CN113746604A

CN113746604A - Communication method and communication device of sidelink

Info

Publication number: CN113746604A
Application number: CN202010474835.6A
Authority: CN
Inventors: 李翔宇; 王君; 范强
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2021-12-03
Also published as: WO2021238669A1

Abstract

The application provides a wireless communication method and a communication device. The method comprises the following steps: after first data is sent to second terminal equipment by first terminal equipment, a first timer is started or restarted, the first terminal equipment does not send first information to the second terminal equipment during the running period of the first timer, the first information indicates the first terminal equipment to schedule retransmission data corresponding to a first HARQ process, and the first HARQ process is an HARQ process corresponding to the first data. Accordingly, the second terminal device starts or restarts the third timer after receiving the first data, and does not receive the first information from the first terminal device during the operation of the third timer. In order to reduce the power consumption of the terminal device.

Description

Communication method and communication device of sidelink

Technical Field

The present application relates to the field of communications, and in particular, to a communication method and a communication apparatus for a sidelink.

Background

The internet of vehicles (V2X) is considered as the system of Internet of thingsThe method has one of the fields with most clear industrial potential and market demand, has the characteristics of wide application space, large industrial potential and strong social benefit, and has important significance for promoting the innovative development of the automobile and information communication industry, constructing a new mode and new state of automobile and traffic service, promoting the innovation and application of the automatic driving technology and improving the traffic efficiency and the safety level. The development of intelligent transportation systems has pushed the development of internet of vehicles (IoV) from the traditional internet of vehicles supporting only on-board information services to the next generation internet of vehicles supporting all-in-vehicle (V2X) services. Applications of the V2X system include: vehicle to vehicle (V2V), vehicle to roadside infrastructure (V2I), vehicle to pedestrian (V2P) or vehicle to network (V2N), etc. The application of the V2X system can improve driving safety, reduce congestion and vehicle energy consumption, improve traffic efficiency, vehicle-mounted entertainment information and the like. Third generation partnership project (the 3)^rdgeneration partially required project, 3GPP) has established a relevant communication standard for V2X in the Long Term Evolution (LTE) system. V2X is also a hot topic of discussion in New Radio (NR) systems, and NR-V2X needs to support more complex and diverse scenarios, such as unicast, broadcast and multicast scenarios. As application scenarios and traffic demands expand, power consumption issues of V2X devices raise concerns.

Disclosure of Invention

The application provides a communication method and a communication device of a sidelink, which aim to reduce the power consumption of terminal equipment.

In a first aspect, a wireless communication method is provided, which may be executed by a first terminal device or a module (such as a chip or a processor) configured (or used) in the first terminal device, and is described as an example executed by the first terminal device.

The method comprises the following steps: a first terminal device sends first data to a second terminal device, wherein the first data corresponds to a first hybrid automatic repeat request (HARQ) process; the first terminal device starts or restarts a first timer, where the first timer is used to indicate a minimum time interval before first information can be sent to the second terminal device, and the first information indicates the first terminal device to schedule retransmission data corresponding to the first HARQ process.

That is, after the first terminal device sends the first data to the second terminal device, the first timer is started or restarted; and the first terminal equipment sends first information to the second terminal equipment after the first timer is overtime.

Or after the first terminal device sends the first data to the second terminal device, starting or restarting the first timer; during the running of the first timer, the first terminal device does not send the first information to the second terminal device.

By way of example and not limitation, the duration of the first timer is protocol specified or preconfigured. Optionally, the duration of the first timer may be related to the data processing time of the second terminal device and/or the time when the first terminal device is ready to retransmit data.

According to the above scheme, after the first terminal device sends data to the second terminal device, the second terminal device needs time to process the data and/or the first terminal device needs time to prepare for retransmission of the data, and the like, the first terminal device stops sending the scheduling indication information (i.e. the first information) of the retransmission data corresponding to the first HARQ process to the second terminal device within a period of time, so that the second terminal device can determine that the first terminal device does not send the first information but does not detect the first information within the period of time, the terminal devices performing sidelink communication can have consistent understanding on the received and sent data, unnecessary power consumption of the terminal devices is reduced, and electric energy is saved.

With reference to the first aspect, in certain implementations of the first aspect, the starting or restarting the first timer includes: the HARQ feedback of the first HARQ process is enabled, and the first terminal device starts or restarts the first timer after receiving HARQ feedback information from the second terminal device, where the HARQ feedback information corresponds to the first HARQ process.

According to the scheme, the first terminal device does not transmit the first information within a period of time after receiving the HARQ feedback information from the second terminal device, and the time period for the first terminal device to transmit the first information is regulated, so that the terminal devices performing the sidelink communication can have consistent understanding on the transmitted and received data, and unnecessary power consumption of the terminal devices is reduced.

With reference to the first aspect, in certain implementations of the first aspect, the HARQ feedback information indicates that the first data was not successfully received.

According to the scheme, after the first terminal device determines that the second terminal device does not successfully receive the first data according to the HARQ feedback information, retransmission preparation is carried out within a period of time, and the first information is not sent to the second terminal device, so that the second terminal device can determine that the first terminal device does not send the first information but does not detect the first information within the period of time, the terminal devices carrying out sidelink communication can have consistent understanding on the received and sent data, unnecessary power consumption of the terminal devices is reduced, and electric energy is saved.

With reference to the first aspect, in certain implementations of the first aspect, HARQ feedback for the first HARQ process is disabled.

According to the above scheme, when the first terminal device determines that the HARQ feedback of the first HARQ process is disabled, the first information is not sent to the second terminal device within a period of time after the first data is sent, so that the second terminal device may determine that the first terminal device does not send the first information and does not detect (detecting) or monitor (monitoring) the first information during the operation of the first timer, and therefore, the terminal device performing sidelink communication can understand the transceiving data consistently, reduce unnecessary power consumption of the terminal device, and save power.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: and after the first timer is overtime, the first terminal equipment starts or restarts a second timer, wherein the first terminal equipment sends a time interval of retransmission data corresponding to the first HARQ process during the running period of the second timer.

According to the scheme, after the time period in which the first information is not transmitted is over, the first terminal device can transmit the first information within a time period, so that the second terminal device can determine that the first terminal device transmits the retransmission data within the time period and detect the retransmission data, the terminal devices performing the sidelink communication can understand the transceiving data consistently, unnecessary power consumption of the terminal devices is reduced, and electric energy is saved.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: and after the second timer is overtime, the first terminal equipment releases the first HARQ process or restarts the first timer.

According to the scheme, the first terminal equipment sending time period is defined, so that the terminal equipment performing the sidelink communication can understand the receiving and sending, unnecessary power consumption of the terminal equipment is reduced, and electric energy is saved.

In a second aspect, a wireless communication method is provided, which may be executed by a second terminal device or a module (such as a chip or a processor) configured (or used) in the second terminal device, and is explained as an example in the following.

The method comprises the following steps: the second terminal equipment receives first data from the first terminal equipment, wherein the first data corresponds to a first hybrid automatic repeat request (HARQ) process; the second terminal device starts or restarts a third timer, the third timer being configured to indicate a minimum time interval before first information can be received, the first information indicating that the first terminal device schedules retransmission data of the first HARQ process.

That is, after the second terminal device receives the first data from the first terminal device, the third timer is started or restarted; and the second terminal equipment detects the first information from the second terminal equipment after the third timer is overtime.

Or after the second terminal device receives the first data from the first terminal device, starting or restarting the third timer; during operation of the third timer, the second terminal device does not detect the first information from the first terminal device. With reference to the second aspect, in some implementations of the second aspect, the starting or restarting the third timer includes: and the second terminal equipment starts or restarts the third timer after sending HARQ feedback information to the first terminal equipment, wherein the HARQ feedback information corresponds to the first HARQ process.

With reference to the second aspect, in some implementations of the second aspect, the HARQ feedback information indicates that the first data was not successfully received.

With reference to the second aspect, in certain implementations of the second aspect, HARQ feedback for the first HARQ process is disabled.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: and after the third timer is overtime, the second terminal equipment starts or restarts a second timer, wherein the second timer indicates a time interval at which the second terminal equipment can receive the retransmission data corresponding to the first HARQ process.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: and after the second timer is overtime, the second terminal equipment releases the first HARQ process or restarts a third timer.

In a third aspect, a wireless communication method is provided, which may be executed by a first terminal device or a module (such as a chip or a processor) configured (or used) in the first terminal device, and is explained as an example in the following.

The method comprises the following steps: the method comprises the steps that a first terminal device determines a first resource, the first resource is used for carrying second information, the second information is used for indicating to stop a fourth timer, and the running period of the fourth timer is the activation time of DRX operation between the first terminal device and a second terminal device; the first terminal device sends the second information to the second terminal device, and the second information is carried on the first resource.

According to the scheme, the first terminal device instructs the second terminal device to stop the fourth timer through the second information, so that the DRX operation between the first terminal device and the second terminal device enters the inactive time, the first terminal device can instruct to stop the fourth timer in time under the condition that the DRX operation condition is not met, and unnecessary power consumption of the terminal device is reduced.

With reference to the third aspect, in some implementations of the third aspect, the determining, by the first terminal device, to stop the fourth timer includes: the first terminal device determines to stop the fourth timer if a first condition is satisfied,

wherein the first condition comprises one or more of:

the first terminal device power is less than or equal to a threshold, the service requirement of the first terminal device indicates to stop the fourth timer, the number of unicast connections established by the first terminal device is greater than or equal to the threshold, or the SL link quality is less than or equal to the threshold.

With reference to the third aspect, in some implementations of the third aspect, the determining, by the first terminal device, the first resource includes: the first terminal device sends third information to the first network device, wherein the third information is used for requesting the first resource; the first terminal device determines the first resource according to fourth information from the first network device, wherein the fourth information is used for indicating the first resource.

According to the scheme, the first terminal equipment requests the first network equipment and acquires the first resource for sending the second information, so that the first terminal equipment can instruct the second terminal equipment to stop the fourth timer through the second information, the DRX operation between the first terminal equipment and the second terminal equipment enters the inactive time, the first terminal equipment can instruct the fourth timer to stop in time, and unnecessary power consumption of the terminal equipment is reduced.

With reference to the third aspect, in some implementations of the third aspect, before the first terminal device sends the third information to the first network device, the method further includes: the first terminal device receives fifth information sent by the first network device, where the fifth information is used to indicate a second resource, and the second resource is a dedicated resource used to carry the third information.

According to the above scheme, the first terminal device sends the request information (i.e. the third information) requesting the first resource through the dedicated resource configured by the first network device, so that the first terminal device can send the third information in time to obtain the first resource, stop the fourth timer in time, and reduce unnecessary power consumption of the terminal device.

With reference to the third aspect, in some implementations of the third aspect, the first resource is a configuration grant resource, or the first resource is a sidelink resource that the first terminal device contends to.

With reference to the third aspect, in some implementations of the third aspect, before the first terminal device determines the first resource, the method further includes: the first terminal device determines to send the second information, and starts a fifth timer, where the fifth timer is used to indicate a time interval in which the first terminal device is able to send the second information.

Or, the first terminal device determines to send the second information, and starts a fifth timer; the first terminal device transmits the second information during the operation of the fifth timer.

According to the scheme, the time interval for the first terminal device to send the second information is defined, and the first terminal device sends the first information in the time interval, so that unnecessary power consumption caused by the fact that the first terminal device sends the first information after the time period for acting the first information is ended can be avoided.

