METHOD AND APPARATUS OF COMMUNICATION AND READABLE STORAGE MEDIUM

Abstract

The modalities of this application provide a communication method and apparatus and a readable storage medium. The method includes: A first device sends information about a first priority and a second priority to a second device. The first priority is used to assist the second device in selecting a resource for sidelink transmission; the information about the first priority is carried in SCI and / or a MAC CE; and the second priority is a physical layer priority of the first device. In the method, the first device sends the information about the first priority and the second priority to the second device. The information about the first priority is used to assist the second device in selecting the resource for sidelink transmission.Therefore, the second device can also select, based on the information about the first priority, the resource for sidelink transmission, to implement the resource selection of the second device.

Description

METHOD AND APPARATUS FOR COMMUNICATION AND READABLE STORAGE MEDIUM +7C / R7n / C7n7 / 3 / YIAI FIELD OF INVENTION This application relates to communication technologies and, in particular, to a communication method and apparatus and a readable storage medium. BACKGROUND OF THE INVENTION The forms of communication in a vehicle-to-everything (V2X) system are collectively known as V2X communication (where X stands for anything). For example, V2X communication can include vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian (V2P) communication, vehicle-to-network (V2N) communication, and similar configurations. Communication between end devices in the V2X system is broadly referred to as sidelink (SL) communication. In a single-user (SL) communication mode, a network device configures a resource pool, and a terminal device performs resource discovery and selection. Therefore, how the terminal device implements resource discovery and selection is a problem worth studying. BRIEF DESCRIPTION OF THE INVENTION The modalities of this application provide a method and apparatus of communication and a readable storage medium, so that a terminal device can triply detect resources and select resources. According to the first aspect, one form of this request provides a method of communication. The method includes: A first device sends information about a first priority and a second priority to a second device. The first priority is used to assist the second device in selecting a resource for sidelink transmission; the information about the first priority is carried in the Sidelink Control Information (SCI) and / or a Media Access Control Element (MACCE). The second priority is a physical layer priority of the first device. In this method, the first device sends first and second priority information to the second device. The first priority information is used to assist the second device in selecting a resource for sidelink transmission. The second device can then further select a resource for sidelink transmission based on the first priority information. In this mode, the first device assists the second device in selecting a resource for sidelink transmission. A resource is selected through assistance or coordination. Therefore, the surrounding environment can be detected from multiple angles. This can overcome scenarios such as resource conflicts caused by a hidden node, IBE problem deterioration caused by a near-far effect, and additional interference information reception near the UE. Furthermore, the first priority information is carried in the SCI or MAC CE to assist another device in a side-link communication system in performing subsequent processes such as resource discovery, resource selection, and preference based on the two priorities. Specifically, compared to a non-assistance-based resource selection mechanism, an assistance-based request and assistance-based resource dispatch require additional time-frequency resources. Therefore, an assistance device is expected to serve a higher-value target or a device with a higher service priority. In this mode, a signaling design is introduced in which the SCI or MAC CE is used to carry the first priority information.By using dynamic indication design, another device can use more information during resource allocation processes such as resource discovery, resource selection, and preference setting. For example, a device assisting with a higher service priority receives more resources for sidelink transmission, while a device assisting with a lower service priority receives fewer resources for sidelink transmission. In a possible implementation, the first device further sends first information to the second device, and the first information includes any of the following: a set of resources for sidelink transmission determined by the first device, and information used by the first device to select a sidelink transmission resource. In a possible implementation, the second priority is a preset value, or the second priority is a priority in a preset priority list, and the preset priority list includes a plurality of priorities. In this possible implementation, the second priority is a fixed value or a value from a priority list. The processing method is simple and straightforward, and can reduce the device's processing complexity. In a possible implementation, the second priority is related to the first priority. In the proposed implementation, the second priority is related to the first priority, and the second priority can be derived from a correlation between the two. This way, information about the first and second priorities can be conveyed using less signaling overhead. In a possible implementation, the second priority is related to a range of the first priority. In a possible implementation, the second priority is a sum of the first priority and a first difference, or the second priority is a difference between the first priority and a first difference. In the possible implementation, the first difference is indicated using Radio Resource Control (RRC) signaling, or the first difference is a preconfigured value. The first difference can be a positive or negative number. In a possible implementation, the second priority is a higher priority between the first priority and a logical channel priority, and the logical channel priority is a higher priority in the logical channel priorities corresponding to the data on a shared PSSCH sidelink physical channel. In a possible implementation, the information about the first priority is carried in a first subprotocol data unit, the first subprotocol data unit is a media access control subprotocol data unit, the first subprotocol data unit includes a first subheader and a first control element, the first subheader includes a first field, and the first field indicates a logical channel number. In the potential implementation, the first priority information can be dynamically specified. Furthermore, because the MAC CE can carry a large amount of information, it can be used to carry the first priority information, as well as other information, such as the geographic location of the second device. In a possible implementation, a first value in the first field in the first subheader indicates that information about the first priority is being transmitted. In the possible implementation, the first subheader includes M bits, M is an integer multiple of 8, the first field occupies N bits in the first subheader, and N is an integer greater than or equal to 6. In a possible implementation, the first control element includes a second field, and the second field indicates information about the first priority. In the possible implementation, the second field includes three bits, two bits, one bit, or four bits. In a possible implementation, the first control element also includes a third field, and the third field indicates the geographic location information of the second device. In a possible implementation, the information about the first priority is carried in the SCI. In a possible implementation, the SCI of a control channel includes a fourth field; the fourth field indicates the first priority, or the fourth field indicates a second difference corresponding to the first priority, and the second difference is a difference between the first priority and the second priority. In a possible implementation, the SCI of a data channel includes a fifth field, and the fifth field indicates the first priority or a second difference corresponding to the first priority. In a possible implementation, the data channel SCI includes SCI2-A, SCI2-B, or SCI other than SCI2-A and SCI2-B. In a possible implementation, the first priority is a sum of the second priority and the second difference, or the first priority is a difference between the second priority and the second difference, and the second difference can be a positive number or a negative number. The information regarding the first priority is carried in the first-order SCI, allowing it to be indicated more flexibly and dynamically. This helps other devices decode the first priority information during resource discovery and also provides additional reference information for resource selection and prioritization. Because the size of the first-order SCI is limited, the first priority information can alternatively be carried in a second-order SCI. This allows the first priority information to be indicated flexibly and dynamically. The second device can demodulate the second-order SCI after demodulating the first-order SCI to obtain the first priority information. When the first priority information is indicated using the second-order SCI in a new format, a format field in the first-order SCI can display the first priority information provided by the second-order SCI. According to a second aspect, one form of this request provides a method of communication. The method includes: A second device receives first and second priority information from a first device. The first priority is used to assist the second device in selecting a resource for sidelink transmission; this information is carried in SCI and / or a MAC CE. The second priority is a physical layer priority of the first device. Based on the first priority information, the second device selects a resource for sidelink transmission. In this method, the first device sends first priority and second priority information to the second device. The first priority information is used to help the second device select the resource for sidelink transmission. +7C / R7n / C7n7 / a / YiAi Therefore, the second device can also select, based on the information about the first priority, the resource for sidelink transmission, to implement the resource selection of the second device. In a possible implementation, the second device also receives first information from the first device, and the first information includes any of the following: a set of resources for sidelink transmission determined by the first device, and information used by the first device to select a sidelink transmission resource. In a possible implementation, the second priority is a preset value, or the second priority is a priority in a preset priority list, and the preset priority list includes a plurality of priorities. In a possible implementation, the second priority is related to the first priority. In a possible implementation, the second priority is related to a range of the first priority. In a possible implementation, the second priority is a sum of the first priority and a first difference, or the second priority is a difference between the first priority and a first difference. In the possible implementation, the first difference is indicated using RRC signaling, or the first difference is a preconfigured value. The first difference can be a positive or negative number. In a possible implementation, the second priority is a higher priority between the first priority and a logical channel priority, and the logical channel priority is a higher priority in the logical channel priorities corresponding to the data of a PSSCH. In a possible implementation, the information about the first priority is carried in a first subprotocol data unit, the first subprotocol data unit is a media access control subprotocol data unit, the first subprotocol data unit includes a first subheader and a first control element, the first subheader includes a first field, and the