Communication methods, communication devices, and communication systems

Abstract

The embodiments of the present application provide a communication method, a communication device, and a communication system, in which a terminal device that preempts resources on an unlicensed spectrum or can preempt resources timely implements avoidance for a terminal device that reserves resources or shares resources with a terminal device that reserves resources, and the terminal device that reserves resources can transmit data timely, which meets service requirements and significantly improves user experience.

Description

[Technical Field]

[0001] This application relates to the field of communications, and more specifically to communication methods, communication devices, and communication systems. [Background technology]

[0002] This application claims priority to China Patent Application No. 202210194217.5, titled "COMMUNICATION METHOD, APPARATUS, AND SYSTEM," filed with the China National Intellectual Property Administration on 1 March 2022, which is incorporated herein by reference in its entirety.

[0003] In wireless communication systems, the frequency bands used can be classified into licensed frequency bands (i.e., licensed spectrum) and unlicensed frequency bands (i.e., unlicensed spectrum). Enabling sidelink (SL) communication over unlicensed frequency bands in local space is a significant development trend. Currently, when multiple user equipment (UEs) communicate with each other over the unlicensed spectrum via sidelinks, these multiple user equipment devices must autonomously compete for resources, and UEs that need to transmit data urgently may lose access to resources through this competition. As a result, service requirements cannot be met, and the user experience is severely affected. Therefore, how to transmit data in a timely manner to meet service requirements is an urgent issue that needs to be resolved. [Overview of the Initiative]

[0004] Embodiments of this application provide a communication method, a communication device, and a communication system. According to this method, data can be transmitted in a timely manner to meet service requirements.

[0005] According to the first embodiment, a communication method is provided. This method comprises: a first terminal device receiving first display information from a second terminal device, wherein the first display information indicates a first resource, the first resource is a resource reserved by the second terminal device for transmitting first data, and the resource corresponding to the first resource in the frequency domain belongs to a first channel; the first terminal device determining a second resource based on the first display information; and the first terminal device transmitting second data on the second resource, wherein the start time unit of the second resource is later than the end time unit of the first resource, and the resource corresponding to the second resource in the frequency domain belongs to a first channel. It may include.

[0006] According to this method, the first terminal device can postpone access to the channel, implement timely evasions when the second terminal device accesses the channel, and the second terminal device can transmit data on the reserved resources. This reduces data transmission delay, meets service requirements, and improves communication efficiency.

[0007] Referring to the first embodiment, in some implementations of the first embodiment, the first terminal device senses in a first sensing time unit that the state of the first channel is idle by using listen-before-talk processing, and interrupts the listen-before-talk processing in the first sensing time unit based on the first resource, where the first sensing time unit is earlier than the start time unit of the first resource.

[0008] Referring to the first embodiment, in some implementations of the first embodiment, the period between the start time unit of the first resource and the first sensing time unit where the counter value is M is less than or equal to a first threshold, where the first threshold is greater than 0 and does not meet the delay requirement of the second data.

[0009] In this way, the duration of the time period during which the first terminal device stops progressively reducing the counter is less than a certain threshold. Since neither the first nor the second terminal device accesses the channel within the time period, resource waste can be avoided by limiting the duration of the time period.

[0010] Referring to the first embodiment, in some implementations of the first embodiment, after progressively reducing the value of the counter to M, the first terminal device interrupts the progressive reduction, where 1 ≤ M ≤ Q, and Q is the initial value of the counter.

[0011] Referring to the first embodiment, in some implementations of the first embodiment, the first threshold is determined based on the period corresponding to the second resource in the time domain.

[0012] Referring to the first embodiment, in some implementations of the first embodiment, the first terminal device senses in a second sensing time unit that the state of the first channel is idle and continues to progressively reduce the value of a counter from M, where the second sensing time unit is later than the end time unit of the first resource, and the start time unit of the second resource is the time unit in which the value of the counter progressively decreases to 0.

[0013] In this way, the first terminal device can access the channel after the second terminal device has finished transmitting data, and the data to be transmitted by the first terminal device can be transmitted successfully. This further satisfies service requirements and avoids wasting time-frequency resources after the resources used by the second terminal device to transmit data.

[0014] Referring to the first embodiment, in some implementations of the first embodiment, the first terminal device receives a first reference signal from the second terminal device, and the first terminal device determines that the power required to receive the first reference signal is equal to or greater than a reference signal reception power threshold.

[0015] After the first terminal device shares resources with the second terminal device, if the second terminal device's reference signal reception power falls below a threshold, another device close to the first terminal device cannot become silent. As a result, the channel may be occupied by another device, and the first terminal device cannot re-access that channel within its resources. Therefore, when the second terminal device's reference signal reception power is equal to or greater than the reference signal reception power threshold, the first terminal device decides to perform a evasion. This prevents the resources from being preempted by devices other than the second terminal device after the first terminal device has performed the evasion, improves the success rate of the second terminal device accessing the channel, and further improves communication efficiency.

[0016] Referring to the first embodiment, in some implementations of the first embodiment, the first terminal device receives third display information from the second terminal device, where the third display information indicates that the first terminal device is the destination to which the second terminal device transmits data.

[0017] In this way, when the first terminal device is the data receiving side (destination side) of the second terminal device, the first terminal device can perform evasion on the second terminal device and receive the data in a timely manner. This satisfies the service requirements.

[0018] Referring to the first embodiment, in some implementations of the first embodiment, the first terminal device receives fourth display information from the second terminal device, where the fourth display information indicates the priority of the first data, and the first terminal device determines that the priority of the first data is greater than or equal to the priority of the second data.

[0019] In this way, the first terminal device can perform evasion against devices corresponding to data with higher priority, and the service requirements for data with higher priority can be met in a timely manner.

[0020] Referring to the first embodiment, in some implementations of the first embodiment, the first display information is carried in at least one of first-stage sidelink control information, second-stage sidelink control information, sidelink medium access control elements, or radio resource control signaling used for communication between user devices (PC5) from a second terminal device.

[0021] Referring to the first embodiment, in some implementations of the first embodiment, the third display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the second terminal device.

[0022] Referring to the first embodiment, in some implementations of the first embodiment, the fourth display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the second terminal device.

[0023] It should be understood that the aforementioned display information may, as an alternative, be carried within signaling configured by another network device or within pre-configured signaling.

[0024] A second embodiment provides a communication method, which may include: a first terminal device receiving first display information from a second terminal device, wherein the first display information indicates a first resource, the first resource being a resource reserved by the second terminal device for transmitting first data; the first terminal device determining a third resource based on the first resource and a first channel occupancy time, wherein the third resource belongs to the first resource and the first channel occupancy time, the third resource being used by the second terminal device for transmitting data; and the first terminal device transmitting data over a fourth resource, wherein the fourth resource belongs to a resource other than the third resource within the first channel occupancy time.

[0025] The first channel occupancy time may be the period corresponding to the fifth resource in the time domain. In other words, the first terminal device receives first display information from the second terminal device, where the first display information indicates a first resource, which is a resource reserved by the second terminal device for transmitting first data; the first terminal device determines a fifth resource, where the start time unit of the fifth resource is earlier than the start time unit of the first resource, and the fifth resource overlaps with the first resource; the first terminal device determines a third resource based on the first and fifth resources, where the third resource belongs to the overlap between the first and fifth resources, and the third resource is used by the second terminal device for transmitting first data; and the first terminal device transmits second data over a fourth resource, where the fourth resource belongs to the portion of the fifth resource other than the third resource.

[0026] In this method, the first terminal device shares resources with the second terminal device, and data from the second terminal device can be transmitted in a timely manner. This satisfies the service requirements.

[0027] Referring to the second aspect, in some implementations of the second aspect, the first terminal device sends second display information to the second terminal device, where the second display information indicates a third resource.

[0028] In this way, the first terminal device shows the shared resources to the second terminal device, and the second terminal device quickly determines which resources to use. This further reduces the delay when the second terminal device transmits data.

[0029] According to a second embodiment, in some implementations of the second embodiment, a first terminal device transmits second display information to a second terminal device within a first time period, where the start moment of the first time period falls within the range between the start time unit of a fourth resource and the start time unit of a third resource, and the period between the start moment of the first time period and the start time unit of a fourth resource is greater than or equal to a second threshold.

[0030] For example, the second threshold is T proc,0 That's fine.

[0031] The first terminal device must ensure that there is sufficient time to transmit the first display information, and the second terminal must have sufficient time to decode the display information. In some cases, the first display information may not be transmitted, or the second terminal device may not be able to learn the resource location when the first display information fails to be transmitted. In this case, neither the first nor the second terminal device uses the third resource. This method avoids wasting resources.

[0032] Referring to the second embodiment, in some implementations of the second embodiment, the first terminal device receives third display information from the second terminal device, where the third display information indicates that the first terminal device is the destination to which the second terminal device transmits data.

[0033] When the first terminal device is the data receiving side (destination side) of the second terminal device, the first terminal device can share resources with the second terminal device and receive data in a timely manner. This satisfies the service requirements.

[0034] Referring to the second embodiment, in some implementations of the second embodiment, the first terminal device receives fourth display information from the second terminal device, where the fourth display information indicates the priority of the first data, and the first terminal device determines that the priority of the first data is greater than or equal to the priority of the second data.

[0035] In this way, the first terminal device shares resources with devices that handle higher-priority data, and the service requirements for higher-priority data can be met in a timely manner.

[0036] Referring to the second embodiment, in some implementations of the second embodiment, the first terminal device receives a first reference signal from the second terminal device, and the first terminal device determines that the power required to receive the first reference signal is equal to or greater than a reference signal reception power threshold.

[0037] After the first terminal device shares resources with the second terminal device, if the second terminal device's reference signal reception power falls below a threshold, another device close to the first terminal device cannot be silent. As a result, the channel may be occupied by another device, and the first terminal device cannot re-access that channel within its resources. Therefore, when the second terminal device's reference signal reception power is equal to or greater than the reference signal reception power threshold, the first terminal device decides to perform a evasion. This prevents the resources from being preempted by devices other than the second terminal device after the first terminal device has performed the evasion, improves the success rate of the second terminal device accessing the channel, and further improves communication efficiency.

[0038] Referring to the second aspect, in some implementations of the second aspect, the first display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the radio resource control signaling from the second terminal device.

[0039] Referring to the second aspect, in some implementations of the second aspect, the second display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the first terminal device.

[0040] Referring to the second aspect, in some implementations of the second aspect, the third display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the second terminal device.

[0041] Referring to the second embodiment, in some implementations of the second embodiment, the fourth display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the second terminal device.

[0042] It should be understood that the aforementioned display information may, as an alternative, be carried within signaling configured by another network device or within pre-configured signaling.

[0043] A third aspect provides a communication method, which may include: a second terminal device transmitting first display information, wherein the first display information indicates a first resource, the first resource being a resource reserved by the second terminal device for transmitting first data; and the second terminal device transmitting first data on a third resource, wherein the third resource is determined based on the first resource and a first channel occupancy time, the third resource belongs to the first resource and the first channel occupancy time, and the start time unit of the first channel occupancy time is earlier than the start time unit of the first resource.

[0044] Referring to the third embodiment, in some implementations of the third embodiment, the second terminal device receives second display information from the first terminal device, where the second display information indicates a third resource.

[0045] According to a third embodiment, in some implementations of the third embodiment, a second terminal device receives second display information from the first terminal device within a first time period, where the start moment of the first time period falls within the range between the start time unit of the fourth resource and the start time unit of the third resource, and the period between the start moment of the first time period and the start time unit of the fourth resource is greater than or equal to a second threshold.

[0046] For example, the second threshold is T proc,0 That's fine.

[0047] Referring to the third aspect, in some implementations of the third aspect, the second terminal device transmits a third indicator information, where the third indicator information indicates that the first terminal device is the destination to which the second terminal device transmits data.

