A method for configuring a logical channel LCH, a communication device and a communication system

Abstract

Embodiments of the present application disclose a method and a communication device for a logical channel (LCH). In the method, a first data radio bearer (DRB) of a terminal corresponds to a first LCH, and the first LCH is used to transmit packet data convergence protocol (PDCP) data corresponding to a source donor node; the method comprises the following steps: a first relay node generates configuration information of a second LCH corresponding to the first DRB, and the second LCH is used to transmit PDCP data corresponding to a target donor node; and the first relay node sends the configuration information of the second LCH to the terminal. The source donor node and the target donor node are respectively a source donor node and a target donor node switched by a first relay node or a second relay node, and the second relay node is a relay node on a link between the first relay node and the source donor node.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, and in particular to a data processing method, a communication device and a communication system. BACKGROUND

[0002] Compared with the fourth generation mobile communication system, the fifth generation (5G) mobile communication system proposes more stringent requirements for all performance indicators of the network. For example, the capacity index is increased by 1000 times, the coverage requirement is wider, and the ultra-high reliability and ultra-low latency are required. The integrated access and backhaul (IAB) system emerges as the times require, and through a large number of densely deployed nodes, it can provide flexible and convenient access and backhaul services for terminals, improve coverage, and thus meet the more stringent performance indicators of 5G.

[0003] In a relay system such as an IAB system, due to link quality and other reasons, the relay node may be switched, and the switching of the relay node will cause the service of the terminal to be interrupted, which greatly reduces the user experience. SUMMARY

[0004] The embodiments of the present application provide a method for configuring a logical channel (LCH), a communication device and a communication system, which can reduce the probability of service interruption of the terminal in the switching of the relay node and ensure the continuity of the service of the terminal.

[0005] The downlink scheme provided by the embodiments of the present application is described below in combination with the first aspect to the fourth aspect. It should be noted that the first aspect to the fourth aspect describe the downlink scheme from the perspective of different network elements, and the contents thereof can be mutually referenced and cited.

[0006] The first aspect of the embodiments of the present application provides a method for configuring a logical channel (LCH). The method can be executed by a relay node or a chip in the relay node. Hereinafter, the method executed by the relay node is taken as an example for description. In the method, a first data radio bearer (DRB) of a terminal corresponds to a first LCH, and the first LCH is used to transmit packet data convergence protocol (PDCP) data corresponding to a source donor node. The method comprises: a first relay node generates configuration information of a second LCH corresponding to the first DRB, and the second LCH is used to transmit PDCP data corresponding to a target donor node; and the first relay node sends the configuration information of the second LCH to the terminal.

[0007] In the method, the first relay node is an access relay node of the terminal.

[0008] In the method, the source donor node is a source donor node of the first relay node switching, the target donor node is a target donor node of the first relay node switching, that is, the first relay node is a node that occurs switching. Alternatively, the source donor node is a source donor node of a second relay node switching, the target donor node is a target donor node of the second relay node switching, and the second relay node is a relay node on a link between the first relay node and the source donor node, that is, the second relay node is a node that occurs switching.

[0009] By the method, the first DRB corresponds to the first LCH, the second LCH can be configured for the first DRB, the first LCH is used for transmitting data corresponding to the source donor node, and the second LCH is used for transmitting data corresponding to the target donor node. The terminal can distinguish the data corresponding to the source donor node and the data corresponding to the target donor node through different LCHs, can ensure that the terminal uses correct configuration information to process data, reduces the probability of service interruption, and improves the continuity of service transmission.

[0010] As a possible implementation manner, the PDCP data corresponding to the source donor node is processed through PDCP configuration information corresponding to the source donor node, and the PDCP data corresponding to the target donor node is processed through PDCP configuration information corresponding to the target donor node.

[0011] As a possible implementation manner, the PDCP data corresponding to the source donor node includes uplink PDCP data and / or downlink PDCP data corresponding to the source donor node, and the PDCP data corresponding to the target donor node includes uplink PDCP data and / or downlink PDCP data corresponding to the target donor node.

