Communication method, terminal and network equipment

Abstract

The invention provides a communication method, a terminal and network equipment. The communication method comprises the following steps: a terminal executes first switching to switch from a first cell to a second cell, the first cell does not support a first service, the second cell supports the first service, and the purpose of the first switching is to enable the terminal to execute the first service; when the first switching fails or a wireless link fails after the first switching succeeds, the terminal sends first information, and the first information is used for optimizing mobility network parameter setting and / or performing mobility robustness optimization. According to the first information, targeted mobility robustness optimization and / or mobility network parameter optimization can be performed on the first handover, so that an optimization strategy which is different from other types of handover and aims at the first handover is provided.

Description

Communication method, terminal and network device Technical Field

[0001] The present application relates to the field of communication technology, and more specifically, to a communication method, a terminal, and a network device. Background Art

[0002] Some communication systems have introduced mobility robust optimization (MRO) to optimize improperly configured mobility network parameters (e.g., handover parameters). For example, based on MRO, network equipment can modify the threshold for triggering measurement reports when premature handover is detected.

[0003] In the case where the terminal switches from a first cell that does not support the first service to a second cell that supports the first service, since the switching is not caused by poor signal quality of the first cell, the MRO for this switching is different from the MRO for premature switching. The switching in this special scenario cannot be optimized using the optimization method for premature switching.

[0004] Summary of the Invention

[0005] The present application provides a communication method, a terminal, and a network device. The following introduces various aspects of the present application.

[0006] In a first aspect, a communication method is provided, including: a terminal performs a first handover to switch from a first cell to a second cell, the first cell does not support a first service, the second cell supports the first service, and the purpose of the first handover is to enable the terminal to perform the first service; in the event of a failure in the first handover or a wireless link failure after a success of the first handover, the terminal sends first information, and the first information is used to optimize the mobility network parameter setting and / or perform mobility robustness optimization.

[0007] According to a second aspect, a communication method is provided, including a network device receiving first information when a first handover fails or a wireless link failure occurs after the first handover succeeds, and the first information is used to optimize the mobility network parameter setting and / or perform mobility robustness optimization; wherein the first handover is a handover of a terminal from a first cell to a second cell, the first cell does not support the first service, and the second cell supports the first service, and the purpose of the first handover is to enable the terminal to execute the first service.

[0008] According to a third aspect, a terminal is provided, including: a switching unit for performing a first switching to switch from a first cell to a second cell, the first cell does not support a first service, the second cell supports the first service, and the purpose of the first switching is to enable the terminal to perform the first service; a first sending unit for sending first information when the first switching fails or a wireless link failure occurs after the first switching is successful, and the first information is used to optimize the mobility network parameter setting and / or perform mobility robustness optimization.

[0009] In a fourth aspect, a network device is provided, including: a first receiving unit, used to receive first information when a first handover fails or a wireless link failure occurs after the first handover is successful, and the first information is used to optimize the mobility network parameter setting and / or perform mobility robustness optimization MRO; wherein the first handover is a handover of the terminal from a first cell to a second cell, the first cell does not support the first service, and the second cell supports the first service, and the purpose of the first handover is to enable the terminal to execute the first service.

[0010] In a fifth aspect, a terminal is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the terminal device executes part or all of the steps in the method of the first aspect.

[0011] In the sixth aspect, a network device is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the network device executes part or all of the steps in the method of the second aspect.

[0012] In a seventh aspect, an embodiment of the present application provides a communication system, which includes the above-mentioned terminal and / or network device. In another possible design, the system may also include other devices that interact with the terminal or network device in the solution provided in the embodiment of the present application.

[0013] In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program enables a terminal to execute part or all of the steps in the methods of the above aspects.

[0014] In a ninth aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a terminal to perform some or all of the steps of the methods described in each of the above aspects. In some implementations, the computer program product may be a software installation package.

[0015] In the tenth aspect, an embodiment of the present application provides a chip, which includes a memory and a processor. The processor can call and run a computer program from the memory to implement some or all of the steps described in the methods of the above aspects.

[0016] According to the first information, targeted mobility network parameter setting optimization and / or mobility robustness optimization may be performed on the first handover, thereby providing an optimization strategy for the first handover that is different from other types of handovers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a wireless communication system used in an embodiment of the present application.

[0018] FIG. 2 is an example diagram of a premature switching scenario.

[0019] FIG3 is a schematic flowchart of a communication method provided in an embodiment of the present application.

[0020] FIG4 is a schematic flowchart of a communication method provided in Example 1 of the present application.

[0021] FIG5 is a schematic flowchart of a communication method provided in Example 2 of the present application.

[0022] FIG6 is a schematic flowchart of a communication method provided in Example 3 of the present application.

[0023] FIG7 is a schematic structural diagram of a terminal provided in an embodiment of the present application.

[0024] FIG8 is a schematic structural diagram of a network device provided in an embodiment of the present application.

[0025] FIG9 is a schematic structural diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] The technical solution in this application will be described below with reference to the accompanying drawings.

[0027] Communication System

[0028] Figure 1 illustrates a wireless communication system 100 used in an embodiment of the present application. The wireless communication system 100 may include a network device 110 and a terminal device 120. The network device 110 may be a device that communicates with the terminal device 120. The network device 110 may provide communication coverage for a specific geographic area and may communicate with the terminal device 120 within the coverage area.

[0029] FIG1 exemplarily shows a network device and two terminals. Optionally, the wireless communication system 100 may include multiple network devices and each network device may include other numbers of terminal devices within its coverage area, which is not limited in the embodiments of the present application.

[0030] Optionally, the wireless communication system 100 may further include other network entities such as a network controller and a mobility management entity, which is not limited in the embodiment of the present application.

[0031] It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: fifth generation (5G) system or new radio (NR), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), etc. The technical solutions provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system, satellite communication system, etc.

[0032] The terminal device in the embodiments of the present application may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal device in the embodiments of the present application may refer to a device that provides voice and / or data connectivity to a user and can be used to connect people, objects and machines, such as a handheld device with wireless connection function, a vehicle-mounted device, etc. The terminal device in the embodiments of the present application can be a mobile phone, a tablet computer, a laptop computer, a PDA, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. Optionally, the UE can be used to act as a base station. For example, the UE can act as a scheduling entity that provides sidelink signals between UEs in V2X or D2D, etc. For example, a cellular phone and a car communicate with each other using sidelink signals. The cellular phone and smart home devices communicate without relaying the communication signal through the base station.

[0033] The network device in the embodiments of the present application may be a device for communicating with a terminal device, and may also be referred to as an access network device or a radio access network device. For example, the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. A base station can broadly cover various names as follows, or be replaced with the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmission point (TRP), transmission point (TP), master station MeNB, secondary station SeNB, multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. A base station can also refer to a communication module, a modem or a chip used to be set in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device that performs base station functions in device-to-device D2D, vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. The base station can support networks with the same or different access technologies. The embodiments of this application do not limit the specific technology and specific device form used by the network equipment.

[0034] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0035] In some deployments, the network device in the embodiments of the present application may refer to a CU or a DU, or the network device may include a CU and a DU. The gNB may also include an AAU.

[0036] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the scenarios in which the network equipment and terminal devices are located.

[0037] It should be understood that all or part of the functions of the communication device in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (such as a cloud platform).

[0038] Switching optimization too early

[0039] While a terminal is connected and maintaining service, it can move, for example, from one cell to another. This movement can cause the original serving cell to no longer provide service to the terminal. In this case, a cell handover (HO) can be performed, allowing the terminal to switch from the source cell to the target cell, which then allows the target cell to continue providing service to the terminal, ensuring uninterrupted service.

[0040] The terminal can regularly measure the signal quality of a cell and report a measurement report to the base station when a measurement event (i.e., a certain condition) is met. The network equipment determines whether to perform a cell handover based on the measurement report reported by the terminal. The conditions for reporting the measurement report event can be configured by the network equipment for the terminal.

