WO2018171744A1

WO2018171744A1 - Radio link monitoring method and user equipment

Info

Publication number: WO2018171744A1
Application number: PCT/CN2018/080308
Authority: WO
Inventors: 牛丽; 吴昱民
Original assignee: 中兴通讯股份有限公司
Priority date: 2017-03-23
Filing date: 2018-03-23
Publication date: 2018-09-27
Also published as: CN108924853A

Abstract

Disclosed is a radio link monitoring method. The method comprises: when a UE is in a preset state, detecting the state of a radio link of the UE according to the data transmission condition of a user plane; and when it is detected that the radio link of the UE fails, repairing the radio link, the preset state referring to a state in which a connection between the UE and an interface of a base station is interrupted, and the bases station and a core network keep the connection of the UE. Also disclosed is a user equipment.

Description

Wireless link monitoring method and user equipment

Technical field

The present disclosure relates to the field of wireless communication technologies, for example, to a wireless link monitoring method and user equipment.

Background technique

Long Term Evolution (LTE) includes: User Equipment (UE), Core Network (CN), and Evolved Node B (eNB).

In the active state, the UE needs to access the eNB to communicate with the eNB, that is, initiate a random access procedure; then, the UE enters a connected state, transmits data, or receives data. In the active state, to ensure the continuity of data transmission, the UE needs to monitor the state of the wireless link, and in the case of a failure of the wireless link, the wireless link needs to be restored in time. In the inactive state, the process of transmitting and receiving data by the UE can be simplified. Similar to the active state, the UE may also experience problems such as poor radio quality when transmitting data in an inactive state. However, unlike the active state, the inactive state does not need to recover the wireless link in time, and in the case where the wireless link is not restored in time, data needs to be transmitted to the network, which may result in data transmission failure.

Summary of the invention

The embodiment of the present application provides a wireless link monitoring method and user equipment.

In an embodiment, a method for monitoring a wireless link is provided, including:

When the user equipment UE is in the preset state, the state of the radio link of the UE is detected according to the data transmission situation of the user plane; wherein the preset state refers to that the interface between the UE and the base station is disconnected and the base station and the core network are maintained. The state of the connection of the UE;

When it is detected that the radio link of the UE fails, the radio link repair is performed.

The manner of detecting the state of the radio link of the UE according to the data transmission situation of the user plane may include at least one of the following manners:

Detecting whether the number of times the UE sends the preamble reaches the set first threshold, and determining that the radio link status of the UE is a radio link when the number of times the UE sends the preamble reaches the set first threshold. failure;

Detecting whether the number of retransmissions of the radio link control layer protocol data unit RLC PDU sent by the UE reaches a set second threshold, and the number of retransmissions of the radio link control layer protocol data unit sent by the UE reaches a set value. Determining, by the second threshold, that the radio link status of the UE is a radio link failure;

Determining, according to the number of times when the number of consecutive retransmissions of the hybrid automatic repeat request HARQ reaches a set threshold, detecting whether the determined number of consecutive retransmission times of the HARQ reaches a set threshold value reaches a set third threshold, and determining When the number of consecutive HARQ consecutive retransmissions reaches a threshold value reaches a third threshold, it is determined that the radio link status of the UE is a radio link failure.

The third threshold may be threshold information that the base station configures to the UE by using a broadcast or radio resource control RRC message.

The performing the radio link repair may include: initiating an application to resume the RRC connection, or initiating cell reselection.

The application for initiating the recovery of the RRC connection may include: an application message for initiating the recovery of the RRC connection, where the application message carries the indication information that the UE is in the preset state or carries the reason information that the data failure occurs in the preset state;

The initiating cell reselection may include: lowering a cell priority of the current cell.

The method may further include: performing, when the UE is in the preset state, performing at least one of the following operations: resetting the medium access control MAC, and The number of retransmissions of the RLC PDU sent by the currently recorded UE is cleared.

In an embodiment, a user equipment is provided, including:

The link detection module is configured to detect the state of the wireless link of the user equipment according to the data transmission situation of the user plane when the user equipment is in the preset state, where the preset state refers to the interface between the user equipment and the base station. Disconnected and the state in which the base station and the core network maintain the connection of the user equipment;

The link repair module is configured to perform radio link repair when the link detection module detects that the radio link of the user equipment fails.

