satellite link; otherwise, it continues to search for the SSB.

[0263] 5. After the terminal completes synchronization with the target satellite (the terminal is in the dual-connection state of the primary cell and the target cell / secondary cell), the terminal sends a MAC CE or RRC message through the primary (source) satellite link to notify the network side (primary cell) of the time to change the satellite. Optionally, the terminal can also send a MAC CE or RRC message through the secondary (target) satellite link to notify the network side of the time to change the satellite.

[0264] 6. After receiving the message of the time to change the primary satellite from the terminal, at the specified time (the second moment), the network side changes the secondary cell or the target cell to the primary cell, starts to transmit downlink data and receive uplink data on the target satellite link, and stops sending downlink data and receiving uplink data on the source satellite link.

[0265] 7. At the specified time (the second moment), the terminal starts to receive downlink data on the target satellite link according to the downlink synchronization with the target satellite link, calculates the timing advance (TA) based on the auxiliary information of the target satellite to transmit uplink data, and stops receiving downlink data and sending uplink data on the source satellite.

[0266] The methods and apparatuses provided in the embodiments of the present application are based on the same inventive concept. Since the principles of the methods and apparatuses for solving problems are similar, the implementations of the apparatuses and methods can be referred to each other, and the repeated parts will not be described again.

[0267] Figure 9 The following is a schematic structural diagram of the terminal provided in the embodiments of the present application. As Figure 9 shown, the terminal includes a memory 920, a transceiver 910, and a processor 900; among them, the processor 900 and the memory 920 can also be physically separated.

[0268] The memory 920 is used to store computer programs; the transceiver 910 is used to transmit and receive data under the control of the processor 900.

[0269] Specifically, the transceiver 910 is used to receive and send data under the control of the processor 900.

[0270] Among them, in Figure 9Among them, the bus architecture may include any number of interconnected buses and bridges, and various circuits represented by one or more processors represented by processor 900 and memory 920 are specifically linked together. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art, and thus will not be further described in this application. The bus interface provides an interface. The transceiver 910 may be multiple components, that is, including a transmitter and a receiver, and provides a unit for communicating with various other devices on a transmission medium, and these transmission media include transmission media such as wireless channels, wired channels, and optical cables. For different user devices, the user interface 930 may also be an interface capable of externally connecting or internally connecting required devices, and the connected devices include but are not limited to a keypad, a display, a speaker, a microphone, a joystick, etc.

[0271] The processor 900 is responsible for managing the bus architecture and general processing, and the memory 920 may store data used by the processor 900 when executing operations.

[0272] The processor 900 may be a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or a Complex Programmable Logic Device (CPLD), and the processor may also adopt a multi-core architecture.

[0273] The processor 900 is used to execute any of the methods provided in the embodiments of the present application by calling a computer program stored in the memory 920 according to the obtained executable instructions. For example: receiving configuration information sent by a network device through a source satellite, where the configuration information includes information about a target satellite and / or information about a target cell; performing downlink synchronization with the target satellite based on the configuration information, and accessing the target satellite after completing the downlink synchronization.

[0274] In some embodiments, the information about the target satellite includes one or more of the following:

[0275] The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, the common timing advance information of the target satellite.

[0276] In some embodiments, the information about the target cell includes one or more of the following:

[0277] The cell identifier of the target cell, the Synchronization Signal Block (SSB) configuration information of the target cell.

[0278] In some embodiments, performing downlink synchronization with a target satellite based on configuration information includes:

[0279] Searching for the SSB of the target satellite based on the configuration information to perform downlink synchronization with the target satellite.

[0280] In some embodiments, searching for the SSB of the target satellite based on the configuration information includes:

[0281] Searching for the SSB of the target satellite based on the configuration information at or after the stop service moment of the source cell; or,

[0282] Searching for the SSB of the target satellite based on the configuration information at a first moment before the stop service moment of the source cell.

[0283] In some embodiments, the method further includes:

[0284] If it is determined that the system information received in downlink synchronization includes the satellite identifier of the target satellite or the cell identifier of the target cell, then complete downlink synchronization with the target satellite.

[0285] In some embodiments, the method further includes:

[0286] After completing downlink synchronization with the target satellite, send information about the second moment to the network device;

[0287] At the second moment, stop data transmission between the source satellite and the network device, and start data transmission between the target satellite and the network device.

