CN114600481A

CN114600481A - Communication method and communication device

Info

Publication number: CN114600481A
Application number: CN201980101568.3A
Authority: CN
Inventors: 张云昊; 陈雁
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-11-15
Filing date: 2019-11-15
Publication date: 2022-06-07
Also published as: WO2021092925A1

Abstract

The application provides a communication method and a communication device, a terminal determines a cluster head of a terminal group by itself, and a process that network equipment participates in the terminal group is not needed, so that signaling overhead is saved, and time delay is reduced. The method comprises the following steps: a first terminal acquires a first parameter of a second terminal; and the first terminal determines that the first terminal is a cooperative terminal or a target terminal according to the first parameter of the second terminal.

Description

Communication method and communication device

Technical Field

The present application relates to the field of communications, and more particularly, to a communication method and a communication apparatus.

Background

The Long Term Evolution (LTE) standard of the 3rd generation partnership project (3 GPP) supports terminal-to-terminal communication using sidelink (sidelink). In some mobile communication scenarios, the terminals and the terminals may form a terminal group for group communication. A terminal group may be under three cellular network coverage conditions during operation, including in-coverage (in-coverage), out-of-coverage (out-of-coverage), and partial-coverage (partial-coverage). For example, as shown in fig. 1, the terminal group in fig. 1 may be located outside the network coverage, or may be located within the network coverage, or a part of terminals in the terminal group may be outside the network coverage and a part of terminals may be within the network coverage. A group of terminals may also be referred to as a cluster of terminals, simply "cluster". The terminal group comprises a cooperative terminal and at least one target terminal. And the cooperative terminal is used for assisting other terminals in the terminal group to forward data. The cooperative terminal may also be referred to as a "cluster head". The target terminal may also be referred to as a "cluster member".

Currently, a base station clusters devices with close distances according to the device-to-device (D2D), and assigns a cluster head to each cluster. The base station plays a controlling role in the clustering and cluster head assigning processes. This means that before entering a cluster, the terminal needs to be in a Radio Resource Control (RRC) CONNECTED (CONNECTED) state, and terminals in other states need to perform random access first, which increases the cluster entry delay of the terminal. And a large amount of signaling interaction is needed between the terminal and the base station, and in a super-large connection scene, the signaling overhead of the base station is very large, so that normal uplink and downlink scheduling is influenced. Moreover, this method is no longer applicable to terminals outside the network coverage of fig. 1.

Disclosure of Invention

In view of the above, the present application provides a communication method and a communication apparatus, where a terminal can determine whether the terminal is a target terminal or a cooperative terminal in a terminal group, which is beneficial to improving group efficiency and saving signaling overhead.

In a first aspect, a communication method is provided, which may be performed by a first terminal, and may also be performed by a device (e.g., one or more of a chip, a processor, or a system of chips) in the first terminal.

The communication method comprises the following steps: a first terminal (or a chip, a processor, a chip system and the like in the first terminal) acquires a first parameter of a second terminal; and the first terminal determines that the first terminal is a cooperative terminal or a target terminal according to the first parameter of the second terminal.

In the embodiment of the application, the first terminal obtains the first parameter of the second terminal, and then may determine its terminal type, such as a cooperative terminal or a target terminal, based on the first parameter. Compared with the mode that the network equipment needs to designate which terminal is the cooperative terminal in the prior art, the embodiment of the application is determined by the terminal.

The embodiment of the application is suitable for the terminals within the network coverage range or outside the network coverage range. For the terminal outside the coverage of the network device, the process of terminal grouping may not need the participation of the network device, but the terminal determines the cooperative terminal, i.e. the cluster head. Therefore, the first terminal does not need to establish connection with the network equipment, report information and the like, which is beneficial to saving signaling overhead and reducing time delay.

In a possible implementation manner, the determining, by the first terminal, that the first terminal is a cooperative terminal or that the first terminal is a target terminal according to the first parameter of the second terminal includes: when the value of the first parameter of the first terminal is larger than the value of the first parameter of the second terminal, determining that the first terminal is a cooperative terminal; and when the value of the first parameter of the first terminal is less than or equal to the value of the first parameter of the second terminal, determining that the first terminal is a target terminal. Here, the first terminal may compare the value of the first parameter of the first terminal with the value of the first parameter of the second terminal, and then determine whether the first terminal is a cooperative terminal of the terminal group or a target terminal of the terminal group based on the comparison result. In this way, a suitable cooperative terminal can be determined for the terminal group.

Optionally, the first parameter is related to: parameters associated with signals from the network device, and/or parameters associated with the terminal.

Optionally, the parameter relating to the signal from the network device comprises one or more of: received power, frequency response flatness.

Optionally, the terminal-related parameters include one or more of: the system comprises the following components of the system, wherein the system comprises a battery total capacity, the number of antennas, maximum transmitting power, receiver sensitivity, processor operation speed, memory capacity, heat dissipation capacity, movement capacity, residual electric quantity, whether an external sufficient power supply is connected, movement speed and whether a head vehicle and a vehicle moving direction exist in a fleet.

An optional way to obtain a first parameter, where a value of the first parameter satisfies the following equation:

P＝γ ^P_SS+τ*P_LO

where P denotes the first parameter, P _ SS denotes a parameter related to a network device signal, P _ LO denotes a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1. In this way, by weighting the P _ SS to emphasize that the channel attenuation between the terminal and the network device is reduced, the terminal with good flatness can be preferentially used as a cooperative terminal, which is helpful for selecting a more appropriate cooperative terminal for the terminal group.

Another optional way to obtain the first parameter is that a value of the first parameter satisfies the following formula:

P＝γ ^P_SS*ln(1+τ*P_LO)

where P denotes the first parameter, P _ SS denotes a parameter related to a network device signal, P _ LO denotes a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1. This way of acquiring the first parameter not only emphasizes the high priority of the network device coverage, but also considers that when the parameter related to the terminal is too low (for example, the processor of the terminal has weak computation capability and the remaining power is seriously insufficient), the terminal is not suitable as a cooperative terminal, which is helpful for selecting a more suitable cooperative terminal for the terminal group. It can be understood that the above provides two methods for calculating the first parameter, and any method can be adopted in the embodiments of the present application, i.e. the method for calculating the first parameter is relatively flexible.

The above description of the first parameter is applicable to the terminals appearing in the embodiments of the present application, such as the first terminal, the second terminal, and the like.

In one possible implementation, the method further includes: a first terminal acquires first information, wherein the first information is used for indicating the number of terminals in a terminal group, and the terminal group comprises a cooperative terminal and at least one target terminal; and the first terminal determines the group entering operation of the first terminal according to the number of the terminals in the terminal group. The embodiment of the application can introduce the upper limit of the number of the terminals in the terminal group. Thus, the first terminal can determine whether to enter the group or not by combining the number of the terminals in the terminal group, so as to ensure that the number of the terminals in the current terminal group does not exceed the upper limit of the number of the terminals in the terminal group.

In a possible implementation manner, the determining, by the first terminal, the group entry operation of the first terminal according to the number of terminals in the terminal group includes: when the number of the terminals in the terminal group meets a preset condition, the first terminal determines to enter the group; and when the number of the terminals in the terminal group does not meet the preset condition, the first terminal determines not to enter the group.

It can be understood that the number presetting condition of the terminals in the terminal group may have multiple possible implementation manners, for example, the number of the terminals in the terminal group may belong to a certain preset number interval, and for example, the number of the terminals in the terminal group may satisfy a certain preset value.

Optionally, the number of terminals in the terminal group satisfies a preset condition, including: and the number of the terminals in the terminal group is less than a preset value. For example, the preset value is an upper limit of the number of terminals in the terminal group.

Optionally, the communication method further includes: the first terminal sends second information, wherein the second information is used for indicating one or more of the following items: the first parameter of the first terminal, the identifier of the first terminal, and the number of terminals in the terminal group after the first terminal is grouped. That is to say, the first terminal may broadcast its own information, for example, the first parameter of the first terminal, the ID of the first terminal, and the number of terminals in the terminal group after the first terminal is grouped, so that other terminals can know the information.

For example, the first terminal determines that the first terminal is the target terminal, and the first terminal may send the second information to the cooperative terminal of the terminal group, so that the cooperative terminal manages the second information.

Optionally, the sending, by the first terminal, second information includes: the first terminal sends the second information on a first resource, wherein the first resource is related to the identification of the first terminal. Here, the first terminal can avoid collision with resources occupied by other terminals by transmitting the second information on the first resource.

Optionally, the communication method further includes: the first terminal receives third information, wherein the third information comprises first parameters and/or identification information corresponding to one or more target terminals. That is, the first terminal may also acquire information broadcast by other terminals.

For example, if the first terminal is a cooperative terminal, the first terminal may assist the one or more target terminals in forwarding data by acquiring the first parameter and/or the identification information corresponding to the one or more target terminals.

In a second aspect, a communication method is provided, which may be performed by a third terminal, and may also be performed by a device (e.g., one or more of a chip, a processor, or a system of chips) in the third terminal.

The communication method comprises the following steps: a third terminal (or a chip, a processor, a chip system and the like in the third terminal) acquires a first parameter of a fourth terminal, wherein the value of the first parameter of the fourth terminal is the maximum value of the values of the first parameters of a plurality of target terminals in a terminal group, and the terminal group comprises a cooperative terminal and at least one target terminal; and the third terminal determines to continue to manage the terminal group or sends fourth information to the fourth terminal based on the first parameter of the fourth terminal, which is favorable for improving the communication reliability of the terminal group.

In a possible implementation manner, the determining, by the third terminal, to continue to manage the terminal group based on the first parameter of the fourth terminal, or sending fourth information to the fourth terminal includes: when the value of the first parameter of the fourth terminal is greater than the value of the first parameter of the third terminal, the third terminal sends fourth information to the fourth terminal, wherein the fourth information comprises the first parameter and/or the identification information corresponding to one or more target terminals in the terminal group; and when the value of the first parameter of the fourth terminal is less than or equal to the value of the first parameter of the third terminal, the third terminal continues to manage the terminal group. Here, the third terminal may compare the value of the first parameter of the third terminal with the value of the first parameter of the fourth terminal, and then determine whether to continue to manage the terminal group based on the comparison result, which may improve reliability of the cluster head of the terminal group.

Optionally, when the value of the first parameter of the fourth terminal is greater than the value of the first parameter of the third terminal, the communication method further includes: and the third terminal receives feedback information from the fourth terminal, wherein the feedback information is used for indicating that the fourth terminal and the third terminal are successfully handed over. "successful handover" can be understood as: the fourth terminal has acquired the related information of the terminal group managed by the third terminal, for example, the P value and/or the ID corresponding to one or more target terminals included in the terminal group, the number of terminals in the terminal group, and the like. In this way, the third terminal can receive the feedback information from the fourth terminal, which contributes to improvement of reliability in handover of the terminal group.

Optionally, the first parameter is related to: parameters associated with signals from the network devices, and/or parameters associated with the terminals.

Optionally, the signal-related parameters from the network device comprise one or more of: received power, frequency response flatness.

P＝γ ^P_SS+τ*P_LO

where P denotes the first parameter, P _ SS denotes a parameter related to a network device signal, P _ LO denotes a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1.

