WO2024001792A1

WO2024001792A1 - Wireless relay communication method and communication apparatus

Info

Publication number: WO2024001792A1
Application number: PCT/CN2023/100254
Authority: WO
Inventors: 徐瑞雄; 彭文杰; 李翔宇
Original assignee: 华为技术有限公司
Priority date: 2022-06-30
Filing date: 2023-06-14
Publication date: 2024-01-04
Also published as: CN117377001A

Abstract

A wireless relay communication method and a communication apparatus, which are applied to the field of wireless communications. For a first terminal and a second terminal having an air interface link therebetween, or a first terminal and a second terminal which are in communication by means of a relay device, when the quality of the air interface link or a relay link between the first terminal and the second terminal is poor, the first terminal can select a new relay device to provide a relay connection for the two terminals, and a unicast connection is separately established with the new relay device; and subsequently, the two terminals are in communication by means of the new relay device. The method provides a solution for ensuring the quality of communication between the two terminals.

Description

Wireless relay communication method and communication device

This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on June 30, 2022, with application number 202210780579.2 and the application name "Wireless Relay Communication Method and Communication Device", the entire content of which is incorporated herein by reference. Applying.

Technical field

Embodiments of the present application relate to the field of wireless communications, and more specifically, to wireless relay communication methods and communication devices.

Background technique

In order to improve network coverage, the 5G new radio (NR) system introduces device-to-device (D2D) communication and relay communication between terminals.

However, whether it is direct communication between terminals or relay communication between terminals, the quality of the link between terminals or the quality of the link between terminals and relays may Deterioration due to some reasons, for example, due to the movement of terminals or relays or changes in the external environment. In this case, the quality of communication between terminals cannot be guaranteed.

Contents of the invention

This application provides a wireless relay communication method in order to ensure the quality of communication between two terminals in a D2D communication scenario.

In a first aspect, a method of wireless relay communication is provided, including: a first terminal acquiring the quality of a source link, where the source link includes an air interface link between the first terminal and the second terminal. , or the source link includes a first source link and a second source link, the first source link is an air interface link between the first terminal and the second relay, and the second source link The source link is the air interface link between the second relay and the second terminal; then, if the first condition is met, the first terminal establishes a unicast connection with the first relay, and the first relay is able to A terminal that provides relay transmission for the first terminal and the second terminal; in addition to establishing a unicast connection with the first relay, the first terminal sends first indication information to the second terminal, and the first terminal The instruction information instructs the second terminal to establish a unicast connection with the first relay, or the first terminal sends first instruction information to the first relay to instruct the first relay to establish a unicast connection with the first relay. A unicast connection is established between the second terminals. The first condition is used to determine whether the quality of the direct air interface link is poor, or the first condition is used to determine whether the quality of the first source link and/or the quality of the second source link is poor.

Based on the above technical solution, the quality of the air interface link between the first terminal and the second terminal is poor, or when the quality of the first source link and/or the quality of the second source link is poor, The first terminal determines the first relay that can provide relay transmission for the first terminal and the second terminal as the target relay. In other words, the first terminal selects a new relay to provide the first terminal and the second terminal with relay transmission. Relay connection, and the first terminal and the second terminal establish unicast connections with the first relay respectively. Subsequently, the first terminal and the second terminal communicate through the first relay, thereby ensuring that the first terminal and the second terminal communicate with each other through the first relay. the quality of communication between

As an implementation manner, the first condition includes at least one of the following: the quality of the first source link is less than a first threshold, and the quality of the second source link is less than the first threshold.

Based on the above technical solution, the first terminal can determine based on the quality of the first source link and/or the quality of the second source link. Determine whether the first condition is met, for example, if the quality of the first source link is less than the first threshold, and/or the quality of the second source link is less than the first threshold, the first terminal may determine that the first condition is met.

As an implementation manner, the first condition includes: the quality of the air interface link between the first terminal and the second terminal is less than a second threshold.

Based on the above technical solution, the first terminal can determine whether the first condition is satisfied based on the quality of the air interface link between the first terminal and the second terminal. For example, if the air interface link between the first terminal and the second terminal If the quality of the air interface link is less than the second threshold, the first terminal may determine that the first condition is met.

As an implementation manner, the difference between the quality of the first target link and the quality of the first source link is greater than or equal to a third threshold, and the quality of the second target link is different from the quality of the second source link. The difference in quality is greater than or equal to the third threshold, the first target link is the air interface link between the first terminal and the first relay, and the second target link is the The air interface link between the first relay and the second terminal.

Based on the above technical solution, the first terminal can determine whether the first condition is satisfied based on the quality of the first target link, the quality of the second target link, the quality of the first source link, and the quality of the second source link, for example , if the difference between the quality of the first target link and the quality of the first source link is greater than or equal to the third threshold, and, the difference between the quality of the second target link and the quality of the second source link If the value is greater than or equal to the third threshold, the first terminal may determine that the first condition is met.

As an implementation manner, the first condition includes: a difference between the quality of the first target link and the quality of the air interface link between the first terminal and the second terminal is greater than or equal to a fourth threshold, and, the second The difference between the quality of the target link and the quality of the air interface link is greater than or equal to the fourth threshold, and the first target link is the air interface link between the first terminal and the first relay. The second target link is an air interface link between the first relay and the second terminal.

Based on the above technical solution, the first terminal can determine whether the first condition is satisfied based on the quality of the air interface link between the first terminal and the second terminal and the quality of the first target link and the quality of the second target link. , for example, if the difference between the quality of the first target link and the quality of the air interface link between the first terminal and the second terminal is greater than or equal to the fourth threshold, and, the quality of the second target link is different from the quality of the air interface link The difference in quality is greater than or equal to the fourth threshold, then the first terminal may determine that the first condition is met.

As an implementation manner, the first indication information carries a first identifier assigned by the first terminal for identifying the second terminal.

As an implementation manner, if the first terminal sends the first indication information to the second terminal, and the first indication information carries the first identifier, the method further includes: the first terminal sends the first indication information to the first relay. the first identifier.

Based on the above technical solution, the first terminal sends the first identifier assigned by the first terminal to the second terminal to identify the second terminal, and the second terminal sends the first identifier to the first relay. When the first relay When data from the first terminal is subsequently received, the second terminal can be determined as the destination terminal of the data based on the first identifier sent along with the data. In other words, the first relay determines that the first target link is associated with the second target link, thereby forwarding the data from the first terminal to the second terminal; or, when the first relay subsequently receives data from the second terminal When receiving data from a terminal, the first terminal can be determined as the destination terminal according to the first identifier sent along with the data.

As an implementation manner, the method further includes: the first terminal receiving a second identification from the second terminal, the second identification being used by the second terminal to establish unicast with the first relay. Layer 2 identification of the connection; sending the second identification to the first relay.

Based on the above technical solution, the second terminal first sends to the first terminal the Layer 2 identifier used by the second terminal to establish a unicast connection with the first relay. After that, the first terminal sends the Layer 2 identifier of the second terminal to the first relay. logo. When a communication connection is established between two terminals, the layer 2 identifier of the source terminal and the layer 2 identifier of the destination terminal are used to identify the communication connection between the two terminals. For example, when a communication connection is established between a first terminal and a second terminal, a pair of the layer 2 identifier of the first terminal and the layer 2 identifier of the second terminal is used to identify the communication connection. When the first relay subsequently receives data from the first terminal, it can determine the layer 2 identifier of the first terminal included in the data according to the source address sent with the data (ie, the layer 2 identifier of the first terminal). The layer 2 identification pair of the second terminal is an identification pair used to identify the communication connection between the first terminal and the second terminal, thereby determining the second terminal as the destination terminal. Alternatively, when the first relay subsequently receives data from the second terminal, it may determine the Layer 2 of the second terminal included in the data based on the source address sent with the data (ie, the Layer 2 identification of the second terminal). The layer 2 identifier pair between the identifier and the first terminal is an identifier pair used to identify the communication connection between the first terminal and the second terminal, thereby determining the first terminal as the destination terminal.

In a second aspect, a method of wireless relay communication is provided, including: a second terminal receiving first indication information from a first terminal, the first indication information indicating a connection between the second terminal and the first relay. Establish a unicast connection. The first relay is a terminal that can provide relay transmission for the first terminal and the second terminal. After that, a unicast connection is established between the second terminal and the first relay. . Regarding the beneficial effects in the second aspect, please refer to the relevant descriptions in the beneficial effects in the first aspect. For the sake of simplicity, they will not be described again here.

As an implementation manner, the first indication information carries an identifier assigned by the first terminal for identifying the second terminal.

As an implementation manner, if the first indication information carries a first identifier, the method further includes: sending the first identifier to the first relay.

As an implementation manner, the method further includes: the second terminal sending a second identification of the second terminal to the first terminal, the second identification being used by the second terminal to communicate with the first terminal. Layer 2 identifier for the relay to establish a unicast connection.

In a third aspect, a method of wireless relay communication is provided, including: a first relay receiving first indication information from a first terminal, the first indication information indicating the communication between the first relay and the second terminal. A unicast connection is established between the first relay and the second terminal; then, a unicast connection is established between the first relay and the second terminal. The first relay is capable of providing relay transmission for the first terminal and the second terminal. terminal. Regarding the beneficial effects in the third aspect, please refer to the relevant descriptions in the beneficial effects in the first aspect. For the sake of simplicity, they will not be described again here.