first field indicates a logical channel number. In a possible implementation, a first value in the first field in the first subheader indicates that information about the first priority is being transmitted. In the possible implementation, the first subheader includes M bits, M is an integer multiple of 8, the first field occupies N bits in the first subheader, and N is an integer greater than or equal to 6. In a possible implementation, the first control element includes a second field, and the second field indicates information about the first priority. In the possible implementation, the second field includes three bits, two bits, one bit, or four bits. In a possible implementation, the first control element also includes a third field, and the third field indicates the geographic location information of the second device. In a possible implementation, the information about the first priority is carried in the SCI. In a possible implementation, the SCI of a control channel includes a fourth field; the fourth field indicates the first priority, or the fourth field indicates a second difference corresponding to the first priority, and the second difference is a difference between the first priority and the second priority. In a possible implementation, the SCI of a data channel includes a fifth field, and the fifth field indicates the first priority or a second difference corresponding to the first priority. In a possible implementation, the data channel SCI includes SCI2-A, SCI2-B, or SCI other than SCI2-A and SCI2-B. In a possible implementation, the first priority is a sum of the second priority and the second difference, or the first priority is a difference between the second priority and the second difference, and the second difference can be a positive number or a negative number. According to a third aspect, one modality of this application provides a communication apparatus, which includes a processing module and a sending module. The processing module is configured to send information about a first priority and a second priority to a second device when using the sending module. The first priority is used to assist the second device in selecting a resource for sidelink transmission; information about the first priority is carried in SCI and / or a MAC CE, and the second priority is a physical layer priority of a first device. In a possible implementation, the processing module is further configured to send initial information to the second device when using the sending module, and the initial information includes any of the following: a set of sidelink transmission resources determined by the first device, and information used by the first device to select a sidelink transmission resource. In a possible implementation, the second priority is a preset value, or the second priority is a priority in a preset priority list, and the preset priority list includes a plurality of priorities. In a possible implementation, the second priority is related to the first priority. In a possible implementation, the second priority is related to a range of the first priority. In a possible implementation, the second priority is a sum of the first priority and a first difference, or the second priority is a difference between the first priority and a first difference. In the possible implementation, the first difference is indicated using RRC signaling, or the first difference is a preconfigured value. The first difference can be a positive or negative number. In a possible implementation, the second priority is a higher priority between the first priority and a logical channel priority, and the logical channel priority is a higher priority in the logical channel priorities corresponding to the data of a PSSCH. In a possible implementation, the information about the first priority is carried in a first subprotocol data unit, the first subprotocol data unit is a media access control subprotocol data unit, the first subprotocol data unit includes a first subheader and a first control element, the first subheader includes a first field, and the first field indicates a logical channel number. In a possible implementation, a first value in the first field in the first subheader indicates that information about the first priority is being transmitted. In the possible implementation, the first subheader includes M bits, M is an integer multiple of 8, the first field occupies N bits in the first subheader, and N is an integer greater than or equal to 6. In a possible implementation, the first control element includes a second field, and the second field indicates information about the first priority. In the possible implementation, the second field includes three bits, two bits, one bit, or four bits. In a possible implementation, the first control element also includes a third field, and the third field indicates the geographic location information of the second device. In a possible implementation, the information about the first priority is carried in the SCI. In a possible implementation, the SCI of a control channel includes a fourth field; the fourth field indicates the first priority, or the fourth field indicates a second difference corresponding to the first priority, and the second difference is a difference between the first priority and the second priority. In a possible implementation, the SCI of a data channel includes a fifth field, and the fifth field indicates the first priority or a second difference corresponding to the first priority. In a possible implementation, the data channel SCI includes SCI2-A, SCI2-B, or SCI other than SCI2-A and SCI2-B. In a possible implementation, the first priority is a sum of the second priority and the second difference, or the first priority is a difference between the second priority and the second difference, and the second difference can be a positive number or a negative number. According to a fourth aspect, one modality of this application provides a communication device, which includes: a receiving module, configured to receive information about a first priority and a second priority from a first device, wherein the first priority is used to assist a second device in selecting a resource for sidelink transmission, the information about the first priority being carried in SCI and / or a MAC CE, and the second priority being a physical layer priority of the first device; and a processing module, configured to select, based on the information about the first priority, a resource for sidelink transmission. In a possible implementation, the receiving module is further configured to receive initial information from the first device, and the initial information includes any of the following: a set of sidelink transmission resources determined by the first device, and information used by the first device to select a sidelink transmission resource. In a possible implementation, the second priority is a preset value, or the second priority is a priority in a preset priority list, and the preset priority list includes a plurality of priorities. In a possible implementation, the second priority is related to the first priority. In a possible implementation, the second priority is related to a range of the first priority. In a possible implementation, the second priority is a sum of the first priority and a first difference, or the second priority is a difference between the first priority and a first difference. In the possible implementation, the first difference is indicated using RRC signaling, or the first difference is a preconfigured value. The first difference can be a positive or negative number. In a possible implementation, the second priority is a higher priority between the first priority and a logical channel priority, and the logical channel priority is a higher priority in the logical channel priorities corresponding to the data of a PSSCH. In a possible implementation, the information about the first priority is carried in a first subprotocol data unit, the first subprotocol data unit is a media access control subprotocol data unit, the first subprotocol data unit includes a first subheader and a first control element, the first subheader includes a first field, and the first field indicates a logical channel number. In a possible implementation, a first value in the first field in the first subheader indicates that information about the first priority is being transmitted. In the possible implementation, the first subheader includes M bits, M is an integer multiple of 8, the first field occupies N bits in the first subheader, and N is an integer greater than or equal to 6. In a possible implementation, the first control element includes a second field, and the second field indicates information about the first priority. In the possible implementation, the second field includes three bits, two bits, one bit, or four bits. In a possible implementation, the first control element also includes a third field, and the third field indicates the geographic location information of the second device. In a possible implementation, the information about the first priority is carried in the SCI. In a possible implementation, the SCI of a control channel includes a fourth field; the fourth field indicates the first priority, or the fourth field indicates a second difference corresponding to the first priority, and the second difference is a difference between the first priority and the second priority. In a possible implementation, the SCI of a data channel includes a fifth field, and the fifth field indicates the first priority or a second difference corresponding to the first priority. In a possible implementation, the data channel SCI includes SCI2-A, SCI2-B, or SCI other than SCI2-A and SCI2-B. In a possible implementation, the first priority is a sum of the second priority and the second difference, or the first priority is a difference between the second priority and the second difference, and the second difference can be a positive number or a negative number. According to a fifth aspect, one modality of this application provides a communication apparatus, which includes a processor and a communication interface. The communication interface is configured to implement +7C / R7n / C7n7 / 3 / YIAI connection and communication between the communication device and a peripheral. The processor is configured to implement the method in either the first aspect or the second aspect. In one possible design, the communication device also includes a memory. The memory is configured to store a computer program. The processor executes the computer program stored in memory, to allow the device to perform the method in either the first or second aspect. In one possible design, the communication device also includes a transceiver. The transceiver is configured to send and receive a message. According to a sixth aspect, one modality of this request provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed, the method in either the first or second aspect is implemented. According to a seventh aspect, one modality of this application provides a chip, which includes a processor and an interface. The processor is configured to read instructions, to implement the information processing method in the first aspect or the second aspect. According to an eighth aspect, one modality of this application provides a computer program product. The computer program product includes computer program code. When the computer program code is executed by a computer, the computer is activated to perform the method in either the first or second aspect. According to a ninth aspect, one modality of this application provides a communication system, which includes the communication apparatus in the fifth aspect. BRIEF DESCRIPTION OF THE FIGURES FIGURE 1 is a schematic diagram of a V2X communication scenario; FIGURE 2 is an interaction flowchart of a communication method according to one modality of this request; FIGURE 3 is a schematic diagram in which a first device sends information about a first priority and a second priority to a second device; FIGURE 4 is an interaction flow diagram of an example in which a terminal device A coordinates with a terminal device B to perform resource discovery and resource selection; FIGURE 5 is a schematic diagram of a side-link MAC PDU structure; FIGURE 6 is a schematic diagram of a subheader structure R / LCID; FIGURE 7 is a schematic diagram of another R / LCID