[0288] In some embodiments, the method further includes:

[0289] Receive transmission point information for cooperative transmission with the target cell sent by the source cell or the target cell.

[0290] In some embodiments, receiving configuration information sent by the network device via the source satellite includes:

[0291] Receive a broadcast message or a Radio Resource Control (RRC) configuration message sent by the network device via the source satellite, where the broadcast message or the RRC configuration message contains the configuration information.

[0292] In some embodiments, sending information about the second moment to the network device includes:

[0293] Send a Medium Access Control layer Control Element (MAC-CE) or an RRC message to the network device, where the MAC-CE or the RRC message contains the information about the second moment.

[0294] Figure 10The structural schematic diagram of the network device provided by the embodiment of the present application is as follows: Figure 10 As shown in the figure, the network device includes a memory 1020, a transceiver 1010, and a processor 1000; among them, the processor 1000 and the memory 1020 may also be physically separated.

[0295] The memory 1020 is used to store computer programs; the transceiver 1010 is used to receive and transmit data under the control of the processor 1000.

[0296] Specifically, the transceiver 1010 is used to receive and transmit data under the control of the processor 1000.

[0297] Among them, in Figure 10 the bus architecture may include any number of interconnected buses and bridges, specifically various circuits represented by one or more processors represented by the processor 1000 and the memory represented by the memory 1020 are linked together. The bus architecture can also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art, so the present application will not further describe them. The bus interface provides an interface. The transceiver 1010 may be multiple elements, that is, including a transmitter and a receiver, and provides a unit for communicating with various other devices on the transmission medium, and these transmission mediums include wireless channels, wired channels, optical fiber cables, and other transmission mediums.

[0298] The processor 1000 is responsible for managing the bus architecture and general processing, and the memory 1020 can store the data used by the processor 1000 when performing operations.

[0299] The processor 1000 may be a CPU, ASIC, FPGA, or CPLD, and the processor may also adopt a multi-core architecture.

[0300] The processor 1000 is used to execute any of the methods provided by the embodiment of the present application by calling the computer program stored in the memory 1020, for example: sending configuration information to the terminal through the source satellite, and the configuration information includes information of the target satellite and / or information of the target cell.

[0301] In some embodiments, the information of the target satellite includes one or more of the following:

[0302] The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, the common timing advance information of the target satellite.

[0303] In some embodiments, the information of the target cell includes one or more of the following:

[0304] The cell identifier of the target cell, the synchronization signal block (SSB) configuration information of the target cell.

[0305] In some embodiments, the method further includes:

[0306] Sending an SSB through a target satellite and broadcasting system information, where the system information includes a satellite identifier of the target satellite or a cell identifier of the target cell.

[0307] In some embodiments, the method further includes:

[0308] Receiving information at a second moment sent by a terminal;

[0309] At the second moment, stopping data transmission between the source satellite and the terminal and starting data transmission between the target satellite and the terminal.

[0310] In some embodiments, the method further includes:

[0311] Sending transmission point information for cooperative transmission with the target cell to the terminal through the source cell or the target cell.

[0312] In some embodiments, sending configuration information to the terminal through the source satellite, including:

[0313] Sending a broadcast message or a radio resource control (RRC) configuration message to the terminal through the source satellite, where the broadcast message or the RRC configuration message includes the configuration information.

[0314] In some embodiments, receiving information at a second moment sent by a terminal, including:

[0315] Receiving a media access control layer control element (MAC-CE) or an RRC message sent by the terminal, where the MAC-CE or the RRC message includes the information at the second moment.

[0316] It should be noted here that the above terminal and network device provided in the embodiments of the present application can implement all the method steps implemented in the above method embodiments and can achieve the same technical effects. The same parts and beneficial effects as those in the method embodiments will not be specifically described in this embodiment again.

[0317] Figure 11 One of the structural schematic diagrams of the satellite handover device provided in the embodiments of the present application, as Figure 11 shown, the device includes:

[0318] A first receiving unit 1100, configured to receive configuration information sent by a network device through a source satellite, where the configuration information includes information of a target satellite and / or information of a target cell;

[0319] A handover unit 1110, configured to perform downlink synchronization with the target satellite based on the configuration information and access the target satellite after completing the downlink synchronization.

[0320] In some embodiments, the information of the target satellite includes one or more of the following:

[0321] The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, and the common timing advance information of the target satellite.

