Patent Description:
Wireless communications technologies have undergone rapid development in the past tens of years, and have successively undergone a first generation wireless communications system based on an analog communications system, a <NUM> wireless communications system represented by a global system for mobile communications (global system for mobile communication, GSM), a <NUM> wireless communications system represented by wideband code division multiple access (wideband code division multiple access, WCDMA), and a long term evolution (long term evolution, LTE) wireless communications system that now has been widely put into commercial use in the world and has achieved great success. Services supported by the wireless communications system also developed from original voice and SMS messages to currently supported wireless high-speed data communication. Meanwhile, a quantity of wireless connections worldwide is continuously increasing at a high speed, and various new wireless service types also emerge in a large amount, for example, the internet of things and intelligent transportation. These impose a higher requirement on the wireless communications system.

Device-to-device (device to device, D2D) communication based on a cellular network is a new technology that allows, under control of a system, terminals to directly communicate with each other by reusing a cell resource. The technology can increase spectral efficiency of a cellular communications system and reduce transmit power of the terminals, and a problem of a lack of spectrum resources in a wireless communications system is resolved to some extent.

To improve security and intelligence of a transportation system, an idea of an intelligent transportation system gradually emerges. Recently, development of an intelligent transportation system mainly focuses on the field of an intelligent road transportation system, which is commonly referred to as vehicle-to-everything (vehicle to everything, V2X). Vehicle-to-vehicle (vehicle to vehicle, V2V), vehicle-to-pedestrian (vehicle to pedestrian, V2P), and vehicle-to-infrastructure (vehicle to infrastructure, V2I) are collectively referred to as V2X. These technologies allow vehicles to continuously communicate with all nearby vehicles and road infrastructures, for example, communicate with infrastructures such as traffic lights, campuses, and railway crossings. In a vehicle-to-everything system, when terminal devices communicate with each other, there are usually two resource allocation modes: One mode is that a network device schedules a resource, and the other mode is that the terminal device autonomously selects a resource. When the terminal device autonomously selects a resource, the terminal device needs to first sense (sensing) resources to identify available resources, and then selects a resource from the available resources for data transmission. A longer delay occurs in this process.

In <NPL>, resource selection for pedestrian UEs is discussed and evaluated. <NPL>; <NPL>; <NPL>; and <CIT> represent further documents useful for understanding the prior art of the present invention. <NPL>, and <NPL>, discuss a reduction of the maximum time between packet arrival and selected resource for data transmission. <NPL>, concerns transmitter behavior for sidelink resource re-selection. In the context of LTE V2V Sidelink Communication, a reduction of the resource selection latency is discussed in <NPL>.

Embodiments of this application provide a communication method, a communications apparatus, a computer-readable storage medium and a computer program product according to the independent claims, to reduce a data transmission delay and improve system communication efficiency. Particular embodiments are defined in the dependent claims Any embodiment, example or implementation that is not claimed is only presented as information.

It should be understood that the technical solutions in embodiments of this application may be applied to various communications systems, for example, a global system for mobile communications (global system of mobile communication, GSM), a code division multiple access (code division multiple access, CDMA) system, a wideband code division multiple access (wideband code division multiple access wireless, WCDMA) system, a general packet radio service (general packet radio service, GPRS) system, a long term evolution (long term evolution, LTE) system, and a new radio (new radio, NR) system.

It should be further understood that, in the embodiments of this application, a terminal device may also refer to user equipment (user equipment, UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communications device, a user agent, or a user apparatus. The access terminal may be a cellular phone, a cordless phone, a session initiation protocol (session initiation protocol, SIP) phone, a wireless local loop (wireless local loop, WLL) station, a personal digital assistant (personal digital assistant, PDA), a handheld device having a wireless communication function, a computing device, another processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a future <NUM> network, or a terminal device in a future evolved public land mobile network (public land mobile network, PLMN) network, or the like.

It should be understood that in the embodiments of this application, the terminal device may be a communications terminal or an in-vehicle communications device installed in a car, or may be another modular and detachable in-vehicle terminal that can implement a communication function. In terms of functions, the terminal device needs to implement information communication of services such as vehicle-to-vehicle (vehicle to vehicle, V2V), vehicle-to-pedestrian (vehicle to pedestrian, V2P), and vehicle-to-infrastructure (vehicle to infrastructure, V2I) services. These services may be collectively referred to as a V2X service. Therefore, the V2X service in the embodiments of this application may include one or more of the following services: the V2V service, the V2I service, and the vehicle-to-pedestrian V2P service.

