Radio resource control (RRC) reestablishment method and device

Abstract

The embodiment of the invention provides a radio resource control (RRC) reestablishment method and device, relates to the field of communication, and can prevent normal services of user equipment (UE) from being affected (for example, the problems that voice services cannot be connected, and voice calls are dropped). The method comprises the following steps that: after the terminal equipment detects that RLF occurs in a first cell, if a preset condition is met, the terminal equipment performs an RRC reestablishment process on the first cell. Wherein the preset condition comprises at least one of the following conditions: the terminal device is about to perform or is performing a time sensitive network (TSN) service; the terminal equipment is in a preset state, and the preset state comprises that the displacement of the terminal equipment in a preset time period is smaller than a first preset threshold value, or the average acceleration / speed of the terminal equipment in the preset time period is smaller than a second preset threshold value; the signal quality of the first cell is higher than a third preset threshold; the number of times that the first cell generates the RLF in unit time is smaller than a fourth preset threshold value.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular to a method and device for re-establishing a radio resource control (RRC). Background Art

[0002] In long term evolution (LTE) or new radio / new air interface (NR) networks, radio link failure (RLF) may occur due to the wireless environment or network coverage loopholes, thus affecting the normal services of user equipment (UE). After the UE detects RLF, it can trigger the RRC re-establishment process.

[0003] For example, Figure 1 As shown in the figure, if RLF occurs in the UE in cell 1 (belonging to base station 1), the UE can select cell 2 (belonging to base station 2) to initiate reconstruction, that is, cross-site RRC reconstruction can be performed. Assuming that the UE's service is a voice service, since cells 1 and 2 belong to different base stations (base station 1 and base station 2), base station 2 may not be able to obtain the UE context, resulting in the core network being unable to establish a dedicated bearer, which in turn leads to problems such as the inability to connect the voice service or voice dropped calls. Summary of the invention

[0004] The embodiments of the present application provide a radio resource control (RRC) re-establishment method and apparatus, which can prevent the normal services of UE from being affected (for example, voice services cannot be connected, voice calls are dropped, etc.).

[0005] In the first aspect, an embodiment of the present application provides a wireless resource control (RRC) re-establishment method, which is applied to a terminal device, including: the terminal device detects that a wireless link failure (RLF) occurs in a first cell; if a preset condition is met, the terminal device performs an RRC re-establishment process on the first cell; wherein the preset condition includes at least one of the following conditions: the terminal device is about to or is performing a time-sensitive network (TSN) service; the terminal device is in a preset state, and the preset state includes that the displacement of the terminal device in a preset time period is less than a first preset threshold, or the average acceleration / speed of the terminal device in a preset time period is less than a second preset threshold; the signal quality of the first cell is higher than a third preset threshold; the number of RLFs that occur in the first cell per unit time is less than a fourth preset threshold.

[0006] Based on the method provided in the embodiment of the present application, after the terminal device detects that RLF occurs in the first cell, if the preset conditions are met, the terminal device can perform the RRC re-establishment process on the first cell, that is, the terminal device can return to the original station (the base station corresponding to the first cell) to perform RRC reconstruction, thereby avoiding the terminal device's business being affected by cross-station RRC reconstruction.

[0007] In a possible implementation, the RRC reestablishment process performed by the terminal device on the first cell includes: the terminal device resides in the first cell; if the terminal device successfully resides in the first cell, the terminal device sends an RRC connection reestablishment request to the first cell. That is, after the terminal device detects that RLF occurs in the first cell, it can return to the original station (the base station corresponding to the first cell) to perform RRC reconstruction, so as to avoid affecting the services of the terminal device due to cross-station RRC reconstruction.

[0008] In a possible implementation, the method also includes: if the terminal device fails to reside in the first cell, the terminal device sends an RRC connection re-establishment request to the second cell, and the frequency of the second cell is the same as that of the first cell. Since the frequency of the second cell is the same as that of the first cell, the probability that the second cell and the original cell (first cell) belong to the same base station (that is, the same-station cell) is relatively high. Although the UE cannot directly identify the same-station cell of the original cell (that is, the cell corresponding to the same access network device (for example, base station) as the original cell), it can directly identify the second cell. Since the probability that the second cell and the original cell belong to the same base station is relatively high, the probability that the UE returns to the original station (the base station of the original cell) to perform the re-establishment process is greater, and the probability that the UE performs cross-site RRC reconstruction is smaller. Therefore, it is possible to avoid the cross-site RRC reconstruction from affecting the UE's services (for example, causing voice establishment to fail, voice dropped calls, and other problems).

[0009] In a possible implementation, the method further includes: if the preset condition is not met, the terminal device resides in a third cell, and the signal quality of the third cell is higher than a fifth preset threshold; the terminal device sends an RRC connection re-establishment request to the third cell. In this way, when the preset condition is not met, that is, when it is impossible to reside in the first cell, the terminal device can initiate an RRC connection re-establishment process to the third cell based on the signal quality to access the network.

[0010] In one possible implementation, the TSN service includes at least one of a voice service, a video service, an augmented reality technology (AR) service, a virtual reality technology (VR) service, a real-time game service, and an industrial Internet of Things service.

[0011] In a second aspect, the present application provides a computer program product, which, when executed on a computer, enables the computer to execute the method described in any one of the above aspects and any one of its possible designs.

[0012] In a third aspect, the present application provides a computer-readable storage medium, the computer-readable storage medium comprising computer instructions. When the computer instructions are executed on a terminal device (such as a mobile phone), the terminal device executes the method described in the first aspect and any possible implementation thereof.

[0013] In a fourth aspect, an embodiment of the present application provides an RRC re-establishment device, including a processor, the processor and a memory are coupled, the memory stores program instructions, and when the program instructions stored in the memory are executed by the processor, the device implements the method described in the first aspect and any possible design thereof. The device may be a terminal device; or may be a component of the terminal device, such as a chip.