[0322] In some embodiments, the information of the target cell includes one or more of the following:

[0323] The cell identifier of the target cell and the synchronization signal block (SSB) configuration information of the target cell.

[0324] In some embodiments, performing downlink synchronization with the target satellite based on the configuration information includes:

[0325] Searching for the SSB of the target satellite based on the configuration information to perform downlink synchronization with the target satellite.

[0326] In some embodiments, searching for the SSB of the target satellite based on the configuration information includes:

[0327] Searching for the SSB of the target satellite based on the configuration information at or after the stop service moment of the source cell; or,

[0328] Searching for the SSB of the target satellite based on the configuration information at a first moment before the stop service moment of the source cell.

[0329] In some embodiments, the switching unit 1110 is further configured to:

[0330] If it is determined that the system information received in the downlink synchronization includes the satellite identifier of the target satellite or the cell identifier of the target cell, then complete the downlink synchronization with the target satellite.

[0331] In some embodiments, the apparatus further includes:

[0332] A first sending unit, configured to send the information of the second moment to the network device after completing the downlink synchronization with the target satellite;

[0333] A first transmission control unit, configured to stop data transmission between the source satellite and the network device at the second moment and start data transmission between the target satellite and the network device.

[0334] In some embodiments, the apparatus further includes:

[0335] A second receiving unit, configured to receive the transmission point information for collaborative transmission with the target cell sent by the source cell or the target cell.

[0336] In some embodiments, the receiving network device receives configuration information sent by the source satellite, including:

[0337] The receiving network device receives a broadcast message or a Radio Resource Control (RRC) configuration message sent by the source satellite, and the configuration information is included in the broadcast message or the RRC configuration message.

[0338] In some embodiments, sending information about the second moment to the network device includes:

[0339] Sending a Medium Access Control layer Control Element (MAC-CE) or an RRC message to the network device, and the information about the second moment is included in the MAC-CE or the RRC message.

[0340] Figure 12 This is the second structural schematic diagram of the satellite handover device provided by the embodiments of the present application. As Figure 12 shown, the device includes:

[0341] A second sending unit 1200, configured to send configuration information to the terminal through the source satellite, where the configuration information includes information about the target satellite and / or information about the target cell.

[0342] In some embodiments, the information about the target satellite includes one or more of the following:

[0343] The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, the common timing advance information of the target satellite.

[0344] In some embodiments, the information about the target cell includes one or more of the following:

[0345] The cell identifier of the target cell, the Synchronization Signal Block (SSB) configuration information of the target cell.

[0346] In some embodiments, the device further includes:

[0347] A third sending unit, configured to send an SSB through the target satellite and broadcast system information, where the system information includes the satellite identifier of the target satellite or the cell identifier of the target cell.

[0348] In some embodiments, the device further includes:

[0349] A third receiving unit, configured to receive the information about the second moment sent by the terminal;

[0350] A second transmission control unit, configured to stop data transmission between the source satellite and the terminal at the second moment, and start data transmission between the target satellite and the terminal.

[0351] In some embodiments, the device further includes:

[0352] A fourth sending unit, configured to send, to a terminal via a source cell or a target cell, transmission point information for performing coordinated transmission with the target cell.

[0353] In some embodiments, configuration information is sent to a terminal via a source satellite, including:

[0354] A broadcast message or a Radio Resource Control (RRC) configuration message is sent to the terminal via the source satellite, and the configuration information is included in the broadcast message or the RRC configuration message.

[0355] In some embodiments, information at a second moment sent by a terminal is received, including:

[0356] A Media Access Control layer control element (MAC-CE) or an RRC message sent by the terminal is received, and the information at the second moment is included in the MAC-CE or the RRC message.

[0357] It should be noted that the division of units in the embodiments of the present application is illustrative. It is only a logical function division, and there may be other division methods in actual implementation. In addition, in each embodiment of the present application, the functional units may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above integrated units may be implemented in the form of hardware or in the form of software functional units.

[0358] If the above integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a processor-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, may be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the methods described in the embodiments of the present application. The foregoing storage medium includes: various media such as a USB flash drive, a mobile hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disc that can store program codes.

[0359] It should be noted here that the above device provided in the embodiments of the present application can implement all the method steps implemented in the above method embodiments and can achieve the same technical effects. The same parts and beneficial effects as those in the method embodiments will not be specifically described in this embodiment.

[0360] On the other hand, an embodiment of the present application further provides a non-transitory readable storage medium storing a computer program for causing a processor to execute the satellite switching method provided in each of the above embodiments.

