TECHNICAL FIELD

Embodiments of this application relate to the communications field, and in particular, to a communication method and an apparatus.

BACKGROUND

With development of light-emitting diode (Light-emitting Diode, LED) technologies, such an LED lamp that is energy-efficient, small in size, and has a long life span is widely applied to scenarios such as lighting, indication, and a screen display. In addition, an LED has a good time response characteristic, and a signal can be sent out by using a high-speed bright-dark flicker that cannot be observed through naked eyes. In this way, the LED has a potential to serve as a signal transmitter in an optical communications system. Therefore, a visible light communication (Visible Light Communication, VLC) technology is becoming a topic of increasing concern in the lighting industry and the communications industry.

Generally, for one LED optical signal, a photodiode (photodiode, PD) may serve as a photodetector, and for a plurality of LED optical signals, an image sensor (Image Sensor, IS) including a PD array may serve as a photoelectric receiver. Currently, modules such as LED light sources and cameras are built in devices such as mobile phones and cars. Although these light sources and these cameras are used only for lighting and video shooting, the light sources and the cameras lay a hardware foundation for actual application of an IS-based VLC system. Optical camera communication (Optical Camera Communication, OCC) between an LED light source and an optical camera can be implemented only by simply reconstructing the light source and the camera. Undersampled pulse width modulation (Undersampled Pulse Width Modulation, UPWM) is a camera communications technology that can implement zero flicker, and can achieve comparatively high spectral utilization. However, in an existing OCC system based on UPWM, only camera communication for a single light source is specified, but a communication method for a plurality of light sources is not specified. Therefore, for a multi-light source scenario, how to simultaneously perform transmission by using the plurality of light sources and increase transmission efficiency is a problem that urgently needs to be resolved.

SUMMARY

Embodiments of this application provide a communication method and an apparatus, to resolve a problem of how to simultaneously perform transmission by using a plurality of light sources and increase transmission efficiency in a multi-light source scenario in an optical camera communications system.

To achieve the foregoing objectives, the following technical solutions are used in the embodiments of this application.

According to a first aspect of the embodiments of this application, a communication method is provided. The method is applied to a sending node, the sending node includes N light sources, and the method includes: generating N physical frames, where each of the physical frames includes a preamble, a mode indication, and valid data, the mode indication is used to indicate a sending mode of the N light sources, the sending mode is a diversity mode or a multiplexing mode, and N is a positive integer greater than or equal to 2; sending the N physical frames by using the N light sources, where one light source sends one physical frame. According to the communication method provided in the embodiments of this application, the mode indication is added to a frame structure of the physical frame, and the mode indication is used to indicate the sending mode of the N light sources, that is, a sending mode in which original data is sent by using the N light sources. In this way, transmission is simultaneously performed by using the N light sources and transmission efficiency is increased. Further, a receiving node parses the received physical frames based on the mode indication to obtain the original data.

It should be noted that a light source may be an LED or a laser diode (Laser Diode, LD). In the diversity mode, valid data sent by using all of the N light sources is the same.

With reference to the first aspect, in a possible implementation, if the sending mode that is of the N light sources and that is indicated by the mode indication is the multiplexing mode, each of the physical frames further includes a port indication. In this way, the receiving node parses the received physical frame based on the mode indication and the port indication, to obtain the original data. The port indication is used to indicate information about the N light sources used to send the valid data.

According to a second aspect of the embodiments of this application, a communication method is provided. The method is applied to a receiving node and includes: receiving P physical frames sent by using P light sources, where each of the physical frames includes a preamble, a mode indication, and valid data, the mode indication is used to indicate a sending mode of N light sources of a sending node, the sending mode is a diversity mode or a multiplexing mode, N is a positive integer greater than or equal to 2, and P is less than or equal to N; determining the sending mode of the N light sources of the sending node based on the mode indication; and if the sending mode that is of the N light sources and that is indicated by the mode indication is the diversity mode, obtaining, based on valid data of one or L physical frames in the P physical frames, original data sent by the sending node by using the N light sources, where L is less than or equal to P. According to the communication method provided in the embodiments of this application, the mode indication is added to a frame structure of the physical frame, and the mode indication is used to indicate the sending mode of the N light sources, that is, a sending mode in which the original data is sent by using the N light sources. In this way, transmission is simultaneously performed by using the N light sources and transmission efficiency is increased. Further, the receiving node parses the received physical frames based on the mode indication to obtain the original data.