[0048] Referring to the third aspect, in some implementations of the third aspect, the second terminal device transmits the first reference signal.

[0049] Referring to the third aspect, in some implementations of the third aspect, the first display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the second terminal device.

[0050] Referring to the third aspect, in some implementations of the third aspect, the second display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the first terminal device.

[0051] Referring to the third aspect, in some implementations of the third aspect, the third display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the second terminal device.

[0052] Referring to the third embodiment, in some implementations of the third embodiment, the fourth display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the radio resource control signaling from the second terminal device.

[0053] The third aspect is an implementation of a second terminal device corresponding to the first terminal device of the second aspect, and it should be understood that the description, supplements, and beneficial effects of the second aspect are also applicable to the third aspect. Further details will not be explained again.

[0054] According to a fourth aspect, a communication device is provided. The communication device includes a transceiver unit and a processing unit. The transceiver unit is configured to receive first indication information from a second terminal device, wherein the first indication information indicates a first resource, the first resource being a resource reserved by the second terminal device for transmitting first data, and the resource corresponding to the first resource in the frequency domain belongs to a first channel. The processing unit is configured to determine a second resource based on the first indication information. The transceiver unit is further configured to transmit second data on the second resource, wherein the disclosure time unit of the second resource is later than the termination time unit of the first resource, and the resource corresponding to the second resource in the frequency domain belongs to a first channel.

[0055] Referring to the fourth aspect, in some implementations of the fourth aspect, the processing unit is configured to sense in a first sensing time unit that the state of a first channel is idle by using listen-before-talk processing, and the processing unit is further configured to suspend the listen-before-talk processing in a first sensing time unit based on a first resource, where the first sensing time unit is earlier than the start time unit of the first resource.

[0056] Referring to the fourth aspect, in some implementations of the fourth aspect, the period between the start time unit of the first resource and the first sensing time unit where the counter value is M is less than or equal to a first threshold, where the first threshold is greater than 0 and does not meet the delay requirement of the second data.

[0057] Referring to the fourth aspect, in some implementations of the fourth aspect, the processing unit is configured to progressively reduce the value of the counter to M, and then interrupt the progressive reduction, where 1 ≤ M ≤ Q, and Q is the initial value of the counter.

[0058] Referring to the fourth aspect, in some implementations of the first aspect, the first threshold is determined based on the period corresponding to the second resource in the time domain.

[0059] Referring to the fourth aspect, in some implementations of the fourth aspect, the processing unit is further configured to determine in a second sensing time unit that the state of the first channel is idle and to continue to progressively reduce the value of a counter from M, where the second sensing time unit is later than the end time unit of the first resource, and the start time unit of the second resource is the time unit in which the value of the counter progressively decreases to 0.

[0060] Referring to the fourth aspect, in some implementations of the fourth aspect, the transceiver unit is further configured to receive fourth indicator information from a second terminal device, where the fourth indicator information indicates the priority of the first data, and the first terminal device determines that the priority of the first data is greater than or equal to the priority of the second data.

[0061] Referring to the fourth aspect, in some implementations of the fourth aspect, the first display information is carried in at least one of first-stage sidelink control information, second-stage sidelink control information, sidelink medium access control elements, or wireless resource control signaling from a second terminal device.

[0062] Referring to the fourth aspect, in some implementations of the fourth aspect, the third display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the radio resource control signaling from the second terminal device.

[0063] Referring to the fourth aspect, in some implementations of the fourth aspect, the fourth display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the radio resource control signaling from the second terminal device.

[0064] The fourth aspect is a device-side implementation corresponding to the first aspect, and it should be understood that the description, supplements, and beneficial effects of the first aspect are also applicable to the fourth aspect. Further details will not be explained again.

[0065] According to a fifth aspect, a communication device is provided. The communication device includes a transceiver unit and a processing unit. The transceiver unit is configured to receive first indication information from a second terminal device, wherein the first indication information indicates a first resource, the first resource being a resource reserved by the second terminal device for transmitting first data. The processing unit is configured to determine a third resource based on the first resource and a first channel occupancy time, wherein the third resource belongs to the first resource and the first channel occupancy time, and the third resource is used by the second terminal device for transmitting second data. The transceiver unit is further configured to transmit first data over a fourth resource, wherein the fourth resource belongs to a resource other than the third resource within the first channel occupancy time.

[0066] Referring to the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is further configured to transmit second display information to a second terminal device, where the second display information indicates a third resource.

[0067] According to a fifth aspect, in some implementations of the fifth aspect, the transceiver unit is specifically configured to transmit second display information to a second terminal device within a first time period, where the start moment of the first time period falls within the range between the start time unit of a fourth resource and the start time unit of a third resource, and the period between the start moment of the first time period and the start time unit of the fourth resource is greater than or equal to a second threshold.

[0068] For example, the second threshold is T proc,0 That's fine.

[0069] Referring to the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is further configured to receive third indication information from a second terminal device, where the third indication information indicates that the first terminal device is the destination side to which the second terminal device transmits first data.

[0070] Referring to the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is further configured to receive fourth indicator information from a second terminal device, where the fourth indicator information indicates the priority of a first data, and the processing unit is further configured to determine that the priority of the first data is greater than or equal to the priority of the second data.

[0071] Referring to the fifth aspect, in some implementations of the fifth aspect, the transceiver unit receives a first reference signal from a second terminal device, and the processing unit is further configured to determine that the power for receiving the first reference signal is greater than or equal to a reference signal reception power threshold.

[0072] Referring to the fifth aspect, in some implementations of the fifth aspect, the first display information is carried in at least one of first-stage sidelink control information, second-stage sidelink control information, sidelink medium access control elements, or wireless resource control signaling from a second terminal device.

[0073] Referring to the fifth aspect, in some implementations of the fifth aspect, the second display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the first terminal device.

[0074] Referring to the fifth aspect, in some implementations of the fifth aspect, the third display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the second terminal device.

[0075] Referring to the fifth aspect, in some implementations of the fifth aspect, the fourth display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the second terminal device.

[0076] The fifth aspect is a device-side implementation corresponding to the second aspect, and it should be understood that the description, supplements, and beneficial effects of the second aspect are also applicable to the fifth aspect. Further details will not be explained again.

[0077] According to a sixth aspect, a communication device is provided. The communication device includes a transceiver unit and a processing unit. The transceiver unit is configured to transmit first indicator information, wherein the first indicator information indicates a first resource, the first resource being a resource reserved by a second terminal device for transmitting first data. The transceiver unit is further configured to transmit first data over a third resource, wherein the third resource is determined based on the first resource and a first channel occupancy time, the third resource belonging to the first resource and the first channel occupancy time, and the start time unit of the first channel occupancy time is earlier than the start time unit of the first resource.

[0078] Referring to the sixth aspect, in some implementations of the sixth aspect, the transceiver unit is configured to receive second display information from a first terminal device, where the second display information indicates a third resource.

[0079] According to the sixth aspect, in some implementations of the sixth aspect, the transceiver unit is specifically configured to receive second display information from a first terminal device within a first time period, where the start moment of the first time period falls within the range between the start time unit of a fourth resource and the start time unit of a third resource, and the period between the start moment of the first time period and the start time unit of the fourth resource is greater than or equal to a second threshold.

[0080] For example, the second threshold is T proc,0 That's fine.

[0081] Referring to the sixth aspect, in some implementations of the sixth aspect, the transceiver unit is further configured to transmit a third indicator information, where the third indicator information indicates that the first terminal device is the destination side to which the second terminal device transmits the first data.

[0082] Referring to the sixth aspect, in some implementations of the sixth aspect, the transceiver unit is further configured to transmit a first reference signal.

[0083] Referring to the sixth aspect, in some implementations of the sixth aspect, the first display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the second terminal device.

[0084] Referring to the sixth aspect, in some implementations of the sixth aspect, the second display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the first terminal device.

[0085] Referring to the sixth aspect, in some implementations of the sixth aspect, the third display information is carried in at least one of the first stage sidelink control information, the second stage sidelink control information, the sidelink medium access control element, or the PC5 wireless resource control signaling from the second terminal device.

[0086] Referring to the sixth aspect, in some implementations of the sixth aspect, the fourth display information is carried in first-stage sidelink control information, sidelink medium access control elements, or wireless resource control signaling from a second terminal device.

[0087] The sixth aspect is a device-side implementation corresponding to the third aspect, and it should be understood that the description, supplements, and beneficial effects of the third aspect are also applicable to the sixth aspect. Further details will not be explained again.

[0088] According to the seventh aspect, a computer-readable medium is provided. The computer-readable medium stores program code to be executed by a communication device, the program code including instructions used to implement a communication method according to any one of the first, second, or third aspects, any possible implementation of the first, second, or third aspects, or all of the possible implementations of the first, second, or third aspects.

[0089] According to the eighth aspect, a computer program product including instructions is provided. When the computer program product is executed on a computer, the computer is made capable of implementing any one of the first, second, or third aspects, any possible implementation of the first, second, or third aspect, or any of the possible implementations of the first, second, or third aspect.

[0090] According to the ninth aspect, a communication system is provided. The communication system includes a device configured to implement a function in any one of the first, second, or third aspects, or any one of the possible implementations of the first, second, or third aspects, or in any way by all of the possible implementations of the first, second, or third aspects, or in any way by any way by any way by any way by any way by any way by any way by any way by any way by any way by any way by any way

[0091] According to the tenth aspect, a processor is provided, which is coupled to memory and configured to implement any one of the possible implementations of the first, second, or third aspect, or all of the possible implementations of the first, second, or third aspect.

[0092] According to the eleventh aspect, a chip is provided. The chip includes a processor and a communication interface. The communication interface is configured to communicate with an external or internal component. The processor is configured to implement any one of the first, second, or third aspects, any possible implementation of the first, second, or third aspect, or any of the possible implementations of the first, second, or third aspect.

[0093] Optionally, the chip may further include memory. The memory stores instructions. The processor is configured to execute instructions stored in memory or instructions from another module. When an instruction is executed, the processor is configured to implement a method in any one of the first, second, or third embodiments thereof.

[0094] Optionally, the chip can be integrated into terminal devices and / or network devices. [Brief explanation of the drawing]

[0095] [Figure 1]This figure shows a system architecture to which the embodiments of this application can be applied. [Figure 2] This figure shows a slot to which the embodiment of this application can be applied. [Figure 3] This figure shows a listen-before-talk process to which the embodiments of this application can be applied. [Figure 4] This figure shows another listen-before-talk process to which embodiments of this application are applicable. [Figure 5] This is a diagram of a communication method according to an embodiment of the present application. [Figure 6] This is a diagram of the transmission resources according to the embodiment of this application. [Figure 7] This is a schematic flowchart of the communication method according to the embodiment of this application. [Figure 8] This is a diagram of another communication method according to an embodiment of the present application. [Figure 9] This is a schematic flowchart of another communication method according to an embodiment of this application. [Figure 10] This is a diagram of another transmission resource according to an embodiment of the present application. [Figure 11] This is a schematic flowchart of another communication method according to an embodiment of this application. [Figure 12] This is a diagram of another transmission resource according to an embodiment of the present application. [Figure 13] This is a block diagram of a communication device according to an embodiment of the present application. [Figure 14] This is a block diagram of another communication device according to an embodiment of the present application. [Modes for carrying out the invention]

[0096] The following describes the technical solution of this application with reference to the attached drawings.

[0097] The technical solutions of the embodiments of this application can be applied to various communication systems, such as 5th generation (5G) or new radio (NR) systems, long-term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, and the like. The technical solutions provided in this application can be further applied to future communication systems, such as sixth-generation mobile communication systems. The technical solutions provided in this application can be further applied to device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), Internet of Things (IoT) communication systems, or other communication systems.

