WO2020198961A1

WO2020198961A1 - Link failure recovery method and device

Info

Publication number: WO2020198961A1
Application number: PCT/CN2019/080484
Authority: WO
Inventors: 王静; 李晨琬; 吴毅凌; 李振宇
Original assignee: 华为技术有限公司
Priority date: 2019-03-29
Filing date: 2019-03-29
Publication date: 2020-10-08
Also published as: CN113455097A

Abstract

Provided are a link failure recovery method and device. The method comprises: a second communication device sending a first radio resource control (RRC) connection re-establishment request message to a first communication device, wherein the first RRC connection re-establishment request message is used for requesting the re-establishment of an RRC connection between the second communication device and a network device; receiving a first RRC connection re-establishment message sent by the first communication device; and then re-establishing, according to the first RRC connection re-establishment message, a packet data convergence protocol (PDCP) and a radio link control (RLC) protocol of a signalling radio bearer (SRB) to recover an SRB of the second communication device, and then recover the RRC connection between the second communication device and the network device, that is, recovering a control plane of multi-hop communication between the second communication device and the network device.

Description

Recovery method and equipment for link failure

Technical field

This application relates to the field of communication technology, and in particular to a method and device for recovering from a link failure.

Background technique

In some communication application scenarios, such as power scenarios, the problem of insufficient base station coverage often occurs. In order to expand the coverage, at least one relay device is usually deployed. In this way, all terminals that are at the edge of the coverage of the base station or cannot be covered by the base station. The relay device can communicate with the base station to form a multi-hop communication link. Multi-hop communication technology can greatly improve the coverage of the base station, enabling more terminals to communicate with the base station.

In a multi-hop communication network, if a radio link failure (Radio Link Failure, RLF) occurs in one of the relay devices, the relay device and the node devices connected to the relay device cannot communicate with the base station. Therefore, in order to ensure that the relay device and the node device connected to the relay device communicate normally with the base station, it is necessary to perform link failure recovery processing. However, in the prior art, only the radio link failure recovery between the terminal and the base station in the one-hop communication mode is supported, and the link recovery after the RLF occurs in the relay device or the terminal device in the multi-hop communication mode is not supported.

Therefore, how to restore communication with the base station after the RLF occurs in the relay device is a technical problem to be solved urgently by those skilled in the art.

Summary of the invention

The present application provides a method and device for recovering from a link failure. After RLF occurs in the relay device, the communication with the base station is restored.

In the first aspect, an embodiment of the present application provides a method for recovering a link failure, and the method for recovering a link failure may

include:

Sending a first radio resource control RRC connection reestablishment request message to the first communication device, where the first RRC connection reestablishment request message is used to request the second communication device to reestablish an RRC connection with the network device;

Receiving the first RRC connection re-establishment message sent by the first communication device;

According to the first RRC connection re-establishment message, the packet data convergence protocol PDCP and the radio link control protocol RLC of the radio bearer SRB are restored to restore the SRB of the second communication device, thereby restoring the RRC between the second communication device and the network device The connection is to restore the control plane of the multi-hop communication between the second communication device and the network device.

In a possible implementation manner, after re-establishing the packet data convergence protocol PDCP and the radio link control protocol RLC of the signaling radio bearer SRB according to the first RRC connection re-establishment message, it may further include:

Send an RRC connection re-establishment complete message to the network device to notify the network device that its RRC connection re-establishment is complete.

In a possible implementation manner, the method may further include:

Rebuild the RLC of the data radio bearer DRB according to the first RRC connection reconfiguration message sent by the first communication device; and/or,

The PDCP of the DRB is reconstructed according to the second RRC connection reconfiguration message sent by the network device to restore the DRB, thereby further restoring the multi-hop communication user plane between the second communication device and the network device. In addition, through the link failure recovery between the second communication device and the network device, the child node device of the second communication device (the third communication device) is prevented from performing the reconstruction process, and the occurrence of the second communication device in the multi-hop link is reduced. After the RLF, the signaling overhead of the communication between the child node device of the second communication device and the base station is restored.

In a possible implementation manner, after re-establishing the RLC of the data radio bearer DRB according to the first RRC connection reconfiguration message sent by the first communication device, the method may further include:

Send a first RRC connection reconfiguration complete message to the first communication device.

In a possible implementation manner, after reestablishing the PDCP of the DRB according to the second RRC connection reconfiguration message sent by the network device, it may further include:

Send a second RRC connection reconfiguration complete message to the network device.

In a possible implementation, if the network device is different from the network device served by the second communication device before re-establishment, the method may further include:

Send the first indication information to the third communication device; the first indication information is used to instruct the third communication device to initiate the RRC connection re-establishment process.

In a possible implementation manner, the first indication information is carried in RRC signaling, media access control element MAC CE, or physical layer signaling.

In a possible implementation manner, the first indication information includes at least one of the following:

The cell identity, the carrier index corresponding to the cell synchronization channel, the dedicated cell radio network temporary identity C-RNTI or the random access channel RACH resource; where the cell is the cell served by the second communication device.

In a possible implementation manner, before sending the first indication information to the third communication device, the method may further include:

Receive the third RRC connection reconfiguration message sent by the network device; the third RRC connection reconfiguration message includes the cell identifier, the carrier index corresponding to the cell synchronization channel, the dedicated cell radio network temporary identifier C-RNTI, and the random access channel RACH resource ; Among them, the cell is a cell served by the second communication device;

According to the third RRC connection reconfiguration message, establish a cell or configure the cell so that other communication devices can search for the cell, and use the second communication device as the parent node (that is, access the second communication device) to communicate with the network Communicate between devices.

In the second aspect, embodiments of the present application also provide a method for recovering from a link failure, and the method for recovering from a link failure may include:

Receiving a first radio resource control RRC connection re-establishment request message sent by the second communication device, where the first RRC connection re-establishment request message is used to request the re-establishment of an RRC connection between the second communication device and the network device;

Send the first RRC connection reestablishment message to the second communication device.

In a possible implementation manner, before sending the first RRC connection reestablishment message to the second communication device, the method may further include:

Receiving the second RRC connection re-establishment message sent by the network device;

The first RRC connection re-establishment message is generated according to the second RRC connection re-establishment message, so that the second communication device re-establishes the packet data convergence protocol PDCP and the radio link control protocol RLC of the signaling radio bearer SRB according to the first RRC connection re-establishment message.

Send a second RRC connection re-establishment request message to the network device, where the second RRC connection re-establishment request message includes the identifier assigned by the first communication device to the second communication device.

In a possible implementation manner, the method may further include:

Generating the first RRC connection reconfiguration message according to the fourth RRC connection reconfiguration message sent by the network device;

The first RRC connection reconfiguration message is sent to the second communication device, so that the second communication device rebuilds the RLC of the data radio bearer DRB after receiving the first RRC connection reconfiguration message.

In a possible implementation manner, after sending the first RRC connection reconfiguration message to the second communication device, it may further include:

Receiving a first RRC connection reconfiguration complete message sent by the second communication device;

Send a fourth RRC connection reconfiguration complete message to the network device.

In the third aspect, an embodiment of the present application also provides a method for recovering from a link failure, and the method for recovering from a link failure may include:

Receiving a second radio resource control RRC connection re-establishment request message sent by the first communication device, where the second RRC connection re-establishment request message includes the identifier assigned by the first communication device to the second communication device;

Send a second RRC connection re-establishment message to the first communication device.

In a possible implementation manner, after sending the second RRC connection re-establishment message to the first communication device, it may further include:

Receive the RRC connection re-establishment complete message sent by the second communication device.

In a possible implementation manner, the method may further include:

Sending a fourth RRC connection reconfiguration message to the first communication device; the fourth RRC connection reconfiguration message is used to instruct the first communication device to reconfigure the bearer according to the fourth RRC connection reconfiguration message;

Send a second RRC connection reconfiguration message to the second communication device.

In a possible implementation manner, after sending the fourth RRC connection reconfiguration message to the first communication device, it may further include:

Receiving a fourth RRC connection reconfiguration complete message sent by the first communication device.

In a possible implementation manner, after sending the second RRC connection reconfiguration message to the second communication device, it may further include:

Receiving a second RRC connection reconfiguration complete message sent by the second communication device.

In a possible implementation manner, the method may further include:

Send a third RRC connection reconfiguration message to the second communication device; the third RRC connection reconfiguration message is used to instruct the second communication device to establish a cell or configure a cell, and the third RRC connection reconfiguration message includes a cell identifier and a cell synchronization channel Corresponding carrier index, dedicated cell radio network temporary identification C-RNTI, and random access channel RACH resource; among them, the cell is the cell served by the second communication device.

In a possible implementation manner, after sending the third RRC connection reconfiguration message to the second communication device, it may further include:

Receiving the third RRC connection reconfiguration complete message sent by the second communication device.