subheader structure; FIGURE 8 is a schematic diagram of a first control element structure; FIGURE 9 is a schematic diagram of another structure of a first control element; FIGURE 10 is a schematic diagram of yet another structure of a first control element; FIGURE 11 is a diagram of a module structure of a communication device according to one modality of this application; FIGURE 12 is a diagram of a module structure of another communication device according to one modality of this application; and FIGURE 13 is a schematic diagram of a communication apparatus structure according to one modality of this request. DETAILED DESCRIPTION OF THE INVENTION This request applies to SL communication, and a V2X communication system is a typical SL communication application. To facilitate understanding of the technical solutions in the modalities of this request by a person skilled in the art, the following modalities provide descriptions using the V2X communication system as an example. However, it should be understood that this should not be interpreted as a limitation of this request. The technical solutions in this request can also be applied to other communication systems based on SL communication. Figure 1 is a schematic diagram of a V2X communication scenario. As shown in Figure 1, a first device communicates with a second device via a side link (SL). The side link is a secondary link in a V2X network. In addition to the secondary link, the V2X network also includes an uplink and a downlink. For example, V2X communication includes vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-person (V2P) communication, and vehicle-to-network (V2N) communication. Figure 1 uses V2V communication, where both the first and second devices are vehicles, as an example. No specific V2X communication scenario is covered in this application.For example, communication between the first and second devices could be vehicle-mounted device communication, communication between a +7C / R7n / C7n7 / 3 / YIAI Roadside Unit (RSU) and a vehicle-mounted device and / or a network device (e.g., a base station device), communication between a network device (e.g., a base station device) and a vehicle-mounted device and / or an RSU, or similar. The network device could be an LTE base station device, an NR base station device, or a base station in a later, evolved system. It can be understood that the specific forms of the first and second devices are not limited in this application. This is merely an example for illustrative purposes. For instance, a radio access network device in FIGURE 1 could be a base station or a device in a network providing radio access. The base station could be an evolved NodeB (eNB) in LTE (Long Term Evolution) or a base station in an NR network. The base station in NR could include a new radio NodeB (NR NodeB, gNB), a next-generation evolved NodeB (NG-eNB), a gNB separated into a central unit (CU) and a distributed unit (DU), a transmission / reception point (TRP), a transmission point (TP), an access point (AP) in a wireless fidelity (Wi-Fi) network, or another node. It can be understood that a communication method provided in this application is applicable not only to the sidelink shown in Figure 1, but also to a cellular link. The scenario to which the communication method applies is not limited to this modality of the application. This is merely an example for illustrative purposes. The first and second devices in these modalities of the application are communication devices, and the communication device can be a terminal device or a network device. When the first device is a network device, the sidelink can be a link between base stations, for example, a link between macro base stations, a link between a macro base station and a small cell, a link between a primary base station and a secondary base station, a link between primary base stations, or a link between secondary base stations.This is not limited to this type of application. The following describes an interaction processing procedure between the first device and the second device. It should be noted that in this request, there may be one or more first devices. There may be one or more second devices. Figure 2 is an interaction flowchart of a communication method according to one modality of this request. As shown in Figure 2, an interaction process between a first device and a second device includes the following steps. S201: The first device sends information about a first priority and a second priority to the second device. Accordingly, the second device receives the information about the first priority and the second priority. The first priority is used to assist the second device in selecting a resource for sidelink transmission, and information about the first priority can be carried in sidelink control information (SCI) and / or a medium access control element (MAC CE). It should be understood that the first priority information can be either the first priority itself or information associated with the first priority. When the first priority information is information associated with the first priority, the first priority information can indicate the first priority. After receiving the first priority information, the second device can determine the first priority based on that information and then select the resource for the sidelink transmission. Optionally, the first device sending the first priority and second priority information to the second device can occur in a phase where the first device initiates a coordination request to the second device, or in a phase where the first device assists the second device in resource selection. In one case, the first device assists the second device in the selection of resources. In the phase, optionally, the first priority can be a priority used by the first device to assist the second device in resource selection, a service priority of the second device, a physical layer priority of the second device, or a priority corresponding to a physical sidelink shared channel (PSSCH) sent by the second device to a third device. The second priority can be a service priority sent by the first device to the second device, a priority carried in the SCI sent by the first device to the second device, a priority corresponding to a PSSCH sent by the first device to the second device, a priority corresponding to a logical channel sent by the first device to the second device, a higher priority in the priorities corresponding to a logical channel sent by the first device to the second device, a priority corresponding to a service of the first device, or a priority used by the first device for resource selection of the first device. In another case, the first device initiates a coordination request to the second device. In the phase, optionally, the first priority can be a priority used by the first device to request the second device to assist in resource selection, a service priority sent by the second device to the third device, a physical layer priority sent by the second device to the third device, or a priority corresponding to a PSSCH sent by the second device to the third device. The second priority can be a service priority sent by the first device to the second device, a priority carried in the SCI sent by the first device to the second device, a priority corresponding to a PSSCH sent by the first device to the second device, a priority corresponding to a logical channel sent by the first device to the second device, a higher priority in the priorities corresponding to a logical channel sent by the first device to the second device, or a priority of a resource that is selected by the first device and is for sidelink transmission to the third device. Optionally, the first and second priority information can be transmitted in a transport block (TB). Specifically, the second priority is carried in the SCI of a PSCCH, and the first priority information is carried in the SCI or MAC CE. As described above, there can be one or more first devices. There can also be one or more second devices. Figure 3 is a schematic diagram where the first device sends the first priority and second priority information to the second device. As shown in Figure 3, the second device could be, for example, a second device 1, and the first device sends the first priority and second priority information to second device 1. This approach can be applied, for example, to a unicast scenario. Alternatively, as shown in Figure 3, the second device could include three devices: a second device 1, a second device 2, and a second device 3. The first device sends the first priority and second priority information to each second device. This approach can be applied to a multicast or broadcast scenario.The first device can establish a first priority, and when a service priority of the second device is higher than the first priority, a pool of resources sent by the first device can be used. Referring to Figure 3, both the first priority and second priority information can be carried in the SCI, or the second priority can be carried in the SCI and the first priority information in the MAC CE. S202: The second device selects, based on the information about the first priority, a resource for sidelink transmission. In different phases or a single phase of data transmission, the first device can represent different devices, and the second device can also represent different devices. Accordingly, for example, when the second device +7C / R7n / C7n7 / a / YiAi selects, based on the first priority information, the resource for sidelink transmission, the second device can assist, based on the first priority information, the first device in performing resource discovery and selection, or it can select, based on the first priority information, the resource from the resource pool provided by the first device. In this mode, the first device sends first and second priority information to the second device. The first priority information is used to assist the second device in selecting a resource for sidelink transmission. The second device can then further select a resource for sidelink transmission based on the first priority information. In this mode, the first device assists the second device in selecting a resource for sidelink transmission. A resource is selected through assistance or coordination. Therefore, the surrounding environment can be detected from multiple angles. This can overcome a scenario of sending resource conflict caused by a hidden node, a scenario of IBE problem deterioration caused by a near-far effect, and a scenario of additional interference information reception near the UE. Furthermore, the first priority information is carried in the SCI or MAC CE to assist another device in a side-link communication system in performing subsequent processes such as resource discovery, resource selection, and preference based on the two priorities. Specifically, compared to a non-assistance-based resource selection mechanism, an assistance-based request and assistance-based resource dispatch require additional time-frequency resources. Therefore, an assistance device is expected to serve a higher-value target or a device with a higher service priority. In this mode, a signaling design is introduced in which the SCI or MAC CE is used to carry the first priority information.By using dynamic indication design, another device can use more information during resource allocation processes such as resource discovery, resource selection, and preference setting. For example, a device assisting with a higher service priority receives more resources for sidelink transmission, while a device assisting with a lower service priority receives fewer resources for sidelink transmission. The interaction between the first and second devices can be applied to a process in which two or more devices coordinate to perform resource discovery and resource selection. The following describes in detail the interaction process between the first and second devices using an example in which two terminal devices, namely terminal device A and terminal device B, coordinate to perform resource discovery and resource selection. It should be understood that the resources described in the following modalities of this request are all resources for sidelink transmission. Figure 4 is an interaction flowchart of an example in which terminal device A coordinates with terminal device B