The manner in which the link detection module detects the status of the radio link of the UE may include at least one of the following manners:

Determining whether the number of retransmissions of the RLC PDUs sent by the UE reaches a set second threshold, and determining that the number of retransmissions of the radio link control layer protocol data unit sent by the UE reaches a set second threshold The radio link status of the UE is a radio link failure;

The link repair module is configured to initiate an application for restoring an RRC connection when the link detection module detects that the radio link of the user equipment fails, or initiate cell reselection.

The link repairing module may be further configured to initiate an application message for restoring the RRC connection, where the application message carries the indication information that the UE is in the preset state or carries the reason information that the data failure occurs in the preset state; the link The repair module may also be configured to lower the cell priority of the current cell when initiating cell reselection.

The user equipment may further include: a processing module, configured to perform at least one of the following operations: resetting the media when the user equipment is in the preset state, and when the UE reselects to connect to the new cell Access control MAC, and clear the number of retransmissions of the currently recorded RLC PDU sent by the UE.

The method and the user equipment provided by the embodiment of the present application may be in a state in which the user equipment is disconnected from the interface of the base station and the base station and the core network maintain the connection of the UE, and the user equipment may be transmitted through the data transmission of the user plane. The state of the wireless link is detected, and when the wireless link of the user equipment fails, the wireless link repair is performed, which is convenient for adapting the mobility of the UE in an inactive state and reducing the delay of data transmission. In the related art, the wireless link in the inactive state cannot be monitored, thereby affecting the problem of data output.

DRAWINGS

The drawings are only for the purpose of illustrating alternative embodiments and are not to be considered as limiting.

FIG. 1 is a structural diagram of LTE provided by an embodiment;

2 is a protocol architecture of a UE, an eNB, and an MME according to an embodiment;

FIG. 3 is a flowchart of random access in LTE according to an embodiment;

4 is a flowchart of uplink transmission in an inactive state according to an embodiment;

FIG. 5 is a flowchart of a method for monitoring a wireless link according to Embodiment 1 of the present application;

FIG. 6 is a flowchart of a method for monitoring a wireless link according to Embodiment 2 of the present application;

FIG. 7 is a flowchart of a method for monitoring a wireless link according to Embodiment 3 of the present application;

FIG. 8 is a flowchart of a method for monitoring a wireless link according to Embodiment 4 of the present application;

FIG. 9 is a structural block diagram of a user equipment according to Embodiment 5 of the present application.

detailed description

Long Term Evolution (LTE) includes: User Equipment (UE), Core Network (CN), and Evolved Node B (eNB), where the mobility management entity (Mobility) in the core network Management Entity (MME) is responsible for the transmission of signaling, and the Serving GetWay (S-GW) is responsible for the transmission of data. The interface between the UE and the eNB is Uu, the interface between the eNB and the core network is S1, and the interface between the eNB and the eNB is X2. As shown in FIG. 1, an architectural diagram of LTE provided for an embodiment. 2 is a protocol architecture of a UE, an eNB, and an MME according to an embodiment. For the UE, the Radio Resource Control (RRC), the Packet Data Convergence Protocol (PDCP), the Radio Link Control (RLC), and the Medium Access Control (Medium Access Control, The MAC) and the Physical Layer (PHY) belong to the Access Stratum (AS), while the upper layer of the AS is the Non Access Stratum (NAS). In the LTE system, the UE needs to access the eNB to communicate with the eNB, that is, initiate a random access procedure. As shown in FIG. 3, the random access procedure includes the following steps: the UE learns the available preamble sequence code for random access by using system information or RRC signaling, and transmits the time-frequency location of the preamble sequence, among available resources, The time-frequency location of the preamble sequence and the transmission preamble sequence are randomly selected and sent to the eNB; the eNB estimates the random access radio network temporary identifier RA-RNTI that the UE may adopt by using the time-frequency location adopted by the random access preamble sequence, and uses the RA- The RNTI decodes the preamble sequence, and after the eNB successfully decodes the preamble sequence, the UE responds with a random access response, and the response carries information such as an uplink grant; the UE sends an RRC setup request message on the uplink authorized resource; the eNB is on the uplink authorized resource. The uplink data is parsed, the UE is confirmed, the conflict is resolved, and the contention resolution identifier is sent to the UE. Then the UE enters the connected state and starts to send and receive data. However, the process has a long delay. In order to simplify the steps, the process of transmitting and receiving data by the UE in the inactive state is proposed. As shown in FIG. 4, the method includes the following steps: the UE sends the preamble sequence to the eNB; when the eNB successfully decodes the preamble sequence Then, the UE is replied to the random access response, and the response carries the information such as the uplink grant; the UE sends the RRC message on the uplink-authorized resource and carries the uplink data, or the UE sends the uplink data and carries the information such as the identifier of the UE; The uplink data is parsed on the authorized resource, the UE is confirmed, the conflict is resolved, and the contention resolution identifier is sent to the UE. It can be seen that this method of transmitting data in an inactive state is smaller and more flexible than the method of transmitting data in an active state.

