WO2024169635A1 - Communication method and related device - Google Patents

Abstract

The present application provides a communication method and a related device, which are used for enabling a terminal device in a radio resource control (RRC) inactive state to carry out an access stratum (AS) signaling uplink transmission while at the same time, a process of using a small data transmission (SDT) method to send the AS signaling can likewise result in the gain of rapidly transmitting the AS signaling, so as to improve communication efficiency. In the method, a terminal device receives configuration information for transmitting AS signaling on the basis of an SDT method; and when the terminal device is in an RRC inactive state, the terminal device sends the AS signaling, wherein the AS signaling is carried in transmission resources of the SDT method.

Description

A communication method and related equipment

This application claims priority to a Chinese patent application filed with the State Intellectual Property Office on February 16, 2023, with application number 202310144884.7 and invention name “A communication method and related equipment”, the entire contents of which are incorporated by reference in this application.

Technical Field

The present application relates to the field of communication technology, and in particular to a communication method and related equipment.

Background Art

In a communication system, the communication protocol stack between a terminal device and a network device may include a radio resource control (RRC) layer. In addition, for a terminal device, there are three RRC states, namely, RRC IDLE state, RRC INACTIVE state, and RRC CONNECTED state.

Among them, the RRC connection between the terminal device in the RRC inactive state and the network device is suspended, that is, the RRC connection between the terminal device and the network device is suspended or unavailable, so that the terminal device cannot transmit uplink signals through the suspended RRC connection.

Therefore, for a terminal device in an RRC inactive state, when there is an uplink signal to be sent, how to achieve the transmission of the uplink signal is a technical problem that needs to be solved urgently.

Summary of the invention

The present application provides a communication method and related equipment, which are used to enable a terminal device in an RRC inactive state to realize uplink transmission of AS signaling, while the process of sending the AS signaling based on the SDT method can also obtain the gain of quickly transmitting the AS signaling, so as to improve communication efficiency.

In a first aspect, the present application provides a communication method applied to a terminal device, which is executed by the terminal device, or the method is executed by some components in the terminal device (such as a processor, a chip or a chip system, etc.), or the method can also be implemented by a logic module or software that can realize all or part of the functions of the terminal device. In the first aspect and its possible implementation, the communication method is described as being executed by a terminal device. In this method, the terminal device receives configuration information of access stratum (AS) signaling based on a small data transmission (SDT) mode; when the terminal device is in an RRC inactive state, the terminal device sends the AS signaling, wherein the AS signaling is carried on the transmission resources of the SDT mode.

Based on the above technical solution, after the terminal device receives the configuration information for transmitting the AS signaling based on the SDT mode, when the terminal device is in the RRC inactive state, the terminal device sends the AS signaling using the transmission resources of the SDT mode. Thus, for the terminal device in the RRC inactive state, based on the configuration information of the AS signaling received by the terminal device, the uplink transmission of the AS signaling can be realized, and the process of sending the AS signaling based on the SDT mode can also obtain the gain of fast transmission of the AS signaling, so as to improve the communication efficiency.

In a possible implementation of the first aspect, the AS signaling includes an RRC message and/or a medium access control control element (MAC CE).

Optionally, the AS signaling involved in the present application may include data/signaling involved in each protocol layer included in the AS layer, including but not limited to at least one of the radio resource control (RRC) protocol, packet data convergence protocol (PDCP), radio link control (RLC) protocol, medium access control (MAC) layer protocol, and physical (PHY) layer protocol. It is understandable that the signaling transmitted by the RRC layer includes RRC messages, and the signaling transmitted by the MAC layer includes MAC CE.

In a possible implementation manner of the first aspect, the configuration information of the AS signaling includes at least one of the following:

The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or,

The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or

The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or

The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode.

Based on the above technical solution, the configuration information of the AS signaling transmitted based on the SDT mode received by the terminal device may include at least one of the above items to improve the flexibility of the solution implementation. And, the terminal device can clearly determine the configuration information of the AS signaling in the RRC inactive state based on the above at least one information. Whether to send RRC messages and/or MAC CE based on SDT.

In a possible implementation manner of the first aspect, the configuration information of the AS signaling is included in an RRC release message or a system message.

Based on the above technical solution, the configuration information of the AS signaling received by the terminal device can also be included in the RRC release message or the system message, and multiple implementation methods for obtaining the configuration information of the AS signaling are provided to enhance the flexibility of the implementation of the solution. In addition, the terminal device can receive the system message when it is in the RRC connected state/RRC inactive state (or the terminal device can receive the RRC release message when it is in the RRC connected state), and the above implementation method can reuse the system message (or RRC release message) to save overhead.

In a possible implementation of the first aspect, the RRC release message includes configured grant (CG) configuration information corresponding to the transmission resources of the SDT mode.

Based on the above technical solution, when the RRC release message includes the CG configuration information corresponding to the transmission resources of the SDT method, the terminal device can send AS signaling based on the configured grant small data transmission (CG-SDT) method, so that the above solution can be applicable to the CG-SDT transmission scenario.

In a possible implementation of the first aspect, the system message includes random access (RA) configuration information corresponding to the transmission resources of the SDT mode.

Based on the above technical solution, when the system message includes the RA configuration information corresponding to the transmission resources of the SDT method, the terminal device can send AS signaling based on random access small data transmission (RA-SDT), so that the above solution can be applicable to the RA-SDT transmission scenario.

In a possible implementation manner of the first aspect, the method further includes: the terminal device receives an RRC release message from a source network device, and the configuration information of the AS signaling is included in a system message from a destination network device.

Based on the above technical solution, the terminal device can also receive an RRC release message from the source network device, so that the terminal device enters the RRC inactive state from the RRC connected state. In addition, the configuration information of the AS signaling used by the terminal device comes from the destination network device, so that the terminal device can send AS signaling based on the configuration from the destination network device when it resides/reselects to the destination network device in the RRC inactive state, so that the above solution can be applied to the station change scenario (or the scenario where the network device to which the terminal device is connected is switched/reselected).

In a possible implementation of the first aspect, the RRC release message also includes configuration information for transmitting AS signaling based on SDT configured by the source network device; the method also includes: the terminal device deletes the configuration information for transmitting AS signaling based on SDT configured by the source network device.

Based on the above technical solution, the RRC release message from the source network device may also include the configuration information of the source network device for transmitting AS signaling based on the SDT mode. Accordingly, when the terminal device resides/cell reselects to the destination network device in the RRC inactive state and sends AS signaling based on the configuration from the destination network device, the terminal device may delete the configuration information configured by the source network device to avoid transmission errors and save storage space.

In a possible implementation manner of the first aspect, the method further includes: when the terminal device is in an RRC inactive state, sending an RRC resume request (RRC resume request) message.

Optionally, the RRC reply request message and the AS signaling transmitted based on the SDT method are located in the same transport block (TB) (or the same data packet).

Based on the above technical solution, when the terminal device sends AS signaling based on the SDT method, the terminal device can also use the SDT upload mechanism to send an RRC recovery request message, so as to provide the network device with relevant information of the terminal device (such as the identification of the terminal device, etc.) through the RRC recovery request message.

In a possible implementation manner of the first aspect, the RRC recovery request message also includes indication information for indicating the reason for RRC recovery, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer (DRB) corresponding to the AS signaling, or the identifier of the signaling radio bearer (SRB) corresponding to the AS signaling.

Based on the above technical solution, the RRC recovery request message sent by the terminal device may also include indication information indicating the reason for RRC recovery. The indication information may include at least one of the above items. By indicating the relevant information of the AS signaling through the indication information, the network device can clarify the reason why the terminal device initiates RRC recovery based on the indication information.

In a possible implementation manner of the first aspect, the method further includes: ignoring at least one of the following:

Resume other DRBs and SRBs configured with SDT; or,

Check at the medium access control (MAC) layer whether the data volume is exceeded; or,

All data is mapped to the DRB or SRB of the SDT; or,

Higher layers request to restore the RRC connection.

Based on the above technical solution, when the terminal device transmits uplink data or non-access stratum (NAS) signaling based on the SDT method, the terminal device needs to consider at least one of the above limitations. In the above technical solution, the information transmitted by the terminal device based on the SDT method is AS signaling. Therefore, the terminal device can ignore the above limitations associated with uplink data or NAS signaling, in order to improve the transmission success rate of the AS signaling.

The second aspect of the present application provides a communication method, which is executed by a (distributed unit, DU), or the method is executed by some components in the DU (such as a processor, a chip or a chip system, etc.), or the method can also be implemented by a logic module or software that can implement all or part of the DU functions. In the second aspect and its possible implementation, the communication method is described as being executed by the DU. In this method, the DU sends configuration information for transmitting AS signaling based on the SDT method; the DU receives the AS signaling from a terminal device in an RRC inactive state, wherein the AS signaling is carried on the transmission resources of the SDT method.

Based on the above technical solution, after the DU sends the configuration information for transmitting the AS signaling based on the SDT mode, when the terminal device is in the RRC inactive state, the DU receives the AS signaling from the terminal device in the transmission resource of the SDT mode. Therefore, for the terminal device in the RRC inactive state, the configuration information of the AS signaling sent by the DU can realize the uplink transmission of the AS signaling, and the process of sending the AS signaling based on the SDT mode can also obtain the gain of fast transmission of the AS signaling, so as to improve the communication efficiency.

In a possible implementation of the second aspect, the AS signaling includes an RRC message and/or a media access control element MAC CE.

Optionally, the AS signaling involved in the present application may include data/signaling involved in each protocol layer contained in the AS layer, including but not limited to at least one of the radio resource control (RRC) protocol, packet data convergence protocol (PDCP), radio link control (RLC) protocol, medium access control (MAC) layer protocol, and physical (PHY) layer protocol.

It can be understood that the signaling transmitted by the RRC layer includes RRC messages, and the signaling transmitted by the MAC layer includes MAC CE.

In a possible implementation manner of the second aspect, the method also includes: the DU sends the AS signaling to a centralized unit (CU); when the AS signaling includes an RRC message, the RRC message is carried on an uplink radio resource control information transmission (UL RRC MESSAGE TRANSFER) message; and/or, when the AS signaling includes a MAC CE, the information carried by the MAC CE is carried on an F1 application protocol (F1-AP) message.

Based on the above technical solution, after the DU receives the AS signaling from the terminal device in the RRC inactive state, the DU can also send the AS signaling to the CU so that the CU can obtain and process the AS signaling. Among them, the DU can send the AS signaling to the CU in the above-mentioned multiple ways to improve the flexibility of the solution implementation.

In a possible implementation manner of the second aspect, the configuration information of the AS signaling includes at least one of the following:

The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or,

The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or

The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or

The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode.

Based on the above technical solution, the configuration information for transmitting AS signaling based on SDT sent by DU may include at least one of the above items to improve the flexibility of the solution implementation. Moreover, the terminal device can clarify whether to send RRC messages and/or MAC CE based on SDT when in RRC inactive state based on at least one of the above information.

In a possible implementation manner of the second aspect, the configuration information of the AS signaling is included in an RRC release message or a system message.

Based on the above technical solution, the configuration information of the AS signaling sent by the DU can also be included in the RRC release message or the system message, providing a variety of implementation methods for obtaining the configuration information of the AS signaling to enhance the flexibility of the implementation of the solution. In addition, the terminal device can receive the system message when it is in the RRC connected state/RRC inactive state (or the terminal device can receive the RRC release message when it is in the RRC connected state), and the above implementation method can reuse the system message (or RRC release message) to save overhead.

In a possible implementation of the second aspect, the configuration information of the AS signaling is included in the system message; the parameters in the system message are determined by the DU, and the method also includes: the DU sends the configuration information of the AS signaling to the CU; or, the parameters in the system message are determined by the CU, and the method also includes: the DU receives the configuration information of the AS signaling from the CU.

Optionally, in the case where the parameters in the system message are determined by the DU, the system message includes SIB1, SIB10, SIB12, SIB13, At least one of SIB14, SIB15, SIB17, SIB18 or SIB20.

Optionally, in the case where the parameters in the system message are determined by the CU, the system message may include other system messages (other SIBs).

Based on the above technical solution, when the configuration information of the AS signaling is included in the system message, the parameters in the system message can be determined by the CU or DU. Accordingly, the DU and the CU can interactively clarify the configuration information of the AS signaling to both parties, and subsequently receive and process the AS signaling from the terminal device based on the configuration information of the AS signaling.

In a possible implementation manner of the second aspect, the configuration information of the AS signaling is included in the RRC release message, and the method also includes: the DU receives a user equipment context modification request (UE CONTEXT MODIFICATION REQUEST) message from the CU; the DU sends a user equipment context modification response (UE CONTEXT MODIFICATION RESPONSE) message to the CU; the DU receives a user context release command (UE CONTEXT RELEASE COMMAND) message from the CU, and the UE CONTEXT RELEASE COMMAND message includes the RRC release message; wherein, the UE CONTEXT MODIFICATION REQUEST message includes the configuration information of the AS signaling, and/or, the UE CONTEXT RELEASE COMMAND message includes the configuration information of the AS signaling.

Based on the above technical solution, when the configuration information of the AS signaling is included in the RRC release message, the DU can obtain the RRC release message in the above manner. Moreover, the configuration information of the AS signaling can be made clear to both parties based on the above interaction process, and the AS signaling from the terminal device can be received and processed based on the configuration information of the AS signaling.

In a possible implementation of the second aspect, the UE CONTEXT MODIFICATION REQUEST message includes indication information for indicating that the configuration information of the AS signaling is retained, or the UE CONTEXT RELEASE COMMAND message includes indication information for indicating that the configuration information of the AS signaling is retained.

Optionally, the indication information is carried in a CG-SDT query (CG-SDT query) message/information sent by the CU to the DU.

Based on the above technical solution, when the configuration information of the AS signaling is included in the RRC release message, the CU can send the indication information to the DU in the above manner, so that the DU retains the configuration information of the AS signaling based on the indication information, so that the subsequent DU can receive and process the AS signaling from the terminal device based on the retained configuration information of the AS signaling.

In a possible implementation of the second aspect, the RRC release message includes CG configuration information corresponding to the transmission resources of the SDT mode.

Based on the above technical solution, when the RRC release message includes the CG configuration information corresponding to the transmission resources of the SDT method, the terminal device can send AS signaling based on the configured grant small data transmission (CG-SDT) method, so that the above solution can be applicable to the CG-SDT transmission scenario.

In a possible implementation manner of the second aspect, the system message includes RA configuration information corresponding to the transmission resource of the SDT mode.

Based on the above technical solution, when the system message includes the RA configuration information corresponding to the transmission resources of the SDT method, the terminal device can send AS signaling based on random access small data transmission (RA-SDT), so that the above solution can be applicable to the RA-SDT transmission scenario.

In a possible implementation manner of the second aspect, the method further includes: when the terminal device is in an RRC inactive state, the DU receives an RRC recovery request message.

Optionally, the RRC reply request message and the AS signaling transmitted based on the SDT method are located in the same transport block (TB) (or the same data packet).

Based on the above technical solution, when the terminal device sends AS signaling based on the SDT method, the terminal device can also use the SDT upload mechanism to send an RRC recovery request message, so as to provide the network device with relevant information of the terminal device (such as the identification of the terminal device, etc.) through the RRC recovery request message.

In a possible implementation of the second aspect, the RRC recovery request message includes indication information for indicating the reason for RRC recovery, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer corresponding to the AS signaling.

Optionally, the method also includes: the DU sends an initial uplink radio resource control information transmission (INITIAL UL RRC MESSAGE TRANSFER) message to the CU, and the INITIAL UL RRC MESSAGE TRANSFER message includes the RRC recovery request message.

Optionally, the method also includes: the DU sends an initial uplink radio resource control information transmission (UL RRC MESSAGE TRANSFER message) to the CU, and the UL RRC MESSAGE TRANSFER message includes the RRC recovery request message.

Based on the above technical solution, the RRC recovery request message received by the DU and sent to the CU may also include indication information indicating the RRC recovery reason, and the indication information may include at least one of the above items, and the manner in which the relevant information of the AS signaling is indicated by the indication information can enable The network device can determine the reason why the terminal device initiates RRC recovery based on the indication information.

The third aspect of the present application provides a communication method, which is executed by a CU, or the method is executed by some components in the CU (such as a processor, a chip or a chip system, etc.), or the method can also be implemented by a logic module or software that can implement all or part of the CU functions. In the third aspect and its possible implementation, the communication method is described as being executed by a CU. In this method, the CU determines the configuration information for transmitting AS signaling based on the SDT mode; the CU receives the AS signaling from the DU, wherein the AS signaling comes from a terminal device in an inactive state of the radio resource control RRC.

