Patent Publication Number: US-2021168690-A1

Title: Information processing method for a radio link failure, terminal, and network device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of International Application No. PCT/CN2019/098556 filed on Jul. 31, 2019, which claims priority to Chinese Patent Application No. 201810935951.6, filed on Aug. 16, 2018 in china, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the field of communications technologies, and in particular, to an information processing method for a radio link failure, a terminal, and a network device. 
     BACKGROUND 
     Dual connection is a technology introduced in long term evolution (Long Term Evolution, LTE) and will also be used in new radio (New Radio, NR). Dual connection means that user equipment (User Equipment, UE, also referred to as a terminal) may be connected to two base stations at the same time, and the two base stations provide data receiving and sending services for the UE at the same time. Because radio resources of the two base stations may be used at the same time, the service data transmission rate of the UE can be doubled. 
     There is a signaling interface between the two base stations serving the same UE, and the interface can exchange configuration information related to the UE. 
     The serving base stations of the dual-connection UE may belong to a same RAT (RAT), for example, are two LTE eNBs, or may belong to different RATs, for example, are one LTE eNB and one NR gNB. 
     One of the serving base stations of the dual-connection UE is a master base station (Master Node, MN) and the other is a secondary base station (Secondary Node, SN). Each base station can support the carrier aggregation (Carrier Aggregation, CA) technology. The network configures two special cells (special cell) for the dual-connection UE, that is, a serving cell of the MN is configured as a primary serving cell (Primary Cell, PCell) of the UE, and a serving cell of the SN is configured as a primary secondary serving cell (Primary Secondary Cell, PSCell) of the UE. Other cells of the MN and the SN that serve the UE are secondary serving cells (Secondary Cell, SCell) of the UE. All serving cells of the MN are collectively referred to as a master serving cell group MCG (Master cell group), and all serving cells of the SN are collectively referred to as a secondary serving cell group SCG (Secondary cell group). 
     In the related art, a radio link failure (Radio Link Failure, RLF) between the UE and the MCG triggers a radio resource control (Radio Resource Control, RRC) re-establishment process, and transmission that is being performed by the UE needs to be suspended and user experience is affected. 
     SUMMARY 
     Embodiments of the present disclosure provide an information processing method for a radio link failure, a terminal, and a network device, to resolve the problem that an RLF between a terminal and an MCG triggers an RRC re-establishment process, and transmission that is being performed by the terminal needs to be suspended and user experience is affected. 
     To resolve the foregoing technical problem, the following technical solutions are used in the present disclosure: 
     According to a first aspect, an embodiment of the present disclosure provides an information processing method for a radio link failure, applied to a terminal, and including:
         determining whether a first condition is met;   if the first condition is met, sending radio link failure information of a master serving cell group MCG to a secondary serving cell group SCG; and   receiving MCG reconfiguration information sent by the SCG, where   the first condition includes at least: a radio link failure occurs between the terminal and the MCG.       

     According to a second aspect, an embodiment of the present disclosure provides an information processing method for a radio link failure, applied to a secondary serving cell group SCG, and including:
         receiving radio link failure information of a master serving cell group MCG that is sent by a terminal;   sending the radio link failure information of the MCG to the MCG;   obtaining MCG reconfiguration information; and   sending the MCG reconfiguration information to the terminal.       

     According to a third aspect, an embodiment of the present disclosure provides an information processing method for a radio link failure, applied to a master serving cell group MCG, and including:
         receiving radio link failure information of the MCG that is sent by a secondary serving cell group SCG; and   sending MCG reconfiguration information to the SCG.       

     According to a fourth aspect, an embodiment of the present disclosure provides a terminal, including:
         a determining module, configured to determine whether a first condition is met;   a first sending module, configured to: if the first condition is met, send radio link failure information of a master serving cell group MCG to a secondary serving cell group SCG; and   a first receiving module, configured to receive MCG reconfiguration information sent by the SCG, where   the first condition includes at least: a radio link failure occurs between the terminal and the MCG.       

     According to a fifth aspect, an embodiment of the present disclosure provides a terminal, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, where the computer program, when executed by the processor, implements steps of the information processing method for a radio link failure. 
     According to a sixth aspect, an embodiment of the present disclosure provides a first network device, where the first network device includes a secondary serving cell group SCG, and includes:
         a second receiving module, configured to receive radio link failure information of a master serving cell group MCG that is sent by a terminal;   a second sending module, configured to send the radio link failure information of the MCG to the MCG;   an obtaining module, configured to obtain MCG reconfiguration information; and   a third sending module, configured to send the MCG reconfiguration information to the terminal.       

     According to a seventh aspect, an embodiment of the present disclosure provides a first network device, the first network device includes a secondary serving cell group SCG, and includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, where the computer program, when executed by the processor, implements steps of the information processing method for a radio link failure. 
     According to an eighth aspect, an embodiment of the present disclosure provides a second network device, where the second network device includes a master serving cell group MCG, and includes:
         a third receiving module, configured to receive radio link failure information of the MCG that is sent by a secondary serving cell group SCG; and   a fourth sending module, configured to send MCG reconfiguration information to the SCG.       