[0012] As a possible implementation manner, the method further includes: the first relay node receives first indication information from the source donor node or the target donor node; and the first relay node generates configuration information of the second LCH according to the first indication information.

[0013] Optionally, the first indication information is carried in a user equipment (UE) context modification request message received by the first relay node from the source donor node or in a UE context establishment request message received by the first relay node from the target donor node.

[0014] As a possible implementation manner, after the first relay node receives the first message from the target donor node, the first relay node generates the configuration information of the second LCH.

[0015] Optionally, the first message is a UE context establishment request message.

[0016] As a possible implementation, the method further comprises:

[0017] The first relay node sends second indication information to the terminal, the second indication information being used for configuring the second LCH for the first DRB, or being used for instructing the terminal to associate two LCHs for the first DRB.

[0018] Optionally, the second indication information can be generated by the first relay node and sent to the terminal by the first relay node. Alternatively, the second indication information can be generated by the target host node, sent to the first relay node by the target host node, and sent to the terminal by the first relay node.

[0019] As a possible implementation, the method further comprises:

[0020] The first relay node sends third indication information to the terminal, the third indication information being used for instructing the terminal to process uplink data using PDCP configuration information corresponding to the target host node. Optionally, the first relay node can be a node that is switched, or the second relay node described above can be a node that is switched, and the second relay node can send the third indication information to the first relay node, and the first relay node sends the third indication information to the terminal.

[0021] Optionally, the source host node is a source host node to which the first relay node is switched, and the target host node is a target host node to which the first relay node is switched, that is, the first relay node is a node that is switched, and the method comprises: after the first relay node performs physical uplink shared channel (PUSCH) conversion, or after the first relay node establishes a GTP tunnel with the target host node, the first relay node sends the third indication information to the terminal.

[0022] As a possible implementation, the method further comprises:

[0023] The first relay node sends fourth indication information to the target host node, the fourth indication information being used for instructing the terminal to delete the first LCH by the target host node.

[0024] Optionally, after the first relay node completes sending, to the terminal, PDCP data corresponding to the source host node and buffered by the first relay node, the first relay node sends the fourth indication information to the target host node.

[0025] As a possible implementation manner, the source donor node is a source donor node for the first relay node to switch, and the target donor node is a target donor node for the first relay node to switch. The method further includes: the first relay node receiving, from the target donor node, fifth indication information through the source donor node; and the first relay node maintaining connection with the source donor node in the switching process according to the fifth indication information.

[0026] As a possible implementation manner, the method further includes: the first relay node sending, to the source donor node, capability indication information, and the source donor node sending the capability indication information to the target donor node, the capability indication information being used to indicate a capability of the first relay node to maintain connection with the source donor node in the switching process.

[0027] As a possible implementation manner, the first LCH corresponds to a GTP-U tunnel between the first relay node and the source donor node, and the second LCH corresponds to a GTP-U tunnel between the first relay node and the target donor node.

[0028] As a possible implementation manner, the method further includes: the first relay node receiving, from the target donor node, information of a BAP address allocated by the target donor node through the source donor node, wherein the BAP address allocated by the target donor node for the first relay node is different from the BAP address allocated by the source donor node for the first relay node.

[0029] In this implementation manner, optionally, the PDCP data corresponding to the source donor node includes PDCP downlink data, the PDCP downlink data corresponding to the source donor node includes the BAP address allocated by the source donor node for the first relay node, the PDCP data corresponding to the target donor node includes PDCP downlink data, and the PDCP downlink data corresponding to the target donor node includes the BAP address allocated by the target donor node for the first relay node. Thus, the first relay node can distinguish, through the BAP address of the downlink data, whether the downlink data is from the source donor node or the target donor node.

[0030] As a possible implementation manner, the method further includes: the first relay node receiving, from the target donor node, sixth indication information, the sixth indication information being used to indicate that the first relay node starts, activates or enables double configuration of the BAP layer, and the double configuration of the BAP layer includes the BAP configuration corresponding to the source donor node and the BAP configuration corresponding to the target donor node.

