A method and apparatus for sidelink communication

Abstract

A method and apparatus for sidelink communication, the method comprising: a first terminal device sending a SCI with a HARQ attribute enabled to a second terminal device; the first terminal device starting or restarting a discontinuous reception inactivity timer upon receiving a HARQ feedback from the second terminal device; and correspondingly, the second terminal device starting or restarting a discontinuous reception inactivity timer upon sending the HARQ feedback to the first terminal device. Optionally, the first terminal device does not start or restart the discontinuous reception inactivity timer upon performing a transmission of a SCI with a HARQ attribute disabled to the second terminal device, so that the first terminal device and the second terminal device start the discontinuous reception inactivity timer synchronously and align their activation times.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a sidelink communication method and apparatus. Background Technology

[0002] In wireless communication systems, to conserve power consumption of user equipment (UE) while ensuring efficient data transmission, a discontinuous reception (DRX) mechanism is introduced to control the UE's behavior when listening to the physical downlink control channel (PDCCH). This DRX mechanism can also be called the air interface DRX (Uu DRX) mechanism.

[0003] Without the UuDRX mechanism, the UE would continuously listen to the PDCCH to check for information from the serving cell. However, in reality, the UE doesn't constantly interact with the network; it doesn't always perform upload or download services, and voice data isn't constantly transmitted during calls. If the UE continuously listens to the PDCCH when there's no data exchange between the UE and the network, it's obviously very power-intensive. Therefore, while ensuring effective data transmission, the UuDRX mechanism can be used to save UE power.

[0004] When configuring Uu DRX, the UE can periodically enter a "sleep state" at certain times. The UE does not need to continuously listen to the PDCCH, and wakes itself from sleep state when listening is required, thus saving power. Although this will have some impact on data transmission latency, if this latency does not affect the user experience, then considering the more important power consumption of the UE, implementing Uu DRX is very meaningful.

[0005] Currently, in the research on sidelink (SL) in Release 17 (R17) of the 3rd Generation Partnership Project (3GPP), the introduction of SL DRX has been proposed. Similar to the Uu DRX mentioned above, SL DRX is used to control the receiving UE to listen for sidelink control information (SCI). That is, the UE wakes up during the active period to listen for SCI sent by other UEs; if the UE enters sleep mode, it cannot receive SCI.

[0006] In SL DRX, the UE's active time includes the running time of the following timers: Discontinuous Receive Active Timer (DRX-on Duration timer), Discontinuous Receive Inactive Timer (DRX-inactivity timer), and Discontinuous Receive Retransmission Timer (DRX-Retransmission timer). Due to various factors, the timers started by the transmitting UE and the receiving UE may become out of sync, resulting in misaligned active times and affecting normal communication between the two. Summary of the Invention

[0007] This application provides a sidelink communication method and apparatus to enable the timers of the transmitting end and the receiving end to start synchronously and align their activation times.

[0008] In a first aspect, a sidelink communication method is provided, comprising: a first terminal device sending a sidelink control information (SCI) with a Hybrid Automatic Repeat Request (HARQ) attribute enabled to a second terminal device, wherein the HARQ attribute being enabled indicates that when the second terminal device receives the SCI or sidelink SL data scheduled by the SCI, it sends HARQ feedback of the SCI or the SCI-scheduled data to the first terminal device; the first terminal device receiving the HARQ feedback of the SCI or the SCI-scheduled data from the second terminal device; and the first terminal device starting or restarting a discontinuous reception inactivity timer. Optionally, the method further comprises: the first terminal device sending an SCI with a HARQ attribute disabled to the second terminal device; the first terminal device keeping the discontinuous reception inactivity timer in an unstarted state; and the HARQ attribute being disabled indicating that when the second terminal device receives the SCI or the SCI-scheduled SL data, it does not send HARQ feedback of the SCI or the SCI-scheduled SL data to the first terminal device.

[0009] As can be seen from the above, for SCIs with HARQ disabled, since the second terminal does not provide HARQ feedback, the first terminal device cannot definitively determine whether the second terminal device has received the current SCI. However, using the first design approach, for SCIs with HARQ disabled, the discontinuous reception inactivity timer is not started or restarted. For SCIs with HARQ enabled, the first terminal device starts the discontinuous reception inactivity timer when it receives HARQ feedback for that SCI, and the second terminal device starts the discontinuous reception inactivity timer again when it sends HARQ feedback. This ensures that the first and second terminal devices start their discontinuous reception inactivity timers synchronously, aligning their activation times.

[0010] In one possible implementation, the SCI includes a first-level SCI, or a first-level SCI and a second-level SCI. Optionally, the SCI can be transmitted within the PSCCH.

[0011] Secondly, a sidelink communication method is provided. The beneficial effects of this second aspect are described in the first aspect above. The method includes: a second terminal device receiving a sidelink control information (SCI) from a first terminal device with its Hybrid Automatic Repeat Request (HARQ) attribute enabled; the enabled HARQ attribute indicating that when the second terminal device receives the SCI or sidelink SL data scheduled by the SCI, it sends HARQ feedback of the SCI or the SCI-scheduled data to the first terminal device; the second terminal device sending HARQ feedback of the SCI or the SCI-scheduled SL data to the first terminal device; and the second terminal device starting or restarting a discontinuous reception inactivity timer. Optionally, the method further includes: the second terminal device receiving an SCI with its HARQ attribute disabled from the first terminal device; the second terminal device keeping the discontinuous reception inactivity timer in an unstarted state; the disabled HARQ attribute indicating that when the second terminal device receives the SCI or the SCI-scheduled SL data, it does not send HARQ feedback of the SCI or the SCI-scheduled SL data to the first terminal device.

[0012] In one possible implementation, the SCI includes a first-level SCI, or a first-level SCI and a second-level SCI. Optionally, the SCI can be transmitted within the PSCCH.

[0013] Thirdly, a sidelink communication method is provided, comprising: a second terminal device sending first information to a first terminal device, wherein the Hybrid Automatic Repeat Request (HARQ) attribute of the first information is enabled, and the enabled HARQ attribute indicates that when the first terminal device receives the first information, it sends HARQ feedback of the first information to the second terminal device; the second terminal device receiving the HARQ feedback of the first information from the first terminal device, and when the HARQ feedback is an acknowledgment (ACK), the second terminal device uses discontinuous reception DRX long period.

[0014] Taking the second terminal device as RX UE and the first terminal device as TX UE as an example. In the design of the third aspect mentioned above, when the RX UE needs to switch from a short DRX cycle to a long DRX cycle, the RX UE can send a first message to the TX UE, where the HARQ attribute of the first message is enabled. Upon receiving the first message, the TX UE can determine whether to agree to the RX UE entering the long DRX cycle. If the TX UE agrees to the RX UE entering the long DRX cycle, the TX UE can send an ACK HARQ feedback to the RX UE. Upon receiving the ACK HARQ feedback, the RX UE then switches from the short DRX cycle to the long DRX cycle. By adopting the design of the third aspect mentioned above, the DRX cycles of the TX UE and the RX UE can be made consistent.

[0015] In one possible implementation, the first information indicates the use of the DRX long period.

[0016] In one possible implementation, the first information is carried in the Media Access Control (MAC) control element (CE).

[0017] In one possible implementation, the first information carries indication information of a first link, which is used by the first terminal device to send SL data information or SL control information to the second terminal device.

[0018] In one possible implementation, the indication information of the first link includes: a destination identifier and a source identifier pair, wherein the destination identifier is the identifier of the receiving end and the source identifier is the identifier of the sending end; or the identifier of the first link; or the connection identifier of the first link.

[0019] Fourthly, a sidelink communication method is provided. Regarding the beneficial effects of this fourth aspect, please refer to the description in the third aspect above. The method includes: a first terminal device receiving first information from a second terminal device, wherein the Hybrid Automatic Repeat Request (HARQ) attribute of the first information is enabled; the enabled HARQ attribute indicates that when the first terminal device receives the first information, it sends HARQ feedback of the first information to the second terminal device; the first terminal device sends HARQ feedback of the first information to the second terminal device; when the HARQ feedback is an acknowledgment (ACK), the first terminal device uses discontinuous reception DRX long period.

[0020] In one possible implementation, the first information indicates the use of the DRX long period.

[0021] In one possible implementation, the first information is carried in the Media Access Control (MAC) control element (CE).

[0022] In one possible implementation, the first information carries indication information of a first link, which is used by the first terminal device to send SL data information or SL control information to the second terminal device.

[0023] In one possible implementation, the indication information of the first link includes a destination identifier and a source identifier pair, wherein the destination identifier is the identifier of the receiving end and the source identifier is the identifier of the sending end; or the identifier of the first link; or the connection identifier of the first link.

[0024] Fifthly, a sidelink communication method is provided, comprising: a first terminal device sending second information to a second terminal device, wherein the Hybrid Automatic Repeat Request (HARQ) attribute of the second information is enabled, and the enabled HARQ attribute indicates that when the second terminal device receives the second information, it sends HARQ feedback of the second information to the first terminal device; the first terminal device receiving the HARQ feedback of the second information from the second terminal device, and when the HARQ feedback is an acknowledgment (ACK), the first terminal device uses discontinuous reception of short DRX cycles.

[0025] Taking the first terminal device as TX UE and the second terminal device as RX UE as an example, using the design of the fifth aspect mentioned above, when the TX UE meets the condition of switching from DRX long period to DRX short period, it sends the second information to the RX UE. When the RX UE agrees to switch to DRX short period, the TX UE and RX UE switch to DRX short period, so that the DRX period of the TX UE and RX UE can be consistent.

[0026] In one possible implementation, the second information indicates the use of the DRX short cycle.

[0027] In one possible implementation, the second information is carried in the Media Access Control (MAC) control element CE.

[0028] In one possible implementation, the second information carries indication information of a first link, which is used by the first terminal device to send SL data information or SL control information to the second terminal device.

[0029] In one possible implementation, the indication information of the first link includes: a destination identifier and a source identifier pair, wherein the destination identifier is the identifier of the receiving end and the source identifier is the identifier of the sending end; or the identifier of the first link; or the connection identifier of the first link.

[0030] Sixthly, a sidelink communication method is provided. The beneficial effects of this sixth aspect can be found in the description of the fifth aspect above. The method includes at least: a second terminal device receiving second information from a first terminal device, wherein the Hybrid Automatic Repeat Request (HARQ) attribute of the second information is enabled, and the enabled HARQ attribute instructs the second terminal device to send HARQ feedback of the second information to the first terminal device upon receiving the second information; the second terminal device sending the HARQ feedback of the second information to the first terminal device, and when the HARQ feedback is an acknowledgment (ACK), the second terminal device uses discontinuous reception of short DRX cycles.

[0031] In one possible implementation, the second information indicates the use of the DRX short cycle.

[0032] In one possible implementation, the second information is carried in the Media Access Control (MAC) control element CE.

[0033] In one possible implementation, the second information carries indication information of a first link, which is used by the first terminal device to send SL data information or SL control information to the second terminal device.

[0034] In one possible implementation, the indication information of the first link includes: a destination identifier and a source identifier pair, wherein the destination identifier is the identifier of the receiving end and the source identifier is the identifier of the sending end; or the identifier of the first link; or the connection identifier of the first link.

[0035] A seventh aspect provides a sidelink communication method, comprising: during the activation period of a long period of discontinuous reception DRX, a first terminal device sends only a sidelink control information SCI with the Hybrid Automatic Repeat Request (HARQ) attribute enabled; the enabled HARQ attribute instructs a second terminal device to send HARQ feedback of the SCI or SL data scheduled by the SCI to the first terminal device; when the first terminal device receives the HARQ feedback of the SCI or SL data, it starts or restarts a discontinuous reception inactivity timer; when the discontinuous reception inactivity timer expires, the first terminal device uses a short period of discontinuous reception DRX.

