CN115412498A

CN115412498A - Communication method and device

Info

Publication number: CN115412498A
Application number: CN202110523511.1A
Authority: CN
Inventors: 朱元萍; 史玉龙; 刘菁; 曹振臻
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-05-11
Filing date: 2021-05-13
Publication date: 2022-11-29

Abstract

The application provides a communication method, which comprises the following steps: the method comprises the steps that a first node receives first information from a second node, wherein the first information comprises the size of available space in a first cache space of the second node, the first cache space is used for caching data packets needing to be transmitted through a first path, the first path is a main path used for transmitting the data packets, and the second node is a next hop node of the first node on the main path; if the size of the available space in the first cache space is smaller than or equal to a first threshold value, the first node determines that a data packet needing to be transmitted through the first path is transmitted through a third node, and the third node is a next hop node of the first node on a standby path for transmitting the data packet. Therefore, the congestion of the second node is relieved, the average transmission time delay of the data packet is reduced, and the user experience is improved.

Description

Communication method and device

The present application claims priority of chinese patent application having application number 202110512937.7 entitled "communication method and apparatus" filed by the chinese patent office on 11/5/2021, which is incorporated herein by reference in its entirety.

Technical Field

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

Background

Currently, in consideration of introduction of an Integrated Access and Backhaul (IAB) node, a multi-hop wireless link is introduced into a wireless air interface. In order to enable the parent node to acquire the congestion status of the child link, a downstream hop-by-hop flow control feedback (flow control feedback) is introduced into the IAB topic of R16, that is, the IAB node may perform flow control feedback to its parent node, and the flow control feedback may reflect the buffer state of the link between the IAB node and its child node.

However, after the parent node receives the flow control feedback information sent by the child node, if it is known that the link of the child node is congested, the sending of downlink data is slowed down, which may cause data packets to be accumulated at the parent node, and still have a risk of overflowing the buffered data packets. If the link congestion cannot be relieved in a short time, the data packet is cached in the wireless return link for a long time and cannot be sent, and finally, the delay of the data packet is too large, and the user experience is influenced.

Therefore, how to control the transmission of the data packet becomes a technical problem to be solved at present.

Disclosure of Invention

The application provides a communication method and device, which can reduce transmission delay of a data packet and improve user experience by rerouting the data packet.

A first aspect provides a method of communication, the method comprising: the method comprises the steps that a first node receives first information from a second node, wherein the first information comprises the size of available space in a first cache space of the second node, the first cache space is used for caching data packets needing to be transmitted through a first path, the first path is a main path used for transmitting the data packets, and the second node is a next-hop node of the first node on the main path; if the size of the available space in the first cache space is smaller than or equal to a first threshold value, the first node determines that a data packet needing to be transmitted through the first path is transmitted through a third node, and the third node is a next hop node of the first node on a standby path for transmitting the data packet.

Based on the technical method, the first node can perform rerouting on the data packet based on the received flow control feedback information of the path identifier granularity under the condition that the link is congested, so that the link congestion can be relieved, the average transmission delay of the data packet can be reduced, and the user experience is improved.

In this application, the first cache space may be a certain storage space of the second node. The size of the available space of the first buffer space may refer to the maximum amount of data sent by the originating.

In the application, when the size of the available space is equal to the threshold, the judgment result of the first node can be flexibly determined without limitation.

In this application, in order to ensure normal transmission of data between a terminal and an IAB host, the IAB host needs to configure a routing table for each IAB node, that is: and configuring next hop nodes corresponding to different paths. Meanwhile, the IAB host needs to determine a transmission path corresponding to data transmission. That is, before data transmission, a transmission path is determined, which may be referred to as a primary path, through which data is routed (routed) between the terminal and the IAB host, and other paths may be regarded as backup (backup) paths.

In this application, the next hop node of the first node may be a child node or a parent node, which is not limited in this application.

With reference to the first aspect, in certain implementations of the first aspect, if the size of the available space in the first buffer space is greater than the first threshold, the first node determines to transmit, through the second node, a data packet that needs to be transmitted through a first path.

Based on the above technical solution, if the first node determines that the cache state of the second node can send the data packet on the first path, it may be determined that the second node is the next hop node. Therefore, timely transmission of the data packets can be guaranteed, transmission realization of the data packets is reduced, and business experience is guaranteed.

With reference to the first aspect, in certain implementations of the first aspect, the receiving, by the first node, first information from a second node includes: the first node receives N pieces of first information from the second node within a first time length, wherein the N pieces of first information comprise the size of available space in N first cache spaces; and if X of the sizes of the available spaces in the N first cache spaces are smaller than or equal to the first threshold, the first node determines to transmit a data packet which needs to be transmitted through a first path through the third node, wherein N is an integer larger than 1, and X is smaller than or equal to N.

Based on the technical scheme, the first node can judge the cache state of the second node within a period of time, and can further ensure the accuracy of judging the congestion of the second node, thereby ensuring that the data packet can be transmitted successfully and timely.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: the first node receives second information from the second node, wherein the second information comprises the size of available space in a second cache space of the second node, the second cache space is used for caching data packets of a first wireless link control channel needing to be mapped on a first link, and the first link is a link between the first node and the second node; and the first node determines to transmit the data packet which needs to be transmitted through the first path through the third node according to the size of the available space in the first cache space and the size of the available space in the second cache space.

Based on the technical scheme, the first node can judge the congestion condition of the second node based on the flow control feedback information with two granularities, and can further ensure the accuracy of judging the congestion of the second node, thereby ensuring the successful and timely transmission of data packets.

With reference to the first aspect, in some implementation manners of the first aspect, the determining, by the first node, that a data packet needs to be transmitted through the first path by using the third node according to the size of the available space in the first cache space and the size of the available space in the second cache space includes: and if the size of the available space in the first cache space is smaller than or equal to a first threshold value and/or the size of the available space in the second cache space is smaller than or equal to a second threshold value, the first node determines to transmit the data packet needing to be transmitted through the first path through a third node.

In this application, the first threshold may be equal to the second threshold, and the first threshold may not be equal to the second threshold.

Based on the technical scheme, the host node can flexibly configure the threshold value according to the actual situation.

With reference to the first aspect, in certain implementation manners of the first aspect, the determining, by the first node, that a data packet needs to be transmitted through a first path through a third node according to a size of an available space in the first cache space and a size of an available space in the second cache space includes: if the size of the available space in the first cache space received by the first node within the first time period is smaller than or equal to a first threshold, and/or the size of the available space in the second cache space received by the first node within the second time period is smaller than or equal to a first threshold, the first node determines to transmit a data packet which needs to be transmitted through a first path through a third node.

In this application, the first duration may be equal to the second duration, and the first duration may not be equal to the second duration.

With reference to the first aspect, in some implementations of the first aspect, if the size of the available space in the first cache space is smaller than or equal to a first threshold, the determining, by the first node, that a data packet that needs to be transmitted through the first path is transmitted through a third node includes: if the first node determines that the data packet which needs to be transmitted through the first path and has the data volume equal to the size of the available space in the first cache space is sent to the second node within a third time period before the first information is received, the first node determines that the data packet which needs to be transmitted through the first path is transmitted through a third node; or, if the first node determines that the data packet required to be transmitted through the first path is transmitted to the second node within a fourth time period after the first node receives the first information, where the size of the data packet is equal to the size of the available space in the first cache space, the first node determines to transmit the data packet required to be transmitted through the first path through the third node.

It should be noted that, in this application, "if the first node determines that the first node sends the packet whose data size is equal to the size of the available space in the first cache space and needs to be transmitted through the first path to the second node within the third time period before receiving the first information," the first node determines that the packet needs to be transmitted through the first path is transmitted through the third node, "may be understood that the first node determines that the second node sends the packet whose data size is equal to the size of the available space in the first cache space and needs to be transmitted through the first path to the second node within the third time period before receiving the first information," where the second type of packet is a packet that the first node needs to be transmitted through the first path. Similarly, the solution for the fourth time period can be understood as such.

In this application, the second type of data packet is a data packet that the first node needs to transmit through the first path. That is, when the second node has sent the second type packet whose data amount is the size of the available space in the first buffer space within a certain time period before receiving the first information, the first node may also determine that the second node is unavailable, and determine to transmit the packet through the third node. Or, when the second node has sent the second type packet whose data amount is the size of the available space in the first cache space within a certain time period after receiving the first information, the first node may also determine that the second node is unavailable, and determine to transmit the packet through the third node. In other words, if the first node determines that a packet of the second type whose data amount is equal to the available space size in the first buffer space size has been transmitted, the first node may also determine that the second node is not used and the packet can be transmitted by the third node.

Based on the technical scheme, the first node can timely judge the congestion condition of the second node, so that the data packet can be timely transmitted, the transmission realization of the data packet is reduced, and the service experience is guaranteed.

With reference to the first aspect, in some implementations of the first aspect, if the size of the available space in the first cache space is smaller than or equal to a first threshold, the determining, by the first node, that a data packet that needs to be transmitted through the first path is transmitted through a third node includes: and if the size of the available space in the first cache space is smaller than or equal to a first threshold value, and the first node determines that the third node can be used for transmitting the data packet needing to be transmitted through the first path, the first node determines to transmit the data packet needing to be transmitted through the first path through the third node.

Based on the technical scheme, when the first node determines that the second node is unavailable, the availability of the backup link can also be determined. Therefore, the congestion of the second node is relieved, the data packet can be timely transmitted from the standby link, the time delay of the data packet is reduced, and the service experience is guaranteed.

With reference to the first aspect, in some implementations of the first aspect, the determining, by the first node, that the third node is available for transmitting the data packet that needs to be transmitted through the first path includes: the first node receives third information from the third node, wherein the third information comprises the size of available space in at least one cache space of the third node, the at least one cache space corresponds to the at least one standby path in a one-to-one manner, and the at least one standby path is the same as a destination node of the first path; if the sum of the sizes of the available spaces in the at least one cache space is larger than a third threshold value, the first node determines that the third node can be used for transmitting the data packet needing to be transmitted through the first path.

In the present application, there may be multiple backup paths for packets that need to be rerouted.

Based on the technical scheme, the first node can judge whether the standby link is available or not through the path identifier granularity, so that the successful rerouting of the data packet is realized.

With reference to the first aspect, in some implementations of the first aspect, the determining, by the first node, that the third node is available for transmitting the data packet that needs to be transmitted through the first path includes: the first node receives fourth information from a third node, where the fourth information includes a size of an available space in a fourth cache space of the third node, the fourth cache space is used for caching a data packet of a first radio link control channel that needs to be mapped on a second link, and the second link is a link between the first node and the third node; if the size of the available space in the fourth buffer space is larger than a fourth threshold, the first node determines that the third node can be used for transmitting the data packet needing to be transmitted through the first path.

With reference to the first aspect, in certain implementations of the first aspect, the determining, by the first node, that the third node is available to transmit the data packet includes: the first node receives fourth information from a third node, where the fourth information includes a size of an available space in at least one cache space of the third node, the at least one cache space is used to cache a data packet that needs to be mapped to at least one radio link control channel on a second link, the at least one cache space corresponds to the at least one radio link control channel one to one, and the second link is a link between the first node and the third node; if the sum of the sizes of the available spaces in the at least one cache space is larger than a fourth threshold value, the first node determines that the third node can be used for transmitting the data packet needing to be transmitted through the first path.

Based on the technical scheme, the first node can judge whether the standby link is available or not through the granularity of the wireless link control channel, so that the successful rerouting of the data packet can be realized.

With reference to the first aspect, in certain implementations of the first aspect, the first node receives fifth information from the second node, where the fifth information includes a size of an available space in a first cache space of the second node, and if the size of the available space in the first cache space is greater than a fifth threshold, the first node determines that the second node is available to transmit a data packet that needs to be transmitted through the first path.

With reference to the first aspect, in certain implementations of the first aspect, the receiving, by the first node, fifth information from a second node includes: the first node receives Y pieces of fifth information from the second node within a fifth time length, wherein the Y pieces of fifth information comprise the size of available space in Y pieces of first cache space; and if the sizes of the available spaces in the Y first cache spaces are all larger than a fifth threshold value, the first node determines that the second node can be used for transmitting the data packet needing to be transmitted through the first path. Wherein Y is an integer greater than 1.

Based on the technical scheme, if the first node determines that the congestion of the main link is relieved, the data packet does not need to be rerouted, so that the influence on the long-term occupation of the backup link can be reduced.

With reference to the first aspect, in certain implementations of the first aspect, the first threshold is configured by a donor node of the first node, or the first threshold is indicated by indication information by the donor node of the first node, or the first threshold is preconfigured to the first node; the first time length is configured by the host node of the first node, or the first time length is indicated by the host node of the first node through indication information, or the first time length is preconfigured to the first node.

It should be understood that, in the present application, the first threshold to the fifth threshold may be configured according to the above technical solution; similarly, the first time period to the fifth time period may also be configured according to the above technical solutions.

Based on the technical scheme, the threshold value in the application can be flexibly configured according to the actual situation.

In a second aspect, a communication method is provided, the method comprising: a first node receives second information from a second node, wherein the second information comprises the size of available space in a second cache space of the second node, the second cache space is used for caching a data packet of a first radio link control channel needing to be mapped on a first link, and the first link is a link between the first node and the second node; if the size of the available space in the second cache space is smaller than or equal to a second threshold, the first node determines to transmit a first data packet through the third node, where the first data packet is a data packet of a first radio link control channel that needs to be mapped on the first link, a main path of the first data packet is a first path, the second node is a next hop node of the first node on the first path, the third node is a next hop node of the first node on a second path for transmitting the first data packet, the second path is a standby path of the first data packet, a link between the first node and the third node is a second link, and the first path and the second path have the same destination node.

Based on the above technical solution, based on the technical method, the first node may perform rerouting on the data packet based on the received flow control feedback information of the radio link control channel granularity, when the link encounters congestion, so that, on one hand, congestion of the link may be alleviated, on the other hand, an average transmission delay of the data packet may be reduced, and user experience may be improved.

With reference to the second aspect, in certain implementations of the second aspect, the first node determines to transmit the first packet through the second node if the size of the available space in the second cache space is greater than the second threshold.

With reference to the second aspect, in certain implementations of the second aspect, the receiving, by the first node, second information from a second node includes: the first node receives K pieces of second information from a second node within a second time length, wherein the K pieces of second information comprise the size of available space in K second cache spaces; and if L of the sizes of the available spaces in the K second cache spaces are smaller than or equal to the second threshold, the first node determines to transmit the first data packet through the third node, wherein K is an integer larger than 1, and L is smaller than or equal to K.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the first node receives first information from the second node, wherein the first information comprises the size of available space in a first cache space of the second node, and the first cache space is used for caching data packets needing to be transmitted through a first path; and the first node determines to transmit the first data packet through the third node according to the size of the available space in the second cache space and the size of the available space in the first cache space, wherein the third node is a next hop node of the first node on a standby path for transmitting the first data packet.

With reference to the second aspect, in some implementations of the second aspect, the determining, by the first node, that the first data packet is transmitted through the third node according to the size of the available space in the second cache space and the size of the available space in the first cache space includes: and if the size of the available space in the second cache space is smaller than or equal to a second threshold value and/or the size of the available space in the first cache space is smaller than or equal to a first threshold value, the first node determines to transmit the first data packet through the third node.

With reference to the second aspect, in some implementations of the second aspect, the determining, by the first node, to transmit the first packet through the third node according to the size of the available space in the second cache space and the size of the available space in the first cache space includes: and if the size of the available space in the second cache space received by the first node within the second time period is smaller than or equal to a second threshold value, and/or the size of the available space in the first cache space received by the first node within the first time period is smaller than or equal to a first threshold value, the first node determines to transmit the first data packet through the third node.

With reference to the second aspect, in some implementations of the second aspect, if the size of the available space in the second cache space is less than or equal to a second threshold, the determining, by the first node, that the first packet is transmitted by a third node includes: if the first node determines that the first type data packet with the data volume equal to the size of the available space in the second cache space is sent to the second node within a third time period before the second information is received, wherein the first type data packet is a data packet which is sent to the first node by the first node on a first wireless link control channel mapped on a first link, and the first node determines to transmit the first data packet through the third node; or, if the first node determines that the first type packet with the data volume size equal to the size of the available space in the second cache space is sent to the second node within a fourth time period after the first node receives the second information, the first node determines to transmit the first packet through the third node.

It should be noted that, in this application, the first type of packet is a packet that is mapped by the first node on the first radio link control channel on the first link and is sent to the first node. That is to say, when the second node has sent the first type packet whose data amount is the size of the available space in the second buffer space within a certain time period before receiving the second information, the first node may also determine that the second node is unavailable, and determine to transmit the first packet through the third node. Or, when the second node has sent the first type packet whose data size is the size of the available space in the second cache space within a certain time period after receiving the second information, the first node may also determine that the second node is unavailable, and determine to transmit the first packet through the third node. In other words, if the first node determines that a packet of the first type whose data amount is the available space size in the second buffer space size has been transmitted, the first node may also determine that the second node is not used and that the packet can be transmitted by the third node.

With reference to the second aspect, in some implementations of the second aspect, if the size of the available space in the second buffer space is smaller than or equal to a second threshold, determining to transmit the first data packet through the third node includes: and if the size of the available space in the second cache space is smaller than or equal to a second threshold value and the first node determines that a third node can be used for transmitting the first data packet, the first node determines to transmit the first data packet through the third node.

With reference to the second aspect, in some implementations of the second aspect, the determining, by the first node, that the third node is available to transmit the first data packet includes: the first node receives fourth information from a third node, wherein the fourth information comprises the size of available space in at least one cache space of the third node, the at least one cache space is used for caching data packets which are mapped on at least one wireless link control channel on a second link and sent to the third node, and the at least one cache space corresponds to the at least one wireless link control channel in a one-to-one mode; if the sum of the sizes of the available spaces in the at least one cache space is greater than a fourth threshold, the first node determines that the third node is available to transmit the first data packet.

With reference to the second aspect, in certain implementations of the second aspect, the determining, by the first node, to transmit the first packet by the third node includes: the first node receives fourth information from a third node, where the fourth information includes the size of an available space in a fourth cache space of the third node, the fourth cache space is used for caching a second radio link control channel mapped on a second link to send a data packet to the third node, and the second link is a link between the first node and the third node; if the size of the available space in the fourth cache space is greater than a fourth threshold, the first node determines to transmit the first data packet through the third node.

With reference to the second aspect, in certain implementations of the second aspect, the determining, by the first node, to transmit the first packet by the third node includes: the first node receives third information from the third node, wherein the third information comprises the size of available space in at least one cache space of the third node, the at least one cache space corresponds to the at least one standby path in a one-to-one manner, and the at least one standby path is the same as a destination node of the first path; if the sum of the sizes of the available spaces in the at least one cache space is greater than a third threshold, the first node determines to transmit the first data packet through the third node.

With reference to the second aspect, in some implementations of the second aspect, the first node receives fifth information from the second node, where the fifth information includes a size of an available space in a second buffer space of the second node, and if the size of the available space in the second buffer space is greater than a fifth threshold, the first node determines that the second node is available for transmitting a packet requiring a first radio link control channel mapped on the first link.

With reference to the second aspect, in some implementations of the second aspect, the receiving, by the first node, fifth information from the second node includes: the first node receives P pieces of fifth information from the second node within a fifth time length, wherein the P pieces of fifth information comprise the size of available space in P second cache spaces; if the sizes of the available spaces in the P second cache spaces are all larger than a fifth threshold value, the first node determines to transmit a data packet of a first radio link control channel needing to be mapped on the first link through the third node; wherein the fifth threshold is greater than or equal to the second threshold, and the fifth duration is greater than or equal to the second duration; and P is an integer greater than 1, and is greater than or equal to K.

With reference to the second aspect, in some implementations of the second aspect, the second threshold is configured by the donor node of the first node, or the second threshold is indicated by indication information by the donor node of the first node, or the second threshold is preconfigured to the first node; the second time length is configured by the host node of the first node, or the second time length is indicated by the host node of the first node through indication information, or the second time length is preconfigured to the first node.

A third aspect provides a method of communication, the method comprising: the host node configures a threshold or a duration for the first node, or the host node indicates the threshold or the duration of the first node through the indication information. The threshold may be a minimum value at which the second node is not congested.

In a fourth aspect, a communication apparatus is provided, which is configured to perform the communication method in the first aspect or any one of the possible implementation manners of the first aspect.

In a fifth aspect, a communication device is provided, which is configured to perform the communication method in the second aspect or any one of the possible implementation manners of the second aspect.

In a sixth aspect, a communication apparatus for performing the communication method in the third aspect is provided.

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

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

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

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

In another implementation, the communication device is a chip configured in the host node. When the communication device is a chip configured in the host node, the communication interface may be an input/output interface. Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input/output interface may be an input/output circuit.

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

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

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

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

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

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

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

In a specific implementation process, the processor may be one or more chips, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a flip-flop, various logic circuits, and the like. The input signal received by the input circuit may be received and input by, for example, but not limited to, a transceiver, the signal output by the output circuit may be, for example, but not limited to, output to and transmitted by a transmitter, and the input circuit and the output circuit may be the same circuit that functions as the input circuit and the output circuit, respectively, at different times. The embodiment of the present application does not limit the specific implementation manner of the processor and various circuits.

In an eleventh aspect, a processing apparatus is provided that includes a processor and a memory. The processor is configured to read instructions stored in the memory, and may receive signals via the transceiver and transmit signals via the transmitter to perform the method of any one of the possible implementations of the first aspect to the third aspect.

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

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

In a specific implementation process, the memory may be a non-transitory (non-transitory) memory, such as a Read Only Memory (ROM), which may be integrated on the same chip as the processor, or may be separately disposed on different chips, and the embodiment of the present application does not limit the type of the memory and the arrangement manner of the memory and the processor.

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

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

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

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

In a fourteenth aspect, a chip system is provided, which includes a processor, and is configured to invoke and run a computer program from a memory, so that a device in which the chip system is installed executes the method in each implementation manner of the first aspect to the third method.

In a fifteenth aspect, a communication system is provided, which comprises the apparatus of any of the above fourth aspect, the apparatus of the fifth aspect, and the communication apparatus of the sixth aspect.

Drawings

Fig. 1 is a schematic diagram of an IAB independent networking provided in the present application.

Fig. 2 is a schematic diagram of an IAB dependent networking provided by the present application.

Fig. 3 is a schematic diagram of an IAB system architecture provided in the present application.

Fig. 4 is a schematic diagram of an IAB network protocol stack provided in the present application.

Fig. 5 is a schematic diagram of an IAB node flow control feedback format provided in the present application.

Fig. 6 is a schematic diagram of node routing in an IAB network provided in the present application.

Fig. 7 is a schematic flow chart of a communication method provided herein.

Fig. 8 is a schematic flow chart of a communication method provided herein.

Fig. 9 is a schematic block diagram of a communication device provided herein.

Fig. 10 is a schematic block diagram of a communication device provided herein.

Detailed Description

The wireless communication system to which the embodiments of the present application can be applied includes, but is not limited to: a global system for mobile communications (GSM) system, a Long Term Evolution (LTE) Frequency Division Duplex (FDD) system, a LTE Time Division Duplex (TDD) system, an LTE-Advanced (LTE-a) system, a next generation communication system (e.g., a 5G, 6G communication system), a convergence system of multiple access systems, or an evolution system.

The technical scheme provided by the application can also be applied to Machine Type Communication (MTC), long Term Evolution-machine (LTE-M) for inter-machine communication, device-to-device (D2D) network, machine-to-machine (M2M) network, internet of things (IoT) network, or other networks. The IoT network may comprise, for example, a car networking network. The communication modes in the car networking system are collectively referred to as car-to-other devices (V2X, X may represent anything), for example, the V2X may include: vehicle to vehicle (V2V) communication, vehicle to infrastructure (V2I) communication, vehicle to pedestrian (V2P) communication, or vehicle to network (V2N) communication, and the like.

The terminal equipment involved in the embodiment of the application is an entrance for interaction between a mobile user and a network, and can provide basic computing capacity and storage capacity, display a service window for the user and receive operation input of the user. The terminal equipment in 5G may use a new air interface technology to establish signal connection and data connection with the wireless access network equipment, thereby transmitting control signals and service data to the mobile network. The terminal devices referred to in the embodiments of the present application may include various access terminals, mobile devices, user terminals or user apparatuses having wireless communication functions. For example, the terminal device may be a User Equipment (UE), such as a mobile phone (mobile phone), a tablet computer (pad), a desktop computer, a computer with a wireless transceiving function, a Virtual Reality (VR) terminal device, a television, an Augmented Reality (AR) terminal device, and the like. The terminal device may also be a wireless terminal in industrial control (industrial control), a Machine Type Communication (MTC) terminal, a Customer Premises Equipment (CPE), a wireless terminal in self-driving (self-driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid, a wireless terminal in transportation security, a wireless terminal in smart city, a smart home, a smart speaker, an electronic door lock, a cellular phone, a cordless phone, a session initiation protocol (session initiation protocol), SIP) phones, wireless Local Loop (WLL) stations, personal Digital Assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, automated Guided Vehicles (AGVs), drones, cars, vehicle devices, wearable devices, terminal devices in a 5G network or terminal devices in a future evolved Public Land Mobile Network (PLMN) or non-public network (NPN), etc.