In a fourth aspect, an embodiment of the present application also provides a communication device, which may include:

The sending unit is configured to send a first radio resource control RRC connection re-establishment request message to the first communication device, where the first RRC connection re-establishment request message is used to request the second communication device to re-establish an RRC connection with the network device;

A receiving unit, configured to receive the first RRC connection re-establishment message sent by the first communication device;

The processing unit is configured to reconstruct the packet data convergence protocol PDCP and the radio link control protocol RLC of the signaling radio bearer SRB according to the first RRC connection re-establishment message.

In a possible implementation manner, the sending unit is also used to send an RRC connection re-establishment complete message to the network device.

In a possible implementation, the processing unit is further configured to reconstruct the RLC of the data radio bearer DRB according to the first RRC connection reconfiguration message sent by the first communication device; and/or, according to the second RRC sent by the network device The connection reconfiguration message rebuilds the PDCP of the DRB.

In a possible implementation manner, the sending unit is further configured to send a first RRC connection reconfiguration complete message to the first communication device.

In a possible implementation manner, the sending unit is further configured to send the second RRC connection reconfiguration complete message to the network device.

In a possible implementation, if the network device is different from the network device served by the second communication device before the reconstruction, the sending unit is also used to send the first indication information to the third communication device; the first indication information is used to indicate The third communication device initiates the RRC connection re-establishment process.

In a possible implementation, the receiving unit is further configured to receive a third RRC connection reconfiguration message sent by the network device; the third RRC connection reconfiguration message includes the cell identity, the carrier index corresponding to the cell synchronization channel, and the dedicated Cell radio network temporary identification C-RNTI and random access channel RACH resource; among them, the cell is the cell served by the second communication device;

The processing unit is further configured to establish a cell or configure a cell according to the third RRC connection reconfiguration message.

In a fifth aspect, an embodiment of the present application also provides a communication device, which may include:

The receiving unit is configured to receive a first radio resource control RRC connection re-establishment request message sent by the second communication device, where the first RRC connection re-establishment request message is used to request the second communication device to re-establish an RRC connection with the network device;

The sending unit is configured to send the first RRC connection reestablishment message to the second communication device.

In a possible implementation manner, the communication device may further include a processing unit;

The receiving unit is further configured to receive a second RRC connection re-establishment message sent by the network device;

The processing unit is configured to generate the first RRC connection reestablishment message according to the second RRC connection reestablishment message.

In a possible implementation manner, the sending unit is configured to send a second RRC connection re-establishment request message to the network device, where the second RRC connection re-establishment request message includes an identifier assigned by the first communication device to the second communication device.

In a possible implementation manner, the processing unit is further configured to generate the first RRC connection reconfiguration message according to the fourth RRC connection reconfiguration message sent by the network device;

The sending unit is further configured to send the first RRC connection reconfiguration message to the second communication device.

In a possible implementation manner, the receiving unit is further configured to receive the first RRC connection reconfiguration complete message sent by the second communication device;

The sending unit is further configured to send a fourth RRC connection reconfiguration complete message to the network device.

In a sixth aspect, an embodiment of the present application also provides a communication device, which may include:

A receiving unit, configured to receive a second radio resource control RRC connection re-establishment request message sent by the first communication device, where the second RRC connection re-establishment request message includes an identifier assigned by the first communication device to the second communication device;

The sending unit is configured to send a second RRC connection re-establishment message to the first communication device.

In a possible implementation manner, the receiving unit is further configured to receive the RRC connection re-establishment complete message sent by the second communication device.

In a possible implementation manner, the sending unit is further configured to send a fourth RRC connection reconfiguration message to the first communication device; the fourth RRC connection reconfiguration message is used to instruct the first communication device to reconfigure according to the fourth RRC connection Message reconfiguration bearer; and send a second RRC connection reconfiguration message to the second communication device.

In a possible implementation manner, the receiving unit is further configured to receive a fourth RRC connection reconfiguration complete message sent by the first communication device.

In a possible implementation manner, the receiving unit is further configured to receive the second RRC connection reconfiguration complete message sent by the second communication device.

In a possible implementation manner, the sending unit is further configured to send a third RRC connection reconfiguration message to the second communication device; the third RRC connection reconfiguration message is used to instruct the second communication device to establish a cell or configure a cell , The third RRC connection reconfiguration message includes the cell identity, the carrier index corresponding to the cell synchronization channel, the dedicated cell radio network temporary identification C-RNTI, and the random access channel RACH resource; where the cell is the cell served by the second communication device .

In a possible implementation manner, the receiving unit is further configured to receive the third RRC connection reconfiguration complete message sent by the second communication device.

In a seventh aspect, an embodiment of the present application further provides a communication device. The communication device may include a processor and a memory, where:

The memory is used to store program instructions;

The processor is configured to read the program instructions in the memory, and execute the link failure recovery method described in any one of the possible implementations of the first aspect according to the program instructions in the memory, or execute any one of the second aspects above The link failure recovery method described in the possible implementation manners, or the link failure recovery method described in any one of the possible implementation manners of the third aspect described above.

In an eighth aspect, an embodiment of the present application further provides a computer storage medium, including instructions. When the instructions are executed by one or more processors, the communication device executes any one of the possible implementations of the first aspect. Link failure recovery method, or execute the link failure recovery method described in any of the possible implementations of the second aspect, or execute the link described in any of the possible implementations of the third aspect Failed recovery method.

In a ninth aspect, an embodiment of the present application also provides a chip on which a computer program is stored. When the computer program is executed by a processor, it executes the link failure described in any one of the possible implementations of the first aspect. Recovery method, or execute the link failure recovery method described in any one of the possible implementation manners of the second aspect, or execute the link failure recovery method described in any of the possible implementation manners of the third aspect above .

In a tenth aspect, an embodiment of the present application also provides a communication system, which can be a first communication device, a second communication device, and a network device, where the second communication device is any possible implementation manner of the fourth aspect above In the communication device described in the above, the first communication device is the communication device described in any possible implementation manner of the fifth aspect, and the network device is the communication device described in any possible implementation manner of the sixth aspect above .

In the method and device for link failure recovery provided in the embodiments of the present application, the second communication device sends a first radio resource control RRC connection reestablishment request message to the first communication device, and the first RRC connection reestablishment request message is used to request the second communication device Re-establish the RRC connection with the network equipment; and receive the first RRC connection re-establishment message sent by the first communication device; and then re-establish the signaling according to the first RRC connection re-establishment message. The packet data convergence protocol PDCP and radio link control protocol of the radio bearer SRB RLC restores the SRB of the second communication device, thereby restoring the RRC connection between the second communication device and the network device, that is, restoring the control plane of multi-hop communication between the second communication device and the network device.

Description of the drawings

FIG. 1 is a schematic diagram of an application scenario provided by an embodiment of the application;

2 is a schematic flowchart of a method for recovering from a link failure provided by an embodiment of the application;

FIG. 3 is a schematic flowchart of another method for recovering a link failure according to an embodiment of the application;

4 is a schematic flowchart of another method for recovering from a link failure provided by an embodiment of the application;

FIG. 5 is a schematic diagram of a reconstruction failure provided by an embodiment of the application;

6 is a schematic diagram of a data recovery process provided by an embodiment of the application;

FIG. 7 is a schematic diagram of the format of a PDCP control PDU provided by an embodiment of the application;

FIG. 8 is a schematic diagram of another PDCP control PDU format provided by an embodiment of this application;

FIG. 9 is a schematic diagram of another PDCP control PDU format provided by an embodiment of this application;

FIG. 10 is a schematic diagram of the format of a PDCP control PDU provided by an embodiment of the application;

FIG. 11 is a schematic structural diagram of a communication device provided by an embodiment of this application;

FIG. 12 is a schematic structural diagram of another communication device provided by an embodiment of this application;

FIG. 13 is a schematic structural diagram of yet another communication device provided by an embodiment of this application;

FIG. 14 is a schematic structural diagram of a communication device provided by an embodiment of this application.

detailed description

The embodiments of this application can be applied to LTE systems, Enterprise LTE Discrete Spectrum Aggregation (eLTE-DSA) systems, and other communication systems, such as New Radio (NR) systems, the fifth generation (the fifth generation, 5G) mobile communication system or other mobile communication systems that may appear in the future.

Hereinafter, some terms in this application are explained to facilitate the understanding of those skilled in the art. It should be noted that when the solutions of the embodiments of this application are applied to 5G or other mobile communication systems that may appear in the future, the names of network devices and terminals may change, but this does not affect the implementation of the solutions of the embodiments of this application.