[0036] Taking the first terminal device as TX UE, the second terminal device as RX UE, and the discontinuous reception inactivity timer as an example, the DRX cycle of TX UE and RX UE is inconsistent. This is mainly because RX UE fails to receive the SCI sent by TX UE, resulting in RX UE not starting the inactivity timer; when the inactivity timer expires, RX UE also does not start the shortcycle timer. Using the design in the seventh aspect mentioned above, TX UE only sends SCIs with HARQ enabled during the active time of the long DRX cycle. TX UE starts or restarts the inactivity timer when it receives the SCI or HARQ feedback of the SCI-scheduled SL data. RX UE starts or restarts the inactivity timer when it sends the SCI or HARQ feedback of the SCI-scheduled SL data. This synchronizes the inactivity timer startup of TX UE and RX UE, thereby synchronizing the startup of their shortcycle timers and allowing TX UE and RX UE to switch to the short DRX cycle synchronously.

[0037] Eighthly, a sidelink communication method is provided, comprising: a first terminal device determining that discontinuous reception retransmission (DRX) between itself and a second terminal device is active, and only a discontinuous reception retransmission timer with the Hybrid Automatic Repeat Request (HARQ) attribute disabled is running, wherein the disabled HARQ attribute indicates that the second terminal device, upon receiving information corresponding to the discontinuous reception retransmission timer, sends HARQ feedback corresponding to that information to the first terminal device; the first terminal device and the second terminal device performing transmission with the HARQ attribute disabled, wherein the disabled HARQ attribute indicates that the second terminal device, upon receiving information corresponding to the transmission, does not send HARQ feedback for that information to the first terminal device.

[0038] Taking the first terminal device as TX UE, the second terminal device as RX UE, and the discontinuous reception retransmission timer as ReTXtimer as an example; adopting the design of the eighth aspect mentioned above, when the DRX between TX UE and RX UE is active, and only the ReTX timer with HARQ attribute disabled is currently running, TX UE and RX UE will no longer transmit with HARQ attribute enabled. This can avoid the problem of SL RLF being triggered because TX UE cannot receive HARQ feedback from RX UE after sending SL information or data with HARQ attribute enabled.

[0039] In one possible implementation, the transmission between the first terminal device and the second terminal device with the HARQ attribute disabled includes: the first terminal device not sending a new transmission with the HARQ attribute enabled to the second terminal device, and / or the first terminal device sending a new transmission or retransmission with the HARQ attribute disabled to the second terminal device.

[0040] In one possible implementation, the first terminal device does not send new transmissions with HARQ enabled to the second terminal device, including: the first terminal device only reuses logical channels (LCHs) with HARQ disabled for the authorization corresponding to the new transmission; or, the first terminal device clears the authorization corresponding to the new transmission.

[0041] In one possible implementation, the new transmission includes a new transport block (TB) or side link control information (SCI) indicating the new transmission.

[0042] In one possible implementation, the retransmission includes a retransmission TB, or an SCI indicating a retransmission.

[0043] One possible implementation also includes:

[0044] When the first terminal device terminates a transmission with the second terminal device where the HARQ attribute is disabled, the first terminal device stops the discontinuous receive retransmission timer of the corresponding side link SL process.

[0045] Ninthly, a sidelink communication device is provided, which can be a first terminal device or a chip in the first terminal device. The communication device has the functions described in the first aspect. For example, the communication device includes modules, units, or means that perform the steps involved in the first aspect. These functions, units, or means can be implemented by software, hardware, or hardware executing corresponding software.

[0046] In one possible design, the communication device includes a processing unit and a transceiver unit. The transceiver unit can be used to send and receive signals to enable communication between the communication device and other devices, such as receiving configuration information from a network device. The processing unit can be used to perform some internal operations of the communication device. The functions performed by the processing unit and the transceiver unit can correspond to the steps involved in the first aspect described above.

[0047] In one possible design, the communication device includes a processor and may further include a transceiver for transmitting and receiving signals. The processor executes program instructions to perform the methods in any possible design or implementation of the first aspect described above. The communication device may also include one or more memories for coupling with the processor. The one or more memories may be integrated with the processor or may be separate from it; this application is not limiting. The memories may store the necessary computer programs or instructions for implementing the functions involved in the first aspect described above. The processor can execute the computer programs or instructions stored in the memories, and when the computer programs or instructions are executed, the communication device implements the methods in any possible design or implementation of the first aspect described above.

[0048] In one possible design, the communication device includes a processor and a memory, the memory of which can store the necessary computer programs or instructions for implementing the functions described in the first aspect above. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, cause the communication device to implement the methods in any possible design or implementation of the first aspect above.

[0049] In one possible design, the communication device includes at least one processor and an interface circuit, wherein the at least one processor is configured to communicate with other devices via the interface circuit and perform the methods in any possible design or implementation of the first aspect described above.

[0050] In a tenth aspect, a sidelink communication device is provided, which can be a second terminal device or a chip in a second terminal device. The communication device has the functions described in the second aspect above. For example, the communication device includes modules, units, or means that perform the steps involved in the second aspect above. These functions, units, or means can be implemented by software, hardware, or hardware executing corresponding software.

[0051] In one possible design, the communication device includes a processing unit and a transceiver unit. The transceiver unit can be used to send and receive signals to enable communication between the communication device and other devices. For example, the transceiver unit can be used to receive configuration information from a network device. The processing unit can be used to perform some internal operations of the communication device. The functions performed by the processing unit and the transceiver unit can correspond to the steps involved in the second aspect above.

[0052] In one possible design, the communication device includes a processor and may further include a transceiver for transmitting and receiving signals. The processor executes program instructions to perform the methods in any possible design or implementation of the second aspect described above. The communication device may also include one or more memories for coupling with the processor. The one or more memories may be integrated with the processor or may be separate from it; this application is not limiting. The memories may store the necessary computer programs or instructions for implementing the functions involved in the second aspect described above. The processor can execute the computer programs or instructions stored in the memories, and when the computer programs or instructions are executed, the communication device implements the methods in any possible design or implementation of the second aspect described above.

[0053] In one possible design, the communication device includes a processor and a memory, the memory of which can store the necessary computer programs or instructions for implementing the functions described in the second aspect above. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, cause the communication device to implement the methods in any possible design or implementation of the second aspect above.

[0054] In one possible design, the communication device includes at least one processor and an interface circuit, wherein the at least one processor is configured to communicate with other devices via the interface circuit and perform the methods in any possible design or implementation of the second aspect described above.

[0055] Eleventhly, a sidelink communication device is provided, which can be a second terminal device or a chip in a second terminal device. The communication device has the functions described in the third aspect above. For example, the communication device includes modules, units, or means corresponding to the steps involved in the third aspect above. These functions, units, or means can be implemented by software, hardware, or hardware executing corresponding software.

[0056] In one possible design, the communication device includes a processing unit and a transceiver unit. The transceiver unit can be used to send and receive signals to enable communication between the communication device and other devices. For example, the transceiver unit can be used to receive configuration information from a network device. The processing unit can be used to perform some internal operations of the communication device. The functions performed by the processing unit and the transceiver unit can correspond to the steps involved in the third aspect above.

[0057] In one possible design, the communication device includes a processor and may further include a transceiver for transmitting and receiving signals. The processor executes program instructions to perform the methods in any possible design or implementation of the third aspect described above. The communication device may also include one or more memories for coupling with the processor. The one or more memories may be integrated with the processor or disposed separately from it; this application is not limiting. The memories may store the necessary computer programs or instructions for implementing the functions involved in the third aspect described above. The processor can execute the computer programs or instructions stored in the memories, and when the computer programs or instructions are executed, the communication device implements the methods in any possible design or implementation of the third aspect described above.

[0058] In one possible design, the communication device includes a processor and a memory, the memory of which can store the necessary computer programs or instructions for implementing the functions involved in the third aspect above. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, cause the communication device to implement the methods in any possible design or implementation of the third aspect above.

[0059] In one possible design, the communication device includes at least one processor and an interface circuit, wherein the at least one processor is configured to communicate with other devices via the interface circuit and to perform the methods in any possible design or implementation of the third aspect described above.

[0060] In a twelfth aspect, a sidelink communication device is provided, which can be a first terminal device or a chip in the first terminal device. The communication device has the functions described in the fourth aspect above. For example, the communication device includes modules, units, or means that perform the steps involved in the fourth aspect above. These functions, units, or means can be implemented by software, hardware, or hardware executing corresponding software.

[0061] In one possible design, the communication device includes a processing unit and a transceiver unit. The transceiver unit can be used to send and receive signals to enable communication between the communication device and other devices, such as receiving configuration information from a network device. The processing unit can be used to perform some internal operations of the communication device. The functions performed by the processing unit and the transceiver unit can correspond to the steps involved in the fourth aspect above.

[0062] In one possible design, the communication device includes a processor and may further include a transceiver for transmitting and receiving signals. The processor executes program instructions to perform the methods in any possible design or implementation of the fourth aspect described above. The communication device may also include one or more memories for coupling with the processor. The one or more memories may be integrated with the processor or may be separate from it; this application is not limiting. The memories may store the necessary computer programs or instructions for implementing the functions involved in the fourth aspect described above. The processor can execute the computer programs or instructions stored in the memories, and when the computer programs or instructions are executed, the communication device implements the methods in any possible design or implementation of the fourth aspect described above.

[0063] In one possible design, the communication device includes a processor and a memory, the memory of which can store the necessary computer programs or instructions for implementing the functions involved in the fourth aspect above. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, cause the communication device to implement the methods in any possible design or implementation of the fourth aspect above.

[0064] In one possible design, the communication device includes at least one processor and an interface circuit, wherein the at least one processor is configured to communicate with other devices via the interface circuit and to perform the methods in any possible design or implementation of the fourth aspect described above.

[0065] In a thirteenth aspect, a sidelink communication device is provided, which can be a first terminal device or a chip in the first terminal device. The communication device has the functions described in the fifth aspect above. For example, the communication device includes modules, units, or means that perform the steps involved in the fifth aspect above. These functions, units, or means can be implemented by software, hardware, or hardware executing corresponding software.

[0066] In one possible design, the communication device includes a processing unit and a transceiver unit. The transceiver unit can be used to send and receive signals to enable communication between the communication device and other devices. For example, the transceiver unit can be used to receive configuration information from a network device. The processing unit can be used to perform some internal operations of the communication device. The functions performed by the processing unit and the transceiver unit can correspond to the steps involved in the fifth aspect above.

[0067] In one possible design, the communication device includes a processor and may further include a transceiver for transmitting and receiving signals. The processor executes program instructions to perform the methods in any possible design or implementation of the fifth aspect described above. The communication device may also include one or more memories for coupling with the processor. The one or more memories may be integrated with the processor or disposed separately; this application is not limiting. The memories may store the necessary computer programs or instructions for implementing the functions involved in the fifth aspect described above. The processor can execute the computer programs or instructions stored in the memories, and when the computer programs or instructions are executed, the communication device implements the methods in any possible design or implementation of the fifth aspect described above.

[0068] In one possible design, the communication device includes a processor and a memory, the memory of which can store the necessary computer programs or instructions for implementing the functions described in the fifth aspect above. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, cause the communication device to implement the methods in any possible design or implementation of the fifth aspect above.

[0069] In one possible design, the communication device includes at least one processor and an interface circuit, wherein the at least one processor is used to communicate with other devices through the interface circuit and to perform the methods in any possible design or implementation of the fifth aspect described above.