The wireless access network equipment related in the embodiment of the application is similar to a base station in a traditional network, is deployed at a position close to the terminal equipment, provides a network access function for authorized users in a specific area, and can determine transmission tunnels with different qualities according to the grade of the users, the service requirements and the like to transmit user data. The radio access network equipment can manage the resources of the radio access network equipment, reasonably utilize the resources, provide access service for the terminal equipment according to needs, and is responsible for forwarding control signals and user data between the terminal equipment and a core network. The radio access network device referred in the embodiments of the present application may be an access device that the terminal device accesses to the mobile communication system in a wireless manner. The radio access network device may be: a base station, an evolved node B (eNB), a home base station, an Access Point (AP) in a wireless fidelity (WiFi) system, a Station (STA), a wireless relay node, a wireless backhaul node, a Transmission Point (TP) or a Transmission and Reception Point (TRP), a macro base station or a micro base station, a high frequency base station, and the like. The radio access network device may also be a next generation base station (gNB) in the NR system, or may also be a component or a part of a device constituting the base station, such as a Central Unit (CU), a Distributed Unit (DU), or a baseband unit (BBU). It should be understood that, in the embodiments of the present application, there is no limitation on the specific technology and the specific device form adopted by the radio access network device. In this application, a radio access network device is referred to as a network device for short, and if no special description is provided, network devices are referred to as radio access network devices in this application. In this application, the network device may refer to the network device itself, or may be a chip applied to the network device to complete a wireless communication processing function.

Compared with the fourth generation mobile communication system, the fifth generation mobile communication (5G) provides more stringent requirements for various network performance indexes in all directions. For example, the capacity index is improved by 1000 times, the coverage requirement is wider, the time delay is ultrahigh and reliable, and the time delay is ultralow. On one hand, in consideration of rich high-frequency carrier frequency resources, in a hot spot area, in order to meet the requirement of 5G ultrahigh capacity, networking by using high-frequency small stations is more popular. The high-frequency carrier wave has poor propagation characteristics, is seriously attenuated by shielding and has a small coverage range, so a large number of densely deployed small stations are needed, and accordingly, the cost of providing optical fiber return for the densely deployed small stations is high, the construction difficulty is high, and an economic and convenient return scheme is needed; on the other hand, from the perspective of wide coverage requirements, network coverage is provided in some remote areas, the deployment difficulty of optical fibers is high, the cost is high, and flexible and convenient access and backhaul schemes also need to be designed. The IAB technique provides ideas for solving the two problems: an access link (access link) and a backhaul link (backhaul link) both adopt wireless transmission schemes, and optical fiber deployment is avoided.

An Integrated Access and Backhaul (IAB) scenario applicable to the embodiment of the present application is described in detail below with reference to fig. 1, fig. 2, and fig. 3.

Fig. 1 shows a scenario of an IAB independent networking (SA). In an IAB network, a relay node RN (RN) or an IAB node (IAB node) may provide a radio access service for a User Equipment (UE), and service data of the UE is transmitted by connecting the IAB node to an IAB host (IAB node) through a radio backhaul link. The IAB node may also be referred to as a donor node (donor node) or a donor base station (donor gdnodeb, dgNB) in this application, and the base station supporting the IAB node may specifically include an IAB-donor-CU portion and at least one IAB-donor-DU portion; the IAB-donor-CU part may also contain one IAB-donor-CU-CP (responsible for user plane) and at least one IAB-donor-CU-UP (responsible for user plane). An IAB node may be composed of a Mobile Termination (MT) part and a DU (distributed unit) part, wherein the IAB node may serve as a terminal device, i.e., the role of MT, when facing its parent node; when an IAB faces its child node (which may be another IAB node, or a general UE), it is treated as a network device, i.e. as a role of DU. Wherein the MT part of the IAB node has part or all of the functions of the UE. The donor base station DgNB may be an access network element with a complete base station function, or may also be an access network element with a Central Unit (CU) and a Distributed Unit (DU) in separate forms, where the donor base station is connected to a core network (for example, connected to a 5G core network, 5 GC) element serving the UE, and provides a wireless backhaul function for the IAB node. For convenience of description, the centralized unit of the host node is referred to as a donor CU (or CU directly) and the distributed unit of the host node is referred to as a donor DU, where a donor CU may also be in a form of a Control Plane (CP) and a User Plane (UP) separation, for example, a CU may consist of one CU-CP and one (or more) CU-UPs.

In the current 5G standard, considering that the coverage area of the high frequency band is small, in order to ensure the coverage performance of the network, multi-hop networking may be adopted in the IAB network. In addition, in consideration of the requirement of traffic transmission reliability, the IAB node may support Dual Connectivity (DC) or multi-connectivity (multi-connectivity) to cope with abnormal situations that may occur in the backhaul link, such as an abnormal situation of a link, such as a link interruption or blocking (block) and a load fluctuation, and improve the reliability guarantee of transmission. Therefore, the IAB network supports multi-hop networking and may also support multi-connection networking. Between the UE served by the IAB node and the IAB donor, there exists at least one transmission path consisting of multiple segments of links. On one transmission path, a plurality of nodes are included, such as UE, one or more IAB nodes, IAB donor (if the IAB donor is a separate form of CU and DU, also includes an IAB-donor-DU part, and an IAB-donor-CU part), each IAB node regards its neighboring nodes providing access and backhaul services as parent nodes, and accordingly, each IAB node can be regarded as a child node of its parent node.

For example, in fig. 1, the parent node of IAB node 1 is IAB donor, IAB node 1 is the parent node of IAB node 2 and IAB node 3, IAB node 2 and IAB node 3 are the parent nodes of IAB node 4, and IAB node 5 is the parent node of IAB node 2. The uplink of the UE may be transmitted to the host site IAB donor via one or more IAB nodes, and then sent to the mobile gateway device (e.g., user plane function unit UPF in the 5G core network) via the IAB donor, after receiving the downlink from the mobile gateway device via the IAB node, sent to the UE via the IAB node. Fig. 1 shows an IAB independent networking scenario, where an IAB node and a UE both establish connection with a network only through an NR air interface.

The IAB independent networking scenario shown in fig. 1 is only exemplary, and in an IAB scenario in which multiple hops and multiple connections are combined, there are still more other possibilities, for example, an IAB node in the figure and an IAB node under another IAB node form a dual connection to serve the UE (i.e., the UE supports dual connection, where one connection 1 directly accesses a cell served by the IAB node DU, and another connection 2 establishes a connection with an IAB node X, where the IAB host to which the IAB node X is connected is different from the IAB host to which the UE connection 1 corresponds), and so on, which are not listed.

Fig. 2 shows a scenario of an IAB non-independent Networking (NSA). As shown in fig. 2, the IAB node supports dual connectivity between 4G and 5G networks, (E-UTRAN NR dual connectivity, EN-DC), where a base station eNB of LTE is a Master base station (Master eNB, meNB), provides an air interface (LTE Uu) connection of LTE for the IAB node, and establishes an S1 interface with a 4G Evolved Packet Core (EPC) for user plane and control plane transmission. For an EN-DC mode UE or an IAB node, the base station eNB of LTE is the primary base station. The base station with the gNB of the 5G standard may be a primary base station or a secondary base station of the IAB node in the dual connectivity mode, for the UE or the IAB node. The IAB-donor gNB provides NR air interface (NR Uu) connection for the IAB node, and establishes an S1 interface with a core network EPC for user plane transmission. Similarly, the UE also supports EN-DC, and is connected to the primary base station eNB through an LTE Uu interface, and is connected to the secondary base station IAB node through an NR Uu interface, and the secondary base station of the UE may also be an IAB donor gNB.

It should be noted that fig. 2 is only an example of networking, and the NSA scenario of the IAB network also supports multi-hop IAB networking, for example, the UE in fig. 2 may be another IAB node, that is, the IAB node may be connected to the IAB donor gNB through a multi-hop wireless backhaul link. The IAB non-independent networking scenario in the present application may also be referred to as an EN-DC networking scenario of the IAB.

Fig. 3 is an architecture diagram of an IAB network system suitable for the present application. As shown in fig. 3, the IAB network includes an IAB network of independent networking (SA) and an IAB network of non-independent Networking (NSA). As mentioned above, the IAB node comprises an MT part and a DU part, the IAB node can be further divided into the DU and CU parts, and the CU can be further divided into the CU-CP and CU-UP parts. And the DU part of each IAB node and the IAB denor CU are provided with an F1 interface, and the F1 interface comprises two parts, namely a control plane part and a user plane part, wherein the part of the user plane is maintained between the IAB-DU and the IAB denor CU-UP, and the part of the control plane is maintained between the IAB-DU and the IAB denor CU-CP. Note that the F1 interface between the IAB-DU and the IAB donor CU is not shown in fig. 3.

When the IAB node operates in the SA mode, the IAB node may be connected to one parent node singly or connected to two parent nodes doubly, wherein the two parent nodes may be controlled by the same IAB node or controlled by different IAB nodes respectively. An F1 interface is established between the DU part of the IAB node and one IAB donor, and the IAB donor may be connected to a 5G core network (5G core, 5gc). Wherein the IAB-donor-CU-CP is connected to a control plane network element (e.g. access and mobility management function AMF) in the 5GC via an NG control plane interface, and wherein the IAB-donor-CU-UP is connected to a user plane network element (e.g. user plane function UPF) in the 5GC via an NG user plane interface. In the application, the 5G core network may be used to perform authentication, mobility management, PDU session management, and the like on the terminal device, and includes functional entities or network elements such as an access and mobility management function AMF, a user plane function UPF, and the like.

When the IAB node operates in the NSA mode (or EN-DC mode), the IAB-donor-CU-UP may be connected to the EPC (e.g., connected to a Serving Gateway (SGW)) through an S1 user plane interface, an LTE Uu air interface is connected between the MeNB and the MT of the IAB node, an X2-C interface is connected between the MeNB and the IAB-donor-CU-CP, and the MeNB is connected to the EPC (including an S1 interface user plane and an S1 interface control plane) through an S1 interface.

In another possible case, the MeNB in fig. 3 may also be replaced with a base station gNB of 5G, a dashed LTE-Uu interface in the drawing is replaced with an NR-Uu interface, the gNB may establish an interface of a user plane and/or a control plane with the 5GC, the gNB and the IAB-donor provide dual connectivity service for the IAB node, and the gNB may serve as a primary base station of the IAB node or a secondary base station.

The IAB node in the present application may be a UE serving as a relay node, or may be a device serving as a relay node, such as a home gateway (RG) or a Customer Premises Equipment (CPE).

In the discussion of the IAB network, it is determined that a new protocol layer, namely, a Backhaul Adaptation Protocol (BAP) layer, is introduced into the wireless backhaul link, and the protocol layer may be located above a Radio Link Control (RLC) layer, and may be used to implement functions such as routing and bearer mapping on the wireless backhaul link.

Fig. 4 is a schematic view of a user plane and a control plane protocol stack of the IAB network, and (a) in fig. 4 is a schematic view of a user plane protocol stack of the IAB network; fig. 4 (b) is an IAB network control plane protocol stack diagram. Between an IAB node (e.g., DU portion of IAB) and a host node (e.g., IAB-donor-CU), an F1 interface (or referred to as F1 interface, which may be collectively referred to as F1 interface in this application, but the name is not limited thereto) needs to be established, which supports user plane protocols (F1-U/F1-U) (e.g., (a) in fig. 4) and control plane protocols (F1-C/F1-C) (e.g., (b) in fig. 4), wherein the user plane protocols include one or more of the following protocol layers: a General Packet Radio Service (GPRS) tunneling protocol user plane (GTP-U), a User Datagram Protocol (UDP), an Internet Protocol (IP), and other protocol layers; the control plane protocol of the interface includes one or more of: f1 application protocol (F1 AP), stream Control Transport Protocol (SCTP), and IP.

As shown in fig. 4 (b): through the control plane of the F1/F1 interface, interface management can be performed between the IAB node and the IAB host, the IAB-DU can be managed, and UE context-related configuration can be performed. Through the user plane of the F1/F1 x interface, the functions of user plane data transmission, downlink transmission state feedback and the like can be executed between the IAB node and the IAB host.

At present, considering the introduction of an IAB node, a multi-hop wireless link is introduced at a wireless air interface, and in order to avoid that an upstream node does not know the congestion status of a downstream link, a downlink hop-by-hop flow control feedback (flow control feedback) is introduced in an R16 IAB topic, that is, the IAB node may perform flow control feedback to its parent node, where the flow control feedback may reflect the buffer state of a link between the IAB node and its child node, and specifically may have two buffer state feedbacks of different granularities, one is to feed back an adaptation protocol layer routing ID (BAP routing ID) granularity (that is, the available buffer size fed back by the IAB node to the parent node is the size of an available buffer space corresponding to each BAP routing ID, and the format of a specific feedback BAP control (control) Protocol Data Unit (PDU) may refer to (a) in fig. 5); another feedback is the granularity of the backhaul link no link control channel (BH RLC CH) (i.e. the available buffer size fed back by the IAB node to the parent node is the size of the available buffer space corresponding to the BH RLC channel on the link between the IAB node and the parent node, and the format of the specifically fed back BAP control PDU can refer to (b) in fig. 5). The flow control feedback of any granularity is carried in the BAP control PDU and sent to the parent node. It should be noted that the IAB node may send a BAP control PDU containing flow control feedback information to the parent node based on a query (polling) of the parent node, or the IAB node may directly trigger sending the BAP control PDU containing flow control feedback information to the parent node based on its own monitoring of the buffer status.

After the IAB donor (when the IAB donor is in a CU-DU separation form, specifically, the IAB donor DU adds the BAP routing ID in downlink) is added with the BAP routing ID, the IAB donor and subsequent nodes can search a configured routing table based on the BAP routing ID to select a next hop node until the next hop node is transmitted to a downlink target IAB node; after the uplink is added with the BAP routing ID at the IAB node, the IAB node and the subsequent nodes both search the configured routing table based on the BAP routing ID and select the next hop node until the next hop node is transmitted to the target IAB donor DU of the uplink.

Based on the hop-by-hop flow control feedback, after the parent node receives the flow control feedback information sent by the child node, if the parent node knows that the link of the child node is congested, the sending of downlink data can be slowed down, so that the downlink data can be accumulated at the parent node, and the risk of cache overflow still exists. If the link congestion cannot be relieved in a short time, the data packet can be cached and cannot be sent in the wireless return link for a long time, and finally, the delay is too large, so that the user experience is influenced.

In view of this, the present application provides a communication method, which performs rerouting on a data packet when a link encounters congestion, so as to alleviate the link congestion, thereby enabling timely transmission of the data packet, reducing an average transmission delay of the data packet, and improving user experience.

It should be noted that, in this application, the size of the available buffer space (or simply referred to as the available buffer size) of a certain granularity, which is fed back from one IAB node # B to another IAB node # a, may refer to the maximum data amount of the data packet corresponding to the certain granularity, which the IAB node # a may also send to the IAB node # B. For example, in the feedback information of the flow control sent by the IAB node # B to the IAB node # a, the size of the available buffer space corresponding to the BAP routing ID #1 is M bytes (byte), which means that the total data volume of the data packet carrying the BAP routing ID #1 that the IAB node # a can also send to the IAB node # B is maximum M bytes. For another example, if the size of the available buffer space corresponding to the BH RLC CH #1 in the feedback information for the flow control feedback sent by the IAB node # B to the IAB node # a is M bytes (byte), the total data amount of the packets mapped on the BH RLC CH #1 that the IAB node # a can still send to the IAB node # B is maximum M bytes. Where BH RLC CH #1 identifies a wireless backhaul RLC channel on a wireless backhaul link between the first node and the second node.

In this application, the first node may be, for example: any node in the IAB network, or an IAB donor DU); the second node in this application may be a next hop node of the first node on some primary path, for example, may be a child node or a parent node of the first node. Referring to fig. 1, the first node in the present application may be any node in the IAB network, for example, an IAB node 1, an IAB node 2, an IAB node 5, or the like, and may also be an IAB host. If node 1 is the first node, the second node may be node 2, which may correspond to downlink transmission; if the IAB node 1 is a first node, the IAB host may be a second node, and at this time, uplink transmission is performed, which is not described in detail below.

Generally, in order to ensure normal transmission of traffic data or signaling (which may be collectively referred to as data in this embodiment for convenience of description) in an IAB network (for example, between a terminal and an IAB host, or between an IAB node and an IAB host), the IAB host needs to configure a routing table for each IAB node, that is: and configuring the next hop nodes corresponding to different transmission paths (each transmission path is identified by the BAP routing ID). Meanwhile, the IAB host needs to determine a transmission path corresponding to data transmission on the wireless backhaul link. That is, before data transmission, a transmission path is determined, which may be referred to as a primary path, through which data is routed (routed) between the IAB node and the IAB host, and other paths may be regarded as backup (backup) paths. It should be understood that the primary or backup path is defined for transmission by the hosting base station.

It should be noted that, in the present application, when the wireless backhaul link of the IAB network is transmitted, routing is performed based on a BAP routing ID carried in a BAP layer header, where the BAP routing ID is composed of a BAP address (address) of a target node and a BAP path label (path ID). That is, the BAP routing ID identifies a specific transmission path to the target node, i.e., a main path for transmitting the data packet. Typically, the BAP routing ID is unique. It can also be understood that the BAP routing ID (which can also be understood as the primary path) configured for each packet is unique. Referring to fig. 1, assume that there is packet # P1, packet # P2, and packet # P3 on IAB node 1. Destination IAB node 5 of packet # P1, the main path is path # a: IAB node 1 → IAB node 2 → IAB node 5, then BAP routing ID includes: IAB node 5 and Path label # Path 1, the BAP routing ID used to identify the Path # a; the destination IAB node 4 of packet # P2, the main path is path # B: IAB node 1 → IAB node 2 → IAB node 4, then BAP routing ID includes: IAB node 4 and Path label # Path 2, the BAP routing ID used to identify the Path # B; destination IAB node 4 of packet # P3, the main path is path # C: IAB node 1 → IAB node 3 → IAB node 4, then BAP routing ID includes: IAB node 4 and Path label # Path 3, the BAP routing ID used to identify the Path # C.

It should be noted that, in the present application, for a certain data packet, the primary path is one (i.e., the transmission path indicated by the BAP routing ID carried in the data packet), but there may be one or more backup paths. For a packet, a backup path and its primary path are two different transmission paths, at least one node of which is different. In the present application, from the perspective of one IAB node # a, the next-hop IAB node # C on the backup path of a certain packet and the next-hop IAB node # B on the primary path are not the same node. As shown in fig. 6, assuming that the destination address of the packet is IAB node 9, as shown in fig. 6, the primary path of the packet is path #2, and the backup path of the packet may have 2 paths, which are path #3 and path #4, respectively. If node 1 determines that the primary path is not available for the data packet (not available), or the next hop node 2 is not available, or the wireless backhaul link between the primary path and the next hop node 2 is not available, at this time, IAB node 1 may further determine whether backup path #3 and/or backup path #4 is available (available), or determine whether IAB node 3 on the backup path is available (available), or determine whether the wireless backhaul link between IAB node 1 and the next hop IAB node 3 on the backup path is available. It should be noted that, the IAB node 1 in fig. 6 may also be understood as an IAB donor DU.

It should be noted that, in the present application, the backup paths may be pre-configured, for example, as shown in fig. 6, for path #2, the iab hosts may configure backup paths of path #2 on node 1 in advance as path #3 and path #4; or, the backup path may also be determined by the first node according to the destination address, for example, for a certain data packet carrying the BAP routing ID corresponding to the path #2, the first node may determine that the destination address of the data packet is the IAB node 9, and then determine, according to a routing table configured on the first node, which transmission paths (such as the path #3 and the path # 4) the destination address of which is the IAB node 9 exist, and further determine a next-hop node on the backup path of the data packet (for example, the next-hop nodes of the IAB node 1 on the path #4 and the path #3 are both the IAB node 3). In this application, for a node, a backup link of a data packet may refer to a link between the node and a next-hop node on a backup path of the data packet, for example, for a scenario shown in fig. 6, for an IAB node 1, a data packet carrying a BAP routing ID corresponding to a path #2, and a backup link of the data packet may refer to a link #2 between the IAB node 1 and an IAB node 3.

It should be noted that, in the present application, the second node is a next hop node of the first node on the main path. If the main path is available, determining that the next hop node of the first node is the second node, that is, it can also be understood that rerouting is not needed or execution of rerouting is stopped; the third node is the next hop node of the first node on the backup path. If the next hop node of the first node is determined to be the third node, it can also be understood that the primary path is unavailable and rerouting needs to be performed. The second node may be a child or a parent of the first node, and similarly, the third node may also be a child or a parent of the first node.

For a data packet, when transmitting the data packet to the next hop node on the wireless backhaul link, the data packet needs to be mapped on a wireless backhaul RLC channel (BH RLC CH for short) to transmit to the next hop node, there may be one or more different BH RLC CHs on a wireless backhaul link, and each BH RLC CH on a wireless backhaul link may provide differentiated QoS guarantee. Note that in the present application, for node # a, "primary path unavailable" means that the wireless backhaul link #1 between the IAB node # a and its next hop IAB node # B on the primary path is unavailable; or it may be understood that its next hop IAB node # B is not available; or may also be understood as at least one segment of the subsequent wireless backhaul links on the primary path being unavailable; it can also be understood that for a specific data packet to be transmitted by the IAB node # a, the next-hop node is not available or the wireless backhaul link between the IAB node # a and the next-hop node is not available, for example, the link between the IAB node # a and the next-hop IAB node # B is not available for a data packet that includes the BAP routing ID #1 in the BAP layer or is to be mapped to the BH RLC CH #1 for transmission to the next-hop IAB node # B, and will not be described in detail below.

Fig. 7 is a communication method provided in the present application, where the method in fig. 7 includes:

in step S701, the second node sends information # M1 to the first node, where the information # M1 includes the size of the available buffer space on the second node corresponding to the BAP routing ID # 1.

The BAP routing ID #1 is used for identifying a first path, and the second node is a next-hop node of the first node on the first path. For example, the information # M1 may be flow control feedback information of the second node, and the flow control feedback information may include buffer status information of the barouting ID granularity, which includes the size of the available buffer space corresponding to the BAP routing ID #1 for identifying the first path.

In the present application, since the information # M1 transmitted by the second node includes the flow control feedback information, the information # M1 may also be regarded as being fed back to the first node by the second node.

In this application, the first path may be regarded as a main path of a data packet carrying a BAP layer routing ID of BAP routing ID #1, and the data packet that needs to be transmitted through the first path, that is, the data packet whose transmission path indicated by the BAP layer routing ID (for example, BAP routing ID # 1) carried in the BAP layer header is the first path. It should be understood that there may be one or more packets having a primary path as the first path.

In step S702, the first node receives the message # M1, and determines that the second node is not available for the data packet that needs to be transmitted through the first path according to the message # M1.

In this application, the first node may determine the next-hop node of the first node according to the size of the available cache space corresponding to the BAP routing ID #1 included in the information # M1 sent by the second node. For example, in a possible implementation manner, if the size of the available buffer space corresponding to the BAP routing ID #1 in the information # M1 fed back by the second node is greater than the threshold TH #1 (or may be equal to the threshold TH # 1), the first node may determine that the primary path of the data packet carrying the BAP routing ID #1 is available, or the second node is available for the data packet carrying the BAP routing ID #1, or a wireless link between the first node and the second node is available for the data packet carrying the BAP routing ID #1, and then the first node may determine that the data packet that needs to be transmitted through the first path is transmitted through the second node.

In another possible implementation manner, if the size of the available buffer space corresponding to the BAP routing ID #1 in the information # M1 fed back by the second node is smaller than or equal to the threshold TH #1, the first node may determine that the primary path of the data packet carrying the BAP routing ID #1 is unavailable, or the second node is unavailable for the data packet carrying the BAP routing ID #1, or the wireless link between the first node and the second node is unavailable for the data packet carrying the BAP routing ID # 1. In this case, the first node needs to select the appropriate backup link for these packets carrying BAP routing ID # 1. For example, if the first node may determine that a backup path is available for transmitting a data packet carrying the BAP routing ID #1, and a next-hop node of the first node on the backup path is a third node, the first node may further determine to transmit the data packet that needs to be transmitted through the first path through the third node.

In this application, the first node does not limit the determination of the condition equal to the threshold. As an example, the first node may determine that the primary path of the packet carrying the BAP routing ID #1 is available if the size of the available cache space corresponding to the BAP routing ID #1 is equal to the threshold TH #1, in which case the first node determines that the primary path of the packet carrying the BAP routing ID #1 is unavailable only if the size of the available cache space corresponding to the BAP routing ID #1 is less than the threshold TH # 1. In this case, the first node may determine that the primary path of the packet carrying the BAP routing ID #1 is available only when the size of the available buffer space corresponding to the BAP routing ID #1 is greater than the threshold TH # 1. The same applies to the case of being equal to the threshold value described later in each specific example.