As an implementation manner, the method further includes: the first relay receiving a second identification of the second terminal from the first terminal, the second identification being used by the second terminal to communicate with the second terminal. Layer 2 identifier for the first relay to establish a unicast connection.

In a fourth aspect, a wireless relay communication method is provided, including: a first terminal broadcasting a direct communication request message, the direct communication request message requesting a second terminal to reselect a relay, and communicating with the wireless relay through the relay. A unicast connection is established between the first terminals; after that, the first terminal receives a direct communication acceptance message, and the direct communication acceptance message indicates that the second terminal has completed the unicast with the first terminal. Connection establishment.

Based on the above technical solution, the first terminal broadcasts a DCR that can instruct the second terminal to reselect the relay. This method can enable the second terminal to receive the DCR when RLF occurs on the source link, and can according to the DCR Instructs to reselect a relay that can provide relay transmission for the first terminal and the second terminal, in order to ensure normal communication between the first terminal and the second terminal.

In a fifth aspect, a wireless relay communication method is provided, including: the second terminal receives a direct connection communication request message, The direct connection communication request message requests the second terminal to reselect a relay and establish a unicast connection with the first terminal through the relay; then, the second terminal sends a direct connection communication to the first terminal Accept the message, and the direct connection communication accept message indicates that the second terminal has completed the establishment of the unicast connection with the first terminal. Regarding the beneficial effects in the fifth aspect, please refer to the relevant descriptions in the beneficial effects in the fourth aspect. For the sake of simplicity, they will not be described again here.

In a sixth aspect, a method of wireless relay communication is provided, including: a second relay acquiring the quality of a source link, where the source link includes an air interface link between the first terminal and the second terminal. path, or the source link includes a first source link and a second source link, the first source link is a link between the first terminal and the second relay, and the second source link The source link is a link between the second relay and the second terminal; then, if the first condition is met, the second relay sends second indication information to the first terminal, and the second The instruction information instructs the first terminal to establish a unicast connection with the first relay, and the second relay sends third instruction information to the second terminal, and the third instruction information instructs the second terminal A unicast connection is established with a first relay, which is a terminal capable of providing relay transmission for the first terminal and the second terminal.

Based on the above technical solution, the quality of the second relay's air interface link between the first terminal and the second terminal is poor, or the quality of the first source link and/or the quality of the second source link is poor. In the case of , the second relay determines the first relay that can provide relay transmission for the first terminal and the second terminal as the target relay. In other words, the second relay selects a new relay as the first relay. The terminal and the second terminal provide a relay connection, and the second relay instructs the first terminal and the second terminal to establish a unicast connection with the first relay respectively. Subsequently, the first terminal and the second terminal communicate through the first relay. , thereby ensuring the quality of communication between the first terminal and the second terminal.

As an implementation manner, the first condition includes: the difference between the quality of the first target link and the quality of the first source link is greater than or equal to a third threshold, and the quality of the second target link is the same as the quality of the first source link. The difference in quality of the second source link is greater than or equal to the third threshold, the first target link is a link between the first terminal and the first relay, and the third The second target link is a link between the first relay and the second terminal.

As an implementation manner, the first condition includes: the difference between the quality of the first target link and the quality of the air interface link is greater than or equal to a fourth threshold, and the quality of the second target link is different from the quality of the air interface link. The difference in quality of the air interface link is greater than or equal to the fourth threshold, the first target link is a link between the first terminal and the first relay, and the second target link is the link between the first relay and the second terminal.

As an implementation manner, the method further includes: the second relay receiving a second identifier of the first terminal from the first terminal, where the second identifier of the first terminal is the username of the first terminal. to establish a layer 2 identifier of a unicast connection with the first relay; thereafter, the second relay sends the second identifier of the first terminal to the second terminal.

Based on the above technical solution, the first terminal sends to the second relay the layer 2 identifier used by the first terminal to establish a unicast connection with the first relay, and then the second relay sends it to the second terminal. After that, the second terminal Send the layer 2 identifier of the first terminal to the first relay. When a communication connection is established between two terminals, the layer 2 identifier of the source terminal and the layer 2 identifier of the destination terminal are used to identify the communication connection between the two terminals. For example, a communication connection is established between the first terminal and the second terminal. When, the layer 2 identifier of the first terminal and the layer 2 identifier of the second terminal are used to identify this communication connection. When the first relay subsequently receives data from the first terminal, it can be based on the source address sent along with the data. (i.e., the Layer 2 identifier of the first terminal), it is determined that the pair of the Layer 2 identifier of the first terminal and the Layer 2 identifier of the second terminal included in the data is used to identify the communication connection between the first terminal and the second terminal. identification pair, thereby determining the second terminal as the destination terminal. Alternatively, when the first relay subsequently receives data from the second terminal, it may determine the Layer 2 of the second terminal included in the data based on the source address sent with the data (ie, the Layer 2 identification of the second terminal). The layer 2 identification pair with the first terminal is used to A pair of identifiers identifies the communication connection between the first terminal and the second terminal, thereby determining the first terminal as the destination terminal.

As an implementation manner, the method further includes: the second relay receiving a second identifier of the second terminal from the second terminal, where the second identifier of the second terminal is a username used by the second terminal. to establish a layer 2 identifier of a unicast connection with the first relay; thereafter, the second relay sends the second identifier of the second terminal to the first terminal.

Based on the above technical solution, the second terminal sends the layer 2 identifier used by the second terminal to establish a unicast connection with the first relay to the second relay, and then the second relay sends it to the first terminal. After that, the first terminal Send the layer 2 identifier of the second terminal to the first relay. The layer 2 identification pair used when establishing a communication connection between two terminals identifies the communication connection between the two terminals. For example, when a communication connection is established between a first terminal and a second terminal, a pair of the layer 2 identifier of the first terminal and the layer 2 identifier of the second terminal is used to identify the communication connection. When the first relay subsequently receives a message from the first terminal, When receiving data from a terminal, it can be determined based on the destination address sent with the data (i.e., the Layer 2 identifier of the second terminal) that the pair of Layer 2 identifier of the first terminal and the Layer 2 identifier of the second terminal included in the data is used for. An identification pair identifying the communication connection between the first terminal and the second terminal, thereby determining the second terminal as the destination terminal. Alternatively, when the first relay subsequently receives data from the second terminal, it may determine the Layer 2 of the second terminal included in the data based on the source address sent with the data (ie, the Layer 2 identification of the second terminal). The layer 2 identifier pair between the identifier and the first terminal is an identifier pair used to identify the communication connection between the first terminal and the second terminal, thereby determining the first terminal as the destination terminal.

In a seventh aspect, a method of wireless relay communication is provided, including: a first terminal receiving second indication information from a second relay, the second indication information instructing an establishment between the first terminal and the first relay. Unicast connection; then, a unicast connection is established between the first terminal and the first relay, and the first relay is a terminal capable of providing relay transmission for the first terminal and the second terminal. Regarding the beneficial effects in the seventh aspect, please refer to the relevant descriptions in the beneficial effects in the sixth aspect. For the sake of simplicity, they will not be described again here.

As an implementation manner, the method further includes: the first terminal sending a second identifier of the first terminal to the second relay, where the second identifier of the first terminal is used by the first terminal. A Layer 2 identifier for establishing a unicast connection with the first relay.

As an implementation manner, the method further includes: the first terminal receiving a second identification from the second terminal of the second relay, where the second identification of the second terminal is used by the second terminal. A layer 2 identifier for establishing a unicast connection with the first relay; the first terminal sends a second identifier of the second terminal to the first relay.

In an eighth aspect, a method of wireless relay communication is provided, including: the second terminal receiving third indication information from the second relay, the third indication information indicating the establishment of a wireless relay communication between the second terminal and the first relay. Unicast connection; then, a unicast connection is established between the second terminal and the first relay, and the first relay is a terminal capable of providing relay transmission for the first terminal and the second terminal. Regarding the beneficial effects in the eighth aspect, please refer to the relevant descriptions in the beneficial effects in the sixth aspect. For the sake of brevity, they will not be described again here.

As an implementation manner, the method further includes: the second terminal sending a second identification of the second terminal to the second relay, where the second identification of the second terminal is used by the second terminal. A Layer 2 identifier for establishing a unicast connection with the first relay.

As an implementation manner, the method further includes: the second terminal receiving a second identification from the first terminal of the second relay, the second identification being used by the first terminal to communicate with the first terminal. The relay establishes the Layer 2 identifier of the unicast connection; thereafter, the second terminal sends the second identifier of the first terminal to the first relay.

A ninth aspect provides a communication device. The communication device may be a terminal or a relay in the above method, or may be a module applied in a terminal or a relay. The communication device includes: a processor coupled to a memory and capable of executing the memory instructions in the memory to implement any of the above aspects and the method executed by the terminal or relay in any possible implementation manner of any aspect. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, and the processor is coupled to the communication interface.

When the communication device is a terminal or a relay, the communication interface may be a transceiver, or an input/output interface.

Optionally, the transceiver may be a transceiver circuit. Optionally, the input/output interface may be an input/output circuit.

A tenth aspect provides a program, which, when executed by a communication device, is used to perform any of the above aspects and any method in its possible implementations.