In some embodiments, the terminal device mentioned in this application may alternatively be a wearable device. The wearable device may also be referred to as a wearable intelligent device, and is a generic term for wearable devices such as glasses, gloves, watches, clothes, and shoes that are developed by applying wearable technologies to intelligent designs of daily wear. The wearable device is a portable device that can be directly worn on a body or integrated into clothes or an accessory of a user. The wearable device is not only a hardware device, but is used to implement powerful functions through software support, data exchange, and cloud interaction. Generalized wearable intelligent devices include full-featured and large-size devices that can implement complete or partial functions without depending on smartphones, for example, smartwatches or smart glasses, and devices that focus on only one type of application function and need to work with other devices such as smartphones, for example, various smart bands or smart jewelry for monitoring physical signs.

It should be understood that in the embodiments of this application, a network device may be a device that is located on a network side and that communicates with the terminal device. The network device may be a base transceiver station (base transceiver station, BTS) in a GSM or in CDMA, or may be a NodeB (NodeB, NB) in a WCDMA system, or may be an evolved NodeB (evolutional Node B, eNB, or eNodeB) in an LTE system, or may be a next generation NodeB (next generation Node B, gNB) in a future <NUM> network, or may be a wireless controller in a cloud radio access network (cloud radio access network, CRAN) scenario. Alternatively, the network device may be a relay station, an access point, a network device in a future <NUM> network, a network device in a future evolved public land mobile network (public land mobile network, PLMN), or the like.

<FIG> is a schematic diagram of a communications system <NUM> used in an embodiment of this application. In an application scenario in <FIG>, the communications system <NUM> may include a network device <NUM> and terminal devices <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. The network device may be connected to the terminal devices in a wireless manner, and the terminal devices may be connected to each other in a wireless manner. It should be understood that <FIG> is described merely by using an example in which the system includes five terminal devices. However, this embodiment of this application is not limited thereto. For example, the communications system <NUM> may further include more terminal devices. Similarly, the system may also include more network devices. This is not limited in this embodiment of this application.

In the application scenario shown in <FIG>, D2D communication may be performed between the terminal devices, and a communications link between the terminal devices may be referred to as a sidelink (sidelink). Release <NUM> (release <NUM>) of the 3rd generation partnership project (3rd generation partnership project, 3GPP) defines a V2X link (for example, may include at least one of the following links: a V2V link, a V2I link, and a V2P link) that is enhanced based on a D2D link. The D2D link and the V2X link may communicate with each other by using different interfaces.

As shown in <FIG>, D2D communication may be classified into three types: D2D communication that is covered by a network, D2D communication that is partially covered by a network, and D2D communication that is not covered by a network. For example, the terminal device <NUM> in <FIG> is within coverage of the network device <NUM>, and can receive a signal of the network device <NUM>. That is, the terminal device <NUM> is covered by the network, and may be referred to as a terminal device within network coverage. The terminal device <NUM> is not within coverage of the network device <NUM>, but the terminal device <NUM> can receive a signal of the terminal device <NUM> that is within network coverage. Therefore, the terminal device <NUM> is partially covered by the network, and may be referred to as a terminal device partially within network coverage. The terminal devices <NUM>, <NUM>, and <NUM> are not within coverage of the network device <NUM>, and the terminal devices <NUM>, <NUM>, and <NUM> cannot receive the signal of the terminal device <NUM> that is within network coverage. In this case, the terminal devices <NUM>, <NUM>, and <NUM> are not covered by the network, and may be referred to as terminal devices beyond network coverage.

There may be two resource allocation manners for the terminal device on the sidelink. One manner is a mode <NUM> (mode <NUM>) in which the network device allocates a resource to the terminal device, and the other manner is a mode <NUM> (mode <NUM>) in which the terminal device autonomously selects an available resource. Usually, the network system may include more than one terminal device. The mode <NUM> may be used for a terminal device that is covered by the network, for example, the terminal device <NUM> in <FIG>. The mode <NUM> may be used for a terminal device that is not covered by the network, for example, the terminal devices <NUM>, <NUM>, and <NUM> in <FIG>. In a conventional technology, the terminal device for which the mode <NUM> is used may obtain a sending resource from a resource pool in a contention manner. The resource pool may be a block of resource that is configured by the network device or that is pre-configured. The terminal device for which the mode <NUM> is used may contend for the resource in the resource pool. Before transmitting data, the terminal device needs to sense resources, to identify available resources and unavailable resources, and then selects the resource from the available resources for data transmission. Because the terminal device obtains the resource in the contention manner, there is a relatively high probability that two or more terminal devices select a same block of resource, and a conflict easily occurs. Consequently, a relatively high delay is generated during data transmission.