As an example, the first node may receive flow control feedback information # M1 with BAP routing ID granularity. Specifically, referring to fig. 1, assuming that the first node is an IAB node 1, the second node is an IAB node 2, and for a packet # P1 (or referred to as a first packet) carrying a BAP routing ID #1, the main path is path 1: IAB node 1 → IAB node 2 → IAB node 4, if the size of the available buffer space corresponding to BAP routing ID #1 fed back by IAB node 2 is smaller than (or equal to) threshold TH #1, then IAB node 1 may determine that the primary path of packet # P1 is not available. It can also be understood that for packet # P1 whose primary path is path #1 (i.e., packet # P1 that needs to be transmitted over path # 1), link #1 is not available, or IAB node 2 is not available. Link #1 is a link between the first node and the second node.

In a possible implementation manner, the first node may receive M pieces of flow control feedback information of the second node within a period of continuous duration # T1, where M is a positive integer greater than or equal to 1, and the M pieces of flow control feedback information are BAP routes of the second nodeg ID granularity, assuming that there are N flow control feedback information including specific values of the size of the available buffer space corresponding to BAP routing ID #1, from the first to the Nth, { A } ₁ ，A ₂ ,…A _N (Ax is an integer greater than 0, x is a positive integer, 1. Ltoreq. X.ltoreq.N), N.ltoreq.M if { A ≦ M ₁ ，A ₂ ,…A _N Each of which is less than or equal to a threshold TH #1, the first node may determine that a data packet carrying a BAP routing ID #1 is congested at the second node. In this case, the first node needs to select the appropriate backup link for these packets carrying BAP routing ID # 1. For example, if the first node may determine that a backup path is available for transmitting the data packet carrying the BAP routing ID #1, and a next-hop node of the first node on the backup path is a third node, the first node may further determine to transmit the data packet that needs to be transmitted through the first path through the third node.

In this application, the first node determines that the data packet carrying the BAP routing ID #1 is congested at the second node, that is, the second node is unavailable for the data packet carrying the BAP routing ID #1, or a primary path of the data packet carrying the BAP routing ID #1 is unavailable, or a link #1 between the first node and the second node is unavailable for the data packet carrying the BAP routing ID # 1. In the path identified by the BAP routing ID #1 (which may be regarded as a main path of a packet carrying the BAP routing ID # 1), the second node is a next-hop node of the first node, and when the first node determines that the next-hop node on the main path of the packet is unavailable for the packet, the second node may reroute the packet, i.e., select an appropriate backup path for the packet, and send the packet to the next-hop node on the backup path.

In yet another possible implementation manner, the first node may receive, within a period of continuous duration # T1, M pieces of flow control feedback information of the second node, where M is a positive integer greater than or equal to 1, the M pieces of flow control feedback information are sizes of available cache spaces of BAP routing ID granularity of the second node, and it is assumed that N pieces of the M pieces of flow control feedback information include and include BAP routing iThe specific value of the available buffer space corresponding to ng ID #1 is { A ] from the first to the Nth ₁ ，A ₂ ,…A _N (Ax is an integer greater than 0, x is a positive integer, 1. Ltoreq. X.ltoreq.N), N is a positive integer less than or equal to M, if { A ≦ N ₁ ，A ₂ ,…A _N At least Y values are less than or equal to a threshold TH #1, Y is a positive integer satisfying 1 ≦ Y ≦ N, and the first node may determine that the data packet carrying BAP routing ID #1 is congested at the second node. In this case, the first node needs to select the appropriate backup link for these packets carrying BAP routing ID # 1. For example, if the first node may determine that a backup path is available for transmitting the data packet carrying the BAP routing ID #1, and a next-hop node of the first node on the backup path is a third node, the first node may further determine to transmit the data packet that needs to be transmitted through the first path through the third node.

For the two foregoing implementation manners of monitoring the flow control feedback information in a continuous time period # T1 to determine whether the second node is available for the packet carrying the BAP routing ID #1, as an example, the first node receives flow control feedback information of BAP routing ID granularity sent by the second node, if a value of an available buffer space corresponding to the BAP routing ID #1 is less than (or may be equal to) a threshold TH #1, starts a timer (taking the timer name as an example) for the BAP routing ID #1, assuming that the timed time period is T1=30s, and if, in the feedback information received within 30s after the timer is started, values of the available buffer space corresponding to the BAP routing ID #1 are all less than (or equal to) the threshold TH #1, at this time, the first node may determine that the packet carrying the BAP routing ID #1 is in the second node, and considers that the second node is not congested for the packet carrying the flow control ID #1 of the BAP routing ID # 1. If the values of the available buffer space corresponding to the BAP routing ID #1 carried in X flow control feedback information are all greater than (or equal to) the threshold TH #1 and X is a positive integer satisfying that X is greater than or equal to 1 and is less than or equal to M1 in the M updated flow control feedback information received before the timer expires (i.e., within 30s after the timer is started), the first node may consider that the second node is still available for the data packet carrying the BAP routing ID #1, may still select the second node as the next-hop node of the data packet carrying the BAP routing ID #1, and may stop the timing of the timer. Or, if the flow control feedback information updated by the next-hop node is received before the timer expires (i.e., within 30s after the timer is started), when the values (or values) of the available buffer space corresponding to the BAP routing ID #1 carried in the accumulated X flow control feedback information are all greater than (or equal to) the threshold TH #1, and X is a positive integer, the first node may consider that the second node is still available for the packet carrying the BAP routing ID #1, may still select the second node as the next-hop node of the packet carrying the BAP routing ID #1, and may stop the timing of the timer.

In this application, the value of the available buffer space of a certain granularity may also be described as the size of the available buffer space of a certain granularity or a numerical value of the available buffer space of a certain granularity, which is not described in detail below.

As an example, if the first node receives M (M is an integer greater than 1) times of flow control feedback information sent by the second node, there is M times of flow control feedback information ₀ The numerical value of the available buffer space corresponding to the BAP routing ID #1 in the secondary feedback is smaller than (or equal to) the threshold TH #1, or the proportion of the quantity of flow control feedback information carrying the available buffer space corresponding to the BAP routing ID #1 and smaller than (or equal to) the threshold TH #1 in M times of flow control feedback information is larger than (or equal to) R _TH1 ，0<R _TH1 ≦ 1, the first node may determine congestion at the second node. In particular, M may be continuous ₀ Sub or discontinuous M ₀ Next, the process is repeated. M is an integer of 1 or more, M ₀ Less than or equal to M.

As an example, if the first node receives that, in the M (M is an integer greater than or equal to 1) times of flow control feedback information sent by the second node, the value of the available buffer space corresponding to the BAP routing ID #1 is smaller than (or equal to) the threshold TH #1 within a time duration # T1 during which the timer runs, the first node may determine that a data packet carrying the BAP routing ID #1 is congested at the second node. In particular, it may be a continuous M ₀ Sub or discontinuousM ₀ Next, the process is carried out.

In this application, the timer duration # T1 of the first node may also be configured by the IAB donor (or the IAB donor CU, or the IAB donor CP) through a Radio Resource Control (RRC) message or an F1AP message, and the configuration mode may have multiple possibilities:

case 1: the duration # T1 may be configured by BAP routing ID, that is, different BAP routing ID values, the configured durations # T1 may be different, and the configuration information provided by the IAB donor for the first node may include a timer duration list, where each item in the list includes a specific value of one or more BAP routing IDs and a corresponding value of the duration # T1.

Case 2: the duration # T1 may be configured next-hop node by next-hop node, that is, the configured duration # T1 may be different for each next-hop node of the first node, but for the same next-hop node, the duration # T1 is applicable to all BAP routing IDs that may be involved in the flow control feedback information of the BAP routing ID granularity that is fed back to the first node by the next-hop node. In this case, the configuration information provided by the IAB donor needs to carry one or more values of the configured time length # T1, and further needs to indicate which next-hop node or next-hop nodes each of the time lengths # T1 is specifically applicable to the first node. The next hop node of the first node may be identified by the BAP address of the next hop node.

Case 3: the configuration of the duration # T1 may also be divided into a BAP routing ID and a BH RLC CH, that is, two different duration values are configured for the feedback information of two different granularities. For example, the duration of the timer corresponding to the flow control feedback information of all the BAP routing ID granularities is duration # T1, and the duration of the timer corresponding to the flow control feedback information of all the BH RLC CH granularities is duration # T2. In this case, the configuration information provided by the IAB donor needs to carry the value of the configured timer duration, and also needs to specify which granularity of the flow control feedback information the timer duration is specifically suitable for, that is, specify whether the duration corresponds to the flow control feedback information of the BAP routing ID granularity or the flow control feedback information of the BH RLC CH granularity. Illustratively, the IAB donor may carry a value of a duration # T1 corresponding to the flow control feedback information of the BAP routing ID granularity in the configuration information provided by the first node, where the duration # T1 is applicable to each different BAP routing ID.

For the configuration of the duration # T1 in case 3, there may also be a modified configuration manner, which distinguishes whether the duration # T1 is configured uplink or downlink, that is, when providing the duration-related configuration information, which is determined based on the flow control feedback information, to the first node, whether the next-hop node is available, the IAB donor may specify that the configured duration # T1 is specifically applicable to uplink flow control feedback (hop-by-hop flow control feedback from the parent node to the first node) or downlink flow control feedback (hop-by-hop flow control feedback from the child node to the first node). For example, as a variation 3a of case 3, the iab donor configures the duration # T1-UL-1 for the flow control feedback of all uplink BAP routing ID granularity and the duration # T1-DL-1 for the flow control feedback of all downlink BAP routing ID granularity.

In one possible implementation manner, the first node receives flow control feedback information of the second node, where the flow control feedback information includes a numerical value of an available cache space corresponding to the BAP routing ID #1, for example, # B1. If the first node detects that the data volume of the data packet carrying the adaptation layer routing identification BAP routing ID #1 is larger than or equal to # B1 and sent to the second node, the first node determines that: for packets carrying an adaptation layer routing identification of BAP routing ID #1, the second node is not available.

As an example, the first node receives flow control feedback information # M1 with BAP routing ID granularity from the second node, wherein the flow control feedback information # M1 includes a value of available buffer space corresponding to the BAP routing ID #1, for example, # B1, and the duration # T of the first node before receiving the flow control feedback information # M1 sent by the second node _A1 In the method, the data volume of the data packet which carries the adaptive layer routing identifier BAP routing ID #1 and is sent to the second node is greater than or equal to # B1. Accordingly, the first node determines: for a packet carrying adaptation layer routing identification, BAP routing ID #1, on the BAP layer, the second node is unavailable (or in other words, the first node and the second node Link #1 between points is not available). The first node may perform rerouting on these packets carrying the adaptation layer routing ID BAP routing ID #1, for example, select an available backup path, and send these packets to the next-hop node on the backup path.

As another example, the first node receives flow control feedback information # M1 with BAP routing ID granularity from the second node, wherein the flow control feedback information # M1 includes a value of an available buffer space corresponding to the BAP routing ID #1, such as # B1, and the first node has a duration # T after receiving the flow control feedback information # M1 sent by the second node _A2 And sending a data packet carrying the adaptive layer routing ID #1 to the second node, wherein the data volume of the data packet is greater than or equal to # B1. Accordingly, the first node determines: for packets carrying the adaptation layer routing identification, BAP routing ID #1, at the BAP layer, the second node is not available (or in other words, link #1 between the first node and the second node is not available). The first node may perform rerouting on these packets carrying the adaptation layer routing ID BAP routing ID #1, for example, select an available backup path, and send these packets to the next-hop node on the backup path. Optionally, the duration # T after the first node receives the flow control feedback information # M1 sent by the second node _A2 And the first node does not receive flow control feedback information of another updated BAP routing ID granularity sent by the second node.

As another example, the first node receives flow control feedback information # M1 with a BAP routing ID granularity from the second node, where the flow control feedback information # M1 includes a numerical value of an available cache space corresponding to the BAP routing ID #1, for example, # B1, and after receiving the flow control feedback information # M1, the first node sends a data volume of a packet carrying an adaptation layer routing ID of the BAP routing ID #1 to the second node, which reaches # B1, and the first node may determine: for packets carrying the adaptation layer routing identification, BAP routing ID #1, at the BAP layer, the second node is not available (or in other words, link #1 between the first node and the second node is not available). The first node may perform rerouting on these packets carrying the adaptation layer routing ID BAP routing ID #1, for example, select an available backup path, and send these packets to the next-hop node on the backup path.

As another example, the first node receives, from the second node, flow control feedback information # M1 of BAP routing ID granularity, where the value of the available buffer space corresponding to BAP routing ID #1 is included, for example, # B1, after receiving the flow control feedback information # M1, the first node sends, to the second node, a packet carrying the adaptation layer routing ID of BAP routing ID #1 with a data volume reaching # B1, and before receiving another updated flow control feedback information of BAP routing ID granularity sent by the second node (i.e., the first node has not received the flow control feedback information of another updated BAP routing ID granularity sent by the second node), the first node may determine: for packets carrying the adaptation layer routing identification, BAP routing ID #1, at the BAP layer, the second node is not available (or in other words, link #1 between the first node and the second node is not available). The first node may perform rerouting on these packets carrying the adaptation layer routing ID BAP routing ID #1, for example, select an available backup path, and send these packets to the next-hop node on the backup path.

In this application, the time length # T of the timer of the first node is long _A1 Or the first node may be configured by the IAB donor (or the IAB donor CU, or the IAB donor CP) through an RRC message or an F1AP message, and the configuration mode may have a plurality of possibilities:

case 1, duration # T _A1 Can be configured by BAP routing ID, that is, different BAP routing ID values and configured duration # T _A1 Alternatively, the configuration information provided by the IAB donor to the first node may include a timer duration list, where each item in the list includes specific values of one or more BAP routing IDs and a corresponding duration # T _A1 The value of (c).

Case 2, duration # T _A1 May be configured next hop by next hop, i.e. for each next hop node of the first node, the configured time duration # T _A1 May be different, but for the same next hop node, duration # T _A1 Flow control feedback of BAP routing ID granularity suitable for being fed back to first node by next hop nodeAll BAP routing IDs that would be involved in the information. In this case, the IAB donor provides the configuration information with the duration # T needed to carry one or more configurations _A The value of (1) is also indicated for each duration # T _A1 In particular to which next hop node or next hop nodes of the first node. The next hop node of the first node may be identified by the BAP address of the next hop node.

Case 3, duration # T _A1 The configuration of (1) or configuring a uniform timer duration # T for the feedback information of BAP routing ID granularity _A1 . That is, the durations of the timers corresponding to the flow control feedback information of all the BAP routing ID granularities are duration # T _A1 . In this case, the IAB donor provides the configuration information, which needs to carry the configured timer duration # T _A1 Also the duration # T of the timer has to be indicated _A1 In particular to the duration of the flow control feedback information applicable to the BAP routing ID granularity.

Similarly, duration # T for case 3 _A1 There may also be a modified configuration mode to distinguish the uplink or downlink operation duration # T _A1 That is, when providing the first node with the duration-related configuration information for determining whether the next-hop node is available based on the flow control feedback information, the IAB donor may specify the configured duration # T _A1 The method is particularly suitable for uplink flow control feedback (hop-by-hop flow control feedback fed back to the first node by the father node) or downlink flow control feedback (hop-by-hop flow control feedback fed back to the first node by the child node). For example, as a variation of case 3, 3a, IAB donor configures duration # T for flow control feedback for all upstream BAP routing ID granularities _A1 ，T _A1 UL-1, configuring duration T of flow control feedback for all downstream BAP routing ID granularity _A1 -DL-1。

For timer duration # T _A2 Acquisition mode and configuration mode and duration # T _A1 Similarly, reference may be made specifically to the timer duration # T described above _A1 The description of (3) is not repeated herein.

In one possible implementation, the first node receives flow control feedback information # M1 of BAP routing ID granularity from the second node, which may include first indication information corresponding to the BAP routing ID # 1. The first indication information is used for indicating that: at the second node, the packet carrying the adaptation layer routing identity BAP routing ID #1 at the BAP layer has been congested, i.e. the second node is not available for packets carrying the adaptation layer routing identity BAP routing ID #1 at the BAP layer. Alternatively, in the flow control feedback information # M1, the first indication information may indicate that the second node is unavailable for data packets corresponding to one or more different BAP routing IDs (including BAP routing ID # 1), that is, the first indication information may correspond to a plurality of BAP routing IDs.

In a possible implementation manner, the first node receives second indication information that is being used for attempting link recovery and sent by the second node, where the second indication information indicates that Radio Link Failure (RLF) occurs between the second node and a next-hop node of the second node and the second node is attempting to recover a connection with the next-hop node, and then the first node may consider that the second node is unavailable or consider that a link between the first node and the second node is unavailable. The first node may reroute all packets that would otherwise need to be sent via the second node. As an example, referring to fig. 1, if IAB node 4 has a packet to send to IAB node 1, the path indicated by the BAP routing ID carried in the packet is: IAB node 4 → IAB node 2 → IAB node 1. If the IAB node 4 receives the second indication information sent by the IAB node 2, that is, the IAB node 2 finds that the RLF occurs on the link between the IAB node 2 and the IAB node 1 and is trying to recover, the node 4 may consider that the link between the node 4 and the IAB node 2 is not available and cannot continue to send any data packets to the IAB node 2.

In a possible implementation manner, if the flow control feedback information received by the first node and sent by the second node includes a flow control feedback report with a BAP routing ID granularity and a flow control feedback report with a BH RLC CH granularity. At this time, the first node may jointly determine, according to the feedback information of the two granularities, that the second node is congested for those data packets, and that the second node is not congested for those data packets, so as to determine the next-hop node for different data packets, respectively.

As an example, a first node receives at least two different BAP layer control PDUs (BAPcontrol PDUs) from a second node, and the BAP control PDUs can be classified into two different BAP control PDUs, which respectively contain two different granularities of flow control feedback information. The method comprises the steps that a flow control feedback information of BAP routing ID granularity is contained in a BAP control PDU, based on the flow control feedback information of the BAP routing ID granularity, a first node judges (or determines) that a data packet carrying the BAP routing ID #1 is congested at a second node, the second node is unavailable for the data packet carrying the BAP routing ID #1, rerouting needs to be carried out on the data packet carrying the BAP routing ID #1, the BAP routing ID #1 is used for indicating a path #1, and the data packet carrying the BAP routing ID #1 can be regarded as a data packet needing to be transmitted on the path # 1. The first node determines (or determines), based on the flow control feedback information of the BAP routing ID granularity, that the data packet carrying the BAP routing ID #1 is congested in the second node, which may be understood with reference to the description of the foregoing multiple possible embodiments in step S702, and details are not repeated here. On the other hand, contained in another BAP control PDU is flow control feedback information of BH RLC CH granularity, based on the feedback information and the threshold TH #2, the first node may determine which BH RLC CH packets mapped to the link between the first node and the second node are not available to the second node, and determine which BH RLC CH packets mapped to the link between the first node and the second node are still available to the second node. How to determine based on the flow control feedback information of the BH RLC CH granularity may specifically be understood by referring to step S802 in the method 800 in the embodiment corresponding to fig. 8, and determining, for the flow control feedback information of the BH RLC CH granularity, a description of determining a next hop node for a data packet (or determining whether to reroute the data packet), which is not described herein again.

Based on two different types of feedback information, the first node judges: there may be four different ways, as follows, for which packets are congested at the second node and the second node (or the link between the first node and the second node) is considered unavailable for these packets, and thus needs to be rerouted.

Mode 1: when the first node determines which data packets the link between the first node and the second node is unavailable for, the decision may be made based on the intersection of the two feedback information determinations. Illustratively, if the first node determines that the second node is unavailable for a data packet carrying a routing identifier of BAP routing ID #1 based on the flow control feedback information of the granularity of BAP routing ID, and determines that the second node is unavailable for a data packet that needs to be mapped onto BH RLC CH #1 according to the flow control feedback information of the granularity of BH RLC CH, where BH RLC CH #1 identifies a wireless backhaul RLC channel on a wireless backhaul link between the first node and the second node. Based on the judgment results of the two types of feedback information, the first node may intersect the two types of data packets, that is, the first node may determine that, for a data packet carrying a routing identifier of BAP routing ID #1 and needing to be mapped to BH RLC CH #1 according to the mapping rule and sent to the second node, the second node is unavailable and needs to reroute the data packets. In this application, which BH RLC CH the first node maps the packet to send to the second node may be determined based on a mapping rule configured by the IAB host, or may be determined based on configuration information of the default BH RLC CH acquired by the first node.

Mode 2: when the first node determines which data packets the link between the first node and the second node is unavailable for, the determination may be made based on a union of the two feedback information determination results. Illustratively, if the first node determines that the second node is unavailable for a data packet carrying a routing identifier of BAP routing ID #1 based on the flow control feedback information of the granularity of BAP routing ID, the second node is determined to be unavailable for a data packet that needs to be mapped onto BH RLC CH #1 according to the flow control feedback information of the granularity of BH RLC CH, where BH RLC CH #1 identifies a wireless backhaul RLC channel on a wireless backhaul link between the first node and the second node. Based on the judgment results of the two types of feedback information, the first node may collect a union of the two types of data packets, that is, when the first node may determine that the data packet conforms to any one of the two types of data packets, the second node is unavailable, that is, for a data packet carrying a routing identifier of BAP routing ID #1 or a data packet to be mapped to BH RLC CH #1 and sent to the second node, the second node is unavailable, and the data packets need to be rerouted.

Mode 3: the flow control feedback information corresponding to the routing identifier granularity is mainly used, that is, the first node can only judge according to the result of the flow control feedback information of the BAP routing ID granularity. Illustratively, if the first node determines, based on the flow control feedback information of the granularity of the BAP routing ID, that the second node is not available for a data packet with a routing identifier of BAP routing ID #1, and determines, according to the flow control feedback information of the granularity of the BH RLC CH, that the second node is not available for a data packet that needs to be mapped onto BH RLC CH #1, but is available for a data packet that needs to be mapped onto BH RLC CH #2, where BH RLC CH #1 and BH RLC CH #2 identify two wireless backhaul RLC channels on a wireless backhaul link between the first node and the second node, respectively. Based on the judgment results of the two types of feedback information, the first node only determines whether the second node is available for the data packet according to the result of the flow control feedback information with the BAP routing ID granularity, that is, as long as the route identifier carried in the data packet is BAP routing ID #1, the first node considers that the second node is unavailable for the data packet. For example, if a type of data packet is to be mapped onto the BH RLC CH #2 according to the mapping rule for transmission to the second node, but the routing identifier carried in the type of data packet is the BAP routing ID #1, the first node considers that the second node is not available for the type of data packet. It can also be understood that, at this time, the flow control information corresponding to the route identification (BAP routing ID) granularity has a higher priority.

Mode 4: the flow control feedback information corresponding to the granularity of the BH RLC CH is mainly used, that is, the first node may determine the flow control feedback information only according to the result of the flow control feedback information of the granularity of the BH RLC CH. Illustratively, if the first node determines, based on the flow control feedback information of the granularity of the BAP routing ID, that the second node is not available for the data packet carrying the routing ID of BAP routing ID #1 and is available for the data packet carrying the routing ID of BAP routing ID #2, and determines, based on the flow control feedback information of the BH RLC CH granularity, that the second node is not available for the data packet that needs to be mapped onto BH RLC CH #1 but is available for the data packet that needs to be mapped onto BH RLC CH #2, where BH RLC CH #1 and BH RLC CH #2 identify two wireless backhaul RLC channels on a wireless backhaul link between the first node and the second node, respectively. Based on the judgment results of the two types of feedback information, the first node only determines whether the second node is available for the data packet according to the result of the flow control feedback information of the BH RLC CH granularity, that is, as long as the next hop node in the transmission path indicated by the routing identifier carried by the data packet is the second node and is to be mapped to the BH RLC CH #1 to be sent to the second node, the first node considers that the second node is unavailable for the data packet. For example, if a type of data packet is to be mapped onto the BH RLC CH #1 according to the mapping rule for transmission to the second node, but the route identifier carried in the type of data packet is BAP routing ID #2, the first node considers that the second node is not available for the type of data packet. It can also be understood that, at this time, the priority of the flow control feedback information corresponding to the BH RLC CH granularity is high.

The first node can determine which decision mode is specifically adopted by the first node; or the second node indicates the first node, for example, the second node sends indication information to the first node, where the indication information is used to indicate that the first node determines availability of a link between the first node and the second node for a data packet by using any one of the manners 1 to 4, and the indication information may be carried by a Media Access Control (MAC) Control Element (CE), a BAP control PDU, or the like; or, by the configuration decision of the IAB donor (or, in the case that the IAB donor is an architecture in which CU-DU is separated, specifically, the IAB donor CU, or, in the case that the CU is further an architecture in which CP-UP is separated, specifically, the IAB donor CU-CP), for example, the IAB donor CU provides the first node with configuration information through an RRC message or an F1AP message, and instructs the first node to determine the availability of the link between the first node and the second node for the data packet by using any one of the modes 1 to 4. Optionally, if the configuration mode is an IAB donor configuration mode, different modes may be configured for the first node on different links (between the first node and different second nodes), and in this case, the configuration information provided by the IAB donor to the first node may also carry an identifier of the second node in addition to the indication information indicating the specific determination mode.

