Lossless data transmission method, device, and system

Abstract

An embodiment of this application provides a lossless data transmission communication method, apparatus, and system. The method includes: a first network node determines a first data packet; a destination node of the first data packet is a third network node or a security gateway at the third network node; the third network node is a source donor node or a source donor node central unit CU of the first network node; the first network node sends the first data packet to a second network node; the second network node is a target donor node distribution unit DU of the first network node. This method can avoid data packet loss in the topology update process of the first network node and ensure service continuity.

Description

[Technical field]

[0001] TECHNICAL FIELD Embodiments of this application relate to the field of communication technologies, and in particular to a lossless data transmission communication method, apparatus, and system. [Background technology]

[0002] The fifth generation (5G) mobile communication comprehensively puts forward more stringent requirements for various network performance indicators. For example, 5G mobile communication requires 1000 times higher capacity indicators, wider coverage, ultra-high reliability and ultra-low latency. Considering the abundant frequency resources of high-frequency carriers, networking using high-frequency small cells is becoming increasingly popular in hotspot areas to meet the ultra-large capacity requirements of 5G. High-frequency carriers have poor propagation characteristics, serious blocking attenuation, and small coverage. Therefore, a large number of small cells need to be deployed densely. Correspondingly, providing fiber backhaul for a large number of small cells deployed densely is very costly and difficult to build. Therefore, an economical and convenient backhaul solution is required. In addition, in view of the wide coverage requirements, it is difficult and costly to deploy optical fiber to provide network coverage in some remote areas. Therefore, flexible and convenient access and backhaul solutions also need to be designed.

[0003] Integrated access and backhaul (IAB) technology provides a solution to solve the above two problems. In IAB technology, wireless transmission solutions are used for both access links and backhaul links, avoiding the deployment of optical fibers. In an IAB network, a relay node (RN) or an IAB node (IAB node) can provide wireless access services to a user equipment (UE). The service data of the UE is transmitted by the IAB node to a connected donor node (IAB donor) or donor base station (donor gNodeB, DgNB) via a wireless backhaul link. To reduce the number of antennas in a base station, an antenna can be shared using an IAB node for access and backhaul.

[0004] In the current IAB network, an IAB node may perform topology updates to meet communication requirements in different scenarios. Topology updates usually occur due to handover or in the process of recovery from radio link failure. However, after an IAB node performs an inter-IAB donor topology update, a problem of data packet loss may occur. Therefore, how to reduce data packet loss when an IAB node performs a topology update process in different IAB donor service areas becomes an issue that needs to be urgently solved. It can be understood that similar problems may exist in other network architectures. Summary of the Invention

[0005] Embodiments of the present application provide a lossless data transmission communication method, apparatus, and system to reduce data packet loss due to topology updates, for example, in topology update processes performed by IAB nodes within different IAB donor service ranges.

[0006] According to a first aspect, an embodiment of this application provides a lossless data transmission communication method. The method may be performed by a network node or may be performed by a component (such as a processor, a chip, or a chip system) of the network node. The method includes: a second network node receives a first data packet from a first network node; the second network node is a target donor node distribution unit DU of the first network node; a destination node of the first data packet is a third network node or a security gateway on the third network node side; the third network node is a source donor node or a source donor node central unit CU of the first network node; the second network node transmits the first data packet to the third network node.

[0007] According to the above method, it is possible to support rerouting and forwarding of donor inter-DU data packets by the IAB node, which avoids data packet loss in the topology update process of the first network node and reduces the impact on uplink service continuity of the terminal served by the first network node.

[0008] Possibly, the second network node updates an Internet Protocol (IP) address filtering rule to transmit the first data packet to the third network node.

[0009] In this manner, the first data packet is not discarded by the second network node.

[0010] In a possible manner, updating the IP address filtering rule by the second network node includes:

[0011] The second network node obtains a first IP address, the first IP address being one or more IP addresses obtained by the first network node when the first network node is connected to the third network node.

[0012] The second network node updates the IP address filtering rule based on the first IP address.

[0013] Optionally, the first IP address is one or more IP addresses obtained when the first network node is connected to the source donor DU.

[0014] Optionally, the second network node adds the first IP address to a whitelist of a source IP address filtering rule, i.e. adds the first IP address to a list of source IP addresses of data packets that are allowed to be forwarded.

[0015] In the foregoing manner, the second network node is allowed to forward the first data packet, so that the first data packet is not discarded by the second network node.

[0016] In a possible manner, the second network node obtaining the first IP address includes: the second network node receiving the first IP address from a third network node.

[0017] Optionally, the second network node obtaining the first IP address includes: the second network node receiving the first IP address from a fourth network node, the fourth network node being a target donor central unit CU of the first network node.

[0018] In the above manner, the second network node may obtain the first IP address of the first data packet so that the first data packet is not discarded.

[0019] In a possible manner, the second network node updating the IP address filtering rule includes: the second network node receiving first suspension indication information from a fourth network node. The first suspension indication information instructs the second network node to suspend the IP address filtering rule. The fourth network node is a target donor CU of the first network node.

[0020] In the above manner, the second network node is allowed to forward the first data packet, so that the first data packet is not discarded by the second network node due to an IP address filtering rule.

[0021] In a possible manner, the first data packet is encapsulated in a second data packet. The second data packet includes a first IP header and a second IP header. A target IP address of the first IP header is an IP address of a third network node or an IP address of a security gateway on the third network node side. A target IP address of the second IP header is an IP address of a fourth network node. The second network node transmits the second data packet to the fourth network node based on the second IP header, so that the fourth network node transmits the first data packet to the third network node.

[0022] In the above scheme, the second network node may transmit the first data packet to the third network node via the fourth network node, which ensures that the first data packet can be transmitted to the source donor CU, so that the first data packet can be correctly processed by the third network node. The processing may be, for example, integrity verification or decryption.

[0023] Possibly, the second data packet further comprises a first removal indication information instructing the fourth network node to remove the second IP header.

[0024] In the above-described scheme, the fourth network node may identify particular data packets that require such special processing, in particular data packets that are forwarded based on the inner IP header after the outer IP header has been removed.

[0025] Possible ways are: a second IP header is added to the first data packet by the second network node, or a second IP header is added to the first data packet by the first network node.

[0026] Optionally, the second IP header is added outside the first IP header or the second IP header is outside the first IP header.

[0027] In the above manner, the first data packet may be forwarded to a fourth network node.

[0028] In one possible manner, the first network node completes a topology update before the second network node receives the first data packet from the first network node.

[0029] According to a second aspect, an embodiment of the application provides a lossless data transmission communication method. The method may be performed by a network node or may be performed by a component (e.g., a processor, a chip, or a chip system) of the network node. The method includes: a first network node determines a first data packet; a destination node of the first data packet is a third network node or a security gateway on the third network node side; the third network node is a source donor node or a source donor node CU of the first network node; the first network node transmits the first data packet to a second network node; the second network node is a target donor node DU of the first network node.

[0030] In the above scheme, the first network node utilizes the second network node to reroute a first data packet sent to a third network node, so that the first data packet can be correctly processed by the third network node, which avoids loss of the data packet when the first network node performs a topology update.

[0031] In a possible manner, the first network node updates a backhaul adaptation protocol layer configuration of the first data packet for transmitting the first data packet to the second network node.

[0032] Optionally, the first network node updates a routing identifier in the first data packet based on the configuration information sent by the fourth network node, where the fourth network node is a target donor CU of the first network node.

[0033] In the above-mentioned scheme, before the first network node forwards the first data packet, the first network node modifies header information of the BAP layer of the first data packet, so that the first data packet can be successfully transmitted to the second network node.

[0034] In one possible scheme, the first network node adds a second IP header to the first data packet, the target IP address of the second IP header being an IP address of a fourth network node, the fourth network node being a target donor central unit CU of the first network node.

[0035] In the above manner, the first data packet may be forwarded to a fourth network node.

[0036] Possible manner, the first data packet further includes first removal indication information instructing the fourth network node to remove the second IP header.

[0037] In the above-described scheme, the fourth network node may identify particular data packets that require such special processing, in particular data packets that are forwarded based on the inner IP header after the outer IP header has been removed.

[0038] In one possible manner, the first network node transmits to the fourth network node a first IP address, the first IP address being one or more IP addresses obtained by the first network node when the first network node is connected to the third network node.

[0039] In the aforementioned manner, it helps the fourth network node obtain the first IP address, and further helps the fourth network node send the first IP address to the second network node.

[0040] Possibly, before the first network node determines the first data packet, the first network node performs a topology update.

[0041] According to a third aspect, an embodiment of the present application provides a lossless data transmission communication method, which may be performed by a network node or by a component (e.g., a processor, a chip, or a chip system) of the network node. The method includes:

[0042] The fourth network node determines the first message, where the fourth network node is a target donor node CU of the first network node.

[0043] The fourth network node sends a first message to a second network node, the first message being utilized by the second network node to update an IP address filtering rule, the second network node being a target donor node DU of the first network node.

[0044] In the above scheme, the fourth network node provides the second network node with the information required to update the IP address filtering rule.

[0045] In a possible manner, the fourth network node determining the first message includes:

[0046] The fourth network node obtains a first IP address. The first IP address is one or more IP addresses obtained by the first network node when the first network node is connected to the third network node. The third network node is a source donor node or a source donor node CU of the first network node. The fourth network node sending a first message to the second network node includes: the first message includes the first IP address.

[0047] Optionally, the fourth network node receives the first IP address from the third network node.

[0048] Alternatively, the fourth network node receives the first IP address from the first network node.

[0049] Alternatively, the fourth network node receives the first IP address from an access and mobility management function AMF.

[0050] In the above manner, the fourth network node provides the second network node with the first IP address, so that the second network node updates the IP address filtering rule based on the first IP address, which further helps ensure the successful forwarding of the first data.

[0051] In a possible manner, the fourth network node determining the first message includes: the fourth network node determining first pause indication information, the first pause indication information instructing the second network node to pause the IP address filtering rule.

[0052] The fourth network node sending the first message to the second network node includes: the first message includes the first pause indication information.

[0053] In the above scheme, the fourth network node indicates to the second network node to suspend IP address filtering rules such that the first data packet is not discarded by the second network node.

[0054] In one possible manner, a fourth network node receives a second data packet from a second network node, the second data packet including a first IP header and a second IP header, a target IP address of the first IP header being a third network node, and a target IP address of the second IP header being an IP address of the fourth network node.

[0055] The fourth network node transmits a first data packet to the third network node, the first data packet being a data packet obtained by processing the second data packet by the fourth network node, the first data packet not including the second IP header.

[0056] In the above scheme, the fourth network node forwards the first data packet to the third network node, which ensures that the first data packet can be correctly processed by the third network node and avoids loss of the first data packet.

[0057] In a possible manner, the first data packet further includes first removal indication information instructing the fourth network node based on the first IP header after removing the second IP header to forward the first data packet to the third network node.

[0058] In the above manner, the fourth network node can determine the particular data packets for which the IP header removal process needs to be performed.

[0059] In one possible manner, the fourth network node receives from the third network node data relating to a terminal device served by the first network node and located within a first data packet.

[0060] In the above manner, the fourth network node may obtain data associated with the terminal and present in the first data packet, further process the data, and send, for example, data of a terminal service to the terminal.

[0061] According to a fourth aspect, an embodiment of the application provides a lossless data transmission communication method. The method may be performed by a network node or may be performed by a component (e.g., a processor, a chip, or a chip system) of the network node. The method includes: a third network node obtains a first data packet. The first data packet is a data packet transmitted to the third network node after the first network node is connected to the second network node. The third network node processes the first data packet. The third network node is a source donor node or a source donor node CU of the first network node. The second network node is a target donor node DU of the first network node.

[0062] In the above manner, the third network node can obtain the first data packet sent by the first network node and correctly process the first data packet, which helps to avoid the loss of the first data packet and the impact on the service continuity of the terminal.

[0063] In a possible manner, the third network node obtaining the first data packet includes: the third network node receiving the first data packet from a fourth network node; the first data packet being a data packet obtained by processing a second data packet from the second network node by the fourth network node; the first data packet being encapsulated in the second data packet.

[0064] Alternatively, the third network node receives the first data packet from the second network node.

[0065] In the above manner, the third network node can obtain the first data packet via a different path.

[0066] In a possible manner, the third network node processing the first data packet includes: the third network node determines, based on the first data packet, data related to the terminal device serviced by the first network node.

[0067] The third network node transmits data relating to the terminal device to a fourth network node.

[0068] Optionally, the data associated with the terminal device is a Packet Data Convergence Protocol PDCP Service Data Unit SDU of the terminal device.

[0069] In the above manner, the third network node can process the first data packet correctly, and the service continuity of the terminal device is ensured.

[0070] According to a fifth aspect, an embodiment of the application provides a lossless data transmission communication method. The method may be executed by a network node or may be executed by a component (e.g., a processor, a chip, or a chip system) of the network node. The method includes: a first network node receives a first handover command from a third network node. The first handover command instructs the first network node to perform a handover. The third network node is a source donor node or a source donor node CU of the first network node. The first network node transmits first transmission completion indication information. The first transmission completion indication information indicates that a transmission of a third data packet is completed. The third data packet includes uplink data from the first network node and a descendant node of the first network node. The descendant node includes a descendant network node and / or a descendant terminal.