     According to a ninth aspect, an embodiment of the present disclosure provides a second network device, the second network device includes a master serving cell group MCG, and includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, where the computer program, when executed by the processor, implements steps of the information processing method for a radio link failure. 
     According to a tenth aspect, an embodiment of the present disclosure provides a computer-readable storage medium, storing a computer program, where the computer program, when executed by a processor, implements steps of the information processing method for a radio link failure. 
     The present disclosure has the following beneficial effects: 
     In the above solution, when it is determined that the first condition for sending the radio link failure information of the MCG is met, the radio link failure information of the MCG is sent to the SCG, and the MCG reconfiguration information sent by the SCG is received, to implement fast link recovery and avoid the problem that an RLF between the terminal and the MCG triggers an RRC re-establishment process, and transmission that is being performed by the terminal needs to be suspended for a long time. This can ensure rapid recovery of data transmission and improve user experience 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic flowchart of an information processing method for a radio link failure applied to a terminal according to an embodiment of the present disclosure; 
         FIG. 2  is a first schematic flowchart of an information processing method for a radio link failure according to an embodiment of the present disclosure; 
         FIG. 3  is a second schematic flowchart of an information processing method for a radio link failure according to an embodiment of the present disclosure; 
         FIG. 4  is a schematic diagram of modules of a terminal according to an embodiment of the present disclosure; 
         FIG. 5  is a structural block diagram of a terminal according to an embodiment of the present disclosure; 
         FIG. 6  is a schematic diagram of modules of a first network device according to an embodiment of the present disclosure; 
         FIG. 7  is a structural block diagram of a first network device according to an embodiment of the present disclosure. 
         FIG. 8  is a schematic diagram of modules of a second network device according to an embodiment of the present disclosure; and 
         FIG. 9  is a structural block diagram of a second network device according to an embodiment of the present disclosure. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     To make the objectives, technical solutions, and advantages of the present disclosure clearer, the following further describes the present disclosure in detail with reference to the accompanying drawings and specific embodiments. 
     Before the embodiments of the present disclosure are described, some concepts used in the following description are explained first. 
     In LTE and NR systems, UE detects whether an RLF occurs through a radio link monitor (Radio Link Monitor, RLM) function. After determining the RLF, the UE performs a corresponding link recovery process. 
     The RLM and the RLF are only performed in a PCell and a PScell. 
     The RLM and the RLF in a PCell: 
     In the RLM function of LTE, UE measures a signal to interference plus noise ratio (Signal to Interference plus Noise Ratio, SINR) of a cell reference signal (Cell Reference Signal, CRS) corresponding to a physical downlink control channel (Physical Downlink Control CHannel, PDCCH) of the PCell, to monitor a radio link. When a physical layer (L1) of the UE obtains through measurement that the SINR of the CRS corresponding to the PDCCH of the PCell is lower than a threshold, it is considered that the radio link is out of sync (“out of sync”). The physical layer notifies an upper layer (RRC layer, L3) of an out-of-sync indication. If the RRC layer continuously receives N 310  out-of-sync indications, the RRC layer of the UE starts a timer (Timer) T 310 . 
     If the measured SINR of the CRS corresponding to the PDCCH of the PCell is higher than a threshold, it is considered that the radio link is in sync (“in sync”). In this case, the physical layer notifies the upper layer (RRC layer) of an in-sync indication. If the RRC layer continuously receives N 311  in-sync indications, the UE stops the operation of the Timer T 310 . 
     If the Timer T 310  expires, the UE determines the RLF and starts the Timer T 311 . During the operation of T 311 , the UE tries to find a suitable cell for RRC connection re-establishment. Before re-establishment succeeds, exchange of user-plane data between the UE and a network is suspended. 
     If the UE does not succeed in re-establishment before T 311  expires, the UE switches from an RRC connected state (RRC_CONNECTED) to an RRC idle state (RRC_IDLE). 
     Duration of N 310 , N 311 , T 310 , and T 311  is configured by the network. 
     The RLM process of NR is similar to that of LTE. In NR, an RLM RS detected by a PCell is configured by the network. 
     The present disclosure provides an information processing method for a radio link failure, a terminal, and a network device, to resolve the problem that an RLF between a terminal and an MCG triggers an RRC re-establishment process, and transmission that is being performed by the terminal needs to be suspended and user experience is affected. 
     As shown in  FIG. 1 , an embodiment of the present disclosure provides an information processing method for a radio link failure, applied to a terminal, and including: 
     Step  101 : Determine whether a first condition is met. 
     It should be noted that the first condition includes at least: a radio link failure occurs between the terminal and the MCG. 
     Step  102 : If the first condition is met, send radio link failure information of a master serving cell group MCG to a secondary serving cell group SCG. 
     Step  103 : Receive MCG reconfiguration information sent by the SCG. 
     It should be noted that when it is determined that a radio link failure occurs between the terminal and the MCG, the MCG reconfiguration information sent by the SCG is received, to implement fast link recovery and avoid the problem that an RLF between the terminal and the MCG triggers an RRC re-establishment process, and transmission that is being performed by the terminal needs to be suspended for a long time. This can ensure rapid recovery of data transmission and improve user experience 
     It should be noted that in the process of determining whether the first condition for sending the radio link failure information of the MCG is met, the terminal may monitor a physical downlink control channel (PDCCH), or the terminal may not monitor a PDCCH. The specific behavior of the terminal is described from these two perspectives as follows: 
     1. The terminal does not monitor a PDCCH 
     The following is a detailed description of this situation. 
     Specifically, when the radio link failure occurs between the terminal and the MCG, the information processing method for a radio link failure further includes at least one of the following steps:
         suspending transmission of a data radio bearer (DRB);   suspending transmission of a signaling radio bearer (SRB); or   stopping monitoring at least one PDCCH of the MCG.       