Based on this, the embodiments of this application provide a communication method, to reduce a data transmission delay and improve system communication efficiency. <FIG> is a schematic flowchart of a communication method according to an embodiment of this application.

The communication method shown in <FIG> may include step <NUM>, step <NUM>, step <NUM>, and step <NUM>.

S210: A first terminal device determines a first parameter, where the first parameter is used to indicate a parameter of a sensing window or a parameter of a first time window, and the first time window includes the sensing window and a resource selection window.

That the first time window includes the sensing window and the resource selection window may be understood as that duration of the first time window is not less than a sum of duration of the sensing window and duration of the resource selection window. In other words, the first time window includes the sensing window and the resource selection window.

In a possible implementation in this embodiment of this application, the first parameter may include at least one of the following parameters: a start time of the sensing window, an end time of the sensing window, a of the sensing window, a start time of the first time window, an end time of the first time window, or a length of the first time window.

S220: The first terminal device determines a first resource pool from at least one resource pool based on the first parameter.

One resource pool in the at least one resource pool may have a corresponding time window parameter, and a time window parameter corresponding to the first resource pool is the first parameter.

In a possible implementation in this embodiment of this application, the at least one resource pool may be one resource pool. In this case, the first terminal device may select the resource pool as the first resource pool.

In this embodiment of this application, that one resource pool in the at least one resource pool has a corresponding time window parameter may be understood as that the resource pool in the at least one resource pool is in a one-to-one correspondence with the time window parameter.

As shown in <FIG>, before transmitting data, the first terminal device may perform sensing in a sensing window (sensing window), to identify available resources and unavailable resources, and then selects a resource in a resource selection window (selection window) for data transmission. As shown in <FIG>, a start time of the sensing window is n a, an end time of the sensing window is n-b, a start time of the resource selection window is n+T1, and an end time of the resource selection window is n+T2, where n, a, b, T1, and T2 are all positive integers, n≥a, and n>b.

In this embodiment of this application, at least one resource pool may be predefined. For example, the at least one resource pool may have separate configurations independent of each other. Optionally, different resource pools in the at least one resource pool may correspond to different time window parameters.

For example, the first parameter is used to indicate the resource selection window, and the first parameter includes the start time and the end time of the resource selection window. Three resource pools may be preconfigured, and respectively correspond to different resource selection windows. For example, it is assumed that the resource selection window in <FIG> corresponds to a case in which T1=<NUM> and <NUM>≤T2<<NUM>. As shown in the following table, three resource pools may be preconfigured, and respectively correspond to end times of different resource selection windows.

It should be understood that start times of resource selection windows in Table <NUM> may be the same. In this case, the start times of the resource selection windows may also be preset. In other words, the time window parameter of the resource pool may be used to indicate only the end time of the resource selection window, and the first terminal device may determine the first resource pool by using the preset start times of the resource selection windows.

Optionally, the start times of the resource selection windows in Table <NUM> may be different. It should be understood that parameters of sensing windows corresponding to resource pools may also be different. Correspondingly, parameters of first time windows are also different. In this embodiment of this application, a case in which the first parameter is used to indicate the sensing window and the first time window is similar to this case.

Optionally, the first parameter may include the end time of the resource selection windows. For example, using the resource pool configuration method in Table <NUM> as an example, the first terminal device may determine the first parameter, namely, the end time of the resource selection window. The first terminal device may select, from the three resource pools in Table <NUM>, a resource pool corresponding to the end time of the resource selection window as the first resource pool. To be specific, if the end time of the resource selection window falls within a range of a specific end time in Table <NUM>, the resource pool corresponding to the end time is used as the first resource pool.

In this embodiment of this application, the sensing window indicated by the first parameter may be an independent sensing window, or may be a sensing window included in the first time window. The resource selection window indicated by the first parameter may be an independent resource selection window, or may be a resource selection window included in the first time window.

Optionally, duration, indicated by the first parameter, of the resource selection window may be greater than or equal to a processing delay of the first terminal device. The processing delay herein may be a delay in processing a sensing result by the first terminal device, or a delay in preparing to-be-sent data by the first terminal device.

Optionally, the duration, indicated by the first parameter, of the resource selection window may be less than or equal to duration of a sensing window of the first resource pool.

