Communication Method, Device, and Computer-Readable Medium in a Wireless Communication System

Abstract

Embodiments of the present disclosure relate to a method, device, and computer-readable medium for reporting a conditional handover (CHO) attempt failure. The method includes obtaining configuration information related to candidate cells for conditional handover of a terminal device. The method further includes initiating at least one conditional handover attempt to at least one candidate cell. The method further includes storing failure information of the at least one conditional handover attempt in response to the at least one conditional handover attempt to the at least one candidate cell failing during the conditional handover process. In this way, a new fault reporting mechanism can be implemented.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of communications, and more particularly, to communication methods, devices, and computer-readable media for reporting conditional handover (CHO) attempt failures. Background Art

[0002] As is well known, if a terminal device successfully executes a handover (HO) process, it can switch from a source cell to a target cell. However, handover failures mainly occur due to failures in handover command transmission. To improve handover reliability, agreement has been reached on applying conditional handover (CHO) in Rel-16 LTE and NR.

[0003] When the channel between the source network device (gNB or eNB) and the terminal device is still in a good state, the source network device can transmit CHO configurations related to multiple CHO candidate cells to the terminal device, including the configurations of the CHO candidate cells and the CHO execution conditions. Once any CHO candidate cell meets the CHO execution conditions, for example, the channel state between the target cell (CHO candidate cell) and the terminal device is offset better than the channel state between the serving cell and the terminal device, the terminal device can autonomously connect to the target cell without the source network device sending a message to indicate the start of CHO execution. Summary of the Invention

[0004] Generally speaking, example embodiments of the present disclosure provide methods, devices, and computer-readable media for reporting conditional handover (CHO) attempt failures.

[0005] In a first aspect, a method implemented at a terminal device is provided. The method includes: obtaining configuration information related to candidate cells for conditional handover for the terminal device. The method further includes: initiating at least one conditional handover attempt to at least one candidate cell. The method further includes: in response to at least one conditional handover attempt to the at least one candidate cell failing during the conditional handover process, storing failure information of the at least one conditional handover attempt.

[0006] In a second aspect, a method implemented at a terminal device is provided. The method includes: obtaining configuration information related to candidate cells for conditional handover for the terminal device. The method further includes: initiating at least one conditional handover attempt to at least one candidate cell. The method further includes: in response to at least one conditional handover attempt to the at least one candidate cell failing during the conditional handover process, ignoring the failure of the at least one conditional handover attempt.

[0007] In a third aspect, a terminal device is provided. The terminal device includes: a processor; and a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the terminal device to perform the actions according to the first aspect.

[0008] In a fourth aspect, a terminal device is provided. The terminal device includes: a processor; and a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the terminal device to perform the actions according to the second aspect.

[0009] In a fifth aspect, a computer-readable medium having instructions stored thereon is provided, the instructions, when executed on at least one processor, causing the at least one processor to perform the method according to the first aspect.

[0010] In a sixth aspect, a computer-readable medium having instructions stored thereon is provided, the instructions, when executed on at least one processor, causing the at least one processor to perform the method according to the second aspect.

[0011] Through the following description, other features of the present disclosure will become readily understandable. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Through a more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:

[0013] Figure 1 is a schematic diagram of a communication environment in which some embodiments of the present disclosure can be implemented;

[0014] Figure 2 shows a schematic diagram illustrating a process 200 for reporting a Conditional Handover (CHO) attempt failure according to an example embodiment of the present disclosure;

[0015] Figure 3 shows a flowchart of an example method 300 according to some embodiments of the present disclosure;

[0016] Figure 4 shows a flowchart of an example method 400 according to some embodiments of the present disclosure;

[0017] Figure 5 shows a flowchart of an example method 500 according to some embodiments of the present disclosure; and

[0018] Figure 6 is a simplified block diagram of a device suitable for implementing embodiments of the present disclosure.