Based on the above technical solution, after the CU determines the configuration information for transmitting the AS signaling based on the SDT mode, when the terminal device is in the RRC inactive state, the DU receives the AS signaling from the terminal device in the transmission resource of the SDT mode, and the DU sends the AS signaling to the CU. Therefore, for the terminal device in the RRC inactive state, based on the configuration information of the AS signaling, the uplink transmission of the AS signaling can be realized, and the process of sending the AS signaling based on the SDT mode can also obtain the gain of fast transmission of the AS signaling, so as to improve the communication efficiency.

In a possible implementation of the third aspect, the AS signaling includes RRC messages and/or MAC CE.

Optionally, the AS signaling involved in the present application may include data/signaling involved in each protocol layer contained in the AS layer, including but not limited to at least one of the radio resource control (RRC) protocol, packet data convergence protocol (PDCP), radio link control (RLC) protocol, medium access control (MAC) layer protocol, and physical (PHY) layer protocol.

It can be understood that the signaling transmitted by the RRC layer includes RRC messages, and the signaling transmitted by the MAC layer includes MAC CE.

In a possible implementation of the third aspect, when the AS signaling includes an RRC message, the RRC message is carried in an uplink radio resource control information transmission UL RRC MESSAGE TRANSFER message; and/or, when the AS signaling includes MAC CE, the information carried by the MAC CE is carried in an F1-AP message.

Based on the above technical solution, after the DU receives the AS signaling from the terminal device in the RRC inactive state, the DU can also send the AS signaling to the CU so that the CU can obtain and process the AS signaling. Among them, the DU can send the AS signaling to the CU in the above-mentioned multiple ways to improve the flexibility of the solution implementation.

In a possible implementation manner of the third aspect, the configuration information of the AS signaling includes at least one of the following:

The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or,

The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or

The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or

The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode.

Based on the above technical solution, the configuration information for transmitting AS signaling based on the SDT mode determined by the CU may include at least one of the above items to enhance the flexibility of the solution implementation. Moreover, the terminal device can clarify whether to send RRC messages and/or MAC CE based on the SDT mode when in the RRC inactive state based on at least one of the above information.

In a possible implementation of the third aspect, the configuration information of the AS signaling is included in a system message sent by the DU to the terminal device; the parameters in the system message are determined by the DU, and the method also includes: the CU receives the configuration information of the AS signaling from the DU; or, the parameters in the system message are determined by the CU, and the method also includes: the CU sends the configuration information of the AS signaling to the DU.

Optionally, when the parameters in the system message are determined by the DU, the system message includes at least one of SIB1, SIB10, SIB12, SIB13, SIB14, SIB15, SIB17, SIB18 or SIB20.

Optionally, in the case where the parameters in the system message are determined by the CU, the system message may include other system messages (other SIBs).

Based on the above technical solution, when the configuration information of the AS signaling is included in the system message, the parameters in the system message can be determined by the CU or DU. Accordingly, the DU and the CU can interactively clarify the configuration information of the AS signaling to both parties, and subsequently receive and process the AS signaling from the terminal device based on the configuration information of the AS signaling.

In a possible implementation manner of the third aspect, the configuration information of the AS signaling is included in the RRC release message sent by the DU to the terminal device, and the method also includes: the CU sends a user equipment context modification request (UE CONTEXT MODIFICATION REQUEST) message to the DU; the CU receives a user equipment context modification response (UE CONTEXT MODIFICATION RESPONSE) message from the DU; the CU sends a user context release command (UE CONTEXT RELEASE COMMAND) message to the DU, and the UE CONTEXT RELEASE COMMAND message includes the RRC release message; wherein, the UE CONTEXT MODIFICATION REQUEST message includes the configuration information of the AS signaling, and/or, the UE CONTEXT RELEASE COMMAND message includes the configuration information of the AS signaling.

Based on the above technical solution, when the configuration information of the AS signaling is included in the RRC release message, the DU can Obtain the RRC release message. In addition, based on the above interaction process, the CU and DU can make the configuration information of the AS signaling clear to both parties, and subsequently receive and process the AS signaling from the terminal device based on the configuration information of the AS signaling.

In a possible implementation of the third aspect, the UE CONTEXT MODIFICATION REQUEST message includes indication information for indicating that the configuration information of the AS signaling is retained, or the UE CONTEXT RELEASE COMMAND message includes indication information for indicating that the configuration information of the AS signaling is retained.

Optionally, the indication information is carried in a CG-SDT query (CG-SDT query) message/information sent by the CU to the DU.

Based on the above technical solution, when the configuration information of the AS signaling is included in the RRC release message, the CU can send the indication information to the DU in the above manner, so that the DU retains the configuration information of the AS signaling based on the indication information, so that the subsequent DU can receive and process the AS signaling from the terminal device based on the retained configuration information of the AS signaling.

In a possible implementation of the third aspect, the RRC release message includes configuration authorization CG configuration information corresponding to the transmission resources of the SDT mode.

Based on the above technical solution, when the RRC release message includes the CG configuration information corresponding to the transmission resources of the SDT method, the terminal device can send AS signaling based on the configured grant small data transmission (CG-SDT) method, so that the above solution can be applicable to the CG-SDT transmission scenario.

In a possible implementation manner of the third aspect, the system message includes random access RA configuration information corresponding to the transmission resource of the SDT mode.

Based on the above technical solution, when the system message includes the RA configuration information corresponding to the transmission resources of the SDT method, the terminal device can send AS signaling based on random access small data transmission (RA-SDT), so that the above solution can be applicable to the RA-SDT transmission scenario.

In a possible implementation of the third aspect, the RRC recovery request message includes indication information for indicating the reason for RRC recovery, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer corresponding to the AS signaling.

Optionally, the method also includes: the CU receives an initial uplink radio resource control information transmission (INITIAL UL RRC MESSAGE TRANSFER) message from the DU, and the INITIAL UL RRC MESSAGE TRANSFER message includes the RRC recovery request message.

Optionally, the method also includes: the CU receives an initial uplink radio resource control information transmission (UL RRC MESSAGE TRANSFER message) from the DU, and the UL RRC MESSAGE TRANSFER message includes the RRC recovery request message.

Based on the above technical solution, the RRC recovery request message received by the DU and sent to the CU may also include indication information indicating the reason for the RRC recovery. The indication information may include at least one of the above items. By indicating the relevant information of the AS signaling through the indication information, the network device can clarify the reason why the terminal device initiates the RRC recovery based on the indication information.

The fourth aspect of the present application provides a communication method, which is executed by a network device, or the method is executed by some components in the network device (such as a processor, a chip or a chip system, etc.), or the method can also be implemented by a logic module or software that can realize all or part of the network device functions. In the fourth aspect and its possible implementation, the communication method is described as an example of being executed by a network device. In this method, the network device determines the configuration information of the access layer AS signaling based on the small data transmission SDT mode; the network device sends the configuration information of the AS signaling.

Based on the above technical solution, after the network device determines the configuration information for transmitting the AS signaling based on the SDT mode, the network device sends the configuration information of the AS signaling, so that when the terminal device is in the RRC inactive state, the network device receives the AS signaling from the terminal device in the transmission resource of the SDT mode. Thus, for the terminal device in the RRC inactive state, based on the configuration information of the AS signaling sent by the network device, the uplink transmission of the AS signaling can be realized, and the process of sending the AS signaling based on the SDT mode can also obtain the gain of fast transmission of the AS signaling, so as to improve the communication efficiency.

In a possible implementation manner of the fourth aspect, the method further includes: when the terminal device is in a radio resource control RRC inactive state, the network device receives the AS signaling, wherein the AS signaling is carried on the transmission resources of the SDT mode.

Based on the above technical solution, when the terminal device is in an RRC inactive state, the network device receives AS signaling from the terminal device in the transmission resources of the SDT mode to implement the process of transmitting AS signaling based on the SDT mode.

In a possible implementation manner of the fourth aspect, the network device is a destination network device of the terminal device, and the configuration information of the AS signaling is included in a system message.

Based on the above technical solution, when the network device is the destination network device of the terminal device, the destination network device can The configuration information of AS signaling is sent through system messages, so that the terminal device can send AS signaling based on random access small data transmission (RA-SDT), so that the above solution can be applied to the transmission scenario of RA-SDT.

In addition, the network device that sends the RRC release message to the terminal device is the source network device, and the configuration information of the AS signaling used by the terminal device comes from the destination network device, so that the terminal device can send AS signaling based on the configuration from the destination network device when residing/cell reselecting to the destination network device in the RRC inactive state, so that the above solution can be applicable to the station change scenario (or the scenario where the network device to which the terminal device is connected is switched/reselected).

Optionally, the network device is the source network device of the terminal device, and accordingly, the configuration information of the AS signaling sent by the source network device to the terminal device can be included in the system message sent by the source network device, so that the above scheme can be applicable to the transmission scenario of RA-SDT. Alternatively, the configuration information of the AS signaling sent by the source network device to the terminal device can be included in the RRC release message sent by the source network device, so that the above scheme can be applicable to the transmission scenario of CG-SDT.

In a possible implementation manner of the fourth aspect, the method also includes: the network device sends a retrieve user device context request (RETRIEVE UE CONTEXT REQUEST) message to the source network device of the terminal device; the network device receives a retrieve user device context response (RETRIEVE UE CONTEXT RESPONSE) message from the source network device, or receives a retrieve user device context failure (RETRIEVE UE CONTEXT FAILURE) message from the source network device.

Based on the above technical solution, when the network device is the destination network device of the terminal device, the destination network device can obtain the context information corresponding to the terminal device through the above-mentioned interaction with the source network device, in order to quickly restore the RRC connection with the terminal device.

Optionally, the RETRIEVE UE CONTEXT RESPONSE message may carry configuration information for transmitting AS signaling based on the SDT method configured by the source network device.

The fifth aspect of the present application provides a communication method, which is executed by a terminal device, or the method is executed by some components in the terminal device (such as a processor, a chip or a chip system, etc.), or the method can also be implemented by a logic module or software that can realize all or part of the functions of the terminal device. In the fifth aspect and its possible implementation, the communication method is described as being executed by a terminal device. In this method, when the terminal device is in an RRC inactive state, the terminal device sends an RRC recovery request message, and the RRC recovery request message includes indication information for indicating that the reason for RRC recovery is AS signaling; the terminal device sends the AS signaling after restoring the RRC connection state.

Based on the above technical solution, when the terminal device is in the RRC inactive state, the RRC recovery request message sent by the terminal device includes indication information for indicating that the RRC recovery reason is AS signaling, and the terminal device sends the AS signaling after restoring the RRC connection state. Thus, for the terminal device in the RRC inactive state, after the RRC connection is restored based on the indication information carried by the RRC recovery request message, the uplink transmission of the AS signaling can be realized.

In a possible implementation manner of the fifth aspect, the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer SRB corresponding to the AS signaling.

Based on the above technical solution, the RRC recovery request message sent by the terminal device may also include indication information indicating the reason for RRC recovery. The indication information may include at least one of the above items. By indicating the relevant information of the AS signaling through the indication information, the network device can clarify the reason why the terminal device initiates RRC recovery based on the indication information.

In a possible implementation manner of the fifth aspect, before sending the RRC recovery request message, the method further includes: receiving, by the terminal device, an RRC release message, where the RRC release message includes at least one of the following information:

Indicates whether RRC connection recovery triggered by AS signaling is supported in RRC non-connected state; or,

The triggering condition of the AS signaling; or

The T319 timer corresponding to the RRC recovery request message.

It is understandable that the T319 timer is started when the RRC recovery request (RRCResumeRequest) message is sent, and when it times out, the terminal device considers that the RRC connection recovery has failed. Optionally, after the terminal device determines that the RRC connection recovery has failed, the terminal device enters the RRC idle state.

Based on the above technical solution, the RRC recovery request message that triggers the terminal device to enter the RRC inactive state can carry at least one of the above information, so that the terminal device can determine whether to realize the uplink transmission of AS signaling by restoring the RRC connection when it is in the RRC inactive state based on the at least one information.

In a possible implementation manner of the fifth aspect, when at least one of the following items is met, sending the RRC recovery request message includes: The terminal device is configured to allow entering the RRC connected state to send the AS signaling, or the terminal device is triggered to send the AS signaling when it is in the RRC inactive state.

Based on the above technical solution, when at least one of the above items is met, the terminal device triggers sending an RRC recovery request message, so that the terminal device can realize uplink transmission of AS signaling by restoring the RRC connection when it is in an RRC inactive state.

The sixth aspect of the present application provides a communication method, which is executed by a network device, or the method is executed by some components in the network device (such as a processor, a chip or a chip system, etc.), or the method can also be implemented by a logic module or software that can realize all or part of the network device functions. In the sixth aspect and its possible implementation, the communication method is described as being executed by a network device. In this method, when the terminal device is in a radio resource control RRC inactive state, the network device receives an RRC recovery request message, and the RRC recovery request message includes indication information for indicating that the RRC recovery reason is AS signaling; after the terminal device restores the RRC connection state, the network device receives the AS signaling.

Based on the above technical solution, when the terminal device is in the RRC inactive state, the RRC recovery request message sent by the terminal device includes indication information for indicating that the RRC recovery reason is AS signaling, and the terminal device sends the AS signaling after restoring the RRC connection state. Thus, for the terminal device in the RRC inactive state, after the RRC connection is restored based on the indication information carried by the RRC recovery request message, the uplink transmission of the AS signaling can be realized.

In a possible implementation manner of the sixth aspect, the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer SRB corresponding to the AS signaling.

Based on the above technical solution, the RRC recovery request message sent by the terminal device may also include indication information indicating the reason for RRC recovery. The indication information may include at least one of the above items. By indicating the relevant information of the AS signaling through the indication information, the network device can clarify the reason why the terminal device initiates RRC recovery based on the indication information.

In a possible implementation manner of the sixth aspect, before sending the RRC recovery request message, the method further includes: the network device sending an RRC release message, where the RRC release message includes at least one of the following information:

Indicates whether RRC connection recovery triggered by AS signaling is supported in RRC non-connected state; or,

The triggering condition of the AS signaling; or,

The T319 timer corresponding to the RRC recovery request message.

It is understandable that the T319 timer is started when the RRC recovery request (RRCResumeRequest) message is sent, and when it times out, the terminal device considers that the RRC connection recovery has failed. Optionally, after the terminal device determines that the RRC connection recovery has failed, the terminal device enters the RRC idle state.

Based on the above technical solution, the RRC recovery request message that triggers the terminal device to enter the RRC inactive state can carry at least one of the above information, so that the terminal device can determine whether to realize the uplink transmission of AS signaling by restoring the RRC connection when it is in the RRC inactive state based on the at least one information.

In the seventh aspect of the present application, a communication device is provided, which is a terminal device, or the device is a partial component in the terminal device (such as a processor, a chip or a chip system, etc.), or the device can also be a logic module or software that can realize all or part of the functions of the terminal device. In the seventh aspect and its possible implementation, the communication device is described as an example of execution as a terminal device. The device includes a transceiver unit and a processing unit; the transceiver unit is used to receive configuration information of access layer AS signaling based on a small data transmission SDT mode; when the terminal device is in a radio resource control RRC inactive state, the processing unit is used to determine the AS signaling, and the transceiver unit is used to send the AS signaling, wherein the AS signaling is carried on the transmission resources of the SDT mode.

In a possible implementation of the seventh aspect, the AS signaling includes an RRC message and/or a media access control element MAC CE.

In a possible implementation manner of the seventh aspect, the configuration information of the AS signaling includes at least one of the following:

The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or,

The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or

The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or,

The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode.

In a possible implementation manner of the seventh aspect, the configuration information of the AS signaling is included in an RRC release message or a system message.

In a possible implementation of the seventh aspect, the RRC release message includes configuration authorization CG configuration information corresponding to the transmission resources of the SDT mode.

In a possible implementation manner of the seventh aspect, the system message includes a random access RA corresponding to the transmission resource in the SDT mode. Configuration information.

In a possible implementation manner of the seventh aspect, the transceiver unit is further used to receive an RRC release message from a source network device, and the configuration information of the AS signaling is included in a system message from a destination network device.

In a possible implementation of the seventh aspect, the RRC release message also includes configuration information for transmitting AS signaling based on SDT configured by the source network device; the processing unit is also used to delete the configuration information for transmitting AS signaling based on SDT configured by the source network device.

In a possible implementation manner of the seventh aspect, when the terminal device is in an RRC inactive state, the transceiver unit is further used to send an RRC recovery request message.

In a possible implementation of the seventh aspect, the RRC recovery request message also includes indication information for indicating the reason for RRC recovery, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer SRB corresponding to the AS signaling.