Optionally, the duration, indicated by the first parameter, of the resource selection window may be a smaller value in the duration of the sensing window of the first resource pool and duration corresponding to a service delay requirement of the first terminal device.

Optionally, the parameter, indicated by the first parameter, of the sensing window may be determined based on a resource location of a control channel and/or a time domain length of the control channel.

In this embodiment of this application, the first terminal device may receive resource pool configuration information from a network device, where the resource pool configuration information is used to indicate the at least one resource pool and at least one time window parameter corresponding to the at least one resource pool.

In this embodiment of this application, the network device may send a resource pool configuration message by using a master information block (master information block, MIB), a system information block (system information block, SIB), radio resource control (radio resource control, RRC) signaling, media access control (media access control, MAC) layer signaling, and physical layer signaling (for example, downlink control information (downlink control information, DCI)).

In this embodiment of this application, the network device may send configuration information of a bandwidth part (band width part, BWP) or configuration information of a carrier (carrier) to the first terminal device. The configuration information of the BWP or of the carrier carries the resource pool configuration information.

It should be noted that the resource pool in this embodiment of this application may alternatively be a BWP. For example, the resource pool may be a BWP used for sidelink transmission. Alternatively, the resource pool in this embodiment of this application may be a resource pool in a BWP, or may be a resource pool in a carrier.

Optionally, the network device may configure different resource pools for different terminal devices, or may configure a same resource pool for a plurality of terminal devices.

Optionally, the resource pool configuration information may be used to indicate a time window parameter of a resource pool in a specific time period. After the time period, the network device may resend the resource pool configuration information to the first terminal device. Alternatively, the network device may resend the resource pool configuration information to the first terminal device after being triggered by a condition or an action.

Optionally, duration of a sensing window, a resource selection window, and/or a first time window, of a first resource pool in the at least one resource pool, may be in a unit of a slot or a symbol.

Optionally, a sensing window of a second resource pool in the at least one resource pool may be a periodic sensing window, or a resource selection window of a second resource pool in the at least one resource pool may be a periodic resource selection window, or a first time window of a second resource pool in the at least one resource pool may be a periodic first time window. The second resource pool in the at least one resource pool herein may be the first resource pool.

Optionally, the sensing window may be located at the beginning of a periodicity. It is assumed that the periodicity P=<NUM> milliseconds (ms), and the terminal device may perform sensing in the first <NUM> of every <NUM>.

Optionally, the resource selection window may be located at the end of a periodicity. It is assumed that the periodicity P=<NUM>, and the terminal device may perform resource selection in the last <NUM> of every <NUM>.

Optionally, a maximum value of the duration of the resource selection window may be duration in a sensing periodicity other than duration of the sensing window.

The sensing periodicity may be configured by the network device for the terminal device, or may be set by the terminal device based on a service periodicity.

In this embodiment of this application, duration of a resource selection window of the first resource pool may be determined based on the sensing result.

In a possible implementation, the duration of the resource selection window of the first resource pool or the resource selection window in the first time window may be determined based on a proportion of available resources in the sensing result. If the proportion of the available resources in the sensing result is relatively small, for example, less than or equal to <NUM>%, a resource selection window with relatively short duration may be selected. If the proportion of the available resources in the sensing result is relatively large, for example, greater than <NUM>%, a resource selection window with relatively long duration may be selected. Optionally, if the first terminal device fails in contention, duration of a next resource selection window may be increased. If the first terminal device succeeds in contention, duration of a next resource selection window may be reduced.

S230: The first terminal device selects a first resource from the first resource pool.

In a possible implementation, the first parameter of the first resource pool may include the parameter of the first time window, and the first time window includes the sensing window and the resource selection window. For example, the first terminal device may determine the duration of the sensing window of the first resource pool based on the sensing result, and the first terminal device may determine the duration of the resource selection window of the first resource pool based on the parameter of the first time window and the duration of the sensing window of the first resource pool. In this case, the first terminal device may select the first resource in the resource selection window of the first resource pool.

In another possible implementation, the duration of the sensing window of the first resource pool may be greater than or equal to the duration of the resource selection window of the first resource pool. The first terminal device may select the first resource in the resource selection window of the first resource pool based on a sensing result of a first time period in the sensing window. In this case, duration of the first time period may be equal to the duration of the resource selection window of the first resource pool.

Optionally, a start time of the first time period may be a start time of the sensing window of the first resource pool.

