Handover method, apparatus, terminal, source network device, and target network device

Abstract

The present disclosure relates to a handover method, an apparatus, a terminal, a source network device, and a target network device. In at least one embodiment of the present disclosure, a terminal receives a cell radio network temporary identifier allocated by a target network device to the terminal, and uses the cell radio network temporary identifier to monitor a control channel sent by the target network device, the control channel being a control channel scrambled by using the cell radio network temporary identifier. Thus, the terminal can obtain, by means of the control channel, information such as a random access resource configured for the terminal by the target network device, so as to complete a random access process to the target network on the basis of the random access resource; and a terminal-specific configuration of the terminal in the target network can be sent to the terminal by the target network device after the random access process has been completed, such that in the handover process, the terminal-specific configuration of the terminal in the target network does not need to be sent from the target network device to a source network device, thereby reducing inter-satellite interaction, reducing system overheads and reducing resource waste and signaling storms.

Description

Handover method, device, terminal, source network device and target network device

[0001] Cross-reference to Related Applications

[0002] The present disclosure claims priority to the Chinese patent application No. 202411229577.X, filed on September 3, 2024, entitled "Handover method, device, terminal, source network device and target network device", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] Embodiments of the present disclosure relate to the field of communication technology, in particular to a handover method, device, terminal, source network device and target network device. BACKGROUND

[0004] In a non-terrestrial network (NTN), the main reason for handover is the change of the cell caused by satellite movement. Since the current cell will definitely leave, handover will definitely be performed. And the target cell to which the handover is performed can be predicted and determined. This will cause a problem: a large number of terminals (User Equipment, UE) will be handed over from the same NTN cell to the same target cell in a short time. According to the traditional handover mechanism, on the one hand, it will bring a signaling storm, and on the other hand, it will bring a large system overhead. Since the target cell is the same, the configuration information about the target cell is sent to each UE that needs to be handed over through dedicated signaling, causing serious resource waste. SUMMARY

[0005] At least one embodiment of the present disclosure provides a handover method, device, terminal, source network device and target network device, which solves the problems of signaling storm and resource overhead caused by handover in the handover scenario of an NTN network.

[0006] In a first aspect, the embodiments of the present disclosure provide a handover method applied to a terminal, the method comprising:

[0007] receiving a cell radio network temporary identifier sent by a source network device, the cell radio network temporary identifier being an identifier allocated to the terminal by a target network device;

[0008] listening to a control channel sent by the target network device according to the cell radio network temporary identifier, the control channel being a control channel scrambled by the cell radio network temporary identifier;

[0009] obtaining a random access resource through the control channel;

[0010] initiating a random access process to the target network device or the target network based on the random access resource.

[0011] In some embodiments, the control channel sent by the target network device is listened according to a cell radio network temporary identifier.

[0012] The first message is acquired through the control channel; the first message carries the timing advance information;

[0013] And / or, the terminal-specific configuration is acquired through the control channel; the terminal-specific configuration is a configuration allocated by the target network device for the terminal.

[0014] In some embodiments, the method further comprises:

[0015] Receiving at least one of the following information sent by the source network device and / or the target network device:

[0016] Security parameters, public configuration information of the target network, and protocol data unit session-related parameters.

[0017] In a second aspect, the embodiments of the present disclosure further provide a handover method, applied to a source network device, comprising:

[0018] Acquiring a cell radio network temporary identifier of the terminal, the cell radio network temporary identifier being an identifier allocated by the target network device for the terminal;

[0019] Sending the cell radio network temporary identifier to the terminal, the cell radio network temporary identifier being used by the terminal to listen to a control channel sent by the target network device, the control channel being a control channel scrambled by the cell radio network temporary identifier.

[0020] In some embodiments, the method further comprises:

[0021] Sending a handover request to the target network device or the target network;

[0022] Performing signaling interaction related to handover between the target network device; or, performing signaling interaction related to handover between the target network device through a core network device.

[0023] In a third aspect, the embodiments of the present disclosure further provide a handover method, applied to a target network device, comprising:

[0024] Acquiring a cell radio network temporary identifier of the terminal;

[0025] Sending the cell radio network temporary identifier to the source network device;

[0026] Sending a control channel based on the cell radio network temporary identifier.

[0027] In some embodiments, the control channel is sent based on the cell radio network temporary identifier, comprising:

[0028] transmitting the random access resource through the control channel;

[0029] and / or transmitting the first message through the control channel, the first message carrying the timing advance information;

[0030] and / or transmitting the terminal-specific configuration through the control channel, the terminal-specific configuration being a configuration allocated by the target network device for the terminal.

[0031] In some embodiments, the method further includes:

[0032] receiving a handover request transmitted by the source network device;

[0033] and the signaling interaction related to the handover between the source network device; or, the signaling interaction related to the handover between the source network device through the core network device.

[0034] In a fourth aspect, the embodiments of the present disclosure further provide a handover method applied to a terminal, the method including:

[0035] listening to a first control channel based on a handover-specific radio network temporary identifier, the first control channel carrying a first cell radio network temporary identifier, a second cell radio network temporary identifier, and a random access resource; wherein the first cell radio network temporary identifier is an identifier allocated by the source network device for the terminal, and the second cell radio network temporary identifier is an identifier allocated by the target network device for the terminal;

[0036] obtaining the random access resource through the first control channel;

[0037] initiating a random access procedure to the target network device or the target network based on the random access resource.

[0038] In some embodiments, the method further includes:

[0039] listening to a second control channel based on the second cell radio network temporary identifier.

[0040] In some embodiments, listening to the second control channel based on the second cell radio network temporary identifier includes:

[0041] obtaining a first message through the second control channel; the first message carrying timing advance information;

[0042] and / or obtaining a terminal-specific configuration through the second control channel; the terminal-specific configuration being a configuration allocated by the target network device for the terminal.

[0043] In some embodiments, the method further includes:

[0044] receiving at least one of the following information transmitted by the source network device and / or the target network device:

[0045] security parameters, public configuration information of the target network, protocol data unit session related parameters.

[0046] In some embodiments, before listening to the first control channel based on the handover-specific wireless network temporary identifier, the method further comprises: receiving the handover-specific wireless network temporary identifier sent by the source network device.

[0047] In a fifth aspect, the embodiments of the present disclosure further provide a handover method, applied to a source network device, comprising:

[0048] sending, to the target network device, a first cell wireless network temporary identifier, the first cell wireless network temporary identifier being an identifier allocated by the source network device to the terminal.

[0049] In some embodiments, the method further comprises:

[0050] receiving a handover-specific wireless network temporary identifier sent by the target network device;

[0051] sending, to the terminal, the handover-specific wireless network temporary identifier.

[0052] In a sixth aspect, the embodiments of the present disclosure further provide a handover method, applied to a target network device, comprising:

[0053] receiving a first cell wireless network temporary identifier sent by the source network device, the first cell wireless network temporary identifier being an identifier allocated by the source network device to the terminal;

[0054] sending a first control channel based on a handover-specific wireless network temporary identifier, the first control channel carrying the first cell wireless network temporary identifier, a second cell wireless network temporary identifier and random access resources; wherein the second cell wireless network temporary identifier is an identifier allocated by the target network device to the terminal.

[0055] In some embodiments, the method further comprises:

[0056] sending, to the source network device, the handover-specific wireless network temporary identifier.

[0057] In some embodiments, the method further comprises:

[0058] sending a second control channel based on the second cell wireless network temporary identifier.

[0059] In some embodiments, sending the second control channel based on the second cell wireless network temporary identifier comprises:

[0060] sending a first message through the second control channel; the first message carrying timing advance information;

[0061] And / or, the terminal-specific configuration is sent through the second control channel, and the terminal-specific configuration is a configuration used by the terminal and allocated to the terminal by the target network device.

[0062] In a seventh aspect, the embodiments of the present disclosure further provide a switching device applied to a terminal, the device comprising:

[0063] a receiving unit configured to receive a cell radio network temporary identifier sent by a source network device, the cell radio network temporary identifier being an identifier allocated to the terminal by a target network device;

[0064] a monitoring unit configured to monitor a control channel sent by the target network device according to the cell radio network temporary identifier, the control channel being a control channel scrambled by the cell radio network temporary identifier;

[0065] an obtaining unit configured to obtain a random access resource through the control channel;

[0066] an accessing unit configured to initiate a random access procedure to the target network device or the target network based on the random access resource.

[0067] In an eighth aspect, the embodiments of the present disclosure further provide a switching device applied to a source network device, the device comprising:

[0068] an obtaining unit configured to obtain a cell radio network temporary identifier of a terminal, the cell radio network temporary identifier being an identifier allocated to the terminal by a target network device;

[0069] a sending unit configured to send the cell radio network temporary identifier to the terminal, the cell radio network temporary identifier being used by the terminal to monitor a control channel sent by the target network device, the control channel being a control channel scrambled by the cell radio network temporary identifier.

[0070] In a ninth aspect, the embodiments of the present disclosure further provide a switching device applied to a target network device, the device comprising:

[0071] an obtaining unit configured to obtain a cell radio network temporary identifier of a terminal;

[0072] a sending unit configured to send the cell radio network temporary identifier to a source network device, and send a control channel based on the cell radio network temporary identifier.

[0073] In a tenth aspect, the embodiments of the present disclosure further provide a switching device applied to a terminal, the device comprising:

[0074] The listening unit is configured to listen to a first control channel based on the switching-specific radio network temporary identifier, and the first control channel carries a first cell radio network temporary identifier, a second cell radio network temporary identifier, and random access resources, wherein the first cell radio network temporary identifier is an identifier allocated to the terminal by the source network device, and the second cell radio network temporary identifier is an identifier allocated to the terminal by the target network device.

[0075] The obtaining unit is configured to obtain the random access resources through the first control channel.

[0076] The access unit is configured to initiate a random access procedure to the target network device or the target network based on the random access resources.

[0077] In an eleventh aspect, the embodiments of the present disclosure further provide a switching device applied to a source network device, comprising:

[0078] The sending unit is configured to send the first cell radio network temporary identifier to the target network device, and the first cell radio network temporary identifier is an identifier allocated to the terminal by the source network device.

[0079] In a twelfth aspect, the embodiments of the present disclosure provide a switching device applied to a target network device, comprising:

[0080] The receiving unit is configured to receive the first cell radio network temporary identifier sent by the source network device, and the first cell radio network temporary identifier is an identifier allocated to the terminal by the source network device.

[0081] The sending unit is configured to send the first control channel based on the switching-specific radio network temporary identifier, and the first control channel carries the first cell radio network temporary identifier, the second cell radio network temporary identifier, and the random access resources, wherein the second cell radio network temporary identifier is an identifier allocated to the terminal by the target network device.

[0082] In a thirteenth aspect, the embodiments of the present disclosure further provide a terminal, wherein the terminal comprises a memory, a transceiver, and a processor.

[0083] The memory is configured to store a computer program, the transceiver is configured to transceive data under the control of the processor, and the processor is configured to read the computer program in the memory and perform:

[0084] Receive the cell radio network temporary identifier sent by the source network device, and the cell radio network temporary identifier is an identifier allocated to the terminal by the target network device.

[0085] Listen to a control channel sent by the target network device according to the cell radio network temporary identifier, and the control channel is a control channel scrambled by the cell radio network temporary identifier.

[0086] Obtain random access resources through the control channel.

[0087] initiate a random access procedure to the target network device or the target network based on the random access resource.

[0088] In some embodiments, the control channel transmitted by the target network device is listened to according to a cell radio network temporary identifier.

[0089] obtaining the first message through the control channel, wherein the first message carries timing advance information;

[0090] And / or, obtaining terminal-specific configuration through the control channel, wherein the terminal-specific configuration is configuration allocated by the target network device for the terminal.

[0091] In some embodiments, the processor is further configured to:

[0092] receiving at least one of the following information transmitted by the source network device and / or the target network device:

[0093] security parameters, public configuration information of the target network, and protocol data unit session related parameters.

[0094] In a fourteenth aspect, the embodiments of the present disclosure further provide a source network device, wherein the source network device comprises a memory, a transceiver, and a processor.

[0095] The memory is configured to store a computer program; the transceiver is configured to transceive data under the control of the processor; and the processor is configured to read the computer program in the memory and perform:

[0096] obtaining a cell radio network temporary identifier of the terminal, wherein the cell radio network temporary identifier is an identifier allocated by the target network device for the terminal;

[0097] transmitting the cell radio network temporary identifier to the terminal, wherein the cell radio network temporary identifier is used by the terminal to listen to a control channel transmitted by the target network device, and the control channel is a control channel scrambled by the cell radio network temporary identifier.