In a possible implementation manner of the seventh aspect, the processing unit is further configured to ignore at least one of the following:

Resume other DRBs and SRBs configured with SDT; or,

Check at the media access control (MAC) layer whether the data volume is exceeded; or,

All data is mapped to the DRB or SRB of the SDT; or,

The higher layer requests to restore the radio access control (RRC) connection.

In the seventh aspect of the embodiment of the present application, the constituent modules of the communication device can also be used to execute the steps performed in each possible implementation method of the first aspect and achieve corresponding technical effects. For details, please refer to the first aspect and will not be repeated here.

In an eighth aspect of the present application, a communication device is provided, which is a DU, or the device is a partial component in the DU (such as a processor, a chip or a chip system, etc.), or the device can also be a logic module or software that can implement all or part of the DU functions. In the eighth aspect and its possible implementation methods, the communication device is described as an example of DU execution. The device includes a transceiver unit and a processing unit. The processing unit is used to determine the configuration information of the AS signaling transmitted based on the small data transmission SDT mode, and the transceiver unit is used to send the configuration information of the AS signaling; the transceiver unit is used to receive the AS signaling from a terminal device in an RRC inactive state, wherein the AS signaling is carried on the transmission resources of the SDT mode.

In a possible implementation of the eighth aspect, the AS signaling includes an RRC message and/or a media access control element MAC CE.

In a possible implementation of the eighth aspect, the transceiver unit is also used to send the AS signaling to the centralized unit CU; when the AS signaling includes an RRC message, the RRC message is carried on an uplink radio resource control information transmission UL RRC MESSAGE TRANSFER message; and/or, when the AS signaling includes MAC CE, the information carried by the MAC CE is carried on the F1-AP message.

In a possible implementation manner of the eighth aspect, the configuration information of the AS signaling includes at least one of the following:

The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or,

The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or

The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or,

The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode.

In a possible implementation manner of the eighth aspect, the configuration information of the AS signaling is included in an RRC release message or a system message.

In a possible implementation of the eighth aspect, the configuration information of the AS signaling is included in the system message; the parameters in the system message are determined by the DU, and the transceiver unit is also used to send the configuration information of the AS signaling to the CU; or, the parameters in the system message are determined by the CU, and the transceiver unit is also used to receive the configuration information of the AS signaling from the CU.

In a possible implementation of the eighth aspect, the configuration information of the AS signaling is included in the RRC release message, and the transceiver unit is also used to receive a user equipment context modification request UE CONTEXT MODIFICATION REQUEST message from the CU; the transceiver unit is also used to send a user equipment context modification response UE CONTEXT MODIFICATION RESPONSE message to the CU; the transceiver unit is also used to receive a user context release command UE CONTEXT RELEASE COMMAND message from the CU, and the UE CONTEXT RELEASE COMMAND message includes the RRC release message; wherein, the UE CONTEXT MODIFICATION REQUEST message includes the configuration information of the AS signaling, and/or, the UE CONTEXT RELEASE COMMAND message includes the configuration information of the AS signaling.

In a possible implementation manner of the eighth aspect, the UE CONTEXT MODIFICATION REQUEST message includes indication information for indicating that the configuration information of the AS signaling is retained, or the UE CONTEXT RELEASE COMMAND message includes indication information for indicating that the configuration information of the AS signaling is retained.

In a possible implementation of the eighth aspect, the RRC release message includes configuration authorization CG configuration information corresponding to the transmission resources of the SDT mode.

In a possible implementation manner of the eighth aspect, the system message includes random access RA configuration information corresponding to the transmission resources of the SDT mode.

In a possible implementation manner of the eighth aspect, when the terminal device is in an RRC inactive state, the transceiver unit is further used to receive an RRC recovery request message.

In a possible implementation of the eighth aspect, the RRC recovery request message includes indication information for indicating the reason for RRC recovery, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer corresponding to the AS signaling.

In the eighth aspect of the embodiments of the present application, the constituent modules of the communication device can also be used to execute the steps performed in each possible implementation method of the second aspect and achieve corresponding technical effects. For details, please refer to the second aspect and will not be repeated here.

In the ninth aspect of the present application, a communication device is provided, which is a CU, or the device is a partial component in the CU (such as a processor, a chip or a chip system, etc.), or the device can also be a logic module or software that can implement all or part of the CU functions. In the ninth aspect and its possible implementation, the communication device is described as a CU. The device includes a transceiver unit and a processing unit; the processing unit is used to determine the configuration information for transmitting AS signaling based on a small data transmission SDT mode; the transceiver unit is used to receive the AS signaling from a distributed unit DU, wherein the AS signaling comes from a terminal device in an inactive state of the radio resource control RRC.

In a possible implementation of the ninth aspect, the AS signaling includes an RRC message and/or a media access control element MAC CE.

In a possible implementation of the ninth aspect, when the AS signaling includes an RRC message, the RRC message is carried in an uplink radio resource control information transmission UL RRC MESSAGE TRANSFER message; and/or, when the AS signaling includes MAC CE, the information carried by the MAC CE is carried in an F1-AP message.

In a possible implementation manner of the ninth aspect, the configuration information of the AS signaling includes at least one of the following:

The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or,

The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or

The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or,

The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode.

In a possible implementation of the ninth aspect, the configuration information of the AS signaling is included in a system message sent by the DU to the terminal device; the parameters in the system message are determined by the DU, and the transceiver unit is used to receive the configuration information of the AS signaling from the DU; or, the parameters in the system message are determined by the CU, and the transceiver unit is used to send the configuration information of the AS signaling to the DU.

In a possible implementation of the ninth aspect, the configuration information of the AS signaling is included in the RRC release message sent by the DU to the terminal device, and the transceiver unit is also used to send a user equipment context modification request UE CONTEXT MODIFICATION REQUEST message to the DU; the transceiver unit is also used to receive a user equipment context modification response UE CONTEXT MODIFICATION RESPONSE message from the DU; the transceiver unit is also used to send a user context release command UE CONTEXT RELEASE COMMAND message to the DU, and the UE CONTEXT RELEASE COMMAND message includes the RRC release message; wherein, the UE CONTEXT MODIFICATION REQUEST message includes the configuration information of the AS signaling, and/or, the UE CONTEXT RELEASE COMMAND message includes the configuration information of the AS signaling.

In a possible implementation of the ninth aspect, the UE CONTEXT MODIFICATION REQUEST message includes indication information for indicating that the configuration information of the AS signaling is retained, or the UE CONTEXT RELEASE COMMAND message includes indication information for indicating that the configuration information of the AS signaling is retained.

In a possible implementation of the ninth aspect, the RRC release message includes configuration authorization CG configuration information corresponding to the transmission resources of the SDT mode.

In a possible implementation manner of the ninth aspect, the system message includes random access RA configuration information corresponding to the transmission resources of the SDT mode.

In a possible implementation of the ninth aspect, the RRC recovery request message includes indication information for indicating the reason for RRC recovery, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer corresponding to the AS signaling.

In the ninth aspect of the embodiments of the present application, the constituent modules of the communication device can also be used to execute the steps performed in each possible implementation method of the third aspect and achieve corresponding technical effects. For details, please refer to the third aspect and will not be repeated here.

In the tenth aspect of the present application, a communication device is provided, which is a network device, or the device is a partial component in the network device (such as a processor, a chip or a chip system, etc.), or the device can also be a logic module or software that can realize all or part of the functions of the network device. In the tenth aspect and its possible implementation, the communication device is described as an example of a network device. The device includes a transceiver unit and a processing unit; the processing unit is used to determine the configuration information of the access layer AS signaling based on the small data transmission SDT mode; the transceiver unit is used to send the configuration information of the AS signaling.

In a possible implementation of the tenth aspect, when the terminal device is in a radio resource control RRC inactive state, the transceiver unit is also used to receive the AS signaling, wherein the AS signaling is carried on the transmission resources of the SDT mode.

In a possible implementation manner of the tenth aspect, the network device is a destination network device of the terminal device, and the configuration information of the AS signaling is included in a system message.

In a possible implementation of the tenth aspect, the transceiver unit is further used to send a retrieval user equipment context request RETRIEVE UE CONTEXT REQUEST message to the source network device of the terminal device; the transceiver unit is further used to receive a retrieval user equipment context response RETRIEVE UE CONTEXT RESPONSE message from the source network device, or, receive a retrieval user equipment context failure RETRIEVE UE CONTEXT FAILURE message from the source network device.

In the tenth aspect of the embodiment of the present application, the constituent modules of the communication device can also be used to execute the steps performed in each possible implementation method of the fourth aspect and achieve corresponding technical effects. For details, please refer to the fourth aspect and will not be repeated here.

In the eleventh aspect of the present application, a communication device is provided, which is a terminal device, or the device is a partial component in the terminal device (such as a processor, a chip or a chip system, etc.), or the device can also be a logic module or software that can realize all or part of the functions of the terminal device. In the eleventh aspect and its possible implementation, the communication device is described as an example of execution of the terminal device. The device includes a transceiver unit and a processing unit; when the terminal device is in a radio resource control RRC inactive state, the processing unit is used to determine an RRC recovery request message, and the transceiver unit is used to send an RRC recovery request message, and the RRC recovery request message includes an indication information for indicating that the RRC recovery reason is AS signaling; after restoring the RRC connection state, the transceiver unit is also used to send the AS signaling.

In a possible implementation of the eleventh aspect, the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer SRB corresponding to the AS signaling.

In a possible implementation manner of the eleventh aspect, before sending the RRC recovery request message, the transceiver unit is further configured to receive an RRC release message, where the RRC release message includes at least one of the following information:

Indicates whether RRC connection recovery triggered by AS signaling is supported in RRC non-connected state; or,

The triggering condition of the AS signaling; or,

The T319 timer corresponding to the RRC recovery request message.

In a possible implementation of the eleventh aspect, the transceiver unit sends the RRC recovery request message when at least one of the following is met, including: the terminal device is configured to allow entering the RRC connected state to send the AS signaling, or the terminal device is in the RRC inactive state and triggers the sending of the AS signaling.

In the eleventh aspect of the embodiment of the present application, the constituent modules of the communication device can also be used to execute the steps performed in each possible implementation method of the fifth aspect and achieve corresponding technical effects. For details, please refer to the fifth aspect and will not be repeated here.

The twelfth aspect of the present application provides a communication device, which is a network device, or the device is a partial component in the network device (such as a processor, a chip or a chip system, etc.), or the device can also be a logic module or software that can implement all or part of the network device functions. In the twelfth aspect and its possible implementation, the communication device is described as an example of execution as a network device. The device includes a transceiver unit and a processing unit; when the terminal device is in a radio resource control RRC inactive state, the transceiver unit is used to receive an RRC recovery request message, and the RRC recovery request message includes an indication information for indicating that the RRC recovery reason is AS signaling; after the processing unit determines that the terminal device restores the RRC connection state, the transceiver unit is also used to receive the AS signaling.

In a possible implementation manner of the twelfth aspect, the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer SRB corresponding to the AS signaling.

In a possible implementation manner of the twelfth aspect, before sending the RRC recovery request message, the transceiver unit is further configured to send an RRC release message, where the RRC release message includes at least one of the following information:

Indicates whether RRC connection recovery triggered by AS signaling is supported in RRC non-connected state; or,

The triggering condition of the AS signaling; or

The T319 timer corresponding to the RRC recovery request message.

In the twelfth aspect of the embodiment of the present application, the constituent modules of the communication device can also be used to execute the steps performed in each possible implementation method of the sixth aspect and achieve corresponding technical effects. For details, please refer to the sixth aspect and will not be repeated here.

A thirteenth aspect of an embodiment of the present application provides a communication device, comprising at least one processor, wherein the at least one processor is coupled to a memory; the memory is used to store programs or instructions; wherein the at least one processor is used to execute the program or instructions so that the device implements the method described in any one of the first to sixth aspects and any possible implementation method thereof.

A fourteenth aspect of an embodiment of the present application provides a communication device, including at least one logic circuit and an input/output interface; the logic circuit is used to execute the method described in any one of the first to sixth aspects and any possible implementation method thereof.

A fifteenth aspect of an embodiment of the present application provides a computer-readable storage medium, which stores instructions. When the instructions are executed by a processor, the processor executes the method described in any one of the first to sixth aspects above and any possible implementation method thereof.

A sixteenth aspect of an embodiment of the present application provides a computer program product (or computer program), which includes a computer program code. When the computer program code is executed by a processor, the processor executes the method described in any one of the first to sixth aspects and any possible implementation method thereof.

A seventeenth aspect of an embodiment of the present application provides a chip system, which includes at least one processor for supporting a communication device to implement the functions involved in any one of the first to sixth aspects above and any possible implementation methods thereof.

In one possible design, the chip system may also include a memory for storing program instructions and data necessary for the first communication device. The chip system may be composed of a chip, or may include a chip and other discrete devices. Optionally, the chip system also includes an interface circuit, which provides program instructions and/or data for the at least one processor.

The eighteenth aspect of the embodiment of the present application provides a communication system, which includes the communication device of the seventh aspect, the communication device of the eighth aspect and the communication device of the ninth aspect. Alternatively, the communication system includes the communication device of the seventh aspect and the communication device of the tenth aspect. Alternatively, the communication system includes the communication devices of the eleventh aspect and the twelfth aspect.

It should be understood that the technical effects brought about by any design method in the seventh to eighteenth aspects can refer to the technical effects brought about by the different design methods in the above-mentioned first to sixth aspects, and will not be repeated here.

It can be seen from the above technical solutions that the solution provided by this application has the following beneficial effects:

In some implementations, for a terminal device in an RRC inactive state, based on the configuration information of the AS signaling received by the terminal device, the uplink transmission of the AS signaling can be achieved. At the same time, the process of sending the AS signaling based on the SDT method can also obtain the gain of quickly transmitting the AS signaling, so as to improve communication efficiency.

In some implementations, the terminal device receives an RRC release message from the source network device, so that the terminal device enters the RRC inactive state from the RRC connected state. In addition, the configuration information of the AS signaling used by the terminal device comes from the destination network device, so that the terminal device can send AS signaling based on the configuration from the destination network device when it resides/reselects to the destination network device in the RRC inactive state, so that the above solution can be applied to the station change scenario (or the scenario where the network device to which the terminal device is connected is switched/reselected).

In some other implementations, when the terminal device is in an RRC inactive state, the RRC recovery request message sent by the terminal device includes indication information for indicating that the RRC recovery reason is AS signaling, and the terminal device sends the AS signaling after restoring the RRC connection state. Thus, for the terminal device in the RRC inactive state, after the RRC connection is restored based on the indication information carried by the RRC recovery request message, uplink transmission of the AS signaling can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a communication system provided by the present application;

FIG2a is another schematic diagram of a communication system provided by the present application;

FIG2b is another schematic diagram of a communication system provided by the present application;

FIG3a is a schematic diagram of a communication method provided by the present application;

FIG3b is another schematic diagram of the communication method provided by the present application;

FIG4 is another schematic diagram of the communication method provided by the present application;

FIG5a is another schematic diagram of the communication method provided by the present application;

FIG5b is another schematic diagram of the communication method provided by the present application;

FIG6a is another schematic diagram of the communication method provided by the present application;

FIG6b is another schematic diagram of the communication method provided by the present application;

FIG7 is another schematic diagram of the communication method provided by the present application;

FIG8 is another schematic diagram of the communication method provided by the present application;

FIG9 is another schematic diagram of the communication method provided by the present application;

FIG10 is a schematic diagram of a communication protocol stack provided by the present application;

FIG11 is another schematic diagram of the communication method provided by the present application;

FIG12 is a schematic diagram of a communication device provided by the present application;

FIG13 is another schematic diagram of a communication device provided by the present application;

FIG14 is another schematic diagram of a communication device provided by the present application;

FIG15 is another schematic diagram of the communication device provided in the present application.

DETAILED DESCRIPTION

First, some terms in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

(1) Terminal device: It can be a wireless terminal device that can receive network device scheduling and instruction information. The wireless terminal device can be a device that provides voice and/or data connectivity to users, or a handheld device with wireless connection function, or other processing devices connected to a wireless modem.

The terminal equipment can communicate with one or more core networks or the Internet via the radio access network (RAN). The terminal equipment can be a mobile terminal equipment, such as a mobile phone (or "cellular" phone, mobile phone), a computer and a data card. For example, it can be a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device that exchanges voice and/or data with the radio access network. For example, personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDA), tablet computers (Pad), computers with wireless transceiver functions and other devices. Wireless terminal equipment can also be called system, subscriber unit, subscriber station, mobile station, mobile station (MS), remote station, access point (AP), remote terminal equipment (remote terminal), access terminal equipment (access terminal), user terminal equipment (user terminal), user agent (user agent), subscriber station (SS), customer premises equipment (CPE), terminal, user equipment (UE), mobile terminal (MT), etc.