[0041] Cell handover may experience a phenomenon called too early HO. The process of too early HO can be as follows: if a handover failure occurs during the process of the terminal accessing the target cell from the source cell, or if a radio link failure (RLF) occurs on the target cell after the handover is completed, the terminal can perform cell selection, reselect the source cell, and initiate reestablishment with the source cell. That is, after the handover fails or succeeds, the terminal selects the source cell again to continue serving the terminal. As shown in Figure 2, the terminal can move along the moving direction shown in Figure 2, and the terminal performs a handover at the position shown in Figure 2. At the position shown in Figure 2, the signal quality of the source cell is strong, while the signal quality of the target cell is weak. Therefore, the terminal fails to handover to the target cell and reconnects to the source cell. It can be understood that the reason for the handover failure is too early HO. That is, if the handover occurs later, and the terminal continues to move along the moving direction, it may move to a location where the target cell signal quality is good and the source cell signal quality is weak. In this case, the success rate of cell handover will increase.

[0042] Network devices can optimize premature handovers to improve handover success rates. For example, some communication systems have implemented a mobility robust optimization (MRO) feature to optimize mobility network parameter settings. For example, this can optimize improperly configured handover parameters. As an implementation, based on the MRO feature, upon detecting premature handovers, network devices can modify the threshold settings for the measurement target corresponding to the measurement report event, such as changing the threshold for the terminal to trigger a measurement report.

[0043] In the event of a premature handover, the terminal may send a radio link failure report (RLF report) related to a cell handover failure (HOF) to a network device so that the network device can perform premature handover optimization. The following describes in detail the process of the terminal reporting a radio link failure report, which may include steps S110 to S120.

[0044] S110: The terminal stores a radio link failure report. During the access process, after timer T304 expires, the terminal may store the radio link failure report. Alternatively, after successfully accessing the target cell, if a RLF occurs in the target cell due to reasons such as timer T310 expiration, the terminal may store the radio link failure report.

[0045] S120: The terminal sends a radio link failure report. The terminal may initiate a reestablishment process with a cell. After the reestablishment is complete or the radio resource control (RRC) connection is established, the terminal may send the radio link failure report related to the last HOF to the reestablished cell. Step S120 may include steps S121 to S123.

[0046] In step S121, the terminal sends a message including RLF or HOF information to the network device. For example, the terminal may notify the network device of the presence of the relevant information via RRC signaling. The RRC signaling may be, for example, the RRC Reestablishment Complete message in message 5 (msg5), which may include an RLF-Info Available field to notify the terminal that the RLF or HOF information is stored in varRLF-Report.

[0047] In step S122, the network device sends information indicating that the terminal needs to report RLF or HOF. For example, the network device may send RRC signaling to the terminal. The RRC signaling may be, for example, a terminal information request (UEInformationRequest) signaling. In the UEInformationRequest signaling, a true value of rlf-ReportReq may indicate that the terminal needs to report RLF or HOF information.

[0048] In step S123, the terminal reports a radio link failure report. The terminal may report the report via RRC signaling. The RRC signaling may be, for example, a terminal information feedback (UEinformationResponse) signaling. In the UEinformationResponse signaling, rlf-Report may be set to the value stored in the terminal variable varRLF-Report.

[0049] The network device can determine that the handover failure or RLF is caused by premature handover based on the information block in the radio link failure report. The information block in the radio link failure report may include one or more of the following information: the measurement result of the last serving cell (measResultLastServCell), the signal measurement result of the neighboring cell (the neighboring cell with good signal and its measurement result are placed at the front of the menu list), geographic location information, the target cell identifier when the handover failure occurs, the connection failure time (timeConnFailure), the reconnected cell identifier, the previous primary cell identifier (previousPCellId), and the connection failure type.

[0050] The last serving cell measurement result can be derived by inferring, for example, the source cell signal measurement result derived based on available SSB and CSI-RS measurements before the terminal detects RLF.

[0051] The geographical location information may be the location information of the terminal when the RLF occurs.

[0052] The connection failure time may be the time from the last handover (reception of the last RRCReconfiguration msg) to the connection failure (UE reported timer).

[0053] In the case of premature handover, the identity of the reconnected cell may be the identity of the source cell, and the identity of the previous primary cell may also be the identity of the source cell.

[0054] The connection failure type may include: Handover Failure (HOF) or Radio Link Failure (RLF).

[0055] In some embodiments, if the timer (including timeConneFailure) reported by the terminal is less than a threshold value (e.g., Tstore_UE_cntxt), and the cell that the terminal attempts to re-establish or reconnect is the source cell before the handover, it can be determined that a premature handover problem has occurred. In some embodiments, if the failed source cell identifier (failledPCellID) in the radio link failure report is the identifier (ID) of the source cell, and the connection failure type (connectionFailureType) is a handover failure ('hof'); or, the failed primary cell identifier (failledPCellID) is the identifier of the target cell, and the connection failure type is a radio link failure ('rlf'), it can be determined that a premature handover problem has occurred.

[0056] Cell switching in special scenarios

[0057] Cell switching can also be applied to some special scenarios. For example, when the source cell does not support a certain service, the terminal can be switched to a target cell that supports the service. Taking voice service as an example, in a scenario where the cell does not support voice service, when the terminal initiates the establishment of voice-related services, the network device can switch or redirect the terminal to a suitable cell that supports voice service. For example, in the early stages of 5G deployment or in scenarios where 5G does not support voice service, the 5G network can switch / redirect the terminal to a suitable network corresponding to a wireless technology that supports voice service, such as an LTE network. In some embodiments, the above-mentioned switching to support voice service can be called voice fallback cross-system switching (HO for voice fallback).

[0058] If the measurement results of the target cell are not good enough, or the random access resources are relatively tight, the terminal may not be able to successfully complete the handover. In this case, the terminal can perform cell selection or reselection to find a suitable cell that supports the first service to reside in. Taking voice fallback cross-system handover as an example, the terminal can try to find a suitable evolved universal terrestrial radio access network (E-UTRAN) cell. If the terminal finds a suitable cell, the terminal can return to the idle state (RRC_IDLE) and reside in a suitable cell. If the terminal does not find a suitable cell, the terminal can perform re-establishment to the source primary cell (source PCell).

[0059] Cell selection criteria

[0060] As mentioned above, after a handover failure or RLF after a handover, the terminal can perform cell selection or cell reselection to find a suitable cell. Cell selection can be achieved using the cell selection criteria (S criteria). The following describes the cell selection criteria.

[0061] The cell selection parameters may, for example, include at least one of the following parameters: minimum required RX level in the cell, minimum required quality level in the cell, reference signal receiving power (RSRP) measured by the terminal device, reference signal receiving quality (RSRQ) measured by the terminal device, an offset of the minimum required reception level in the cell, an offset temporarily applied to the cell, an offset of the minimum required quality level in the cell, an offset temporarily applied to the cell, and power compensation, as well as parameters for some special scenarios.

[0062] It should be noted that the minimum required reception level in a cell can also be referred to as the minimum RSRP required by the network equipment. The minimum required quality level in a cell can also be referred to as the minimum RSRQ required by the network equipment. The offset of the minimum required reception level in a cell and the offset of the minimum required quality level in a cell are offsets to prevent the ping-pong effect caused by radio environment fluctuations between two public land mobile networks (PLMNs). The power compensation is the larger value of the difference between the maximum transmit power value and the maximum RF output power value of the terminal device and 0. The offset temporarily applied to the cell can be used in special scenarios and may not be applicable under normal circumstances. For example, it can be used in the "Chiba Problem" scenario.

[0063] Based on the above cell selection criteria parameters, the cell selection criteria can be: if and only if the cell selection reception level value Srxlev and the cell selection quality value Squal of a certain cell satisfy both Srxlev>0 and Squal>0, the cell is a suitable cell and the terminal can select the cell. The calculation formulas of Srxlev and Squal are as follows:

[0064] Srxlev=Q rxlevmeas -(Q rxlevmin +Q rxlevminoffset )-P compensation

[0065] Squal=Q qualmeas -(Q qualmin +Q qualminoffset )

[0066] Among them, Q rxlevmeas and Q qualmeas RSRP and RSRQ can be measured separately for terminal devices.