     It should be noted that when the radio link failure occurs between the terminal and the MCG, the terminal suspends transmission of a DRB and transmission of an SRB, and stops monitoring at least one PDCCH of the MCG. Transmission of the DRB includes: at least one of at least one MCG DRB, an MCG part of at least one MCG split DRB (MCG part of MCG split DRB), or an MCG part of at least one SCG split DRB (MCG part of SCG split DRB). Transmission of the SRB includes: at least one of at least one MCG signaling radio bearer  1 , at least one MCG signaling radio bearer  2 , an MCG part of at least one MCG split signaling radio bearer  1  (MCG part of MCG split SRB 1 ), and an MCG part of at least one MCG split signaling radio bearer  2  (MCG part of MCG split SRB 2 ). The at least one PDCCH includes at least one of the following information: a PDCCH of a master serving cell; or a PDCCH of at least one secondary serving cell. 
     Further, it should be noted that in this case, when it is determined that a radio link failure occurs between the terminal and the master serving cell group MCG, the terminal sends the radio link failure information of the MCG to the SCG. Specifically, the radio link failure information of the MCG is sent through a preset bearer. 
     The preset bearer includes: at least one of an SCG part of an MCG signaling split radio bearer  1  (SCG part of MCG split SRB 1 ) or an SCG signaling radio bearer  3  (SCG SRB 3 ). 
     After the terminal sends the radio link failure information of the MCG to the SCG, the SCG forwards the radio link failure information of the MCG to the MCG, then the MCG sends the MCG reconfiguration information to the SCG, and finally the SCG forwards the MCG reconfiguration information to the terminal. It should be noted that the MCG sends the MCG reconfiguration information to the SCG through an SCG part of an MCG split signaling radio bearer  1  (SCG part of MCG split SRB 1 ) or an Xn interface between the MCG and the SCG, and then the SCG forwards the MCG reconfiguration information to the terminal. 
     In this case, an actual execution process of the terminal is as follows: 
     When the terminal determines that a radio link failure occurs between the terminal and the MCG, the terminal suspends transmission of a DRB and transmission of an SRB, does not monitor at least one PDCCH of the MCG, and directly sends the radio link failure information of the MCG to the SCG. 
     2. The terminal monitors a PDCCH 
     The following is a detailed description of this situation. 
     Specifically, when the radio link failure occurs between the terminal and the MCG, the information processing method for a radio link failure further includes at least one of the following manners:
         suspending transmission of a DRB;   suspending transmission of an SRB; or   monitoring at least one PDCCH of the MCG.       

     It should be noted that when it is determined that the radio link failure occurs between the terminal and the MCG, the terminal suspends transmission of a DRB and transmission of an SRB, and monitors at least one PDCCH of the MCG. Transmission of the DRB includes: at least one of at least one MCG DRB, an MCG part of at least one MCG split DRB, or an MCG part of at least one SCG split DRB. Transmission of the SRB includes: at least one of at least one MCG signaling radio bearer  1 , at least one MCG signaling radio bearer  2 , an MCG part of at least one MCG split signaling radio bearer  1 , and an MCG part of at least one MCG split signaling radio bearer  2 . The at least one PDCCH includes at least one of the following information: a PDCCH of a master serving cell; or a PDCCH of at least one secondary serving cell. 
     Specifically, in this case, the first condition further includes at least one of the following information:
         a radio link is not recovered; or   no contention random access channel indication is detected, where   the contention random access channel indication is triggered by downlink control information in a PDCCH.       

     It should be noted that when monitoring a PDCCH, the terminal may determine, within the timing duration of the first timer, whether the radio link is recovered. If the radio link is not recovered, it indicates that the first condition for sending the radio link failure information of the MCG is met. It should be noted that if the terminal has not determined, when the timing duration of the first timer is exceeded, whether the radio link is recovered, the radio link failure information of the MCG is sent. The terminal may determine whether a content random access channel indication is detected. If the content random access channel indication is not detected, it indicates that the first condition for sending the radio link failure information of the MCG is met. 
     Further, it should be noted that the terminal specifically determines, in the following manner, whether a radio link is recovered:
         running a first timer; specifically, running the first timer means starting the first timer or restarting the first timer.   during running of the first timer, when a physical layer synchronization indication count value is greater than or equal to a first physical layer synchronization indication count threshold, determining that a radio link recovers, and stopping running the first timer; and   when running of the first timer expires (that is, timing duration is exceeded), determining that a radio link cannot be recovered.       