In an eleventh aspect, a program product is provided. The program product includes: program code. When the program code is run by a communication device, the communication device causes the communication device to perform any of the above aspects and any of its possible implementations. method.

In a twelfth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores a program. When the program is executed, the communication device causes the communication device to perform any of the above aspects and any of its possible implementations. One method.

In a thirteenth aspect, a communication system is provided. The communication system includes the above-mentioned first terminal, second terminal, first relay and second relay.

Description of drawings

Figure 1 is a schematic diagram of the architecture of a communication system applied in an embodiment of the present application;

Figure 2 is a schematic flow chart of an example of a method for determining a target relay provided by an embodiment of the present application;

Figure 3 is a schematic diagram of an application scenario provided by the embodiment of the present application;

Figure 4 is a schematic flow chart of another example of a method for determining a target relay provided by an embodiment of the present application;

Figure 5 is a schematic diagram of another application scenario provided by the embodiment of the present application;

Figure 6 is a schematic flow chart of an example of a wireless relay communication method provided by an embodiment of the present application;

Figure 7 is a schematic flow chart of a method for establishing a unicast connection provided by an embodiment of the present application;

Figure 8 is a schematic flow chart of another example of a wireless relay communication method provided by an embodiment of the present application;

Figure 9 is a schematic flow chart of yet another method for determining a target relay provided by an embodiment of the present application;

Figure 10 is a schematic flow chart of yet another example of a wireless relay communication method provided by an embodiment of the present application;

Figure 11 is a schematic flow chart of yet another example of a wireless relay communication method provided by an embodiment of the present application;

Figure 12 is a schematic block diagram of an example communication device provided by an embodiment of the present application;

FIG. 13 is a schematic block diagram of another communication device provided by an embodiment of the present application.

Detailed ways

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

FIG. 1 is a schematic architectural diagram of a communication system 100 applied in an embodiment of the present application. As shown in Figure 1, the communication system includes multiple terminals (101, 102, and 103 in Figure 1), and multiple terminals can directly communicate with each other.

In the embodiment of the present application, the link between the two terminals may be a sidelink (SL), and the communication interface between the two terminals may be a PC5 interface.

Optionally, the communication system 100 may also include one or more wireless access network devices (as shown in 104 in Figure 1), and multiple terminals may communicate with the wireless access network devices.

Wireless access network equipment is access equipment for terminals to access the communication system through wireless means. The radio access network equipment may be a base station (base station), an evolved base station (evolved NodeB, eNodeB), a transmission reception point (TRP), or the next generation in the fifth generation (5th generation, 5G) mobile communication system. Base station (next generation NodeB, gNB), the next generation base station in the sixth generation (6th generation, 6G) mobile communication system, A base station in a future mobile communication system or an access node in a WiFi system, etc.; it can also be a module or unit that completes part of the functions of a base station, for example, it can be a centralized unit (central unit, CU) or a distributed unit ( distributed unit (DU).

The terminal is a device with wireless transceiver function that can send signals to the base station or receive signals from the base station. The terminal can also be called terminal equipment, user equipment (UE), mobile station, mobile terminal, etc. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle to everything (V2X) communication, machine-type communication (MTC), Internet of Things ( internet of things (IOT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. Terminals can be mobile phones, tablets, computers with wireless transceiver functions, wearable devices, vehicles, airplanes, ships, robots, robotic arms, smart home devices, etc. The embodiments of this application do not limit the specific technology and specific equipment form used by the terminal. In the embodiments of the present application, the functions of the terminal can also be performed by modules in the terminal (such as chips or modems), or can also be performed by devices containing terminal functions.

In a D2D communication scenario, when the wireless signal quality between two terminals is poor or one terminal is outside the coverage of the other terminal, in order to enhance the network coverage of SL, you can find a terminal near the two terminals and move the terminal As a relay for the two terminals, that is, the relay device can transmit data and signaling between the two terminals.

However, when either of the two terminals and the relay device moves or the external environment changes, the link between one terminal and the relay device and/or the link between the relay and another terminal may be affected. The quality of the link deteriorates or even is interrupted, making it impossible to guarantee the quality of D2D communication.

In view of this, embodiments of the present application provide a wireless relay communication method for two terminals with an air interface link, or two terminals that communicate through a relay device, for example, a first terminal and a second terminal. Terminal, the first terminal can obtain the quality of the air interface link between the two terminals or the quality of the relay link between the two terminals (for example, the relay link between the first terminal and the second relay , and the relay link between the second terminal and the second relay), when the quality of the air interface link or relay link is poor, the first terminal selects a new relay device to provide the two terminals with Relay connection, and establish a unicast connection with the new relay device respectively. Subsequently, the two terminals communicate through the new relay device, in order to ensure the quality of communication between the two terminals. In this application, the air interface link can also be called an air interface direct link, that is, two terminals communicate directly through the air interface without relay transmission through other devices.

Below, the communication method provided by the embodiment of the present application will be described in detail with reference to FIGS. 2 to 11 .

In the embodiment of the present application, the communication method provided by the embodiment of the present application is explained, taking the terminal as the execution subject as an example. As an example and not a limitation, the execution subject that executes the communication method provided by the embodiments of the present application may also be a module applied to the terminal.

FIG. 2 shows a schematic flowchart of an example method 200 for determining a target relay provided by an embodiment of the present application. Below, each step of the method 200 is described in detail.

Step 201: The first terminal obtains the quality of the first source link and the quality of the second source link.

Assume that there is currently a communication connection between the first terminal and the second terminal. For example, the first terminal and the second terminal currently communicate through the second relay in Figure 3, where the first terminal and the second relay The link between them is called the first source link, and the link between the second relay and the second terminal is called the second source link. In this application, the relay device is simply called a relay, and the relay may be other terminals except the first terminal and the second terminal.

The first terminal may obtain the quality of the link between itself and the second relay, that is, the quality of the first source link, and obtain the quality of the link between the second relay and the second terminal, that is, the quality of the first source link. The quality of the secondary source link.

In this application, the quality of the link can be characterized by any one of the following parameters: reference signal received power (RSRP), signal to interference plus noise ratio (SINR) ), reference signal received quality (RSRQ), and received signal strength indicator (RSSI).

The measurement signal (for example, the first measurement signal and the second measurement signal here) may be a demodulation reference signal (DMRS), data or other signals.

The first terminal sends the first measurement configuration and the first measurement signal to the second relay, and sends measurement instruction information to the second relay. The measurement instruction information instructs the second relay to send the second measurement configuration and the second measurement signal to the second terminal. Measure the signal. The second relay measures the quality of the first measurement signal received through the first source link according to the received first measurement configuration to obtain the quality of the first source link, and then reports the first source link to the first terminal. A first measurement report corresponding to the link, the first measurement report including the quality of the first source link.

The second relay sends the second measurement configuration and the second measurement signal to the second terminal according to the received measurement instruction information. The second terminal measures the second measurement signal according to the second measurement configuration to obtain the second source link. Afterwards, the second terminal may report a second measurement report corresponding to the second source link to the second relay, and the second relay reports the second measurement report to the first terminal. The second measurement report includes the second measurement report. The quality of the secondary source link. The content of the second measurement configuration may be the same as or different from the content of the first measurement configuration. The second measurement configuration may be sent by the first terminal to the second relay, and forwarded by the second relay to the second terminal. The second measurement configuration may also be generated by the second relay based on the measurement indication information (for example, generated based on the measurement indication information and the first measurement configuration), thereby saving signaling overhead between the first terminal and the second relay. The second measurement signal is generated by the second relay and may be different from the first measurement signal.

The second relay may periodically report the first measurement report corresponding to the first source link to the first terminal. The reporting period may be configured by the first terminal for the second relay through the first measurement configuration, or the second After receiving the request message from the first terminal, the relay may report the first measurement report corresponding to the first source link to the first terminal, or the second relay may report the first measurement report corresponding to the first source link when the quality of the first source link is less than a certain If the threshold is reached, the first measurement report corresponding to the first source link is reported to the first terminal. In the embodiments of the present application, the link quality participates in mathematical operations, including addition, subtraction operations or numerical comparisons, etc. It can be understood that the specific numerical values of parameters characterizing the link quality participate in mathematical operations.

The second terminal may periodically report the second measurement report corresponding to the second source link to the second relay. The reporting period may be configured by the second relay for the second terminal through the second measurement configuration, or the second After receiving the request message from the second relay, the terminal may report the second measurement report corresponding to the second source link to the second relay, or the second terminal may report the second measurement report corresponding to the second source link when the quality of the second source link is less than a certain If the threshold is reached, the second measurement report corresponding to the second source link is reported to the second relay.

Step 202: If the first condition is met, the first terminal determines the first relay as the target relay.

Assume that there are one or more relays distributed around the first terminal and the second terminal. These relays can broadcast notification messages. The notification messages can be received by terminals located around the relays. The notification messages are used to notify the terminals located in the central terminal. Relay surrounding terminals: The relay has relay transmission capabilities and is located around the terminal that receives the notification message. In this application, being around a device means being within the coverage range of the device's signal. The notification message may be an announcement message from one or more relays, or a response message from one or more relays in response to the received solicitation message.

