CN109936878A - A kind of method and terminal device of triggering state recovery - Google Patents

Abstract

The present application provides a method for triggering state recovery and a terminal device. The method includes: when the terminal device is in the RRC inactive state, after determining that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state, sending a request to the network device for the The first message that the terminal device is restored from the RRC inactive state to the RRC connected state; and then can be restored to the RRC connected state under the control of the network device, and receives a message sent by the network device to indicate that the terminal device has been restored. It is the second message in the RRC connected state. Specifically, the preset conditions may include at least one of the following conditions: the RAN notification area of the radio access network where the terminal equipment is located is updated; the RAN notification area where the terminal equipment is located has not been updated within a preset time period ; the size of the data packet to be sent by the terminal device is greater than the preset threshold.

Description

Method for triggering state recovery and terminal device

technical field

The present application relates to the field of communication technologies, and in particular, to a method for triggering state recovery and a terminal device.

Background technique

In a communication system, such as a Long Term Evolution (Long Term Evolution, LTE) system, a New Radio (New Radio, NR) system, etc., when data transmission needs to be performed between a terminal device and a network device (eg, a base station), the terminal device and the network A radio resource control (Radio Resource Control, RRC) connection needs to be established between the devices first, and then data transmission can be performed between the terminal device and the network device.

Currently, in the LTE system, two RRC states are defined for terminal equipment: RRC Connected (RRC connected state) and RRC Idle (RRC idle state). Among them, when the terminal device is in the RRC connected state, it can perform data transmission with the network device. When the terminal device is in the RRC idle state, it cannot perform data transmission with the network device, but can perform cell reselection and detect paging messages sent by the network device. . Since the terminal equipment switches back and forth between the RRC connected state and the RRC idle state, it will generate more signaling overhead and the switching time is too long. Therefore, in the new-generation NR system, the terminal equipment is in the RRC connected state and the RRC idle state. An intermediate state is also introduced between the states: RRC Inactive (RRC inactive state), and it is defined that when the terminal device is in the RRC inactive state, it can not only perform cell reselection and detect paging messages sent by the network device, but also Able to send and receive small data packet services. However, although the concept of the RRC inactive state is proposed in the NR system, how to trigger the terminal equipment to recover from the RRC inactive state to the RRC connected state is still an urgent problem to be solved in the current NR system.

SUMMARY OF THE INVENTION

The present application provides a method for triggering state recovery and a terminal device, so as to trigger the terminal device to recover from an RRC inactive state to an RRC connected state.

In a first aspect, the present application provides a method for triggering state recovery. When a terminal device is in a RRC inactive state, it can be determined that the terminal device meets a preset condition for recovering from an RRC inactive state to an RRC connected state. , send a first message to the network device, where the first message is used to request that the terminal device be restored from the RRC inactive state to the RRC connected state; and the terminal device can be restored to the RRC state under the control of the network device connected state, and can receive a second message sent by the network device, where the second message is used to indicate that the terminal device has returned to the RRC connected state. Wherein, the preset condition includes at least one of the following conditions: a radio access network (Radio Access Network, RAN) notification area where the terminal device is located is updated; the RAN notification area includes at least one cell; the The RAN notification area where the terminal device is located has not been updated within a preset time period; the size of the data packet to be sent by the terminal device is greater than the preset threshold.

The above method provides that the terminal device complies with the preset condition for returning from the RRC inactive state to the RRC connected state. The first message that the device is restored from the RRC inactive state to the RRC connected state, and then can be restored to the RRC connected state under the control of the network device, thereby realizing the recovery process of the terminal device from the RRC inactive state to the RRC connected state.

In a possible implementation manner, when it is determined that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state, the non-access stratum entity, the RRC layer entity, or the service data adaptation A protocol (Service Data Adaptation Protocol, SDAP) is used to detect whether the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state.

Specifically, the non-access layer entity and the RRC layer entity of the terminal device may detect that the RAN notification area where the terminal device is located is updated, or detect that the RAN notification area where the terminal device is located has not been updated within a preset period of time. , it is determined that the terminal equipment meets the preset condition for returning from the RRC inactive state to the RRC connected state, wherein the RAN notification area includes at least one cell.

The SDAP entity of the terminal device may determine that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state after detecting that the size of the data packet to be sent by the terminal device is greater than the preset threshold. In addition, the SDAP entity of the terminal device may also notify the RRC layer entity or the non-access layer entity of the detection result, so that the RRC layer entity or the non-access layer entity of the terminal device initiates the RRC connected state recovery process.

In a possible implementation manner, the first message is a non-access stratum message or an RRC message.

Wherein, if the first message is a non-access stratum message, the terminal device may notify the non-access stratum entity through the SDAP entity or the RRC layer entity that the terminal device complies with the recovery from the RRC inactive state to the RRC connected state After the preset condition is set, the first message is sent to the network device.

If the first message is an RRC message, the terminal device may send the first message to the network device after notifying the RRC layer entity through the SDAP entity that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state a message.

In the above manner, different protocol entities inside the terminal device can support the operation of determining that the terminal device complies with the preset condition for returning from the RRC inactive state to the RRC connected state. Accordingly, when it is determined that the terminal device meets the preset condition Afterwards, the recovery process of the RRC connected state can also be triggered through different protocol entities.

In a possible implementation manner, the first message includes identification information of the terminal device, so that the network device can determine which terminal device's RRC connection to restore according to the identification information of the terminal device.

In a possible implementation manner, the first message includes the identification information of the terminal device and the identification information of the RAN notification area where the terminal device is currently located. In this way, the network device is in the process of restoring the RRC connection of the terminal device. During the process, an update process of the RAN notification area may also be performed, and the identification information of the RAN notification area previously recorded in the network device is replaced with the updated identification information of the RAN notification area.

In a possible implementation manner, the first message includes identification information of the terminal device and identification information of a Data Radio Bearer (DRB) requested to be rebuilt for the terminal device, so that the network device can When restoring the RRC connection of the terminal device, a DRB can be created according to the requirements of the terminal device.

In a possible implementation manner, the second message is a non-access stratum message or an RRC message. Specifically, if the first message is a non-access stratum message, the second message is also a non-access stratum message; if the first message is an RRC layer message, the second message is also an RRC layer message. In this way, the interaction process between the terminal device and the network device can be consistent, that is, the terminal device triggers the recovery process of the RRC connected state through the non-access stratum entity, and accordingly, the core network device feeds back the RRC connected state to the terminal device. Response of successful restoration; the terminal device triggers the restoration process of the RRC connected state through the RRC layer entity, and accordingly, the RAN device feeds back the response of the successful restoration of the RRC connected state to the terminal device.