[0067] Q rxlevmin and Q qualmin They may be the minimum RSRP required by the network device and the minimum RSRQ required by the network device, respectively.

[0068] Q rxlevminoffset and Q qualminoffset The offsets can be the minimum required reception level in the cell and the minimum required quality level in the cell, respectively. rxlevminoffset and Q qualminoffset It can be the offset that needs to be used when the terminal device camps on a suitable cell of the visited PLMN and periodically searches for a higher priority PLMN.

[0069] P compensationFor example, when the maximum transmission power allowed by the network equipment is greater than the maximum uplink transmission power determined by the terminal equipment's own capabilities, P compensation It can compensate for the power loss caused by low power of terminal equipment.

[0070] The terminal device can obtain the cell selection criteria parameters from the message sent by the network device. Taking the offset of the minimum reception level required in the cell as an example, the terminal device can receive the system message sent by the network device and obtain the minimum RSRP required by the network device from the q-RxLevMinCE parameter in the system message, that is, Q in the above formula rxlevmin .

[0071] The definition and calculation method of the parameters for cell reselection are similar to those for cell selection, and will not be described in detail in this application.

[0072] As can be seen from the above, in the case where the terminal switches from a source cell that does not support the first service to a target cell that supports the first service, since the switching is not caused by poor signal quality of the source cell, the MRO for this switching is different from the MRO for the purpose of premature switching. The switching in this special scenario cannot be optimized using the optimization method of premature switching.

[0073] Taking voice fallback cross-system switching as an example, even if the signal quality of the 5G source cell is very good, the terminal needs to access the target cell that supports voice services to perform voice services. Therefore, for voice fallback cross-system switching, the threshold for triggering measurement report reporting is usually set lower to increase the probability that the terminal can switch to the LTE cell. Accordingly, there will be differences in the optimization strategy for the threshold for triggering measurement report reporting. Therefore, the optimization of the threshold for triggering measurement report reporting or switching events for MRO for the purpose of voice fallback is different from the optimization of the threshold for triggering measurement report reporting or switching events for premature switching. In other words, the MRO for the purpose of voice fallback cannot apply the optimized threshold for triggering measurement report reporting for premature switching.

[0074] FIG3 is a schematic flowchart of a communication method provided in an embodiment of the present application, for optimizing handover of a terminal from a source cell that does not support a first service to a target cell that supports the first service.

[0075] The method shown in Figure 3 can be performed by a terminal and a network device. The network device can be a first network device belonging to the first cell, a second network device belonging to the second cell, a third network device belonging to the cell where the terminal resides after the first handover, or a fourth network device belonging to a cell near the terminal. It is understood that any two or more of the first network device, the second network device, and the third network device can be the same network device.

[0076] The method shown in FIG3 may include steps S310 to S320 .

[0077] Step S310: The terminal performs a first handover to switch from a first cell to a second cell.

[0078] The first cell may not support the first service. The second cell may support the first service. In some embodiments, the first service may be a voice service. Accordingly, the first handover may be a cross-system handover with voice fallback. For example, the first cell may be a 5G cell. The second cell may be an LTE cell. The 5G cell may not support voice services, while the LTE cell may support voice services.

[0079] The purpose of the first handover may be to enable the terminal to perform the first service. It is understood that the terminal cannot perform the first service in the first cell. Through the first handover, the terminal can be handed over to the second cell, thereby enabling the terminal to perform the first service. In the first handover, the first cell may be the source cell, and the second cell may be the target cell.

[0080] The following takes the first service being a voice service and the first handover being a voice fallback cross-system handover as an example to illustrate the first handover process. The first handover process may include S311 to S314.

[0081] In step S311, the network device updates the measurement configuration of the cell switching. Step S311 can be executed after the network device receives the request from the terminal to establish a voice service. The terminal can request to establish a QoS flow for a voice flow (5QI=1). Taking the first cell as a 5G cell and the second cell as an LTE cell as an example, in the new measurement configuration, the measurement target can be the corresponding frequency of LTE, and the relevant measurement reporting parameters can be set around the B1 event. Among them, the B1 event can be that the quality of the cross-radio access technology (RAT) neighboring cell (i.e., the inter-system neighboring cell) is higher than a certain threshold (inter RAT neighbor becomes better than a certain threshold).

[0082] Step S312: The terminal reports a measurement report. After measuring the surrounding LTE cells, if the measurement results meet the network device settings, the terminal may report the measurement report. For example, if the measurement result of the LTE cell exceeds the threshold that triggers the measurement report, the terminal may report the measurement report.

[0083] Step S313: Perform the first handover. The network device may search for a suitable target cell for the terminal and inquire whether the target cell accepts the handover. When the target cell replies that it accepts the handover, the network device may send an indication message to the terminal, instructing the terminal to perform the handover. The target cell may be a second cell. For example, the network device may send a MobilityFromNRCommand signaling message carrying a voice fallback indication (VoiceFallbackIndication) to the terminal, thereby instructing the terminal to perform an inter-RAT handover.

[0084] Step S314: The terminal performs random access to the second cell to switch to the second cell.

[0085] The first handover may need to be optimized, such as MRO. In some embodiments, the first handover may fail. The failure of the first handover may be caused by problems encountered by the terminal during the process of performing random access to the second cell. For example, the terminal cannot receive message 2 (msg2) sent by the network device, which may cause problems in the random access process. Alternatively, in contention-based random access, the failure of the terminal to compete may cause problems in the random access process. Alternatively, the second cell does not allocate dedicated random access resources to the terminal, which may cause problems in the random access process. In other embodiments, after the first handover is successful, a radio link failure may also occur. In the above embodiment, it can be determined that the first handover needs to be optimized.

[0086] In some embodiments, the network device may determine whether a radio link failure or handover failure has occurred based on the information carried in the radio link failure report. For example, if the connection failure type in the radio link failure report is RLF and timeConnFailure is less than a certain threshold, the network device may determine that RLF occurred after the first handover. Alternatively, if the connection failure type in the radio link failure report is handover failure, the network device may determine that the first handover failed.

[0087] The present application proposes that step S320 may be executed when a first handover fails or a radio link failure occurs after a first handover succeeds.

[0088] In step S320, the terminal may send first information, and the network device may receive the first information.

[0089] The first information may be used to optimize mobility network parameter settings and / or perform mobility robustness optimization. For example, the first information may be used to indicate optimization of mobility network parameter settings and / or perform mobility robustness optimization for the first handover. It is understood that mobility robustness optimization may optimize mobility network parameter settings. In other words, optimization of mobility network parameter settings may be achieved through mobility robustness optimization.

[0090] According to the first information, it can be determined which type of mobility robustness optimization to perform. For example, targeted mobility network parameter setting optimization and / or mobility robustness optimization can be performed on the first handover, thereby providing an optimization strategy for the first handover.

[0091] In some embodiments, optimization of mobility network parameter settings and / or mobility robustness optimization may include adjusting a threshold for triggering measurement report reporting. For example, a network device may adjust a threshold for triggering measurement report reporting for a B1 event. In some implementations, the network device may increase or decrease the threshold for triggering measurement report reporting.

[0092] In some embodiments, mobility network parameter setting optimization and / or mobility robustness optimization may include adjusting one or more cell selection or cell reselection parameters. The cell selection or reselection parameters may be parameters related to the cell selection criteria or the cell reselection criteria. For example, the cell selection or reselection parameters may include the following parameters: a minimum required reception level in the cell, a minimum required quality level in the cell, a reference signal received power measured by a terminal device, a reference signal received quality measured by a terminal device, an offset for the minimum required reception level in the cell, an offset temporarily applied to the cell, an offset for the minimum required quality level in the cell, an offset temporarily applied to the cell, and power compensation, etc.