The embodiment of the present application provides a radio link monitoring method and a user equipment. When the UE is in a preset state (including but not limited to an inactive state and a lightly connected state), the UE is wireless according to the data transmission situation of the user plane. The status of the link is detected, and when the radio link of the UE fails, the radio link is repaired. The method and the user equipment in the embodiment of the present application can monitor the radio link status of the user equipment in the preset state, and can detect the link repair in time when detecting the radio link failure, which is convenient for adapting to the UE. The mobility of the inactive state can reduce the delay of data transmission. Embodiment 1

An embodiment of the present application provides a method for monitoring a wireless link. As shown in FIG. 5, the method includes the following steps:

Step S501: When the UE is in the preset state, it is detected whether the number of times the UE sends the preamble reaches the set first threshold, and when the number of times the UE sends the preamble reaches the set first threshold, the UE is determined. The wireless link status is a radio link failure.

In the embodiment of the present application, the preset state refers to a state in which the interface between the UE and the base station is disconnected, and the base station and the core network maintain the connection of the UE.

Further, in an embodiment, detecting whether the number of times that the UE sends the preamble reaches the set first threshold, specifically includes:

The UE detects whether the number of times of sending the preamble reaches the set first threshold by using the MAC layer. When the number of times that the UE sends the preamble through the MAC layer detects that the number of times of sending the preamble reaches the set first threshold, the MAC layer indicates random access to the RRC layer. There is a problem with the process, and the RRC considers that the radio link of the UE has failed.

Step S502, when it is detected that the radio link of the UE fails, perform radio link repair.

In this embodiment, the manner of performing radio link repair includes but is not limited to:

Method 1: initiate an application to resume the RRC connection;

Optionally, in the embodiment, the application message for initiating the recovery of the RRC connection carries the UE status indication information (for example, the UE is in a preset state) or carries the reestablishment reason information (for example, the UE fails to send data in the preset state).

In this embodiment, the application message may be an RRC Connection Reestablishment Request, an RRC Connection Resume Request, or a new message.

After receiving the application message, the base station may determine that the radio link fails in the preset state, and finds the base station that saves the UE context according to the UE identification information carried in the message, and then obtains the context information of the UE, which is the UE. Establish an RRC connection. In the case where the context information of the UE is not found, the base station will re-establish an RRC connection for the UE and update the configuration of the UE.

Method 2: Initiate cell reselection. Specifically, when initiating cell reselection, in order to avoid reselecting to the current cell, the cell priority of the current cell is also lowered.

If the UE reselects a cell and the cell can support data transmission in the preset state, the UE continues to perform data transmission in the preset state under the cell.

In the method of the embodiment, when the user equipment is disconnected from the interface of the base station and the base station and the core network maintain the connection of the UE, the state of the wireless link of the user equipment may be performed by using the preamble transmission status. Detecting, and detecting the failure of the radio link of the user equipment, performing radio link repair, which is convenient for adapting to the mobility of the UE in an inactive state, and reducing the delay of data transmission, thereby solving the problem of non-alignment The wireless link in the active state is monitored, which in turn affects the problem of data output.

Embodiment 2

In this embodiment, a wireless link monitoring method is provided. As shown in FIG. 6, the method includes the following steps:

In step S601, when the UE is in the preset state, it is detected whether the number of retransmissions of the RLC PDU sent by the UE reaches the set second threshold, and when the number of retransmissions of the RLC PDU sent by the UE reaches the set second threshold, it is determined. The radio link status of the UE is a radio link failure;

In this embodiment, the preset state refers to a state in which the interface between the UE and the base station is disconnected, and the base station and the core network maintain the connection of the UE.