[0098] In some embodiments, the processor is further configured to:

[0099] transmitting a handover request to the target network device or the target network;

[0100] performing signaling interaction related to handover between the target network device; or performing signaling interaction related to handover between the target network device through a core network device.

[0101] In a fifteenth aspect, the embodiments of the present disclosure further provide a target network device, wherein the target network device comprises a memory, a transceiver, and a processor.

[0102] The memory is configured to store a computer program; the transceiver is configured to transceive data under control of the processor; the processor is configured to read the computer program in the memory and perform:

[0103] Obtaining a cell radio network temporary identifier of the terminal;

[0104] Sending the cell radio network temporary identifier to the source network device;

[0105] Sending a control channel based on the cell radio network temporary identifier.

[0106] In some embodiments, the control channel is sent based on the cell radio network temporary identifier, comprising:

[0107] Sending a random access resource through the control channel;

[0108] And / or, sending a first message through the control channel, the first message carrying timing advance information;

[0109] And / or, sending a terminal-specific configuration through the control channel, the terminal-specific configuration being a configuration allocated by the target network device for the terminal.

[0110] In some embodiments, the processor is further configured to:

[0111] Receiving a handover request sent by the source network device;

[0112] And performing signaling interaction related to handover between the source network device; or, performing signaling interaction related to handover between the source network device through the core network device.

[0113] In a sixteenth aspect, the embodiments of the present disclosure further provide a terminal, wherein the terminal comprises a memory, a transceiver, and a processor;

[0114] The memory is configured to store a computer program; the transceiver is configured to transceive data under control of the processor; the processor is configured to read the computer program in the memory and perform:

[0115] Listening to a first control channel based on a handover-specific radio network temporary identifier, the first control channel carrying a first cell radio network temporary identifier, a second cell radio network temporary identifier, and a random access resource; wherein the first cell radio network temporary identifier is an identifier allocated by the source network device for the terminal, and the second cell radio network temporary identifier is an identifier allocated by the target network device for the terminal;

[0116] Obtaining the random access resource through the first control channel;

[0117] Initiating a random access procedure to the target network device or the target network based on the random access resource.

[0118] In some embodiments, the processor is further configured to:

[0119] monitor the second control channel based on the second cell radio network temporary identifier.

[0120] In some embodiments, the monitoring the second control channel based on the second cell radio network temporary identifier comprises:

[0121] obtaining the first message through the second control channel; the first message carrying the timing advance information;

[0122] and / or obtaining the terminal-specific configuration through the second control channel; the terminal-specific configuration being a configuration allocated by the target network device for the terminal.

[0123] In some embodiments, the processor is further configured to:

[0124] receive at least one of the following information sent by the source network device and / or the target network device:

[0125] the security parameter, the public configuration information of the target network, and the protocol data unit session-related parameter.

[0126] In some embodiments, before the monitoring the first control channel based on the handover-specific radio network temporary identifier, the processor is further configured to: receive the handover-specific radio network temporary identifier sent by the source network device.

[0127] In a seventeenth aspect, the embodiments of the present disclosure further provide a source network device, wherein the source network device comprises a memory, a transceiver, and a processor.

[0128] The memory is configured to store a computer program; the transceiver is configured to transceive data under the control of the processor; and the processor is configured to read the computer program in the memory and perform:

[0129] sending the first cell radio network temporary identifier to the target network device, the first cell radio network temporary identifier being an identifier allocated by the source network device for the terminal.

[0130] In some embodiments, the processor is further configured to:

[0131] receive the handover-specific radio network temporary identifier sent by the target network device;

[0132] send the handover-specific radio network temporary identifier to the terminal.

[0133] In an eighteenth aspect, the embodiments of the present disclosure further provide a target network device, wherein the target network device comprises a memory, a transceiver, and a processor.

[0134] a memory for storing a computer program; a transceiver for transceiving data under control of the processor; the processor for reading the computer program in the memory and performing:

[0135] receiving the first cell radio network temporary identifier sent by the source network device, the first cell radio network temporary identifier being an identifier allocated to the terminal by the source network device;

[0136] sending the first control channel based on the handover-specific radio network temporary identifier, the first control channel carrying the first cell radio network temporary identifier, the second cell radio network temporary identifier and the random access resource; wherein the second cell radio network temporary identifier is an identifier allocated to the terminal by the target network device.

[0137] In some embodiments, the processor is further configured to:

[0138] sending the handover-specific radio network temporary identifier to the source network device.

[0139] In some embodiments, the processor is further configured to:

[0140] sending the second control channel based on the second cell radio network temporary identifier.

[0141] In some embodiments, sending the second control channel based on the second cell radio network temporary identifier comprises:

[0142] sending a first message through the second control channel; the first message carrying timing advance information;

[0143] and / or sending a terminal-specific configuration through the second control channel, the terminal-specific configuration being a configuration allocated to the terminal by the target network device for use by the terminal.

[0144] In a nineteenth aspect, the embodiments of the present disclosure further provide a processor-readable storage medium, wherein the processor-readable storage medium stores a program, and the program is configured to cause a processor to perform the handover method of any one of the first aspect, or perform the handover method of any one of the second aspect, or perform the handover method of any one of the third aspect, or perform the handover method of any one of the fourth aspect, or perform the handover method of any one of the fifth aspect, or perform the handover method of any one of the sixth aspect.

[0145] In at least one embodiment of the present disclosure, the terminal receives a cell radio network temporary identifier allocated by the target network device for the terminal, and listens to a control channel sent by the target network device using the cell radio network temporary identifier, the control channel being a control channel scrambled using the cell radio network temporary identifier. Therefore, the terminal can obtain information such as random access resources configured by the target network device for the terminal through the control channel, and complete a random access process with the target network based on the random access resources. The terminal-specific configuration of the terminal in the target network can be sent by the target network device to the terminal after the random access process is completed. Therefore, in the handover process, the terminal-specific configuration of the terminal in the target network does not need to be sent from the target network device to the source network device, reducing inter-satellite interaction, reducing system overhead, reducing resource waste and signaling storm. BRIEF DESCRIPTION OF DRAWINGS

[0146] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings needed in the embodiments or related technical descriptions will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can also be obtained by those skilled in the art based on these drawings.

[0147] FIG. 1 is a flowchart of a handover method according to an embodiment of the present disclosure;

[0148] FIG. 2 is a flowchart of a handover method according to an embodiment of the present disclosure;

[0149] FIG. 3 is a flowchart of a handover method according to an embodiment of the present disclosure;

[0150] FIG. 4 is a handover flowchart according to an embodiment of the present disclosure;

[0151] FIG. 5 is a flowchart of a handover method according to an embodiment of the present disclosure;

[0152] FIG. 6 is a flowchart of a handover method according to an embodiment of the present disclosure;

[0153] FIG. 7 is a flowchart of a handover method according to an embodiment of the present disclosure;

[0154] FIG. 8 is a handover flowchart according to an embodiment of the present disclosure;

[0155] FIG. 9 is a schematic diagram of a handover device according to an embodiment of the present disclosure;

[0156] FIG. 10 is a schematic diagram of another handover device according to an embodiment of the present disclosure;

[0157] FIG. 11 is a schematic diagram of another handover device according to an embodiment of the present disclosure;

[0158] FIG. 12 is a schematic diagram of another switching device according to an embodiment of the present disclosure;

[0159] FIG. 13 is a schematic diagram of another switching device according to an embodiment of the present disclosure;

[0160] FIG. 14 is a schematic diagram of another switching device according to an embodiment of the present disclosure;

[0161] FIG. 15 is a terminal according to an embodiment of the present disclosure;

[0162] FIG. 16 is a source network device according to an embodiment of the present disclosure;

[0163] FIG. 17 is a target network device according to an embodiment of the present disclosure;

[0164] FIG. 18 is a terminal according to an embodiment of the present disclosure;

[0165] FIG. 19 is a source network device according to an embodiment of the present disclosure;

[0166] FIG. 20 is a target network device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0167] In order to more clearly understand the above-mentioned purposes, features and advantages of the present disclosure, the present disclosure will be further described in detail below with reference to the drawings and embodiments. It can be understood that the described embodiments are part of the embodiments of the present disclosure, rather than all the embodiments. The specific embodiments described herein are only used to explain the present disclosure, and not to limit the present disclosure. Based on the described embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present disclosure.

[0168] It should be noted that in this paper, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between the entities or operations.

[0169] In satellite communication, the connection link between the terminal and the satellite is called user link, and the connection link between the satellite and the gateway station is called feeder link. There are two working modes in satellite communication:

[0170] One is transparent forwarding mode, the satellite only transparently forwards the signal without any processing, the terminal and the gateway station communicate, that is, the satellite only performs frequency conversion, wireless signal amplification and other operations on the uplink / downlink signal, and its function is similar to that of radio frequency relay.

[0171] One is a regenerative communication mode, the satellite can detect the information of the received signal and process and forward, complete the function of the base station, connect the terminal and the gateway station. That is, the satellite can perform functions such as frequency conversion, wireless signal amplification, coding / modulation, demodulation / decoding on the uplink / downlink signal. That is, the satellite can have all or part of the functions of the base station, and can regenerate the signal.

[0172] There are two types of cells in NTN:

[0173] Earth-Fixed cell: refers to the ground coverage area of the satellite's service cell does not change with the movement of the satellite within a certain time, that is, in the "staring" mode, the satellite is moving, but within a certain time, the satellite "stares" at a certain area on the ground. For example, the satellite moves from T1 time to T2 time, and the satellite's coverage area on the ground is always the same area or approximately the same area. Quasi-Earth Fixed cell refers to an approximate (similar) Earth-Fixed cell, which means that the satellite "stares" at the ground for a relatively short time, that is, T1 and T2 are separated by a short time. In this scenario, as the satellite moves, the angle between the satellite antenna and the ground changes, thereby ensuring that the area covered by the satellite antenna remains unchanged or approximately unchanged.

[0174] Earth-moving cell: refers to the ground coverage area of the satellite's service cell changes with the movement of the satellite. For example, the coverage area of the satellite is area A at T1 time and area B at T2 time. In this scenario, as the satellite moves, the angle between the satellite antenna and the ground hardly changes.

[0175] As the satellite moves, whether it is an Earth-Fixed cell or an Earth-moving cell, the cell mapped to the ground will move. If a large number of terminals reside in the NTN cell, because of the movement of the cell, a large number of terminals will perform handover from the same source NTN cell to the same target NTN cell, which will cause a signaling storm in a short period of time.

[0176] In a conventional handover mechanism, the common configuration information of the target cell (especially the information contained in ServingCellConfigCommon) is sent to each terminal participating in the handover through a handover command in a dedicated signaling manner. This handover mechanism is reasonable in a terrestrial network (TN) because in a terrestrial network, the handover is mainly caused by the movement of the terminal, and the direction or speed of each terminal movement is unpredictable, so the target cell of each terminal may be different. However, in an NTN network, the main reason for triggering the handover is the movement of the satellite cell, and as a result, a large number of terminals will be handed over to the same target cell. In this case, if the common configuration information of the target cell is sent to each terminal through a handover command, it will cause a waste of resources for repeated sending, and the resource efficiency is not high.

[0177] In some related technologies, an unchanged physical cell identifier (PCI) is used, that is, an unchanged PCI scheme. The unchanged PCI scheme assumes that the PCIs of the source cell and the target cell are the same, and the cell configurations are also the same. When the handover is performed, the terminal only needs to re-synchronize.

[0178] In another related technology, a common configuration signaling is used. The main idea of the common configuration signaling mechanism is to send the common configuration information of the target cell through broadcasting, and the UE specific configuration, such as the cell radio network temporary identifier (C-RNTI) and contention free random access (CFRA) resource, is still sent to the terminal through the handover command.

[0179] However, the unchanged PCI scheme is not universal and cannot always assume that the next cell has the same PCI and configuration as the current cell. The common configuration signaling mechanism still needs to interact with a large number of UE specific configurations between two satellite cells, and the resource waste is obvious.