With reference to the third aspect, in some implementations of the third aspect, the method further includes stopping the fifth timer after the first terminal device sends the second information, or when the fifth timer runs out and the first terminal device does not determine a resource for sending the second information, the first terminal device determines not to send the second information to the second terminal device.

According to the scheme, the fifth timer is used for indicating the time interval at which the second information can be sent, after the first terminal device sends the second information, the first terminal device does not need to operate the fifth timer, and the first terminal device stops the fifth timer in time, so that unnecessary power consumption of the terminal device can be reduced, and electric energy is saved.

With reference to the third aspect, in certain implementations of the third aspect, the second information is a medium access control element, MAC CE.

In a fourth aspect, a wireless communication method is provided, which may be executed by a first network device or a module (such as a chip or a processor) configured (or used) in the network device, and is explained as an example in which the method is executed by the first network device.

The method comprises the steps that a first network device receives third information from a first terminal device, the third information is used for requesting a first resource, and the first resource is a side link resource used for the first terminal device to send a first wireless access control element (MAC CE); the first network device sends fourth information to the first terminal device, wherein the fourth information is used for indicating the first resource.

According to the above scheme, after receiving the third information requesting the first resource from the first terminal device, the first network device configures the first resource for transmitting the first MAC CE for the first terminal device through the fourth information, so that the first terminal device can transmit the first MAC CE on the sidelink resource. With reference to the fourth aspect, in some implementations of the fourth aspect, the first MAC CE is configured to control discontinuous reception, DRX, operation of a sidelink between the first terminal device and the second terminal device.

According to the above scheme, the first network device configures a first resource for the first terminal device to transmit the first MAC CE, so that the first terminal device can transmit the first MAC CE on the sidelink resource, so that the first terminal device can control the DRX operation of the sidelink through the first MAC CE.

With reference to the fourth aspect, in some implementations of the fourth aspect, before the first network device receives the third information from the first terminal device, the method further includes: and the first network equipment sends fifth information to the first terminal equipment, wherein the fifth information is used for indicating second resources, and the second resources are special resources used for sending the third information.

According to the above scheme, the first network device configures the dedicated resource for the first terminal device to send the request information (i.e. the third information) requesting the first resource, so that the first terminal device can send the third information in time to obtain the first resource quickly, stop the fourth timer in time, and reduce unnecessary power consumption of the terminal device.

In a fifth aspect, a communication apparatus is provided, which may be configured with or may be a first terminal device (e.g., a processor or chip in the first terminal device). The communication device includes: a transceiving unit, configured to send first data by a second terminal device, where the first data corresponds to a first HARQ process; and the processing unit is configured to start or restart a first timer, where the first timer is used to indicate a minimum time interval before first information can be sent to the second terminal device, and the first information schedules retransmission data corresponding to the first HARQ process.

That is, the processing unit starts or restarts the first timer after the transceiver unit transmits the first data; the transceiver unit does not transmit the first information during the operation of the first timer.

Or, the processing unit starts or restarts the first timer after the transceiver unit sends the first data; the transceiver unit sends the first message after the first timer is overtime.

With reference to the fifth aspect, in certain implementations of the fifth aspect, HARQ feedback of the first HARQ process is enabled, and the processing unit is specifically configured to start or restart the first timer after the transceiving unit receives HARQ feedback information from the second terminal device, where the HARQ feedback information corresponds to the first HARQ process.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the HARQ feedback information indicates that the first data was not successfully received.

With reference to the fifth aspect, in certain implementations of the fifth aspect, HARQ feedback of the first HARQ process is disabled, and the processing unit is specifically configured to start or restart the first timer after the transceiving unit transmits the first data.

With reference to the fifth aspect, in some implementations of the fifth aspect, after the first timer expires, the processing unit starts a second timer, where the second timer indicates a time interval at which the transceiver unit can send the retransmission data corresponding to the first HARQ process.

With reference to the fifth aspect, in some implementations of the fifth aspect, after the second timer expires, the processing unit releases the first HARQ process or restarts the first timer.

In a sixth aspect, a communication apparatus is provided, which may be configured with or be a second terminal device (e.g., a processor or chip in a first terminal device). The communication device includes: a transceiving unit, configured to receive first data from a first terminal device, where the first data corresponds to a first hybrid automatic repeat request HARQ process; a processing unit, configured to start or restart a third timer, where the third timer is used to indicate a minimum time interval before first information can be received, and the first information indicates that the first terminal device schedules retransmission data of the first HARQ process.

That is, the processing unit starts or restarts the first timer after the transceiver unit receives the first data; the processing unit does not listen for the first information during the first timer run.

Or, the processing unit starts or restarts the first timer after the transceiver unit sends the first data; the transceiver unit monitors the first message after the first timer expires.

With reference to the sixth aspect, in some implementations of the sixth aspect, HARQ feedback of the first HARQ process is enabled, and the processing unit is specifically configured to start or restart the third timer after the transceiving unit sends HARQ feedback information, where the HARQ feedback information corresponds to the first HARQ process.

With reference to the sixth aspect, in certain implementations of the sixth aspect, the HARQ feedback information indicates that the first data was not successfully received.

With reference to the sixth aspect, in certain implementations of the sixth aspect, HARQ feedback of the first HARQ process is disabled, and the processing unit is specifically configured to start or restart the third timer after receiving the first data.

With reference to the sixth aspect, in some implementations of the sixth aspect, after the third timer expires, the processing unit starts a second timer, where the second timer indicates a time interval at which the transceiver unit can receive the retransmitted data corresponding to the first HARQ process.

With reference to the sixth aspect, in certain implementations of the sixth aspect, the method further comprises: after the second timer is over time, the processing unit releases the first HARQ process or restarts the third timer.

In a seventh aspect, a communication apparatus is provided, which may be configured with or may be a first terminal device (e.g., a processor or chip in the first terminal device). The communication device includes: a processing unit, configured to determine a first resource, where the first resource is used to carry second information, where the second information is used to instruct to stop a fourth timer, where a running period of the fourth timer is an activation time of DRX operation between the first terminal device and the second terminal device; a transceiving unit, configured to send the second information to the second terminal device, where the second information is carried on the first resource.

With reference to the seventh aspect, in certain implementations of the seventh aspect, the processing unit determines to stop the fourth timer specifically when a first condition is met, where the first condition includes one or more of:

With reference to the seventh aspect, in some implementations of the seventh aspect, the transceiver unit is further configured to send third information to the first network device, where the third information is used to request the first resource; the processing unit specifically determines the first resource according to fourth information, where the fourth information is from the first network device, and the fourth information is used to indicate the first resource.

With reference to the seventh aspect, in some implementations of the seventh aspect, before the transceiving unit sends the third information to the first network device, the transceiving unit is further configured to receive fifth information sent by the first network device, where the fifth information is used to indicate a second resource, and the second resource is a dedicated resource used for carrying the third information.

With reference to the seventh aspect, in some implementations of the seventh aspect, the first resource is a configuration authorization resource, or the first resource is a sidelink resource that the first terminal device contends to.

With reference to the seventh aspect, in certain implementations of the seventh aspect, before the processing unit determines the first resource, the processing unit is further configured to determine to send the second information, and start a fifth timer, where the fifth timer is used to indicate a time interval during which the transceiver unit may send the first information.

With reference to the seventh aspect, in some implementations of the seventh aspect, the processing unit is further configured to stop the fifth timer after determining the first resource, or, when the fifth timer runs out of time and the processing unit does not determine the resource for sending the second information, the processing unit determines that the transceiver unit does not send the second information to the second terminal device.

With reference to the seventh aspect, in some implementations of the seventh aspect, the second information is a medium access control element, MAC CE.

In an eighth aspect, a communication apparatus is provided, which may be configured with or be a first network device (e.g., a processor or chip in the first network device). The communication device includes: a transceiving unit, configured to receive third information from a first terminal device, where the third information is used to request a first resource, and the first resource is a sidelink resource used to transmit a first radio access control element, MAC CE; a processing unit for determining the first resource; the transceiver unit is further configured to send fourth information to the first terminal device, where the fourth information is used to indicate the first resource.

With reference to the eighth aspect, in some implementations of the eighth aspect, before the transceiving unit receives the third information from the first terminal device, the transceiving unit is further configured to transmit fifth information to the first terminal device, where the fifth information indicates a second resource, and the second resource is a dedicated resource for transmitting the third information.

With reference to the eighth aspect, in some implementations of the eighth aspect, the first MAC CE is configured to control discontinuous reception, DRX, operation of a sidelink between the first terminal device and the second terminal device.

In a ninth aspect, a communications apparatus is provided that includes a processor. The processor is coupled to the memory and is operable to execute the instructions in the memory to implement the method of the first aspect or the third aspect and any possible implementation manner of the first aspect or the third aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface.

In one implementation, the communication device is a first terminal device. When the communication device is a first terminal device, the communication interface may be a transceiver, or an input/output interface.

In another implementation, the communication device is a chip configured in the first terminal device. When the communication device is a chip configured in a terminal device, the communication interface may be an input/output interface.

Alternatively, the transceiver may be a transmit-receive circuit. Alternatively, the input/output interface may be an input/output circuit.

In a tenth aspect, a communication device is provided that includes a processor. The processor is coupled to the memory and is operable to execute the instructions in the memory to implement the method of any one of the possible implementations of the second aspect and the second aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface.

In one implementation, the communication device is a second terminal device. When the communication device is a second terminal device, the communication interface may be a transceiver, or an input/output interface.

In another implementation, the communication device is a chip configured in the second terminal device. When the communication device is a chip configured in the second terminal equipment, the communication interface may be an input/output interface.

In an eleventh aspect, a communications apparatus is provided that includes a processor. The processor is coupled to the memory and is operable to execute the instructions in the memory to implement the method of any one of the possible implementations of the fourth aspect and the fourth aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface.

In one implementation, the communication device is a first network device. When the communication device is a first network device, the communication interface may be a transceiver, or an input/output interface.

In another implementation, the communication device is a chip configured in the first network device. When the communication device is a chip configured in a network device, the communication interface may be an input/output interface.

In a twelfth aspect, a processor is provided, comprising: input circuit, output circuit and processing circuit. The processing circuit is configured to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor performs the method of any one of the possible implementations of the first to fourth aspects and the first to fourth aspects.

In a specific implementation process, the processor may be one or more chips, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a flip-flop, various logic circuits, and the like. The input signal received by the input circuit may be received and input by, for example and without limitation, a receiver, the signal output by the output circuit may be output to and transmitted by a transmitter, for example and without limitation, and the input circuit and the output circuit may be the same circuit that functions as the input circuit and the output circuit, respectively, at different times. The embodiment of the present application does not limit the specific implementation manner of the processor and various circuits.

In a thirteenth aspect, a processing apparatus is provided that includes a processor and a memory. The processor is configured to read instructions stored in the memory, and may receive a signal via the receiver and transmit a signal via the transmitter to perform the method of any one of the possible implementations of the first to fourth aspects and the first to fourth aspects.

Optionally, the number of the processors is one or more, and the number of the memories is one or more.

Alternatively, the memory may be integral to the processor or provided separately from the processor.

In a specific implementation process, the memory may be a non-transient memory, such as a Read Only Memory (ROM), which may be integrated on the same chip as the processor, or may be separately disposed on different chips.