In a second aspect, the present application further provides a terminal device for triggering state recovery, the terminal device including a determining unit, a sending unit, a restoring unit, and a receiving unit;

Wherein, the determining unit is configured to determine that the terminal equipment in the RRC inactive state meets the preset condition for returning from the RRC inactive state to the RRC connected state; the preset condition includes at least one of the following conditions: the terminal equipment The RAN notification area of the radio access network where the equipment is located is updated; the RAN notification area includes at least one cell; the RAN notification area where the terminal equipment is located has not been updated within a preset time period; the terminal equipment is to send The size of the packet is larger than the preset threshold.

A sending unit, configured to send a first message to a network device, where the first message is used to request to restore the terminal device from an RRC inactive state to an RRC connected state.

A restoration unit, configured to restore to the RRC connected state under the control of the network device.

A receiving unit, configured to receive a second message sent by the network device, where the second message is used to indicate that the terminal device has returned to the RRC connection state.

In a possible implementation manner, the determining unit may detect through the non-access stratum entity of the terminal device that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state; or, by The RRC layer entity of the terminal device detects that the terminal device meets the preset conditions for returning from the RRC inactive state to the RRC connected state; or, detects through the SDAP entity of the terminal device that the terminal device conforms to the RRC inactive state. A preset condition for the active state to return to the RRC connected state.

In a possible implementation manner, the first message is a non-access stratum message or an RRC message.

Wherein, if the first message is a non-access stratum message, before sending the first message to the network device, the sending unit may also notify the non-access stratum entity through the SDAP entity or the RRC layer entity of the terminal device The terminal equipment complies with the preset condition for returning from the RRC inactive state to the RRC connected state.

Wherein, if the first message is an RRC message, before sending the first message to the network device, the sending unit may also use the SDAP entity of the terminal device to notify the RRC layer entity that the terminal device complies with the RRC inactive The preset condition for restoring the state to the RRC connected state.

In a possible implementation manner, the first message includes identification information of the terminal device; or the first message includes identification information of the terminal device and the RAN notification area where the terminal device is currently located. identification information; or the first message includes the identification information of the terminal device and the identification information of the data radio bearer DRB requested to be rebuilt for the terminal device.

In a possible implementation manner, the second message is a non-access stratum message or an RRC message.

In a third aspect, the present application also provides a terminal device for triggering state recovery, the terminal device includes a processor and a memory; the memory is used for storing software instructions, the processor is configured to read the software instructions stored in the memory, execute The software instructions cause the device to perform the method for triggering state recovery as described in the first aspect or any of its possible implementations.

In a fourth aspect, the present application also provides a computer-readable storage medium, where software instructions are stored in the computer-readable storage medium, and when it is run on a computer or a processor, the computer or the processor is made to execute the above-mentioned first step. The method for triggering state recovery described in one aspect or any of its possible implementation manners.

In a fifth aspect, the present application also provides a computer program product comprising software instructions, when the software instructions are run on a computer or processor, the computer or processor is made to execute the above-mentioned first aspect or any one thereof The method for triggering state recovery described in possible implementations.

In addition, for the technical effects brought by any one of the implementation manners of the second aspect to the fifth aspect, reference may be made to the technical effects brought by different implementation manners in the first aspect, which will not be repeated here.

Description of drawings

FIG. 1 is a schematic diagram of a communication system architecture provided by an embodiment of the present application;

2 is a schematic flowchart of a method for triggering state recovery provided by the present application;

FIG. 3 is a schematic diagram of a recovery process of triggering an RRC connected state by a non-access stratum entity of a terminal device according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a recovery process of triggering an RRC connected state by an RRC layer entity of a terminal device according to an embodiment of the present application;

5 is a schematic structural diagram of a terminal device that triggers state recovery according to an embodiment of the present application;

FIG. 6 is a schematic structural diagram of another terminal device that triggers state recovery according to an embodiment of the present application.

Detailed ways

The present application will be described in further detail below with reference to the accompanying drawings.

FIG. 1 exemplarily shows a schematic diagram of the architecture of a communication system applicable to the embodiment of the present application. The communication system may be an NR system, also called a fifth generation (the 5th generation, 5G) communication system. The communication system It includes terminal equipment, RAN equipment, and control plane network elements of the core network. The control plane network elements of the core network include an Access and Mobility Management Function (AMF) network element, a Unified Data Management (UDM) network element, and a Policy Control Function (Policy Control Function) PCF) network elements, etc.

Terminal equipment may refer to User Equipment (UE), access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The access terminal can be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a wireless communication function handheld devices, computing devices or other processing devices connected to wireless modems, in-vehicle devices, wearable devices, end devices in future 5G networks, etc. For the convenience of description, only one terminal device is illustrated in FIG. 1 , and multiple terminal devices may coexist in an actual communication network, which will not be repeated here.

RAN equipment is mainly responsible for providing wireless connections for terminal equipment and ensuring reliable transmission of uplink and downlink data of terminal equipment. RAN equipment includes base stations, specifically, including but not limited to: next-generation base stations (g NodeB, gNB) in 5G, evolved Node B (evolved Node B, eNB), Radio Network Controller (Radio Network Controller, RNC) , Node B (Node B, NB), Base Station Controller (Base Station Controller, BSC), Base Transceiver Station (Base Transceiver Station, BTS), Home Base Station (for example, Home evolved Node B, or Home Node B, HNB), baseband Unit (Base Band Unit, BBU), transmission point (Transmitting and Receiving Point, TRP), transmitting point (Transmitting Point, TP), mobile switching center, etc.

The AMF network element is mainly responsible for the mobility management in the mobile network, such as user location update, user registration network, user handover, etc.

The UDM network element is mainly responsible for storing user data, such as subscription information and authentication/authorization information.

The PCF network element is mainly responsible for providing unified policy control for network behavior management and policy rules for the network control panel.

Of course, the control plane network elements of the core network are not limited to the above network elements. Since the embodiment of this application mainly involves the interaction process between the terminal device and the AMF network elements, the control plane network elements of the core network are not in the Figure 1 shows them one by one.

In addition, FIG. 1 also shows possible implementations of interfaces between some devices in the communication system, such as the N1 interface between the terminal device and the AMF network element, the N2 interface between the RAN device and the AMF network element, etc. .

It should be noted that the present application is not limited to the communication system architecture shown in FIG. 1 , and can also be applied to other communication systems in the future, such as a 6G communication system architecture. In addition, the names of the network elements used above in this application may keep the same functions in future communication systems, but the names may be changed.