[0361] It should be noted here that the non-transitory readable storage medium provided in the embodiment of the present application can implement all the method steps implemented in the above method embodiment and can achieve the same technical effect. The same parts and beneficial effects as those in the method embodiment will not be specifically described herein.

[0362] The non-transitory readable storage medium may be any available medium or data storage device accessible by a computer, including but not limited to magnetic memories (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc.), optical memories (such as CDs, DVDs, BDs, HVDs, etc.), and semiconductor memories (such as ROMs, EPROMs, EEPROMs, non-volatile memories (NANDFLASH), solid state drives (SSD)).

[0363] The technical solutions provided by the embodiments of the present application can be applied to a variety of systems, especially 5G systems. For example, the applicable systems can be the global system of mobile communication (GSM) system, code division multiple access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) general packet radio service (GPRS) system, long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, long term evolution advanced (LTE-A) system, universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) system, 5G New Radio (NR) system, etc. Both terminal devices and network devices are included in these various systems. The system may also include a core network part, such as the Evolved Packet System (EPS), 5G System (5GS), etc.

[0364] The terminal involved in the embodiments of the present application can be a device that provides voice and / or data connectivity to users, such as a handheld device with wireless connection capabilities, or other processing devices connected to a wireless modem, etc. In different systems, the name of the terminal may also be different. For example, in a 5G system, the terminal can be called a User Equipment (UE). The wireless terminal device can communicate with one or more core networks (CN) via a radio access network (RAN). The wireless terminal device can be a mobile terminal device, such as a mobile phone (or a "cellular" phone) and a computer with a mobile terminal device. For example, it can be a portable, pocket-sized, handheld, computer-integrated, or vehicle-mounted mobile device that exchanges language and / or data with the radio access network. For example, devices such as Personal Communication Service (PCS) phones, cordless phones, Session Initiated Protocol (SIP) phones, Wireless Local Loop (WLL) stations, and Personal Digital Assistants (PDAs). The wireless terminal device can also be referred to as a system, a subscriber unit, a subscriber station, a mobile station, a mobile, a remote station, an access point, a remote terminal, an access terminal, a user terminal, a user agent, a user device, which is not limited in the embodiments of the present application.

[0365] The network device involved in the embodiments of the present application may be a base station, which may include multiple cells that provide services to terminals. Depending on the specific application scenarios, the base station may also be referred to as an access point, or may be a device in the access network that communicates with wireless terminal devices through one or more sectors over the air interface, or other names. The network device can be used to mutually replace the received air frames and Internet Protocol (IP) packets, and act as a router between the wireless terminal device and the rest of the access network, where the rest of the access network may include an Internet Protocol (IP) communication network. The network device can also coordinate the attribute management of the air interface. For example, the network device involved in the embodiments of the present application may be a network device (Base Transceiver Station, BTS) in the Global System for Mobile communications (GSM) or Code Division Multiple Access (CDMA), or may be a network device (NodeB) in Wide-band Code Division Multiple Access (WCDMA), or may also be an evolved network device (evolutional Node B, eNB or e-NodeB) in the Long Term Evolution (LTE) system, a 5G base station (gNB) in the 5G network architecture (next generation system), or may be a Home evolved Node B (HeNB), a relay node, a femto, a pico, etc. The embodiments of the present application do not limit this. In some network architectures, the network device may include a centralized unit (CU) node and a distributed unit (DU) node, and the centralized unit and the distributed unit may also be arranged separately geographically.

[0366] The network device and the terminal may each use one or more antennas for Multi-Input Multi-Output (MIMO) transmission, and the MIMO transmission may be Single User MIMO (SU-MIMO) or Multiple User MIMO (MU-MIMO). Depending on the form and quantity of the combined antennas, the MIMO transmission may be 2D-MIMO, 3D-MIMO, FD-MIMO or massive-MIMO, or may also be diversity transmission, precoding transmission, beamforming transmission, etc.

[0367] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories and optical memories, etc.) that contain computer-usable program code.

[0368] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer-executable instructions. These computer-executable instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0369] These processor-executable instructions can also be stored in a processor-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the processor-readable memory generate a manufactured article including instruction means that implement the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0370] These processor-executable instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0371] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A satellite switching method, It is characterized in that Applied to terminals, including: Receiving configuration information sent by a network device via a source satellite, wherein the configuration information includes information of a target satellite and / or information of a target cell; Perform downlink synchronization with the target satellite based on the configuration information, and access the target satellite after completing the downlink synchronization.