With reference to the second aspect, in a possible implementation, if the sending mode that is of the N light sources and that is indicated by the mode indication is the multiplexing mode, each of the physical frames further includes a port indication, and the method further includes: determining whether P is equal to N; and if P is equal to N, parsing valid data of the P physical frames based on port indications of the P physical frames, to obtain the original data sent by the sending node by using the N light sources. In this way, the receiving node parses the received physical frames based on the mode indication and the port indication, to obtain the original data.

According to a third aspect of the embodiments of this application, a sending node is provided. The sending node includes N light sources and includes: a processing unit, configured to generate N physical frames, where each of the physical frames includes a preamble, a mode indication, and valid data, the mode indication is used to indicate a sending mode of the N light sources, the sending mode is a diversity mode or a multiplexing mode, and N is a positive integer greater than or equal to 2; and a sending unit, configured to send the N physical frames by using the N light sources, where one light source sends one physical frame.

With reference to the third aspect, in a possible implementation, if the sending mode that is of the N light sources and that is indicated by the mode indication is the multiplexing mode, each of the physical frames further includes a port indication.

According to a fourth aspect of the embodiments of this application, a receiving node is provided and includes: a receiving unit, configured to receive P physical frames sent by using P light sources, where each of the physical frames includes a preamble, a mode indication, and valid data, the mode indication is used to indicate a sending mode of N light sources of a sending node, the sending mode is a diversity mode or a multiplexing mode, N is a positive integer greater than or equal to 2, and P is less than or equal to N; and a processing unit, configured to determine the sending mode of the N light sources of the sending node based on the mode indication; where the processing unit is further configured to: if the sending mode that is of the N light sources and that is indicated by the mode indication is the diversity mode, obtain, based on valid data of one or L physical frames in the P physical frames, original data sent by the sending node by using the N light sources, where L is less than or equal to P.

With reference to the fourth aspect, in a possible implementation, if the sending mode that is of the N light sources and that is indicated by the mode indication is the multiplexing mode, each of the physical frames further includes a port indication; the processing unit is further configured to determine whether P is equal to N; and the processing unit is further configured to: if P is equal to N, parse valid data of the P physical frames based on port indications of the P physical frames, to obtain the original data sent by the sending node by using the N light sources.

With reference to the foregoing possible implementations, in another possible implementation, the preamble of each of the physical frames includes a symbol 0 to a symbol m+1, a duty cycle corresponding to the symbol 0 is a first duty cycle, a duty cycle corresponding to the symbol m+1 is a second duty cycle, duty cycles corresponding to m symbols from a symbol 1 to a symbol m one-to-one correspond to all m duty cycles used for m-order UPWM, and m is a modulation order used for the valid data included in the physical frame. It should be noted that, before the sending mode of the N light sources of the sending node is determined based on the mode indication, synchronization, phase error correction, and nonlinear compensation need to be performed on the received physical frame based on the preamble.

With reference to the foregoing possible implementations, in another possible implementation, the preamble of each of the physical frames includes a symbol 0, a symbol m+1, and one of T preamble blocks, a duty cycle corresponding to the symbol 0 is a first duty cycle, a duty cycle corresponding to the symbol m+1 is a second duty cycle, T is a quantity of groups of the N light sources, each of the T preamble blocks includes K symbols, duty cycles corresponding to the K symbols are some of all m duty cycles used for m-order UPWM, and duty cycles corresponding to K×T symbols included in the T preamble blocks include the m duty cycles, where T is a positive integer greater than or equal to 2, and K is an integer greater than or equal to 1 and less than or equal to m.

With reference to the foregoing possible implementations, in another possible implementation, before synchronization, phase error correction, and nonlinear compensation are performed on the received physical frame based on the preamble, preamble blocks included in all of the physical frames are combined to constitute the preamble.