Combined with the communication system shown in Figure 1, in order to maximize the power consumption, signaling transmission and network resource utilization of the terminal equipment, a new RRC state is introduced for the terminal equipment, that is, the RRC inactive state, the terminal equipment It is possible to switch between the RRC inactive state and the RCC connected state. However, in the current 5G communication standard protocol, it is not clear under what circumstances and what method the terminal device adopts to recover from the RRC inactive state to the RRC connected state. Based on this, the present application provides a method for triggering state recovery and a terminal device to solve the above technical problems.

Below, some terms involved in the embodiments of the present application will be explained first, so as to facilitate the understanding of those skilled in the art.

(1), RRC inactive state

The RRC inactive state is an intermediate state between the RRC connected state and the RRC idle state. When the terminal device is in the RRC inactive state, it can perform operations such as cell reselection and detection of paging messages sent by the network device as in the RRC idle state. However, compared with the RRC idle state, the terminal device in the RRC inactive state. , you can also do the following:

The terminal device can save the context information when it is in the RRC connection state, including its own context information and the context information of the radio access network device. Specifically, the context information includes network capabilities, authentication information, and created radio bearer information of the terminal device. In this way, when the terminal device needs to restore the RRC connection state, it can restore the RRC connection under the control of the network device and according to the saved context information. Compared with when the terminal device is in the RRC idle state, it needs to re-request the context information from the network device. , which can effectively shorten the process of RRC connection recovery, and can also reduce the signaling overhead between the terminal device and the network device.

The terminal equipment can also send and receive small data packet services. Since the terminal device is in the RRC inactive state or the RRC idle state, the RAN device will release the resources allocated for the terminal device. Therefore, the terminal device cannot perform uplink data services when the terminal device is in the RRC idle state, but the terminal device is in the RRC inactive state. In the state, small data packets with a small amount of data can be sent to the network device through the common channel.

The resources allocated by the RAN device to the terminal device mainly include radio link resources allocated for the terminal device and radio bearers created for the terminal device. The radio link resources include frequency points, bandwidth, etc., and the radio link A path refers to a logical path between a terminal device and a RAN device, and a radio bearer is mainly used to carry radio signaling and user plane data between the terminal device and the RAN.

(2), the non-access layer entity, the RRC layer entity and the SDAP entity of the terminal device

The protocol entity of the terminal device can be divided into two layers: a non-access stratum (Non-Access Stratum, NAS) and an access stratum (Access Stratum, AS). The terminal device can communicate with the control plane network element (such as AMF network element, etc.) of the core network through the NAS entity, and the terminal device can communicate with the RAN device through the AS entity. Specifically, the AS entity of the terminal device includes the RRC layer entity. The terminal device communicates with the RAN device through the RRC layer entity, and can complete the establishment of the RRC connection, the transmission of the RRC message, the disconnection of the RRC connection, and the establishment and release of the radio bearer. Wait. The AS entity of the terminal device also includes the SDAP entity. The SDAP entity is mainly used to transmit data on the user plane. The SDAP entity can notify the RRC layer entity or the NAS entity of the data information of the service performed by the terminal device.

(3) RAN notification area (RAN-based Notification Area, RNA), which can be understood as an area between a cell and a location area, and the RAN notification area includes at least one cell. For example, assuming that the cell where the terminal device is currently located is cell 1, and the location area to which cell 1 belongs includes cell 1 to cell 6, then the RAN notification area of the terminal device may include cell 1 to cell 3, and cell 2 and cell 3 are cells 1's neighbors.

With reference to the above content, the trigger state recovery method provided by the embodiment of the present application is described in detail below.

Referring to FIG. 2, a schematic flowchart of a method for triggering state recovery provided by the present application includes the following steps:

Step 201: When the terminal device is in the RRC inactive state, it is determined that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state. Wherein, the preset condition that meets the restoration from the RRC inactive state to the RRC connected state may include at least one of the following conditions:

The RAN notification area of the radio access network where the terminal device is located is updated;

The RAN notification area includes at least one cell; the RAN notification area where the terminal equipment is located has not been updated within a preset time period;

The size of the data packet to be sent by the terminal device is larger than a preset threshold.

In the embodiment of the present application, the non-access stratum entity, the RRC layer entity and the SDAP entity of the terminal equipment can all detect whether the terminal equipment meets the preset conditions for returning from the RRC inactive state to the RRC connected state. For example, the non-access stratum entity and the RRC layer entity of the terminal equipment can detect whether the RAN notification area where the terminal equipment is located is updated, and when the RAN notification area where the terminal equipment is located is updated, it is determined that the terminal equipment complies with the recovery from the RRC inactive state It is the preset condition of the RRC connected state. Optionally, the non-access stratum entity and the RRC layer entity of the terminal equipment can also detect whether the RAN notification area where the terminal equipment is located is updated within the preset time period. When the RAN notification area is in the If no update occurs within the preset time period, that is, the RAN-based Notification Area Update (RNAU) process times out, the preset condition for the terminal device to be restored from the RRC inactive state to the RRC connected state is determined. Optionally, the SDAP entity of the terminal device can detect whether the size of the data packet to be sent by the terminal device is greater than a preset threshold, and when it is greater than the preset threshold, it is determined that the terminal device is in compliance with the RRC inactive state to return to the RRC connected state. preset conditions.

Step 202: The terminal device sends a first message to the network device, where the first message is used to request to restore the terminal device from an RRC inactive state to an RRC connected state.

In this embodiment of the present application, the terminal device may trigger the process of restoring the RRC connected state through the non-access layer entity or the RRC layer entity. That is to say, the first message sent by the terminal device to the network device may be a non-access layer message or an RRC layer message. Specifically, the first message carries a small amount of data, and can be sent to the network device in the form of small data packets through a common channel. In addition, the first message may adopt the original message format, such as the message format adopted by the existing servicerequest message, etc., or may adopt a new message format, and the new message format may be applied to the In the scenario where the active state is switched to the RRC connected state, it can also be applied to other scenarios of the RRC state switching, for example, in the scenario where the RRC connected state is the RRC inactive state.

In a specific implementation, if the first message is a non-access stratum message, the first message may be that the non-access stratum entity of the terminal device detects that the terminal device complies with the recovery from RRC inactive state to RRC It can also be sent after the preset condition of the connected state, and may also be that the terminal device that the non-access stratum entity of the terminal device receives notification from the SDAP entity or the RRC layer entity complies with the state of being restored from the RRC inactive state to the RRC connected state. Sent after preset conditions.

If the first message is an RRC layer message, the first message may be sent after the RRC layer entity of the terminal device detects that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state It can also be sent by the RRC layer entity of the terminal device after receiving the terminal device notified by the SDAP entity that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state.