Figure 1 is a schematic diagram of an application scenario provided by an embodiment of the application. The communication system may include a terminal device, three communication devices, and a network device. The three communication devices are the first communication device, the second communication device, and the original device. Communication equipment, due to the limited coverage of network equipment, enables the terminal to communicate with the network equipment through the second communication equipment and the original communication equipment for data transmission, that is, the second communication equipment and the original communication equipment are used as relay equipment to achieve Communication between terminal equipment and network equipment. For example, in the uplink transmission process, the terminal device can transmit data to its parent node device, that is, the second communication device; the second communication device then transmits the data to its parent node device, that is, the original communication device; The original communication device transmits the data to the network device, thereby completing the data uplink transmission process. In the downlink transmission process, the network device can transmit data to the original communication device, and the original communication device transmits the data to its child node device, that is, the second communication device; the second communication device transmits the data to the terminal device, So as to complete the downlink transmission process of data. By arranging the second communication device and the original communication device between the terminal device and the network device, the coverage of the network device can be increased, so that more terminal devices can communicate with the network device. When the second communication device has a wireless link failure or a handover failure, which causes the link between the second communication device and the original communication device to be interrupted, at this time, the second communication device can access the first communication device and communicate with the first communication device. The device is determined to be the parent node device of the second communication device, so that the second communication device can implement communication with the network device through the first communication device. In the multi-hop communication mode, for a communication device, the communication device it accesses can be called the parent node.

Among them, terminal equipment, also known as terminal, user equipment (UE), is a device that provides users with voice and/or data connectivity, such as handheld devices with wireless connectivity, vehicle-mounted devices, and the Internet of Things. Equipment etc. Common terminal equipment includes, for example, mobile phones, tablet computers, laptops, palmtop computers, mobile internet devices (MID), power communication equipment, customer premises equipment (CPE), and wearable devices. Among them, Wearable devices include, for example, smart watches, smart bracelets, and pedometers.

Network equipment, also known as radio access network (RAN) equipment, is the access equipment that terminal equipment accesses to the mobile communication system in a wireless manner. It can be a base station NodeB, an evolved base station (evolved NodeB, eNB), transmission reception point (TRP), next generation NodeB (gNB) in 5G mobile communication system, base station in future mobile communication system or access node in WiFi system, etc.; also It is a module or unit that completes part of the functions of the base station. For example, it may be a centralized unit (CU) or a distributed unit (DU). The embodiment of the present application does not limit the specific technology and specific device form adopted by the radio access network device.

A relay device is a device that can provide data forwarding. For example, an integrated access and backhaul node (IAB node) can be accessed. The integrated access and backhaul node can not only provide data forwarding, but also Other communication devices provide wireless access services and wireless backhaul services. The communication equipment can be connected to the IAB node, and multi-hop communication with the network equipment through the IAB node. The relay device can also be a terminal device with a relay function, or a CPE.

It is understandable that when the second communication device can access the first communication device, the network device accessed by the first communication device may be connected to the original parent node device of the second communication device (that is, the original communication device). The network device of is the same network device, or it may be a different network device from the network device that the original communication device accesses. Hereinafter, the two possible scenarios will be described in detail through the embodiments shown in FIG. 2 and FIG. 3 respectively.

In the embodiments of the present application, "at least one" refers to one or more, and "multiple" refers to two or more. "And/or" describes the association relationship of the associated objects, indicating that there can be three relationships, for example, A and/or B, which can mean: A alone exists, A and B exist at the same time, and B exists alone. A and B can be singular or plural. In the text description of this application, the character "/" generally indicates that the associated objects before and after are in an "or" relationship.

In the first possible scenario, the network device accessed by the first communication device and the network device accessed by the original communication device are the same network device. For an example, please refer to Figure 2 which is an implementation of this application. The example provides a schematic flowchart of a method for recovering from a link failure, and the method for recovering from a link failure may include:

S201. The second communication device sends a first radio resource control (radio resource control, RRC) connection re-establishment request message to the first communication device.

Wherein, the first RRC connection reestablishment request message is used to request the reestablishment of the RRC connection between the second communication device and the network device.

It is understandable that after detecting that RLF occurs, the second communication device either fails in handover, or fails in integrity check, or fails in RRC connection reconfiguration, and sends the first RRC connection reestablishment request message to the first communication device. To request the second communication device to reestablish the RRC connection with the network device. For example, the first RRC connection re-establishment request message may include the reason for re-establishment and the identity information of the second communication device; wherein, the identity information of the second communication device may include: a short message authentication code (short message authentication code for integrity) , ShortMAC-I), the cell radio network temporary Identifier (C-RNTI) used by the second communication device when RLF occurs, and the physical cell ID (physical cell ID) of the serving cell when the second communication device generates RLF , PCI). For example, the first RRC connection reestablishment request message may be an RRCConnectionReestablishmentRequest-UR message.

The first communication device and the second communication device can be relay user equipment (relay yser equipment, Relay UE), or access and backhaul integrated node (integrated access and backhaul node, IAB node) or other communication with relay function equipment.

The network equipment can be a base station or an integrated base station (IAB Donor).

S202: The first communication device sends a second RRC connection re-establishment request message to the network device.

Wherein, the second RRC connection re-establishment request message includes the identifier allocated by the first communication device to the second communication device. For example, the identifier assigned by the first communication device to the second communication device is C-RNTI. For example, the second RRC connection reestablishment request message is an RRCConnectionReestablishmentRequest-IAB message.

After receiving the first RRC connection re-establishment request message, the first communication device assigns an identifier to the second communication device, and carries the identifier in the second RRC connection re-establishment request message and sends it to the network device to request the network device to perform the second The communication device needs to reestablish the RRC connection. For example, the second RRC connection re-establishment request message may also include the reason for re-establishment and the identity information of the second communication device; similarly, the identity information of the second communication device may include: shortMAC-I, used when RLF occurs in the second communication device The C-RNTI and the PCI of the serving cell when the second communication device generates RLF.

After assigning the identifier to the second communication device, the first communication device may send a second RRC connection re-establishment request message including the identifier of the second communication device to the network device, so that the network device receives the second RRC connection re-establishment request message , Execute the following S203:

S203: The network device sends a second RRC connection reestablishment message to the first communication device.

For example, the second RRC connection re-establishment message may include a security parameter, such as nextHopChainingCount, which is used by the second communication device to update the air interface key, so that the second communication device can update the air interface according to the updated air interface. The key is encrypted.

For example, the second RRC connection reestablishment message may include the C-RNTI of the second communication device, and is used to indicate that the second RRC connection reestablishment message is used to reestablish the RRC connection between the second communication device and the network device. For example, the second RRC connection reestablishment message may be an RRCConnectionReestablishment-IAB message.

S204. The first communication device sends a first RRC connection reestablishment message to the second communication device.

For example, the first RRC connection reestablishment message may include security parameters, such as the next hop chain count. Optionally, the first RRC connection reestablishment message may also include radio resource configuration information, and the configuration information may be one or more of the following: Items: RLC configuration information, logical channel configuration information, media access control address (MAC) configuration information, physical layer (PHY) configuration information, etc. For example, the first RRC connection reestablishment message may be an RRCConnectionReestablishment-UR message.

After the first communication device receives the second RRC connection re-establishment message sent by the network device, it generates a corresponding first RRC connection re-establishment message according to the second RRC connection re-establishment message, and passes it through the communication between the first communication device and the second communication device. The interface sends the first RRC connection reestablishment message to the second communication device.

S205. The second communication device re-establishes the packet data convergence protocol PDCP and the radio link control protocol RLC of the signaling radio bearer SRB according to the first RRC connection re-establishment message.

After receiving the first RRC connection re-establishment message sent by the first communication device, the second communication device rebuilds the packet data convergence protocol (PDCP) and radio link of the signaling radio bearer (SRB) The control protocol RLC performs radio resource configuration according to the received radio resource configuration information, thereby restoring the SRB of the second communication device, and using the security parameters carried in the first RRC connection re-establishment message to update the corresponding air interface key.

Optionally, the second communication device may send an RRC connection reestablishment complete message to the network device after reestablishing the packet data convergence protocol PDCP and radio link control protocol RLC of the radio bearer SRB according to the first RRC connection reestablishment message , To notify the network device that its RRC connection re-establishment is complete.

It can be seen that, in the embodiment of the present application, the second communication device sends a first RRC connection reestablishment request message to the first communication device, and the first communication device sends a second RRC connection reestablishment request message to the network device to request the network The second communication device needs to re-establish the RRC connection, and receives the first RRC connection re-establishment message generated by the second RRC connection re-establishment message sent by the first communication device, and then re-establishes the signaling radio bearer SRB according to the first RRC connection re-establishment message. Packet Data Convergence Protocol PDCP and Radio Link Control Protocol RLC restore the SRB of the second communication device, thereby restoring the RRC connection between the second communication device and the network device, that is, between the second communication device and the network device The control plane of multi-hop communication.

It is understandable that the PDCP and RLC of the SRB can be reconstructed through S201-S205 in the embodiment shown in FIG. 2 to restore the SRB, thereby restoring the multi-hop communication control plane between the second communication device and the network device. Based on the embodiment shown in Figure 2, further, the PDCP and RLC of the data radio bearers (DRB) can be reconstructed through the following S301-S306 to restore DRB, that is, restore the relationship between the second communication device and the network device. Inter-multi-hop communication user plane. For example, please refer to FIG. 3. FIG. 3 is a schematic flowchart of another link failure recovery method provided by an embodiment of the application, and the link failure recovery method may further include:

S301. The network device sends a fourth RRC connection reconfiguration message to the first communication device.