[0019] In all the drawings, the same or similar reference numerals represent the same or similar elements. Detailed implementation manners

[0020] The principles of the present disclosure will now be described with reference to some exemplary embodiments. It should be understood that the description of these embodiments is only for illustration and to assist those skilled in the art in understanding and implementing the present disclosure, and does not imply any limitation on the scope of the present disclosure. The present disclosure described herein can be implemented in various ways other than those described below.

[0021] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0022] As used herein, the term "network device" or "base station" (BS) refers to a device that can provide or accommodate a cell or coverage area in which a terminal device can communicate. Examples of network devices include, but are not limited to, Node B (Node B or NB), evolved Node B (eNodeB or eNB), next-generation Node B (gNB), remote radio unit (RRU), radio head (RH), remote radio head (RRH), low-power nodes such as femto nodes, pico nodes, etc. For the purpose of discussion, some embodiments will be described below with reference to gNB as an example of a network device.

[0023] As used herein, the term "terminal device" refers to any device having wireless communication capabilities or wired communication capabilities. Examples of terminal devices include, but are not limited to, user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smart phones, personal digital assistants (PDA), portable computers, image capture devices such as digital cameras, gaming devices, music storage and playback devices, or Internet devices capable of wireless or wired Internet access and browsing, etc.

[0024] As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly indicates otherwise. The term "comprising" and its variants should be understood as open terms, meaning "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "an embodiment" and "one embodiment" should be understood as "at least one embodiment". The term "another embodiment" should be understood as "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may be included below.

[0025] In some examples, values, processes, or devices are referred to as "optimal", "lowest", "highest", "minimum", "maximum", etc. It should be understood that such descriptions are intended to indicate that a selection can be made among many functional alternatives in use, and that such a selection does not need to be better, smaller, higher, or more preferred than other selections.

[0026] Figure 1 FIG. 100 shows an example communication network 100 in which embodiments of the present disclosure can be implemented. Network 100 includes terminal devices 110 and network devices 120-1 to 120-4 (collectively referred to as network devices 120). For example, terminal device 110 can be served by network device 120-1. The service area of network device 120-1 is referred to as cell 101. It should be understood that the number of network devices and terminal devices is for illustrative purposes only and does not imply any limitation. Network 100 can include any suitable number of network devices and terminal devices suitable for implementing the embodiments of the present disclosure. Although not shown, it should be understood that one or more terminal devices can be in cell 101 and be served by network device 120-1.

[0027] In communication network 100, network device 120 can transmit data and control information to terminal device 110, and terminal device 110 can also transmit data and control information to network device 120. The link from network device 120 to terminal device 110 is referred to as the downlink (DL) or forward link, while the link from terminal device 110 to network device 120 is referred to as the uplink (UL) or reverse link.

[0028] In one embodiment, a terminal device can be connected to a first network device and a second network device. One of the first network device and the second network device can be a master node, and the other can be a slave node. The first network device and the second network device can use different radio access technologies (RATs). In one embodiment, the first network device can be a first RAT device and the second network device can be a second RAT device. In one embodiment, the first RAT device is an eNB and the second RAT device is a gNB. Information related to different RATs can be transmitted from at least one of the first network device and the second network device to the terminal device. In one embodiment, first information can be transmitted from the first network device to the terminal device, and second information can be transmitted directly or through the first network device from the second network device to the terminal device. In one embodiment, information related to the configuration of the terminal device configured by the second network device can be transmitted from the second network device through the first network device. Information related to the reconfiguration of the terminal device configured by the second network device can be transmitted directly from the second network device to the terminal device or can also be transmitted through the first network device.

[0029] Depending on the communication technology, network 100 can be a Code Division Multiple Access (CDMA) network, a Time Division Multiple Access (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency Division Multiple Access (OFDMA) network, a Single Carrier Frequency Division Multiple Access (SC-FDMA) network, or any other network. The communications discussed in network 100 can use any suitable standard, including but not limited to New Radio Access (NR), Long Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), cdma2000, Global System for Mobile Communications (GSM), etc. Additionally, the communications can be performed according to any generation of communication protocols known currently or developed in the future. Examples of communication protocols include but are not limited to the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols. The technologies described herein can be used for the above-mentioned wireless networks and radio technologies as well as other wireless networks and radio technologies. For clarity, certain aspects of these technologies are described below for LTE, and LTE terms are used in most of the following descriptions.