[0014] In the fifth aspect, an embodiment of the present application provides a chip system, which includes an application processor (AP) for executing an operating system, a user interface and an application and a baseband processor (BP) for radio frequency communication control, and the BP is used to execute the method described in the first aspect and any possible design method thereof.

[0015] In a sixth aspect, the present application provides a chip system, the chip system comprising one or more interface circuits and one or more processors. The interface circuit and the processor are interconnected via a line.

[0016] The chip system can be applied to a terminal device including a communication module and a memory. The interface circuit is used to receive a signal from the memory of the terminal device and send the received signal to the processor, where the signal includes a computer instruction stored in the memory. When the processor executes the computer instruction, the terminal device can execute the method described in the first aspect and any possible design thereof.

[0017] It can be understood that the beneficial effects that can be achieved by the computer program product described in the second aspect, the computer-readable storage medium described in the third aspect, the RRC re-establishment device described in the fourth aspect, and the chip system described in the fifth and sixth aspects provided above can refer to the beneficial effects in the first aspect and any possible design method thereof, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of RRC re-establishment after RLF occurs;

[0019] Figure 2 A schematic diagram of an RRC re-establishment interaction provided in an embodiment of the present application;

[0020] Figure 3 A signal interaction diagram of a voice establishment process provided in an embodiment of the present application;

[0021] Figure 4 A schematic diagram of a communication system provided in an embodiment of the present application;

[0022] Figure 5A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0023] Figure 6 A schematic diagram of a protocol stack provided in an embodiment of the present application;

[0024] Figure 7 A method flow chart of an RRC re-establishment method provided in an embodiment of the present application;

[0025] Figure 8 A signal interaction diagram of an RRC re-establishment method provided in an embodiment of the present application;

[0026] Fig. 9 A schematic diagram of the structure of a chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the description of the following embodiments clear and concise, a brief introduction to the relevant concepts or technologies is first given:

[0028] Session Initiation Protocol (SIP): SIP is an application layer protocol that can establish, modify and release multimedia sessions in Internet Protocol (IP) networks. The main applications of SIP include but are not limited to voice, messaging, video, call control and other aspects.

[0029] A SIP message may include a start line, a message header, a blank line marking the end of the message header, and an optional message body. The start line of a SIP message includes a request line and a status line. The request line is the start line of a request message, and the status line is the start line of a response message. That is, a request message includes a request line, a message header, a blank line, and a message body; a response message includes a status line, a message header, a blank line, and a message body.

[0030] Both the request message and the response message include the SIP message header field and the SIP message body field. The SIP message header is mainly used to indicate the initiator and receiver of the message, as well as basic information such as the number of jumps; the SIP message body is mainly used to describe the specific implementation method of this session.

[0031] Common SIP messages include the following:

[0032] INVITE message is used to establish a dialog for media exchange with a user agent.

[0033] 100trying, temporary response. Indicates that the request has been received and is being processed. The sender's timer is stopped and there is no need to resend the request.

[0034] 183session progress, used to convey detailed information about the progress of the call. Also, it can be used to provide remote ringback tone to the caller.

[0035] The reliable response of unreliable transmission (the provisional response acknowledgement, PRACK) indicates that the 183 session progress has been received.

[0036] PRACK 200OK is the response message of PRACK, indicating that PRACK has been received.

[0037] IMS_SIP_UPDATE is used to update the media stream status when the call has not been established.

[0038] IMS_SIP_UPDATE / OK is a response message to the IMS_SIP_UPDATE message, indicating that the IMS_SIP_UPDATE message has been received.

[0039] IMS_SIP_CANCEL is used to cancel the INVITE request initiated by the client (calling UE).

[0040] In LTE or NR networks, UE may experience RLF due to the wireless environment or network coverage loopholes. RLF will reduce the reliability of communication and increase latency, thereby affecting the normal services of the UE.

[0041] After the UE detects the RLF, the RRC re-establishment process is triggered (ie, the RRC re-establishment process is started). After the RRC re-establishment process is triggered, the UE may first reselect a cell, and after reselecting a suitable cell, initiate RRC connection re-establishment (eg, send an RRC connection re-establishment request).

[0042] When the UE performs cell reselection, the following steps may be performed (upon initiation of the procedure, the UE shall):

[0043] 1) Start timer T311 (start timer T311).

[0044] 2) Perform cell selection in accordance with the cell selection process as specified in TS 38.304.

[0045] The relevant description of the timer T 311 is shown in Table 1.

[0046] Table 1

[0047]

[0048] Among them, T311 controls the time required for the UE to start the RRC connection re-establishment process to the UE selecting a cell. During this period, the UE performs the cell selection process and times out to enter IDLE.

[0049] After reselecting a suitable cell, the UE may send an RRC Connection Reestablishment Request to the cell. At this time, the UE may start timer T301.

[0050] The relevant description of the timer T 301 is shown in Table 2.

[0051] Table 2

[0052]

[0053]

[0054] That is, timer T301 starts after the UE sends an RRC Connection Reestablishment Request. If an RRC Connection Reestablishment or RRC Connection Reestablishment Reject message is received before the timeout, timer T301 stops and the UE enters the idle state (RRC_IDLE state) after the timeout.

[0055] For example, Figure 1 As shown, if RLF occurs in the UE in cell 1 (belonging to base station 1), the UE can select cell 2 (belonging to base station 2) to initiate reconstruction, that is, the UE can perform cross-site RRC reconstruction. Cross-site RRC reconstruction may include the following two situations:

[0056] Case 1, such as Figure 2As shown in (a), the UE sends an RRC Connection Reestablishment Request to cell 2. When cell 2 retrieves or verifies the UE context, cell 2 may send an RRC Connection Reestablishment message to the UE. Finally, the UE sends an RRC Connection Reconfiguration Complete message to cell 2 to indicate that the RRC connection reestablishment is successful.