The fourth RRC connection reconfiguration message is used to instruct the first communication device to establish or reconfigure the bearer according to the fourth RRC connection reconfiguration message. For example, the fourth RRC connection reconfiguration message may include at least one of the following: C-RNTI of the second network device, quality of service (QoS) information of the second network device, and DRB ID.

For example, the fourth RRC connection reconfiguration message may be an RRCConnectionReconfiguration-IAB message or a RadioBearerSetUpRequest-IAB message.

For example, after determining that the RRC connection re-establishment of the second communication device is completed, the network device may send a fourth RRC connection reconfiguration message to the first communication device, so that the first communication device performs the following S302:

S302: The first communication device sends a first RRC connection reconfiguration message to the second communication device.

The first RRC connection reconfiguration message includes at least one of the following: DRB ID, logical channel ID, RLC configuration information, logical channel configuration information, MAC configuration information, PHY configuration information, etc. of the second communication device.

For example, the first RRC connection reconfiguration message is an RRCConnectionReconfiguration-UR message.

For example, after receiving the fourth RRC connection reconfiguration message, the first communication device may generate the corresponding first RRC connection reconfiguration message according to the fourth RRC connection reconfiguration message, and pass it between the first communication device and the second communication device. The inter-interface sends the first RRC connection reconfiguration message to the second communication device.

S303. After receiving the first RRC connection reconfiguration message, the second communication device rebuilds the RLC of the data radio bearer DRB.

After receiving the first RRC connection reconfiguration message sent by the first communication device, the second communication device reconstructs the RLC of the data DRB. Optionally, if the first RRC connection reconfiguration message includes radio resource configuration information, perform radio resource configuration according to the radio resource configuration information. Optionally, after re-establishing the RLC of the data DRB according to the first RRC connection reconfiguration message, the second communication device may also send a first RRC connection reconfiguration complete message to the first communication device to notify the first communication device of the RRC connection The reconfiguration process is complete. Correspondingly, after receiving the first RRC connection reconfiguration complete message, the first communication device will also send a fourth RRC connection reconfiguration complete message to the network device. For example, the fourth RRC connection reconfiguration complete message may carry the C-RNTI allocated by the first communication device to the second communication device. For example, the fourth RRC connection reconfiguration complete message may be an RRCConnectionReconfigurationComplete-IAB or RadioBearerSetupResponse-IAB message.

S304. The second communication device rebuilds the PDCP of the DRB.

For example, the network device sends the second RRC connection reconfiguration message to the second communication device. The second RRC connection reconfiguration message may include the DRB ID. Optionally, the second RRC connection reconfiguration message may also include radio resource configuration information, such as PDCP configuration information. After receiving the second RRC connection reconfiguration message, the second communication device re-establishes the PDCP of the DRB. If the second RRC connection reconfiguration message includes radio resource configuration information, perform radio resource configuration according to the radio resource configuration information, thereby restoring the first RRC connection reconfiguration message. 2. DRB of communication equipment. Optionally, after restoring the DRB, the second communication device may also send an RRC connection reconfiguration complete message to the network device to notify the network device that the RRC connection reconfiguration is complete and the DRB has been restored.

For example, after receiving the first RRC connection reconfiguration message sent by the first communication device, the second communication device re-establishes the PDCP of the DRB.

It should be understood that this application does not limit the sequence of steps S303 and S304, that is, S303 can be executed first, then S304, or S304 can be executed first, then S303, of course, S303 and S304 can also be executed at the same time, which can be carried out according to actual needs. Setting, here, the embodiment of the present application only takes the execution of S303 and then the execution of S304 as an example for description, but it does not mean that the embodiment of the present application is limited to this.

It can be seen that the PDCP and RLC of the DRB can be reconstructed through S301-S304 in the embodiment shown in FIG. 3 to restore the DRB, thereby further restoring the multi-hop communication user plane between the second communication device and the network device. In addition, through the link failure recovery between the second communication device and the network device, the child node device of the second communication device (the third communication device) is prevented from performing the reconstruction process, and the occurrence of the second communication device in the multi-hop link is reduced. After the RLF, the signaling overhead of the communication between the child node device of the second communication device and the base station is restored.

It should be noted that in the embodiment shown in FIG. 2 or FIG. 3, if the network device determines that the parent node of the second communication device has changed or it is determined that the second communication device has been rebuilt or switched to another network device, the network device still An RRC connection release message that can be sent to the original parent node device (original communication device) of the second communication device. The RRC connection release message is used to instruct the original communication device to release the stored context information and related radio resource configuration of the second communication device. information. For example, the RRC connection release message may carry the C-RNTI allocated by the original communication device to the second communication device, and is used to instruct the original communication device to release the stored context information and related radio resource configuration information of the second communication device. Correspondingly, after receiving the RRC connection release message, the original communication device releases the context information and related radio resource configuration information of the second communication device. For example, the RRC connection release message is an RRCConnectionRelease-IAB message.

The embodiments shown in Figures 2 and 3 above describe in detail that in a possible scenario, the network device that the second communication device accesses when RLF occurs and the network device corresponding to the second communication device's request to reestablish the RRC connection is In the same network device, how to realize the technical solution of link failure recovery, the following will describe in detail in another possible scenario, the network device connected to the second communication device when RLF occurs and the second communication device requests reconstruction When the network devices corresponding to the RRC connection are different network devices, how to realize the technical solution of link failure recovery. For an example, please refer to Figure 4, the recovery method of the link failure may include:

On the basis of the embodiment shown in FIG. 2, the difference from the above-mentioned embodiment shown in FIG. 2 is that the network device (the network device corresponding to the second communication device's request to re-establish the RRC connection) receives the data sent by the first communication device After the second RRC connection re-establishment request message, before sending the second RRC connection re-establishment message to the first communication device in S203, it needs to communicate with the original network device of the second communication device (that is, the network that the second communication device accesses when RLF occurs. Devices) communicate with each other to verify the reconstruction information of the second communication device and determine whether to reject the reconstruction request of the second communication device. For example, the network device may use the identity information of the second communication device, including shortMAC-I, the C-RNTI used when the second communication device generates RLF, and the PCI of the serving cell when the second communication device generates RLF, so that the original network device The identity information of the second communication device can be used to authenticate the identity of the second communication device, or the original network device can retrieve the context of the second communication device and send it to the network device. The identity is authenticated to determine the legitimacy of the second communication device.

It should be understood that the above S201-S205 and S301-S304 are also applicable to the link failure recovery of the terminal device in the multi-hop communication mode after RLF occurs.

In addition, the difference in the embodiment shown in FIG. 3 above is that after S304 the second communication device reconstructs the PDCP of the DRB according to the second RRC connection reconfiguration message sent by the network device, the following S401-S402 may also be included. For example, Please refer to FIG. 4. FIG. 4 is a schematic flowchart of another method for recovering from a link failure provided by an embodiment of the application, and the method for recovering from a link failure may further include:

S401: The network device sends a third RRC connection reconfiguration message to the second communication device.

The third RRC connection reconfiguration message is used to instruct the second communication device to establish a cell or configure a cell. For example, the third RRC connection reconfiguration message may include one or more of the following: cell identification, carrier index corresponding to the cell synchronization channel, cell radio network temporary identification C-RNTI set, random access channel RACH resource, downlink control Channel resources; where the cell is a cell served by the second communication device, and the C-RNTI set is used by the second communication device to allocate the C-RNTI to the child node device accessing the second communication device. For example, the cell may be a relay cell or an integrated IAB cell with access and backhaul. The child node device of the second communication device refers to the communication device that accesses the second communication device in the multi-hop communication mode.

Illustratively, the third RRC connection reconfiguration message is an RRCConnectionReconfiguration-IAB message.

S402: The second communication device establishes a cell or configures the cell according to the third RRC connection reconfiguration message.

After receiving the third RRC connection reconfiguration message, the second communication device can establish a cell or configure the cell according to the third RRC connection reconfiguration message, so that other communication devices can search for the cell and transfer the second As the parent node, the communication device communicates with the network device. Wherein, the cell is a cell served by the second communication device. For example, the cell may be a relay cell or an integrated IAB cell with access and backhaul.

Optionally, after establishing or configuring the cell according to the third RRC connection reconfiguration message, the second communication device may also send a third RRC connection reconfiguration complete message to the network device to notify the network device of the RRC connection reconfiguration. The configuration process is complete. For example, the third RRC connection reconfiguration complete message is an RRCConnectionReconfigurationComplete-IAB message.

It should be noted that after the link failure of the second communication device is restored, the second communication device also needs to instruct its child node device to initiate the RRC connection reestablishment process, and may send the first indication information to the third communication device.