[0098] In addition, the technical solutions provided in the embodiments of this application may be applied to links between network devices and terminal devices, or to links between devices, such as device-to-device (D2D) links. D2D links are sometimes called side links, and side links may also be called secondary links, etc. In the embodiments of this application, D2D links, side links, or secondary links are links established between devices of the same type and have the same meaning. Links between devices of the same type may be links between terminal devices, links between network devices, links between relay nodes, etc. This is not limited to the embodiments of this application. In the case of links between terminal devices, there are D2D links as defined in the 3rd generation partnership project (3GPP) release (Rel)-12 / 13, and there are also vehicle-to-everything links as defined by 3GPP for the Internet of Cars. It should be understood that V2X specifically includes vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P) direct communication, and vehicle-to-network (V2N), or vehicle-to-any entity V2X links, including the V2X links of Rel-14 / 15. V2X further includes NR system-based B2X links in later releases currently being studied by Rel-16 and 3GPP. V2X is communication between vehicles. V2P is communication between vehicles and people (including pedestrians, cyclists, drivers, and passengers). V2I is communication between vehicles and infrastructure, where infrastructure is, for example, a roadside unit (RSU) or network device.In addition, V2N may be included within V2I, and V2N is communication between vehicles and network devices. RSUs include two types: terminal-type RSUs and base station-type RSUs. Terminal-type RSUs are deployed on the roadside, so they are in a non-mobile state and mobility does not need to be considered. Base station-type RSUs can provide timing synchronization and resource scheduling to vehicles communicating with them.

[0099] The following provides diagrams of the architecture of a mobile communication system to which embodiments of the present application apply. Figure 1 is a diagram of the architecture of a communication system 1000 to which embodiments of the present application apply apply. As shown in Figure 1, the communication system includes a radio access network 100. Optionally, the communication system 1000 may further include a core network 200 and an internet 300. The radio access network 100 may include at least one radio access network device (e.g., 110a and 110b in Figure 1) and may further include at least one terminal (e.g., 120a to 120 in Figure 1). The terminal is connected to the radio access network device wirelessly, and the radio access network device is connected to the core network wirelessly or wired. The core network device and the radio access network device may be independent, different physical devices, or the functions of the core network and the logical functions of the radio access network device may be integrated into the same physical device, or some functions of the core network device and some functions of the radio access network device may be integrated into one physical device. The terminals may be connected to each other by wired or wireless means, and the wireless access network devices may be connected to each other by wired or wireless means. Figure 1 is merely a diagram. The communication system may further include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1.

[0100] In the communication system of this application, the information transmitting side may be a network device or a terminal device, and the information receiving side may also be a network device or a terminal device. This is not limited to the present application.

[0101] In embodiments of this application, UE may be referred to as terminal device, access terminal, subscriber unit, subscriber station, mobile station, mobile console, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user equipment.

[0102] A terminal device can be a device that provides voice / data to a user. For example, a terminal device may be a handheld device or a vehicle-mounted device with wireless connectivity. A terminal device may include user equipment and is sometimes referred to as a terminal, access station, UE station, remote station, wireless communication device, user equipment, etc. A terminal device is configured to connect to people, objects, machines, etc., and can be widely used in a variety of scenarios. For example, a terminal device may include, but is not limited to, terminal devices used in the following scenarios: cellular communication, D2D, V2X, machine-to-machine / machine-type communication (M2M / MTC), Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, unmanned aerial vehicles, and robots. For example, terminal devices may include mobile phones, tablet computers, computers with wireless transceiver functionality, VR terminals, AR terminals, wireless terminals in industrial control, vehicles, in-vehicle wireless communication modules, vehicle-mounted T-boxes (telematics boxes), roadside RSUs, wireless terminals in autonomous driving, smart speakers in IoT networks, wireless terminal devices in telemedicine, wireless terminal devices in smart grids, wireless terminal devices in traffic safety, wireless terminal devices in smart cities, and wireless terminal devices in smart homes. This is not limited to the embodiments of this application.

[0103] Without limitation, and as an example, in embodiments of this application, the terminal device may be a wearable device instead. Wearable devices, sometimes called wearable intelligent devices, are a general term for wearable devices that are intelligently designed and developed for everyday wear, such as glasses, gloves, watches, clothing, and shoes, by using wearable technology. Wearable devices are portable devices that can be worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not merely hardware devices, but also implement powerful functionality through software support, data exchange, and cloud interaction. In a broad sense, wearable intelligent devices include full-featured large devices that can implement full or partial functionality without relying on a smartphone, such as smartwatches or smart glasses, and devices that need to be used in conjunction with other devices such as smartphones, such as various smart bands or smart jewelry that focus on only one type of application and are used to monitor physical signs. In addition, the terminal device in embodiments of this application may be a terminal device in an IoT system instead. IoT is an important part of the future development of information technology. The main technological characteristic of IoT is the use of communication technologies to connect things to a network in order to implement intelligent networks for interconnection between people and machines or between things themselves.

[0104] If any of the terminal devices described above are located within a vehicle (for example, placed or installed within a vehicle), then all terminal devices may be considered vehicle-mounted terminal devices. Vehicle-mounted terminal devices are also referred to as, for example, on-board units (OBUs). In this application, terminal devices may, alternatively, be vehicle-mounted modules, vehicle-mounted assemblies, vehicle-mounted components, vehicle-mounted chips, or vehicle-mounted units, which are constructed within a vehicle as one or more components or units. The vehicle uses vehicle-mounted modules, vehicle-mounted assemblies, vehicle-mounted components, vehicle-mounted chips, or vehicle-mounted units that are constructed within the vehicle and implement the method of this application.

[0105] It should be understood that a network device in a wireless communication system may be any device capable of communicating with terminal devices, and that network devices may also be called access network devices or radio access network devices. For example, the network may be a base station. The network device in the embodiments of this application may be a radio access network (RAN) node (or device) that connects terminal devices to a wireless network. A base station can broadly refer to various names, or to any of the following, for example: Node B, evolved Node B (eNB), next generation Node B (gNB, also called future Node B), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master eNode B (MeNB), secondary eNode B (SeNB), multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmitting node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit A base station may be replaced with a unit (DU), positioning node, etc. A base station may be a macro base station, a micro base station, a relay node, a donor node, etc., or a combination thereof. Alternatively, a base station may be a communication module, modem, or chip located within the aforementioned device or apparatus.A base station may, as an alternative, be a mobile switching station, a device implementing a base station in D2D, V2X, and M2M communications, a network-side device in a future network (i.e., a future communication network), or a device implementing base station functionality in a future communication system. A base station may support networks with the same or different access technologies. The specific technologies and device configurations used by network devices are not limited to the embodiments of this application.

[0106] In embodiments of this application, base station functions may be implemented by modules (e.g., chips) within the base station, or by a control subsystem having base station functions. In this specification, a control subsystem having base station functions may be a control center for the aforementioned application scenarios, such as smart grids, industrial control, smart transportation, and smart cities. Terminal functions may be implemented by modules (e.g., chips or modems) within the terminal, or by a device having terminal functions.

[0107] To facilitate understanding of this application, random access processing and related concepts are briefly explained.

[0108] 1. Interface: The communication interface between user equipment and network devices (Uu interface) is sometimes called the Uu interface, and the communication interface between user equipment (PC5 interface) is sometimes called the PC5 interface. The transmit link in the PC5 interface is defined as a sidelink (SL).

[0109] 2. Unlicensed Spectrum: In wireless communication systems, the frequency bands used can be classified into licensed and unlicensed spectra. On the licensed spectrum, users utilize spectrum resources based on the scheduling of a central node. On the unlicensed spectrum, transmitting nodes must utilize spectrum resources through competition. Specifically, transmitting nodes compete for channels using the listen-before-talk (LBT) method. In next-generation 5G NR systems, NR protocol technologies for the unlicensed spectrum are collectively referred to as NR-U, and the communication performance of the corresponding Uu interface is expected to be further improved by using NR-U. Enabling SL communication on the unlicensed spectrum in local space is an important development trend, and the corresponding protocol technologies are sometimes collectively referred to as SL-U. Similar to the Uu interface, UEs that operate using SL-U also need to coexist with nearby Wi-Fi devices based on the LBT mechanism. The reason why the LBT mechanism is an essential feature of the unlicensed spectrum is that each region of the world has regulation requirements for the use of the unlicensed spectrum. Various forms of UEs operating under different communication protocols can use unlicensed spectrum only when regulations are met. In this way, UEs can use spectrum resources fairly and efficiently.

[0110] 3. Time Domain Resources: One or more time units are contained within the time domain of the SL resource pool, and a time unit may be one or more symbols, one or more slots, one or more mini-slots, one or more subframes, one or more frames, etc. One or more time units may be temporally continuous or discrete. It should be understood that time domain units in a resource pool are logically continuous. For understanding the definitions of symbols, mini-slots, slots, subframes, and frames in the embodiments of this application, please refer to 3GPP TS38.211.

[0111] As shown in Figure 2, slots 1 through 8 are temporally continuous slots, and these slots are called physical slots. Physical slots: slots 1, 3, 5, and 8 are configured as slots belonging to the same resource pool. Slots included in a resource pool may not be temporally continuous. Therefore, from the perspective of the resource pool, physical slots: slots 1, 3, 5, and 8 correspond to slots 1', 2', 3', and 4' in the resource pool. Continuous slots included in a resource pool (i.e., slots 1', 2', 3', and 4') are logically continuous slots from the resource pool's perspective, while slots that are logically continuous but not necessarily temporally continuous are called logical slots.

[0112] Start time unit: The start time unit is the first time unit of a resource within the time domain.

[0113] End time unit: The end time unit is the last time unit of a resource within a time domain.

[0114] In the example where slots are time units, the resource shown in Figure 2 contains slots 1 through 8 within the time domain. In this example, slot 1 is the start time unit of the resource, and slot 8 is the end time unit of the resource.

[0115] 4. Frequency Domain Resources: One or more frequency domain units are contained within the frequency domain of the SL resource pool, and a frequency domain unit may be one resource element (RE) or several REs, one resource block (RB) or several RBs, or one sub-channel or several sub-channels. The size of one sub-channel indicates the amount of one or more RBs contained within the sub-channel that are continuous or interfaced in the frequency domain, and may be an integer such as 10, 12, 15, 20, 25, or 50.

[0116] 5. Sidelink resource allocation mode: NR SL supports two resource allocation modes: Mode 1 and Mode 2.

[0117] Mode 1 (SL Mode 1): The network device allocates resources used for sidelink transmission, and Mode 1 is typically for sidelink communication within the network device's coverage area.

[0118] Mode 2 (SL Mode 2): The UE autonomously selects resources for sidelink transmission. Autonomous resource selection method: The transmitting UE autonomously selects transmission resources within the resource selection window for communication based on sensing results within the transmitting UE's sensing window. It is assumed that the transmitting UE triggers resource selection within slot n. The specific resource selection procedure is as follows:

[0119] Step 1: Determine the resource selection window [n+T1, n+T2], where 0≦T1≦T(proc,1) SL ,T 2min where T1 ≤ T2 ≤ PDB (packet delay), and T1 and T2 are selected based on implementation.

[0120] Step 2: Determine the sensing window [n - T0, n - T (proc,0) SL .

[0121] Step 3: Determine the reference signal received power (RSRP) threshold, where the RSRP threshold and the priority prio of the data to be transmitted TX are related to the priority prio indicated by the received sidelink control information (SCI), and the RSRP threshold is specifically the (prio RX + (prio RX - 1) * 8)-th threshold within the RSRP threshold set configured by the resource pool. TX

[0122] Step 4: Initialize the available resource set S to include all time - frequency resources (in units of one slot and one sub - channel) within the resource selection window. A

[0123] Step 5: Exclude from S the time - frequency resources within the guaranteed slots corresponding to all periodic resources configured by the resource pool and not sensed within the sensing window (the slots where transmission is to be performed). A

[0124] S A If the amount of time - frequency resources excluded from S is less than X% of the total resources within the resource selection window, the initialization in Step 4 is performed again.