[0093] This application does not limit the triggering conditions for sending the first information. For example, after a first handover failure occurs or a wireless link failure occurs after a first handover is successful, the terminal can immediately send the first information. Alternatively, the terminal can store the first information and send a first indication message to the network device indicating that the terminal stores the first information. The network device can learn from the first indication message that the terminal stores the first information. If the network device wishes to obtain the first information, it can send a second indication message to the terminal to obtain the first information. After receiving the second indication message to obtain the first information, the terminal can send the first information to the network device.

[0094] The first information may include information related to the first service. For example, if the first service is a voice service, the first information may include relevant indication information that the purpose of the first switching is voice fallback.

[0095] The first information may be sent alone or together with other information. For example, the first information may be included in a first report. The first report may be, for example, a radio link failure report. The first report may be generated by the terminal. For example, if handover to the second cell fails, the terminal may generate the first report.

[0096] The first report may include the first information and may also include other information. The other information may include other information blocks in the radio link failure report. For example, the first report may include one or more of the following information: connection failure type, the identifier of the first cell (or source cell identifier), the identifier of the second cell (or target cell identifier), the radio signal measurement result of the neighboring cell of the target RAT before the first handover failure or before the first handover is performed, the radio signal measurement result of the second cell before the first handover failure or before the first handover is performed, the random access situation during the access to the second cell, the cause value of RLF or HOF, the geographical location of the terminal, etc.

[0097] The connection failure type may include: RLF or HOF. The type of the connection failure may be indicated by an RLF identifier or a HOF identifier.

[0098] The cause values ​​of RLF or HOF may include: T310 timer timeout (t310-Expiry), (random access problem) randomAccessProblem, RLC maximum retransmission drop (rlc-MaxNumRetx), beam failure recovery failure (beamFailureRecoveryFailure), listen before talk failure (lbtFailure-r16), wireless backhaul RLF recovery failure (bh-rlfRecoveryFailure), etc.

[0099] In the event of a first handover failure or a radio link failure after the first handover succeeds, the terminal may perform cell selection or cell reselection to find a suitable cell.

[0100] The wireless signal measurement results of the neighboring cells may include measurement results of multiple neighboring cells. The multiple neighboring cells and their corresponding measurement results may be presented in a list. Optionally, the neighboring cell with a good signal and the measurement result of the neighboring cell may be placed at the front of the multiple measurement results.

[0101] The suitable cell may be a cell that meets the cell selection criteria or the cell reselection criteria. The suitable cell may be a cell that supports the first service. For example, if the first service is a voice service, the cell that supports the first service may be an E-UTRAN cell.

[0102] If the terminal finds a suitable cell, the terminal can send the second information, and the network device can receive the second information. For example, the terminal can send the second information to the first network device to which the first cell belongs. The second information can be forwarded by a third network device and / or core network device to which the cell in which the terminal is currently located belongs.

[0103] If the terminal fails to find a suitable cell, the terminal may send third information, and the network device may receive the third information. For example, the terminal may send the third information to a fourth network device associated with a cell supporting the first service in the terminal's vicinity. The third information may be forwarded by the third network device and / or core network device associated with the cell in which the terminal is currently located.

[0104] The second information may be used to indicate that the terminal has found a suitable cell. The second information may include, for example, one or more of the following information: an identifier of a suitable cell, a frequency of a suitable cell, a measurement result of a suitable cell, and indication information of the first service.

[0105] The network device can adjust the threshold for triggering the measurement report based on the second information. For example, the second information may include the appropriate cell-related signal measurement value selected by the terminal during cell selection after handover failure, and the network device can optimize the threshold for triggering the measurement report based on the measurement value.

[0106] In some embodiments, the network device may determine an adjustment value X of the threshold for triggering measurement report reporting based on the second information. For example, the network device may determine that the adjustment value X is 1 dBm based on the second information. If the adjustment value X is 4 dBm, and if the threshold for triggering measurement report reporting is -80 dBm before the first handover, the threshold for triggering measurement report reporting may be -76 dBm after MBO is performed.

[0107] The third information may be used to indicate that the terminal has not found a suitable cell. The third information may include, for example, one or more of the following: indication information indicating that a suitable cell has not been found; indication information for the first service; measurement results of cells supporting the first service detected by the terminal; and setting parameters for cell selection or reselection.

[0108] The setting parameters for cell selection or reselection may be cell selection parameters or cell reselection parameters set before the first handover. The setting parameters for cell selection or reselection may be parameters related to cell selection or cell reselection. For example, the setting parameters for cell selection or reselection may include one or more of the following parameters: intra-frequency reference signal reception power threshold (s-IntraSearchP), intra-frequency reference signal reception quality threshold (s-IntraSearchQ), inter-frequency / inter-system reference signal reception power threshold (s-NonIntraSearchP), inter-frequency / inter-system reference signal reception quality threshold (s-NonIntraSearchQ), cell minimum reception level (q-RxLevMin), cell minimum reception level (q-RxLevMinOffset), cell minimum reception level under uplink enhancement (q-RxLevMinSUL), cell minimum quality level (q-QualMin), and cell minimum quality level offset (q-QualMinOffset).

[0109] This application does not limit the manner in which a terminal obtains the cell selection or reselection setting parameters. For example, a network device may send the cell selection or reselection setting parameters to the terminal. The terminal may obtain the cell selection or reselection setting parameters via one or more of the following messages: dedicated signaling, cell system broadcast message.

[0110] The network device may adjust cell selection or reselection parameters based on the third information. For example, the third information may include measurement results obtained by the terminal when performing cell selection. If the terminal fails to select a suitable target RAT cell after handover failure, the network device may adjust the S criterion-related parameters for cell selection based on the measurement results obtained by the terminal when performing cell selection.

[0111] In some embodiments, the network device may determine, based on the third information, an adjustment value corresponding to one or more cell selection or reselection parameters. For example, the network device may determine, based on the third information, that the adjustment value Y for the minimum required reception level in the cell is 1 dB. After performing MBO, the minimum required reception level in the cell may be increased by 1 dB.

[0112] The measurement result of the cell supporting the first service detected by the terminal may include measurement results of one or more cells. Optionally, the measurement result of the cell supporting the first service detected by the terminal may be the highest neighboring cell measurement result measured by the terminal. In addition, the fourth network device may be the network device to which the neighboring cell with the highest measurement result belongs. It is understandable that, if the terminal fails to find a suitable cell, sending the third information to the fourth network device to which the cell with the highest measurement result belongs may only cause the fourth network device to adjust the cell selection criteria, thereby reducing the computational workload of other network devices.

[0113] The second information or the third information may be carried in a radio link failure report and / or a logged measurement report. The logged measurement report may be used to record measurement results of cells supporting the first service around the terminal.

[0114] The recording of the logged measurement report may be triggered by a first event, the first event including a first handover and / or the terminal being outside the coverage of a cell supporting the first service (out-of-coverage). In some embodiments, the first event includes the terminal being outside the coverage of a cell supporting the first service. When the terminal is outside the coverage of any neighboring cell supporting the first service, the recording of the logged measurement report may be triggered.

[0115] In the event of a first handover failure or a radio link failure after the first handover is successful, the network device may optimize and adjust the first handover based on the cause of the first handover failure or the cause of the RLF. The cause of the first handover failure or the cause of the RLF may be obtained from the cause value of the RLF or HOF in the radio link failure report. For example, in the event that the first handover failure is caused by a contention-based random access failure and / or the second cell does not allocate dedicated random access resources for the terminal, based on the first information, the network device and / or the terminal may not handover other terminals with the first service demand to the second cell.

[0116] It is understandable that if the second cell does not allocate dedicated random access resources for the terminal, or if the first handover fails due to contention-based random access, it will be difficult for other terminals to successfully perform random access in the second cell. Therefore, other terminals with first service requirements may not be handed over to the second cell, which can avoid handover failures caused by similar problems, allowing other terminals to access other cells, thereby improving the handover success rate.

[0117] The network device may not switch other terminals with the first service requirement to the second cell within a period of time. After the period of time has expired, the network device may attempt to switch other terminals with the first service requirement to the second cell.

[0118] The communication method provided by this application is described in detail below through three embodiments.