It will be appreciated that the associated data interaction process, for example, sending the indication information, may be a process of outputting the indication information from the processor, and receiving the capability information may be a process of receiving the input capability information from the processor. In particular, data output by the processor may be output to a transmitter and input data received by the processor may be from a receiver. The transmitter and receiver may be collectively referred to as a transceiver, among others.

The processing means in the above-mentioned thirteenth aspect may be one or more chips. The processor in the processing device may be implemented by hardware or may be implemented by software. When implemented in hardware, the processor may be a logic circuit, an integrated circuit, or the like; when implemented in software, the processor may be a general-purpose processor implemented by reading software code stored in a memory, which may be integrated with the processor, located external to the processor, or stand-alone.

In a fourteenth aspect, there is provided a computer program product comprising: a computer program (which may also be referred to as code, or instructions), which when executed, causes a computer to perform the method of any of the possible implementations of the first to fourth aspects and of the first to fourth aspects described above.

In a fifteenth aspect, a computer-readable storage medium is provided, which stores a computer program (which may also be referred to as code or instructions) that, when executed on a computer, causes the computer to perform the method of any one of the possible implementations of the first to fourth aspects and the first to fourth aspects described above.

In a sixteenth aspect, a communication system is provided, which includes the aforementioned first terminal device and second terminal device.

Drawings

Fig. 1 is a schematic diagram of a communication system 100 suitable for use in embodiments of the present application.

Fig. 2 is a schematic flowchart of a communication method of a sidelink according to an embodiment of the present disclosure.

Fig. 3 is another schematic flow chart of a communication method of a sidelink according to an embodiment of the present disclosure.

Fig. 4 is a diagram illustrating an example of a communication method of a sidelink according to an embodiment of the present application.

Fig. 5 is another exemplary flowchart of a communication method of a sidelink according to an embodiment of the present disclosure.

Fig. 6 is another exemplary flowchart of a communication method of a sidelink according to an embodiment of the present disclosure.

Fig. 7 is a schematic block diagram of an example of a communication apparatus according to the present application.

Fig. 8 is a schematic configuration diagram of an example of a terminal device according to the present application.

Fig. 9 is a schematic configuration diagram of an example of a network device according to the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: a Long Term Evolution (LTE) system, a LTE Frequency Division Duplex (FDD) system, a LTE Time Division Duplex (TDD) system, a Universal Mobile Telecommunications System (UMTS), a universal internet microwave access (WiMAX) communication system, a fifth generation (5G) system or a New Radio (NR) system, a Vehicle-to-other device (Vehicle-to-X V2X), wherein the V2 network 82 may include a Vehicle-to-internet (V2N), a Vehicle-to-Vehicle (V2V), a Vehicle-to-infrastructure (infrastructure) system, a Vehicle-to-Vehicle (V2I, a Vehicle-to-Vehicle (MTC) system, a Vehicle-to-Vehicle (MTC) communication system, a Vehicle-to-Vehicle (MTC P, a Long Term Evolution (LTE) communication system, a UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a Vehicle-to-Vehicle (5G) system, or a New Radio (NR) system, a Vehicle-to-other device (Vehicle-to-X V2X), and a Vehicle-to-infrastructure (Vehicle-to-Vehicle-to-Vehicle (Vehicle-to-Vehicle) system, a Vehicle (MTC) communication system, a Vehicle-to-Vehicle (Vehicle-to-Vehicle-to-Vehicle (Vehicle) system, a Vehicle-to-Vehicle (Vehicle-to-Vehicle (Vehicle, MTC) system, a Vehicle-to-Vehicle (Vehicle, a Vehicle, Vehicle-to, Internet of Things (IoT), long term evolution (LTE-M) for inter-machine communication, machine to machine (M2M), non-terrestrial communication (NTN) system or other communication system evolving in the future, and so on.

The communication system applicable to the embodiment of the present application may include at least two terminal devices, such as the

terminal devices

102, 103, 104, 105 in the communication system 100 shown in fig. 1. The communication system applicable to the embodiment of the present application may further include at least one network device, such as the network device 101 in the wireless communication system 100 shown in fig. 1. Sidelink (SL) may be established between the at least two terminal devices, such as

links

120, 121, 122, 123, and 124 in fig. 1, and communication may be directly performed between the terminal devices that establish the sidelink. Wherein one terminal device can establish a sidelink with one or more terminal devices. The terminal devices in the communication system may also establish wireless connections with network devices for data communication, and as shown in fig. 1, the

terminal devices

102 and 103 establish wireless links 110 and 111 with the network devices, respectively. The terminal devices in the communication system may not establish a wireless link with the network device, such as the terminal devices 104 and 105 shown in fig. 1, which is not limited in this application.

The terminal device in the embodiments of the present application may also be referred to as a User Equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment. The terminal device in the embodiment of the present application may be a mobile phone (mobile phone), a tablet (pad), a computer with a wireless transceiving function, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation security (transportation security), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), a cellular phone, a cordless phone, a session initiation protocol (session initiation protocol, SIP) phone, a wireless local loop (wireless local area, PDA) station, a personal digital assistant (wldigital assistant), a handheld wireless communication device with a wireless transceiving function, and a handheld personal communication device with a wireless communication function, A computing device or other processing device connected to a wireless modem, an in-vehicle device, an in-vehicle communication apparatus, an in-vehicle communication processing chip, a wearable device, a terminal device in a 5G network or a terminal device in a Public Land Mobile Network (PLMN) for future evolution, etc.

Wherein, wearable equipment also can be called as wearing formula smart machine, is the general term of using wearing formula technique to carry out intelligent design, developing the equipment that can dress to daily wearing, like glasses, gloves, wrist-watch, dress and shoes etc.. A wearable device is a portable device that is worn directly on the body or integrated into the clothing or accessories of the user. The wearable device is not only a hardware device, but also realizes powerful functions through software support, data interaction and cloud interaction. The generalized wearable smart device includes full functionality, large size, and can implement full or partial functionality without relying on a smart phone, such as: smart watches or smart glasses and the like, and only focus on a certain type of application functions, and need to be used in cooperation with other devices such as smart phones, such as various smart bracelets for physical sign monitoring, smart jewelry and the like.

In addition, the terminal device may also be a terminal device in an internet of things (IoT) system. The IoT is an important component of future information technology development, and is mainly technically characterized in that articles are connected with a network through a communication technology, so that an intelligent network with man-machine interconnection and object interconnection is realized.

It should be understood that the present application is not limited to the particular form of the terminal device.

The technical scheme in the embodiment of the application can also be applied to network equipment. The network devices include, but are not limited to: evolved Node B (eNB), Radio Network Controller (RNC), roadside unit (RSU), Node B (NB), Base Station Controller (BSC), Base Transceiver Station (BTS), home base station (e.g., home Node B, or home Node B), Base Band Unit (BBU), Access Point (AP) in wireless fidelity (WIFI) system, wireless relay Node, wireless backhaul Node, Transmission Point (TP) or transmission receiving point (TRP ), etc., may also be a gNB or TP in a 5G (NR) system, or a group of antennas or antennas in a 5G system, or a network panel may also be a network panel or a group of antennas comprising one or more RNCs, such as a baseband unit (BBU), a Distributed Unit (DU), or the like, the network device may also be a network side apparatus in the car networking, which provides communication service or communication control for the terminal device.

The network device provides communication service for terminal devices in a cell, and the terminal devices in the cell communicate with the network device through transmission resources (e.g., frequency domain resources, time domain resources, etc.) allocated by the network device, and the cell may belong to a macro base station (e.g., a macro eNB or a macro gNB, etc.).

To facilitate understanding of embodiments of the present application, first, a brief description of terms referred to in the present application will be given.

1. Broadcast and multicast communication mode in side link

The broadcast and multicast of the sidelink refers to broadcast or multicast data transmitted by one terminal device, and can be received by one or more terminal devices. For example, a Destination Layer 2 identifier (Destination Layer-2 ID) used when the service data is transmitted on the PC5 interface is predefined. When the transmitting device transmits the broadcast service data, the data can be directly transmitted through a user plane protocol stack, and a Destination Layer-2 ID corresponding to the broadcast service is filled in a Medium Access Control (MAC) Layer and/or a physical Layer (PHY) Layer. The terminal device interested in the broadcast service may monitor whether there is service data of Destination Layer-2 ID corresponding to the broadcast service in the PHY Layer, and receive and analyze the service data, but the application is not limited thereto.

2. Unicast communication mode in sidelink

Unicast is a one-to-one communication mode of terminal equipment, a sending device indicates a receiving device of unicast data sent by the sending device through a destination address, the receiving device determines whether the unicast data is unicast data sent to the receiving device according to the destination address of the unicast data, and determines which device the unicast data is sent by according to a source address of the unicast data. Optionally, the two terminal devices may establish a unicast connection between the two devices through signaling interaction, and may perform unicast communication after the establishment of the unicast connection is completed.

3. Sidelink transmission mode 1(mode1)

The sidelink mode1 refers to that the terminal device determines the resource for transmitting the sidelink data according to the sidelink scheduling grant (sidelink grant) transmitted by the network device. The sidelink scheduling grant is for granting resources dedicated to the terminal device for transmitting sidelink data. For example, before sending the sidelink, the terminal device reports a Buffer Status Report (BSR) to the network device to notify the network device of the amount of data to be sent, and the network device grants corresponding resources for the terminal device according to the amount of data reported by the terminal device.

4. Sidelink transmission mode 2(mode2)

Sidelink mode2 refers to a sidelink resource that is pre-allocated by a network device for contention, and a plurality of terminal devices can contend for the resource in the sidelink resource for contention, and in case of contending for the resource, the terminal device can transmit data of the sidelink on the contended resource. For example, the terminal device selects an unoccupied resource for transmission according to whether each time-frequency resource in the resources for the sidelink is occupied or not, but the application is not limited thereto.

The method for communicating the sidelink according to the embodiment of the present application is described in detail below with reference to the accompanying drawings.

The application provides that power consumption can be reduced among a plurality of terminal devices communicating through a sidelink by means of appointing the behaviors of sending and receiving between a sending device and a receiving device and maintaining a timer.

S210, the first terminal device sends first data to the second terminal device.

Accordingly, the second terminal device receives the first data from the first terminal device.

Optionally, the first terminal device further sends control information to the second terminal device, for example, the control information may be first Sidelink Control Information (SCI), and the following description takes the control information as the first SCI as an example, but the application is not limited thereto. The first SCI is used to instruct the first terminal device to schedule the first data. The first data corresponds to a first HARQ process, and optionally, the first SCI includes an identifier of the first HARQ process.

Alternatively, the first data may be sidelink communication data between the first terminal device and the second terminal device, for example, the first data includes a MAC Protocol Data Unit (PDU) or a Transport Block (TB), and the first data may be carried on a physical sidelink shared channel (psch), but the application is not limited thereto.

S220, the first terminal device starts or restarts the timer a (i.e., an example of the first timer), and the second terminal device starts or restarts the timer a (i.e., an example of the third timer).

In the embodiment shown in fig. 2, the first timer maintained by the first terminal device and the third timer maintained by the second terminal device have the same timing duration, that is, are both the timer a.

After the first terminal device sends the first signal, the first terminal device starts or restarts the timer A, and after the second terminal device receives the first signal, the second terminal device starts or restarts the timer A. Wherein the first signal is the first SCI or first data. That is, the timer a corresponds to the first HARQ process, and after the first terminal device sends the first SCI or the first data corresponding to the first HARQ process, the timer a is started or restarted. Correspondingly, the second terminal device starts or restarts the timer a after receiving the first SCI or the first data corresponding to the first HARQ process.

