CN112789895B

CN112789895B - Switching method and device, terminal and network equipment

Info

Publication number: CN112789895B
Application number: CN201980064851.3A
Authority: CN
Inventors: 尤心
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2019-03-29
Filing date: 2019-03-29
Publication date: 2023-12-22
Anticipated expiration: 2039-03-29
Also published as: WO2020199003A1; CN112789895A

Abstract

The embodiment of the application provides a switching method and device, a terminal and network equipment, wherein the method comprises the following steps: and the terminal sends first information to the source base station, wherein the first information is used for indicating the source base station to reselect a target cell to be switched.

Description

Switching method and device, terminal and network equipment

Technical Field

The embodiment of the application relates to the technical field of mobile communication, in particular to a switching method and device, a terminal and network equipment.

Background

In the new wireless unlicensed (New Radio Unlicensed, NR-U), since the target base station fails to perform the listen before transmit (Listen Before Talk, LBT), even if the NR-U cell is selected as a target cell to be handed over or the terminal selects the NR-U cell as a cell to be accessed, since the NR-U cell is not within the maximum channel occupation time (Maximum Channel Occupy Time, MCOT), the terminal cannot perform a random access procedure or a handover procedure for the NR-U cell, and must wait until the NR-U cell is within the MCOT to perform a corresponding operation, which will cause an increase in handover delay, in other words, increase in transmission interruption time, and may even cause handover failure.

Disclosure of Invention

The embodiment of the application provides a switching method and device, a terminal and network equipment.

The switching method provided by the embodiment of the application comprises the following steps:

and the terminal sends first information to the source base station, wherein the first information is used for indicating the source base station to reselect a target cell to be switched.

and the source base station receives first information sent by the terminal, wherein the first information is used for indicating the source base station to reselect a target cell to be switched.

the terminal receives a second switching command sent by a source base station, wherein the second switching command is used for selecting a target cell to be switched from a plurality of candidate target cells based on switching conditions;

the second handover command carries second information, where the second information is used to indicate priority information corresponding to each of the plurality of candidate target cells.

the source base station sends a second switching command to the terminal, wherein the second switching command is used for selecting a target cell to be switched from a plurality of candidate target cells by the terminal based on a switching condition;

the terminal reselects a target cell to be switched under the condition that the terminal meets a second condition; wherein the second condition includes at least one of:

the currently selected target cell is a second type candidate target cell, wherein the second type candidate target cell refers to a cell on an unlicensed spectrum;

the target base station fails to execute LBT;

the target cell is not within the MCOT;

other candidate target cells meet the handover condition, wherein the other candidate target cells refer to candidate target cells other than the currently selected target cell;

other candidate target cells meet the switching condition, wherein the other candidate target cells refer to first-type candidate target cells except the currently selected target cell;

there is a specific first class of candidate target cells, the specific meaning at least one of: the switching condition is not satisfied, the switching condition is not judged, and the switching attempt is not executed;

there is a specific second class of candidate target cells, the specific meaning being at least one of: the switching condition is not satisfied, the switching condition is not judged, and the switching attempt is not executed;

There is a particular candidate target cell, the particular meaning being at least one of: the handover condition is not satisfied, the handover condition is not judged, and the handover attempt is not performed.

The switching device provided by the embodiment of the application comprises:

and the sending unit is used for sending first information to the source base station, wherein the first information is used for indicating the source base station to reselect a target cell to be switched.

The switching device provided by the embodiment of the application comprises:

and the receiving unit is used for receiving first information sent by the terminal, wherein the first information is used for indicating the source base station to reselect a target cell to be switched.

The switching device provided by the embodiment of the application comprises:

the terminal comprises a receiving unit, a switching unit and a switching unit, wherein the receiving unit is used for receiving a second switching command sent by a source base station, and the second switching command is used for selecting a target cell to be switched from a plurality of candidate target cells based on switching conditions;

The switching device provided by the embodiment of the application comprises:

a sending unit, configured to send a second handover command to a terminal, where the second handover command is used for the terminal to select a target cell to be handed over from multiple candidate target cells based on a handover condition;

The switching device provided by the embodiment of the application comprises:

a selecting unit, configured to reselect a target cell to be handed over if the second condition is satisfied; wherein the second condition includes at least one of:

the target base station fails to execute LBT;

the target cell is not within the MCOT;

The terminal provided by the embodiment of the application comprises a processor and a memory. The memory is used for storing a computer program, and the processor is used for calling and running the computer program stored in the memory to execute the switching method.

The network device provided by the embodiment of the application comprises a processor and a memory. The memory is used for storing a computer program, and the processor is used for calling and running the computer program stored in the memory to execute the switching method.

The chip provided by the embodiment of the application is used for realizing the switching method.

Specifically, the chip includes: and a processor for calling and running the computer program from the memory, so that the device mounted with the chip executes the above-mentioned switching method.

The computer readable storage medium provided in the embodiments of the present application is used for storing a computer program, where the computer program makes a computer execute the above-mentioned handover method.

The computer program product provided by the embodiment of the application comprises computer program instructions, wherein the computer program instructions enable a computer to execute the above-mentioned switching method.

The computer program provided in the embodiments of the present application, when executed on a computer, causes the computer to execute the above-described handover method.

According to the technical scheme, under the condition that the target base station fails to execute LBT and/or the condition that the time for executing switching by the terminal is not in the MCOT of the target base station, the terminal timely reports the condition to the source base station through the first information, so that the auxiliary source base station reselects the target cell to be switched according to the first information, and the purpose of completing switching as soon as possible is achieved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:

fig. 1 is a schematic diagram of a communication system architecture provided in an embodiment of the present application;

fig. 2 is a HO flowchart provided by an embodiment of the present application;

fig. 3 is a conditional HO flowchart provided in an embodiment of the present application;

fig. 4 is a schematic flow chart of a switching method according to an embodiment of the present application;

fig. 5 is a second flow chart of a switching method provided in the embodiment of the present application;

fig. 6 is a flowchart of a switching method according to an embodiment of the present application;

Fig. 7 is a flow chart diagram of a switching method provided in an embodiment of the present application;

fig. 8 is a flow chart diagram of a switching method provided in an embodiment of the present application;

fig. 9 is a flowchart of a switching method provided in an embodiment of the present application;

fig. 10 is a schematic diagram of the structural composition of a switching device according to an embodiment of the present disclosure;

fig. 11 is a schematic diagram of a second structural component of the switching device according to the embodiment of the present application;

fig. 12 is a schematic diagram III of the structural composition of the switching device according to the embodiment of the present application;

fig. 13 is a schematic diagram showing the structural composition of a switching device according to an embodiment of the present disclosure;

fig. 14 is a schematic diagram of the structural composition of the switching device according to the embodiment of the present application;

fig. 15 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

FIG. 16 is a schematic block diagram of a chip of an embodiment of the present application;

fig. 17 is a schematic block diagram of a communication system provided in an embodiment of the present application.