[0180] In the embodiments of the present disclosure, the number of UE specific configurations of inter-satellite (inter-station) interaction is reduced; the amount of information of UE specific configurations of UE in a target cell sent to the UE by a source station (i.e., a source network device) is reduced, and even the sending of UE specific configurations of UE in the target cell to the UE by the source station is avoided, thereby reducing resource overhead. Scheme 1 or scheme 2 can be used:

[0181] Scheme 1: The UE receives the C-RNTI of the UE in the target cell and the security parameters in the target cell from the source station; the UE switches to the target cell, listens to the control channel (for example, a physical downlink control channel (PDCCH)) in the target cell through the above C-RNTI, obtains random access resources, mainly non-contention random access resources; the UE completes random access in the target cell and receives UE specific configurations from the target cell.

[0182] Scheme 2: The source cell packs the C-RNTI of the UE in the source cell that needs to be switched to the target cell and sends it to the target cell; the target cell sends the PDCCH scrambled by a handover dedicated RNTI (HO-RNTI), which carries the C-RNTI of the UE in the source cell, the newly allocated C-RNTI in the target cell, and the non-contention random access resource; the UE listens to the PDCCH in the target cell through the HO-RNTI, if the PDCCH containing the C-RNTI of the UE in the source cell is listened to, the C-RNTI of the target cell carried in the PDCCH is used as the new C-RNTI, and the non-contention random access resource carried in the PDCCH is used to initiate the non-contention random access, and then the new C-RNTI is used for subsequent operations. Optionally, the PDCCH scrambled by the HO-RNTI can carry the C-RNTI (allocated by the target cell) of multiple UEs and the non-contention random access resource, so as to speed up the handover process.

[0183] It should be noted that in scheme 2, there can be no radio resource control (RRC) synchronous reconfiguration. The source cell sends the public configuration of the target cell in a broadcast manner, and the UE can complete the downlink synchronization to the target cell and receive the PDCCH through the public configuration.

[0184] It should be noted that the parts not explicitly described in Scheme 1 and Scheme 2 are still generally performed with reference to the existing flow. For example, if data forwarding is to be supported, the source station still needs to support SN transfer, and the target station (i.e., the target network device) can also feed back information of a Protocol Data Unit (PDU) session that does not support to the source station, and the like.

[0185] FIG. 1 is a flow diagram of a handover method provided by an embodiment of the present disclosure, which is applied to a terminal. As shown in FIG. 1, the handover method can include but is not limited to step 101 and step 102:

[0186] In step 101, a cell radio network temporary identifier is received, which is an identifier allocated by a target network device to a terminal.

[0187] The cell radio network temporary identifier (C-RNTI) is an identifier allocated by the target network device to the terminal (i.e., the terminal that needs to be handed over to the target network). The C-RNTI can also be referred to as the cell radio network temporary identifier of the terminal in the target network. The target network is a network defined by the target network device, or a network supported by the target network device, or a target cell to which the target network device belongs.

[0188] In order to distinguish the cell radio network temporary identifiers of the terminal in the source network and the target network, the cell radio network temporary identifier of the terminal in the source network is referred to as a first C-RNTI, and the cell radio network temporary identifier of the terminal in the target network is referred to as a second C-RNTI. The source network is a network defined by a source network device, or a network supported by the source network device, or a source cell to which the source network device belongs.

[0189] In this embodiment, the second C-RNTI is sent by the source network device to the terminal. The difference from the related art is that the source network device sends the second C-RNTI to the terminal instead of a terminal specific configuration (UE specific configuration) of the terminal in the target network, that is, the source network device sends the second C-RNTI to the terminal without carrying the terminal specific configuration of the terminal in the target network. The terminal specific configuration is a configuration allocated by the target network device to the terminal for use. It can be seen that the terminal specific configuration does not need to be sent from the target network device to the source network device, reducing inter-satellite interaction, reducing system overhead, reducing resource waste and signaling storm.

[0190] It should be noted that the cell radio network temporary identifier is the concept of the current C-RNTI (Cell RNTI (Radio Network Temporary Identifier, C-RNTI)), and in the future, this concept can not be used. As long as the temporary identifier (Temporary Identifier) similar to the function of the C-RNTI is suitable for the implementation of the scheme embodiment.

[0191] In step 102, the control channel sent by the target network device is monitored according to the cell radio network temporary identifier.

[0192] In this embodiment, when the terminal meets the handover condition, the terminal completes the downlink synchronization with the target network device. After the downlink synchronization is completed, the terminal monitors the control channel sent by the target network device according to the second C-RNTI. The control channel sent by the target network device is the control channel scrambled by the second C-RNTI. Therefore, the terminal can monitor the control channel scrambled by the second C-RNTI using the second C-RNTI, and realize the monitoring of the control channel sent by the target network device.

[0193] The control channel can be a physical downlink control channel (PDCCH), or other control channels. The control channel carries the random access resource in any one of the following (1) to (3): (1) The control channel can directly carry the random access resource, mainly the non-contention random access resource; or (2) The control channel can carry the scheduling information of a data channel, and the data channel carries the random access resource, mainly the non-contention random access resource; or (3) The control channel can carry the scheduling information of a data channel, and the data channel carries a signaling or data, and the signaling or data carries the random access resource, mainly the non-contention random access resource. It should be noted that the control channel carrying the random access resource mentioned below can be one of the three ways described above.

[0194] The terminal can obtain the random access resource through the control channel. For example, the terminal monitors the control channel according to the second C-RNTI. If the control channel scrambled by the second C-RNTI is monitored, the random access resource carried in the control channel is obtained; or the data channel scheduled by the control channel (for example, the control channel carries the scheduling information of the data channel, and the data channel is obtained according to the scheduling information) is obtained, and the random access resource carried by the data channel is obtained; or the data channel scheduled by the control channel is obtained, and the random access resource carried in the signaling or data carried by the data channel is obtained.

[0195] After obtaining the random access resource, the terminal can initiate a random access procedure to the target network device or the target network based on the random access resource. For example, the terminal initiates a non-contention random access procedure based on a random access preamble defined by the non-contention random access resource and / or a random access occasion (RO, RACH occasion), such as sending a random access preamble on the random access occasion.

[0196] It can be seen that the terminal initiates the random access procedure in the target network by listening to the control channel sent by the target cell, and therefore, the timing of initiating the random access procedure is controllable, reducing the short-term random access resource overhead.

[0197] It should be noted that although the base station or the access network device actually sends the control channel, in general description, it is described that the source cell or the target cell sends the control channel, and in this paper, it is described that the source network device or the target network device sends the control channel, wherein the source network device belongs to or defines the source cell, and the target network device belongs to or defines the target cell. The source network and the target network can also send the control channel.

[0198] It can be seen that in the embodiments of the present disclosure, the terminal receives the cell radio network temporary identifier allocated by the target network device for the terminal, and listens to the control channel sent by the target network device using the cell radio network temporary identifier. The control channel is a control channel scrambled by the cell radio network temporary identifier, and therefore, the terminal can obtain the random access resource configured by the target network device for the terminal through the control channel, so as to complete the random access procedure with the target network based on the random access resource. The terminal-specific configuration in the target network can be sent to the terminal by the target network device after the random access procedure is completed. Therefore, in the handover process, the terminal-specific configuration of the terminal in the target network does not need to be sent from the target network device to the source network device, reducing inter-satellite interaction, reducing system overhead, reducing resource waste and signaling storm.

[0199] In some embodiments, in step 102, listening to the control channel sent by the target network device according to the cell radio network temporary identifier further includes:

[0200] Obtaining a first message through the control channel; the first message carries timing advance information.

[0201] In this embodiment, the terminal obtains a first message through the control channel based on the second C-RNTI if the second C-RNTI scrambled control channel is listened to. The first message can be a random access response (Random Access Response, RAR), or it can not be RAR, but other messages, signaling or MAC control elements (MAC Control Element, MAC CE) and the like.

[0202] In some embodiments, in step 102, according to the cell radio network temporary identifier, the terminal listens to the control channel sent by the target network device, and the step further includes:

[0203] obtaining a terminal specific configuration through the control channel; wherein the terminal specific configuration is a configuration allocated by the target network device for the terminal.

[0204] The control channel can or can not carry the terminal specific configuration.

[0205] If the control channel does not carry the terminal specific configuration, the target network device schedules high layer signaling (for example, RRC reconfiguration information) and / or data through the control channel, and carries the terminal specific configuration in the high layer signaling and / or data. The terminal receives the high layer signaling and / or data through the control channel, and then obtains the terminal specific configuration from the high layer signaling and / or data. The data includes MAC CE (Media Access Control Control Element).

[0206] For example, after the terminal completes the non-contention random access in the target network device or the target network, the terminal receives the RRC reconfiguration information sent by the target network device through the control channel, obtains the terminal specific configuration carried in the RRC reconfiguration information, and completes the handover.

[0207] In some embodiments, the handover method shown in FIG. 1 further includes the following steps not shown in FIG. 1:

[0208] receiving at least one of the following information sent by the source network device and / or the target network device:

[0209] security parameters, common configuration information of the target network, and PDU (Protocol Data Unit) session related parameters.

[0210] The security parameters are security parameters used by the terminal in the target network. The target network is a network defined by the target network device, or a network supported by the target network device, or a target cell to which the target network device belongs. The PDU session related parameters include indication information of acceptable / unacceptable PDU sessions.

[0211] As an example, the common configuration information of the target network is mandatory information, and the security parameters and the PDU session related parameters are optional information.

[0212] Embodiment one

[0213] The flow of switching on the terminal (UE) side includes the following steps 1 to 3:

[0214] 1. The UE receives the C-RNTI allocated by the target cell for the UE, the necessary security parameters and the public configuration information of the target cell sent by the source cell, wherein the C-RNTI and the security parameters can be sent in the form of unicast (i.e. through dedicated signaling), and the public configuration information of the target cell can be sent in the form of broadcast or multicast, thereby reducing resource overhead.

[0215] 2. When the switching condition is met, the UE completes downlink synchronization with the target cell, listens to the control channel through the C-RNTI allocated by the target cell for the UE, obtains non-contention random access resources, and initiates non-contention random access to the target cell.

[0216] 3. After the UE completes non-contention random access in the target cell, the UE receives the RRC reconfiguration information from the target cell, obtains the terminal-specific configuration of the UE in the target cell, and completes the switching.

[0217] FIG. 2 is a flowchart of a switching method provided by an embodiment of the present disclosure, which is applied to a source network device, which can be a device of a source cell, a base station of the source cell or an access network device of the source cell. As shown in FIG. 2, the switching method can include but is not limited to steps 201 and 202.

[0218] In step 201, a cell radio network temporary identifier of a terminal is obtained, which is an identifier allocated by a target network device for the terminal.

[0219] In this embodiment, the source network device obtains the cell radio network temporary identifier C-RNTI of the terminal (i.e. which needs to be switched to the target cell) from the target network device, which is an identifier allocated by the target network device for the terminal.

[0220] In this embodiment, the source network device does not carry the terminal-specific configuration of the terminal in the target network when sending the cell radio network temporary identifier to the terminal. The terminal-specific configuration is the configuration allocated by the target network device for the terminal.

[0221] In order to distinguish the cell radio network temporary identifiers of the terminal in the source network and the target network, the cell radio network temporary identifier of the terminal in the source network is referred to as the first C-RNTI, and the cell radio network temporary identifier of the terminal in the target network is referred to as the second C-RNTI.

[0222] In step 202, the cell radio network temporary identifier is sent to the terminal, which is used by the terminal to listen to the control channel sent by the target network device.

[0223] In this embodiment, the source network device sends the second C-RNTI to the terminal. For example, the source network device sends the second C-RNTI to the terminal in the form of unicast.

[0224] The second C-RNTI is used by the terminal to monitor a control channel scrambled by the second C-RNTI sent by the target network device. For example, the terminal monitors the control channel scrambled by the second C-RNTI sent by the target network device according to the second C-RNTI, and receives random access resources carried in the control channel if the control channel scrambled by the second C-RNTI is monitored. After obtaining the random access resources, the terminal can initiate a random access procedure to the target network device or the target network based on the random access resources.

[0225] In some embodiments, the handover method shown in FIG. 2 further includes the following steps not shown in FIG. 2:

[0226] sending a handover request to the target network device or the target network.

[0227] In this embodiment, if the source network device triggers the handover, the source network device sends a handover request to the target network device or the target network. The timing or condition of triggering the handover can be used in related technologies, for example, the source network device determines to change the coverage range, and triggers the handover.

[0228] In this embodiment, after the source network device sends the handover request to the target network device or the target network, the source network device and the target network device perform signaling interaction related to the handover; or, the source network device and the target network device perform signaling interaction related to the handover through the core network device.