     It should be noted that the first timer is a timer used in a process of determining whether the radio link is recovered. 
     It should also be noted that before performing the above steps, the terminal needs to obtain the timing duration of the first timer and the first physical layer synchronization indication count threshold. Specifically, the timing duration of the first timer is configured by using at least one of the following information: a broadcast message, radio resource control (RRC) signaling, and protocol stipulation. The first physical layer synchronization indication count threshold is configured by using at least one of the following information: a broadcast message, RRC signaling, and protocol stipulation. 
     It should be noted that when the timing duration of the first timer (or the first physical layer synchronization indication count threshold) is configured by using the broadcast message or the RRC signaling, the timing duration of the first timer (or the first physical layer synchronization indication count threshold) is sent to the terminal by the MCG through the broadcast message or the RRC signaling when the terminal and MCG are in a communication state. 
     It should also be noted that in this case, the terminal may or may not send the radio link failure information of the MCG. Therefore, before sending the radio link failure information of the MCG to the secondary serving cell group SCG, the method further includes:
         generating the radio link failure information of the MCG.       

     It should be noted that the radio link failure information of the MCG is to-be-sent radio link failure information of the MCG. That is, after the to-be-sent radio link failure information of the MCG is generated, the to-be-sent radio link failure information of the MCG is not sent to the SCG. Only when the first condition for sending the radio link failure information of the MCG is met (that is, a radio link is not recovered and/or the contention random access channel indication is not detected), the radio link failure information of the MCG is sent to the SCG. If a radio link recovers and/or the contention random access channel indication is detected, the radio link failure information of the MCG is not sent (that is, the to-be-sent radio link failure information of the MCG is canceled). 
     In this case, an actual execution process of the terminal is as follows: 
     When the terminal determines that a radio link failure occurs between the terminal and the MCG, the terminal suspends transmission of a DRB and transmission of an SRB, monitors at least one PDCCH of the MCG, and generates the to-be-sent radio link failure information of the MCG. At the same time, the terminal performs the follow-up process in one of the following manners: 
     Manner 1: The radio link is monitored again when at least one PDCCH of the MCG is monitored, to determine whether the radio link is recovered. When it is determined that the radio link is recovered again, reporting of the radio link failure information of the MCG to the SCG is canceled (that is, the radio link failure information of the MCG is not sent to the SCG). If the terminal determines that the radio link cannot be recovered again, the terminal reports the radio link failure information of the MCG to SCG (that is, the radio link failure information of the MCG is sent to the SCG). 
     Manner 2: When the terminal detects, when at least one PDCCH of the MCG is monitored, a contention random access channel (RACH) indication triggered by downlink control information in a PDCCH, the terminal cancels reporting of the radio link failure information of the MCG to the SCG (that is, the radio link failure information of the MCG is not sent to the SCG) and initiates the RACH process. When the terminal has not detected the RACH indication triggered by the downlink control information in the PDCCH, the terminal reports the radio link failure information of the MCG to the SCG (that is, the radio link failure information of the MCG is sent to the SCG). 
     After the terminal sends the radio link failure information of the MCG to the SCG, the SCG forwards the radio link failure information of the MCG to the MCG, then the MCG sends the MCG reconfiguration information to the SCG, and finally the SCG forwards the MCG reconfiguration information to the terminal. 
     It should be noted that the embodiments of the present disclosure may be mainly applied to dual-connection scenarios. Further, the embodiments of the present disclosure may be extended to multi-connection scenarios. 
     In the embodiments of the present disclosure, initiation of an RRC connection re-establishment process by the terminal is avoided, the SCG is used to recover a radio link, and the terminal processes the MCG to reduce suspenions of data receiving and sending of the terminal as much as possible. 
     Specifically, as shown in  FIG. 2 ,  FIG. 2  is a schematic flowchart of an information processing method for a radio link failure according to an embodiment of the present disclosure. The information processing method for a radio link failure is applied to an SCG, and includes: 
     Step  201 : Receive radio link failure information of a master serving cell group MCG that is sent by a terminal. 
     Step  202 : Send the radio link failure information of the MCG to the MCG. 
     Step  203 : Obtain MCG reconfiguration information. 
     Step  204 : Send the MCG reconfiguration information to the terminal. 
     Further, a specific implementation of the step  203  is as follows:
         receiving the MCG reconfiguration information sent by the MCG in a preset manner, where   the preset manner includes: at least one of an SCG part of an MCG split signaling radio bearer  1  or an Xn interface between the MCG and the SCG.       

     It should be noted that all the descriptions about the SCG in the foregoing embodiments are applicable to the embodiment of the information processing method for a radio link failure, and the same technical effect thereof can be achieved. 
     Specifically, as shown in  FIG. 3 ,  FIG. 3  is a schematic flowchart of an information processing method for a radio link failure according to an embodiment of the present disclosure. The information processing method for a radio link failure is applied to an MCG, and includes: 
     Step  301 : Receive radio link failure information of the MCG that is sent by a secondary serving cell group SCG. 
     Step  302 : Send MCG reconfiguration information to the SCG. 
     Specifically, an implementation of the step  302  is as follows:
         sending the MCG reconfiguration information to the SCG in a preset manner, where   the preset manner includes: at least one of an SCG part of an MCG split signaling radio bearer  1  or an Xn interface between the MCG and the SCG.       