to perform resource discovery and resource selection. As shown in Figure 4, an interaction process between terminal device A and terminal device B includes the following steps. S401: Terminal device B sends a coordination request to terminal device A. The coordination request is used to request terminal device A to discover a resource for terminal device B. It should be noted that when terminal device A coordinates with terminal device B to perform resource discovery and selection, this coordination can also be referred to as assistance. Assistance might mean that terminal device A recommends that terminal device B use certain resources, and terminal device B then determines which resources to use. Alternatively, assistance might mean that terminal device A specifies that terminal device B use certain resources, and terminal device B uses the resources based on the indication from terminal device A, without making the determination independently. Specifically, terminal device B adds first priority and second priority information to the coordination request. The first priority information is used to assist terminal device A in selecting a resource for the sidelink transmission, and the second priority is a physical layer priority of terminal device B. Optionally, the coordination request may include initial information, and initial information includes information about the selection of a resource for sidelink transmission by terminal device B. For example, the coordination request may include a parameter used by terminal device B to select the resource for sidelink transmission. S402: If terminal device A can detect a resource for terminal device B, terminal device A sends, to terminal device B, an acceptance response of the collaboration request. In steps S401 and S402, terminal device B can serve as the first device, and terminal device A can serve as the second device. After receiving the coordination request and sending the acceptance response, terminal device A can select, based on the first priority information, the resource for sidelink transmission. Optionally, in step S401, terminal device B can also send geographical location information from terminal device A to terminal device A, to request a second device, i.e., terminal device A, in a specific geographical location. In steps S401 and S402, coordinated resource detection and selection are triggered by terminal device B. Alternatively, coordinated resource detection and selection by terminal device A and terminal device B can be performed using a non-triggering mechanism. In this way, steps S401 and S402 are not required, and step S403 is performed directly. It should be noted that, in one case, if coordinated resource discovery and selection are performed based on an activation method, a resource selection priority used by terminal device A to determine assistance information in step S403 can be obtained based on the first priority indicated by the coordination request from terminal device B in step S401. It is assumed that the first priorities indicated by the coordination requests from a plurality of terminal devices B are {Pai, Pa2, Pa3...}. In a unicast scenario, the resource selection priority used by terminal device A to determine assistance information in step S403 can be equal to Pai. In a multicast scenario, the resource selection priority used by terminal device A to determine assistance information can be calculated in the following two ways: Way 1: Pa = max {Pai, Pa2, Pa3···} Way 2: Pa = mean {Pai, Pa2, Pa3-..} In another case, if coordinated resource detection and selection are performed on the basis of a non-activation method, a resource selection priority used by terminal device A to determine assistance information in step S403 can be determined by terminal device A. S403: Terminal device A performs resource selection based on the resource selection priority used to determine attendance information. It should be understood that terminal device A can perform resource selection based on the resource selection priority used to determine assistance information, a location and length of a resource detection window, a number of resource selection domain frequency subwidths, a transmission period of terminal device B, resource group information, and the like. After resource selection, terminal device A can obtain a set of detected resources for resource selection from terminal device A and terminal device B. S404: Terminal device A sends support information to terminal device B. The support information may include the resource set for sidelink transmission, as determined by terminal device A. It should be noted that the resource set included in the support information does not include any resources that terminal device A will use for transmission. Optionally, the resource set included in the support information may be a set of resources that terminal device A recommends terminal device B use, or it may be a set of resources that terminal device A does not recommend terminal device B use. In addition, terminal device A also sends information about the first priority and second priority to terminal device B. The first priority information is used to assist terminal device B in selecting the resource for sidelink transmission, and the second priority is a physical layer priority of terminal device A. Accordingly, terminal device B receives assistance information, first priority information, and second priority information. Optionally, in step S404, terminal device A can further send geographical location information from terminal device B to terminal device B, to assist the second device, i.e., terminal device B, in a specific geographical location. In steps S403 and S404, terminal device A can serve as the first device, and terminal device B can serve as the second device. Support information can be used as the first information. Specifically, when sending support information to terminal device B, terminal device A can also send first priority and second priority information. The first priority information is used to assist terminal device B in selecting the resource for sidelink transmission, and the second priority is a physical layer priority of terminal device A. After receiving the support information, first priority information, and second priority information, terminal device B can select the resource for sidelink transmission based on the first priority information. It should be understood that, in the phase corresponding to steps S401 and S402, and in the phase corresponding to steps S403 and S404, the meanings represented by the first device are different, and the meanings represented by the second device are also different. Correspondingly, the meanings represented by the information regarding the first priority are different, and the meanings represented by the second priority are also different. S405: Terminal device B selects, based on the resource set of terminal device A and the resource set detected by terminal device B, a +7C / R7n / C7n7 / a / viAi time frequency resource for sidelink communication between terminal device B and a terminal device C. Sidelink communication between terminal device B and terminal device C may include an initial transmission and several retransmissions. Terminal device B can determine, based on a hybrid automatic repeat request (HARQ) response from terminal device C, whether to perform a retransmission. S406: If resource reselection is supported, terminal device B can repeatedly perform steps S401 through S405 to reselect resources. A specific processing procedure is not described again. As described above, the first device sends the first priority and second priority information to the second device. Before sending the second priority, the first device can determine the second priority first. The following describes several optional ways to determine the second priority. The first option is optional; the second priority is a preset value. For example, the second priority is a preset value M, where M is an integer greater than or equal to 1 and less than or equal to 8, or an integer greater than or equal to 0 and less than or equal to 7. The range of values ​​also applies to the first priority. It should be understood that, in this application format, the second priority is represented by a value, and this value is the opposite of the level actually indicated by the second priority. A higher second priority value indicates a lower second priority level. For example, assuming the priority range is an integer from 1 to 8, a second priority value of 1 indicates a higher priority, and a second priority value of 8 indicates a lower priority. It should be understood that the explanations and descriptions also apply to the first priority. In other words, a higher first priority value indicates a higher level of the first priority, and a lower first priority value indicates a lower level of the first priority. Alternatively, the second priority is a priority in a pre-established priority list. Optionally, the preset priority list may include a plurality of priorities, and the first device may select one priority from the plurality of priorities as the second priority. For example, each priority in the predefined priority list can be an integer greater than or equal to 1 and less than or equal to 8. In one example, the priority list might be {1, 3, 5, 7}. In another example, the priority list might be {2, 4, 6, 8}. +7C / R7n / C7n7 / 3 / YIAI For example, the priority list is {1, 3, 5, 7}, and only two bits are required to represent any priority in the priority list. This can reduce signaling overhead. In both methods, the second priority is either a fixed value or a value from a priority list. The processing method is simple and straightforward, and can reduce the device's processing complexity. In a third, optional way, the second priority is related to the first priority. The method can be any of the following three examples. 1. Example 1 In a first example of the optional approach, the second priority can be related to a range of the first priority. The range of the first priority can correspond to the value of the second priority. For example, assume that a priority range is an integer from 1 to 8. The first priority range is {1, 2, 3, 4}, and the second priority might be 4. The first priority range is {5, 6, 7, 8}, and the second priority might be 8. Only one bit is required to represent any priority in the priority list. This can reduce signaling overhead. Alternatively, each second priority value corresponds to four first priority values, and only two bits are required to represent any priority in the priority list. This can also reduce signaling overhead. As another example, assume that a priority range is an integer from 1 to 8. The first priority range is {1, 2, 3, 4}, and the second priority can be 1. The first priority range is {5, 6, 7, 8}, and the second priority can be 5. Only one bit is required to represent any priority in the priority list. This can reduce signaling overhead. Alternatively, each value of the second priority corresponds to four values ​​of the first priority, and only two bits are required to represent any priority in the priority list. This can also reduce signaling overhead. 