[0229] For example, if there is an interface between the source network device and the target network device, the source network device and the target network device can directly perform signaling interaction related to the handover; otherwise, the source network device and the target network device can complete the signaling interaction related to the handover through the core network device.

[0230] In some embodiments, the handover method shown in FIG. 2 further includes the following steps not shown in FIG. 2:

[0231] sending the terminal at least one of the following information:

[0232] security parameters, public configuration information of the target network, and PDU session related parameters.

[0233] The security parameters are security parameters used by the terminal in the target network. The target network is a network defined by the target network device, or a network supported by the target network device, or a target cell to which the target network device belongs. The PDU session related parameters include indication information of acceptable / unacceptable PDU sessions.

[0234] As an example, the common configuration information of the target network is optional information, the security parameters and the PDU session related parameters are mandatory information.

[0235] As an example, the security parameters are sent in the form of unicast, and the common configuration information of the target network is sent in the form of broadcast or multicast.

[0236] Embodiment two

[0237] The flow of the network side (source network device) performing the handover includes the following steps 1 and 2.

[0238] 1. The source network device obtains, from the target network device, the C-RNTI allocated to the UE (the UE that needs to be handed over to the target cell) in the target cell, the necessary security parameters (optional), and the common configuration information of the target cell.

[0239] The target cell is a cell to which the target network device belongs, or a cell defined or supported by the target network device.

[0240] Optionally, the source network device can also obtain, from the target network device, the PDU session related parameters, such as the indication information of the acceptable / unacceptable PDU session.

[0241] The source network device needs to trigger the handover.

[0242] 2. The source network device sends, to the UE, the C-RNTI allocated in the target cell, the necessary security parameters, and the common configuration information of the target cell. The C-RNTI and the security parameters can be sent in the form of unicast, and the common configuration information of the target cell can be sent in the form of broadcast or multicast.

[0243] FIG. 3 is a flowchart of a handover method provided by an embodiment of the present disclosure, which is applied to a target network device. As shown in FIG. 3, the handover method includes but is not limited to steps 301 and 302.

[0244] In step 301, a cell radio network temporary identifier of a terminal is obtained.

[0245] For example, the target network device allocates a cell radio network temporary identifier C-RNTI to the terminal that needs to be handed over to the target network.

[0246] In this embodiment, after the target network device allocates the cell radio network temporary identifier to the terminal, the target network device can send a control channel based on the cell radio network temporary identifier.

[0247] For example, the target network device scrambles the control channel using the cell radio network temporary identifier, and then sends the scrambled control channel.

[0248] The target network device sends the control channel based on the cell radio network temporary identifier, including: sending a random access resource through the control channel. The random access resource is, for example, a non-contention random access resource.

[0249] In order to distinguish the cell radio network temporary identifier of the terminal in the source network and the target network, the cell radio network temporary identifier of the terminal in the source network is referred to as a first C-RNTI, and the cell radio network temporary identifier of the terminal in the target network is referred to as a second C-RNTI.

[0250] In step 302, the cell radio network temporary identifier is sent to the source network device, and the cell radio network temporary identifier is used for the terminal to listen to the control channel sent by the target network device.

[0251] In this embodiment, when the target network device sends the second C-RNTI to the source network device, the terminal-specific configuration (UE specific configuration) of the terminal in the target network is not carried. The terminal-specific configuration is the configuration used by the terminal allocated by the target network device for the terminal.

[0252] In this embodiment, after the target network device sends the second C-RNTI to the source network device, the source network device sends the second C-RNTI to the terminal. For example, the source network device sends the second C-RNTI to the terminal in the form of unicast.

[0253] The second C-RNTI is used for the terminal to listen to the control channel scrambled by the second C-RNTI sent by the target network device. For example, the terminal listens to the control channel scrambled by the second C-RNTI according to the second C-RNTI, and if the control channel scrambled by the second C-RNTI is listened to, the terminal receives the random access resource carried in the control channel. After the terminal obtains the random access resource, the terminal can initiate a random access process to the target network device or the target network based on the random access resource.

[0254] In some embodiments, the target network device sends the control channel based on the cell radio network temporary identifier, and further includes: sending a first message through the control channel, and the first message carries timing advance information.

[0255] The first message can be a random access response (RAR), or can not be an RAR, but other messages, signaling, or MAC control elements (MAC CEs), etc.

[0256] In some embodiments, the target network device sends the control channel based on the cell radio network temporary identifier, and further includes:

[0257] The terminal specific configuration is sent through a control channel, and the terminal specific configuration is a configuration used by the terminal and allocated to the terminal by the target network device.

[0258] The control channel can or can not carry the terminal specific configuration.

[0259] If the control channel does not carry the terminal specific configuration, the target network device schedules high-layer signaling (for example, RRC reconfiguration information) and / or data through the control channel, and carries the terminal specific configuration in the high-layer signaling and / or data. The terminal receives the high-layer signaling and / or data through the control channel, and then obtains the terminal specific configuration from the high-layer signaling and / or data. The data includes a MAC CE (Media Access Control Control Element).

[0260] For example, after the terminal completes the non-contention random access to the target network device or the target network, the terminal receives the RRC reconfiguration information sent by the target network device through the control channel, obtains the terminal specific configuration carried in the RRC reconfiguration information, and completes the handover.

[0261] In some embodiments, the handover method shown in FIG. 3 further includes the following steps not shown in FIG. 3:

[0262] Receiving a handover request sent by the source network device.

[0263] In this embodiment, if the source network device triggers the handover, the source network device sends a handover request to the target network device or the target network. The timing or condition of triggering the handover can be used in related technologies, for example, the source network device determines that its coverage will change, and triggers the handover.

[0264] In this embodiment, after the target network device receives the handover request sent by the source network device, the source network device and the target network device perform signaling interaction related to the handover; or the source network device and the target network device perform signaling interaction related to the handover through a core network device.

[0265] For example, if there is an interface between the source network device and the target network device, the source network device and the target network device can directly perform signaling interaction related to the handover; otherwise, the source network device and the target network device can complete the signaling interaction related to the handover through the core network device.

[0266] In some embodiments, the handover method shown in FIG. 3 further includes the following steps not shown in FIG. 3:

[0267] Sending the following at least one information to the terminal:

[0268] a security parameter, common configuration information of the target network, and PDU session related parameters.

[0269] The security parameter is a security parameter used by the terminal in the target network. The target network is a network defined by the target network device, or a network supported by the target network device, or a target cell to which the target network device belongs. The PDU session related parameters include indication information of acceptable / unacceptable PDU sessions.

[0270] As an example, the common configuration information of the target network is mandatory information, and the security parameter and the PDU session related parameters are optional information.

[0271] As an example, the security parameter is sent in the form of unicast, and the common configuration information of the target network is sent in the form of broadcast or multicast.

[0272] Embodiment three

[0273] The flow of the network side (the target network device) performing the handover includes the following steps 1 to 4:

[0274] 1. The target network device sends, to the source network device, a C-RNTI allocated to a UE (a UE that needs to be handed over to a target cell) in the target cell, necessary security parameters (optional), and common configurations of the target cell.

[0275] The target cell is a cell to which the target network device belongs, or a cell defined or supported by the target network device.

[0276] In some embodiments, the target network device can also send PDU session related parameters, such as indication information of acceptable / unacceptable PDU sessions, to the source network device.

[0277] The target network device needs to receive a handover request from the source network device. If there is an interface between the source network device and the target network device, the source network device and the target network device can directly perform signaling interaction related to the handover; otherwise, the source network device and the target network device can complete the signaling interaction related to the handover through a core network device.

[0278] The condition or occasion for the source network device to trigger the handover can refer to related technologies, such as the source network device determining that its coverage will change, and triggering the handover.

[0279] 2. The target network device sends a control channel to the UE with the C-RNTI of the UE in the target cell, and the control channel carries non-contention random access resources.

[0280] 3. The target network device completes a non-contention random access process with the UE.

[0281] 4. The target network device sends RRC reconfiguration information to the UE, and the RRC reconfiguration information carries terminal-specific configuration.

[0282] Embodiment Four

[0283] FIG. 4 is a schematic diagram of a handover procedure provided by an embodiment of the present disclosure. As shown in FIG. 4, the handover procedure includes the following steps 1 to 4:

[0284] 1. The source network device obtains, from the target network device, a C-RNTI allocated to the UE (a UE that needs to be handed over to a cell of the target station) in the target cell, necessary security parameters (optional), and public configuration information of the target cell.

[0285] Optionally, PDU session-related parameters, such as indication information of acceptable / unacceptable PDU sessions, can also be included.

[0286] The source network device needs to trigger handover and request handover from the target network device. If there is an interface between the source network device and the target network device, the source network device and the target network device can directly perform signaling interaction related to handover; otherwise, the source network device and the target network device can complete signaling interaction related to handover through a core network device.

[0287] The condition or occasion for the source network device to trigger handover can refer to related technologies, such as the source network device determining that its coverage will change, and triggering handover.

[0288] 2. The source network device sends the C-RNTI allocated to the UE in the target cell, the necessary security parameters (optional), and the public configuration information of the target cell to the UE. The C-RNTI and the security parameters can be sent in a unicast form, and the public configuration information of the target cell can be sent in a broadcast or multicast form.

[0289] 3. The UE obtains the C-RNTI allocated to the UE in the target cell, the security parameters, and the public configuration information of the target cell. When a handover condition is met, the UE completes downlink synchronization with the target cell, listens to a control channel (PDCCH) using the C-RNTI allocated to the UE by the target cell, obtains a non-contention random access resource, and initiates non-contention random access to the target cell through a non-contention physical random access channel (PRACH).

[0290] 4. After the UE completes non-contention random access in the target cell, the UE receives RRC reconfiguration information from the target cell, obtains terminal-specific configuration of the UE in the target cell, and completes handover.

[0291] FIG. 5 is a flow diagram of a handover method according to an embodiment of the present disclosure, which is applied to a terminal. As shown in FIG. 1, the handover method can include but is not limited to step 501.

[0292] In step 501, a first control channel is monitored based on a handover-specific wireless network temporary identifier, and the first control channel carries a first cell wireless network temporary identifier, a second cell wireless network temporary identifier, and a random access resource. The first cell wireless network temporary identifier is an identifier allocated to the terminal by a source network device, and the second cell wireless network temporary identifier is an identifier allocated to the terminal by a target network device.

[0293] The handover-specific wireless network temporary identifier can be a protocol predefined identifier.

[0294] The first control channel can or can not carry a terminal-specific configuration of the terminal in the target network. The terminal-specific configuration is a configuration allocated to the terminal by the target network device for use by the terminal. The first control channel is sent by the target network device, and the first control channel is a control channel scrambled using the handover-specific wireless network temporary identifier. It should be noted that the first control channel can carry the terminal-specific configuration of the terminal in the target network, but this solution is not friendly. Because the target network device does not know whether the terminal has been handed over to the target network when sending the first control channel, if the terminal-specific configuration of the terminal is sent through the first control channel, it may cause a certain waste of resources if the terminal has not been handed over to the target network. Of course, if the communication delay is considered, the first control channel can also carry the terminal-specific configuration of the terminal in the target network. At this time, the terminal can obtain the wireless network temporary identifier and the terminal-specific configuration of the terminal in the target network through the first control channel.

[0295] For example, based on the handover-specific wireless network temporary identifier, if the terminal monitors the first control channel scrambled using the handover-specific wireless network temporary identifier, the terminal obtains the first cell wireless network temporary identifier (first C-RNTI) carried in the first control channel.

[0296] After obtaining the first C-RNTI, the terminal compares the first C-RNTI with the C-RNTI of the terminal in the source cell, and if the two are the same, the terminal obtains the second cell wireless network temporary identifier (second C-RNTI) and the random access resource carried in the first control channel, and uses the obtained second C-RNTI as the C-RNTI of the terminal in the target network.

[0297] After obtaining the random access resource, the terminal initiates a random access process to the target network device or the target network based on the random access resource.

[0298] For example, the terminal initiates a non-contention random access procedure based on a random access preamble defined by a non-contention random access resource and / or a random access occasion (RO, RACH occasion), for example, sends the random access preamble on the random access occasion.

[0299] Therefore, in the handover process, the terminal-specific configuration of the terminal in the target network does not need to be sent from the target network device to the source network device, reducing inter-satellite interaction, reducing system overhead, reducing resource waste and signaling storm.

[0300] In some embodiments, in step 501, the first control channel is listened to based on the handover-specific wireless network temporary identifier, including the following steps 1 and 2 not shown in FIG. 5:

[0301] Step 1, obtain the second cell wireless network temporary identifier through the first control channel.