As an implementation manner, the first condition may include at least one of the following: the quality of the first source link is less than the first threshold, and the quality of the second source link is less than the second threshold. Assume that the first terminal receives a notification message from one or more relays. In this case, if the first terminal determines that the above-mentioned first condition is met, the first terminal can select from the one or more relays. The first relay that provides relay transmission for the first terminal and the second terminal serves as the target relay. The so-called first relay here can provide relay transmission for the first terminal and the second terminal means: the first relay supports relay transmission; at the same time, the first relay is within the signal coverage of the first terminal , is also within the coverage range of the signal of the second terminal, which can also be understood to mean that both the first terminal and the second terminal are within the coverage range of the signal of the first relay.

As another implementation manner, the first condition may include: the difference between the quality of the first target link and the quality of the first source link is greater than or equal to the third threshold, and the quality of the second target link is different from the second The difference in quality of the source link is greater than or equal to the third threshold. The first target link is a link between the first terminal and the first relay, and the second target link is a link between the first relay and the second terminal.

During the communication connection period between the first terminal and the second terminal, in addition to obtaining the quality of the first source link and the quality of the second source link, the first terminal can also obtain the relationship between itself and the relay for the same relay located around it. and the quality of the link between the second terminal and the relay. After that, the first terminal selects the first relay that satisfies the first condition from one or more relays around it as the target. relay.

The quality of the link between the first terminal and a certain relay is determined by the first terminal after measuring the signal of the notification message from the relay. The quality of the link between the second terminal and a certain relay is determined by the second terminal after measuring the signal of the notification message from the relay. After the second terminal obtains the link quality, it can use the second relay to determine the link quality. The link quality is then reported to the first terminal.

The following is an introduction to the method for the first terminal to obtain the quality of the link between itself and the relay and the quality of the link between the second terminal and the relay for the same relay (for example, the third relay). .

Way 1

After receiving the notification message from the third relay, the first terminal can measure the quality of the signal of the notification message from the third relay, thereby obtaining the quality of the link between itself and the third relay. After receiving the notification message from the third relay, the second terminal will also measure the signal quality of the notification message from the third relay, thereby obtaining the quality of the link between itself and the third relay. Afterwards, the second terminal reports to the first terminal a measurement report corresponding to the link between itself and the third relay, where the measurement report includes the quality of the link and the identifier of the third relay. It can be understood that the second terminal can report the measurement report to the first terminal through the second relay.

Way 2

The first terminal may send a third measurement configuration to the second terminal to instruct the second terminal to determine the quality of the link between itself and the relay after receiving the notification message from the relay, and report it to the first terminal. The measurement report corresponding to this link. The third measurement configuration may configure at least one of the following information to the second terminal: a period for the second terminal to report a measurement report to the first terminal and a trigger condition for the second terminal to report a measurement report to the first terminal. The trigger condition may be that the quality of the link between the second terminal and the relay is greater than a certain threshold. According to the third measurement configuration, the second terminal reports to the first terminal a measurement report corresponding to the link between itself and a certain relay (for example, the third relay). The measurement report includes the quality of the link and the link between the second terminal and the third relay. Successive identification. It can be understood that the first terminal can send the third measurement configuration to the second terminal through the second relay, and the second terminal can report the measurement report to the first terminal through the second relay.

After receiving the notification message from the third relay, the first terminal can measure the signal quality of the notification message from the third relay, thereby obtaining the quality of the link between itself and the third relay. Understandably, the first relay can So some third relay.

As an implementation manner, the first terminal may send the third measurement configuration to the second terminal after receiving the notification message from the third relay. The third measurement configuration may include information related to the measurement object. The relevant information of the measurement object may include the identity of the relay that sent the notification message. The identifier of the relay may be a layer-2 identifier (L2ID) used by the relay when sending the notification message. The second terminal determines that it needs to measure the signal quality of the notification message from the relay corresponding to the layer 2 identifier based on the received third measurement configuration. After that, after receiving the notification message from the relay, the second terminal determines that it The quality of the link to this relay.

In this case, the measurement report sent by the second terminal to the first terminal may not include the identifier of the relay. After receiving the measurement report, the first terminal may assume that the quality of the link in the measurement report is consistent with its own. The quality of the link measured after receiving the above notification message is for the same relay.

By causing the measurement configuration sent by the first terminal to the second terminal to include the identifier of the relay, the second terminal can be prevented from measuring the signal quality of the notification message received from other relays, thereby saving the second terminal the need for the notification message. The power consumed for measuring the signal quality can be guaranteed, and the first terminal and the second terminal can be guaranteed to measure the notification message from the same relay.

As an implementation manner, the relevant information of the above-mentioned measurement object may also include the cell identity corresponding to the relay that sends the above-mentioned notification message, the carrier information on which the relay works, and the public land mobile network (public land mobile network) served by the relay. PLMN). By including at least one of the cell identity corresponding to the relay that sends the notification message, the carrier information of the relay, and the serving PLMN of the relay in the third measurement configuration, the second terminal can perform the operation according to the third measurement configuration. When searching for the relay, the identification of the included relay reduces the search difficulty of the second terminal.

Based on the method 200, the quality of the first source link and/or the quality of the second source link of the first terminal is poor, or the quality of the first target link is better than the quality of the first source link, and When the quality of the second target link is better than the quality of the second source link, the first relay that can provide relay transmission for the first terminal and the second terminal is determined as the target relay. In other words , the first terminal and the second terminal will subsequently communicate through the first relay, in order to ensure the quality of communication between the first terminal and the second terminal.

FIG. 4 shows a schematic flowchart of another method 400 for determining a target relay provided by an embodiment of the present application. Below, each step of the method 400 is described in detail.

Step 401: The first terminal obtains the quality of the air interface link between the first terminal and the second terminal.

Assume that there is currently a communication connection between the first terminal and the second terminal. For example, the first terminal currently communicates with the second terminal through the air interface link in Figure 5. The first terminal can obtain the quality of the air interface link.

The first terminal sends a fourth measurement configuration and a fourth measurement signal to the second terminal. The second terminal measures the fourth measurement signal according to the fourth measurement configuration to obtain the air interface link between the first terminal and the second terminal. quality, and then report a measurement report corresponding to the air interface link to the first terminal, where the measurement report includes the quality of the air interface link.

The second terminal may periodically report the measurement report corresponding to the air interface link to the first terminal. The reporting period may be configured by the first terminal for the second terminal through the fourth measurement configuration, or the second terminal may receive the report from After receiving the request message from the first terminal, the first terminal reports the measurement report corresponding to the air interface link to the first terminal. Alternatively, the second terminal can report the air interface link to the first terminal when the quality of the air interface link is less than a certain threshold. Corresponding measurement report.

Step 402: If the first condition is met, the first terminal determines the first relay as the target relay.

Assume that there are one or more relays distributed around the first terminal and the second terminal. These relays can broadcast notification messages. The notification messages can be received by terminals located around the relays. The notification messages are used to notify the terminals located in the central terminal. Following the ending around Terminal: The relay has relay transmission capabilities and is located around the terminal that receives the notification message.

As an implementation manner, the first condition may include: the quality of the air interface link between the first terminal and the second terminal is less than the second threshold.

Assume that the first terminal receives a notification message from one or more relays. In this case, if the first terminal determines that the above-mentioned first condition is met, the first terminal can select from the one or more relays. The first relay that provides relay transmission for the first terminal and the second terminal serves as the target relay.

As another implementation manner, the first condition may include: the difference between the quality of the first target link and the quality of the above-mentioned air interface link is greater than or equal to the fourth threshold, and the quality of the second target link is different from the quality of the above-mentioned air interface link. The difference in road quality is greater than or equal to the fourth threshold. For an introduction to the first target link and the second target link, please refer to the relevant description in method 200. For the sake of brevity, they will not be described again here.

During the communication connection between the first terminal and the second terminal, in addition to obtaining the quality of the air interface link between the first terminal and the second terminal, the first terminal can also obtain the quality of the air interface link between itself and the middle terminal for the same relay located around it. The quality of the link between the relays and the quality of the link between the second terminal and the relay. After that, the first terminal can select the first relay that satisfies the first condition from one or more relays around it. relay as the target relay. Regarding the method for a first terminal to obtain the quality of the link between itself and the relay and the quality of the link between the second terminal and the relay for the same relay, and the first terminal obtains the quality of the link between itself and a certain relay. For the method of link quality between relays and the method for the second terminal to obtain the link quality between itself and a certain relay, please refer to the relevant description in method 200. For the sake of brevity, details will not be repeated here.

Based on method 400, the quality of the air interface link between the first terminal and the second terminal is poor, or the quality of the first target link is better than the quality of the air interface link, and the quality of the second target link is When the quality is superior to the quality of the air interface link, the first relay that can provide relay transmission for the first terminal and the second terminal is determined as the target relay. In other words, the first terminal and the second terminal Subsequent communication will be carried out through the first relay, in order to ensure the quality of communication between the first terminal and the second terminal.

FIG. 6 is a schematic flowchart of an example of a wireless relay communication method 600 provided by an embodiment of the present application. Below, each step of the method 600 is described in detail.

Step 601: The first terminal establishes a unicast connection with the first relay.

Assume that there is currently a communication connection between the first terminal and the second terminal. For example, the first terminal currently communicates with the second terminal through the second relay in Figure 3, or the first terminal currently communicates with the second terminal. communicate through the air interface link in Figure 5.