[0071] Optionally, the method further includes: the first network node performs a handover.

[0072] Optionally, in another possible manner, the first network node decides to perform a topology update. The first network node sends first transmission completion indication information. The first transmission completion indication information indicates that transmission of the third data packet is completed. The third data packet includes uplink data from the first network node and a descendant node of the first network node. The descendant node includes a descendant network node and / or a descendant terminal. Optionally, the method further includes: the first network node performs a topology update.

[0073] Optionally, the first network node sending the first transmission completion indication information includes:

[0074] The first network node transmits the first transmission completion indication information to the third network node.

[0075] Optionally, the first network node sending the first transmission completion indication information includes:

[0076] The first network node transmits the first transmission completion indication information to a fifth network node, which provides access and backhaul services to the first network node.

[0077] In the above manner, the first network node does not perform a topology update until all in-transit uplink data packets buffered by the first network node and the descendant nodes of the first network node are transmitted to the source parent node of the first network node, and the first transmission completion indication information is transmitted to the source parent node or the source donor node, which ensures that no data packets are lost in the topology update process.

[0078] Possibly, the first network node transmits the third data packet to a third network node.

[0079] In the above scheme, after determining to perform a topology update, the first network node transmits a third data packet to the third network node, and performs the topology update only after determining that all the third data packets have been transmitted.

[0080] In a possible manner, the first network node stops uplink scheduling for the sixth network node, the sixth network node being a descendant network node of the first network node.

[0081] Optionally, stopping uplink scheduling for the sixth network node includes: the first network node receiving, from the sixth network node, second transmission completion indication information indicating that a transmission of a fourth data packet is completed, the fourth data packet including uplink data from the sixth network node and a descendant node of the sixth network node; and the first network node receiving, from the sixth network node, second transmission completion indication information indicating that a transmission of a fourth data packet is completed, the fourth data packet including uplink data from the sixth network node and a descendant node of the sixth network node, completion Based on the indication information, stop uplink scheduling for the sixth network node.

[0082] Optionally, stopping uplink scheduling for the sixth network node includes: the first network node receiving first scheduling stop indication information from the third network node, and the first network node stopping uplink scheduling for the sixth network node based on the first scheduling stop indication information.

[0083] In the above-mentioned scheme, after the first network node decides to perform a topology update and the transmission of the uplink data packet at the sixth network node is completed, the first network node stops uplink scheduling for the sixth network node.

[0084] In a possible manner, after the first network node receives the first handover command from the third network node, the method further includes: the first network node stops uplink scheduling of the terminal device, and the first network node provides access and backhaul services to the terminal device.

[0085] Optionally, after the first network node decides to perform a topology update, the first network node stops uplink scheduling of the terminal device, and the first network node provides access and backhaul services to the terminal device.

[0086] In the manner described above, after receiving the handover command or after deciding to perform a topology update, the first network node stops uplink scheduling of the terminal device. In a possible manner, the first transmission completion indication information is carried in a third data packet, or the first transmission completion indication information is carried in a control protocol data unit PDU of a backhaul adaptation protocol BAP layer.

[0087] In the above manner, the first transmission completion indication information may be transmitted together with the last data packet of the third data packets, or may be transmitted alone.

[0088] According to a sixth aspect, an embodiment of the present application provides a lossless data transmission communication method. The method may be performed by a network node or may be performed by a component (e.g., a processor, a chip, or a chip system) of the network node. The method includes: a fifth network node receives transmission indication information indicating to stop uplink scheduling for a first network node. The fifth network node provides access and backhaul services to the first network node. The fifth network node determines to stop uplink scheduling for the first network node based on the transmission indication information.

[0089] Optionally, the fifth network node receiving the transmission indication information includes: the fifth network node receiving first transmission completion indication information from the first network node. The first transmission completion indication information indicates that transmission of the third data packet is completed. The third data packet includes uplink data from the first network node and a descendant node of the first network node. The descendant node includes a descendant network node and / or a descendant terminal. The fifth network node determines to stop uplink scheduling for the first network node based on the first transmission completion indication information.

[0090] Optionally, the fifth network node receiving the transmission indication information includes: the fifth network node receiving the second scheduling stop indication information from a third network node, where the third network node is a source donor node or a source donor node CU of the first network node.

[0091] In the above manner, the fifth network node may receive transmission completion indication information transmitted by different network elements in multiple manners, and the fifth network node decides to stop uplink scheduling for the first network node based on the transmission completion indication information.

[0092] In a possible manner, the second scheduling stop indication information is included in a second handover command, the second handover command instructing the fifth network node to perform the handover.

[0093] In the above scheme, when the fifth network node is instructed to perform a handover, uplink scheduling for the first network node is also shown to be stopped.

[0094] According to a seventh aspect, an embodiment of the application provides a lossless data transmission communication method. The method may be performed by a network node or may be performed by a component (e.g., a processor, a chip, or a chip system) of the network node. The method includes: a third network node receives first transmission completion indication information from the first network node. The first transmission completion indication information indicates that a transmission of a third data packet is completed. The third data packet includes uplink data from the first network node and a descendant node of the first network node. The descendant node includes a descendant network node and / or a descendant terminal.

[0095] The third network node sends second scheduling stop indication information to a fifth network node, where the second scheduling stop indication information indicates to the fifth network node to stop uplink scheduling for the first network node, and the fifth network node provides access and backhaul services to the first network node.

[0096] Optionally, the first transmission completion indication information is carried in uplink data, or the first transmission completion indication information is carried in an RRC message or an F1AP message.

[0097] Optionally, the second scheduling stop indication information is included in a second handover command, the second handover command instructing the fifth network node to perform the handover.

[0098] In the above manner, after the third network node determines that the transmission of all uplink data on the first network node performing topology update has been completed, the fifth network node is instructed to stop uplink scheduling for the first network node, which avoids the loss of data packets in the topology update process of the first network node.

[0099] According to an eighth aspect, an embodiment of the present application provides a lossless data transmission communication device. The device may be a network node, or may be a chip used in a network node. The device has a function of implementing any one of the first to seventh aspects or possible implementations of the first to seventh aspects. The function may be implemented by hardware, or may be implemented by the hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the function.

[0100] According to a ninth aspect, an embodiment of the present application provides a lossless data transmission communication device, including a processor and a memory. The memory is configured to store computer-executable instructions. When the device operates, the processor executes the computer-executable instructions stored in the memory, thereby causing the device to perform any of the methods in the first to seventh aspects or possible implementations of the first to seventh aspects.

[0101] According to a tenth aspect, an embodiment of the present application provides a lossless data transmission communication device comprising units or means configured to perform any of the method steps of the first to seventh aspects or possible implementations of the first to seventh aspects.

[0102] According to an eleventh aspect, an embodiment of the present application provides a lossless data transmission communication device including a processor and an interface circuit. The processor is configured to communicate with another device via the interface circuit and to perform any of the methods in the first to seventh aspects or possible implementations of the first to seventh aspects. There are one or more processors.

[0103] According to a twelfth aspect, an embodiment of the present application provides a lossless data transmission communication device including a processor. The processor is connected to a memory and configured to call a program stored in the memory to execute any of the methods in the first to seventh aspects or possible implementations of the first to seventh aspects. The memory may be located inside or outside the device. There may be one or more processors.

[0104] According to a thirteenth aspect, an embodiment of the present application further provides a computer-readable storage medium storing instructions which, when executed on a computer, enable a processor to perform any of the methods of the first to seventh aspects or possible implementations of the first to seventh aspects.

[0105] According to a fourteenth aspect, an embodiment of the present application further provides a computer program product, the computer product including a computer program, which when executed is capable of performing any of the methods of the first to seventh aspects or possible implementations of the first to seventh aspects.

[0106] According to a fifteenth aspect, an embodiment of the present application further provides a chip system including a processor, the processor being configured to execute any of the methods of the first to seventh aspects or possible implementations of the first to seventh aspects. [Brief description of the drawings]

[0107] [Figure 1A]1 is a schematic diagram of a communication system to which an embodiment of the present application can be applied; [Figure 1B] 1 is a schematic diagram of the architecture of an IAB network system according to an embodiment of the present application. [Figure 1C] FIG. 2 is a schematic diagram of a non-standalone networking IAB scenario according to an embodiment of the present application. [Figure 1D] FIG. 2 is a schematic diagram of a user plane protocol stack in an IAB network according to an embodiment of this application. [Figure 1E] FIG. 2 is a schematic diagram of a control plane protocol stack in an IAB network according to an embodiment of the present application. [Figure 1F] FIG. 2 is a schematic diagram of IAB inter-donor topology update according to an embodiment of the present application. [Figure 1G] FIG. 2 is a schematic diagram of IAB intra-donor topology update according to an embodiment of the present application. [Figure 2A] 1 is a schematic diagram of a lossless data transmission communication method according to an embodiment of this application; [Figure 2B] 2 is a schematic diagram of another lossless data transmission communication method according to an embodiment of the present application; [Figure 2C] 2 is a schematic diagram of another lossless data transmission communication method according to an embodiment of the present application; [Diagram 3] 2 is a schematic diagram of another lossless data transmission communication method according to an embodiment of the present application; [Figure 4] 2 is a schematic diagram of another lossless data transmission communication method according to an embodiment of the present application; [Diagram 5] 1 is a schematic diagram of a lossless data transmission communication device according to an embodiment of the present application; [Figure 6] 1 is a schematic diagram of the structure of a lossless data transmission communication device according to an embodiment of this application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0108] The embodiments of this application provide a lossless data transmission communication method and device, which are based on the same concept. Because the principles of solving problems by using the method and device are similar, cross-references may be made between the implementations of the device and method, and repeated descriptions will be omitted.

[0109] In the description of the embodiments of this application, the term "and / or" describes an association relationship between associated objects and indicates that three relationships may exist. For example, A and / or B may indicate three cases: only A exists, both A and B exist, and only B exists. The symbol " / " generally indicates an "or" relationship between associated objects. In this application, "at least one" means one or more, and "multiple" means two or more. Furthermore, in the description of this application, terms such as "first" and "second" may be understood to be used merely for distinction and explanation, but should not be understood as indicating or implying a relative importance, and should not be understood as indicating or implying an order.

[0110] The lossless data transmission communication method provided in the embodiments of this application may be applied to a 4th generation (4G) communication system, such as a long term evolution (LTE) system, a 5th generation (5G) communication system, such as a 5G new radio (NR) system, or various future communication systems, such as a 6th generation (6G) communication system, and as another example, a 7th generation (7G) communication system. The embodiments of this application may also be applied to an integrated access and backhaul (IAB) scenario.

[0111] Hereinafter, the embodiments of this application will be described with reference to the accompanying drawings. Features or contents marked with dashed lines in the accompanying drawings can be understood as optional operations or optional structures in the embodiments of this application.

[0112] 1A is a schematic diagram of a communication system to which an embodiment of this application is applicable. The communication system 100 includes at least one IAB node (IAB node 110 to IAB node 150 are shown) and at least one IAB donor 160. Optionally, the communication system further includes at least one terminal (terminal 170 and terminal 180 are shown) connected to the IAB node. Optionally, the communication system further includes a core network device 190 connected to the IAB donor 160. The IAB node 140 may provide wireless access services to the terminal 170 via an access link (AL). Service data of the terminal 170 may be transmitted by the IAB node 140 to the connected IAB donor 160 via a wireless backhaul link (BL).

[0113] The terminal in Figure 1A may be a user equipment, a mobile termination (MT), an access terminal device, a subscriber unit, a subscriber station, a mobile station, a remote station, a remote terminal device, a mobile device, a user terminal device, a wireless terminal device, a user agent, a user equipment, etc. Alternatively, the terminal may be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication capabilities, a computing device, another processing device connected to a wireless modem, an in-vehicle device, a wearable device (such as a smart watch or smart band), smart furniture or home appliances, a terminal device in a 5G network, a terminal device of a future evolving public land mobile network (PLMN), a vehicle device of a vehicle-to-everything (V2X), a customer premises equipment (CPE), etc. The specific implementation of the user equipment is not limited in this application.

[0114] The IAB node in FIG. 1A may include a mobile terminal and a distributed unit (DU). When facing a parent node of the IAB node, the IAB node may be regarded as a terminal device, i.e., a role of an MT. When facing a descendant device of the IAB node (the descendant device may be another child IAB node or a common UE), the IAB node may be regarded as a network device, i.e., a role of a DU. For ease of explanation, in the embodiment of this application, an IAB node (e.g., IAB node 140) or a terminal (e.g., terminal 170) connected to the IAB donor 160 via the IAB node 130 is referred to as a descendent IAB node, a descendant node, a descendant network node, or a descendant terminal of the IAB node 130.

[0115] The IAB donor in FIG. 1A may be a donor base station, and the IAB donor may be abbreviated as DgNB (donor gNodeB) in a 5G network. The IAB donor may be a complete entity, or may exist in a form in which a central unit (CU) (for simplicity in this application, may be abbreviated as donor-CU, CU, or gNB-CU) and a distributed unit (DU) (for short, in this application, may be abbreviated as donor-DU, DU, or gNB-DU) are separated. As shown in FIG. 1B, the IAB donor may be a gNB in ​​a 5G radio access network (5G RAN). The IAB donor may include a gNB-CU and a gNB-DU. The gNB-CU and the gNB-DU are connected via an F1 interface, and the F1 interface may further include a control plane interface (F1-C) and a user plane interface (F1-U). The CU and the core network are connected via a next generation (NG) interface. The gNB-CU or donor-CU may alternatively exist in a form in which the user plane (UP) (abbreviated as CU-UP in this application) and the control plane (CP) (abbreviated as CU-CP in this application) are separated. In other words, the gNB-CU or donor-CU includes a CU-CP and a CU-UP. The gNB-CU may include one gNB-CU-CP and at least one gNB-CU-UP. Alternatively, the donor-CU may include one donor-CU-CP and at least one donor-CU-UP.