[0302] Step 2, listen to the second control channel based on the second cell wireless network temporary identifier.

[0303] In this embodiment, since the second cell wireless network temporary identifier (second C-RNTI) is carried in the first control channel, the terminal can obtain the second C-RNTI through the first control channel, and then listen to the second control channel based on the second C-RNTI. The second control channel is sent by the target network device, and the second control channel is a control channel scrambled by the second C-RNTI.

[0304] In some embodiments, in step 2, listening to the second control channel based on the second cell wireless network temporary identifier includes:

[0305] Obtain the first message through the second control channel; the first message carries timing advance information.

[0306] In this embodiment, the terminal based on the second C-RNTI, if the second C-RNTI scrambled second control channel is listened to, the first message is obtained through the second control channel. The first message can be a random access response (Random Access Response, RAR), but also can not be RAR, but other messages, signaling or MAC control element (MAC Control Element, MAC CE) and the like.

[0307] In some embodiments, in step 2, listening to the second control channel based on the second cell wireless network temporary identifier further includes:

[0308] obtaining a terminal specific configuration through the second control channel; the terminal specific configuration is a configuration used by the terminal and allocated by the target network device for the terminal.

[0309] The second control channel can carry the terminal specific configuration or not.

[0310] If the second control channel does not carry the terminal specific configuration, the target network device schedules high layer signaling (for example, RRC reconfiguration information) and / or data through the control channel, and carries the terminal specific configuration in the high layer signaling and / or data. The terminal receives the high layer signaling and / or data through the second control channel, and then obtains the terminal specific configuration from the high layer signaling and / or data. The data includes a MAC CE (Media Access Control Control Element).

[0311] For example, after the terminal completes the non-contention random access in the target network device or the target network, the terminal receives the RRC reconfiguration information sent by the target network device through the second control channel, obtains the terminal specific configuration carried in the RRC reconfiguration information, and completes the handover.

[0312] In some embodiments, the handover method shown in FIG. 5 further includes the following steps not shown in FIG. 5:

[0313] receiving at least one of the following information sent by the source network device and / or the target network device:

[0314] security parameters, common configuration information of the target network, and PDU session related parameters.

[0315] The security parameters are security parameters used by the terminal in the target network. The target network is a network defined by the target network device, or a network supported by the target network device, or a target cell to which the target network device belongs. The PDU session related parameters include indication information of acceptable / unacceptable PDU sessions.

[0316] As an example, the common configuration information of the target network is mandatory information, and the security parameters and the PDU session related parameters are optional information.

[0317] In some embodiments, before step 501, based on the handover specific radio network temporary identifier, the handover method shown in FIG. 5 further includes the following steps not shown in FIG. 5:

[0318] receiving the handover specific radio network temporary identifier sent by the source network device.

[0319] In this embodiment, the switching dedicated radio network temporary identifier (denoted as HO-RNTI) is not a protocol predefined identifier, but an identifier sent by the source network device.

[0320] It should be noted that the HO-RNTI is sent by the target network device to the source network device, and then sent by the source network device to the terminal.

[0321] Embodiment five

[0322] The flow of the terminal (UE) side switching includes the following steps 1 to 4:

[0323] 1. The UE receives the public configuration information of the target cell sent by the source cell (broadcast or multicast), and the UE receives the security parameters of the target cell (sent by dedicated signaling).

[0324] 2. After the UE receives the public configuration information of the target cell, the UE switches to the target cell at a determined switching time point or based on a location, mainly to complete the downlink synchronization with the target cell, complete the control channel reception configuration in the target cell, and then listen to the first control channel (PDCCH) sent by the target cell through the HO-RNTI.

[0325] 3. If the PDCCH listened by the UE contains the cell radio network temporary identifier (denoted as C-RNTI-s) of the UE in the source cell, the UE takes the cell radio network temporary identifier (denoted as C-RNTI-t) of the target cell contained in the PDCCH as the cell radio network temporary identifier of the UE in the target cell, and uses the non-contention random access resource contained in the PDCCH to initiate non-contention random access, and then obtains the timing advance (TA) information, and uses the TA information to complete the uplink synchronization with the target cell.

[0326] 4. After the UE completes the non-contention random access in the target cell, the UE receives the RRC reconfiguration information from the target cell, obtains the terminal dedicated configuration of the UE in the target cell, completes the reconfiguration of the UE by the target cell, and realizes the switching.

[0327] FIG. 6 is a flowchart of a switching method provided by an embodiment of the present disclosure, which is applied to a source network device. The source network device can be a device of a source cell, a base station of a source cell, or an access network device of a source cell. As shown in FIG. 6, the switching method can include but is not limited to the following step 601:

[0328] sending a first cell radio network temporary identifier to a target network device, the first cell radio network temporary identifier being an identifier allocated by the source network device to a terminal.

[0329] In this embodiment, the source network device sends a first cell radio network temporary identifier (first C-RNTI) of a terminal that needs to be switched to a target cell to the target network device.

[0330] After receiving the first C-RNTI, the target network device can send a first control channel to the terminal, and the first control channel carries the first C-RNTI, a second cell radio network temporary identifier (second C-RNTI), and random access resources; the second C-RNTI is an identifier allocated to the terminal by the target network device.

[0331] The first control channel sent by the target network device to the terminal can not carry a terminal-specific configuration (UE specific configuration) of the terminal in the target network. The terminal-specific configuration is a configuration allocated to the terminal by the target network device for the terminal to use.

[0332] In some embodiments, the handover method shown in FIG. 6 further includes the following steps 1 and 2 not shown in FIG. 6:

[0333] Step 1: receiving a handover-specific radio network temporary identifier sent by the target network device;

[0334] Step 2: sending the handover-specific radio network temporary identifier to the terminal.

[0335] The handover-specific radio network temporary identifier (denoted as HO-RNTI) is generated by the target network device, and the HO-RNTI is used by the terminal to monitor the first control channel sent by the target network device.

[0336] For example, based on the HO-RNTI, if the terminal monitors the first control channel scrambled by the HO-RNTI, the terminal acquires the first C-RNTI carried in the first control channel, compares the first C-RNTI with the C-RNTI of the terminal in the source cell, and if the two are the same, acquires the second cell radio network temporary identifier (second C-RNTI) and the random access resources carried in the first control channel. After acquiring the random access resources, the terminal initiates a random access procedure to the target network device or the target network based on the random access resources.

[0337] In some embodiments, the handover method shown in FIG. 6 further includes the following steps not shown in FIG. 6:

[0338] The terminal is sent at least one of the following information: security parameters, public configuration information of the target network.

[0339] The security parameters are security parameters used by the terminal in the target network. The target network is a network defined by the target network device, or a network supported by the target network device, or a target cell to which the target network device belongs.

[0340] As an example, the security parameters are sent in unicast, and the public configuration information of the target network is sent in broadcast or multicast.

[0341] Embodiment six

[0342] The flow of the network side (source network device) performing handover includes the following steps 1 to 3:

[0343] 1. The source network device determines the target network device, and the determination process is not the focus of the embodiment. The source network device can determine the target cell covering the current area of the source cell according to the ephemeris information. The source network device can also determine the data radio bearer (DRB) configuration information of the UE in the source cell.

[0344] 2. The source network device sends the cell radio network temporary identifier (denoted as C-RNTI-s) of the UE in the source cell that needs to be handed over to the target cell to the determined target network device, and obtains the public configuration information of the target cell, the necessary security parameters, the PDU session related parameters, etc. from the target cell.

[0345] 3. The source network device sends the obtained public configuration information of the target cell in the source cell through broadcast, and sends the security parameters to the UE through dedicated signaling.

[0346] FIG. 7 is a flowchart of a handover method provided by an embodiment of the present disclosure, which is applied to a target network device. As shown in FIG. 7, the handover method includes but is not limited to step 701.

[0347] In step 701, a first cell radio network temporary identifier sent by a source network device is received, and the first cell radio network temporary identifier is an identifier allocated by the source network device for a terminal.

[0348] In the embodiment, the target network device receives the first cell radio network temporary identifier (first C-RNTI) of the terminal that needs to be handed over to the target cell sent by the source network device.

[0349] After receiving the first C-RNTI, the target network device sends a first control channel based on a handover dedicated radio network temporary identifier (denoted as HO-RNTI), and the first control channel carries the first cell radio network temporary identifier (first C-RNTI), a second cell radio network temporary identifier (second C-RNTI), and a random access resource.

[0350] The HO-RNTI can be a protocol predefined identifier. The second C-RNTI is an identifier allocated by the target network device for the terminal.

[0351] The first control channel can not carry a terminal-specific configuration of the terminal in the target network. The terminal-specific configuration is a configuration allocated by the target network device for the terminal. The first control channel is sent by the target network device, and the first control channel is a control channel scrambled by the HO-RNTI.

[0352] Optionally, the first control channel carries a plurality of first cell radio network temporary identifiers, a plurality of second cell radio network temporary identifiers, and a plurality of random access resources corresponding to the plurality of terminals respectively.

[0353] In some embodiments, after receiving the first cell radio network temporary identifier sent by the source network device in step 701, the handover method shown in FIG. 7 further includes the following steps not shown in FIG. 7:

[0354] sending a handover-specific radio network temporary identifier to the source network device.

[0355] In this embodiment, after receiving the first cell radio network temporary identifier (first C-RNTI), the target network device sends a handover-specific radio network temporary identifier (denoted as HO-RNTI) to the source network device. The HO-RNTI is generated by the target network device and sent to the terminal by the source network device.

[0356] In some embodiments, after receiving the first cell radio network temporary identifier sent by the source network device in step 701, the handover method shown in FIG. 7 further includes the following steps not shown in FIG. 7:

[0357] sending the second control channel based on the second cell radio network temporary identifier.

[0358] The target network device sends the second control channel based on the second cell radio network temporary identifier, for example, by scrambling the second control channel using the second cell radio network temporary identifier (second C-RNTI) and then sending the scrambled second control channel.

[0359] In some embodiments, the target network device sends the second control channel based on the second cell radio network temporary identifier, including: sending a first message through the second control channel; and the first message carries timing advance information.

[0360] The first message can be a random access response (RAR), or can not be an RAR, but other messages, signaling, or MAC control elements (MAC CEs), etc.

[0361] In some embodiments, the target network device sends the second control channel based on the second cell radio network temporary identifier, and the method further comprises:

[0362] sending a terminal specific configuration through the second control channel, the terminal specific configuration being a configuration allocated by the target network device for the terminal.

[0363] The second control channel can or can not carry the terminal specific configuration.

[0364] If the second control channel does not carry the terminal specific configuration, the target network device sends high layer signaling (e.g., RRC reconfiguration information) and / or data through the control channel, and carries the terminal specific configuration in the high layer signaling and / or data. The terminal receives the high layer signaling and / or data through the second control channel, and then obtains the terminal specific configuration from the high layer signaling and / or data. The data includes MAC CE (Media Access Control Control Element).

[0365] For example, after the terminal completes the non-contention random access to the target network device or the target network, the terminal receives the RRC reconfiguration information sent by the target network device through the second control channel, obtains the terminal specific configuration carried in the RRC reconfiguration information, and completes the handover.

[0366] In some embodiments, the handover method shown in FIG. 7 further comprises the following steps not shown in FIG. 7:

[0367] sending at least one of the following information to the source network device:

[0368] security parameters, common configuration information of the target network, and PDU session related parameters.

[0369] The security parameters are security parameters used by the terminal in the target network. The target network is a network defined by the target network device, or a network supported by the target network device, or a target cell to which the target network device belongs. The PDU session related parameters include indication information of acceptable / unacceptable PDU sessions.

[0370] As an example, the common configuration information of the target network is mandatory information, and the security parameters and the PDU session related parameters are optional information.

[0371] As an example, the security parameters are sent in a unicast form, and the common configuration information of the target network is sent in a broadcast or multicast form.

[0372] Embodiment Seven

[0373] The flow of the network side (target network device) for switching includes the following steps 1 to 4.

[0374] 1. The target network device receives the cell radio network temporary identifier (denoted as C-RNTI-s) of the UE that needs to be switched to the target cell in the source cell sent by the source network device, and sends the public configuration information of the target cell, necessary security parameters, PDU session related parameters, etc. to the source network device.