With reference to the foregoing possible implementations, in another possible implementation, the mode indication of each of the physical frames includes a first symbol, if the sending mode that is of the N light sources and that is indicated by the mode indication is the diversity mode, a duty cycle corresponding to the first symbol is a third duty cycle, and if the sending mode that is of the N light sources and that is indicated by the mode indication is the multiplexing mode, the duty cycle corresponding to the first symbol is a fourth duty cycle.

With reference to the foregoing possible implementations, in another possible implementation, the mode indication of each of the physical frames includes a second symbol and a third symbol, second symbols of all of the physical frames correspond to a same duty cycle, and third symbols of all of the physical frames correspond to a same duty cycle; and if the sending mode that is of the N light sources and that is indicated by the mode indication is the diversity mode, the second symbol and the third symbol of each of the physical frames correspond to different duty cycles, and if the sending mode that is of the N light sources and that is indicated by the mode indication is the multiplexing mode, the second symbol and the third symbol of each of the physical frames correspond to a same duty cycle; or if the sending mode that is of the N light sources and that is indicated by the mode indication is the diversity mode, the second symbol and the third symbol of each of the physical frames correspond to a same duty cycle, and if the sending mode that is of the N light sources and that is indicated by the mode indication is the multiplexing mode, the second symbol and the third symbol of each of the physical frames correspond to different duty cycles.

With reference to the foregoing possible implementations, in another possible implementation, if the sending mode that is of the N light sources and that is indicated by the mode indication is the diversity mode, the valid data included in each of the physical frames includes to-be-sent original data, and if the sending mode that is of the N light sources and that is indicated by the mode indication is the multiplexing mode, the valid data included in each of the physical frames includes one data block, and the data block includes one Nth of the to-be-sent original data.

With reference to the foregoing possible implementations, in another possible implementation, the port indication includes a light source sum field and a first light source sequence number field, the light source sum field is used to indicate a quantity N of light sources used by the sending node to send the N physical frames, and the first light source sequence number field is used to indicate a sequence number of a light source used to send a current physical frame; the port indication includes a light source sum field, a first light source sequence number field, and a first check bit field; the port indication includes a first light source sequence number field and an Nthlight source indication field, and the Nthlight source indication field is used to indicate whether a light source indicated by the first light source sequence number field is an Nthlight source; the port indication includes a first light source sequence number field, an Nthlight source indication field, and a first check bit field; the port indication includes an extended indication field, an Nthlight source indication field, a second light source sequence number field, and a second check bit field; the port indication includes an extended indication field, an Nthlight source indication field, a second light source sequence number field, a second check bit field, a third light source sequence number field, and a third check bit field; the port indication includes Q symbols, the Q symbols are used to indicate a total quantity of light sources and a light source sequence number, the total quantity of light sources indicates a quantity N of light sources used by the sending node to send the N physical frames, and the light source sequence number indicates a sequence number of a light source used to send a current physical frame; or the port indication includes Q symbols, Q−1 symbols in the Q symbols are used to indicate the light source sequence number, and a symbol other than the Q−1 symbols in the Q symbols is used to indicate whether a light source indicated by the light source sequence number is an Nthlight source.

According to a fifth aspect of the embodiments of this application, a communication method is provided. The method is applied to a sending node, the sending node includes N light sources, and the method includes: generating N physical frames, where each of the physical frames includes a preamble and valid data, and N is a positive integer greater than or equal to 2; sending the N physical frames by using the N light sources, where one light source sends one physical frame; where the preamble includes a symbol 0 to a symbol m+1, a duty cycle corresponding to the symbol 0 is a first duty cycle, a duty cycle corresponding to the symbol m+1 is a second duty cycle, duty cycles corresponding to m symbols from a symbol 1 to a symbol m one-to-one correspond to all m duty cycles used for m-order UPWM, m is a modulation order used for the valid data included in the physical frame, different sequences of the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate sending modes of the N light sources of the sending node, or different sequences of X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate sending modes, and the sending mode is a diversity mode or a multiplexing mode. According to the communication method provided in the embodiments of this application, the preamble is used to indicate the sending mode of the N light sources, that is, a sending mode in which original data is sent by using the N light sources. In this way, transmission is simultaneously performed by using the N light sources and transmission efficiency is increased. Further, a receiving node parses the received physical frames based on the preamble to obtain the original data.