As an example but not limitation, in the embodiments of the present application, the terminal device may also be a wearable device. Wearable devices may also be referred to as wearable smart devices or smart wearable devices, etc., which are a general term for the application of wearable technology to intelligently design and develop wearable devices for daily wear, such as glasses, gloves, watches, clothing and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also powerful functions achieved through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include full-featured, large-sized, and independent of smartphones to achieve complete or partial functions, such as smart watches or smart glasses, etc., as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various types of smart bracelets, smart helmets, smart jewelry, etc.

The terminal can also be a drone, a robot, a terminal in device-to-device (D2D) communication, a terminal in vehicle to everything (V2X), a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc.

In addition, the terminal device may also be a terminal device in a communication system that evolves after the fifth generation (5th generation, 5G) communication system (e.g., a sixth generation (6th generation, 6G) communication system, etc.) or a terminal device in a public land mobile network (PLMN) that evolves in the future, etc. Exemplarily, the 6G network can further expand the form and function of the 5G communication terminal, and the 6G terminal includes but is not limited to a car, a cellular network terminal (with integrated satellite terminal function), a drone, and an Internet of Things (IoT) device.

(2) Network equipment: It can be equipment in a wireless network. For example, the network equipment can be a RAN node (or device) that connects a terminal device to a wireless network, which can also be called a base station. At present, some examples of RAN equipment are: base station gNB (gNodeB) in a 5G communication system, transmission reception point (TRP), evolved Node B (eNB), radio network controller (RNC), Node B (NB), home base station (e.g., home evolved Node B, or home Node B, HNB), baseband unit (BBU). In addition, in a network structure, the network equipment may include a centralized unit (CU) node, a distributed unit (DU) node, or a RAN device including a CU node and a DU node.

The network device may be any other device that provides wireless communication functions for the terminal device. The embodiments of the present application do not limit the specific technology and specific device form used by the network device. For the convenience of description, the embodiments of the present application do not limit.

In the embodiment of the present application, the device for realizing the function of the network device may be a network device, or may be a device capable of supporting the network device to realize the function, such as a chip system, which may be installed in the network device. In the technical solution provided in the embodiment of the present application, the technical solution provided in the embodiment of the present application is described by taking the device for realizing the function of the network device as an example that the network device is used as the device.

(3) Configuration and pre-configuration: In this application, configuration and pre-configuration are used at the same time. Configuration refers to the network device/server sending some parameter configuration information or parameter values to the terminal through messages or signaling, so that the terminal can determine the communication parameters or resources during transmission based on these values or information. Pre-configuration is similar to configuration, and can be parameter information or parameter values pre-negotiated between the network device/server and the terminal device, or parameter information or parameter values used by the base station/network device or terminal device specified by the standard protocol, or parameter information or parameter values pre-stored in the base station/server or terminal device. This application does not limit this.

Furthermore, these values and parameters can be changed or updated.

(4) The terms "system" and "network" in the embodiments of the present application can be used interchangeably. "Multiple" refers to two or more. "And/or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character "/" generally indicates that the objects associated with each other are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of A, B and C" includes A, B, C, AB, AC, BC or ABC. And, unless otherwise specified, the ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the order, timing, priority or importance of multiple objects.

In this application, unless otherwise specified, the same or similar parts between the various embodiments can refer to each other. In the various embodiments in this application, and the various methods/designs/implementations in each embodiment, if there is no special description and logical conflict, the terms and/or descriptions between different embodiments and the various methods/designs/implementations in each embodiment are consistent and can be referenced to each other. The technical features in different embodiments and the various methods/designs/implementations in each embodiment can be combined to form new embodiments, methods, or implementations according to their inherent logical relationships. The implementation methods of this application described below do not constitute a limitation on the scope of protection of this application.

FIG1 is a schematic diagram of the architecture of a communication system 1000 used in an embodiment of the present application.

As shown in FIG1 , the communication system includes a wireless access network 100 and a core network 200. Optionally, the communication system 1000 may also include the Internet 300. The wireless access network 100 may include at least one wireless access network device (which may also be understood as a network device introduced in the foregoing text, such as 110a and 110b in FIG1 ), and may also include at least one terminal (which may also be understood as a terminal device introduced in the foregoing text, such as 120a-120j in FIG1 ). In addition, the wireless access network device may be a macro base station (such as 110a in FIG1 ), a micro base station or an indoor station (such as 110b in FIG1 ), or a relay node or a donor node, etc. It can be understood that all or part of the functions of the wireless access network device in the present application may also be implemented by software functions running on hardware, or by virtualization functions instantiated on a platform (such as a cloud platform). The embodiments of the present application do not limit the specific technology and specific device form adopted by the wireless access network device.

For ease of description, a base station is used as a wireless access network device, and a terminal device is recorded as a terminal as an example for description. It can be understood that when the communication system includes an integrated access and backhaul (IAB) network, the base station can be an IAB node.

In this application, the base station and the terminal can be fixed or movable. The base station and the terminal can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted, or on the water surface, or on aircraft, balloons, and artificial satellites in the air. The embodiments of this application do not limit the application scenarios of the base station and the terminal.

The roles of the base station and the terminal may be relative. For example, the helicopter or drone 120i in FIG. 1 may be configured as a mobile base station. For the terminal 120j that accesses the wireless access network 100 through 120i, the terminal 120i is a base station. However, for the base station 110a, 120i is a terminal, that is, 110a and 120i communicate with each other through a wireless air interface protocol. Of course, 110a and 120i can also communicate with each other through an interface protocol between base stations. In this case, relative to 110a, 120i is also a base station. Therefore, base stations and terminals can be collectively referred to as communication devices. 110a and 110b in FIG1 can be referred to as communication devices with base station functions, and 120a-120j in FIG1 can be referred to as communication devices with terminal functions.

Communication between base stations and terminals, between base stations and base stations, and between terminals and terminals can be carried out through authorized spectrum, unauthorized spectrum, or both. Communication can be carried out through spectrum below 6 gigahertz (GHz), spectrum above 6 GHz, or spectrum below 6 GHz and spectrum above 6 GHz at the same time. The embodiments of the present application do not limit the spectrum resources used for wireless communication.

In the embodiments of the present application, the functions of the base station may also be performed by a module (such as a chip) in the base station, or by a control subsystem including the base station function. The control subsystem including the base station function here may be a control center in the application scenarios of the above-mentioned terminals such as smart grid, industrial control, smart transportation, smart city, etc. The functions of the terminal may also be performed by a module (such as a chip or a modem) in the terminal, or by a device including the terminal function.

In this application, the base station sends a downlink signal (or downlink information) to the terminal, and the downlink signal (or downlink information) is carried on a downlink channel. The terminal sends an uplink signal (or uplink information) to the base station, and the uplink signal (or uplink information) is carried on an uplink channel.

It should be understood that the present application can be applied to a long term evolution (LTE) system, a new radio (NR) system, or a communication system evolved after 5G (such as 6G, etc.). The communication system includes a network device and a terminal device.

In one possible implementation, in order to meet the needs of increased network capacity, wider coverage, ultra-high reliability and ultra-low latency, integrated access and backhaul (IAB) technology can be introduced into the communication network. IAB technology can reduce the deployment of optical fibers by using wireless transmission solutions for both access links and backhaul links.

In the IAB network, the relay node, or IAB-node, can provide wireless access services for terminal devices. The service data of the terminal device is transmitted by the IAB-node to the IAB host (IAB-donor) through the wireless backhaul link. The IAB-node consists of an MT part and a DU part. When the IAB-node faces its parent node, it can act as a terminal device, that is, the role of MT; when the IAB-node faces its child node (the child node may be another IAB-node, or an ordinary terminal device), it is regarded as a network device, that is, the role of DU. The IAB-donor is an access network element with complete base station (such as gNB) functions, including CU and DU. The IAB-donor is connected to the core network that serves the terminal device (for example, connected to the 5G core network).

The IAB network will be introduced below in conjunction with the implementation examples shown in FIG. 2a and FIG. 2b.

FIG. 2a is a schematic diagram of a wireless relay scenario.

In the IAB network shown in FIG2a, the terminal devices include UE1 and UE2, and the IAB nodes include IAB Node 1 to IAB Node 5, and an IAB donor node. One or more IAB-nodes may be included in a transmission path between any UE and an IAB-donor. Each IAB-node needs to maintain a wireless backhaul link to the parent node, and also needs to maintain a wireless link with the child node. If the child node of the IAB-node is a terminal device (such as UE1 or UE2 in FIG2a), the wireless access link is between the IAB-node and the child node (ie, the UE). If the child node of the IAB-node is another IAB-node, the wireless backhaul link is between the IAB-node and the child node (ie, the other IAB-node). For example, in Figure 2a, in the path "UE1→IAB-node4→IAB-node3→IAB-node1→IAB-donor", UE1 accesses IAB-node4 through a wireless access link, IAB-node4 is connected to IAB-node3 through a wireless backhaul link, IAB-node3 is connected to IAB-node1 through a wireless backhaul link, and IAB-node1 is connected to IAB-donor through a wireless backhaul link.

As shown in FIG. 2 b , it is a schematic diagram of realizing a wireless relay scenario through standalone (SA) networking.

As shown in Figure 2b, the communication nodes include the 5G core network (5G core, 5GC), the 5G access network equipment (denoted as gNodeB in the figure), the IAB-donor, and one or more IAB-nodes. In Figure 2b, the IAB-node DU (hereinafter simply expressed as IAB-DU) is logically connected to the IAB-donor CU (hereinafter simply expressed as CU) through the F1 interface. In fact, the connection between the IAB-DU and the CU is realized through the NR Uu interface between the IAB-node MT and the parent node DU of each hop, but because the IAB-DU can communicate with the CU in the end, it can be considered that the F1 interface exists logically.

Optionally, the F1 interface supports a user plane protocol (F1-user plane, F1-U) and a control plane protocol (F1-control plane, F1-C). Accordingly, the CU may include a CU control plane entity (CU-CP) and a CU user plane entity (CU-UP). The user plane protocol includes the following: One or more of the protocol layers: general packet radio service tunneling protocol user plane (GTP-U), user datagram protocol (UDP), internet protocol (IP) and other protocol layers. The control plane protocol includes one or more of the following: F1 application protocol (F1AP), stream control transport protocol (SCTP), IP and other protocol layers. Through F1-C, interface management, IAB-DU management, and UE context-related configuration can be performed between IAB-donor and IAB-node. Through F1-U, user plane data transmission and downlink transmission status feedback can be performed between IAB-donor and IAB-node.

In a communication system, the communication protocol stack between a terminal device and a network device may include a radio resource control (RRC) layer. In addition, for a terminal device, there are three RRC states, namely, RRC IDLE state, RRC INACTIVE state, and RRC CONNECTED state. Among them, the RRC connection between the terminal device in the RRC INACTIVE state and the network device is suspended, that is, the RRC connection between the terminal device and the network device is suspended or unavailable, so that the terminal device cannot transmit uplink signals through the suspended RRC connection.

Therefore, for a terminal device in an RRC inactive state, when there is an uplink signal to be sent, how to achieve the transmission of the uplink signal is a technical problem that needs to be solved urgently.

In a possible solution, for a terminal device in an RRC inactive state, the transmission of uplink signals can be achieved through the SDT process. Generally, the terminal device can send SDT in the process of initiating RRC connection recovery, wherein the process of triggering RRC connection recovery may include the step of the terminal device sending an RRC recovery request (RRCResumeRequest) message, and for the terminal device, the sending of the RRCResumeRequest message may be triggered based on at least one of the following conditions, including:

Next generation access network paging (NG-RAN paging), triggered by higher layers (i.e. NAS layer), and access network update (RAN update).

In addition, for a terminal device in an RRC inactive state, the process of initiating SDT needs to meet at least one of the following conditions:

The higher layer (ie, NAS layer) requests to restore the RRC connection. The system information block 1 (SIB1) contains the normal small data transmission configuration (sdt-ConfigCommon). The network side configures the small data transmission configuration (sdt-Config) for the terminal device. All uplink data (data) is mapped to the radio bearer (RB) configured with SDT. The MAC layer indicates that the sending conditions of SDT are met.

Optionally, the MAC layer indicates that the conditions for sending SDT include: the amount of all data mapped to the SDT RB is lower than a threshold, the downlink path loss is higher than a threshold or the threshold is not configured, and the terminal device can send at least one of RA-SDT or CG-SDT.

For ease of understanding, CG-SDT and RA-SDT are introduced below through the processes shown in Figures 3a and 3b. It should be understood that in the following Figures 3a and 3b, the terminal device is UE, and the network device includes DU (denoted as gNB-DU) and CU (denoted as gNB-CU-CP and gNB-CU-UP) as an example for explanation.

As shown in FIG3a , it is a schematic diagram of an implementation process of CG-SDT, which includes the following steps.

Step 1. gNB-CU-CP decides to move UE into RRC_INACTIVE state (gNB-CU-CP decides to move UE into RRC_inactive).

Step 2. gNB-CU-CP decides to configure CG-SDT and sends a UE CONTEXT MODIFICATION REQUEST message to gNB-DU. The UE CONTEXT MODIFICATION REQUEST message contains an indication of a request for CG-SDT resources, namely, a query indicator for configuring authorized small data transmission (CG-SDT query indicator).

Step 3. The gNB-DU sends a UE CONTEXT MODIFICATION RESPONSE message to the gNB-CU-CP, which contains the configuration of the authorized small data transmission lower layer resource (CG-SDT lower layer resource).

Step 4. The gNB-CU-CP sends a BEARER CONTEXT MODIFICATION REQUEST message to the gNB-CU-UP. The BEARER CONTEXT MODIFICATION REQUEST message includes a suspend indication to indicate the suspension of user plane resources.

Step 5. The gNB-CU-UP sends a BEARER CONTEXT MODIFICATION RESPONSE message to the gNB-CU-CP.

Step 6. The gNB-CU-CP sends a UE CONTEXT RELEASE COMMAND message to the gNB-DU, which carries the RRCRelease message indicating the UE CG-SDT configuration.

In the UE CONTEXT RELEASE COMMAND message, the gNB-CU-CP instructs the gNB-DU to save the SDT RLC config, F1-U tunnels, F1AP UE association, etc. through an explicit CG-SDT kept indicator, so that the gNB-DU stores the CG-SDT. Configuration of resources.

Step 7. The gNB-DU sends a RRCRelease message to the UE. The RRCRelease message carries a suspend indication and a CG-SDT config.

Step 8. gNB-DU sends a UE CONTEXT RELEASE COMPLETE message; after that, the UE enters the RRC_INACTIVE state.

After step 8, the UE may implement the CG-SDT process through subsequent steps, that is, execute step 9 after a period of time of UE being in RRC_INACTIVE mode.

Step 9. When the UE wants to send CG-SDT, the UE sends a RRCResumeRequest message and carries uplink small data transmission data and/or uplink small data transmission signaling (UL SDT data and/or UL SDT signalling).

Step 10. gNB-DU sends UL RRC MESSAGE TRANSFER message including RRCResumeRequest message.

Step 11. The gNB-CU-CP sends a BEARER CONTEXT MODIFICATION REQUEST message to the gNB-CU-UP, which is used to request the resumption of the small data transmission data radio bearer (SDT DRB resume).

Step 12. gNB-CU-UP sends a BEARER CONTEXT MODIFICATION RESPONSE message to gNB-CU-CP.

Step 13. When the UE carries UL SDT data in step 9, the gNB-DU sends the cached UL SDT data to the gNB-CU-UP.

Step 13a. When the UE carries the UL SDT signalling in step 9, the gNB-DU sends the cached UL SDT signalling to the gNB-CU-CP.

After that, the UE performs subsequent small data transmission (Subsequent SDT Data transmission).

As shown in FIG3 b , it is a schematic diagram of an implementation process of RA-SDT, which includes the following steps.

Step 1. Uplink data and/or signaling arrives. If the conditions for triggering RA-SDT are met, a RRCResumeRequest message is sent to the gNB-DU, along with UL SDT data and/or UL SDT signalling.

Step 2. gNB-DU buffers UL data/UL signalling.

Step 3. The gNB-DU transmits the RRC message RRCResumeRequest to the gNB-CU through the INITIAL UL RRC MESSAGE TRANSFER message, and carries the SDT indication and assistance information.

Step 4. The gNB-CU-CP sends the NG-AP message UE CONTEXT SETUP REQUEST to the gNB-DU. The message includes the UE’s uplink tunnel endpoint IDs (UL TEIDs).

Step 5. The gNB-DU sends the NG-AP message UE CONTEXT SETUP RESPONSE to the gNB-CU-CP. The message includes the UE’s downlink tunnel endpoint IDs (DL TEIDs).