Detailed Description

The following description of the technical solutions in the embodiments of the present application will be made with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

The technical solution of the embodiment of the application can be applied to various communication systems, for example: global system for mobile communications (Global System of Mobile communication, GSM), code division multiple access (Code Division Multiple Access, CDMA), wideband code division multiple access (Wideband Code Division Multiple Access, WCDMA) systems, general packet radio service (General Packet Radio Service, GPRS), long term evolution (Long Term Evolution, LTE) systems, LTE frequency division duplex (Frequency Division Duplex, FDD) systems, LTE time division duplex (Time Division Duplex, TDD), universal mobile telecommunications system (Universal Mobile Telecommunication System, UMTS), worldwide interoperability for microwave access (Worldwide Interoperability for Microwave Access, wiMAX) communication systems, or 5G systems, and the like.

Exemplary, a communication system 100 to which embodiments of the present application apply is shown in fig. 1. The communication system 100 may include a network device 110, and the network device 110 may be a device that communicates with a terminal 120 (or referred to as a communication terminal, terminal). Network device 110 may provide communication coverage for a particular geographic area and may communicate with terminals located within the coverage area. Alternatively, the network device 110 may be a base station (Base Transceiver Station, BTS) in a GSM system or a CDMA system, a base station (NodeB, NB) in a WCDMA system, an evolved base station (Evolutional Node B, eNB or eNodeB) in an LTE system, or a radio controller in a cloud radio access network (Cloud Radio Access Network, CRAN), or the network device may be a mobile switching center, a relay station, an access point, a vehicle device, a wearable device, a hub, a switch, a bridge, a router, a network-side device in a 5G network, or a network device in a future evolved public land mobile network (Public Land Mobile Network, PLMN), etc.

The communication system 100 further includes at least one terminal 120 located within the coverage area of the network device 110. "terminal" as used herein includes, but is not limited to, connection via wireline, such as via public-switched telephone network (Public Switched Telephone Networks, PSTN), digital subscriber line (Digital Subscriber Line, DSL), digital cable, direct cable connection; and/or another data connection/network; and/or via a wireless interface, e.g., for a cellular network, a wireless local area network (Wireless Local Area Network, WLAN), a digital television network such as a DVB-H network, a satellite network, an AM-FM broadcast transmitter; and/or means of the other terminal arranged to receive/transmit communication signals; and/or internet of things (Internet of Things, ioT) devices. Terminals arranged to communicate over a wireless interface may be referred to as "wireless communication terminals", "wireless terminals" or "mobile terminals". Examples of mobile terminals include, but are not limited to, satellites or cellular telephones; a personal communications system (Personal Communications System, PCS) terminal that may combine a cellular radiotelephone with data processing, facsimile and data communications capabilities; a PDA that can include a radiotelephone, pager, internet/intranet access, web browser, organizer, calendar, and/or a global positioning system (Global Positioning System, GPS) receiver; and conventional laptop and/or palmtop receivers or other electronic devices that include a radiotelephone transceiver. A terminal may refer to an access terminal, user Equipment (UE), subscriber unit, subscriber station, mobile station, remote terminal, mobile device, user terminal, wireless communication device, user agent, or User Equipment. An access terminal may be a cellular telephone, a cordless telephone, a session initiation protocol (Session Initiation Protocol, SIP) phone, a wireless local loop (Wireless Local Loop, WLL) station, a personal digital assistant (Personal Digital Assistant, PDA), a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal in a 5G network or a terminal in a future evolved PLMN, etc.

Alternatively, direct to Device (D2D) communication may be performed between the terminals 120.

Alternatively, the 5G system or 5G network may also be referred to as a New Radio (NR) system or NR network.

Fig. 1 illustrates one network device and two terminals, alternatively, the communication system 100 may include multiple network devices and each network device may include other numbers of terminals within a coverage area, which is not limited in this embodiment.

Optionally, the communication system 100 may further include a network controller, a mobility management entity, and other network entities, which are not limited in this embodiment of the present application.

It should be understood that a device having a communication function in a network/system in an embodiment of the present application may be referred to as a communication device. Taking the communication system 100 shown in fig. 1 as an example, the communication device may include a network device 110 and a terminal 120 with communication functions, where the network device 110 and the terminal 120 may be specific devices described above, and are not described herein again; the communication device may also include other devices in the communication system 100, such as a network controller, a mobility management entity, and other network entities, which are not limited in this embodiment of the present application.

It should be understood that the terms "system" and "network" are used interchangeably herein. The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In order to facilitate understanding of the technical solutions of the embodiments of the present application, technical concepts related to the embodiments of the present application are described below.

NR can operate in unlicensed bands, including the following several operating scenarios:

1) Carrier aggregation scenario: a Primary Cell (PCell) is a licensed spectrum, and Secondary cells (scells) operating on an unlicensed spectrum are aggregated by carrier aggregation.

2) Double connection working scenario: the PCell is an LTE licensed spectrum and the primary and secondary cells (Primary Secondary cell, PScell) are NR unlicensed spectrum.

3) Independent working scene: NR operates as an independent cell on unlicensed spectrum.

Generally, the operating Band (Band) of NR-U is 5GHz unlicensed spectrum and 6GHz unlicensed spectrum; on unlicensed spectrum, the design of the NR-U should ensure fairness with other systems already operating on these unlicensed spectrum. The principle of fairness is that the NR-U cannot have more impact on systems that have been deployed on unlicensed spectrum than between these systems.

In order to ensure fair coexistence between systems on unlicensed spectrum, energy detection has been agreed as a basic coexistence mechanism. A general energy detection mechanism is an LBT mechanism, whose basic principle is that a base station or a terminal (transmitting end) needs to listen for a period of time as specified before transmitting data on an unlicensed spectrum. If the result of interception indicates that the channel is in an idle state, the transmitting end can transmit data to the receiving end. If the interception result indicates that the channel is in an occupied state, the transmission end needs to intercept the channel again according to a set back-off period, and knows that the channel interception result is in an idle state, and then the transmission end can transmit data to the receiving end.

For downlink data transmission, on an unlicensed frequency band, a base station needs to execute LBT; in LAA, the priority of channel access is determined by the following table 1:

TABLE 1

Wherein Mp has a relationship with listening channel time for performing channel access. Specifically, the base station needs to perform channel listening for Td time first, where td=16us+mp×9us.