In this application, in the first node, the threshold TH #1 and/or TH #2 used for determining the available buffer space in the flow control feedback information related to the availability of the second node may be configured for the first node by the IAB donor (the IAB donor CU or the IAB donor CP) through an RRC message or an F1AP message, and the configuration mode may have multiple cases:

in case 1, the threshold TH #1 may be configured by BAP routing ID, that is, different values of the BAP routing ID may be configured, and the configured thresholds may be different, and the configuration information provided by the IAB donor for the first node may include a threshold list, where each entry (item) in the threshold list includes a specific value of one or more BAP routing IDs and a corresponding value of the threshold TH # 1.

In case 2, the threshold TH #2 may be configured by BH RLC CHs, that is, different BH RLC CH values, and configured thresholds may be different, and configuration information provided by the IAB donor for the first node may include a threshold list, where each item in the threshold list includes an identifier of one or more BH RLC CHs and a value of the corresponding threshold TH # 2. In this application, the identifier of each BH RLC CH may be determined by the identifier of the next hop node and the BH RLC CH ID on the link between the first node and the next hop node, where the identifier of the next hop node may be the BAP address of the next hop node.

In case 3, the threshold TH #1 may be configured from one next hop node to another, that is, the configured threshold TH #1 may be different for each next hop node of the first node, but for the same next hop node, the threshold TH #1 is applicable to all BAP routing IDs that may be involved in the flow control feedback information of the BAP routing ID granularity fed back to the first node by the next hop node. In this case, the configuration information provided by the IAB donor needs to carry values of one or more configured thresholds TH #1, and further needs to indicate which next-hop node or next-hop nodes of the first node each of the thresholds is specifically applicable to. The next hop node of the first node may be identified by the BAP address of the next hop node.

In case 4, the threshold TH #2 may be configured on a next hop node by next hop node basis, that is, the configured threshold TH #2 may be different for each next hop node of the first node, but for the same next hop node, the threshold TH #2 is applicable to all BH RLC CHs involved in the flow control feedback information of the BH RLC CH granularity fed back to the first node by the next hop node, or to all BH RLC CHs on the wireless backhaul link between the first node and the next hop node. In this case, the configuration information provided by the IAB donor needs to carry values of one or more configured thresholds TH #2, and further needs to indicate which next-hop node or next-hop nodes of the first node each of the thresholds is specifically applicable to. The next hop node of the first node may be identified by the BAP address of the next hop node.

In case 5, the threshold TH #1 or TH #2 may be configured by dividing the BAP routing ID and the BH RLC CH, and two different thresholds are configured, for example, the threshold corresponding to the flow control feedback information of all the BAP routing ID granularities is TH #1, and the threshold corresponding to the flow control feedback information of all the BH RLC CH granularities is TH #2. In this case, the configuration information provided by the IAB donor needs to carry the value of the configured threshold, and also needs to indicate which granularity the threshold is specifically applicable to, that is, the threshold corresponding to the flow control feedback information of the BAP routing ID granularity or the threshold corresponding to the flow control feedback information of the BH RLC CH granularity is specified. Exemplarily, the IAB donor may carry a value of a threshold TH #1 corresponding to the flow control feedback information of the BAP routing ID granularity in the configuration information provided by the first node, where the threshold TH #1 is applicable to each different BAP routing ID; or, the configuration information carries a value of a threshold TH #2 corresponding to the flow control feedback information of the BH RLC CH granularity, and the threshold TH #2 is applicable to each different BH RLC CH between the first node and the next hop node.

In case 6, the threshold TH #1 and TH #2 may be configured by configuring the same threshold TH # S for two different granularities of flow control feedback. That is, the configuration information provided by the IAB donor carries the configured value of the threshold TH # S, and the threshold TH # S is simultaneously applicable to the flow control feedback information of the BAP routing ID granularity of the first node and the flow control feedback information of the BH RLC CH granularity. It is to be understood that the threshold TH # S is applicable to each different BH RLC CH between the first node and the next hop node, and also to each different BAP routing ID of the first node. In this case, the configuration information provided by the IAB donor needs to carry the value of the configured threshold TH # S, and optionally, the configuration information may indicate that the threshold TH # S is simultaneously applicable to two different types of flow control feedback information.

In this application, for the configuration of the thresholds in case 5 and case 6, there may also be a modified configuration manner, which distinguishes whether uplink or downlink is configured for the threshold, that is, when providing the first node with the threshold-related configuration information that is determined based on the flow control feedback information whether the next-hop node is available, the IAB donor may specify that the configured threshold is specifically applicable to uplink flow control feedback (hop-by-hop flow control feedback that the parent node feeds back to the first node) or downlink flow control feedback (hop-by-hop flow control feedback that the child node feeds back to the first node). For example, as a modification 5a of case 5, the iab donor configures a threshold TH-UL-1 for the flow control feedback of all uplink BAP routing ID granularity, the threshold corresponding to the flow control feedback of all uplink BH RLC CH granularity is TH-UL-2, the threshold TH-DL-1 for the flow control feedback of all downlink BAP routing ID granularity, and the threshold corresponding to the flow control feedback of all downlink BH RLC CH granularity is TH-DL-2. For another example, for one variant 6a, iab donor of case 6, the thresholds TH-UL are configured for all upstream and TH-DL for all downstream flow control feedback.

As described above, if the first node determines that the second node is unavailable for certain packets of the BAP routing ID, the first node may perform rerouting for the packets, select an appropriate backup path, and then send the packets to the next hop node (e.g., third node) on the selected backup path.

At this time, optionally, the embodiment of the present application further includes step S703, where the third node sends the flow control feedback information to the first node.

The flow control feedback information sent by the third node to the first node may include: flow control feedback information # M3 of BAP routing ID granularity, and/or flow control feedback information # M4 of BH RLC CH granularity.

For example, the first node may receive a BAP control PDU from the third node, where the BAP routing ID granularity flow control feedback information is included, and the flow control feedback information of the BAP routing ID granularity includes values of multiple available buffer spaces corresponding to different BAP routing IDs.

Step S704, the first node determines, according to the flow control feedback information sent by the third node, that the third node can be used to transmit the data packet that needs to be rerouted.

It will be appreciated that the data packets that the first node needs to reroute may be the data packets that need to be transmitted over the first path. The first path may be regarded as a main path of a data packet carrying a BAP layer routing ID of BAP routing ID # 1. In a possible implementation manner, the first node may determine, according to the flow control feedback information # M3, that the third node is available to transmit a data packet carrying a BAP layer routing ID # 1.

The first node determines, according to the information # M3, that the third node is available to transmit the data packet carrying the BAP layer routing ID #1, or it may be understood that the first node determines that the third node is available to transmit the data packet that needs to be rerouted, where the data packet needs to be rerouted, that is, the first node determines that the second node is unavailable and the data packet needs to be rerouted in step S702 (for example, the data packet carrying the BAP layer routing ID # 1).

In a possible implementation manner, the first node receives flow control feedback information # M3 sent by the third node, where the flow control feedback information # M3 may be flow control feedback information of a BAP routing ID granularity, where the flow control feedback information # M3 includes multiple values of an available cache space corresponding to different BAP routing IDs, and if, in the different BAP routing IDs, one or more BAP address fields of the included destination nodes are the same, for a certain BAP address, if all the BAP routing IDs including the BAP address in # M3 are the sameIf the sum of the corresponding available buffer space values is greater than or equal to the preset threshold TH #3, the first node may determine that the third node is available for the data packet whose destination node is the BAP address, or the third node may serve as a next hop node on a selectable backup path when the first node reroutes the data packet whose destination node is the BAP address. On the contrary, if the sum of the available buffer space values corresponding to all the BAP routing IDs including the BAP address in # M3 is smaller than (or equal to) the preset threshold TH #3, the first node may determine that the data packet of the target node, which is the BAP address, is unavailable for the third node. Illustratively, in the flow control feedback information # M3 sent by the third node to the first node, the destination node fields of three BAP routing IDs (BAP routing ID #2, BAP routing ID #3, BAP routing ID # 4) are all BAP address #1, and the Sum of the dereferences of the available cache spaces corresponding to the three BAP routing IDs is Sum _{BAP address#1} (Sum _{BAP address#1} Is an integer greater than or equal to 0), if assumed to be A2 (A2 is an integer greater than 0), if the BAP address is the same, the Sum of the available cache space sizes of those BAP routing IDs _{BAP address#1} Greater than or equal to the threshold TH #3, the first node may determine that the third node is available for the data packet with the destination node being BAP address 1, i.e., that the link #2 is available for the data packet with the destination node being BAP address 1. Link #2 is a wireless backhaul link between the first node and the third node. If the BAP address of the destination node carried in the BAP routing ID #1 is also the BAP address #1, the first node may select the third node as the next hop node if rerouting is performed on the data packets carrying the BAP layer routing ID #1 when it is determined that the second node is unavailable for the data packets carrying the BAP routing ID # 1. Therefore, link #2 can also be understood as a backup link carrying a packet with the BAP routing ID #1 as the BAP layer routing ID to be rerouted. It will be appreciated that if Sum _{BAP address#1} Less than (or equal to) the threshold TH #3, the first node may consider that the third node is not available for the packet with the destination node being BAP address 1, i.e. the link #2 is not available for the packet with the destination node being BAP address 1.

As an example, as shown in fig. 6, it is assumed that at IAB node 1 (first node), the path indicated by the BAP routing identification BAP routing ID #1 contained in the data packet to be sent is path 2, i.e. the destination node of the data packet is IAB node 9, the main path is path #2, and IAB node 1 has determined that IAB node 2 is not available for the data packet to be sent based on the flow control feedback information of IAB node 2 (second node), and needs to perform rerouting on the data packet to be sent. In the IAB node 1 receiving the BAP routing ID granular flow control feedback information of the IAB node 3 (third node), the value of the available buffer space corresponding to the BAP routing ID3 is B3, and the value of the available buffer space corresponding to the BAP routing ID4 is B4, where the BAP routing ID3 is used to identify a path 3 to the IAB node 9, the BAP routing ID4 is used to identify a path 4 to the IAB node 9, and the IAB node 1 preconfigured threshold TH #3, and if B3+ B4 is greater than (or equal to) the threshold TH #3 (or may also be equal to the threshold TH # 3), the IAB node 1 determines that a link between the IAB node 3 and the IAB node 1 is an available link for a packet identified by a destination node as the BAP address of the IAB node 9 carried in the BAP layer. The IAB node 1 may send the data packet containing the BAP routing ID #1 to be sent to the IAB node 3 while performing rerouting.

In the present application, the granularity of the threshold TH #3 preset on the first node may have the following possibilities: for example, the threshold TH #3 may be of a destination node granularity (or a target BAP address granularity carried by a data packet in a BAP layer), that is, different target nodes may set different thresholds; or, the threshold TH #3 is the granularity of the first node, that is, the first node configures one threshold TH #3, which is applicable to different BAP addresses; or, the threshold TH #3 may also be of a next hop node granularity, that is, different thresholds TH #3 may be provided for different next hop nodes of the first node, where the threshold TH #3 corresponding to each next hop node is applicable to all BAP addresses involved in the flow control feedback information of the BAP routing ID granularity fed back to the first node by the next hop node.

In this application, the specific obtaining manner of the threshold TH #3 may be configured to the first node (for example, the IAB node 1 in fig. 6) in advance by the IAB node (which may be an IAB node CU or an IAB node CU-CP), and the IAB node may specifically configure the threshold TH #3 to the first node through an RRC message or an F1AP message; or, the third node (e.g., IAB node 3 in fig. 6) notifies the first node of the threshold TH #3 after determining (e.g., the third node notifies the first node of the threshold TH #3 through the BAP control PDU or the MAC CE); alternatively, the threshold TH #3 may be determined by the first node itself. Optionally, in consideration of multiple possibilities of the granularity of the threshold TH #3, if the first node acquires the threshold TH #3 by using the configuration of the IAB node or the manner notified by the third node, in the configuration message sent by the IAB node to the first node (for configuring the threshold TH #3 for the first node) or the notification message sent by the third node to the first node (for configuring the threshold TH #3 for the first node), it may be indicated what granularity (destination node granularity, or next-hop node granularity, or first node granularity) the configuration of the threshold TH #3 provided for the first node is specifically. Further optionally, if the first node acquires the threshold TH #3 by using a mode of configuration by the IAB node or notification by the third node, for a case that the threshold TH #3 is of a different granularity, the applicable range of each configured threshold TH #3 may be indicated in a configuration message sent by the IAB node to the first node or a notification message sent by the third node to the first node. For example, if the threshold TH #3 of the first node is the destination node granularity, in a configuration message (used to configure the threshold TH #3 for the first node) sent to the first node by the IAB donor in a notification message (used to configure the threshold TH #3 for the first node) sent to the first node by the third node, the configuration message carries one or more different values of the threshold TH #3, and it is necessary to indicate the identifier (i.e., the BAP address of the destination node) of one or more destination nodes to which the value of each threshold TH #3 is applicable; for another example, if the threshold TH #3 of the first node is of the next hop node granularity, in the configuration message (used to configure the threshold TH #3 for the first node) sent by the IAB donor the notification message (used to configure the threshold TH #3 for the first node) sent by the third node to the first node, the threshold TH #3 carries one or more different values of the threshold TH #3, and the identifier of the one or more next hop nodes to which the value of each threshold TH #3 is applicable needs to be indicated.

Optionally, if the first node acquires the threshold TH #3 by using a manner notified by the third node, the third node may acquire configuration information from the IAB donor (may be the IAB donor CU, or the IAB donor CU-CP) in advance, where the configuration information may include any one or more of the following: the third node provides the first node with what granularity of the threshold TH #3, the third node needs to provide the first node with specific values of the threshold TH #3 with different granularities and the applicable range of each threshold TH #3, and the applicable range of each threshold TH #3 can be understood by combining the description in the previous paragraph.

In another possible implementation manner, the first node may receive W pieces of flow control feedback information of the third node within a period of continuous duration # T3, where W is a positive integer greater than or equal to 1, the W pieces of flow control feedback information are the size of an available cache space of a BAP routing ID granularity of the third node, it is assumed that Z pieces of flow control feedback information include specific numerical values of the size of the available cache space corresponding to a backup path of a certain rerouting packet, it is assumed that a target node of the rerouting packet is a node identified by BAP address #1, in the Z pieces of flow control feedback information, values of the available cache space corresponding to all BAP routing IDs of the BAP address #1 included in each piece of flow control feedback information are summed, and an obtained result is { B } from the first to the Z th ₁ ，B ₂ ,…B _Z }(B _j Is an integer greater than 0, j is a positive integer, j is greater than or equal to 1 and less than or equal to Z), Z is less than or equal to W, if { B ≦ ₁ ，B ₂ ,…B _z That is, the first node may determine that the third node is available for the data packet to be rerouted, or that the third node may serve as a next-hop node on a backup path selectable when the first node performs rerouting for the data packet to be rerouted; on the contrary, if { B } ₁ ，B ₂ ,…B _z Any one of the values is less than (or equal to) the threshold TH #3, the first node may determine that the third node is not available for the data packet to be rerouted. Or, in yet another possible implementation, if { B } B ₁ ，B ₂ ,…B _z In which there is at least RIf the threshold TH #3 is greater than (or equal to) R, R is a positive integer satisfying 1 ≦ R ≦ Z, the first node may determine that the third node is available for the packet to be rerouted, or the third node may act as a next hop node on a backup path that may be selected when the first node performs rerouting for the packet to be rerouted. On the contrary, if { B } ₁ ，B ₂ Less than R of \8230bz } are greater than (or equal to) the threshold TH #3, the first node may determine that the third node is not available for the packet to be rerouted. Or, in another possible implementation, if for { B } ₁ ，B ₂ The result of the summation of \8230andbz is greater than (or equal to) the threshold TH #3, then the first node may determine that the third node is available for the packet to be rerouted; on the contrary, if to { B ₁ ，B ₂ The result of the summation of \8230Bzis less than (or equal to) the threshold TH #3, then the first node may determine that the third node is not available for the packet to be rerouted. Or, in yet another possible implementation, if { B } ₁ ，B ₂ The number of TH #3 greater than or equal to the threshold value in (8230); bz)' is N _above ，N _above The ratio to Z being greater than (or equal to) a threshold value R _TH5 ，0<R _TH5 The first node may determine that the third node is available for the packet to be rerouted; on the contrary, if N _above The ratio of W to W is less than a threshold value R _TH5 The first node may determine that the third node is unavailable for the packet to be rerouted. Or, in another possible implementation, if { B } ₁ ，B ₂ N is the number of TH #3 which is greater than (or equal to) the threshold value in (8230); bz) _above ，N _above The ratio of Z to Z is greater than (or equal to) a threshold value R _TH5 ，0<R _TH5 The first node may determine that the third node is available for the packet to be rerouted; on the contrary, if N _above The ratio of W to W is less than a threshold value R _TH5 The first node may determine that the third node is unavailable for the packet to be rerouted

As an example, the first node receives flow control feedback information of the BAP routing ID granularity sent by the third node, where the flow control feedback information includes one or more BAP routing IDs (for example, the BAP routing ID of the BAP address #1 as the destination node) For example, BAP routing ID #2 and BAP address contained in BAP routing ID #3 are values of the available cache space corresponding to BAP address # 1). If only the value of the available cache space corresponding to the BAP routing ID of the target node BAP address #1 exists, or if the sum of the values of the available cache space corresponding to the BAP routing ID of the target node BAP address #1 is greater than a threshold TH #3, starting a timer (taking the timer name as an example), assuming that the duration of the timer is # T3=40s, if W pieces of flow control feedback information are received within 40s after the timer is started, wherein a plurality of (assuming that Z pieces of) available cache space values corresponding to the BAP routing ID of the target node BAP address #1 are included, and if the sum of the values of the available cache space corresponding to the BAP routing ID of the target node BAP address #1 included in each piece of the Z pieces of flow control feedback information is greater than (or equal to) the threshold TH #3, the first node may determine that the first node is the target node BAP address #1 and the destination node is the available cache space of the target node BAP address data packet # 1. That is, the third node may be configured to transmit a data packet to be rerouted with the destination node being BAP address # 1. Or, if R pieces of flow control feedback information satisfy, among the flow control feedback information received from the W updates of the third node, before the timer times out (i.e. within 40s after the timer is started): in each flow control feedback information of the R, a sum of values of an available cache space corresponding to a BAP routing ID including a target node as BAP address #1 is greater than (or equal to) a threshold TH #3 (e.g., R =2, where one includes a value P of the available cache space corresponding to the BAP routing ID #2, where P is greater than TH #3, and the other includes a value Q of the available cache space corresponding to the BAP routing ID #2 ₂ And the available buffer space value Q corresponding to BAP routing ID #3 ₃ And Q ₂ +Q ₃ Greater than TH # 3), where R is a positive integer satisfying 1 ≦ R ≦ W, the first node may consider the third node to be available for the rerouted data packet whose destination node is BAP address #1, may select the third node as the next hop node whose destination node is the BAP address #1 data packet, and may stop the timing of the timer. It should be noted that the S pieces of flow control feedback may be continuous R pieces of flow control feedback information, or discontinuousR pieces of flow control feedback information.

In the present application, the obtaining manner and the configuration manner of the duration # T3 of the first node are similar to the obtaining manner and the configuration manner of the duration # T1, and are not described herein again.

The flow control feedback information W, Z, R received for the first node in the above embodiments _TH5 The configuration and the obtaining manner of the threshold TH #1 are similar to those of the threshold TH #1, and are not described herein again.

In a possible implementation manner, the first node may determine, according to the flow control feedback information # M4 of the BH RLC CH granularity sent by the third node, that the third node is available to transmit a packet that needs to be rerouted.

It will be appreciated that the data packets that the first node needs to reroute may be the data packets that need to be transmitted over the first path. The first path may be regarded as a main path of a data packet carrying a BAP layer routing ID of BAP routing ID # 1.

As an example, as shown in fig. 6, it is assumed that at IAB node 1 (the first node), the path indicated by the BAP routing identifier (e.g., BAP routing ID # 1) included in the data packet to be sent is path 2, that is, the destination node of the data packet is IAB node 9, the main path is path #2, and IAB node 1 has determined that IAB node 2 is not available for the data packet to be sent based on the flow control feedback information of IAB node 2 (the second node), and needs to perform rerouting on the data packet to be sent. The IAB node 1 receives BH RLC CH granularity flow control feedback information from the IAB node 3 (third node), and further determines whether the third node is available for the data packet to be sent (or referred to as a reroute data packet) based on the feedback information. The first node determines, based on the flow control feedback information # M4 of the BH RLC CH granularity of the third node, whether a rerouted packet (for example, a packet carrying a BAP routing ID of BAP routing ID # 1) is available from the third node, and specifically, there may be several possibilities as described below, which are described below.

Possibility 1, a data packet that needs to be rerouted at the first node (taking the data packet carrying the BAP routing ID of BAP routing ID #1 as an example) is configured with an appropriate BH RLC CH (for example, BH RLC CH #02 on link # 103) that needs to be mapped to on a link (for convenience of description, abbreviated as link # 103) between IAB node 1 (the first node) and IAB node 3 (the third node), that is, the first node is configured with one BH RLC CH that needs to be mapped to by a rerouted data packet on backup link # 103. In this case, if the value of the available buffer space corresponding to the BH RLC CH #02 in the flow control feedback information # M4 sent by the third node is greater than (or equal to) the threshold TH #4, the first node (IAB node 1) may determine that the third node (IAB node 3) is available for the rerouted packet carrying the BAP routing ID #1, otherwise, the IAB node 1 may determine that the IAB node 3 is not available for the rerouted packet carrying the BAP routing ID # 1.

Possibility 2, a packet that needs to be rerouted at IAB node 1 (taking the packet carrying the BAP routing ID identified as BAP routing ID #1 as an example) is on link #103 between IAB node 1 and IAB node 3, and is not configured with the appropriate BH RLC CH to which it needs to be mapped, i.e., the first node is not configured with a BH RLC CH to which it needs to be mapped on backup link # 103. In this case, considering that the BH RLC CH on any one link #103 may be selected to be sent to the third node when the first node determines that the rerouting packet needs to be sent to the third node, if a value of an available buffer space corresponding to any BH RLC CH in the flow control feedback information # M4 sent by the third node to the first node is greater than (or equal to) the threshold TH #4, the first node (IAB node 1) may determine that the third node (IAB node 3) is available for a rerouting packet carrying a BAP routing ID of BAP routing ID # 1. It can be understood that, if the values of the available buffer space corresponding to all BH RLC CHs in # M4 are all smaller than (or equal to) the threshold TH #4, the IAB node 1 may determine that the IAB node 3 is unavailable for the rerouted packet carrying the BAP routing identifier BAP routing ID # 1.

Possibility 3, a packet that needs to be rerouted at IAB node 1 (taking the packet carrying the BAP routing ID identified as BAP routing ID #1 as an example) is on link #103 between IAB node 1 and IAB node 3, and is not configured with the appropriate BH RLC CH to which it needs to be mapped, i.e., the first node is not configured with a BH RLC CH to which it needs to be mapped on backup link # 103. In this case, considering that the BH RLC CHs on any one link #103 may be selected to be sent to the third node when the first node determines that the rerouting packet needs to be sent to the third node, if the sum of values of available buffer spaces corresponding to all different BH RLC CHs in the flow control feedback information # M4 sent by the third node to the first node is greater than (or equal to) the threshold TH #4, the first node (IAB node 1) may determine that the third node (IAB node 3) is available for the rerouting packet carrying the BAP routing ID # 1. It can be understood that if the sum of the values of the available buffer space corresponding to all BH RLC CHs in # M4 is smaller than (or equal to) the threshold TH #4, the IAB node 1 may determine that the IAB node 3 is not available for the rerouted packet carrying the BAP routing identifier BAP routing ID # 1.

The IAB node 1 determines the third node (IAB node 3) by any one of the three possibilities, and after the rerouting packet carrying the BAP routing ID #1 is available, the IAB node 1 may send the packet containing the BAP routing ID #1 to the IAB node 3 when performing rerouting.

In this application, the granularity of the threshold TH #4 preset on the first node may have the following possibilities: for example, the threshold TH #4 may be a BH RLC CH granularity, that is, different thresholds may be set corresponding to different BH RLC CHs on a link between the first node and the third node; or, the threshold TH #4 is a granularity of the first node, that is, the first node configures a threshold TH #4, where the threshold is applicable to all BH RLC CHs on links between the first node and different nodes (or third nodes) serving as next hops on the backup path; or, the threshold TH #4 may be of a next hop node granularity, that is, different thresholds TH #4 may be provided for different next hop nodes of the first node, where the threshold TH #4 corresponding to each next hop node is applicable to all BH RLC CHs involved in the flow control feedback information of the BH RLC CH granularity fed back to the first node by the next hop node.