Another alternative way to obtain the first parameter is to determine that the value of the first parameter satisfies the following formula:

P＝γ ^P_SS*ln(1+τ*P_LO)

It is understood that the above provides two methods for calculating the first parameter, and the embodiments of the present application may adopt either method, i.e. the method for calculating the first parameter is relatively flexible.

In a third aspect, there is provided a communication device comprising means for performing the method of the first aspect or any possible implementation manner of the first aspect; or comprise means for performing the method of the second aspect described above or any possible implementation of the second aspect.

In a fourth 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 of the possible implementations of the first aspect or 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 terminal device. When the communication device is a 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 terminal equipment. 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 fifth 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 in any one of the possible implementations of the first and second aspects.

In a specific implementation process, the processor may be a chip, 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 sixth aspect, an apparatus is provided that 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 possible implementations of the first and second 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, the data output by the processing may be output to a transmitter and the 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 apparatus in the above sixth aspect may be a chip, the processor may be implemented by hardware or may be implemented by software, and when implemented by 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 seventh aspect, a computer-readable storage medium is provided, in which a computer program or instructions are stored, which, when executed, implement the method of the first aspect or any possible implementation manner of the first aspect.

In an eighth aspect, there is provided a computer readable storage medium having stored therein a computer program or instructions which, when executed, implement the method of the second aspect or any possible implementation of the second aspect.

A ninth aspect provides a computer program product comprising instructions which, when executed, implement the first aspect or the method of any possible implementation of the first aspect, or the method of any possible implementation of the second aspect described above.

A tenth aspect provides a communication chip having instructions stored thereon, which when run on a computer device, cause the communication chip to perform the method of the first aspect or any possible implementation manner of the first aspect.

In an eleventh aspect, there is provided a communication chip having instructions stored therein, which when run on a computer device, cause the communication chip to perform the method of the second aspect or any possible implementation manner of the second aspect.

In a twelfth aspect, a communication system is provided that includes a first terminal and a second terminal.

Optionally, the communication system further comprises other devices for communicating with the first terminal and/or the second terminal.

In a thirteenth aspect, a communication system is provided that includes a third terminal and a fourth terminal.

Optionally, the communication system further comprises other devices for communicating with the third terminal and/or the fourth terminal.

Drawings

FIG. 1 is a diagram of a terminal group under different network coverage conditions;

FIG. 2 is a schematic diagram of a system architecture to which embodiments of the present application are applied;

FIG. 3 is a schematic interaction diagram of a communication method according to an embodiment of the present application;

FIG. 4 is a schematic flow chart diagram of one example of a communication method according to an embodiment of the present application;

fig. 5 is an exemplary diagram of a Physical Sidelink Discovery Channel (PSDCH) resource in a PSDCH period;

FIG. 6 is a schematic flow chart diagram of another example of a communication method according to an embodiment of the present application;

FIG. 7 is a schematic interaction diagram of a communication method according to another embodiment of the present application;

FIG. 8 is a schematic flow chart diagram of one example of a communication method according to another embodiment of the present application;

FIG. 9 is a schematic diagram of an apparatus according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a terminal device provided in an embodiment of the present application;

FIG. 11 is a schematic block diagram of an apparatus according to an embodiment of the present application.

Detailed Description

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

In the embodiments of the present application, "a plurality" may be understood as "at least two" or "two or more"; "A plurality" is to be understood as "at least two" or "two or more".

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 fifth generation (5G) communication system, a New Radio (NR) system, a device to device (D2D) system, a vehicle networking (V2X) system, and a future-evolution communication system.

V2X may implement information interaction between vehicle and internet (V2N), vehicle to vehicle (V2V), vehicle to person (V2P), or vehicle to infrastructure communication (V2I), etc., which may improve the intelligence level and automatic driving capability of the vehicle.

One participant of V2N is a terminal device and the other participant is a network device. V2N is a commonly used form of car networking, and its main function is to connect the vehicle to a network device (e.g. a server, or a cloud server, etc.) via a network, so that navigation, entertainment, or anti-theft functions can be obtained via the network device.

Both participants of V2V are terminal devices. V2V may be used as an inter-vehicle information interaction reminder, for example, for an inter-vehicle collision avoidance safety system.

Both participants of V2P are terminal devices. V2P may be used to provide safety warnings to pedestrians or non-motor vehicles on the road.

One participant in V2I is a terminal device and the other participant is an infrastructure (or infrastructure). V2I may be used for vehicle-to-infrastructure communications, e.g., where the infrastructure may be roads, traffic lights, roadblocks, etc., where road management information such as timing of traffic light signals may be obtained.

Fig. 2 is a schematic diagram of a system architecture to which an embodiment of the present application is applied. As shown in fig. 2, the architecture includes a network device 110 and a plurality of terminals. Taking a camped terminal 140 as an example, the camped terminal 140 has a group requirement. Optionally, there may or may not be a group of terminals in the vicinity of the camped terminal 140. The terminal group includes a cooperative terminal 120 and at least one target terminal 130. All of the terminals shown in fig. 2 may be entirely within the coverage of the network device 110, may be entirely outside the coverage of the access network device 110, may be partly within the coverage of the network device 110, and partly outside the coverage of the network device 110.

It is understood that fig. 2 is only a schematic diagram, and other network devices, such as a wireless relay device and a wireless backhaul device, may also be included in the communication system, which are not shown in fig. 2. The embodiments of the present application do not limit the number of access network devices and terminal devices included in the communication system.

In terminal cooperative communication, a terminal that needs to establish contact with an access network device by means of other terminals is called a target terminal, for example, a Target User Equipment (TUE). The target terminal does not communicate directly with the access network device. A terminal that assists in forwarding information is called a cooperative terminal, for example, a cooperative user equipment (ue). The cooperative terminal communicates directly with the access network device. The target terminal may communicate with the network device and/or other terminals with the assistance of the cooperative terminal. For example, the cooperative terminal may serve as a cluster head of a terminal group, the target terminal may serve as a cluster member, and the target terminal communicates with the base station through relay forwarding information of the cooperative terminal, or the cluster member communicates with other members in the cluster through scheduling and forwarding of the cluster head.

The network device is an access device that the terminal device accesses to the communication system in a wireless manner, and may be a Radio Access Network (RAN) device, a base station NodeB, an evolved NodeB (eNB), a base station (gNB) in the 5G communication system, a transmission point, a base station in a future communication system or an access node in a wireless fidelity (Wi-Fi) system, one or a group (including multiple antenna panels) of the base stations in the 5G system, or may also be a network node forming the gNB or the transmission point, such as a baseband unit (BBU), a Centralized Unit (CU), or a distributed unit (distributed unit, DU). The embodiment of the present application does not limit the specific technology and the specific device form adopted by the access network device. In some deployments, the gNB may include CUs and DUs. The gNB may also include an Active Antenna Unit (AAU). The CU implements part of the function of the gNB and the DU implements part of the function of the gNB. For example, the CU is responsible for processing non-real-time protocols and services to implement functions of Radio Resource Control (RRC) layer and Packet Data Convergence Protocol (PDCP) layer. The DU is responsible for processing physical layer protocols and real-time services to implement functions of a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer. The AAU implements part of the physical layer processing functions, radio frequency processing and active antenna related functions. Since the information of the RRC layer eventually becomes or is converted from the information of the PHY layer, the higher layer signaling, such as the RRC layer signaling, may also be considered to be transmitted by the DU or transmitted by the DU and the AAU under this architecture. It is to be understood that the network device may be a device comprising one or more of a CU node, a DU node, an AAU node. In addition, the CU may serve as a network device in an access network, and may also serve as a network device in a Core Network (CN), which is not limited in this application.

A terminal device may also be referred to as a terminal (terminal), a User Equipment (UE), a Mobile Station (MS), a Mobile Terminal (MT), etc. The terminal device may be a mobile phone (mobile phone), a tablet computer (Pad), a computer with 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 surgery (remote medical supply), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), a D2D device, a V2X device, a Roadside Station Unit (RSU), and so on. The embodiment of the present application does not limit the specific technology and the specific device form adopted by the terminal device.

The network equipment and the terminal equipment can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; can also be deployed on the water surface; it may also be deployed on airborne airplanes, balloons, and satellites. The embodiment of the application does not limit the application scenes of the access network equipment and the terminal equipment.

The embodiment of the application can be applied to downlink signal transmission, uplink signal transmission, and device-to-device D2D signal transmission. For downlink signal transmission, the sending device is an access network device, and the corresponding receiving device is a terminal device. For uplink signal transmission, the sending device is a terminal device, and the corresponding receiving device is an access network device. For the signaling of D2D, the transmitting device is a terminal device and the corresponding receiving device is another terminal device.

The network device and the terminal device may communicate with each other through a licensed spectrum (licensed spectrum), may communicate with each other through an unlicensed spectrum (unlicensed spectrum), and may communicate with each other through both the licensed spectrum and the unlicensed spectrum. The access network device and the terminal device may communicate with each other through a frequency spectrum of less than 6 gigahertz (GHz), may communicate through a frequency spectrum of more than 6GHz, and may communicate using both a frequency spectrum of less than 6GHz and a frequency spectrum of more than 6 GHz. The embodiment of the application does not limit the frequency spectrum resources used between the access network device and the terminal device.

In the embodiment of the present application, if not specifically stated, the network devices all refer to access network devices. The terminal device or the network device includes a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on top of the operating system layer. The hardware layer includes hardware such as a Central Processing Unit (CPU), a Memory Management Unit (MMU), and a memory (also referred to as a main memory). The operating system may be any one or more computer operating systems that implement business processing through processes (processes), such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a windows operating system. The application layer comprises applications such as a browser, an address list, word processing software, instant messaging software and the like. Furthermore, the embodiment of the present application does not particularly limit the specific structure of the execution subject of the method provided by the embodiment of the present application, as long as the execution subject can communicate with the method provided by the embodiment of the present application by running the program recorded with the code of the method provided by the embodiment of the present application, for example, the execution subject of the method provided by the embodiment of the present application may be a terminal device or a network device, or a functional module (for example, a processor, a chip, or a system-on-chip, etc.) capable of calling the program and executing the program in the terminal device or the network device.

In addition, various aspects or features of the present application may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROM), card, stick, or key drive, etc.). In addition, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data.

The following is a brief description of terms or concepts that may be involved in embodiments of the application.

The terminal group in the embodiment of the application comprises a cooperative terminal and at least one target terminal. The cooperating terminals may also be referred to as cluster heads of the terminal group. The target terminals in the terminal group have group requirements and need to forward data by means of the cooperative terminals. For example, in a large connection scenario of mass machine type communication (mtc), there are some terminals and network devices that have poor channel quality, and a nearby terminal is required to assist in forwarding data. In a low-latency requirement scenario such as V2X, information needs to be directly exchanged between terminals to reduce latency.

The link for device-to-device direct communication is referred to as a sidelink, or a sidelink (sidelink). The sidelink is distinguished from the uplink (uplink) and downlink (downlink) between the device and the network device. Links for device-to-device direct communication include sidelink communication (sidelink communication) and sidelink discovery (sidelink discovery). The Physical Sidelink Control Channel (PSCCH) may be used for sidelink communication, and a period of the PSCCH is referred to as a PSCCH period. Sidelink discovery may use a PSDCH, with a period referred to as a PSDCH period.