     Further, before step  301 , the method further includes:
         sending timing duration of a first timer and/or a first physical layer synchronization indication count threshold to the terminal by using a target message, where   the target message includes: at least one of a broadcast message or radio resource control RRC signaling       

     It should be noted that when the terminal and MCG are connected (that is, the terminal can communicate directly with the MCG), the MCG directly sends the target message to the terminal. 
     It should be noted that all the descriptions about the MCG in the foregoing embodiments are applicable to the embodiment of the information processing method for a radio link failure, and the same technical effect thereof can be achieved. 
     Referring to  FIG. 4 , an embodiment of the present disclosure provides a terminal  400 , including:
         a determining module  401 , configured to determine whether a first condition is met;   a first sending module  402 , configured to: if the first condition is met, send radio link failure information of a master serving cell group MCG to a secondary serving cell group SCG; and   a first receiving module  403 , configured to receive MCG reconfiguration information sent by the SCG, where   the first condition includes at least: a radio link failure occurs between the terminal and the MCG.       

     Specifically, when the radio link failure occurs between the terminal and the MCG, the terminal further includes at least one of the following modules:
         a first execution module, configured to suspend transmission of a data radio bearer DRB;   a second execution module, configured to suspend transmission of a signaling radio bearer SRB; or   a third execution module, configured to stop monitoring at least one physical downlink control channel PDCCH of the MCG.       

     Specifically, when the radio link failure occurs between the terminal and the MCG, the terminal further includes at least one of the following modules:
         a fourth execution module, configured to suspend transmission of a DRB;   a fifth execution module, configured to suspend transmission of an SRB; or   a sixth execution module, configured to monitor at least one PDCCH of the MCG.       

     Optionally, the first condition further includes at least one of the following information:
         a radio link is not recovered; or   no contention random access channel indication is detected, where   the contention random access channel indication is triggered by downlink control information in a PDCCH.       

     Further, when the terminal monitors at least one PDCCH of the MCG, the terminal further includes:
         a running module, configured to run a first timer;   a first determining module, configured to: during running of the first timer, when a physical layer synchronization indication count value is greater than or equal to a first physical layer synchronization indication count threshold, determine that a radio link recovers, and stopping running the first timer; and   a second determining module, configured to: when running of the first timer expires, determine that a radio link cannot be recovered.       

     Specifically, timing duration of the first timer is configured by using at least one of the following information:
         a broadcast message, a radio resource control RRC signaling, and protocol stipulation.       

     Specifically, the first the physical layer synchronization indication count threshold is configured by using at least one of the following information:
         a broadcast message, a radio resource control RRC signaling, and protocol stipulation.       

     Alternatively, on the basis that the first condition further includes: a radio link is not recovered and/or the contention random access channel indication is not detected, the terminal further includes:
         a seventh execution module, configured to: if a radio link is recovered and/or detecting a contention random access channel indication, skip sending the radio link failure information of the MCG.       

     Optionally, before the first sending module  402  sends the radio link failure information of the MCG to the secondary serving cell group SCG, the terminal further includes:
         an eighth execution module, configured to generate the radio link failure information of the MCG.       

     Specifically, the at least one PDCCH includes at least one of the following information:
         a PDCCH of a master serving cell; or   a PDCCH of at least one secondary serving cell.       

     Specifically, transmission of the DRB includes: at least one of at least one MCG DRB, an MCG part of at least one MCG split DRB, or an MCG part of at least one SCG split DRB. 
     Specifically, transmission of the SRB includes: at least one of at least one MCG signaling radio bearer  1 , at least one MCG signaling radio bearer  2 , an MCG part of at least one MCG split signaling radio bearer  1 , and an MCG part of at least one MCG split signaling radio bearer  2 . 
     Specifically, the radio link failure information of the MCG is sent by using a preset bearer; and
         the preset bearer includes: at least one of an SCG part of an MCG split radio bearer  1  or an SCG signaling radio bearer  3 .       

     It should be noted that this embodiment of the terminal provides the terminal corresponding to the information processing method for a radio link failure applied to the terminal, all implementations in the foregoing embodiments are applicable to this terminal embodiment, and the same technical effect thereof can be achieved. 
       FIG. 5  is a schematic diagram of a hardware structure of a terminal according to an embodiment of the present disclosure. 
     The terminal  50  includes, but is not limited to: a radio frequency unit  510 , a network module  520 , an audio output unit  530 , an input unit  540 , a sensor  550 , a display unit  560 , a user input unit  570 , an interface unit  580 , a memory  590 , a processor  511  and a power supply  512 . It can be understood by those skilled in the art that the structure of the terminal shown in  FIG. 5  does not constitute a limitation on the terminal, and the terminal may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements. In the embodiments of the present disclosure, the terminal includes, but is not limited to, a mobile phone, a tablet computer, a notebook computer, a palmtop computer, a vehicle-mounted terminal, a wearable device, a pedometer, or the like. 
     The processor  511  is configured to determine whether a first condition is met; if the first condition is met, send radio link failure information of a master serving cell group MCG to a secondary serving cell group SCG; and receive MCG reconfiguration information sent by the SCG, where
         the first condition includes at least: a radio link failure occurs between the terminal and the MCG.       