In this application, the specific obtaining manner of the threshold TH #4 may be configured to the first node (for example, the IAB node 1 in fig. 6) in advance by the IAB node (or may be the IAB node CU, or the IAB node CU-CP), and the IAB node may specifically configure the threshold TH #4 to the first node through an RRC message or an F1AP message; or, the third node (e.g., IAB node 3 in fig. 6) notifies the first node of the threshold TH #4 after determining (e.g., the third node notifies the first node of the threshold TH #4 through the BAP control PDU or the MAC CE); alternatively, the threshold TH #4 may be determined by the first node itself. Optionally, in consideration of multiple possibilities of the granularity of the threshold TH #4, if the first node obtains the threshold TH #4 by using the IAB donor the third node to configure the threshold TH #4, in the configuration message sent by the IAB donor to the first node (for configuring the threshold TH #4 for the first node) or in the notification message sent by the third node to the first node (for configuring the threshold TH #4 for the first node), it may indicate what granularity (BH RLC CH granularity, or next-hop node granularity, or first-node granularity) the configuration of the threshold TH #4 provided for the first node is specifically. Further optionally, if the first node acquires the threshold TH #4 by using a mode of configuration by the IAB node or notification by the third node, for a case where the threshold TH #4 is of a different granularity, the applicable range of each configured threshold TH #4 may be indicated in a configuration message sent by the IAB node to the first node or a notification message sent by the third node to the first node. For example, if the threshold TH #4 of the first node is a BH RLC CH granularity, in a configuration message (used to configure the threshold TH #4 for the first node) sent by the IAB node to the first node or in a notification message (used to configure the threshold TH #4 for the first node) sent by the third node to the first node, the configuration message carries one or more different values of the threshold TH #4 and needs to indicate one or more BH RLC CHs to which the value of each threshold TH #4 is applicable, where each BH RLC CH may specifically be identified by a link identifier BH RLC CH ID, and the link identifier may be indicated by an identifier of a next-hop node of the first node (e.g., a BAP address of the next-hop node); for another example, if the threshold TH #4 of the first node is of the next-hop node granularity, in a configuration message (used to configure the threshold TH #4 for the first node) sent by the IAB node to the first node or in a notification message (used to configure the threshold TH #4 for the first node) sent by the third node to the first node, the configuration message carries one or more different values of the threshold TH #4, and it is necessary to indicate an identifier (e.g., BAP address of the next-hop node) of one or more next-hop nodes to which the value of each threshold TH #4 is applicable.

Optionally, if the first node acquires the threshold TH #4 by using a manner notified by the third node, the third node may acquire configuration information from the IAB donor (may be the IAB donor CU, or the IAB donor CU-CP) in advance, where the configuration information may include any one or more of the following: the third node provides the first node with the threshold TH #4 of what granularity, and the third node needs to provide the first node with specific values of the threshold TH #4 of different granularities and a range to which each threshold TH #4 is applicable, and the range to which each threshold TH #4 is applicable can be understood by combining the description in the previous paragraph.

It should be noted that, in the present application, the method for determining whether the backup path is available may also refer to the method for determining whether the primary path is available in step S702, which is not described again.

It should be noted that, in the case that a certain data packet to be transmitted at the first node needs to be rerouted, but there are multiple (at least two) available backup links (or backup paths), the first node may arbitrarily select one of the backup links (or backup paths) to be used for rerouting the data packet; alternatively, the IAB donor (or the IAB donor CU, or the IAB donor CU-CP) may set different priorities for different backup links (or backup paths) and provide the different priorities to the first node, and the first node selects a backup link (or backup path) with the highest priority from among a plurality of available backup links (or backup paths) to reroute the packet. After selecting a backup link (or backup path) for rerouting the data packet, the first node transmits the rerouted data packet to a next hop node corresponding to the backup link (or backup path).

It should be noted that the configuration of the backup links (or the backup links and the priority, or the backup paths and the priority) may be configured with BAP routing IDs as granularity.

In this application, the determining, by the first node, whether to reroute a packet may specifically be: in addition to determining whether the primary path of the data is available (or whether the first link on the primary path is available, or whether the next-hop node of the first node on the primary path, that is, the second node is available), it is also necessary to determine whether the data packet has an available backup path (or an available backup link, or whether the next-hop node of the first node on the available backup path, that is, the third node is available). If the first node determines that the primary path of the data packet is unavailable and at least one backup path is available, the first node may reroute the data packet (i.e., select the backup path and send the data packet to the next-hop node on the backup path), otherwise, the first node does not reroute the data packet.

It should be noted that, in the present application, the first node may receive the flow control feedback information sent by the second node and the flow control feedback information sent by the third node at the same time. Or the first node receives the flow control feedback information sent by the third node firstly and then receives the flow control feedback information of the second node. It is also understood that the relative order between step S703 and step S704 and the preceding steps S701-S702 is not subject to any restrictions. In this application, step S701 and step S702 may constitute a separate embodiment, and are used to determine whether the main path of the data packet is available, and which data packets need to perform rerouting; step S703 and step S704 are optional steps, and may also constitute a separate embodiment for determining whether the backup link of the data packet is available.

In the application, the first node determines that the second node is unavailable, and after determining that the next hop is the third node, the first node can also continue to monitor the cache state of the second node to determine whether the second node is available. It can also be understood that the first node (specifically, the IAB node or the IAB node DU) may also cancel the rerouting of the data packets after the congestion on the primary path of the data packets is relieved, so that the data packets may continue to be transmitted on the primary path. For example, the first node may start a timer (e.g., a timer T-routing back) when rerouting of the packet is performed, so as to monitor whether congestion at the second node is relieved and determine whether the second node can continue to be used.

In this case, optionally, the embodiment of the present application further includes step S705 and step S706. The specific description is as follows.

In step S705, the first node receives the information # M5 sent by the second node.

The information # M5 may be flow control feedback information sent by the second node, where the flow control feedback information may be flow control feedback information of barouting ID granularity, where the flow control feedback information includes a size of an available cache space corresponding to the BAP routing ID #1 (used to indicate the first path, where the first path is a main path of the data packet, and a next-hop node of the main path is the second node).

In step S706, the first node determines whether the second node is available for the rerouted packet carrying the BAP routing ID #1 according to the information # M5.

If the first node judges (or determines) that the second node is available for the data packet carrying the BAP routing ID #1, which has already performed rerouting, according to the information # M5, the first node may stop rerouting the data packet carrying the BAP routing ID #1 to be transmitted, perform routing again according to the BAP routing ID part in the packet header, and send such data packet to the second node. Otherwise, the first node may continue to perform rerouting of such packets.

During specific execution, if the first node determines, based on the description of step S702, that the link between the first node and the second node is not available for the packet carrying the BAP routing ID #1 and reroutes the packet carrying the BAP routing ID #1 (it may also be understood that another backup path is selected for transmission, for example, the packets are sent to the third node), and if the first node receives the updated flow control feedback information # M5 of the second node, and the value of the available buffer space corresponding to the BAP routing ID #1 is greater than (or equal to) the threshold TH #5, the first node may consider that the link between the first node and the second node is already available for the packet carrying the BAP routing ID #1, and reroute the packets to the second node when performing routing selection, that is, the rerouting of the packets is cancelled, and the packet is continuously sent to the second node.

As an example, the first node determines whether to stop the re-routing mechanism that has been executed, and may determine based on the threshold TH #5 and a re-routing recovery timer (for example, the timer name T-routing back # 1): if the first node has determined, based on the description of step S702, that the link between the first node and the second node is not available for the packets carrying the BAP routing ID #1 and has rerouted the packets carrying the BAP routing ID #1 (it can also be understood that other backup paths are selected for transmission, for example, these packets are sent to the third node), if the first node receives one or more updated flow control feedback information sent by the second node during the time that the timer T-routing back #1 is running, and the value of the available buffer space corresponding to the BAP routing ID #1 is greater than (or equal to) the threshold TH #5, then the first node may consider that the second node is available for the packets carrying the BAP routing ID #1, in other words, the link between the first node and the second node may be considered to be available for the packets carrying the BAP routing ID #1, and the first node may consider that these packets are rerouted to the second node when performing routing, and then reroute the packets to the second node, that the packets carrying the BAP routing ID #1, and the second node may cancel the packets.

As another example, if the first node has determined, based on the foregoing description of step S702, that the link between the first node and the second node is not available for the packets carrying the BAP routing ID #1, and has rerouted the packets carrying the BAP routing ID #1 (it may also be understood that another backup path is selected for transmission, for example, the packets are sent to the third node), the first node receives T flow control feedback information of the second node within a continuous time period # T4, where T is a positive integer greater than or equal to 1, the T feedback information is the size of the available buffer space of the BAP routing ID granularity of the second node, and it is assumed that S of the T flow control feedback information include the size of the available buffer space corresponding to the BAP routing ID #1Specific values, from the first to the S-th are { C ₁ ，C ₂ ,…C _S (Cx is an integer greater than 0, x is a positive integer, 1. Ltoreq. X.ltoreq.S), S is a positive integer less than or equal to T, if { C ≦ S ₁ ，C ₂ ,…C _S Each of the values is greater than (or equal to) the threshold TH #5, the first node may consider that the second node is already available for the packet carrying the BAP routing ID #1, in other words, the link between the first node and the second node is already available for the packet carrying the BAP routing ID #1, and the first node may reroute the packets to the second node while performing routing, that is, cancel the rerouting of the packets, and continue to send the packets to the second node.

As another example, if the first node has determined, based on the description of the foregoing step S702, that the link between the first node and the second node is not available for the packets carrying the BAP routing ID #1, and has rerouted (it may also be understood that another backup path is selected for transmission, for example, the packets are sent to the third node) the packets carrying the BAP routing ID #1, the first node receives T pieces of flow control feedback information of the second node within a continuous time period # T4, where T is a positive integer greater than or equal to 1, the T pieces of flow control feedback information are the size of the available buffer space of the BAP routing ID granularity of the second node, and it is assumed that S of the T pieces of flow control feedback information include specific values of the size of the available buffer space corresponding to the BAP routing ID #1, and { C is set from the first node to the second node ₁ ，C ₂ ,…C _S (Cx is an integer greater than 0, x is a positive integer, 1. Ltoreq. X.ltoreq.S), S is a positive integer less than or equal to T, if { C ₁ ，C ₂ ,…C _S At least V is greater than or equal to a threshold TH #5, V is a positive integer satisfying 1 ≦ V ≦ S, the first node may consider the second node available for packets carrying BAP routing ID #1, in other words, the link between the first node and the second node may be considered available for packets carrying BAP routing ID #1, and the first node may reroute these packets to the first node while performing routing The two nodes cancel the rerouting of the data packets and continue to send the data packets to the second node.

For the two foregoing implementation manners of monitoring the flow control feedback information within a continuous time period # T4 to determine whether the second node is available for the packet carrying the BAP routing ID #1, as an example, the first node receives the flow control feedback information of the BAP routing ID granularity sent by the second node, if the value of the available buffer space corresponding to the BAP routing ID #1 is greater than (or equal to) the threshold TH #5, starts a timer (taking the timer name as an example) for the BAP routing ID #1, assuming that the timed time period is # T1=35s, if the values of the available buffer space corresponding to the BAP routing ID #1 in the flow control feedback information received within 35s after the timer is started are all greater than (or equal to) the threshold TH #5, at this time, the first node may consider that the second node is already available for the packet carrying the BAP routing ID # 1. Or, if, before the timer expires (i.e., within 35s after the timer is started), of the T updated flow control feedback information of the next hop node, J values of available buffer space corresponding to the BAP routing ID #1 carried in J flow control feedback information are all greater than (or equal to) the threshold TH #5, and J is a positive integer satisfying that J is greater than or equal to 1 and less than or equal to T, the first node may consider that the second node is still available for the packet carrying the BAP routing ID # 1. Or, if the flow control feedback information updated by the next-hop node is received before the timer expires (i.e., within 35s after the timer is started), when the values (or values) of the available buffer space corresponding to the BAP routing ID #1 carried in the J flow control feedback information are all greater than (or equal to) the threshold TH #5 and J is a positive integer, the first node may consider that the second node is still available for the packet carrying the BAP routing ID #1, and may reroute the packets to the second node when performing routing, that is, cancel the rerouting of the packets, continue to send the packets to the second node, and may stop the timing of the timer.

In this application, the obtaining manner and the configuration manner of the first node duration # T4 are similar to the obtaining manner and the configuration manner of the duration # T1, and are not described herein again.

As an example, if the first node receives T (T is an integer greater than 1) sub-flow control feedback information sent by the second node, there is T ₁ The numerical threshold TH #5 of the available buffer space corresponding to the BAP routing ID #1 in the sub-feedback, or the flow control feedback information of T times, wherein the ratio of the number of flow control feedback information carrying that the numerical value of the available buffer space corresponding to the BAP routing ID #1 is greater than (or equal to) the threshold TH #5 in the flow control feedback information of T times is greater than (or equal to) R _TH2 ，0<R _TH2 ≦ 1, the first node determines that the second node is already available. In particular, it may be a continuous T ₁ Secondary or discontinuous T ₁ Next, the process is carried out. T is a unit of ₁ Less than or equal to T.

In this application, the threshold TH #5 of the flow control feedback information used for determining the availability of the second node in the first node may be configured for the first node by the IAB node (or the IAB node CU, or the IAB node CP) through the RRC message or the F1AP message, and the configuration manner may have a variety of cases:

in case 1, the threshold TH #5 may be configured by the BAP routing ID, that is, different values of the BAP routing ID may be configured, and the configured thresholds may be different, and in the configuration information provided by the IAB donor for the first node, a threshold list may be included, where each entry (item) in the threshold list includes a specific value of one or more BAP routing IDs and a corresponding value of the threshold TH # 5.

In case 2, the threshold TH #5 may be configured from one next hop node to another, that is, the configured threshold TH #5 may be different for each next hop node of the first node, but for the same next hop node, the threshold TH #5 is applicable to all BAP routing IDs that may be involved in the flow control feedback information of the BAP routing ID granularity fed back to the first node by the next hop node. In this case, the configuration information provided by the IAB donor needs to carry values of one or more configured thresholds TH #5, and further needs to indicate which next-hop node or next-hop nodes of the first node each of the thresholds is specifically applicable to. The next hop node of the first node may be identified by the BAP address of the next hop node.

In case 3, the threshold TH #5 may be configured for the flow control feedback information with the BAP routing ID granularity, for example, the thresholds corresponding to the flow control feedback information with all BAP routing ID granularities are TH #5. In this case, the configuration information provided by the IAB donor needs to carry the value of the configured threshold TH #5, and also needs to indicate that the threshold is the flow control feedback information specifically applicable to the BAP routing ID granularity. Exemplarily, the IAB donor may carry a value of a threshold TH #5 corresponding to the flow control feedback information of the BAP routing ID granularity in the configuration information provided by the first node, where the threshold TH #5 is applicable to different BAP routing IDs.

In this application, for the configuration of the threshold in case 3, there may also be a modified configuration manner, which distinguishes whether to perform threshold configuration in an uplink or downlink manner, that is, when providing the first node with threshold-related configuration information that is determined based on the flow control feedback information whether the next-hop node is available, the IAB donor may specify that the configured threshold is specifically applicable to uplink flow control feedback (hop-by-hop flow control feedback from the parent node to the first node) or downlink flow control feedback (hop-by-hop flow control feedback from the child node to the first node). For example, as a variation 3a of case 3, the iab donor configures the threshold value TH #5-UL-1 for the flow control feedback for all uplink BAP routing ID granularity, and the threshold value TH #5-DL-1 for the flow control feedback for all downlink BAP routing ID granularity.

Similarly, the flow control feedback information T, T received by the first node in the above embodiment ₁ S, J, V and R _TH2 The configuration and the obtaining manner of the threshold TH #1 are similar to those of the threshold TH #1, and are not described herein again.

Similarly, in the above embodiment, the configuration manner of the X, Y, M, N, and B1 and the obtaining manner of the threshold TH #1 related to the first node determining whether the second node is available based on the flow control feedback information are similar to each other, and details are not repeated here.

For the implementation manner that the flow control feedback information is monitored based on the threshold TH #5 and the rerouting recovery timer to determine whether the second node is available for the rerouted data packet carrying the BAP routing ID #1, the start operation of the rerouting timer may be: as an example, after determining that the second node is unavailable for the data packet carrying the BAP routing ID #1 in step S702, the first node may start a timer T-routing back #1 for monitoring the congestion relief condition of the second node; or, after determining that the second node is unavailable for the data packet carrying the BAP routing ID #1 in step S702, if receiving the updated flow control feedback information sent by the second node, the first node may restart the timer T-routing back #1 when the value of the available buffer space corresponding to the BAP routing ID (for example, the BAP routing ID # 1) carried in the data packet on which rerouting is performed is greater than (or equal to) the threshold TH # 5. The operation of the rerouting timer may specifically be: if the first node receives the flow control feedback information updated by the second node before the rerouting timer T-routing back #1 times out, and the numerical value of the available buffer space corresponding to the BAP routing ID #1 in the flow control feedback information is smaller than (or equal to) the threshold TH #1, stopping the timing of the timer T-routing back #1. That is to say, if it is detected that the flow control feedback information is smaller than the threshold TH #1, the first node considers that the second node is still unavailable for the data packets carrying the BAP routing ID #1, and at this time, the first node may continue to perform the rerouting operation on the data packets.

In this application, the duration of the reroute recovery timer T-routing back #1 of the first node may also be configured by the IAB node (or the IAB node CU, or the IAB node CP) for the first node through the RRC message or the F1AP message, and the configuration mode may have multiple possibilities:

case 1: the duration of the timer T-routing back #1 may be configured by the BAP routing ID, that is, different values of the BAP routing ID may be configured, the duration of the configured timer T-routing back may be different, and the configuration information provided by the IAB node for the first node may include a timer duration list, where each item in the list includes a specific value of one or more BAP routing IDs and a value of the duration of the corresponding timer T-routing back.

Case 2: the duration of the timer T-routing back #1 may be configured from one next hop node to another, that is, the duration of the configured timer T-routing back may be different for each next hop node corresponding to the first node, but for the same next hop node, the duration of the timer T-routing back #1 is suitable for all BAP routing IDs that may be involved in the flow control feedback information of the BAP routing ID granularity fed back to the first node by the next hop node. In this case, the configuration information provided by the IAB node needs to carry one or more values of the configured time length of the T-routing back #1, and it needs to indicate that the time length of each T-routing back #1 is specifically applicable to which next-hop node or next-hop nodes of the first node. The next hop node of the first node may be identified by the BAP address of the next hop node.

Case 3: the configuration of the duration of the timer T-routing back #1 may also be a duration value configured for the feedback information of the BAP routing ID granularity. That is, the durations of the timers corresponding to the flow control feedback information of all the BAP routing ID granularities are the durations of T-routing back # 1. In this case, the configuration information provided by the IAB donor needs to carry the value of the configured timer duration T-routing back #1, and also needs to indicate that the duration of the timer is specifically the duration corresponding to the flow control feedback information applicable to the BAP routing ID granularity. Exemplarily, the IAB donor may carry a value of a duration of a timer T-routing back #1 corresponding to the flow control feedback information of the BAP routing ID granularity in the configuration information provided by the first node, where the duration of the timer T-routing back #1 is applicable to different BAP routing IDs.

For the configuration of the duration of the timer T-routing back #1 in case 3, there may also be a modified configuration manner, to distinguish the configuration of the duration of the timer T-routing back #1 in uplink or downlink, that is, when providing the configuration information related to the duration for the first node, which is determined based on the flow control feedback information, to determine whether the next-hop node is available, the IAB node may specify whether the configured duration of the timer T-routing back #1 is specifically applicable to uplink flow control feedback (hop-by-hop flow control feedback from the parent node to the first node) or downlink flow control feedback (hop-by-hop flow control feedback from the child node to the first node). For example, as a variation 3a of case 3, the IAB donor configures the duration of a timer T-routing back, T-routing back #1-UL-1, for all upstream BAP routing ID granularities, and configures the duration T-routing back #1-DL-1 for all downstream BAP routing ID granularities.

In the present application, the threshold TH #5 may be equal to or greater than the threshold TH #1. If the threshold TH #5 is set to be greater than the threshold TH #1, the occurrence of the situation that the first node judges frequent switching to the second node can be reduced, and resources are saved.

In a possible implementation manner, the first node receives fifth indication information of the second node, where the fifth indication information indicates that the link is successfully recovered, or; the first node receives sixth indication information of the second node, wherein the sixth indication information indicates that the second node is available for a data packet carrying an adaptation layer routing identification (BAP routing ID # 1) on a BAP layer. The first node may consider that the second node is already available for the packet carrying the BAP routing ID #1, or consider that the link between the first node and the second node is already available for the packet carrying the BAP routing ID #1, and the first node may reroute the packets to the second node while performing routing, that is, cancel the rerouting of the packets, and continue to send the packets to the second node.

That is to say, the method and the device can flexibly determine whether the data packet needs to be rerouted or not according to the feedback information of the second node, and can continue to detect the cache state of the second node after the data packet is rerouted, so that the data packet can be transmitted by using the main path as soon as possible after the congestion of the main path is relieved.

According to the communication method provided by the application, the first node can perform rerouting under the condition that the link is congested based on the received flow control feedback information, so that the link congestion can be relieved, the average transmission delay of data packets can be reduced, and the user experience is improved.

Fig. 8 is a communication method provided in the present application, where the method in fig. 8 includes:

in step S801, the second node sends information # M2 to the first node, where the information # M2 includes the size of the available buffer space of the BH RLC CH #1 of the second node.

The BH RLC CH #1 is configured to identify a first radio link control channel on a link #1 between a first node and a second node, where the second node is a next-hop node of the first node on the first link. For example, the information # M2 may be flow control feedback information of the second node, which may include a size of an available buffer space of the first radio link control channel on the first link.

In the present application, different types of service data or signaling may be mapped by the first node on different transmission channels for transmission to the next hop node, where the transmission channel may be a backhaul RLC channel (BH RLC CH) between the first node and the next hop node. If the second node feeds back the caching information of the BH RLC CH granularity in the flow control feedback information, it may be understood that the second node feeds back the size of the available caching space corresponding to different BH RLC channels on the link #1 in the caching state thereof, and the size of the available caching space corresponding to each BH RLC CH reflects a value of the maximum data amount that the first node can also send a data packet to the second node through the BH RLC CH of the link # 1. The flow control feedback information of the BH RLC CH granularity of the second node may include the size of one or more available buffer spaces corresponding to one or more BH RLC CHs. For example, there are 3 RLC channels on the link #1, which are BH RLC CH #1, BH RLC CH #2, and BH RLC CH #3, and the flow control feedback information # M2 of the second node may include the size of the available buffer space corresponding to BH RLC CH #1, the size of the available buffer space corresponding to BH RLC CH #2, and/or the size of the available buffer space corresponding to BH RLC CH # 3.

In step S802, the first node receives the message # M2, and determines that the data packet transmitted through the second node and requiring the first rlc channel mapped on the first link is unavailable according to the message # M2.

The first data packet is a data packet of a first radio link control channel that needs to be mapped on the first link, a main path of the first data packet is a first path, and the second node is a next hop node of the first node on the first path. In other words, if the first node performs routing according to the BAP routing ID carried in the first packet, the first packet needs to be sent to the second node, and according to the mapping rule configured by the first node, the first node needs to map the first packet to the first radio link control channel on the first link and send the first packet to the second node. Therefore, the first packet can also be regarded as a packet that one of the packets to be transmitted at the first node originally needs to be mapped to BH RLC CH #1 for transmission to the second node.

In this application, the first link is a link between the first node and the second node.

In this application, the first node may determine, according to the size of the available buffer space corresponding to the BH RLC CH #1 included in the information # M2 sent by the second node, a next hop node at which the first node transmits the first data packet. For example, in one possible implementation manner, if the size of the available buffer space corresponding to the BH RLC CH #1 in the information # M2 fed back by the second node is greater than the threshold TH #2 (or equal to the threshold TH # 2), the first node may determine that the second node is available for a packet mapped to the BH RLC CH #1 of the link between the first node and the second node, or determine that the wireless link between the first node and the second node is available for a packet of the BH RLC CH #1, and then the first node may determine to transmit the first packet through the second node.