[0116] It is easy to understand that the IAB nodes and IAB donors in the embodiments of this application may be referred to as network nodes or network devices.

[0117] The core network device in FIG. 1A may be a network management device, e.g., an operation, administration and maintenance (OAM) network element. The network management device may include an element management system (EMS) and a network management system (NMS). As shown in FIG. 1B, the network management device may be a functional network element in a Next Generation Core (NGC) or 5G core (5GC). Alternatively, the network management device may be a functional network element located in a backbone network behind the 5GC, or the network management device may be located elsewhere. The particular location of the network management device is not limited by this application.

[0118] As shown in FIG. 1B, the IAB node is connected to the core network via an IAB donor. For example, in a standalone (SA) 5G architecture, the IAB node is connected to the 5GC via an IAB donor. 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. 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 a dual connectivity (DC) or multi-connectivity (MC) 5G architecture (e.g., a non-standalone (NSA) networking scenario or an NR-NR DC scenario), on the primary path, the IAB node may be connected to an evolved packet core (EPC) (e.g., connected to a serving gateway, SGW) via an evolved NodeB (eNB). There is an LTE Uu air interface connection between the MeNB and the MT of the IAB node. There is an X2-C interface between the MeNB and the IAB-Donor-CU-CP. The MeNB is connected to the EPC via an S1 interface (including an S1 interface user plane and an S1 interface control plane). The 5G core network may be configured to perform authentication, mobility management, protocol data unit (PDU) session management, etc. on the terminal device, and includes functional entities or network elements such as AMF and UPF. The 4G core network may be configured to perform authentication, mobility management, packet data network connection management, etc. on the terminal device, and includes network elements such as mobility management entities and packet data gateways.

[0119] In order to ensure the reliability of service transmission, the IAB network supports multi-hop IAB node networking and multi-connection IAB node networking. Therefore, there may be multiple transmission paths between a terminal and an IAB donor. In one path, there is a determined hierarchical relationship between IAB nodes and between the IAB nodes and the IAB donors connected to the IAB nodes. Each IAB node regards a node that provides backhaul services to the IAB node as a parent node. Correspondingly, each IAB node may be regarded as a child node of the IAB node's parent node.

[0120] For example, see FIG. 1A. The parent node of IAB node 110 is IAB donor 160, IAB node 110 is the parent node of IAB node 120 and IAB node 130, both IAB node 120 and IAB node 130 are the parent nodes of IAB node 140, and the parent node of IAB node 150 is IAB node 120. An uplink data packet of a terminal may be transmitted to the IAB donor via one or more IAB nodes, and then transmitted by the IAB donor to a core network device 190 (e.g., a user plane function (UPF) network element in a 5G network). After the IAB donor 160 receives a downlink data packet from a core network device (e.g., a mobile gateway device), the IAB donor transmits the downlink data packet to the terminal via one or more IAB nodes. There are two available paths for data packet transmission between the terminal 170 and the IAB donor 160. One path is as follows: terminal 170 → IAB node 140 → IAB node 130 → IAB node 110 → IAB donor 160. Another path is as follows: terminal 170 → IAB node 140 → IAB node 120 → IAB node 110 → IAB donor 160. There are three available paths for data packet transmission between terminal 180 and IAB donor 160. The three paths are as follows: terminal 180 → IAB node 140 → IAB node 130 → IAB node 110 → IAB donor 160; terminal 180 → IAB node 140 → IAB node 120 → IAB node 110 → IAB donor 160; terminal 180 → IAB node 150 → IAB node 120 → IAB node 110 → IAB donor 160. Each intermediate IAB node on an uplink path from an IAB node to an IAB donor may be referred to as upstream of the IAB node. For example, both IAB nodes 110 and 120 in FIG. 1A may be referred to as upstream IAB nodes of IAB node 150. For example, descendant devices or descendant nodes of an IAB node may include devices that directly access the IAB node, such as child nodes of the IAB node or UEs that access the IAB node.For example, IAB node 120 and IAB node 130 in FIG. 1A may be referred to as descendant devices of IAB node 110, and terminal 170 and terminal 180 may be referred to as descendant devices of IAB node 140.

[0121] It can be understood that in an IAB network, there may be one or more IAB nodes on the transmission path between a terminal and an IAB donor. Each IAB node needs to maintain a wireless backhaul link to a parent node and also needs to maintain a wireless link to a child node. If an IAB node is a node accessed by a terminal, there is a wireless access link AL between the IAB node and the child node (i.e., the terminal). If an IAB node is a node that provides backhaul services to another IAB node, there is a wireless backhaul link BL between the IAB node and the child node (i.e., another IAB node). See, for example, FIG. 1A. On the route "terminal 170 → IAB node 140 → IAB node 130 → IAB node 110 → IAB donor 160," terminal 170 accesses IAB node 140 via a wireless access link, IAB node 140 accesses IAB node 130 via a wireless backhaul link, IAB node 130 accesses IAB node 110 via a wireless backhaul link, and IAB node 110 accesses the IAB donor via a wireless backhaul link.

[0122] The aforementioned IAB networking scenarios are merely examples. In an IAB scenario that combines multi-hop and multi-connection, there are further possible IAB networking scenarios. For example, an IAB donor and an IAB node connected to another IAB donor form a dual connection to serve a terminal. The possible IAB networking scenarios are not listed one by one here.

[0123] The IAB network also supports non-standalone (NSA) networking, also referred to as EN-DC (E-UTRAN NR dual connectivity) networking scenario. FIG. 1C is a schematic diagram of a non-standalone networking IAB scenario according to an embodiment of this application. The IAB node supports dual connectivity of 4G and 5G networks. The LTE base station eNB is a master base station (Master eNB, MeNB), provides an LTE air interface (LTE Uu) connection to the IAB node, and establishes an S1 interface with the evolved packet core (EPC) of the 4G core network for user plane and control plane transmission. The IAB donor gNB is a secondary base station, provides an NR air interface (NR Uu) connection to the IAB node, and establishes an S1 interface with the core network EPC for user plane transmission. Similarly, the UE also supports EN-DC. The UE is connected to the master base station eNB via an LTE Uu interface and connected to the secondary base station IAB node via an NR Uu interface. Alternatively, the secondary base station of the UE can be an IAB donor gNB.

[0124] It is easy to understand that Fig. 1C is just a networking example. The NSA scenario of the IAB network also supports multi-hop IAB networking. For example, the UE in Fig. 1C can be another IAB node, in other words, the IAB node can be connected to the IAB donor gNB via a multi-hop wireless backhaul link.

[0125] Figure 1D is a schematic diagram of a user plane protocol stack in an IAB network according to an embodiment of this application, and Figure 1E is a schematic diagram of a control plane protocol stack in an IAB network according to an embodiment of this application. The following provides an explanation with reference to Figures 1D and 1E.

[0126] In the current discussions on the IAB network, it has been decided that a new protocol layer, the backhaul adaptation protocol (BAP) layer, will be introduced on the wireless backhaul link, which is placed on top of the radio link control (RLC) layer and implements functions such as routing and bearer mapping of data packets on the wireless backhaul link.

[0127] An F1 interface (or called F1* interface, and may be collectively called F1 interface in the embodiment of this application, but the name is not limited) needs to be established between an IAB node (the DU part of the IAB) and a donor node (or IAB-donor-CU). The interface supports a user plane protocol (F1-U / F1*-U) and a control plane protocol (F1-C / F1*-C). The user plane protocol includes one or more of the following protocol layers: a general packet radio service (GPRS) tunneling protocol user plane (GTP-U) protocol layer, a user datagram protocol (UDP) layer, an internet protocol (IP) layer, etc. The control plane protocol of the interface includes one or more of the following protocol layers: an F1 application protocol (F1AP) layer, a stream control transport protocol (SCTP) layer, an IP layer, etc.

[0128] For the user plane, as shown in FIG. 1D, functions such as user plane data transmission and downlink transmission status feedback may be performed between the IAB node and the IAB donor via the user plane of the F1 / F1* interface.

[0129] For the control plane, as shown in FIG. 1D, interface management, management at the IAB-DU, UE context related configuration, etc. may be performed between the IAB node and the IAB donor via the control plane of the F1 / F1* interface.

[0130] 1D and 1E are described using the protocol stack of the IAB scenario shown in FIG. 1A as an example. In particular, one IAB node may play one or more roles. The IAB node may have one or more protocol stacks for one or more roles. Alternatively, the IAB node may have a protocol stack, and for different roles of the IAB node, protocol layers corresponding to different roles in the protocol stack may be used for processing. In the following, an explanation is provided using an example in which the IAB node has one or more protocol stacks for one or more roles.

[0131] (1) Protocol stack for common terminals

[0132] When accessing the IAB network, the IAB node can function as a common terminal. In this case, the MT of the IAB node has a protocol stack of the common terminal. After the IAB node accesses the IAB network, the IAB node can still play the role of the common terminal. For example, the IAB node transmits uplink and / or downlink data packets (e.g., OAM data packets) for the IAB node together with the IAB donor and performs measurements using the RRC layer.

[0133] (2) Protocol stack of access IAB node

[0134] After the IAB node accesses the IAB network, the IAB node can provide an access service to the terminal and act as an access IAB node. In this case, the IAB node has a protocol stack of an access IAB node, for example, the protocol stack of the IAB node 2 in FIG. 1D and FIG. 1E.

[0135] In this case, there may be two protocol stacks on the interface that belongs to the IAB node and faces the parent node of the IAB node: one is the protocol stack of the common terminal and the other is the protocol stack that provides backhaul services to the terminal (i.e., the protocol stack of the access IAB node).

[0136] (3) Protocol stack of intermediate IAB node

[0137] After an IAB node accesses the IAB network, the IAB node may play the role of an intermediate IAB node, in which case the IAB node has a protocol stack of an intermediate IAB node, for example, the protocol stack of IAB node 1 in Figures 1D and 1E.

[0138] In this case, there may be two protocol stacks on the interface of the IAB node that faces the parent node of the IAB node: the protocol stack of the common terminal, and the protocol stack that provides backhaul services to the IAB child node (i.e., the protocol stack of the intermediate IAB node).

[0139] Furthermore, an IAB node may act as both an access IAB node and an intermediate IAB node. For example, an IAB node may be an access IAB node for some terminals and an intermediate IAB node for other terminals. In this case, the IAB node may have three protocol stacks: a protocol stack of the common terminal, a protocol stack of the access IAB node, and a protocol stack of the intermediate IAB node.

[0140] In particular, FIG. 1D and FIG. 1E are described using an IAB network as an example. The contents of FIG. 1D and FIG. 1E are also applicable to other types of relay networks different from the IAB network. For the control plane protocol stack architecture of the relay network, please refer to FIG. 1D. For the user plane protocol stack architecture of the relay network, please refer to FIG. 1E. The IAB nodes in FIG. 1D and FIG. 1E can be replaced by relays. For example, the IAB node 1 can be replaced by the relay node 1, the IAB node 2 can be replaced by the relay node 2, the IAB donor can be replaced by a donor node, and the donor node has a CU protocol stack and a DU protocol stack. The other contents are the same as those described in FIG. 1D and FIG. 1E. For details, please refer to the description of FIG. 1D and FIG. 1E, and the details will not be described again here.

[0141] An IAB node in an IAB network may perform topology updates, such as those occurring during a handover process or a radio link failure recovery process. In the embodiment of this application, a handover process is used as an example for illustration, but the topology updates are not limited to those occurring only due to handover.

[0142] Based on different types of topology updates, the following describes some possible scenarios in which an IAB node performs topology updates by utilizing the accompanying drawings.

[0143] Scenario 1: IAB donor-to-donor topology update as shown in FIG. 1F, e.g., IAB donor-to-donor topology update caused by handover of an IAB node

[0144] IAB node 3 (denoted as the first network node) hands over from a source parent node (e.g., IAB node 1 in FIG. 1F) to a target parent node (e.g., IAB node 2 in FIG. 1F, shown as the fifth network node) and changes the connected IAB donor, specifically, hands over from a source IAB donor (e.g., IAB donor 1 in FIG. 1F, denoted as the first donor node) to a target IAB donor (e.g., IAB donor 2 in FIG. 1F, shown as the second donor node). The first network node also hands over from a source IAB donor DU (e.g., IAB donor DU1 in FIG. 1F) to a target IAB donor DU (e.g., IAB donor DU2 in FIG. 1F, shown as the second network node). For simplicity, the source IAB donor CU may be denoted as the third network node, and the target IAB donor CU may be denoted as the fourth network node. This type of handover may be referred to as an IAB inter-donor handover, an IAB inter-donor topology update, an IAB inter-donor CU topology update, or an inter-donor CU handover (inter-donor CU transition).