[0119] Example 1

[0120] Figure 4 is a schematic flow chart of a communication method provided in Example 1. Figure 4 illustrates a method using a voice service as an example of a first service. The method shown in Figure 4 can be performed by a network device and a terminal. The network device may include a first network device belonging to a first cell, a second network device belonging to a second cell, and a third network device belonging to a cell where the terminal resides after a first handover failure or a radio link failure. The method shown in Figure 4 may include steps S410 to S470.

[0121] Step S410: The network device configures a measurement reporting event for the terminal. For example, the network device may configure a B1 measurement reporting event for the terminal, and the network configures a -80dBm B1 measurement reporting event for the terminal.

[0122] Step S420: The terminal measures a neighboring cell, which may be an LTE cell supporting voice services.

[0123] Step S430: The terminal sends a measurement report.

[0124] In some embodiments, when a terminal finds that a neighboring cell meets the measurement reporting conditions, it can send a measurement report. For example, if the measurement result of the second cell is -79dBm, which meets the B1 measurement reporting event, the terminal can send the measurement report to the first cell (i.e., the current serving cell).

[0125] Step S440: The network device sends a switching instruction.

[0126] The handover instruction may be used to implement a first handover of the terminal from the first cell to the second cell (target cell). The handover instruction may be, for example, a MobilityFromNRCommand signaling including a voiceFallbackIndication.

[0127] In some embodiments, after receiving the terminal measurement result, the first network device of the first cell may start the handover process. After the first network device and the network device of the second cell complete the handover preparation, the first network device may send a handover instruction to the terminal.

[0128] Step S450: The terminal performs random access to the second cell.

[0129] In some cases, a problem may occur during the random access process of the terminal. For example, the terminal cannot receive Msg2 sent by the network device. The problem with random access may cause the first handover to fail.

[0130] In some cases, the terminal successfully completes random access to the second cell, but soon afterward, an RLF occurs in the second cell.

[0131] Step S460: The terminal sends a wireless link failure report.

[0132] The radio link failure report may include first information.

[0133] In some embodiments, after re-accessing the network, the terminal may forward the radio link failure report to the second cell to which it is switched via the current cell.

[0134] The network device may determine that MRO is required for the first handover based on the first information in the radio link failure report. For example, based on the first information, the network device may determine that MRO is required for the first handover based on timeConnFailure < a certain threshold or encountering a problem during the random access process.

[0135] Step S470: The second network device sends a handover report. The handover report may be sent to the network device where the first cell is located.

[0136] Step S480: The first network device adjusts one or more of the threshold for triggering measurement report reporting, the cell selection parameter, and the cell reselection parameter.

[0137] For example, according to the handover report, the first cell may adjust the B1 measurement reporting event triggering threshold (eg, increase it to -72 dBm).

[0138] Optionally, the adjustment amount may be determined with reference to a cell signal measurement result sent by the terminal when the terminal subsequently finds a suitable E-UTRA cell.

[0139] Example 2

[0140] Figure 5 is a schematic flow chart of a communication method provided in Example 2. Figure 5 illustrates the method using a voice service as an example. The method shown in Figure 5 can be performed by a network device and a terminal. The network device may include a first network device belonging to the first cell, a second network device belonging to the second cell, and a third network device belonging to the cell where the terminal resides after the first handover failure or radio link failure. The method shown in Figure 5 may include steps S510 to S580.

[0141] Step S510: The network device configures a measurement reporting event for the terminal. For example, the network device configures a B1 measurement reporting event for the terminal, and the network configures a B1 measurement reporting event of -80dBm for the terminal.

[0142] Step S520: The terminal measures a neighboring cell, which may be an LTE cell supporting voice services.

[0143] Step S530: The terminal sends a measurement report.

[0144] In some embodiments, when a terminal finds that a neighboring cell meets the measurement reporting conditions, it can send a measurement report. For example, if the measurement result of the second cell is -79dBm, which meets the B1 measurement reporting event, the terminal can send the measurement report to the first cell (i.e., the current serving cell).

[0145] Step S540: The network device sends a switching instruction.

[0146] The handover instruction may be used to implement a first handover of the terminal from the first cell to the second cell (ie, the target cell). The handover instruction may be, for example, a MobilityFromNRCommand signaling including a voiceFallbackIndication.

[0147] In some embodiments, after receiving the terminal measurement result, the first network device of the current serving cell may start the first handover process. After the first network device and the network device of the second cell complete the handover preparation, the first network device may send a handover instruction to the terminal.

[0148] Step S550: The terminal performs random access to the second cell to perform a first handover.

[0149] In some cases, the terminal may encounter problems during random access to the second cell, resulting in failure to complete the first handover. For example, the terminal may repeatedly fail during contention-based random access. Alternatively, the second cell may not have previously allocated dedicated random access resources for the terminal.

[0150] Step S560: The terminal sends a wireless link failure report.

[0151] The radio link failure report may include first information.

[0152] In some embodiments, after re-accessing the network, the terminal may forward the radio link failure report to the second cell to which it is switched via the current cell.

[0153] The network device may determine, based on the first information in the radio link failure report, that the terminal encounters a random access problem.

[0154] Step S570: The second network device sends a handover report. The handover report may be sent to the network device where the first cell is located.

[0155] In step S580, the first network device can prevent the terminal that subsequently requires voice fallback from switching to the second cell.

[0156] Example 3

[0157] Figure 6 is a schematic flow chart of a communication method provided in Example 3. Figure 6 illustrates a method in which the first service is a voice service. The method shown in Figure 6 can be performed by a network device and a terminal. The network device may include a first network device to which the first cell belongs, a second network device to which the second cell belongs, a third network device to which the cell resides after the first handover failure or radio link failure belongs, and a fourth network device to which the E-UTRAN cell measured by the terminal belongs. The method shown in Figure 6 may include steps S610 to S670.

[0158] Step S610: The network device configures a measurement reporting event for the terminal. For example, the network device configures a B1 measurement reporting event for the terminal, and the network configures a B1 measurement reporting event of -80 dBm for the terminal.

[0159] Step S620: The terminal measures a neighboring cell, which may be an LTE cell supporting voice services.

[0160] Step S630: The terminal sends a measurement report.

[0161] In some embodiments, when a terminal finds that a neighboring cell meets the measurement reporting conditions, it can send a measurement report. For example, if the measurement result of the second cell is -79dBm, which meets the B1 measurement reporting event, the terminal can send the measurement report to the first cell (i.e., the current serving cell).

[0162] Step S640: The network device sends a switching instruction.

[0163] The handover instruction may be used to implement a first handover of the terminal from the first cell to the second cell (ie, the target cell). The handover instruction may be, for example, a MobilityFromNRCommand signaling including a voiceFallbackIndication.

[0164] In some embodiments, after receiving the terminal measurement result, the first network device of the current serving cell may start the first handover process. After the first network device and the network device of the second cell complete the handover preparation, the first network device may send a handover instruction to the terminal.

[0165] Step S650: The terminal performs random access to the second cell to perform a first handover.

[0166] In some cases, the terminal may encounter problems while performing random access to the second cell, resulting in failure to complete the first handover. For example, the terminal may repeatedly fail during contention-based random access. Alternatively, the second cell may not have previously allocated dedicated random access resources for the terminal. Alternatively, the terminal may fail to receive Msg2 sent by the network device.

[0167] In some cases, the terminal successfully completes random access to the second cell, but soon afterward, an RLF occurs in the second cell.

[0168] Step S660: When the first handover fails or RLF occurs after the first handover succeeds, the terminal may select a suitable E-UTRA cell. The terminal may determine a suitable E-UTRAN cell based on a cell selection parameter or a cell reselection parameter.

[0169] Step S670: The terminal sends a radio link failure report.

[0170] The radio link failure report may include first information.

[0171] If the terminal fails to find a suitable E-UTRA cell, the terminal may send third information to the network device. The third information may include one or more of the following information: indication that a suitable E-UTRA cell has not been found, a measurement result of the measured E-UTRA cell, and a corresponding E-UTRA cell ID.