[0125] Step 6: Time - frequency resources that satisfy the following conditions are in S AContinue to exclude from: The decoding of the received first-stage SCI was successful, the result of the RSRP measurement performed on the demodulation reference signal (DMRS) on the physical sidelink shared channel (PSSCH) corresponding to the time-frequency resources secured by the received first-stage SCI is greater than the RSRP threshold determined in step 3, and the time-frequency resources secured by the received first-stage SCI are within the resource selection window.

[0126] Step 7: S A If the amount of resources remaining is less than X% of the total resources in the resource selection window, and the value of X% is comprised of the resource pool, then S A Increase the RSRP threshold determined in step 3 until the amount of resources remaining within falls below X% of the total resources in the resource selection window (for example, increase the RSRP threshold by 3 times each time).

[0127] For example, time-frequency resources (r0, r1, r2, ...) are used to transmit data. A A random selection is made from (r0, r1, r2, ...), and a resource re-evaluation is performed on (r0, r1, r2, ...) before data transmission, and after the re-evaluation, S A Preemption detection is performed on the selected resources (r0', r1', r2', ...). The resources (r0', r1', r2', ...) are logical slots.

[0128] The user must have at least slot m-T3(T3=T (proc,1) SL Within this, resource reevaluation and preemption detection are performed, and the UE may trigger resource reevaluation and / or preemption detection before and after slot m-T3, depending on the implementation. Whether (r0, r1, r2, ...) and (r0', r1', r2', ...) need to be excluded is determined based on steps 1 through 7.

[0129] If r1 and / or r1' are in (r0, r1, r2, ...) and (r0', r1', r2', ...), then S A Not belonging to (i.e., r i and r i 'If it is not excluded during re-evaluation and / or preemption detection, respectively, i and / or r i ' is reselected. Slot m is the next slot in which the transmission will be performed, i.e., slot m belongs to (r0, r1, r2, ...) and (r0', r1', r2', ...).

[0130] 6. Channel Busy Ratio (CBR): The channel busy ratio represents the ratio of the number of channels whose sidelink-received signal strength indicator (S-RSSI) exceeds a pre-configured critical value to the total number of channels within a preset measurement period (e.g., 100 slots or 100*2^μ slots). CBR is an indicator for measuring interference. A higher CBR indicates a higher channel busyness, higher system load, and stronger interference between different terminal devices. If a channel's S-RSSI is greater than the pre-configured critical value, it indicates that the channel is occupied. If a channel's S-RSSI is less than or equal to the pre-configured critical value, it indicates that the channel is not occupied. CBRs obtained using different CBR measurement methods may represent the busyness of different types of channels. For example, if a terminal device performs CBR measurements on three types of channels: physical sidelink feedback channel (PSFCH), PSSCH, and physical sidelink control channel (PSCCH) within a preset measurement cycle of 100 slots (or 100 * 2^μ slots), the acquired CBR represents the channel busyness of PSFCH, PSSCH, and PSCCH within the preset measurement cycle. If the terminal device performs CBR measurements on PSFCH, the acquired CBR indicates the busyness of one type of channel, namely PSFCH, within the preset measurement cycle. If the terminal device performs CBR measurements on two types of channels: PSSCH and PSCCH, the acquired CBR indicates the channel busyness of PSSCH and PSCCH within the preset measurement cycle. For detailed procedures on how a terminal device can perform CBR measurements on different channels and acquire CBRs, please refer to related technologies. Further details are not described herein. In the embodiments of this application, μ represents the sequence number of the subcarrier interval.

[0131] 7. LBT: The LBT mechanism is a channel access rule. Before accessing a channel (starting to transmit data), the UE needs to know if that channel is idle. If the channel is idle over a period of time, the UE can occupy that channel. If the channel is not idle, the UE can only occupy that channel after it has been recovered and become idle again.

[0132] Generally, channel status can be determined using energy-based detection and signal type-based detection. For example, NR-U uses energy-based detection, while Wi-Fi uses a combination of the two detection methods. A detection threshold (energy detection threshold) must be set for energy-based detection. When the detected energy exceeds the detection threshold, the channel is determined to be busy and access to that channel is not permitted. When the detected energy is below the detection threshold over a period of time, access to the channel is permitted. According to national and local regulations on the use of unlicensed spectrum, when a 20 MHz channel is accessed, for example, on the 5 GHz frequency band, the 20 MHz channel can only be occupied if the requirement of at least the minimum occupied channel bandwidth (OCB) is met. Generally, the minimum OCB is at least 80% of the normal bandwidth. For example, when the normal bandwidth is 20 MHz, the UE must preempt the 20 MHz channel by occupying at least 16 MHz of bandwidth.

[0133] There are several types of LBTs. The following describes two types of LBTs.

[0134] Type 1 LBT: A communication device can only access a channel and transmit data after performing a random backoff. For example, a user device can only access a channel and transmit data after a first time (T) within the period of a defer sensing time.d The channel may be sensed to be idle over a period of time (as indicated by the sensing slot duration), and after gradually reducing counter N to zero within the sensing slot duration, data transmission may begin. d After that, m p The continuous sensing slot period (T sl This is followed by (as indicated). Specifically, user devices can access the channel based on the following steps.

[0135] Step 1: N=N init Set N init 0 and CW p These are random numbers uniformly distributed among them, and step 2 is performed, where CW p This is the conflict window for channel access priority p (the conflict window for a given priority class).

[0136] Step 2: If N > 0, the network device or terminal device chooses to progressively decrease the counter and set N = N-1.

[0137] Step 3: If the channel is idle during the sensing slot, perform Step 4.

[0138] Otherwise, if the channel is not idle during the sensing slot, perform step 5.

[0139] Step 4: If N=0, stop.

[0140] Otherwise (i.e., if N≠0), perform step 2.

[0141] Step 5: T d Until the channel is detected as busy within a different time range, or until the channel is T d The channel is sensed until it is detected as idle within all sensing slots within a different time range.

[0142] Step 6: Channel is T d If idle is detected within all sensing slots within a different time range, perform step 4.

[0143] Otherwise, the channel is T d If non-idle is detected within all sensing slots within a different time range, perform step 5.

[0144] CW min,p ≤CW p ≤CW max,p , here, CW min,p This is the minimum value of the conflict window for channel access priority p, and CW max,p This is the minimum value of the conflict window for channel access priority p.

[0145] CW min,p and CW max,p This is selected before step 1 mentioned above, m p , CW min,p , and CW max,p This is determined based on the channel access priority class p associated with transmission from the network device or terminal device, as shown in Table 1.

[0146] [Table 1]

[0147] In Table 1, T m cot,p T is the maximum channel occupancy time for a given channel access priority p (the maximum channel occupancy time for a given priority class), and the channel occupancy time (COT) during which a network device or terminal device transmits on the channel is T m cot,pIt does not exceed [a certain value]. In other words, COT is the time in which a communication device is allowed to occupy a channel after successfully accessing it, or the time in which a communication device can preempt the right to use a channel within a time period after completing LBT processing. Channel access processing is performed based on the channel access priority class p associated with the transmission of the network device or terminal device. Smaller values ​​in the priority classes in Table 1 indicate higher priority. For example, priority 1 is the highest priority.

[0148] Network devices or terminal devices are subject to competition windows (CW). p Maintain the value and, before performing step 1, CW based on the following steps p Adjust the value: For each priority in the table, the corresponding CW p =CW min,p Set it.

[0149] In reference subframe k, the hybrid automatic repeat request acknowledgment (HARQ-ACK) value corresponds to the data transmitted by the network device or terminal device. If a negative acknowledgment (NACK) is fed back for at least 80% of the data, the corresponding CW value for each priority is... p The value of is increased to the next highest possible value, which is used in step 2. Otherwise, step 1 is performed. The reference subframe k is the starting subframe for the most recent data transmission from a network device or terminal device on the channel.

[0150] As shown in Figure 3, N is used as an example where it is 6. The user device senses that the channel is the first T d It is determined that it is always in an idle state within the period range of the first T sl In this case, N is gradually reduced from 6 to 5, and the second T slIn this case, N is gradually reduced from 5 to 4. Next, the user device senses that the channel state is busy, and that the channel state is idle, T d After waiting for a period of time that lasts for a certain duration, the third T sl In this case, N is gradually reduced to 3. The user device detects that the channel is busy again, and the channel state is idle, T d After waiting for a period of time that lasts for several hours, the user equipment will then enter the fourth T sl In this case, N is gradually reduced to 2, and the fifth T sl In this case, N is gradually reduced to 1, and the sixth T sl N is gradually reduced to 0. The user device accesses the channel and transmits data within the COT.

[0151] The second type of LBT is LBT without random backoff, and there are two examples of this second type of LBT.

[0152] Case A: A communication device may detect that a channel is idle, and after the idle state persists for a period of time, transmit data without performing a random backoff.

[0153] Case B: Transmission is performed immediately after a short switching gap. For example, a communication device transmits immediately after the switching gap in which the communication device switches from the receiving state to the transmitting state within the COT, and the switching gap time is 16 μs or less.

[0154] As shown in Figure 4, the UE can sense the channel, determine that the channel is idle within a gap, and access the channel at the moment the gap ends.

[0155] The time-domain resources used by the UE to perform LBT processing include one or more sensing time units. For example, one sensing time unit is 9 μs. The UE may sense a channel within a sensing time unit and simultaneously perform random backoff. Note that the length of the sensing time unit is different from the length of the time unit in the time-domain resource used by the UE to transmit data. For example, in an example where a slot is a time unit contained within the time-domain resource used by the UE to transmit data, the length of the time unit is as follows: when the subcarrier interval is 15 kHz, the length of the time unit is 1 ms; when the subcarrier interval is 30 kHz, the length of the time unit is 0.5 ms, and so on.

[0156] In an unlicensed SL system, user devices autonomously compete for transmission resources based on LBT (Least Backoff Time), and UEs that need to transmit data urgently may lose access to transmission resources through competition. For example, UE1 may have a higher data priority, but the transmission resource may have been preempted by another UE. For instance, according to the LBT rule, UE1's random backoff process may not be complete, while the other UE's random backoff process has completed before UE1's. In this scenario, the other UE may have access to the channel first, while UE1 cannot access it. UE1 can only attempt to access the channel again based on LBT after the other UE has completed its data transmission. This fails to meet the quality of service (QoS) requirements for different services on an unlicensed spectrum SL. For example, UE1 may have strict delay requirements for the data to be transmitted, but UE1 cannot acquire the resource through competition. As a result, data cannot be transmitted in a timely manner, and the user experience is severely affected.

[0157] To solve the aforementioned problems, embodiments of this application provide a communication method. According to this method, data can be transmitted in a timely manner to satisfy service requirements. As shown in Figure 5, this method may include the following steps.

[0158] Step 501: The first terminal device receives the first display information from the second terminal device.

[0159] The first display information indicates a first resource, which is a resource reserved by the second terminal device for transmitting the first data. The first resource corresponds to a first COT in the time domain. The first resource is sometimes referred to as the resource reserved by the second terminal device or the reserved COT.

[0160] The first display information may be carried in at least one of the following signalings: first-stage sidelink control information (SCI), second-stage SCI, sidelink media access control control element (SL-MAC CE), or PC5 interface radio resource control (PC5-RRC). For example, the first display information may be carried in only one of the aforementioned signalings. Alternatively, the first display information may be carried in multiple of the aforementioned signalings. For example, the complete content of the first display information may be carried in the SL-MAC CE and in the PC5-RRC signaling. Alternatively, the content of the first display information may be collectively represented by using multiple signalings. For example, part of the content of the first display information may be carried in the first-stage SCI, and another part of the content may be carried in the PC5-RRC signaling. This is not limited to the embodiments of this application.