Step 203: The terminal device is restored to the RRC connected state under the control of the network device.

The terminal device may receive the RRC reconfiguration message from the network device, and based on the configuration information carried in the reconfiguration message, restore to the RRC connected state, and then send an RRC reconfiguration complete message to the network device. Specifically, the configuration information may include a field for re-establishing radio resources, and the terminal device may reconfigure radio link resources and radio bearers according to the field for re-establishing radio resources, so as to restore the RRC connection.

Step 204: The terminal device receives a second message sent by the network device, where the second message is used to indicate that the terminal device has returned to the RRC connection state.

The second message may be a non-access stratum message or an RRC stratum message. Specifically, if the first message is a non-access stratum message, the second message is also a non-access stratum message; if the first message is an RRC layer message, the second message is also an RRC layer message. In this way, the interaction process between the terminal device and the network device can be consistent, that is, the terminal device triggers the recovery process of the RRC connected state through the non-access stratum entity, and accordingly, the core network device feeds back the RRC connected state to the terminal device. Response of successful restoration; the terminal device triggers the restoration process of the RRC connected state through the RRC layer entity, and accordingly, the RAN device feeds back the response of the successful restoration of the RRC connected state to the terminal device.

It can be seen from the above that the embodiment of the present application provides that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state. The first message requesting to restore the terminal device from the RRC inactive state to the RRC connected state, and then can be restored to the RRC connected state under the control of the network device, so that the terminal device can be changed from the RRC inactive state to the RRC connected state. recovery process.

In addition, the present application refines the manner in which the terminal device triggers the RRC connected state restoration process, and provides which protocol entity is responsible for the triggering of the terminal device and the implementation of the corresponding RRC connected state restoration process after the trigger. Referring to Figures 3 and 4 .

Referring to Figure 3, the recovery process of the RRC connected state triggered by the non-access stratum entity of the terminal device specifically includes the following steps:

Step 301: The RAN device instructs the RRC layer entity of the terminal device to switch from the RRC connected state to the RRC inactive state.

In the embodiment of the present application, when the terminal device is in the RRC connection state, it can perform data transmission with the RAN device based on the established RRC connection. When the RAN device determines that the terminal device meets the preset conditions for switching from the RRC connected state to the RRC inactive state, it may send a state switching message (such as a state switching message for instructing the RRC layer entity to switch from the RRC connected state to the RRC inactive state to the terminal device) RRC Connection Inactivation message, etc.), and release the resources allocated for the terminal device.

The RAN device determines that the terminal device meets the preset conditions for switching from the RRC connected state to the RRC inactive state. This is not limited.

In addition, in this embodiment of the present application, the RAN device may save the context information of the terminal device after instructing the RRC layer entity of the terminal device to switch from the RRC connected state to the RRC inactive state. After the message is sent, its own context information can also be saved, so that the subsequent process of restoring the RRC connected state can be quickly initiated and completed based on the pre-saved context information of the terminal device.

Step 302: The RRC layer entity of the terminal device notifies the non-access layer entity of the terminal device that it is in an RRC inactive state.

Specifically, since the RAN device instructs the terminal device to switch from the RRC connected state to the RRC inactive state, the resources allocated for the terminal device are released. Therefore, when the RRC layer entity of the terminal device updates its state to the RRC inactive state, it can The wireless link configuration parameters using the dedicated channel are converted into configuration parameters using the common channel, so that the terminal device can use the common channel to send and receive small data packets.

After learning that the RRC layer entity is in the RRC inactive state, the non-access stratum entity of the terminal device can record this state.

Step 303: When the terminal device is in the RRC inactive state, the non-access stratum entity of the terminal device determines that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state.

In this embodiment of the present application, the non-access stratum entity of the terminal device can detect whether the terminal device meets the preset conditions for returning from the RRC inactive state to the RRC connected state, and can also receive other protocol entities from the terminal device, such as the RRC layer entity Or a notification message of the SDAP entity, where the notification message is used to indicate that the terminal device complies with the preset condition for returning from the RRC inactive state to the RRC connected state.

In a first possible implementation manner, after detecting that the RAN notification area where the terminal device is located is updated, the non-access stratum entity of the terminal device determines that the terminal device complies with the preset from the RRC inactive state to the RRC connected state. condition.

Since the location area of the terminal equipment changes, the communication quality between the terminal equipment and the RAN equipment may be affected. Therefore, when the location area of the terminal equipment changes significantly, in order to ensure the normal communication between the terminal equipment and the RAN equipment, the RAN equipment is often required. The device synchronously updates the location area where the terminal device is located and reallocates resources to the terminal device in the new location area. Therefore, the terminal device in the RRC inactive state needs to re-request to the RAN device to return to the RRC connected state.

In the embodiment of the present application, considering that the range of the cell is too small and the range of the location area is too large, if the cell update is used as the condition for triggering the restoration process of the RRC connected state, it may occur that the restoration process of the RRC connected state is triggered too frequently. This leads to a waste of resources, and if the location area update is used as the condition for triggering the RRC connected state restoration process, it may occur that the communication quality between the terminal equipment and the RAN equipment has been affected when the conditions for not triggering the RRC connected state restoration process are met. loss problem. Therefore, the concept of the RAN notification area is introduced in the embodiments of this application. The RAN notification area is used as an area between the cell and the location area, and the RAN notification area update is used as a condition for triggering the recovery process of the RRC connected state, so that the RRC connection is triggered. The state recovery process is more reasonable.

In the second possible implementation manner, the non-access stratum entity of the terminal device determines that the terminal device complies with the RRC inactive state to return to RRC after detecting that the RAN notification area where the terminal device is located has not been updated within a preset time period. Preconditions for the connected state.

Under normal circumstances, the terminal device will initiate an RNAU process at regular intervals to notify the RAN device that it is still in the area covered by the RAN device. If the terminal device does not initiate the RANU process for a long time, the RAN device may determine that the state of the terminal device is abnormal, and then release the RRC connection with the terminal device. Therefore, in this embodiment of the present application, a timer may be configured in the terminal device. When the timer is detected to expire, it can be determined that the RAN notification area of the terminal device has not been updated within a preset period of time. The incoming layer entity triggers the recovery process of the RRC connected state, so that the normal RRC connection can be maintained between the terminal device and the RAN device.

In a third possible implementation manner, the non-access stratum entity of the terminal device may receive a message sent by the RRC layer entity of the terminal device to indicate that the terminal device complies with the preset condition for returning from the RRC inactive state to the RRC connected state After the notification message is sent, it is determined that the terminal device meets the preset conditions for returning from the RRC inactive state to the RRC connected state.