[0031] The first aspect of the embodiment of the present application provides a method for configuring a logical channel LCH. The method can be executed by a terminal, or can be executed by a chip in the terminal. The following is an introduction taking the terminal execution as an example. In this method, the first DRB of the terminal corresponds to the first LCH, and the first LCH is used to transmit PDCP data corresponding to the source host node. The method includes: the terminal receives configuration information of the second LCH from the first relay node, and the second LCH is used to transmit PDCP data corresponding to the target host node; the terminal configures the second LCH for the first DRB;

[0032] In the method, the first relay node is an access relay node of the terminal.

[0033] In this method, the source host node is the source host node of the first relay node switching, and the target host node is the target host node of the first relay node switching, that is, the first relay node is the node where the switching occurs. Alternatively, the source host node is the source host node of the second relay node switching, the target host node is the target host node of the second relay node switching, and the second relay node is a relay node on the link between the first relay node and the source host node, that is, the second relay node is the node where the switching occurs.

[0034] As a possible implementation method, the PDCP data corresponding to the source host node is processed through the PDCP configuration information corresponding to the source host node, and the PDCP data corresponding to the target host node is processed through the PDCP configuration information corresponding to the target host node.

[0035] As a possible implementation method, the PDCP data corresponding to the source host node includes the uplink PDCP data and / or downlink PDCP data corresponding to the source host node, and the PDCP data corresponding to the target host node includes the uplink PDCP data and / or downlink PDCP data corresponding to the target host node.

[0036] As a possible implementation manner, the method also includes: the terminal receives first indication information from the first relay node; the terminal configures the second LCH for the first DRB, including: the terminal configures the second LCH for the first DRB according to the first indication information, so as to associate two LCHs for the first DRB.

[0037] As a possible implementation manner, the PDCP data corresponding to the source donor node includes downlink PDCP data, the PDCP data corresponding to the target donor node includes downlink PDCP data, and the method further includes:

[0038] The terminal receives downlink PDCP data corresponding to the source host node mapped to the first LCH from the first relay node; and the terminal processes the downlink PDCP data corresponding to the source host node through the PDCP configuration information corresponding to the source host node; and / or

[0039] The terminal receives downlink PDCP data corresponding to the target host node mapped to the second LCH from the first relay node; and the terminal processes the downlink PDCP data corresponding to the target host node through the PDCP configuration information corresponding to the target host node.

[0040] As a possible implementation manner, the PDCP data corresponding to the source donor node includes uplink PDCP data, and the PDCP data corresponding to the target donor node includes uplink PDCP data; the method further includes:

[0041] The terminal processes the uplink data through the PDCP configuration information corresponding to the source host node to obtain the uplink PDCP data corresponding to the source host node; and maps the uplink PDCP data corresponding to the source host node to the first LCH, and the terminal sends the uplink PDCP data corresponding to the source host node mapped to the first LCH to the first relay node; and / or

[0042] The terminal processes the uplink data through the PDCP configuration information corresponding to the target host node to obtain the uplink PDCP data corresponding to the target host node; and maps the uplink PDCP data corresponding to the target host node to the second LCH, and the terminal sends the uplink PDCP data corresponding to the target host node mapped to the second LCH to the first relay node.

[0043] As a possible implementation manner, the PDCP data corresponding to the target donor node includes PDCP uplink data corresponding to the target donor node, and the method further includes:

[0044] The terminal receives second indication information from the first relay node;

[0045] The terminal processes the uplink data according to the second indication information using the PDCP configuration information corresponding to the target host node to obtain the PDCP uplink data corresponding to the target host node.

[0046] As a possible implementation manner, the PDCP data corresponding to the target donor node includes PDCP uplink data corresponding to the target donor node, and the method further includes:

[0047] After the terminal receives the configuration information of the second LCH from the target host node through the first relay node, the terminal processes the uplink data according to the PDCP configuration information corresponding to the target host node to obtain the PDCP uplink data corresponding to the target host node.

[0048] As a possible implementation manner, the method further includes: the terminal receiving third indication information from the first relay node; and the terminal deleting the first LCH according to the third indication information.