[0161] It should be understood that the first display information may, as an alternative, be carried in signaling configured by another network device or in pre-configured signaling. For example, the resource reservation period field may indicate a resource that is periodically reserved for data transmission, and the value of the resource reservation period field may be configured by the network device, predefined, or otherwise predefined. For example, a network device may indicate a periodic resource through RRC signaling, which includes periodic information (sl-ResourceReservePeriod1). This is not limited to the present embodiments of this application.

[0162] For example, the first display information is transported within the first stage SCI. In this example, the frequency domain resource assignment field and the time domain resource assignment field within the first stage SCI indicate the frequency domain and time domain resources, respectively, used by the first terminal device to transmit data. After decoding the first stage SCI, the second terminal device may determine the first resources.

[0163] The first display information may indicate the LBT time-frequency start location of the second terminal device. The LBT time-frequency start location can be understood as the start location of the time-frequency resource used by the second terminal device to perform LBT processing. Alternatively, the first display information may indicate the time-frequency start location of the COT secured by the second terminal device.

[0164] When the first display information indicates the LBT time frequency start location of the second terminal device, the second terminal device further needs to provide the first terminal device with LBT parameters, and the first terminal device determines the first resource based on the LBT parameters. It should be understood that the LBT parameters are the LBT parameters of the second terminal device. The LBT parameters of the second terminal device are LBT counters, for example, the total amount of backoff time N init and may include the current value N of the counter. The LBT parameter may further include the LBT channel access priority p.

[0165] LBT parameters may be transported within the second-stage SCI, for example, in SCI format 2-D. The second-stage SCI format may be shown using the first-stage SCI, and possible second-stage SCI format fields are shown in Table 2.

[0166] [Table 2]

[0167] Table 2 should be understood as being used simply as an example rather than an limitation. Some of the contents of Table 2 may be used for implementation, all of the contents of Table 2 may be used for implementation, or Table 2 may be used as part of other contents for implementation. This is not limited to the present embodiments of this application.

[0168] Optionally, the second terminal device may transmit indication information (i.e., third indication information) to the first terminal device, where the indication information indicates that the first terminal device is the destination to which the second terminal device is transmitting data. For example, the indication information may include identification (identification document, ID) of the sender and destination of the data to be transmitted, where the sender ID (sender ID) is the ID of the second terminal device and the destination ID (destination ID) is the ID of the first terminal device. Alternatively, the indication information may include the ID of the second terminal device. Alternatively, the indication information may include the ID of the second terminal device and the ID of the first terminal device. After receiving the indication information, the first terminal device may determine that both the first and second terminal devices are parties to the data transmission.

[0169] Alternatively, the display information may include a temporary user group identifier (temporary UE group ID, abbreviated as group ID below), where the temporary user group is a group predefined by the network device. For example, the network device groups UE1 and UE2 into the same group. Alternatively, the display information may include a cell ID, where the cell may be a cell in which UE1 and UE2 coexist in a geographical sense, where the cell may be a cell obtained through division based on the network device's scheduling range, or where the cell may be a cell predefined by the network device. The first terminal device is further required to receive display information of the same content from the network device. For example, the first terminal device may receive a group ID from the network device and then receive the same group ID from a second terminal device, and the first terminal device may determine that the first and second terminal devices have the same group ID. The network device may predefine that the IDs included in the temporary group are the IDs of both parties to the data transmission. In this case, the first terminal device may determine that both the first terminal device and the second terminal device are parties to the data transmission.

[0170] Alternatively, a network device may pre-configure correspondences between a first terminal device and a second terminal device. For example, a network device may pre-configure a table within the first terminal device of correspondences between the first terminal device and its potential interacting peers. Upon receiving an ID transmitted by the second terminal device, the first terminal device may determine that the second terminal device is the peer interacting with the first terminal device.

[0171] The third indication information may be carried within at least one of the following: first-stage SCI, second-stage SCI, SL-MAC CE, or PC5-RRC signaling. The aforementioned methods for indicating both parties to data transmission are examples, not limitations. For methods of carrying the third indication information, see the related description of the first indication information. Further details will not be provided again.

[0172] The second terminal device is further required to transmit data priority indication information (i.e., fourth indication information) to the first terminal device to indicate the priority of the data to be transmitted by the second terminal device. The priority indication information can be carried in at least one of the following: first-stage SCI, second-stage SCI, SL-MAC CE, or PC5-RRC signaling. For the method of carrying the fourth indication information, please refer to the related description of the first indication information. Further details will not be explained again.

[0173] It should be understood that the first and fourth display information may be transmitted by broadcast, multicast, or unicast. This is not limited to the embodiments of this application.

[0174] Step 502: The first terminal device determines the second resource based on the first display information.

[0175] The first terminal device may determine a second resource based on a first resource indicated by first display information. For example, the first terminal device may determine a second resource based on the time-domain location of the first resource. Specifically, if the first terminal device determines a portion of a resource and the time-domain location of that resource is after the time-domain location of the first resource and does not overlap with the time-domain location of the first resource, that portion of the resource may be the second resource.

[0176] Optionally, the first terminal device may further sense in a first sensing time unit that the state of the first channel is idle and interrupt the listen before talk processing in the first sensing time unit based on the first resource, where the first sensing time unit is earlier than the start time unit of the first resource.

[0177] The first terminal device suspending listen-before-talk processing in a first sensing time unit based on a first resource can be understood as the first terminal device suspending listen-before-talk processing in a first sensing time unit based on the time domain location of the first resource after determining the first resource.

[0178] For example, when the first terminal device receives LBT time-frequency start location and LBT parameter information, the first terminal device needs to determine the time-frequency location of the first resource based on the LBT time-frequency start location and LBT parameter information. For example, the first terminal device needs to determine the total amount N of LBT backoff time. init Based on the current value N of the counter, the first terminal device calculates the period required for the value of the counter in the second terminal device to progressively decrease from N to 0. The first terminal device then determines the LBT time frequency end location based on the LBT time frequency start location and period, where the LBT time frequency end location is the start location (start time unit) of the first resource.

[0179] The interruption of the listen-before-talk process by the first terminal device can be understood as the first terminal device stopping or temporarily suspending the process of accessing the channel. In other words, the first terminal device may not access the channel within the time domain range corresponding to the first resource, or the first terminal device may stop progressively reducing the value of the counter, for example, after progressively reducing the value of the counter from Q to M, the first terminal device may stop the progressive reduction, where 1 ≤ M ≤ Q, and Q is the initial value of the counter.

[0180] Before interrupting the listen-before-talk process, the first terminal device must further determine at least one of the following:

[0181] A. The priority of the data to be transmitted by the second terminal device is higher than the priority of the data to be transmitted by the first terminal device.

[0182] The first terminal device may determine priority relationships based on the fourth display information in step 501 and the data priority of the first terminal device.

[0183] B. The RSRP of the reference signal transmitted by the second terminal device is greater than the RSRP threshold determined by the first terminal device.

[0184] According to the LBT rule, after preempting a channel, the first terminal device allows UEs within a certain RSRP threshold to silence based on the strength of the signal transmitted by the first terminal device. These UEs cannot complete the LBT backoff process because they detect that the channel is busy. A low RSRP of a UE indicates a long distance between the UE and the first terminal device. After the first terminal device shares resources with the second terminal device, the second terminal device's low RSRP prevents another device closer to the first terminal device from silencing. As a result, the channel may be occupied by another device. Therefore, when the RSRP of a reference signal transmitted by the second terminal device is greater than the RSRP threshold determined by the first terminal device, data cannot be transmitted normally.

[0185] The second terminal device may transmit a reference signal to the first terminal device. For example, the reference signal may be carried within the first stage SCI, and the reference signal may be a PSCCH DMRS. Alternatively, the reference signal may be a reference signal on a PSSCH, for example, a PSSCH DMRS. The first terminal device obtains the received power of the reference signal by measuring the first stage SCI. For determining the RSRP threshold, see the relevant explanation in SL mode 2. Further details will not be explained again.

[0186] C. The start time unit of the first resource is later than the start time unit of the resource that will be preempted by the first terminal device.

[0187] The resources to be preempted by the first terminal device can be understood as the time-frequency resources that will be occupied by the first terminal device after the first terminal device has completed backoff based on the current LBT processing. As shown in Figure 6(a), the resources to be preempted by the first terminal device are T UE1S and T UE1EThese are time-frequency resources during that period.

[0188] D. The period between the start time unit of the first resource and the first sensing time unit where the counter value is M is less than or equal to the first threshold, where 1 ≤ M ≤ N, and N is the value of the counter when the gradual reduction is interrupted.

[0189] The first threshold may be greater than zero and less than the delay required by the data to be transmitted by the first terminal device. In other words, there is an upper limit to the period during which the first terminal device stops progressively reducing the counter. That is, the first terminal device decides to interrupt progressive reduction if the period during which progressive reduction is interrupted is less than or equal to the upper limit, and the value of the counter at the time of the interruption does not need to be considered. In other words, the moment the first terminal device decides to interrupt progressive reduction may be the moment when the value of the counter is greater than zero and the upper limit is met. The first threshold may be a value configured by the network device, a pre-configured value, or a fixed value predefined in a standard protocol. This is not limited to the present embodiments of this application.

[0190] The first terminal device ceasing to progressively reduce the counter can be understood as the first terminal device ceasing to progressively reduce the counter from an instant, and the counter value remains the value of the counter before the progressive reduction. In addition, the minimum value of the counter is limited to 1. According to the LBT rule, this means that the first terminal device cannot access the channel and transmit data.

[0191] The first sensing time unit where the counter value is M is the sensing time unit (i.e., the first sensing time unit) in which the moment when the reduction begins is located. For example, the gradual reduction is interrupted within sensing time unit 1, and the counter value is 2 in this case. Start of the first resource timePrior to the unit, there are further sensing time units 2 and 3, where the counter values ​​in sensing time unit 2 and sensing time unit 3 are always 2. In this example, the first sensing time unit with a counter value of 2 is sensing time unit 1. Please understand that the values ​​and indices mentioned above are merely examples and not limitations.

[0192] Please understand that the first terminal device will need to successfully decode the first stage SCI.

[0193] Optionally, the first terminal device may further determine, based on the third display information, that the second terminal device is the destination to which the first terminal device transmits information (data).

[0194] Optionally, the first terminal device may further determine the CBR of the first channel. When the CBR is below a third threshold, the first terminal device may interrupt the LBT processing. The CBR represents the busyness of the first channel within a first preset period. For example, the first preset period is a preset measurement cycle, e.g., 100 slots, 100 T sl , or 100 T d (or 100*2 μ Slot / T sl / T d ) is possible.

[0195] Alternatively, the first terminal device has a preset measurement cycle, for example, 100 T sl (T d ) or 100*2 μ Individual T sl (T d In this case, if the energy detection result is greater than the energy detection threshold T sl (T d ) the amount of T sl (T d The ratio of the total amount of ) can be determined, where the energy detection threshold is X Thresh This is possible. Channel energy detection result or Tsl (T d ) is greater than the energy detection threshold, it indicates that the channel or T sl (T d ) is occupied. If the energy detection result of the channel is below the energy detection threshold, it indicates that the channel or T sl (T d ) is not occupied. When the ratio is below the third threshold, the first terminal device may interrupt the LBT process.

[0196] The third threshold may be predefined. For example, the third threshold may be 20%. This is not limited in the present embodiment of this application. In the time domain, it should be understood that the first preset period or preset measurement period is before the slot where the moment when the first terminal device interrupts the LBT process is located at that time.