[0057] Case 2, such as Figure 2 As shown in (b) in FIG. 1 , the UE sends an RRC Connection Reestablishment Request to cell 2. When cell 2 cannot obtain (retrieve or verify) the UE context, cell 2 may send an RRC Connection Setup message to the UE. Finally, the UE sends an RRC Connection Setup Complete message to cell 2 to indicate that the RRC connection setup is complete. That is, the RRC connection reestablishment falls back to the RRC connection setup success.

[0058] In case 1, that is, when the RRC connection re-establishment is successful, base station 2 can send an RLF Indication to base station 1 according to the RRC connection re-establishment request of the UE, which contains the identification information of the UE, such as the cell-radio network temporary identifier (C-RNTI) of the UE and the message check value (ShortMAC-I). After receiving the RLF Indication, base station 1 can obtain the context of the UE according to the identification information of the UE.

[0059] However, in case 2, that is, when the RRC connection reestablishment falls back to the RRC establishment, the network generally cannot obtain the context before the RRC connection reestablishment. The detailed protocol is as follows:

[0060] The connection re-establishmentsucceeds if the network is able to find and verify a valid UE context or,if the UE context cannot be retrieved,and the network responds with an RRC Setupaccording to clause 5.3.3.4.

[0061] When testing the voice over new radio (VoNR) use case on the existing network, there is a probability that the called party cannot get through. The reason is that the UE receives an incoming call in the original cell (for example, cell A) and enters the prack phase. Since the original cell has RLF, the UE selects a new cell (for example, cell B) to initiate the RRC connection re-establishment process. However, the UE initiates the RRC connection re-establishment process in cell B as in case 2. The new cell cannot obtain the UE context, resulting in the network being unable to establish a dedicated bearer (for example, a data resource bearer (data RB, DRB) with a QCI of 1) after the RRC connection is successfully re-established. After a period of time (for example, 4 seconds later), the network sends a cancel message and the called party fails.

[0062] For example, Figure 3As shown, the core network & IMS network (core network and IMS network) can send a paging message (INVITE message) to cell A, and cell A can send an INVITE message to the UE (called UE). After receiving the INVITE message, the UE can send 100trying to cell A, and cell A can send 100trying to the core network & IMS network. The UE can send 183session progress to cell A, and cell A can send 183session progress to the core network & IMS network. The core network & IMS network can send prack to cell A, and cell A can send prack to the UE. After receiving prack, the UE can send prack 200OK to cell A, and cell A can send prack200OK to the core network & IMS network. Then, due to network failure, poor signal quality or other reasons, RLF occurs in cell A, and the UE can select cell B to initiate the RRC connection re-establishment process. The UE can send an RRC connection re-establishment request to cell B. After cell B receives the RRC connection re-establishment request sent by the UE, it fails to successfully obtain the UE context due to some reasons (for example, the interface between the base stations is incompatible or fails), resulting in cell B only being able to send an RRC connection establishment message (RRC Setup) to the UE. Finally, the UE sends an RRC connection establishment completion (RRCSetup Complete) message to cell 2 to indicate that the RRC connection establishment is complete. That is, the RRC connection re-establishment falls back to the RRC connection establishment success. Then, the core network & IMS network can send IMS_SIP_UPDATE to cell A, and cell A can send IMS_SIP_UPDATE to the UE. After receiving IMS_SIP_UPDATE, the UE can send IMS_SIP_UPDATE / OK to cell A, and cell A can send IMS_SIP_UPDATE / OK to the core network & IMS network. However, since cell B cannot obtain the UE context, the core network cannot establish a dedicated bearer after the RRC connection is successfully reestablished. After a period of time (for example, 4 seconds), the core network & IMS network can only send IMS_SIP_CANCEL to the UE through cell A. IMS_SIP_CANCEL is used to cancel the INVITE request initiated by the client (calling UE). The reason for cancellation can be, for example: cause = 503: text = insufficient bearer resource. That is, the INVITE request is cancelled due to insufficient bearer.

[0063] The inventors of the embodiments of the present application have discovered through research (for example, through joint debugging) that the reason why the network fails to establish a dedicated bearer for the UE is that the UE context is not obtained during the cross-site RRC reconstruction process, resulting in the core network being unable to identify and verify the UE, so a dedicated bearer is not established, which in turn leads to problems such as failure to connect during voice establishment and dropped calls during voice.

[0064] At present, the solution to the above problem is to optimize the network (e.g., 5G network) quality of the test section and enhance the main coverage of the cell. However, the above solution is to solve the above problem from the network side, which can only solve the problem of a single station (single base station) and has a small scope of application.

[0065] The embodiment of the present application provides an RRC re-establishment method, which can solve the above problems from the terminal side. After RLF occurs, the RRC re-establishment strategy is determined based on the UE status and usage scenario to avoid affecting the normal business of the UE. For example, it can ensure that the UE context before RLF is restored as successfully as possible after RLF occurs during a call, reduce the abnormal rate of calls, and improve the experience.

[0066] Figure 4 1 is a schematic diagram of a communication system provided in an embodiment of the present application, and the communication system may include network equipment and terminal equipment. Among them, the network equipment includes one or more access network equipment, core network equipment, and may also include IMS network elements, etc., which are not limited in the present application.

[0067] Among them, the access network device communicates with the core network device through a wired network or a wireless network, such as communicating with each other through the next generation (NG) interface. The core network device can communicate with the IMS network element through a wired network or a wireless network. Access network devices communicate with each other through a wired network or a wireless network. For example, access network device 1 and access network device 2 can communicate with each other through the Xn interface. The access network device can cover one or more cells, such as: access network device 1 covers cell 1, and access network device 2 covers cell 2. The terminal device can access the access network device (for example, access network device 1) in one of the cells (for example, cell 1). TSN service data can be transmitted between the terminal device and access network device 1. TSN services are services with high latency requirements, such as voice, video, AR, VR real-time battle games, industrial Internet of Things, etc. If RLF occurs between the terminal device and access network device 1, the terminal device 1 can refer to Figure 7 or Figure 8 The method shown initiates the RRC connection re-establishment procedure.