For example, the first terminal device starts or restarts the timer a after sending the first data, and accordingly, the second terminal device starts or restarts the timer a after receiving the first data.

For another example, the first terminal device starts or restarts the timer a after sending the first SCI, and accordingly, the second terminal device starts or restarts the timer a after receiving the first SCI.

In one embodiment, the timer a is used to indicate a time interval during which the first terminal device does not transmit a signal, or, for the second terminal device, the timer a is used to indicate a time interval during which the second terminal device does not listen to a signal from the first terminal device. The signal may comprise indicative information and/or data. That is, the first terminal device does not transmit the indication information and/or data during the operation of the timer a. The first terminal device does not transmit a signal for a period of time after transmitting the first SCI or the first data, which can reduce power consumption of the first terminal device, and accordingly, the second terminal device does not listen to the signal from the first terminal device for a period of time when the first terminal device does not transmit a signal, which can reduce unnecessary power consumption of the second terminal device.

In another embodiment, the timer a is used to indicate a time interval before the first terminal device (i.e. the transmitting device that transmits the data) can transmit the first information, or the timer a is used to indicate a time before the second terminal device (i.e. the receiving device that receives the data) can receive the first information. That is, the first terminal device does not transmit the first information during the running of the timer a it maintains, and accordingly, the second terminal device does not listen to the first information during the running of the timer a it maintains. Or, the first terminal device sends the first information after the timer a maintained by the first terminal device expires, and correspondingly, the second terminal device monitors the first information after the timer a maintained by the second terminal device expires. The first information is used to indicate that the first terminal device schedules retransmission data of the first data, or the first information is used to indicate that the first terminal device schedules retransmission data corresponding to the first HARQ process. Optionally, the first information is SCI. According to the above scheme, after the terminal device performing the sidelink communication transmits or receives the first information or data corresponding to the first HARQ process, the terminal device does not receive or transmit the first information corresponding to the first HARQ process during the operation of the timer a in consideration of the data processing time of the terminal device, thereby avoiding unnecessary power consumption of the terminal device and saving electric energy.

Alternatively, the duration of timer a may be protocol specified or preconfigured.

For example, the duration of the timer a is preconfigured for the first terminal device and/or the second terminal device by the network device that establishes the connection with the first terminal device and/or the second terminal device, but the application is not limited thereto.

For another example, the timer a is determined for the first terminal device and configured by the first terminal device for the second terminal device. Alternatively, the first terminal device may determine the duration of the timer a according to the preparation time required before the first terminal device transmits the retransmission data, and notify the second terminal device. Alternatively, the first terminal device may determine the duration of the timer a according to an indication of the network device, but the application is not limited thereto.

For another example, the timer a is determined for the second terminal device and configured by the second terminal device for the first terminal device. Optionally, the second terminal device may determine the duration of the timer a according to the preparation time required for receiving the data post-processing data corresponding to one HARQ process, and notify the first terminal device. Alternatively, the second terminal device may determine the duration of the timer a according to the indication of the network device, but the application is not limited thereto

Optionally, the time at which timer a starts or restarts may be, but is not limited to, one of the following:

an end time of a last symbol carrying the first signal;

a first symbol start time after the first signal;

a preset time interval end time after the last symbol carrying the first signal.

For example, the first terminal device and the second terminal device both start or restart the timer a at the end of the last symbol carrying the first data. For another example, the first terminal device and the second terminal device both start or restart the timer a after a preset time interval after the last symbol carrying the first SCI, but the application is not limited thereto. According to the scheme, the first terminal device and the second terminal device can agree on the time for starting or restarting the timer.

In this application, the start of a timer is understood to mean the first time the timer is started. Restarting of the timer may be understood as restarting the timer from an initial value when the timer has run for a period of time in a stopped state (i.e. the timer is at a value between 0 and a maximum value). Or the restarting of the timer may be understood as restarting the timer to continue counting from the current value when the timer has run for a period of time in the stopped state.

In the present application, a timer is taken as an example for description, and in a specific implementation, the timer may be a device or a module that can be used to measure a time length, such as a timer and a counter. Alternatively, the timer in the present application may be replaced by a time interval, wherein the time when the timer is started or restarted may be understood as a starting point of the time interval; during the running of the timer, it can be understood that within this time interval; a stop timer, which may be understood as a stop of a function, action or operation corresponding to the time interval within the time interval; the timer may be expired after the time interval is over, but the application is not limited thereto.

Optionally, the first HARQ process may be HARQ feedback enabled (enable) or HARQ feedback disabled (disable).

For example, a Radio Bearer (RB) of the sidelink may be configured as HARQ feedback enabled, and a HARQ process corresponding to data of the radio bearer is correspondingly HARQ feedback enabled. Alternatively, a Radio Bearer (RB) of the sidelink may be configured to be HARQ feedback disabled, and a HARQ process corresponding to data of the radio bearer is correspondingly disabled for HARQ feedback, but the application is not limited thereto.

Optionally, the first SCI includes a HARQ feedback indication field, where the HARQ feedback indication field is used to indicate whether HARQ feedback of the first HARQ process is enabled.

In an embodiment, when the HARQ feedback of the first HARQ process is disabled, a first SCI is sent by a first terminal device to a second terminal device, where the first SCI indicates that the first terminal device schedules the first data corresponding to the first HARQ process, and a HARQ feedback indication field in the first SCI indicates that the first HARQ process is disabled, and the first terminal device starts or restarts a timer a after sending a first signal. The second terminal device determines that the HARQ feedback of the first HARQ process is disabled according to the HARQ feedback indication field in the first SCI, and then the second terminal device starts or restarts the timer a after receiving the first signal.

According to the scheme, when the first HARQ process is disabled, the first terminal equipment is specified to start or restart the timer A after sending the first signal, and the second terminal equipment starts or restarts the timer A after receiving the first signal, so that the time for starting the timer can be consistent between the first terminal number and the second terminal equipment, unnecessary power consumption of the terminal equipment is reduced, and electric energy is saved.

In another embodiment, HARQ feedback for the first HARQ process is enabled. Specific implementations may include, but are not limited to, the following two ways:

in the first mode, the first terminal device starts or restarts the timer a after receiving the HARQ feedback information from the second terminal device. Accordingly, the second terminal device starts or restarts the timer a after transmitting HARQ feedback information indicating successful reception of the first data (e.g., the HARQ feedback information indicates ACK) or unsuccessful reception of the first data (e.g., the HARQ feedback information indicates NACK).

That is, in the first mode, the first terminal device starts or restarts the timer a after receiving the HARQ feedback information from the second terminal device, regardless of whether the second terminal device successfully receives the first data. Correspondingly, the second terminal device starts or restarts the timer a after sending the HARQ feedback information.

In the second mode, the second terminal device determines that the first data is not successfully received, sends an indication that the HARQ feedback information is not successfully received to the first terminal device, and starts the timer a, and accordingly, the first terminal device starts or restarts the timer a after receiving the HARQ feedback information indicating that the second terminal device is not successfully received to the first data.

That is, in the second mode, when the HARQ feedback information indicates that the first data is not successfully received, the first terminal device and the second terminal device start or restart the timer a. When the HARQ feedback information indicates successful reception of the first data, the first terminal device and the second terminal device do not start or restart the timer a. Or when the second terminal device successfully receives the first data, the second terminal device does not send HARQ feedback information, but the application is not limited thereto. Optionally, the starting or restarting of the timer a by the first terminal device and the second terminal device may be an end time of a last symbol carrying the HARQ feedback information or a start time of a first symbol after the HARQ feedback information.

For example, the second terminal device receives the first SCI from the first terminal device, receives the first data according to the first SCI, but does not successfully decode the first data. And if the HARQ feedback indication field in the first SCI indicates that HARQ feedback of the first HARQ process is enabled, the second terminal device sends HARQ feedback information to the first terminal device, where the HARQ feedback information indicates that the second terminal device has not successfully received the first data. The second terminal device starts or restarts the timer a at the end time of the last symbol carrying the HARQ feedback information. After receiving the HARQ feedback information, the first terminal device starts or restarts the timer a at the end time of the last symbol of the HARQ feedback information.

According to the scheme, when the first HARQ process is enabled, the first terminal equipment is specified to start the timer A after receiving the HARQ feedback information, and the second terminal equipment starts or restarts the timer A after sending the HARQ feedback information, so that the time for starting the timer can be consistent between the first terminal number and the second terminal equipment, unnecessary power consumption of the terminal equipment is reduced, and electric energy is saved.

Optionally, the condition for starting or restarting the timer a further comprises that the first HARQ process is not released. That is, after the first terminal device receives the HARQ feedback information and determines that the first HARQ process is not released, the first terminal device starts or restarts the timer a. Correspondingly, after the second terminal device sends the HARQ feedback information, and under the condition that it is determined that the first HARQ process is not released, the second terminal device starts or restarts the timer a. Unnecessary power consumption caused by the fact that the terminal equipment still starts or restarts the timer after the first HARQ process is released can be avoided.

By way of example and not limitation, the first HARQ process not being released may include, but is not limited to: the retransmission times of the first data do not reach the maximum retransmission times, and/or retransmission resources of the first data exist.

S230, during the running period of the timer a, the first terminal device does not send the first information, and the second terminal device does not monitor the first information.

The first terminal device does not transmit the first information during the running of the timer a maintained by the first terminal device, that is, the first terminal device can transmit the first information only after the timer a is expired. Accordingly, the second terminal device does not monitor the first information during the running period of the timer a maintained by the second terminal device, and starts to monitor the first information after the timer a is overtime.

According to the above scheme, after the plurality of terminal devices performing the sidelink communication transmit or receive the first information or data corresponding to the first HARQ process, the data processing time of the terminal device is considered, and the first information corresponding to the first HARQ process is not monitored or transmitted during the running period of the timer a, so that unnecessary power consumption of the terminal device can be avoided, and electric energy can be saved.

It should be noted that, in the embodiment of fig. 3, the same or similar parts as those in the embodiment of fig. 2 may refer to the description in the embodiment of fig. 2, and are not repeated herein for brevity.

S310, the first terminal device sends first data to the second terminal device.

Optionally, the first terminal device further sends a first SCI to the second terminal device, where the first SCI is used to instruct the first terminal device to schedule the first data. The first data corresponds to a first HARQ process. HARQ feedback for the first HARQ process is enabled.

S320, the first terminal device starts or restarts the timer B (i.e., another example of the first timer).

The first terminal device starts or restarts the timer B after sending the first SCI or the first data. That is, the timer B corresponds to a first HARQ process, and after the first terminal device sends the first SCI or the first data corresponding to the first HARQ process, the timer B corresponding to the first HARQ process is started or restarted. During the running of the timer B, the first terminal device does not transmit the first information. Or, the first terminal device can send the first information after the timer B expires. The timer B is used to indicate a time interval before the first terminal device can send the first information to the second terminal device. In other words, the first terminal device does not send the first information to the second terminal device during the running of the timer B, that is, the first terminal device sends the first information to the second terminal device after the timer B expires. The first information is used to indicate that the first terminal device schedules retransmission data of the first data, or the first information is used to indicate that the first terminal device schedules retransmission data corresponding to the first HARQ process. Optionally, the first information is SCI. By way of example and not limitation, the time at which the first terminal device starts or restarts the timer B may include, but is not limited to, one of:

carrying the end time of the first SCI or the last symbol of the first data;

the first SCI or the start time of the first symbol after the first data;

a time interval after the last symbol carrying the first SCI or the first data.