In another possible implementation, if, in the information # M2 fed back by the second node, the size of the available buffer space corresponding to the BH RLC CH #1 is less than or equal to the threshold TH #2, the first node may determine that the second node is not available for a packet of the BH RLC CH #1 that needs to be mapped to a link between the first node and the second node, or that a radio link between the first node and the second node is not available for a packet of the BH RLC CH # 1. In this case, the first node needs to select appropriate backup links for those packets that would otherwise need to be mapped for transmission on BH RLC CH #1 to the second node. For example, according to the foregoing description, it is known that the first packet belongs to a packet that needs to be mapped on BH RLC CH #1 for transmission to the second node, and if the first node can determine that a backup path (e.g., the second path) is available for transmitting the first packet, the backup path and the main path of the first packet have the same target node, and the next hop node of the first node on the backup path is the third node, the first node can further determine to transmit the first packet through the third node. In summary, the backup path and the main path have the same target node, which may mean that the BAP routing ID used to identify the backup path and the BAP address field of the target node included in the BAP routing ID used to identify the main path are the same, that is, the backup path and the main path have the same target node in the wireless backhaul link; or, it may also mean that the backup path and the primary path are the same at the target node of the IP layer.

In this application, it should be understood that the first node selects an appropriate backup link for the data packets that would otherwise need to be mapped on BH RLC CH #1 for transmission to the second node, which may be understood as selecting an appropriate backup path for the data packets by the first node, where the backup link for the data packets is a link between the first node and a next hop node on the backup path.

In this embodiment, the determination of the case equal to the threshold value is also not limited. As an example, if the size of the available buffer space corresponding to the BH RLC CH #1 is equal to the threshold TH #2, the first node may determine that the second node is available for a packet mapped to the BH RLC CH #1 of the link between the first node and the second node, in which case the first node may determine that the second node is not available for a packet mapped to the BH RLC CH #1 of the link between the first node and the second node only when the size of the available buffer space corresponding to the BH RLC CH #1 is less than the threshold TH # 2. In this case, the first node may determine that the second node is available for the packet mapped to the BH RLC CH #1 of the link between the first node and the second node only when the size of the available buffer space corresponding to the BH RLC CH #1 is greater than the threshold TH # 2. The same applies to the case of being equal to the threshold value described later in each specific example.

As an example, the flow control feedback information # M2 received by the first node may be of BH RLC CH granularity. Specifically, referring to fig. 1, assuming that the first node is IAB node 1, the second node is IAB node 2, and the primary path of packet # P1 (i.e., the first packet) is path #1: IAB node 1 → IAB node 2 → IAB node 4, if the data packet # P1 is transmitted along the path #1, according to the mapping rule configured on the IAB node 1, the data packet # P1 can be mapped on the BH RLC CH #1 to be transmitted to the IAB node 2, wherein the BH RLC CH #1 is an RLC channel (or referred to as BH RLC channel) on the backhaul link between the IAB node 1 and the IAB node 2, and if the flow control feedback information # M2 fed back by the IAB node 2 to the IAB node 1, the size of the available buffer space corresponding to the BH RLC CH #1 is smaller than (or equal to) the threshold TH #2, at this time, the IAB node 1 determines that the IAB node 2 is unavailable for the data packet mapped to the BH RLC CH #1 of the link therebetween, that is, that the IAB node 1 determines that the IAB node 2 is unavailable for the data packet transmitted to the IAB node 2 by the BH CH #1 that needs to be mapped to the link therebetween, that the IAB node 1 can determine that the data packet # P1 is unavailable.

It should be noted that the obtaining manner and the configuring manner of the threshold TH #2 of the first node are already described in step S702 of the method 700, and are not described herein again.

In one possible implementation, the first node may receive M of the second node for a continuous duration # T2 _z Individual flow control feedback information, M _z Is a positive integer of 1 or more, M _z The individual flow control feedback information is the size of the available buffer space of the BH RLC CH granularity of the second node, which is assumed to be the M _z N2 flow control feedback information comprise specific numerical values of the size of the available buffer space corresponding to the BH RLC CH #1, and the first to the N2 are { A1, A2, \8230A _N2 (Ax is an integer greater than 0, x is a positive integer, x is greater than or equal to 1 and less than or equal to N2), and N2 is greater than or equal to M _z If { A1, A2, \ 8230%; A _N2 Each of which is less than or equal to a threshold TH #2, the first node may determine that a data packet mapped for transmission on BH RLC CH #1 to the second node is congested at the second node. In this caseThe first node needs to select a suitable backup link for a data packet to be sent to the second node, which is originally mapped on BH RLC CH #1, in the data packet to be sent. For example, if the first node may determine that a backup path is available for transmitting the packet # P1 (first packet) that needs to be mapped to the BH RLC CH #1, and a next-hop node of the first node on the backup path is a third node, the first node may further determine to transmit the first packet through the third node.

In the present application, the first node determines that a data packet mapped on BH RLC CH #1 and transmitted to the second node is congested at the second node, that is, the second node is not available for a subsequent data packet mapped on BH RLC CH #1 and transmitted to the second node, or is understood as being unavailable for a data packet mapped on BH RLC CH #1 and transmitted to the second node, or is understood as being unavailable for a data packet mapped on BH RLC CH # 1. The second node is a next hop node of the first node, and when the first node determines that the data packets sent to the second node by the second node for the BH RLC CH #1 which needs to be mapped to the link between the first node and the second node are unavailable, the data packets may be rerouted, that is, appropriate backup paths are selected for the data packets, and the data packets are sent to the next hop node on the backup paths.

In the present application, a packet mapped on BH RLC CH #1 may be understood as a packet mapped on BH RLC CH #1 and transmitted to the second node. The data packet to be mapped on BH RLC CH #1 may be understood as a data packet to be mapped on BH RLC CH #1 by the first node and sent to the second node, that is, a data packet to be mapped on BH RLC CH #1 by the first node and sent to the second node according to the configured mapping rule.

In yet another possible implementation, the first node may receive M of the second node for a continuous duration # T2 _z Individual flow control feedback information, M _z Is greater than or equal to1, the M is a positive integer _z The individual flow control feedback information is the size of the available buffer space of the granularity of BH RLC CH #1 of the second node, and is assumed to be M _z N2 flow control feedback information contains specific numerical values of the size of the available buffer space corresponding to BH RLC CH #1, and the first to the N2 th flow control feedback information are { A ₁ ，A ₂ ,…A _N2 (Ax is an integer greater than 0, x is a positive integer, 1. Ltoreq. X.ltoreq.N 2), N2 is less than or equal to M _z If { A } is a positive integer ₁ ，A ₂ ,…A _N2 At least Y2 of the data packets are less than or equal to the threshold TH #2, Y2 is a positive integer satisfying 1 ≦ Y2 ≦ N2, the first node may determine that the data packet mapped to BH RLC CH #1 and sent to the second node is congested at the second node. In this case, the first node needs to select an appropriate backup link for the data packet to be mapped on BH RLC CH #1 and transmitted to the second node. For example, if the first node may determine that a backup path is available for transmitting the packet # P1 (first packet) that needs to be mapped to the BH RLC CH #1, and a next-hop node of the first node on the backup path is a third node, the first node may further determine to transmit the first packet through the third node.

For the two aforementioned implementation manners of monitoring the flow control feedback information in a continuous time period # T2 to determine whether the second node is available for the data packet that needs to be mapped to the BH RLC CH #1, as an example, the first node receives flow control feedback information of the granularity of the BH RLC CH sent by the second node, if the value of the available buffer space corresponding to the BH RLC CH #1 is smaller than (or equal to) the threshold TH #2, a timer (for example, the name of the timer is timer) is started for the BH RLC CH #1, assuming that the time duration of the timer is # T2=28s, if the first node receives the flow control feedback information sent by the second node in 28s after the timer is started, the values of the available buffer space corresponding to the BH CH #1 are all smaller than (or equal to) the threshold TH #2, at this time, the first node may determine that the data packet that is sent to the second node by being mapped to the BH CH #1 is congested at the second node, and considers that the second node is not the data packet that needs to be mapped to the BH RLC CH #1, and the first node is considered as the first node is not the data packet that the BH RLC CH #1 is congested at this point, or the flow control feedback information is not consideredThe link between the node and the second node is not available for transmitting the first data packet. If the first node received the second node M before the timer expired (i.e., within 28s after the timer started), the first node M _z In the updated flow control feedback information, values corresponding to the available buffer space mapped in the BH RLC CH #1 and carried in X2 flow control feedback information are all larger than (or equal to) a threshold TH #2, and X2 is more than or equal to 1 and less than or equal to X2 and less than or equal to M _z The first node may consider the second node to be still available for the data packet mapped in BH RLC CH #1, may still select the second node as the next hop node for transmitting the first data packet, and may stop the timing of the timer. Or, if the flow control feedback information updated by the next hop node is received before the timer expires (i.e., within 28s after the timer is started), when the values (or values) corresponding to the available buffer space of the BH RLC CH #1, which are carried in the accumulated X2 flow control feedback information, are all greater than (or equal to) the threshold TH #2, where X2 is a positive integer, the first node may consider that the second node is still available for the packet mapped to the BH RLC CH #1, may still select the next hop node where the second node transmits the first packet, and may stop the timing of the timer.

As an example, if a first node receives M sent by a second node _z (M _z Integer greater than 1) sub-stream control feedback information, there is M ₀₁ The value of the available buffer space corresponding to the sub-feedback BH RLC CH #1 is smaller than (or equal to) threshold TH #2, or M _z In the sub-flow control feedback information, the number of flow control feedback information of which the numerical value of the available buffer space corresponding to the BH RLC CH #1 is smaller than (or equal to) the threshold TH #2 is M _z The ratio in the next generation is greater than (or equal to) R _TH3 ，0<R _TH3 ≦ 1, the first node may determine that a data packet mapped for transmission on BH RLC CH #1 to the second node is congested at the second node. In particular, it may be a continuous M ₀₁ Sub or discontinuous M ₀₁ Next, the process is repeated. M is a group of _z Is an integer of 1 or more, M ₀₁ Less than or equal to M _z 。

As an example, if the first node is within duration # T2 of timer operation, receiveM sent to the second node _z (M _z An integer greater than or equal to 1), the values of the available buffer spaces corresponding to the BH RLC CH #1 are all less than (or equal to) the threshold TH #2, and the first node may determine that a packet mapped on the BH RLC CH #1 and transmitted to the second node is congested at the second node. In particular, it may be a continuous M ₀₁ Sub or discontinuous M ₀₁ Next, the process is carried out.

In this application, the timer duration # T2 of the first node may also be configured for the first node by the IAB donor (or the IAB donor CU, or the IAB donor CP) through an RRC message or an F1AP message, and the configuration mode may have multiple possibilities:

In case 1, the duration # T2 may be configured by BH RLC CHs, that is, different BH RLC CH values, and the configured duration # T2 may be different, where the configuration information provided by the IAB donor for the first node may include a timer duration list, where each item in the list includes an identifier of one or more BH RLC CHs and a value of the corresponding duration # T2.

In case 2, the duration # T2 may be configured by next hop nodes, that is, the configured duration # T2 may be different for each next hop node of the first node, but for the same next hop node, the duration # T2 is applicable to all BH RLC CHs involved in the flow control feedback information of the BH RLC CH granularity fed back to the first node by the next hop node, or to all BH RLC CHs on the wireless backhaul link between the first node and the next hop node. In this case, the configuration information provided by the IABdonor needs to carry one or more values of the configured time length # T2, and further needs to indicate which next-hop node or next-hop nodes each time length # T2 is specifically applicable to the first node. The next hop node of the first node may be identified by the BAP address of the next hop node.

In case 3, the duration # T2 may be configured, or the durations of the timers corresponding to all BH RLC CHs in the flow control feedback information of the BH RLC CH granularity are all duration # T2. In this case, the configuration information provided by the IAB donor needs to carry the value of the configured timer duration # T2, and also needs to indicate that the duration of the timer is the duration corresponding to the flow control feedback information of the BH RLC CH granularity. For example, the IAB donor may carry a value of a duration # T2 corresponding to the flow control feedback information of the BH RLC CH granularity in the configuration information provided by the first node, where the duration # T2 is suitable for each different BH RLC CH.

Case 4: the duration # T2 may also be configured to configure the same duration # TS for two different granularities of flow control feedback. That is, the configuration information provided by the IAB donor carries the value of the configured time length # TS, and the time length # TS is simultaneously applicable to the flow control feedback information of the BAP routing ID granularity of the first node and the flow control feedback information of the BH RLC CH granularity. It is understood that the duration # TS is applicable to each different BH RLC CH between the first node and the next hop node, and also to each different BAP routing ID of the first node. In this case, the configuration information provided by the IAB donor needs to carry the value of the configured duration # TS, and optionally, the configuration information may indicate that the duration # TS is simultaneously applicable to two different types of flow control feedback information.

For the configuration of the duration # T2 in the cases 3 and 4, there may also be a modified configuration manner, to distinguish whether to perform the configuration of the duration # T2 in the uplink or the downlink, that is, when providing the configuration information related to the duration that is determined whether the next-hop node is available based on the flow control feedback information for the first node, the IAB donor may specify whether the configured duration # T2 is specifically applicable to uplink flow control feedback (hop-by-hop flow control feedback fed back to the first node by the parent node) or downlink flow control feedback (hop-by-hop flow control feedback fed back to the first node by the child node). For example, as a variation 3a of case 3, the iab donor configures a duration # T2-UL-2 for flow control feedback for all uplink BH RLC CH granularities, and a duration # T2-DL-2 for flow control feedback for all downlink BH RLC CH granularities. For example, as a modification 4a of case 4, the iab donor configures a duration # T2-UL for all uplink and a duration # T2-DL for all downlink fluidic feedback.

In one possible implementation manner, the first node receives flow control feedback information of the second node, where the flow control feedback information includes a numerical value of an available buffer space corresponding to the BH RLC CH #1, for example, # B2. If the first node detects that the data amount of the data packet mapped in the BH RLC CH #1 is larger than or equal to # B2 and sent to the second node (namely, the first node sends the data packet with the data amount larger than or equal to # B2 to the second node through the BH RLC CH # 1), the first node determines that: the second node is unavailable for data packets of BH RLC CH #1 mapped on the first link between the first node and the second node.

As an example, the first node receives flow control feedback information # M2 of BH RLC CH granularity from the second node, where the flow control feedback information # M2 includes a value of available buffer space corresponding to BH RLC CH #1, for example, # B2, and a duration # T of the first node before receiving the flow control feedback information # M2 sent by the second node _B1 In this case, a packet having an excessive amount of data greater than or equal to # B2 has been transmitted to the second node through the BH RLC CH # 1. Accordingly, the first node determines: the second node is not available for data packets sent to the second node by BH RLC CH #1 that needs to be mapped to a link between the first node and the second node. The first node may reroute the packets, i.e., select a suitable backup path for the packets, and send the packets to the next-hop node on the backup path.

As another example, the first node receives the flow control feedback information # M2 of the BH RLC CH granularity from the second node, which includes the value of the available buffer space corresponding to the BH RLC CH #1, for example, # B2, and the first node receives the flow control feedback information # M2 sent by the second node for a duration # T _B2 Meanwhile, the data amount of the data packet transmitted to the second node by the BH RLC CH #1 is equal to or larger than # B2 (that is, the first node transmits the data packet whose data amount is equal to or larger than # B2 to the second node by the BH RLC CH # 1). Accordingly, the first node determines: the second node is not available for data packets sent to the second node by BH RLC CH #1 that need to be mapped to the link between the first node and the second node. The first node may perform rerouting of the data packets, e.g., select an available backup path and send the data packets to the next hop node on the backup path. Optionally, the duration # T after the first node receives the flow control feedback information # M2 sent by the second node _B2 In this case, the first node has not received the flow control feedback information of another updated BH RLC CH granularity sent by the second node.

As another example, the first node receives flow control feedback information # M2 of BH RLC CH granularity from the second node, where the flow control feedback information # M2 includes a numerical value of an available buffer space corresponding to BH RLC CH #1, for example, # B2, and after receiving the flow control feedback information # M2, the first node sends a data amount of a data packet of BH RLC CH #1 to the second node, which reaches # B2 (that is, a data amount of a data packet sent by the first node to the second node through BH RLC CH #1 reaches # B2), and the first node may determine: the second node is not available for data packets sent to the second node by BH RLC CH #1 that needs to be mapped to a link between the first node and the second node. The first node may perform rerouting of the packets, e.g., select an available backup path and send the packets to the next hop node on the backup path.

As another example, the first node receives flow control feedback information # M2 of the BH RLC CH granularity from the second node, where a value of an available buffer space corresponding to the BH RLC CH #1 is included, for example, # B2, the first node sends a data amount of a packet of the BH RLC CH #1 to the second node to # B2 after receiving the flow control feedback information # M2 (i.e., a data amount of a packet sent by the first node to the second node through the BH RLC CH #1 reaches # B2), and before receiving another updated feedback information of the BH RLC CH granularity sent by the second node (i.e., the first node has not received flow control feedback information of another updated BH RLC CH granularity sent by the second node), the first node may determine: the second node is not available for data packets sent to the second node by BH RLC CH #1 that need to be mapped to the link between the first node and the second node. The first node may perform rerouting of the packets, e.g., select an available backup path and send the packets to the next hop node on the backup path.

In this application, the time length # T of the timer of the first node is long _B1 Or the IAB donor (or IAB donor CU or IAB donor CP) configures the first node through RRC message or F1AP message, and the configuration mode can have various modesPossibility:

case 1: duration # T _B1 Can be configured by BH RLC CH, namely different BH RLC CH values and configured time length # T _B1 Alternatively, the configuration information provided by the IAB donor to the first node may comprise a timer duration list, where each item in the list comprises an identification of one or more BH RLC CHs, and a corresponding duration # T _B1 The value of (c).

Case 2: duration # T _B1 May be configured next hop node by next hop node, i.e. the configured time length # T corresponds to each next hop node of the first node _B1 May be different, but for the same next hop node, duration # T _B1 The method is applicable to all BH RLC CHs which are involved in flow control feedback information of BH RLC CH granularity fed back to the first node by the next hop node, or all BH RLC CHs on a wireless backhaul link between the first node and the next hop node. In this case, the IAB donor provides the configuration information that needs to carry one or more configured time lengths # T _B1 The value of (1) is also indicated for each duration # T _B1 In particular to which next hop node or next hop nodes of the first node. The next hop node of the first node may be identified by the BAP address of the next hop node.

Case 3: duration # T _B1 The configuration of (3) may be that the durations of the timers corresponding to all BH RLC CHs in the flow control feedback information of the BH RLC CH granularity are duration # T _B1 . In this case, the IAB donor needs to carry the configured timer duration # T in the configuration information provided by the IAB donor _B1 Also needs to specify the timer duration # T _B1 That is, the duration corresponding to the flow control feedback information of the BH RLC CH granularity. For example, in the configuration information provided by the IAB donor for the first node, the duration # T corresponding to the flow control feedback information of the BH RLC CH granularity may be carried _B1 Is taken to be the time length # T _B1 Applicable to each different BH RLC CH.

Case 4: duration # T _B1 The configuration of (3) may also be to configure the same duration # T for two different granularities of flow control feedback _S . That is, the configured duration # T is carried in the configuration information provided by the IAB donor _S Is taken to be the value of time length # T _S Meanwhile, the method is suitable for the flow control feedback information of the BAP routing ID granularity of the first node and the flow control feedback information of the BH RLC CH granularity. It is understood that the duration # T _S The method is applicable to different BH RLC CHs between the first node and the next hop node and different BAP routing IDs of the first node. In this case, the IAB donor provides the configuration information, which needs to carry the configured time length # T _S Optionally, the duration # T may also be indicated in the configuration information _S And meanwhile, the method is suitable for two different types of flow control feedback information.

Duration # T for case 3 and case 4 _B1 There may also be a modified configuration mode to distinguish between the uplink and downlink execution time periods # T _B1 When the configuration information related to the time length that is determined whether the next hop node is available based on the flow control feedback information is provided for the first node, the IAB donor may specify the configured time length # T _B1 The method is particularly suitable for uplink flow control feedback (hop-by-hop flow control feedback fed back to the first node by the father node) or downlink flow control feedback (hop-by-hop flow control feedback fed back to the first node by the child node). For example, as a variation of case 3, 3a, the flow control feedback configuration duration # T for all uplink BH RLC CH granularities for the iab donor _B1 UL-2, flow control feedback configuration duration T for all downlink BH RLC CH granularity _B1 -DL-2. For example, one variation 4a, iab donor as scenario 4 configures a duration # T for all upstream fluidic feedback _B1 UL, configuring duration T for all downstream flow control feedback _B1 -DL。

For timer duration # T _B2 Acquisition mode and configuration mode and duration # T _B1 Similarly, reference may be made specifically to the timer duration # T described above _B1 The description of (3) is not repeated herein.

Similarly, the X2, Y2, M involved in determining whether the second node is available for the first node based on the flow control feedback information in the above embodiments ₀₁ ，M _z N2, B2 and R _TH3 Arrangement mode and acquisition mode ofSimilar to the obtaining and configuring manner of the threshold TH #2, the description is omitted here.

In one possible implementation, the first node receives flow control feedback information # M2 of BH RLC CH granularity from the second node, which may include third indication information corresponding to BH RLC CH # 1. The third indication information is used for indicating that: at the second node, the data packet mapped on BH RLC CH #1 has been congested (or the data packet mapped on BH RLC CH #1 and sent to the second node is congested at the second node), i.e., the second node is unavailable for the data packet that needs to be mapped on BH RLC CH # 1. Alternatively, in the flow control feedback information # M2, the third indication information may indicate that the second node is not available for a packet that needs to be mapped on one or more different BH RLC CHs (including BH RLC CH # 1), that is, the third indication information may correspond to a plurality of BH RLC CHs.

In a possible implementation manner, the first node receives fourth indication information that the second node is attempting to perform link recovery, where the fourth indication information indicates that a radio link failure occurs between the second node and a next-hop node of the second node and the second node is attempting to recover a connection with the next-hop node, and then the first node may consider that the second node is unavailable or consider that a link between the first node and the second node is unavailable. The first node may reroute all packets that would otherwise need to be sent via the second node. As an example, referring to fig. 1, if there is a packet on the IAB node 4 to send to the IAB node 1, if the IAB node 4 receives the fourth indication information sent by the IAB node 2, that is, if the IAB node 2 finds that the RLF occurs on the link between the IAB node 2 and the IAB node 1 and is trying to recover, the IAB node 4 may consider that the link between itself and the IAB node 2 is not available, and cannot continue sending any packet to the node 2.

It should be understood that, in this embodiment, the first node may also receive the feedback information of the BAP routing ID granularity of the second node at the same time. At this time, the flow control feedback information received by the first node includes a flow control feedback report of the granularity of the BH RLC CH and a flow control feedback report of the granularity of the BAP routing ID. At this time, the first node may jointly determine, according to the feedback information of the two granularities, that the second node is congested for those data packets, and that the second node is not congested for those data packets, so as to determine next-hop nodes for different data packets, respectively. Specifically, the decision may be made by referring to any one of the determination methods in the mode 1 to the mode 4 in the step S702 in the method 700, and details are not described here.

As described above, if the first node determines that the second node is unavailable for packets requiring certain BH RLC CHs mapped to the first link, the first node may perform rerouting for the packets, select an appropriate backup path, and then transmit the packets to a next hop node (e.g., a third node) on the selected backup path.

At this time, optionally, the embodiment of the present application further includes step S803, where the third node sends the flow control feedback information to the first node.

The flow control feedback information sent by the third node to the first node may include: flow control feedback information # M4 of BH RLC CH granularity, and/or flow control feedback information # M3 of BAP routing ID granularity.

For example, the first node may receive a BAP control PDU from the third node, where the BAP control PDU includes flow control feedback information of BH RLC CH granularity, and the flow control feedback information of the BH RLC CH granularity includes values of a plurality of available buffer spaces corresponding to different BH RLC CHs.

Step S804, the first node determines, according to the flow control feedback information sent by the third node, that the third node can be used to transmit the data packet that needs to be rerouted.

It is understood that the data packet that the first node needs to be rerouted may be a data packet that needs to be mapped on the first radio link control channel (i.e., BH RLC CH # 1) on the first link. The first link is a link between the second node and the first node. In a possible implementation manner, the first node may determine, according to the flow control feedback information # M4: the third node may be configured to transmit packets that need to be rerouted, i.e., the link between the first node and the third node may be configured to transmit packets that would otherwise need to be mapped on BH RLC CH #1 for transmission to the second node, or it may be understood that the third node may be configured to transmit packets that would otherwise need to be mapped on BH RLC CH #1 for transmission to the second node.

For example, the first node may determine, according to the information # M4, that the third node is available to transmit a packet that needs to be mapped on the BH RLC CH #1 to the second node, or it may be understood that the first node determines that the third node is available to transmit a packet that needs to be rerouted, where the packet that needs to be rerouted is a packet that the first node determines in the foregoing step S802 that the second node is unavailable and needs to be rerouted (for example, according to the BAP routing ID in the packet and the mapping rule configured at the first node, those packets that need to be mapped on the BH RLC CH #1 of the link between the first node and the second node and sent to the second node).

In one possible implementation manner, the first node may determine, according to the flow control feedback information # M4 of the BH RLC CH granularity sent by the third node, that the third node is available to transmit data packets that need to be rerouted (those data packets that would otherwise need to be mapped to the BH RLC CH #1 of the link between the first node and the second node and sent to the second node).