     When the terminal in the embodiments of the present disclosure determines that the first condition for sending the radio link failure information of the MCG is met, the radio link failure information of the MCG is sent to the SCG, and the MCG reconfiguration information sent by the SCG is received, to implement fast link recovery and avoid the problem that an RLF between the terminal and the MCG triggers an RRC re-establishment process, and transmission that is being performed by the terminal needs to be suspended for a long time. This can ensure rapid recovery of data transmission and improve user experience 
     It should be understood that, in this embodiment of the present disclosure, the radio frequency unit  510  can be configured to receive and transmit signals during information receiving and sending or a call. Specifically, the radio frequency unit  510  receives downlink data from a network device, and transmits the downlink data to the processor  511  for processing; and in addition, transmits uplink data to the network device. Generally, the radio frequency unit  510  includes but is not limited to an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, and the like. In addition, the radio frequency unit  510  may also communicate with another device through a wireless communications system and network. 
     The terminal provides wireless broadband Internet access for a user by using the network module  520 , for example, helps the user send and receive an email, browse a web page, and access streaming media. 
     The audio output unit  530  can convert audio data received by the radio frequency unit  510  or the network module  520  or stored in the memory  590  into an audio signal, and output the audio signal into sound. In addition, the audio output unit  530  can also provide audio output related to a specific function performed by the terminal  50  (for example, call signal receiving sound or message receiving sound). The audio output unit  530  includes a speaker, a buzzer, a telephone receiver, and the like. 
     The input unit  540  is configured to receive audio or video signals. The input unit  540  may include a graphics processing unit (Graphics Processing Unit, GPU)  541  and a microphone  542 . The graphics processing unit  541  processes image data of a static image or a video obtained by an image capturing apparatus (such as, a camera) in a video capturing mode or an image capturing mode. A processed image frame may be displayed on the display unit  560 . The image frame processed by the graphics processing unit  541  can be stored in the memory  590  (or another storage medium) or sent via the radio frequency unit  510  or the network module  520 . The microphone  542  may receive sound and can process such sound into audio data. Processed audio data can be converted, in telephone call mode, into a format that can be sent to a mobile communication network device via the radio frequency unit  510  for output. 
     The terminal  50  further includes at least one sensor  550 , such as a light sensor, a motion sensor, and other sensors. Specifically, the light sensor includes an ambient light sensor and a proximity sensor, where the ambient light sensor can adjust brightness of the display panel  561  based on brightness of ambient light, and the proximity sensor can turn off the display panel  561  and/or backlight when the terminal  50  moves towards the ear. As a type of motion sensor, an accelerometer sensor can detect the magnitude of acceleration in various directions (usually three axes) and detect the magnitude and the direction of gravity when stationary, and can be configured to identify terminal postures (such as switching between a portrait mode and a landscape mode, related games, and magnetometer posture calibration), and perform functions related to vibration identification (such as a pedometer and a knock), and the like. The sensor  550  may further include a fingerprint sensor, a pressure sensor, an iris sensor, a molecular sensor, a gyroscope, a barometer, a hygrometer, a thermometer, an infrared sensor, or the like. Details are not described herein. 
     The display unit  560  is configured to display information entered by a user or information provided for the user. The display unit  560  may include a display panel  561 , and the display panel  561  may be configured in a form of liquid crystal display (Liquid Crystal Display, LCD), organic light-emitting diode (Organic Light-Emitting Diode, OLED), or the like. 
     The user input unit  570  may be configured to receive inputted digit or character information and generate key signal input related to user setting and function control of the terminal. Specifically, the user input unit  570  includes a touch panel  571  and another input device  572 . The touch panel  571  is also referred to as a touchscreen, and may collect a touch operation performed by a user on or near the touch panel  571  (such as an operation performed by a user on the touch panel  571  or near the touch panel  571  by using any proper object or accessory, such as a finger or a stylus). The touch panel  571  may include two parts: a touch detection apparatus and a touch controller. The touch detection apparatus detects a touch location of the user, detects a signal carried by a touch operation, and transmits the signal to the touch controller. The touch controller receives touch information from the touch detection apparatus, converts the touch information to point coordinates, and sends the point coordinates to the processor  511 , and receives and executes a command sent by the processor  511 . In addition, the touch panel  571  may be implemented in various types such as resistive, capacitive, infrared, and surface acoustic wave. In addition to the touch panel  571 , the user input unit  570  may further include the another input device  572 . Specifically, the another input device  572  may include but is not limited to one or more of a physical keyboard, a function key (such as a volume control key or an on/off key), a trackball, a mouse, a joystick, and the like. Details are not described herein. 
     Further, the touch panel  571  can cover the display panel  561 . When detecting a touch operation on or near the touch panel  571 , the touch panel  571  transmits the touch operation to the processor  511  to determine a type of a touch event. Then, the processor  511  provides corresponding visual output on the display panel  561  based on the type of the touch event. In  FIG. 5 , the touch panel  571  and the display panel  561  are used as two independent components to implement input and output functions of the terminal. However, in some embodiments, the touch panel  571  and the display panel  561  may be integrated to implement the input and output functions of the terminal. This is not specifically limited herein. 
     The interface unit  580  is an interface connecting an external apparatus to the terminal  50 . For example, the external apparatus may include a wired or wireless headphone port, an external power supply (or a battery charger) port, a wired or wireless data port, a storage card port, a port used to connect to an apparatus having an identity module, an audio input/output (I/O) port, a video I/O port, and a headset port. The interface unit  580  may be configured to receive input (for example, data information and power) from an external apparatus and transmit the received input to one or more elements within the terminal  50 , or may be configured to transmit data between the terminal  50  and the external apparatus. 
     The memory  590  may be configured to store software programs and various data. The memory  590  may mainly include a program storage area and a data storage area. The program storage area may store an operating system, an application program required by at least one function (such as a sound playback function and an image playback function), and the like. The data storage area may store data (such as audio data and an address book) created based on the use of the mobile phone, and the like. In addition, the memory  590  may include a high-speed random access memory or a nonvolatile memory, for example, at least one magnetic disk storage device, a flash memory, or another volatile solid-state storage device. 
     The processor  511  is a control center of the terminal, connects various parts of the entire terminal by using various interfaces and circuits, and performs various functions of the terminal and processes data by running or executing software programs and/or modules stored in the memory  590  and invoking data stored in the memory  590 , so as to monitor the terminal as a whole. The processor  511  may include one or more processing units. Optionally, the processor  511  may integrate an application processor and a modem processor. The application processor mainly deals with an operating system, a user interface, an application program, and the like. The modem processor mainly deals with wireless communication. It may be understood that alternatively, the modem processor may not be integrated into the processor  511 . 
     The terminal  50  may further include a power supply  512  (such as a battery) that supplies power to each component. Optionally, the power supply  512  may be logically connected to the processor  511  by using a power management system, to implement functions such as charging, discharging, and power consumption management by using the power management system. 
     In addition, the terminal  50  includes some function modules not shown, and details are not described herein again. 
     Optionally, an embodiment of the present disclosure further provides a terminal, including a processor  511 , a memory  590 , and a computer program stored in the memory  590  and executable on the processor  511 . When the computer program is executed by the processor  511 , each process of the embodiment of the information processing method for a radio link failure applied to a terminal side is implemented, and a same technical effect can be achieved. To avoid repetition, details are not described herein again. 
     An embodiment of the present disclosure further provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program. The computer program, when executed by a processor, implements each process of the embodiment of the information processing method for a radio link failure, and the same technical effect can be achieved. To avoid repetition, details are not described herein again. The computer-readable storage medium is, for example, a read-only memory (Read-Only Memory, ROM for short), a random access memory (Random Access Memory, RAM for short), a magnetic disk, or an optical disk. 
     As shown in  FIG. 6 , an embodiment of the present disclosure further provides a first network device  600 . The first network device includes a secondary serving cell group SCG, and includes:
         a second receiving module  601 , configured to receive radio link failure information of a master serving cell group MCG sent by a terminal;   a second sending module  602 , configured to send the radio link failure information of the MCG to the MCG;   an obtaining module  603 , configured to obtain MCG reconfiguration information; and   a third sending module  604 , configured to send the MCG reconfiguration information to the terminal.       