[0070] In a fourteenth aspect, a sidelink communication device is provided, which can be a second terminal device or a chip in a second terminal device. The communication device has the functions described in the sixth aspect above. For example, the communication device includes modules, units, or means that perform the steps involved in the sixth aspect above. These functions, units, or means can be implemented by software, hardware, or hardware executing corresponding software.

[0071] In one possible design, the communication device includes a processing unit and a transceiver unit. The transceiver unit can be used to send and receive signals to enable communication between the communication device and other devices. For example, the transceiver unit can be used to receive configuration information from a network device. The processing unit can be used to perform some internal operations of the communication device. The functions performed by the processing unit and the transceiver unit can correspond to the steps involved in the sixth aspect above.

[0072] In one possible design, the communication device includes a processor and may further include a transceiver for transmitting and receiving signals. The processor executes program instructions to perform the methods in any possible design or implementation of the sixth aspect described above. The communication device may also include one or more memories for coupling with the processor. The one or more memories may be integrated with the processor or may be separate from it; this application is not limiting. The memories may store the necessary computer programs or instructions for implementing the functions involved in the sixth aspect described above. The processor can execute the computer programs or instructions stored in the memories, and when the computer programs or instructions are executed, the communication device implements the methods in any possible design or implementation of the sixth aspect described above.

[0073] In one possible design, the communication device includes a processor and a memory, the memory of which can store the necessary computer programs or instructions for implementing the functions described in the sixth aspect above. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, cause the communication device to implement the methods in any possible design or implementation of the sixth aspect above.

[0074] In one possible design, the communication device includes at least one processor and an interface circuit, wherein the at least one processor is configured to communicate with other devices via the interface circuit and to perform the methods in any possible design or implementation of the sixth aspect described above.

[0075] In a fifteenth aspect, a sidelink communication device is provided, which can be a first terminal device or a chip in the first terminal device. The communication device has the functions described in the seventh aspect above. For example, the communication device includes modules, units, or means corresponding to the steps involved in the seventh aspect above. These functions, units, or means can be implemented by software, hardware, or hardware executing corresponding software.

[0076] In one possible design, the communication device includes a processing unit and a transceiver unit. The transceiver unit can be used to send and receive signals to enable communication between the communication device and other devices. For example, the transceiver unit can be used to receive configuration information from a network device. The processing unit can be used to perform some internal operations of the communication device. The functions performed by the processing unit and the transceiver unit can correspond to the steps involved in the seventh aspect above.

[0077] In one possible design, the communication device includes a processor and may further include a transceiver for transmitting and receiving signals. The processor executes program instructions to perform the methods in any possible design or implementation of the seventh aspect described above. The communication device may also include one or more memories for coupling with the processor. The one or more memories may be integrated with the processor or may be separate from it; this application is not limiting. The memories may store the necessary computer programs or instructions for implementing the functions involved in the seventh aspect described above. The processor can execute the computer programs or instructions stored in the memories, and when the computer programs or instructions are executed, the communication device implements the methods in any possible design or implementation of the seventh aspect described above.

[0078] In one possible design, the communication device includes a processor and a memory, the memory of which can store the necessary computer programs or instructions for implementing the functions described in the seventh aspect above. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, cause the communication device to implement the methods in any possible design or implementation of the seventh aspect above.

[0079] In one possible design, the communication device includes at least one processor and an interface circuit, wherein the at least one processor is configured to communicate with other devices via the interface circuit and perform the methods in any possible design or implementation of the seventh aspect described above.

[0080] In a sixteenth aspect, a sidelink communication device is provided, which can be a first terminal device or a chip in the first terminal device. The communication device has the functions described in the eighth aspect above. For example, the communication device includes modules, units, or means that perform the steps involved in the eighth aspect above. These functions, units, or means can be implemented by software, hardware, or hardware executing corresponding software.

[0081] In one possible design, the communication device includes a processing unit and a transceiver unit. The transceiver unit can be used to send and receive signals to enable communication between the communication device and other devices. For example, the transceiver unit can be used to receive configuration information from a network device. The processing unit can be used to perform some internal operations of the communication device. The functions performed by the processing unit and the transceiver unit can correspond to the steps involved in the eighth aspect above.

[0082] In one possible design, the communication device includes a processor and may further include a transceiver for transmitting and receiving signals. The processor executes program instructions to perform the methods in any possible design or implementation of the eighth aspect described above. The communication device may also include one or more memories for coupling with the processor. The one or more memories may be integrated with the processor or disposed separately from it; this application is not limiting. The memories may store the necessary computer programs or instructions for implementing the functions involved in the eighth aspect described above. The processor can execute the computer programs or instructions stored in the memories, and when the computer programs or instructions are executed, the communication device implements the methods in any possible design or implementation of the eighth aspect described above.

[0083] In one possible design, the communication device includes a processor and a memory, the memory of which can store the necessary computer programs or instructions for implementing the functions described in the eighth aspect above. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, cause the communication device to implement the methods in any possible design or implementation of the eighth aspect above.

[0084] In one possible design, the communication device includes at least one processor and an interface circuit, wherein the at least one processor is configured to communicate with other devices via the interface circuit and perform the methods in any possible design or implementation of the eighth aspect described above.

[0085] In a seventeenth aspect, a communication system is provided, the communication system including the communication devices of the ninth, twelfth, thirteenth, fifteenth, or sixteenth aspects described above, as well as the communication devices of the tenth, eleventh, or fourteenth aspects.

[0086] In an eighteenth aspect, this application provides a computer-readable storage medium storing computer-readable instructions that, when read and executed by a computer, cause the computer to perform any of the possible designs in the first to eighth aspects described above.

[0087] In a nineteenth aspect, this application provides a computer program product that, when read and executed by a computer, causes the computer to perform any of the possible designs in the first to eighth aspects described above.

[0088] In a twentieth aspect, this application provides a chip including a processor coupled to a memory for reading and executing a software program stored in the memory to implement the method in any of the possible designs of the first to eighth aspects described above. Attached Figure Description

[0089] Figure 1 This is a schematic diagram of the system architecture provided for an embodiment of this application;

[0090] Figure 2 A schematic diagram of the SLDRX cycle provided in the embodiments of this application;

[0091] Figure 3 A schematic diagram illustrating the startup of the inactivity timer in the current solution provided in the embodiments of this application;

[0092] Figure 4 A flowchart illustrating the side-link communication method provided in an embodiment of this application;

[0093] Figure 5 A schematic diagram illustrating the startup of the inactivity timer provided in an embodiment of this application;

[0094] Figure 6 A schematic diagram illustrating the inconsistency of DRX cycles in the current solution provided in the embodiments of this application;

[0095] Figure 7 A flowchart illustrating the side-link communication method provided in an embodiment of this application;

[0096] Figure 8 A schematic diagram of DRX cycle switching provided in an embodiment of this application;

[0097] Figure 9 A flowchart illustrating the side-link communication method provided in an embodiment of this application;

[0098] Figure 10 A flowchart illustrating the side-link communication method provided in an embodiment of this application;

[0099] Figure 11 A schematic diagram illustrating the configuration of the RTT timer and ReTx timer provided in an embodiment of this application;

[0100] Figure 12 A flowchart illustrating the side-link communication method provided in an embodiment of this application;

[0101] Figure 13 A schematic diagram of the device provided in the embodiments of this application;

[0102] Figure 14 Another schematic diagram of the device provided in the embodiments of this application. Detailed Implementation

[0103] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0104] Figure 1 This illustration shows a communication system 100 to which embodiments of this application can be applied. The communication system 100 can be a Long Term Evolution (LTE) system, a fifth-generation (5G) system, or a third-generation (5G) system. th It can also refer to generation 5G communication systems, new radio (NR) systems, machine-to-machine (M2M) communication systems, vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, sixth-generation and subsequent future evolution communication systems, etc.

[0105] like Figure 1 As shown, the communication system 100 may include two or more terminal devices 101. The terminal devices 101 can communicate with each other via a wireless interface (such as a PC5 interface). On the PC5 interface, the link for data transmission between terminal devices 101 is called a sidelink (SL).

[0106] SL communication is generally used in scenarios involving direct device-to-device communication, such as vehicle-to-everything (V2X) or device-to-device (D2D) communication. V2X refers to connecting vehicles to the network or connecting vehicles into a network, encompassing four different types of applications: vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). Through these four applications, vehicles, roadside infrastructure, application servers, and pedestrians can collect, process, and share status information about surrounding vehicles and the environment to provide more intelligent services, such as unmanned driving, automated driving, driver assistance, intelligent driving, connected driving, intelligent network driving, and car sharing.

[0107] like Figure 1As shown, in a V2V scenario, terminal device 101 can be an in-vehicle terminal. On the PC5 interface, in-vehicle terminals exchange data via SL (Signal Transfer), such as vehicle position, speed, and direction of travel, indicating vehicle dynamics. For example, in-vehicle terminal A can send SL data to another in-vehicle terminal B, which indicates the content expressed by the aforementioned data. For instance, the content displayed on the user interface of in-vehicle terminal B could be "the license plate number of the vehicle behind" ("FAF787"), the driving operation being performed by the vehicle behind ("the vehicle behind FAF787 is performing an overtaking operation"), the current speed of the vehicle behind ("80 km / h"), etc. Of course, "the vehicle behind" refers to in-vehicle terminal A. This can reduce the incidence of traffic accidents and enhance driving safety.

[0108] Optionally, in the above Figure 1 The communication system 100 shown may further include a network device 102. The communication interface between the network device 102 and the terminal device 101 is an air interface. The network device 102 can communicate with the terminal device 101 via the air interface under the control of the network control device. The air interface is also referred to as a Uu interface in some communication systems.

[0109] In one possible implementation, network device 102 can send downlink control information (DCI) to terminal device 101 via the air interface. The DCI is used to allocate SL resources to terminal device 101. The two terminal devices 101 can then perform SL communication on the allocated SL resources. In this embodiment, in the SL-based communication method, SL resource allocation includes two methods: The first method is resource allocation scheduled by the base station, also known as mode-1. When a UE needs to transmit data on the SL, the UE can send a request to the base station via the air interface. The base station can allocate SL resources to the UE according to the request and indicate the allocated SL resources to the UE via the DCI. The second method is UE-selected mode, also known as mode-2. When a UE needs to transmit data on the SL, the UE can select SL resources from the resource pool configured or pre-configured by the base station.

[0110] It should be noted that the above Figure 1 The communication system 100 shown is merely for illustrating the technical solution of this application and does not constitute a limitation thereof. Those skilled in the art will recognize that, with the evolution of network architecture and the emergence of new service scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0111] For ease of understanding, the nouns or terms involved in the embodiments of this application will be introduced first, and these nouns or terms will also be part of the invention content of the embodiments of this application.

[0112] 1. Terminal equipment

[0113] A terminal device, often simply referred to as a terminal, is a device with wireless transceiver capabilities. Terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water (such as on ships); and in the air (such as on airplanes, balloons, and satellites). These terminal devices can include mobile phones, tablets, computers with wireless transceiver capabilities, virtual reality (VR) terminal devices, augmented reality (AR) terminal devices, wireless terminal devices in industrial control, self-driving, remote medical, smart grid, transportation safety, smart city, and smart home applications, and may also include user equipment (UE). Terminal devices can also be cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, wearable devices, terminal devices in future 5th generation (5G) networks, or terminal devices in future evolved public land mobile networks (PLMNs), etc. Terminal devices may also be referred to as terminals, access terminal devices, in-vehicle terminal devices, industrial control terminal devices, UE units, UE stations, mobile stations, mobile stations, remote stations, remote terminal devices, mobile devices, UE terminal devices, terminal devices, wireless communication devices, UE agents, or UE devices, etc. Terminal devices can be fixed or mobile. This application does not limit this.