In another possible implementation, the first node determines, according to the information # M3, that the third node is available to transmit the data packets that need to be rerouted (those data packets that would otherwise need to be mapped to be sent to the second node on BH RLC CH #1 of the link between the first node and the second node). Wherein, the information # M3 is flow control feedback information of the BAP routing ID granularity.

Taking the data packet that needs to be rerouted as the first data packet as an example, and the BAP routing identifier included in the first data packet is BAP routing ID #1, the first node determines that the third node is available for the first data packet that needs to be rerouted, which may refer to the above two embodiments, and the specific process may refer to step S704 in the method 700, which is not described herein again.

It should be understood that, in this embodiment, the method for determining whether the third node is used may also refer to the method for determining whether the second node is available in step S802, and the second node may be replaced by the third node for understanding, which is not described again.

It should be noted that, in the case that a certain to-be-transmitted data packet at the first node needs to be rerouted but there are multiple (at least two) available backup links (or backup paths), the first node may arbitrarily select one of the backup links to reroute the data packet; alternatively, the IAB donor (or the IAB donor CU, or the IAB donor CU-CP) may set different priorities for different backup links (or backup paths) and provide the different priorities to the first node, and the first node selects the backup link (or backup path) with the highest priority among the multiple available backup links (or backup paths) to reroute the packet. After selecting a backup link (or backup path) for rerouting the data packet, the first node transmits the rerouted data packet to a next hop node corresponding to the backup link (or backup path).

It should be noted that the configuration of the backup link (or the backup link and priority, or the backup path and priority) may be configured with the granularity of BH RLC CH.

In this application, the first node determines whether to reroute a packet, which may specifically be: in addition to determining whether the primary path of the data packet is available (or whether the first link on the primary path is available, or whether the second node, which is the next hop node of the first node on the primary path, is available), it also needs to determine whether the data packet has an available backup link (or whether an available backup path is available, or whether the third node, which is the next hop node of the first node on the backup path, is available). If the first node determines that the first link on the primary path of the data packet is unavailable and at least one backup path is available, the data packet may be rerouted (i.e., the backup path is selected and the data packet is sent to the next-hop node on the backup path), otherwise the first node does not reroute the data packet.

It should be noted that, in the present application, the first node may receive the flow control feedback information sent by the second node and the flow control feedback information sent by the third node at the same time. Or the first node receives the flow control feedback information sent by the third node firstly and then receives the flow control feedback information of the second node. It is also understood that the relative order between step S803 and step S804 and the previous steps S801-S802 is not limited in any way. In this application, step S801 and step S802 may constitute a single embodiment, and are used to determine whether a primary path of a packet is available, and which packets need to be rerouted; step S803 and step S804 are optional steps, and may also constitute a separate embodiment for determining whether a backup link of a data packet is available.

In the application, the first node determines that the second node is unavailable, and after determining that the next hop is the third node, the first node can also continue to monitor the cache state of the second node to determine whether the second node is available. It can also be understood that the first node (specifically, the IAB node or the IAB node DU) may also cancel the rerouting of the data packets after the congestion of the second node of the data packets is relieved, so that the data packets may continue to be transmitted on the originally intended link. For example, the first node may start a timer (e.g., a timer T-routing back) when rerouting is performed on the data packet, so as to monitor whether congestion at the second node is relieved and determine whether the second node can continue to be used.

In this case, optionally, the embodiment of the present application further includes step S805 and step S806. The specific description is as follows.

In step S805, the first node receives the information # M6 sent by the second node.

The information # M6 may be flow control feedback information sent by the second node, where the flow control feedback information may be flow control feedback information of a BH RLC CH granularity, where the flow control feedback information includes a size of an available buffer space corresponding to BH RLC CH #1 (used to indicate a first radio link control channel on a link between the first node and the second node, or an ID of the BH RLC CH of the first radio link control channel).

In step S806, the first node determines whether the second node is available for the data packet to be mapped on the BH RLC CH #1 and transmitted to the second node according to the information # M6.

It should be noted that, in this step, the first node determines whether the second node is available for the data packet that needs to be mapped on the BH RLC CH #1 and sent to the second node, which can be described as follows: the first node determines whether the second node is available for data packets that need to be mapped on BH RLC CH # 1.

If the first node determines (or determines) that the second node is available for the data packet that needs to be mapped on the BH RLC CH #1 according to the information # M6, the first node may stop rerouting the data packet to be transmitted, which originally needs to be mapped on the BH RLC CH #1 and sent to the second node, and then resend such data packet to the second node. Otherwise, the first node may continue to perform rerouting of such packets.

It is understood that, before step S806, the first node has performed rerouting on the data packets that should be mapped on the BH RLC CH #1 and sent to the second node, for example, the first node determines, according to step S802, that the second node is not available for the data packets that should be mapped on the BH RLC CH #1 and sent to the second node, and needs to perform rerouting on the data packets, and the first node further determines, based on the descriptions of steps S803 and S804, that the third node is available for the data packets that need to be rerouted, and reroutes the data packets (i.e., selects the third node as the next hop node). If the first node receives the updated flow control feedback information # M6 of the second node, and the value corresponding to the available buffer space of the BH RLC CH #1 is greater than (or equal to) the threshold TH #6, it may determine that the link between the first node and the second node is already available for the data packets that need to be mapped to the BH RLC CH #1, and the first node may reroute the data packets to the second node while performing routing, that is, cancel the rerouting of the data packets, and continue to send the data packets to the second node.

As an example, the first node determines whether it is necessary to stop the rerouting mechanism that has been executed, and may determine based on the threshold TH #6 and a rerouting recovery timer (for example, with the timer name T-routing back # 2): if the first node has determined, based on the foregoing description in step S802, that the link between the first node and the second node is not available for the packets that need to be mapped to BH RLC CH #1, and has rerouted the packets that need to be mapped to BH RLC CH #1 (it may also be understood that other backup links are selected for transmission, for example, the packets are transmitted to the third node), if the first node receives one or more updated flow control feedback messages sent by the second node during the time that the timer T-routing back #2 is running, and the values of the available buffer space corresponding to BH RLC CH #1 are all greater than (or equal to) the threshold TH #6, the first node may consider that the second node is available for the packets that need to be mapped to BH RLC CH #1, in other words, the link between the first node and the second node may be considered to be available for the packets that need to be mapped to BH RLC CH #1, and the first node may reroute the packets to the second node while performing routing, i.e., may cancel the packets that the packets are rerouted to the second node, and the second node may continue to send the packets to the second node.

As another example, if the first node has determined, based on the description of step S802, that the link between the first node and the second node is not available for the data packets that need to be mapped to BH RLC CH #1, and has rerouted the data packets that need to be mapped to BH RLC CH #1 (it may also be understood that other backup links are selected for transmission, for example, the data packets are transmitted to the third node), the first node receives T1 pieces of flow control feedback information of the second node within a continuous time period # T5, T1 is a positive integer greater than or equal to 1, the T1 pieces of flow control feedback information are the size of the available buffer space of the BH RLC CH granularity of the second node, and assuming that S1 pieces of flow control feedback information include specific values of the size of the available buffer space corresponding to BH RLC CH #1, and { C is provided from the first to S1 ₁ ，C ₂ ,…C _S1 (Cx is an integer greater than 0, x is a positive integer, 1. Ltoreq. X.ltoreq.S 1), S1 is a positive integer less than or equal to T1, if { C ₁ ，C ₂ ,…C _S1 Each of which is greater than (or equal to) the threshold TH #6, the first node can consider the second node as being available for the data packets that need to be mapped in BH RLC CH #1, i.e., can consider the link pair between the first node and the second node When the mapping is needed to be available in BH RLC CH #1, the first node may reroute the packets to the second node while performing routing, i.e., the packets are rerouted, and continue to be sent to the second node.

As another example, if the first node has determined, based on the description of the foregoing step S802, that the link between the first node and the second node is not available for the data packets that need to be mapped to BH RLC CH #1, and has rerouted (it may also be understood that other backup links are selected for transmission, for example, these data packets are transmitted to the third node) the data packets that need to be mapped to BH RLC CH #1, the first node receives T1 pieces of flow control feedback information of the second node within a continuous time period # T5, T1 is a positive integer greater than or equal to 1, the T1 pieces of flow control feedback information are the size of the available buffer space of the BH RLC CH granularity of the second node, and assuming that S1 pieces of flow control feedback information include specific values of the size of the available buffer space corresponding to BH RLC CH #1, and { C is provided from the first to S1 ₁ ，C ₂ ,…C _S1 (Cx is an integer greater than 0, x is a positive integer, 1. Ltoreq. X.ltoreq.S 1), S1 is a positive integer less than or equal to T1, if { C ₁ ，C ₂ ,…C _N At least U1 is less than or equal to a threshold TH #5, U1 is a positive integer satisfying 1 ≦ U1 ≦ S1, the first node may consider the second node available for the data packets to be mapped to BH RLC CH #1, in other words, the link between the first node and the second node may be considered available for the data packets to be mapped to BH RLC CH #1, and the first node may reroute the data packets to the second node while performing routing, i.e., the data packets are rerouted, and continue to send the data packets to the second node.

For the two implementation manners in this step of monitoring the flow control feedback information within a period of continuous time # T5 to determine whether the second node is available for the data packet that needs to be mapped to the BH RLC CH #1, as an example, the first node receives flow control feedback information of the BH RLC CH granularity sent by the second node, and if the value of the available buffer space corresponding to the BH RLC CH #1 is smaller than (or equal to) the threshold TH #6, starts a timer (taking the timer name as an example), assuming that the timed time length is # T5=20s, if the values of the available buffer space corresponding to the BH RLC CH #1 in the flow control feedback information sent by the second node received within 20s after the timer is started are all greater than (or equal to) the threshold TH #6, at this time, the first node may consider that the second node is already available for the data packet that needs to be mapped to the BH RLC CH # 1. If, before the timer expires (i.e., within 20s after the timer is started), among T1 pieces of updated flow control feedback information of the second node, values of available buffer spaces corresponding to the BH RLC CH #1 carried in J1 pieces of flow control feedback information are all greater than (or equal to) a threshold TH #5, and J1 is a positive integer satisfying that J1 is greater than or equal to 1 and is greater than or equal to T1, the first node may consider that the second node is still available for a packet that needs to be mapped to the BH RLC CH # 1. Or, if the flow control feedback information updated by the next-hop node is received before the timer expires (i.e., within 20s after the timer is started), when the values (or values) of the available buffer space corresponding to the BH RLC CH #1 carried in the J1 flow control feedback information are accumulated and are all greater than (or equal to) the threshold TH #6, and J1 is a positive integer, the first node may consider that the second node is still available for the packets that need to be mapped on the BH RLC CH #1, and the first node may reroute the packets to the second node when performing routing, that is, cancel the rerouting of the packets, continue to send the packets to the second node, and may stop the timing of the timer.

In the present application, the obtaining manner and the configuration manner of the duration # T5 of the first node are similar to the obtaining manner and the configuration manner of the duration # T2, and are not described herein again.

As an example, if the first node receives T1 (T1 is an integer greater than 1) sub-flow control feedback information sent by the second node, there is T ₀₁ The numerical threshold TH #6 of the available buffer space corresponding to the BH RLC CH #1 for the sub-feedback, or the ratio of the number of flow control feedback information in which the numerical value of the available buffer space corresponding to the BH RLC CH #1 is greater than (or equal to) the threshold TH #6 in the T1 flow control feedback information is greater than or equal to T1(or equal to) R _TH4 ，0<R _TH4 ≦ 1, the first node determines that the second node is already available. In particular, it may be a continuous T ₀₁ Sub or discontinuous T ₀₁ Next, the process is repeated. T is ₀₁ Less than or equal to T1.

In this application, in the first node, the threshold TH #6 used for determining the available buffer space in the flow control feedback information related to the availability of the second node may be configured for the first node by the IAB donor (or the IAB donor CU, or the IAB donor CP) through an RRC message or an F1AP message, and the configuration mode may have multiple situations:

in case 1, the threshold TH #6 may be configured by BH RLC CH, that is, different BH RLC CH values, and configured thresholds may be different, and the configuration information provided by the IAB donor for the first node may include a threshold list, where each entry (item) in the threshold list includes an identifier of one or more BH RLC CHs and a corresponding threshold TH #6 value.

In case 2, the threshold TH #6 may be configured on a next hop node by next hop node basis, that is, the configured threshold TH #6 may be different for each next hop node of the first node, but for the same next hop node, the threshold TH #6 is applicable to all BH RLC CHs involved in the flow control feedback information of the BH RLC CH granularity fed back to the first node by the next hop node. In this case, the configuration information provided by the IAB donor needs to carry values of one or more configured thresholds TH #6, and further needs to indicate which next-hop node or next-hop nodes of the first node each of the thresholds is specifically applicable to. The next hop node of the first node may be identified by the BAP address of the next hop node.

In case 3, the threshold TH #6 may be a threshold corresponding to all BH RLC CHs in the flow control feedback information of the BH RLC CH granularity. In this case, the configuration information provided by the IAB donor needs to carry the value of the configured threshold TH #6, and also needs to specify that the threshold TH #6 is the threshold corresponding to the flow control feedback information of the BH RLC CH granularity. For example, the IAB donor may carry a value of a threshold TH #6 corresponding to the flow control feedback information of the BH RLC CH granularity in the configuration information provided by the first node, where the threshold TH #6 is applicable to each different BH RLC CH.

In case 4, the threshold TH #6 and the threshold TH #5 may be configured by configuring the same threshold TH # S for two different granularities of flow control feedback. That is, the configuration information provided by the IAB donor carries the value of the configured threshold TH # S, and the threshold TH # S is simultaneously applicable to the flow control feedback information of the BAP routing ID granularity of the first node and the flow control feedback information of the BH RLC CH granularity. It is to be understood that the threshold TH # S is applicable to the respective different BH RLC CHs between the first node and the next hop node, and also to the respective different BAP routing IDs of the first node. In this case, the configuration information provided by the IAB donor needs to carry the value of the configured threshold TH # S, and optionally, the configuration information may indicate that the threshold TH # S is simultaneously applicable to two different types of flow control feedback information.

In this application, for the configuration of the threshold values in case 3 and case 4, there may also be a modified configuration manner, which distinguishes whether to perform threshold configuration in uplink or downlink, that is, when providing the first node with threshold-related configuration information that is determined whether the next-hop node is available based on the flow control feedback information, the IAB denor may specify that the configured threshold value is specifically applicable to uplink flow control feedback (hop-by-hop flow control feedback that the parent node feeds back to the first node) or downlink flow control feedback (hop-by-hop flow control feedback that the child node feeds back to the first node). For example, as a variation 3a of case 3, the iab donor configures a threshold TH #6-UL-2 for the flow control feedback of all uplink BH RLC CH granularities, and configures a threshold TH #6-DL-2 for the flow control feedback of all downlink BH RLC CH granularities. For another example, for one variation 4a of case 4, the iab donor configures the threshold TH-UL for all uplink fluidic feedback, and configures the threshold TH-DL for all downlink fluidic feedback.

For the foregoing implementation manner that the flow control feedback information is monitored based on the threshold TH #6 and the rerouting recovery timer to determine whether the second node is available for the data packet that needs to be mapped to BH RLC CH #1 and that has already performed rerouting, the start operation of the rerouting timer may be: as an example, the first node may start a timer T-routing back #2 for monitoring the congestion relief condition of the second node after determining in step S802 that the second node is unavailable for the data packet that needs to be mapped to the BH RLC CH # 1; alternatively, after determining in step S802 that the second node is unavailable for the packet that needs to be mapped to the BH RLC CH #1, the first node may restart the timer T-routing back #2 when the updated flow control feedback information sent by the second node is received and the value of the available buffer space corresponding to the BH RLC CH #1 is greater than (or equal to) the threshold TH # 6. The operation of the rerouting timer may specifically be: if the first node receives the flow control feedback information updated by the second node before the rerouting timer T-routing back #2 times out, and the value corresponding to the available buffer space to be mapped on the BH RLC CH #1 in the flow control feedback information is smaller than (or equal to) the threshold TH #2, the timing of the timer T-routing back #2 is stopped. That is, if it is detected that the flow control feedback information is smaller than the threshold TH #2, the first node considers that the second node is still unavailable for the data packets that need to be mapped to the BH RLC CH #1, and at this time, the first node may continue to perform the rerouting operation on the data packets.

in case 1, the duration of the timer T-routing back #1 may be configured by BH RLC CHs, that is, different BH RLC CH values, and the duration of the configured timer T-routing back may be different, and configuration information provided by the IAB node for the first node may include a timer duration list, where each item in the list includes an identifier of one or more BH RLC CHs and a duration value of the corresponding timer T-routing back.

In case 2, the duration of the timer T-routing back #2 may be configured on a next hop node by next hop node basis, that is, the duration of the configured timer T-routing back may be different for each next hop node of the first node, but for the same next hop node, the duration of the timer T-routing back #2 is suitable for all BH RLC CHs that may be involved in the flow control feedback information of the BH RLC CH granularity fed back to the first node by the next hop node. In this case, the configuration information provided by the IAB node needs to carry one or more values of the configured time length of the T-routing back #2, and it needs to indicate that the time length of each T-routing back #2 is specifically applicable to which next-hop node or next-hop nodes of the first node. The next hop node of the first node may be identified by the BAP address of the next hop node.

In case 3, the configuration of the duration of the timer T-routing back #2 may be that the durations of the timers T-routing back #2 corresponding to all BH RLC CHs in the flow control feedback information of the BH RLC CH granularity are the same value. In this case, the configuration information provided by the IAB node needs to carry the value of the configured timer duration T-routing back #2, and the timer duration T-routing back #2 needs to be specified as the duration corresponding to the flow control feedback information of the BH RLC CH granularity. For example, the IAB node may carry a value of a time length T-routing back #2 corresponding to the flow control feedback information of the BH RLC CH granularity in the configuration information provided by the first node, where the time length T-routing back #2 is applicable to each different BH RLC CH.

In case 4, the configuration of the duration of the timer T-routing back #2 may also be to configure the same duration # TS for two different granularity flow control feedbacks. That is, the configuration information provided by the IAB donor carries the value of the configured time length # TS, and the time length # TS is simultaneously applicable to the flow control feedback information of the BAP routing ID granularity of the first node and the flow control feedback information of the BH RLC CH granularity. It is to be understood that the duration # TS applies to each different BH RLC CH between the first node and the next hop node, and also to each different BAP routing ID of the first node. In this case, the configuration information provided by the IAB donor needs to carry the value of the configured duration # TS, and optionally, the configuration information may indicate that the duration # TS is simultaneously applicable to two different types of flow control feedback information.

For the configuration of the duration of the timer T-routing back #2 in the case 3 and the case 4, there may also be a modified configuration manner, which distinguishes whether to perform the configuration of the duration of the timer T-routing back #2 in the uplink or in the downlink, that is, when providing the configuration information related to the duration for the first node, which is determined based on the flow control feedback information, whether the next-hop node is available, the IAB node may specify whether the configured duration of the timer T-routing back #2 is specifically applicable to the uplink flow control feedback (the hop-by-hop flow control feedback fed back to the first node by the parent node) or the downlink flow control feedback (the hop-by-hop flow control feedback fed back to the first node by the child node). For example, as a variation 3a of case 3, the iab donor configures the duration of a timer T-routing back, T-routing back #2-UL-2, for flow control feedback of all uplink BH RLC CH granularities, and configures the duration T-routing back #2-DL-2 for flow control feedback of all downlink BH RLC CH granularities. For example, as a variation 4a of case 4, the IAB donor configures the duration of the timer T-routing back, T-routing back-UL, for all uplink flow control feedback, and configures the duration T-routing back-DL for all downlink BH RLC CH granularities.

Similarly, the T1, S1, J1, U1 and R involved in determining whether the second node is available for the first node based on the flow control feedback information in the above embodiments _TH4 The configuration manner and the obtaining manner of the threshold TH #1 in step S702 in the method 700 are similar to each other, and are not described again here.

In the present application, the threshold TH #6 may be greater than or equal to the threshold TH #2. If the threshold TH #6 is set to be greater than the threshold TH #2, the occurrence of the situation that the first node judges frequent switching to the second node can be reduced, and resources are saved.

In a possible implementation manner, the first node receives fifth indication information of the second node, where the fifth indication information indicates that the link between the second node and the next-hop node is successfully recovered, or; the first node receives sixth indication information of the second node indicating that the second node is available for data packets that need to be mapped to BH RLC CH # 1. The first node may determine that the second node is available or that a link between the second node and the first node is available or that the second node is available for data packets that need to be mapped to BH RLC CH # 1. The first node may reroute the packets to the second node while performing routing, i.e., cancel the rerouting of the packets, and continue to send the packets to the second node.

According to the communication method provided by the application, the first node can execute rerouting under the condition that the link is congested based on the received flow control feedback information, so that the link congestion can be relieved on one hand, the average transmission delay of a data packet can be reduced on the other hand, and the user experience is improved.

The communication method provided by the embodiment of the present application is described in detail above with reference to fig. 7 and 8. The following describes a communication apparatus provided in an embodiment of the present application with reference to fig. 9 and 10. It should be understood that the description of the apparatus embodiment corresponds to the description of the method embodiment, and therefore, for the sake of brevity, details which are not described in detail above may be referred to the method embodiment.

The above-mentioned scheme provided by the embodiments of the present application is mainly introduced from the perspective of interaction between the nodes. It is understood that each node, for example, the transmitting end device or the receiving end device, includes a corresponding hardware structure and/or software module for performing each function in order to implement the above functions. Those of skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed in hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiment of the present application, the functional modules may be divided according to the above method example for the transmitting end device or the receiving end device, for example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. It should be noted that, in the embodiment of the present application, the division of the module is schematic, and is only one logic function division, and another division manner may be available in actual implementation. The following description will be given by taking an example in which each function module is divided for each function.

Fig. 9 is a schematic block diagram of a communication device 100 provided in an embodiment of the present application. As shown, the apparatus 100 may include: a transceiving unit 110 and a processing unit 120.

The communication apparatus 100 may be the first node in the above method embodiment, and may also be a chip for implementing the function of the first node in the above method embodiment. It should be understood that the apparatus 100 may correspond to the first node in the methods 700 and 800 according to the embodiments of the present application, and the apparatus 100 may perform the steps corresponding to the first node in the methods 700 and 800 according to the embodiments of the present application. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

In one possible design, the transceiver unit is configured to receive first information, where the first information includes a size of an available space in a first cache space of a second node, the first cache space is used to cache a data packet that needs to be transmitted through a first path, the first path is a main path used to transmit the data packet, and the second node is a next-hop node of the first node on the main path; the processing unit is configured to determine that a size of an available space in the first buffer space is smaller than or equal to a first threshold, determine that a data packet that needs to be transmitted through a first path is transmitted through the third node, and the third node is a next-hop node of the first node on a backup path for transmitting the data packet.

In a possible implementation manner, the processing unit is configured to determine that a size of an available space in the first buffer space is larger than the first threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through the first path is transmitted through the third node.

In a possible implementation manner, the transceiver unit is configured to receive N pieces of first information within a first time duration, where the N pieces of first information include sizes of available spaces in N first buffer spaces; the processing unit is configured to determine that X of the sizes of the available spaces in the N first buffer spaces are smaller than or equal to the first threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through a first path is transmitted through the third node; wherein N is an integer greater than 1, and X is less than or equal to N.

In a possible implementation manner, the transceiver unit is configured to receive second information, where the second information includes a size of an available space in a second cache space of the second node, where the second cache space is used to cache a packet of a first radio link control channel that needs to be mapped on a first link, and the first link is a link between the first node and the second node; the processing unit is configured to determine, according to the size of the available space in the first cache space and the size of the available space in the second cache space, that the data packet needs to be transmitted through the first path is transmitted through the third node.

In a possible implementation manner, the determining, by the processing unit, that a data packet to be transmitted through a first path is transmitted through the third node according to a size of an available space in the first buffer space and a size of an available space in the second buffer space includes: the processing unit is configured to determine that a size of an available space in the first buffer space is smaller than or equal to a first threshold, and/or that a size of an available space in the second buffer space is smaller than or equal to a second threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through the first path is transmitted through the third node.

In a possible implementation manner, the processing unit is configured to determine, according to a size of an available space in the first buffer space and a size of an available space in the second buffer space, that a data packet that needs to be transmitted through a first path is transmitted through the third node, and includes: the processing unit is configured to determine that the size of the available space in the first buffer space received by the transceiver unit in the first duration is smaller than or equal to a first threshold, and/or that the size of the available space in the second buffer space received by the transceiver unit in the second duration is smaller than or equal to a first threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through the first path is transmitted through the third node.