CWmin, p and CWmax, p are related to the random listening channel time during channel access. Specifically, when the base station listens to the Td time channel to be idle, it needs to listen to the channel N times again, each time the duration is 9us. Where N is a random number from 0 to CWp.

Tmcot, p is the longest time that a base station occupies a channel after preempting the channel, and has a relation with the channel priority adopted by the base station, for example, the priority is 1, and after channel interception is successful, the channel is occupied for 2ms at most.

To sum up, for the terminal side, the base station needs to transmit data to the terminal in the MCOT, if the base station does not preempt the channel, the terminal will not receive the scheduling data from the base station to the terminal beyond the MCOT.

Referring to fig. 2, fig. 2 is a flowchart of a Handover (HO) procedure provided in an embodiment of the present application, where the procedure mainly includes the following steps:

1. the source base station issues measurement configuration to the terminal.

2. And the terminal performs relevant measurement based on the measurement configuration and reports the measurement result to the source base station.

3. The source base station makes a handover decision (handover decision) based on the measurement result.

4. The source base station initiates a Handover Request (Handover Request) to the target base station.

5. The target base station performs admission control (Admission Control).

6. The target base station sends a handover request-acknowledgement feedback message (Handover Request Ack) to the source base station.

7. The source base station transmits an RRC connection reconfiguration message to the terminal, the RRC connection reconfiguration message carrying mobility control information (mobility control information) of the target base station.

Here, the RRC connection reconfiguration message is carried in the handover command.

8. The source base station forwards the SN status to the target base station (SN Status Transfer).

9. The terminal synchronizes to the target base station.

10a, the target base station performs periodic uplink allocation (Periodic UL allocation) to the terminal.

And 10b, the target base station configures an uplink allocation and Tracking Area (TA) for the terminal.

11. The terminal transmits an RRC connection reconfiguration complete message to the target base station.

12. The target base station initiates a path switching request to the MME.

13. The MME initiates a modify bearer request to a Serving Gateway (Serving Gateway).

14. The service gateway switches the downstream path.

15. The serving gateway sends a modify bearer response message to the MME.

16. The MME sends a path switching request-acknowledgement feedback message to the target base station.

17. The target base station informs the source base station to release the terminal context.

18. The source base station releases the resources.

The above-mentioned switching process in fig. 2 mainly includes the following procedures:

-handover preparation (steps 1-6 in fig. 2): the source base station configures the terminal to carry out measurement reporting, and sends a switching request to the target base station based on the reporting result of the terminal. After the target base station agrees to the handover request, an RRC message is configured for the terminal, where the RRC message carries mobility control information (RACH) including random access channel (Random Access Channel) resources, cell-Radio Network Temporary Identifier, C-RNTI, a target base station security algorithm, and a system message of the target base station.

-handover execution (step 7-11 in fig. 2): the source base station forwards the mobile control information to the terminal through the switching command, and the terminal initiates a random access flow to the target base station after receiving the switching command. Meanwhile, the source base station forwards the sequence number STATUS (Serial Number STATUS TRANSFER, SN STATUS TRANSFER) to the target base station, and tells the target base station the uplink packet data convergence protocol (Packet Data Convergence Protocol, PDCP) SN receiving STATUS and the downlink PDCP SN sending STATUS.

Handover complete (steps 12-18 in fig. 2): after the terminal successfully accesses the target base station (i.e. the random access is successful), the target base station initiates a path switching REQUEST (PATH SWITCH REQUEST) to REQUEST the mobility management entity (Mobility Management Entity, MME) to switch the downlink path, and after the path switching is completed, the target base station indicates the source base station to release the terminal context, and the switching is completed.

For some special scenarios, such as high-speed movement of the terminal or high-frequency conditions, frequent handovers are required. The conditional HO (conditional handover) avoids the problem that the handover preparation time is too long, which results in the terminal having passed late when it is to be handed over, and configures the handover command for the terminal in advance. On the other hand, for a high-speed rail scenario, the moving track of the terminal is specific, so the base station may allocate the target base station to the terminal in advance, and include a condition for triggering the terminal to perform handover (hereinafter referred to as a handover condition) in the handover command, and when the target base station satisfies the handover condition, the terminal initiates an access request to the target base station.

As shown in fig. 3, conditional handover mainly includes the following procedures:

1. and carrying out measurement configuration/reporting of measurement results between the terminal and the source base station.

Here, the source base station issues measurement configuration to the terminal, and the terminal performs relevant measurement based on the measurement configuration and reports the measurement result to the source base station.

2. And performing a switching preparation flow between the source base station and the target base station.

3. And the source base station transmits a switching command to the terminal, wherein the switching command carries configuration information and switching conditions of a plurality of target base stations.

4. And when the target base station meets the switching condition, synchronizing the terminal to the target base station (namely, accessing the terminal to the target base station).

Further, a plurality of target cells and handover conditions may be configured in the handover command in the conditional handover scenario. The terminal judges which target cell to access based on the configured handover conditions.

In the third generation partnership project (3 ^rd Generation Partnership Project,3 GPP) mobility enhancement problem, an optimization method for reducing the interruption time at the time of handover is proposed, which includes the following two configurations:

1) Dual connectivity based handover (DC based HO)

During the handover, the target base station is added as a Secondary Node (SN), then the SN (target base station) is changed into a Master Node (MN) through role change signaling, and finally the source base station is released, so as to achieve the effect of reducing the interruption time during the handover.

2) eMBB-based handover (eMBB based HO)

Based on the existing switching flow, the terminal continuously keeps the connection with the source base station when receiving the switching command, and initiates random access to the target base station until the terminal and the target base station are accessed to complete, and then the connection of the source base station is released.

In NR-U, the target base station fails to perform LBT, so that NR-U cell is not in MCOT, and the terminal cannot directly perform random access process or handover process. Therefore, the embodiment of the application provides a switching method (particularly a switching method based on conditions) under an NR-U scene, which is used for selecting a more suitable target cell by a terminal or a network, and reducing switching time delay in a switching process.

Fig. 4 is a schematic flow chart of a switching method provided in an embodiment of the present application, as shown in fig. 4, where the switching method includes the following steps:

step 401: and the terminal sends first information to the source base station, wherein the first information is used for indicating the source base station to reselect a target cell to be switched.

In this embodiment of the present application, the terminal may be any device capable of communicating with a network, such as a mobile phone, a tablet computer, a notebook, a vehicle-mounted terminal, and a wearable device.

In the embodiment of the application, the cell in the source base station may be an NR-U cell, or an NR cell, or an LTE cell.

In the embodiment of the present application, the cell in the target base station is referred to as a target cell.

The embodiments of the present application apply to a handover procedure, which may be DC based HO in one embodiment, and ebb based HO in another embodiment.