[0049] A third aspect of the present application provides a method for assigning a BAP address. This method can be executed by a source host node, or by a chip within the source host node. The following description uses execution by a source host node as an example. The method includes: the source host node sending a BAP address assigned by the source host node to a target host node.

[0050] In this method, the source host node is the source host node of the access relay node or the intermediate relay node handover, and the target host node is the target host node of the access relay node or the intermediate relay node handover, wherein the intermediate relay node is connected to the access relay node. The relay node that undergoes handover can be called a migration relay node.

[0051] Optionally, the method further includes: the source host node receiving from the target host node and sending to the access relay node a BAP address allocated by the target host node to the access relay node.

[0052] As a possible implementation manner, the BAP address allocated by the source host node to the access IAB node is different from the BAP address allocated by the target host node to the access IAB node.

[0053] The source host node and the target host node allocate different BAP addresses to the access relay node, so that after the access relay node receives the downlink data, it can distinguish whether the downlink data comes from the source host node or the target host node based on the BAP address carried in the downlink data, so that the correct configuration information can be used to process the downlink data to ensure data continuity.

[0054] Optionally, the method further includes that the source donor node sends first indication information to the access relay node, so that the access relay node generates configuration information of the second LCH. The first indication information can be carried in a UE context modification request message. Optionally, the access relay node is a relay node that has performed handover, and the method further includes that the source donor node receives second indication information from the target donor node, and sends the second indication information to the access relay node, where the second indication information is used for the access relay node to maintain connection with the source donor node during handover.

[0055] Optionally, the access relay node is a relay node that has performed handover, and the method further includes that the source donor node receives capability indication information from the access relay node, where the capability indication information is used to indicate a capability of the first relay node to support maintaining connection with the source donor node during handover, and the source donor node sends the capability indication information to the target donor node.

[0056] The fourth aspect of the embodiments of the present application provides a BAP address allocation method. The method can be executed by a target donor node or a chip in the target donor node. Hereinafter, the target donor node is taken as an example for description. The method includes that the target donor node receives a BAP address allocated by a source donor node for an access relay node.

[0057] In the method, the source donor node is a source donor node of handover of the access relay node or an intermediate relay node, and the target donor node is a target donor node of handover of the access relay node or the intermediate relay node, where the intermediate relay node is connected with the access relay node. The relay node that has performed handover can be referred to as a migration relay node.

[0058] Optionally, the method further includes that the target donor node sends, through the source donor node, a BAP address allocated by the target donor node for the access IAB node to the access IAB node.

[0059] As a possible implementation manner, the BAP address allocated by the source donor node for the access IAB node is different from the BAP address allocated by the target donor node for the access IAB node.

[0060] As a possible implementation manner, the method further includes that the target donor node sends first indication information to the access relay node, so that the access relay node generates configuration information of the second LCH. Optionally, the first indication information is carried in a UE context establishment request message.

[0061] As a possible implementation, the method further includes that the target donor node can send second indication information to the terminal through the access relay node, the second indication information being used for configuring the second LCH for the first DRB, or being used for instructing the terminal to associate two LCHs for the first DRB.

[0062] As a possible implementation, the method further includes that the target donor node receives third indication information sent by the access relay node, the third indication information being used for instructing the terminal to delete the first LCH by the target donor node.

[0063] As a possible implementation, the method further includes that the target donor node sends fourth indication information to the access relay node through the source donor node, the fourth indication information instructing the access relay node to maintain the connection with the source donor node in the handover process.

[0064] Optionally, the method includes that the target donor node receives capability indication information from the access relay node through the source donor node, the capability indication information indicating the capability of the access relay node in maintaining the connection with the source donor node in the handover process.

[0065] As a possible implementation, the method further includes that the target donor node sends fifth indication information to the access relay node, the fifth indication information being used for instructing the access relay node to start, activate or enable the dual configuration of the BAP layer, the dual configuration of the BAP layer including the BAP configuration corresponding to the source donor node and the BAP configuration corresponding to the target donor node.