[0145] Alternatively, it is easy to understand that the target IAB donor DU and the target IAB donor CU are not separated in scenario 1. Similarly, alternatively, the source donor DU and the source donor CU are not separated.

[0146] Scenario 2: Intra-IAB donor topology update as shown in FIG. 1G, e.g., intra-IAB donor topology update caused by IAB node handover

[0147] IAB node 3 (denoted as the first network node) hands over from a source parent node (e.g., IAB node 1 in FIG. 1G) to a target parent node (e.g., IAB node 2 in FIG. 1G) but does not change the IAB donor, in other words, hands over from a source donor DU (e.g., IAB donor DU 1 in FIG. 1G, also called original donor DU) to a target donor DU (e.g., IAB donor DU 2 in FIG. 1G, shown as the second network node, also called new donor DU) under IAB donor CU (denoted as the third network node). This type of handover may be called intra-IAB donor handover, inter-IAB donor DU handover, inter-DU handover, or intra-donor CU handover (intra-donor CU transition). It is easy to understand that the above scenarios 1 and 2 describe the IAB node handover scenario. Similarly, a parent node of an IAB node (e.g., IAB node 1 in FIG. 1F) may perform a handover, e.g., from a source IAB donor to a target IAB donor. Similarly, a child node of an IAB node (e.g., IAB node 4 in FIG. 1F) may perform a handover together with the IAB node, i.e., from a source IAB donor to a target IAB donor. The method provided in the embodiment of this application is applicable to a handover of an IAB node, and also applicable to a scenario in which a child node of an IAB node performs a handover together with the IAB node, and also applicable to another scenario in which an IAB parent node or a donor node connected to an IAB node changes, e.g., a scenario in which an IAB node changes a new parent node and further changes a connected IAB donor node after performing link recovery after a radio link failure occurs. In other words, in this application, a topology update in an IAB network may be understood as a topology update caused by an IAB node performing a handover. For example, an IAB node performs a handover according to a handover command.Alternatively, it may be understood as a topology update triggered by performing a Radio Link Failure (RLF) recovery process after an IAB node experiences a Radio Link Failure (RLF) or after an IAB node receives a BH RLF notification signaled by a parent node.

[0148] In this application, the MT of the IAB node may be abbreviated as IAB-MT, the DU of the IAB node may be abbreviated as IAB-DU, the CU of the IAB donor may be abbreviated as donor-CU, and the DU of the IAB donor may be abbreviated as donor-DU.

[0149] In this application, an IAB donor connected to an IAB node may be referred to as the IAB donor of the IAB node or the donor node of the IAB node, or simply referred to as IAB donor. An IAB node may directly access a cell served by the IAB donor (e.g., directly access a cell served by a DU of the IAB donor, or directly access a cell served by an IAB donor where CU and DU are not separated), or an IAB node may be connected to an IAB donor by utilizing another IAB node (e.g., a parent node of the IAB node, which is an IAB node that accesses a cell served by the IAB donor).

[0150] After an IAB node performs a topology update, some data packets on the IAB node (e.g., service data units (SDUs) at the BAP layer or PDUs at the BAP layer) are not successfully transmitted to the source parent node. When an IAB node changes the connected donor DU after a topology update (e.g., an IAB node is individually connected to different donor DUs of the same IAB donor before and after a topology update, or is individually connected to different donor DUs of different IAB donors), how to reduce the loss of data packets is an issue that needs to be urgently solved.

[0151] In order to avoid the loss of these data packets, the IAB node may buffer these data packets first (e.g., buffer them at the BAP layer) and send these buffered data packets to the new parent node after the topology update is completed. However, to avoid the loss of these buffered data packets, at least the following two problems that still exist in the above data packet sending process need to be solved:

[0152] Problem 1: For the case where the connected IAB donor DU is changed after the topology update, for example, in the above scenarios 1 and 2, after the topology update, the IAB node can send the buffered uplink data packets to the new parent node, and connect the new parent node not to the original IAB donor DU (or called source IAB donor DU), but only to the new IAB donor DU (or called target IAB donor DU). However, the conventional technology does not support rerouting and forwarding of uplink data packets between different IAB donor DUs (e.g., different IAB donor DUs of the same IAB donor, or different IAB donor DUs of different IAB donors).

[0153] Problem 2: Even if problem 1 is solved and these buffered data packets are forwarded to the target IAB donor DU, the problem of how the target IAB donor DU correctly forwards the data packets needs to be further solved.

[0154] Even if the IAB node performs an inter-IAB donor topology update and some uplink data packets that should originally be sent to the source IAB donor node can be sent to the target IAB donor DU on the wireless backhaul link, the source IP address of these uplink data packets may be the original IP address obtained by the IAB node when the IAB node is connected to the source IAB donor node. If the target IAB donor DU configures a source IP address filtering mechanism, the target IAB donor DU may not forward these data packets or may even discard these data packets because the original IP address of the IAB node does not belong to the range of source IP addresses that are allowed to be forwarded. If these uplink data packets cannot be sent to the source IAB donor CU at the IAB node or the target IAB donor DU, for a conventional terminal, the terminal also cannot send the corresponding packet data convergence protocol (PDCP) SDUs in these data packets to the target IAB donor CU. Therefore, some data packets may be lost in the topology update process.

[0155] Furthermore, even after the data packets are forwarded by the target IAB donor DU to the target IAB donor CU, if security protection (e.g., UE integrity protection or encryption at the PDCP layer, or IAB node encryption at the IPsec layer) is performed on the data packets based on the security mechanism negotiated with the source IAB donor CU, the data packets may not be parsed correctly by the target IAB donor CU, or the integrity protection check may fail. Therefore, these data packets still need to be sent to the source IAB donor CU for processing.

[0156] As shown in FIG. 2A, in order to solve the above-mentioned problem occurring when the target donor node DU and the target donor node CU are separated in the above-mentioned scenario 1, an embodiment of this application provides a lossless data transmission communication method 200A, which includes the following steps:

[0157] S210A: A first network node performs a topology update. The topology update includes the first network node changing a connected IAB donor DU. For example, an IAB donor DU connected to the first network node is changed to a second network node. The second network node is a target IAB donor DU of the topology update performed by the first network node.

[0158] S230A: The first network node transmits a first data packet to the second network node. The destination node of the IP layer of the first data packet is the third network node. It is easy to understand that when the CU and DU of the source IAB donor of the first network node are separated, the third network node is the source IAB donor CU of the first network node, or when the CU and DU of the source IAB donor of the first network node are not separated, the third network node is the source IAB donor of the first network node, in other words, the first data packet is a data packet transmitted to the third network node. For example, the first data packet may be a data packet buffered by the first network node at the BAP layer and transmitted to the third network node before the first network node performs a topology update. It may be understood that the destination node of the first data packet may alternatively be a security gateway (SeGW) device on the third network node side.

[0159] Optionally, before the first network node transmits the first data packet to the second network node,S 230A further includes S231A: the first network node performs a first processing operation on the first data packet. For example, the first processing operation is to update the header information of the BAP layer of the first data packet. For example, the first network node receives BAP layer configuration information from the target IAB donor CU, and the first network node updates the header information of the BAP layer of the first data packet based on the BAP layer configuration information. Specifically, the first network node replaces the BAP routing identifier in the header information of the BAP layer of the first data packet with the configured new routing identifier based on the BAP layer configuration information. The new routing identifier points to a transmission path to the second network node. In this manner, the first network node can successfully transmit the first data packet to the second network node. In a possible implementation, before S230A, the method further includes S220A. The second network node updates the IP address filtering rule to forward the first data packet to the third network node.

[0160] The second network node updates the IP address filtering rule and sends the first data packet to the third network node. For example, updating the IP address filtering rule may be adding the source IP address of the first data packet to a whitelist of the source IP address filtering rule, or the second network node may temporarily disable the source IP address filtering rule. This can avoid a case where the second network node does not forward the first data packet or discards the first data packet because the IP address of the first data packet does not belong to a range of source IP addresses that are allowed to be forwarded.

[0161] S240A: A second network node transmits a first data packet to a third network node.

[0162] Considering it in some possible scenarios, if the second network node can only see the outer IP header of the first data packet, and the destination node of the IP layer of the first data packet may be a third network node or may be a security gateway device arranged on the third network node side, and the corresponding IP routing is configured in the second network node, and the destination node for forwarding the IP layer can be found to be a suitable next-hop node of the third network node (specifically, may be the third network node CU-CP or the third network node CU-UP) or a security gateway arranged on the third network node side (called source SeGW for short), the first data packet can be sent to the source IAB donor CU or source SeGW by utilizing the next-hop node. However, if the IP layer of the target second network node is not configured with IP routing where the destination node is the third network node, the second network node cannot directly send the first data packet to the third network node via routing and forwarding at the IP layer.

[0163] Regarding the question of how to ensure that the second network node can transmit the first data packet to the third network node, optionally, the method 240A further includes:

[0164] S241A: A second network node obtains a second data packet. The first data packet is encapsulated into a second data packet, and the second data packet includes a first IP header and a second IP header, and a target IP address of the first IP header is an IP address of a third network node or an IP address of a first security gateway device connected to the third network node, and a target IP address of the second IP header is an IP address of a fourth network node. Optionally, the first security gateway device may be a security gateway device disposed on the third network node side.

[0165] Optionally, the second IP header may be added to the first data packet by the second network node, or may be added to the first data packet by the first network node. In other words, in a manner in which the second network node obtains the second data packet, after the second network node receives the first data packet sent by the first network node, the second network node adds the second IP header to the first data packet to obtain the second data packet. In another manner in which the second network node obtains the second data packet, in S220A, when sending the first data packet to the second network node, the first network node adds the second IP header to the first data packet, in other words, the second network node receives the second data packet encapsulated in the first data packet from the first network node.

[0166] S242A: The second network node sends the second data packet to the fourth network node. It may be understood that the second network node sends the second data packet to the fourth network node based on the second IP header.

[0167] Optionally, the second data packet further includes first removal indication information instructing the fourth network node to remove the second IP header. Optionally, the first removal indication information may be indicated using a bit or a special field. Other implementations that may indicate to the fourth network node to remove the second IP header are not limited in this application.

[0168] S243A: The fourth network node transmits the first data packet to the third network node.

[0169] Optionally, after removing the second IP header of the second data packet based on the first removal indication information, the fourth network node determines to send the first data packet to the third network node based on the first IP header of the second data packet. It may be understood that the first IP header is included in the first data packet, and the first data packet may be obtained after the second IP header is removed from the second data packet.

[0170] In other words, the second network node or the first network node encapsulates a new outer IP header (second IP header) outside the first data packet, whose target IP address is the IP address of the third network node (or the source SeGW), to obtain a second data packet. The target address of the new IP header is the IP address of the fourth network node. After the second network node forwards the second data packet to the fourth network node via IP routing based on the IP address of the destination node in the new outer IP header, the fourth network node removes the new outer IP header and then forwards the first data packet to the destination node (i.e., the third network node or the source SeGW) at the IP layer of the data packet via IP routing. In order to enable the fourth network node to identify a particular received IP data packet for which such special reception processing (specifically, the processing is that the packet is forwarded based on the inner IP header after the outer IP header is removed) needs to be performed, the node that adds the outer IP header may include first removal indication information in the outer IP header.

[0171] According to the method 200A, forwarding or rerouting of uplink data packets between the second network node and the third network node (e.g., between IAB donors or between IAB donor DUs) may be allowed, which avoids the uplink data packets being discarded by the second network node in the rerouting process, and the rerouting and forwarding of data packets between different donor nodes is completed, reducing data packet loss.

[0172] In the above S210A, the topology update may include a topology update caused due to a handover or in a radio link recovery process.

[0173] At S231A, this embodiment of this application lists two cases as examples in which the first network node performs a first process on the first data packet.

[0174] Case 1: The first data packet is an SDU at a BAP layer received from an upper layer protocol layer, and the first process is that the first network node adds header information of the BAP layer to the SDU of the first data packet based on a new BAP layer configuration received. Optionally, the new BAP layer The configuration is transmitted by the fourth network node to the first network node.

[0175] Specifically, when the first data packets buffered by the first network node (e.g., IAB node 3 shown in FIG. 1F) are SDUs of the BAP layer received from an upper layer protocol layer, after the topology update, e.g., after S210A is executed, the first network node adds BAP layer header information to these buffered SDUs based on the received new BAP layer configuration (wherein the BAP layer header information includes a routing identifier (BAP routing ID) corresponding to a target path, the target path includes a target parent node (e.g., IAB node 1 shown in FIG. 1F), the BAP routing ID includes a BAP address and a BAP path identifier (BAP Path ID). 1F) or the target IAB donor DU (e.g., IAB donor DU2 shown in FIG. 1F), and the BAP path ID indicates the transmission path between the first network node and the target IAB donor or the target IAB donor DU.) The first network node sends the first data packet to the target IAB donor DU based on the new routing identifier and new routing configuration provided by the target IAB donor CU.In the case where the first data packet is a PDU of the F1 interface protocol layer of the first network node, for example, the first data packet is an IP packet of an IP layer included in a protocol stack of a user plane or control plane of the F1 interface, and the protocol layer of the F1 interface may be considered as an upper layer of the BAP layer in an IP layer header added to an upper layer protocol layer of the BAP layer (e.g., an IP layer on the DU side of the first network node), the IP address entered in the source IP address field is an IP address (for brevity, denoted as the first IP address) still obtained by the first network node when the first network node is connected to a source IAB donor (e.g., the first donor node shown in FIG. 1F), and the IP address entered in the target IP address field is an IP address of the source IAB donor (specifically, which may be a source IAB donor CU, a source IAB donor CU CP, or a source IAB donor CU UP).