In an embodiment, the terminal sends the first information to the source base station when the first condition is satisfied, and the source base station receives the first information sent by the terminal, where the first condition includes at least one of the following: the target base station fails to perform LBT, and the time for the terminal to perform handover is not within the MCOT of the target base station, during handover. Specifically, in the handover process, if the target base station fails to perform LBT and/or the time for the terminal to perform handover is not within the MCOT of the target base station, the terminal sends the first information to the source base station.

It should be noted that, the first information is used to instruct the source base station to reselect the target cell to be handed over, which may be implemented in at least one of the following ways:

1) The first information comprises indication information of reselecting a target cell to be switched;

2) The first information includes indication information that the target base station fails to perform LBT, and the indication information may also instruct the source base station to reselect a target cell to be switched;

3) The first information includes indication information that the target cell is not in the MCOT, and the indication information may also instruct the source base station to reselect the target cell to be handed over.

Step 402: the source base station reselects a target cell to be switched and/or modifies the priority of a candidate target cell based on the first information.

It should be noted that the technical solution of this embodiment may be applied to the HO procedure, or the conditional HO procedure. Wherein,

1) In the case of the HO procedure, the source base station sends a first handover command to the terminal, and the terminal receives the first handover command sent by the source base station, where the first handover command includes a configuration message of a target cell.

2) And under the condition of the conditional HO process, the source base station sends a second switching command to the terminal, and the terminal receives the second switching command sent by the source base station, wherein the second switching command comprises a configuration message of at least one candidate target cell and switching conditions. In particular, the second handover command includes a configuration message of one candidate target cell and handover conditions. In this scenario, the candidate target cells involved may include NR-U cells, NR cells, LTE cells.

A disadvantage of the prior art is that when the currently selected target cell is an NR-U cell, the terminal needs to be in a waiting state until MCOT due to LBT failure, which will cause handover delay and even handover failure. According to the technical scheme, the terminal can report the situation to the source base station through the first information in time under the situation (on the premise that the terminal and the source base station are connected), so that the source base station is assisted to reselect a proper target cell based on the first information to finish switching as soon as possible.

Fig. 5 is a second flow chart of a switching method provided in an embodiment of the present application, as shown in fig. 5, where the switching method includes the following steps:

step 501: the source base station selects a target cell to be switched and sends a switching request message to a target base station where the target cell is located.

Step 502: the target base station makes a handover decision (HO decision) to determine whether the terminal can access the target cell.

Step 503: if the terminal can access the target cell, the target base station sends a switching request confirmation message to the source base station.

Step 504: and the source base station sends a switching command to the terminal.

Step 505: and the terminal executes the switching process according to the switching command.

Step 506: when the terminal determines that the first condition is met, first information is sent to the source base station, wherein the first information is used for indicating at least one of the following: the target base station performs LBT failure, the target cell is not in the MCOT, and the target cell to be handed over is reselected.

Wherein the first condition includes at least one of: the target base station fails to perform LBT, the time for the terminal to perform handover is not within the MCOT of the target base station, during handover, handover/attempted handover is being performed.

After the above step 506, the source base station reselects the target cell to be handed over or modifies the priority of the candidate target cell according to the first information.

Fig. 6 is a flowchart third of a switching method provided in an embodiment of the present application, as shown in fig. 6, where the switching method includes the following steps:

step 601: the source base station sends a second switching command to the terminal, and the terminal receives the second switching command sent by the source base station, wherein the second switching command is used for selecting a target cell to be switched from a plurality of candidate target cells based on switching conditions by the terminal; the second handover command carries second information, where the second information is used to indicate priority information corresponding to each of the plurality of candidate target cells.

In this embodiment of the present application, the second information is used to indicate priority information corresponding to each of the plurality of candidate target cells, which may be implemented in at least one of the following manners:

1) The second information includes priority information;

2) The second information includes cell type information for indicating priority information.

In this application example, the cell type information may be divided according to the type of the spectrum where the cell is located, specifically, the cell on the licensed spectrum may be used as the first type candidate target cell, and the cell on the unlicensed spectrum may be used as the second type candidate target cell.

Of course, the cell type information may also be divided in other ways, e.g. by cell identity, by cell priority, etc.

In this application example, the plurality of candidate target cells includes a first type candidate target cell and/or a second type candidate target cell. The priority of the first type candidate target cells is different from that of the second type candidate target cells, wherein the first type candidate target cells refer to cells on authorized spectrums, and the second type candidate target cells refer to cells on unlicensed spectrums.

In this embodiment of the present application, the terminal selects a target cell to be switched. Here, the terminal may select a target cell to be handed over according to the priority of the cell. Specifically, after the terminal receives the second handover command sent by the source base station, the terminal performs at least one of the following actions: the method comprises the steps of sorting the candidate target cells based on priority, determining the judging sequence of the switching conditions based on the priority, sorting the priority of the candidate target cells meeting the switching conditions under the condition that the candidate target cells meet the switching conditions, and selecting the target cells to be switched according to the priority sequence in the candidate target cells meeting the switching conditions.

In an embodiment, the priority of a cell may be determined based on the type of cell or a target cell to be handed over may be selected, e.g. a cell on a licensed spectrum has a higher priority than a cell on an unlicensed spectrum. Based on this, the terminal may also rank the plurality of candidate target cells based on cell type. The terminal may also determine the order of handover condition decisions based on the cell type. The terminal may also determine a priority of a cell among a plurality of candidate target cells satisfying the handover condition or select a target cell to be handed over based on the cell type.

It should be noted that, determining the sequence of switching condition judgment based on the priority refers to: and judging the switching condition after sequencing the candidate target cells based on the priority. For example: the second handover command includes 2 candidate target cells, cell1 and cell2, where the priority of cell1 is higher than that of cell2, and then, whether cell1 meets the handover condition is determined first, and then whether cell2 meets the handover condition is determined.

When the plurality of candidate target cells satisfy the handover condition, the plurality of candidate target cells satisfying the handover condition are prioritized, and the target cell to be handed over is selected from the plurality of candidate target cells satisfying the handover condition according to the priority order, which means that: and under the condition that the plurality of candidate target cells meet the switching conditions, sequencing the candidate target cells meeting the switching conditions, and selecting the target cells to be switched from the sequenced candidate target cells. For example: the second handover command includes 2 candidate target cells, cell1 and cell2, where the priority of cell1 is higher than that of cell2, and if the handover conditions of the two candidate target cells are satisfied, then cell1 is considered as the target cell to be handed over.