Assume that the first terminal determines the first relay as the target relay according to the foregoing method of determining the target relay. After that, the first terminal can establish a unicast connection with the first relay.

Figure 7 shows a schematic flow chart for establishing a unicast connection between two terminals. For convenience of description, the two terminals are denoted as terminal 1 and terminal 2 respectively.

During the establishment of a unicast connection, terminal 1 first sends a direct communication request (direct communication request, DCR) message to terminal 2. After receiving the DCR message from Terminal 1, Terminal 2 sends a direct security mode command message to Terminal 1, which requests the establishment of a secure connection with Terminal 1. Then, terminal 1 sends a direct security mode complete message to terminal 2. After receiving the direct connection security mode completion message, terminal 2 sends a direct communication accept (DCA) message to terminal 1. At this point, a unicast connection is established between terminal 1 and terminal 2.

Terminal 1 and terminal 2 here may be the above-mentioned first terminal, first relay, second relay or second terminal. It should be reasonable Solution: During the process of establishing a unicast connection between the first terminal and the first relay, the first terminal corresponds to the above-mentioned terminal 1 and performs the above steps performed by terminal 1. The first relay corresponds to the above-mentioned terminal 2 and executes are the above steps performed by terminal 2.

Step 602: The first terminal sends first instruction information to the second terminal. The first instruction information instructs the second terminal to establish a unicast connection with the first relay. Correspondingly, the second terminal receives the first indication information from the first terminal.

For the scenario shown in Figure 3, the first terminal can send the first indication information to the second terminal through the second relay. In other words, the first terminal can send the first indication information to the second terminal through the first source link between itself and the second relay. The second source link between the second relay and the second terminal sends the first indication information to the second terminal. For the scenario shown in Figure 5, the first terminal may directly send the first indication information to the second terminal. The first indication information may carry a first identifier assigned by the first terminal for identifying the second terminal.

Step 603: Establish a unicast connection between the second terminal and the first relay.

After receiving the first indication information from the first terminal, the second terminal establishes a unicast connection with the first relay.

As an implementation manner, after the second terminal receives the first indication information, if the first indication information carries the above-mentioned first identifier, the method 600 may further include step 604, in which the second terminal sends the first identifier to the first relay. Correspondingly, the first relay receives the first identification from the second terminal. The second terminal may send the first identifier to the first relay during the process of establishing a unicast connection with the first relay. For example, the second terminal may send the first identifier to the first relay through a DCR message sent to the first relay during the process of establishing a unicast connection with the first relay.

Alternatively, the second terminal may configure the first identifier to the first relay through PC5-S signaling or PC5-RRC signaling after establishing a unicast connection with the first relay.

As another possible implementation manner, method 600 may also include step 605, where the first terminal sends the first identifier to the first relay. Correspondingly, the first relay receives the first identification from the first terminal.

For example, the first terminal may send the first identifier to the first relay during the process of establishing a unicast connection with the first relay. For example, the first terminal may send the first identifier to the first relay during the process of establishing a unicast connection with the first relay. The DCR message sent to the first relay sends the first identifier to the first relay.

For another example, after establishing a unicast connection with the first relay, the first terminal may configure the first identifier to the first relay through PC5 interface signaling (PC5-signaling, PC5-S) or PC5-RRC signaling. Among them, RRC is the English abbreviation of Radio Resource Control.

The first terminal sends the first identifier assigned by the first terminal to the second terminal to identify the second terminal, and the first terminal sends the first identifier to the first relay. When the first relay subsequently receives the first identifier from the first When receiving data from one terminal, the second terminal can be determined to be the destination terminal of the data based on the first identifier sent along with the data. In other words, the first relay determines that the first target link is associated with the second target link, thereby forwarding the data from the first terminal to the second terminal; or, when the first relay subsequently receives data from the second terminal When receiving data from a terminal, the first terminal can be determined as the destination terminal according to the first identifier sent along with the data.

As another implementation manner, method 600 may also include step 606. The second terminal sends a second identification of the second terminal to the first terminal. The second identification may be when the second terminal establishes a unicast connection with the first relay. The Layer 2 identifier of the second terminal used at the time. Correspondingly, the first terminal receives the second identification from the second terminal.

For example, taking the scenario shown in Figure 3 as an example, the second terminal can send the second identification of the second terminal to the first terminal through the second relay. In other words, the second terminal can send the second identification of the second terminal to the first terminal through the second relay. The first source link between the second source link, the second relay and the first terminal sends the second identification of the second terminal to the first terminal.

The second terminal may send the second identification to the first terminal after receiving the first indication information from the first terminal. Alternatively, the second terminal may send the second identifier to the first terminal after establishing a unicast connection with the first relay.

Method 600 may also include step 607. After receiving the second identification from the second terminal, the first terminal sends the second identification to the first relay.

Specifically, the first terminal may send the second identifier to the first relay during the process of establishing a unicast connection with the first relay. For example, the first terminal may send the second identifier to the first relay through a DCR message.

The second terminal first sends to the first terminal the Layer 2 identifier used by the second terminal to establish a unicast connection with the first relay, and then the first terminal sends the Layer 2 identifier of the second terminal to the first relay. When a communication connection is established between two terminals, the layer 2 identifier of the source terminal and the layer 2 identifier of the destination terminal are used to identify the communication connection between the two terminals. For example, when a communication connection is established between a first terminal and a second terminal, a pair of the layer 2 identifier of the first terminal and the layer 2 identifier of the second terminal is used to identify the communication connection. When the first relay subsequently receives data from the first terminal, it can determine the layer 2 identifier of the first terminal included in the data according to the source address sent with the data (ie, the layer 2 identifier of the first terminal). The layer 2 identification pair of the second terminal is an identification pair used to identify the communication connection between the first terminal and the second terminal, thereby determining the second terminal as the destination terminal. Alternatively, when the first relay subsequently receives data from the second terminal, it may determine the Layer 2 of the second terminal included in the data based on the source address sent with the data (ie, the Layer 2 identification of the second terminal). The layer 2 identifier pair between the identifier and the first terminal is an identifier pair used to identify the communication connection between the first terminal and the second terminal, thereby determining the first terminal as the destination terminal.

It should be understood that it is also possible to send both the first identifier and the layer 2 identifier of the second terminal to the first relay. When the first relay subsequently receives data from the first terminal or the second terminal, , the data can be forwarded to the first terminal or the second terminal according to the first identifier and the layer 2 identifier of the second terminal.

FIG. 8 is a schematic flowchart of another wireless relay communication method 800 provided by an embodiment of the present application. Below, each step of the method 800 is described in detail.

Step 801: The first terminal establishes a unicast connection with the first relay. For the specific description of step 801, please refer to the relevant description in step 601. For the sake of brevity, details will not be repeated here.

Step 802: The first terminal sends first indication information to the first relay, and the first indication information instructs the first relay to establish a unicast connection with the second terminal. Correspondingly, the first relay receives the first indication information from the first terminal.

For example, after establishing a unicast connection with the first relay, the first terminal may send first indication information to the first relay to instruct the first relay to establish a unicast connection with the second terminal through the first indication information. .

Step 803: Establish a unicast connection between the first relay and the second terminal.

Regarding the beneficial effects of establishing unicast connections between the first terminal, the first relay and the second terminal respectively, please refer to the relevant description in method 600. For the sake of brevity, details will not be described here.

As an implementation manner, the method 800 may also include step 805. The second terminal sends a second identification of the second terminal to the first terminal. The second identification of the second terminal may be that the second terminal establishes a unicast with the first relay. The layer 2 identifier of the second terminal used to connect. Correspondingly, the first terminal receives the second identification of the second terminal from the second terminal. Regarding the specific method for the second terminal to send the second identification of the second terminal to the first terminal, please refer to the relevant description in step 606. For the sake of brevity, details will not be repeated here.

As an implementation manner, before step 805, step 804 may also be included, in which the first terminal sends a request message to the second terminal, and the request message requests the second terminal to send the second identification of the second terminal to the first terminal. Correspondingly, the second terminal receives the request message from the first terminal.

Taking the scenario shown in Figure 3 as an example, the first terminal can send a request message to the second terminal through the second relay. In other words, the first terminal passes the first source link between itself and the second relay. The second source link between the second relay and the second terminal sends a request message to the second terminal.

According to the request message from the first terminal, the second terminal sends the second terminal to the second terminal through the second source link between itself and the second relay and the first source link between the second relay and the second terminal. The second identifier of the second terminal.

As an implementation manner, method 800 may also include step 806. After receiving the second identification from the second terminal, the first terminal sends the second identification of the second terminal to the first relay. Regarding the specific method for the first terminal to send the second identifier of the second terminal to the first relay, please refer to the relevant description in step 607. For the sake of brevity, details will not be repeated here.

Regarding the beneficial effect of the first terminal sending the second terminal's Layer 2 identifier to the first relay, please refer to the relevant description in method 600. For the sake of brevity, details will not be repeated here.

FIG. 9 is a schematic flowchart of yet another method 900 for determining a target relay provided by an embodiment of the present application. Below, each step of the method 900 is described in detail.

Step 901: The second relay obtains the quality of the first source link and the quality of the second source link.

Assume that there is currently a communication connection between the first terminal and the second terminal. For example, the first terminal and the second terminal currently communicate through the second relay in FIG. 3 .