[0114] 2. Network equipment

[0115] Network equipment, also known as access network equipment or radio access network (RAN) equipment, is a device that provides wireless communication capabilities to terminal devices. Examples of access network equipment include, but are not limited to: next-generation node B (gNB), evolved node B (eNB), radio network controller (RNC), node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved node B, or home node B (HNB)), baseband unit (BBU), transmitting and receiving point (TRP), transmitting point (TP), and mobile switching center, etc., in 5G. Access network equipment can also be a radio controller, centralized unit (CU), and / or distributed unit (DU) in a cloud radio access network (CRAN) scenario. Alternatively, network equipment can be a relay station, access point, vehicle-mounted equipment, wearable devices, or network equipment in future 5G networks or future evolved PLMN networks. Terminal equipment can communicate with multiple access network devices using different technologies. For example, a terminal device can communicate with access network devices supporting long-term evolution (LTE), or with access network devices supporting 5G, or even have dual connectivity with both LTE-enabled and 5G-enabled access network devices. The embodiments in this application are not limited to these specific examples.

[0116] 3. Sidelink (SL)

[0117] Sidelinks are used for communication between terminal devices, and the communication interface between terminal devices is the PC5 interface. The channels involved in sidelink communication may include the physical sidelink shared channel (PSSCH), the physical sidelink control channel (PSCCH), and the physical sidelink feedback channel (PSFCH).

[0118] The PSSCH carries sidelink data (SL data), while the PSCCH carries sidelink control information (SCI), also known as sidelink scheduling allocation (SL SA). SL SA contains information related to data scheduling, such as resource configuration and / or modulation and coding scheme (MCS) information used to carry the PSSCH. The PSFCH may include information such as hybrid automatic repeat request (HARQ). The HARQ information can specifically include negative acknowledgment (NACK) or positive acknowledgment (ACK).

[0119] It should be noted that in the sidelink communication method provided in this application embodiment, the first terminal device can be a transmitting user equipment (TX UE), and the second terminal device can be a receiving user equipment (RX UE). The communication between the first and second terminal devices can be unicast or multicast, etc., without limitation. When using multicast communication, the number of second terminal devices can be one or more. In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can represent A or B. "And / or" in this application is merely a description of the association relationship between the objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple. Furthermore, to facilitate a clear description of the technical solutions of the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" do not necessarily imply difference.

[0120] Based on the above Figure 1 The communication system 100 shown provides an application scenario: a discontinuous reception (DRX) mechanism is configured between the TX UE and the RX UE. When SL DRX is configured, the UE can periodically enter a "sleep state" at certain times. The UE does not need to continuously listen to SCIs, and when it needs to listen, the UE wakes up from the sleep state, thus saving power. In other words, SL DRX is used to control the behavior of the RX UE listening to SCIs. That is, the UE can wake up during specific time periods to listen to SCIs sent by other UEs. If the UE enters a sleep state, the UE cannot receive SCIs at least for data reception. In the embodiments of this application, the SCI can be a first-level SCI, or a first-level SCI and a second-level SCI, etc. Optionally, the SCI can be transmitted in the PSCCH.

[0121] For example, such as Figure 2 As shown, a single SL DRX cycle consists of an active period (on-duration) and an inactive period (opportunity for DRX). During the active period (on-duration), the UE is awake; during the inactive period (opportunity for DRX), the UE is asleep. In one possible implementation, an active timer (on-duration timer) can be set. When the on-duration timer is running, the UE is in the active period (on-duration); or, when the on-duration timer expires, the UE is in the inactive period (opportunity for DRX). To reduce data transmission latency, the following timers are also proposed in SL DRX:

[0122] 1. Discontinuous reception inactivity timer DRX - inactivity timer

[0123] The following description uses TX UE and RX UE as examples to illustrate how the DRX-inactivity timer is started. TX UE refers to the terminal device acting as the sender in the SL transmission; RX UE refers to the terminal device acting as the receiver in the SL transmission.

[0124] In most cases, after an RX UE is scheduled to receive SL data at a certain SCI occasion, it is likely to be scheduled to continue receiving SL data in the following subframes to complete the reception of a large number of SL data bytes. If the RX UE has already entered a sleep state, it needs to wait until the next SL DRX cycle to listen for an SCI to receive subsequent scheduling. This increases data transmission latency. To reduce this latency, a timer, the DRX-inactivity timer, is introduced in the DRX mechanism. When the RX UE listens for and receives an SCI for scheduling SL data, it starts or restarts the DRX-inactivity timer. The RX UE listens for an SCI in every subframe during the DRX-inactivity timer's operation until the timer expires. It can be seen that the introduction of the DRX-inactivity timer ensures that the RX UE is active during the DRX-inactivity timer's operation, receiving scheduling from subsequent TX UEs, which is equivalent to extending the "on duration" period.

[0125] As described above, when the RX UE receives an SCI sent by the TX UE, it will start or restart the DRX-inactivity timer. Similarly, after sending the SCI, the TX UE will start or restart its DRX-inactivity timer. This process may cause the DRX-inactivity timers of the TX UE and RX UE to start asynchronously, resulting in misalignment of their activation times.

[0126] For example, such as Figure 3 As shown, the TX UE transmits three SCIs, designated SCI1, SCI2, and SCI3. This is based on an example where each system frame (SF) comprises 10 subframes, and each subframe contains 2 slots. For further examples, please refer to [link to example]. Figure 3 As shown, SCI1 is transmitted in time slot 1 of subframe 0 within system frame number (SFN) 0, that is, SCI1 is transmitted in the second time slot of subframe (0, 0). SCI2 is transmitted in the first time slot of subframe (0, 2), and SCI3 is transmitted in the first time slot of subframe (0, 3). In the following description of this application, the above expression (system frame, subframe) = (A, B) will be used, where A represents the SFN corresponding to the subframe, and B represents the subframe number used for transmitting SCI in the system frame corresponding to the SFN.

[0127] In one possible implementation, the TX UE's behavior is as follows: During the on-duration timer period, the TX UE sends SCI1 and starts the DRX-inactivity timer. It then sends SCI2 to restart the DRX-activity timer. Finally, it sends SCI3 to restart the DRX-activity timer again.

[0128] Behavior of the RX UE: During the on-duration timer period, the RX UE receives SCI1 and starts the DRX-inactivity timer. However, SCI2 and SCI3 transmissions fail. The RX UE fails to receive SCI2 and SCI3 and also fails to restart the DRX-activity timer, resulting in a misalignment of the activation times of the TX UE and the RX UE. In one possible implementation, because the RX UE fails to receive SCI2, it does not restart the corresponding DRX-activity timer. The TX UE, unaware that the RX UE has failed to receive SCI2, restarts the corresponding DRX-activity timer after sending SCI2. Consequently, when the TX UE subsequently sends SCI3, it believes the RX UE is in its activation time, even though the RX UE is not actually in its activation time, and therefore the RX UE does not receive SCI3.

[0129] To address the aforementioned issues, this application provides the following solution: First, HARQ attributes are introduced. HARQ attributes include HARQ enabled and HARQ disabled. In one possible implementation, the TX UE can send a SCI to the RX UE, which includes a HARQ attribute field. When the RX UE receives the SCI, it determines whether to send HARQ feedback to the TX UE based on the HARQ attribute carried by the HARQ attribute field included in the SCI. For example, if the HARQ attribute field in the SCI carries HARQ enabled, the RX UE needs to provide HARQ feedback for the SCI or the SL data scheduled by the SCI. Conversely, if the HARQ attribute field in the SCI carries HARQ disabled, the RX UE does not need to provide HARQ feedback for the SCI or the SL data scheduled by the SCI.

[0130] In the embodiments of this application, the startup conditions of the DRX-inactivity timer are modified. For an SCI with HARQ enabled, the TX UE starts or restarts the DRX-inactivity timer upon receiving HARQ feedback for that SCI. For the RX UE, the DRX-inactivity timer starts or restarts upon receiving an SCI with HARQ enabled and sending HARQ feedback for that SCI. Optionally, for transmissions of SCIs with HARQ disabled, neither the TX UE nor the RX UE starts or restarts the DRX-inactivity timer. The DRX-inactivity timer can be referred to as the SL-inactivity timer. Hereinafter referred to as the inactivity timer. The inactivity timer is explained as follows:

[0131] The RX UE wakes up to listen for the SCI during each on-duration period. If the RX UE successfully decodes the SCI and sends the corresponding HARQ feedback, the RX UE will remain awake and start an inactivity timer. The inactivity timer can be considered as the duration for which the UE waits to continue listening for the SCI since the last successful decoding. If this timer expires, the UE can return to sleep.

[0132] like Figure 4 As shown, a flow diagram of a side-link communication method is provided, which can solve the problem of asynchronous inactivitytimer startup, leading to misalignment of activation times between the TX UE and RX UE. This flow diagram includes at least the following:

[0133] Step 400: The first terminal device sends an SCI with HARQ enabled to the second terminal device. Optionally, the first terminal device can be a TX UE, and the second terminal device can be an RX UE.

[0134] In one possible implementation, the SCI may include a field for HARQ attributes, where the HARQ attribute carried in the field can be either HARQ enabled or HARQ disabled. Specifically, if the HARQ attribute carried in the field is HARQ enabled, the SCI can be called an SCI with HARQ enabled. The HARQ enabled attribute indicates that when the second terminal device receives the SCI or SL data scheduled by the SCI, it sends HARQ feedback to the first terminal device. This HARQ feedback is the HARQ feedback of the SCI or the SL data scheduled by the SCI. Alternatively, if the HARQ attribute carried in the field is HARQ disabled, the SCI can be called an SCI with HARQ disabled. The HARQ disabled attribute indicates that when the second terminal device receives the SCI or SL data scheduled by the SCI, it does not send HARQ feedback to the first terminal device. Regarding the SCI, it can be noted that it can schedule the receiving UE, i.e., the second terminal device, to receive SL data. The SCI may include an SL grant, which is used to schedule the receiving UE to receive SL data on the corresponding SL resource. In this embodiment, if the HARQ attribute of an SCI is enabled, the receiving UE can send HARQ feedback to the sending UE, i.e., the first terminal device, when it receives the SCI or the SL data scheduled by the SCI. Taking an SCI as an example, if the sending UE sends an SCI with its HARQ attribute enabled, and the receiving UE successfully decodes the SCI, the receiving UE sends an ACK to the sending UE; or, if decoding of the SCI fails, the receiving UE sends a NACK to the sending UE. A disabled HARQ attribute indicates that when the second terminal device receives the SCI or the SL data scheduled by the SCI, it does not send HARQ feedback for the SCI or the SL data scheduled by the SCI to the first terminal device.

[0135] Step 401: The second terminal device sends HARQ feedback of SCI or SCI-scheduled SL data to the first terminal device, and the second terminal device starts or restarts the inactivity timer.

[0136] For example, the second terminal device can start or restart the inactivity timer when or after sending HARQ feedback. For instance, the RX UE can start the inactivity timer in the next symbol or time slot after sending HARQ feedback.

[0137] Step 402: The first terminal device receives SCI or SCI scheduling HARQ feedback from the second terminal device, and the first terminal device starts or restarts the inactivity timer.

[0138] For example, the first terminal device can start or restart the inactivity timer when or after receiving HARQ feedback. For instance, the TX UE can start the inactivity timer in the next symbol or time slot after receiving HARQ feedback.