[0030] In communication network 100, if the channel state between terminal device 110 and network device 120-1 deteriorates, network device 120-1 can initiate a handover (HO) procedure to notify terminal device 110 to hand over from its serving cell to a target cell. During the handover process, terminal device 110 can attempt to access the target cell. If the handover process is successfully executed, terminal device 110 can be served by other serving areas, such as the serving cell 102 of network device 120-2.

[0031] However, if terminal device 110 does not receive a response indicating the success of the access attempt from network device 120-2 until the timer for the handover process expires, the access attempt fails. The failure information of this failed access attempt (which can be referred to as a handover failure (HOF)) can be recorded at terminal device 110.

[0032] In addition, if the connection between terminal device 110 and its serving network device 120-1 fails, the failure information of this failed connection (which can be referred to as a radio link failure (RLF)) can also be recorded at terminal device 110.

[0033] The terminal device 110 may indicate the availability of RLF report information during subsequent RRC connection establishment (re-establishment) and handover to the target cell. If the higher layer device requires an RLF report, the newly connected network device (e.g., network device 120-2) may send a UEInformationRequest message to request the terminal device 110 to feedback RLF report information, and the terminal device 110 will reply using a UEInformationResponse message.

[0034] The recorded failure information may be introduced into the RLF report variable. According to the current failure recording mechanism, the terminal device 110 can only store the information of the latest radio link failure or handover failure. Before setting the information field, the terminal device 110 always clears the information contained in the current RLF report variable.

[0035] As described above, conditional handover (CHO) has been proposed to improve handover reliability. For the conditional handover process, when the channel between the network device 120-1 and the terminal device 110 is still in a good state, the network device 120-1 may send a CHO configuration associated with multiple CHO candidate cells (e.g., cells 102 to 104 as Figure 1 shown) to the terminal, including the configuration of the CHO candidate cells and the CHO execution conditions.

[0036] As an option, once any CHO candidate cell meets the CHO execution conditions, the terminal device 110 may initiate an autonomous access attempt to the CHO candidate cell without the network device 120-1 sending a message to indicate the start of CHO execution. Since a set of candidate cells can be provided to the terminal device 110 to perform the conditional handover process, it is possible to perform multiple access attempts before the handover is successful.

[0037] As another option, if an RLF or HOF has occurred, the terminal device 110 may initiate the CHO process even if the CHO candidate cells do not meet the CHO execution conditions.

[0038] According to the above failure recording mechanism, the previous failure information can always be removed before recording new failure information. In this case, the RLF report may not reflect the overall network state. For example, when recording the failure information of CHO, the information related to RLF and HOF recorded before CHO execution can be removed. In addition, if the CHO execution attempts to multiple CHO candidate cells all fail, the terminal device 110 can only submit an RLF report related to the last CHO execution. In addition, as to how to indicate a handover failure during the CHO process, this is still under discussion.

[0039] For this purpose, methods for reporting conditional handover (CHO) attempt failures will be discussed in this disclosure.

[0040] The principles and example embodiments will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will readily understand that this disclosure extends beyond these limited embodiments, and thus the detailed description given here with respect to these drawings is for illustrative purposes.

[0041] Figure 2 A schematic diagram showing a process 200 for reporting CHO attempt failures according to an example embodiment of the present disclosure is shown. For the purpose of discussion, process 200 will be described with reference to Figure 1 Process 200. Process 200 may involve a terminal device 110 and network devices 120-1 to 120-4 as Figure 1 shown.