In one embodiment of the present application, the first type of candidate target cell is higher in priority than the second type of candidate target cell in the plurality of candidate target cells. Based on this, the terminal performs at least one of the following actions: the method comprises the steps of selecting a first type candidate target cell preferentially from a plurality of candidate target cells to execute switching, selecting a first type candidate target cell preferentially to execute switching condition judgment, selecting a first type candidate target cell preferentially to execute switching when the plurality of candidate target cells meet switching conditions, and selecting a first type candidate target cell preferentially to execute switching when the plurality of candidate target cells meet switching conditions.

The technical scheme of the embodiment of the application can be applied to a conditional HO process, and in the conditional HO process, if the candidate target cell contains an NR-U cell, the priority of the NR cell is different from (such as higher than) the priority of the NR-U cell.

In this embodiment of the present application, the second handover command further includes cell type information and/or priority information corresponding to each of the plurality of candidate target cells. In this way, the terminal may determine the priority of the candidate target cell according to the cell type information and/or the priority information corresponding to the candidate target cell. For example: the cell type information of the cell1 is an NR-U cell, and the cell type information of the cell2 is an NR cell, and then the terminal may determine that the priority of the cell1 is lower than the priority of the cell2 according to the cell type information. Another example is: the cell type information of the cell1 is an NR-U cell and the priority is indicated as 1, the cell type information of the cell2 is an NR cell and the priority is indicated as 2, and then the terminal may determine that the priority of the cell1 is lower than the priority of the cell2 according to the cell type information and the priority.

It should be noted that, when performing handover, a higher priority cell is preferentially selected/used by the terminal or the base station.

The higher priority cell is preferentially selected/used when performing cell selection/reselection.

In this embodiment of the present application, if all candidate target cells that satisfy the handover condition are candidate target cells of the second class, the terminal selects a target cell to be handed over from all candidate target cells that satisfy the handover condition based on priority information and/or channel quality of the candidate target cells.

According to the technical scheme, the terminal selects the NR cell with the high priority as the target cell to be switched by utilizing the priority of the candidate target cell, so that switching time delay caused by LBT failure under the condition that the target cell is an NR-U cell is avoided.

Fig. 7 is a flow chart diagram of a switching method provided in an embodiment of the present application, as shown in fig. 7, where the switching method includes the following steps:

step 701: the source base station selects a target cell to be switched and sends a switching request message to a target base station where the target cell is located.

Step 702: the target base station makes a handover decision (HO decision) to determine whether the terminal can access the target cell.

Step 703: if the terminal can access the target cell, the target base station sends a switching request confirmation message to the source base station.

Step 704: and the source base station sends a switching command to the terminal, wherein the switching command carries configuration messages and switching conditions of a plurality of candidate target cells.

Further, the handover command also carries cell type information and/or priorities corresponding to the candidate target cells respectively.

Here, the cell type information may be an NR cell, or an LTE cell, or an NR-U cell, or the like.

Here, the priority refers to a selection priority or a use priority for cell handover/selection/reselection.

Step 705: and the terminal executes a switching process according to the switching condition and the priority of the candidate target cell.

For example: the terminal firstly determines candidate target cells meeting the switching conditions; then, among the candidate target cells satisfying the handover condition, the candidate target cell having the highest priority is selected as the target cell to be handed over. Further, if the candidate target cells satisfying the handover condition are all NR-U cells, the terminal selects a target cell to be handed over according to the priority and/or channel quality of the candidate target cells.

For example: the terminal sorts the candidate target cells according to the priority; then judging whether the cell meets the switching condition from high to low according to the priority sorting order; if the current cell meets the switching condition, the cell is a target cell to be switched, the switching process is executed or attempted to be executed in the cell, and if the current cell does not meet the switching condition, the attempt is continued or the attempt is continued periodically according to the polling mode until the target cell to be switched is found. Further, if the candidate target cells satisfying the handover condition are all NR-U cells, the terminal selects a target cell to be handed over according to the priority and/or channel quality of the candidate target cells.

Alternatively, the terminal may also preferentially use the NR-U cell or the NR cell as the target cell to be handed over according to a predefined rule.

Fig. 8 is a flowchart fifth of a switching method provided in an embodiment of the present application, as shown in fig. 8, where the switching method includes the following steps:

step 801: the terminal reselects the target cell to be handed over.

Further, the terminal reselects the target cell to be handed over if the second condition is satisfied. Wherein the second condition includes at least one of: the currently selected target cell is a second type candidate target cell, wherein the second type candidate target cell refers to a cell on an unlicensed spectrum; the target base station fails to execute LBT; the target cell is not within the MCOT; other candidate target cells meet the handover condition, wherein the other candidate target cells refer to candidate target cells other than the currently selected target cell; other candidate target cells meet the switching condition, wherein the other candidate target cells refer to first-type candidate target cells except the currently selected target cell; there is a specific first class of candidate target cells, the specific meaning at least one of: the switching condition is not satisfied, the switching condition is not judged, and the switching attempt is not executed; there is a specific second class of candidate target cells, the specific meaning being at least one of: the switching condition is not satisfied, the switching condition is not judged, and the switching attempt is not executed; there is a particular candidate target cell, the particular meaning being at least one of: the handover condition is not satisfied, the handover condition is not judged, and the handover attempt is not performed.

In the embodiment of the present application, when the second condition is satisfied, the terminal does not perform the handover procedure on the currently selected target cell, or does not continue to perform the handover procedure, but reselects the target cell to be handed over.

Here, when the terminal reselects the target cell to be handed over, the target cell to be handed over may be selected from other candidate target cells satisfying the handover condition based on channel quality and/or priority of the candidate target cells.

In an embodiment, when the terminal starts to perform the handover procedure on the currently selected target cell, if the second condition is satisfied, the terminal does not perform the handover procedure on the currently selected target cell.

In another embodiment, the second condition is not satisfied when the terminal starts to perform the handover procedure on the currently selected target cell; in the process of executing the switching process on the currently selected target cell, if the second condition is met, the terminal does not continue to execute the switching process on the currently selected target cell.

According to the technical scheme, when the terminal meets the second condition, the target cell to be switched is reselected, so that switching time delay caused by LBT failure under the condition that the target cell is an NR-U cell is avoided.

Fig. 9 is a flowchart sixth of a switching method provided in an embodiment of the present application, as shown in fig. 9, where the switching method includes the following steps:

step 901: the source base station selects a target cell to be switched and sends a switching request message to a target base station where the target cell is located.

Step 902: the target base station makes a handover decision (HO decision) to determine whether the terminal can access the target cell.

Step 903: if the terminal can access the target cell, the target base station sends a switching request confirmation message to the source base station.

Step 904: and the source base station sends a switching command to the terminal, wherein the switching command carries configuration messages and switching conditions of a plurality of candidate target cells.