The first indication information is used to instruct the third communication device to initiate an RRC connection re-establishment process. Optionally, the first indication information includes at least one of a cell identity, a carrier index corresponding to a cell synchronization channel, a dedicated cell radio network temporary identity C-RNTI, or a random access channel RACH resource. Wherein, the cell is a cell served by the second communication device. For example, the cell may be a relay cell or an integrated IAB cell with access and backhaul.

In detail, the first indication information may only include any one of the cell identifier, the carrier index corresponding to the cell synchronization channel, the dedicated cell radio network temporary identifier C-RNTI, or the random access channel RACH resource, or it may include the cell identifier. , Any two of the carrier index corresponding to the cell synchronization channel, the dedicated cell radio network temporary identification C-RNTI, or the random access channel RACH resource can also include the cell identification, the carrier index corresponding to the cell synchronization channel, and the dedicated Any three of the cell radio network temporary identification C-RNTI or random access channel RACH resources, of course, can also include the cell identification, the carrier index corresponding to the cell synchronization channel, the dedicated cell radio network temporary identification C-RNTI and random There are four access channel RACH resources, which can be specifically set according to actual needs. Here, the embodiment of the present application does not make specific restrictions.

Optionally, when the second communication device sends the first indication information to the third communication device, the first indication information may be carried in RRC signaling, media access control control element MAC CE, or physical layer signaling, which may be specifically based on Actual settings need to be performed, and the embodiments of the present application do not make specific limitations here. For example, the first indication information may be carried in the RRCConnectionReconfiguration-UR message or the RRCConnectionRelease-UR message.

It should be understood that, as another implementation method of instructing the third communication device to initiate the RRC connection reestablishment process, the second communication device may implicitly instruct the third communication device to initiate the RRC connection reestablishment process, for example, the second communication device stops being the third communication device. The communication device provides the communication service, thereby triggering the third communication device to detect the RLF and initiate the RRC connection re-establishment process.

Optionally, the original network device sends an RRC connection release-IAB message to the fourth communication device.

Wherein, the RRC connection release-IAB message is used to instruct the fourth communication device to release the context information and radio resource configuration information of the second communication device; the second communication device serves the fourth communication device before the reestablishment Community. In the embodiment of the present application, the fourth communication device is the original communication device.

It can be seen that through the embodiment shown in FIG. 4, the communication between the second communication device and the network device can also be restored. The difference from the embodiment shown in FIG. 3 is that the second communication device accesses when RLF occurs. The network device of is different from the network device corresponding to the request to reestablish the RRC connection.

It should be noted that the above-mentioned embodiments shown in Figures 2 to 4 describe in detail how the network device accessed by the second communication device when RLF occurs and the network device corresponding to the request to reestablish the RRC connection are the same network device. The technical solution to realize the recovery of the link failure, and the technical solution of how to realize the recovery of the link failure when the network device accessed by the second communication device when the RLF occurs and the network device corresponding to the request to reestablish the RRC connection are different network devices. In these two possible scenarios, the second communication device is successfully re-established. On the contrary, if the second communication device is in the process of link recovery, the second communication device initiates the RRC connection re-establishment process, but the re-establishment fails (by the network device Reject or find a suitable parent node), at this time, the second communication device can explicitly or implicitly instruct its child node device (that is, the third communication device) to trigger the third communication device to initiate the RRC connection re-establishment process to Make it find a new parent node device as a relay device to communicate with the network device. For an example, please refer to FIG. 5, which is a schematic diagram of a reconstruction failure provided by an embodiment of the application.

In addition, for the network device, if the network device does not receive the data sent by the second communication device within the first preset time period, it means that the second communication device has RLF failure or the second communication device has no service for a long time. The network device can release the context information and wireless resource configuration information of the second communication device. Among them, the first preset duration can be set according to actual needs. Here, the embodiment of the present application does not make specific limitations.

For example, the first preset duration can be implemented by a timer T1. The timer T1 can be maintained by the network device. If the timer T1 maintained by the network device times out, the network device releases the context information and related information of the second communication device. Configure information, and initiate routing update and bearer reconfiguration process. For timer T1, it is maintained by the network equipment and is a UE-specific timer (related to the service type). When receiving an uplink data packet sent by the corresponding UE or relay device, the timer T1 starts/restarts and starts timing. When T1 times out and the uplink data packet sent by the corresponding UE or relay device is no longer received, the network device releases the context information and radio resource configuration information of the corresponding UE or relay device.

Further, for the second communication device, if the second communication device does not receive the data sent by the third communication device within the second preset time period, it indicates that the third communication device has RLF failure or the third communication device has a long time If there is no service, the second communication device can release the context information and radio resource configuration information of the third communication device. Among them, the second preset duration can be set according to actual needs. Here, the embodiment of the present application does not make specific limitations.

For example, the second preset duration can be implemented by a timer T2, and the timer T2 can be maintained by the second communication device. If the timer T2 maintained by the second communication device expires, the second communication device releases the third communication device Context information and related configuration information, and initiate routing update and bearer reconfiguration process. For timer T2, it is maintained by the second communication device and configured by the network device. It is a UE specific timer (related to the service type). When an uplink data packet sent by the corresponding child node device is received, the timer T2 is started/restarted. Start timing, and if timer T2 times out and the uplink data packet sent by the corresponding child node device is not received anymore, the second communication device releases the context information and radio resource configuration information of the corresponding child node device.

For the third communication device, if the third communication device does not receive the data sent by the corresponding child node within the third preset time period, it indicates that the child node of the third communication device has failed in RLF or the child node of the third communication device If there is no service for a long time, the third communication device can release the context information and wireless resource configuration information of the corresponding child node. Among them, the third preset duration can be set according to actual needs. Here, the embodiment of the present application does not make specific limitations. The child node device of the third communication device refers to the communication device that accesses the third communication device in the multi-hop communication mode.

For example, the third preset duration can be realized by timer T3, which can be maintained by the third communication device. If the timer T3 maintained by the third communication device expires, the third communication device releases the corresponding child node device Context information and related configuration information, and initiate routing update and bearer reconfiguration process. For timer T3, it is maintained by the third communication device and configured by the network device. It is a UE-specific timer (related to the service type). When an uplink data packet sent by the corresponding child node device is received, the timer T3 starts/restarts. Start timing, if timer T3 times out and no longer receives the uplink data packet sent by the corresponding child node device, the third communication device releases the context information and radio resource configuration information of the corresponding child node device; or the third communication device triggers Leave the connected state by yourself.

Based on the embodiment shown in FIG. 3 or FIG. 4, the connection reconstruction of the second communication device and the reconfiguration process after the reconstruction can be realized. In the reconfiguration process of the second communication device, it is necessary to rebuild the RLC of the data radio bearer DRB according to the first RRC connection reconfiguration message, and then rebuild the PDCP of the DRB according to the second RRC connection reconfiguration message; or reconfigure according to the first RRC connection The message reconstruction data radio bears the RLC and PDCP of the DRB. In the RLC reconstruction process, the RLC cache data (including the data of the second communication device and the child node device of the second communication device) will be cleared, resulting in the second communication device and the child node device of the second communication device. data lost. When recovering the data lost during the RLC reconstruction process, the data lost during the uplink transmission process can be recovered, and the data lost during the downlink transmission process can also be recovered. For example, please refer to FIG. 6. FIG. 6 is a schematic diagram of a data recovery process provided by an embodiment of this application. The data recovery method may include:

S601: The network device sends uplink PDCP reception status information to the second communication device or its child node device.

The uplink PDCP reception status information may include: the sequence number (sequence number, SN) of the first missing uplink PDCP SDU or the first missing uplink PDCP PDU. Optionally, the uplink PDCP reception status information may further include a bitmap indicating whether each PDCP SDU is successfully received from the next PDCP SDU of the first missing PDCP service data unit (service data unit, SDU). Optionally, the uplink PDCP reception status information may also include a bitmap indicating whether each PDCP PDU is successfully received from the next PDCP PDU of the first lost PDCP protocol data unit (PDU). The child node of the second communication device refers to the communication device that accesses the second communication device in the multi-hop communication mode.