[0042] As Figure 2 shown, the terminal device 110 obtains 205 configuration information related to candidate cells for CHO from the network device 120-1. When the channel between the network device 120-1 and the terminal device 110 is still in a good state, the configuration information may be sent from the network device 120-1. The configuration information may include the cell ID of each candidate cell and other related configurations for CHO. For example, the candidate cells may refer to cells 102 to 104 as Figure 1 shown.

[0043] If the condition for triggering CHO is met, for example, if the channel state between the network devices 102-2 to 102-4 and the terminal device 100 deviates better than the channel state between the network device 120-1 and the terminal device 110, the terminal device 110 may initiate 210 a conditional handover. The terminal device 110 may perform at least one conditional handover attempt to the candidate cells.

[0044] For the first conditional handover attempt, the terminal device 110 may, for example, send 215 an access request to one of the candidate cells (e.g., cell 102 of the network device 120-2). If the timer for the conditional handover attempt expires and no response is received from the network device 120-2, the handover attempt may be considered a failed attempt. If the handover attempt to cell 102 fails, the terminal device 110 stores 220 the failure information of the failed conditional handover attempt.

[0045] In some example embodiments, the terminal device 110 may determine whether the failure of the first handover attempt to cell 102 during the CHO process is the first connection failure after the terminal device 110 is connected to the current serving cell (i.e., cell 102) (in this case, the connection between the terminal device 110 and the network device does not fail). If the failure of the first handover attempt to cell 102 is the first connection failure, the terminal device 110 may remove the previously stored failure information, such as removing the historical failure information associated with any other cell other than cells 101 to 104.

[0046] As another option, the terminal device 110 may determine whether the handover attempt to cell 102 is triggered due to RLF or HOF. If the terminal device 110 determines that the handover attempt to cell 102 is triggered due to RLF or HOF, the terminal device 110 may ignore the failure information.

[0047] In some example embodiments, the terminal device 110 may perform a further conditional handover attempt. For example, the terminal device 110 may send a 225 access request to one of the candidate cells (e.g., cell 103 of the network device 120-3). Similarly, if the timer for the conditional handover attempt expires and no response is received from the network device 120-3, the handover attempt may be considered a failed attempt.

[0048] If the handover attempt to cell 103 fails, the failure information of this failed conditional handover attempt may also be stored in the terminal device 110. As described above, the failure information of the first conditional handover attempt has been stored.

[0049] In some example embodiments, the terminal device 110 may store 230 both the failure information of the first conditional handover attempt to cell 102 and the failure information of the second conditional handover attempt to cell 103 based on the start time points of the first conditional handover attempt and the second conditional handover attempt.

[0050] In some example embodiments, if the first conditional handover attempt to cell 102 is the first conditional handover attempt during the conditional handover process, the terminal device 110 may store only the failure information of this first conditional handover attempt.

[0051] In some example embodiments, if the second conditional handover attempt to cell 103 is the last conditional handover attempt during this conditional handover process, the terminal device 110 may store only the failure information of this second conditional handover attempt.

[0052] In some example embodiments, the terminal device 110 may store a predetermined number of failed conditional handover attempts.

[0053] For example, if the predetermined number is 2 and the terminal device 110 can store the earliest failure, the failure information of only the first conditional handover attempt and the second conditional handover attempt may be stored. That is, any other failed conditional handover attempts that occur after the first conditional handover attempt and the second conditional handover attempt will no longer be stored.

[0054] As another option, if the predetermined number is 2 and the terminal device can store the most recent failure, in the case where the failure information of the first conditional handover attempt and the second conditional handover attempt has been stored, if further failure information is to be stored, the terminal device 110 may determine whether the sum of the number of failures of the previously stored failure information and the number of failures of the further failure information exceeds a threshold number. If the sum exceeds the threshold number, some of the previously stored failure information may be removed to allow the storage of the failure information of further conditional handover attempts.

[0055] Before at least one conditional handover attempt initiated by the terminal device 110, some previous failure information may have been stored at the terminal device 110. This previous failure information may be referred to as RLF, HOF, or another CHO failure. RLF may indicate a connection failure between the terminal device 110 and the network device 120-1, while HOF may indicate that the terminal device has attempted to access a dedicated cell before CHO and the access attempt has failed.