With reference to the fifth aspect, in a possible implementation, if the sending mode indicated by the different sequences of the symbols from the symbol 1 to the symbol m included in the preamble is the multiplexing mode, each of the physical frames further includes a first port indication; or if the sending mode indicated by the different sequences of the X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble is the multiplexing mode, and when X2 symbols other than the X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble of each of the physical frames are used to indicate a light source sequence number, each of the physical frames further includes a second port indication, where X1+X2≤m, or X3 symbols other than the X1 symbols and the X2 symbols in the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate a total quantity of light sources, where X1+X2+X3≤m. The light source sequence number indicates a sequence number of a light source used to send a current physical frame, and the total quantity of light sources indicates a quantity N of light sources used by the sending node to send the N physical frames.

According to a sixth aspect of the embodiments of this application, a communication method is provided. The method is applied to a receiving node and includes: receiving P physical frames sent by using P light sources, where each of the physical frames includes a preamble and valid data, the preamble includes a symbol 0 to a symbol m+1, a duty cycle corresponding to the symbol 0 is a first duty cycle a duty cycle corresponding to the symbol m+1 is a second duty cycle, duty cycles corresponding to m symbols from a symbol 1 to a symbol m one-to-one correspond to all m duty cycles used for m-order UPWM, m is a modulation order used for the valid data included in the physical frame, different sequences of the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate sending modes of N light sources of a sending node, or different sequences of X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate sending modes, and the sending mode is a diversity mode or a multiplexing mode, where N is a positive integer greater than or equal to 2, and P is less than or equal to N; determining the sending mode of the N light sources of the sending node based on the preamble; and if the sending mode indicated by the preamble is the diversity mode, obtaining, based on valid data of one or L physical frames in the P physical frames, original data sent by the sending node by using the N light sources, where L is less than or equal to P. According to the communication method provided in the embodiments of this application, the preamble is used to indicate the sending mode of the N light sources, that is, a sending mode in which the original data is sent by using the N light sources. In this way, transmission is simultaneously performed by using the N light sources and transmission efficiency is increased. Further, the receiving node parses the received physical frames based on the preamble to obtain the original data.

With reference to the sixth aspect, in a possible implementation, if the sending mode indicated by the different sequences of the symbols from the symbol 1 to the symbol m included in the preamble is the multiplexing mode, each of the physical frames further includes a first port indication; or if the sending mode indicated by the different sequences of the X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble is the multiplexing mode, and when X2 symbols other than the X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble of each of the physical frames are used to indicate a light source sequence number, each of the physical frames further includes a second port indication, where X1+X2≤m, or X3 symbols other than the X1 symbols and the X2 symbols in the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate a total quantity of light sources, where X1+X2+X3≤m. The light source sequence number indicates a sequence number of a light source used to send a current physical frame, and the total quantity of light sources indicates a quantity N of light sources used by the sending node to send N physical frames. The method further includes: determining whether P is equal to N; and if P is equal to N, parsing valid data of the P physical frames based on preambles and/or port indications of the P physical frames, to obtain the original data sent by the sending node by using the N light sources, where the port indication includes the first port indication or the second port indication. In this way, the receiving node parses the received physical frames based on the preamble and the port indication, to obtain the original data.

According to a seventh aspect of the embodiments of this application, a sending node is provided. The sending node includes N light sources and includes: a processing unit, configured to generate N physical frames, where each of the physical frames includes a preamble and valid data, and N is a positive integer greater than or equal to 2; and a sending unit, configured to send the N physical frames by using the N light sources, where one light source sends one physical frame. The preamble includes a symbol 0 to a symbol m+1, a duty cycle corresponding to the symbol 0 is a first duty cycle, a duty cycle corresponding to the symbol m+1 is a second duty cycle, duty cycles corresponding to m symbols from a symbol 1 to a symbol m one-to-one correspond to all m duty cycles used for m-order UPWM, m is a modulation order used for the valid data included in the physical frame, different sequences of the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate sending modes of the N light sources of the sending node, or different sequences of X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate sending modes, and the sending mode is a diversity mode or a multiplexing mode.