For example, when the network device sends uplink PDCP reception status information to the second communication device or its child node device, the uplink PDCP reception status information may be carried in the PDCP control PDU and sent to the second communication device or its child node device. It can be carried in an RRC message and sent to the second communication device or its child node device, and can be specifically set according to actual needs. Here, the embodiment of the present application does not further limit the manner of sending uplink PDCP reception status information. For example, when the uplink PDCP reception status information can be carried in the PDCP control PDU and sent to the second communication device or its child node device, please refer to FIG. 7, which is a PDCP control PDU provided by an embodiment of the application. Schematic diagram of the format. Optionally, in the PDCP control PDU format shown in FIG. 7, the value of the PDU type field can be 000 or 010 or 011. The value of the first missing SDU (first missing SDU, FMS) field is the first missing uplink PDCP SDU SN or the first missing uplink PDCP PDU SN. R is a reserved field. The Bitmap field is optional. D/C (data/control) indicates whether the PDCP PDU is a data PDU or a control PDU. By way of example, FIG. 8 is a schematic diagram of another PDCP control PDU format provided by an embodiment of the application. Among them, SR Type (status report type) is a status report type field, which is used to indicate the type of the status report. Different values correspond to different types and correspond to different receiving operations. For example, a value of 0 for SR Type indicates that the status report is used to retransmit PDCP PDU, and the corresponding operation of retransmitting PDCP PDU is performed after receiving the status report; when the value of SR Type is 1, it indicates that the status report is used for retransmission. Transmit the PDCP SDU, and perform the corresponding operation of retransmitting the PDCP SDU after receiving the status report. By way of example, FIG. 9 is a schematic diagram of another PDCP control PDU format provided by an embodiment of this application. For example, when the SR Type value is 01 or 00, it indicates that the status report is used to retransmit PDCP PDU, and the corresponding operation of retransmitting PDCP PDU is performed after receiving the status report; when the SR Type value is 10 or 01, it indicates The status report is used to retransmit the PDCP SDU, and the corresponding operation of retransmitting the PDCP SDU is performed after receiving the status report.

S602: The second communication device or its child node device receives uplink PDCP reception status information, and performs retransmission.

For example, the second communication device or its child node device performs a retransmission operation before reestablishing PDCP. Wherein, when the second communication device or its child node device performs the retransmission operation, it can start retransmission from the first missing PDCP SDU indicated by the uplink PDCP receiving status information, or transmit all PDCP SDUs that already have PDCP SN; or , Retransmit from the first missing PDCP SDU indicated by the uplink PDCP reception status information, or transmit all PDCP SDUs that already have PDCP SN, except for the successfully received PDCP SDU indicated by the bitmap; or, receive from the uplink PDCP The first PDCP SDU indicated by the status information and the first PDCP SDU that was not sent successfully indicated by the RLC layer to the PDCP layer, the corresponding PDCP SDU with a smaller COUNT value starts retransmission or transmission.

For example, the second communication device or its child node device performs a retransmission operation after receiving the uplink PDCP reception status information. Wherein, when the second communication device or its child node device performs the retransmission operation, it can start retransmission from the first lost PDCP PDU indicated by the uplink PDCP receiving status information, or transmit all the buffered PDCP PDUs; or, from the uplink PDCP receives the first lost PDCP PDU indicated by the status information and starts retransmission, or transmits all buffered PDCP PDUs, except for the successfully received PDCP PDU indicated by the bitmap; or, receives the first PDCP PDU indicated by the uplink PDCP status information. Among the first unsuccessfully sent PDCP PDUs indicated to the PDCP layer by the missing PDCP PDUs and the RLC layer, the earlier PDCP PDU with a smaller COUNT value starts retransmission or transmission. Optionally, if the SR Type field of the PDCP control PDU corresponding to the uplink PDCP reception status information indicates to perform the PDCP PDU retransmission operation, for example, the value of the SR Type field is 1 or 10 or 01.

For example, the second communication device or its child node device performs a retransmission operation after receiving the uplink PDCP reception status information. Wherein, when the second communication device or its child node device performs the retransmission operation, it can start retransmission from the first missing PDCP SDU indicated by the uplink PDCP receiving status information, or transmit all PDCP SDUs that already have PDCP SN; or , Retransmit from the first missing PDCP SDU indicated by the uplink PDCP reception status information, or transmit all PDCP SDUs that already have PDCP SN, except for the successfully received PDCP SDU indicated by the bitmap; or, receive from the uplink PDCP The first PDCP SDU indicated by the status information and the first PDCP SDU that was not sent successfully indicated by the RLC layer to the PDCP layer, the PDCP SDU with the smaller COUNT value and the earlier PDCP SDU starts retransmission or transmission. Optionally, if the SR Type field of the PDCP control PDU corresponding to the uplink PDCP reception status information indicates to perform the PDCP SDU retransmission operation, for example, the value of the SR Type field is 0 or 01 or 00.

It can be seen that, in the embodiment of the present application, the data lost during the uplink transmission can be recovered through the above S601 and S602.

S603: The second communication device or its child node device generates downlink PDCP reception status information.

Wherein, the downlink PDCP reception status information may include: the SN of the first lost downlink PDCP SDU or the SN of the first lost downlink PDCP PDU. Optionally, the downlink PDCP reception status information may also include a bitmap indicating whether each PDCP SDU is successfully received since the next PDCP SDU of the first missing PDCP SDU. Optionally, the uplink PDCP reception status information may also include a bitmap indicating whether each PDCP PDU is successfully received from the next PDCP PDU of the first lost PDCP protocol data unit (PDU).

For example, before the second communication device or its child node device reestablishes PDCP, and/or when the second communication device or its child node device is configured by RRC signaling to send downlink PDCP reception status information, the second communication device or its child node device The child node device can generate downlink PDCP reception status information.

For example, when the second communication device receives the polling information, the polling information is used to request the second communication device or its child node device to send downlink PDCP reception status information. The polling information may be a field of PDCP control PDU, or RRC signaling or PDCP data PDU. For example, when the polling information is a PDCP control PDU, the corresponding PDCP control PDU format can be seen in FIG. 10, which is a schematic diagram of a PDCP control PDU format provided by an embodiment of the application. Optionally, in the PDCP control PDU format shown in FIG. 10, the value of the type field of the PDU type can be 010 or 111.

S604: The second communication device or its child node device sends downlink PDCP reception status information to the network device.

After receiving the polling information, the second communication device or its child node device sends downlink PDCP reception status information.

For example, after receiving the polling information sent by the network device, the second communication device or its child node device sends downlink PDCP reception status information to the network device.

S605: The network device performs a retransmission operation according to the downlink PDCP reception status information.

For example, when a network device performs a retransmission operation, it can start retransmission or transmit all PDCP SDUs that already have PDCP SN from the first missing PDCP SDU indicated by the downlink PDCP receiving status information; or, receive the status information indication from the downlink PDCP Start the retransmission of the first missing PDCP SDU or transmit all PDCP SDUs that already have PDCP SN, except the successfully received PDCP SDU indicated by the bitmap; or, receive the first missing PDCP indicated by the downlink PDCP status information The earlier PDCP SDU among the first unsuccessfully sent PDCP SDU indicated by the SDU and RLC layer to the PDCP layer starts retransmission or transmission.

For example, when a network device performs a retransmission operation, it can start retransmission or transmit all PDCP PDUs from the first PDCP PDU indicated by the downlink PDCP reception status information; or, receive the first PDCP PDU indicated by the downlink PDCP status information. The PDCP PDU starts to retransmit or transmits all PDCP PDUs, except the successfully received PDCP PDU indicated by the bitmap; or, the first missing PDCP SDU indicated by the downlink PDCP reception status information and the first missing PDCP SDU indicated by the RLC layer to the PDCP layer The PDCP PDU corresponding to the smaller COUNT value among the unsuccessfully sent PDCP PDU starts to be retransmitted or transmitted.

It can be seen that in the embodiment of the present application, the data lost in the downlink transmission process can be recovered through the above S603-S605. It should be noted that there is no sequence between the above S601-S602 and S603-S605. You can execute the above S601-S602 first, and then execute S603-S605; you can also execute S603-S605 first, and then execute S601-S602; of course, The above S601-S602 and S603-S605 can also be executed at the same time. Here, the embodiment of this application only takes the above S601-S602 and then S603-S605 as an example for description, but it does not mean that the embodiment of the application is limited to this.

It can be understood that the above S601-S605 are not only applicable to child nodes of the second communication device, but also applicable to other lower-level nodes of the second communication device. The lower-level nodes of the second communication device include the child nodes of the second communication device, the child nodes of the child node of the second communication device, and so on. Wherein, the child node of the child node of the second communication device is a communication device that accesses the child node of the second communication device in the multi-hop communication mode.

It is understandable that the above S601-S605 are not limited to data recovery after RLF occurs in a communication device in a multi-hop network, and can also be applied to data recovery when a communication device in a multi-hop network is switched, which is not limited in this application .

It is understandable that the link failure recovery method provided in this application is not limited to communication devices that have RLF in a multi-hop network, but can also be applied to communication devices that fail RRC connection reconfiguration or communication devices that fail integrity verification Or the communication device that fails to switch, this application does not limit this.

FIG. 11 is a schematic structural diagram of a communication device 110 provided by an embodiment of the application. For an example, please refer to FIG. 11. The communication device 110 may include:

The sending unit 1101 is configured to send a first radio resource control RRC connection re-establishment request message to the first communication device, where the first RRC connection re-establishment request message is used to request the second communication device to re-establish an RRC connection with the network device.

The receiving unit 1102 is configured to receive the first RRC connection re-establishment message sent by the first communication device.

The processing unit 1103 is configured to reconstruct the packet data convergence protocol PDCP and the radio link control protocol RLC of the signaling radio bearer SRB according to the first RRC connection re-establishment message.