For the case where the terminal is within the coverage of the network device, the PSDCH period is configured by the network device. For example, the PSDCH period may be configured by the network device through higher layer signaling. For the case that the terminal is out of the coverage of the network device, the PSDCH period can have various configurations. For example, the PSDCH period may be selected by the sending terminal, or the PSDCH period may be predefined in a Subscriber Identity Module (SIM) card.

The resources (sometimes also referred to as physical resources) in the embodiments of the present application may include one or more of time domain resources, frequency domain resources, code domain resources, or spatial domain resources. For example, the time domain resource included in the physical resource may include at least one frame, at least one sub-frame, at least one slot (slot), at least one mini-slot (mini-slot), at least one time unit, or at least one time domain symbol. For example, the frequency domain resources included in the physical resources may include at least one carrier (carrier), at least one Component Carrier (CC), at least one bandwidth part (BWP), at least one Resource Block Group (RBG), at least one physical resource block group (PRG), at least one Resource Block (RB), or at least one subcarrier (sub-carrier, SC), and the like. For example, the spatial domain resources included in the physical resources may include at least one beam, at least one port, at least one antenna port, or at least one layer/spatial layer, etc. For example, the code domain resource included in the physical resource may include at least one Orthogonal Cover Code (OCC), at least one non-orthogonal multiple access (NOMA) code, and the like.

The time unit may be other time domain units such as a frame, a subframe, a slot (slot), a mini-slot (mini-slot), or a time domain symbol (or symbol for short). The micro time slot is a time domain unit with the time domain length smaller than the time slot. For example, one frame has a time length of 10 milliseconds (ms), and includes 10 subframes, and one subframe has a time length of 1 ms. One slot includes 12 time domain symbols in the case of an extended cyclic prefix and 14 time domain symbols in the case of a normal cyclic prefix. The time domain symbol may be an Orthogonal Frequency Division Multiplexing (OFDM) symbol, for example. A minislot includes fewer than 14 time domain symbols, such as 2 or 4 or 7, and so on. Or, a time slot may include 7 time domain symbols, and the number of time domain symbols included in a micro time slot is less than 7, such as 2 or 4, and the specific value is not limited.

Fig. 3 is a schematic diagram of a communication method 300 according to an embodiment of the present application. It is understood that the first terminal in fig. 3 may be the to-be-grouped terminal 140 in fig. 2, and may also refer to a device or a component (e.g., a processor, a chip, or a system-on-chip, etc.) in the terminal. It is further understood that, in the method 300, part or all of information interacted between the first terminal and the network, or part or all of information interacted between the first terminal and the second terminal may be carried in an existing message, channel, signal, or signaling, or may be a newly defined message, channel, signal, or signaling, which is not limited specifically. As shown in fig. 3, the method 300 includes:

s310, the first terminal obtains a first parameter of the second terminal.

Alternatively, the second terminal may be the cooperative terminal 120 in fig. 2. The embodiment of the present application does not specifically limit how the first terminal obtains the first parameter of the second terminal.

Alternatively, the first terminal may receive the first parameter from the second terminal, that is, obtain the first parameter of the second terminal from the second terminal. For example, the second terminal broadcasts its first parameters. Alternatively, the first terminal may also obtain the first parameter of the second terminal from other devices. For example, the first terminal obtains the first parameter of the second terminal from the network device. For another example, the first terminal device obtains the first parameter of the second terminal from the other terminal.

Illustratively, the first terminal blindly detects the PSDCH to obtain the first parameter of the second terminal.

Optionally, the first parameter is related to: parameters associated with signals from the network device, and/or parameters associated with the terminal. It is to be understood that "terminal" in "terminal-related parameters" herein is meant to be generic. For example, for a first parameter of a first terminal, a "terminal-related parameter" is a "first terminal-related parameter"; for a first parameter of the second terminal, the "terminal-related parameter" is a "second terminal-related parameter".

Illustratively, the first parameter relates to: parameters related to signals from the network device, and parameters related to the terminal. Alternatively, the first parameter is related to: a parameter associated with a signal from a network device. Alternatively, the first parameter is related to: a parameter associated with the terminal.

Optionally, the parameters relating to the signal from the network device comprise one or more of: received power (such as received power of a signal from a network device), frequency response flatness (such as frequency response flatness of a signal from a network device).

An alternative way to obtain the received power is: and the terminal obtains the receiving power of the main synchronizing signal, or obtains the receiving power of the auxiliary synchronizing signal, or obtains the sum of the receiving power of the main synchronizing signal and the receiving power of the auxiliary synchronizing signal in the detected synchronizing signal block. Optionally, the received power is normalized. An alternative way to obtain frequency response flatness is to: the terminal obtains a variance of a demodulation reference signal (DMRS) over a plurality of symbols and normalizes the variance. For example, DMRSs of 2 nd and 4 th symbols of the synchronization signal block occupy 240 × 3 × 2 Resource Elements (REs), each symbol occupies 240 × 3 — 720 REs, and the variance of 720 × 2 — 1440 DMRSs of 2 nd and 4 th symbols is calculated.

For example, assuming that parameters related to a signal from a network device are denoted by P _ SS, received power is denoted by P _ SS _ a, and frequency response flatness is denoted by P _ SS _ B, then P _ SS satisfies the following formula (1):

in equation (1), the parameters α, β may be predefined. If the terminal is not in the coverage of the network device, or the terminal is in a signal blind area of the network device and does not detect the synchronization broadcast block, the value of the P _ SS may be considered to be 0.

Optionally, the terminal-related parameters include one or more of: the system comprises the following components of the system, wherein the system comprises a battery total capacity, the number of antennas, maximum transmitting power, receiver sensitivity, processor operation speed, memory capacity, heat dissipation capacity, movement capacity, residual electric quantity, whether an external sufficient power supply is connected, movement speed and whether a head vehicle and a vehicle moving direction exist in a fleet. The terminal-related parameters may include fixed parameters of the terminal and/or variable parameters of the terminal. The fixed parameters of the terminal may include one or more of: the terminal comprises the following components of the terminal, such as total battery capacity, the number of antennas, maximum transmitting power, receiver sensitivity, processor operation speed, memory capacity, heat dissipation capacity, moving capacity and the like. The variable parameters of the terminal may include one or more of: the remaining power, whether the vehicle is externally connected with a sufficient power supply, the moving speed, whether the vehicle is a head vehicle in the motorcade, the moving direction of the vehicle and the like.

In one possible implementation manner, the value of the terminal fixed parameter satisfies the following formula (2):

in the formula (2), x represents a value of a fixed parameter of the terminal, N represents a total number of terms of the fixed parameter of the terminal, α (i) represents a weight of the ith parameter, and P _ st (i) represents a value of the ith parameter.

Illustratively, in one possible implementation, the value of the first parameter satisfies the following formula (3):

P＝γ ^P_SS+τ*P_LO (3)

in equation (3), P represents the first parameter, P _ SS represents a parameter related to a network device signal, P _ LO represents a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1. With equation (3), a terminal with good flatness can be prioritized as a cooperative terminal by weighting P _ SS to emphasize the reduction of channel attenuation with the network device.

In another possible implementation manner, the value of the first parameter satisfies the following formula (4):

P＝γ ^P_SS*ln(1+τ*P_LO) (4)

in equation (4), P represents the first parameter, P _ SS represents a parameter related to a network device signal, P _ LO represents a parameter related to a terminal, γ and τ are predefined values, γ>1，0<τ<1. For equation (4), when P _ LO is not close to zero, ln (1+ τ × P _ LO) tends to be zeroIn 1, the main term influencing the value of P is gamma^P_SS(ii) a When P _ LO approaches zero, ln (1+ τ × P _ LO) quickly goes to zero, resulting in the value of P quickly going to zero. In this implementation, both the high priority of the network device coverage is emphasized, and a case where the terminal-related parameter is too low (for example, the processor of the terminal has low calculation capability, the remaining power is severely insufficient, or the like) is considered to be unsuitable as a cooperative terminal.

It is understood that the possible implementation manners of the first parameter introduced above are only exemplary descriptions and do not limit the embodiments of the present application.

It is further understood that the above description regarding the first parameter is applicable to the terminals (including the terminals that have appeared, and the terminals that appear below) appearing in the embodiments of the present application, such as the first terminal, the second terminal, and the like.

After the first terminal acquires the first parameter of the second terminal, the first terminal may compare the value of the first parameter of the second terminal with the value of the first parameter of the first terminal, and then determine whether the first terminal can be used as a cooperative terminal based on the comparison result.

It can be understood that the value of the first parameter of the first terminal and the value of the first parameter of the second terminal can be compared after being obtained in the same manner. For example, the value of the first parameter of the first terminal and the value of the first parameter of the second terminal are obtained by using formula (3). For another example, the value of the first parameter of the first terminal and the value of the first parameter of the second terminal are obtained by using the formula (4).

And S320, the first terminal determines that the first terminal is a cooperative terminal or a target terminal according to the first parameter of the second terminal.

In the embodiment of the application, the first terminal obtains the first parameter of the second terminal, and then may determine its terminal type, such as a cooperative terminal or a target terminal, based on the first parameter. Compared with the mode that the network equipment needs to designate which terminal is the cooperative terminal in the prior art, the embodiment of the application is determined by the terminal. The embodiment of the application is suitable for the terminals within the network coverage range or outside the network coverage range. For the terminal outside the coverage of the network device, the process of terminal grouping may not need the participation of the network device, but the terminal determines the cooperative terminal, i.e. the cluster head. Therefore, the first terminal does not need to establish connection with the network equipment, report information and the like, signaling overhead is saved, and time delay is reduced.

Exemplarily, S320 includes: when the value of the first parameter of the first terminal is larger than that of the second terminal, determining the first terminal as a cooperative terminal; and when the value of the first parameter of the first terminal is less than or equal to the value of the first parameter of the second terminal, determining the first terminal as a target terminal.

For example, assuming that the first parameter is represented by P, when the P value of the first terminal is greater than the P value of the second terminal, the first terminal may determine that the first terminal is a cooperative terminal, that is, a cluster head of a terminal group; when the P value of the first terminal is less than or equal to the P value of the second terminal, the first terminal may determine that it is a target terminal rather than a cluster head of a terminal group.

It should be understood that the above corresponding cases of the respective size relationships are only exemplary descriptions and do not limit the embodiments of the present application. In fact, different size relationships may correspond to other situations. For example, when the value of the first parameter of the first terminal is greater than the value of the first parameter of the second terminal, the first terminal is determined to be a target terminal; and when the value of the first parameter of the first terminal is less than or equal to the value of the first parameter of the second terminal, determining that the first terminal is a cooperative terminal.

It should be further understood that the above division of the boundary case that the value of the first parameter of the first terminal is equal to the value of the first parameter of the second terminal is also only described by way of example, and does not limit the embodiment of the present application. For example, the "value of the first parameter of the first terminal is equal to the value of the first parameter of the second terminal" may also be divided together with the "value of the first parameter of the first terminal is greater than the value of the first parameter of the second terminal".