S330, the second terminal device sends HARQ feedback information to the first terminal device.

After receiving the first SCI, the second terminal device may determine that HARQ feedback of the first HARQ process is enabled according to the HARQ feedback indication field in the first SCI. The second terminal equipment receives the first data according to the indication of the first SCI, determines whether the first data is decoded correctly, and sends HARQ feedback information to the first terminal equipment.

S340, the second terminal device starts or restarts the timer C (i.e. another instance of the third timer).

And after the second terminal equipment sends the HARQ feedback information, starting or restarting the timer C. During the running period of the timer C, the second terminal device does not listen to the first information from the first terminal device, that is, the control information of the retransmitted data corresponding to the first HARQ process is scheduled, or in other words, the second terminal device starts to listen to the first information after the timer C is overtime. That is, the timer C corresponds to the first HARQ process, and when the second terminal device receives the first SCI or the first data corresponding to the first HARQ process, the timer C corresponding to the first HARQ process is started or restarted.

In the embodiment shown in fig. 3, the timing duration of the first timer (i.e., timer B) maintained by the first terminal device is different from the timing duration of the third timer (i.e., timer C) maintained by the second terminal device.

In an embodiment, after the second terminal device sends the HARQ feedback information, the timer C is started or restarted. Wherein the HARQ feedback information indicates that the second terminal device successfully receives the first data or unsuccessfully receives the first data.

That is, the timer C is started or restarted after the second terminal device sends the HARQ feedback information, regardless of whether the second terminal device successfully receives the first data.

In another embodiment, the second terminal device determines that the first data is not successfully received, and sends HARQ feedback information to the first terminal device, where the HARQ feedback information indicates that the second terminal device does not successfully receive the first data, and the second terminal device starts or restarts the timer C.

That is, the second terminal device starts or restarts the timer C after transmitting the HARQ feedback information only when the second terminal device has not successfully received the first data. The timer C is not started or restarted when the second terminal device successfully receives the first data.

The timer C is used to indicate a minimum time interval before the second terminal device can listen to the first information from the first terminal device. Or, the second terminal device does not listen to the first information sent by the first terminal device during the running period of the timer C, that is, the second terminal device listens to the first information after the timer C expires. The first information is used to indicate that the first terminal device schedules retransmission data of the first data, or the first information is used to indicate that the first terminal device schedules retransmission data corresponding to the first HARQ process. Optionally, the first information is SCI.

It should be noted that the timer C is used to indicate a minimum time interval before the second terminal device can listen to the first information from the first terminal device. It is to be understood that the value indicated by the timer C indicates the minimum time interval between the time when the second terminal device can hear the first information and the current time, that is, the first terminal device does not send the first information before the timer C times out, and can send the first information after the timer C times out, but the first information is not necessarily sent immediately after the timer C times out, and may send the first information after a period of time after the timer C times out, or does not send the first information, so that the value indicated by the timer C is the minimum time interval before the second terminal device can hear the first information. The timer A, B operates on the same or similar principle as the timer C and is not described again for brevity. In addition, the duration of the timer in the present application refers to the maximum value that the timer can indicate, and the value indicated by the running period of one timer is smaller than the duration of the timer.

By way of example and not limitation, the time at which the second terminal device starts or restarts the timer C may include, but is not limited to, one of:

the end time of the last symbol carrying the HARQ feedback information;

the starting time of the first symbol after the HARQ feedback information;

a time interval after the last symbol carrying the HARQ feedback information.

For example, as shown in fig. 4, in the embodiment of fig. 3, the timer B is started after the first SCI or the first data, the timer C is started after the HARQ feedback information, the timer B is different from the starting or restarting time of the timer C, but the stopping time is the same, that is, the timeout time of the timer B and the timeout time of the timer C are the same, so that the first terminal device and the second terminal device agree on the reception and transmission of the signal.

In one embodiment, the durations of the timer B and the timer C are negotiated between a first network device that establishes a connection with a first terminal device and a second network device that establishes a connection with a second terminal device, so that the timeout time is agreed. And the first network device configures the duration of the timer B for the first terminal device, and the second network device configures the duration of the timer C for the second terminal device. Alternatively, the first network device and the second network device may be the same network device, that is, the first terminal device and the second terminal device are connected to the same network device, but the application is not limited thereto.

In another embodiment, the first terminal device determines the durations of the timer B and the timer C and notifies the second terminal device, or the second terminal device determines the durations of the timer B and the timer C and notifies the first terminal device.

In another embodiment, the first terminal device determines the duration of the timer C and notifies the second terminal device, and the first terminal device determines the duration of the timer B according to the duration of the timer C and the time difference between the HARQ feedback information and the first SCI or the first data. Or, the first terminal device determines the duration of the timer B and notifies the second terminal device, and the second terminal device determines the duration of the timer C according to the duration of the timer B and the time difference between the HARQ feedback information and the first SCI or the first data. Or otherwise, the second terminal device determines the duration of the timer B or the timer C and informs the first terminal device, and the first terminal device determines the duration of the other timer according to the time difference between the HARQ feedback information and the first SCI or the first data.

Alternatively, the determination of the duration of the timer A, B, C may take into account the length of time required by the second terminal device to process the data and/or the length of time required by the first terminal device to prepare for retransmission of the data, but the application is not limited thereto. Optionally, the condition for starting or restarting the timer C may include that the first HARQ process is not released in addition to transmitting the HARQ feedback information. That is, after the second terminal device sends the HARQ feedback information, and determines that the first HARQ process is not released, the second terminal device starts or restarts the timer C.

According to the scheme, after the plurality of terminal devices performing the sidelink communication transmit or receive the first information or data corresponding to the first HARQ process, the data processing time of the terminal devices is considered, the timers maintained by the terminal devices are started or restarted, and the first information corresponding to the first HARQ process is not received or transmitted during the running period of the timers, so that unnecessary power consumption of the terminal devices can be avoided, and electric energy is saved.

Optionally, after the first timer and the third timer are expired, the first terminal device and the second terminal device start or restart the second timer respectively maintained, where the second timer is used to indicate a time interval at which retransmission data corresponding to the first HARQ process can be transmitted. Or, the second timer is configured to indicate a time interval at which the first terminal device can send the retransmitted data corresponding to the first HARQ process, or, the second timer is configured to indicate a time interval at which the second terminal device can receive the retransmitted data corresponding to the first HARQ process.

In one embodiment, when the HARQ feedback of the first HARQ process is enabled, the second terminal device may determine that the HARQ feedback of the first HARQ process is enabled according to the first SCI, and start or restart a second timer maintained by the second terminal device after the third timer expires and HARQ feedback information (e.g., NACK) indicating that the first data is not successfully received is sent; correspondingly, the first terminal device starts or restarts the second timer maintained by the first terminal device after the first timer expires and the HARQ feedback information indicating that the first data is not successfully received is received. Optionally, in a case that the HARQ feedback information indicates that the first data is successfully received, the first terminal device and the second terminal device do not start or restart the second timer.

According to the scheme, the second timer is started or restarted to receive the retransmission data corresponding to the first HARQ process under the condition that the second terminal equipment does not successfully receive the first data, and the second timer is not started or restarted after the second terminal equipment successfully receives the first data, so that the terminal equipment performing the sidelink communication can understand the receiving and sending data consistently, unnecessary power consumption of the terminal equipment is reduced, and electric energy is saved.

Optionally, the first terminal device may send the first data to one second terminal device, or the first terminal device may also send the first data to a plurality of second terminal devices, for example, after the first terminal device multicasts the first data, and after a first timer expires, the first terminal device starts or restarts the second timer when the number of NACK feedbacks from the plurality of second terminal devices received by the first terminal device is greater than or equal to a first threshold, or when the energy of NACK feedbacks from the plurality of second terminal devices received by the first terminal device is greater than or equal to a second threshold. For example, the physical layer of the first terminal device sends indication information indicating the number of NACK feedbacks (or the number of second terminal devices feeding NACK back) or the energy of the received NACK feedbacks to a Medium Access Control (MAC) layer, and the MAC layer of the first terminal device determines whether to start or restart the second timer according to the received indication information. For example, the MAC layer determines that the number of received NACK feedbacks is greater than or equal to a first threshold according to the indication information, and determines to start or restart the second timer. Or the MAC layer determines that the energy of the received NACK feedback is greater than or equal to a second threshold value according to the indication information, and determines to start or restart the second timer. As an example limitation, the first threshold or the second threshold may be protocol-specified, network-configured, or preconfigured.

In another embodiment, when the HARQ feedback of the first HARQ process is disabled, the first terminal device starts or restarts the second timer after the first timer expires. The second terminal device may determine that HARQ feedback of the first HARQ process is disabled according to the first SCI, and start or restart the second timer after the third timer expires.

According to the above scheme, when the HARQ feedback of the first HARQ process is disabled, the first timer is timed out and then the second timer is started, so that the first terminal device can send the retransmission data corresponding to the first HARQ process to the second terminal device during the operation period of the second timer, and the corresponding second terminal device can receive the retransmission data corresponding to the first HARQ process sent by the first terminal device during the operation period of the second timer. The terminal equipment for performing sidelink communication can understand the received and transmitted data consistently, unnecessary power consumption of the terminal equipment is reduced, and electric energy is saved.

Optionally, after the first timer expires, the first terminal device starts or restarts the second timer when determining that the transmission frequency or the retransmission frequency of the data (e.g., a MAC Protocol Data Unit (PDU) or a Transport Block (TB)) corresponding to the first HARQ process is less than or equal to a preset maximum value. And when the transmission times or the retransmission times of the data corresponding to the first HARQ process are greater than or equal to the preset maximum value, the second terminal equipment does not start or restart the second timer.

Optionally, after the third timer expires, the second terminal device starts or restarts the second timer when determining that the number of transmission times or the number of retransmission times of the data (e.g., MAC PDU or TB) corresponding to the first HARQ process is less than or equal to a preset maximum value. And when the transmission times or the retransmission times of the data corresponding to the first HARQ process are greater than or equal to the preset maximum value, the second terminal equipment does not start or restart the second timer.

According to the scheme, under the condition that the data transmission of the first HARQ process reaches a certain condition, the second timer corresponding to the first HARQ process is not started or restarted, namely, the retransmission data corresponding to the HARQ process is not transmitted, so that the terminal equipment performing sidelink communication can understand the received and transmitted data consistently, the unnecessary power consumption of the terminal equipment is reduced, and the electric energy is saved.

In the embodiment of the present application, when the value is compared with the threshold or the threshold, the case of "equal to" may be the same as the operation performed in the case of "greater than" or the same as the operation performed in the case of "less than," and the present application does not limit this.

Optionally, the condition that the first terminal device and the second terminal device start or restart the second timer further includes that the first HARQ process is not released. That is, the first terminal device starts or restarts the second timer if the first timer expires and it is determined that the first HARQ process is not released. Correspondingly, the second terminal device starts or restarts the second timer if the third timer expires and it is determined that the first HARQ process is not released. Optionally, this embodiment may also be implemented in combination with the case that the HARQ feedback of the first HARQ process is enabled and/or disabled, that is, the first terminal device and the second terminal device determine whether the first HARQ process is released, and in case that the first HARQ process is not released, determine whether to start or restart the second timer, but the application is not limited thereto.