Optionally, the sending unit 1101 is further configured to send an RRC connection re-establishment complete message to the network device.

Optionally, the processing unit 1103 is further configured to rebuild the RLC of the data radio bearer DRB according to the first RRC connection reconfiguration message sent by the first communication device; and/or, according to the second RRC connection reconfiguration message sent by the network device Rebuild the PDCP of DRB.

Optionally, the sending unit 1101 is further configured to send a first RRC connection reconfiguration complete message to the first communication device.

Optionally, the sending unit 1101 is further configured to send a second RRC connection reconfiguration complete message to the network device.

Optionally, if the network device is different from the network device served before the second communication device is rebuilt, the sending unit 1101 is further configured to send first indication information to the third communication device; the first indication information is used to indicate the third communication device Initiate the RRC connection re-establishment process.

Optionally, the first indication information is carried in RRC signaling, media access control control element MAC CE, or physical layer signaling.

Optionally, the first indication information includes at least one of the following:

Optionally, the receiving unit 1102 is further configured to receive a third RRC connection reconfiguration message sent by a network device; the third RRC connection reconfiguration message includes a cell identity, a carrier index corresponding to a cell synchronization channel, and a dedicated cell wireless network temporary Identifies the C-RNTI and the random access channel RACH resource; where the cell is the cell served by the second communication device;

The processing unit 1103 is further configured to establish a cell or configure a cell according to the third RRC connection reconfiguration message.

The communication device 110 shown in the embodiment of the present application can execute the method for recovering the link failure on the second communication device side in the embodiment shown in FIG. 2 to FIG. 6. The implementation principle and beneficial effects are similar to those on the second communication device side. The implementation principles and beneficial effects of the method for recovering from a link failure are similar, and will not be repeated here.

FIG. 12 is a schematic structural diagram of another communication device 120 provided by an embodiment of the application. For an example, please refer to FIG. 12, the communication device 120 may include:

The receiving unit 1201 is configured to receive a first radio resource control RRC connection re-establishment request message sent by the second communication device, where the first RRC connection re-establishment request message is used to request the second communication device to re-establish an RRC connection with the network device.

The sending unit 1202 is configured to send the first RRC connection reestablishment message to the second communication device.

Optionally, the communication device 120 may further include a processing unit 1203.

The receiving unit 1201 is further configured to receive the second RRC connection re-establishment message sent by the network device.

The processing unit 1203 is configured to generate a first RRC connection reestablishment message according to the second RRC connection reestablishment message.

Optionally, the sending unit 1202 is configured to send a second RRC connection re-establishment request message to the network device, where the second RRC connection re-establishment request message includes the identifier assigned by the first communication as the second communication device.

Optionally, the processing unit 1203 is further configured to generate the first RRC connection reconfiguration message according to the fourth RRC connection reconfiguration message sent by the network device.

The sending unit 1202 is further configured to send the first RRC connection reconfiguration message to the second communication device.

Optionally, the receiving unit 1201 is further configured to receive the first RRC connection reconfiguration complete message sent by the second communication device.

The sending unit 1202 is further configured to send a fourth RRC connection reconfiguration complete message to the network device.

The communication device 120 shown in the embodiment of the present application can execute the method for recovering the link failure on the first communication device side in the embodiment shown in FIG. 2 to FIG. 6, and its implementation principle and beneficial effects are similar to those on the first communication device side. The implementation principles and beneficial effects of the method for recovering from a link failure are similar, and will not be repeated here.

FIG. 13 is a schematic structural diagram of another communication device 130 provided by an embodiment of this application. For an example, please refer to FIG. 13. The communication device 130 may include:

The receiving unit 1301 is configured to receive a second radio resource control RRC connection re-establishment request message sent by the first communication device, where the second RRC connection re-establishment request message includes an identifier allocated by the first communication device to the second communication device.

The sending unit 1302 is configured to send a second RRC connection re-establishment message to the first communication device.

Optionally, the receiving unit 1301 is further configured to receive an RRC connection re-establishment complete message sent by the second communication device.

Optionally, the sending unit 1302 is further configured to send a fourth RRC connection reconfiguration message to the first communication device; the fourth RRC connection reconfiguration message is used to instruct the first communication device to reconfigure the bearer according to the fourth RRC connection reconfiguration message ; And send a second RRC connection reconfiguration message to the second communication device.

Optionally, the receiving unit 1301 is further configured to receive a fourth RRC connection reconfiguration complete message sent by the first communication device.

Optionally, the receiving unit 1301 is further configured to receive a second RRC connection reconfiguration complete message sent by the second communication device.

Optionally, the sending unit 1302 is further configured to send a third RRC connection reconfiguration message to the second communication device; the third RRC connection reconfiguration message is used to instruct the second communication device to establish a cell or configure a cell, and the third RRC The connection reconfiguration message includes the cell identifier, the carrier index corresponding to the cell synchronization channel, the dedicated cell radio network temporary identifier C-RNTI, and the random access channel RACH resource; the cell is the cell served by the second communication device.

Optionally, the receiving unit 1301 is further configured to receive a third RRC connection reconfiguration complete message sent by the second communication device.

The communication device 130 shown in the embodiment of the present application can perform the method for recovering the link failure on the network device side in the embodiment shown in FIG. 2 to FIG. 6, and its implementation principle and beneficial effects are similar to the link failure on the network device side. The implementation principle and beneficial effects of the recovery method of, are similar, and will not be repeated here.

FIG. 14 is a schematic structural diagram of a communication device 140 provided by an embodiment of this application. For an example, please refer to FIG. 14. The communication device 140 may include a processor 1401 and a memory 1402, where:

The memory 1402 is used to store program instructions;

The processor 1401 is configured to read the program instructions in the memory 1402, and execute the method for recovering the link failure on the second communication device side in the embodiment shown in FIGS. 2-6 according to the program instructions in the memory 1402, or execute The method for recovering the link failure on the side of the first communication device in the embodiment shown in Figs. 2-6, or the method for recovering the link failure on the network device side in the embodiment shown in Figs. 2-6, The implementation principle and beneficial effects are similar to the implementation principles and beneficial effects of the link failure recovery method, and will not be repeated here.

The embodiment of the present application also provides a communication system, which can be a first communication device, a second communication device, and a network device, wherein the first communication device is used to execute the first communication device in the embodiment shown in FIG. 2 to FIG. A method for restoring a link failure on the communication device side. The second communication device is used to perform the method for restoring a link failure on the second communication device side in the embodiments shown in FIGS. 2-6. The network device is used to perform the above The implementation principle and beneficial effects of the method for restoring a link failure on the network device side in the embodiments shown in FIGS. 2 to 6 are similar to those of the method for restoring a link failure and will not be repeated here.

The embodiment of the present application also provides a computer storage medium, including instructions, when the instructions are executed by one or more processors, the communication device is caused to execute the chain on the second communication device side in the embodiment shown in FIG. 2 to FIG. 6. The method for restoring the path failure, or the method for restoring the link failure on the first communication device side in the embodiment shown in Figure 2 to Figure 6, or the method for restoring on the network device side in the embodiment shown in Figure 2 to Figure 6 above The implementation principle and beneficial effects of the method for restoring a link failure are similar to those of the method for restoring a link failure, and will not be repeated here.

The embodiment of the present application also provides a chip on which a computer program is stored. When the computer program is executed by the processor, the recovery of the link failure on the second communication device side in the embodiment shown in FIGS. 2 to 6 is performed. Method, or execute the method for recovering the link failure on the first communication device side in the embodiment shown in Figure 2 to Figure 6, or execute the link failure on the network device side in the embodiment shown in Figure 2 to Figure 6 above The implementation principle and beneficial effects of the recovery method for the link failure are similar to the implementation principles and beneficial effects of the recovery method for link failure, and will not be repeated here.

The processor in each of the foregoing embodiments may be a general-purpose processor, a digital signal processor (digital signal processor, DSP), an application specific integrated circuit (ASIC), and a field programmable gate array (FPGA) Or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like. The steps of the method disclosed in the embodiments of the present application may be directly embodied as being executed and completed by a hardware decoding processor, or executed and completed by a combination of hardware and software modules in the decoding processor. The software module can be located in random access memory (RAM), flash memory, read-only memory (read-only memory, ROM), programmable read-only memory, or electrically erasable programmable memory, registers, etc. mature in the field Storage medium. The storage medium is located in the memory, and the processor reads the instructions in the memory and completes the steps of the above method in combination with its hardware.

In the several embodiments provided in this application, it should be understood that the disclosed device and method may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components can be combined or It can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

In addition, the functional units in each embodiment of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware, or may be implemented in the form of hardware plus software functional units.