The notification message may be sent after the RRC layer entity of the terminal device detects that the RAN notification area where the terminal device is located is updated, or the RAN notification area where the terminal device is located has not been updated within a preset time period.

In a fourth possible implementation manner, the non-access stratum entity of the terminal device may receive a message sent by the SDAP entity of the terminal device to indicate that the terminal device complies with the preset condition for returning from the RRC inactive state to the RRC connected state. After the notification message is sent, it is determined that the terminal equipment meets the preset conditions for returning from the RRC inactive state to the RRC connected state.

The notification message may be sent after the SDAP entity of the terminal device detects that the data packet to be sent by the terminal device is larger than a preset threshold. Specifically, the notification message may refer to a DRB reconstruction request message.

When the terminal equipment is in the RRC inactive state, the RAN equipment has released a series of resources on the RB established between the terminal equipment and the RAN equipment, so the terminal equipment can only use the common channel to send and receive small data packets, while the terminal equipment When the SDAP entity detects that the size of the data packet to be sent is larger than the preset threshold, that is, when the small data packet cannot be sent and received, it also needs to re-request to rebuild the DRB for the terminal device. Therefore, in the embodiment of the present application, after detecting that the size of the data packet to be sent is larger than the preset threshold, the SDAP entity of the terminal device can send a DRB reconstruction request message to the non-access stratum entity of the terminal device, and then the non-access stratum entity of the terminal device can send a DRB reconstruction request message. The access layer entity triggers the recovery process of the RRC connected state, so that the RAN device re-allocates resources to the terminal device and ensures the normal operation of the data service of the terminal device.

Of course, in practical applications, determining that the terminal device meets the preset conditions for returning from the RRC inactive state to the RRC connected state may not be limited to the above four implementation manners provided in this application, and may also be the result of receiving a paging message sent by the network device. Messages, etc., will not be listed one by one in this application.

Step 304: The non-access stratum entity of the terminal device sends a first message to the AMF network element, where the first message is used to request to restore the terminal device from the RRC inactive state to the RRC connected state.

In this embodiment of the present application, the non-access stratum entity of the terminal device triggers the RRC connected state restoration process. Specifically, the non-access stratum entity of the terminal device may send the first message to the AMF network element via the RAN device, and the The first message is a non-access stratum message. It should be noted that, if the RAN device recognizes that the received message is a non-access stratum message, it only forwards the non-access stratum message, and does not parse the message content in the non-access stratum message.

Specifically, since there are various ways to determine that the terminal device meets the preset conditions for returning from the RRC inactive state to the RRC connected state, the message content carried in the first message also has various situations, specifically including:

Case 1: The first message may include the identification information of the terminal device and the identification information of the RAN notification area where the terminal device is currently located.

Case 1 may be applicable to the scenario where it is determined that the terminal equipment meets the preset conditions for returning from the RRC inactive state to the RRC connected state according to the RAN notification area of the terminal equipment being updated or not being updated within a preset time period.

The identification information of the terminal device may include an International Mobile Subscriber Identification (International Mobile Subscriber Identification, IMSI) code of the terminal device, and the like. By sending the identification information of the terminal device to the AMF network element, the AMF network element can instruct the RAN device to restore the RRC connection of the terminal device that matches the identification information of the terminal device. Wherein, the RAN device stores the identification information of the terminal device that has established an RRC connection with itself.

Wherein, if it is determined that the terminal equipment meets the preset condition according to the update of the RAN notification area where the terminal equipment is located, then the identification information of the RAN notification area carried in the first message actually refers to the updated RAN notification area. area corresponding identification information. By sending the identification information corresponding to the updated RAN notification area to the AMF network element, the AMF network element can instruct the RAN device to change the previously recorded identification information of the RAN notification area of the terminal device to the updated RAN notification area Corresponding identification information, so that the network side can synchronously complete the RNAU process for the terminal device.

Case 2: The first message may include the identification information of the terminal device and the DRB identification information requested to be rebuilt for the terminal device.

Case 2 may be applicable to the scenario where it is determined that the terminal device meets the preset conditions for returning from the RRC inactive state to the RRC connected state according to the DRB re-establishment request message sent by the SDAP entity of the terminal device received by the non-access stratum entity of the terminal device .

Since the terminal device is in the RRC connection state, the RAN device can create a DRB for the terminal device according to the type of service currently performed by the terminal device. For example, DRB1 is created for service A and DRB2 is created for service B. When the terminal device is in the RRC inactive state , the RAN device will release the DRB created for the terminal device. Therefore, the DRB reconstruction request message sent by the SDAP entity of the terminal device may carry the identification information of the DRB requested to be reconstructed for the terminal device. Device requirements to create DRBs.

Of course, in practical application, the DRB identifier may not be carried in the first message, and subsequent RAN devices can directly reconstruct the DRB previously recorded by the terminal device according to the previously recorded DRB identifier information created for the terminal device.

Case 3: The first message may only carry the identification information of the terminal device.

The first message may only be used to request the AMF terminal device to restore the terminal device from the RRC inactive state to the RRC connected state. The updating process of initiating the RAN notification area to the network side can be performed after the terminal equipment successfully returns to the RRC connected state.

For example, the non-access stratum entity of the terminal device can send the identification information of the RAN notification area where the terminal device is currently located to the AMF network element, or the RRC entity of the terminal device can directly send the RAN device where the terminal device is currently located. The identification information of the RAN notification area, so that the network side completes the RNAU process for the terminal equipment.

Step 305: The AMF network element sends a request message for re-allocating resources for the terminal device to the RAN device.

With reference to the above description of step 304, if the first message received by the AMF network element includes the identification information of the DRB requested to be rebuilt for the terminal device in addition to the identification information of the terminal device, the AMF network element can indicate that the RAN device is the terminal device. The device reconstructs a DRB that matches the identification information of the DRB, and allocates resources for the reconstructed DRB.

If the first message received by the AMF network element includes, in addition to the identification information of the terminal equipment, the updated identification information of the RAN notification area, the AMF network element instructs the RAN equipment to reallocate resources for the terminal equipment at the same time. The RAN device may be instructed to change the previously recorded identification information of the RAN notification area of the terminal device to the updated identification information of the RAN notification area.

Of course, the AMF network element may also instruct the RAN device to change the previously recorded identification information of the RAN notification area of the terminal equipment to the updated identification information of the RAN notification area after determining that the RAN equipment has successfully re-allocated resources for the terminal equipment. This application is not limited to this.

Step 306: The RAN device sends an RRC reconfiguration message to the terminal device, where the reconfiguration message includes configuration information for restoring the RRC connection, such as resource information allocated to it by the RAN device.