[0375] 2. The target network device sends a first control channel based on the HO-RNTI, and the first control channel carries the C-RNTI-s of the UE in the source cell, the cell radio network temporary identifier (denoted as C-RNTI-t) of the UE in the target cell, and the non-contention random access resource.

[0376] The time of sending the first control channel is based on the base station implementation, for example, the base station determines to send the first control channel when it covers the location where the UE is located.

[0377] 3. The target network device completes the random access process with the UE.

[0378] 4. The target network device sends the RRC reconfiguration information to the UE, and the terminal dedicated configuration carried in the RRC reconfiguration information.

[0379] Embodiment eight

[0380] FIG. 8 is a schematic diagram of a switching flow provided by an embodiment of the present disclosure, as shown in FIG. 8, the switching flow includes the following steps 1 to 6:

[0381] 1. The source network device determines the target network device, and the determination process is not the focus of the embodiment. The source network device can determine the target cell covering the current area of the source cell according to the ephemeris information. The source network device can also determine the data radio bearer (DRB) configuration information of the UE in the source cell.

[0382] 2. The source network device sends the cell radio network temporary identifier (denoted as C-RNTI-s) of the UE that needs to be switched to the target cell in the source cell to the determined target network device, and obtains the public configuration information of the target cell, necessary security parameters, PDU session related parameters, etc. from the target cell.

[0383] 3. The source network device sends the obtained public configuration information of the target cell in the source cell by broadcasting, and sends the security parameters to the UE by dedicated signaling.

[0384] 4. After the UE receives the common configuration information of the target cell, the UE switches to the target cell at a determined handover time point or based on a location, mainly to complete downlink synchronization with the target cell, complete control channel receiving configuration in the target cell, and then monitor a first control channel (PDCCH) sent by the target cell through the HO-RNTI.

[0385] 5. If the PDCCH monitored by the UE contains the C-RNTI-s of the UE in the source cell, the UE takes the cell radio network temporary identifier (denoted as C-RNTI-t) of the target cell contained in the PDCCH as the cell radio network temporary identifier of the UE in the target cell, uses the non-contention random access resource contained in the PDCCH, initiates non-contention random access through a non-contention physical random access channel (PRACH), and then obtains timing advance (TA) information, and uses the TA information to complete uplink synchronization with the target cell.

[0386] 6. After the UE completes the non-contention random access in the target cell, the UE receives RRC reconfiguration information from the target cell, obtains terminal-specific configuration of the UE in the target cell, completes reconfiguration of the UE by the target cell, and realizes handover.

[0387] It should be noted that, for the foregoing method embodiments, in order to simply describe, they are all described as a series of action combinations, but those skilled in the art can understand that the disclosure embodiments are not limited to the action sequence described, because according to the disclosure embodiments, certain steps can be performed in other sequences or simultaneously. In addition, those skilled in the art can understand that the embodiments described in the specification all belong to optional embodiments.

[0388] FIG. 9 is a schematic diagram of a handover device provided by an embodiment of the disclosure, which is applied to a terminal, as shown in FIG. 9, the handover device includes but is not limited to a receiving unit 91 and a monitoring unit 92, which are described as follows.

[0389] The receiving unit 91 is configured to receive a cell radio network temporary identifier sent by a source network device, the cell radio network temporary identifier being an identifier allocated by a target network device for the terminal;

[0390] The monitoring unit 92 is configured to monitor a control channel sent by the target network device according to the cell radio network temporary identifier, the control channel being a control channel scrambled by the cell radio network temporary identifier.

[0391] In some embodiments, the handover device further includes:

[0392] The obtaining unit is configured to obtain a random access resource through the control channel.

[0393] accessing, by an access unit, a random access procedure to the target network device or the target network based on a random access resource.

[0394] In some embodiments, the listening unit 92 is further configured to:

[0395] obtain the first message through a control channel; the first message carries timing advance information.

[0396] In some embodiments, the listening unit 92 is further configured to:

[0397] obtain a terminal-specific configuration through a control channel; the terminal-specific configuration is a configuration allocated by the target network device for the terminal.

[0398] In some embodiments, the receiving unit 91 is further configured to:

[0399] receive at least one of the following information sent by the source network device and / or the target network device:

[0400] security parameters, public configuration information of the target network, and protocol data unit session-related parameters.

[0401] Details of each embodiment of the switching device shown in FIG. 9 can refer to each embodiment of the switching method shown in FIG. 1, and will not be repeated here.

[0402] FIG. 10 is a schematic diagram of another switching device according to an embodiment of the present disclosure, which is applied to a source network device. As shown in FIG. 10, the switching device includes but is not limited to an obtaining unit 1001 and a sending unit 1002, and specific descriptions are as follows:

[0403] The obtaining unit 1001 is configured to obtain a cell radio network temporary identifier of the terminal, the cell radio network temporary identifier being an identifier allocated by the target network device for the terminal.

[0404] The sending unit 1002 is configured to send the cell radio network temporary identifier to the terminal, the cell radio network temporary identifier being used by the terminal to listen to a control channel sent by the target network device, the control channel being a control channel scrambled by the cell radio network temporary identifier.

[0405] In some embodiments, the sending unit 1002 is further configured to:

[0406] send a switching request to the target network device or the target network.

[0407] In some embodiments, the switching device further includes an interaction unit configured to:

[0408] After the sending unit 1002 sends a handover request to the target network device or the target network, it performs handover-related signaling interaction with the target network device; or, it performs handover-related signaling interaction with the target network device through the core network device.

[0409] In some embodiments, the sending unit 1002 is further configured to: send at least one of the following information to the terminal:

[0410] Security parameters, common configuration information of the target network, and protocol data unit session-related parameters.

[0411] In some embodiments, the acquisition unit 1001 is used for:

[0412] The terminal receives the temporary identifier of the cell's wireless network sent by the target network device.

[0413] For details of the various embodiments of the switching device shown in Figure 10, please refer to the various embodiments of the switching method shown in Figure 2. To avoid repetition, they will not be described again.

[0414] Figure 11 is a schematic diagram of another switching device provided in an embodiment of this disclosure, which is applied to a target network device. As shown in Figure 11, the switching device includes, but is not limited to, an acquisition unit 1101 and a sending unit 1102, as detailed below:

[0415] The acquisition unit 1101 is used to acquire the temporary identifier of the cell wireless network of the terminal;

[0416] The transmitting unit 1102 is used to send a temporary identifier of the cell network to the source network device. The temporary identifier of the cell network is used by the terminal to listen to the control channel sent by the target network device.

[0417] In some embodiments, the sending unit 1102 is further configured to: after the obtaining unit 1101 obtains the temporary identifier of the cell radio network of the terminal, send a control channel based on the temporary identifier of the cell radio network.

[0418] In some embodiments, the sending unit 1102 sends a control channel based on the temporary identifier of the cell radio network, including sending random access resources through the control channel.

[0419] In some embodiments, the sending unit 1102 sends a control channel based on the temporary identifier of the cell radio network, and further includes sending a first message through the control channel, wherein the first message carries timing advance information.

[0420] In some embodiments, the sending unit 1102 sends a control channel based on the temporary identifier of the cell radio network, and further includes: sending a terminal-specific configuration through the control channel, wherein the terminal-specific configuration is a configuration allocated by the target network device for the terminal to use.

[0421] In some embodiments, the switching apparatus further comprises a receiving unit, configured to:

[0422] receive the switching request sent by the source network device.

[0423] In some embodiments, the switching apparatus further comprises an interacting unit, configured to: after the receiving unit receives the switching request sent by the source network device, perform signaling interaction related to switching between the target network device; or perform signaling interaction related to switching between the target network device through the core network device.

[0424] In some embodiments, the sending unit 1102 is further configured to: send at least one of the following information to the terminal:

[0425] a security parameter, public configuration information of the target network, and a protocol data unit session related parameter.

[0426] Details of each embodiment of the switching apparatus shown in FIG. 11 can refer to each embodiment of the switching method shown in FIG. 3, and details are not repeated here.

[0427] FIG. 12 is a schematic diagram of another switching apparatus provided by an embodiment of the present disclosure, which is applied to a terminal. As shown in FIG. 12, the switching apparatus comprises but is not limited to a listening unit 1201, which is specifically described as follows:

[0428] The listening unit 1201 is configured to listen to a first control channel based on a switching-specific wireless network temporary identifier, and the first control channel carries a first cell wireless network temporary identifier, a second cell wireless network temporary identifier, and a random access resource; wherein the first cell wireless network temporary identifier is an identifier allocated by the source network device for the terminal, and the second cell wireless network temporary identifier is an identifier allocated by the target network device for the terminal.

[0429] In some embodiments, the switching apparatus further comprises:

[0430] The obtaining unit is configured to obtain the random access resource through the first control channel.

[0431] The accessing unit is configured to initiate a random access procedure to the target network device or the target network based on the random access resource.

[0432] In some embodiments, the obtaining unit is further configured to: obtain the second cell wireless network temporary identifier through the first control channel.

[0433] The listening unit 1201 is further configured to listen to a second control channel based on the second cell wireless network temporary identifier.

[0434] In some embodiments, the listening unit 1201 listens to the second control channel based on the second cell radio network temporary identifier, including: obtaining the first message through the second control channel; the first message carries the timing advance information.

[0435] In some embodiments, the listening unit 1201 listens to the second control channel based on the second cell radio network temporary identifier, further including: obtaining the terminal-specific configuration through the second control channel; the terminal-specific configuration is a configuration allocated by the target network device for the terminal.

[0436] In some embodiments, the switching device further includes a first receiving unit, configured to:

[0437] receive at least one of the following information sent by the source network device and / or the target network device:

[0438] the security parameter, the public configuration information of the target network, and the protocol data unit session related parameter.

[0439] In some embodiments, the switching device further includes a second receiving unit, configured to:

[0440] receive the switching-specific radio network temporary identifier sent by the source network device before the listening unit 1201 listens to the first control channel based on the switching-specific radio network temporary identifier.

[0441] Details of each embodiment of the switching device shown in FIG. 12 can refer to each embodiment of the switching method shown in FIG. 5, and details are not repeated here.

[0442] FIG. 13 is a schematic diagram of another switching device according to an embodiment of the present disclosure, which is applied to a source network device. As shown in FIG. 13, the switching device includes but is not limited to a sending unit 1301, which is configured to perform the following operations:

[0443] The sending unit 1301 is configured to send a first cell radio network temporary identifier to a target network device, the first cell radio network temporary identifier being an identifier allocated by the source network device for a terminal.

[0444] In some embodiments, the switching device further includes:

[0445] a receiving unit configured to receive a switching-specific radio network temporary identifier sent by the target network device;

[0446] The sending unit 1301 is further configured to send the switching-specific radio network temporary identifier to the terminal.

[0447] In some embodiments, the sending unit 1301 is further configured to send at least one of the following information to the terminal:

[0448] Security parameters, public configuration information of the target network.

[0449] Details of the switching device embodiments shown in FIG. 13 can refer to the switching method embodiments shown in FIG. 6, and will not be repeated here.

[0450] FIG. 14 is a schematic diagram of another switching device provided by an embodiment of the present disclosure, which is applied to a target network device. As shown in FIG. 14, the switching device includes but is not limited to a receiving unit 1401, which is described as follows.

[0451] The receiving unit 1401 is configured to receive a first cell radio network temporary identifier sent by a source network device, the first cell radio network temporary identifier being an identifier allocated by the source network device to a terminal.

[0452] In some embodiments, the switching device further includes a sending unit configured to send a first control channel based on the switching-specific radio network temporary identifier, the first control channel carrying the first cell radio network temporary identifier, a second cell radio network temporary identifier, and a random access resource; wherein the second cell radio network temporary identifier is an identifier allocated by the target network device to the terminal.

[0453] In some embodiments, the sending unit is further configured to send the switching-specific radio network temporary identifier to the source network device.

[0454] In some embodiments, the sending unit is further configured to send a second control channel based on the second cell radio network temporary identifier.

[0455] In some embodiments, the sending unit sends the second control channel based on the second cell radio network temporary identifier, including sending a first message through the second control channel; the first message carries timing advance information.

[0456] In some embodiments, the sending unit sends the second control channel based on the second cell radio network temporary identifier, further including sending a terminal-specific configuration through the second control channel, the terminal-specific configuration being a configuration allocated by the target network device to the terminal for use.

[0457] In some embodiments, the first control channel carries a plurality of first cell radio network temporary identifiers corresponding to a plurality of terminals respectively, second cell radio network temporary identifiers, and random access resources.