[0176] It can be understood that the upper layer protocol layer of the BAP layer in this embodiment of this application can be the IP layer on the DU side of the first network node.

[0177] Case 2: The first data packet is a PDU at the BAP layer, in other words, the first data packet already carries the header information of the BAP layer. In this case, the first process is: the first network node updates the header information of the BAP layer for the PDU of the first data packet based on the received new BAP layer configuration; optionally, the first network node updates the header information of the BAP layer for the PDU of the first data packet based on the received new BAP layer configuration; layer The configuration is transmitted by the fourth network node to the first network node.

[0178] Specifically, if the uplink data packet buffered by the first network node is a PDU of the BAP layer, i.e., already carries header information of the BAP layer, in which the destination node of the BAP layer indicated by the BAP address carried in the routing identifier BAP routing ID is the source IAB donor DU (e.g., IAB donor DU1 shown in FIG. 1F), the path indicated by the BAP path ID carried in the BAP routing ID is still the transmission path to the source IAB donor DU, and the routing selection in the IAB network is performed based on the routing identifier in the adaptation layer header; in other words, for a node performing routing selection, when a routing is selected for a data packet carrying the BAP routing ID, if there is an entry corresponding to the BAP routing ID in the configured routing table and the next hop node specified in the entry is an available next hop node, the data packet is sent to the next hop node specified in the entry. If an entry corresponding to the BAP routing ID cannot be found in the routing table, or the next hop node specified in the entry corresponding to the BAP routing ID is unavailable, an available next hop node specified in any entry that is the same as the BAP address portion carried in the data packet may be selected as the next hop node for transmitting the data packet from one or more entries in the routing table. When the first network node performs the topology update at S210A, if the target IAB donor DU connected via the target parent node is different from the source IAB donor DU connected via the source parent node, it may be understood that in addition to the transmission path, the uplink destination node (uplink) of the BAP layer changes. Therefore, before the first network node forwards the first data packet, the header information of the BAP layer of the data packet needs to be modified.For example, the first network node may receive configuration information provided by a target IAB donor CU (e.g., the fourth network node shown in FIG. 1F), and the configuration information may be sent to the first network node by utilizing an RRC message or an F1AP message. The specific content may include one or more new routing identifiers (e.g., a default / default BAP routing ID that may be utilized to forward all buffered data packets) for the target IAB donor DU, and may optionally further include a next-hop node corresponding to each routing identifier and an original routing identifier (pointing to an original transmission path to the source IAB donor DU) that maps to each new routing identifier. Based on the configuration information provided by the target IAB donor CU, the first network node replaces the BAP routing ID in the header information of the BAP layer carried in the BAP PDU buffered by the first network node with the configured new routing identifier, performs routing selection based on the new routing identifier, and sends the data packet to the next hop node (i.e., the target parent node), and ensures that the data packet buffered before the handover is forwarded to the target IAB donor CU after the handover is completed. Optionally, if the BAP layer PDU buffered by the first network node does not include a routing identifier (e.g., the PDU is a BAP control PDU), the first network node may directly send the BAP control PDU (e.g., a flow control feedback control PDU including a backhaul RLC channel (BH RLC channel) granularity) to the target parent node, or remove the BAP control PDU (e.g., a flow control feedback control PDU including a BAP routing ID granularity).

[0179] If the first network node does not add a second IP header to the first data packet in S220A, this embodiment of the application provides several possible ways for the second network node to update the IP address filtering rules.

[0180] Method 1: Add the source IP address of the first data packet to the whitelist of the source IP address filtering rule

[0181] Optionally, S 220A further includes:

[0182] S221A: A fourth network node sends a first message to a second network node, the first message carrying a first IP address, the first IP address being one or more IP addresses obtained by the first network node when the first network node is connected to a third network node.

[0183] After receiving the first message, the second network node updates the IP address filtering rule based on the first message, for example, the second network node adds the first IP address to a whitelist of the source IP address filtering rule.

[0184] In this embodiment of the application, it can be understood that the fourth network node obtains the first IP address in a number of possible ways.

[0185] Optionally, S222A: The fourth network node receives a second message sent by the third network node, wherein the second message includes the first IP address.

[0186] Optionally, the fourth network node receives a third message (not shown in FIG. 2A ) sent by the first network node, the third message including the first IP address, and the third message may be an RRC message.

[0187] Specifically, the fourth network node may send to the second network node one or more IP addresses (for ease of explanation, referred to as first IP addresses for short) obtained by the first network node when the first network node is connected to the third network node. After receiving the first IP addresses, the second network node may add the first IP addresses to a whitelist (i.e., a list of source IP addresses of data packets that are allowed to be forwarded) of a source IP address filtering rule of the second network node. The first IP addresses may be sent by the third network node to the fourth network node. For example, the first network node performs an Xn interface-based handover, and the third network node includes the first IP address of the first network node in an Xn interface message (e.g., an Xn interface Handover Request message) and sends the Xn interface message to the fourth network node. Alternatively, the AMF sends the first IP address to the fourth network node. For example, the first network node performs an NG interface-based handover, the third network node includes the first IP address of the first network node in an NG interface message (e.g., an NG interface handover required message) and sends the NG interface message to the target AMF, and the AMF sends the first IP address of the first network node in an NG interface message (e.g., an NG interface handover required message) to the fourth network node. Alternatively, the first network node may send the first IP address to the fourth network node. For example, the first network node sends the first IP address to the fourth network node using an RRC message (which may be an RRC reconfiguration complete message in particular) after a topology update is completed.

[0188] Method 2: Temporarily disable source IP address filtering rules

[0189] Optionally, S 220A further includes:

[0190] S221A: The fourth network node sends a first message to the second network node, where the first message carries first suspension indication information, and the first suspension indication information instructs the second network node to temporarily disable a source IP address filtering rule.

[0191] The second network node temporarily disables the source IP address filtering rule based on the first suspension indication information.

[0192] It can be understood that the first pause indication information can be a bit indication or timer setting information, which is not limited to this embodiment of the application, as long as it can indicate to the second network node to temporarily disable the source IP address filtering rule.

[0193] In this embodiment of the present application, the second network node may temporarily disable the source IP address filtering rule in multiple ways. For example, the implementation is performed by utilizing a timer or by waiting for information indicating to re-enable (or resume) the filtering rule. Specifically, for example, after the first pause indication information is received, the source IP address filtering rule is temporarily disabled. filtering The rule may be disabled, a timer is started, and the source IP address filtering rule is resumed after a preset condition is met. The preset condition may be that the timer expires or that an indication of another network node is received. This is not limited in this embodiment of the application.

[0194] In S240A, the third network node obtains the first data packet in two ways: receiving the first data packet directly sent by the second network node, or receiving the first data packet forwarded by a fourth network node, where the fourth network node receives a second data packet, in which the first data packet is encapsulated, from the second node in the network, where the second data packet is obtained by encapsulating the first data packet by the second network node and includes a second IP header. After removing the second IP header of the second data packet, the fourth network node sends the first data packet to the third network node.

[0195] In this embodiment of the application, after the third network node obtains the first data packet, there may be several data packet processing manners.

[0196] Data packet processing method 1: The third network node determines data related to the terminal device served by the first network node based on the first data packet. The data may be data related to the service continuity of the terminal, such as PDCP SDU.

[0197] The third network node transmits data relating to the terminal device to a fourth network node.

[0198] Specifically, after receive processing is performed on the first data packet by the third network node (e.g., a PDCP SDU is obtained after receive processing is performed on the user plane data packet by the third network node), if necessary (e.g., the uplink data packet is still not completely transmitted after the user plane transmission channel to the core network is switched to the fourth network node), the first data packet may be further forwarded by the third network node to the fourth network node via an Xn user plane (Xn-U) interface, to ensure service continuity of the terminal device served by the first network node after the first network node performs handover.

[0199] Data packet processing method 2: The third network node determines, based on the first data packet, data, such as PDCP SDU, related to the terminal device served by the first network node.

[0200] The third network node transmits data related to the terminal device to the UPF.

[0201] Specifically, when the third network node wants to send PDCP SDUs to the UPF via the NG interface, the UPF may separately maintain two general packet radio service tunneling protocol tunnels (GPRS tunneling protocol tunnels, GTP tunnels) of the N3 interface between the UPF and the third network node and between the UPF and the fourth network node during a topology update performed by the first network node for PDU sessions of UEs served by the first network node (including UEs accessing a serving cell of the first network node or UEs accessing a serving cell of a descendant IAB node of the first network node). The UPF may receive data packets of the UE from the two GTP tunnels in a certain period of time. After the third network node determines that transmission of all uplink PDCP SDUs has been completed, the UPF may release the GTP user plane tunnel (GTP-User tunnel, GTP-U tunnel) of the N3 interface between the UPF and the third network node based on an uplink end-marker (UL end-marker) for the third network node.

[0202] As shown in FIG. 2B, in order to solve the above-mentioned problem occurring when the target donor node DU and the target donor node CU are separated in the above-mentioned scenario 1, an embodiment of this application provides a lossless data transmission communication method 200B, which includes the following steps:

[0203] S210B: The first network node performs a topology update. The topology update includes the first network node changing a connected IAB donor. For example, the IAB donor connected to the first network node is changed to a second network node. The second network node may be referred to as a target IAB donor node of the topology update performed by the first network node, and the DU and CU of the second network node are not separated.

[0204] S230B: The first network node transmits a first data packet to the second network node.

[0205] It is easy to understand that the destination node of the IP layer of the first data packet is the third network node. When the CU and DU of the source IAB donor of the first network node are separated, the third network node is the source IAB donor CU of the first network node, or when the CU and DU of the source IAB donor of the first network node are not separated, the third network node is the source IAB donor of the first network node, in other words, the first data packet is a data packet transmitted to the third network node. For example, the first data packet may be a data packet buffered by the first network node at the BAP layer and transmitted to the third network node before the first network node performs a topology update. It may be understood that the destination node of the first data packet may alternatively be a SeGW device on the third network node side. Optionally, before the first network node transmits the first data packet to the second network node, S230B further includes S231B: the first network node performs a first processing operation on the first data packet. For example, the first processing operation is to update the header information of the BAP layer of the first data packet. For example, the first network node receives BAP layer configuration information from the target IAB donor, and the first network node updates the header information of the BAP layer of the first data packet based on the BAP layer configuration information. Specifically, the first network node replaces the BAP routing identifier in the header information of the BAP layer of the first data packet with the configured new routing identifier based on the BAP layer configuration information. The new routing identifier points to a transmission path to the second network node. In this manner, the first network node can successfully transmit the first data packet to the second network node.

[0206] In a possible implementation, before S230B, the method further includes S220B. The second network node updates an IP address filtering rule to forward the first data packet to the third network node.

[0207] The second network node updates the IP address filtering rule and sends the first data packet to the third network node. For example, updating the IP address filtering rule may be adding the source IP address of the first data packet to a whitelist of the source IP address filtering rule, or the second network node temporarily disabling the source IP address filtering rule. This can avoid a case where the second network node does not forward the first data packet or even discards the first data packet because the IP address of the first data packet does not belong to a range of source IP addresses that are allowed to be forwarded.

[0208] In the method 200B, the second network node obtains the source IP address of the first data packet in a number of possible manners. The source IP address of the first data packet is one or more IP addresses when the first network node is connected to a third network node. Specifically, when the third network node is an IAB donor node in which a CU and a DU are separated, the source IP address of the first data packet is one or more IP addresses when the first network node is connected to a DU of the third network node.

[0209] In one possible scheme, the second network node receives a source IP address sent by the first network node.

[0210] In another possible manner, the second network node receives a source IP address sent by a third network node. In this case, method 200B further includes S221B. The second network node receives a source IP address of the first data packet sent by the third network node or pause indication information. The pause indication information instructs the second network node to pause the source IP address filtering rule. It is easy to understand that for the implementation of the second network node temporarily disabling the source IP address filtering rule, the description of step S221A of method 200A should be referred to.

[0211] In yet another possible scheme, the second network node receives the source IP address sent by the AMF.

[0212] S240B: The second network node transmits the first data packet to a third network node.

[0213] According to the method 200B, forwarding or rerouting of uplink data packets between the second network node and the third network node (e.g., between IAB donors or between IAB donor DUs) may be allowed, which avoids the uplink data packets being discarded by the second network node in the rerouting process, and the rerouting and forwarding of data packets between different donor nodes is completed, reducing data packet loss.

[0214] As shown in FIG. 2C, in order to solve the aforementioned problem occurring during intra-donor node topology update in the aforementioned scenario 2, an embodiment of the present application provides a lossless data transmission communication method 200C, which includes the following steps:

[0215] S210C: The first network node performs a topology update. The topology update includes: the first network node changes a connected IAB donor DU under the same donor node, i.e., the IAB donor DU connected to the first network node is changed to a second network node. The second network node may be called a target IAB donor DU of the topology update performed by the first network node, and the second network node is a DU under a source donor node of the first network node.

[0216] S230C: The first network node transmits the first data packet to the second network node.