[0172] The third information may be recorded in a radio link failure report or other signaling (eg, a logged measurement report).

[0173] The third information may be sent to the cell after successful reestablishment. The cell after successful reestablishment may be, for example, the first cell.

[0174] The network device where the first cell is located may send the third information (for example, including: the highest E-UTRA cell measurement result obtained by the terminal, and indication information that a suitable E-UTRA cell was not found) and the first information to a fourth network device where the E-UTRA cell corresponding to the highest measurement result is located (which may be forwarded via the core network). The fourth network device may adjust corresponding parameters of a cell selection criterion and / or a cell reselection criterion for determining whether the terminal is suitable for camping based on the third information.

[0175] The method embodiment of the present application is described in detail above in conjunction with Figures 1 to 6 , and the device embodiment of the present application is described in detail below in conjunction with Figures 7 to 9 . It should be understood that the description of the method embodiment corresponds to the description of the device embodiment, and therefore, for portions not described in detail, reference can be made to the above method embodiment.

[0176] FIG7 is a schematic structural diagram of a terminal 700 provided in an embodiment of the present application. The terminal shown in FIG7 may include a switching unit 710 and a first sending unit 720.

[0177] A switching unit 710 is configured to perform a first handover to switch from a first cell to a second cell, where the first cell does not support a first service, and the second cell supports the first service, and a purpose of the first handover is to enable the terminal to perform the first service;

[0178] The first sending unit 720 is configured to send first information when the first handover fails or when a radio link failure occurs after the first handover succeeds, where the first information is used to improve mobility robustness and optimize MRO.

[0179] Optionally, the terminal 700 may also include: a selection unit, used to perform cell selection to find a suitable cell when the first switching fails or a wireless link failure occurs after the first switching succeeds, and the suitable cell supports the first service; a second sending unit, used to send second information when the terminal finds a suitable cell, and the second information is used to indicate that the terminal has found the suitable cell; a third sending unit, used to send third information when the terminal has not found a suitable cell, and the third information is used to indicate that the terminal has not found the suitable cell.

[0180] Optionally, the second information is used to adjust the threshold for triggering measurement report reporting; the third information is used to adjust one or more of the following parameters: the threshold for triggering measurement report reporting, the cell selection parameter, and the cell reselection parameter.

[0181] Optionally, the second information includes one or more of the following information: an identifier of the suitable cell; a frequency of the suitable cell; a measurement result of the suitable cell; and indication information of the first service.

[0182] Optionally, the third information includes one or more of the following information: indication information that the suitable cell is not found; indication information of the first service; measurement results of the cell supporting the first service; setting parameters for cell selection or reselection.

[0183] Optionally, the setting parameters for cell selection or reselection include one or more of the following parameters: same-frequency measurement reference signal receiving power threshold, same-frequency measurement reference signal receiving quality threshold, different-frequency / different-system measurement threshold, different-frequency / different-system measurement reference signal receiving quality threshold, cell minimum receiving level, cell minimum receiving level, cell minimum receiving level under uplink enhancement, cell minimum quality level, and cell minimum quality level offset.

[0184] Optionally, the terminal obtains the setting parameters for the cell selection or reselection through one or more of the following messages: dedicated signaling; cell system broadcast message.

[0185] Optionally, the second information or the third information is carried in one or more of the following messages: a radio link failure report; a logged-in measurement report.

[0186] Optionally, the registered measurement report is used to record measurement results of cells around the terminal that support the first service.

[0187] Optionally, the recording of the logged measurement report is triggered by a first event, where the first event includes the first handover and / or the terminal being out of coverage of the second cell.

[0188] Optionally, the cell supporting the first service is an E-UTRA cell.

[0189] Optionally, in the case where the first switching failure is due to a failure of contention-based random access and / or the second cell does not allocate dedicated random access resources for the terminal, the first information is also used by the network device not to switch other terminals with the first service demand to the second cell.

[0190] Optionally, the first information is carried in a radio link failure report.

[0191] Optionally, the first service is a voice service, and the first switching is a voice fallback cross-system switching.

[0192] FIG8 is a schematic structural diagram of a network device 800 provided in an embodiment of the present application. The network device 800 may include a first receiving unit 810 .

[0193] The first receiving unit 810 is used to receive first information when a first handover fails or a radio link failure occurs after the first handover is successful, and the first information is used to improve mobility robustness and optimize MRO; wherein the first handover is the handover of the terminal from a first cell to a second cell, the first cell does not support the first service, and the second cell supports the first service, and the purpose of the first handover is to enable the terminal to perform the first service.

[0194] Optionally, the network device 800 may also include: a second receiving unit, used to receive second information if the terminal finds a suitable cell when the first switching fails or a wireless link failure occurs after the first switching succeeds, and the second information is used to indicate that the terminal has found the suitable cell, and the suitable cell supports the first service; a third receiving unit, used to receive third information if the terminal has not found a suitable cell when the first switching fails or a wireless link failure occurs after the first switching succeeds, and the third information is used to indicate that the terminal has not found the suitable cell.

[0195] Optionally, the second information is used to adjust the threshold for triggering measurement report reporting; the third information is used to adjust one or more of the following parameters: the threshold for triggering measurement report reporting, the cell selection parameter, and the cell reselection parameter.

[0196] Optionally, the second information includes one or more of the following information: an identifier of the suitable cell; a frequency of the suitable cell; a measurement result of the suitable cell; and indication information of the first service.

[0197] Optionally, the third information includes one or more of the following information: indication information that the suitable cell is not found; indication information of the first service; measurement results of the cell supporting the first service detected by the terminal; setting parameters for cell selection or reselection.

[0198] Optionally, the setting parameters for cell selection or reselection include one or more of the following parameters: same-frequency measurement reference signal receiving power threshold, same-frequency measurement reference signal receiving quality threshold, different-frequency / different-system measurement threshold, different-frequency / different-system measurement reference signal receiving quality threshold, cell minimum receiving level, cell minimum receiving level, cell minimum receiving level under uplink enhancement, cell minimum quality level, and cell minimum quality level offset.

[0199] Optionally, the terminal obtains the setting parameters for cell selection or reselection through one or more of the following messages: dedicated signaling; cell system broadcast message.

[0200] Optionally, the second information or the third information is carried in one or more of the following messages: a radio link failure report; a logged-in measurement report.

[0201] Optionally, the registered measurement report is used to record measurement results of cells around the terminal that support the first service.

[0202] Optionally, the recording of the logged measurement report is triggered by a first event, where the first event includes the first handover and / or the terminal being out of coverage of the second cell.

[0203] Optionally, the cell supporting the first service is an E-UTRA cell.

[0204] Optionally, in the case where the first switching failure is due to a failure of contention-based random access and / or the second cell does not allocate dedicated random access resources for the terminal, the first information is also used by the network device to prevent other terminals with the first service demand from switching to the second cell.

[0205] Optionally, the first information is carried in a radio link failure report.

[0206] Optionally, the first service is a voice service, and the first switching is a voice fallback cross-system switching.

[0207] Figure 9 is a schematic block diagram of a communication device 900 according to an embodiment of the present application. The dashed lines in Figure 9 indicate that the unit or module is optional. The device 900 may be used to implement the method described in the above method embodiment. The device 900 may be a chip, a terminal device, or a network device.

[0208] The device 900 may include one or more processors 910. The processor 910 may support the device 900 to implement the method described in the method embodiment above. The processor 910 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0209] The apparatus 900 may further include one or more memories 920. The memories 920 store programs that can be executed by the processor 910, causing the processor 910 to perform the methods described in the above method embodiments. The memories 920 may be independent of the processor 910 or integrated into the processor 910.

[0210] The apparatus 900 may further include a transceiver 930. The processor 910 may communicate with other devices or chips via the transceiver 930. For example, the processor 910 may transmit and receive data with other devices or chips via the transceiver 930.