[0139] Optional, Figure 4 The illustrated process may further include: the first terminal device sending a HARQ feedback SCI with the HARQ attribute disabled to the second terminal device, while the first terminal device keeps its inactivity timer in a disabled state. Correspondingly, upon receiving a HARQ feedback SCI with the HARQ attribute disabled from the first terminal device, the second terminal device keeps its inactivity timer in a disabled state. Optionally, keeping the inactivity timer in a disabled state can be understood as the first terminal device not starting or restarting the inactivity timer. That is, in this scheme, when the first terminal device and the second terminal device are transmitting an SCI with the HARQ attribute enabled, the inactivity timer is started or restarted upon receiving or sending HARQ feedback. For the transmission of an SCI with the HARQ attribute disabled, the inactivity timer is not started or restarted between the first terminal device and the second terminal device.

[0140] As can be seen from the above, for SCIs with HARQ disabled, the sending end cannot definitively determine whether the receiving end has received the current SCI because the receiving end does not provide HARQ feedback. In this embodiment, for SCIs with HARQ disabled, the inactivity timer is not started or restarted. For SCIs with HARQ enabled, the sending end starts the inactivity timer when it receives HARQ feedback for that SCI, and the receiving end starts the inactivity timer again when it sends HARQ feedback; thus, the receiving end and the sending end start the inactivity timer synchronously, aligning their activation times.

[0141] It should be noted that, in the description of the embodiments of this application, SCI can be transmitted in PSCCH, SL data scheduled by SCI can be transmitted in PSSCH, and HARQ feedback can be transmitted in PSFCH.

[0142] To address the misalignment of TX UE and RX UE activation times caused by the inactivity timer startup, an example is provided, which can be described as follows: Figure 4 One specific implementation of the process shown includes at least:

[0143] Modify the startup conditions of the inactivity timer to: only start the inactivity timer when SCI extensions are enabled by HARQ. For example:

[0144] For TX UE: Send a HARQ-enabled SCI, and start the inactivitytimer when an ACK or NACK feedback is received.

[0145] For RX UE: After receiving the HARQ-enabled SCI and sending ACK or NACK feedback, start the inactivitytimer.

[0146] For example, such as Figure 5 As shown, the TX UE sends an SCI to the RX UE within the time unit (SFN, subframe) = (0, 0). The RX UE successfully receives the SCI and sends a HARQ feedback message to the TX UE within the time unit (0, 2). After sending the HARQ feedback message, the RX UE starts an inactivity timer, and the inactivity timer runs for 4 time slots. Correspondingly, after receiving the HARQ feedback from the RX UE within the time unit (0, 2), the TX UE starts its inactivity timer. For example, the above HARQ feedback can be carried in the PSFCH and sent.

[0147] TX UE sends SCI to RX UE in time unit (0, 2), but RX UE does not receive it. Therefore, RX UE will not send HARQ feedback information to TX UE in time unit (0, 4), when it should be sending HARQ feedback information, and TX UE will not start the inactivity timer. Correspondingly, since TX UE did not receive HARQ feedback information from RX UE in time unit (0, 4), TX UE will not start the inactivty timer.

[0148] As can be seen from the above, by modifying the inactivity timer's startup conditions to: only starting the inactivity timer for HARQ-enabled SCIs, and starting the inactivity timer only when the RX UE sends HARQ feedback, and only when the TX UE receives HARQ feedback, the startup time of the inactivity timer of the TX UE and the RX UE can be aligned, thus aligning the activation time of the TX UE and the RX UE.

[0149] The previous section introduced the inactivity timer in the SL DRX. The following section continues with the description of the discontinuous reception short-cycle timer, the DRXshortcycle timer, in the SL DRX. The DRXshortcycle timer is described as follows:

[0150] In this embodiment, when the inactivity timer expires, the TX UE or RX UE can start or restart the DRX shortcycle timer. As described above, the DRX cycle consists of an active duration (on duration) and an inactive opportunity for DRX (opportunity for DRX). During the operation of the DRX shortcycle timer, the UE uses the DRX short cycle. When the DRX shortcycle timer expires, the UE uses the DRX long cycle. Optionally, if the UE successfully decodes the PDCCH for scheduling new transmissions during the operation of the DRX long cycle, it can start using the DRX short cycle. In the following description, the DRX shortcycle timer can be simply referred to as the shortcycle timer.

[0151] In the current solution, the TX UE or RX UE starts a shortcycle timer when the inactivity timer times out. Based on the above analysis, when SCI transmission fails, the inactivity timers started by the sending and receiving ends become asynchronous, which in turn leads to the shortcycle timers started by the sending and receiving ends becoming asynchronous, resulting in inconsistent DRX cycles between the sending and receiving ends.

[0152] For example, such as Figure 6 As shown, during the on-duration timer, the TX UE is in the active period and sends two SCIs, SCI1 and SCI2. After sending SCI1, the TX UE starts the inactivity timer, and after the inactivity timer times out, it starts the shortcycle timer. Similarly, after sending SCI2, the TX UE starts the inactivity timer, and after the inactivity timer times out, it restarts the shortcycle timer.

[0153] During the on-duration timer, the RX UE is in its active period, successfully receives SCI1, starts the inactivity timer, and starts the shortcycle timer when the inactivity timer expires. Due to transmission conditions or other reasons, the RX UE may fail to receive SCI2, thus failing to restart the inactivity and shortcycle timers. The RX UE only starts the shortcycle timer once, and when the started shortcycle timer expires, the RX UE enters a long DRX cycle. At this time, the TX UE is still in a short DRX cycle. It can be seen that due to SCI transmission failures or other reasons, the DRX cycles of the TX UE and the RX UE may be inconsistent.

[0154] To address the above, this application provides a solution. The method includes: when an RX UE needs to switch from a DRX short cycle to a DRX long cycle, the RX UE can send first information to the TX UE, wherein the HARQ attribute of the first information is enabled. Upon receiving the first information, the TX UE can determine whether to agree to the RX UE entering the DRX long cycle, or it can reply to the RX UE whether it is aware that it wants to enter the DRX long cycle. If it agrees, or replies to the RX UE whether it is aware that it wants to enter the DRX long cycle, the TX UE can send an ACK HARQ feedback to the RX UE. Upon receiving the ACK HARQ feedback, the RX UE then switches from the DRX short cycle to the DRX long cycle. Optionally, when the TX UE sends the ACK HARQ feedback, the TX UE can simultaneously switch from the DRX short cycle to the DRX long cycle, etc.

[0155] like Figure 7 As shown, a flow chart of a side-link communication method is provided, which includes at least the following steps:

[0156] Step 700: The second terminal device sends first information to the first terminal device. The HARQ attribute of the first information is enabled. The enabled HARQ attribute indicates that when the first terminal device receives the first information, it sends HARQ feedback of the first information to the second terminal device.

[0157] Step 701: The first terminal device sends the HARQ feedback of the first information to the second terminal device, and when the HARQ feedback is ACK, the first terminal device uses the DRX long period.

[0158] Step 702: The second terminal device receives HARQ feedback of the first information from the first terminal device, and the HARQ feedback is ACK. The second terminal device uses DRX long period.

[0159] Optionally, when the HARQ feedback is NACK, the first terminal device and / or the second terminal device may continue to use the current DRX cycle. In one possible implementation, when the first terminal device receives the aforementioned first information, it may determine whether it agrees to the second terminal device using a long DRX cycle. If it agrees, the first terminal device sends an ACK. If it disagrees, the first terminal device sends a NACK; correspondingly, when the second terminal device receives an ACK, it uses a long DRX cycle. Alternatively, when the second terminal device receives a NACK, it continues to maintain the current DRX cycle. In one possible implementation, when the second terminal device receives a NACK, if it is currently using a short DRX cycle, it continues to use the short DRX cycle. Similarly, if it is currently using a long DRX cycle, it continues to use the long DRX cycle, and so on.

[0160] For example, in this embodiment, the second terminal device can be an RX UE, and the first terminal device can be a TX UE. When the RX UE meets the condition for switching from a DRX short cycle to a DRX long cycle, for example, the condition can be a shortcycletimer timeout, the RX UE executes the process described in step 700 above and sends first information to the TX UE. Optionally, the first information can be used to indicate the use of a DRX long cycle. In this embodiment, regarding "using a DRX long cycle," the following explanation is given: In one possible implementation, the TX UE or RX UE is currently in a DRX short cycle, and the above-mentioned use of a DRX long cycle can refer to the TX UE or RX UE switching from a DRX short cycle to a DRX long cycle. Alternatively, in another possible implementation, the TX UE or RX UE is currently in a DRX long cycle, and the above-mentioned use of a DRX long cycle can refer to the TX UE or RX UE continuing to remain in a DRX long cycle, etc.

[0161] For example, in this embodiment of the application, the aforementioned first information may be carried in the media access control element (MAC CE). Optionally, the aforementioned first information may also include indication information for the first link. There may be two links between the first terminal device and the second terminal device, namely the first link and the second link. In the first link, the first terminal device acts as the sender and the second terminal device acts as the receiver, and the first terminal device may send SL data information or SL control information, etc., to the second terminal device. In the second link, the first terminal device acts as the receiver and the second terminal device acts as the sender, and the second terminal device may send SL data information or SL control information, etc., to the first terminal device. As can be seen from the above description, the first information is specifically used to indicate the use of DRX long period in the first link. Therefore, the first information may carry indication information for the first link. For example, the aforementioned indication information for the first link may include a destination identifier and a source identifier pair, where the destination identifier is the identifier of the receiver, and the source identifier is the identifier of the sender, or the identifier of the first link, or the connection identifier of the first link, etc., without limitation. In one possible implementation, the aforementioned destination identifier and source identifier can be described as follows: {DST ID, SRC ID}. Here, "DST ID" represents the destination identifier, which can be fully named "destination ID," and "SRC ID" represents the source identifier, which can be fully named "source ID."

[0162] It should be pointed out that, in the above Figure 7 In the illustrated process, there is no limitation on the duration of the DRX long cycle used by the first terminal device and / or the second terminal device. The second terminal device may use the DRX long cycle upon or after receiving the ACK feedback. For example, in Figure 8 In the example shown, taking the second terminal device as the RX UE, the RX UE uses the DRX long period when it first starts the on-duration timer after receiving the ACK feedback. The same applies to the first terminal device; the first terminal device can use the DRX long period when sending the ACK feedback; or, the first terminal device can use the DRX long period at any time after sending the ACK feedback, as long as the start time of the DRX long period is consistent between the TX UE and the RX UE. The specific time can be determined by protocol rules or pre-configuration, and is not limited.

[0163] against Figure 7 The provided sidelink communication methods, such as Figure 8 As shown, a specific example is provided, which includes at least:

[0164] When the RX UE meets the conditions for switching from a short-cycle DRX to a long-cycle DRX, such as when the shortcycle timer expires, the RX UE sends a MAC CE to the TX UE, with the HARQ attribute enabled. Upon receiving the MAC CE and sending an ACK, the TX UE performs a DRX handover, switching from a short-cycle DRX to a long-cycle DRX. Similarly, upon receiving the ACK, the RX UE performs a DRX handover, switching from a short-cycle DRX to a long-cycle DRX. Specifically:

[0165] For a single-level (SL) transmission pair, if the RX UE meets the conditions for entering the DRX long period, the RX UE triggers a MACCE with its HARQ attribute enabled. When the TX UE receives this MACCE, it can agree to enter the DRX long period by sending an ACK to the RX UE, and the TX UE then enters the DRX long period. Conversely, when the RX UE receives the aforementioned ACK, it can enter the DRX long period.