Claims

A method for recovering from link failure, which is characterized in that it includes:

Sending a first radio resource control RRC connection reestablishment request message to the first communication device, where the first RRC connection reestablishment request message is used to request the second communication device to reestablish an RRC connection with the network device;

Receiving the first RRC connection reestablishment message sent by the first communication device;

According to the first RRC connection re-establishment message, the packet data convergence protocol PDCP and the radio link control protocol RLC of the signaling radio bearer SRB are reconstructed.
The method according to claim 1, wherein after re-establishing the packet data convergence protocol PDCP and radio link control protocol RLC of the signaling radio bearer SRB according to the first RRC connection re-establishment message, the method further comprises:

Send an RRC connection re-establishment complete message to the network device.
The method according to claim 1 or 2, wherein the method further comprises:

Re-establish the RLC of the data radio bearer DRB according to the first RRC connection reconfiguration message sent by the first communication device; and/or,

The PDCP of the DRB is reconstructed according to the second RRC connection reconfiguration message sent by the network device.
The method according to any one of claims 1 to 3, wherein if the network device is different from the network device served by the second communication device before re-establishment, the method further comprises:

Send first indication information to a third communication device; the first indication information is used to instruct the third communication device to initiate an RRC connection re-establishment process; wherein, the first indication information is carried in RRC signaling, media access control Control element MAC CE or physical layer signaling.
The method according to claim 4, wherein:

The first indication information includes at least one of the following:

Cell identification, carrier index corresponding to the cell synchronization channel, dedicated cell radio network temporary identification C-RNTI or random access channel RACH resource; wherein, the cell is a cell served by the second communication device.
The method according to claim 4 or 5, wherein before the sending the first indication information to the third communication device, the method further comprises:

Receive the third RRC connection reconfiguration message sent by the network device; the third RRC connection reconfiguration message includes the cell identifier, the carrier index corresponding to the cell synchronization channel, the dedicated cell radio network temporary identifier C-RNTI, and the random access Incoming channel RACH resource; wherein, the cell is a cell served by the second communication device;

According to the third RRC connection reconfiguration message, establish the cell or configure the cell.
A method for recovering from link failure, which is characterized in that it includes:

Receiving a first radio resource control RRC connection re-establishment request message sent by the second communication device, where the first RRC connection re-establishment request message is used to request the re-establishment of an RRC connection between the second communication device and the network device;

Sending a first RRC connection reestablishment message to the second communication device.
The method according to claim 7, wherein before the sending the first RRC connection re-establishment message to the second communication device, the method further comprises:

Receiving a second RRC connection reestablishment message sent by the network device;

The first RRC connection reestablishment message is generated according to the second RRC connection reestablishment message.
The method according to claim 7 or 8, wherein before the sending the first RRC connection re-establishment message to the second communication device, the method further comprises:

A second RRC connection reestablishment request message is sent to the network device, where the second RRC connection reestablishment request message includes an identifier allocated by the first communication device to the second communication device.
The method according to any one of claims 7-9, wherein the method further comprises:

Generating a first RRC connection reconfiguration message according to the fourth RRC connection reconfiguration message sent by the network device;

Sending the first RRC connection reconfiguration message to the second communication device.
A method for recovering from link failure, which is characterized in that it includes:

Receiving a second radio resource control RRC connection re-establishment request message sent by the first communication device, where the second RRC connection re-establishment request message includes the identifier assigned by the first communication device to the second communication device;

Sending a second RRC connection reestablishment message to the first communication device.
The method according to claim 11, wherein after the sending a second RRC connection re-establishment message to the first communication device, the method further comprises:

Receiving the RRC connection re-establishment complete message sent by the second communication device.
The method according to claim 11 or 12, wherein the method further comprises:

Sending a fourth RRC connection reconfiguration message to the first communication device; the fourth RRC connection reconfiguration message is used to instruct the first communication device to reconfigure a bearer according to the fourth RRC connection reconfiguration message;

Sending a second RRC connection reconfiguration message to the second communication device.
The method according to any one of claims 11-13, wherein the method further comprises:

Send a third RRC connection reconfiguration message to the second communication device; the third RRC connection reconfiguration message is used to instruct the second communication device to establish a cell or configure a cell; the third RRC connection reconfiguration The message includes a cell identification, a carrier index corresponding to a cell synchronization channel, a dedicated cell radio network temporary identification C-RNTI, and a random access channel RACH resource; wherein, the cell is a cell served by the second communication device.
A communication device, characterized by comprising:

A sending unit, configured to send a first radio resource control RRC connection re-establishment request message to the first communication device, where the first RRC connection re-establishment request message is used to request the second communication device to re-establish an RRC connection with the network device;

A receiving unit, configured to receive a first RRC connection reestablishment message sent by the first communication device;

The processing unit is configured to reestablish the packet data convergence protocol PDCP and the radio link control protocol RLC of the signaling radio bearer SRB according to the first RRC connection reestablishment message.
The device according to claim 15, wherein:

The sending unit is further configured to send an RRC connection re-establishment complete message to the network device.
The device according to claim 15 or 16, characterized in that:

The processing unit is further configured to reconstruct the RLC of the data radio bearer DRB according to the first RRC connection reconfiguration message sent by the first communication device; and/or according to the second RRC connection reconfiguration message sent by the network device Rebuild the PDCP of DRB.
The device according to any one of claims 15-17, wherein if the network device is different from the network device served by the second communication device before reconstruction, the sending unit is further configured to send The communication device sends first indication information; the first indication information is used to instruct the third communication device to initiate an RRC connection re-establishment process; wherein, the first indication information is carried in RRC signaling, media access control control element MAC CE or physical layer signaling.
The device of claim 18, wherein:

The first indication information includes at least one of the following:

Cell identification, carrier index corresponding to the cell synchronization channel, dedicated cell radio network temporary identification C-RNTI or random access channel RACH resource; wherein, the cell is a cell served by the second communication device.
The device according to claim 18 or 19, characterized in that:

The receiving unit is further configured to receive a third RRC connection reconfiguration message sent by the network device; the third RRC connection reconfiguration message includes a cell identity, a carrier index corresponding to a cell synchronization channel, and a dedicated cell wireless network Temporary identification C-RNTI and random access channel RACH resource; wherein, the cell is a cell served by the second communication device;

The processing unit is further configured to establish or configure the cell according to the third RRC connection reconfiguration message.
A communication device, characterized by comprising:

The receiving unit is configured to receive a first radio resource control RRC connection re-establishment request message sent by the second communication device, where the first RRC connection re-establishment request message is used to request the second communication device to re-establish an RRC connection with the network device;

The sending unit is configured to send the first RRC connection reestablishment message to the second communication device.
The device according to claim 21, wherein the communication device further comprises a processing unit;

The receiving unit is further configured to receive a second RRC connection re-establishment message sent by the network device;

The processing unit is configured to generate the first RRC connection reestablishment message according to the second RRC connection reestablishment message.
The device according to claim 21 or 22, wherein:

The sending unit is configured to send a second RRC connection reestablishment request message to the network device, where the second RRC connection reestablishment request message includes an identifier allocated by the first communication device to the second communication device.
The device according to claim 22, wherein:

The processing unit is further configured to generate a first RRC connection reconfiguration message according to a fourth RRC connection reconfiguration message sent by the network device;

The sending unit is further configured to send the first RRC connection reconfiguration message to the second communication device.
A communication device, characterized by comprising:

A receiving unit, configured to receive a second radio resource control RRC connection re-establishment request message sent by the first communication device, where the second RRC connection re-establishment request message includes the identifier assigned by the first communication device to the second communication device;

The sending unit is configured to send a second RRC connection reestablishment message to the first communication device.
The device according to claim 25, wherein:

The receiving unit is further configured to receive an RRC connection re-establishment complete message sent by the second communication device.
The device according to claim 25 or 26, wherein:

The sending unit is further configured to send a fourth RRC connection reconfiguration message to the first communication device; the fourth RRC connection reconfiguration message is used to instruct the first communication device to reconfigure according to the fourth RRC connection The configuration message reconfigures the bearer; and sends a second RRC connection reconfiguration message to the second communication device.
The device according to any one of claims 25-27, wherein:

The sending unit is further configured to send a third RRC connection reconfiguration message to the second communication device; the third RRC connection reconfiguration message is used to instruct the second communication device to establish a cell or configure a cell, The third RRC connection reconfiguration message includes a cell identity, a carrier index corresponding to a cell synchronization channel, a dedicated cell radio network temporary identity C-RNTI, and a random access channel RACH resource; wherein, the cell is the second The cell served by the communication device.
A communication device is characterized by comprising a processor and a memory, wherein:

The memory is used to store program instructions;

The processor is configured to read the program instructions in the memory, and execute the link failure recovery method according to any one of claims 1-6 according to the program instructions in the memory, or execute claims 7-10 Any one of the link failure recovery method, or implement the link failure recovery method according to any one of claims 11-14.
A computer storage medium, comprising instructions, characterized in that, when the instructions are run by one or more processors, cause a communication device to execute the method for recovering a link failure according to any one of claims 1 to 6, or Perform the link failure recovery method according to any one of claims 7-10, or perform the link failure recovery method according to any one of claims 11-14.