The second relay may obtain the quality of the first source link and the quality of the second source link.

For example, the second relay may obtain the quality of the first source link and the quality of the second source link in the following manner.

The second relay sends the fifth measurement configuration and the fifth measurement signal to the first terminal. The first terminal measures the quality of the fifth measurement signal received through the first source link according to the received fifth measurement configuration to obtain the third After that, the first terminal reports the fifth measurement report corresponding to the first source link to the second relay, and the fifth measurement report includes the quality of the first source link.

The second relay sends the sixth measurement configuration and the sixth measurement signal to the second terminal. The second terminal measures the quality of the sixth measurement signal received through the second source link according to the received sixth measurement configuration, and obtains the sixth measurement signal. the quality of the second source link. Afterwards, the second terminal reports a sixth measurement report corresponding to the second source link to the second relay. The sixth measurement report includes the quality of the second source link.

The first terminal may periodically report the fifth measurement report corresponding to the first source link to the second relay. The reporting period may be configured by the second relay for the first terminal through the fifth measurement configuration, or the first After receiving the request message from the second relay, the terminal may report the fifth measurement report corresponding to the first source link to the second relay, or the first terminal may report the first source link when the quality of the first source link is less than a certain If the threshold is reached, the fifth measurement report corresponding to the first source link is reported to the second relay.

The second terminal may periodically report the sixth measurement report corresponding to the second source link to the second relay. The reporting period may be configured by the second relay for the second terminal through the sixth measurement configuration, or the second After receiving the request message from the second relay, the terminal may report the sixth measurement report corresponding to the second source link to the second relay, or the second terminal may report the sixth measurement report corresponding to the second source link when the quality of the second source link is less than a certain If the threshold is reached, the sixth measurement report corresponding to the second source link is reported to the second relay.

Step 902: If the first condition is met, the second relay determines the first relay as the target relay.

Assume that there are one or more relays distributed around the first terminal and the second terminal. These relays can broadcast notification messages. The notification messages can be received by terminals located around the relays. The notification messages are used to notify the terminals located in the central terminal. Relay surrounding terminals: The relay has relay transmission capabilities and is located around the terminal that receives the notification message.

As an implementation manner, the first condition may include: the difference between the quality of the first target link and the quality of the first source link is greater than or equal to the third threshold, and the quality of the second target link is different from the quality of the second source link. The difference in link quality is greater than or equal to the third threshold. For an introduction to the first target link and the second target link, please refer to the relevant description in method 200. For the sake of brevity, they will not be described again here.

During the communication connection between the second relay and the second terminal, in addition to obtaining the quality of the first source link and the quality of the second source link, the second relay can also target the same center located around the first terminal and the second terminal. Next, the quality of the link between the first terminal and the relay and the quality of the link between the second terminal and the relay are obtained. After that, the second relay can obtain the quality of the link around the first terminal and the second terminal. Select the first relay that satisfies the first condition among the one or more relays as the target relay.

Next, for the second relay, for the same relay (for example, the third relay) located around the first terminal and the second terminal, the quality of the link between the first terminal and the relay and the quality of the link between the second terminal and the second terminal are obtained. The method of link quality between relays is introduced.

The second relay may send a seventh measurement configuration to the first terminal to instruct the first terminal to determine the quality of the link between itself and the relay after receiving the notification message from the relay, and send the second relay to the second relay. Then report the measurement report corresponding to the link. The seventh measurement configuration may configure at least one of the following information to the first terminal: a period for the first terminal to report a measurement report to the second relay and a trigger condition for the first terminal to report a measurement report to the second relay. The trigger condition may be that the quality of the link between the first terminal and the relay is greater than a certain threshold. According to the seventh measurement configuration, the first terminal reports to the second relay a measurement report corresponding to the link between itself and a certain relay (for example, the third relay). The measurement report includes the quality of the link and the The ID of the relay.

The second relay may send the eighth measurement configuration to the second terminal to instruct the second terminal to determine the quality of the link between itself and the relay after receiving the notification message from the relay, and send the second terminal to the second terminal. Then report the measurement report corresponding to the link. The eighth measurement configuration may configure at least one of the following information to the second terminal: a period for the second terminal to report a measurement report to the second relay and a trigger condition for the second terminal to report a measurement report to the second relay. The trigger condition may be that the quality of the link between the second terminal and the relay is greater than a certain threshold. According to the eighth measurement configuration, the second terminal reports to the second relay a measurement report corresponding to the link between itself and a certain relay (for example, the third relay). The measurement report includes the quality of the link and the The ID of the relay.

Regarding the method for the first terminal to obtain the quality of the link between itself and a certain relay, and the method for the second terminal to obtain the quality of the link between itself and a certain relay, please refer to the relevant description in method 200. In order It is concise and will not be repeated here.

Based on the identifier of the relay included in the measurement report from the first terminal and the identifier of the relay included in the measurement report of the second terminal, the second relay can compare the quality of the link from the first terminal corresponding to the same identifier with The quality of the link from the second terminal is determined as the quality of the link between the first terminal, the second terminal and the same relay respectively.

Based on the method 900, the second relay performs the following tasks when the quality of the first target link is better than the quality of the first source link, and the quality of the second target link is better than the quality of the second source link. , determine the first relay corresponding to the first target link and the second target link as the target relay. In other words, the first terminal and the second terminal will subsequently communicate through the first relay, in order to ensure that the first The quality of communication between one terminal and a second terminal.

FIG. 10 is a schematic flowchart of yet another example of a wireless relay communication method 1000 provided by an embodiment of the present application. Below, each step of the method 1000 is described in detail.

Step 1001: The second relay sends second instruction information to the first terminal, and the second instruction information instructs the first terminal to establish a unicast connection with the first relay. Correspondingly, the first terminal receives the second indication information from the second relay.

Assume that the second relay determines the first relay as the target relay according to the aforementioned method of determining the target relay. After that, the second relay can instruct the first terminal, the second terminal and the first relay to establish unicast respectively. connect. For specific descriptions of the first condition and determining whether the first condition is satisfied, please refer to the relevant descriptions in method 200 or method 400. For the sake of brevity, they will not be described again here.

Step 1002: The first terminal establishes a unicast connection with the first relay.

Step 1003: The second relay sends third instruction information to the second terminal, and the third instruction information instructs the second terminal to establish a unicast connection with the first relay. Correspondingly, the second terminal receives the third indication information from the second relay.

Step 1004: The second terminal establishes a unicast connection with the first relay.

As an implementation manner, method 1000 may also include steps 1005 to 1010:

Step 1005: The first terminal sends the second identifier of the first terminal to the second relay. The second identifier is the layer 2 identifier of the first terminal used by the first terminal when establishing a unicast connection with the first relay. Correspondingly, the second relay receives the second identification of the first terminal from the first terminal.

Step 1006: The second relay sends the second identification of the first terminal to the second terminal. Correspondingly, the second terminal receives the second identification of the first terminal from the second relay.

Step 1007: The second terminal sends the second identification of the first terminal to the first relay. Correspondingly, the first relay receives the second identification of the first terminal from the second terminal.

The first terminal sends the Layer 2 identifier used by the first terminal to establish a unicast connection with the first relay to the second relay, and then the second relay sends it to the second terminal. After that, the second terminal sends the layer 2 identifier to the first relay. Send the layer 2 identification of the first terminal. When a communication connection is established between two terminals, the layer 2 identifier of the source terminal and the layer 2 identifier of the destination terminal are used to identify the communication connection between the two terminals. For example, a communication connection is established between the first terminal and the second terminal. When, the layer 2 identifier of the first terminal and the layer 2 identifier of the second terminal are used to identify this communication connection. When the first relay subsequently receives data from the first terminal, it can be based on the source address sent along with the data. (i.e., the Layer 2 identifier of the first terminal), it is determined that the pair of the Layer 2 identifier of the first terminal and the Layer 2 identifier of the second terminal included in the data is used to identify the communication connection between the first terminal and the second terminal. identification pair, thereby determining the second terminal as the destination terminal. Alternatively, when the first relay subsequently receives data from the second terminal, it may determine the Layer 2 of the second terminal included in the data based on the source address sent with the data (ie, the Layer 2 identification of the second terminal). The layer 2 identifier pair between the identifier and the first terminal is an identifier pair used to identify the communication connection between the first terminal and the second terminal, thereby determining the first terminal as the destination terminal.

Step 1008: The second terminal sends the second identifier of the second terminal to the second relay. The second identifier is the layer 2 identifier of the second terminal used by the second terminal when establishing a unicast connection with the first relay. Correspondingly, the second relay receives the second identification of the second terminal from the second terminal.

Step 1009: The second relay sends the second identification of the second terminal to the first terminal. Correspondingly, the first terminal receives the second identification of the second terminal from the second relay.

Step 1010: The first terminal sends the second identification of the second terminal to the first relay. Correspondingly, the first relay receives the second identification of the second terminal from the first terminal.