[0166] Regarding SL transmission pairs, the following explanation applies: Any two terminal devices communicating via SL can form a transmission pair. For example, if UE1 and UE2 communicate via SL, then UE1 and UE2 can form an SL transmission pair. Each SL transmission pair may include two links. For example, in the first link, UE1 acts as the sender and UE2 acts as the receiver. In the second link, UE2 can act as the sender and UE1 can act as the receiver. Optionally, the MAC CE may carry identification information of the control link. For example, if the MAC CE is used to control the DRX handover of the first link, then the MAC CE may carry the identification information of the first link. Alternatively, if the MAC CE is used to control the DRX handover of the second link, then the MAC CE may carry the identification information of the second link. Optionally, the identification information of the link may specifically be a destination identifier and source identifier pair, which can be represented as {DST ID, SRC ID}. The destination identifier is the identifier of the UE acting as the receiver, and the source identifier can be the identifier of the UE acting as the sender, etc.

[0167] As can be seen from the above description, using the method in this embodiment, for a single SL transmission pair, when the receiving UE meets the conditions for performing DRX cycle handover, it can send a MAC CE to the sending UE. If the sending UE agrees to the DRX cycle handover, the entire SL link follows the receiving UE's DRX pattern. For example:

[0168] If UE1 is a TX UE and UE2 is an RX UE, this link can be called Link 1, and Link 1 follows the DRX pattern of the receiving UE2. Alternatively,

[0169] If UE2 is a TX UE and UE1 is an RX UE, the link can be called link 2, and link 2 follows the DRX pattern of the receiving end UE1.

[0170] As can be seen, in this embodiment of the application, the DRX cycle switching between the TX UE and the RX UE can be controlled by the MAC CE, which does not depend on whether the shortcycle timer has expired, thereby enabling the DRX cycles between the TX UE and the RX UE to be aligned.

[0171] This application also provides a side-link communication method, which can also solve the problem of inconsistent DRX periods between TX UE and RX UE. In the above... Figure 7 In the method shown, the RX UE sends a first message to the TX UE when the condition for switching from a short DRX period to a long DRX period is met. In the other method, the TX UE sends a second message to the RX UE when the condition for switching from a long DRX period to a short DRX period is met, to ensure that the DRX periods of the TX UE and the RX UE are consistent.

[0172] like Figure 9 As shown, a flow chart of a side-link communication method is provided, which includes at least:

[0173] Step 900: The first terminal device sends second information to the second terminal device. The HARQ attribute of the second information is enabled. The enabled HARQ attribute indicates that the second terminal device sends HARQ feedback of the second information to the first terminal device when it receives the second information.

[0174] In one possible implementation, the second terminal device, acting as the receiving end, upon receiving the second information, can determine whether to agree to use the DRX short cycle, or whether to acknowledge that it is aware the first terminal device wishes to use the DRX short cycle. If the second terminal device determines that it can use the DRX short cycle, it can send an ACK to the first terminal device; otherwise, it sends a NACK to the first terminal device. Correspondingly, upon receiving an ACK, the first terminal device can use the DRX short cycle. Alternatively, upon receiving a NACK, the first terminal device can continue to enable the current DRX cycle without modification. Similarly, when sending an ACK, the second terminal device uses the DRX short cycle; when sending a NACK, it continues to use the current DRX cycle without restriction.

[0175] Step 901: The second terminal device sends a HARQ feedback of the second information to the first terminal device, and the HARQ feedback is ACK. The second terminal device uses the DRX short cycle.

[0176] Step 902: The first terminal device receives HARQ feedback of the second information from the second terminal device, and the HARQ feedback is ACK. The first terminal device uses the DRX short cycle.

[0177] Optionally, in this process, the first terminal device can be a TX UE, and the second terminal device can be an RX UE. The aforementioned second information can indicate the use of a short DRX cycle. In the embodiments of this application, the use of a short DRX cycle is explained as follows: If the TX UE or RX UE is currently in a long DRX cycle, then using a short DRX cycle means that the TX UE or RX UE switches from a long DRX cycle to a short DRX cycle. Alternatively, if the TX UE or RX UE is currently in a short DRX cycle, then using a short DRX cycle means that the TX UE or RX UE continues to remain in the short DRX cycle.

[0178] For example, in this embodiment, the second information can be carried in the MAC CE. Optionally, the second information may carry indication information of the first link, in which the first terminal device is the sender and the second terminal device is the receiver, and the first terminal device can send SL data information or SL control information, etc., to the second terminal device. Optionally, the indication information of the first link includes a destination identifier and a source identifier pair, wherein the destination identifier is the identifier of the receiver, the source identifier is the identifier of the sender, or the identifier of the first link, or the connection identifier of the first link, etc., without limitation. For the destination identifier and source identifier pair, please refer to the above. Figure 7 The details described in the text will not be repeated here.

[0179] This application also provides a sidelink communication method that can similarly solve the problem of inconsistent DRX periods between TX UE and RX UE. The method includes: the TX UE only sending SCIs with HARQ attribute enabled during the long-duration on-time period.

[0180] like Figure 10 As shown, a flow chart of a side-link communication method is provided, which includes at least:

[0181] Step 1000: During the long-term activation period of DRX, the first terminal device only sends an SCI with the HARQ attribute enabled to the second terminal device. The HARQ attribute being enabled indicates that when the second terminal device receives the SCI or the SL data scheduled by the SCI, it sends HARQ feedback of the SCI or the SL data scheduled by the SCI to the first terminal device.

[0182] Step 1001: When the first terminal device sends HARQ feedback of SCI or SCI-scheduled SL data to the second terminal device, it starts or restarts the inactivity timer, and when the inactivity timer times out, the first terminal device uses the DRX short cycle.

[0183] Step 1002: When the first terminal device receives HARQ feedback of SCI or SL data scheduled by SCI from the second terminal device, it starts or restarts the inactivity timer, and when the inactivity timer times out, the first terminal device uses the DRX short cycle.

[0184] Based on the foregoing analysis, regarding the inconsistency in DRX cycles between the TX UE and RX UE, it can be seen that the inconsistency is mainly due to the failure of the RX UE to receive the SCI sent by the TX UE, resulting in the RX UE not starting its inactivity timer; and when the inactivity timer times out, the RX UE also fails to start its shortcycle timer. In this embodiment, by having the TX UE only send SCIs with HARQ enabled during the active period of the long DRX cycle, the TX UE starts or restarts its inactivity timer upon receiving the SCI or HARQ feedback of the SCI-scheduled SL data. Similarly, the RX UE starts or restarts its inactivity timer upon sending the SCI or HARQ feedback of the SCI-scheduled SL data. This synchronizes the inactivity timer startup of the TX UE and RX UE, thereby synchronizing the startup of their shortcycle timers and allowing them to switch to the short DRX cycle synchronously.

[0185] In one possible implementation, as described above Figure 10 In the illustrated process, by sending only a HARQ-enabled SCI during the long on-duration period, both the TX UE and RX UE can synchronously start the shortcycle timer and enter the DRX short cycle. However, if the TX UE does not send a HARQ-enabled SCI during the long on-duration period, or if the RX UE does not receive a HARQ-enabled SCI, neither the TX UE nor the RX UE may be able to enter the DRX short cycle. To address this situation, communication between the TX UE and RX UE can be facilitated through the aforementioned... Figure 9 The second piece of information shown indicates a switch from DRX long cycle to DRX short cycle.

[0186] The following section continues the discussion of timers in the SL DRX: the discontinuous reception round trip timer (DRX-RTT timer) and the discontinuous reception retransmission timer (DRX-ReTx timer). The DRX-RTT timer can also be referred to as the SL-DRX-HARQ-RTT-Timer; in the following description, it will be simply referred to as the RTT timer. The RTT timer indicates the minimum time before the resource configuration information or authorization information expected for SL retransmission arrives at the receiving end. In other words, the RTT timer value can be "the minimum time before the resource configuration information or authorization information expected for SL retransmission arrives at the receiving end." The DRX-ReTX timer can also be called the SL-DRX-RetransmissionTimer, hereinafter referred to as the ReTx timer. The ReTx timer indicates the maximum time until the receiving end receives the resource configuration information or authorization information retransmitted from the SL. In other words, the ReTx timer value can be "the maximum time until the resource configuration information or authorization information retransmitted from the SL is received." During the operation of the ReTx timer, the UE is in the active time.

[0187] In one possible implementation, such as Figure 11 As shown, an RTT timer and a ReTx timer are configured for SCIs with HARQ enabled and disabled, respectively. For example, RTTtimer1 and ReTx timer1 are configured for SCIs with HARQ enabled, and RTT timer2 and ReTx timer2 are configured for SCIs with HARQ disabled. It should be noted that... Figure 11 In the code, "d" indicates an SCI with HARQ enabled, "e" indicates an SCI with HARQ disabled, and "×" indicates that the RX UE failed to receive the SCI. The HARQ attribute of the SCI is not restricted.

[0188] See also Figure 11As shown, for an SCI with HQRQ attribute disabled, the TX UE starts or restarts RTT timer1 when sending the SCI, and starts ReTx timer1 when RTT timer1 times out. If the RX UE does not receive the SCI due to transmission link failure or other reasons, the RX UE will not start or restart the corresponding RTT timer1 and ReTx timer1, resulting in a desynchronization between the RTT timer and ReTx timer started by the TX UE and the RX UE. For SCIs with HARQ enabled, the TX UE starts RTT timer2 and ReTx timer2 when it receives HARQ feedback for the enabled SCI. Alternatively, the TX UE starts RTT timer2 in the first time unit after the HARQ feedback resource for the enabled SCI. If HARQ feedback is received when RTT timer2 expires, ReTx timer2 is started. The RX UE starts RTT timer2 and ReTx timer2 when it sends HARQ feedback for the enabled SCI, ensuring that the RTT timer and ReTx timer started by the TX UE and RX UE are aligned.

[0189] The above analysis shows that for SCI transmissions with HARQ disabled, there is a high possibility of misalignment between the RTT timer and ReTx timer between the TX UE and RX UE, resulting in asynchronous activation times. For example, if enabled transmission occurs between the TX UE and RX UE during the operation of the disabled ReTx timer (ReTx timer1), the following situation may occur: While the TX UE's ReTx timer1 is running, the TX UE is in its active period and sends SL information or data with HARQ enabled to the RX UE. However, the RX UE's ReTX timer1 is not running, and the RX UE is in its sleep period. The RX UE fails to receive the aforementioned SL information or data, and therefore cannot provide HARQ feedback for this SL information or data. This may lead to the TX UE not receiving HARQ feedback for the enabled SL information or data, thereby triggering SL radio link failure (RLC).

[0190] Based on the above, the embodiments of this application propose the following solution: When the DRX between the TX UE and the RX UE is active, and only the ReTX timer with the HARQ attribute disabled is currently running, the TX UE and the RX UE will no longer transmit with the HARQ attribute enabled. This can avoid the problem of SL RLF being triggered because the TX UE cannot receive the HARQ feedback from the RX UE after sending SL information or data with the HARQ attribute enabled.

[0191] like Figure 12 As shown, a flow chart of a side-link communication method is provided, which includes at least:

[0192] Step 1200: The DRX between the first terminal device and the second terminal device is active, and only the ReTx timer with the HARQ attribute disabled is running. The HARQ attribute being disabled indicates that when the second terminal device receives the information corresponding to the ReTx timer, it sends the HARQ feedback corresponding to that information to the first terminal device.