2. Example 2 In a second example of the optional way, the second priority can be a sum of the first priority and a first difference, or the second priority is a difference between the first priority and a first difference. Optionally, the first difference can be a positive number or a negative number. In one example, it is assumed that the second priority is P1, the first priority is Pa, the first difference is deltal, and the second priority is the sum of the first priority and the first difference. The second priority is obtained according to the following formula (1): P1 = Pa + deltal (1) It should be noted that if the value obtained through calculation according to formula (1) is greater than a maximum priority value, the maximum priority value is used as the second priority value. For example, a priority range is an integer from 1 to 8. If the value obtained through calculation according to formula (1) is greater than 8, the second priority value can be considered to be 8. If the value obtained through calculation according to formula (1) is less than a minimum priority value, the minimum priority value is used as the second priority value. For example, a priority range is an integer from 1 to 8. If the value obtained through calculation according to formula (1) is less than 1, the second priority value can be considered to be 1. In another example, it is assumed that the second priority is P1, the first priority is P2, the first difference is deltal, and the second priority is the difference between the first priority and the first difference. The second priority is obtained according to the following formula (2): P1 = P2 - deltal (2) It should be noted that if the value obtained through calculation according to formula (2) is greater than a maximum priority value, the maximum priority value is used as the second priority value. For example, a priority range is an integer from 1 to 8. If the value obtained through calculation according to formula (2) is greater than 8, the second priority value can be considered to be 8. If the value obtained through calculation according to formula (2) is less than a minimum priority value, the minimum priority value is used as the second priority value. For example, a priority range is an integer from 1 to 8. If the value obtained through calculation according to formula (2) is less than 1, the second priority value can be considered to be 1. In the second example, the first difference can be indicated using radio resource control (RRC) signaling, or it can be a preconfigured value. It's important to understand that the first difference can be either a positive or a negative number. 3. Example 3 In a third example of the optional way, the second priority is a higher priority between the first priority and a logical channel priority. The logical channel priority is a higher priority in the logical channel priorities corresponding to the data of a PSSCH. It should be noted that the shared physical sidelink channel can also be referred to as a physical sidelink data channel. For example, the PSSCH includes eight logical channel priorities. A physical layer priority for the first device is a higher priority in the logical channel priorities. In the third way, the second priority is related to the first priority, and the second priority can be obtained based on a correlation between the two priorities. In this way, information about the first and second priorities can be conveyed using less signaling overhead. The above describes several optional ways in which the first device determines the second priority before sending the second priority. In light of this, the following describes one way in which the first device sends the first priority information. It should be understood that the method for determining the second priority can be implemented in combination with any of the following methods for sending the first priority information. As described above, the first priority information can be carried in the SCI and / or the MAC CE. The following provides descriptions. It should be understood that the first device can select at least one of the SCI or the MAC CE to carry the first priority information. When both the SCI and the MAC CE are selected to carry the first priority information, the first device adds the first priority information to both the SCI and the MAC CE. First, a way in which information about the first priority is carried in the MAC CE is described. In an optional implementation, the first priority information can be carried in a first subprotocol data unit, and the first subprotocol data unit is a medium access control subprotocol data unit (MAC subPDU) in a protocol data unit (PDU) MAC. The first subprotocol data unit includes a first subheader and a first control element. The first subheader includes a first field, and the first field indicates a logical channel number. A specific value in the first field may indicate that information about the first priority is being transmitted. Additionally, a specific field in the first control element may indicate information about the first priority. Figure 5 is a schematic diagram of a sidelink MAC PDU structure. As shown in Figure 5, the MAC PDU includes a sidelink shared channel (SL-SCH) subheader, a MAC subPDU that includes an SDU MAC, a MAC subPDU that includes a CE MAC, and a MAC subPDU that includes padding. With reference to Figure 5, the MAC subPDU that includes an SDU MAC includes an R / F / LCID / L subheader and an SDU MAC. The MAC subPDU that includes a CE MAC includes an R / LCID subheader and a CE MAC. The R / F / LCID / L subheader includes an R field, an F field, a logical channel identifier (LCID) field, and an L field, and may also include an extended LCID (eLCID) field. The field definitions are described as follows: (1) LCID Field: The LCID field corresponds to a logical channel instance of a MAC SDU, a MAC CE, or a padding type. (2) eLCID field: The eLCID field corresponds to a logical channel instance of a MAC SDU. (3) L field: L indicates a length, and the L field indicates a length of a corresponding MAC SDU or a length of a variable MAC CE, and is in a byte unit. (4) Field F: F indicates a format, and field F indicates a size of field L. (5) Field R: The R field indicates a reserved bit. The R / LCID subheader includes an R field and an LCID field. The field definitions are the same as the field definitions in the R / F / LCID / L subheader, and no further details are described. In this modality of the present application, the first subprotocol data unit may be a subPDU MAC that includes a CE MAC. In the first subprotocol data unit, the first subheader may be an R / LCID subheader in the subPDU MAC that includes a CE MAC in FIGURE 5, and the first control element may be a CE MAC in the subPDU MAC that includes a CE MAC in FIGURE 5. Optionally, an R / LCID subheader structure can be any of the following: Figure 6 is a schematic diagram of an R / LCID subheader structure. As shown in Figure 6, the R / LCID subheader includes eight bits, where six bits are an LCID field, a value in the LCID field indicates a logical channel number, and the other two bits are reserved bits. When using this structure, the first field can be the six-bit LCID field in Figure 6. With six bits, there can be 64 values. In an optional implementation, the first value of the first field can be used to identify that the information being transmitted is of the highest priority. For example, the first value may be 61. When the value of the LCID field in the R / LCID subheader is 61, it indicates that the information about the first priority is carried in the MAC CE for transmission. Figure 7 is a schematic diagram of another R / LCID subheader structure. As shown in Figure 7, the R / LCID subheader includes 16 bits, where a reserved bit is one bit, an F bit is one bit, an LCID field is six bits, and an extended LCID (eLCID) field is eight bits. A definition indicated by the F bit is the same as a definition of the F field described in Figure 5. When using this structure, the first field can be the six-bit LCID field in FIGURE 7, the eight-bit eLCID field in FIGURE 7, or some or all of the bits of both the six-bit LCID and the eight-bit eLCID fields. Accordingly, the first field can have multiple values. In an optional implementation, a first value from the first field can be used to identify which priority information is being transmitted. Based on the R / LCID subheader structure shown in FIGURE 6 or FIGURE 7, the first subheader can include M bits, M is an integer multiple of 8, the first field occupies N bits in the first subheader, and N is an integer greater than or equal to 6. In an optional implementation, the first control element includes a second field, and the second field can indicate information about the first priority. Optionally, the second field can include three bits, two bits, one bit, or four bits. Figure 8 is a schematic diagram of the structure of the first control element. As shown in Figure 8, the first control element includes eight bits, the second field occupies three bits, and the remaining bits are reserved. It is assumed that the priority range is from 1 to 8. In the structure shown in FIGURE 8, the second field can indicate a priority. For example, when the second field is 000, it indicates that the priority is 1, that is, a higher priority. Figure 9 is a schematic diagram of another structure for the first control element. As shown in Figure 9, the first control element includes eight bits, the second field occupies two bits, and the remaining bits are reserved. For example, the first priority is a priority in the priority list {1, 3, 5, 7}. When the second field is 00, it indicates that the first priority is 1, that is, a higher priority. Optionally, the priority list is preset or preconfigured and stored on the first device and the second device. Figure 10 is a schematic diagram of yet another structure for the first control element. As shown in Figure 10, the first control element includes eight bits, the second field occupies one bit, and the remaining bits are reserved. For example, the first priority is a priority in the priority list {1, 3, 5, 7}. When the second field is 0, it indicates that the first priority is 1, that is, a higher priority. Optionally, the priority list is preset or preconfigured and stored on the first device and the second device. +7C / R7n / C7n7 / a / YiAi It should be understood that, because the second field indicates information about the first priority, a value in the second field can be the first priority, or it can be a value related to the first priority. In another example, the second field includes four bits, and these four bits can indicate a difference corresponding to the first priority. It is assumed that the priority range is an integer from 1 to 8, and the four bits can include an integer range of [-7, 8]. For example, it is assumed that a value indicated by the four bits is -7, meaning a difference of -7. The second device can obtain the first priority through calculation based on this first difference. It should be noted that the solutions in this application are applicable to unicast, multicast, and broadcast scenarios. Therefore, the structures of the first control element shown in Figures 8 through 10 are also applicable to unicast, multicast, and broadcast scenarios. In an optional implementation, the first control element may also include a third field, and the third field may indicate geographic location information of the second device. The structure of the first control element shown in FIGURE 8 is used as an example. The third field can occupy the remaining five bits other than the second field. Alternatively, the third field can occupy fewer or more bits in the third control element. For example, the geographic location information of the second device can be a zone ID of the second device. The first device adds the geographic location information of the second device to the first control element, so that the second device can perform resource selection or other operations based on the geographic location information. As described above, geographic location information can be used to request a second device in a specific geographic location, or it can assist a second device in a specific geographic location. For example, if the first device is terminal device B, the geographic location information can be used to request terminal device A in a specific geographic location. If the first device is terminal device A, the geographic location information can assist terminal device B in a specific geographic location. The above describes one way in which the MAC CE carries first priority information. This first priority information can be dynamically specified. Furthermore, because the MAC CE can carry a large amount of +7C / R7n / O7n7 / 3 / YIAI information, it can be used to carry both the first priority information and other information, such as the second device's geographic location. The following describes one way in which information about the first priority is carried in the SCI. Optionally, the information about the first priority can be carried in SCI from a control channel, or it can be carried in SCI from a data channel. The control channel SCI can also be referred to as SC11 or first-order SCI. The data channel SCI can also be referred to as SCI2 or second-order SCI. The information regarding the first priority is carried in the first-order SCI, allowing it to be indicated more flexibly and dynamically. This helps other devices decode the first priority information during resource