According to the above scheme, the plurality of terminal devices performing sidelink communication do not receive or send the first information corresponding to the first HARQ process within a period of time after sending the first data, and limit the time length during which the retransmission data can be sent by the second timer after the period of time, so that unnecessary power consumption of the terminal devices can be further avoided on the basis that the plurality of terminal devices understand the data transmission in a consistent manner.

Optionally, in this application, when the first terminal device starts a first timer (e.g., timer a or timer B) corresponding to the first HARQ process, the second timer corresponding to the first HARQ process maintained by the first terminal device is stopped, and accordingly, when the second terminal device starts a third timer (e.g., timer a or timer C) corresponding to the first HARQ process, the second timer corresponding to the first HARQ process maintained by the second terminal device is stopped.

In another embodiment of the present application, the above-mentioned fig. 2 embodiment or fig. 3 embodiment may also be implemented in combination with the discontinuous reception DRX operation of the sidelink.

The discontinuous reception operation of the sidelink means that the terminal device may discontinuously monitor the SCI according to the configuration information of the discontinuous reception operation. For example, the discontinuous operation of the sidelink may be configured with one or more of the following parameters:

a first period of the DRX operation;

the maximum duration of the timer D (i.e. an example of the fourth timer) is the length of time that the terminal device is in DRX active time at the beginning of each cycle of DRX operation;

the maximum duration of the timer E (i.e. another example of the fourth timer) is the length of time that the terminal device is in DRX active time after receiving the second SCI indicating a new data transmission.

The second terminal device in this embodiment of the present application may perform discontinuous reception, that is, the second terminal device is a receiving device for control information or data of DRX operation, and the first terminal device may be a transmitting device for transmitting the control information or data in the DRX operation. The second terminal device starts a timer D at the beginning of each first period and detects the SCI during the running of the timer D. And after receiving the second SCI in the DRX activation time, the second terminal equipment starts a timer E, and detects the SCI during the running period of the timer E. Accordingly, the first terminal device also starts a timer D at the beginning of each cycle of discontinuous reception by the second terminal device, and starts a timer E after transmitting the second SCI, and transmits the SCI or data to the second terminal device within the DRX active time of the second terminal device.

The configuration information for the DRX operation may further include a maximum duration of the third timer and/or a maximum duration of the second timer.

The second terminal device is in active time for DRX operation during the second timer run, and the third timer run is in inactive time for DRX operation.

Optionally, the DRX operation may also configure a second periodicity, the second periodicity being smaller than the first periodicity. And a timer F corresponding to the DRX operation of the second cycle, the maximum duration of the timer F being a maximum length of time for which the terminal device can apply the DRX operation of the second cycle. After the timer F expires, the terminal device stops applying the DRX operation of the second cycle and starts the DRX operation of the first cycle. That is, the terminal device changes (or switches) the period of the DRX operation from the second period to the first period after the timer F expires. Wherein, the timers D and E are applicable to both the first cycle and the second cycle. That is, when the second terminal device performs the DRX operation of the second period, the first terminal device and the second terminal device start the timer D at the start time of each second period, and the first terminal device starts the timer E after transmitting the second SCI, and the second terminal device starts the timer E after receiving the second SCI.

According to the scheme, the first terminal device and the second terminal device respectively serve as the sending device and the receiving device of the DRX operation to execute the DRX operation, the timer is used for controlling the terminal device to receive and send data, so that the terminal device which performs the DRX operation understands the received and sent data consistently, unnecessary power consumption of the terminal device is reduced, and electric energy is saved.

In one embodiment, the first terminal device may receive indication information a from the second terminal device, the indication information a being used for indicating that the DRX operation of the second cycle is started or changed from the DRX operation of the first cycle to the DRX operation of the second cycle, and after receiving the indication information a, the first terminal device starts the DRX operation of the second cycle and starts a timer F corresponding to the second cycle, and the DRX operation of the second cycle may be applied during the running of the timer F. Accordingly, the second terminal device starts a timer F after transmitting the indication information a, and applies the DRX operation of the second cycle during the running of the timer F. After the timer F expires, the first terminal device and the second terminal device change (or switch) the DRX operation cycle from the second cycle to the first cycle.

In another embodiment, the first terminal device may send the indication information a to the second terminal device, start the DRX operation of the second cycle and start the timer F after the first terminal device sends the indication information a, and apply the DRX operation of the second cycle during the running of the timer F. Accordingly, the second terminal device starts a timer F after receiving the indication information a from the first terminal device, and applies the DRX operation of the second cycle during the running of the timer F. After the timer F expires, the first terminal device and the second terminal device change (or switch) the DRX operation cycle from the second cycle to the first cycle.

In one embodiment, the first terminal device may receive indication information B from the second terminal device, the indication information B indicating that the first periodic DRX operation is started, and the first terminal device stops the timer F and starts the first periodic DRX operation after receiving the indication information B. Accordingly, the second terminal device stops the timer F after transmitting the indication information B to start the DRX operation of the first cycle.

For example, the first terminal device is performing DRX operation of the second cycle, and the timer F is running. The first terminal device may transmit control information or data to the second terminal device during the DRX active time in each cycle (second cycle), and upon receiving the indication information B transmitted by the second terminal device, the first terminal device stops the timer F and changes (or switches) the cycle of the DRX operation from the second cycle to the first cycle.

In another embodiment, the first terminal device may send indication information B to the second terminal device, and after sending the indication information B, the first terminal device stops the timer F and starts the DRX operation of the first cycle. Accordingly, the second terminal device stops the timer F and starts the DRX operation of the first cycle after receiving the indication information B from the first terminal device.

According to the scheme, the terminal equipment for performing the sidelink communication can switch the period of the sidelink DRX operation through the indication information A according to the service requirement, so that the power consumption of the terminal equipment is reduced, and the flexibility of data receiving and transmitting is improved.

For example, when the first terminal device performs sidelink multicast or broadcast, the plurality of second terminal devices start or restart the timer a after receiving the first data multicast or broadcast from the first terminal device.

As an example and not limitation, the indication information a and/or the indication information B may be a MAC Control Element (CE), for example, the indication information a may be written as a DRX Command MAC CE or a SL DRX Command MAC CE, and the indication information B may be written as a Long DRX Command MAC CE or a SL Long DRX Command MAC CE, but the application is not limited thereto.

Optionally, after the first terminal device and the second terminal device receive the indication information a and/or the indication information B, the timer D and/or the timer E are stopped.

According to the scheme, the behaviors of the plurality of terminal devices for performing the sidelink communication are regulated, so that the behaviors of the transmitting device and the receiving device are kept consistent, the power consumption of the terminal devices can be reduced under the condition of ensuring normal communication, and the electric energy is saved.

Fig. 5 is another exemplary flowchart of a sidelink communications method provided by an embodiment of the present application.

And S510, the first terminal equipment determines to send second information, wherein the second information is used for indicating to stop the fourth timer.

The fourth timer running period is an active time of DRX operation between the second terminal device and the first terminal device. Optionally, the second information may be indication information a or indication information B, and the fourth timer may include, but is not limited to, timer D and/or timer E.

Optionally, the first terminal device may determine to send the second information according to one or more of the following conditions:

Alternatively, S510 may be performed by the MAC layer of the first terminal device, for example, the MAC layer of the first terminal device may determine whether to transmit the second information according to whether a condition for transmitting the second information is satisfied, or the first terminal device may determine whether to transmit the second information according to received indication information C, which may be from a physical layer, a Radio Resource Control (RRC) layer, or a V2X layer.

The first terminal device determines (or selects) a first resource to transmit the second information after S510.

In one embodiment, the first terminal device starts a fifth timer after determining to send the second message. The fifth timer runs for the time when the first terminal device can transmit the second information, that is, the first terminal device needs to determine the first resource and transmit the second information on the first resource during the fifth timer runs. And the first terminal equipment stops the fifth timer after sending the second information. If the first terminal device does not determine (or select) the first resource during the operation of the fifth timer, or the first terminal device does not send the second information after the fifth timer expires, the first terminal device does not send the second information, so as to save power consumption.

In another embodiment, the second information is used to indicate to stop the fourth timer in one cycle (for example, a cycle in which the DRX operation is being performed, or a cycle next to the cycle in which the DRX operation is being performed, which may be referred to as cycle a, but the present application is not limited thereto), and the cycle length of cycle a may be the first cycle or the second cycle. If the first terminal device does not determine (or select) the first resource before the end of the period a, the first terminal device does not send the second information. The first terminal device does not need to send the second information again because the period acted by the second information is already finished, so that the power consumption is saved.

The manner in which the first terminal device selects the first resource includes, but is not limited to, one or more of the following.

In a first mode

S520, the first terminal device sends third information to the first network device, where the third information is used to request the first resource.

Accordingly, the first network device receives the third information from the first terminal device. The first network device establishes a wireless communication connection for the first terminal device.

Alternatively, the third information may be a Scheduling Request (SR).

Optionally, the first terminal device sends the third information to the first network device on a second resource, where the second resource is a dedicated resource for sending the third information. That is, the second resource is a dedicated resource for the first terminal device to transmit request information (i.e., the third information) for requesting the first resource.

Optionally, before S520, the first terminal device may receive eighth information from the first network device, where the eighth information is used to configure the second resource. For example, the eighth information includes an identifier of SR configuration information, where the SR configuration information corresponding to the identifier is used to configure one or more SR resources, and the second resource is one SR resource of the one or more SR resources, but the application is not limited thereto.

S521, fourth information sent by the first network device to the first terminal device, where the fourth information is used to indicate the first resource.

Correspondingly, the first terminal device receives fourth information from the first network device, and the terminal device determines the first resource according to the fourth information.

Mode two

S520, the first terminal device determines a first resource in the configuration authorized resource.

For example, the first network device configures a Configuration Granted (CG) resource for the first terminal device, and the first terminal device determines a first resource for transmitting the second information in the configuration granted resource.

Optionally, the first terminal device starts the fifth timer, and the first resource is a configuration authorized resource during a running period of the fifth timer. And if the duration range of the fifth timer does not include the configuration authorized resource, the first terminal equipment does not send the second information.

Optionally, the second indication information indicates to stop the fourth timer in the period a, and the first resource is a configuration authorized resource in the period a. And if the period A does not comprise the configuration authorization resource, the first terminal equipment does not send the second information.

Mode III

S520, the first terminal device determines a first resource in the sidelink resources for contention.

For example, the first terminal device uses the sidelink mode2 transmission mode to contend for the resource in the sidelink resource configured by the first network device for contention, and determines the contended resource as the first resource, or the first terminal device sends the second information on the contended resource.

Optionally, the first terminal device starts the fifth timer, and if the first terminal device competes for the resource during the operation of the fifth timer, the competed resource may serve as the first resource to send the second information; and if the first terminal equipment does not compete to the resources during the running period of the fifth timer or does not comprise the sidelink resources for competition during the running period of the fifth timer, the first terminal equipment does not send the second information.

Optionally, the second information indicates to stop the fourth timer in the period a, and if the first terminal device competes for the resource of the period a, the competed resource may serve as the first resource to send the second information; if the first terminal device does not compete for the resources in the period a or does not include the sidelink resources for competition in the period a, the first terminal device does not send the second information.

According to the scheme, the first terminal device determines the first resource through one of the above manners, so that the terminal device can send the second information through the resource, thereby stopping the fourth timer in time and avoiding unnecessary power consumption of the terminal device. After determining the first resource, the first terminal device executes S530.