[0197] Optionally, the first terminal device may further perform re - evaluation or pre - emption detection on the resource. For example, after the sensing window, the first terminal device may perform re - evaluation or pre - emption detection on the time - domain resource before the second terminal device accesses the channel. For example, the first terminal device determines that r i and / or r i ’ belongs to / does not belong to S A (that is, r i and r i ’ are respectively excluded during re - evaluation and / or pre - emption detection / Not excluded ). In this case, r i and / or r i ’ may be determined to be used by the second terminal device to transmit data. Before performing re - evaluation or pre - emption detection, the first terminal device may determine the sensing window, selection window, and reference signal reception power threshold, and initialize the available resource set. For details, refer to the description of steps 1 to 4 of SL mode 2. Details will not be described again.

[0198] The aforementioned channel can be understood as a bandwidth. For example, in an unlicensed SL communication system, there may be multiple access channels with a bandwidth of 20 MHz, and the UE may perform LBT access separately for each 20 MHz channel, with the channel access processing being independent of each other. After completing LBT, the UE occupies the corresponding 20 MHz bandwidth. It should be understood that 20 MHz is merely an example of a channel, and not an limitation, in this embodiment of the application. For example, the channel in this embodiment of the application may be a different bandwidth, such as 30 MHz, 40 MHz, or 45 MHz.

[0199] Step 503: The first terminal device transmits data on the second resource.

[0200] The start time unit of the second resource is later than the end time unit of the first resource. As shown in Figure 6(b), T* UE1S is T UE2E This occurs after the second terminal device has finished transmitting data. In other words, the first terminal device accesses the channel and transmits data after the second terminal device has finished transmitting data. It should be understood that the first terminal device will either defer or avoid channel access, thereby sparing the use of resources reserved by the second terminal device.

[0201] The first threshold in step 502 may be determined based on the duration of the second resource. For example, the first threshold may be 1 / 10, 1 / 8, or the duration of the second resource.

[0202] A possible implementation of the first terminal device accessing the second resource is as follows: The first terminal device determines in the second sensing time unit that the channel state is idle and continues to progressively decrement the counter, where the second sensing time unit is later than the end time unit of the first resource, and the first terminal device progressively decrements the counter to 0 in the start time unit within the second resource, accesses the channel and transmits data.

[0203] The continuous progressive reduction of the counter means that the value of the counter at the start of this progressive reduction is the value of the count when the progressive reduction is interrupted in step 502. For example, in step 502, the value of the counter when the progressive reduction is interrupted is 2, and the value of the counter is then progressively reduced from 2 to 0. It should be understood that this value is merely an example and not an exhaustive one. According to the LBT rule, the progressive reduction of the counter to 0 means that the first terminal device has accessed the channel and transmitted data.

[0204] Alternatively, the first terminal device may determine that the channel is idle during a time period and access the channel. The duration of this time period may be 16 μs, for example. For further details, please refer to the description of second-type listen-before-talk. Further details will not be explained again.

[0205] Optionally, the first terminal device may perform further sensing at the start time unit of the first resource to determine whether the second terminal device has successfully accessed the channel. If the second terminal device has successfully accessed the channel, the first terminal device accesses the channel and transmits data as in step 503. Otherwise, the first terminal device continues the LBT process directly and accesses the channel after the LBT process is complete.

[0206] It should be understood that the transmission of data on the first channel by the first terminal device can be understood as an example of sidelink transmission performed by the first terminal device on the first channel. The first terminal device may transmit or receive sidelink control information and / or feedback information, etc., on the first channel.

[0207] In this method, devices that can preempt resources can avoid them within the time domain, and devices with higher data priority can transmit data in a timely manner on the reserved resources. This satisfies service requirements and significantly improves the user experience.

[0208] Embodiments of this application provide a communication method. As shown in Figure 7, it is used as an example that first display information and fourth display information are transported within a first-stage SCI, where UE1 is an example of a first terminal device, UE2 is an example of a second terminal device, COT1 is an example of a first resource, COT2 is an example of a second resource, SCI#A is an example of a first-stage SCI, and SCI#B is an example of a second-stage SCI. The method may include the following steps.

[0209] Step 701: UE2 sends SCI#A to UE1, and in response, UE1 receives SCI#A.

[0210] SCI#A is carried over the PSCCH. SCI#A includes resource indication information, data priority information, reference signals, and the format of SCI#B. Specifically, see the related descriptions of the first and fourth indication information in step 501. Further details will not be explained again.

[0211] Step 702: UE2 sends SCI#B to UE1, and in response, UE1 receives SCI#B.

[0212] SCI#B is transported on PSSCH. SCI#B contains the LBT parameters for UE2.

[0213] Step 703: UE1 determines COT1 based on SCI#A and SCI#B.

[0214] Step 704: UE1 determines that the avoidance condition is met.

[0215] For the conditions to avoid, please refer to the related explanations of A, B, C, and D in Step 502. Further details will not be explained again.

[0216] Optionally, UE1 may perform resource reassessment or preemption detection. See the explanation in step 502 for details. Further details will not be explained again.

[0217] Step 705: UE1 stops progressively decreasing the counter in sensing time unit #A.

[0218] For example, when the gradual reduction is interrupted, the counter value is 3. For step 703, see the related explanation in step 502. Further details will not be explained again.

[0219] Step 706: UE2 accesses the Channel in the start time unit of COT1.

[0220] Step 707: UE1 performs sensing at the start time unit of COT1 and determines that the channel state is busy.

[0221] Step 708: UE1 determines that the channel state is idle in sensing time unit #B and continues to progressively decrease the counter until it progressively decreases to 0 in the start time unit of COT2.

[0222] For example, UE1 progressively reduces the counter from 3. For step 707, see the related explanation in step 503. Further details will not be explained again.

[0223] Step 709: UE1 sends data within COT2.

[0224] Before step 701, it should be understood that UE1 may determine the sensing window and selection window and select a resource. Details are not described herein. For specific steps, please refer to the above description of steps 1 through 7 of Mode 2 (SL Mode 2).

[0225] In this method, when the avoidance condition is met, UE1 interrupts the LBT backoff process, does not access the channel, waits for UE2 to access the channel and transmit data, and then accesses the channel and transmits data after UE2 has finished transmitting data. In this way, UE2's data can be transmitted in a timely manner. This satisfies the service requirements.

[0226] In the method described above, a device that can preempt a resource can perform avoidance, and data of higher priority can be transmitted in a timely manner. Embodiments of this application provide another communication method. A device that has preempted a resource shares that resource with a device that should transmit data, and the data can be transmitted normally. The method is described in detail below. As shown in Figure 8, the method may include the following steps.

[0227] Step 801: The first terminal device receives the first display information from the second terminal device.

[0228] The first display information indicates a first resource, which is a resource reserved by the second terminal device for transmitting the first data. For details of the first display information, please refer to the description of the first display information and the first resource in step 501. Further details will not be described again in this specification.

[0229] The relationship between the first terminal device and the second terminal device can be divided into two cases.

[0230] Example 1: The first terminal device is the destination to which the second terminal device transmits data.

[0231] In this example, the second terminal device needs to transmit display information (i.e., third display information) to the first terminal device, where the display information indicates that the first terminal device is the destination to which the second terminal device will transmit data. For example, the display information may include identification (identification document, ID) of the sender and destination of the data to be transmitted, where the sender's ID (sender ID) is the ID of the second terminal device, and the destination's ID (destination ID) is the ID of the first terminal device. Alternatively, the display information may include the ID of the second terminal device. Alternatively, the display information may include the ID of the second terminal device and the ID of the first terminal device. After receiving the display information, the first terminal device may determine that both the first and second terminal devices are parties to the data transmission.

[0232] Alternatively, the display information may include a temporary user group identifier (temporary UE group ID, abbreviated as group ID below), where the temporary user group is a group predefined by the network device. For example, the network device groups UE1 and UE2 into the same group. Alternatively, the display information may include a cell ID, where the cell may be a cell in which UE1 and UE2 coexist in a geographical sense, where the cell may be a cell obtained through division based on the network device's scheduling range, or where the cell may be a cell predefined by the network device. The first terminal device is further required to receive display information of the same content from the network device. For example, the first terminal device may receive a group ID from the network device and then receive the same group ID from a second terminal device, and the first terminal device may determine that the first and second terminal devices have the same group ID. The network device may predefine that the IDs included in the temporary group are the IDs of both parties to the data transmission. In this case, the first terminal device may determine that both the first terminal device and the second terminal device are parties to the data transmission.

[0233] Alternatively, a network device may pre-configure correspondences between a first terminal device and a second terminal device. For example, a network device may pre-configure a table within the first terminal device of correspondences between the first terminal device and its potential interacting peers. Upon receiving an ID transmitted by the second terminal device, the first terminal device may determine that the second terminal device is the peer interacting with the first terminal device.

[0234] The third indication information may be carried within at least one of the following: Stage 1 SCI, Stage 2 SCI, SL-MAC CE, or PC5-RRC signaling. For Stage 2 SCI, see the relevant description in Step 501. It should be understood that the aforementioned methods of indicating both parties to data transmission are examples only, and not limiting.

[0235] Case 2: The first terminal device and the second terminal device are not both parties to the data transmission.

[0236] In this example, the first terminal device does not need to determine whether the second terminal device is the peer for data transmission. Optionally, the first terminal device may receive data priority indicator information (i.e., the fourth indicator information) from the second terminal device, and the first terminal device may determine that the priority of the data transmitted by the second terminal device is greater than or equal to the priority of the data transmitted by the first terminal device. For details regarding the fourth indicator information, please refer to the relevant explanation in step 501. Further details will not be explained again.

[0237] Optionally, the first terminal device further receives a reference signal from the second terminal device, and the first terminal device determines that the power required to receive the reference signal is equal to or greater than the reference signal reception power threshold. For details, please refer to the relevant explanation in Content B of Step 502. Further details will not be explained again.

[0238] Step 802: The first terminal device determines the third resource based on the first resource and the first channel occupancy time.

[0239] The first channel occupancy time (COT) is a time-domain resource corresponding to a fifth resource in the time domain, where the fifth resource is a resource preempted by the first terminal device. For example, if the first terminal device accesses the channel (transmits data) earlier than the second terminal device, the channel usage period that the first terminal device is allowed to occupy is the first channel occupancy time. Within the first COT, the first terminal device may transmit data by using a time-frequency resource (the fifth resource). In other words, the first terminal device determines the third resource based on the first and fifth resources.

[0240] The third resource is used by the second terminal device to transmit data, and the third resource belongs to the first resource and the first channel occupancy time. Since the start moment (start time unit) of the first channel occupancy time is earlier than the start moment (start time unit) of the first resource, the fact that the third resource belongs to the first resource and the first channel occupancy time can be understood as the third resource belonging to the intersection or overlap between the first resource and the first channel occupancy time. In other words, the third resource belongs to the overlap between the first resource and the fifth resource. The third resource can be an overlap between the first resource and the first channel occupancy time, that is, the resource corresponding to the third resource in the time domain can be understood as the intersection between the resource corresponding to the first resource in the time domain and the first channel occupancy time. Alternatively, the third resource may be part of the overlap between the first resource and the first channel occupancy time; that is, the resource corresponding to the third resource in the time domain falls within the intersection of the resource corresponding to the first resource in the time domain and the first channel occupancy time.

[0241] After optionally determining a third resource, the first terminal device transmits second display information to the second terminal device, where the second display information indicates the third resource. Furthermore, the first terminal device transmits second display information to the second terminal device within a first time period, where the start moment of the first time period falls within the range between the start time unit of the fourth resource and the start time unit of the third resource, and the period between the start moment of the first time period and the start time unit of the fourth resource is greater than or equal to a second threshold. For example, the second threshold is T proc,0 This may be the case, meaning that the first terminal device must provide the second terminal device with information about the third resource before the start time unit of the third resource.

[0242] In other words, in Example 1 of Step 801, the first terminal device needs to determine at least one of the following:

[0243] E: The first terminal device is the destination side where the second terminal device secures resources for transmission. F: The start location of the first resource is after the start location of the fifth resource, and the first resource overlaps with the fifth resource, and G: The first terminal device has sufficient time to transmit the second display information.