discovery and also provides additional reference information for resource selection and prioritization. Because the size of the first-order SCI is limited, the first priority information can be carried in the second-order SCI. This allows the first priority information to be indicated flexibly and dynamically. The second device can demodulate the second-order SCI after demodulating the first-order SCI to obtain the first priority information. When the first priority information is indicated using the second-order SCI in a new format, a second-order SCI format field in the first-order SCI can display the first priority information provided by the second-order SCI. When information about the first priority is carried in the SCI of the control channel, either of the following two methods can be used. In one way, the SCI of the control channel may include a fourth field, and the fourth field may indicate the first priority. The fourth field occupies a preset bit in the control channel's SCI; for example, it can occupy three bits, two bits, or one bit. The preset bit can be used to indicate a specific priority, a priority range, or similar. In one example, the fourth field occupies three bits. It is assumed that a range of priority values ​​is from 1 to 8, and the fourth field can indicate a specific first priority. In another example, the fourth field occupies two bits. For example, suppose the first priority is a priority in the priority list {1, 3, 5, 7}. When the fourth field is 00, it indicates that the first priority is 1, that is, a higher priority. Optionally, the priority list is preset or preconfigured and stored on the first device and the second device. In another example, the fourth field occupies one bit. For example, suppose the first priority is a priority in the priority list {1, 3, 5, 7}. When the fourth field is 0, it indicates that the first priority is 1, that is, a higher priority. Optionally, the priority list is preset or preconfigured and stored on the first device and the second device. In a second way, the control channel SCI may include a fourth field, and the fourth field may indicate a second difference corresponding to the first priority. The second difference is a difference between the first priority and the second priority. In the second way, the first priority can be the sum of the second priority and the second difference, or the difference between the second priority and the second difference. Furthermore, the second difference can be either a positive or a negative number. In one example, it is assumed that the second priority is P1, the first priority is Pa, the second difference is delta2, and the first priority is the sum of the second priority and the second difference. The first priority is obtained according to the following formula (3): Pa = P1 + delta2 (3) It should be noted that if the value obtained through calculation according to formula (3) is greater than a maximum priority value, the maximum priority value is used as the first priority value. For example, a priority range is an integer from 1 to 8. If the value obtained through calculation according to formula (3) is greater than 8, the first priority value can be considered to be 8. If the value obtained through calculation according to formula (3) is less than a minimum priority value, the minimum priority value is used as the first priority value. For example, a priority range is an integer from 1 to 8. If the value obtained through calculation according to formula (3) is less than 1, the first priority value can be considered to be 1. In another example, it is assumed that the second priority is P1, the first priority is Pa, the second difference is delta2, and the first priority is the difference between the second priority and the second difference. The first priority is obtained according to the following formula (4): Pa = P1 - delta2 (4) It should be noted that if the value obtained through calculation according to formula (4) is greater than a maximum priority value, the maximum priority value is used as the first priority value. For example, a priority range is an integer from 1 to 8. If the value obtained through calculation according to formula (4) is greater than 8, the first priority value can be considered to be 8. If the value obtained through calculation according to formula (4) is less than a minimum priority value, the minimum priority value is used as the value of the first priority. For example, a priority range is an integer from 1 to 8. If the value obtained through calculation according to formula (4) is less than 1, the value of the first priority can be considered to be 1. When information about the first priority is carried in the SCI of the data channel, either of the following two methods can be used. In one way, the SCI of the data channel may include a fifth field, and the fifth field may indicate the first priority. In one example, the fifth field occupies three bits. It is assumed that a range of priority values ​​is from 1 to 8, and the fifth field can indicate a specific first priority. In another example, the fifth field occupies two bits. For example, suppose the first priority is a priority in the priority list {1, 3, 5, 7}. When the fifth field is 00, it indicates that the first priority is 1, that is, a higher priority. Optionally, the priority list is preset or preconfigured and stored on the first device and the second device. In another example, the fifth field occupies one bit. For example, suppose the first priority is a priority in the priority list {1, 3, 5, 7}. When the fifth field is 0, it indicates that the first priority is 1, that is, a higher priority. Optionally, the priority list is preset or preconfigured and stored on the first device and the second device. In a second way, the SCI of the data channel may include a fifth field, and the fifth field may indicate a second difference corresponding to the first priority. The second difference is a difference between the first priority and the second priority. In the second way, the first priority can be the sum of the second priority and the second difference, or the difference between the second priority and the second difference. Furthermore, the second difference can be either a positive or a negative number. One way to obtain first priority based on the second difference in manner is the same as one way to obtain first priority based on the second difference in control channel. For details, refer to the descriptions above. No further details are described herein. Optionally, when the first priority information is carried in the data channel SCI, the data channel SCI can be SCI2-A, or SCI2-B, or it can be an SCI, for example, SCI2-C, other than SCI2-A and SCI2-B. Figure 11 is a diagram of a module structure for a communication device according to one modality of this application. The device may be the first device or a device that enables the first device to implement a function of the first device using the method provided in the modalities of this application. For example, the device may be a device or a system-on-a-chip within the first device. As shown in Figure 11, the device includes a processing module 1101 and a sending module 1102. The processing module 1101 is configured to send information about a first priority and a second priority to a second device when using the sending module 1102. The first priority is used to assist the second device in selecting a resource for sidelink transmission; information about the first priority is carried in SCI and / or a MAC CE, and the second priority is a physical layer priority of a first device. In an optional implementation, processing module 1101 is further configured to send initial information to the second device when using sending module 1102, and the initial information includes any of the following: a set of sidelink transmission resources determined by the first device, and information used by the first device to select a sidelink transmission resource. In an optional implementation, the second priority is a preset value, or the second priority is a priority in a preset priority list, and the preset priority list includes a plurality of priorities. In an optional implementation, the second priority is related to the first priority. In an optional implementation, the second priority is related to a range of the first priority. In an optional implementation, the second priority is either the sum of the first priority and a first difference, or the second priority is the difference between the first priority and a first difference. In an optional implementation, the first difference is indicated by using RRC signaling, or the first difference is a preconfigured value. The first difference can be a positive or negative number. In an optional implementation, the second priority is a higher priority between the first priority and a logical channel priority, and the logical channel priority is a higher priority in the logical channel priorities corresponding to the data of a PSSCH. In an optional implementation, the first priority information is carried in a first subprotocol data unit, the first subprotocol data unit is an access control subprotocol data unit, the first subprotocol data unit includes a first subheader and a first control element, the first subheader includes a first field, and the first field indicates a logical channel number +7C / R7n / C7n7 / a / viAi. In an optional implementation, a first value in the first field in the first subheader indicates that information about the first priority is being transmitted. In the optional implementation, the first subheader includes M bits, M is an integer multiple of 8, the first field occupies N bits in the first subheader, and N is an integer greater than or equal to 6. In an optional implementation, the first control element includes a second field, and the second field indicates information about the first priority. In an optional implementation, the second field includes three bits, two bits, one bit, or four bits. In an optional implementation, the first control element also includes a third field, and the third field indicates the geographic location information of the second device. In an optional implementation, information about the first priority is carried in the SCI. In an optional implementation, the SCI of a control channel includes a fourth field; the fourth field indicates the first priority, or the fourth field indicates a second difference corresponding to the first priority, and the second difference is a difference between the first priority and the second priority. In an optional implementation, the SCI of a data channel includes a fifth field, and the fifth field indicates the first priority or a second difference corresponding to the first priority. In an optional implementation, the data channel SCI includes SCI2-A, SCI2-B, or SCI other than SCI2-A and SCI2-B. In an optional implementation, the first priority is a sum of the second priority and the second difference, or the first priority is a difference between the second priority and the second difference, and the second difference can be a positive number or a negative number. Figure 12 is a diagram of a module structure for another communication device according to one modality of this application. The device may be the second device itself or a device that enables the second device to implement a function of the second device using the method provided in the modalities of this application. For example, the device may be a device or a system-on-a-chip in the second device. As shown in Figure 12, the device includes: a 1201 receiving module, configured to receive information about a first priority and a second priority from a first device, wherein the first priority is used to assist a second device in selecting a resource for sidelink transmission, the information about the first priority being carried in SCI and / or a MAC CE, and the second priority being a physical layer priority of the first device; and a 1202 processing module, configured to select, based on the information about the first priority, a resource for sidelink transmission. In an optional implementation, the 1201 receiver module is further configured to receive first information from the first device, and the first information includes any of the following: a set of sidelink transmission resources determined by the first device, and