     Optionally, the obtaining module  603  is configured to:
         receive the MCG reconfiguration information sent by the MCG in a preset manner, where   the preset manner includes: at least one of an SCG part of an MCG split signaling radio bearer  1  or an Xn interface between the MCG and the SCG.       

     It should be noted that this embodiment of the first network device provides the first network device corresponding to the information processing method for a radio link failure applied to the SCG, all implementations in the foregoing embodiments are applicable to this embodiment of the first network device, and the same technical effect thereof can be achieved. 
     An embodiment of the present disclosure further provides a first network device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. The computer program, when executed by the processor, implements processes in the embodiment of the information processing method for a radio link failure applied to the SCG, and the same technical effect can be achieved. To avoid repetition, details are not described herein again. 
     An embodiment of the present disclosure further provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, the computer program, when executed by the processor, implements the processes of the foregoing embodiments of the information processing method for a radio link failure applied to the SCG, and the same technical effects can be achieved. To avoid repetition, details are not described herein again. The computer-readable storage medium may be a read-only memory (Read-Only Memory, ROM for short), a random access memory (Random Access Memory, RAM for short), a magnetic disk, a compact disc, or the like. 
       FIG. 7  is a structural diagram of a first network device according to an embodiment of the present disclosure. The first network device can implement details of the information processing method for a radio link failure, and achieve the same effect. As shown in  FIG. 7 , the network device  700  includes: a processor  701 , a transceiver  702 , a memory  703 , and a bus interface. 
     The processor  701  is configured to read a program in the memory  703  to perform the following process: 
     The transceiver  702  receives radio link failure information of a master serving cell group MCG sent by a terminal; sends the radio link failure information of the MCG to the MCG; obtains MCG reconfiguration information; and sends the MCG reconfiguration information to the terminal. 
     In  FIG. 7 , the bus architecture may include any quantity of interconnected buses and bridges, which are specifically connected together by various circuits of one or more processors represented by the processor  701  and a memory represented by the memory  703 . The bus architecture may further connect together various other circuits of a peripheral device, a voltage stabilizer, a power management circuit, and the like, which are known in this art and will not be further described herein. The bus interface provides an interface. The transceiver  702  may include a plurality of elements, that is, include a transmitter and a receiver, and provide units for communication with various other apparatuses on a transmission medium. 
     The processor  701  is responsible for managing the bus architecture and common processing, and the memory  703  may store data used when the processor  701  performs an operation. 
     Optionally, the processor  701  is configured to read a program in the memory  703  to perform the following process:
         receiving, by using the transceiver  702 , MCG reconfiguration information sent by the MCG in a preset manner, where   the preset manner includes: at least one of an SCG part of an MCG split signaling radio bearer  1  or an Xn interface between the MCG and the SCG.       