[0244] In Case 2 of Step 801, the first terminal device needs to determine at least one of the following.

[0245] H: The priority of the data to be transmitted by the second terminal device is higher than the priority of the data to be transmitted by the first terminal device. I: The start location of the first resource is after the start location of the fifth resource, and the first resource overlaps with the fifth resource. J: The first terminal device has sufficient time to transmit the second display information, and K: The RSRP of the first resource is greater than the RSRP threshold.

[0246] It should be understood that the first terminal device further needs to successfully decode the first-stage SCI.

[0247] According to the LBT rule, after pre-empting the channel, the first terminal device enables silent operation based on the strength of the signal transmitted by the first terminal device for UEs within a specific RSRP threshold range. These UEs cannot complete the LBT back-off process because they detect that the channel is busy. When the RSRP of a UE is low, it indicates that the distance between the UE and the first terminal device is long. After the first terminal device shares resources with the second terminal device, the second terminal device cannot enable another device closer to the first terminal device to become silent due to the low RSRP of the second terminal device. As a result, the channel can be occupied by another device, the second terminal device cannot transmit data, and the first terminal device cannot re-access the channel. Therefore, when the RSRP of the reference signal transmitted by the second terminal device is greater than the RSRP threshold determined by the first terminal device, data cannot be transmitted normally. Specifically, refer to content B in step 502. Details will not be described again.

[0248] Optionally, the first terminal device may perform resource re-evaluation or pre-emption detection. For details, refer to the description of step 502. Details will not be described again.

[0249] The second display information may be carried in at least one of the first-stage SCI, second-stage SCI, SL-MAC CE, or PC5-RRC signaling. Specifically, for the method of carrying the second display information, refer to the relevant description of the first display information. Details will not be described again.

[0250] Step 803: The first terminal device transmits the first data on the fourth resource, where the fourth resource belongs to a resource other than the third resource within the first channel occupancy time.

[0251] The fourth resource belongs to the resources within the fifth resource other than the third resource, which can be understood as meaning that the fourth resource can be any resource within the fifth resource other than the third resource, or that the fourth resource can be part of the resources within the fifth resource other than the third resource.

[0252] It can be further understood that if the start moment (start time unit) of the third resource is later than the start moment of the fifth resource, it means that the first terminal device has transmitted part of the data on the resource prior to the third resource. After the second terminal device has completed transmitting data on the third resource, the first terminal device re-accesses the channel and transmits data on the resource after the third resource. Before accessing the channel, the first terminal device may sense the channel. For example, if it is determined that the channel is idle in a time period, the first terminal device may access the channel. See the description of the second type listen-before-talk for further details. Further details will not be described again. Alternatively, the first terminal device may access the channel within a time period based on the first type listen-before-talk. This is not limited to the present embodiments of this application.

[0253] In a possible implementation, the fourth resource belonging to a resource other than the third resource within the first channel occupancy time can be understood as the fourth resource being a frequency domain resource other than the frequency domain resource corresponding to the third resource within the first channel occupancy time; that is, the first and second terminal devices simultaneously transmit data on the time domain resource corresponding to the third resource, but the frequency domain resources used by the first and second terminal devices to transmit data do not overlap.

[0254] In this method, a device that preempts a resource shares that resource with a device that has a higher data priority, or shares that resource with a device that is the sender for data transmission to the device that preempted the resource. High stomach data Priority devices can transmit data in a timely manner. This meets service requirements and improves the user experience.

[0255] Embodiments of this application provide a communication method. As shown in Figure 9, an example is used in which first display information, third display information, and fourth display information are carried within a first-stage SCI, where UE1 is an example of a first terminal device, UE2 is an example of a second terminal device, COT1 is an example of a first resource, COT3 is an example of a third resource, COT4 is an example of a fourth resource, COT5 is an example of a fifth resource, SCI#C is an example of a first-stage SCI, and SCI#D is an example of a second-stage SCI. It should be understood that the duration of one COT includes the period for transmitting PSCCH and the period for transmitting PSSCH. The method may include the following steps.

[0256] Step 901: UE2 sends SCI#C to UE1, and in response, UE1 receives SCI#C.

[0257] SCI#C is carried over PSCCH. SCI#C is the first stage SCI. SCI#C includes resource indication information, a reference signal, and the format of SCI#D. Specifically, for resource indication information, see the relevant description of the first indication information in step 801. For reference signals and the format of SCI#D, see the relevant description in step 801. Further details will not be explained again.

[0258] Optionally, if UE2 and UE1 are not both parties to data transmission at this time, SCI#C may include the priority of the data to be transmitted by UE2.

[0259] Step 902: UE2 sends SCI#D to UE1, and in response, UE1 receives SCI#D.

[0260] SCI#D is transported on PSSCH. SCI#D is the second stage SCI. SCI#D includes the LBT parameters of UE2.

[0261] When UE2 and UE1 are both parties to the data transmission at this time, SCI#D further includes the ID of UE2 and the ID of UE1. For details on these IDs, see the description of the third display information in step 801. For details on SCI#D, see the description of the second stage SCI in step 501. Further details will not be explained again.

[0262] If UE2 and UE1 are not both parties to the data transmission at this time, SCI#D does not need to include the IDs of UE2 and UE1.

[0263] Optionally, UE1 may perform resource reassessment or preemption detection. For example, UE1 may perform resource reassessment from T1 to T proc,1 SL Resource reassessment or preemption detection may be performed up to this point. See the explanation in step 502 for details. Further details will not be explained again.

[0264] Step 903: UE1 sends data within COT5.

[0265] As shown in Figure 10, UE1 accesses the channel (sends data) at T1. The resource between T1 and T2 in Figure 10 is the fifth resource in step 802.

[0266] Step 904: UE1 determines COT1 based on SCI#C and SCI#D.

[0267] As shown in FIG. 10, COT1 is the period between T3 and T4. Specifically, for COT1, please refer to the description of the first resource in step 802. Details will not be described again. In other words, the resource between T3 and T4 is the first resource in step 801.

[0268] Step 905: UE1 determines that the avoidance condition is satisfied.

[0269] When UE2 and UE1 are both parties at this time of data transmission, for the avoidance condition, please refer to the relevant descriptions of E, F, and G in step 802. When UE2 and UE1 are not both parties at this time of data transmission, for the avoidance condition, please refer to the relevant descriptions of H, I, J, and K in step 802. Details will not be described again.

[0270] Step 906: UE1 transmits the second display information to UE2.

[0271] As shown in FIG. 10, UE1 transmits the second display information to UE2 between T5 and T6. The second display information indicates COT3. For example, the second display information may include the start location T8 of COT3 and the length L of COT3. Alternatively, the second display information may include the start location T8 of COT3 and the end location T9 of COT3.

[0272] Step 907: UE1 stops data transmission at T7.

[0273] Step 908: UE2 determines that the channel state between T7 and T8 is idle.

[0274] Optionally, UE2 may determine that the channel state between T7 and T8 is idle based on the second type listen before talk mechanism.

[0275] Step 909: UE2 starts transmitting data at T8.

[0276] As shown in Figure 10, UE2 transmits data between T8 and T9. In other words, the resource between T8 and T9 is the third resource in step 802.

[0277] Step 910: UE1 determines that the channel state between T9 and T10 is idle.

[0278] Optionally, UE1 may determine that the channel state between T9 and T10 is idle based on a second-type listen-before-talk mechanism.

[0279] Step 911: UE1 starts transmitting data at T10.

[0280] Optionally, as shown in Figure 10, UE1 may terminate data transmission at T2, i.e., the resources between T1 and T7 and the resources between T10 and T2 are the fourth resources in step 803.

[0281] Before step 901, it should be understood that UE1 may determine the sensing window and selection window and select a resource (COT5). Details are not described herein. For specific steps, please refer to the above description of steps 1 to 7 of Mode 2 (SL Mode 2). It should be further understood that Figure 10 is intended to illustrate relationships in the time domain, and the multiple COTs in the figure are drawn separately simply for clarity, and no distinction in the frequency domain is necessary.

[0282] In this method, UE1, which has preempted resources, functions as a receiver for UE2, or when UE2's data priority is higher than UE1's, UE1 shares part or all of the preempted resources with UE2, allowing UE2 to transmit data in a timely manner. This satisfies service requirements and improves communication efficiency.

[0283] In the methods shown in Figures 5 to 10, the resources preempted by the first terminal device and the resources reserved by the second terminal device are on the same channel. Alternatively, the resources preempted by the first terminal device and the resources reserved by the second terminal device may be on different channels, or some frequency domain resources within the resources reserved by the second terminal device may be on the same channel as the resources preempted by the first terminal device, while other frequency domain resources reserved by the second terminal device are on different channels. This is not limited to the present application.

[0284] Embodiments of this application provide a communication method. As shown in Figure 11, it is used as an example that first display information and fourth display information are transported within a first-stage SCI, where UE1 is an example of a first terminal device, UE2 is an example of a second terminal device, COT1 is an example of a first resource, COT2 is an example of a second resource, SCI#E is an example of a first-stage SCI, and SCI#F is an example of a second-stage SCI. The method may include the following steps.

[0285] Step 1101: UE2 sends SCI#E to UE1, and in response, UE1 receives SCI#E.

[0286] SCI#E is carried over PSCCH. SCI#E includes resource indication information, data priority information, reference signals, and the format of SCI#F. Specifically, see the related descriptions of the first and fourth indication information in step 501. Further details will not be explained again.

[0287] Step 1102: UE2 sends SCI#F to UE1, and in response, UE1 receives SCI#F.

[0288] SCI#F is transported on PSSCH. SCI#F contains the LBT parameters of UE2.

[0289] Step 1103: UE1 determines the first resource based on SCI#E and SCI#F.

[0290] As shown in Figure 12, the first resource is a time-frequency resource on channel #3 within the range of COT1, and the time length between T1 and T2 is the time length of COT1.

[0291] Step 1104: Determine that the avoidance conditions are met.

[0292] In addition to A, B, C, and D in step 502, the avoidance conditions in this step further include: the amount of remaining available channels in UE1 is threshold T. th That is all. The remaining available channel amount may be the amount of channels occupied by UE1 other than the channels where the resources reserved by UE2 are located, with threshold T'. th This can be determined by the total amount of channels occupied by UE1. For example, as shown in Figure 12, UE1 preempts three channels, channel #1, channel #2, and channel #3. The resources reserved by UE2 are on channel #1, and threshold T' thIt is assumed that the threshold is 1, and the remaining available channels for UE1 are 2, which is greater than the threshold. In this case, UE1 may avoid channel #1 for UE2 to send data, and channels #2 and #3 may be used by UE1 to send data.

[0293] Optionally, UE1 may perform resource reassessment or preemption detection. See the explanation in step 502 for details. Further details will not be explained again.

[0294] Step 1105: UE1 transmits data on channels #2 and #3.

[0295] Specifically, as shown in Figure 12, UE1 transmits data on channels #2 and #3 of the time-frequency resource within the range of COT2, and the time length between T3 and T4 is the time length of COT2.

[0296] Step 1106: UE2 sends data on channel #1.

[0297] Specifically, UE2 transmits data on channel #1 of the time-frequency resource within the range of COT1.

[0298] In this method, UE1 preempts multiple channels, and when a resource reserved by UE2 lies on one of the channels preempted by UE1, UE1 can bypass that channel and transmit data on another available channel, which is then used by UE2 to transmit data, allowing UE2's data to be transmitted in a timely manner. This satisfies service requirements and improves communication efficiency.

[0299] The embodiments described herein may be independent solutions or may be combined based on internal logic. All of these solutions fall within the scope of protection of this application. It should be understood that the steps of the embodiments described above are merely intended to clearly illustrate the technical solutions of the embodiments, and the order in which the steps are performed is not limited.