Step 6. The gNB-CU-CP sends a BEARER CONTEXT MODIFICATION REQUEST message to the gNB-CU-UP. This message is used to indicate the resumption of SDT DRB (SDT DRB resume) and carries DL TEIDs.

Step 7. gNB-CU-UP sends BEARER CONTEXT MODIFICATION RESPONSE to gNB-CU-CP.

As can be seen from the description of the trigger conditions above, the uplink signaling (i.e., UL SDT signalling) of the SDT transmission involved in Figures 3a and 3b is a high-level signaling, i.e., NAS signaling. In future communication systems, when the terminal device is in an RRC inactive state, it may be necessary to send other signaling (such as AS signaling, including RRC messages or MAC CE, etc.). However, the above-mentioned CG-SDT and RA-SDT processes cannot support the SDT triggering process of other signaling other than NAS signaling. Therefore, for a terminal device in an RRC inactive state, when there is AS signaling to be sent, how to send the AS signaling to the network device is a technical problem that needs to be solved urgently.

In order to solve the above problems, the present application provides a communication method and related equipment, which are used to enable a terminal device in an RRC inactive state to realize uplink transmission of AS signaling, and the process of sending the AS signaling based on the SDT mode can also obtain the gain of fast transmission of the AS signaling, so as to improve communication efficiency. The following will be further described in detail with reference to the accompanying drawings.

Please refer to FIG. 4 , which is a schematic diagram of an implementation of the communication method provided in the present application. The method includes the following steps.

Step S401. The DU and the CU determine the configuration information for transmitting AS signaling based on the SDT mode.

Step S402. DU sends the configuration information of AS signaling to the terminal device, and correspondingly, the terminal device receives the configuration information of the AS signaling.

In one possible implementation, the AS signaling includes RRC messages and/or medium access control elements (MAC CE).

Optionally, the AS signaling involved in the present application may include data/signaling involved in each protocol layer included in the AS layer, including but not limited to the radio resource control (RRC) protocol, the packet data convergence protocol, the At least one of the following: protocol, PDCP, radio link control (RLC), medium access control (MAC) layer protocol, and physical (PHY) layer protocol. It can be understood that the signaling transmitted by the RRC layer includes RRC messages, and the signaling transmitted by the MAC layer includes MAC CE.

Exemplarily, the RRC message may include an RRC message for carrying any of the following items, including a dedicated system information block request (Dedicated SIB request), a location measurement indication (Location Measurement Indication) and a user equipment positioning assistance information (UE Positioning Assistance Info), etc. The MAC CE may include a MAC CE for carrying any of the following items, including (multiple entries) Configured Grant Confirmation ((multiple entry) Configured Grant Confirmation), a positioning measurement gap activation/deactivation request (Positioning measurement gap Activation/deactivation request) and a listen-before-talk failure (LBT failure).

In a possible implementation manner, the configuration information of the AS signaling includes at least one of the following:

The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or,

The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or

The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or,

The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode.

Specifically, the configuration information of the AS signaling transmitted based on the SDT mode exchanged between the DU and the CU may include at least one of the above items to enhance the flexibility of the scheme implementation. Moreover, after the terminal device subsequently obtains the configuration information of the AS signaling, the terminal device can clarify whether to send RRC messages and/or MAC CE based on the SDT mode when in the RRC inactive state based on at least one of the above information.

Exemplarily, the first configuration information may include the correspondence between the bits in the MAC CE transmitted based on the SDT method and the configuration; similarly, the second configuration information may include the specific meaning of the RRC message content transmitted based on the SDT method.

In a possible implementation, the configuration information of the AS signaling sent by the DU to the terminal device in step S402 is included in an RRC release message or a system message. Among them, the configuration information of the AS signaling received by the terminal device may also be included in an RRC release message or a system message, and multiple implementation methods for obtaining the configuration information of the AS signaling are provided to enhance the flexibility of the implementation of the solution. In addition, the terminal device may receive the system message when it is in an RRC connected state or an RRC inactive state (or the terminal device may receive an RRC release message when it is in an RRC connected state), and the above implementation method can reuse the system message (or RRC release message) to save overhead.

The following will provide an exemplary description of the process of determining the configuration information of the AS signaling between the DU and the CU in step S401 in conjunction with the implementation examples shown in FIG. 5a and FIG. 5b.

As shown in FIG. 5 a , in the case where the configuration information of the AS signaling is included in the system message, the configuration information of the AS signaling can be determined between the DU and the CU through the following system message interaction process.

Step 1. The parameters of the system messages exchanged between DU and CU can be recorded as system information-related parameters.

Step 2. DU sends a system message to the terminal device, which can be recorded as system information. The system message includes configuration information including AS signaling.

It should be noted that the implementation process of step 1 is an implementation example of determining the configuration information of AS signaling between CU and DU in step S401, and the implementation process of step 2 is an implementation example of the implementation process of the terminal device receiving the configuration information of AS signaling in step S402.

In an implementation example, in the implementation shown in FIG5a, when the parameters in the system message are determined by the DU, in step 1, the DU sends the configuration information of the AS signaling to the CU. Exemplarily, the DU may provide the configuration information of the AS signaling to the CU in the served cell information.

Optionally, when the parameters in the system message are determined by the DU, the system message includes at least one of SIB1, SIB10, SIB12, SIB13, SIB14, SIB15, SIB17, SIB18 or SIB20.

In another implementation example, in the implementation shown in FIG. 5a, when the parameters in the system message are determined by the CU, the DU receives the configuration information of the AS signaling from the CU in step 1. Exemplarily, the CU may provide the configuration information of the AS signaling to the DU in the information element (IE) of each cell (per cell) in the relevant message of the F1-AP.

Optionally, in the case where the parameters in the system message are determined by the CU, the system message may include other system messages (other SIBs).

It can be seen from the process shown in Figure 5a that when the configuration information of the AS signaling is included in the system message, the parameters in the system message can be determined by the CU or DU. Accordingly, the DU and the CU can interact with each other to make the configuration information of the AS signaling clear to both parties, and subsequently receive and process the AS signaling from the terminal device based on the configuration information of the AS signaling.

As shown in Figure 5b, when the configuration information of AS signaling is included in the RRC release message, the configuration information of the AS signaling can be determined between the DU and the CU through the following interaction process of the "UE CONTEXT RELEASE COMMAND message" including the RRC release message.

Step 1. CU sends a user equipment context modification request (UE CONTEXT MODIFICATION REQUEST) message to DU.

Step 2. DU sends a user equipment context modification response (UE CONTEXT MODIFICATION RESPONSE) message to CU.

Step 3. CU sends a user context release command (UE CONTEXT RELEASE COMMAND) message to DU, where the UE CONTEXT RELEASE COMMAND message includes the RRC release message.

Step 4. The DU sends an RRC release message to the UE, where the RRC release message includes the configuration information of the AS signaling.

It should be noted that the implementation process of steps 1 to 3 is an implementation example of determining the configuration information of AS signaling between CU and DU in step S401, and the implementation process of step 4 is an implementation example of the implementation process of the terminal device receiving the configuration information of AS signaling in step S402.

In the implementation process shown in Figure 5b, the UE CONTEXT MODIFICATION REQUEST message in step 1 includes the configuration information of the AS signaling, and/or the UE CONTEXT RELEASE COMMAND message in step 3 includes the configuration information of the AS signaling.

Specifically, when the configuration information of the AS signaling is included in the RRC release message, the DU can obtain the RRC release message in the above manner. Moreover, the configuration information of the AS signaling can be made clear to both parties based on the above interaction process, and the AS signaling from the terminal device can be received and processed based on the configuration information of the AS signaling.

In one possible implementation, in the implementation process shown in FIG. 5b , the UE CONTEXT MODIFICATION REQUEST message in step 1 includes indication information for indicating that the configuration information of the AS signaling is retained, or the UE CONTEXT RELEASE COMMAND message in step 3 includes indication information for indicating that the configuration information of the AS signaling is retained. Specifically, in the case where the configuration information of the AS signaling is included in the RRC release message, the CU can send the indication information to the DU in the above manner, so that the DU retains the configuration information of the AS signaling based on the indication information, so that the subsequent DU can receive and process the AS signaling from the terminal device based on the retained configuration information of the AS signaling.

Optionally, the indication information is carried in a CG-SDT query (CG-SDT query) message/information sent by the CU to the DU.

Step S403. When in the RRC inactive state, the terminal device sends AS signaling, and correspondingly, the DU receives AS signaling.

In one possible implementation, the terminal device may receive an RRC release message to trigger the terminal device to enter an RRC inactive state, wherein the RRC release message includes the configured grant (CG) configuration information corresponding to the transmission resources of the SDT mode. Specifically, in the case where the RRC release message includes the CG configuration information corresponding to the transmission resources of the SDT mode, in step S403, the terminal device may send AS signaling based on the configured grant small data transmission (CG-SDT) mode, so that the above scheme can be applied to the transmission scenario of CG-SDT (such as the implementation process shown in FIG. 3a above).

In a possible implementation, the terminal device may receive a system message when it is in an RRC connected state or an RRC inactive state, and the system message includes random access (RA) configuration information corresponding to the transmission resources of the SDT mode. Specifically, in the case where the system message includes the RA configuration information corresponding to the transmission resources of the SDT mode, in step S403, the terminal device may send AS signaling based on random access small data transmission (RA-SDT), so that the above scheme can be applicable to the transmission scenario of RA-SDT (such as the implementation process shown in Figure 3b above).

In a possible implementation, in step S403, the method further includes: when the terminal device is in an RRC inactive state, sending an RRC resume request message. Specifically, when the terminal device sends AS signaling based on the SDT method, the terminal device may also send the RRC resume request message using the SDT upload mechanism, so as to provide the network device with relevant information of the terminal device (such as the identification of the terminal device, etc.) through the RRC resume request message.

Optionally, the RRC reply request message and the AS signaling transmitted based on the SDT method are located in the same transport block (TB) (or the same data packet).

In a possible implementation, the RRC recovery request message further includes indication information for indicating the reason for RRC recovery, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer (DRB) corresponding to the AS signaling, or the identifier of the signaling radio bearer (SRB) to which the AS signaling corresponds. Specifically, the RRC recovery request message sent by the terminal device may further include indication information indicating the reason for RRC recovery, and the indication information may include at least one of the above items. By indicating the relevant information of the AS signaling through the indication information, the network device can clarify the reason why the terminal device initiates RRC recovery based on the indication information.

In a possible implementation, before sending the AS signaling in step S403, the method further includes: the terminal device ignores the following At least one of the following:

Resume other DRBs and SRBs configured with SDT; or,

Check at the medium access control (MAC) layer whether the data volume is exceeded; or,

All data is mapped to the DRB or SRB of the SDT; or,

Higher layers request to restore the RRC connection.

Specifically, when the terminal device transmits uplink data or non-access stratum (NAS) signaling based on the SDT method, the terminal device needs to consider at least one of the above limitations. In the technical solution shown in Figure 4, the information transmitted by the terminal device based on the SDT method is AS signaling. For this reason, the terminal device can ignore the above limitations associated with uplink data or NAS signaling, in order to improve the transmission success rate of the AS signaling.

Step S404: DU sends AS signaling to CU, and correspondingly, CU receives the AS signaling.

In a possible implementation, the DU receives AS signaling through the resources corresponding to the CG-SDT in step S403. Accordingly, when the AS signaling received by the DU in step S403 includes an RRC message, the RRC message sent by the DU to the CU in step S404 is carried in an uplink radio resource control information transmission (UL RRC MESSAGE TRANSFER) message; and/or, when the AS signaling received by the DU in step S403 includes a MAC CE, the information carried by the MAC CE sent by the DU to the CU in step S404 is carried in an F1 application protocol (F1 application protocol, F1-AP) message. Specifically, after the DU receives the AS signaling from a terminal device in an RRC inactive state, the DU can also send the AS signaling to the CU so that the CU can obtain and process the AS signaling. Among them, the DU can send the AS signaling to the CU in the above-mentioned multiple ways to enhance the flexibility of the solution implementation.

In a possible implementation, the DU receives the AS signaling through the resources corresponding to the RA-SDT in step S403. Correspondingly, the AS signaling sent by the DU in step S404 is carried in the initial uplink radio resource control information transmission (INITIAL UL RRC MESSAGE TRANSFER) message.

In a possible implementation, the UL RRC MESSAGE TRANSFER message or the INITIAL UL RRC MESSAGE TRANSFER message sent by the DU to the CU may carry the RRC recovery request message sent by the terminal device in step S403, and the RRC recovery request message includes indication information for indicating the reason for RRC recovery, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer to which the AS signaling corresponds. Specifically, the RRC recovery request message received by the DU and sent to the CU may also include indication information indicating the reason for RRC recovery, and the indication information may include at least one of the above items. By indicating the relevant information of the AS signaling through the indication information, the CU can clearly understand the reason why the terminal device initiates RRC recovery based on the indication information.

Based on the above technical solution, after the terminal device receives the configuration information for transmitting the AS signaling based on the SDT mode in step S402, in step S403, when the terminal device is in the RRC inactive state, the terminal device sends the AS signaling using the transmission resources of the SDT mode. Thus, for the terminal device in the RRC inactive state, based on the configuration information of the AS signaling received by the terminal device, the uplink transmission of the AS signaling can be realized, and the process of sending the AS signaling based on the SDT mode can also obtain the gain of fast transmission of the AS signaling, so as to improve the communication efficiency.

In the implementation process shown in FIG4 , the terminal device can transmit AS signaling based on CG-SDT or RA-SDT in step S403. The following will use the implementation examples shown in FIG6a and FIG6b to exemplarily describe the two implementation processes. It should be understood that in the following FIG6a and FIG6b , the terminal device is UE, the network device includes DU (denoted as gNB-DU) and CU (denoted as gNB-CU-CP), and the AS signaling includes RRC message and/or MAC CE.

Please refer to FIG. 6a , which shows the process of UE triggering CG-SDT to send AS signaling, including the following steps.

Step 0. UE in RRC_CONNECTED and gNB decides to transit the UE to RRC_INACTIVE.

Step 1a/b. The configuration information of AS signaling is exchanged between the DU and the CU. The configuration information of the AS signaling may include at least one of the following:

(a) Whether to support sending a certain MAC CE using SDT (sdt-MAC CExxx-Enabled);

(b) Whether to support sending certain RRC messages using SDT (sdt-RRCxxx-Enabled);

(c) Use SDT to send RRC messages;

(d) Use SDT to send MAC CE related configurations.

It can be understood that at least one item included in the configuration information of the above AS signaling can be recorded as [sdt-RRCxxx/MAC CE-enabled/RRCmsg_config/MAC CE-config].

In step 1a, the gNB-CU-CP exchanges system information-related parameters with the gNB-DU, including the following process:

If it is a parameter set by gNB-DU, such as SDT-MAC CExx-enabled, and the relevant system information needs to be encoded in gNB-CU-CP, then DU should add it to served cell information to provide relevant information to gNB-CU-CP;

If the parameters are set by gNB-CU-CP and gNB-DU encodes related system messages, gNB-CU-CP needs to add this content in the per cell IE in the related messages of F1AP to inform gNB-DU.

Afterwards, in step 1b, the gNB-DU sends the configuration to the UE via a system message.

It can be understood that step 1a is an implementation example of determining the configuration information of the AS signaling between the CU and the DU in step S401. Step 1b is an implementation example of receiving the configuration information of the AS signaling by the terminal device in step S402.

Step 2. gNB-CU-CP sends a UE CONTEXT MODIFICATION REQUEST message to gNB-DU, which carries the configuration information of AS signaling.

Optionally, the UE CONTEXT MODIFICATION REQUEST message may also carry a CG-SDT query and sdt-RRCxx/MAC CE-enable Kept Indicator to instruct the gNB-DU to retain the configuration of SDT triggered by RRC message and MAC CE. Optionally, this indication is carried together with the CG-SDT query.

Step 3. The gNB-DU passes the UE CONTEXT MODIFICATION RESPONSE message to the gNB-CU-CP, which contains the configuration of the CG-SDT lower layer resource (which can be recorded as "CG-SDT resource").

Step 4. gNB-CU-CP sends a UE CONTEXT RELEASE COMMAND message to gNB-DU, which carries the RRCRelease message to indicate the UE CG-SDT configuration.

Optionally, the gNB-CU-CP instructs the gNB-DU to save the SDT RLC config, F1-U tunnels, and/or F1AP UE association via an explicit CG-SDT kept indicator; the gNB-CU-CP instructs the gNB-DU to save the indication and configuration of whether the UE supports sending a certain MAC CE or a certain RRC message via SDT in the RRC_INACTIVE state via an explicit sdt-RRCxxx-Enabled kept indicator or sdt-MAC CE-Enabled kept indicator. Thereafter, the gNB-DU stores the configuration of the CG-SDT resources.