For ease of understanding, the following description is made in conjunction with the flowchart in fig. 4. Assuming that the first terminal is a camped terminal and the first parameter is represented by P, as shown in fig. 4, the camped terminal may perform the following steps:

401, the pending terminal blindly detects the sidelink broadcast channel.

The pending terminal may blindly detect the sidelink broadcast channel after the sidelink broadcast period starts. For example, the sidelink broadcast period may be a PSCCH period, or a PSDCH period; the sidelink broadcast channel includes one or more of: PSCCH, physical sidelink shared channel (PSCCH), Physical Sidelink Broadcast Channel (PSBCH), PSDCH.

Taking a sidelink broadcast period as an example of the PSDCH period, after the PSDCH period starts, the current cooperative terminal broadcasts its ID and P value on one or more PSDCH resources in the PSDCH period. If the cooperative terminal is within the coverage of the network device, the PSDCH resource for broadcasting the ID and P values of the cooperative terminal may be configured by the network device; if the cooperative terminal is out of the coverage of the network device, the PSDCH resource for broadcasting the ID and P values of the cooperative terminal may be predefined or selected by the cooperative terminal. And the terminal to be grouped performs blind detection on the PSDCH resource.

402, the pending terminal determines whether a cooperative terminal is detected.

When the ID and P values broadcast by the cooperative terminal are detected, the camped terminal executes 403.

When no information broadcast by any terminal is detected, the camped terminal executes 406.

Optionally, 403, the pending terminal records an ID (e.g., ID _ c) and a P value (e.g., P _ c) of the cooperative terminal.

404, the camped terminal determines whether P _ i is greater than P _ c.

Wherein, P _ i represents the P value of the terminal to be grouped. And P _ c represents the P value of the cooperative terminal detected by the terminal to be grouped.

When P _ i is greater than P _ c, the camped terminal executes 405.

When P _ i is not greater than P _ c, the camped terminal executes 406.

And 405, the terminal to be grouped determines that the terminal is a cooperative terminal.

Illustratively, if the value of P _ i of the terminal to be grouped is greater than the value of the current cooperative terminal P _ c, the terminal to be grouped determines that the terminal to be grouped is a cooperative terminal, and broadcasts the ID and P _ i of the terminal to be grouped on the side-chain broadcast channel, so that other terminals can acquire the ID and P _ i of the cooperative terminal.

406, the terminal to be grouped determines itself as the target terminal.

Illustratively, if the value of P _ i of the terminal to be grouped is not greater than the value of the current cooperative terminal P _ c, the terminal to be grouped determines that the terminal to be grouped is the target terminal. After determining that the terminal is the target terminal, the terminal to be grouped can continue to monitor the side-chain broadcast channel. In this way, when the cooperative terminal is replaced, the target terminal can know the ID of the new cooperative terminal.

It is understood that the camped terminal may repeatedly perform the above steps 401 and 406.

For example, after the to-be-grouped terminal determines that it is a cooperative terminal, the above step 401 and 406 may be periodically repeated to determine whether a new cooperative terminal exists, and if so, it is determined that it is a target terminal and does not broadcast its ID and P value any more.

In the flow of fig. 4, the cooperative terminal broadcasts its ID and P value through a sidelink, so that the terminal to be grouped can determine whether it is a new cooperative terminal by comparing its P value with the P value of the cooperative terminal; and the terminal to be grouped can know the ID of the cooperative terminal after determining that the terminal is the target terminal.

In this embodiment of the application, before entering the group, the first terminal may further determine whether to enter the group by combining the number of terminals in the terminal group. Optionally, the method 300 further comprises:

the method comprises the steps that a first terminal obtains first information, the first information is used for indicating the number of terminals in a terminal group, and the terminal group comprises a cooperative terminal and at least one target terminal. And the first terminal determines the group entering operation of the first terminal according to the number of the terminals in the terminal group.

Optionally, the first information may be obtained by the first terminal from a cooperative terminal of the terminal group. For example, the cooperative terminal broadcasts the number of terminals currently included in the terminal group. Alternatively, the first information may be acquired by the first terminal from other terminals (e.g., a newly-grouped terminal). For example, the newly grouped terminal may broadcast the number of terminals in the terminal group after entering the group. If the first information is acquired from the cooperative terminal, the first terminal needs to add one before judging whether the number of the terminals in the terminal group meets the preset condition, namely, the first terminal also counts the number of the terminals in the terminal group.

Optionally, the determining, by the first terminal, the group entry operation of the first terminal according to the number of terminals in the terminal group includes: when the number of the terminals in the terminal group meets a preset condition, the first terminal determines to enter the group; and when the data of the terminals in the terminal group do not meet the preset condition, the first terminal determines not to enter the group.

That is, the first terminal determines whether to join the group according to a preset condition before joining the group. If the number of the terminals in the terminal group meets a preset condition, the first terminal determines that the terminal can enter the group; and if the number of the terminals in the terminal group does not meet the preset condition, the first terminal determines not to enter the group.

In this embodiment of the application, there may be multiple implementation manners for the above-mentioned "the number of terminals in the terminal group satisfies the preset condition".

Illustratively, the "the number of terminals in the terminal group satisfies the preset condition" may be "the number of terminals in the terminal group satisfies the preset interval". For example, when the number of terminals in a terminal group is within a preset interval, the first terminal determines that the terminal can enter the group; and when the number of the terminals in the terminal group is not in the preset interval, the first terminal determines not to enter the group.

Illustratively, the "the number of terminals in the terminal group satisfies the preset condition" may be "the data of the terminals in the terminal group satisfies the preset value". The preset value is the upper limit of the number of terminals in the terminal group. For example, when the number of terminals in the terminal group is smaller than a preset value, the first terminal determines that the terminal can enter the group; and when the number of the terminals in the terminal group is greater than or equal to a preset value, the first terminal determines not to enter the group.

It is understood that the implementation manner of the above "the number of terminals in the terminal group satisfies the preset condition" is only an exemplary description, and does not limit the protection scope of the embodiment of the present application.

Optionally, the method 300 further comprises: the first terminal sends second information, and the second information is used for indicating one or more of the following items: the method comprises the steps of obtaining a first parameter of a first terminal, an identifier of the first terminal, and the number of terminals in a terminal group after the first terminal is grouped.

For example, the first terminal may broadcast second information indicating the first parameter, the identifier, and the number of terminals in the terminal group after the terminal group is grouped, so that other terminals can know the second information.

For example, the first terminal may send second information to the cooperative terminals of the terminal group, where the second information is used to indicate the identity of the first terminal, so as to notify the cooperative terminals of the identity of the first terminal.

Optionally, the first terminal may send the second information on a first resource, the first resource being associated with an identity of the first terminal. The first resource is a resource obtained by the first terminal according to the identifier of the first terminal. Illustratively, the first terminal obtains an identifier of a resource corresponding to the ID of the first terminal according to the ID of the first terminal, for example, the identifier is denoted by Rn, and Rn satisfies the following equation: rn ═ χ (ID). χ (x) may be a compression or expansion mapping function, and if the ID of the first terminal is taken as a variable, the ID of the first terminal may be mapped to the available resources with the head and tail removed in 1 sidelink broadcasting cycle. "remove the head and tail available resources" refers to the side link broadcast resources corresponding to the side link broadcast cycle: the first block of resources and the last segment of resources are removed from other resources. The first block resource refers to a time-frequency resource which occupies a first time unit (for example, a time slot) in a time domain and occupies a part of a frequency domain unit corresponding to the first time unit in a frequency domain in a side link broadcast resource; the last section of resource refers to time-frequency resources which occupy the last time unit in the time domain and occupy part or all of the frequency domain units corresponding to the last time unit in the frequency domain in the side link broadcast resources. For example, the frequency domain unit may be other frequency domain units such as RBG, PRG, RB, or SC.

The "first block resource" is different from the "last segment resource" in that: the number of frequency domain units occupied by the first block of resources in the frequency domain is smaller than the number of frequency domain units occupied by the last segment of resources in the frequency domain. Illustratively, the first block resource occupies a first time unit in the time domain and occupies a first frequency unit in the frequency domain; the last section of resource occupies the last time unit in the time domain and occupies all the frequency domain units corresponding to the last time unit in the frequency domain. The first block of resources is used for broadcasting of the current cooperative terminal of the terminal group. The last segment of resources is generally used for cooperating terminals to handover information related to the terminal group, for example, for an old cluster head to send information related to the terminal group to a new cluster head. Alternatively, the resource Rn cannot be the first block resource and the last segment resource in the sidelink broadcast resource. Here, the first terminal sends the second information on the resource acquired through the identifier of the first terminal, so that the collision of the resource occupied by other terminals to be grouped can be reduced.

As a unified illustration, for example, the sidelink broadcast period may be a PSDCH period, and the sidelink broadcast resource corresponding to the sidelink broadcast period may be a PSDCH resource. Described herein in connection with the PSDCH resources diagram of fig. 5. Fig. 5 shows an exemplary diagram of PSDCH resources in one PSDCH cycle. As shown in fig. 5, in one PSDCH cycle, the first block of resources is used for broadcasting the number of terminals currently included in the terminal group, the ID of the cooperative terminal, and the P value of the cooperative terminal by the current cooperative terminal. Suppose that the first terminal is a to-be-grouped terminal UE _ i, and Rn is an identifier of a block of resource obtained by the to-be-grouped terminal UE _ i according to its ID, for example, the resource Rn shown in fig. 5. The terminal UE _ i to be grouped may declare grouping on the resource Rn. "declare to be included" means: the terminal UE _ i to be grouped may broadcast its own information on the resource Rn, for example, an ID of the UE _ i, and/or a P value of the UE _ i. In fig. 5, the resource Rn cannot be the last segment of resource. And the resource from the first block resource to the resource Rn is the detection range of the terminal UE _ i to be grouped. In the detection range, the to-be-grouped terminal UE _ i detects whether there is information or parameter sent by another terminal, for example, one or more of a P value of the terminal, an ID of the terminal, or the number of terminals in the terminal group after the terminal is grouped. The last period of time in a PSDCH cycle is for cooperative terminal handover or handoff and is not used for declaring group entry.

It is to be understood that the example in fig. 5 is merely for facilitating the understanding of the embodiments of the present application by those skilled in the art, and is not intended to limit the embodiments of the present application to the specific context illustrated. It will be apparent to those skilled in the art from the example of fig. 5 that various equivalent modifications or variations can be made, and such modifications or variations also fall within the scope of the embodiments of the present application.

For ease of understanding, this is described herein in connection with the flowchart in FIG. 6. Still assuming that the first terminal is UE _ i, the identification information of UE _ i is represented by ID _ i, and the first parameter of UE _ i is represented by P _ i, as shown in fig. 6, including:

601, UE _ i determines resource Rn.

Specifically, after the sidelink broadcasting period starts, UE _ i determines the meaning of one resource Rn, Rn in the sidelink broadcasting period, which may refer to the foregoing description, and may specifically refer to the example in fig. 5.

UE _ i detects 602 sidelink broadcast resources.

Exemplarily, as described in fig. 5, the detection range of UE _ i is the resource corresponding to all time units between the first block resource to Rn illustrated in fig. 5.

603, UE _ i determines whether the parameter of UE _ k is detected.