[0068] Among them, the access network equipment may include a 5G base station and a 4G base station. The 5G base station may be a next generation NodeB (gNB). The 4G base station may be an evolved Node B (eNB).

[0069] The core network equipment may include network elements of the 5G core network and network elements of the 4G core network (evolved packet core, EPC). Exemplarily, the network elements in the 5G core network are functional virtual units, which may include but are not limited to: AMF, a unit for session management function (session management function, SMF), a network element for unified data management (unified data management, UDM), etc. The 4G core network (evolved packet core, EPC) may include the following network elements: mobility management entity (mobility management entity, MME), serving gateway (servinggateway, SGW), packet data network gateway (packet data networkgateway, PGW), home subscriber server (home subscriber server, HSS) and application server (application server, AS), etc. The main functions of MME include access control, mobility management, attachment and detachment, session management (such as bearer establishment, modification and release), etc. SGW is mainly used for routing and forwarding data packets. The main functions of PGW include user-based packet filtering function, legal interception function IP address allocation function, etc. HSS is used to store user contract information, user contract data, and mobile user location information.

[0070] IMS network elements may include a service centralization and continuity application server (SCC AS), which may perform a terminating-access domain selection (T-ADS) function to determine the access domain information of the called user. IMS 400 may also include a call session control function (CSCF) and a home subscriber server (HSS). CSCF is used to control signaling, authentication, and control sessions in cooperation with other network entities during multimedia call sessions. HSS is used to manage user data.

[0071] The terminal device 100 may include various user equipment (UE), handheld devices, vehicle-mounted devices, wearable devices (such as smart watches, smart bracelets, etc.), mobile internet devices (MID) computing devices or other processing devices connected to a wireless modem; it may also include a subscriber unit, a cellular phone, a smart phone, a wireless data card, a personal digital assistant (PDA) computer, a wireless modem, a handheld device, a laptop computer, a cordless phone or a wireless local loop (WLL) station, a machine type communication (MTC) terminal, a user equipment (UE), a mobile station (MS) or a relay user device, etc. In the embodiment of the present application, the terminal device may be a device sold independently or a chip in the terminal.

[0072] In one possible design, user information may be stored in the terminal device 100. The user information may include an international mobile subscriber identification number (IMSI). The IMSI may be stored in a subscriber identity module (SIM) card of the terminal device 100. The terminal device 100 may use the user information as an identity to initiate or receive calls through various voice solutions.

[0073] Understandably, Figure 4 The units shown do not constitute a specific limitation on the communication system. The communication system may also include more or fewer units than shown in the figure, or combine certain units, or split certain units, or arrange the units differently, which is not limited in this application.

[0074] The terminal device in the embodiment of the present application can be Figure 5 This is achieved by the communication equipment in the system. Figure 5 The hardware structure diagram of the communication device provided in the embodiment of the present application is shown as follows. The communication device 500 includes at least one processor 501 , a communication line 502 , a memory 503 and at least one communication interface 504 .

[0075] The processor 501 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the present application.

[0076] Communication link 502 may include a pathway for transmitting information between the above-mentioned components.

[0077] The communication interface 504 uses any transceiver or other device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0078] The memory 503 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may exist independently and be connected to the processor via a communication line 502. The memory may also be integrated with the processor.

[0079] The memory 503 is used to store computer-executable instructions for executing the solution of the present application, and the execution is controlled by the processor 501. The processor 501 is used to execute the computer-executable instructions stored in the memory 503, thereby implementing the RRC re-establishment method provided in the following embodiments of the present application.

[0080] Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application code, which is not specifically limited in the embodiments of the present application.

[0081] In a specific implementation, as an embodiment, the processor 501 may include one or more CPUs, such as Figure 5 CPU0 and CPU1 in.

[0082] In a specific implementation, as an embodiment, the communication device 500 may include multiple processors, such as Figure 5 501 and processor 508 in the embodiment of the present invention. Each of these processors may be a single-CPU processor or a multi-CPU processor. The processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0083] In a specific implementation, as an embodiment, the communication device 500 may also include an output device 505 and an input device 506. The output device 505 communicates with the processor 501 and can display information in a variety of ways. For example, the output device 505 may be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. The input device 506 communicates with the processor 501 and can receive user input in a variety of ways. For example, the input device 506 may be a mouse, a keyboard, a touch screen device, or a sensor device.

[0084] The communication device 500 may be a general purpose device or a dedicated device. In a specific implementation, the communication device 500 may be a desktop computer, a portable computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, an embedded device or a computer with a plurality of CPUs. Figure 5 The embodiment of the present application does not limit the type of the communication device 500.

[0085] For example, a terminal device (eg, UE) and an access network device may establish a Figure 6 The protocol stack shown. Among them, the UE may include an RRC layer, a PDCP layer, an RLC layer, a MAC layer, and a PHY layer. The access network device may include an RRC layer, a PDCP layer, an RLC layer, a MAC layer, and a PHY layer. Exemplarily, the RRC layer, PDCP layer, RLC layer, MAC layer, and PHY layer of the UE correspond to the RRC layer, PDCP layer, RLC layer, MAC layer, and PHY layer of the access network device, and the wireless communication interface technology between the relay device and the wireless network device is used between these protocol layers.

[0086] It should be noted that the above Figure 6 The naming of the network elements, the interface names between the network elements, and the protocol stacks is only an example. In a specific implementation, the network elements, the interface names between the network elements, and the protocol stacks can be other names, and the embodiments of the present application do not specifically limit this.

[0087] The technical scheme in the embodiment of the present application will be described below in conjunction with the drawings in the embodiment of the present application. Wherein, in the description of the present application, unless otherwise specified, "at least one" refers to one or more, and "a plurality of" refers to two or more than two. In addition, in order to facilitate the clear description of the technical scheme of the embodiment of the present application, in the embodiment of the present application, the words "first", "second" and the like are used to distinguish the same items or similar items with substantially the same functions and effects. Those skilled in the art will understand that the words "first", "second" and the like do not limit the quantity and execution order, and the words "first", "second" and the like do not limit necessarily different.