[0458] In some embodiments, the sending unit is further configured to send at least one of the following information to the source network device:

[0459] Security parameters, public configuration information of the target network, and protocol data unit session-related parameters.

[0460] Details of the switching device embodiments shown in FIG. 14 can refer to the switching method embodiments shown in FIG. 7, and will not be repeated here.

[0461] The embodiments of the present disclosure further provide a processor-readable storage medium, which stores a program for causing a processor to perform the steps of the switching method embodiments. The processor-readable storage medium can be any available medium or data storage device that can be accessed by the processor, including but not limited to a magnetic memory (such as a floppy disk, a hard disk, a magnetic tape, a magneto-optical disk (MO), etc.), an optical memory (such as a CD, a DVD, a BD, a HVD, etc.), and a semiconductor memory (such as a ROM, an EPROM, an EEPROM, a non-volatile memory (NAND FLASH), a solid-state disk (SSD)), etc.

[0462] FIG. 15 is a terminal provided by an embodiment of the present disclosure, wherein the terminal includes a memory 1501, a transceiver 1502, and a processor 1503;

[0463] The memory 1501 is configured to store a computer program; the transceiver 1502 is configured to transceive data under the control of the processor 1503; and the processor 1503 is configured to read the computer program in the memory 1501 and perform the following steps:

[0464] receiving a cell radio network temporary identifier sent by the source network device, the cell radio network temporary identifier being an identifier allocated to the terminal by the target network device;

[0465] listening to a control channel sent by the target network device according to the cell radio network temporary identifier, the control channel being a control channel scrambled by the cell radio network temporary identifier;

[0466] obtaining a random access resource through the control channel;

[0467] initiating a random access procedure to the target network device or the target network based on the random access resource.

[0468] In some embodiments, the listening to the control channel sent by the target network device according to the cell radio network temporary identifier includes: obtaining a first message through the control channel; and the first message carries timing advance information.

[0469] In some embodiments, the listening to the control channel sent by the target network device according to the cell radio network temporary identifier further includes: obtaining a terminal-specific configuration through the control channel; and the terminal-specific configuration is a configuration allocated to the terminal by the target network device for use by the terminal.

[0470] In some embodiments, the processor 1503 is further configured to:

[0471] receiving at least one of the following information sent by the source network device and / or the target network device:

[0472] security parameters, public configuration information of the target network, and protocol data unit session related parameters.

[0473] FIG. 16 is a source network device provided by an embodiment of the present disclosure, wherein the source network device comprises a memory 1601, a transceiver 1602, and a processor 1603;

[0474] The memory 1601 is configured to store a computer program; the transceiver 1602 is configured to transceive data under the control of the processor 1603; and the processor 1603 is configured to read the computer program in the memory 1601 and perform the following steps:

[0475] obtaining a cell radio network temporary identifier of the terminal, wherein the cell radio network temporary identifier is an identifier allocated to the terminal by the target network device;

[0476] sending the cell radio network temporary identifier to the terminal, wherein the cell radio network temporary identifier is used by the terminal to monitor a control channel sent by the target network device, and the control channel is a control channel scrambled by the cell radio network temporary identifier.

[0477] In some embodiments, the processor 1603 is further configured to:

[0478] sending a handover request to the target network device or the target network.

[0479] In some embodiments, after sending the handover request to the target network device or the target network, the processor 1603 is further configured to perform signaling interaction related to handover between the target network device, or perform signaling interaction related to handover between the target network device through a core network device.

[0480] In some embodiments, the processor 1603 is further configured to send at least one of the following information to the terminal:

[0481] security parameters, public configuration information of the target network, and protocol data unit session related parameters.

[0482] In some embodiments, the obtaining of the cell radio network temporary identifier of the terminal comprises:

[0483] receiving the cell radio network temporary identifier of the terminal sent by the target network device.

[0484] FIG. 17 is a target network device provided by an embodiment of the present disclosure, wherein the target network device comprises a memory 1701, a transceiver 1702, and a processor 1703;

[0485] The memory 1701 is configured to store a computer program; the transceiver 1702 is configured to transceive data under the control of the processor 1703; the processor 1703 is configured to read the computer program in the memory 1701 and execute:

[0486] Obtaining a cell radio network temporary identifier of the terminal;

[0487] Sending the cell radio network temporary identifier to the source network device, the cell radio network temporary identifier being used for the terminal to monitor a control channel sent by the target network device;

[0488] Sending the control channel based on the cell radio network temporary identifier.

[0489] In some embodiments, the control channel is sent based on the cell radio network temporary identifier, comprising:

[0490] Sending a random access resource through the control channel.

[0491] In some embodiments, the control channel is sent based on the cell radio network temporary identifier, further comprising:

[0492] Sending a first message through the control channel, the first message carrying timing advance information.

[0493] In some embodiments, the control channel is sent based on the cell radio network temporary identifier, further comprising:

[0494] Sending a terminal-specific configuration through the control channel, the terminal-specific configuration being a configuration allocated by the target network device for the terminal.

[0495] In some embodiments, the processor 1703 is further configured to receive a handover request sent by the source network device.

[0496] In some embodiments, after receiving the handover request sent by the source network device, the processor 1703 is further configured to:

[0497] Perform signaling interaction related to handover between the terminal and the source network device;

[0498] Or, perform signaling interaction related to handover between the terminal and the source network device through a core network device.

[0499] In some embodiments, the processor 1703 is further configured to send at least one of the following information to the terminal:

[0500] Security parameters, public configuration information of the target network, and protocol data unit session-related parameters.

[0501] FIG. 18 is a terminal provided by an embodiment of the present disclosure, wherein the terminal comprises a memory 1801, a transceiver 1802, and a processor 1803;

[0502] a memory 1801 for storing a computer program; a transceiver 1802 for transceiving data under control of the processor 1803; and a processor 1803 for reading the computer program in the memory 1801 and performing:

[0503] listening to the first control channel based on the handover-specific radio network temporary identifier, the first control channel carrying the first cell radio network temporary identifier, the second cell radio network temporary identifier, and the random access resource; wherein the first cell radio network temporary identifier is an identifier allocated to the terminal by the source network device, and the second cell radio network temporary identifier is an identifier allocated to the terminal by the target network device.

[0504] obtaining the random access resource through the first control channel.

[0505] initiating a random access procedure to the target network device or the target network based on the random access resource.

[0506] In some embodiments, the processor 1803 is further configured to:

[0507] listening to the second control channel based on the second cell radio network temporary identifier.

[0508] In some embodiments, listening to the second control channel based on the second cell radio network temporary identifier comprises:

[0509] obtaining the first message through the second control channel; the first message carrying timing advance information.

[0510] In some embodiments, listening to the second control channel based on the second cell radio network temporary identifier further comprises: obtaining a terminal-specific configuration through the second control channel; the terminal-specific configuration being a configuration allocated to the terminal by the target network device for use by the terminal.

[0511] In some embodiments, the processor 1803 is further configured to:

[0512] receiving at least one of the following information sent by the source network device and / or the target network device:

[0513] security parameters, public configuration information of the target network, and protocol data unit session-related parameters.

[0514] In some embodiments, before listening to the first control channel based on the handover-specific radio network temporary identifier, the processor 1803 is further configured to: receive the handover-specific radio network temporary identifier sent by the source network device.

[0515] FIG. 19 is a source network device provided by an embodiment of the present disclosure, wherein the source network device comprises a memory 1901, a transceiver 1902, and a processor 1903;

[0516] a memory 1901 for storing a computer program; a transceiver 1902 for transceiving data under control of the processor 1903; and the processor 1903 for reading the computer program in the memory 1901 and performing:

[0517] sending, to the target network device, a first cell radio network temporary identifier, the first cell radio network temporary identifier being an identifier allocated by the source network device for the terminal.

[0518] In some embodiments, the processor 1903 is further configured to:

[0519] receiving a handover-specific radio network temporary identifier sent by the target network device;

[0520] sending, to the terminal, the handover-specific radio network temporary identifier.

[0521] In some embodiments, the processor 1903 is further configured to send, to the terminal, at least one of the following information:

[0522] a security parameter, and public configuration information of the target network.

[0523] FIG. 20 is a target network device provided by an embodiment of the present disclosure, wherein the target network device comprises a memory 2001, a transceiver 2002, and a processor 2003;

[0524] the memory 2001 for storing a computer program; the transceiver 2002 for transceiving data under control of the processor 2003; and the processor 2003 for reading the computer program in the memory 2001 and performing:

[0525] receiving a first cell radio network temporary identifier sent by the source network device, the first cell radio network temporary identifier being an identifier allocated by the source network device for the terminal;

[0526] sending a first control channel based on a handover-specific radio network temporary identifier, the first control channel carrying the first cell radio network temporary identifier, a second cell radio network temporary identifier, and a random access resource; wherein the second cell radio network temporary identifier is an identifier allocated by the target network device for the terminal.

[0527] In some embodiments, the processor 2003 is further configured to:

[0528] sending, to the source network device, the handover-specific radio network temporary identifier.

[0529] In some embodiments, the processor 2003 is further configured to:

[0530] sending a second control channel based on the second cell radio network temporary identifier.

[0531] In some embodiments, the second control channel is transmitted based on the second cell radio network temporary identifier, including:

[0532] The first message is transmitted through the second control channel; the first message carries the timing advance information.

[0533] In some embodiments, the second control channel is transmitted based on the second cell radio network temporary identifier, and further including: transmitting a terminal-specific configuration through the second control channel, the terminal-specific configuration being a configuration allocated by the target network device for the terminal to use.

[0534] In some embodiments, the first control channel carries a plurality of first cell radio network temporary identifiers, a plurality of second cell radio network temporary identifiers, and a plurality of random access resources corresponding to a plurality of terminals respectively.

[0535] In some embodiments, the processor 2003 is further configured to send at least one of the following information to the source network device:

[0536] The security parameters, the public configuration information of the target network, and the protocol data unit session-related parameters.

[0537] In the above embodiments, the transceiver is configured to receive and send data under the control of the processor. The bus architecture can include any number of interconnected buses and bridges, various circuit links of which are linked together by the processor representing one or more processors and the memory representing the memory. The bus architecture can also link various other circuits such as peripheral devices, voltage stabilizers, and power management circuits, which are well known in the art and will not be further described herein. The bus interface provides an interface. The transceiver can be a plurality of elements, i.e., including a transmitter and a receiver, providing a unit for communicating with various other devices over transmission media, including wireless channels, wired channels, optical cables, and other transmission media. The processor is responsible for managing the bus architecture and general processing, and the memory can store data used by the processor in performing operations.

[0538] The processor can be an integrated circuit chip with a processing capability. In implementation process, each step of the above method can be completed by integrated logic circuit of hardware in the processor or by instructions in the form of software. The processor can be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0539] It should be noted that, in this document, the terms "comprising", "including", or any other variant thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements recited, but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the statement "comprising" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0540] Those skilled in the art can understand that although some embodiments described herein include certain features included in other embodiments but not others, the combination of features of different embodiments means within the scope of the disclosure and forms different embodiments.

[0541] Those skilled in the art can understand that the description of each embodiment is focused on, and the part not detailed in a certain embodiment can refer to the relevant description of other embodiments.

[0542] Although the embodiments of the present disclosure are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present disclosure, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A handover method applied to a terminal, the method comprising: receiving a cell radio network temporary identifier (C-RNTI) sent by a source network device, the C-RNTI being an identifier allocated to the terminal by a target network device; monitoring a control channel sent by the target network device according to the C-RNTI, the control channel being a control channel scrambled by the C-RNTI; obtaining a random access resource through the control channel; and initiating a random access procedure to the target network device or a target network based on the random access resource. The monitoring of the control channel sent by the target network device according to the C-RNTI comprises: obtaining a first message through the control channel, the first message carrying timing advance information; and / or obtaining a terminal-specific configuration through the control channel, the terminal-specific configuration being a configuration allocated to the terminal by the target network device for use by the terminal. The method further comprises: receiving at least one of the following information sent by the source network device and / or the target network device: security parameters, common configuration information of the target network, and protocol data unit (PDU) session-related parameters. 4.A handover method applied to a source network device, the method comprising: obtaining a C-RNTI of a terminal, the C-RNTI being an identifier allocated to the terminal by a target network device; and sending the C-RNTI to the terminal, the C-RNTI being used by the terminal to monitor a control channel sent by the target network device, the control channel being a control channel scrambled by the C-RNTI. The method further comprises: sending a handover request to the target network device or a target network; and performing signaling interaction related to handover between the source network device and the target network device, or performing signaling interaction related to handover between the source network device and the target network device through a core network device.