Optionally, the parameters of UE _ k include one or more of: ID _ k, P _ k, N _ k. Wherein, ID _ k represents the ID of UE _ k, and P _ k represents the P value of UE _ k; n _ k represents the number of terminals in the terminal group after UE _ k is grouped. When UE _ i detects the parameter of UE _ k within the detection range of step 602, step 604 is executed.

When the UE _ i does not detect the parameter of the UE _ k within the detection range of step 602, step 605 is executed.

Optionally 604, UE _ i records ID _ k, P _ k, N _ k broadcasted by UE _ k.

605, UE _ i determines whether the time unit of resource Rn is reached.

When the time unit in which the resource Rn is located is not reached, UE _ i performs 602. When the time unit of the resource Rn is reached, the UE _ i executes 606 to judge whether the group member upper limit of the terminal group is reached.

606, UE _ i determines if N _ k is less than Nmax.

Nmax denotes the group member upper limit of the terminal group. When N _ k is less than Nmax, then UE _ i declares grouping on Rn, 607 is performed. When N _ k is not less than Nmax, UE _ i is not grouped in this period, and step 609 is performed.

607, UE _ i broadcasts ID _ i, P _ i, N _ i on resource Rn.

Where N _ i is N _ k + 1. N _ i is the number of members of the terminal group after UE _ i enters the group.

And 608, the UE _ i successfully enters the group.

609, UE _ i fails to join the group in this cycle.

It is understood that one time unit may carry information of one or more UEs to be grouped. It should be noted that fig. 6 is described by taking a case where information of one to-be-grouped UE is carried on one time unit as an example. In addition, even if a situation that a plurality of UEs are declared to be in a group in the same time unit occurs subsequently, the UE to be subsequently declared to be in a group or a cooperative terminal of a terminal group can recognize that the time unit has a plurality of UEs to be in a group, and the UE that is declared to be in a group in the next time slot can count the number of UEs that are in a plurality of groups in the time unit, that is, the number of members of the terminal group broadcasted by the UE that is declared to be in a group in the next time slot includes the number of UEs that are in a plurality of groups in the time unit.

The first terminal may know the relevant information of other terminals, such as the P value, the ID of the terminal, etc. Optionally, the method 300 further comprises: the first terminal receives third information, which includes first parameters and/or identification information (e.g., ID) corresponding to one or more target terminals.

For example, if the first terminal is a cooperative terminal, the first terminal may receive third information sent by a previous cooperative terminal from the terminal group (for example, a value of a first parameter of the previous cooperative terminal is smaller than a value of the first parameter of the first terminal). The third information comprises first parameters and/or identification information corresponding to one or more target terminals in the terminal group. Therefore, the first terminal can assist the one or more target terminals in forwarding data by acquiring the first parameter and/or the identification information corresponding to the one or more target terminals.

For the cooperative terminals in the terminal group, the cooperative terminals may determine whether to continue to manage the terminal group or determine whether to continue to make a cluster head of the terminal group by combining the acquired values of the first parameters of the other terminals. The application also provides a communication method. Fig. 7 is a schematic diagram of a communication method 700 according to an embodiment of the present application. It is understood that the third terminal in fig. 7 may be the cooperative terminal 120 in fig. 2, and may also refer to a device or a component (e.g., a processor, a chip, or a system of chips, etc.) in the terminal. It is further understood that, in the method 700, part or all of information interacted between the third terminal and the network, or part or all of information interacted between the third terminal and the fourth terminal may be carried in an existing message, channel, signal, or signaling, or may be a newly defined message, channel, signal, or signaling, which is not limited specifically. As shown in fig. 7, the method 700 includes:

s701, a third terminal acquires a first parameter of a fourth terminal, wherein the value of the first parameter of the fourth terminal is the maximum value of the values of the first parameters of a plurality of target terminals in a terminal group, and the terminal group comprises a cooperative terminal and at least one target terminal.

The third terminal is a cooperative terminal in the terminal group for managing the terminal group. The third terminal may also be understood as a cluster head of the group of terminals.

Optionally, the third terminal may receive the first parameter of the fourth terminal from the fourth terminal. Alternatively, the third terminal may acquire the first parameter of the fourth terminal from the network device. Alternatively, the third terminal may obtain the first parameters of the fourth terminal from other terminals.

The explanation of the first parameter can refer to the description in the method 300, and is not repeated here for brevity.

And S702, the third terminal determines to continue to manage the terminal group or send fourth information to the fourth terminal based on the first parameter of the fourth terminal. The fourth information comprises first parameters and/or identification information corresponding to one or more target terminals in the terminal group.

Here, the third terminal may determine whether to continue to be a cooperative terminal of the terminal group or determine whether to continue to manage the terminal group based on the value of the first parameter of the fourth terminal, which is beneficial to improving the reliability of communication of the terminal group.

Optionally, the third terminal may determine whether a value of the first parameter of the fourth terminal meets a preset condition. If the value of the first parameter of the fourth terminal meets the preset condition, the third terminal does not continue to manage the terminal group, or fourth information is sent to the fourth terminal; and if the value of the first parameter of the fourth terminal does not meet the preset condition, the third terminal continues to manage the terminal group.

Exemplarily, the value of the first parameter of the fourth terminal satisfies a preset condition, including: and the value of the first parameter of the fourth terminal is in a preset interval. For example, if the value of the first parameter of the fourth terminal is within the preset interval, the third terminal does not manage the terminal group any more or sends fourth information to the fourth terminal; and if the value of the first parameter of the fourth terminal is not in the preset interval, the third terminal continues to manage the terminal group.

Exemplarily, the value of the first parameter of the fourth terminal satisfies a preset condition, including: the value of the first parameter of the fourth terminal is greater than the value of the first parameter of the third terminal. For example, when the value of the first parameter of the fourth terminal is greater than the value of the first parameter of the third terminal, the third terminal sends fourth information to the fourth terminal; and when the value of the first parameter of the fourth terminal is less than or equal to the value of the first parameter of the third terminal, the third terminal continues to manage the terminal group.

It is to be understood that the division of the boundary case "the value of the first parameter of the fourth terminal is equal to the value of the first parameter of the third terminal" is also only described by way of example, and does not limit the embodiment of the present application. For example, the "value of the first parameter of the fourth terminal is equal to the value of the first parameter of the third terminal" may also be divided together with the "value of the first parameter of the fourth terminal is greater than the value of the first parameter of the third terminal".

For the case that the third terminal sends the fourth information to the fourth terminal, after the fourth terminal and the third terminal are successfully handed over, the fourth terminal may send feedback information to the third terminal to indicate that the fourth terminal and the third terminal are successfully handed over. "successful handover" can be understood as: the fourth terminal has acquired the related information of the terminal group managed by the third terminal, for example, the P value and/or the ID corresponding to one or more target terminals included in the terminal group, the number of terminals in the terminal group, and the like. Optionally, when the value of the first parameter of the fourth terminal is greater than the value of the first parameter of the third terminal, the third terminal receives feedback information from the fourth terminal, where the feedback information is used to indicate that the handover between the fourth terminal and the third terminal is successful.

For example, after receiving the member information of the terminal group, the fourth terminal may send an Acknowledgement (ACK) to the third terminal, where the ACK is used to indicate that the fourth terminal and the third terminal are successfully handed over. This contributes to improvement in reliability at the time of terminal group handover.

For ease of understanding, the following description is made in conjunction with the flowchart in fig. 8. The flow in fig. 8 is described by taking the example of one sidelink broadcast period from the beginning to the end. For example, the sidelink broadcast period is a PSDCH period. Assuming that the third terminal is a CUE, the ID of the CUE is represented by ID _ c, and the first parameter of the CUE is represented by P _ c, as shown in fig. 8, the CUE may perform the following steps:

the CUE sends ID _ c, P _ c and N _ c on the first block resource of the sidelink broadcasting period, wherein N _ c is the number of the UE in the current group.

The first block resource refers to a time domain resource occupied by a first time unit in a sidelink broadcast resource (e.g., a PSDCH resource).

802, CUE detects sidelink broadcast resources.

The CUE detects on the sidelink broadcast resource. The CUE obtains the information of the newly-grouped terminals detected in the sidelink broadcasting resource, including the ID of the terminal, the P value of the terminal and the number of the terminals in the terminal group after the terminal is grouped. For example, UE _ i represents the ith newly-grouped terminal, ID _ i represents the ID of UE _ i, P _ i represents the P value of UE _ i, and N _ i represents the number of terminals in the terminal group after UE _ i is grouped. The CUE may compare the maximum value of the plurality of P values of all newly grouped terminals with its own P value. For example, max (P) is the maximum value among the P values of all newly grouped terminals.

803, the CUE determines if max (P) is greater than P _ c. P _ c represents the P value of CUE.

When max (P) is greater than P _ c, the CUE sends the information of the terminal group to max (P) corresponding terminal, and step 804 is executed.

When max (P) is not greater than P _ c, the CUE performs step 807.

804, the CUE sends the member information of the terminal group to the UE _ m in the last section of the sidelink broadcasting period, namely, the member information of the terminal group is handed over to the UE _ m.

The last segment of resources may refer to the description above. To avoid redundancy, it is not described here in detail.

Let P _ m denote the P value of UE _ m, where P _ m is max (P), i.e., UE _ m is the terminal corresponding to max (P).

For example, taking the PSDCH resource in fig. 5 as an example, the CUE may send information of all target terminals in the terminal group to the UE _ m on the last resource in one PSDCH cycle, for example, the P value and/or ID of one or more target terminals.

805, the CUE determines whether an ACK is received from UE _ m.

When the CUE receives the ACK from UE _ m, the CUE determines that the handover is successful, and performs step 806.

When the CUE does not receive the ACK from UE _ m, the CUE determines that the handover fails, and proceeds to step 807.

806, the CUE determines itself to be a TUE or a fallback group.

807, the CUE determines that it is still a CUE for the terminal group.

It is understood that the flow in fig. 8 is described by taking a sidelink broadcasting cycle as an example, and after the sidelink broadcasting cycle is ended, the next sidelink broadcasting cycle can be started. The CUE may also perform the flow in fig. 8 in the next sidelink broadcast cycle.

It is further understood that the examples in fig. 4, 6 and 8 are only for facilitating the understanding of the embodiments of the present application by those skilled in the art, and are not intended to limit the embodiments of the present application to the specific scenarios illustrated. It will be apparent to those skilled in the art that various equivalent modifications or variations can be made from the examples of fig. 4, 6 and 8, and such modifications or variations also fall within the scope of the embodiments of the present application.

The above describes a method for a cooperative terminal to quit, that is, a cooperative terminal (e.g., a third terminal) sends member information of a terminal group to a new cooperative terminal (e.g., a fourth terminal). Of course, the target terminal may also select to quit the group. For a target terminal in a terminal group, if it is determined that the terminal group is to be withdrawn, it is necessary to broadcast its own information, such as an ID and the number of terminals in the terminal group after the withdrawal, on the next resource of the resource in which the number of terminals in the terminal group is monitored after monitoring the number of terminals in the terminal group broadcast by a cooperative terminal or a newly entered terminal. And the cooperative terminal records the information broadcasted by the target terminal to be quitted so as to update the number of the terminals in the terminal group.