Step 307: The RRC layer entity of the terminal device sends an RRC reconfiguration complete message to the RAN device after returning to the RRC connected state according to the configuration information carried in the RRC reconfiguration message.

Step 308: The RAN device sends a response message that the resource allocation is successful to the AMF network element.

Step 309: The AMF network element sends a second message to the non-access stratum entity of the terminal device, where the second message is used to indicate that the terminal device has returned to the RRC connection state.

In the above method, the non-access stratum entity of the terminal device requests the AMF network element to restore the RRC connected state after determining that the terminal device meets the preset conditions for returning from the RRC inactive state to the RRC connected state, and then the AMF network element can indicate. The RAN device controls the terminal device to restore the RRC connection, thereby realizing the restoration process from the RRC inactive state to the RRC connected state. And considering that in the existing LTE system, the terminal equipment is restored from the RRC idle state to the RRC connected state, which is triggered by the non-access stratum of the terminal equipment, so in this application, the non-access stratum entity of the terminal equipment is triggered by The recovery process of switching from the RRC inactive state to the RRC connected state can make the signaling exchange process of the RRC state switching as unified as possible.

Referring to Figure 4, the RRC connected state recovery process triggered by the RRC layer entity of the terminal device specifically includes the following steps:

Step 401: The RAN device instructs the RRC layer entity of the terminal device to switch from the RRC connected state to the RRC inactive state.

Step 401 is the same as the above-mentioned step 301, and reference may be made to the foregoing description, which will not be described in detail here.

Step 402: When the terminal device is in the RRC inactive state, the RRC layer entity of the terminal device determines that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state.

In the embodiment of the present application, the RRC layer entity of the terminal device can detect whether the terminal device meets the preset conditions for returning from the RRC inactive state to the RRC connected state, and can also receive notification messages from other protocol entities of the terminal device, such as the SDAP entity , the notification message is used to indicate that the terminal equipment meets the preset condition for returning from the RRC inactive state to the RRC connected state.

In a first possible implementation manner, after detecting that the RAN notification area where the terminal device is located is updated, the RRC layer entity of the terminal device determines that the terminal device meets the preset conditions for returning from the RRC inactive state to the RRC connected state.

In the second possible implementation manner, after detecting that the RAN notification area where the terminal device is located has not been updated within a preset time period, the RRC layer entity of the terminal device determines that the terminal device conforms to the state of being restored from the RRC inactive state to the RRC connected state. preset conditions.

In a third possible implementation manner, the RRC layer entity of the terminal device may receive a notification message sent by the SDAP entity of the terminal device to indicate that the terminal device complies with the preset condition for returning from the RRC inactive state to the RRC connected state Afterwards, it is determined that the terminal device meets the preset conditions for returning from the RRC inactive state to the RRC connected state.

The notification message may be sent after the SDAP entity of the terminal device detects that the data packet to be sent by the terminal device is larger than a preset threshold. Specifically, the notification message may refer to a DRB reconstruction request message.

For the specific description of the above several implementation manners, reference may be made to the description in the foregoing step 303, which will not be described one by one here.

Step 403: The RRC layer entity of the terminal device sends a first message to the RAN device, where the first message is used to request to restore the terminal device from the RRC inactive state to the RRC connected state.

For the content contained in the first message, reference may be made to the description in the above step 304, which will not be described one by one here.

Step 404: The RAN device sends an RRC reconfiguration message to the terminal device, where the reconfiguration message includes configuration information for restoring the RRC connection, such as resource information allocated by the RAN device.

Step 405: The RRC layer entity of the terminal device sends an RRC reconfiguration complete message to the RAN device after returning to the RRC connected state according to the configuration information carried in the RRC reconfiguration message.

Step 406: The AMF device sends a second message to the RRC layer entity of the terminal device, where the second message is used to indicate that the terminal device has returned to the RRC connected state.

In the above method, the RRC layer of the terminal device directly requests the RAN device to restore the RRC connection after determining that the terminal device meets the preset conditions for returning from the RRC inactive state to the RRC connected state, and then the RAN device passes the RRC reconfiguration message. The terminal equipment is controlled to restore the RRC connection, thereby realizing the restoration process from the RRC inactive state to the RRC connected state. In addition, the RRC layer entity triggers the RRC connected state restoration process, which does not involve the interaction process between the non-access layer entity and the core network control plane network element, which can reduce the burden of the non-access layer entity.

Based on the same technical concept, an embodiment of the present application further provides a terminal device for triggering state recovery, which is used to implement the above method embodiment for triggering state recovery.

Referring to FIG. 5 , it is a schematic structural diagram of a terminal device 500 for triggering state recovery according to an embodiment of the present application. The terminal device 500 includes physical devices such as a transceiver 501 and a processor 502, wherein the processor 502 may be a central processing unit (central processing unit, CPU), a microprocessor, an application-specific integrated circuit, a programmable logic circuit, a large Large-scale integrated circuits, or digital processing units, etc. Transceiver 501 is used for terminal equipment and other equipment to send and receive data. Transceiver 501 can be a radio frequency transceiver device, which is mainly used to modulate the baseband signal processed by the processor 502 into a high-frequency wireless signal and send it out. The high-frequency wireless signal is processed into a baseband data signal by the sending processor 502 for processing.

The terminal device may further include a memory 503 for storing software instructions executed by the processor 502, and of course other data required by the terminal device, such as identification information of the terminal device, encryption information of the terminal device, user data, etc. The memory 503 may be a volatile memory (volatile memory), such as random-access memory (RAM); the memory 503 may also be a non-volatile memory (non-volatile memory), such as a read-only memory (read-only memory) memory, ROM), flash memory (flash memory), hard disk drive (HDD) or solid-state drive (SSD), or memory 503 is capable of carrying or storing instructions or data structures in the form of desired program code and any other medium that can be accessed by a computer, but is not limited thereto. The memory 503 may be a combination of the above-mentioned memories.

The specific connection medium between the processor 502 , the memory 503 , and the transceiver 501 is not limited in the embodiments of the present application. In FIG. 5 , the embodiment of the present application only takes the connection between the memory 503 , the processor 502 , and the transceiver 501 through the bus 504 as an example for description. The bus is represented by a thick line in FIG. 5 . It is a schematic illustration and is not intended to be limiting. The bus can be divided into an address bus, a data bus, a control bus, and the like. For ease of presentation, only one thick line is used in FIG. 5, but it does not mean that there is only one bus or one type of bus.

The processor 502 can be a dedicated hardware or a processor running software. When the processor 502 can run software, the processor 502 reads the software instructions stored in the memory 503 and, under the drive of the software instructions, executes the preceding embodiments. methods involved.