information used by the first device to select a sidelink transmission resource. In an optional implementation, the second priority is a preset value, or the second priority is a priority in a preset priority list, and the preset priority list includes a plurality of priorities. In an optional implementation, the second priority is related to the first priority. In an optional implementation, the second priority is related to a range of the first priority. In an optional implementation, the second priority is either the sum of the first priority and a first difference, or the second priority is the difference between the first priority and a first difference. In an optional implementation, the first difference is indicated by using RRC signaling, or the first difference is a preconfigured value. The first difference can be a positive or negative number. In an optional implementation, the second priority is a higher priority between the first priority and a logical channel priority, and the logical channel priority is a higher priority in the logical channel priorities corresponding to the data of a PSSCH. In an optional implementation, the information about the first priority is carried in a first subprotocol data unit, the first subprotocol data unit is an access control subprotocol data unit, the first subprotocol data unit includes a first subheader and a first control element, the first subheader includes a first field, and the first field indicates a logical channel number. In an optional implementation, a first value in the first field in the first subheader indicates that information about the first priority is being transmitted. In the optional implementation, the first subheader includes M bits, M is an integer multiple of 8, the first field occupies N bits in the first subheader, and N is an integer greater than or equal to 6. In an optional implementation, the first control element includes a second field, and the second field indicates information about the first priority. In an optional implementation, the second field includes three bits, two bits, one bit, or four bits. In an optional implementation, the first control element also includes a third field, and the third field indicates the geographic location information of the second device. In an optional implementation, information about the first priority is carried in the SCI. In an optional implementation, the SCI of a control channel includes a fourth field; the fourth field indicates the first priority, or the fourth field indicates a second difference corresponding to the first priority, and the second difference is a difference between the first priority and the second priority. In an optional implementation, the SCI of a data channel includes a fifth field, and the fifth field indicates the first priority or a second difference corresponding to the first priority. In an optional implementation, the data channel SCI includes SCI2-A, SCI2-B, or SCI other than SCI2-A and SCI2-B. In an optional implementation, the first priority is a sum of the second priority and the second difference, or the first priority is a difference between the second priority and the second difference, and the second difference can be a positive number or a negative number. The communication device provided in the modalities of this application can perform the steps of the method described in the method modalities. The implementation principles and technical effects of the optical module are similar to those in the method modality. Details are not described again herein. It should be observed and understood that the division of the modules of the previous device is merely a division of logical functions. During actual implementation, some or all of the modules may be integrated into a single physical entity, or the modules may be physically separated. The modules may all be implemented in software invoked by a processing element, or they may all be implemented in hardware. Alternatively, some modules may be implemented in software invoked by a processing element, and some modules may be implemented in hardware. For example, a determination module may be a separate processing element, or it may be integrated into a chip of the previous device for implementation.Furthermore, the determination module can be stored in the memory of the preceding device in program code form (+7C / R7n / C7n7 / 3 / YIAI) and is invoked by a processing element of the preceding device to perform a function of the determination module. Implementations of other modules are similar to the implementation of the determination module. Additionally, all or some of the modules can be integrated together or implemented independently. The processing element herein can be an integrated circuit and have signal processing capabilities. In an implementation process, the steps in the methods or modules can be implemented using a hardware integrated logic circuit in the processing element or using software instructions. For example, the modules described above can be configured as one or more integrated circuits to implement the method described above, such as one or more application-specific integrated circuits (ASIOs), one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs). As another example, when one of the modules described above is implemented as program code programmed by a processing element, the processing element can be a general-purpose processor, such as a central processing unit (CPU), or another processor capable of invoking the program code. As yet another example, the modules can be integrated together and implemented as a system-on-a-chip (SoC). All or some of the modalities can be implemented using software, hardware, firmware, or any combination thereof. When software is used to implement the modalities, all or some of the modalities can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the procedure or functions according to the modalities of this application are generated, in whole or in part. The computer can be a general-purpose computer, a dedicated computer, a computer network, or another programmable device. The computer instructions can be stored on a computer-readable storage medium or transmitted from one computer-readable storage medium to another.For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired connection (e.g., coaxial cable, fiber optic cable, or digital subscriber line (DSL)) or wirelessly (e.g., infrared, radio, or microwave). The computer-readable storage medium can be any usable medium accessible by the computer, or a data storage device, such as a server or data center, that integrates one or more usable media. The usable medium can be magnetic (e.g., a floppy disk, hard disk, or magnetic tape), optical (e.g., a DVD), semiconductor (e.g., a solid-state disk, SSD), or similar. Figure 13 is a schematic diagram of a communication device structure according to one modality of this application. The communication device may be either the first or second device described in the preceding modalities. As shown in Figure 13, a communication device 1300 may include a processor 131 (e.g., a CPU). Optionally, the communication device may also include a memory 132 and / or a transceiver 133. The transceiver 133 is coupled to the processor 131, and the processor 131 controls the transmit and receive actions of the transceiver 133. The memory 132 may store various instructions to implement various processing functions and to carry out steps of the method performed by the first or second device in the modalities of this application. Optionally, the communication apparatus in this modality of the present application may also include a power supply 134, a system bus 135, and a communication interface 136. The transceiver 133 may be integrated into a transceiver unit of the communication apparatus, or it may be a transceiver antenna independent of the communication apparatus. The system bus 135 is configured to implement communication connections between components. The communication interface 136 is configured to implement connection and communication between the communication apparatus and another peripheral device. In this modality of this application, processor 131 is configured to interface with memory 132 and read and execute instructions in memory 132 to implement the steps of the method performed by either the first or second device in the method modalities. Transceiver 133 is interfaced with processor 131, and processor 131 controls transceiver 133 to send and receive a message. The implementation principles and technical effects of transceiver 133 are similar to those in the method modalities. Details are not described again herein. The system bus mentioned in Figure 13 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or similar. The system bus can be classified as an address bus, a data bus, a control bus, or similar. For ease of indication, the system bus is shown with a single thick line in the figure. However, this does not imply that there is only one bus or only one type of bus. The communication interface is configured to implement communication between a database access device and another device (for example, a client, a read / write database, and a read-only database). The memory may include RAM and may also include non-volatile memory, such as at least one magnetic disk drive. The processor referred to in FIGURE 13 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP) or similar, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, discrete hardware components, or similar. Optionally, one version of this application also provides a readable storage medium. The storage medium stores instructions. When the instructions are executed on a computer, the computer is activated to perform the method in the modes shown in Figures 2 through 10. Optionally, one modality of this application further provides a chip for execution instructions, and the chip is configured to perform the method in the modalities shown in FIGURE 2 to FIGURE 10. One embodiment of this application further provides a program product, which includes a computer program. The computer program is stored on a storage medium, at least one processor can read the computer program from the storage medium, and the at least one processor executes the computer program, to implement the method in the embodiments shown in Figures 2 through 10. In the forms of this application, “at least one” means one or more, and “a plurality of” means two or more. AND / OR describes an association relationship between associated objects and represents that three relationships can exist. For example, A AND / OR B can represent the following cases: Only A exists, both A and B exist, and only B exists, where A and B can be singular or plural. The character / generally indicates an OR relationship between the associated objects. In a formula, the character / indicates a division relationship between the associated objects. “At least one of the following elements” or a similar expression thereof refers to any combination of these elements, including any combination of singular or plural elements. For example, “at least one element” of a, b, c can indicate: a, b, c, a and b, a and c, b and c, where a and b and c can be singular or plural. It can be understood that various numbers in the modalities of this application are simply for ease of description and are not intended to limit the scope of the modalities of this application. It can be understood that the sequence numbers of the preceding processes do not signify execution sequences in the various embodiments of the present invention. The execution sequences of the processes must be determined based on the functions and internal logic of the processes and should not be interpreted as any limitation on the implementation processes of the embodiments of this application. Finally, it should be noted that the preceding embodiments are proposed merely to describe the technical solutions of the present invention, but not to limit this application. Although the present invention is described in detail with reference to the preceding embodiments, those skilled in the art should understand that they may still make modifications to the technical solutions described in the preceding embodiments or make equivalent replacements for some or all of their technical features, without departing from the scope of the technical solutions of the present invention.