In another possible implementation, the duration of the sensing window of the first resource pool may be less than or equal to the duration of the resource selection window of the first resource pool. The first terminal device selects the first resource in a second time period in the resource selection window of the first resource pool based on a sensing result of the sensing window of the first resource pool. Duration of the second time period is equal to the duration of the sensing window of the first resource pool.

Optionally, a start time of the second time period may be a start time of the resource selection window of the first resource pool.

S240: The first terminal device transmits sidelink information on the first resource.

The sidelink information may be specifically a sidelink channel or a sidelink signal, and may include resource selection of a physical sidelink control channel (physical sidelink control channel, PSCCH), resource selection of a physical sidelink shared channel (physical sidelink shared channel, PSSCH), resource selection of a physical sidelink feedback channel (physical sidelink feedback channel, PSFCH), resource selection of a physical sidelink discovery channel (physical sidelink discovery channel, PSDCH), or resource selection of a physical sidelink broadcast channel (physical sidelink broadcast channel, PSBCH), or may be used for another channel or signal.

That the first terminal device transmits sidelink information on the first resource may be that the first terminal device transmits the sidelink information with a second terminal device, or may be that the first terminal device transmits the sidelink information with a plurality of second terminal devices. The method in this embodiment of this application may be used in a unicast scenario, may be used in a multicast scenario, and may further be used in a broadcast scenario. For example, in the unicast scenario, a terminal device <NUM> (transmit end) sends information on a link A, and a terminal device <NUM> (receive end) may receive the information on the link A. In the multicast scenario, the terminal device <NUM> sends information on the link A, and a terminal device <NUM> (receive end) and a terminal device <NUM> (receive end) that are in a same group as the terminal device <NUM> may receive the information on the link A. In the broadcast scenario, the terminal device <NUM> sends information on the link A, and any terminal device that can receive information from the terminal device <NUM> may receive the information on the link A.

In the unicast scenario, the transmit end may establish links to a plurality of receive ends. For example, for a terminal device <NUM> at a transmit end, the terminal device <NUM> may independently communicate with a plurality of terminal devices. For another example, the terminal device <NUM> and a terminal device <NUM> may establish a link A. The terminal device <NUM> sends information on the link A, and the terminal device <NUM> receives the information on the link A. The terminal device <NUM> and a terminal device <NUM> establish a link B. The terminal device <NUM> sends information on the link B, and the terminal device <NUM> receives the information on the link B.

The communication method in <FIG> may be used for the resource selection of the physical sidelink control channel PSCCH, or may be used for the resource selection of the physical sidelink shared channel PSSCH, or may be used for the resource selection of the physical sidelink feedback channel PSFCH, or may be used for the resource selection of the physical sidelink discovery channel PSDCH, or may be used for the resource selection of the physical sidelink broadcast channel PSBCH, or may be used for the resource selection of the another channel or signal. This is not limited in this embodiment of this application.

<FIG> is a schematic flowchart of a communication method according to an embodiment of this application. The communication method shown in <FIG> may include step <NUM>, step <NUM>, and step <NUM>.

S410: A first terminal device determines a first parameter, where the first parameter is used to indicate a parameter of a sensing window or a parameter of a first time windowand the first time window includes the sensing window and a resource selection window.

The duration of the sensing window, the resource selection window, and/or the first time window is in a unit of a slot or a symbol. In this embodiment of this application, for a subcarrier spacing of <NUM> kilohertz (kHz), a slot may be <NUM>. For a normal cyclic prefix (normal cyclic prefix, NCP), a slot may include <NUM> symbols, and for an extended cyclic prefix (extended cyclic prefix, ECP), a slot may include <NUM> symbols.

Optionally, when the duration of the sensing window, the resource selection window, and/or the first time window is in a unit of a slot, the duration of the sensing window, the resource selection window, and/or the first time window is at least one slot.

Optionally, when the duration of the sensing window, the resource selection window, and/or the first time window is in a unit of a symbol, the duration of the sensing window, the resource selection window, and/or the first time window is at least one symbol.

The first parameter includes at least one of the following parameters: a start time of the sensing window, an end time of the sensing window, a length of the sensing window, a length of the resource selection window, a start time of the first time window, an end time of the first time window, or a length of the first time window.

In this embodiment of this application, duration, indicated by the first parameter, of the resource selection window may be greater than or equal to a processing delay of the first terminal device. The processing delay herein may be a delay in processing a sensing result by the first terminal device, or a delay in preparing to-be-sent data by the first terminal device.