Specifically, when the terminal device is in the RRC inactive state, the processor 502 may determine that the terminal device complies with the preset condition for returning from the RRC inactive state to the RRC connected state, and transmits and receives through the transceiver. The device 501 sends a first message to the network device, where the first message is used to request that the terminal device be restored from the RRC inactive state to the RRC connected state. Specifically, the transceiver 501 sends the first message to the network device. Including the processor driving or controlling the transceiver 501 to send the first message to the network device; and then returning to the RRC connection state under the control of the network device; subsequently, receiving the second message sent by the network device through the transceiver message, the second message is used to indicate that the terminal device has returned to the RRC connection state, specifically, receiving the second message sent by the network device through the transceiver includes the processor driving or The second message sent by the network device is accepted under control.

Wherein, in a possible implementation manner, the preset condition includes at least one of the following conditions: the RAN notification area of the radio access network where the terminal device is located is updated; the RAN notification area includes at least one cell ; the RAN notification area where the terminal equipment is located has not been updated within a preset time period; the size of the data packet to be sent by the terminal equipment is greater than a preset threshold.

In a possible implementation manner, when the processor determines that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state, the processor may detect through the non-access stratum entity of the terminal device The terminal equipment complies with the preset conditions for returning from the RRC inactive state to the RRC connected state; or the RRC layer entity of the terminal equipment detects that the terminal equipment meets the preset conditions for returning from the RRC inactive state to the RRC connected state. condition; or, through the service data adaptation protocol SDAP entity of the terminal device, it is detected that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state.

In a possible implementation manner, the first message is a non-access stratum message or an RRC message. Moreover, the first message may include identification information of the terminal device; or the first message includes identification information of the terminal device and identification information of the RAN notification area where the terminal device is currently located; or the The first message includes the identification information of the terminal device and the identification information of the data radio bearer DRB requested to be rebuilt for the terminal device.

Specifically, if the first message is a non-access stratum message, the processor, before sending the first message to the network device through the transceiver, may also use the service data adaptation protocol of the terminal device The SDAP entity or the RRC layer entity notifies the non-access stratum entity that the terminal equipment meets the preset conditions for returning from the RRC inactive state to the RRC connected state.

Specifically, if the first message is an RRC message, the processor, before sending the first message to the network device through the transceiver, may also notify the SDAP entity of the service data adaptation protocol of the terminal device The terminal equipment of the RRC layer entity meets the preset conditions for returning from the RRC inactive state to the RRC connected state.

In a possible implementation manner, the second message is a non-access stratum message or an RRC message.

As will be appreciated by those skilled in the art, the embodiments of the present application may be provided as a method, a system, or a computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-readable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having software instructions embodied therein.

When the methods provided in the embodiments are implemented by software or hardware or a combination of software and hardware, the terminal device may include multiple functional modules, and each functional module may include software, hardware, or a combination thereof. Specifically, referring to FIG. 6 , which is a schematic structural diagram of a terminal device 600 for triggering state recovery provided by an embodiment of the present application, the terminal device 600 includes a determining unit 601 , a sending unit 602 , a recovery unit 603 , and a receiving unit 604 .

Determining unit 601, configured to determine that a terminal device in an RRC inactive state meets a preset condition for returning from an RRC inactive state to an RRC connected state; the preset condition includes at least one of the following conditions: where the terminal device is located The RAN notification area of the radio access network is updated; the RAN notification area includes at least one cell; the RAN notification area where the terminal equipment is located has not been updated within a preset period of time; The size is greater than the preset threshold.

The sending unit 602 is configured to send a first message to a network device, where the first message is used to request to restore the terminal device from an RRC inactive state to an RRC connected state.

The restoring unit 603 is configured to restore to the RRC connected state under the control of the network device.

The receiving unit 604 is configured to receive a second message sent by the network device, where the second message is used to indicate that the terminal device has returned to the RRC connection state.

In a possible implementation manner, the determining unit 601 may detect through the non-access stratum entity of the terminal device that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state; or, It is detected by the RRC layer entity of the terminal device that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state; The preset condition for the inactive state to return to the RRC connected state.

In a possible implementation manner, the first message is a non-access stratum message or an RRC message.

Wherein, if the first message is a non-access stratum message, before sending the first message to the network device, the sending unit 602 may also notify the non-access stratum through the SDAP entity or the RRC layer entity of the terminal device Entity that the terminal equipment meets the preset conditions for returning from the RRC inactive state to the RRC connected state.

Wherein, if the first message is an RRC message, before sending the first message to the network device, the sending unit 602 may also use the SDAP entity of the terminal device to notify the RRC layer entity that the terminal device complies with the RRC non-compliant A preset condition for the active state to return to the RRC connected state.

In a possible implementation manner, the first message includes identification information of the terminal device; or the first message includes identification information of the terminal device and the RAN notification area where the terminal device is currently located. identification information; or the first message includes the identification information of the terminal device and the identification information of the data radio bearer DRB requested to be rebuilt for the terminal device.

In a possible implementation manner, the second message is a non-access stratum message or an RRC message.

The division of modules in the embodiments of the present application is schematic, and is only a logical function division. In actual implementation, there may be other division methods. In addition, the functional modules in the various embodiments of the present application may be integrated into one processing unit. In the device, it can also exist physically alone, or two or more modules can be integrated into one module. The coupling between the various modules may be implemented through some interfaces, which are usually electrical communication interfaces, but may be mechanical interfaces or other forms of interfaces. Thus, modules described as separate components may or may not be physically separate, and may be located in one place or distributed in different locations on the same or different devices. The above-mentioned integrated modules can be implemented in the form of hardware, and can also be implemented in the form of software function modules. In an optional solution, when the integrated modules can be implemented in the form of hardware, the physical hardware corresponding to the determining unit 601 and the restoring unit 603 may be the processor 502, and the physical hardware corresponding to the sending unit 602 and the receiving unit 604 may be is transceiver 501.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the present application. It will be understood that each flow and/or block in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus may be a computer device, a mobile terminal or a processor therein, and the instruction apparatus may implement all or part of the steps of the methods described in the various embodiments of the present application.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. For example, for the apparatus or apparatus embodiments, reference may be made to the previous method embodiments for part of the processing procedures. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims (22)