With reference to the seventh aspect, in a possible implementation, if the sending mode indicated by the different sequences of the symbols from the symbol 1 to the symbol m included in the preamble is the multiplexing mode, each of the physical frames further includes a first port indication; or if the sending mode indicated by the different sequences of the X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble is the multiplexing mode, and when X2 symbols other than the X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble of each of the physical frames are used to indicate a light source sequence number, each of the physical frames further includes a second port indication, where X1+X2≤m, or X3 symbols other than the X1 symbols and the X2 symbols in the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate a total quantity of light sources, where X1+X2+X3≤m. The light source sequence number indicates a sequence number of a light source used to send a current physical frame, and the total quantity of light sources indicates a quantity N of light sources used by the sending node to send the N physical frames.

According to an eighth aspect of the embodiments of this application, a receiving node is provided and includes: a receiving unit, configured to receive P physical frames sent by using P light sources, where each of the physical frames includes a preamble and valid data, the preamble includes a symbol 0 to a symbol m+1, a duty cycle corresponding to the symbol 0 is a first duty cycle, a duty cycle corresponding to the symbol m+1 is a second duty cycle, duty cycles corresponding to m symbols from a symbol 1 to a symbol m one-to-one correspond to all m duty cycles used for m-order UPWM, m is a modulation order used for the valid data included in the physical frame, different sequences of the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate sending modes of N light sources of a sending node, or different sequences of X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate sending modes, and the sending mode is a diversity mode or a multiplexing mode, where N is a positive integer greater than or equal to 2, and P is less than or equal to N; and a processing unit, configured to determine the sending mode of the N light sources of the sending node based on the preamble; where the processing unit is further configured to: if the sending mode indicated by the preamble is the diversity mode, obtain, based on valid data of one or L physical frames in the P physical frames, original data sent by the sending node by using the N light sources, where L is less than or equal to P.

With reference to the eighth aspect, in a possible implementation, if the sending mode indicated by the different sequences of the symbols from the symbol 1 to the symbol m included in the preamble is the multiplexing mode, each of the physical frames further includes a first port indication; or if the sending mode indicated by the different sequences of the X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble is the multiplexing mode, and when X2 symbols other than the X1 symbols in the symbols from the symbol 1 to the symbol m included in the preamble of each of the physical frames are used to indicate a light source sequence number, each of the physical frames further includes a second port indication, where X1+X2≤m, or X3 symbols other than the X1 symbols and the X2 symbols in the symbols from the symbol 1 to the symbol m included in the preamble are used to indicate a total quantity of light sources, where X1+X2+X3≤m. The light source sequence number indicates a sequence number of a light source used to send a current physical frame, and the total quantity of light sources indicates a quantity N of light sources used by the sending node to send N physical frames. The processing unit is further configured to determine whether P is equal to N; and the processing unit is further configured to: if P is equal to N, parse valid data of the P physical frames based on preambles and/or port indications of the P physical frames, to obtain the original data sent by the sending node by using the N light sources, where the port indication includes the first port indication or the second port indication.

With reference to the foregoing possible implementations, in another possible implementation, when the symbols from the symbol 1 to the symbol in are sorted in descending order, the sending mode is the diversity mode, and when the symbols from the symbol 1 to the symbol m are sorted in ascending order, the sending mode is the multiplexing mode; or when the symbols from the symbol 1 to the symbol m are sorted in ascending order, the sending mode is the diversity mode, and when the symbols from the symbol 1 to the symbol n are sorted in descending order, the sending mode is the multiplexing mode.