Corresponding to the method provided by the above method embodiment, the embodiment of the present application further provides a corresponding apparatus, where the apparatus includes a module for executing the above embodiment. The module may be software, hardware, or a combination of software and hardware. It is understood that the technical features described in the method embodiments are equally applicable to the following apparatus embodiments.

Fig. 9 shows a schematic of the structure of an apparatus. The apparatus 1500 may be a terminal device, or may be a chip, a chip system, or a processor that supports the terminal device to implement the method described above. The apparatus may be configured to implement the method described in the method embodiment, and refer to the description in the method embodiment.

The apparatus 1500 may comprise one or more processors 1501, which processors 1501 may also be referred to as processing units, which may implement certain control functions. The processor 1501 may be a general-purpose processor, a special-purpose processor, or the like. For example, a baseband processor or a central processor. The baseband processor may be used to process communication protocols and communication data, and the central processor may be used to control a communication device (e.g., a terminal chip, etc.), execute a software program, and process data of the software program.

In an alternative design, the processor 1501 may also store instructions and/or data 1503, which may be executed by the processor to cause the apparatus 1500 to perform the methods described in the above method embodiments.

In an alternative design, processor 1501 may include a transceiver unit to perform receive and transmit functions. The transceiving unit may be, for example, a transceiving circuit, or an interface circuit. The transmit and receive circuitry, interfaces or interface circuitry used to implement the receive and transmit functions may be separate or integrated. The transceiver circuit, the interface circuit or the interface circuit may be used for reading and writing code/data, or the transceiver circuit, the interface circuit or the interface circuit may be used for transmitting or transferring signals.

In yet another possible design, apparatus 1500 may include circuitry that may perform the functions of transmitting or receiving or communicating in the foregoing method embodiments.

Optionally, the apparatus 1500 may include one or more memories 1502, on which instructions 1504 may be stored, which are executable on the processor to cause the apparatus 1500 to perform the methods described in the above method embodiments. Optionally, the memory may further store data therein. Optionally, instructions and/or data may also be stored in the processor. The processor and the memory may be provided separately or may be integrated together. For example, the correspondence described in the above method embodiments may be stored in a memory or in a processor.

Optionally, the device 1500 may also include a transceiver 1505 and/or an antenna 1506. The processor 1501, which may be referred to as a processing unit, controls the apparatus 1500. The transceiver 1505 may be referred to as a transceiver unit, a transceiver, a transceiving circuit or a transceiver, etc. for implementing transceiving functions.

In one possible design, an apparatus 1500 (e.g., an integrated circuit, a wireless device, a circuit module, or a terminal, etc.) may comprise: the processor 1501 is configured to control the transceiver 1505 to obtain a first parameter of the second terminal; and determining the first terminal as a cooperative terminal or determining the first terminal as a target terminal according to the first parameter of the second terminal.

Optionally, the processor 1501 is configured to determine that the first terminal is a cooperative terminal or a target terminal according to the first parameter of the second terminal, and includes: when the value of the first parameter of the first terminal is larger than the value of the first parameter of the second terminal, determining that the first terminal is a cooperative terminal; and when the value of the first parameter of the first terminal is less than or equal to the value of the first parameter of the second terminal, determining that the first terminal is a target terminal.

It is to be understood that reference may be made to the description in the foregoing method embodiments for the description of the first parameter, and details are not repeated here for brevity.

Optionally, the processor 1501 is further configured to control the transceiver 1505 to obtain first information, where the first information is used to indicate the number of terminals in a terminal group, where the terminal group includes a cooperative terminal and at least one target terminal; and the terminal group access control module is used for determining the group access operation of the first terminal according to the number of the terminals in the terminal group.

Optionally, the processor 1501 is configured to determine a grouping operation of the first terminal according to the number of terminals in the terminal group, and includes: when the number of the terminals in the terminal group meets a preset condition, determining that the first terminal enters the group; and when the number of the terminals in the terminal group does not meet the preset condition, determining that the first terminal does not enter the group.

Optionally, the number of terminals in the terminal group satisfies a preset condition, including: and the number of the terminals in the terminal group is less than a preset value.

Optionally, the processor 1501 is further configured to control the transceiver 1505 to send second information, where the second information is used to indicate one or more of the following: the first parameter of the first terminal, the identifier of the first terminal, and the number of terminals in the terminal group after the first terminal is grouped.

Optionally, the processor 1501 is further configured to control the transceiver 1505 to transmit the second information on a first resource, the first resource being associated with an identity of the first terminal.

Optionally, the processor 1501 is further configured to control the transceiver 1505 to receive third information, where the third information includes first parameters and/or identification information corresponding to one or more target terminals.

It can be understood that the apparatus 1500 according to the embodiment of the present application can be used to implement corresponding steps of the method of the first terminal in the foregoing method embodiment, for example, the methods in fig. 3 to fig. 6, so that beneficial effects in the foregoing method embodiment can also be implemented, and for brevity, details are not described here.

In another possible design, an apparatus 1500 (e.g., an integrated circuit, a wireless device, a circuit module, or a terminal, etc.) may include: the processor 1501 is configured to control the transceiver 1505 to obtain a first parameter of a fourth terminal, where a value of the first parameter of the fourth terminal is a maximum value among values of first parameters of a plurality of target terminals in a terminal group, where the terminal group includes a cooperative terminal and at least one target terminal; and determining that the third terminal continues to manage the terminal group or determining that the third terminal sends fourth information to the fourth terminal based on the first parameter of the fourth terminal.

Optionally, the processor 1501 is configured to determine, based on the first parameter of the fourth terminal, that the third terminal continues to manage the terminal group, or determine that the third terminal sends fourth information to the fourth terminal, where the determining includes: when the value of the first parameter of the fourth terminal is greater than the value of the first parameter of the third terminal, controlling the transceiver 1505 to send fourth information to the fourth terminal, where the fourth information includes first parameters and/or identification information corresponding to one or more target terminals in the terminal group; and when the value of the first parameter of the fourth terminal is less than or equal to the value of the first parameter of the third terminal, determining that the third terminal continues to manage the terminal group.

Optionally, the processor 1501 is further configured to control the transceiver 1505 to receive feedback information from the fourth terminal, where the feedback information is used to indicate that the handover between the fourth terminal and the third terminal is successful.

It can be further understood that the apparatus 1500 according to the embodiment of the present application can be used to implement corresponding steps of the method of the third terminal in the foregoing method embodiment, for example, the methods in fig. 7 to fig. 8, so that beneficial effects in the foregoing method embodiment can also be implemented, and for brevity, details are not described here.

The processors and transceivers described herein may be implemented on Integrated Circuits (ICs), analog ICs, Radio Frequency Integrated Circuits (RFICs), mixed signal ICs, Application Specific Integrated Circuits (ASICs), Printed Circuit Boards (PCBs), electronic devices, and the like. The processor and transceiver may also be fabricated using various IC process technologies, such as Complementary Metal Oxide Semiconductor (CMOS), N-type metal oxide semiconductor (NMOS), P-type metal oxide semiconductor (PMOS), Bipolar Junction Transistor (BJT), bipolar CMOS (bicmos), silicon germanium (SiGe), gallium arsenide (GaAs), and the like.

The apparatus in the description of the above embodiment may be a network device or a terminal device, but the scope of the apparatus described in the present application is not limited thereto, and the structure of the apparatus may not be limited by fig. 9. The apparatus may be a stand-alone device or may be part of a larger device. For example, the apparatus may be:

(1) a stand-alone integrated circuit IC, or chip, or system-on-chip or subsystem;

(2) having a set of one or more ICs, which may optionally also include storage means for storing data and/or instructions;

(3) an ASIC, such as a modem (MSM);

(4) a module that may be embedded within other devices;

(5) receivers, terminals, smart terminals, cellular phones, wireless devices, handsets, mobile units, in-vehicle devices, network devices, cloud devices, artificial intelligence devices, and the like;

(6) others, and so forth.

Fig. 10 provides a schematic structural diagram of a terminal device. The terminal device may be adapted to the scenario shown in fig. 2. For convenience of explanation, fig. 10 shows only main components of the terminal device. As shown in fig. 10, the terminal apparatus 1600 includes a processor, a memory, a control circuit, an antenna, and an input-output device. The processor is mainly used for processing communication protocols and communication data, controlling the whole terminal, executing software programs and processing data of the software programs. The memory is used primarily for storing software programs and data. The radio frequency circuit is mainly used for converting baseband signals and radio frequency signals and processing the radio frequency signals. The antenna is mainly used for receiving and transmitting radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, keyboards, etc., are used primarily for receiving data input by a user and for outputting data to the user.

When the terminal device is started, the processor can read the software program in the storage unit, analyze and execute the instruction of the software program, and process the data of the software program. When data needs to be sent wirelessly, the processor performs baseband processing on the data to be sent and outputs baseband signals to the radio frequency circuit, and the radio frequency circuit processes the baseband signals to obtain radio frequency signals and sends the radio frequency signals outwards in the form of electromagnetic waves through the antenna. When data is transmitted to the terminal device, the radio frequency circuit receives a radio frequency signal through the antenna, the radio frequency signal is further converted into a baseband signal, the baseband signal is output to the processor, and the processor converts the baseband signal into the data and processes the data.

For ease of illustration, FIG. 10 shows only one memory and processor. In an actual terminal device, there may be multiple processors and memories. The memory may also be referred to as a storage medium or a storage device, and the like, which is not limited in this respect in the embodiment of the present invention.

As an alternative implementation manner, the processor may include a baseband processor and a central processing unit, where the baseband processor is mainly used to process a communication protocol and communication data, and the central processing unit is mainly used to control the whole terminal device, execute a software program, and process data of the software program. The processor in fig. 10 integrates the functions of the baseband processor and the central processing unit, and those skilled in the art will understand that the baseband processor and the central processing unit may also be independent processors, and are interconnected through a bus or the like. Those skilled in the art will appreciate that the terminal device may include a plurality of baseband processors to accommodate different network formats, the terminal device may include a plurality of central processors to enhance its processing capability, and various components of the terminal device may be connected by various buses. The baseband processor can also be expressed as a baseband processing circuit or a baseband processing chip. The central processing unit can also be expressed as a central processing circuit or a central processing chip. The function of processing the communication protocol and the communication data may be built in the processor, or may be stored in the storage unit in the form of a software program, and the processor executes the software program to realize the baseband processing function.

In one example, the antenna and the control circuit with transceiving functions can be considered as the transceiving unit 1611 of the terminal device 1600, and the processor with processing function can be considered as the processing unit 1612 of the terminal device 1600. As shown in fig. 10, the terminal device 1600 includes a transceiving unit 1611 and a processing unit 1612. A transceiver unit may also be referred to as a transceiver, a transceiving device, etc. Optionally, a device in the transceiving unit 1611 for implementing a receiving function may be regarded as a receiving unit, and a device in the transceiving unit 1611 for implementing a transmitting function may be regarded as a transmitting unit, that is, the transceiving unit 1611 includes a receiving unit and a transmitting unit. For example, the receiving unit may also be referred to as a receiver, a receiving circuit, etc., and the sending unit may be referred to as a transmitter, a transmitting circuit, etc. Optionally, the receiving unit and the sending unit may be integrated into one unit, or may be multiple units independent of each other. The receiving unit and the transmitting unit can be in one geographical position or can be dispersed in a plurality of geographical positions.