1. A method for triggering state recovery, wherein the method comprises: When the terminal device is in the RRC inactive state, it is determined that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state; sending, by the terminal device, a first message to the network device, where the first message is used to request that the terminal device be restored from an RRC inactive state to an RRC connected state; The terminal device is restored to the RRC connected state under the control of the network device; receiving, by the terminal device, a second message sent by the network device, where the second message is used to indicate that the terminal device has returned to the RRC connection state; Wherein, the preset condition includes at least one of the following conditions: The RAN notification area of the radio access network where the terminal device is located is updated; the RAN notification area includes at least one cell; The RAN notification area where the terminal device is located has not been updated within a preset time period; The size of the data packet to be sent by the terminal device is larger than a preset threshold. 2. The method according to claim 1, wherein the determining that the terminal equipment complies with a preset condition for restoring from an RRC inactive state to an RRC connected state comprises: The terminal device detects through the non-access stratum entity that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state; or The terminal device detects through the RRC layer entity that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state; or The terminal device detects through the service data adaptation protocol SDAP entity that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state. 3. The method according to claim 1 or 2, wherein the first message is a non-access stratum message or an RRC message. The method according to any one of claims 1 to 3, wherein if the first message is a non-access stratum message, before the terminal device sends the first message to the network device, the method further comprises: The terminal device informs the non-access layer entity through the service data adaptation protocol SDAP entity or the RRC layer entity that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state. The method according to any one of claims 1 to 3, wherein if the first message is an RRC message, before the terminal device sends the first message to the network device, the method further comprises: The terminal device informs the RRC layer entity through the service data adaptation protocol SDAP entity that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state. 6. The method according to any one of claims 1 to 5, wherein, the first message includes identification information of the terminal device; or The first message includes the identification information of the terminal device and the identification information of the RAN notification area where the terminal device is currently located; or The first message includes the identification information of the terminal device and the identification information of the data radio bearer DRB requested to be rebuilt for the terminal device. 7. The method according to any one of claims 1 to 3, wherein the second message is a non-access stratum message or an RRC message. 8. A terminal device for triggering state recovery, comprising: a determining unit, configured to determine that the terminal equipment in the RRC inactive state meets the preset condition for returning from the RRC inactive state to the RRC connected state; a sending unit, configured to send a first message to a network device, where the first message is used to request that the terminal device be restored from an RRC inactive state to an RRC connected state; a restoration unit, configured to restore to the RRC connected state under the control of the network device; a receiving unit, configured to receive a second message sent by the network device, where the second message is used to indicate that the terminal device has returned to the RRC connection state; Wherein, the preset condition includes at least one of the following conditions: The RAN notification area of the radio access network where the terminal device is located is updated; the RAN notification area includes at least one cell; The RAN notification area where the terminal device is located has not been updated within a preset time period; The size of the data packet to be sent by the terminal device is larger than a preset threshold. 9. The terminal device according to claim 8, wherein the determining unit is specifically configured to: It is detected by the non-access stratum entity of the terminal device that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state; or It is detected by the RRC layer entity of the terminal device that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state; or It is detected through the service data adaptation protocol SDAP entity of the terminal device that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state. 10. The terminal device according to claim 8 or 9, wherein the first message is a non-access stratum message or an RRC message. The terminal device according to any one of claims 8 to 10, wherein if the first message is a non-access stratum message, the sending unit is further configured to: Before sending the first message to the network device, notify the non-access stratum entity through the service data adaptation protocol SDAP entity or the RRC layer entity of the terminal device that the terminal device complies with the pre-recovery from the RRC inactive state to the RRC connected state. Set conditions. The terminal device according to any one of claims 8 to 10, wherein if the first message is an RRC message, the sending unit is further configured to: Before sending the first message to the network device, notify the RRC layer entity through the service data adaptation protocol SDAP entity of the terminal device that the terminal device complies with the preset condition for returning from the RRC inactive state to the RRC connected state. 13. The terminal device according to any one of claims 8 to 12, wherein, the first message includes identification information of the terminal device; or The first message includes the identification information of the terminal device and the identification information of the RAN notification area where the terminal device is currently located; or The first message includes the identification information of the terminal device and the identification information of the data radio bearer DRB requested to be rebuilt for the terminal device. The terminal device according to any one of claims 8 to 10, wherein the second message is a non-access stratum message or an RRC message. 15. A terminal device for triggering state recovery, comprising: a processor, and a memory and a transceiver connected to the processor; The processor is configured to read software instructions in the memory and execute the software instructions to perform the following operations: When the terminal device is in the RRC inactive state, determining that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state; Send a first message to the network device through the transceiver, where the first message is used to request that the terminal device be restored from the RRC inactive state to the RRC connected state; restore to the RRC connected state under the control of the network device; receiving, by the transceiver, a second message sent by the network device, where the second message is used to indicate that the terminal device has returned to the RRC connection state; Wherein, the preset condition includes at least one of the following conditions: The RAN notification area of the radio access network where the terminal device is located is updated; the RAN notification area includes at least one cell; The RAN notification area where the terminal device is located has not been updated within a preset time period; The size of the data packet to be sent by the terminal device is larger than a preset threshold. 16. The terminal device according to claim 15, wherein the processor, when determining that the terminal device meets a preset condition for restoring from an RRC inactive state to an RRC connected state, is specifically configured to: It is detected by the non-access stratum entity of the terminal device that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state; or It is detected by the RRC layer entity of the terminal device that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state; or It is detected through the service data adaptation protocol SDAP entity of the terminal device that the terminal device meets the preset condition for returning from the RRC inactive state to the RRC connected state. 17. The terminal device according to claim 15 or 16, wherein the first message is a non-access stratum message or an RRC message. 18. The terminal device according to any one of claims 15 to 17, wherein the processor is further configured to: If the first message is a non-access stratum message, before sending the first message to the network device through the transceiver, notify the non-access stratum through the service data adaptation protocol SDAP entity or RRC layer entity of the terminal device Entity that the terminal equipment meets the preset conditions for returning from the RRC inactive state to the RRC connected state. 19. The terminal device according to any one of claims 15 to 17, wherein the processor is further configured to: If the first message is an RRC message, before sending the first message to the network device through the transceiver, notify the RRC layer entity through the service data adaptation protocol SDAP entity of the terminal device. A preset condition for the active state to return to the RRC connected state. 20. The terminal device according to any one of claims 15 to 19, wherein, the first message includes identification information of the terminal device; or The first message includes the identification information of the terminal device and the identification information of the RAN notification area where the terminal device is currently located; or The first message includes the identification information of the terminal device and the identification information of the data radio bearer DRB requested to be rebuilt for the terminal device. 21. The terminal device according to any one of claims 15 to 17, wherein the second message is a non-access stratum message or an RRC message. 22. A computer-readable storage medium, characterized in that, the computer-readable storage medium stores software instructions, and when the software instructions are read and executed by one or more processors, the software instructions according to claims 1 to 1 can be implemented. 7. The method of any one.