2. The method of claim 1, wherein, 6.A handover method applied to a target network device, the method comprising: obtaining a C-RNTI of a terminal; sending the C-RNTI to a source network device; and sending a control channel based on the C-RNTI. The sending of the control channel based on the C-RNTI comprises: sending a random access resource through the control channel; and / or sending a first message through the control channel, the first message carrying timing advance information; and / or sending a terminal-specific configuration through the control channel, the terminal-specific configuration being a configuration allocated to the terminal by the target network device for use by the terminal. The method further comprises: receiving a handover request sent by the source network device; and performing signaling interaction related to handover between the source network device and the target network device, or performing signaling interaction related to handover between the source network device and the target network device through a core network device.

3. The method of claim 1, wherein, 9.A handover method applied to a terminal, the method comprising: ​ ​ ​ ​ ​ 5. The method of claim 4, wherein, ​ ​ ​ ​ ​ ​ ​ 7. The method of claim 6, wherein, ​ ​ ​ ​ 8. The method of claim 6, wherein, ​ ​ ​ ​ listening to a first control channel based on a handover-specific radio network temporary identifier, the first control channel carrying a first cell radio network temporary identifier, a second cell radio network temporary identifier, and random access resources, wherein the first cell radio network temporary identifier is an identifier allocated by a source network device to the terminal, and the second cell radio network temporary identifier is an identifier allocated by a target network device to the terminal; obtaining random access resources through the first control channel; initiating a random access procedure to the target network device or target network based on the random access resources.

10. The method of claim 9, wherein, The method further comprises: listening to a second control channel based on the second cell radio network temporary identifier.

11. The method of claim 10, wherein, The listening to the second control channel based on the second cell radio network temporary identifier comprises: obtaining a first message through the second control channel, the first message carrying timing advance information; and / or obtaining a terminal-specific configuration through the second control channel, the terminal-specific configuration being a configuration allocated by the target network device to the terminal for use by the terminal.

12. The method of claim 9, wherein, The method further comprises: receiving at least one of the following information sent by the source network device and / or the target network device: security parameters, common configuration information of the target network, and protocol data unit session-related parameters.

13. The method of claim 9, wherein, Before the listening to the first control channel based on the handover-specific radio network temporary identifier, the method further comprises: receiving the handover-specific radio network temporary identifier sent by the source network device.

14. A handover method applied to a source network device, the method comprising: sending a first cell radio network temporary identifier to a target network device, the first cell radio network temporary identifier being an identifier allocated by the source network device to a terminal.

15. The method of claim 14, wherein, The method further comprises: receiving a handover-specific radio network temporary identifier sent by the target network device; sending the handover-specific radio network temporary identifier to the terminal.

16. A handover method applied to a target network device, the method comprising: receiving a first cell radio network temporary identifier sent by a source network device, the first cell radio network temporary identifier being an identifier allocated by the source network device to a terminal; sending a first control channel based on a handover-specific radio network temporary identifier, the first control channel carrying a first cell radio network temporary identifier, a second cell radio network temporary identifier, and random access resources, wherein the second cell radio network temporary identifier is an identifier allocated by the target network device to the terminal.

17. The method of claim 16, wherein, The method further comprises: sending the handover-specific radio network temporary identifier to the source network device.

18. The method of claim 16, wherein, The method further comprises: sending a second control channel based on the second cell radio network temporary identifier.

19. The method of claim 18, wherein, The sending of the second control channel based on the second cell radio network temporary identifier comprises: sending a first message through the second control channel, the first message carrying timing advance information; and / or sending a terminal-specific configuration through the second control channel, the terminal-specific configuration being a configuration allocated by the target network device to the terminal for use by the terminal.

20. A switching apparatus applied to a terminal, the apparatus comprising: a receiving unit configured to receive a cell radio network temporary identifier sent by a source network device, the cell radio network temporary identifier being an identifier allocated to the terminal by a target network device; a listening unit configured to listen to a control channel sent by the target network device according to the cell radio network temporary identifier, the control channel being a control channel scrambled by the cell radio network temporary identifier; an obtaining unit configured to obtain a random access resource through the control channel; an accessing unit configured to initiate a random access procedure to the target network device or target network based on the random access resource.

21. A switching apparatus applied to a source network device, the apparatus comprising: an obtaining unit configured to obtain a cell radio network temporary identifier of a terminal, the cell radio network temporary identifier being an identifier allocated to the terminal by a target network device; a sending unit configured to send the cell radio network temporary identifier to the terminal, the cell radio network temporary identifier being used by the terminal to listen to a control channel sent by the target network device, the control channel being a control channel scrambled by the cell radio network temporary identifier.

22. A switching apparatus applied to a target network device, the apparatus comprising: an obtaining unit configured to obtain a cell radio network temporary identifier of a terminal; a sending unit configured to send the cell radio network temporary identifier to a source network device, and send a control channel based on the cell radio network temporary identifier.

23. A switching apparatus applied to a terminal, the apparatus comprising: a listening unit configured to listen to a first control channel based on a switching-specific radio network temporary identifier, the first control channel carrying a first cell radio network temporary identifier, a second cell radio network temporary identifier and a random access resource; wherein the first cell radio network temporary identifier is an identifier allocated to the terminal by a source network device, and the second cell radio network temporary identifier is an identifier allocated to the terminal by a target network device; an obtaining unit configured to obtain a random access resource through the first control channel; an accessing unit configured to initiate a random access procedure to the target network device or target network based on the random access resource.

24. A switching apparatus applied to a source network device, the apparatus comprising: a sending unit configured to send a first cell radio network temporary identifier to a target network device, the first cell radio network temporary identifier being an identifier allocated to a terminal by the source network device.

25. A switching apparatus applied to a target network device, the apparatus comprising: a receiving unit configured to receive a first cell radio network temporary identifier sent by a source network device, the first cell radio network temporary identifier being an identifier allocated to a terminal by the source network device; a sending unit configured to send a first control channel based on a switching-specific radio network temporary identifier, the first control channel carrying a first cell radio network temporary identifier, a second cell radio network temporary identifier and a random access resource; wherein the second cell radio network temporary identifier is an identifier allocated to the terminal by the target network device.

26. A terminal, wherein, The terminal comprises a memory, a transceiver, and a processor; The memory is configured to store a computer program; the transceiver is configured to transceive data under the control of the processor; and the processor is configured to read the computer program in the memory and perform the following steps: receiving a cell radio network temporary identifier sent by a source network device, the cell radio network temporary identifier being an identifier allocated to the terminal by a target network device; listening to a control channel sent by the target network device according to the cell radio network temporary identifier, the control channel being a control channel scrambled by the cell radio network temporary identifier; obtaining a random access resource through the control channel; initiating a random access procedure to the target network device or target network based on the random access resource.

27. The terminal of claim 26, wherein, The listening to the control channel sent by the target network device according to the cell radio network temporary identifier comprises: obtaining a first message through the control channel, the first message carrying timing advance information; and / or obtaining a terminal-specific configuration through the control channel, the terminal-specific configuration being a configuration allocated to the terminal by the target network device for use by the terminal.

28. The terminal of claim 26, wherein, The processor is further configured to: receiving at least one of the following information sent by the source network device and / or the target network device: security parameters, public configuration information of the target network, and protocol data unit session-related parameters.

29. A source network device, wherein, The source network device comprises a memory, a transceiver, and a processor; The memory is configured to store a computer program; the transceiver is configured to transceive data under the control of the processor; and the processor is configured to read the computer program in the memory and perform the following steps: obtaining a cell radio network temporary identifier of a terminal, the cell radio network temporary identifier being an identifier allocated to the terminal by a target network device; sending the cell radio network temporary identifier to the terminal, the cell radio network temporary identifier being used by the terminal to listen to a control channel sent by the target network device, the control channel being a control channel scrambled by the cell radio network temporary identifier.

30. The source network device of claim 29, wherein, The processor is further configured to: sending a handover request to the target network device or target network; and performing signaling interaction related to handover between the target network device; or performing signaling interaction related to handover between the target network device through a core network device.

31. A target network device, wherein, The target network device comprises a memory, a transceiver, and a processor; The memory is configured to store a computer program; the transceiver is configured to transceive data under the control of the processor; and the processor is configured to read the computer program in the memory and perform the following steps: obtaining a cell radio network temporary identifier of a terminal; sending the cell radio network temporary identifier to a source network device; sending a control channel based on the cell radio network temporary identifier.

32. The target network device of claim 31, wherein, The sending of the control channel based on the cell radio network temporary identifier comprises: sending a random access resource through the control channel; and / or sending a first message through the control channel, the first message carrying timing advance information; And / or, sending a terminal-specific configuration through the control channel, the terminal-specific configuration being a configuration allocated by the target network device for the terminal to use.

33. The target network device of claim 31, wherein, The processor is further configured to: receive a handover request sent by the source network device; and the source network device related signaling interaction; or, and the source network device related signaling interaction through the core network device for handover.

34. A terminal, wherein, The terminal comprises a memory, a transceiver, a processor; The memory is configured to store a computer program; the transceiver is configured to transceive data under the control of the processor; and the processor is configured to read the computer program in the memory and perform: listening to a first control channel based on a handover-specific radio network temporary identifier, the first control channel carrying a first cell radio network temporary identifier, a second cell radio network temporary identifier, and random access resources; wherein the first cell radio network temporary identifier is an identifier allocated by the source network device for the terminal, and the second cell radio network temporary identifier is an identifier allocated by the target network device for the terminal; acquiring random access resources through the first control channel; initiating a random access procedure to the target network device or target network based on the random access resources.

35. The terminal of claim 34, wherein, The processor is further configured to: listening to a second control channel based on the second cell radio network temporary identifier.

36. The terminal of claim 35, wherein, The listening to the second control channel based on the second cell radio network temporary identifier comprises: acquiring a first message through the second control channel; the first message carries timing advance information; And / or, acquiring a terminal-specific configuration through the second control channel; the terminal-specific configuration is a configuration allocated by the target network device for the terminal to use.

37. The terminal of claim 34, wherein, The processor is further configured to: receive at least one of the following information sent by the source network device and / or the target network device: security parameters, public configuration information of the target network, and protocol data unit session related parameters.

38. The terminal of claim 34, wherein, Before listening to the first control channel based on the handover-specific radio network temporary identifier, the processor is further configured to: receive the handover-specific radio network temporary identifier sent by the source network device.

39. A source network device, wherein, The source network device comprises a memory, a transceiver, a processor; The memory is configured to store a computer program; the transceiver is configured to transceive data under the control of the processor; and the processor is configured to read the computer program in the memory and perform: sending a first cell radio network temporary identifier to the target network device, the first cell radio network temporary identifier being an identifier allocated by the source network device for the terminal.

40. The source network device of claim 39, wherein, The processor is further configured to: receive a handover-specific radio network temporary identifier sent by the target network device; send the handover-specific radio network temporary identifier to the terminal.

41. A target network device, wherein, The target network device comprises a memory, a transceiver, a processor; The memory is configured to store a computer program; the transceiver is configured to transceive data under the control of the processor; and the processor is configured to read the computer program in the memory and perform: receive a first cell radio network temporary identifier sent by a source network device, the first cell radio network temporary identifier being an identifier allocated to a terminal by the source network device; send a first control channel based on a handover-specific radio network temporary identifier, the first control channel carrying the first cell radio network temporary identifier, a second cell radio network temporary identifier and a random access resource, wherein the second cell radio network temporary identifier is an identifier allocated to the terminal by a target network device.

42. The target network device of claim 41, wherein, The processor is further configured to: send the handover-specific radio network temporary identifier to the source network device.

43. The target network device of claim 41, wherein, The processor is further configured to: send a second control channel based on the second cell radio network temporary identifier.

44. The target network device of claim 43, wherein, The sending of the second control channel based on the second cell radio network temporary identifier comprises: sending a first message through the second control channel, the first message carrying timing advance information; and / or sending a terminal-specific configuration through the second control channel, the terminal-specific configuration being a configuration allocated to the terminal by the target network device for use by the terminal.

45. A processor-readable storage medium, wherein, The processor readable storage medium stores a program for causing the processor to perform the handover method of any one of claims 1 to 3, or the handover method of claim 4 or 5, or the handover method of any one of claims 6 to 8, or the handover method of any one of claims 9 to 13, or the handover method of claim 14 or 15, or the handover method of any one of claims 16 to 19.

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