Further, in an embodiment, detecting whether the number of retransmissions of the RLC PDU sent by the UE reaches a set second threshold, specifically includes:

The UE detects whether the transmitted RLC PDU reaches the maximum number of retransmissions through the RLC layer. When the number of retransmissions of the RLC PDU transmitted by the UE through the RLC layer reaches the maximum number of retransmissions, the RLC layer indicates to the RRC that the RLC layer reaches the maximum number of retransmissions. After receiving the indication, the RRC considers that the radio link of the UE fails or the quality deteriorates, and the current cell is not suitable for providing the data transmission service.

Step S602, when it is detected that the radio link of the UE fails, perform radio link repair.

Method 1: initiate an application to resume the RRC connection;

In the method of this embodiment, when the user equipment is disconnected from the interface of the base station and the base station and the core network maintain the connection state of the UE, the state of the wireless link of the user equipment may be performed by retransmission of the RLC PDU. Detecting, and detecting the failure of the radio link of the user equipment, performing radio link repair, which is convenient for adapting to the mobility of the UE in an inactive state, and reducing the delay of data transmission, thereby solving the problem of non-alignment The wireless link in the active state is monitored, which in turn affects the problem of data output.

Embodiment 3

In this embodiment, a wireless link monitoring method is provided. As shown in FIG. 7, the method includes the following steps:

Step S701: When the UE is in the preset state, it is detected whether the number of consecutive retransmission times of the hybrid automatic repeat request HARQ reaches the set threshold is reached, and the continuous retransmission of the hybrid automatic repeat request HARQ is performed. When the number of times when the number of times reaches the set threshold reaches the third threshold, it is determined that the radio link status of the UE is a radio link failure;

Further, in an embodiment, whether the number of times that the number of consecutive retransmissions of the hybrid automatic repeat request HARQ reaches the set threshold is a third threshold is determined, which specifically includes:

When the UE sends a data packet, the HARQ reaches the maximum number of retransmissions, and the MAC layer indicates to the RRC that the HARQ reaches the maximum number of retransmissions. If the number of consecutive MAC layer indications received by the RRC layer reaches the set third threshold, the radio link is considered. Failure or current cell is not suitable for providing data transmission services.

In this embodiment, the third threshold may be broadcast to the UE by the base station or configured by the RRC message, for example, by using system information, RRC connection reconfiguration, RRC Connection Release, or new message configuration.

Step S702, when it is detected that the radio link of the UE fails, perform radio link repair.

Method 1: initiate an application to resume the RRC connection;

In the method of the embodiment, when the user equipment is disconnected from the interface of the base station and the base station and the core network maintain the connection of the UE, the status of the wireless link of the user equipment may be detected by the retransmission of the HARQ. And when detecting that the wireless link of the user equipment fails, performing radio link repair, which is convenient for adapting the mobility of the UE in an inactive state, and reducing the delay of data transmission, and is well solved for inactive The wireless link is monitored to affect the data output.

Embodiment 4

In this embodiment, a wireless link monitoring method is provided. As shown in FIG. 8, the method includes the following steps:

Step S801, when the UE is in the preset state, detecting the state of the radio link of the UE according to the data transmission situation of the user plane;

In step S802, it is determined whether the radio link failure of the UE is detected. If the radio link failure of the UE is detected, step S803 is performed. If the radio link failure of the UE is not detected, step S804 is performed.

The method for detecting the state of the radio link may be the method described in any one of the foregoing embodiments.

Step S803, performing radio link repair; wherein, in the manner of performing radio link repair, refer to the manner described in any of the foregoing embodiments.

Step S804, detecting whether cell reselection occurs due to UE mobility, when cell reselection occurs, and reselecting to other cells, the RRC instructs the MAC layer to reset the MAC and apply configuration information of the new cell.

In an embodiment, the MAC is reset but the cache is not cleared, and the data in the cache is retransmitted as new data in the new cell. If the UE is not synchronized with the new cell, the MAC layer initiates a random access procedure.

Further, in this embodiment, when the radio link state detection mode is used in the second embodiment, after reselecting to other cells, the RRC layer further indicates the RLC layer, and retransmits the number of RLC PDUs recorded by the RLC layer. Cleared.

In the method of the embodiment, when the user equipment is disconnected from the interface of the base station and the base station and the core network maintain the connection state of the UE, the state of the wireless link of the user equipment may be performed by using the data transmission of the user plane. Detecting, and detecting the failure of the radio link of the user equipment, performing radio link repair, which is convenient for adapting to the mobility of the UE in an inactive state, and reducing the delay of data transmission, thereby solving the problem of non-alignment The wireless link in the active state is monitored, which in turn affects the problem of data output.