2. The satellite switching method according to claim 1, It is characterized in that The target satellite information includes one or more of the following: The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, and the public timing advance information of the target satellite.

3. The satellite switching method according to claim 1, It is characterized in that The target cell information includes one or more of the following: The cell identifier of the target cell and the synchronization signal block (SSB) configuration information of the target cell.

4. The satellite switching method according to any one of claims 1 to 3, It is characterized in that The performing downlink synchronization with the target satellite based on the configuration information includes: The SSB of the target satellite is searched based on the configuration information, and downlink synchronization with the target satellite is performed.

5. The satellite switching method according to claim 4, It is characterized in that The searching for the SSB of the target satellite based on the configuration information comprises: At or after the out-of-service time of the source cell, searching for the SSB of the target satellite based on the configuration information; or, At a first moment before the time when the source cell stops serving, the SSB of the target satellite is searched based on the configuration information.

6. The satellite switching method according to any one of claims 1 to 3, It is characterized in that The method further comprises: If it is determined that the system information for downlink synchronous reception includes the satellite identifier of the target satellite or the cell identifier of the target cell, downlink synchronization with the target satellite is completed.

7. The satellite switching method according to claim 1, It is characterized in that The method further comprises: After completing downlink synchronization with the target satellite, sending information at the second moment to the network device; At the second moment, data transmission between the source satellite and the network device is stopped, and data transmission between the target satellite and the network device is started.

8. The satellite switching method according to claim 1, It is characterized in that The method further comprises: receiving transmission point information for coordinated transmission with the target cell sent by a source cell or the target cell.

9. The satellite switching method according to claim 1, It is characterized in that The receiving network device sends configuration information via the source satellite, including: A broadcast message or a radio resource control (RRC) configuration message is received from a network device via a source satellite, wherein the broadcast message or the RRC configuration message includes the configuration information.

10. The satellite switching method according to claim 7, It is characterized in that The sending the information at the second moment to the network device includes: A media access control layer control element MAC-CE or RRC message is sent to the network device, where the MAC-CE or RRC message includes information about the second moment.

11. A satellite switching method, It is characterized in that Applied to network equipment, including: Configuration information is sent to the terminal via the source satellite, where the configuration information includes information of the target satellite and / or information of the target cell.

12. The satellite switching method according to claim 11, It is characterized in that The target satellite information includes one or more of the following: The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, and the public timing advance information of the target satellite.

13. The satellite switching method according to claim 11, It is characterized in that The target cell information includes one or more of the following: The cell identifier of the target cell and the synchronization signal block (SSB) configuration information of the target cell.

14. The satellite switching method according to any one of claims 11 to 13, It is characterized in that The method further comprises: The SSB is sent through the target satellite and system information is broadcast, where the system information includes the satellite identifier of the target satellite or the cell identifier of the target cell.

15. The satellite switching method according to claim 11, It is characterized in that The method further comprises: Receiving information at a second moment sent by the terminal; At the second moment, data transmission between the source satellite and the terminal is stopped, and data transmission between the target satellite and the terminal is started.

16. The satellite switching method according to claim 11, It is characterized in that The method further comprises: The transmission point information for coordinated transmission with the target cell is sent to the terminal through the source cell or the target cell.

17. The satellite switching method according to claim 11, It is characterized in that The sending of configuration information to the terminal through the source satellite includes: A broadcast message or a radio resource control (RRC) configuration message is sent to the terminal via a source satellite, wherein the broadcast message or the RRC configuration message includes the configuration information.

18. The satellite switching method according to claim 15, It is characterized in that The receiving the information of the second moment sent by the terminal includes: A media access control layer control element MAC-CE or RRC message sent by the terminal is received, where the MAC-CE or RRC message includes information about the second moment.

19. A terminal, It is characterized in that Including memory, transceiver, processor; A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations: Receiving configuration information sent by a network device via a source satellite, wherein the configuration information includes information of a target satellite and / or information of a target cell; Perform downlink synchronization with the target satellite based on the configuration information, and access the target satellite after completing the downlink synchronization.

20. The terminal according to claim 19, It is characterized in that The target satellite information includes one or more of the following: The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, and the public timing advance information of the target satellite.