Here, the priority refers to a selection priority or a use priority for cell selection/reselection.

Step 905: and the terminal executes the switching process according to the switching command. When the second condition is satisfied, the terminal does not or does not continue to perform the handover procedure on the currently selected target handover cell, but reselects the target cell to be handed over.

The second condition includes at least one of: the target cell currently selected is an NR-U cell, the base station fails to execute LBT, the target cell is not in MCOT, and other candidate target cells meet the switching condition.

Further, the terminal may select a cell with the best channel quality among other candidate target cells as the target cell to be handed over.

Fig. 10 is a schematic diagram of the structural composition of a switching device provided in the embodiment of the present application, where the switching device is applied to a terminal side, as shown in fig. 10, and the switching device includes:

a sending unit 1001, configured to send first information to a source base station, where the first information is used to instruct the source base station to reselect a target cell to be switched.

In an embodiment, the sending unit 1001 is configured to send first information to the source base station if a first condition is met, where the first condition includes at least one of: the target base station fails to perform LBT, and the time for the terminal to perform handover is not within the MCOT of the target base station, during handover.

In one embodiment, the apparatus further comprises:

a receiving unit 1002, configured to receive a first handover command sent by the source base station, where the first handover command includes a configuration message of a target cell.

In one embodiment, the apparatus further comprises:

a receiving unit 1002, configured to receive a second handover command sent by the source base station, where the second handover command includes a configuration message of at least one candidate target cell and a handover condition.

Those skilled in the art will appreciate that the above description of the switching device of the embodiments of the present application may be understood with reference to the description of the switching method of the embodiments of the present application.

Fig. 11 is a schematic diagram ii of the structural composition of a switching device provided in the embodiment of the present application, where the switching device is applied to a source base station side, as shown in fig. 11, and the switching device includes:

a receiving unit 1101, configured to receive first information sent by a terminal, where the first information is used to instruct the source base station to reselect a target cell to be switched.

In an embodiment, the first information is sent by the terminal to a source base station if a first condition is met; wherein the first condition includes at least one of: the target base station fails to perform LBT, and the time for the terminal to perform handover is not within the MCOT of the target base station, during handover.

In one embodiment, the apparatus further comprises:

A sending unit 1102, configured to send a first handover command to the terminal, where the first handover command includes a configuration message of a target cell.

In one embodiment, the apparatus further comprises:

a sending unit 1102, configured to send a second handover command to the terminal, where the second handover command includes a configuration message of at least one candidate target cell and a handover condition.

Fig. 12 is a schematic diagram III of the structural composition of a switching device provided in the embodiment of the present application, where the switching device is applied to a terminal side, as shown in fig. 12, and the switching device includes:

a receiving unit 1201, configured to receive a second handover command sent by a source base station, where the second handover command is used for the terminal to select a target cell to be handed over from a plurality of candidate target cells based on a handover condition;

In one embodiment, the second information includes priority information; or,

The second information includes cell type information for indicating priority information.

In an embodiment, the plurality of candidate target cells includes a first type of candidate target cell and/or a second type of candidate target cell, where the first type of candidate target cell has a priority different from that of the second type of candidate target cell, the first type of candidate target cell is a cell on an licensed spectrum, and the second type of candidate target cell is a cell on an unlicensed spectrum.

In one embodiment, the apparatus further comprises:

a sorting unit (not illustrated in the figures) for performing at least one of the following actions: the method comprises the steps of sorting the candidate target cells based on priority, determining the judging sequence of the switching conditions based on the priority, sorting the priority of the candidate target cells meeting the switching conditions under the condition that the candidate target cells meet the switching conditions, and selecting the target cells to be switched according to the priority sequence in the candidate target cells meeting the switching conditions.

In an embodiment, the first type of candidate target cell is higher in priority than the second type of candidate target cell in the plurality of candidate target cells.

In one embodiment, the apparatus further comprises:

a selection unit 1202 for performing at least one of the following actions: the method comprises the steps of selecting a first type candidate target cell preferentially from a plurality of candidate target cells to execute switching, selecting a first type candidate target cell preferentially to execute switching condition judgment, selecting a first type candidate target cell preferentially to execute switching when the plurality of candidate target cells meet switching conditions, and selecting a first type candidate target cell preferentially to execute switching when the plurality of candidate target cells meet switching conditions.

In one embodiment, the apparatus further comprises:

a selecting unit 1202, configured to select a target cell to be switched from all candidate target cells that satisfy the switching condition based on priority information and/or channel quality of the candidate target cells if all candidate target cells that satisfy the switching condition are candidate target cells of the second class.

Fig. 13 is a schematic diagram of a structural composition of a switching device according to an embodiment of the present application, where the switching device is applied to a source base station side, as shown in fig. 13, and the switching device includes:

a sending unit 1301 configured to send a second handover command to a terminal, where the second handover command is used for the terminal to select a target cell to be handed over from a plurality of candidate target cells based on a handover condition;

In one embodiment, the second information includes priority information; alternatively, the second information includes cell type information for indicating priority information.

Fig. 14 is a schematic diagram of the structural composition of a switching device provided in the embodiment of the present application, where the switching device is applied to a terminal side, as shown in fig. 14, and the switching device includes:

a selecting unit 1401 for reselecting a target cell to be handed over in case that the second condition is satisfied; wherein the second condition includes at least one of:

the target base station fails to execute LBT;

the target cell is not within the MCOT;

In one embodiment, the apparatus further comprises:

a receiving unit 1402, configured to receive a second handover command sent by a source base station, where the second handover command includes configuration messages of a plurality of candidate target cells and handover conditions.

In an embodiment, the selecting unit 1401 is configured to select the target cell to be handed over from other candidate target cells that meet the handover condition based on the channel quality and/or priority of the candidate target cells.

Fig. 15 is a schematic structural diagram of a communication device 1500 provided in an embodiment of the present application. The communication device may be a terminal or a network device (e.g., a source base station), and the communication device 1500 shown in fig. 15 includes a processor 1510, where the processor 1510 may call and execute a computer program from a memory to implement the methods in the embodiments of the present application.

Optionally, as shown in fig. 15, the communication device 1500 may also include a memory 1520. Wherein the processor 1510 may invoke and run a computer program from the memory 1520 to implement the methods in embodiments of the present application.

Wherein the memory 1520 may be a separate device from the processor 1510 or may be integrated into the processor 1510.

Optionally, as shown in fig. 15, the communication device 1500 may further include a transceiver 1530, and the processor 1510 may control the transceiver 1530 to communicate with other devices, and in particular, may send information or data to other devices, or receive information or data sent by other devices.

Wherein the transceiver 1530 may include a transmitter and a receiver. The transceiver 1530 may further include an antenna, the number of which may be one or more.