[0193] Regarding the HARQ attribute being used to disable the ReTx timer, the following explanation is provided: (Based on the above...) Figure 11 As the introduction states, an RTT timer and a ReTx timer are configured for SCIs with HARQ enabled and those with HARQ disabled, respectively. The ReTx timer with HARQ disabled can refer to the ReTx timer configured for the SCI with HARQ disabled, i.e., ReTx timer2.

[0194] Step 1201: The first terminal device and the second terminal device perform a transmission with the HARQ attribute disabled. The disabled HARQ attribute indicates that when the second terminal device receives the information corresponding to the transmission, it does not send a HARQ feedback to the first terminal device. Alternatively, no SL transmission occurs between the first terminal device and the second terminal device.

[0195] Optionally, the above-mentioned transmission between the first terminal device and the second terminal device with HARQ attribute disabled can be replaced by: the first terminal device and the second terminal device only transmitting with HARQ attribute disabled, and / or, the first terminal device and the second terminal device not transmitting with HARQ attribute enabled, etc.

[0196] In one possible implementation, the transmission between the first terminal device and the second terminal device with HARQ attribute disabled can be implemented as follows: the first terminal device does not send a new transmission with HARQ attribute enabled to the second terminal device, and / or, the first terminal device sends a new transmission or retransmission with HARQ attribute disabled to the second terminal device. It should be noted that in this embodiment, there is no limitation on whether retransmission with HARQ attribute enabled is performed between the first terminal device and the second terminal device. For example, the first terminal device may send a retransmission with HARQ attribute enabled to the second terminal device, or the first terminal device may not send a retransmission with HARQ attribute enabled to the second terminal device, etc.

[0197] For example, the first terminal device not sending a new transmission with HARQ enabled to the second terminal device includes: the first terminal device only reusing the logical channel (LCH) with HARQ disabled for the grant corresponding to the new transmission; or, the first terminal device clearing the grant corresponding to the new transmission. The grant corresponding to the new transmission includes at least the following two types: first, it has not yet been determined whether the grant is for a specific transport block (TB) or media access control protocol data unit (MAC PDU); second, it has been determined whether the grant is for a specific TB or MAC PDU, etc.

[0198] Optionally, in the embodiments of this application, the new transmission includes a new transport block (TB) or an SCI indicating a new transmission, i.e., a new transmission indicated by an SCI; the retransmission includes a retransmission TB or an SCI indicating a retransmission, i.e., a retransmission indicated by an SCI, etc.

[0199] Optionally, in the above Figure 12The illustrated process further includes: Step 1202: When the first terminal device terminates a transmission with HARQ attribute disabled between itself and the second terminal device, the first terminal device stops the ReTx timer of the SL process corresponding to the transmission. The termination of a transmission with HARQ attribute disabled may include: the current transmission with HARQ attribute disabled reaching the maximum retransmission count, or the first terminal device receiving a new transmission schedule from the network device, or the first terminal device reaching the next cycle of the configured grant (CG), etc. Regarding CG, it is explained as follows: CG refers to the uplink transmission of the terminal device not requiring scheduling by the network device; the terminal device performs uplink transmission according to configuration information. In this embodiment, the first terminal device, as the sending UE, can provide HARQ feedback for the SL to the network device based on the uplink transmission resources configured in the CG. That is, in one possible implementation, when the sending UE receives the SL HARQ feedback from the receiving UE, the sending UE can also send the SL HARQ feedback to the network device based on the uplink resources configured in the CG. For example, if the SL HARQ feedback is NACK, the base station can reallocate SL resources for SL retransmission for the current SL transmission.

[0200] Taking the first terminal device as TX UE and the second terminal device as RX UE as an example, a specific implementation method is provided:

[0201] For example, such as Figure 11 As shown, in Figure 11 In the example, within the time range from the second time slot (1, 6) to (1, 7), only the deactivated ReTx timer is running inside the TX UE, see [link to example]. Figure 11 The units filled with " / " indicate that no other timers (such as on-duration timers and inactivity timers) are running within this time range. During this period, no SL transmission with HARQ enabled is performed between the TX UE and the RX UE. Optionally, the above-mentioned SL transmission without HARQ enabled between the TX UE and the RX UE includes: no new transmission of HARQ enabled TB between the TX UE and the RX UE. This TB can be considered as a resource used for transmitting SL data, etc. For new transmission grants, if the above-mentioned condition of only disabled ReTx timers running is met, then during the logical channel prioritization (LCP) process, the TX UE only reuses the LCH with HARQ disabled; or, clears the grant, etc.

[0202] Optionally, HARQ-enabled SL transmissions are not allowed between the TX UE and RX UE, but HARQ-disabled SL transmissions are allowed. When the TX UE ends the aforementioned HARQ-disabled transmission, the TX UE may stop the ReTx timer running the SL process. Optionally, ending the transmission may include: reaching the maximum number of retransmissions, receiving a new transmission schedule, or reaching the next cycle of the CG, etc.

[0203] refer to Figure 13 This is a schematic diagram of the apparatus 1300 provided in an embodiment of this application. This apparatus is used to implement the various steps performed by the first terminal device or the second terminal device in the above embodiments. Figure 13 As shown, the device 1300 includes a transceiver unit 1310 and a processing unit 1320.

[0204] In the first embodiment, the device 1300 can be a first terminal device or a chip in the first terminal device, then:

[0205] The transceiver unit 1310 is configured to send an SCI with the HARQ attribute enabled to the second terminal device. The HARQ attribute enabling indicates that when the second terminal device receives the SCI or the SL data scheduled by the SCI, it sends HARQ feedback of the SCI or the SCI-scheduled data to the first terminal device. The transceiver unit 1310 is also configured to receive HARQ feedback of the SCI or the SCI-scheduled data from the second terminal device. The processing unit 1320 is configured to start or restart the DRX-inactivity timer.

[0206] In one possible implementation, the processing unit 1320 is further configured to keep the DRX-inactivity timer in an unstarted state when sending an SCI with the HARQ attribute set to disabled to the second terminal device, and not send HARQ feedback of the SCI or the SL data scheduled by the SCI to the first terminal device when the HARQ attribute set to disabled indicates that the second terminal device has received the SCI or the SL data scheduled by the SCI.

[0207] In the second embodiment, the aforementioned device 1300 can be a second terminal device or a chip in the second terminal device, then:

[0208] The transceiver unit 1310 is configured to receive an SCI with its HARQ attribute enabled from a first terminal device, wherein the HARQ attribute being enabled indicates that when the second terminal device receives the SCI or SL data scheduled by the SCI, it sends HARQ feedback of the SCI or the SCI-scheduled data to the first terminal device; the transceiver unit 1310 is also configured to send HARQ feedback of the SCI or the SCI-scheduled SL data to the first terminal device; the processing unit 1320 is configured to start or restart the DRX-inactivity timer.

[0209] In one possible implementation, the processing unit 1320 is further configured to, when receiving an SCI with a HARQ attribute of disabled from the first terminal device, keep the DRX-inactivity timer in an unstarted state, and when the HARQ attribute being disabled indicates that the second terminal device has received the SCI or the SL data scheduled by the SCI, not send HARQ feedback of the SCI or the SL data scheduled by the SCI to the first terminal device.

[0210] In the third embodiment, the aforementioned device 1300 can be a second terminal device or a chip in the second terminal device, then:

[0211] The transceiver unit 1310 is configured to send first information to a first terminal device, wherein the HARQ attribute of the first information is enabled, and the HARQ attribute being enabled indicates that when the second terminal device receives the first information, it sends HARQ feedback of the first information to the first terminal device; the transceiver unit 1310 is also configured to receive HARQ feedback of the first information from the first terminal device; the processing unit 1320 is configured to use a long period of DRX when the HARQ feedback is an acknowledgment ACK.

[0212] In one possible implementation, the first information indicates the use of the DRX long period.

[0213] In one possible implementation, the first information is carried in the MAC CE.

[0214] In one possible implementation, the first information carries indication information of a first link, which is used by the first terminal device to send SL data information or SL control information, etc., to the second terminal device.

[0215] In one possible implementation, the indication information of the first link includes: a destination identifier and a source identifier pair, wherein the destination identifier is the identifier of the receiving end and the source identifier is the identifier of the sending end; or the identifier of the first link; or the connection identifier of the first link.

[0216] In the fourth embodiment, the device 1300 can be a first terminal device or a chip in the first terminal device, then:

[0217] The transceiver unit 1310 is configured to receive first information from a second terminal device, wherein the HARQ attribute of the first information is enabled, and the HARQ attribute being enabled indicates that when the second terminal device receives the first information, it sends HARQ feedback of the first information to the first terminal device; the transceiver unit 1310 is also configured to send the HARQ feedback of the first information to the second terminal device; the processing unit 1320 is configured to use a long period of DRX when the HARQ feedback is ACK.

[0218] In one possible implementation, the first information indicates the use of the DRX long period.

[0219] In one possible implementation, the first information is carried in the MAC CE.

[0220] In one possible implementation, the first information carries indication information of a first link, which is used by the first terminal device to send SL data information or SL control information to the second terminal device.

[0221] In one possible implementation, the indication information of the first link includes: a destination identifier and a source identifier pair, wherein the destination identifier is the identifier of the receiving end and the source identifier is the identifier of the sending end; or the identifier of the first link; or the connection identifier of the first link.

[0222] In the fifth embodiment, the device 1300 can be a first terminal device or a chip in the first terminal device, then:

[0223] The transceiver unit 1310 is configured to send second information to the second terminal device, wherein the HARQ attribute of the second information is enabled, and the HARQ attribute being enabled indicates that when the second terminal device receives the second information, it sends HARQ feedback of the second information to the first terminal device; the transceiver unit 1310 is configured to receive HARQ feedback of the second information from the second terminal device; the processing unit 1320 is configured to use a short DRX cycle when the HARQ feedback is ACK.

[0224] In one possible implementation, the second information indicates the use of the DRX short cycle.

[0225] In one possible implementation, the second information is carried in the MAC CE.

[0226] In one possible implementation, the second information carries indication information of the first link, which is used by the first terminal device to send SL data information or SL control information, etc., to the second terminal device.

[0227] In one possible implementation, the indication information of the first link includes a destination identifier and a source identifier pair, wherein the destination identifier is the identifier of the receiving end and the source identifier is the identifier of the sending end; or the identifier of the first link; or the connection identifier of the first link.

[0228] In the sixth embodiment, the device 1300 can be a second terminal device or a chip in the second terminal device, then:

[0229] The transceiver unit 1310 is configured to receive second information from a first terminal device, wherein the HARQ attribute of the second information is enabled, and the enabled HARQ attribute indicates that the second terminal device sends HARQ feedback of the second information to the first terminal device when it receives the second information; the transceiver unit 1310 is also configured to send the HARQ feedback of the second information to the first terminal device; the processing unit 1320 is configured to use a short DRX cycle when the HARQ feedback is ACK.

[0230] In one possible implementation, the second information indicates the use of the DRX short cycle.

[0231] In one possible implementation, the second information is carried in the MAC CE.

[0232] In one possible implementation, the second information carries indication information of the first link, which is used by the first terminal device to send SL data information or SL control information, etc., to the second terminal device.

[0233] In one possible implementation, the indication information of the first link includes a destination identifier and a source identifier pair, wherein the destination identifier is the identifier of the receiving end and the source identifier is the identifier of the sending end; or the identifier of the first link; or the connection identifier of the first link.

[0234] In the seventh embodiment, the device 1300 can be a first terminal device or a chip in the first terminal device, then:

[0235] The transceiver unit 1310 is configured to send only SCIs with HARQ enabled during the activation period of the long DRX period. The HARQ enabled attribute indicates that when the second terminal device receives the SCI or SL data scheduled by the SCI, it should send HARQ feedback of the SCI or SL data to the first terminal device. The processing unit 1320 is configured to start or restart the DRX-inactivity timer when it receives the HARQ feedback of the SCI or SL data, and use the short DRX period when the DRX-inactivity timer times out.