Embodiment 5

In this embodiment, a user equipment is provided, as shown in FIG. 9, including:

The link detection module 910 is configured to detect, according to the data transmission situation of the user plane, the state of the wireless link of the user equipment when the user equipment is in the preset state, where the preset state refers to the user equipment and the base station. a state in which the interface is disconnected and the base station and the core network maintain the connection of the user equipment;

The link repair module 920 is configured to perform radio link repair when the link detection module 910 detects that the radio link of the user equipment fails.

Further, in this embodiment, the manner in which the link detection module 910 detects the state of the radio link of the UE includes one or more of the following manners:

The first method is to detect whether the number of times the UE sends the preamble reaches the set first threshold, and when the number of times the UE sends the preamble reaches the set first threshold, determine that the radio link status of the UE is a radio link. failure.

Specifically, in this embodiment, the UE detects whether the number of times of sending the preamble reaches the set first threshold by using the MAC layer, and when detecting that the number of times of sending the preamble is reached, the MAC layer indicates the random access procedure to the RRC layer. If a problem occurs, the RRC considers that the UE's radio link has failed.

The second method is to detect whether the number of retransmissions of the RLC PDUs sent by the UE reaches a second threshold, and determine the radio link status of the UE when the number of retransmissions of the RLC PDUs sent by the UE reaches a second threshold. Failed for the wireless link;

Specifically, in this embodiment, the UE detects whether the transmitted RLC PDU reaches the maximum number of retransmissions through the RLC layer, and when the number of retransmissions of the transmitted RLC PDU reaches the maximum number of retransmissions, the RLC layer indicates that the RLC layer reaches the maximum. The number of retransmissions. After receiving the indication, the RRC considers that the radio link of the UE fails or the quality deteriorates, and the current cell is not suitable for providing the data transmission service.

Manner 3: determining the number of times when the number of consecutive retransmissions of the hybrid automatic repeat request HARQ reaches a set threshold, detecting whether the determined number of times reaches a set third threshold, and determining that the number of times reaches the third threshold, and determining The radio link status of the UE is a radio link failure;

Specifically, in this embodiment, when the UE sends a data packet, the HARQ reaches the maximum number of retransmissions, and the MAC layer indicates to the RRC that the HARQ reaches the maximum number of retransmissions, if the number of consecutive MAC layer indications received by the RRC layer reaches the set number. A three-threshold value is considered to be a failure of the radio link or that the current cell is not suitable for providing a data transmission service.

Optionally, the third threshold may be configured by the base station to the UE by using a broadcast or radio resource control RRC message. For example, the UE is configured by system information, RRC connection reconfiguration, RRC Connection Release, or new message.

Further, in an embodiment, the link repair module 920 performs link repair by initiating an application to resume the RRC connection, or initiating cell reselection.

Optionally, when the application for restoring the RRC connection is initiated, the indication message of the UE status or the indication information of the re-establishment reason is carried in the application message; or, when the cell reselection is initiated, the cell priority of the current cell is lowered.

Optionally, in an optional embodiment, the user equipment further includes:

The processing module 930 is configured to reset the MAC when the user equipment is in the preset state, and reset the MAC address due to the mobile reselection to the new cell, and/or clear the number of retransmissions of the RLC PDU sent by the currently recorded UE.

The user equipment in this embodiment may be in a state in which the user equipment is disconnected from the interface of the base station and the base station and the core network maintain the connection of the UE, and the data link of the user plane may be used to the wireless link of the user equipment. The state is detected, and when the radio link of the user equipment fails, the radio link repair is performed, which is convenient for adapting to the mobility of the UE in an inactive state, and can reduce the delay of data transmission, which is a good solution to the problem. The wireless link in the inactive state is monitored, which in turn affects the problem of data output.

One of ordinary skill in the art can understand that all or part of the steps of one or more of the above embodiments can be completed by a program to instruct related hardware, the program can be stored in a computer readable storage medium, the storage medium It can include: ROM, RAM, disk or CD, and so on.

Industrial applicability

The radio link monitoring method and user equipment provided by the present disclosure can not only adapt to the mobility of the UE in an inactive state, but also reduce the delay of data transmission, and solve the problem that the wireless link in the inactive state cannot be monitored, and thus A problem that affects data output.