Optionally, the communication device 1500 may be specifically a network device in the embodiments of the present application, and the communication device 1500 may implement corresponding flows implemented by the network device in the methods in the embodiments of the present application, which are not described herein for brevity.

Optionally, the communication device 1500 may be a mobile terminal/terminal in the embodiment of the present application, and the communication device 1500 may implement a corresponding flow implemented by the mobile terminal/terminal in each method in the embodiment of the present application, which is not described herein for brevity.

Fig. 16 is a schematic structural diagram of a chip of an embodiment of the present application. The chip 1600 shown in fig. 16 includes a processor 1610, and the processor 1610 may call and execute a computer program from a memory to implement the methods in the embodiments of the present application.

Optionally, as shown in fig. 16, the chip 1600 may also include a memory 1620. Wherein the processor 1610 may invoke and run a computer program from the memory 1620 to implement the methods in embodiments of the present application.

Wherein memory 1620 may be a separate device from processor 1610 or may be integrated within processor 1610.

Optionally, the chip 1600 may also include an input interface 1630. Wherein processor 1610 may control the input interface 1630 to communicate with other devices or chips, and in particular may obtain information or data sent by other devices or chips.

Optionally, the chip 1600 may also include an output interface 1640. Wherein processor 1610 may control the output interface 1640 to communicate with other devices or chips, and in particular may output information or data to other devices or chips.

Optionally, the chip may be applied to a network device in the embodiment of the present application, and the chip may implement a corresponding flow implemented by the network device in each method in the embodiment of the present application, which is not described herein for brevity.

Optionally, the chip may be applied to a mobile terminal/terminal in the embodiments of the present application, and the chip may implement a corresponding flow implemented by the mobile terminal/terminal in each method in the embodiments of the present application, which is not described herein for brevity.

It should be understood that the chips referred to in the embodiments of the present application may also be referred to as system-on-chip chips, or the like.

Fig. 17 is a schematic block diagram of a communication system 1700 provided by an embodiment of the present application. As shown in fig. 17, the communication system 1700 includes a terminal 1710 and a network device 1720.

The terminal 1710 may be configured to implement the corresponding function implemented by the terminal in the above method, and the network device 1720 may be configured to implement the corresponding function implemented by the network device in the above method, which are not described herein for brevity.

It should be appreciated that the processor of an embodiment of the present application may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method embodiments may be implemented by integrated logic circuits of hardware in a processor or instructions in software form. The processor may be a general purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), an off-the-shelf programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The disclosed methods, steps, and logic blocks in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present application may be embodied directly in hardware, in a decoded processor, or in a combination of hardware and software modules in a decoded processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in a memory, and the processor reads the information in the memory and, in combination with its hardware, performs the steps of the above method.

It will be appreciated that the memory in embodiments of the present application may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The nonvolatile Memory may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable EPROM (EEPROM), or a flash Memory. The volatile memory may be random access memory (Random Access Memory, RAM) which acts as an external cache. By way of example, and not limitation, many forms of RAM are available, such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double Data Rate SDRAM (Double Data Rate SDRAM), enhanced SDRAM (ESDRAM), synchronous DRAM (SLDRAM), and Direct RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It should be understood that the above memory is exemplary but not limiting, and for example, the memory in the embodiments of the present application may be Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous Link DRAM (SLDRAM), direct RAM (DR RAM), and the like. That is, the memory in embodiments of the present application is intended to comprise, without being limited to, these and any other suitable types of memory.

Embodiments of the present application also provide a computer-readable storage medium for storing a computer program.

Optionally, the computer readable storage medium may be applied to a network device in the embodiments of the present application, and the computer program causes a computer to execute a corresponding flow implemented by the network device in each method in the embodiments of the present application, which is not described herein for brevity.

Optionally, the computer readable storage medium may be applied to a mobile terminal/terminal in the embodiments of the present application, and the computer program causes a computer to execute a corresponding procedure implemented by the mobile terminal/terminal in each method of the embodiments of the present application, which is not described herein for brevity.

Embodiments of the present application also provide a computer program product comprising computer program instructions.

Optionally, the computer program product may be applied to a network device in the embodiments of the present application, and the computer program instructions cause the computer to execute corresponding flows implemented by the network device in the methods in the embodiments of the present application, which are not described herein for brevity.

Optionally, the computer program product may be applied to a mobile terminal/terminal in the embodiments of the present application, and the computer program instructions cause the computer to execute corresponding processes implemented by the mobile terminal/terminal in the methods in the embodiments of the present application, which are not described herein for brevity.

The embodiment of the application also provides a computer program.

Optionally, the computer program may be applied to a network device in the embodiments of the present application, and when the computer program runs on a computer, the computer is caused to execute a corresponding flow implemented by the network device in each method in the embodiments of the present application, which is not described herein for brevity.

Optionally, the computer program may be applied to a mobile terminal/terminal in the embodiments of the present application, where the computer program when run on a computer causes the computer to execute corresponding processes implemented by the mobile terminal/terminal in the methods in the embodiments of the present application, and for brevity, will not be described in detail herein.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a usb disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of handover, the method comprising:

the terminal sends first information to a source base station, wherein the first information is used for indicating the source base station to reselect a target cell to be switched; the terminal sends first information to the source base station under the condition that a first condition is met, wherein the first condition comprises: the time for the terminal to execute the switching is not within the maximum channel occupation time MCOT of the target base station;

and the terminal receives a second switching command sent by the source base station, wherein the second switching command comprises a configuration message of at least one candidate target cell and switching conditions.

2. The handover method according to claim 1, wherein,

the second switching command is used for selecting a target cell to be switched from a plurality of candidate target cells by the terminal based on a switching condition;

The second handover command carries second information, where the second information is used to indicate priority information corresponding to each of the candidate target cells; the plurality of candidate target cells comprise a first type of candidate target cell and/or a second type of candidate target cell, the priority of the first type of candidate target cell is different from the priority of the second type of candidate target cell, the first type of candidate target cell refers to a cell on an authorized spectrum, and the second type of candidate target cell refers to a cell on an unlicensed spectrum; the priority of a first type candidate target cell is higher than that of a second type candidate target cell in the plurality of candidate target cells;

the terminal performs at least one of the following actions: and in the plurality of candidate target cells, the first type candidate target cells are preferentially selected to execute switching condition judgment, and in the case that the plurality of candidate target cells meet the switching condition, the first type candidate target cells meeting the switching condition are preferentially selected to execute switching.