FIG. 11 is a schematic block diagram of an apparatus of an embodiment of the present application. As shown in fig. 11, yet another embodiment of the present application provides an apparatus 1700. The device may be a terminal or a component of a terminal (e.g., an integrated circuit, a chip, etc.). The apparatus may also be another communication module, which is used to implement the method in the embodiment of the method of the present application. The apparatus 1700 may include: a processing unit 1702 (processing module). Optionally, the apparatus 1700 may further include a transceiver 1701 (transceiver module) and a memory 1703 (memory module).

In one possible design, one or more of the elements in FIG. 11 may be implemented by one or more processors or by one or more processors and memory; or by one or more processors and transceivers; or by one or more processors, memories, and transceivers, which are not limited in this application. The processor, the memory and the transceiver can be arranged independently or integrated.

The apparatus has a function of implementing the terminal device (the first terminal or the third terminal) described in the embodiment of the present application, for example, the apparatus includes a module or a unit or means (means) corresponding to the step of executing the terminal device described in the embodiment of the present application by the terminal device, and the function or the unit or the means (means) may be implemented by software or hardware, or may be implemented by hardware executing corresponding software, or may be implemented by a combination of software and hardware. Reference may be made in detail to the respective description of the corresponding method embodiments hereinbefore.

Optionally, each module in the apparatus 1700 in this embodiment of the present application may be configured to perform the method described in fig. 3 to fig. 6 in this embodiment of the present application.

In one possible embodiment, the apparatus 1700 is a first terminal or a component of a first terminal, and the apparatus 1700 may include: a transceiver unit 1701 and a processing unit 1702.

The transceiver unit 1701 is configured to obtain a first parameter of the second terminal.

The processing unit 1702 is configured to determine, according to the first parameter of the second terminal, that the first terminal is a cooperative terminal, or that the first terminal is a target terminal.

Optionally, the processing unit 1702 is configured to determine that the first terminal is a cooperative terminal according to the first parameter of the second terminal, or determine that the first terminal is a target terminal, including: when the value of the first parameter of the first terminal is larger than the value of the first parameter of the second terminal, determining that the first terminal is a cooperative terminal; and when the value of the first parameter of the first terminal is less than or equal to the value of the first parameter of the second terminal, determining that the first terminal is a target terminal.

Optionally, a value of the first parameter satisfies the following formula:

P＝γ ^P_SS+τ*P_LO

Optionally, a value of the first parameter satisfies the following formula:

P＝γ ^P_SS*ln(1+τ*P_LO)

Optionally, the transceiver unit 1701 is further configured to obtain first information, where the first information is used to indicate the number of terminals in a terminal group, where the terminal group includes a cooperative terminal and at least one target terminal; the processing unit 1702 is further configured to determine a group entry operation of the first terminal according to the number of terminals in the terminal group.

Optionally, the processing unit 1702 is configured to determine, according to the number of terminals in the terminal group, an entry operation of the first terminal, and includes: when the number of the terminals in the terminal group meets a preset condition, determining that the first terminal enters the group; and when the number of the terminals in the terminal group does not meet the preset condition, determining that the first terminal does not enter the group.

Optionally, the transceiver unit 1701 is further configured to transmit second information, where the second information is used to indicate one or more of the following: the first parameter of the first terminal, the identifier of the first terminal, and the number of terminals in the terminal group after the first terminal is grouped.

Optionally, the transceiver 1701 is configured to send second information, including: the transceiver unit 1701 is configured to send the second information on a first resource, where the first resource is related to an identity of the first terminal.

Optionally, the transceiver unit 1701 is further configured to receive third information, where the third information includes first parameters and/or identification information corresponding to one or more target terminals. It is understood that the apparatus 1700 may correspond to the method of the first terminal in the foregoing method embodiment, for example, the methods in fig. 3 to fig. 6, and the above and other management operations and/or functions of each unit in the apparatus 1700 are respectively for implementing corresponding steps of the method of the first terminal in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, no further description is provided here.

In another possible embodiment, the apparatus 1700 is a third terminal or a component of a third terminal, and the apparatus 1700 may include: a transceiver unit 1701 and a processing unit 1702.

The transceiver unit 1701 is configured to obtain a first parameter of a fourth terminal, where a value of the first parameter of the fourth terminal is a maximum value among values of first parameters of a plurality of target terminals in a terminal group, where the terminal group includes a cooperative terminal and at least one target terminal.

The processing unit 1702 is configured to determine, based on the first parameter of the fourth terminal, that the third terminal continues to manage the terminal group, or determine that the third terminal sends fourth information to the fourth terminal.

Optionally, the processing unit 1702 is configured to determine, based on the first parameter of the fourth terminal, that the third terminal continues to manage the terminal group, or determine that the third terminal sends fourth information to the fourth terminal, where the determining includes: when the value of the first parameter of the fourth terminal is greater than the value of the first parameter of the third terminal, controlling the transceiver unit 1701 to send fourth information to the fourth terminal, where the fourth information includes first parameters and/or identification information corresponding to one or more target terminals in the terminal group; and when the value of the first parameter of the fourth terminal is less than or equal to the value of the first parameter of the third terminal, determining that the third terminal continues to manage the terminal group.

Optionally, the transceiver unit 1701 is further configured to: and receiving feedback information from the fourth terminal, wherein the feedback information is used for indicating that the fourth terminal and the third terminal are successfully handed over.

Optionally, a value of the first parameter satisfies the following formula:

P＝γ ^P_SS+τ*P_LO

Optionally, a value of the first parameter satisfies the following formula:

P＝γ ^P_SS*ln(1+τ*P_LO)

It is to be understood that the apparatus 1700 may correspond to the method of the third terminal in the foregoing method embodiment, for example, the methods in fig. 7 and fig. 8, and the above and other management operations and/or functions of each module in the apparatus 1700 are respectively for implementing corresponding steps of the method of the third terminal in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, no further description is provided here.

It is understood that some optional features in the embodiments of the present application may be implemented independently without depending on other features in some scenarios, such as a currently-based solution, to solve corresponding technical problems and achieve corresponding effects, or may be combined with other features according to requirements in some scenarios. Accordingly, the apparatuses provided in the embodiments of the present application may also implement these features or functions, which are not described herein again.

Those skilled in the art will also appreciate that the various illustrative logical blocks and steps (step) set forth in the embodiments of the present application may be implemented in electronic hardware, computer software, or combinations of both. Whether such functionality is implemented as hardware or software depends upon the particular application and design requirements of the overall system. Those skilled in the art 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 embodiments of the present application.

It should be understood 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 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, a discrete gate or transistor logic device, a discrete hardware component, a system on chip (SoC), a Central Processing Unit (CPU), a Network Processor (NP), a Digital Signal Processor (DSP), a Microcontroller (MCU), a programmable logic controller (PLD), or other integrated chip. 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.

The techniques described herein may be implemented by various means. For example, these techniques may be implemented in hardware, software, or a combination of hardware and software. For a hardware implementation, the processing units used to perform these techniques at a communication device (e.g., a base station, terminal, network entity, or chip) may be implemented in one or more general-purpose processors, DSPs, digital signal processing devices, ASICs, programmable logic devices, FPGAs, or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combinations of the above. A general-purpose processor may be a microprocessor, but, in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other similar configuration.

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. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (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.

The present application also provides a computer-readable medium having stored thereon a computer program which, when executed by a computer, performs the functions of any of the method embodiments described above.

The present application also provides a computer program product which, when executed by a computer, implements the functionality of any of the method embodiments described above.

According to the method provided by the embodiment of the present application, the present application further provides a system, which includes the aforementioned one or more terminal devices (e.g., the first terminal, the second terminal) and one or more network devices.

According to the method provided by the embodiment of the present application, the present application further provides a system, which includes the aforementioned one or more terminal devices (e.g., the third terminal, the fourth terminal) and one or more network devices.

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.

It should be appreciated that reference throughout this specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the various embodiments are not necessarily referring to the same embodiment throughout the specification. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

It should also be understood that, in the present application, "when …", "if" and "if" all refer to the fact that the UE or the base station will perform the corresponding processing under certain objective conditions, and are not limited time, and do not require the UE or the base station to perform certain judgment actions, nor do they mean that there are other limitations.

Those of ordinary skill in the art will understand that: the various numbers of the first, second, etc. mentioned in this application are only used for the convenience of description and are not used to limit the scope of the embodiments of this application, but also to indicate the sequence.

Reference in the present application to an element using the singular is intended to mean "one or more" rather than "one and only one" unless specifically stated otherwise. In the present application, unless otherwise specified, "at least one" is intended to mean "one or more" and "a plurality" is intended to mean "two or more".

Additionally, the terms "system" and "network" are often used interchangeably herein. The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A can be singular or plural, and B can be singular or plural.

The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

Herein, the term "at least one of … …" or "at least one of … …" means all or any combination of the listed items, e.g., "at least one of A, B and C", may mean: the compound comprises six cases of separately existing A, separately existing B, separately existing C, simultaneously existing A and B, simultaneously existing B and C, and simultaneously existing A, B and C, wherein A can be singular or plural, B can be singular or plural, and C can be singular or plural.

It should be understood that in the embodiments of the present application, "B corresponding to a" means that B is associated with a, from which B can be determined. It should also be understood that determining B from a does not mean determining B from a alone, but may be determined from a and/or other information.

As used herein, the term "predefined" in the context of the present application may be understood to mean defining, predefining, storing, pre-negotiating, pre-configuring, curing, or pre-firing. The configuration in the embodiment of the present application may be understood as being notified by RRC signaling, MAC signaling, and physical layer information, where the physical layer information may be transmitted through a PDCCH or a PDSCH.

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.