It can be understood that steps 2 to 4 are an implementation example of determining the configuration information of the AS signaling between the CU and the DU in step S401. Step 5 is an implementation example of the configuration information of the AS signaling received by the terminal device in step S402.

Step 5. The gNB-DU sends an RRCRelease message to the UE to release the UE to the RRC_INACTIVE state, which carries the configuration information of the AS signaling.

Step 6. The UE enters the RRC_INACTIVE state. When a MAC CE or RRC message is triggered, if the UE has relevant configuration (such as configuration information of AS signaling), it is determined to send the MAC CE or RRC message based on the CG-SDT in step 7.

Optionally, for RRC messages, if the conditions for triggering SDT are met, the RRC layer in the UE triggers the bottom layer to send SDT and triggers the RRC layer to send RRCResumeRequest. The conditions for triggering SDT include at least one of the following: no need to resume other DRBs and SRBs configured with SDT, no need to check at the MAC layer whether the data volume is exceeded, no need for all data to be mapped to the DRB or SRB of SDT, and no need for the upper layer to request to resume the RRC connection.

Optionally, for MAC CE, there are two cases:

Case 1: For MAC CE triggered by the RRC layer, the RRC layer triggers the underlying layer to send SDT and triggers the RRC layer to send RRCResumeRequest.

Case 2: For MAC CE triggered by the MAC layer, the MAC layer triggers the RRC layer to check whether the conditions are met. If the conditions for triggering SDT are met, the RRC layer in the UE triggers the MAC layer to send MAC CE and initiate RRCResumeRequest. The conditions for triggering SDT include at least one of the following: no need to resume other DRBs and SRBs configured with SDT, no need to check at the MAC layer whether the data volume is exceeded, no need for all data to be mapped to the DRB or SRB of SDT, and no need for the upper layer to request to resume the RRC connection.

Step 7. The UE sends a RRCResumeRequest message and an RRC message (or MAC CE) to the gNB via CG-SDT. The RRCResumeRequest message carries the resume cause (resume cause) of sending a MAC CE or RRC message via SDT. The resume cause can be based on the type of MAC CE and RRC message.

Step 8. The gNB-DU sends a UL RRC MESSAGE TRANSFER to the gNB-CU-CP, carrying the RRCResumeRequest message, which carries the cause value of triggering SDT, i.e., the cause value of SDT triggered by (a) a certain MAC CE; (b) a certain RRC message; (c) a certain DRB; or (d) a certain SRB.

Step 9a. When the UE sends an RRC message, the gNB-DU sends the message to the gNB-CU-CP via UL RRC MESSAGE TRANSFER gNB-DU. send.

Step 9b. When the UE sends a MAC CE, the gNB-DU sends the information carried by the MAC CE to the gNB-CU-CP via the F1-AP message.

It can be seen from the implementation process shown in Figure 6a that the terminal device in the RRC inactive state can realize the uplink transmission of AS signaling, and the process of sending the AS signaling based on the CG-SDT method can also obtain the gain of fast transmission of the AS signaling, so as to improve communication efficiency.

Please refer to FIG. 6 b , which is a process of UE triggering RA-SDT to send AS signaling, including the following steps.

The implementation process of step 0 and step 1a/b can refer to the implementation process of step 0 and step 1a/b in Figure 6a, and the corresponding technical effects can be achieved, which will not be repeated here.

Step 2. gNB-CU-CP sends a UE CONTEXT RELEASE COMMAND message to gNB-DU, which carries the RRCRelease message.

Step 3. The gNB-DU sends a RRCRelease message to the UE, which carries the configuration information of the AS signaling.

Step 4. The UE enters the RRC_INACTIVE state. When a MAC CE or RRC message is triggered, if the UE has relevant configuration (such as configuration information of AS signaling), it is determined to send the MAC CE or RRC message based on RA-SDT in step 5.

Optionally, for RRC messages, if the conditions for triggering SDT are met, the RRC layer in the UE triggers the bottom layer to send SDT, and triggers the RRC layer to send RRCResumeRequest. The conditions for triggering SDT include at least one of the following: no need to resume other DRBs and SRBs configured with SDT, no need to check at the MAC layer whether the data volume is exceeded, no need for all data to be mapped to the DRB or SRB of SDT, and no need for the upper layer to request to resume the RRC connection.

Optionally, for MAC CE, there are two cases:

Case 1: For MAC CE triggered by the RRC layer, the RRC layer triggers the underlying layer to send SDT and triggers the RRC layer to send RRCResumeRequest.

Case 2: For MAC CE triggered by the MAC layer, the MAC layer triggers the RRC layer to check whether the conditions are met. If the conditions for triggering SDT are met, the RRC layer in the UE triggers the MAC layer to send MAC CE and initiate RRCResumeRequest. The conditions for triggering SDT include at least one of the following: no need to resume other DRBs and SRBs configured with SDT, no need to check at the MAC layer whether the data volume is exceeded, no need for all data to be mapped to the DRB or SRB of SDT, and no need for the upper layer to request to resume the RRC connection.

Step 5. The UE sends a RRCResumeRequest message and an RRC message (or MAC CE) to the gNB via CG-SDT.

Optionally, the RRCResumeRequest message carries a resume cause for sending a MAC CE or RRC message using SDT. The resume cause may be based on the granularity of the type of MAC CE and RRC message.

Step 6. The gNB-DU sends an INITIAL UPLINK RRC MESSAGE TRANSFER message to the gNB-CU-CP, which carries the RRCResumeRequest message and indicates the cause value of the SDT triggered by the gNB-CU-CP, which is (a) a MAC CE; (b) a RRC message; (c) a DRB; (d) the cause value of the SDT triggered by a SRB.

Step 7. gNB-CU-CP sends UE CONTEXT SETUP REQEUST message to gNB-DU.

Optionally, the UE CONTEXT SETUP REQEUST message can carry configuration information for AS signaling.

Step 8. gNB-DU sends UE CONTEXT SETUP RESPONSE message to gNB-CU-CP.

Step 9a. When the UE sends an RRC message, the gNB-DU sends an UL RRC MESSAGE TRANSFER message to the gNB-CU-CP, carrying the RRC message received by the gNB.

Step 9b. When the UE sends a MAC CE, the gNB-DU sends the information carried by the MAC CE to the gNB-CU-CP via the F1-AP message.

From the implementation process shown in FIG6b , it can be seen that the terminal device in the RRC inactive state can realize the uplink transmission of the AS signaling, and the process of sending the AS signaling based on the RA-SDT method can also obtain the gain of fast transmission of the AS signaling, so as to improve communication efficiency.

In the aforementioned Figure 4 and related implementation processes, the network device that sends the RRC release message to the terminal device and the network device that receives the AS signaling sent by the terminal device can be the same network device or different network devices. The latter will be exemplarily described below through the implementation process shown in Figure 7.

Please refer to FIG. 7 , which is a schematic diagram of an implementation of the communication method provided in the present application. The method includes the following steps.

S701. The source network device sends the configuration information of the source network device for transmitting AS signaling based on SDT. Correspondingly, the terminal device receives the configuration information of the source network device for transmitting AS signaling based on SDT.

Optionally, in step S701, the configuration information of the AS signaling sent by the source network device to the terminal device may be included in the system message sent by the source network device, so that the above solution can be applied to the transmission scenario of RA-SDT. The configuration information of the AS signaling sent by the device to the terminal device can be included in the RRC release message sent by the source network device, so that the above solution can be applicable to the CG-SDT transmission scenario.

S702. The destination network device sends the configuration information of the destination network device based on the SDT transmission AS signaling, and correspondingly, the terminal device receives the configuration information of the destination network device based on the SDT transmission AS signaling.

S703. The terminal device sends AS signaling to the destination network device.

In a possible implementation, the method further includes: before step S702, the terminal device receives an RRC release message from the source network device, and, in step S702, the configuration information of the AS signaling is included in a system message from the destination network device. Specifically, the terminal device can also receive an RRC release message from the source network device, so that the terminal device enters an RRC inactive state from an RRC connected state. In addition, the configuration information of the AS signaling used by the terminal device comes from the destination network device, so that the terminal device can send AS signaling based on the configuration from the destination network device when residing/cell reselecting to the destination network device in the RRC inactive state, so that the above scheme can be applicable to the station change scenario (or the scenario in which the network device to which the terminal device is connected switches/reselects).

In a possible implementation, the method further includes: the terminal device deletes the configuration information for transmitting AS signaling based on the SDT mode configured by the source network device. Specifically, in step S701, the RRC release message or system message from the source network device may also include the configuration information for transmitting AS signaling based on the SDT mode configured by the source network device. Accordingly, when the terminal device resides/cell reselects to the destination network device in the RRC inactive state and sends AS signaling based on the configuration from the destination network device, the terminal device can delete the configuration information configured by the source network device to avoid transmission errors and save storage space.

In one possible implementation, in step S702, the destination network device may send the configuration information of the AS signaling through a system message, so that the terminal device can send the AS signaling based on random access small data transmission (RA-SDT), so that the above scheme can be applicable to the transmission scenario of RA-SDT.

In addition, the network device that sends the RRC release message to the terminal device is the source network device, and the configuration information of the AS signaling used by the terminal device comes from the destination network device, so that the terminal device can send AS signaling based on the configuration from the destination network device when residing/cell reselecting to the destination network device in the RRC inactive state, so that the above solution can be applicable to the station change scenario (or the scenario where the network device to which the terminal device is connected is switched/reselected).

In a possible implementation, the method further includes: the network device sends a RETRIEVE UE CONTEXT REQUEST message to the source network device of the terminal device; the network device receives a RETRIEVE UE CONTEXT RESPONSE message from the source network device, or receives a RETRIEVE UE CONTEXT FAILURE message from the source network device. Specifically, in the case where the network device is the destination network device of the terminal device, the destination network device can obtain the context information corresponding to the terminal device through the above-mentioned interaction with the source network device, so as to quickly restore the RRC connection with the terminal device.

Optionally, the RETRIEVE UE CONTEXT RESPONSE message may carry configuration information for transmitting AS signaling based on the SDT method configured by the source network device.

The implementation process shown in FIG8 is an implementation example of the implementation process shown in FIG7. As shown in FIG8, the implementation process includes the following steps. It should be understood that in the following FIG8, the terminal device is UE, the network device includes a source network device (denoted as source gNB) and a destination network device (denoted as receiving gNB), and the AS signaling includes RRC message and/or MAC CE.

Step 0. UE receives RRCRelease message at source gNB and enters RRC_INACTIVE state.

Optionally, the RRCRelease message carries the configuration information of the source gNB for transmitting AS signaling based on the SDT method.

Step 1. The UE selects the receiving gNB after cell reselection in the RRC_INACTIVE state and executes the subsequent step 3 when initiating the SDT process. In addition, the UE deletes the configuration received by the source gNB.

Step 2. Send the configuration information of receiving gNB for transmitting AS signaling based on SDT to UE using system message.

Step 3.UE initiates RA-SDT in receiving gNB.

Step 4. After receiving RA-SDT, gNB sends XN-AP message RETRIEVE UE CONTEXT REQUEST to source gNB.

Step 5. The source gNB sends a RETRIEVE UE CONTEXT RESPONSE message to the receiving gNB.

Optionally, the RETRIEVE UE CONTEXT RESPONSE message may include configuration information for transmitting AS signaling based on SDT configured by the source gNB.

Step 5b. The source gNB sends a RETRIEVE UE CONTEXT FAILURE message to the receiving gNB.

Optionally, when the source gNB executes step 5b, it means that the source gNB disagrees to perform anchor relocation, that is, it disagrees to convert the anchor to the receiving gNB. At this time, the replied downlink RRC message and downlink MAC CE should be generated by the source gNB and sent by the source gNB to the UE through the receiving gNB.

In the implementation process shown in Figures 4 to 8 above, for a terminal device in an RRC inactive state, the transmission of AS signaling is implemented by means of SDT to solve the problem that the AS signaling cannot be transmitted in this case. In order to solve this problem, for the terminal device, it is also possible to enter the RRC connection state by restoring the RRC connection, and implement the sending of AS signaling after the RRC connection is restored. The implementation process shown in Figure 9 is used to illustrate this.

Please refer to FIG9 , which is a schematic diagram of an implementation of the communication method provided in the present application. The method includes the following steps.

S901. When the terminal device is in an RRC inactive state, it sends an RRC recovery request message. Correspondingly, the network device receives the RRC recovery request message.

S902. After restoring the RRC connection, the terminal device sends AS signaling. Correspondingly, the network device receives the AS signaling.

In one possible implementation, the RRC recovery request message sent by the terminal device in step S901 includes indication information, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer SRB corresponding to the AS signaling. Specifically, the RRC recovery request message sent by the terminal device may also include indication information indicating the reason for RRC recovery, and the indication information may include at least one of the above items. By indicating the relevant information of the AS signaling through the indication information, the network device can clarify the reason why the terminal device initiates RRC recovery based on the indication information.

For example, if a certain RRC message is configured to trigger RRC connection resume in RRC_INACTIVE state, when the trigger condition is met, the RRC layer triggers RRCResumeRequest and sets the corresponding resumeCause; if a certain MAC CE is configured to trigger RRC connection resume in RRC_INACTIVE state, when the trigger condition is met, the MAC layer triggers the RRC layer to trigger RRCResumeRequest and sets the corresponding resumeCause.

In a possible implementation, before the terminal device sends the RRC recovery request message in step S901, the method further includes: the terminal device receives an RRC release message, where the RRC release message includes at least one of the following information:

Indicates whether RRC connection recovery triggered by AS signaling is supported in RRC non-connected state; or,

The triggering condition of the AS signaling; or

The T319 timer corresponding to the RRC recovery request message.

It is understandable that the T319 timer is started when the RRC recovery request (RRCResumeRequest) message is sent, and when it times out, the terminal device considers that the RRC connection recovery has failed. Optionally, after the terminal device determines that the RRC connection recovery has failed, the terminal device enters the RRC idle state.

Specifically, the RRC recovery request message that triggers the terminal device to enter the RRC inactive state may carry at least one of the above information, so that the terminal device can determine based on the at least one piece of information whether to realize uplink transmission of AS signaling by restoring the RRC connection when it is in the RRC inactive state.

In a possible implementation, the RRC recovery request message is sent when at least one of the following conditions is met, including: the terminal device is configured to allow entry into the RRC connection state to send the AS signaling, or the terminal device is in an RRC inactive state and triggers the sending of the AS signaling. Specifically, when at least one of the above conditions is met, the terminal device triggers the sending of the RRC recovery request message, so that the terminal device, when in an RRC inactive state, implements uplink transmission of the AS signaling by restoring the RRC connection.

Based on the technical solution shown in FIG9 , when the terminal device is in the RRC inactive state, the RRC recovery request message sent by the terminal device in step S901 includes indication information for indicating that the RRC recovery reason is AS signaling, and after the terminal device recovers the RRC connection state, the terminal device sends the AS signaling in step S902. Thus, for the terminal device in the RRC inactive state, after the RRC connection is restored based on the indication information carried by the RRC recovery request message, the uplink transmission of the AS signaling can be realized.

When the integrated access and backhaul (IAB) technology is introduced in the communication network, the implementation diagram of the communication protocol stack during the communication between the terminal device and the DU and CU is shown in Figure 10. Among them, the terminal device may include an RRC entity, a PDCP entity, an RLC entity, a MAC entity and a PHY entity; the DU includes an RCL entity, a MAC entity and a PHY entity; and the CU includes an RRC entity and a PDCP entity. Generally, since the DU has an RCL entity, a MAC entity and a PHY entity, the RLC/MAC/PHY data/signaling sent by the terminal device is processed locally in the DU, and the DU needs to convert the RRC/PDCP data/signaling from the terminal device to the DU. Sent to CU for processing.

However, with the evolution of communication systems, in future communication systems, the information carried by RLC/MAC/PHY data/signaling may need to be processed by CU, and the current communication protocol stack does not support the transmission of this information between DU and CU. Therefore, how to transmit this information between CU and DU is a technical problem that needs to be solved urgently. In order to solve this problem, the implementation process shown in Figure 11 will be explained below.

Please refer to FIG. 11 , which is a schematic diagram of an implementation of the communication method provided in the present application. The method includes the following steps.

S1101. The terminal device sends the first information, and correspondingly, the DU receives the first information.

It should be noted that the first information may include RLC/MAC/PHY data or signaling. In an implementation example, the first information may be MAC CE.

Optionally, in AS, compared with RRC/PDCP, RLC/MAC/PHY can be called a lower layer, and accordingly, the first information can be described as lower layer data or lower layer signaling.