In this embodiment of this application, the first terminal device may receive resource pool configuration information from a network device, where the resource pool configuration information is used to indicate a window parameter corresponding to the first resource pool.

In this embodiment of this application, the network device may send a resource pool configuration message by using a master information block MIB, a system information block SIB, radio resource control RRC signaling, media access control MAC layer signaling, and physical layer signaling (for example, DCI).

In this embodiment of this application, the network device may send configuration information of a BWP or of a carrier to the first terminal device, where the configuration information of the BWP or of the carrier carries the resource pool configuration information.

Optionally, the duration of the sensing window, the resource selection window, and/or the first time window, of the first resource pool, may be in a unit of a slot or a symbol.

Optionally, the network device may configure configuration information of a plurality of resource pools for the first terminal device.

For example, the resource pool configuration information is used to indicate a symbol-level resource selection window. Three resource pools may be preconfigured, and respectively correspond to different resource selection windows. As shown in <FIG>, three resource pools may be preconfigured, and respectively correspond to resource granularities of different resource selection windows.

In this embodiment of this application, a case in which the first parameter is used to indicate the sensing window and the first time window is similar to this case.

Optionally, the sensing window of the first resource pool may be a periodic sensing window, or the resource selection window of the first resource pool may be a periodic resource selection window, or the first time window of the first resource pool may be a periodic first time window.

Optionally, the sensing window may be located at the beginning of a periodicity. It is assumed that the periodicity P=<NUM>, and the terminal device may perform sensing in the first L1 slots of every <NUM>. It is assumed that the periodicity P=<NUM> slot, for example, <NUM> symbols, and the terminal device may perform sensing in the first L1 symbols of a slot. L1 herein is a positive integer.

Optionally, the resource selection window may be located at the end of a periodicity. It is assumed that the periodicity P=<NUM>, and the terminal device may perform resource selection in the last L1 slots of every <NUM>. It is assumed that the periodicity P=<NUM> slot, for example, <NUM> symbols, and the terminal device may perform resource selection in the last L1 symbols of a slot.

In this embodiment of this application, the duration of the resource selection window of the first resource pool may be determined based on the sensing result.

In a possible implementation, the duration of the resource selection window of the first resource pool or the resource selection window in the first parameter may be determined based on a proportion of available resources in the sensing result. If the proportion of the available resources in the sensing result is relatively small, for example, less than or equal to <NUM>%, a resource selection window with relatively short duration may be selected. If the proportion of the available resources in the sensing result is relatively large, for example, greater than <NUM>%, a resource selection window with relatively long duration may be selected. Optionally, if the first terminal device fails in contention, duration of a next resource selection window may be increased. If the first terminal device succeeds in contention, duration of a next resource selection window may be reduced.

S420: The first terminal device selects a first resource from the first resource pool based on the first parameter.

Optionally, the duration of the first time period is at least one slot or one symbol.

S430: The first terminal device transmits sidelink information on the first resource.

The sidelink information may be specifically a sidelink channel or a sidelink signal, and may include resource selection of a physical sidelink control channel PSCCH, resource selection of a physical sidelink shared channel PSSCH, resource selection of a physical sidelink feedback channel PSFCH, resource selection of a physical sidelink discovery channel PSDCH, resource selection of a physical sidelink broadcast channel PSBCH, or another channel or signal.

In the unicast scenario, the transmit end may establish links to a plurality of receive ends. For example, for a terminal device <NUM> at a transmit end, the terminal device <NUM> may independently communicate with a plurality of terminal devices. For example, the terminal device <NUM> and a terminal device <NUM> establish a link A. The terminal device <NUM> sends information on the link A, and the terminal device <NUM> receives the information on the link A. The terminal device <NUM> and a terminal device <NUM> establish a link B. The terminal device <NUM> sends information on the link B, and the terminal device <NUM> receives the information on the link B.

<FIG> is a schematic block diagram of a communications apparatus <NUM> according to an embodiment of this application. It should be understood that the communications apparatus <NUM> is merely an example. The communications apparatus in this embodiment of this application may further include other modules or units, may include modules having functions similar to those of the modules in <FIG>, or may not necessarily include all the modules in <FIG>.

In an embodiment of this application, a processing unit <NUM> is configured to determine a first parameter, where the first parameter is used to indicate a parameter of a sensing window, or a parameter of a first time window, and the first time window includes the sensing window and a resource selection window.

The processing unit <NUM> is configured to determine a first resource pool from at least one resource pool based on the first parameter.

The processing unit <NUM> is configured to select a first resource from the first resource pool.