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 think 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

A method of communication, comprising:

a first terminal acquires a first parameter of a second terminal;

and the first terminal determines that the first terminal is a cooperative terminal or a target terminal according to the first parameter of the second terminal.
The communication method according to claim 1, wherein the determining, by the first terminal, that the first terminal is a cooperative terminal or that the first terminal is a target terminal according to the first parameter of the second terminal includes:

when the value of the first parameter of the first terminal is larger than the value of the first parameter of the second terminal, determining that the first terminal is a cooperative terminal;

and when the value of the first parameter of the first terminal is less than or equal to the value of the first parameter of the second terminal, determining that the first terminal is a target terminal.
A communication method according to claim 1 or 2, characterized in that the first parameter relates to: parameters associated with signals from the network device, and/or parameters associated with the terminal.
The communication method according to claim 3, wherein the parameters related to the signal from the network device comprise one or more of: received power, frequency response flatness.
A method of communicating according to claim 3 or 4, the terminal-related parameters comprising one or more of: the system comprises the following components of the system, wherein the system comprises a battery total capacity, the number of antennas, maximum transmitting power, receiver sensitivity, processor operation speed, memory capacity, heat dissipation capacity, movement capacity, residual electric quantity, whether an external sufficient power supply is connected, movement speed and whether a head vehicle and a vehicle moving direction exist in a fleet.
The communication method according to any one of claims 1 to 5, wherein a value of the first parameter satisfies the following formula:

P＝γ ^P_SS+τ*P_LO

where P denotes the first parameter, P _ SS denotes a parameter related to a network device signal, P _ LO denotes a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1.
The communication method according to any one of claims 1 to 5, wherein a value of the first parameter satisfies the following formula:

P＝γ ^P_SS*ln(1+τ*P_LO)

where P denotes the first parameter, P _ SS denotes a parameter related to a network device signal, P _ LO denotes a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1.
The communication method according to any one of claims 1 to 7, further comprising:

the first terminal acquires first information, wherein the first information is used for indicating the number of terminals in a terminal group, and the terminal group comprises a cooperative terminal and at least one target terminal;

and the first terminal determines the group entering operation of the first terminal according to the number of the terminals in the terminal group.
The communication method according to claim 8, wherein the determining, by the first terminal, the group entry operation of the first terminal according to the number of terminals in the terminal group comprises:

when the number of the terminals in the terminal group meets a preset condition, the first terminal determines to enter the group;

and when the number of the terminals in the terminal group does not meet the preset condition, the first terminal determines not to enter the group.
The communication method according to claim 9, wherein the number of terminals in the terminal group satisfies a preset condition, and the preset condition comprises: and the number of the terminals in the terminal group is less than a preset value.
The communication method according to any one of claims 1 to 10, characterized in that the communication method further comprises:

the first terminal sends second information, wherein the second information is used for indicating one or more of the following items: the first parameter of the first terminal, the identifier of the first terminal, and the number of terminals in the terminal group after the first terminal is grouped.
The communication method according to claim 11, wherein the first terminal sends the second information, and wherein the sending comprises:

the first terminal sends the second information on a first resource, wherein the first resource is related to the identification of the first terminal.
The communication method according to any one of claims 1 to 12, characterized in that the communication method further comprises:

the first terminal receives third information, wherein the third information comprises first parameters and/or identification information corresponding to one or more target terminals.
A method of communication, comprising:

a third terminal acquires a first parameter of a fourth terminal, wherein the value of the first parameter of the fourth terminal is the maximum value of the values of the first parameters of a plurality of target terminals in a terminal group, and the terminal group comprises a cooperative terminal and at least one target terminal;

and the third terminal determines to continue to manage the terminal group or sends fourth information to the fourth terminal based on the first parameter of the fourth terminal.
The communication method according to claim 14, wherein the third terminal determines to continue to manage the terminal group or send fourth information to the fourth terminal based on the first parameter of the fourth terminal, and wherein the determining comprises:

when the value of the first parameter of the fourth terminal is greater than the value of the first parameter of the third terminal, the third terminal sends fourth information to the fourth terminal, wherein the fourth information comprises the first parameter and/or the identification information corresponding to one or more target terminals in the terminal group;

and when the value of the first parameter of the fourth terminal is less than or equal to the value of the first parameter of the third terminal, the third terminal continues to manage the terminal group.
The communication method according to claim 15, wherein when the value of the first parameter of the fourth terminal is greater than the value of the first parameter of the third terminal, the communication method further comprises:

and the third terminal receives feedback information from the fourth terminal, wherein the feedback information is used for indicating that the fourth terminal and the third terminal are successfully handed over.
The communication method according to any of claims 14 to 16, wherein the first parameter relates to: parameters associated with signals from the network device, and/or parameters associated with the terminal.
The communication method of claim 17, wherein the signal-related parameters from the network device include one or more of: received power, frequency response flatness.
The communication method according to claim 17, wherein the terminal-related parameters comprise one or more of: the system comprises the following components of the system, wherein the system comprises a battery total capacity, the number of antennas, maximum transmitting power, receiver sensitivity, processor operation speed, memory capacity, heat dissipation capacity, movement capacity, residual electric quantity, whether an external sufficient power supply is connected, movement speed and whether a head vehicle and a vehicle moving direction exist in a fleet.
The communication method according to any one of claims 14 to 19, wherein a value of the first parameter satisfies the following equation:

P＝γ ^P_SS+τ*P_LO

where P denotes the first parameter, P _ SS denotes a parameter related to a network device signal, P _ LO denotes a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1.
The communication method according to any one of claims 14 to 19, wherein the value of the first parameter is determined according to the following formula:

P＝γ ^P_SS*ln(1+τ*P_LO)

where P denotes the first parameter, P _ SS denotes a parameter related to a network device signal, P _ LO denotes a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1.
A communications apparatus, characterized in that the apparatus is a first terminal or a component of a first terminal, the apparatus comprising:

the receiving and sending unit is used for acquiring a first parameter of the second terminal;

and the processing unit is used for determining the first terminal as a cooperative terminal or determining the first terminal as a target terminal according to the first parameter of the second terminal.
The apparatus of claim 22, wherein the processing unit is configured to determine that the first terminal is a cooperative terminal or a target terminal according to the first parameter of the second terminal, and includes:

when the value of the first parameter of the first terminal is larger than the value of the first parameter of the second terminal, determining that the first terminal is a cooperative terminal;

and when the value of the first parameter of the first terminal is less than or equal to the value of the first parameter of the second terminal, determining that the first terminal is a target terminal.
The apparatus according to claim 22 or 23, wherein the first parameter relates to: parameters associated with signals from the network device, and/or parameters associated with the terminal.
The apparatus of claim 24, wherein the parameters related to the signal from the network device comprise one or more of: received power, frequency response flatness.
The apparatus of claim 24 or 25, the terminal-related parameters comprising one or more of: the system comprises the following components of the system, wherein the system comprises a battery total capacity, the number of antennas, maximum transmitting power, receiver sensitivity, processor operation speed, memory capacity, heat dissipation capacity, movement capacity, residual electric quantity, whether an external sufficient power supply is connected, movement speed and whether a head vehicle and a vehicle moving direction exist in a fleet.
The apparatus according to any one of claims 22 to 26, wherein the value of the first parameter satisfies the following equation:

P＝γ ^P_SS+τ*P_LO

where P denotes the first parameter, P _ SS denotes a parameter related to a network device signal, P _ LO denotes a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1.
The apparatus according to any one of claims 22 to 26, wherein the value of the first parameter satisfies the following equation:

P＝γ ^P_SS*ln(1+τ*P_LO)

where P denotes the first parameter, P _ SS denotes a parameter related to a network device signal, P _ LO denotes a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1.
The apparatus of any one of claims 22 to 28, comprising:

the transceiver unit is further configured to acquire first information, where the first information is used to indicate the number of terminals in a terminal group, and the terminal group includes a cooperative terminal and at least one target terminal;

the processing unit is further configured to determine a group entry operation of the first terminal according to the number of terminals in the terminal group.
The apparatus of claim 29, wherein the processing unit is configured to determine the grouping operation of the first terminal according to the number of terminals in the terminal group, and comprises:

when the number of the terminals in the terminal group meets a preset condition, determining that the first terminal enters the group;

and when the number of the terminals in the terminal group does not meet the preset condition, determining that the first terminal does not enter the group.
The apparatus of claim 30, wherein the number of terminals in the terminal group satisfies a predetermined condition, comprising: and the number of the terminals in the terminal group is less than a preset value.
The apparatus according to any of claims 22 to 31, wherein the transceiver unit is further configured to transmit second information, and the second information is used to indicate one or more of the following: the first parameter of the first terminal, the identifier of the first terminal, and the number of terminals in the terminal group after the first terminal is grouped.
The apparatus as claimed in claim 32, wherein the transceiver unit is configured to transmit the second information, and comprises:

the transceiver unit is configured to send the second information on a first resource, where the first resource is related to an identifier of the first terminal.
The apparatus according to any one of claims 22 to 33, wherein the transceiver unit is further configured to receive third information, where the third information includes first parameters and/or identification information corresponding to one or more target terminals.
A communications apparatus, characterized in that the apparatus is a third terminal or a component of a third terminal, the apparatus comprising:

a transceiver unit, configured to obtain a first parameter of a fourth terminal, where a value of the first parameter of the fourth terminal is a maximum value among values of first parameters of multiple target terminals in a terminal group, where the terminal group includes a cooperative terminal and at least one target terminal;

and the processing unit is configured to determine, based on the first parameter of the fourth terminal, that the third terminal continues to manage the terminal group, or determine that the third terminal sends fourth information to the fourth terminal.
The apparatus of claim 35, wherein the processing unit is configured to determine that the third terminal continues to manage the set of terminals or that the third terminal sends fourth information to the fourth terminal based on the first parameter of the fourth terminal, and wherein the determining comprises:

when the value of the first parameter of the fourth terminal is greater than the value of the first parameter of the third terminal, controlling the transceiver unit to send fourth information to the fourth terminal, wherein the fourth information comprises the first parameter and/or the identification information corresponding to one or more target terminals in the terminal group;

and when the value of the first parameter of the fourth terminal is less than or equal to the value of the first parameter of the third terminal, determining that the third terminal continues to manage the terminal group.
The apparatus of claim 36, wherein the transceiver unit is further configured to:

and receiving feedback information from the fourth terminal, wherein the feedback information is used for indicating that the fourth terminal and the third terminal are successfully handed over.
The apparatus according to any one of claims 35 to 37, wherein the first parameter relates to: parameters associated with signals from the network device, and/or parameters associated with the terminal.
The apparatus of claim 38, wherein the signal-related parameters from the network device comprise one or more of: received power, frequency response flatness.
The apparatus of claim 38, the terminal-related parameters comprising one or more of: the system comprises the following components of the system, wherein the system comprises a battery total capacity, the number of antennas, maximum transmitting power, receiver sensitivity, processor operation speed, memory capacity, heat dissipation capacity, movement capacity, residual electric quantity, whether an external sufficient power supply is connected, movement speed and whether a head vehicle and a vehicle moving direction exist in a fleet.
The apparatus according to any one of claims 35 to 40, wherein the value of the first parameter satisfies the following equation:

P＝γ ^P_SS+τ*P_LO

where P denotes the first parameter, P _ SS denotes a parameter related to a network device signal, P _ LO denotes a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1.
The apparatus according to any one of claims 35 to 40, wherein the value of the first parameter is determined by the following equation:

P＝γ ^P_SS*ln(1+τ*P_LO)

where P denotes the first parameter, P _ SS denotes a parameter related to a network device signal, P _ LO denotes a parameter related to a terminal, γ and τ are predefined values, γ >1, 0< τ < 1.
An apparatus for performing the method of any one of claims 1 to 13 or for performing the method of any one of claims 14 to 21.
An apparatus, comprising: a processor coupled with a memory for storing a program or instructions that, when executed by the processor, cause the apparatus to perform the method of any of claims 1 to 13 or perform the method of any of claims 14 to 21.
A computer readable medium having stored thereon a computer program or instructions, which when executed cause a computer to perform the method of any of claims 1 to 13 or the method of any of claims 14 to 21.
A computer program product comprising computer program code which, when run on a computer, causes the computer to carry out the method of any one of claims 1 to 13 or to carry out the method of any one of claims 14 to 21.
A chip, comprising: a processor coupled with a memory for storing a program or instructions that, when executed by the processor, cause the apparatus to perform the method of any of claims 1 to 13 or the method of any of claims 14 to 21.
A communication system, comprising: a first terminal and a second terminal, the first terminal being configured to perform the method of any of claims 1 to 13.
A communication system, comprising: a third terminal and a fourth terminal, the third terminal being configured to perform the method of any of claims 14 to 21.