[0300] In the embodiments provided in this application, the methods provided in the embodiments of this application are described in terms of device-to-device interaction. To implement the functionality of the methods provided in the embodiments of this application, a network device or terminal device may include a hardware structure and / or software modules, and the aforementioned functionality may be implemented in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module. Whether the functionality within the aforementioned functionality is implemented using a hardware structure, a software module, or a combination of a hardware structure and a software module depends on the design constraints of the particular application and technical solution.

[0301] In embodiments of this application, the division into modules is illustrative and merely a logical functional division. Other division methods may be used in actual implementations. In addition, the functional modules in embodiments of this application may be integrated into a single processor, exist physically independently, or consist of two or more modules integrated into a single module. The integrated module may be implemented in hardware form or in the form of a software functional module.

[0302] The following describes in detail the communication device provided in the embodiments of this application with reference to Figures 13 and 14. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment. Therefore, for matters not described in detail, please refer to the method embodiment. For brevity, further details are not described herein.

[0303] Similar to the concept described above, as shown in Figure 13, embodiments of the present application further provide a device 1300 configured to implement the functionality of a session management function network element in the method described above. For example, the device may be a software module or a chip system. In these embodiments of the present application, the chip system may include a chip or include a chip and other discrete components. The device 1300 may include a processing unit 1310 and a communication unit 1320.

[0304] In this embodiment of the present application, the communication unit may also be called a transceiver unit and may include a transmitting unit and / or a receiving unit, which are configured to perform the transmitting and receiving steps by the session management function network element in the method embodiment described above.

[0305] The communication unit may also be called a transceiver, transceiver device, or transceiver equipment. The processing unit may also be called a processor, processing board, processing module, or processing unit. Optionally, any component located within the communication unit 1320 and configured to implement a receiving function may be considered a receiving unit, and any component located within the communication unit 1320 and configured to implement a transmitting function may be considered a transmitting unit. In other words, the communication unit 1320 includes receiving units and transmitting units. The communication unit may sometimes be called a transceiver device, transceiver, or interface circuit. The receiving unit may sometimes be called a receiver device, receiver, or receiving circuit. The transmitting unit may sometimes be called a transmitter device, transmitter, or transmitting circuit.

[0306] When the communication device 1300 performs the function of the first terminal device in the procedure shown in any one of Figures 5 to 11 in the above-described embodiment, The communication unit may be configured to receive sidelink control information and transmit data. The processing unit may be configured to parse sidelink control information, determine the transmission resource, determine the first channel occupancy status, determine whether avoidance conditions are met, and / or perform LBT processing, among other things.

[0307] When the communication device 1300 performs the function of the second terminal device in the procedure shown in any one of Figures 5 to 12 in the above-described embodiment, The communication unit may be configured to transmit sidelink control information, receive second display information, and / or transmit data. The processing unit may be configured to perform tasks such as determining the transmission resource and performing LBT processing.

[0308] The foregoing is merely an example. The processing unit 1310 and the communication unit 1320 may perform other functions. For a more detailed explanation, please refer to the method embodiments shown in Figures 5 to 12 or other relevant descriptions in method embodiments. Further details are not described herein.

[0309] Figure 14 shows an apparatus 1400 according to an embodiment of the present application, which may be a hardware circuit implementation. The communication apparatus is applicable to the flowchart described above and performs the functions of a terminal device or network device in the method embodiment described above. For ease of explanation, Figure 14 shows only the main components of the communication apparatus.

[0310] The communication device 1400 may be a terminal device that can implement the functions of the first or second terminal device in the method provided in the embodiments of this application. Alternatively, the communication device 1400 may be a device that can support the first or second terminal device in implementing the corresponding functions in the method provided in the embodiments of this application. The communication device 1400 may be a chip system. In these embodiments of this application, the chip system may include a chip, or include a chip and other discrete components. For specific functions, see the description in the method embodiments above.

[0311] The communication device 1400 includes one or more processors 1410 configured to implement or support the communication device 1400 in implementing the functions of the first or second terminal device in the method provided in the embodiments of this application. For further details, see the detailed description in the example method. Further details are not described again herein. The processors 1410 may also be called processing units or processing modules and may implement specific control functions. The processors 1410 may be general-purpose processors or dedicated processors. For example, the device may include a central processing unit, an application processor, a modem processor, a graphics processing unit, an image signal processor, a digital signal processor, a video codec processor, a controller, memory, and / or a neural network processor. The central processing unit may be configured to control the communication device 1400, execute software programs, and / or process data. Different processors may be independent components or may be integrated into one or more processors, for example, integrated into one or more application-specific integrated circuits. The processor in this embodiment of the application may be a central processing unit (CPU), or it may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or another programmable logic device, a transistor logic device, a hardware component, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0312] Optionally, the communication device 1400 includes one or more memories 1420 configured to store instructions 1440. Instructions may be executed on the processor 1410 to enable the communication device 1400 to carry out the methods described in the above-described method embodiments. The memory 1420 is coupled to the processor 1410. The coupling in this embodiment of the application may be an indirect coupling, or a communication connection between devices, units, or modules in electrical, mechanical, or other forms, used for information exchange between devices, units, or modules. The processor 1410 may cooperate with the memory 1420. At least one of the at least one memory may be included in the processor. Note that the memory 1420 is not mandatory. Therefore, the memory 1420 is indicated by the use of a dashed line in Figure 14.

[0313] Optionally, memory 1420 may store further data. The processor and memory may be disposed separately or integrated together. In this embodiment of the application, memory 1420 may be non-volatile memory, such as a hard disk drive (HDD) or solid-state drive (SSD), or volatile memory, such as random access memory (RAM). Alternatively, the memory in this embodiment of the application may be flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, removable hard disks, CD-ROMs, or any other form of storage medium well known in the art. For example, the storage medium may be coupled to a processor, which may read information from and write information to the storage medium. Of course, storage media can be components of a processor. Processors and storage media can be located within an ASIC. In addition, ASICs can reside within network devices or terminal devices. Of course, alternatively, processors and storage media can exist as discrete components within network devices or terminal devices.

[0314] Memory is any other medium that can carry or store expected program code in the form of instructions or data structures, and is accessible by a computer. Alternatively, memory in this embodiment of the application may be a circuit or any other device that can implement a storage function and is configured to store program instructions and / or data.

[0315] Optionally, the communication device 1400 may include instructions 1430 (sometimes called code or program) which may be executed on the processor to enable the communication device 1400 to perform the methods described in the above embodiments. The processor 1410 may store data.

[0316] Optionally, the communication system 1400 includes a transceiver 1450 and an antenna. 1460 It may also include the following: The transceiver 1450 may also be called a transceiver unit, transceiver module, transceiver device, transceiver circuit, transceiver, input / output interface, etc., and an antenna 1460 The communication device 1400 is configured to implement receiving and transmitting functions through this.

[0317] The processor 1410 and transceiver 1450 described herein may be implemented in integrated circuits (ICs), analog ICs, radio frequency identification (RFID) integrated circuits, mixed-signal ICs, ASICs, printed circuit boards (PCBs), electronic devices, etc. The communication devices described herein may be standalone devices (e.g., standalone integrated circuits or mobile phones) or part of larger devices (e.g., modules that may be incorporated into another device). For further details, see the preceding descriptions of terminal devices and network devices. Further details are not described herein again.

[0318] Optionally, the communication device 1400 may further include one or more of the following components: a wireless communication module, an audio module, an external memory interface, internal memory, a universal serial bus (USB) interface, a power management module, an antenna, a speaker, a microphone, an input / output module, a sensor module, a motor, a camera, a display, etc. In some embodiments, the communication device 1400 may include more or fewer components, and it may be understood that some components are integrated or some components are split. These components may be implemented by hardware, software, or a combination of software and hardware.

[0319] Those skilled in the art will understand that embodiments of this application may be provided as methods, systems, or computer program products. Accordingly, this application may take the form of hardware-only embodiments, software-only embodiments, or embodiments of a combination of software and hardware. Furthermore, this application may take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk memory, optical memory, etc.) containing computer-usable program code.

[0320] This application is described with reference to flowcharts and / or block diagrams of the methods, devices (systems), and computer program products described herein. It should be understood that computer program instructions may be used to implement each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams. These computer program instructions may be provided to a processor of a general-purpose computer, a dedicated computer, an embedded processor, or any other programmable processing device for generating machines, and instructions executed by a computer or processor of any other programmable data processing device will generate a device for implementing a particular function in one or more processes in the flowchart and / or one or more blocks in the block diagram.

[0321] These computer program instructions can be stored in computer-readable memory, which can instruct a computer or any other programmable data processing device to work in a specific manner. Instructions stored in computer-readable memory generate artifacts, including instruction units. Instruction units implement specific functions within one or more processes in a flowchart and / or within one or more blocks in a block diagram.

[0322] It will be apparent to those skilled in the art that various modifications and changes can be made to this application without departing from the scope of this application. This application is intended to cover such modifications and changes, provided that they fall within the scope of protection defined by the following claims and equivalent art.

[0323] The above description is merely a specific implementation of the present invention and is not intended to limit the scope of protection of this application. Any modification or substitution that is readily conceivable to a person skilled in the art within the scope of the art disclosed herein falls within the scope of protection of this application. Therefore, the scope of protection of this application must be subject to the scope of protection of the claims.

Claims

1. A method of communication, A first terminal device receives first display information from a second terminal device, wherein the first display information indicates a first resource, the first resource is a resource reserved by the second terminal device for transmitting first data, and the resource corresponding to the first resource in the frequency domain belongs to a first channel. The first terminal device determines a second resource based on the first display information, A step of transmitting second data on the second resource by the first terminal device, wherein the start time unit of the second resource is later than the end time unit of the first resource, and the resource corresponding to the second resource in the frequency domain belongs to the first channel. Includes, The first terminal device, by using listen-before-talk processing, senses in a first sensing time unit that the state of the first channel is idle, and suspends the listen-before-talk processing in the first sensing time unit based on the first resource, further comprising the step that the first sensing time unit is earlier than the start time unit of the first resource. Communication method.

2. The step of the first terminal device interrupting the listen before talk processing in the first sensing time unit based on the first resource is: Steps include: when it is determined that the period between the start time unit and the first sensing time unit of the first resource is less than or equal to a first threshold, the first terminal device interrupts the listen before talk processing in the first sensing time unit, wherein the first threshold is greater than 0 and less than or equal to the delay requirement for the second data. The communication method according to claim 1, including the following:

3. The step of interrupting the listen before talk processing in the first sensing time unit based on the first resource by the first terminal device is: Steps include: gradually reducing the value of a counter from Q to M using the first terminal device, and then interrupting the gradual reduction, wherein 1 < M < Q, and Q is the initial value of the counter; The communication method according to claim 1, including the following:

4. The first terminal device senses in a second sensing time unit that the state of the first channel is idle, and progressively reduces the value of the counter from M, wherein the second sensing time unit is later than the end time unit of the first resource, and the start time unit of the second resource is a time unit in which the value of the counter progressively decreases to 0. The communication method according to claim 3, further comprising:

5. The first terminal device receives a first reference signal from the second terminal device, The first terminal device determines that the power required to receive the first reference signal is equal to or greater than the reference signal reception power threshold. The communication method according to claim 1, further comprising:

6. A step of receiving third display information from the second terminal device by the first terminal device, wherein the third display information indicates the destination side to which the second terminal device transmits data. The communication method according to claim 5, further comprising:

7. A step of receiving a fourth display information from a second terminal device by the first terminal device, wherein the fourth display information indicates the priority of the first data, The first terminal device determines that the priority of the first data is equal to or greater than the priority of the second data. The communication method according to claim 6, further comprising:

8. A device including a processor and memory, wherein the memory stores instructions, and when an instruction is executed by the processor, the communication method described in any one of claims 1 to 7 is performed.

9. The apparatus according to claim 8, wherein the apparatus includes a first terminal device or a chip within the first terminal device.

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