[0217] The destination node of the IP layer of the first data packet is the third network node. It is easy to understand that the third network node is the source IAB donor CU of the first network node. In other words, the first data packet is a data packet transmitted to the third network node. For example, the first data packet may be a data packet buffered by the first network node at the BAP layer and transmitted to the third network node before the first network node performs a topology update. It may be understood that the destination node of the first data packet may alternatively be a SeGW device on the third network node side. Optionally, before the first network node transmits the first data packet to the second network node, S 230C further includes S231C: the first network node performs a first processing operation on the first data packet. For example, the first processing operation is to update the header information of the BAP layer of the first data packet. For example, the first network node receives BAP layer configuration information from the third network node, and the first network node updates the header information of the BAP layer of the first data packet based on the BAP layer configuration information. Specifically, the first network node replaces the BAP routing identifier in the header information of the BAP layer of the first data packet with the configured new routing identifier based on the BAP layer configuration information. The new routing identifier points to a transmission path to the second network node. In this manner, the first network node can successfully transmit the first data packet to the second network node.

[0218] In a possible implementation, before S230C, the method further includes S220C: the second network node updates the IP address filtering rule to forward the first data packet to the third network node.

[0219] The second network node updates the IP address filtering rule and sends the first data packet to the third network node. For example, updating the IP address filtering rule may be to add the source IP address of the first data packet to a whitelist of the source IP address filtering rule, or the second network node may temporarily disable the source IP address filtering rule. This can avoid a case where the second network node does not forward the first data packet or even discards the first data packet because the IP address of the first data packet does not belong to a range of source IP addresses that are allowed to be forwarded.

[0220] In the method 200C, the second network node obtains the source IP address of the first data packet in a number of possible manners: When the first network node is connected to a source donor DU, the source IP address of the first data packet is one or more IP addresses.

[0221] In one possible scheme, the second network node receives a source IP address sent by the first network node.

[0222] In another possible manner, the second network node receives a source IP address sent by the third network node. Optionally, method 200C further includes S221C: the second network node receives a source IP address of the first data packet sent by the third network node or pause indication information. The pause indication information instructs the second network node to pause the source IP address filtering rule. It is easy to understand that for the implementation of the second network node temporarily disabling the source IP address filtering rule, refer to the description of step S221A of method 200A.

[0223] S240C: The second network node transmits the first data packet to a third network node.

[0224] According to the method 200C, forwarding or rerouting of uplink data packets between the second network node and the third network node may be allowed, which avoids the uplink data packets being discarded by the second network node in the rerouting process, and the rerouting and forwarding of data packets between different donor nodes is completed, and the loss of data packets is reduced.

[0225] As shown in Fig. 3, yet another embodiment of this application provides a lossless data communication method. Similarly, for the problem of how to ensure that no data packets are lost in the IAB donor-to-donor topology update process, compared with the embodiment shown in Fig. 2A to Fig. 2C, the main idea of ​​the design solution of the method shown in Fig. 3 is to ensure that the IAB node 3 performs an IAB donor-to-donor topology update only when all the outgoing uplink data packets buffered by the IAB node performing handover (e.g., IAB node 3 in Fig. 1F) and the descendant node of the IAB node 3 (e.g., IAB node 4 in Fig. 1F) are sent to the source parent node of the IAB node 3. In this embodiment, the type of topology update in which the IAB node 3 performs handover is used as an example for explanation. The method 300 in the embodiment shown in Fig. 3 includes the following steps.

[0226] S310: The third network node sends a first handover command to the first network node.

[0227] In response, the first network node receives a first handover command from the third network node, the first handover command indicating that the first network node will hand over to the second network node, the second network node being a target donor node of the first network node, and the third network node being a source donor node CU of the first network node. For example, the first handover command may be carried in an RRC reconfiguration message.

[0228] S320: The first network node stops scheduling for a descendant node. The descendant node may be a descendant network node (denoted as a sixth network node) and / or a first network In this embodiment of the present application, after receiving the first handover command, the first network node may immediately stop scheduling the terminals in the cell accessing the service and the sixth network node, or may immediately stop scheduling the terminals in the cell accessing the service but not immediately stop scheduling for the sixth network node.

[0229] In this embodiment of the application, two manners for the first network node to stop uplink scheduling for the sixth network node are provided as examples.

[0230] Method 1 of stopping uplink scheduling: S321: The sixth network node sends a second transmission completion indication information to the first network node. The second transmission completion indication information indicates that the transmission of the fourth data packet is completed, and the fourth data packet includes uplink data from the sixth network node, the descendant node of the sixth network node, and the descendant terminal corresponding to the sixth network node. The second transmission completion indication information can be understood to indicate that all uplink data buffered by the sixth network node, the descendant node of the sixth network node, and the descendant terminal have been transmitted. It is easy to understand that the fourth data packet in this embodiment of this application can include one or more data packets. The fourth data packet may be transmitted once or multiple times.

[0231] Optionally, the second transmission completion indication information may be carried in the fourth data packet, for example, in the last uplink BAP layer data PDU of the fourth data packet, or in the BAP layer control PDU. For example, a special BAP control PDU may be defined to indicate the second transmission completion indication information. The second transmission completion indication information may be transmitted together with the last data packet in the fourth data packet, or it may be understood that the second transmission completion indication information is transmitted independently after the last data packet of the fourth data packet is transmitted. For example, the second transmission completion indication information is carried in a BAP layer control PDU that is transmitted separately by the sixth network node to the first network node. The second transmission completion indication information may be indicated by using a bit, or may be indicated by using a special field. This is not limited in this application. When one or more data packets of the fourth data packet are transmitted multiple times, the sixth network node utilizes the first network node to transmit one or more data packets in the fourth data packet to the first network node or the third network node before the sixth network node transmits the second transmission completion indication information.

[0232] Correspondingly, after receiving the second transmission completion indication information, the first network node completion Based on the indication information, stop uplink scheduling for the sixth network node.

[0233] Method 2 for stopping uplink scheduling: S322: A first network node receives first scheduling stop indication information from a third network node. The first scheduling stop indication information instructs the first network node to stop scheduling for a sixth network node.

[0234] Correspondingly, after receiving the first scheduling stop indication information, the first network node stops uplink scheduling for the sixth network node based on the first scheduling stop indication information.

[0235] S330: The first network node transmits a third data packet to a third network node. Optionally, the first network node transmits the third data packet to the third network node by utilizing a fifth network node, and the fifth network node can be understood to be a parent node of the first network node. The third data packet includes uplink data from the first network node and / or a descendant node of the first network node. The third network node is a source IAB donor CU.

[0236] S340: The first network node sends a first transmission completion indication information, the first transmission completion indication information indicating that the transmission of the third data packet is completed. In other words, the first transmission completion indication information indicates that all in-transit uplink data packets buffered by the first network node performing handover and the descendant node of the first network node are transmitted to a parent node or a donor node of the first network node.

[0237] Optionally, the second transmission completion indication information may be transmitted together with the last data packet in the third data packet, or may be transmitted independently after it is determined that all the third data packets have been transmitted. This is similar to the transmission opportunity and conveyance manner of the second transmission completion indication information. For details, please refer to the above related description.

[0238] This embodiment of the application provides two manners for sending the first transmission completion indication information by the first network node as an example.

[0239] Method 1:

[0240] S341: The first network node sends a first transmission completion indication information to the third network node. Correspondingly, after the third network node receives the first transmission completion indication information, the method 300 may further include: S350: The third network node sends a second scheduling stop indication information to the fifth network node. The second scheduling stop indication information instructs the fifth network node to stop scheduling for the first network node.

[0241] Method 2:

[0242] S342: The first network node transmits the first transmission completion indication information to the fifth network node. In response, the fifth network node receives the first transmission completion indication information.

[0243] The method 300 may further include: S360: the fifth network node stops scheduling for the first network node. It is easy to understand that the manner in which the fifth network node stops scheduling for the first network node can be that after receiving the first transmission completion indication information in S342, the fifth network node stops scheduling for the first network node based on the first transmission completion indication information. Alternatively, after receiving the second scheduling stop indication information in S350, the second network node stops scheduling for the first network node based on the second scheduling stop indication information.

[0244] Optionally, S370: The first network node performs a handover, for example, the handover is that a donor node of the first network node is changed from a third network node to a second network node.

[0245] According to the above method 300, after receiving the first handover command and transmitting all buffered uplink data packets to the parent node, the first network node transmits information indicating that the transmission of uplink data is completed, so that the first network node performs handover only after determining that the uplink data packets for the first network node and the descendant nodes of the first network node have been successfully transmitted, thereby ensuring the lossless transmission of the uplink data packets in the handover process.

[0246] If an IAB node performing handover (e.g., IAB node 3 in FIG. 1F) can maintain communication with both the IAB donor connected before the handover and the IAB donor connected after the handover, for example, if the IAB node supports dual connectivity (DC) or dual active protocol stack (DAPS) in the handover process, data transmission with both IAB donors can be maintained by migrating the IAB node. Considering that an IAB node performs routing on a wireless backhaul link based on a routing identifier of a BAP layer and identifies a target node on a wireless backhaul link based on a BAP address, the BAP address of an IAB donor DU is assigned by an IAB donor CU and can only be guaranteed to be unique within a CU range, but when an IAB node is allowed to be simultaneously connected to IAB donor DUs of multiple different IAB donors, it is necessary to avoid confusion of the IAB node between two donors, and further, it is necessary to avoid discontinuity of terminal service caused by data packet loss in the IAB topology update process.

[0247] 4, to solve the problem that may occur when an IAB node can communicate with multiple donors simultaneously, an embodiment of this application provides a lossless data transmission method 400. The method 400 includes the following steps:

[0248] S410: A first network node performs a topology update. The topology update includes the first network node changing a connected IAB donor DU. For example, an IAB donor DU connected to the first network node is changed to a second network node. The second network node may be referred to as a target IAB donor node DU of the topology update performed by the first network node.

[0249] Optionally, before S410, the first network node receives a handover command sent by the third network node.

[0250] S420: The first network node can communicate with multiple donor nodes. In other words, the first network node has both a route for communicating with a third network node (source IAB donor CU) and denoted as an original route or a first route, and a route for communicating with a second network node (target IAB donor DU) and denoted as a new route or a second route. It is easy to understand that the first network node may communicate with the target IAB donor CU via the second route.

[0251] In order to avoid confusion between different IAB donor DUs, IAB donor CUs, e.g., IAB nodes among third network nodes, the BAP address assigned to the IAB donor DU carries identification information for distinguishing the donor CUs, e.g., the identification information is an identifier associated with the donor CU.

[0252] To avoid the problem of data packet loss in the IAB topology update process, the method 400 provides two possible implementations:

[0253] Implementation 1:

[0254] S430: The first network node transmits a first data packet via a second path.

[0255] After the first network node transmits to the second network node a first data packet to be transmitted to a third network node or a security gateway device on the third network node side, the second network node transmits the first data packet to the third network node.

[0256] It is easy to understand that for the specific implementation of step S430, reference should be made to the description of method 200A.

[0257] Implementation 2:

[0258] S440: A first network node transmits a first data packet via a first path.

[0259] Because the first network node has the capability to communicate with the third network node after the topology update is completed, the first network node may transmit the first data packet to the third network node via the first route.

[0260] The method 400 further proposes an implementation in which the first network node disconnects the first path. In other words, the first network node may disconnect from the third network node (or source donor node or source parent node). It is easy to understand that the IAB node is allowed to disconnect from the source parent node of the IAB node only after the IAB node successfully transmits uplink data packets on the descendant IAB nodes of the IAB node and uplink data packets buffered by the IAB node to the source parent node, where the uplink data packets are of the BAP layer and the target address of the uplink data packets is the third network node, the source donor node, the source parent node, or the source IAB donor DU.

[0261] The method 400 further includes the steps of:

[0262] In a possible manner, after completing the transmission of uplink data, each IAB node of the first network node and the descendant IAB node of the first network node sends a first indication information to a third network node, indicating that the transmission of uplink data for the IAB node is completed. After receiving the first indication information sent by the first network node and the descendant IAB node of the first network node, the third network node determines that the transmission of uplink data packets that need to be sent by the first network node and the descendant IAB node of the first network node via the first path has been completed. Specifically, the method includes the following steps:

[0263] S450A: The first network node sends first indication information to the third network node. The first indication information indicates that the transmission of the uplink data packet at the first network node is completed. Optionally, the first indication information is sent using an RRC message or sent using an F1AP message.

[0264] For ease of explanation, in this embodiment of this application, it is assumed that a first network node has N descendant IAB nodes, and after completing the transmission of uplink data, each of the N descendant IAB nodes sends first indication information to a third network node, where the first indication information indicates that the transmission of the uplink data packet at the descendant IAB node is completed, and N is a positive integer.

[0265] Correspondingly, the third network node receives first indication information from the first network node and N descendant IAB nodes of the first network node. After receiving the N+1 pieces of first indication information, the third network node determines that the transmission of the uplink data packet at the first network node and the descendant node of the first network node is completed based on the N+1 pieces of first indication information. In other words, the third network node determines that the transmission of the uplink data packet that needs to be transmitted via the first path by the first network node and the descendant IAB node of the first network node is completed.

[0266] S460: The third network node decides to disconnect the first path.