[0056] As an option, the failure information of at least one conditional handover attempt may also be stored without removing the previous failure information.

[0057] As a further option, if the terminal device 110 stores the predetermined number of failed conditional handover attempts, the terminal device 110 may determine whether the sum of the number of failures associated with the previous failure information and the number of failures associated with the failure information exceeds the threshold number of failure events allowed to be stored. If the terminal device 110 determines that the sum does not exceed the threshold number, the terminal device 110 may store the failure information without removing the previous failure information.

[0058] If the terminal device 110 determines that the sum exceeds the threshold number, the terminal device 110 may remove some of the previous failure information to allow the storage of the failure information.

[0059] Return to reference Figure 2,The terminal device 110 may also send a 235 access request to another cell 104 of the network device 120-4 during the conditional handover process. If the terminal device 110 receives a 240 response indicating that the access is acceptable from the network device, the terminal device 110 may determine that the 245 conditional handover attempt to the cell 104 is successful.

[0060] As another option, the handover attempt to the cell 104 may also fail. However, the terminal device 110 may successfully access an available cell. That is, the connection between the terminal device 110 and the network may be re-established.

[0061] Both the cell 104 and the available cell may hereinafter be referred to as the target cell.

[0062] The terminal device 110 may send a 250 message to the target cell, and the message indicates that the information about at least one connection failure that occurred at the terminal device is available.

[0063] For example, the message may include at least one of the following: the failure type of at least one connection failure (i.e., one of RLF, HOF, and CHOF), the number of at least one connection failure, and the information about the successful handover attempt to the target cell. In some embodiments, the failure report may also indicate the number of failures that occurred during the CHO process. An example of the information related to at least one connection failure (i.e., the RLF variable of the terminal device) may be shown in the following table.

[0064] Table 1: RLF variable

[0065]

[0066] If the terminal device 110 receives a 255 request for the information related to at least one connection failure, the terminal device 110 may generate a 260 failure report. The failure report may include at least one of the following: previous failure information, failure information, and the information related to the successful handover attempt to the target cell.

[0067] In some embodiments, the information related to the successful handover attempt to the target cell may include one or more of the following parameters: the identifier of the target cell, the timestamp of accessing the target cell, the location of the target cell, the channel condition of the target cell, and the channel condition of at least one neighboring cell of the target cell.

[0068] In some embodiments, the failure report may indicate the type of failure that occurred at the terminal device and the failure information of each type. An example of the failure report may be shown in the following table.

[0069] Table 2: Failure report

[0070]

[0071]

[0072]

[0073]

[0074] Then, the terminal device 110 may send a failure report to the target cell.

[0075] In some embodiments, at the terminal device 110, any failures that occur during the CHO process will not be stored. In other words, failures associated with the CHO process will be ignored.

[0076] In some embodiments, the terminal device 110 may determine whether a radio link failure or a legacy handover failure has occurred before at least one conditional handover attempt. If the terminal device 110 determines that a radio link failure or a legacy handover failure has occurred before at least one conditional handover attempt, the terminal device 110 may ignore the failures during the CHO process.

[0077] In this way, a new failure reporting mechanism can be implemented.

[0078] Refer to Figures 3 to 5 to describe more details of the example embodiments according to the present disclosure.

[0079] Figure 3 The flowchart of an example method 300 according to some embodiments of the present disclosure is illustrated. The method 300 may be implemented on the terminal device 110, as Figure 1 shown. For the purpose of discussion, the method 300 will be described with reference to Figure 1 as follows.

[0080] At 310, the terminal device 110 obtains configuration information related to at least one candidate cell for conditional handover of the terminal device.

[0081] At 320, the terminal device 110 initiates at least one conditional handover attempt to the at least one candidate cell.

[0082] At 330, if at least one conditional handover attempt to the at least one candidate cell fails during the conditional handover process, the terminal device 110 stores the failure information of the at least one conditional handover attempt at 340.