     The first network device may be a base transceiver station (Base Transceiver Station, BTS for short) in global system for mobile communications (Global System of Mobile communication, GSM for short) or code division multiple access (Code Division Multiple Access, CDMA for short), or may be a NodeB (NodeB, NB for short) in wideband code division multiple access (Wideband Code Division Multiple Access, WCDMA for short), or may be an evolved NodeB (Evolutional NodeB, eNB or eNodeB for short) in LTE, or a relay station or an access point, or a base station in the future 5G network. This is not limited herein. 
     As shown in  FIG. 8 , an embodiment of the present disclosure further provides a second network device  800 . The second network device includes a master serving cell group MCG, and includes:
         a third receiving module  801 , configured to receive radio link failure information of the MCG that is sent by a secondary serving cell group SCG; and   a fourth sending module  802 , configured to send MCG reconfiguration information to the SCG.       

     Specifically, the fourth sending module  802  is configured to:
         send the MCG reconfiguration information to the SCG in a preset manner, where   the preset manner includes: at least one of an SCG part of an MCG split signaling radio bearer  1  or an Xn interface between the MCG and the SCG.       

     Optionally, before the third receiving module  801  receives the radio link failure information of the MCG that is sent by the secondary serving cell group SCG, the second network device further includes:
         a fifth sending module, configured to send timing duration of a first timer and/or a first physical layer synchronization indication count threshold to the terminal by using a target message, where   the target message includes: at least one of a broadcast message or radio resource control RRC signaling       

     It should be noted that this embodiment of the second network device provides the second network device corresponding to the information processing method for a radio link failure applied to the MCG, all implementations in the foregoing embodiments are applicable to this embodiment of the second network device, and the same technical effect thereof can be achieved. 
     An embodiment of the present disclosure further provides a second network device, including: a memory, a processor, and a computer program stored in the memory and executable the processor. The computer program, when executed by the processor, implements processes in the embodiment of the information processing method for a radio link failure applied to the MCG, and the same technical effect can be achieved. To avoid repetition, details are not described herein again. 
     An embodiment of the present disclosure further provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, the computer program, when executed by the processor, implements the processes of the foregoing embodiments of the information processing method for a radio link failure applied to the MCG, and the same technical effects can be achieved. To avoid repetition, details are not described herein again. The computer-readable storage medium may be a read-only memory (Read-Only Memory, ROM for short), a random access memory (Random Access Memory, RAM for short), a magnetic disk, a compact disc, or the like. 
       FIG. 9  is a structural diagram of a second network device according to an embodiment of the present disclosure. The second network device can implement details of the information processing method for a radio link failure, and achieve the same effect. As shown in  FIG. 9 , the network device  900  includes: a processor  901 , a transceiver  902 , a memory  903 , and a bus interface. 
     The processor  901  is configured to read a program in the memory  903  to perform the following process:
         receiving, by using the transceiver  902 , radio link failure information of the MCG that is sent by a secondary serving cell group SCG; and sending MCG reconfiguration information to the SCG.       

     In  FIG. 9 , the bus architecture may include any quantity of interconnected buses and bridges, which are specifically connected together by various circuits of one or more processors represented by the processor  901  and a memory represented by the memory  903 . The bus architecture may further connect together various other circuits of a peripheral device, a voltage stabilizer, a power management circuit, and the like, which are known in this art and will not be further described herein. The bus interface provides an interface. The transceiver  902  may include a plurality of elements, that is, include a transmitter and a receiver, and provide units for communication with various other apparatuses on a transmission medium. 
     The processor  901  is responsible for managing the bus architecture and common processing, and the memory  903  may store data used when the processor  901  performs an operation. 
     Optionally, the processor  901  is configured to read a program in the memory  903  to perform the following process:
         sending MCG reconfiguration information to SCG in a preset manner by using the transceiver  902 , where   the preset manner includes: at least one of an SCG part of an MCG split signaling radio bearer  1  or an Xn interface between the MCG and the SCG.       

     Optionally, the processor  901  is configured to read a program in the memory  903  to perform the following process:
         sending timing duration of a first timer and/or a first physical layer synchronization indication count threshold to the terminal by using a target message and by using the transceiver  902 , where   the target message includes: at least one of a broadcast message or radio resource control RRC signaling.       

     The second network device may be a base transceiver station (Base Transceiver Station, BTS for short) in global system for mobile communications (Global System of Mobile communication, GSM for short) or code division multiple access (Code Division Multiple Access, CDMA for short), or may be a NodeB (NodeB, NB for short) in wideband code division multiple access (Wideband Code Division Multiple Access, WCDMA for short), or may be an evolved NodeB (Evolutional NodeB, eNB or eNodeB for short) in LTE, or a relay station or an access point, or a base station in the future 5G network. This is not limited herein. 
     The optional implementations of the present disclosure are described above. It should be noted that persons of ordinary skill in the art may further make several improvements and refinements without departing from the principles described in the present disclosure, and these improvements and refinements also fall within the protection scope of the present disclosure.