S530, the first terminal device sends the second information to the second terminal device on the first resource.

Accordingly, the second terminal device receives second information from the first network device, which is carried on the first resource. Optionally, before the first terminal device sends the second information, the first terminal device determines whether an event for sending the second information is cancelled, and if the event is not cancelled, the first terminal device sends the second information to the second terminal device on the first resource.

Optionally, after the second terminal device receives the second information, S540 may be executed to send sixth information to the second network device, where the sixth information is used to indicate that the second terminal device receives information from the first terminal device to stop the fourth timer. Or the sixth information is used to indicate that the second terminal device requests to stop the fourth timer (i.e. the timer between the second terminal device and the first terminal device). Optionally, S540 is executed when the second terminal device is in an RRC connected state or when the second terminal device adopts a sidelink mode1 transmission mode. By way of example and not limitation, the sixth information may be one or more of an RRC message, a MAC CE, or Uplink Control Information (UCI).

It should be noted that, in the embodiment shown in fig. 5, the second terminal device performs a DRX operation with the first terminal device, the second terminal device may be a terminal device performing discontinuous reception in the DRX operation, and the corresponding first terminal device may be a sending device of control information or data in the DRX operation. Alternatively, the first terminal device may be a terminal device performing discontinuous reception in the DRX operation, and the corresponding second terminal device may be a transmitting device of control information or data in the DRX operation.

Fig. 6 is another illustration of a communication method of a sidelink according to an embodiment of the present application.

S610, establishing unicast connection between the first terminal device and the second terminal device.

The first terminal device and the second terminal device may communicate by establishing a unicast connection.

And S620, the first terminal equipment and the second terminal equipment perform capability information interaction.

After the unicast connection is established between the first terminal device and the second terminal device, the capability information between the first terminal device and the second terminal device can be interacted.

For example, the first terminal device sends a request message of capability information to the second terminal device, and the second terminal device sends the capability information of the second terminal device to the first terminal device after receiving the request message. Optionally, the request message may further include capability information of the first terminal device. By way of example and not limitation, the capability information may be sidelink communication-related capability information, for example, including but not limited to one or more of the following:

whether DRX of the sidelink is supported, whether DRX of a long cycle (i.e., a first cycle) of the sidelink is supported, or whether DRX of a short cycle (i.e., a second cycle) of the sidelink is supported.

According to the scheme, the capability of the terminal equipment for establishing the sidelink is determined through capability interaction so that subsequent communication can be normally carried out. Optionally, the first terminal device may send a first message to the first network device in S630 after receiving the capability information of the second terminal device. Alternatively, the first message may be a sidelink message of the terminal device, for example, the sidelink message of the terminal device may be written as SidelinkUEInformation. Or the first message may be in a terminal equipment assistance message, for example, the terminal equipment assistance message may be written as ueassisinceinformation, or the first message may be in another RRC message.

Optionally, the first message includes seventh information, where the seventh information is used to indicate that the first terminal device needs to send second information (e.g., the second information in the implementation of fig. 5 described above). Optionally, the seventh information may include identification information (e.g., layer 2 identification, etc.) of the second terminal device to notify the first network device that the first terminal device needs to send the second information to the second terminal device. The seventh information may further include one or more of whether the second information supports HARQ feedback, a maximum number of transmissions of the second information, or a length of the second information, but the application is not limited thereto.

Optionally, after the first terminal device sends the first message to the first network device, the first network device sends a second message to the first terminal device in S640. The second message includes eighth information, where the eighth information is used to configure the second resource in the embodiment of fig. 5, for example, the eighth information includes an identifier of SR configuration information.

Optionally, the second message may further include configuration information for configuring the authorized resource. The configuration granted resource may be a first type of configuration granted (configured grant type1) resource and/or a second type of configuration granted (configured grant type2) resource.

According to the scheme, the terminal equipment reports the relevant information of the sidelink to the network equipment so that the network equipment configures the resources for the sidelink for the terminal equipment, and the terminal equipment utilizes the configured resources to carry out sidelink communication. It should be understood that, in the foregoing embodiments, the sequence numbers of the processes do not imply an execution sequence, and the execution sequence of the processes should be determined by functions and internal logic of the processes, and should not constitute any limitation to the implementation process of the embodiments of the present application.

The method provided by the embodiment of the present application is described in detail above with reference to fig. 2 to 6. Hereinafter, the apparatus provided in the embodiment of the present application will be described in detail with reference to fig. 7 to 9.

Fig. 7 is a schematic block diagram of a communication device provided in an embodiment of the present application. As shown in fig. 7, the communication device 700 may include a processing unit 710 and a transceiver unit 720.

For example, the communication device 700 may be a terminal device, may be a vehicle-mounted communication device, or a device included in the terminal device, such as various types of vehicles, or a device included in the terminal device, such as a system chip; for example, the communication apparatus 700 may also be used to implement the network device or the system chip in the network device mentioned in the above embodiments; illustratively, the communication device 700 may include modules, units or means (means) for implementing the method operations in the above embodiments, and the modules, units or means may be implemented by hardware, software or hardware to execute corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

In one possible design, the communication apparatus 700 may correspond to the first terminal device in the above method embodiment, or a chip configured (or used) in the first terminal device.

It is to be understood that the communication apparatus 700 may correspond to the first terminal device in the

methods

200, 300, 500, 600 according to embodiments of the present application, and that the communication apparatus 700 may include means for performing the methods of the previous embodiments, such as the

methods

200, 300, 500, 600 in fig. 2, 3, 5 or 6. The units and other operations and/or functions described above in the communication apparatus 700 are respectively for implementing the corresponding flows of the

methods

200, 300, 500, 600 in fig. 2, 3, 5 or 6.

For example, when the communication device 700 is used to execute the method 200 in fig. 2, the transceiver 720 may be used to execute S210 in the method 200, and the processing unit 710 may be used to execute S220 and S230 in the method 200. When the communication device 700 is configured to perform the method 300 of fig. 3, the transceiver 720 may be configured to perform S310 of the method 300, and the processing unit 710 may be configured to perform S320 of the method 300. When the communication device 700 is configured to perform the method 500 in fig. 5, the transceiver 720 may be configured to perform S520 and S521 in the first mode of the method 500, and S530 in the method 500, and the processing unit 710 may be configured to perform S510, S520 in the second mode, or S520 in the third mode of the method 500. When the communication device 700 is configured to perform the method 600 in fig. 6, the transceiver 720 may be configured to perform S630 and S640 in the method 600, and the processing unit 710 may be configured to perform S610 and S620 in the method 600. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

In another possible design, the communication apparatus 700 may correspond to the second terminal device in the above method embodiment, or a chip configured (or used) in the second terminal device.

It is to be understood that the communication apparatus 700 may correspond to the second terminal device in the

methods

200, 300, 500, 600 according to the embodiments of the present application, and the communication apparatus 700 may include means for performing the methods performed by the second terminal device in the aforementioned embodiments, such as the

methods

200, 300, 500, 600 in fig. 2, 3, 5, or 6. The units and other operations and/or functions described above in the communication apparatus 700 are respectively for implementing the corresponding flows of the

methods

200, 300, 500, 600 in fig. 2, 3, 5 or 6.

For example, when the communication device 700 is used to execute the method 200 in fig. 2, the transceiver 720 may be used to execute S210 in the method 200, and the processing unit 710 may be used to execute S220 and S230 in the method 200. When the communication device 700 is configured to perform the method 300 in fig. 3, the transceiver 720 may be configured to perform S310 in the method 300, and the processing unit 710 may be configured to perform S330 and S340 in the method 300. When the communication apparatus 700 is configured to perform the method 500 in fig. 5, the transceiver 720 is configured to perform S530 and S540 in the method 500. When the communication apparatus 700 is configured to perform the method 600 in fig. 6, the processing unit 710 may be configured to perform S610 and S620 in the method 600. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

Optionally, the communication apparatus 700 may further include a storage unit, and the storage unit may be configured to store instructions or data, and the processing unit 710 may execute the instructions or data stored in the storage unit to enable the communication apparatus to implement corresponding operations, where the transceiver unit 720 in the communication apparatus 700 may correspond to the transceiver 810 in the terminal device 800 shown in fig. 8, and the storage unit may correspond to a memory in the terminal device 800 shown in fig. 8.

It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

It should also be understood that when the communication apparatus 700 is a terminal device, the transceiver unit 720 in the communication apparatus 700 may be implemented by a communication interface (such as a transceiver or an input/output interface), for example, may correspond to the transceiver 810 in the terminal device 800 shown in fig. 8, the processing unit 710 in the communication apparatus 700 may be implemented by at least one processor, for example, may correspond to the processor 820 in the terminal device 800 shown in fig. 8, and the processing unit 710 in the communication apparatus 700 may be implemented by at least one logic circuit. Alternatively, the transceiver may be a transmit-receive circuit. Alternatively, the input/output interface may be an input/output circuit.

It should also be understood that, when the communication apparatus 700 is a chip configured in (or used in) a terminal device, the transceiver unit 720 in the communication apparatus 700 may be an input/output interface or circuit of the chip, and the processing unit 710 in the communication apparatus 700 may be a processor in the chip.

In another possible design, the communication apparatus 700 may correspond to the first network device in the above method embodiment, or a chip configured (or used) in the first network device.

It should be understood that the communication apparatus 700 may correspond to the first network device in the

methods

500, 600 according to the embodiments of the present application, and the communication apparatus 700 may include means for performing the method performed by the first network device in the

methods

500, 600 in fig. 5 or fig. 6. The units and other operations and/or functions described above in the communication apparatus 700 are for implementing the corresponding flows of the

methods

500, 600 in fig. 5 or fig. 6, respectively.

For example, when the communication apparatus 700 is used to execute the method 500 in fig. 5, the transceiver 720 may be used to execute S520 and S521 in the method 500. When the communication apparatus 700 is configured to perform the method 600 in fig. 6, the transceiver 720 is configured to perform S630 and S640 in the method 600. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

In another possible design, the communication apparatus 700 may correspond to the second network device in the above method embodiment, or a chip configured (or used) in the second network device.

It should be understood that the communication apparatus 700 may correspond to the second network device in the method 500 according to the embodiment of the present application, and the communication apparatus 700 may include a unit for performing the method performed by the second network device in the method 500 in fig. 5. The units and other operations and/or functions described above in the communication apparatus 700 are respectively for implementing the corresponding flow of the method 500 in fig. 5.

For example, when the communication apparatus 700 is used to execute the method 500 in fig. 5, the transceiver 720 may be used to execute S540 in the method 500. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

Optionally, the communication apparatus 700 may further include a storage unit, and the storage unit may be configured to store instructions or data, and the processing unit 710 may execute the instructions or data stored in the storage unit to enable the communication apparatus to implement corresponding operations, where the transceiver unit 720 in the communication apparatus 700 may correspond to the transceiver 910 in the network device 900 shown in fig. 9, and the storage unit may correspond to a memory in the network device 900 shown in fig. 9.

It should also be understood that when the communication apparatus 700 is a network device, the transceiving unit 720 in the communication apparatus 700 may be implemented by a communication interface (such as a transceiver or an input/output interface), for example, may correspond to the transceiver 910 in the network device 900 shown in fig. 9, the processing unit 710 in the communication apparatus 700 may be implemented by at least one processor, for example, may correspond to the processor 920 in the network device 900 shown in fig. 9, and the processing unit 710 in the communication apparatus 700 may be implemented by at least one logic circuit. Alternatively, the transceiver may be a transmit-receive circuit. Alternatively, the input/output interface may be an input/output circuit.