[0267] In another possible manner, after completing the transmission of uplink data, each of the N descendant IAB nodes of the first network node transmits second indication information to the first network node, indicating that the transmission of uplink data at the descendant IAB node is completed. After receiving the N second indication information transmitted by the N descendant IAB nodes, the first network node determines that the transmission of uplink data packets that need to be transmitted by the descendant IAB node via the first path is completed. Furthermore, after the first network node determines that the transmission of uplink data for the first network node is completed, the first network node transmits third indication information to the third network node. The third indication information indicates that the transmission of uplink data packets that need to be transmitted by the first network node and the descendant IAB node of the first network node via the first path is completed. Specifically, in this manner, the method 400 includes the following steps.

[0268] S450B: The first network node receives N pieces of second indication information sent by the N descendant IAB nodes, where the second indication information has a corresponding relationship with the descendant IAB nodes, and the first indication information indicates that the transmission of uplink data at the descendant IAB nodes is completed.

[0269] After the first network node determines that the transmission of uplink data for the first network node is completed, the first network node sends third indication information to the third network node, where the third indication information indicates that the transmission of uplink data packets that need to be transmitted by the first network node and descendant IAB nodes of the first network node via the first path is completed.

[0270] In response, the third network node receives third indication information from the first network node, the third indication information indicating that transmission of uplink data packets that need to be transmitted via the first path by the first network node and descendant IAB nodes of the first network node has been completed.

[0271] S460: The third network node decides to disconnect the first path.

[0272] In this embodiment of the present application, it is easy to understand that there are multiple possible implementations for the third network node to decide to disconnect the first path at S460.

[0273] Method 1:

[0274] S470: The third network node sends a fourth indication information to a fifth network node (a source parent node of the first network node). The fourth indication information indicates to stop scheduling for the first network node and release the context of the first network node. In other words, 4 The indication information instructs the fifth network node to release the connection to the first network node.

[0275] Method 2:

[0276] S480: The third network node sends fifth indication information to the first network node. The fifth indication information indicates that the first network node releases a connection to the source parent node. For example, the first network node releases a cell served by the source parent node based on the fifth indication information. In other words, the fifth indication information indicates that the connection to the fifth network node is released.

[0277] It is easy to understand that the execution order of steps in the method 400 is not strictly limited, and the execution order of steps can be appropriately adjusted to solve different problems. Moreover, the method 400 provides multiple optional ways, and the steps corresponding to the ways are correspondingly optional.

[0278] According to method 400, lossless data transmission of an IAB node in an inter-CU handover scenario can be ensured when the IAB node supports maintaining multiple connections to multiple donor nodes.

[0279] It may be understood that in the above-described method embodiments of this application, these steps or operations are merely examples. In the embodiments of this application, other operations or variations of various operations may be further performed. Furthermore, steps may be performed in a different order than the order presented in the embodiments of this application, and all operations in the embodiments of this application may not necessarily be performed.

[0280] The foregoing mainly describes the solutions provided in the embodiments of this application from the perspective of interactions between network elements. Correspondingly, the embodiments of this application further provide a communication device, which is configured to implement the aforementioned method. The communication device may be a network node in the aforementioned method embodiments, a device including the aforementioned network node, or a component (chip or circuit) available in the network node. Alternatively, the communication device may be a terminal device in the aforementioned method embodiments, a device including the aforementioned terminal device, or a component available in the terminal device. Alternatively, the communication device may be a gateway device in the aforementioned method embodiments, or a component available in the gateway device. It may be understood that, to implement the aforementioned functions, the communication device includes a hardware structure and / or a software module for performing each corresponding function. Those skilled in the art should easily recognize that this application can be implemented in the form of hardware or a combination of hardware and computer software by referring to the example units and algorithm steps described in the embodiments disclosed in this specification. Those skilled in the art may utilize different methods to implement the functions described for each specific application, but the implementation should not be considered to go beyond the scope of this application.

[0281] In the embodiment of this application, the communication device may be divided into functional modules according to the above method embodiment. For example, each functional module may be obtained through division based on each corresponding function, or two or more functions may be integrated into one processing module. The integrated module may be implemented in the form of hardware, or may be implemented in the form of a software functional module.

[0282] Fig. 5 is a schematic block diagram of a communication device 500 according to an embodiment of this application. The structure and function of the communication device 500 will be specifically described below with reference to Fig. 5. The communication device 500 may include a processing module 510 (or referred to as a processing unit). Optionally, the communication device 500 may further include a transceiver module 520 (or referred to as a transceiver unit or a communication interface) and a storage module 530 (or referred to as a storage unit).

[0283] In a possible design, one or more modules in FIG. 5 may be implemented by one or more processors, one or more processors and one or more memories, one or more processors and one or more transceivers, or one or more processors, one or more memories, and one or more transceivers. This is not limited to this embodiment of the application. The processor, memory, and transceiver may be located separately or may be integrated.

[0284] Optionally, the modules in the apparatus 500 in this embodiment of the application may be configured to perform the methods described in FIG. 2A to FIG. 2C, FIG. 3 or FIG. 4 in the embodiment of the application.

[0285] In a possible design, the apparatus 500 may include a transceiver module 520 and a processing module 510. The transceiver module 520 is configured to receive a first data packet from a first network node. The second network node is a target donor node distribution unit DU of the first network node. A destination node of the first data packet is a third network node or a security gateway on the third network node side. The third network node is a source donor node or a source donor node central unit CU of the first network node. The transceiver module 520 is further configured to transmit the first data packet to the third network node.

[0286] The apparatus can support rerouting and forwarding of donor-DU data packets by the IAB node, which avoids data packet loss in the topology update process of the first network node and reduces the impact on uplink service continuity of the terminal served by the first network node.

[0287] Optionally, the processing module 510 is configured to update an Internet Protocol IP address filtering rule to transmit the first data packet to the third network node.

[0288] Optionally, the transceiver module 520 is further configured to obtain a first IP address, the first IP address being one or more IP addresses obtained by the first network node when the first network node is connected to a third network node. Optionally, the processing module 510 is further configured to update an IP address filtering rule based on the first IP address.

[0289] Optionally, the processing module 510 is further configured to add the first IP address to a whitelist of the source IP address filtering rule.

[0290] Optionally, the transceiver module 520 is further configured to receive the first IP address from a third network node.

[0291] Optionally, the transceiver module 520 is further configured to receive the first IP address from the fourth network node.

[0292] Optionally, the transceiver module 520 is further configured to receive a first pause indication information from the fourth network node, the first pause indication information instructing the second network node to pause the IP address filtering rule.

[0293] Optionally, the processing module 510 is further configured to encapsulate the first data packet.

[0294] In another possible design, the apparatus 500 may include a transceiver module 520 and a processing module 510. The processing module 510 is configured to determine a first data packet, a destination node of the first data packet being a third network node or a security gateway at the third network node.

[0295] Optionally, the processing module 510 is further configured to update a backhaul adaptation protocol layer configuration of the first data packet for transmitting the first data packet to the second network node.

[0296] Optionally, the processing module 510 is further configured to add a second IP header to the first data packet, wherein a target IP address of the second IP header is the IP address of the fourth network node.

[0297] Optionally, the transceiver module 520 is further configured to transmit to the fourth network node the first IP address, the first IP address being one or more IP addresses obtained by the first network node when the first network node is connected to the third network node.

[0298] Optionally, the processing module 510 is further configured to perform a topology update.

[0299] In another possible design, the apparatus 500 may include a transceiver module 520 and a processing module 510. The processing module 510 is configured to determine a first message. The transceiver module 520 is configured to transmit the first message to a second network node. The first message is utilized by the second network node to update an IP address filtering rule. Optionally, the processing module 510 is further configured to obtain a first IP address. The first IP address is one or more IP addresses obtained by the first network node when the first network node is connected to a third network node.

[0300] Optionally, the transceiver module 520 is further configured to receive the first IP address from a third network node.

[0301] Optionally, the transceiver module 520 is further configured to receive the first IP address from the first network node.

[0302] Optionally, the transceiver module 520 is further configured to receive the first IP address from the AMF.

[0303] Optionally, the processing module 510 is further configured to determine a first pause indication information. The first pause indication information instructs the second network node to pause the IP address filtering rule. Optionally, the transceiver module 520 is further configured to receive a second data packet from the second network node. The second data packet includes a first IP header and a second IP header. A target IP address of the first IP header is a third network node. A target IP address of the second IP header is an IP address of a fourth network node.

[0304] Optionally, the transceiver module 520 is further configured to transmit the first data packet to a third network node. Optionally, the transceiver module 520 is further configured to receive, from the third network node, data associated with a terminal device served by the first network node and located within the first data packet. In another possible design, the apparatus 500 may include the transceiver module 520 and the processing module 510. The transceiver module 520 is configured to obtain the first data packet. The first data packet is a data packet transmitted to the third network node after the first network node is connected to the second network node.

[0305] Optionally, the processing module 510 is configured to process the first data packet. Optionally, the transceiver module 520 is further configured to receive the first data packet from a fourth network node.

[0306] Optionally, the processing module 510 is further configured to determine, based on the first data packet, data associated with the terminal device served by the first network node. Optionally, the transceiver module 520 is further configured to transmit data associated with the terminal device to a fourth network node. In another possible design, the apparatus 500 may include the transceiver module 520 and the processing module 510. The transceiver module 520 is configured to receive a first handover command from the third network node. Optionally, the transceiver module 520 is further configured to transmit a first transmission completion indication information. The first transmission completion indication information indicates that the transmission of the third data packet is completed.

[0307] Optionally, the processing module 510 is further configured to determine to perform a topology update.

[0308] Optionally, the transceiver module 520 is further configured to transmit the first transmission completion indication information to the fifth network node. Optionally, the transceiver module 520 is further configured to transmit the third data packet to the third network node. Optionally, the processing module 510 is further configured to stop uplink scheduling performed at the sixth network node.

[0309] In another possible design, the apparatus 500 may include a transceiver module 520 and a processing module 510. The transceiver module 520 is configured to receive transmission indication information indicating to stop uplink scheduling for the first network node. The processing module 510 is configured to determine to stop uplink scheduling for the first network node based on the transmission indication information. Optionally, the transceiver module 520 is further configured to receive a first transmission completion indication information from the first network node.

[0310] Optionally, the transceiver module 520 is further configured to receive a second scheduling stop indication information from a third network node.

[0311] In another possible design, the apparatus 500 may include a transceiver module 520 and a processing module 510. The transceiver module 520 is configured to receive a first transmission completion indication information from a first network node. The transceiver module 520 is further configured to transmit a second scheduling stop indication information to a fifth network node.

[0312] 6 is a schematic diagram of the structure of an apparatus. The apparatus 600 may be a network device, a terminal device, a server, or a centralized controller, or may be a chip, a chip system, a processor, etc. that supports a network device, a terminal device, a server, or a centralized controller in implementing the aforementioned method. The apparatus may be configured to implement the method described in the aforementioned method embodiment. For details, please refer to the description of the aforementioned method embodiment.

[0313] The device 600 may include one or more processors 610. The processor 610 may be referred to as a processing unit and may implement a specific control function. The processor 610 may be a general-purpose processor, a special-purpose processor, etc. For example, the processor 610 may be a baseband processor or a central processing unit. The baseband processor may be configured to process communication protocols and communication data. The central processing unit may be configured to control a communication device (e.g., a base station, a baseband chip, a terminal, a terminal chip, a DU, or a CU), execute a software program, and process data of the software program.

[0314] In an optional design, the processor 610 may alternatively store instructions and / or data 630, which may be executed by the processor to enable the apparatus 600 to perform the method of the previously described method embodiments.

[0315] In another optional design, the processor 610 may include a transceiver unit configured to implement receiving and transmitting functions. For example, the transceiver unit may be a transceiver circuit, an interface, an interface circuit, or a communication interface. The transceiver circuit, the interface, or the interface circuit configured to implement the receiving and transmitting functions may be separate or integrated together. The transceiver circuit, the interface, or the interface circuit may be configured to read and write code / data. Alternatively, the transceiver circuit, the interface, or the interface circuit may be configured to transmit or forward signals.

[0316] In yet another possible design, the apparatus 600 may include circuitry that may implement the transmitting, receiving, or communication functionality of the method embodiments described above.

[0317] Optionally, the apparatus 600 may include one or more memories 620. The memories may store instructions 640. The instructions may be executed on the processor to enable the apparatus 600 to perform the methods in the above method embodiments. Optionally, the memories may further store data. Optionally, the processor may store instructions and / or data. The processor and the memories may be located separately or integrated together. For example, the correspondences described in the above method embodiments may be stored in the memory or stored in the processor.

[0318] Optionally, the apparatus 600 may further include a transceiver 650 and / or an antenna 660. The processor 610 may be referred to as a processing unit and may control the apparatus 600. The transceiver 650 may be referred to as a transceiver unit, transceiver machine, transceiver circuitry, transceiver equipment, transceiver module, etc., and is configured to implement receiving and transmitting functions.

[0319] Optionally, the apparatus 600 in this embodiment of the application may be configured to perform the method described in FIG. 2A to FIG. 2C, FIG. 3 or FIG. 4 in the embodiment of the application.