The second terminal sends the Layer 2 identifier used by the second terminal to establish a unicast connection with the first relay to the second relay, and then the second relay sends it to the first terminal. After that, the first terminal sends a message to the first relay. Send the layer 2 identification of the second terminal. The layer 2 identification pair used when establishing a communication connection between two terminals identifies the communication connection between the two terminals. For example, when a communication connection is established between a first terminal and a second terminal, a pair of the layer 2 identifier of the first terminal and the layer 2 identifier of the second terminal is used to identify the communication connection. When the first relay subsequently receives a message from the first terminal, When receiving data from a terminal, it can be determined based on the destination address sent with the data (i.e., the Layer 2 identifier of the second terminal) that the pair of Layer 2 identifier of the first terminal and the Layer 2 identifier of the second terminal included in the data is used for. An identification pair identifying the communication connection between the first terminal and the second terminal, thereby determining the second terminal as the destination terminal. Alternatively, when the first relay subsequently receives data from the second terminal, it may determine the Layer 2 of the second terminal included in the data based on the source address sent with the data (ie, the Layer 2 identification of the second terminal). The layer 2 identifier pair between the identifier and the first terminal is an identifier pair used to identify the communication connection between the first terminal and the second terminal, thereby determining the first terminal as the destination terminal. FIG. 11 is a schematic flowchart of yet another example of a wireless relay communication method 1100 provided by an embodiment of the present application. Below, each step of the method 1100 is described in detail.

Step 1101: The first terminal broadcasts a DCR message. The DCR message requests the second terminal to reselect a relay and establish a unicast connection with the first terminal through the reselected relay.

The first terminal communicates with the second terminal through the second relay in Figure 3. It is assumed that a wireless link occurs between the first source link and/or the second source link between the first terminal and the second relay. Radio link failure (RLF). In this case, in order to continue communicating with the second terminal, the first terminal can broadcast a DCR message for the second terminal to request the second terminal to reselect a relay, thereby Communication with the second terminal is carried out through the reselected relay. It is worth mentioning that the "DCR message for the second terminal" can be understood as: the DCR message carries the user information of the second terminal.

Assume that there are one or more relays around the second terminal. In this case, what the first terminal broadcasts may be received by the one or more relays, and the one or more relays can help the first terminal broadcast After receiving the DCR message, the second terminal can determine that the DCR message is sent to itself based on the user information of the second terminal carried in the DCR message. In other words, the second terminal determines that the first terminal wants to Establish a unicast connection with yourself.

Optionally, as an implementation manner, the DCR message carries relay re-selection indication information (Relay re-selection indication), and the indication information instructs the second terminal to reselect a relay.

After receiving the DCR message, the second terminal can select a relay from one or more surrounding relays as a relay for subsequent communication with the first terminal according to the instructions of the DCR message. For example, the second terminal can For the same relay, obtain the quality of the link between itself and the relay and the quality of the link between the first terminal and the relay, and obtain the quality of the link between itself and the first terminal and the same relay respectively. According to the quality of the road, one relay is selected from one or more surrounding relays as the relay for subsequent communication with the first terminal. Regarding the specific method for the second terminal to determine the relay that provides relay transmission between itself and the first terminal, please refer to the foregoing relevant descriptions. For the sake of brevity, details will not be repeated here.

Step 1102: The second terminal sends a DCA message to the first terminal. The DCA message indicates that the second terminal has completed the establishment of the unicast connection with the first terminal.

After determining the relay and establishing a secure connection with the first terminal, the second terminal may send a DCA message to the first terminal to indicate to the first terminal that the second terminal has completed the communication with the first terminal. Establishment of unicast connection between

It should be understood that method 1100 is also applicable to the scenario where the source link between the first terminal and the second terminal is an air interface link.

It should also be understood that the DCR message broadcast by the first terminal can also be directly received by the second terminal. In this case In this case, the second terminal can re-determine an air interface link between itself and the first terminal according to the instruction of the DCR message, and subsequently communicate with the first terminal through the link.

Based on method 1100, the first terminal broadcasts a DCR that can instruct the second terminal to reselect the relay. This method can enable the second terminal to receive the DCR when RLF occurs on the source link, and can perform the DCR according to the instruction of the DCR. , reselect a relay that can provide relay transmission for the first terminal and the second terminal, in order to ensure normal communication between the first terminal and the second terminal.

It is worth mentioning that in the method for establishing a unicast connection provided by the embodiments of the present application, a unicast connection is established between the first terminal and the first relay, and the connection between the second terminal and the first relay is determined. After a unicast connection is also established between The terminal may not release the first source link.

After a unicast connection is established between the second terminal and the first relay, and it is determined that a unicast connection is also established between the first terminal and the first relay, in one implementation, the second terminal may send a request to the first relay. The second relay sends a unicast connection release message to release the second source link; in another implementation, the second terminal does not need to release the second source link.

It is worth mentioning that the situation in which the first source link and the second source link are released can be called path switch, and the situation in which the first source link and the second source link are not released can be called path switch. This situation is called multi-path.

It can be understood that, in order to implement the functions in the above embodiments, the terminal includes corresponding hardware structures and/or software modules that perform each function. Those skilled in the art should easily realize that, in conjunction with the units and method steps of each example described in the embodiments disclosed in the embodiments of the present application, the embodiments of the present application can be implemented in the form of hardware or a combination of hardware and computer software. accomplish. Whether a certain function is executed by hardware or computer software driving the hardware depends on the specific application scenarios and design constraints of the technical solution.

Figures 12 and 13 are schematic structural diagrams of possible communication devices provided by embodiments of the present application. These communication devices can be used to implement the functions of the terminal or relay in the above method embodiments, and therefore can also achieve the beneficial effects of the above method embodiments. In the embodiment of the present application, the communication device may be one of the terminals 101-103 shown in Figure 1, or may be a module (such as a chip) applied to the terminal.

As shown in Figure 12, in one implementation, the communication device 1200 includes a processing unit 1210 and a transceiver unit 1220. The communication device 1200 is used to implement the functions of the terminal in the method embodiments shown in FIG. 2, FIG. 4, FIG. 6 to FIG. 11.

When the communication device 1200 is used to implement the functions of the first terminal in the method embodiment shown in Figure 2: the processing unit 1210 is used to obtain the quality of the first source link and the quality of the second source link. When the first condition is met In the case of , the first relay is determined as the target relay.

For a more detailed description of the above processing unit 1210, please refer to the relevant description in the method embodiment shown in FIG. 2 .

When the communication device 1200 is used to implement the functions of the first terminal in the method embodiment shown in Figure 4: the processing unit 1210 is used to obtain the quality of the air interface link between the first terminal and the second terminal. When the first condition is met In the case of , the first relay is determined as the target relay.

For a more detailed description of the above processing unit 1210, please refer to the relevant description in the method embodiment shown in FIG. 4 .

When the communication device 1200 is used to implement the functions of the first terminal in the method embodiment shown in Figure 6: the processing unit 1210 is used to establish a unicast connection with the first relay; the transceiver unit 1220 is used to send the first terminal to the second terminal. Instruction information, the first instruction information instructs the second terminal to establish a unicast connection with the first relay.

For a more detailed description of the processing unit 1210 and the transceiver unit 1220, please refer to the relevant description in the method embodiment shown in FIG. 6 .

When the communication device 1200 is used to implement the functions of the second terminal in the method embodiment shown in Figure 6: the transceiver unit 1220 is used to receive the first instruction information from the first terminal, and the first instruction information instructs the second terminal to communicate with the first terminal. A unicast connection is established between relays; the processing unit 1210 is configured to establish a unicast connection with the first relay.

When the communication device 1200 is used to implement the functions of the first terminal in the method embodiment shown in Figure 8: the processing unit 1210 is used to establish a unicast connection with the first relay; the transceiver unit 1220 is used to send the first relay to the first relay. An indication information, the first indication information indicates establishing a unicast connection between the first relay and the second terminal.

For a more detailed description of the processing unit 1210 and the transceiver unit 1220, please refer to the relevant description in the method embodiment shown in FIG. 8 .

When the communication device 1200 is used to implement the function of the first relay in the method embodiment shown in Figure 8: the transceiver unit 1220 is used to receive the first indication information from the first terminal, and the first indication information indicates that the first relay is connected to the first relay. A unicast connection is established between the second terminals; the processing unit 1210 is configured to establish a unicast connection with the second terminal.

When the communication device 1200 is used to implement the function of the second relay in the method embodiment shown in Figure 9: the processing unit 1210 is used to obtain the quality of the first source link and the quality of the second source link, under the first condition If satisfied, the first relay is determined as the target relay.

For a more detailed description of the above processing unit 1210, please refer to the relevant description in the method embodiment shown in FIG. 9 .

When the communication device 1200 is used to implement the function of the second relay in the method embodiment shown in Figure 10: the transceiver unit 1220 is used to send the second instruction information to the first terminal, and the second instruction information instructs the first terminal to communicate with the first terminal. The relay establishes a unicast connection and is also used to send third instruction information to the second terminal. The third instruction information instructs the second terminal to establish a unicast connection with the first relay; the processing unit 1210 is used to communicate with the second terminal. Establish a unicast connection.

For a more detailed description of the processing unit 1210 and the transceiver unit 1220, please refer to the relevant description in the method embodiment shown in FIG. 10 .

When the communication device 1200 is used to implement the functions of the first terminal in the method embodiment shown in Figure 10: the transceiver unit 1220 is used to receive the second instruction information from the second relay, and the second instruction information instructs the first terminal to communicate with the third terminal. A relay establishes a unicast connection; the processing unit 1210 is configured to establish a unicast connection with the first relay.