[0083] At 330, if at least one conditional handover attempt to the at least one candidate cell fails during the conditional handover process, the actions of the terminal device may be described with reference to Figure 4 as follows.

[0084] Figure 4 The flowchart of an example method 400 in accordance with some embodiments of the present disclosure is illustrated. Method 400 may be implemented at a terminal device 110 as shown in Figure 1 For purposes of discussion, method 400 will be described with reference to Figure 1 the description of method 400.

[0085] At 410, the terminal device 110 sends a message to a target cell, the message indicating that information about at least one connection failure that occurred at the terminal device is available. The target cell may include at least one candidate cell or one of the available cells other than the at least one candidate cell.

[0086] At 420, if the terminal device 110 receives a request for the information from the target cell, then the terminal device 110 generates, at 430, a failure report including at least one of the following: previous failure information; failure information; and information related to a successful conditional handover attempt.

[0087] At 440, the terminal device 110 sends the failure report to the target cell.

[0088] Figure 5 The flowchart of an example method 500 in accordance with some embodiments of the present disclosure is illustrated. Method 500 may be implemented at a terminal device 110 as shown in Figure 1 For purposes of discussion, method 500 will be described with reference to Figure 1 the description of method 500.

[0089] At 510, the terminal device 110 obtains configuration information related to at least one candidate cell for conditional handover for the terminal device.

[0090] At 520, the terminal device 110 initiates at least one conditional handover attempt to the at least one candidate cell.

[0091] At 530, if at least one conditional handover attempt to the at least one candidate cell fails during the conditional handover process, then the terminal device 110 ignores the failure of the at least one conditional handover attempt at 540.

[0092] Figure 6 is a simplified block diagram of a device 600 suitable for implementing embodiments of the present disclosure. Device 600 may be considered a further example implementation of the terminal device 110 as shown in Figure 1 Accordingly, device 600 may be implemented at the terminal device 110 or as at least a part of the terminal device 110.

[0093] As shown in Figure 6As shown, device 600 includes a processor 610, a memory 620 coupled to the processor 610, a suitable transmitter (TX) and receiver (RX) 640 coupled to the processor 610, and a communication interface coupled to the TX / RX 640. The memory 610 stores at least a portion of a program 630. The TX / RX 640 is used for two-way communication. The TX / RX 640 has at least one antenna to facilitate communication, but in practice, the access nodes mentioned in this application may have several antennas. The communication interface may represent any interface required for communicating with other network elements, such as the X2 interface for two-way communication between eNBs, the S1 interface for communication between a mobility management entity (MME) / serving gateway (S-GW) and an eNB, the Un interface for communication between an eNB and a relay node (RN), or the Uu interface for communication between an eNB and a terminal device.

[0094] Assume that the program 630 includes program instructions that, when executed by the associated processor 610, enable the device 600 to operate according to embodiments of the present disclosure as discussed herein with reference to Figures 2 to 5 the embodiments. The embodiments herein can be implemented by computer software executable by the processor 610 of the device 600, or by hardware, or by a combination of software and hardware. The processor 610 can be configured to implement various embodiments of the present disclosure. In addition, the combination of the processor 610 and the memory 610 can form a processing component 650 suitable for implementing various embodiments of the present disclosure.

[0095] The memory 610 can be of any type suitable for the local technical network and can be implemented using any suitable data storage technology (as non-limiting examples, such as non-transitory computer-readable storage media, semiconductor-based storage devices, magnetic storage devices and systems, optical storage devices and systems, fixed memories, and removable memories). Although only one memory 610 is shown in the device 600, there can be multiple physically distinct memory modules in the device 600. As non-limiting examples, the processor 610 can be of any type suitable for the local technical network and can include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device 600 can have multiple processors, such as an application-specific integrated circuit chip that is subordinate to the clock of a synchronous main processor in time.