It should also be understood that, when the communication apparatus 700 is a chip configured (or used) in a network device, the transceiver unit 720 in the communication apparatus 700 may be an input/output interface or circuit of the chip, and the processing unit 710 in the communication apparatus 700 may be a processor in the chip.

Fig. 8 is a schematic structural diagram of a terminal device 800 according to an embodiment of the present application. The terminal device 800 can be applied to the system shown in fig. 1, and performs the functions of the terminal device in the above method embodiment. As shown, the terminal device 800 includes a processor 820 and a transceiver 810. Optionally, the terminal device 800 further comprises a memory 830. Illustratively, the processor 820, the transceiver 810 and the memory 830 can communicate with each other via internal connection paths to transmit control and/or data signals, the memory is used for storing a computer program, and the processor 820 is used for executing the computer program in the memory 830 to control the transceiver 810 to transmit and receive signals. Optionally, the terminal device 800 may include a bus system 840, and information may be communicated between the transceiver 810, the processor 820, and the memory 830 via the bus system 840.

The processor 820 and the memory 830 may be combined into a processing device, and the processor 820 is configured to execute the program codes stored in the memory 830 to realize the functions. In particular implementations, the memory may also be integrated with the processor 820 or separate from the processor 820. The processor 820 may correspond to the processing unit in fig. 7.

The transceiver 810 may correspond to the transceiver unit 720 in fig. 7. The transceiver 810 may include a receiver (or receiver, receiving circuit) and a transmitter (or transmitter, transmitting circuit). Illustratively, the receiver is for receiving signals and the transmitter is for transmitting signals.

It should be understood that the terminal device 800 shown in fig. 8 is capable of implementing various processes involving the terminal device in the method embodiments shown in fig. 2, fig. 3, or fig. 5. The operations and/or functions of the modules in the terminal device 800 are respectively to implement the corresponding flows in the above-described method embodiments. Reference may be made specifically to the description of the above method embodiments, and a detailed description is appropriately omitted herein to avoid redundancy.

The processor 820 may be used to perform the actions described in the previous method embodiments that are implemented internally by the terminal device, and the transceiver 810 may be used to perform the actions described in the previous method embodiments that the terminal device transmits to or receives from the network device. Please refer to the description of the previous embodiment of the method, which is not repeated herein.

Optionally, the terminal device 800 may further include a power supply for supplying power to various devices or circuits in the terminal device.

In addition, in order to improve the functions of the terminal device, the terminal device 800 may further include one or more of an input unit, a display unit, an audio circuit, a camera, a sensor, and the like, and the audio circuit may further include a speaker, a microphone, and the like.

Fig. 9 is a schematic structural diagram of a network device 900 according to an embodiment of the present application. The network device 900 may be applied to the system shown in fig. 1 or fig. 2, and performs the functions of the network device in the above method embodiments. As shown, the network device 900 includes a processor 920 and a transceiver 910. Optionally, the network device 900 further comprises a memory. Illustratively, the processor 920, the transceiver 910 and the memory can communicate with each other via the internal connection path to transmit control and/or data signals, the memory is used for storing a computer program, and the processor 920 is used for executing the computer program in the memory to control the transceiver 910 to transmit and receive signals. Optionally, the transceiver 910 of the network device 900 may include an antenna and/or radio frequency circuitry.

It should be appreciated that the network device 900 shown in fig. 9 is capable of implementing various processes involving the network device in the method embodiments shown in fig. 2, 3, or 5. The operations and/or functions of the modules in the network device 900 are respectively for implementing the corresponding flows in the above method embodiments. Reference may be made specifically to the description of the above method embodiments, and a detailed description is appropriately omitted herein to avoid redundancy.

It should be understood that the network device 900 shown in fig. 9 is only one possible architecture of a network device and should not constitute any limitation to the present application. The method provided by the application can be applied to network equipment with other architectures. E.g. network devices containing CUs, DUs and AAUs etc. The present application is not limited to the specific architecture of the network device.

An embodiment of the present application further provides a processing apparatus, which includes a processor and a memory. The processor is configured to read instructions stored in the memory, and to receive signals via the receiver and transmit signals via the transmitter to perform the method of any of the above method embodiments.

It is to be understood that the processing means described above may be one or more chips. For example, the processing device may be a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), a system on chip (SoC), a Central Processing Unit (CPU), a Network Processor (NP), a digital signal processing circuit (DSP), a Microcontroller (MCU), a Programmable Logic Device (PLD), or other integrated chips.

In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The steps of a method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in a processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor. To avoid repetition, it is not described in detail here.

It should be noted that the processor in the embodiments of the present application may be an integrated circuit chip having signal processing capability. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The processor described above may be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

It will be appreciated that the memory in the embodiments of the subject application can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. Illustratively, the non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM, enhanced SDRAM, SLDRAM, Synchronous Link DRAM (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

According to the method provided by the embodiment of the present application, the present application further provides a computer program product, which includes: computer program code which, when executed by one or more processors, causes an apparatus comprising the processor to perform the method in the embodiment of fig. 2, 3, 5 or 6.

There is also provided a computer readable storage medium storing program code which, when executed by one or more processors, causes an apparatus including the processors to perform the method in the embodiments shown in fig. 2, fig. 3, fig. 5 or fig. 6.

According to the method provided by the embodiment of the present application, the present application further provides a system, which includes the foregoing one or more network devices. The system may further comprise one or more of the terminal devices as previously described.

The network device in the foregoing device embodiments completely corresponds to the terminal device and the network device or the terminal device in the method embodiments, and the corresponding module or unit executes the corresponding steps, for example, the communication unit (transceiver) executes the steps of receiving or transmitting in the method embodiments, and other steps besides transmitting and receiving may be executed by the processing unit (processor). The functions of the specific elements may be referred to in the respective method embodiments. Illustratively, the processor may be one or more.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a Digital Video Disk (DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), among others.

The network device in the foregoing device embodiments completely corresponds to the terminal device and the network device or the terminal device in the method embodiments, and the corresponding module or unit executes the corresponding steps, for example, the communication unit (transceiver) executes the steps of receiving or transmitting in the method embodiments, and other steps besides transmitting and receiving may be executed by the processing unit (processor). The functions of the specific elements may be referred to in the respective method embodiments. The number of the processors may be one or more.

As used in this specification, the terms "component," "module," "system," and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between 2 or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from two components interacting with another component in a local system, distributed system, and/or across a network such as the internet with other systems by way of the signal).

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

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, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

In the above embodiments, the functions of the functional units may be fully or partially implemented by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions (programs). The procedures or functions described in accordance with the embodiments of the present application are generated in whole or in part when the computer program instructions (programs) are loaded and executed on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of wireless communication, comprising:

after first data is sent to second terminal equipment by first terminal equipment, starting or restarting a first timer, wherein the first data corresponds to a first hybrid automatic repeat request (HARQ) process;

and the first terminal equipment sends first information to the second terminal equipment after the first timer is overtime, wherein the first information indicates the first terminal equipment to schedule retransmission data corresponding to the first HARQ process.

2. The method of claim 1, wherein the starting or restarting the first timer comprises:

and the first terminal equipment starts or restarts the first timer after receiving HARQ feedback information from the second terminal equipment, wherein the HARQ feedback information corresponds to the first HARQ process.

3. The method of claim 2, wherein the HARQ feedback information indicates that the first data was not successfully received.

4. The method of claim 1, wherein HARQ feedback for the first HARQ process is de-enabled.

5. The method according to any one of claims 1 to 4, further comprising:

after the first timer is overtime, the first terminal equipment starts or restarts a second timer;

and the first terminal equipment transmits retransmission data corresponding to the first HARQ process during the running period of a second timer.

6. The method of claim 5, further comprising:

and after the second timer is overtime, the first terminal equipment releases the first HARQ process or restarts the first timer.

7. A method of wireless communication, comprising:

after receiving first data of first terminal equipment, second terminal equipment starts or restarts a third timer, wherein the first data corresponds to a first hybrid automatic repeat request (HARQ) process;

and after the third timer is overtime, the second terminal equipment monitors first information from the first terminal equipment, wherein the first information indicates the first terminal equipment to schedule retransmission data of the first HARQ process.

8. The method of claim 7, wherein the starting or restarting a third timer comprises:

and the second terminal equipment starts or restarts the third timer after sending HARQ feedback information to the first terminal equipment, wherein the HARQ feedback information corresponds to the first HARQ process.

9. The method of claim 8, wherein the HARQ feedback information indicates that the first data was not successfully received.

10. The method of claim 7, wherein HARQ feedback for the first HARQ process is de-enabled.

11. The method according to any one of claims 7 to 10, further comprising:

after the third timer is overtime, the second terminal equipment starts or restarts a second timer;

and the second terminal equipment receives the retransmission data corresponding to the first HARQ process during the running period of the second timer.

12. The method of claim 11, further comprising:

and after the second timer is overtime, the second terminal equipment releases the first HARQ process or restarts a third timer.

13. A method of communication, comprising:

a first terminal device determines a first resource, wherein the first resource is used for carrying second information, the second information is used for indicating to stop a fourth timer, and the running period of the fourth timer is the activation time of DRX operation between the first terminal device and a second terminal device;

and the first terminal equipment sends the second information to the second terminal equipment, and the second information is carried on the first resource.

14. The method of claim 13, wherein the first terminal device determines the first resource, comprising:

the first terminal equipment sends third information to first network equipment, and the third information is used for requesting the first resource;

and the first terminal equipment determines the first resource according to fourth information from the first network equipment, wherein the fourth information is used for indicating the first resource.

15. The method of claim 14, wherein before the first terminal device sends the third information to the network device, the method further comprises:

and the first terminal equipment receives fifth information sent by the first network equipment, wherein the fifth information is used for indicating a second resource, and the second resource is a dedicated resource for bearing the third information.

16. The method of claim 13, wherein the first resource is a configuration grant resource, or wherein the first resource is a sidelink resource that the first terminal device contends to.

17. The method according to any of claims 13 to 16, characterized in that before the first terminal device determines the first resource, the method further comprises:

the determining, by the first terminal device, to send the second information and start a fifth timer, and sending, by the first terminal device, the second information to the second terminal device includes:

and the first terminal equipment sends the second information to the second terminal equipment during the running period of the fifth timer.

18. The method of claim 17, further comprising:

stopping the fifth timer after the first terminal device sends the second information, or,

and when the fifth timer runs overtime and the first terminal equipment does not determine the resource for sending the second information, the first terminal equipment determines not to send the second information to the second terminal equipment.

19. The method according to any of claims 13 to 18, wherein the second information is a medium access control element, MAC CE.

20. A communication device for implementing the method of any one of claims 1 to 6 or the method of any one of claims 13 to 19.

21. A communication device, characterized in that it is adapted to implement the method according to any of claims 7 to 12.

22. A communications apparatus comprising at least one processor coupled to a memory, the memory configured to store programs or instructions;

the at least one processor is configured to execute the program or instructions to cause the apparatus to implement the method of any one of claims 1 to 6, or to implement the method of any one of claims 7 to 12, or to implement the method of any one of claims 13 to 19.

23. A computer-readable storage medium, comprising a computer program which, when run on a computer, causes the computer to perform the method of any one of claims 1 to 19.

24. A communication system comprising an apparatus according to claim 20 and an apparatus according to claim 21.