When the communication device 1200 is used to implement the functions of the second terminal in the method embodiment shown in Figure 10: the transceiver unit 1220 is used to receive the third instruction information from the second relay, and the third instruction information instructs the second terminal to communicate with the third terminal. A relay establishes a unicast connection; the processing unit 1210 is configured to establish a unicast connection with the first relay.

When the communication device 1200 is used to implement the functions of the first terminal in the method embodiment shown in Figure 11: the transceiver unit 1220 is used to broadcast a DCR message, and the DCR message requests the second terminal to reselect a relay and communicate with the relay through the relay. Establishing a unicast connection between the first terminals is also used to receive a DCA message from the second terminal. The DCA message indicates that the second terminal has completed the establishment of the unicast connection with the first terminal.

For a more detailed description of the processing unit 1210 and the transceiver unit 1220, please refer to the relevant description in the method embodiment shown in FIG. 11 .

When the communication device 1200 is used to implement the functions of the second terminal in the method embodiment shown in Figure 11: the transceiver unit 1220 receives a DCR message from the first terminal, and the DCR message requests the second terminal to reselect a relay, and passes The relay establishes a unicast connection with the first terminal and is also used to send a DCA message to the first terminal. The DCA message indicates that the second terminal has completed the establishment of the unicast connection with the first terminal.

As shown in FIG. 13, the communication device 1300 includes a processor 1310 and an interface circuit 1320. The processor 1310 and the interface circuit 1320 are coupled to each other. It can be understood that the interface circuit 1320 may be a transceiver or an input-output interface. Optionally, the communication device 1300 may also include a memory 1330 for storing instructions executed by the processor 1310 or input data required for the processor 1310 to run the instructions or data generated after the processor 1310 executes the instructions.

When the communication device 1300 is used to implement the method shown in Figure 2, the processor 1310 is used to implement the functions of the above-mentioned processing unit 1210.

When the communication device 1300 is used to implement the method shown in Figure 4, the processor 1310 is used to implement the functions of the above-mentioned processing unit 1210.

When the communication device 1300 is used to implement the method shown in Figure 6, the processor 1310 is used to implement the functions of the above-mentioned processing unit 1210, and the interface circuit 1320 is used to implement the functions of the above-mentioned transceiver unit 1220.

When the communication device 1300 is used to implement the method shown in Figure 8, the processor 1310 is used to implement the functions of the above-mentioned processing unit 1210, and the interface circuit 1320 is used to implement the functions of the above-mentioned transceiver unit 1220.

When the communication device 1300 is used to implement the method shown in Figure 9, the processor 1310 is used to implement the functions of the above-mentioned processing unit 1210.

When the communication device 1300 is used to implement the method shown in Figure 10, the processor 1310 is used to implement the functions of the above-mentioned processing unit 1210, and the interface circuit 1320 is used to implement the functions of the above-mentioned transceiver unit 1220.

When the communication device 1300 is used to implement the method shown in Figure 11, the interface circuit 1320 is used to implement the functions of the above-mentioned transceiver unit 1220.

When the above communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal in the above method embodiment. The terminal chip receives information from other modules in the terminal (such as radio frequency modules or antennas), and the information is sent to the terminal by other terminals; or, the terminal chip sends information to other modules in the terminal (such as radio frequency modules or antennas) , this information is sent by this terminal to other terminals.

It can be understood that the processor in the embodiment of the present application can be a central processing unit (Central Processing Unit, CPU), or other general-purpose processor, digital signal processor (Digital Signal Processor, DSP), or application specific integrated circuit. (Application Specific Integrated Circuit, ASIC), Field Programmable Gate Array (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

The method steps in the embodiments of the present application can be implemented in hardware or in software instructions that can be executed by a processor. Software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory Memory, register, hard disk, mobile hard disk, CD-ROM or any other form of storage medium well known in the art middle. An exemplary storage medium is coupled to the processor such that the processor can read information from the storage medium and write information to the storage medium. The storage medium may also be an integral part of the processor. The processor and storage media may be located in an ASIC. Additionally, the ASIC can be located in the terminal. The processor and storage medium may also be present in the terminal as discrete components.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it 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 programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are executed in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer program or instructions may be transmitted from a website, computer, A server or data center transmits via wired or wireless means to another website site, computer, server, or data center. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media, such as floppy disks, hard disks, and tapes; optical media, such as digital video optical disks; or semiconductor media, such as solid-state hard drives. The computer-readable storage medium may be volatile or nonvolatile storage media, or may include both volatile and nonvolatile types of storage media.

In the various embodiments of the present application, if there is no special explanation or logical conflict, the terms and/or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments are based on Their internal logical relationships can be combined to form new embodiments.

In the embodiments of this application, "at least one" refers to one or more, and "multiple" refers to two or more. "And/or" describes the relationship between associated objects, indicating that there can be three relationships, for example, A and/or B, which can mean: A exists alone, A and B exist simultaneously, and B exists alone, where A, B can be singular or plural. In the text description of the embodiments of this application, the character "/" generally indicates that the related objects are in an "or" relationship; in the formulas of the embodiments of this application, the character "/" indicates that the related objects are A "division" relationship. "Including at least one of A, B and C" may mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C.

It can be understood that the various numerical numbers involved in the embodiments of the present application are only for convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the serial numbers of the above processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic.

Claims

A wireless relay communication method, executed by a first terminal or a module applied to the first terminal, is characterized by including:

Obtain the quality of the source link, the source link includes the air interface link between the first terminal and the second terminal, or the source link includes the first source link and the second source link, so The first source link is an air interface link between the first terminal and the second relay, and the second source link is an air interface link between the second relay and the second terminal. ;

When the first condition is met, establish a unicast connection with a first relay, which is a terminal capable of providing relay transmission for the first terminal and the second terminal;

Send first indication information to the second terminal, where the first indication information instructs the second terminal to establish a unicast connection with the first relay, or send first indication information to the first relay. Instruction information indicating establishing a unicast connection between the first relay and the second terminal.
The method of claim 1, wherein the first condition includes at least one of the following: the quality of the first source link is less than a first threshold, the quality of the second source link is less than the The first threshold.
The method according to claim 1, wherein the first condition includes: the quality of the air interface link between the first terminal and the second terminal is less than a second threshold.
The method of claim 1, wherein the first condition includes: the difference between the quality of the first target link and the quality of the first source link is greater than or equal to a third threshold, and, The difference between the quality of the second target link and the quality of the second source link is greater than or equal to the third threshold, and the first target link is between the first terminal and the first relay. The air interface link is an air interface link between the first relay and the second terminal.
The method according to claim 1, wherein the first condition includes: the difference between the quality of the first target link and the quality of the air interface link is greater than or equal to a fourth threshold, and, the second target link The difference between the quality of the link and the quality of the air interface link is greater than or equal to the fourth threshold, and the first target link is the air interface link between the first terminal and the first relay. , the second target link is an air interface link between the first relay and the second terminal.
The method according to any one of claims 1 to 5, characterized in that the first indication information carries a first identifier assigned by the first terminal for identifying the second terminal.
The method of claim 6, further comprising:

Send the first identification to the first relay.
The method according to any one of claims 1 to 7, characterized in that the method further includes:

Receive a second identification from the second terminal, where the second identification is a Layer 2 identification used by the second terminal to establish a unicast connection with the first relay;

Send the second identification to the first relay.
A communication method, executed by a second terminal or a module applied to the second terminal, is characterized by including:

Receive first instruction information from the first terminal, the first instruction information instructs the second terminal to establish a unicast connection with a first relay, and the first relay is capable of providing the first terminal, The second terminal provides a terminal for relay transmission;

Establish a unicast connection with the first relay.
The method according to claim 9, characterized in that the first indication information carries the first terminal A first identifier assigned to identify the second terminal.
The method of claim 10, further comprising:

Send the first identification to the first relay.
The method according to any one of claims 9 to 11, characterized in that the method further includes:

Send a second identifier of the second terminal to the first terminal, where the second identifier is a layer 2 identifier used by the second terminal to establish a unicast connection with the first relay.
A communication method, executed by a first relay or a module applied to the first relay, the first relay being a terminal capable of providing relay transmission for a first terminal and a second terminal, characterized in that it includes:

Receive first indication information from the first terminal, the first indication information indicating the establishment of a unicast connection between the first relay and the second terminal;

Establish a unicast connection with the second terminal.
The method of claim 13, further comprising:

Receive a second identification of the second terminal from the first terminal, where the second identification is a layer 2 identification used by the second terminal to establish a unicast connection with the first relay.
A communication device, characterized by comprising a processor and an interface circuit, the interface circuit being used to receive signals from other communication devices and transmit them to the processor or to send signals from the processor to other communication devices. , the processor is used to implement the method as described in any one of claims 1 to 8 through logic circuits or execution code instructions, or is used to implement the method as described in any one of claims 9 to 12, Or, used to implement the method as claimed in claim 13 or 14.
A computer-readable storage medium, characterized in that a computer program or instructions are stored in the storage medium. When the computer program or instructions are executed by a communication device, the implementation as described in any one of claims 1 to 8 is achieved. method, or implement the method as described in any one of claims 9 to 12, or implement the method as described in claim 13 or 14.