Claims

A wireless link monitoring method includes:

When the user equipment UE is in the preset state, the state of the radio link of the UE is detected according to the data transmission situation of the user plane; wherein the preset state refers to that the interface between the UE and the base station is disconnected, and a state in which the base station and the core network maintain the connection of the UE;

When it is detected that the radio link of the UE fails, the radio link repair is performed.
The method according to claim 1, wherein the manner of detecting the state of the radio link of the UE according to the data transmission situation of the user plane comprises at least one of the following manners:

Determining whether the number of times the UE sends the preamble reaches the set first threshold, and determining that the radio link status of the UE is a radio link failure when the number of times the UE sends the preamble reaches the first threshold ;

Detecting whether the number of retransmissions of the radio link control layer protocol data unit RLC PDU sent by the UE reaches a set second threshold, and the number of retransmissions of the radio link control layer protocol data unit sent by the UE reaches the first Determining, by the second threshold, that the radio link status of the UE is a radio link failure;

Determining, according to the number of times when the number of consecutive retransmissions of the hybrid automatic repeat request HARQ reaches a set threshold, detecting whether the determined number of consecutive retransmission times of the HARQ reaches a set threshold value reaches a set third threshold, and determining When the number of consecutive HARQ consecutive retransmissions reaches the set threshold reaches the third threshold, it is determined that the radio link status of the UE is a radio link failure.
The method of claim 2, wherein the third threshold is threshold information that the base station configures to the UE by broadcast or radio resource control RRC message.
The method according to any one of claims 1 to 3, wherein said performing radio link repair comprises: initiating an application to resume an RRC connection, or initiating cell reselection.
The method of claim 4, wherein the request for initiating the restoration of the RRC connection comprises: initiating an application message for restoring an RRC connection, wherein the application message carries indication information of a UE status or indication information carrying a reestablishment reason;

The initiating cell reselection includes: lowering a cell priority of the current cell.
The method of claim 1 or 2, further comprising:

When the UE is in the preset state, when the UE reselects to connect to the new cell, performing at least one of the following operations: resetting the medium access control MAC, and transmitting the currently recorded UE The number of retransmissions of the RLC PDU is cleared.
A user equipment comprising:

The link detection module is configured to detect, according to the data transmission situation of the user plane, the state of the wireless link of the user equipment when the user equipment is in the preset state, where the preset state refers to the user equipment The interface disconnected from the base station, and the state in which the base station and the core network maintain the connection of the user equipment;

The link repair module is configured to perform radio link repair when the link detection module detects that the radio link of the user equipment fails.
The user equipment according to claim 7, wherein the manner in which the link detection module detects the state of the radio link of the UE comprises at least one of the following manners:

Determining whether the number of times the UE sends the preamble reaches the set first threshold, and determining that the radio link status of the UE is a radio link failure when the number of times the UE sends the preamble reaches the first threshold ;

Detecting whether the number of retransmissions of the radio link control layer protocol data unit RLC PDU sent by the UE reaches a set second threshold, and the number of retransmissions of the radio link control layer protocol data unit sent by the UE reaches the first Determining, by the second threshold, that the radio link status of the UE is a radio link failure;

Determining, according to the number of times when the number of consecutive retransmissions of the hybrid automatic repeat request HARQ reaches a set threshold, detecting whether the determined number of consecutive retransmission times of the HARQ reaches a set threshold value reaches a set third threshold, and determining When the number of consecutive HARQ consecutive retransmissions reaches the set threshold reaches the third threshold, it is determined that the radio link status of the UE is a radio link failure.
The user equipment according to claim 8, wherein the third threshold is threshold information that the base station configures to the UE by using a broadcast or radio resource control RRC message.
The user equipment according to any one of claims 7 to 9, wherein the link repair module is configured to initiate recovery of the RRC when the link detection module detects that the radio link of the user equipment fails. The application for the connection, or, initiates a cell reselection.
The user equipment of claim 10, wherein the link repair module is further configured to initiate an application message for restoring an RRC connection, where the application message carries indication information of a UE status or indication information carrying a reestablishment reason; The link repair module is further configured to: when the cell reselection is initiated, lower the cell priority of the current cell.
The user equipment of claim 7 or 8, further comprising:

a processing module, configured to: when the user equipment is in the preset state, perform the following at least one operation: resetting the medium access control MAC, and The recorded number of retransmissions of the RLC PDU sent by the UE is cleared.