[0088] For ease of understanding, the RRC re-establishment method provided in an embodiment of the present application is specifically introduced below with reference to the accompanying drawings.

[0089] like Figure 7 As shown, an embodiment of the present application provides an RRC re-establishment method, including:

[0090] 701. The terminal device detects that RLF occurs in the first cell.

[0091] That is, when the UE is connected to the first cell, it is determined that RLF occurs in the first cell.

[0092] The occurrence of RLF in the first cell may refer to the failure of normal data transmission between the terminal device and the first cell or the access network device corresponding to the first cell, such as failure of uplink data transmission and / or downlink data transmission. Figure 3 Taking the terminal device 100 in the example where the first cell is cell 1, the terminal device detects that RLF occurs in the first cell, which may mean that the connection between the terminal device 100 and cell 1 is disconnected, or the terminal device cannot transmit data with the access network device 1, and cannot receive the service data or configuration information sent by the access network device 1.

[0093] In an embodiment of the present application, the UE can determine whether RLF occurs in the link between the UE and the first cell based on the number of RLC retransmissions, in sync (or insynchronization, IS) / out of sync (or Out of synchronization, OoS) indications, the number of failures of the terminal device to send service data, random access (Random Access) results, cell switching results, and RRC reconfiguration results.

[0094] For example, if the number of RLC retransmissions of the UE on the link reaches the maximum number of RLC retransmissions, it is considered that RLF occurs in the first cell. For another example, if on the link between the UE and the first cell, the UE receives a preset number of consecutive OoS indications within a preset time period, and has not recovered before the timer 310 (timer T310 is activated when a preset number (for example, N310 times) of OoS is detected) expires, it is considered that RLF occurs in the first cell. For another example, if the number of failures of the terminal device to send service data to the first cell within a preset time period is greater than or equal to the preset number of failures, the terminal device believes that RLF occurs in the first cell. For another example, if a random access failure occurs, the terminal device believes that RLF occurs in the first cell. For another example, if a handover failure (Handover Failure, HO) occurs, that is, before the timer T304 (timer T304 is activated when the UE receives the RRCConnection Reconfiugration command and prepares for Handover) expires, the UE cannot successfully access the first cell, and the terminal device believes that RLF occurs in the first cell. For another example, if the RRC reconfiguration fails, the terminal device believes that RLF occurs in the first cell.

[0095] Among them, the preset time, preset number of failures, and preset number can be set as needed, and can be agreed upon in the protocol or configured by the network device without restriction.

[0096] 702. The terminal device determines whether a preset condition is met.

[0097] The preset conditions include at least one of the following conditions (condition 1 to condition 4):

[0098] Condition 1: The terminal device is about to or is currently performing TSN services.

[0099] Among them, time-sensitive network (TSN) services refer to services with high latency requirements. TSN services may include, for example, voice services, video services, augmented reality (AR) services, virtual reality (VR) services, real-time gaming services, industrial Internet of Things services, etc., which are not limited in this application.

[0100] Condition 2: The terminal device is in a preset state, which includes that the displacement of the terminal device in a preset time period is less than a first preset threshold, or that the average acceleration / speed of the terminal device in the preset time period is less than a second preset threshold.

[0101] The preset state includes that the displacement of the UE in a preset time period is less than a first preset threshold, or that the average acceleration of the UE in a preset time period is greater than a second preset threshold. For example, if the displacement of the UE in 1 minute is less than 1 meter (including the case where the displacement of the UE in 1 minute is 0), or the average acceleration / speed of the UE in 1 minute is less than 0.01 m / s (including the case where the average acceleration of the UE in 1 minute is 0), it means that the UE is in a preset state (stationary or slightly moving state).

[0102] Condition 3: The signal quality of the first cell is higher than a third preset threshold.

[0103] The signal quality of the first cell may be characterized by the measured value of RSRP and the measured value of RSRQ of the first cell, and the third preset threshold may include the thresholds corresponding to RSRP and RSRQ respectively. For example, the threshold corresponding to RSRP of the first cell may be -115dbm, and the threshold corresponding to RSRQ of the first cell may be -15db. The thresholds corresponding to RSRP and RSRQ may also have other values, which are not limited in this application.

[0104] Condition 4: The number of RLF occurrences in the first cell within a unit time is less than a fourth preset threshold.

[0105] The unit time may be 1 minute, 1 hour, etc. For example, if the unit time is 1 minute, the fourth preset threshold may be 3 times; if the unit time is 1 hour, the fourth preset threshold may be 6 times. Of course, the unit time and the fourth preset threshold may have other values, which are not limited in this application.

[0106] If the preset condition is met, step 703 may be executed; if the preset condition is not met, step 705 may be executed.

[0107] 703. If the preset conditions are met, the terminal device performs an RRC re-establishment process in the first cell.

[0108] 704. If the terminal device fails to stay in the first cell, the terminal device sends an RRC connection re-establishment request to the second cell, and the frequency of the second cell is the same as that of the first cell.

[0109] 705. If the preset condition is not met, the terminal device resides in the third cell, and the signal quality of the third cell is higher than the fifth preset threshold, the terminal device sends an RRC connection re-establishment request to the third cell.

[0110] Based on the method provided in the embodiment of the present application, after the terminal device detects that RLF occurs in the first cell, if the preset conditions are met, the terminal device can perform the RRC re-establishment process on the first cell, that is, the terminal device can return to the original station to perform RRC reconstruction, thereby avoiding the terminal device's business being affected by cross-station RRC reconstruction.

[0111] For example, assuming that the preset conditions include all conditions 1 to 4, then Figure 8 As shown, the RRC re-establishment method provided in the embodiment of the present application may include the following steps:

[0112] 801. UE detects that RLF occurs in the first cell.

[0113] The specific process can be referred to step 701 and will not be described in detail here.