[0096] Generally, the various embodiments of the present disclosure may be implemented in hardware or special-purpose circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be executed by a controller, a microprocessor, or other computing devices. Although aspects of the embodiments of the present disclosure are shown and described as block diagrams, flowcharts, or using some other graphical representation, it will be understood that the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, special-purpose circuits or logic, general-purpose hardware or controllers, or other computing devices, or some combination thereof, as non-limiting examples.

[0097] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, that are executed in a device on a target real processor or a target virtual processor to perform the processes or methods described above with reference to Figure 2 the processes or methods described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The functions of program modules may be combined or separated as needed in various embodiments. The machine-executable instructions of program modules may be executed within a local device or within a distributed device. In a distributed device, program modules may be located in both local storage media and remote storage media.

[0098] The program code for performing the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or a controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that the functions / operations specified in the flowchart and / or block diagram can be implemented when the program codes are executed by the processor or the controller. The program code may be executed entirely on the machine, partially on the machine, may be executed as a stand-alone software package, may be executed partially on the machine and partially on a remote machine, or may be executed entirely on a remote machine or a server.

[0099] The above program code can be implemented on a machine-readable medium, which can be any tangible medium that contains or stores a program used by or in conjunction with an instruction execution system, apparatus, or device. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of the machine-readable storage medium will include an electrical connection having one or more wires, a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0100] Moreover, although the operations are described in a particular order, this should not be construed as requiring that the operations be performed in the particular order shown or in sequential order, or that all of the illustrated operations be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these details should not be construed as limiting the scope of the present disclosure, but rather as descriptions of features specific to particular embodiments. Certain features described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately or in any suitable sub-combination in multiple embodiments.

[0101] Although the present disclosure has been described in terms of structural features and / or methodological acts, it should be understood that the present disclosure defined in the appended claims is not necessarily limited to the above specific features or acts. Rather, the above specific features and acts are disclosed as example forms of implementing the claims.

Claims

1. A method performed by a terminal device, comprising: Receiving a conditional handover (CHO) configuration; And In response to a first failure and a second failure, storing, in a radio link failure (RLF) report, failure-related information of two consecutive failures including the first failure and the second failure, Wherein the first failure is an RLF in a source cell, and the second failure is the failure to connect to a configured candidate CHO cell after selecting the configured candidate CHO cell; or Wherein the first failure is a handover (HO) failure experienced when performing CHO to a configured first candidate CHO cell under satisfied configuration conditions, and the second failure is the failure to connect to a configured second candidate CHO cell after selecting the configured second candidate CHO cell; or Wherein the first failure is an HO failure experienced when performing HO to a target cell, and the second failure is the failure to connect to a configured candidate CHO cell after selecting the configured candidate CHO cell.

2. The method according to claim 1, further comprising: In response to a successful CHO, transmitting a message including information of the successful CHO.

3. The method according to claim 2, wherein the information of the successful CHO includes at least one of the following: An identifier of the target cell; or Location information.

4. A terminal device, comprising a processor configured to: Receive a conditional handover (CHO) configuration; and In response to a first failure and a second failure, store, in a radio link failure (RLF) report, failure-related information of two consecutive failures including the first failure and the second failure, Wherein the first failure is an RLF in a source cell, and the second failure is the failure to connect to a configured candidate CHO cell after selecting the configured candidate CHO cell; or Wherein the first failure is a handover (HO) failure experienced when performing CHO to a configured first candidate CHO cell under satisfied configuration conditions, and the second failure is the failure to connect to a configured second candidate CHO cell after selecting the configured second candidate CHO cell; or Wherein the first failure is an HO failure experienced when performing HO to a target cell, and the second failure is the failure to connect to a configured candidate CHO cell after selecting the configured candidate CHO cell.

5. The terminal device according to claim 4, wherein the processor is further configured to: In response to a successful CHO, transmit a message including information of the successful CHO.

6. The terminal device according to claim 5, wherein the information of the successful CHO includes at least one of the following: An identifier of the target cell; or Location information.

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