[0236] In the eighth embodiment, the device 1300 can be a first terminal device or a chip in the first terminal device, then:

[0237] Processing unit 1320 is configured to determine that the DRX between the first terminal device and the second terminal device is active, and only the DRX-ReTx timer with the HARQ attribute disabled is running. The HARQ attribute being disabled indicates that the second terminal device, upon receiving information corresponding to the DRX-ReTx timer, sends the HARQ feedback corresponding to that information to the first terminal device. Transceiver unit 1310 is configured to control the transmission between the first terminal device and the second terminal device to be disabled with the HARQ attribute disabled. The HARQ attribute being disabled indicates that the second terminal device, upon receiving the information corresponding to the transmission, does not send the HARQ feedback for that information to the first terminal device.

[0238] In one possible implementation, the transmission between the first terminal device and the second terminal device with the HARQ attribute disabled includes: the first terminal device not sending a new transmission with the HARQ attribute enabled to the second terminal device, and / or the first terminal device sending a new transmission or retransmission with the HARQ attribute disabled to the second terminal device.

[0239] In one possible implementation, the first terminal device does not send new transmissions with HARQ attribute enabled to the second terminal device, including: for the grant corresponding to the new transmission, only reusing logical channels (LCH) with HARQ attribute disabled; or, clearing the grant corresponding to the new transmission.

[0240] In one possible implementation, the new transmission includes a new transport block (TB) or an SCI indicating the new transmission.

[0241] In one possible implementation, the retransmission includes a retransmission TB, or an SCI indicating a retransmission.

[0242] In one possible implementation, the processing unit 1320 is further configured to: stop the DRX-ReTxtimer of the SL process corresponding to the transmission when the transmission between the first terminal device and the second terminal device with the HARQ attribute disabled ends.

[0243] It should be understood that the division of units in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, all units in the device can be implemented entirely through software calls from processing elements; all units can be implemented entirely in hardware; or some units can be implemented through software calls from processing elements, and some units can be implemented in hardware. For example, each unit can be a separately established processing element, or it can be integrated into a chip within the device. Alternatively, it can be stored as a program in memory, called and executed by a processing element of the device. Moreover, these units can be fully or partially integrated together, or implemented independently. The processing element mentioned here can also be called a processor, which can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above units can be implemented through integrated logic circuits in the processor element or through software calls from processing elements.

[0244] In one example, a unit in any of the above devices can be one or more integrated circuits configured to implement the methods described above, such as: one or more application-specific integrated circuits (ASICs), or one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs), or a combination of at least two of these forms of integrated circuits. As another example, when a unit in the device can be implemented in the form of a processing element scheduler, the processing element can be a general-purpose processor, such as a central processing unit (CPU) or other processor capable of calling programs. Furthermore, these units can be integrated together to implement a system-on-a-chip (SOC).

[0245] The transceiver unit 1310 described above is an interface circuit of the device, used to receive signals from other devices or send signals to other devices. For example, when the device is implemented as a chip, the transceiver unit 1310 is an interface circuit for the chip to receive signals from other chips or devices, or to send signals to other chips or devices.

[0246] refer to Figure 14 This is a schematic diagram of the apparatus provided in an embodiment of this application. It is used to implement the operation of the first terminal device or the second terminal device in the above method embodiments. Figure 14 As shown, the device includes a processor 1410 and an interface 1430. Optionally, the device may also include a memory 1420. The interface 1430 is used to enable communication with other devices.

[0247] The methods executed by the first terminal device and the second terminal device in the above embodiments can be implemented by the processor 1410 calling a program stored in the memory (which can be the memory 1420 in the first terminal device, the second terminal device, or an external memory). That is, the first terminal device, the second terminal device, or the terminal device may include a processor 1410, which executes the methods executed by the first terminal device and the second terminal device in the above method embodiments by calling a program in the memory. The processor here can be an integrated circuit with signal processing capabilities, such as a CPU. The first terminal device or the second terminal device can be implemented by one or more integrated circuits configured to implement the above methods. For example: one or more ASICs, or one or more microprocessors (DSPs), or one or more FPGAs, or a combination of at least two of these integrated circuit forms. Alternatively, the above implementation methods can be combined.

[0248] Specifically, Figure 13 The functions / implementation process of the transceiver unit 1310 and the processing unit 1320 can be obtained through Figure 14 The processor 1410 in the illustrated device 1400 calls computer-executable instructions stored in memory 1420 to implement the function. Alternatively, Figure 13 The function / implementation process of the processing unit 1310 can be achieved through... Figure 14 The processor 1410 in the illustrated device 1400 calls computer execution instructions stored in memory 1420 to implement this. Figure 13 The function / implementation process of the transceiver unit 1310 in the middle can be obtained through Figure 14 This is achieved through interface 1430 in the device 1400 shown.

[0249] It should be understood that, in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this invention.

[0250] This application also provides a computer-readable medium having a computer program stored thereon, which, when executed by a computer, implements the functions of any of the above method embodiments.

[0251] This application also provides a computer program product that, when executed by a computer, implements the functions of any of the above method embodiments.

[0252] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0253] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0254] The various illustrative logic units and circuits described in the embodiments of this application can be implemented or operate the described functions using a general-purpose processor, digital signal processor, application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor; alternatively, it can also be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented using a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0255] The steps of the methods or algorithms described in the embodiments of this application can be directly embedded in hardware, software units executed by a processor, or a combination of both. The software units can be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from and write information to the storage medium. Optionally, the storage medium can also be integrated into the processor. The processor and storage medium can be housed in an ASIC.

[0256] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0257] In one or more exemplary designs, the functions described herein can be implemented in hardware, software, firmware, or any combination of these three. If implemented in software, these functions can be stored on a computer-readable medium or transmitted on a computer-readable medium in the form of one or more instructions or code. Computer-readable media includes computer storage media and communication media that facilitate the transfer of computer programs from one location to another. Storage media can be any available media accessible to a general-purpose or special-purpose computer. For example, such computer-readable media can include, but is not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store program code in the form of instructions or data structures and other formats readable by a general-purpose or special-purpose computer or processor. Furthermore, any connection can be suitably defined as a computer-readable medium, for example, if the software is transmitted from a website, server, or other remote resource via a coaxial cable, fiber optic computer, twisted pair, digital subscriber line (DSL), or wirelessly, such as infrared, wireless, and microwave, it is also included in the definition of a computer-readable medium. The disks and discs mentioned include compressed disks, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs. Disks typically copy data magnetically, while discs typically copy data optically using lasers. Combinations of the above can also be contained in computer-readable media.

[0258] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in this application can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium accessible to a general-purpose or special-purpose computer.

[0259] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, or improvements made based on the technical solution of this application should be included within the scope of protection of this application. The above description in this application specification allows for the utilization or implementation of the content of this application by anyone skilled in the art. Any modifications based on the disclosed content should be considered obvious in the art. The basic principles described in this application can be applied to other variations without departing from the inventive nature and scope of this application. Therefore, the content disclosed in this application is not limited to the described embodiments and designs but can be extended to the maximum extent consistent with the principles and novel features disclosed in this application.

[0260] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely illustrative descriptions of the application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of the claims and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A side-link communication method, characterized in that, include: The first terminal device sends a Hybrid Automatic Repeat Request (HARQ) attribute-enabled Sidelink Control Information (SCI) to the second terminal device. The HARQ attribute being enabled indicates that when the second terminal device receives the SCI or the sidelink SL data scheduled by the SCI, it sends HARQ feedback of the SCI or the data scheduled by the SCI to the first terminal device. The first terminal device receives HARQ feedback of the SCI or the SCI-scheduled data from the second terminal device, and the first terminal device starts or restarts the discontinuous reception inactivity timer; during the operation of the discontinuous reception inactivity timer, the first terminal device listens to the SCI; The first terminal device sends an SCI with the HARQ attribute disabled to the second terminal device. The first terminal device keeps the discontinuous reception inactive timer in an unstarted state. The HARQ attribute being disabled indicates that when the second terminal device receives the SCI or the SL data scheduled by the SCI, it does not send HARQ feedback of the SCI or the SL data scheduled by the SCI to the first terminal device.

2. A side-link communication method, characterized in that, include: The second terminal device receives a Hybrid Automatic Repeat Request (HARQ) attribute enabled sidelink control information (SCI) from the first terminal device. The HARQ attribute enabling indicates that when the second terminal device receives the SCI or the sidelink SL data scheduled by the SCI, it sends HARQ feedback of the SCI or the data scheduled by the SCI to the first terminal device. The second terminal device sends the SCI or the SL data scheduled by the SCI to the first terminal device, and the second terminal device starts or restarts the discontinuous reception inactivity timer; during the operation of the discontinuous reception inactivity timer, the first terminal device listens to the SCI; The second terminal device receives an SCI with the HARQ attribute disabled from the first terminal device. The second terminal device keeps the discontinuous reception inactive timer in an unstarted state. The HARQ attribute being disabled indicates that when the second terminal device receives the SCI or the SL data scheduled by the SCI, it does not send HARQ feedback of the SCI or the SL data scheduled by the SCI to the first terminal device.

3. A sidelink communication device, characterized in that, include: The transceiver unit is used to send a Hybrid Automatic Repeat Request (HARQ) attribute enabled sidelink control information (SCI) to the second terminal device. The HARQ attribute enabling indicates that when the second terminal device receives the SCI or the sidelink SL data scheduled by the SCI, it sends HARQ feedback of the SCI or the data scheduled by the SCI to the sidelink communication device. The transceiver unit is also configured to receive HARQ feedback of the SCI or the SCI-scheduled data from the second terminal device; A processing unit is used to start or restart a discontinuous reception inactivity timer; during the operation of the discontinuous reception inactivity timer, the side link communication device listens for SCI; The transceiver unit is further configured to send an SCI with the HARQ attribute disabled to the second terminal device. The side link communication device keeps the discontinuous reception inactive timer in an unstarted state. The HARQ attribute being disabled indicates that when the second terminal device receives the SCI or the SL data scheduled by the SCI, it does not send HARQ feedback of the SCI or the SL data scheduled by the SCI to the side link communication device.

4. A side-link communication device, characterized in that, include: The transceiver unit is used to receive a side link control information (SCI) with the Hybrid Automatic Repeat Request (HARQ) attribute enabled from a first terminal device. The HARQ attribute being enabled indicates that when the side link communication device receives the SCI or the side link SL data scheduled by the SCI, it sends HARQ feedback of the SCI or the data scheduled by the SCI to the first terminal device. The processing unit is configured to start or restart a discontinuous reception inactivity timer when sending the SCI or the SL data scheduled by the SCI to the first terminal device via HARQ feedback; during the operation of the discontinuous reception inactivity timer, the first terminal device listens to the SCI. The processing unit is further configured to, when receiving an SCI with HARQ attribute disabled from the first terminal device, keep the discontinuous reception inactive timer in an unstarted state, and when the HARQ attribute being disabled indicates that the side link communication device receives the SCI or the SL data scheduled by the SCI, not send HARQ feedback of the SCI or the SL data scheduled by the SCI to the first terminal device.

5. A sidelink communication device, characterized in that, The device includes a processor and a memory, the memory storing instructions, which, when executed by the processor, cause the device to perform the method of claim 1 or 2.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the method of claim 1 or 2.

7. A computer program product, characterized in that, It includes a computer program or instructions that, when executed, cause the communication device to perform the method of claim 1 or 2.

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