[0114] 802. The UE determines whether a TSN service is about to be or is being performed.

[0115] For the TSN service, please refer to the relevant description of step 702, which will not be repeated here.

[0116] It should be noted that when the UE determines that a TSN service is about to (needs to) or is in progress, it may consider selecting the original cell (for example, the first cell) for RRC reconstruction to avoid the problem of TSN service being unable to be established or continued due to cross-site RRC re-establishment (for example, voice establishment cannot be connected, voice calls are dropped, etc.).

[0117] If the UE determines that a TSN service is about to be or is being provided, step 803 may be executed; if the UE determines that a TSN service is not required or is not being provided, step 810 may be executed.

[0118] 803. The UE determines whether it is in a preset state.

[0119] The preset state may also be referred to as a stationary or slightly moving state. The preset state includes that the displacement of the UE in a preset time period is less than a first preset threshold, or the average acceleration of the UE in a preset time period is greater than a second preset threshold.

[0120] For example, the UE may detect the acceleration / speed of the UE in the horizontal direction through an acceleration sensor. The UE may obtain the geographical location of the UE through a positioning system (GPS or Beidou system), and determine the displacement of the UE according to the geographical location at different times.

[0121] In one possible scenario, the UE may misjudge the state of the UE based on the data collected by the acceleration sensor. For example, if the UE is moving in a straight line at a uniform speed, and the acceleration sensor detects that the acceleration of the UE in the horizontal direction is 0, the state of the UE cannot be accurately determined. In this case, the UE can determine whether the UE is in a stationary or slightly moving state through the acceleration sensor and the positioning system (GPS or Beidou system). For example, when it is detected that the output data of the positioning system (GPS or Beidou system) has not changed or has changed slightly in the recent period of time, and the acceleration value is zero or less than the threshold, the UE is determined to be in a stationary or slightly moving state.

[0122] When the UE is stationary or slightly moving, it means that the UE's position has not changed significantly and it is still within the coverage of the first cell. Therefore, you can consider selecting the original cell for RRC reconstruction to avoid the problem of TSN services being unable to be established or continued due to cross-site RRC reconstruction (for example, voice establishment cannot be connected, voice calls are dropped, etc.).

[0123] If the UE is in a stationary or slightly moving state, the original cell can be selected for RRC reconstruction, and step 804 can be executed; if the UE is not in a stationary or slightly moving state (for example, the UE is in a high-speed moving state), it is unreasonable to insist on selecting the original cell for RRC reconstruction, and the cell can be selected according to the signal quality to initiate RRC reconstruction, that is, step 810 can be executed.

[0124] 804. The UE determines whether the signal quality of the first cell is higher than a third preset threshold.

[0125] The UE may measure network environment parameters of the first cell. The network environment parameters may include reference signal received power (RSRP) and reference signal received quality (RSRQ).

[0126] The signal quality of the first cell may be characterized by the measured value of RSRP and the measured value of RSRQ of the first cell, and the third preset threshold may include the thresholds corresponding to RSRP and RSRQ respectively. For example, the threshold corresponding to RSRP of the first cell may be -115dbm, and the threshold corresponding to RSRQ of the first cell may be -15db. The thresholds corresponding to RSRP and RSRQ may also have other values, which are not limited in this application.

[0127] If the UE determines that the signal quality of the first cell is higher than the third preset threshold (for example, RSRP>-115dbm, RSRQ>-15db), step 805 can be executed; if the UE determines that the signal quality of the first cell is not higher than (lower than or equal to) the third preset threshold, step 810 can be executed.

[0128] It should be noted that when the signal quality of the first cell is higher than the third preset threshold, it means that the channel quality of the first cell is good, so the UE can select the original cell for RRC reconstruction to avoid the problem that the TSN service cannot be established or continued due to cross-site RRC reconstruction (for example, voice establishment cannot be connected, voice dropped, etc.). When the signal quality of the first cell is not higher than the third preset threshold, it means that the channel quality of the first cell is poor, and it is unreasonable to insist on selecting the original cell for RRC reconstruction, so the cell can be selected to initiate reconstruction based on the signal quality.

[0129] If the signal quality of the first cell is higher than the third preset threshold, step 805 may be executed. If the signal quality of the first cell is not higher than the third preset threshold, step 810 may be executed.

[0130] 805. The UE determines whether the number of RLFs that occur in the first cell per unit time is less than a fourth preset threshold.

[0131] That is, the UE determines whether the number of RLFs that occur per unit time during the period of residing in the first cell is less than the fourth preset threshold. It should be noted that the number of RLFs that occur per unit time can characterize the stability and service quality of the cell (for example, the first cell). If the UE determines that the number of RLFs that occur per unit time during the period of residing in the first cell is less than the threshold, it means that the stability of the first cell is better and the probability of wireless abnormalities is lower. Therefore, during reconstruction, it can be considered to continue to reside in the original cell to avoid the problem that TSN cannot be established or interrupted due to cross-site RRC reconstruction. If the UE determines that the number of RLFs that occur per unit time during the period of residing in the first cell is greater than or equal to the threshold, it means that the stability of the first cell is poor and the probability of wireless abnormalities is higher, or the first cell may continue to have RLFs, which in turn causes the UE to be unable to access the network. Therefore, during reconstruction, it is not necessary to consider continuing to reside in the original cell, but to reside in other cells with better signal quality and stability to improve user experience.

[0132] If the number of RLFs that occur in the first cell per unit time is less than the fourth preset threshold, step 806 may be executed; if the number of RLFs that occur in the first cell per unit time is greater than or equal to the fourth preset threshold, step 810 may be executed.

[0133] 806. The UE attempts to camp on the first cell.

[0134] If the UE wants to successfully camp on the first cell, the first cell must meet the S criterion. The terminal can determine whether it meets the camping criteria based on the measurement results (network environment parameters) of the first cell. If the first cell meets the S criterion, the UE can camp on the first cell.