S1102. The DU sends an F1-AP message, and correspondingly, the CU receives the F1-AP message, wherein the F1-AP message includes information carried by the first information.

As an implementation example, when the first information is MAC CE, the MAC CE can be used to carry semi-static sounding reference signal (SRS) activation information, and accordingly, the F1-AP message sent by the DU can carry the semi-static SRS activation information.

Based on the technical solution shown in FIG11, after receiving the first information from the terminal device, the DU can send the information carried by the first information to the CU through the F1-AP message, wherein the first information may include RLC/MAC/PHY data or signaling. Thus, through the transmission of the F1-AP message, the information carried by the RLC/MAC/PHY data or signaling can be transmitted between the CU and the DU to optimize the information transmission method between the CU and the DU.

The present application is described above from the perspective of method, and other embodiments provided by the present application will be further described below.

Please refer to Figure 12, which is a schematic diagram of an implementation of the communication device provided in the present application. The communication device 1200 includes a processing unit 1201 and a transceiver unit 1202. The communication device 1200 can implement the functions of the communication device (including terminal equipment, DU, CU, network equipment, etc.) in the above method embodiment, and therefore can also achieve the beneficial effects of the above method embodiment. In an embodiment of the present application, the communication device 1200 can be a terminal device (or DU, CU, network equipment, etc.), or it can be an integrated circuit or component inside the terminal device (or DU, CU, network equipment, etc.), such as a chip. The following embodiments are described by taking the communication device 1200 as a terminal device (or DU, CU, network equipment, etc.) as an example.

In one possible implementation, when the device 1200 is used to execute the method executed by the terminal device in the aforementioned embodiment, the device includes a processing unit 1201 and a transceiver unit 1202; the transceiver unit 1202 is used to receive configuration information of access layer AS signaling based on a small data transmission SDT method; when the terminal device is in an inactive state of radio resource control RRC, the processing unit 1201 is used to determine the AS signaling, and the transceiver unit 1202 is used to send the AS signaling, wherein the AS signaling is carried on the transmission resources of the SDT method.

In one possible implementation, the AS signaling includes RRC messages and/or media access control elements MAC CE.

In a possible implementation manner, the configuration information of the AS signaling includes at least one of the following:

The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or,

The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or

The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or,

The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode.

In a possible implementation manner, the configuration information of the AS signaling is included in an RRC release message or a system message.

In one possible implementation, the RRC release message includes the configuration authorization CG configuration information corresponding to the transmission resources of the SDT mode.

In a possible implementation manner, the system message includes random access RA configuration information corresponding to the transmission resource in the SDT mode.

In a possible implementation, the transceiver unit 1202 is further configured to receive an RRC release message from a source network device, and the configuration information of the AS signaling is included in a system message from a destination network device.

In a possible implementation, the RRC release message also includes configuration information of the source network device for transmitting AS signaling based on the SDT mode; the processing unit 1201 is also used to delete the configuration information of the source network device for transmitting AS signaling based on the SDT mode.

In a possible implementation, when the terminal device is in an RRC inactive state, the transceiver unit 1202 is further used to send an RRC recovery request message.

In one possible implementation, the RRC recovery request message also includes indication information for indicating the reason for RRC recovery, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer SRB corresponding to the AS signaling.

In a possible implementation, the processing unit 1201 is further configured to ignore at least one of the following:

Resume other DRBs and SRBs configured with SDT; or,

Check at the media access control (MAC) layer whether the data volume is exceeded; or,

All data is mapped to the DRB or SRB of the SDT; or,

The higher layer requests to restore the radio access control (RRC) connection.

In one possible implementation, when the device 1200 is used to execute the method executed by the DU in the aforementioned embodiment, the device includes a processing unit 1201 and a transceiver unit 1202; the processing unit 1201 is used to determine the configuration information for transmitting AS signaling based on a small data transmission SDT mode, and the transceiver unit 1202 is used to send the configuration information of the AS signaling; the transceiver unit 1202 is used to receive the AS signaling from a terminal device in an RRC inactive state, wherein the AS signaling is carried on the transmission resources of the SDT mode.

In one possible implementation, the AS signaling includes RRC messages and/or media access control elements MAC CE.

In one possible implementation, the transceiver unit 1202 is also used to send the AS signaling to the centralized unit CU; when the AS signaling includes an RRC message, the RRC message is carried in an uplink radio resource control information transmission UL RRC MESSAGE TRANSFER message; and/or, when the AS signaling includes MAC CE, the information carried by the MAC CE is carried in an F1-AP message.

In a possible implementation manner, the configuration information of the AS signaling includes at least one of the following:

The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or,

The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or

The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or,

The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode.

In a possible implementation manner, the configuration information of the AS signaling is included in an RRC release message or a system message.

In one possible implementation, the configuration information of the AS signaling is included in the system message; the parameters in the system message are determined by the DU, and the transceiver unit 1202 is also used to send the configuration information of the AS signaling to the CU; or, the parameters in the system message are determined by the CU, and the transceiver unit 1202 is also used to receive the configuration information of the AS signaling from the CU.

In one possible implementation, the configuration information of the AS signaling is included in the RRC release message, and the transceiver unit 1202 is also used to receive a user equipment context modification request UE CONTEXT MODIFICATION REQUEST message from the CU; the transceiver unit 1202 is also used to send a user equipment context modification response UE CONTEXT MODIFICATION RESPONSE message to the CU; the transceiver unit 1202 is also used to receive a user context release command UE CONTEXT RELEASE COMMAND message from the CU, and the UE CONTEXT RELEASE COMMAND message includes the RRC release message; wherein, the UE CONTEXT MODIFICATION REQUEST message includes the configuration information of the AS signaling, and/or, the UE CONTEXT RELEASE COMMAND message includes the configuration information of the AS signaling.

In one possible implementation, the UE CONTEXT MODIFICATION REQUEST message includes indication information for indicating that the configuration information of the AS signaling is retained, or the UE CONTEXT RELEASE COMMAND message includes indication information for indicating that the configuration information of the AS signaling is retained.

In one possible implementation, the RRC release message includes the configuration authorization CG configuration information corresponding to the transmission resources of the SDT mode.

In a possible implementation manner, the system message includes random access RA configuration information corresponding to the transmission resource in the SDT mode.

In a possible implementation, when the terminal device is in an RRC inactive state, the transceiver unit 1202 is further used to receive an RRC recovery request message.

In one possible implementation, the RRC recovery request message includes indication information for indicating the reason for RRC recovery, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer corresponding to the AS signaling.

In a possible implementation, when the device 1200 is used to execute the method executed by the CU in the above-mentioned embodiment, the device includes a processing unit 1201 and a transceiver unit 1202; the processing unit 1201 is used to determine the configuration of transmitting AS signaling based on the small data transmission SDT mode. the transceiver unit 1202 is used to receive the AS signaling from the distributed unit DU, wherein the AS signaling comes from a terminal device in an inactive state of the radio resource control RRC.

In one possible implementation, the AS signaling includes RRC messages and/or media access control elements MAC CE.

In one possible implementation, when the AS signaling includes an RRC message, the RRC message is carried in an uplink radio resource control information transmission UL RRC MESSAGE TRANSFER message; and/or, when the AS signaling includes MAC CE, the information carried by the MAC CE is carried in an F1-AP message.

In a possible implementation manner, the configuration information of the AS signaling includes at least one of the following:

The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or,

The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or

The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or,

The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode.

In one possible implementation, the configuration information of the AS signaling is included in the system message sent by the DU to the terminal device; the parameters in the system message are determined by the DU, and the transceiver unit 1202 is used to receive the configuration information of the AS signaling from the DU; or, the parameters in the system message are determined by the CU, and the transceiver unit 1202 is used to send the configuration information of the AS signaling to the DU.

In one possible implementation, the configuration information of the AS signaling is included in the RRC release message sent by the DU to the terminal device, and the transceiver unit 1202 is also used to send a user equipment context modification request UE CONTEXT MODIFICATION REQUEST message to the DU; the transceiver unit 1202 is also used to receive a user equipment context modification response UE CONTEXT MODIFICATION RESPONSE message from the DU; the transceiver unit 1202 is also used to send a user context release command UE CONTEXT RELEASE COMMAND message to the DU, and the UE CONTEXT RELEASE COMMAND message includes the RRC release message; wherein, the UE CONTEXT MODIFICATION REQUEST message includes the configuration information of the AS signaling, and/or, the UE CONTEXT RELEASE COMMAND message includes the configuration information of the AS signaling.

In one possible implementation, the UE CONTEXT MODIFICATION REQUEST message includes indication information for indicating that the configuration information of the AS signaling is retained, or the UE CONTEXT RELEASE COMMAND message includes indication information for indicating that the configuration information of the AS signaling is retained.

In one possible implementation, the RRC release message includes the configuration authorization CG configuration information corresponding to the transmission resources of the SDT mode.

In a possible implementation manner, the system message includes random access RA configuration information corresponding to the transmission resource in the SDT mode.

In one possible implementation, the RRC recovery request message includes indication information for indicating the reason for RRC recovery, and the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer corresponding to the AS signaling.

In one possible implementation, when the device 1200 is used to execute the method executed by the network device in the aforementioned embodiment, the device includes a processing unit 1201 and a transceiver unit 1202; the processing unit 1201 is used to determine the configuration information of the access layer AS signaling transmitted based on the small data transmission SDT mode; the transceiver unit 1202 is used to send the configuration information of the AS signaling.

In a possible implementation, when the terminal device is in a radio resource control RRC inactive state, the transceiver unit 1202 is further used to receive the AS signaling, wherein the AS signaling is carried on the transmission resources of the SDT mode.

In a possible implementation, the network device is the destination network device of the terminal device, and the configuration information of the AS signaling is included in a system message.

In one possible implementation, the transceiver unit 1202 is further used to send a retrieval user equipment context request RETRIEVE UE CONTEXT REQUEST message to the source network device of the terminal device; the transceiver unit 1202 is further used to receive a retrieval user equipment context response RETRIEVE UE CONTEXT RESPONSE message from the source network device, or, receive a retrieval user equipment context failure RETRIEVE UE CONTEXT FAILURE message from the source network device.

In one possible implementation, when the device 1200 is used to execute the method executed by the terminal device in the aforementioned embodiment, the device includes a processing unit 1201 and a transceiver unit 1202; when the terminal device is in a radio resource control RRC inactive state, the processing unit 1201 is used to determine an RRC recovery request message, and the transceiver unit 1202 is used to send an RRC recovery request message, and the RRC recovery request message includes indication information for indicating that the RRC recovery reason is AS signaling; after restoring the RRC connection state, the transceiver unit 1202 is also used to send the AS signaling.

In a possible implementation, the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer SRB corresponding to the AS signaling.

In a possible implementation, before sending the RRC recovery request message, the transceiver unit 1202 is further configured to receive an RRC release message, where the RRC release message includes at least one of the following information:

Indicates whether RRC connection recovery triggered by AS signaling is supported in RRC non-connected state; or,

The triggering condition of the AS signaling; or

The T319 timer corresponding to the RRC recovery request message.

In one possible implementation, the transceiver unit 1202 sends the RRC recovery request message when at least one of the following is met, including: the terminal device is configured to allow entering the RRC connected state to send the AS signaling, or the terminal device is in the RRC inactive state and triggers the sending of the AS signaling.

In one possible implementation, when the device 1200 is used to execute the method executed by the network device in the aforementioned embodiment, the device includes a processing unit 1201 and a transceiver unit 1202; when the terminal device is in a radio resource control RRC inactive state, the transceiver unit 1202 is used to receive an RRC recovery request message, and the RRC recovery request message includes indication information for indicating that the RRC recovery reason is AS signaling; after the processing unit 1201 determines that the terminal device restores the RRC connection state, the transceiver unit 1202 is also used to receive the AS signaling.

In a possible implementation, the indication information includes at least one of the following: the type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer SRB corresponding to the AS signaling.

In a possible implementation, before sending the RRC recovery request message, the transceiver unit 1202 is further configured to send an RRC release message, where the RRC release message includes at least one of the following information:

Indicates whether RRC connection recovery triggered by AS signaling is supported in RRC non-connected state; or,

The triggering condition of the AS signaling; or,

The T319 timer corresponding to the RRC recovery request message.

In one possible implementation, when the device 1200 is used to execute the method executed by the DU in the aforementioned embodiment, the device includes a processing unit 1201 and a transceiver unit 1202; the transceiver unit 1202 receives first information from the terminal device, and the processing unit 1201 is used to determine the F1-AP message based on the first information; the transceiver unit 1202 is also used to send the F1-AP message to the CU.

In one possible implementation, when the device 1200 is used to execute the method executed by the CU in the aforementioned embodiment, the device includes a processing unit 1201 and a transceiver unit 1202; the transceiver unit 1202 receives an F1-AP message from the DU, and the processing unit 1201 is used to determine the information carried by the first information based on the F1-AP message.

It should be noted that the information execution process and other contents of the units of the above-mentioned communication device 1200 can be specifically referred to the description in the method embodiment shown in the above-mentioned application, and will not be repeated here.

Please refer to Fig. 13, which is another schematic structural diagram of a communication device 1300 provided in the present application. The communication device 1300 at least includes an input and output interface 1302. The communication device 1300 may be a chip or an integrated circuit.

Optionally, the communication device also includes a logic circuit 1301.

The transceiver unit 1202 shown in Figure 12 may be a communication interface, which may be the input/output interface 1302 in Figure 13, which may include an input interface and an output interface. Alternatively, the communication interface may also be a transceiver circuit, which may include an input interface circuit and an output interface circuit.

Optionally, when the communication device 1300 is a terminal device (or a component in a terminal device) in the aforementioned embodiment, the input-output interface 1302 is used to receive configuration information for transmitting access layer AS signaling based on a small data transmission SDT method; when the terminal device is in an inactive state of the radio resource control RRC, the logic circuit 1301 is used to determine the AS signaling, and the input-output interface 1302 is used to send the AS signaling, wherein the AS signaling is carried on the transmission resources of the SDT method.

Optionally, when the communication device 1300 is the DU (or a component in the DU) in the aforementioned embodiment, the logic circuit 1301 is used to determine the configuration information for transmitting AS signaling based on the small data transmission SDT method, and the transceiver unit is used to send the configuration information of the AS signaling; the input-output interface 1302 is used to receive the AS signaling from a terminal device in an RRC inactive state, wherein the AS signaling is carried on the transmission resources of the SDT method.

Optionally, when the communication device 1300 is a CU (or a component in a CU) in the aforementioned embodiment, the logic circuit 1301 is used to determine the configuration information of transmitting AS signaling based on the small data transmission SDT mode; the input and output interface 1302 is used to receive the configuration information from the distributed The AS signaling of the unit DU, wherein the AS signaling comes from a terminal device that is in an inactive state of the radio resource control RRC.

Optionally, when the communication device 1300 is a network device (or a component in a network device) in the aforementioned embodiment, the logic circuit 1301 is used to determine the configuration information of the access layer AS signaling transmitted based on the small data transmission SDT method; the input and output interface 1302 is used to send the configuration information of the AS signaling.

Optionally, when the communication device 1300 is a terminal device (or a component in the terminal device) in the aforementioned embodiment, when the terminal device is in a radio resource control RRC inactive state, the logic circuit 1301 is used to determine an RRC recovery request message, and the input-output interface 1302 is used to send an RRC recovery request message, and the RRC recovery request message includes indication information for indicating that the RRC recovery reason is AS signaling; after restoring the RRC connection state, the input-output interface 1302 is also used to send the AS signaling.

Optionally, when the communication device 1300 is the network device (or a component in the network device) in the aforementioned embodiment, when the terminal device is in the radio resource control RRC inactive state, the input-output interface 1302 is used to receive an RRC recovery request message, and the RRC recovery request message includes indication information for indicating that the RRC recovery reason is AS signaling; after the logic circuit 1301 determines that the terminal device has restored the RRC connection state, the input-output interface 1302 is also used to receive the AS signaling.

The logic circuit 1301 and the input/output interface 1302 may also execute other steps executed by the communication device in any embodiment and achieve corresponding beneficial effects, which will not be described in detail here.

In a possible implementation, the processing unit 1201 shown in FIG. 12 may be the logic circuit 1301 in FIG. 13 .

Optionally, the logic circuit 1301 may be a processing device, and the functions of the processing device may be partially or completely implemented by software. The functions of the processing device may be partially or completely implemented by software.

Optionally, the processing device may include a memory and a processor, wherein the memory is used to store a computer program, and the processor reads and executes the computer program stored in the memory to perform corresponding processing and/or steps in any one of the method embodiments.