[0320] The processors and transceivers described in this application may be implemented as integrated circuits (ICs), analog ICs, radio frequency integrated circuits (RFICs), mixed signal ICs, application specific integrated circuits (ASICs), printed circuit boards (PCBs), electronic devices, etc. The processors and transceivers may be fabricated using a variety of IC technologies, such as complementary metal oxide semiconductor (CMOS), nMetal-oxide-semiconductor (NMOS), pMetal-oxide-semiconductor (PMOS), bipolar junction transistor (BJT), bipolar CMOS (BiCMOS), silicon germanium (SiGe), and gallium arsenide (GaAs).

[0321] The devices described in the above embodiments may be network devices or terminal devices. However, the scope of the devices described in this application is not limited thereto, and the structure of the devices may not be limited to that of FIG. 6. The devices may be independent devices or may be part of a larger device. For example, the devices may be:

[0322] (1) An independent integrated circuit IC, chip or chip system, or subsystem;

[0323] (2) a set of one or more ICs, where, optionally, the set of ICs may also include a storage component configured to store data and / or instructions;

[0324] (3) ASIC, e.g., modem (MSM),

[0325] (4) A module that can be incorporated into another device;

[0326] (5) Receivers, terminals, intelligent terminals, cellular phones, wireless devices, handheld devices, mobile units, in-vehicle devices, network devices, cloud devices, artificial intelligence devices, mechanical devices, household devices, medical devices, industrial devices, etc.;

[0327] (6)Others.

[0328] Those skilled in the art may understand that, for convenient and concise description, the detailed operation processes of the above-mentioned systems, devices and units should be referred to the corresponding processes in the above-mentioned method embodiments, and the details will not be described again here.

[0329] It may be understood that the systems, devices, and methods described in this application may alternatively be implemented in different manners. For example, the device embodiments described are merely examples. For example, the division into units is merely a logical division of functionality, and may be a different division in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some functions may be ignored or not performed. Furthermore, the shown or discussed mutual couplings or direct couplings or communication connections may be implemented via some interfaces. Indirect couplings or communication connections between devices or units may be implemented in an electrical, mechanical, or other form.

[0330] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one location or distributed among multiple network units. Some or all of the units may be selected based on the actual requirements to achieve the objectives of the solutions of the embodiments.

[0331] Furthermore, the functional units in the embodiments of this application may be integrated into one processing unit, each of the units may exist physically alone, or two or more units may be integrated into one unit.

[0332] When a function is implemented in the form of a software functional unit and sold or used as an independent product, the function may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of this application may be essentially implemented in the form of a software product, or a part of the technical solution may be implemented in the form of a software product. The computer software product is stored in a storage medium and includes some instructions for instructing a computer device (which may be a personal computer, a server, a network device, etc.) to execute all or part of the steps of the method described in the embodiments of this application. The storage medium includes any medium, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, that can store program code.

[0333] It can be understood that in some scenarios, some optional features in the embodiments of this application can be implemented independently to solve corresponding technical problems and achieve corresponding effects, without relying on another feature, for example, the solution on which the optional feature is currently based. Alternatively, in some scenarios, the optional feature is combined with other features based on requirements. Correspondingly, the device provided in the embodiments of this application may implement these features or functions accordingly. Details will not be described here.

[0334] Those skilled in the art may further understand that various exemplary logic blocks and steps listed in the embodiments of this application may be implemented by using electronic hardware, computer software, or a combination thereof. Whether a function is implemented using hardware or software depends on a specific application and the design requirements of the entire system. Those skilled in the art may use various methods to implement the functions of the corresponding application, but the implementation should not be considered to go beyond the scope of the embodiments of this application.

[0335] It can be understood that the processor in the embodiments of this application can be an integrated circuit chip and has signal processing capabilities. In the implementation process, the steps of the above-mentioned method embodiments can be implemented using hardware integrated logic circuits in a processor or instructions in the form of software. The above-mentioned processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or another programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component.

[0336] The solutions described in this application may be implemented in various ways. For example, the techniques may be implemented by utilizing hardware, software, or a combination thereof. For hardware implementation, a processing unit configured to execute these techniques in a communication device (e.g., a base station, a terminal, a network entity, or a chip) may be implemented with one or more general-purpose processors, DSPs, digital signal processors, ASICs, programmable logic devices, FPGAs or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or any combination thereof. The general-purpose processor may be a microprocessor. Optionally, the general-purpose processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented by a combination of computing devices such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors with a digital signal processor core, or any other similar configuration.

[0337] It may be understood that the memory in the embodiments of this application may be volatile or non-volatile memory, or may include volatile and non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory may be random access memory (RAM) used as an external cache. By way of example and not limitation, many forms of RAM may be utilized, such as static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous dynamic random access memory (synchrounous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDRSDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synchlink DRAM, SLDRAM), and direct rambus random access memory (direct rambus RAM, DRRAM). In particular, memory in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable type of memory.

[0338] The application further provides a computer-readable medium storing a computer program, which, when executed by a computer, implements the functions of any one of the aforementioned method embodiments.

[0339] This application further provides a computer program product, which, when executed by a computer, implements the functions of any one of the aforementioned method embodiments.

[0340] All or part of the above-mentioned embodiments may be implemented using software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the procedures or functions according to the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (e.g., coaxial cable, fiber optic, or digital subscriber line (DSL)) or wireless (e.g., infrared, radio, microwave, etc.) manner. A computer readable storage medium may be any available medium accessible by a computer, or a data storage device such as a server or data center that consolidates one or more available media. The available medium may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes, etc.), optical media (e.g., digital video discs (DVDs)), semiconductor media (e.g., solid state disks (SSDs)), etc.

[0341] It may be understood that an "embodiment" referred to throughout the specification means that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of this application. Thus, the embodiments throughout the specification do not necessarily refer to the same embodiment. Moreover, these particular features, structures, or characteristics may be combined in one or more embodiments by utilizing any suitable manner. It may be understood that the sequence numbers of the processes described above do not imply the order of execution in various embodiments of this application. The order of execution of the processes should be determined based on the functions and internal logic of the processes, and should not be interpreted as any limitation on the implementation process of the embodiments of this application.

[0342] In this application, it can be understood that "when" and "in the case of" mean that the device executes the corresponding process in an objective situation, and are not intended to limit the time. These terms do not imply that the device must have a decision operation during implementation, nor do they imply any other limitations.

[0343] "Simultaneously" in this application may be understood as being at the same time, within a certain period of time, or within the same cycle.

[0344] Those skilled in the art may understand that various numerals such as first and second are used in this application merely for distinction to facilitate description and are not used to limit the scope of the embodiments of this application. Specific values ​​of numbers (sometimes called indexes), specific values ​​of quantities, and positions in this application may be used merely as examples, but are not unique representation formats and are not used to limit the scope of the embodiments of this application. Various numerals such as first and second are used in this application merely for distinction to facilitate description and are not used to limit the scope of the embodiments of this application.

[0345] In this application, elements referred to in the singular are intended to mean "one or more" but not "one and only one," unless otherwise specified. In this application, "at least one" is intended to mean "one or more," and "plurality" is intended to mean "two or more," unless otherwise specified.

[0346] Furthermore, the terms "system" and "network" may be used interchangeably in this specification. In this specification, the term "at least one" refers to all or any combination of the listed items. For example, "at least one of A, B, and C" may refer to the following six cases: only A is present, only B is present, only C is present, both A and B are present, both B and C are present, and both A, B, and C are present. A may be singular or plural, B may be singular or plural, and C may be singular or plural.

[0347] In the embodiments of this application, it can be understood that "B corresponding to A" represents that B is associated with A, and B can be determined based on A. However, it should be further understood that determining B based on A does not mean that B is determined based only on A. Alternatively, B may be determined based on A and / or other information.

[0348] Those skilled in the art may understand that the units and algorithm steps in the examples described with reference to the embodiments disclosed in this specification can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether a function is performed in a hardware manner or a software manner depends on the design constraints of a specific application and technical solution. Those skilled in the art may utilize different methods to implement the described functions for each specific application, but the implementation should not be considered to go beyond the scope of this application.

[0349] The same or similar parts in the embodiments of this application should be referred to each other. In the embodiments and implementations / implementation methods in the embodiments of this application, unless otherwise specified or logical contradiction occurs, the terms and / or descriptions are consistent and can be mutually referenced between different embodiments and implementations / implementation methods in the embodiments. The technical features in different embodiments and the implementations / implementation methods in the embodiments can be combined to form new embodiments, implementations, or implementation methods based on their internal logical relationships. The above implementations of this application are not intended to limit the protection scope of this application.

[0350] The above description is merely a specific implementation of this application, and is not intended to limit the scope of protection of this application. Any variations or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed in this application should fall within the scope of protection of this application.

Claims

1. A communication method applied to a second network node or a component of said second network node, comprising: receiving a first data packet from a first network node, the second network node being a target donor node distribution unit DU of the first network node, a destination node of the first data packet being a third network node, the third network node being a source donor node of the first network node; obtaining at least one first IP address, the at least one first IP address including at least one IP address obtained by the first network node when the first network node is connected to the third network node; updating an IP address filtering rule based on the at least one first IP address; transmitting the first data packet to the third network node based on the IP address filtering rule; A communication method comprising:

2. The step of updating the IP address filtering rule based on the at least one first IP address further comprises: adding said at least one first IP address to a list of source IP addresses of data packets that are allowed to be forwarded; The method of claim 1.

3. The step of obtaining at least one first IP address includes: receiving the at least one first IP address from a fourth network node, the fourth network node being a target donor central unit CU of the first network node; The method according to claim 1 or 2.

4. Before the second network node receives the first data packet from the first network node, a connected donor DU of the first network node is changed. The method according to any one of claims 1 to 3.

5. A communication method applied to a fourth network node or a component of the fourth network node, comprising: obtaining at least one first IP address, the at least one first IP address comprising at least one IP address obtained by the first network node when the first network node is connected to a third network node, the third network node being a source donor node or a source donor node CU of the first network node, and the fourth network node being a target donor node CU of the first network node; sending the at least one first IP address to a second network node, the at least one first IP address being for updating an IP address filtering rule of the second network node, the second network node being a target donor node DU of the first network node; A communication method comprising:

6. said step of obtaining at least one first IP address comprises receiving said at least one first IP address from said third network node; The method according to claim 5.

7. The method includes receiving, from the third network node, data associated with a terminal device served by the first network node and located in a first data packet; The method according to claim 5 or 6.

8. and updating an IP address filtering rule of the second network node by adding the at least one first IP address to a list of source IP addresses of data packets that are allowed to be forwarded. The method according to claim 5 or 6.

9. A communication device including a processing module and a transceiver module, The transceiver module is configured to receive a first data packet from a first network node, the apparatus being a target donor node distribution unit DU of the first network node, a destination node of the first data packet being a third network node, the third network node being a source donor node of the first network node; the transceiver module is further configured to: obtain at least one first IP address, the at least one first IP address including at least one IP address obtained by the first network node when the first network node is connected to the third network node; The processing module is configured to update an IP address filtering rule based on the at least one first IP address; the transceiver module is further configured to transmit the first data packet to the third network node based on the IP address filtering rule. Communications equipment.

10. The processing module is further configured to update the IP address filtering rule based on the at least one first IP address, the processing module is further configured to add the at least one first IP address to a list of source IP addresses of data packets that are allowed to be forwarded.

10. The apparatus of claim 9.

11. The transceiver module is further configured to obtain at least one first IP address. the transceiver module is further configured to receive the at least one first IP address from a fourth network node, the fourth network node being a target donor central unit CU of the first network node.

11. Apparatus according to claim 9 or 10.

12. a connected donor DU of the first network node is changed before the transceiver module is configured to receive the first data packet from the first network node; An apparatus according to any one of claims 9 to 11.

13. A communication device including a processing module and a transceiver module, the processing module is configured to: obtain at least one first IP address, the at least one first IP address including at least one IP address obtained by the first network node when the first network node is connected to a third network node, the third network node being a source donor node of the first network node, and the apparatus being a target donor node CU of the first network node; the transceiver module is configured to transmit the at least one first IP address to a second network node, the at least one first IP address being for updating an IP address filtering rule of the second network node, the second network node being a target donor node DU of the first network node. Communications equipment.

14. The transceiver module is configured to obtain at least one first IP address, the transceiver module is further configured to receive the at least one first IP address from the third network node.

14. The apparatus of claim 13.

15. the transceiver module is further configured to receive, from the third network node, data associated with a terminal device served by the first network node and located within a first data packet.

15. Apparatus according to claim 13 or 14.

16. The at least one first IP address is for updating an IP address filtering rule of the second network node, adding the at least one first IP address to a list of source IP addresses of data packets that are allowed to be forwarded.

15. Apparatus according to claim 13 or 14.

17. A communications device including a processor, the processor coupled to a memory, the memory configured to store a program or instructions, the program or instructions being enabled by the processor to perform a method according to any one of claims 1 to 4 or 5 to 8.

18. A computer readable storage medium storing a computer program or instructions, which when executed enables a computer to carry out a method according to any one of claims 1 to 4 or 5 to 8.

19. A chip system including a processor, the processor configured to enable the chip system to perform the method of any one of claims 1 to 4 or 5 to 8.

20. A communication system comprising a second network node and a fourth network node, the second network node configured to perform the method according to any one of claims 1 to 4 and the fourth network node configured to perform the method according to any one of claims 5 to 8.

21. A computer program, which when executed on a computer enables the computer to carry out the method according to any one of claims 1 to 4 or 5 to 8.

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