[0135] The first cell satisfies the S criterion, that is, the receiving power Srxlev corresponding to the first cell is greater than 0 dB and the signal quality Squal corresponding to the first cell is greater than 0 dB.

[0136] If the UE successfully camps on the first cell, step 807 may be executed; if the UE fails to camp on the first cell (for example, the first cell does not meet the S criterion and the UE cannot camp on the first cell), step 808 may be executed.

[0137] 807. The UE initiates RRC connection re-establishment to the first cell.

[0138] Exemplarily, the UE may send an RRC connection reestablishment request (RRC ConnectionReestablishment Request) to the first cell, the first cell may send an RRC connection reestablishment message (RRC ConnectionReestablishment) to the UE, and finally the UE sends an RRC connection reconfiguration completion (RRC ConnectionReconfiguration Complete) message to the first cell to indicate that the RRC connection reestablishment is successful.

[0139] That is, if RLF occurs during a call, unless the signal quality is lower than the threshold, the number of reconstructions in the cell per unit time exceeds the threshold, or the fast motion scenario, you should try to return to the original cell to re-establish the RRC connection to avoid the problem of TSN service being unable to be established or continued due to cross-site RRC reconstruction (for example, voice establishment cannot be connected, voice dropped, etc.). When it is impossible to stay in the original cell, it is preferred to stay in the cell with the same frequency point as the original cell, that is, step 808 can be executed.

[0140] 808. The UE attempts to camp on a cell with the same frequency as the original cell (a second cell).

[0141] It can be understood that the frequency of the same frequency cell as the original cell (the second cell) is the same as that of the original cell (the first cell).

[0142] It should be noted that, since the frequency points of the cells of the same base station are usually the same, the probability that the co-frequency point cell of the original cell belongs to the same base station (i.e., the co-station cell) as the original cell is relatively high. Although the UE cannot directly identify the co-station cell of the original cell (i.e., the cell corresponding to the same access network device (e.g., base station) as the original cell), it can directly identify the co-frequency point cell of the original cell. The probability that the co-frequency point cell of the original cell belongs to the same base station as the original cell is relatively high, and the probability that the UE returns to the original station (the base station of the original cell) to perform the re-establishment process is higher, and the probability that the UE performs cross-station RRC reconstruction is lower. Therefore, it is possible to avoid the cross-station RRC reconstruction from affecting the UE's services (for example, causing voice establishment to fail, voice dropped calls, and other problems).

[0143] If the UE successfully camps on the same frequency cell as the original cell, step 809 may be executed; if the UE fails to camp on the same frequency cell as the original cell (for example, the same frequency cell as the original cell does not meet the S criterion and the UE cannot camp on the same frequency cell as the original cell), step 810 may be executed.

[0144] 809. The UE initiates RRC connection re-establishment to the same frequency cell as the original cell.

[0145] The UE can send an RRC connection reestablishment request (RRC ConnectionReestablishment Request) to the same-frequency cell, and the same-frequency cell can send an RRC connection reestablishment message (RRCConnection Reestablishment) to the UE. Finally, the UE sends an RRC connection reconfiguration completion (RRCConnection Reconfiguration Complete) message to the same-frequency cell to indicate that the RRC connection reestablishment is successful.

[0146] Since the probability that the co-frequency cell of the original cell belongs to the same base station as the original cell is high, the probability that the UE returns to the original station (the base station of the original cell) to re-establish the process is higher, and the probability that the UE performs cross-site RRC reconstruction is lower. The cross-site RRC reconstruction can be avoided as much as possible to affect the UE's service (TSN service). For example, taking the TSN service as a voice service, after RLF occurs, you can return to the original station for RRC reconstruction. Since the original station saves the UE context, the core network can obtain the UE context from the original station, and there will be no problem that the core network cannot identify and verify the UE (there will be no problem that the core network cannot establish a dedicated bearer for the UE), which can avoid the problem that the UE context cannot be restored due to cross-site RRC reconstruction, thereby causing abnormal calls.

[0147] 810. The UE selects a target cell based on signal quality and resides in the target cell.

[0148] The terminal device selects a cell that meets the S criterion among at least one candidate cell (cell searched by the UE) as a target cell and resides in the target cell. The detailed process of the UE searching for a cell can refer to the relevant content of standard TS 38.331 5.3.7.2, which will not be described here.

[0149] The S criterion may be used to select a cell for RRC re-establishment. It should be noted that the S criterion may also be replaced by other criteria capable of selecting a cell for RRC re-establishment, without limitation.

[0150] Exemplarily, the terminal device uses a cell that satisfies the S criterion among at least one candidate cell (cell searched by the UE) as a target cell, which may include: the terminal device determines whether at least one candidate cell satisfies the S criterion, and obtains one or more cells that satisfy the S criterion; if there is only one cell that satisfies the S criterion, the cell that satisfies the S criterion is used as the target cell. Alternatively, the cell with the best (or highest) signal quality (for example, RSRP\RSRQ) among multiple cells that satisfy the S criterion is used as the target cell.

[0151] 811. The UE initiates RRC re-establishment on the target cell (third cell).

[0152] The terminal device may send an RRC re-establishment request message to the target cell, and the RRC re-establishment request message may be used to request the establishment of an RRC connection with the network device corresponding to the target cell; if the network device corresponding to the target cell accepts the RRC re-establishment request message sent by the terminal device, the network device corresponding to the target cell sends an RRC re-establishment message to the terminal device; the terminal device receives the RRC re-establishment message and establishes an RRC connection with the network device corresponding to the target cell. After the terminal device establishes an RRC connection with the network device corresponding to the target cell, it sends an RRC re-establishment completion message to the network device corresponding to the target cell. Alternatively, after the network device corresponding to the target cell receives the RRC re-establishment request message sent by the terminal device, it may send an RRC setup message to the terminal device; the terminal device receives the RRC setup message and establishes an RRC connection with the network device corresponding to the target cell. After the terminal device establishes an RRC connection with the network device corresponding to the target cell, it sends an RRC setup complete message to the network device corresponding to the target cell.