Claims

1. A communication method, characterized in that it comprises: sending, by means of a first device, a first priority and a second priority to a second device, wherein the first priority is used by the second device in the selection of a sidelink transmission resource of the first device, the first priority is carried in the sidelink control information (SCI) in a shared physical sidelink channel (PSSCH), and / or a media access control element (MAC CE), and the second priority indicates a priority of the PSSCH, the second priority is carried in SCI in a physical sidelink control channel (PSCCH).

2. The method according to claim 1, characterized in that a coordination request is sent by the first device to the second device.

3. The method according to claim 2, characterized in that the coordination request comprises the first priority and the second priority.

4. The method according to claim 1, characterized in that the value of the second priority is 1.

5. The method according to claim 1, characterized in that the first priority is carried in the SCI 2-C ​​in the PSSCH, the SCI 2-C ​​comprises a fifth field, the fifth field indicates the first priority, the fifth field occupies 3 bits.

6. The method according to claim 1, characterized in that the second priority is carried in SCI 1 in the PSCCH.

7. The method according to claim 2, characterized in that the first priority is obtained on the basis of the coordination request.

8. The method according to claim 1, characterized in that the first priority is carried in a first subprotocol data unit, the first subprotocol data unit is a media access control subprotocol data unit, the first subprotocol data unit comprises a first subheader and a first control element, the first subheader comprises a first field, and the first field indicates a logical channel number.

9. The method according to claim 8, characterized in that a first value of the first field in the first subheader indicates that the first priority is transmitted.

10. A communication method, characterized in that it comprises: receiving, by a second device, a first priority and a second priority from a first device, wherein the first priority is used by the second device in selecting a sidelink transmission resource from the first device, the first priority being carried in the sidelink control information (SCI) on a shared sidelink physical channel (PSSCH) and / or a media access control element (MAC CE), and the second priority indicating a PSSCH priority, the second priority being carried in the SCI on a sidelink physical channel (PSCCH); and selecting, by the second device based on the first priority, a sidelink transmission resource from the first device.

11. The method according to claim 10, characterized in that the second device receives a coordination request from the first device.

12. The method according to claim 11, characterized in that the coordination request comprises the first priority and the second priority.

13. The method according to claim 10, characterized in that the value of the second priority is 1.

14. The method according to claim 10, characterized in that the first priority is carried in the SCI 2-C ​​in the PSSCH, the SCI 2-C ​​comprises a fifth field, the fifth field indicates the first priority, the fifth field occupies 3 bits.

15. The method according to claim 10, characterized in that the second priority is carried in SCI 1 in the PSCCH.

16. The method according to claim 11, characterized in that the first priority is obtained on the basis of the coordination request.

17. The method according to claim 10, characterized in that the first priority is carried in a first subprotocol data unit, the first subprotocol data unit is a media access control subprotocol data unit, the first subprotocol data unit comprises a first subheader and a first control element, the first subheader comprises a first field, and the first field indicates a logical channel number.

18. The method according to claim 17, characterized in that a first value of the first field in the first subheader indicates that the first priority is transmitted.

19. The method according to claim 10, characterized in that the sidelink transmission resource of the first device is selected by the second device based on the first priority, a location and length of a resource detection window, a number of resource selection frequency domain sub-bandwidths, a transmission period, and resource group information.

20. A wireless apparatus, characterized in that it comprises: one or more processors; and a memory, wherein the memory stores instructions, and when the instructions stored in the memory are executed, the one or more processors execute operations comprising: sending a first priority and a second priority to a second device, wherein the first priority is used by the second device in selecting a sidelink transmission resource from a first device, the first priority being carried in the sidelink control information (SCI) on a shared physical sidelink channel (PSSCH), and / or a media access control element (MAC CE), and the second priority indicating a PSSCH priority, the second priority being carried in SCI on a physical sidelink control channel (PSCCH).

21. The wireless apparatus according to claim 20, characterized in that the operations further comprise: sending a coordination request to the second device.

22. The wireless apparatus according to claim 21, characterized in that the coordination request comprises the first priority and the second priority.

23. The wireless apparatus according to claim 20, characterized in that the value of the second priority is 1.

24. The wireless apparatus according to claim 20, characterized in that the first priority is carried in the SCI 2-C ​​in the PSSCH, the SCI 2-C ​​comprises a fifth field, the fifth field indicates the first priority, the fifth field occupies 3 bits.

25. The wireless apparatus according to claim 20, characterized in that the second priority is carried in SCI 1 in the PSCCH.

26. The wireless apparatus according to claim 21, characterized in that the first priority is obtained on the basis of the coordination request.

27. The wireless apparatus according to claim 20, characterized in that the first priority is carried in a first subprotocol data unit, the first subprotocol data unit is a media access control subprotocol data unit, the first subprotocol data unit comprises a first subheader and a first control element, the first subheader comprises a first field, and the first field indicates a logical channel number.

28. The wireless apparatus according to claim 27, characterized in that a first value of the first field in the first subheader indicates that the first priority is transmitted.

29. A wireless apparatus, characterized in that it comprises: one or more processors; and a memory, wherein the memory stores instructions, and when the instructions stored in the memory are executed, the one or more processors execute operations comprising: receiving a first priority and a second priority from a first device, where the first priority is used to select a sidelink transmission resource from the first device, the first priority being carried in the sidelink control information, SCI, on a shared physical sidelink channel, PSSCH, and / or a Media Access Control Element (MACCE), and the second priority indicating a priority of the PSSCH, the second priority being carried in the SCI on a physical sidelink control channel, PSCCH; and selecting, based on the first priority, a sidelink transmission resource from the first device.

30. The wireless apparatus according to claim 29, characterized in that it receives a coordination request from the first device.

31. The wireless apparatus according to claim 30, characterized in that the coordination request comprises the first priority and the second priority.

32. The wireless apparatus according to claim 29, characterized in that the value of the second priority is 1.

33. The wireless apparatus according to claim 29, characterized in that the first priority is carried in the SCI 2-C ​​in the PSSCH, the SCI 2-C ​​comprises a fifth field, the fifth field indicates the first priority, the fifth field occupies 3 bits.

34. The wireless apparatus according to claim 29, characterized in that the second priority is carried in SCI 1 in the PSCCH.

35. The wireless apparatus according to claim 30, characterized in that the first priority is obtained on the basis of the coordination request.

36. The wireless apparatus according to claim 29, characterized in that the first priority is carried in a first subprotocol data unit, the first subprotocol data unit is a media access control subprotocol data unit, the first subprotocol data unit comprises a first subheader and a first control element, the first subheader comprises a first field, and the first field indicates a logical channel number.

37. The wireless apparatus according to claim 36, characterized in that a first value of the first field in the first subheader indicates that the first priority is transmitted.

38. The wireless apparatus according to claim 29, characterized in that it selects the resource for sidelink transmission from the first device, based on first priority, a location and length of a resource detection window, a number of resource selection frequency domain sub-bandwidths, a transmission period, and resource group information.

39. A first device, characterized in that it is configured to implement the +7C / R7n / C7n7 / a / viAi method steps in accordance with any of claims 1 to 9.

40. A second device, characterized in that it is configured to implement the method steps in accordance with any of claims 10 to 19.

41. A communication apparatus, characterized in that it comprises a processor and a communication interface, wherein the communication interface is configured to implement connection and communication between the communication apparatus and a peripheral; and the processor is configured to implement the method according to any of claims 1 to 9 or the method according to any of claims 10 to 19.

42. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any of claims 1 to 9 or the method according to any of claims 10 to 19 is implemented.

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