A transmission unit <NUM> is configured to transmit sidelink information on the first resource.

It should be understood that the transmission unit <NUM> may be a sending unit, and is used by the communications apparatus <NUM> to send sidelink control information or sidelink data to another communications apparatus. Alternatively, the transmission unit <NUM> may be a receiving unit, and is used by the communications apparatus <NUM> to receive sidelink control information or sidelink data from another communications apparatus.

Optionally, one resource pool in the at least one resource pool has a corresponding time window parameter, and a time window parameter corresponding to the first resource pool is the first parameter.

Optionally, duration, indicated by the first parameter, of the resource selection window is greater than or equal to a processing delay of the first terminal device.

Optionally, the duration, indicated by the first parameter, of the resource selection window is less than or equal to duration of the sensing window.

Optionally, the duration, indicated by the first parameter, of the resource selection window is a smaller value in duration of a sensing window of the first resource pool and duration corresponding to a service delay requirement of the first terminal device.

Optionally, the parameter, indicated by the first parameter, of the sensing window is determined based on a resource location of a control channel and/or a time domain length of the control channel.

Optionally, the duration, indicated by the first parameter, of the resource selection window is determined based on a sensing result.

Optionally, that the processing unit <NUM> is configured to select a first resource from the first resource pool includes: The duration of the sensing window of the first resource pool is greater than or equal to duration of a resource selection window of the first resource pool, the processing unit is configured to select the first resource from the first resource pool based on a sensing result of a first time period in the sensing window, and duration of the first time period is equal to the duration of the resource selection window of the first resource pool.

Optionally, a start time of the first time period is a start time of the sensing window of the first resource pool.

Optionally, that the processing unit <NUM> is configured to select a first resource from the first resource pool includes: The duration of the sensing window of the first resource pool is less than or equal to duration of a resource selection window of the first resource pool, the processing unit is configured to select the first resource in a second time period in the resource selection window of the first resource pool based on a sensing result of the sensing window of the first resource pool, and duration of the second time period is equal to the duration of the sensing window of the first resource pool.

Optionally, a start time of the second time period is a start time of the resource selection window of the first resource pool.

The first parameter includes at least one of the following parameters: a start time of the sensing window, an end time of the sensing window, a start time of the first time window, an end time of the first time window, or a length of the first time window.

Optionally, the transmission unit <NUM> is further configured to: receive resource pool configuration information from a network device, where the resource pool configuration information is used to indicate the at least one resource pool and at least one time window parameter corresponding to the at least one resource pool.

In another embodiment of this application, a processing unit <NUM> is configured to determine a first parameter, where the first parameter is used to indicate a parameter of a sensing window, a parameter of a resource selection window, and/or a parameter of a first time window, and the first time window includes the sensing window and the resource selection window, or the first parameter is used to indicate: the parameter of the sensing window, or the parameter of the first time window.

The processing unit <NUM> is configured to select a first resource from a first resource pool based on the first parameter.

Optionally, duration of the sensing window, the resource selection window, and/or the first time window is in a unit of a slot or a symbol.

Optionally, a sensing window of the first resource pool is located before a resource selection window of the first resource pool in time domain.

Optionally, that the processing unit <NUM> is configured to select a first resource from a first resource pool based on the first parameter includes: Duration of the sensing window of the first resource pool is greater than or equal to duration of the resource selection window of the first resource pool, the processing unit is configured to select the first resource from the first resource pool based on a sensing result of a first time period in the sensing window, and duration of the first time period is equal to the duration of the resource selection window of the first resource pool.

Optionally, that the processing unit <NUM> is configured to select a first resource from a first resource pool based on the first parameter includes: Duration of the sensing window of the first resource pool is less than or equal to duration of the resource selection window of the first resource pool, the processing unit is configured to select the first resource in a second time period in the resource selection window of the first resource pool based on a sensing result of the sensing window of the first resource pool, and duration of the second time period is equal to the duration of the sensing window of the first resource pool.

Optionally, the sensing window of the first resource pool is a periodic sensing window, or the resource selection window of the first resource pool is a periodic resource selection window, or a first time window of the first resource pool is a periodic first time window.

<FIG> is a schematic structural diagram of a network element according to an embodiment of this application. It should be understood that the communications apparatus <NUM> shown in <FIG> is merely an example. The communications apparatus in this embodiment of this application may further include other modules or units, or may include modules having functions similar to those of the modules in <FIG>.