[0211] The present application also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to a terminal or network device provided in the present application, and the program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0212] The present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to a terminal or network device provided in the present application, and the program causes a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0213] The embodiments of the present application also provide a computer program. The computer program can be applied to the terminal or network device provided in the embodiments of the present application, and the computer program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0214] It should be understood that the terms "system" and "network" in this application can be used interchangeably. In addition, the terms used in this application are only used to explain the specific embodiments of this application and are not intended to limit this application. The terms "first", "second", "third", and "fourth" in the specification and claims of this application and the accompanying drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0215] In the embodiments of this application, the term "indication" may refer to a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" may refer to a direct indication of B, e.g., B can obtain information through A; it may refer to an indirect indication of B, e.g., A indicates C, e.g., B can obtain information through C; or it may refer to an association between A and B.

[0216] In the embodiment of the present application, "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should be understood that determining B based on A does not mean determining B based solely on A, but B can also be determined based on A and / or other information.

[0217] In the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and indication, configuration and configuration, etc.

[0218] In the embodiments of the present application, "pre-definition" or "pre-configuration" may be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (e.g., a terminal device and a network device). The present application does not limit the specific implementation method. For example, pre-definition may refer to information defined in a protocol.

[0219] In the embodiments of the present application, the “protocol” may refer to a standard protocol in the communications field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

[0220] In the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0221] In various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0222] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0223] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0224] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0225] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be read by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0226] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that, The method includes: The terminal performs a first handover to hand over from a first cell to a second cell. The first cell does not support a first service, and the second cell supports the first service. The purpose of the first handover is to enable the terminal to perform the first service; In the case where the first handover fails or a radio link failure occurs after the first handover is successful, the terminal sends first information, which is used to optimize the mobility network parameter settings and / or perform mobility robustness optimization.

2. The method according to claim 1, wherein It further includes: In the case where the first handover fails or a radio link failure occurs after the first handover is successful, the terminal performs cell selection or reselection to find a suitable cell, and the suitable cell supports the first service; In the case where the terminal finds a suitable cell, the terminal sends second information, which is used to indicate that the terminal has found the suitable cell; In the case where the terminal does not find a suitable cell, the terminal sends third information, which is used to indicate that the terminal has not found the suitable cell.

3. The method according to claim 2, wherein The second information is used to adjust the threshold for triggering the reporting of a measurement report; The third information is used to adjust one or more of the following parameters: the threshold for triggering the reporting of a measurement report, cell selection parameters, cell reselection parameters.

4. The method according to claim 2 or 3, characterized in that, The second information includes one or more of the following information: The identifier of the suitable cell; The frequency point of the suitable cell; The measurement result of the suitable cell; The indication information of the first service.

5. The method according to any one of claims 2-4, characterized in that, The third information includes one or more of the following information: The indication information that the suitable cell has not been found; The indication information of the first service; The measurement result of the cell that supports the first service; The setting parameters of cell selection or reselection.

6. The method according to claim 5, wherein The setting parameters of the cell selection or reselection include one or more of the following parameters: The same-frequency start measurement reference signal received power threshold, the same-frequency start measurement reference signal received quality threshold, the different-frequency / different-system start measurement threshold, the different-frequency / different-system start measurement reference signal received quality threshold, the minimum received level of the cell, the minimum received level of the cell, the minimum received level of the cell under uplink enhancement, the minimum quality level of the cell, the minimum quality level offset of the cell.

7. The method according to claim 5 or 6, characterized in that, The terminal obtains the setting parameters of the cell selection or reselection through one or more of the following messages: Dedicated signaling; Cell system broadcast message.

8. The method according to any one of claims 2 - 7, characterized in that, The second information or the third information is carried in one or more of the following messages: Radio link failure report; Logged measurement report.

9. The method according to claim 8, wherein The logged measurement report is used to record the measurement results of the cells around the terminal that support the first service.

10. The method according to claim 8 or 9, characterized in that, The recording of the logged measurement report is triggered by a first event, and the first event includes the first handover and / or the terminal being outside the coverage area of the cell that supports the first service.

11. The method according to claim 5, 9 or 10, characterized in that The cell that supports the first service is an E-UTRA cell.

12. The method according to any one of claims 1-11, characterized in that, In the case where the first handover failure is due to a contention-based random access failure and / or the failure that the second cell does not allocate dedicated random access resources to the terminal, the first information is further used to prevent other terminals with the first service requirement from being handed over to the second cell.

13. The method according to any one of claims 1-12, characterized in that, The first information is carried in a radio link failure report.

14. The method according to any one of claims 1-13, characterized in that, The first service is a voice service, and the first handover is a voice fallback inter-system handover.

15. A communication method, characterized in that, The method includes: In the case of a first handover failure or a radio link failure occurring after the first handover is successful, the network device receives first information, where the first information is used to optimize the settings of mobility network parameters and / or perform mobility robustness optimization; Wherein, the first handover is a handover of the terminal from a first cell to a second cell, the first cell does not support the first service, the second cell supports the first service, and the purpose of the first handover is to enable the terminal to execute the first service.

16. The method according to claim 15, wherein It further includes: In the case of a first handover failure or a radio link failure occurring after the first handover is successful, if the terminal finds a suitable cell, the network device receives second information, where the second information is used to indicate that the terminal has found the suitable cell, and the suitable cell supports the first service; In the case of a first handover failure or a radio link failure occurring after the first handover is successful, if the terminal does not find a suitable cell, the network device receives third information, where the third information is used to indicate that the terminal has not found the suitable cell.

17. The method according to claim 16, wherein: The second information is used to adjust the threshold for triggering the reporting of a measurement report; The third information is used to adjust one or more of the following parameters: the threshold for triggering the reporting of a measurement report, cell selection parameters, cell reselection parameters.

18. The method according to claim 16 or 17, characterized in that, The second information includes one or more of the following information: The identifier of the suitable cell; The frequency point of the suitable cell; The measurement result of the suitable cell; The indication information of the first service.

19. The method according to any one of claims 16 - 18, characterized in that, The third information includes one or more of the following information: The indication information that the suitable cell has not been found; The indication information of the first service; The measurement result of the cell supporting the first service detected by the terminal; The setting parameters of cell selection or reselection.

20. The method according to claim 19, wherein The setting parameters of cell selection or reselection include one or more of the following parameters: The same-frequency start measurement reference signal received power threshold, the same-frequency start measurement reference signal received quality threshold, the different-frequency / different-system start threshold, the different-frequency / different-system start measurement reference signal received quality threshold, the minimum cell received level, the minimum cell received level, the minimum cell received level under uplink enhancement, the minimum cell quality level, the minimum cell quality level offset.

21. The method according to claim 19 or 20, characterized in that, The terminal obtains the setting parameters of cell selection or reselection through one or more of the following messages: Dedicated signaling; Cell system broadcast message.

22. The method according to any one of claims 16-21, characterized in that, The second information or the third information is carried in one or more of the following messages: Radio link failure report; Logged measurement report.

23. The method according to claim 22, wherein The logged measurement report is used to record the measurement results of the cells around the terminal that support the first service.

24. The method according to claim 22 or 23, characterized in that, The recording of the logged measurement report is triggered by a first event, which includes the first handover and / or the terminal being outside the coverage area of a cell that supports the first service.

25. The method according to claim 19, 23 or 24, characterized in that, The cell that supports the first service is an E-UTRA cell.

26. The method according to any one of claims 15 - 25, characterized in that, In the case where the first handover fails due to a contention-based random access failure and / or the second cell fails to allocate dedicated random access resources to the terminal, the first information is further used to prevent other terminals with the first service requirement from being handed over to the second cell.

27. The method according to any one of claims 15-26, characterized in that, The first information is carried in a radio link failure report.

28. The method according to any one of claims 15-27, characterized in that, The first service is a voice service, and the first handover is a voice fallback inter-system handover.

29. A terminal, characterized in that, The terminal includes: A handover unit configured to perform a first handover to switch from a first cell that does not support the first service to a second cell that supports the first service, the purpose of the first handover being to enable the terminal to perform the first service; A first transmitting unit configured to transmit first information in the case where the first handover fails or a radio link failure occurs after the first handover succeeds, the first information being used to optimize the setting of mobility network parameters and / or perform mobility robustness optimization.