In a possible implementation manner, the processing unit is configured to determine that a size of an available space in the first buffer space is smaller than or equal to a first threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through a first path is transmitted through the third node, and the method includes: the processing unit is configured to determine that the transceiving unit sends, to the second node, a data packet that requires transmission through the first path and has an excessive data size equal to the size of the available space in the first cache space within a third time period before receiving the first information, and the processing unit is configured to determine that the data packet requires transmission through the first path and is transmitted through the third node; or, the processing unit is configured to determine that, within a fourth duration after the transceiver unit receives the first information, the transceiver unit sends, to the second node, a data packet whose data size is equal to the size of the available space in the first cache space and needs to be transmitted through the first path, and the processing unit is configured to determine that the data packet needs to be transmitted through the first path is transmitted through the third node.

In a possible implementation manner, the processing unit is configured to determine that a size of an available space in the first buffer space is smaller than or equal to a first threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through a first path is transmitted through a third node, and the method includes: the processing unit is configured to determine that a size of an available space in the first buffer space is smaller than or equal to a first threshold, and the third node is configured to transmit the data packet that needs to be transmitted through the first path, and the processing unit is configured to determine that the data packet that needs to be transmitted through the first path is transmitted through the third node.

In one possible implementation manner, the processing unit is configured to determine that the third node is available for transmitting the data packet that needs to be transmitted through the first path, and includes: the transceiver unit is configured to receive third information, where the third information includes a size of an available space in at least one cache space of the third node, the at least one cache space corresponds to the at least one backup path in a one-to-one manner, and the at least one backup path is the same as a destination node of the first path; the processing unit is configured to determine that a sum of sizes of available spaces in the at least one buffer space is greater than a third threshold, and the processing unit is configured to determine that the third node is available for transmitting the data packet that needs to be transmitted through the first path.

In one possible implementation manner, the processing unit is configured to determine that the third node is available for transmitting the data packet that needs to be transmitted through the first path, and includes: the transceiver unit is configured to receive fourth information, where the fourth information includes a size of an available space in a fourth cache space of the third node, the fourth cache space is used to cache a data packet of a first radio link control channel that needs to be mapped on a second link, and the second link is a link between the first node and the third node; the processing unit is configured to determine that the size of the available space in the fourth buffer space is greater than a fourth threshold, and the processing unit is configured to determine that the third node is available to transmit the data packet that needs to be transmitted through the first path.

In one possible implementation manner, the processing unit is configured to determine that the third node is available to transmit the data packet, and includes: the transceiver unit receives fourth information, where the fourth information includes a size of an available space in at least one cache space of the third node, where the at least one cache space is used to cache a data packet that needs to be mapped to at least one radio link control channel on a second link, the at least one cache space corresponds to the at least one radio link control channel one to one, and the second link is a link between the first node and the third node; the processing unit is configured to determine that a sum of sizes of available spaces in the at least one buffer space is greater than a fourth threshold, and the processing unit is configured to determine that the third node is available for transmitting the data packet that needs to be transmitted through the first path.

In a possible implementation manner, the transceiver unit is configured to receive fifth information, where the fifth information includes a size of an available space in a first cache space of the second node, the processing unit is configured to determine that the size of the available space in the first cache space is greater than a fifth threshold, and the processing unit is configured to determine that the second node is available to transmit a data packet that needs to be transmitted through a first path.

In a possible implementation manner, the transceiver unit is configured to receive fifth information, and includes: the receiving and sending unit is used for receiving Y pieces of fifth information in a fifth time length, wherein the Y pieces of fifth information comprise the size of available space in Y pieces of first cache space; the processing unit is configured to determine that sizes of available spaces in the Y first cache spaces are all larger than a fifth threshold, and the processing unit is configured to determine that the second node is available to transmit the data packet that needs to be transmitted through the first path. Wherein Y is an integer greater than 1.

In one possible design, the transceiver unit is configured to receive second information, where the second information includes a size of an available space in a second buffer space of the second node, and the second buffer space is used to buffer a packet of a first radio link control channel that needs to be mapped on a first link, where the first link is a link between the first node and the second node; the processing unit is configured to determine that a size of an available space in the second buffer space is smaller than or equal to a second threshold, and determine to transmit a first packet data packet through the third node, where the first packet data packet is a packet of a first radio link control channel that needs to be mapped on the first link, a main path of the first packet data packet is a first path, the second node is a next-hop node of the first node on the first path, the third node is a next-hop node of the first node on a second path used for transmitting the first packet data packet, the second path is a backup path of the first packet data packet, a link between the first node and the third node is a second link, and the first path and the second path have the same destination node.

In a possible implementation manner, the processing unit is configured to determine that a size of an available space in the second buffer space is larger than the second threshold, and the processing unit is configured to determine to transmit the first data packet through the second node.

In a possible implementation manner, the transceiver unit is configured to receive the second information, and includes: the receiving and sending unit is used for receiving K pieces of second information in a second time length, wherein the K pieces of second information comprise the size of available space in K second cache spaces; the processing unit is configured to determine that the first packet is transmitted through the third node when L of the sizes of the available spaces in the K second cache spaces are smaller than or equal to the second threshold, where K is an integer greater than 1, and L is smaller than or equal to K.

In a possible implementation manner, the transceiver unit is configured to receive first information, where the first information includes a size of an available space in a first cache space of the second node, the first cache space is used to cache a data packet that needs to be transmitted through a first path, and the first path is a main path used to transmit the data packet; the processing unit is configured to determine, according to the size of the available space in the second cache space and the size of the available space in the first cache space, that the first data packet needs to be mapped to be transmitted by the third node, where the third node is a next-hop node of the first node on the backup path for transmitting the data packet.

In a possible implementation manner, the determining, by the processing unit, that the first data packet is transmitted through the third node according to the size of the available space in the second cache space and the size of the available space in the first cache space includes: the processing unit is configured to determine that a size of an available space in the second cache space is smaller than or equal to a second threshold, and/or that a size of an available space in the first cache space is smaller than or equal to a first threshold, and the processing unit is configured to determine that the first packet is transmitted through the third node.

In a possible implementation manner, the processing unit is configured to determine to transmit the first data packet through the third node according to a size of an available space in the second buffer space and a size of an available space in the first buffer space, and includes: the processing unit is configured to determine that the size of the available space in the second buffer space received by the transceiver unit in the second duration is smaller than or equal to a second threshold, and/or that the size of the available space in the first buffer space received by the transceiver unit in the first duration is smaller than or equal to a first threshold, and the processing unit is configured to determine that the first data packet is transmitted by the third node.

In a possible implementation manner, the processing unit is configured to determine that a size of an available space in the second buffer space is smaller than or equal to a second threshold, and the determining that the first data packet needs to be transmitted by the third node through transmission by the third node includes: the processing unit is configured to determine that, within a third duration before the transceiver unit receives the second information, the transceiver unit sends, to the second node, a first type packet whose size of an excessive amount of data is equal to a size of an available space in the second cache space, where the first type packet is a packet that is sent to the first node by the first node on a first radio link control channel mapped on a first link, and the processing unit is configured to determine that the first packet is transmitted by the third node; or, the processing unit is configured to determine that the transceiving unit sends the first type of data packet with an excessive data size equal to the size of the available space in the second cache space to the second node within a fourth time period after receiving the second information, and the processing unit is configured to determine that the first data packet is transmitted by the third node.

In a possible implementation manner, the processing unit is configured to determine that a size of an available space in the second buffer space is smaller than or equal to a second threshold, and the determining, by the third node, that the first data packet is transmitted includes: the processing unit is configured to determine that a third node is available to transmit the first data packet, and determine that the size of available space in the second buffer space is smaller than or equal to a second threshold, and transmit the first data packet through the third node.

In one possible implementation manner, the determining, by the processing unit, that the first data packet is transmitted by the third node includes: the transceiver unit is configured to receive fourth information, where the fourth information includes a size of an available space in at least one cache space of the third node, the at least one cache space is used to cache a data packet that is sent to the third node on at least one radio link control channel mapped on a second link, the at least one cache space corresponds to the at least one radio link control channel in a one-to-one manner, and the second link is a link between the first node and the third node; the processing unit is configured to determine that a sum of sizes of available spaces in the at least one buffer space is greater than a fourth threshold, and the processing unit is configured to determine that the first data packet is available for transmission by the third node.

In a possible implementation manner, the processing unit is configured to determine to transmit the first data packet through the third node, and includes: the transceiver unit is configured to receive fourth information, where the fourth information includes a size of an available space in a fourth cache space of the third node, the fourth cache space is used to cache a data packet sent to the third node by a second radio link control channel mapped on a second link, and the second link is a link between the first node and the third node; the processing unit is configured to determine that a size of an available space in the fourth cache space is greater than a fourth threshold, and the first node determines to transmit the first data packet through the third node.

In a possible implementation manner, the processing unit is configured to determine to transmit the first data packet through the third node, and includes: the transceiver unit is configured to receive third information, where the third information includes a size of an available space in at least one cache space of the third node, the at least one cache space corresponds to the at least one backup path in a one-to-one manner, and the at least one backup path is the same as a destination node of the first path; the processing unit is configured to determine that a sum of sizes of available spaces in the at least one buffer space is greater than a third threshold, and the processing unit is configured to determine that the first packet is transmitted through the third node.

In a possible implementation manner, the transceiver unit is configured to receive fifth information, where the fifth information includes a size of an available space in a second buffer space of the second node, the processing unit is configured to determine that the size of the available space in the second buffer space is greater than a fifth threshold, and the processing unit is configured to determine that the second node is available for transmitting a data packet of a first radio link control channel that needs to be mapped on the first link.

In a possible implementation manner, the transceiver unit is configured to receive and receive fifth information, and includes: the transceiver unit is configured to receive P fifth messages within a fifth duration, where the P fifth messages include sizes of available spaces in P second cache spaces; the processing unit is configured to determine, when it is determined that the sizes of the available spaces in the P second buffer spaces are all greater than a fifth threshold, that the data packet of the first radio link control channel that needs to be mapped on the first link is transmitted by the third node; wherein, the P is an integer larger than 1.

Fig. 10 is a schematic block diagram of a communication apparatus 200 according to an embodiment of the present application. As shown, the apparatus 200 includes: at least one processor 220. The processor 220 is coupled to the memory for executing instructions stored in the memory to transmit signals and/or receive signals. Optionally, the apparatus 200 further comprises a memory 230 for storing instructions. Optionally, the apparatus 200 further comprises a transceiver 210, and the processor 220 controls the transceiver 210 to transmit and/or receive signals.

It should be appreciated that the processor 220 and the memory 230 may be combined into a single processing device, and that the processor 220 is configured to execute the program code stored in the memory 230 to implement the functions described above. In particular implementations, the memory 230 may be integrated into the processor 220 or may be separate from the processor 220.

It should also be understood that the transceiver 210 may include a transceiver (or, referred to as a receiver) and a transmitter (or, referred to as a transmitter). The transceiver may further include an antenna, and the number of antennas may be one or more. The transceiver 210 may be a communication interface or interface circuit.

In particular, the transceiver 210 in the apparatus 200 may correspond to the transceiving unit 110 in the apparatus 100, and the processor 220 in the apparatus 200 may correspond to the processing unit 120 in the apparatus 200.

It should be understood that the specific processes of each transceiver processor for executing the above corresponding steps have been described in detail in the above method embodiments, and are not described herein again for brevity.

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

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

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

According to the method provided by the embodiment of the present application, the present application further provides a computer program product, which includes: computer program code which, when run on a computer, causes the computer to perform the method of any one of the embodiments of the methods 700, 800.

According to the method provided by the embodiment of the present application, a computer-readable medium is further provided, and the computer-readable medium stores program code, which when executed on a computer, causes the computer to execute the method of any one of the embodiments of the method 700 and the method 800.

According to the method provided by the embodiment of the application, the application also provides a system which comprises the device or the equipment.

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

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

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

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

It can be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the system, the apparatus and the unit described above may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

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

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

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

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

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

Claims

1. A method of communication, comprising:

a first node receives first information from a second node, wherein the first information comprises the size of available space in a first cache space of the second node, the first cache space is used for caching a data packet which needs to be transmitted through a first path, the first path is a main path used for transmitting the data packet, and the second node is a next hop node of the first node on the main path;

if the size of the available space in the first cache space is smaller than or equal to a first threshold, the first node determines to transmit a data packet needing to be transmitted through a first path through a third node, and the third node is a next-hop node of the first node on a standby path for transmitting the data packet.

2. The method of claim 1,

and if the size of the available space in the first cache space is larger than the first threshold, the first node determines to transmit the data packet needing to be transmitted through the first path through the second node.

3. The method according to any of claims 1 or 2, wherein the first node receives first information from a second node, comprising:

the first node receives N pieces of first information from a second node within a first time length, wherein the N pieces of first information comprise the size of available space in N first cache spaces;

if X of the available spaces in the N first cache spaces are smaller than or equal to the first threshold, the first node determines to transmit a data packet needing to be transmitted through a first path through the third node;

wherein N is an integer greater than 1, and X is less than or equal to N.

4. The method according to any one of claims 1 to 3, further comprising:

the first node receives second information from the second node, wherein the second information comprises the size of available space in a second cache space of the second node, the second cache space is used for caching data packets of a first wireless link control channel needing to be mapped on a first link, and the first link is a link between the first node and the second node;

And the first node determines to transmit the data packet needing to be transmitted through the first path through the third node according to the size of the available space in the first cache space and the size of the available space in the second cache space.

5. The method of claim 4, wherein the determining, by the first node, that the data packet needs to be transmitted through the first path by the third node according to the size of the available space in the first buffer space and the size of the available space in the second buffer space comprises:

and if the size of the available space in the first cache space is smaller than or equal to a first threshold value and/or the size of the available space in the second cache space is smaller than or equal to a second threshold value, the first node determines to transmit the data packet which needs to be transmitted through the first path through the third node.

6. The method according to claim 4, wherein the first node determines, according to the size of the space available in the first buffer space and the size of the space available in the second buffer space, that the data packet needs to be transmitted through the first path is transmitted through the third node, and the method comprises:

If the size of the available space in the first cache space received by the first node within the first time period is smaller than or equal to a first threshold, and/or the size of the available space in the second cache space received by the first node within the second time period is smaller than or equal to a first threshold, the first node determines to transmit a data packet which needs to be transmitted through a first path through the third node.

7. The method according to any of claims 1 to 6, wherein if the size of the available space in the first buffer space is smaller than or equal to a first threshold, the first node determines to transmit the data packet needing to be transmitted through the first path through the third node, and the method comprises:

if the first node determines that the data packets needing to be transmitted through the first path are transmitted to the second node within a third time length before the first information is received, the first node determines to transmit the data packets needing to be transmitted through the first path through the third node, wherein the size of the data packets is equal to the size of the available space in the first cache space; alternatively, the first and second electrodes may be,

if the first node determines that the data packets needing to be transmitted through the first path are transmitted to the second node within a fourth time after the first node receives the first information, the data packets with the data volume size equal to the size of the available space in the first cache space are transmitted to the second node through the third node.

8. The method according to any of claims 1 to 7, wherein if the size of the available space in the first buffer space is smaller than or equal to a first threshold, the first node determines to transmit the data packet needing to be transmitted through the first path through the third node, including:

and if the size of the available space in the first cache space is smaller than or equal to a first threshold value, and the first node determines that the third node can be used for transmitting the data packet needing to be transmitted through the first path, the first node determines to transmit the data packet needing to be transmitted through the first path through the third node.

9. The method of claim 8, wherein the first node determining that the third node is available to transmit the data packet that needs to be transmitted over the first path comprises:

the first node receives third information from the third node, wherein the third information comprises the size of available space in at least one cache space of the third node, the at least one cache space corresponds to the at least one standby path in a one-to-one manner, and the at least one standby path is the same as a destination node of the first path;

If the sum of the sizes of the available spaces in the at least one cache space is larger than a third threshold value, the first node determines that the third node can be used for transmitting the data packet needing to be transmitted through the first path.

10. The method according to claim 8 or 9, wherein the first node determining that the third node is available to transmit the data packet that needs to be transmitted through the first path comprises:

the first node receives fourth information from a third node, where the fourth information includes a size of an available space in a fourth cache space of the third node, the fourth cache space is used for caching a data packet of a first radio link control channel that needs to be mapped on a second link, and the second link is a link between the first node and the third node;

if the size of the available space in the fourth cache space is larger than a fourth threshold, the first node determines that the third node is available for transmitting the data packet that needs to be transmitted through the first path.

11. The method according to claim 8 or 9, wherein the first node determining that the third node is available to transmit the data packet comprises:

The first node receives fourth information from a third node, where the fourth information includes a size of an available space in at least one cache space of the third node, the at least one cache space is used to cache a data packet that needs to be mapped to at least one radio link control channel on a second link, the at least one cache space corresponds to the at least one radio link control channel one to one, and the second link is a link between the first node and the third node;

if the sum of the sizes of the available spaces in the at least one cache space is larger than a fourth threshold, the first node determines that the third node is available for transmitting the data packet which needs to be transmitted through the first path.

12. The method according to any of claims 1 to 11, wherein the first node receives fifth information from the second node, the fifth information comprising a size of available space in a first cache space of the second node,

and if the size of the available space in the first cache space is larger than a fifth threshold value, the first node determines that the second node is available for transmitting the data packet which needs to be transmitted through the first path.

13. The method of claim 12, wherein the first node receives fifth information from the second node, comprising:

the first node receives Y pieces of fifth information from the second node within a fifth time length, wherein the Y pieces of fifth information comprise the size of available space in Y pieces of first cache space;

if the size of the available space in the Y first cache spaces is larger than a fifth threshold value, the first node determines that the second node can be used for transmitting the data packet needing to be transmitted through the first path;

wherein Y is an integer greater than 1.

14. The method according to any one of claims 1 to 12,

the first threshold is configured by the host node of the first node, or the first threshold is indicated by the host node of the first node through indication information, or the first threshold is preconfigured to the first node;

the first time length is configured for the host node of the first node, or the first time length is indicated by the host node of the first node through indication information, or the first time length is preconfigured to the first node.

15. A communications apparatus, comprising: a transceiving unit and a processing unit, wherein the transceiving unit,

The transceiving unit is configured to receive first information, where the first information includes a size of an available space in a first cache space of a second node, the first cache space is used to cache a data packet that needs to be transmitted through a first path, the first path is a main path used to transmit the data packet, and the second node is a next-hop node of the first node on the main path;

the processing unit is configured to determine that a size of an available space in the first cache space is smaller than or equal to a first threshold, determine that a data packet that needs to be transmitted through a first path is transmitted through the third node, and the third node is a next-hop node of the first node on a backup path for transmitting the data packet.

16. The apparatus of claim 15,

the processing unit is configured to determine that a size of an available space in the first buffer space is greater than the first threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through a first path is transmitted through the second node.

17. The apparatus according to any one of claims 15 or 16,

the receiving and sending unit is used for receiving N pieces of first information in a first time period, wherein the N pieces of first information comprise the size of available space in N first cache spaces;

The processing unit is configured to determine that X of the sizes of the available spaces in the N first buffer spaces are smaller than or equal to the first threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through a first path is transmitted through the third node;

wherein N is an integer greater than 1, and X is less than or equal to N.

18. The apparatus of any one of claims 15 to 17,

the transceiver unit is configured to receive second information, where the second information includes a size of an available space in a second cache space of the second node, and the second cache space is used to cache a packet of a first radio link control channel that needs to be mapped on a first link, where the first link is a link between the first node and the second node;

the processing unit is configured to determine, according to the size of the available space in the first buffer space and the size of the available space in the second buffer space, that the data packet needs to be transmitted through the first path is transmitted through the third node.

19. The apparatus of claim 18, wherein the processing unit is configured to determine, according to a size of an available space in the first buffer space and a size of an available space in the second buffer space, that a data packet needs to be transmitted through the first path by the third node, and includes:

The processing unit is configured to determine that a size of an available space in the first buffer space is smaller than or equal to a first threshold, and/or that a size of an available space in the second buffer space is smaller than or equal to a second threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through the first path is transmitted through the third node.

20. The apparatus of claim 18, wherein the processing unit is configured to determine, according to a size of an available space in the first buffer space and a size of an available space in the second buffer space, that a data packet needs to be transmitted through the first path by the third node, and includes:

the processing unit is configured to determine that the size of the available space in the first buffer space received by the transceiver unit in the first time period is smaller than or equal to a first threshold, and/or that the size of the available space in the second buffer space received by the transceiver unit in the second time period is smaller than or equal to the first threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through the first path is transmitted through the third node.

21. The apparatus according to any of claims 15 to 20, wherein the processing unit is configured to determine that a size of an available space in the first buffer space is smaller than or equal to a first threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through a first path is transmitted through the third node, and the method includes:

The processing unit is configured to determine that the transceiving unit sends, to the second node, a data packet that requires transmission through the first path and has an excessive data size equal to the size of the available space in the first cache space within a third time period before receiving the first information, and the processing unit is configured to determine that the data packet requires transmission through the first path and is transmitted through the third node; alternatively, the first and second electrodes may be,

the processing unit is configured to determine that the transceiving unit sends, to the second node, a data packet that requires transmission through the first path and has an excess data size equal to the size of the available space in the first cache space within a fourth duration after receiving the first information, and the processing unit is configured to determine that the data packet that requires transmission through the first path is transmitted through the third node.

22. The apparatus according to any of claims 15 to 20, wherein the processing unit is configured to determine that a size of an available space in the first buffer space is smaller than or equal to a first threshold, and the processing unit is configured to determine that a data packet that needs to be transmitted through the first path is transmitted through a third node, and the method includes:

the processing unit is configured to determine that a size of an available space in the first buffer space is smaller than or equal to a first threshold, and the third node is configured to transmit the data packet that needs to be transmitted through the first path, and the processing unit is configured to determine that the data packet that needs to be transmitted through the first path is transmitted through the third node.

23. The apparatus of claim 22, wherein the processing unit is configured to determine that the third node is available to transmit the data packet that needs to be transmitted via the first path, and wherein the determining unit comprises:

the transceiver unit is configured to receive third information, where the third information includes a size of an available space in at least one cache space of the third node, the at least one cache space corresponds to the at least one backup path in a one-to-one manner, and a destination node of the at least one backup path is the same as a destination node of the first path;

the processing unit is configured to determine that a sum of sizes of available spaces in the at least one buffer space is greater than a third threshold, and the processing unit is configured to determine that the third node is available to transmit the data packet that needs to be transmitted through the first path.

24. The apparatus according to claim 22 or 23, wherein the processing unit is configured to determine that the third node is available to transmit the data packet that needs to be transmitted through the first path, and includes:

the transceiver unit is configured to receive fourth information, where the fourth information includes a size of an available space in a fourth cache space of the third node, the fourth cache space is used to cache a data packet of a first radio link control channel that needs to be mapped on a second link, and the second link is a link between the first node and the third node;

The processing unit is configured to determine that the size of the available space in the fourth buffer space is greater than a fourth threshold, and the processing unit is configured to determine that the third node is available to transmit the data packet that needs to be transmitted through the first path.

25. The apparatus of claim 22 or 23, wherein the processing unit is configured to determine that the third node is available to transmit the data packet, and further comprising:

the transceiver unit receives fourth information, where the fourth information includes a size of an available space in at least one cache space of the third node, where the at least one cache space is used to cache a data packet that needs to be mapped to at least one radio link control channel on a second link, the at least one cache space corresponds to the at least one radio link control channel one to one, and the second link is a link between the first node and the third node;

the processing unit is configured to determine that a sum of sizes of available spaces in the at least one buffer space is greater than a fourth threshold, and the processing unit is configured to determine that the third node is available for transmitting the data packet that needs to be transmitted through the first path.

26. The apparatus according to any of claims 15 to 25, wherein the transceiver unit is configured to receive fifth information, the fifth information comprising a size of an available space in a first buffer space of the second node,

the processing unit is configured to determine that the size of the available space in the first cache space is greater than a fifth threshold, and the processing unit is configured to determine that the second node is available to transmit a data packet that needs to be transmitted through the first path.

27. The apparatus of claim 26, wherein the transceiver unit is configured to receive fifth information, and wherein the fifth information comprises:

the receiving and sending unit is configured to receive Y fifth information within a fifth duration, where the Y fifth information includes sizes of available spaces in Y first cache spaces;

the processing unit is configured to determine that sizes of available spaces in the Y first cache spaces are all greater than a fifth threshold, and the processing unit is configured to determine that the second node is available to transmit the data packet that needs to be transmitted through the first path;

wherein Y is an integer greater than 1.

28. The apparatus of any one of claims 15 to 27,

the first threshold is configured by the host node of the first node, or the first threshold is indicated by the host node of the first node through indication information, or the first threshold is preconfigured to the device;

The first time length is configured by the host node of the first node, or the first time length is indicated by the host node of the first node through indication information, or the first time length is preconfigured to the apparatus.

29. A communications apparatus, comprising at least one processor configured to execute a computer program stored in a memory to cause the communications apparatus to implement the method of any of claims 1 to 14.

30. A computer-readable storage medium comprising a computer program which, when run on a computer, causes the computer to perform the method of any one of claims 1 to 14.

31. A computer program product, the computer program product comprising: computer program, which, when executed, causes a computer to perform the method of any one of claims 1 to 14.