[0153] Exemplarily, the RRC reestablishment request (RRC connection reestablishment request or RRCconnection reestablishment request) may be generated by the RRC layer of the first terminal, and the RRC layer of the first terminal corresponds to the RRC layer of the wireless access network device.

[0154] Based on the method provided in the embodiment of the present application, after RLF occurs, the cell selection can be performed based on the service scenario (the service that the UE is about to or is currently performing), the status of the UE (whether it is in a stationary or slightly moving state), the signal quality and service quality of the original cell (whether RLF has occurred multiple times), and other conditions, and the original cell (or original station) can be returned to the original cell (or original station) for RRC reconstruction as much as possible to avoid the service of the terminal device being affected by the cross-site RRC reconstruction. For example, taking the TSN service as a voice service as an example, after RLF occurs, the RRC can be returned to the original station for RRC reconstruction, which can avoid the problem that the UE context cannot be restored due to the cross-site RRC reconstruction, thereby causing abnormal calls.

[0155] In other embodiments, after step 801, at least one of steps 802-805 can be executed (that is, any one, any two, any three or all of steps 802-805 can be executed), and there is no necessary order of execution between steps 802-805.

[0156] If the judgment result of one or more steps in step 802-step 805 is "yes" (i.e., one or more conditions in condition 1-condition 4 are met), step 806 and step 807 can be executed, otherwise step 810 and step 811 can be executed. If the execution of step 806 and step 807 fails, step 808 and step 809 can be executed.

[0157] Based on the method provided in the embodiment of the present application, after RLF occurs, cell selection can be performed based on one or more of the following conditions: business scenario (business that the UE is about to or is currently performing), UE status (whether it is in a stationary or slightly moving state), signal quality and service quality of the original cell (whether RLF occurs multiple times), and try to return to the original cell (or original station) for RRC reconstruction to avoid affecting the business of the terminal device due to cross-station RRC reconstruction.

[0158] The present application also provides a chip system, such as Fig. 9As shown, the chip system includes at least one processor 901 and at least one interface circuit 902. The processor 901 and the interface circuit 902 can be interconnected through a line. For example, the interface circuit 902 can be used to receive signals from other devices (e.g., a memory of an electronic device). For another example, the interface circuit 902 can be used to send signals to other devices (e.g., the processor 901).

[0159] For example, the interface circuit 902 can read the instruction stored in the memory of the electronic device and send the instruction to the processor 901. When the instruction is executed by the processor 901, the terminal device (such as Figure 5 The communication device 500 shown in FIG. 5 performs each step in the above embodiment.

[0160] Of course, the chip system may also include other discrete devices, which is not specifically limited in the embodiments of the present application.

[0161] The present application also provides a computer-readable storage medium, which includes computer instructions. When the computer instructions are in an electronic device (such as Figure 5 When the method is executed on the communication device 500 shown in the figure, the terminal device 100 executes each function or step executed by the calling terminal device or the called terminal device in the above method embodiment.

[0162] The embodiment of the present application also provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute each function or step executed by the electronic device in the above method embodiment.

[0163] The embodiment of the present application also provides a voice call device, which can be divided into different logical units or modules according to functions, and each unit or module performs a different function, so that the device performs each function or step performed by the electronic device in the above method embodiment.

[0164] Through the description of the above implementation methods, technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0165] In the several embodiments provided in this embodiment, 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 only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, 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 an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0166] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0167] In addition, each functional unit in each embodiment of the present embodiment 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. The above integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0168] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to perform all or part of the steps of the method described in each embodiment. The aforementioned storage medium includes: flash memory, mobile hard disk, read-only memory, random access memory, disk or optical disk and other media that can store program codes.

[0169] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A radio resource control (RRC) re-establishment method, characterized in that: Applied to terminal equipment, including: The terminal device detects that a radio link failure RLF occurs in the first cell; If the preset condition is met, the terminal device performs an RRC re-establishment process on the first cell; The preset condition includes at least one of the following conditions: The terminal device is about to perform or is performing a time-sensitive network TSN service; The terminal device is in a preset state, and the preset state includes that the displacement of the terminal device in a preset time period is less than a first preset threshold, or the average acceleration / speed of the terminal device in the preset time period is less than a second preset threshold; The signal quality of the first cell is higher than a third preset threshold; The number of RLF occurrences in the first cell within a unit time is less than a fourth preset threshold.

2. The method according to claim 1, characterized in that: The terminal device performs an RRC re-establishment process on the first cell, including: The terminal device resides in the first cell; If the terminal device successfully resides in the first cell, the terminal device sends an RRC connection re-establishment request to the first cell.

3. The method according to claim 2, characterized in that The method further comprises: If the terminal device fails to reside in the first cell, the terminal device sends an RRC connection re-establishment request to a second cell, and the frequency of the second cell is the same as that of the first cell.

4. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: If the preset condition is not met, the terminal device resides in a third cell, and the signal quality of the third cell is higher than a fifth preset threshold; The terminal device sends an RRC connection re-establishment request to the third cell.

5. The method according to any one of claims 1 to 4, characterized in that: The TSN service includes at least one of a voice service, a video service, an augmented reality technology (AR) service, a virtual reality technology (VR) service, a real-time game service, and an industrial Internet of Things service.

6. A terminal device, characterized in that: The terminal device comprises: a wireless communication module, a memory and one or more processors; the wireless communication module and the memory are coupled to the processor; The memory is used to store computer program code, and the computer program code includes computer instructions; when the computer instructions are executed by the processor, the terminal device executes the method as described in any one of claims 1 to 5.

7. A computer-readable storage medium, characterized in that: including computer instructions; When the computer instructions are executed on a terminal device, the terminal device is caused to execute the method according to any one of claims 1 to 5.

8. A chip system, characterized in that: The chip system includes an application processor AP for executing an operating system, a user interface and application programs and a BP for radio frequency communication control, and the BP is used to execute the method as described in any one of claims 1-5.

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