30. The terminal according to claim 29, wherein It further includes: A selection unit configured to perform cell selection or reselection to find a suitable cell in the case where the first handover fails or a radio link failure occurs after the first handover succeeds, the suitable cell supporting the first service; A second transmitting unit configured to transmit second information in the case where the terminal finds a suitable cell, the second information being used to indicate that the terminal has found the suitable cell; A third transmitting unit configured to transmit third information in the case where the terminal fails to find a suitable cell, the third information being used to indicate that the terminal has not found the suitable cell.

31. The terminal according to claim 30, wherein The second information is used to adjust the threshold for triggering the reporting of the measurement report; The third information is used to adjust one or more of the following parameters: the threshold for triggering the reporting of the measurement report, cell selection parameters, cell reselection parameters.

32. The terminal according to claim 30 or 31, characterized in that, The second information includes one or more of the following information: The identifier of the suitable cell; The frequency point of the suitable cell; The measurement results of the suitable cell; The indication information of the first service.

33. The terminal according to any one of claims 30-32, characterized in that, The third information includes one or more of the following information: The indication information that the suitable cell has not been found; The indication information of the first service; The measurement results of the cells that support the first service; The setting parameters for cell selection or reselection.

34. The terminal according to claim 33, wherein The setting parameters for cell selection or reselection include one or more of the following parameters: Threshold of reference signal received power for same-frequency initial measurement, threshold of reference signal received quality for same-frequency initial measurement, threshold of inter-frequency / heterogeneous system initial measurement, threshold of reference signal received quality for inter-frequency / heterogeneous system initial measurement, minimum received level of the cell, minimum received level of the cell, minimum received level of the cell under uplink enhancement, minimum quality level of the cell, offset of minimum quality level of the cell.

35. The terminal according to claim 33 or 34, characterized in that, The terminal obtains the setting parameters for cell selection or reselection through one or more of the following messages: Dedicated signaling; Cell system broadcast message.

36. The terminal according to any one of claims 30-35, characterized in that, The second information or the third information is carried in one or more of the following messages: Radio link failure report; Logged measurement report.

37. The terminal according to claim 36, wherein The logged measurement report is used to record the measurement results of the cells around the terminal that support the first service.

38. The terminal according to claim 36 or 37, characterized in that The recording of the logged measurement report is triggered by a first event, and the first event includes the first handover and / or the terminal being outside the coverage area of the cell supporting the first service.

39. The terminal according to claim 33, 37 or 38, characterized in that, The cell supporting the first service is an E-UTRA cell.

40. The terminal according to any one of claims 29-39, characterized in that, In the case where the first handover fails due to contention-based random access failure and / or the second cell fails to allocate dedicated random access resources to the terminal, the first information is also used to prevent other terminals with the first service requirement from being handed over to the second cell.

41. The terminal according to any one of claims 29-40, characterized in that, The first information is carried in the radio link failure report.

42. The terminal according to any one of claims 29-41, characterized in that, The first service is a voice service, and the first handover is a voice fallback inter-system handover.

43. A network device, characterized in that, Including: A first receiving unit, configured to receive first information in the case of a first handover failure or a radio link failure occurring after the first handover is successful, where the first information is used to optimize the setting of mobility network parameters and / or perform mobility robustness optimization; Wherein, the first handover is a handover of the terminal from a first cell to a second cell, the first cell does not support the first service, the second cell supports the first service, and the purpose of the first handover is to enable the terminal to execute the first service.

44. The network device according to claim 43, characterized in that, Further including: A second receiving unit, configured to receive second information in the case of a first handover failure or a radio link failure occurring after the first handover is successful, if the terminal finds a suitable cell, where the second information is used to indicate that the terminal has found the suitable cell, and the suitable cell supports the first service; A third receiving unit, configured to receive third information in the case of a first handover failure or a radio link failure occurring after the first handover is successful, if the terminal does not find a suitable cell, where the third information is used to indicate that the terminal has not found a suitable cell.

45. The network device according to claim 44, wherein The second information is used to adjust the threshold for triggering the reporting of the measurement report; The third information is used to adjust one or more of the following parameters: the threshold for triggering the reporting of the measurement report, cell selection parameters, cell reselection parameters.

46. The network device according to claim 44 or 45, characterized in that, The second information includes one or more of the following information: The identifier of the suitable cell; The frequency point of the suitable cell; The measurement result of the suitable cell; The indication information of the first service.

47. The network device according to any one of claims 44-46, characterized in that, The third information includes one or more of the following information: Indication information that the appropriate cell is not found; Indication information of the first service; Measurement results of the cell that supports the first service detected by the terminal; Setting parameters for cell selection or reselection.

48. The network device according to claim 47, wherein The setting parameters for cell selection or reselection include one or more of the following parameters: Same-frequency start measurement reference signal received power threshold, same-frequency start measurement reference signal received quality threshold, different-frequency / different-system start measurement threshold, different-frequency / different-system start measurement reference signal received quality threshold, minimum cell received level, minimum cell received level, minimum cell received level under uplink enhancement, minimum cell quality level, minimum cell quality level offset.

49. The network device according to claim 47 or 48, characterized in that, The terminal obtains the setting parameters for cell selection or reselection through one or more of the following messages: Dedicated signaling; Cell system broadcast message.

50. The network device according to any one of claims 44-49, characterized in that, The second information or the third information is carried in one or more of the following messages: Radio link failure report; Logged measurement report.

51. The network device according to claim 50, wherein, The logged measurement report is used to record the measurement results of the cells around the terminal that support the first service.

52. The network device according to claim 50 or 51, characterized in that, The recording of the logged measurement report is triggered by a first event, and the first event includes the first handover and / or the terminal being outside the coverage area of the cell that supports the first service.

53. The network device according to claim 47, 51 or 52, characterized in that, The cell that supports the first service is an E-UTRA cell.

54. The network device according to any one of claims 43 to 53, characterized in that, In the case where the first handover fails due to contention-based random access failure and / or the second cell fails to allocate dedicated random access resources to the terminal, the first information is further used to prevent other terminals with the first service requirement from being handed over to the second cell.

55. The network device according to any one of claims 43-54, characterized in that, The first information is carried in the radio link failure report.

56. The network device according to any one of claims 43-55, characterized in that, The first service is a voice service, and the first handover is a voice fallback inter-system handover.

57. A terminal, characterized in that, It includes a memory and a processor. The memory is used to store a program, and the processor is used to call the program in the memory so that the terminal executes the method according to any one of claims 1-14.

58. A network device, characterized in that, It includes a memory and a processor. The memory is used to store a program, and the processor is used to call the program in the memory so that the network device executes the method according to any one of claims 15-28.

59. A device, characterized in that, It includes a processor, which is used to call a program from a memory so that the device executes the method according to any one of claims 1-14.

60. A device, characterized in that, It includes a processor, which is used to call a program from a memory so that the device executes the method according to any one of claims 15-28.

61. A chip, characterized in that, It includes a processor, which is used to call a program from a memory so that the device installed with the chip executes the method according to any one of claims 1-14.

62. A chip, characterized in that, It includes a processor, which is used to call a program from a memory so that the device installed with the chip executes the method according to any one of claims 15-28.

63. A computer-readable storage medium, characterized in that, A program is stored thereon, and the program causes a computer to execute the method according to any one of claims 1-14.

64. A computer-readable storage medium, characterized in that, A program is stored thereon, and the program causes a computer to execute the method according to any one of claims 15-28.

65. A computer program product, characterized in that, Comprising a program that causes a computer to perform the method according to any one of claims 1-14.

66. A computer program product, characterized in that, Comprising a program that causes a computer to perform the method according to any one of claims 15-28.

67. A computer program, characterized in that, The computer program causes a computer to perform the method according to any one of claims 1-14.

68. A computer program, characterized in that, The computer program causes a computer to perform the method according to any one of claims 15-28.

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