3. The method of claim 2, wherein,

the second information includes priority information; or,

4. A method according to claim 2 or 3, wherein the method further comprises:

the terminal performs at least one of the following actions: the method comprises the steps of sorting the candidate target cells based on priority, determining the judging sequence of the switching conditions based on the priority, sorting the priority of the candidate target cells meeting the switching conditions under the condition that the candidate target cells meet the switching conditions, and selecting the target cells to be switched according to the priority sequence in the candidate target cells meeting the switching conditions.

5. The method of claim 4, wherein the method further comprises:

and if all the candidate target cells meeting the switching conditions are the second type of candidate target cells, the terminal selects the target cell to be switched from all the candidate target cells meeting the switching conditions based on the priority information and/or the channel quality of the candidate target cells.

6. The handover method according to claim 2, further comprising:

the terminal reselects a target cell to be switched under the condition that a second condition is met; wherein the second condition includes at least one of:

the target base station fails to execute LBT;

the target cell is not within the MCOT;

7. The method of claim 6, wherein the reselecting the target cell to be handed over comprises:

And the terminal selects a target cell to be switched from other candidate target cells meeting the switching condition based on the channel quality and/or the priority of the candidate target cells.

8. A method of handover, the method comprising:

the method comprises the steps that a source base station receives first information sent by a terminal, wherein the first information is used for indicating the source base station to reselect a target cell to be switched; wherein the first information is sent by the terminal to the source base station if a first condition is satisfied; wherein the first condition includes: the time for the terminal to execute the switching is not in the MCOT of the target base station;

and the source base station sends a second switching command to the terminal, wherein the second switching command comprises a configuration message of at least one candidate target cell and switching conditions.

9. The handover method of claim 8, wherein,

the second handover command carries second information, where the second information is used to indicate priority information corresponding to each of the candidate target cells; the plurality of candidate target cells comprise a first type of candidate target cell and/or a second type of candidate target cell, the priority of the first type of candidate target cell is different from the priority of the second type of candidate target cell, the first type of candidate target cell refers to a cell on an authorized spectrum, and the second type of candidate target cell refers to a cell on an unlicensed spectrum; the first type candidate target cells of the plurality of candidate target cells have a higher priority than the second type candidate target cells.

10. The method of claim 9, wherein,

the second information includes priority information; or,

11. A switching device, the device comprising:

a sending unit, configured to send first information to a source base station, where the first information is used to instruct the source base station to reselect a target cell to be switched; the sending unit is configured to send first information to a source base station when a first condition is met, where the first condition includes: the time for the terminal to execute the switching is not in the MCOT of the target base station;

and the receiving unit is used for receiving a second switching command sent by the source base station, wherein the second switching command comprises a configuration message of at least one candidate target cell and switching conditions.

12. The switching device according to claim 11, wherein,

the second switching command is used for selecting a target cell to be switched from a plurality of candidate target cells by the terminal based on a switching condition; the second handover command carries second information, where the second information is used to indicate priority information corresponding to each of the candidate target cells; the plurality of candidate target cells comprise a first type of candidate target cell and/or a second type of candidate target cell, the priority of the first type of candidate target cell is different from the priority of the second type of candidate target cell, the first type of candidate target cell refers to a cell on an authorized spectrum, and the second type of candidate target cell refers to a cell on an unlicensed spectrum; the priority of a first type candidate target cell is higher than that of a second type candidate target cell in the plurality of candidate target cells;

The apparatus further comprises: a selection unit for performing at least one of the following actions: and in the plurality of candidate target cells, the first type candidate target cells are preferentially selected to execute switching condition judgment, and in the case that the plurality of candidate target cells meet the switching condition, the first type candidate target cells meeting the switching condition are preferentially selected to execute switching.

13. The apparatus of claim 12, wherein,

the second information includes priority information; or,

14. The apparatus according to claim 12 or 13, wherein the apparatus further comprises:

a sorting unit for performing at least one of the following actions: the method comprises the steps of sorting the candidate target cells based on priority, determining the judging sequence of the switching conditions based on the priority, sorting the priority of the candidate target cells meeting the switching conditions under the condition that the candidate target cells meet the switching conditions, and selecting the target cells to be switched according to the priority sequence in the candidate target cells meeting the switching conditions.

15. The apparatus of claim 14, wherein,

the selecting unit is configured to select a target cell to be switched from all candidate target cells that satisfy the switching condition based on priority information and/or channel quality of the candidate target cells if all candidate target cells that satisfy the switching condition are candidate target cells of the second class.

16. The switching device of claim 12, the device further comprising:

the target base station fails to execute LBT;

the target cell is not within the MCOT;

17. The apparatus of claim 16, wherein the selecting unit is configured to select a target cell to be handed over from other candidate target cells that meet the handover condition based on channel quality and/or priority of the candidate target cells.

18. A switching device, the device comprising:

the receiving unit is used for receiving first information sent by the terminal, wherein the first information is used for indicating the source base station to reselect a target cell to be switched; the first information is sent to a source base station by the terminal under the condition that a first condition is met; wherein the first condition includes: the time for the terminal to execute the switching is not in the MCOT of the target base station;

And the sending unit is used for sending a second switching command to the terminal, wherein the second switching command comprises a configuration message of at least one candidate target cell and switching conditions.

19. The switching device of claim 18, wherein,

the second switching command is used for selecting a target cell to be switched from a plurality of candidate target cells by the terminal based on a switching condition; the second handover command carries second information, where the second information is used to indicate priority information corresponding to each of the candidate target cells; the plurality of candidate target cells comprise a first type of candidate target cell and/or a second type of candidate target cell, the priority of the first type of candidate target cell is different from that of the second type of candidate target cell, the first type of candidate target cell refers to a cell on an authorized spectrum, and the second type of candidate target cell refers to a cell on an unlicensed spectrum; the first type candidate target cells of the plurality of candidate target cells have a higher priority than the second type candidate target cells.

20. The apparatus of claim 19, wherein,

the second information includes priority information; or,

21. A terminal, comprising: a processor and a memory for storing a computer program, the processor being adapted to invoke and run the computer program stored in the memory for performing the method according to any of claims 1 to 7.

22. A network device, comprising: a processor and a memory for storing a computer program, the processor being adapted to invoke and run the computer program stored in the memory, to perform the method according to any of claims 8 to 10.

23. A chip, comprising: a processor for calling and running a computer program from a memory, causing a device on which the chip is mounted to perform the method of any one of claims 1 to 7.

24. A chip, comprising: a processor for calling and running a computer program from a memory, causing a device on which the chip is mounted to perform the method of any of claims 8 to 10.

25. A computer readable storage medium storing a computer program for causing a computer to perform the method of any one of claims 1 to 7.

26. A computer readable storage medium storing a computer program for causing a computer to perform the method of any one of claims 8 to 10.