21. The terminal according to claim 19, It is characterized in that The target cell information includes one or more of the following: The cell identifier of the target cell and the synchronization signal block (SSB) configuration information of the target cell.

22. The terminal according to any one of claims 19 to 21, It is characterized in that The performing downlink synchronization with the target satellite based on the configuration information includes: The SSB of the target satellite is searched based on the configuration information, and downlink synchronization with the target satellite is performed.

23. The terminal according to claim 22, It is characterized in that The searching for the SSB of the target satellite based on the configuration information comprises: At or after the out-of-service time of the source cell, searching for the SSB of the target satellite based on the configuration information; or, At a first moment before the time when the source cell stops serving, the SSB of the target satellite is searched based on the configuration information.

24. The terminal according to any one of claims 19 to 21, It is characterized in that The operations also include: If it is determined that the system information for downlink synchronous reception includes the satellite identifier of the target satellite or the cell identifier of the target cell, downlink synchronization with the target satellite is completed.

25. The terminal according to claim 19, It is characterized in that The operations also include: After completing downlink synchronization with the target satellite, sending information at the second moment to the network device; At the second moment, data transmission between the source satellite and the network device is stopped, and data transmission between the target satellite and the network device is started.

26. The terminal according to claim 19, It is characterized in that The operations also include: receiving transmission point information for coordinated transmission with the target cell sent by a source cell or the target cell.

27. The terminal according to claim 19, It is characterized in that The receiving network device sends configuration information via the source satellite, including: A broadcast message or a radio resource control (RRC) configuration message is received from a network device via a source satellite, wherein the broadcast message or the RRC configuration message includes the configuration information.

28. The terminal according to claim 25, It is characterized in that The sending the information at the second moment to the network device includes: A media access control layer control element MAC-CE or RRC message is sent to the network device, where the MAC-CE or RRC message includes information about the second moment.

29. A network device, It is characterized in that Including memory, transceiver, processor; A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations: Configuration information is sent to the terminal via the source satellite, where the configuration information includes information of the target satellite and / or information of the target cell.

30. The network device according to claim 29, It is characterized in that The target satellite information includes one or more of the following: The satellite identifier of the target satellite, the epoch time information of the target satellite, the ephemeris information of the target satellite, and the public timing advance information of the target satellite.

31. The network device according to claim 29, It is characterized in that The target cell information includes one or more of the following: The cell identifier of the target cell and the synchronization signal block (SSB) configuration information of the target cell.

32. The network device according to any one of claims 29 to 31, It is characterized in that The operations also include: The SSB is sent through the target satellite and system information is broadcast, where the system information includes the satellite identifier of the target satellite or the cell identifier of the target cell.

33. The network device according to claim 29, It is characterized in that The operations also include: Receiving information at a second moment sent by the terminal; At the second moment, data transmission between the source satellite and the terminal is stopped, and data transmission between the target satellite and the terminal is started.

34. The network device according to claim 29, It is characterized in that The operations also include: The transmission point information for coordinated transmission with the target cell is sent to the terminal through the source cell or the target cell.

35. The network device according to claim 29, It is characterized in that The sending of configuration information to the terminal through the source satellite includes: A broadcast message or a radio resource control (RRC) configuration message is sent to the terminal via a source satellite, wherein the broadcast message or the RRC configuration message includes the configuration information.

36. The network device according to claim 33, It is characterized in that The receiving the information of the second moment sent by the terminal includes: A media access control layer control element MAC-CE or RRC message sent by the terminal is received, where the MAC-CE or RRC message includes information about the second moment.

37. A satellite switching device, It is characterized in that include: A first receiving unit, configured to receive configuration information sent by a network device via a source satellite, wherein the configuration information includes information of a target satellite and / or information of a target cell; A switching unit is used to perform downlink synchronization with the target satellite based on the configuration information, and access the target satellite after completing the downlink synchronization.

38. A satellite switching device, It is characterized in that include: The second sending unit is used to send configuration information to the terminal via the source satellite, where the configuration information includes information of the target satellite and / or information of the target cell.

39. A non-transitory readable storage medium, It is characterized in that The non-transitory readable storage medium stores a computer program, and the computer program is used to enable a processor to execute the method according to any one of claims 1 to 10.

40. A non-transitory readable storage medium, It is characterized in that The non-transitory readable storage medium stores a computer program, and the computer program is used to enable a processor to execute the method according to any one of claims 11 to 18.

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