With reference to the foregoing possible implementations, in another possible implementation, the first port indication includes a light source sum field and a first light source sequence number field, the light source sum field is used to indicate a quantity N of light sources used by the sending node to send the N physical frames, and the first light source sequence number field is used to indicate a sequence number of a light source used to send a current physical frame; the first port indication includes a light source sum field, a first light source sequence number field, and a first check bit field; the first port indication includes a first light source sequence number field and an Nthlight source indication field, and the Nthlight source indication field is used to indicate whether a light source indicated by the first light source sequence number field is an Nthlight source; the first port indication includes a first light source sequence number field, an Nthlight source indication field, and a first check bit field; the first port indication includes an extended indication field, an Nthlight source indication field, a second light source sequence number field, and a second check bit field; the first port indication includes an extended indication field, an Nthlight source indication field, a second light source sequence number field, a second check bit field, a third light source sequence number field, and a third check bit field; the first port indication includes Q symbols, the Q symbols are used to indicate the total quantity of light sources and the light source sequence number, the total quantity of light sources indicates a quantity N of light sources used by the sending node to send the N physical frames, and the light source sequence number indicates a sequence number of a light source used to send a current physical frame; or the first port indication includes Q symbols, Q−1 symbols in the Q symbols are used to indicate the light source sequence number, and a symbol other than the Q−1 symbols in the Q symbols is used to indicate whether a light source indicated by the light source sequence number is an Nthlight source.

With reference to the foregoing possible implementations, in another possible implementation, the second port indication includes a light source sum field, and the light source sum field is used to indicate a quantity N of light sources used by the sending node to send the N physical frames; or the second port indication includes a light source sum field and a fourth check bit field; or the second port indication includes R symbols, and the R symbols are used to indicate the total quantity of light sources or indicate whether a light source indicated by the light source sequence number is an Nthlight source.

It should be noted that the functional modules in the third aspect, the fourth aspect, the seventh aspect, and the eighth aspect may be implemented by hardware, or may be implemented by hardware by executing corresponding software. The hardware or software includes one or more modules corresponding to the foregoing functions. For example, a transceiver is configured to complete functions of the receiving unit and the sending unit, a processor is configured to complete functions of the processing unit, and a memory is configured to store a program instruction of the communication method in the embodiments of this application. The processor, the transceiver, and the memory are connected and communicate with each other by using a bus. For details, refer to functions of behaviors of the sending node in the communication methods provided in the first aspect and the fifth aspect, and functions of behaviors of the receiving node in the communication methods provided in the second aspect and the sixth aspect.

According to a ninth aspect of the embodiments of this application, a sending node is provided and includes a processor, a memory, a bus, and a communications interface. The memory is configured to store a computer executable instruction. The processor and the memory are connected by using the bus. When the processor executes the computer execution instruction stored in the memory, the sending node is enabled to perform the method according to any one of the foregoing aspects, the processor executes the computer executable instruction stored in the memory, so that the sending node performs the method according to any one of the foregoing aspects.

According to a tenth aspect of the embodiments of this application, a receiving node is provided and includes a processor, a memory, a bus, and a communications interface. The memory is configured to store a computer executable instruction. The processor and the memory are connected by using the bus. When the processor executes the computer execution instruction stored in the memory, the sending node is enabled to perform the method according to any one of the foregoing aspects, the processor executes the computer executable instruction stored in the memory, so that the receiving node performs the method according to any one of the foregoing aspects.

According to an eleventh aspect of the embodiments of this application, a computer-readable storage medium is provided and includes a computer software instruction. When the computer software instruction is run on a sending node or a chip built in a sending node, the sending node is enabled to perform the foregoing communication method.

According to a twelfth aspect of the embodiments of this application, a computer-readable storage medium is provided and includes a computer software instruction. When the computer software instruction is run on a receiving node or a chip built in a receiving node, the receiving node is enabled to perform the foregoing communication method.

According to a thirteenth aspect of the embodiments of this application, a computer program product including an instruction is provided. When the computer program product is run on a sending node or a chip built in a sending node, the sending node is enabled to perform the foregoing communication method.

According to a fourteenth aspect of the embodiments of this application, a computer program product including an instruction is provided. When the computer program product is run on a receiving node or a chip built in a receiving node, the receiving node is enabled to perform the foregoing communication method.

In addition, for technical effects brought by the designs of any one of the foregoing aspects, refer to technical effects brought by different designs of the first aspect and the fifth aspect. Details are not described herein.

In the embodiments of this application, names of the sending node and the receiving node constitute no limitation on devices. During actual implementation, these devices may have other names, provided that functions of each device are similar to those in the embodiments of this application and fall within the scope of the claims of this application and their equivalent technologies.