The communications apparatus <NUM> may include one or more processors <NUM>, one or more memories <NUM>, a receiver <NUM>, and a transmitter <NUM>. The receiver <NUM> and the transmitter <NUM> may be integrated together to obtain a transceiver. The memory <NUM> is configured to store program code executed by the processor <NUM>. The processor <NUM> may be integrated with the memory <NUM>, or the processor <NUM> is coupled to one or more memories <NUM>, and is configured to invoke instructions in the memory <NUM>.

In an embodiment, the processor <NUM> may be configured to implement operations or steps that can be implemented by a determining module <NUM> and a selection module <NUM> in <FIG>. The receiver <NUM> and the transmitter <NUM> may be configured to implement operations or steps that can be implemented by a transmission module <NUM> in <FIG>.

It should be understood that the processor in the embodiments of this application may be a central processing unit (central processing unit, CPU), or the processor may be another general-purpose processor, a digital signal processor (digital signal processor, DSP), an application-specific integrated circuit (application specific integrated circuit, ASIC), a field programmable gate array (field programmable gate array, FPGA) or another programmable logic device, a discrete gate or a transistor logic device, a discrete hardware component, or the like. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor or the like.

It should be further understood that the memory in the embodiments of this application may be a volatile memory or a non-volatile memory, or may include both a volatile memory and a non-volatile memory. The non-volatile memory may be a read-only memory (read-only memory, ROM), a programmable read-only memory (programmable ROM, PROM), an erasable programmable read-only memory (erasable PROM, EPROM), an electrically erasable programmable read-only memory (electrically EPROM, EEPROM), or a flash memory. The volatile memory may be a random access memory (random access memory, RAM), and is used as an external cache. Through example but not limitative description, random access memories (random access memory, RAM) in various forms are available, for example, a static random access memory (static RAM, SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (synchronous DRAM, SDRAM), a double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), an enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), a synchlink dynamic random access memory (synchlink DRAM, SLDRAM), and a direct rambus random access memory (direct rambus RAM, DR RAM).

All or some of the foregoing embodiments may be implemented by using software, hardware, firmware, or any other combination thereof. When software is used to implement the embodiments, all or some of the foregoing embodiments may be implemented in a form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or some of the procedures or functions according to the embodiments of this application are generated. The computer may be a general-purpose computer, a dedicated computer, a computer network, or another programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or may be transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (for example, infrared, radio, or microwave) manner. The computer-readable storage medium may be any usable medium accessible by a computer, or a data storage device, such as a server or a data center, integrating one or more usable media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, or a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium may be a solid-state drive.

It should be understood that the term "and/or" in this specification describes only an association relationship between associated objects and represents that three relationships may exist.

It should be understood that sequence numbers of the foregoing processes do not mean execution sequences in the embodiments of this application.

A person of ordinary skill in the art may be aware that units, algorithms, and steps in the examples described with reference to the embodiments disclosed in this application can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed in a manner of hardware or software depends on particular applications and design constraint conditions of the technical solutions.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in another manner. For example, the apparatus embodiments described above are merely examples. For example, division into the units is merely logical function division, and may be other division during actual implementation. In addition, the displayed or discussed mutual couplings, direct couplings, or communication connections may be implemented by using some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electrical, mechanical, or other forms.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, that is, may be located in one position, or may be distributed on a plurality of network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solutions in the embodiments.

When the functions are implemented in a form of a software functional unit and sold or used as an independent product, the functions may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions in this application essentially, the part contributing to the conventional technology, or some of the technical solutions may be implemented in a form of a software product. The computer software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) to perform all or some of the steps of the methods in the embodiments of this application. The storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk, or an optical disc.

Claim 1:
A communication method, comprising:
determining (S210, S410), by a first terminal device (<NUM>, ..., <NUM>), a first parameter;
determining (S220), by the first terminal device (<NUM>,...,<NUM>), a first resource pool from at least one resource pool based on the first parameter;
selecting (S230, S420), by the first terminal device (<NUM>, ..., <NUM>) a first resource from the first resource pool and
transmitting (S240, S430) , by the first terminal device (<NUM>, ..., <NUM>), sidelink information on the first resource;
characterized in that
the first parameter is used to indicate:
a parameter of a sensing window, or a parameter of a first time window, and the first time window comprises the sensing window and a resource selection window;
wherein the first parameter comprises at least one of the following parameters: a start time of the sensing window, an end time of the sensing window, a length of the sensing window, a start time of the first time window, an end time of the first time window, or a length of the first time window.