Alternatively, the processing device may include only a processor. A memory for storing a computer program is located outside the processing device, and the processor is connected to the memory via a circuit/wire to read and execute the computer program stored in the memory. The memory and the processor may be integrated together, or may be physically independent of each other.

Optionally, the processing device may be one or more chips, or one or more integrated circuits. For example, the processing device may be one or more field-programmable gate arrays (FPGA), application specific integrated circuits (ASIC), system on chip (SoC), central processor unit (CPU), network processor (NP), digital signal processor (DSP), microcontroller unit (MCU), programmable logic device (PLD) or other integrated chips, or any combination of the above chips or processors.

Please refer to FIG. 14 , which shows a communication device 1400 involved in the above embodiments provided in an embodiment of the present application. The communication device 1400 may specifically be a communication device as a terminal device in the above embodiments.

Herein, a possible logical structure diagram of the communication device 1400 is shown. The communication device 1400 may include but is not limited to at least one processor 1401 and a communication port 1402 .

Further optionally, the device may also include at least one of a memory 1403 and a bus 1404 . In an embodiment of the present application, the at least one processor 1401 is used to control and process the actions of the communication device 1400 .

In addition, the processor 1401 can be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a transistor logic device, a hardware component or any combination thereof. It can implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. The processor can also be a combination that implements a computing function, such as a combination of one or more microprocessors, a combination of a digital signal processor and a microprocessor, and the like. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

It should be noted that the communication device 1400 shown in Figure 14 can be specifically used to implement the steps implemented by the terminal device in the aforementioned method embodiment, and to achieve the corresponding technical effects of the terminal device. The specific implementation methods of the communication device shown in Figure 14 can refer to the description in the aforementioned method embodiment, and will not be repeated here.

Please refer to FIG. 15, which is a schematic diagram of the structure of a communication device 1500 involved in the above-mentioned embodiment provided in an embodiment of the present application. The communication device 1500 may specifically be a communication device as a network device (eg, DU, CU, network device, etc.) in the above embodiments. The structure of the communication device may refer to the structure shown in FIG. 15 .

The communication device 1500 includes at least one processor 1511 and at least one network interface 1514. Further optionally, the communication device also includes at least one memory 1512, at least one transceiver 1513 and one or more antennas 1515. The processor 1511, the memory 1512, the transceiver 1513 and the network interface 1514 are connected, for example, through a bus. In an embodiment of the present application, the connection may include various interfaces, transmission lines or buses, etc., which are not limited in this embodiment. The antenna 1515 is connected to the transceiver 1513. The network interface 1514 is used to enable the communication device to communicate with other communication devices through a communication link. For example, the network interface 1514 may include a network interface between the communication device and the core network device, such as an S1 interface, and the network interface may include a network interface between the communication device and other communication devices (such as other network devices or core network devices), such as an X2 or Xn interface.

The processor 1511 is mainly used to process the communication protocol and communication data, and to control the entire communication device, execute the software program, and process the data of the software program, for example, to support the communication device to perform the actions described in the embodiment. The communication device may include a baseband processor and a central processor. The baseband processor is mainly used to process the communication protocol and communication data, and the central processor is mainly used to control the entire terminal device, execute the software program, and process the data of the software program. The processor 1511 in Figure 15 can integrate the functions of the baseband processor and the central processor. It can be understood by those skilled in the art that the baseband processor and the central processor can also be independent processors, interconnected by technologies such as buses. It can be understood by those skilled in the art that the terminal device can include multiple baseband processors to adapt to different network formats, and the terminal device can include multiple central processors to enhance its processing capabilities. The various components of the terminal device can be connected through various buses. The baseband processor can also be described as a baseband processing circuit or a baseband processing chip. The central processor can also be described as a central processing circuit or a central processing chip. The function of processing the communication protocol and communication data can be built into the processor, or it can be stored in the memory in the form of a software program, and the processor executes the software program to realize the baseband processing function.

The memory is mainly used to store software programs and data. The memory 1512 can be independent and connected to the processor 1511. Optionally, the memory 1512 can be integrated with the processor 1511, for example, integrated into a chip. Among them, the memory 1512 can store program codes for executing the technical solutions of the embodiments of the present application, and the execution is controlled by the processor 1511. The various types of computer program codes executed can also be regarded as drivers of the processor 1511.

FIG15 shows only one memory and one processor. In an actual terminal device, there may be multiple processors and multiple memories. The memory may also be referred to as a storage medium or a storage device, etc. The memory may be a storage element on the same chip as the processor, i.e., an on-chip storage element, or an independent storage element, which is not limited in the embodiments of the present application.

The transceiver 1513 can be used to support the reception or transmission of radio frequency signals between the communication device and the terminal, and the transceiver 1513 can be connected to the antenna 1515. The transceiver 1513 includes a transmitter Tx and a receiver Rx. Specifically, one or more antennas 1515 can receive radio frequency signals, and the receiver Rx of the transceiver 1513 is used to receive the radio frequency signal from the antenna, and convert the radio frequency signal into a digital baseband signal or a digital intermediate frequency signal, and provide the digital baseband signal or the digital intermediate frequency signal to the processor 1511, so that the processor 1511 further processes the digital baseband signal or the digital intermediate frequency signal, such as demodulation processing and decoding processing. In addition, the transmitter Tx in the transceiver 1513 is also used to receive a modulated digital baseband signal or a digital intermediate frequency signal from the processor 1511, and convert the modulated digital baseband signal or the digital intermediate frequency signal into a radio frequency signal, and send the radio frequency signal through one or more antennas 1515. Specifically, the receiver Rx can selectively perform one or more stages of down-mixing and analog-to-digital conversion processing on the RF signal to obtain a digital baseband signal or a digital intermediate frequency signal, and the order of the down-mixing and analog-to-digital conversion processing is adjustable. The transmitter Tx can selectively perform one or more stages of up-mixing and digital-to-analog conversion processing on the modulated digital baseband signal or digital intermediate frequency signal to obtain a RF signal, and the order of the up-mixing and digital-to-analog conversion processing is adjustable. The digital baseband signal and the digital intermediate frequency signal can be collectively referred to as a digital signal.

The transceiver 1513 may also be referred to as a transceiver unit, a transceiver, a transceiver device, etc. Optionally, a device in the transceiver unit for implementing a receiving function may be regarded as a receiving unit, and a device in the transceiver unit for implementing a sending function may be regarded as a sending unit, that is, the transceiver unit includes a receiving unit and a sending unit, and the receiving unit may also be referred to as a receiver, an input port, a receiving circuit, etc., and the sending unit may be referred to as a transmitter, a transmitter, or a transmitting circuit, etc.

It should be noted that the communication device 1500 shown in Figure 15 can be specifically used to implement the steps implemented by the network equipment in the aforementioned method embodiment, and to achieve the corresponding technical effects of the network equipment. The specific implementation methods of the communication device 1500 shown in Figure 15 can refer to the description in the aforementioned method embodiment, and will not be repeated here one by one.

An embodiment of the present application further provides a computer-readable storage medium storing one or more computer-executable instructions. When the computer-executable instructions are executed by a processor, the processor executes the method described in the possible implementation manner of the terminal device in the aforementioned embodiment.

An embodiment of the present application also provides a computer-readable storage medium storing one or more computer-executable instructions. When the computer-executable instructions are executed by a processor, the processor executes the method described in the possible implementation method of the network device (such as DU, CU, network device, etc.) in the aforementioned embodiment.

An embodiment of the present application also provides a computer program product (or computer program) storing one or more computers. When the computer program product is executed by the processor, the processor executes the method of the possible implementation mode of the above-mentioned terminal device.

An embodiment of the present application also provides a computer program product storing one or more computers. When the computer program product is executed by the processor, the processor executes a method of possible implementation of the above-mentioned network device (such as DU, CU, network device, etc.).

The embodiment of the present application also provides a chip system, which includes at least one processor for supporting a communication device to implement the functions involved in the possible implementation methods of the above-mentioned communication device. Optionally, the chip system also includes an interface circuit, which provides program instructions and/or data for the at least one processor. In one possible design, the chip system may also include a memory, which is used to store the necessary program instructions and data for the communication device. The chip system can be composed of chips, and may also include chips and other discrete devices, wherein the communication device can specifically be a terminal device in the aforementioned method embodiment.

An embodiment of the present application also provides a chip system, which includes at least one processor for supporting a communication device to implement the functions involved in the possible implementation methods of the above-mentioned communication device. Optionally, the chip system also includes an interface circuit, which provides program instructions and/or data for the at least one processor. In one possible design, the chip system may also include a memory, which is used to store the necessary program instructions and data for the communication device. The chip system may be composed of chips, or may include chips and other discrete devices, wherein the communication device may specifically be a network device (such as DU, CU, network device, etc.) in the aforementioned method embodiment.

An embodiment of the present application also provides a communication system, which includes the terminal device and network device (including DU, CU, network device, etc.) in any of the above embodiments.

In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

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

In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk.

Claims (33)

A communication method applied to a terminal device, characterized by comprising: Receive configuration information of access layer AS signaling transmitted in small data transmission (SDT) mode; When the terminal device is in a radio resource control RRC inactive state, the AS signaling is sent, wherein the AS signaling is carried on the transmission resources of the SDT mode. The method according to claim 1 is characterized in that the AS signaling includes RRC messages and/or media access control elements MAC CE. The method according to claim 1 or 2, characterized in that the configuration information of the AS signaling includes at least one of the following: The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or, The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or, The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode. The method according to any one of claims 1 to 3 is characterized in that the configuration information of the AS signaling is included in an RRC release message or a system message. The method according to any one of claims 1 to 4, characterized in that the method further comprises: An RRC release message is received from a source network device, wherein the configuration information of the AS signaling is included in a system message from a destination network device. The method according to claim 5, characterized in that the RRC release message also includes configuration information of the source network device for transmitting AS signaling based on the SDT mode; the method further includes: The configuration information of the source network device for transmitting AS signaling based on the SDT mode is deleted. The method according to any one of claims 1 to 6, characterized in that the method further comprises: When the terminal device is in an RRC inactive state, an RRC recovery request message is sent. The method according to claim 7, characterized in that the RRC recovery request message further includes indication information for indicating the RRC recovery reason, and the indication information includes at least one of the following: The type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer SRB corresponding to the AS signaling. The method according to any one of claims 1 to 8, characterized in that the method further comprises: ignoring at least one of the following: Resume other DRBs and SRBs configured with SDT; or, Check at the media access control (MAC) layer whether the data volume is exceeded; or, All data is mapped to the DRB or SRB of the SDT; or, The higher layer requests to restore the radio access control (RRC) connection. A communication method applied to a distributed unit DU, characterized by comprising: Send configuration information for transmitting AS signaling based on small data transmission (SDT); Receive the AS signaling from a terminal device that is in an inactive state of radio resource control (RRC), wherein the AS signaling is carried on the transmission resources of the SDT mode. The method according to claim 10 is characterized in that the AS signaling includes RRC messages and/or media access control elements MAC CE. The method according to claim 10 or 11, characterized in that the method further comprises: Sending the AS signaling to a centralized unit CU; When the AS signaling includes an RRC message, the RRC message is carried in an uplink radio resource control information transmission UL RRC MESSAGE TRANSFER message; and/or, When the AS signaling includes MAC CE, the information carried by the MAC CE is carried in the F1 application protocol F1-AP message. The method according to any one of claims 10 to 12, characterized in that the configuration information of the AS signaling includes at least one of the following: The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or, The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or, The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode. The method according to any one of claims 10 to 13 is characterized in that the configuration information of the AS signaling is included in an RRC release message or a system message. The method according to any one of claims 10 to 14, characterized in that the configuration information of the AS signaling is included in the system message; The parameters in the system message are determined by the DU, and the method further includes: sending configuration information of the AS signaling to the CU; or, The parameters in the system message are determined by the CU, and the method further includes: receiving configuration information of the AS signaling from the CU. The method according to any one of claims 10 to 14, characterized in that the configuration information of the AS signaling is included in the RRC release message, and the method further comprises: The DU receives a user equipment context modification request UE CONTEXT MODIFICATION REQUEST message from the CU; The DU sends a user equipment context modification response UE CONTEXT MODIFICATION RESPONSE message to the CU; The DU receives a user context release command UE CONTEXT RELEASE COMMAND message from the CU, wherein the UE CONTEXT RELEASE COMMAND message includes the RRC release message; Wherein, the UE CONTEXT MODIFICATION REQUEST message includes the configuration information of the AS signaling, and/or the UE CONTEXT RELEASE COMMAND message includes the configuration information of the AS signaling. The method according to claim 16 is characterized in that the UE CONTEXT MODIFICATION REQUEST message includes indication information for indicating that the configuration information of the AS signaling is retained, or the UE CONTEXT RELEASE COMMAND message includes indication information for indicating that the configuration information of the AS signaling is retained. The method according to any one of claims 10 to 17, characterized in that the method further comprises: When the terminal device is in an RRC inactive state, an RRC recovery request message is received. The method according to claim 18, characterized in that the RRC recovery request message includes indication information for indicating the RRC recovery reason, and the indication information includes at least one of the following: The type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer to which the AS signaling corresponds. A communication method applied to a centralized unit CU, characterized by comprising: Determine the configuration information for transmitting AS signaling based on the small data transmission (SDT) mode; Receive the AS signaling from the distributed unit DU, wherein the AS signaling comes from a terminal device in an inactive state of radio resource control RRC. The method according to claim 20 is characterized in that the AS signaling includes RRC messages and/or media access control elements MAC CE. The method according to claim 21, characterized in that When the AS signaling includes an RRC message, the RRC message is carried in an uplink radio resource control information transmission UL RRC MESSAGE TRANSFER message; and/or, When the AS signaling includes MAC CE, the information carried by the MAC CE is carried in the F1 application protocol F1-AP message. The method according to any one of claims 20 to 22, characterized in that the configuration information of the AS signaling includes at least one of the following: The first indication information indicates whether the transmission of MAC CE based on SDT is supported; or, The second indication information indicates whether the RRC message transmission based on the SDT mode is supported; or The first configuration information includes configuration information for transmitting MAC CE based on the SDT method; or, The second configuration information includes configuration information for transmitting the RRC message based on the SDT mode. The method according to any one of claims 20 to 23, characterized in that the configuration information of the AS signaling is included in a system message sent by the DU to the terminal device; The parameters in the system message are determined by the DU, and the method further comprises: receiving configuration information of the AS signaling from the DU; or, The parameters in the system message are determined by the CU, and the method further includes: sending configuration information of the AS signaling to the DU. The method according to any one of claims 20 to 23, characterized in that the configuration information of the AS signaling is included in the RRC release message sent by the DU to the terminal device, and the method further comprises: The CU sends a user equipment context modification request UE CONTEXT MODIFICATION REQUEST message to the DU; The CU receives a user equipment context modification response UE CONTEXT MODIFICATION RESPONSE message from the DU; The CU sends a user context release command UE CONTEXT RELEASE COMMAND message to the DU, wherein the UE CONTEXT RELEASE COMMAND message includes the RRC release message; Wherein, the UE CONTEXT MODIFICATION REQUEST message includes the configuration information of the AS signaling, and/or the UE CONTEXT RELEASE COMMAND message includes the configuration information of the AS signaling. The method according to claim 25 is characterized in that the UE CONTEXT MODIFICATION REQUEST message includes indication information for indicating that the configuration information of the AS signaling is retained, or the UE CONTEXT RELEASE COMMAND message includes indication information for indicating that the configuration information of the AS signaling is retained. The method according to any one of claims 20 to 26, characterized in that the RRC recovery request message includes indication information for indicating the RRC recovery reason, and the indication information includes at least one of the following: The type of the AS signaling, or the identifier of the data radio bearer DRB corresponding to the AS signaling, or the identifier of the signaling radio bearer to which the AS signaling corresponds. A communication device, characterized in that: A communication device, characterized in that, comprises a processing unit and a transceiver unit; The processing unit and the transceiver unit are used to execute the method according to any one of claims 1 to 9. A communication device, characterized in that it comprises a processing unit and a transceiver unit; The processing unit and the transceiver unit are used to execute the method according to any one of claims 10 to 19. A communication device, characterized in that it comprises a processing unit and a transceiver unit; The processing unit and the transceiver unit are used to execute the method according to any one of claims 20 to 27. A communication device, characterized in that it comprises at least one processor coupled to a memory; The memory is used to store programs or instructions; The at least one processor is configured to execute the program or instruction so that the apparatus implements the method according to any one of claims 1 to 27. A communication system, characterized in that the communication system comprises at least two of the communication device described in claim 28, the communication device described in claim 29, or the communication device described in claim 30. A computer-readable storage medium, characterized in that the medium stores instructions, and when the instructions are executed by a computer, the method described in any one of claims 1 to 27 is implemented.