[0066] One or more methods in the above first aspect to the fourth aspect can be combined with each other, and in the method of each aspect, one or more of the possible implementations can be combined with each other.

[0067] The fifth aspect of the embodiments of the present application provides a communication apparatus, which can be a terminal or a chip in the terminal, or the communication apparatus can be a relay node or a chip in the relay node, or the communication apparatus can be a target donor node or a chip in the target donor node, or the communication apparatus can be a source donor node or a chip in the source donor node. The communication apparatus includes a processor, which is used to execute computer programs or instructions, so that the communication apparatus executes the method of the first aspect to the fourth aspect.

[0068] Optionally, the communication apparatus further includes the memory. The processor is coupled with the memory, and the memory is used to store the computer programs or instructions, and the processor is used to execute the computer programs or instructions in the memory.

[0069] Optionally, the communication apparatus can further comprise a communication unit for communicating with other devices or other components in the communication apparatus. For example, the communication apparatus is a terminal, and the communication unit is a transceiver. For example, the communication apparatus is a chip in the terminal, and the communication unit is an input / output circuit or an interface of the chip.

[0070] The sixth aspect of the embodiments of the present application provides a communication apparatus having functions of implementing the behaviors of the terminal, the relay node, the source donor node or the target donor node in the above method aspects, which comprises means corresponding to the steps or functions described in the above method aspects of the first aspect to the sixth aspect. The steps or functions can be implemented by software, or hardware, or by a combination of hardware and software.

[0071] The seventh aspect of the embodiments of the present application provides a chip comprising a processor and an interface circuit, wherein the interface circuit is coupled to the processor, the processor is configured to run a computer program or instructions to implement the method of any one of the first aspect to the fourth aspect, and the interface circuit is configured to communicate with other modules outside the chip.

[0072] The eighth aspect of the embodiments of the present application provides a computer storage medium storing a program for implementing the method of any one of the first aspect to the fourth aspect. When the program is run in a wireless communication apparatus, the wireless communication apparatus is caused to perform the method of any one of the first aspect to the fourth aspect.

[0073] The ninth aspect of the embodiments of the present application provides a computer program product comprising a program, when the program is run, the method of any one of the first aspect to the fourth aspect is performed.

[0074] The tenth aspect of the embodiments of the present application provides a communication system comprising one or more of the terminal, the relay node, the source donor node and the target donor node involved in the method of the first aspect to the fourth aspect. Optionally, the communication system can further comprise a core network element. Optionally, the core network element is connected to the source donor node and the target donor node. BRIEF DESCRIPTION OF DRAWINGS

[0075] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the background art, the drawings needed to be used in the embodiments of the present application or the background art will be described below.

[0076] Figure 1 is a schematic diagram of a mobile communication system 100 provided by the embodiments of the present application;

[0077] Figure 2 is a schematic diagram of an IAB network 200 provided by the embodiments of the present application;

[0078] Figure 3 is a schematic diagram of a CU-DU separation architecture provided by an embodiment of the present application;

[0079] Figure 4 is a schematic diagram of a control plane protocol stack under the CU-DU separation architecture provided by an embodiment of the present application;

[0080] Figure 5 is a schematic diagram of a user plane protocol stack under the CU-DU separation architecture provided by an embodiment of the present application;

[0081] Figure 6 is a schematic diagram of a control plane protocol stack in an IAB network provided by an embodiment of the present application;

[0082] Figure 7 is a schematic diagram of a user plane protocol stack in an IAB network provided by an embodiment of the present application;

[0083] Figure 8 is a schematic diagram of a DAPS provided by an embodiment of the present application;

[0084] Figure 9 is a flowchart of a DAPS-based handover under a single air interface provided by an embodiment of the present application;

[0085] Figure 10 is a schematic diagram of a relay node handover provided by an embodiment of the present application;

[0086] Figure 11 is a schematic diagram of an Inter-donor CU handover provided by an embodiment of the present application;

[0087] Figure 12 is a schematic diagram of a user plane protocol stack of a dual LCH provided by an embodiment of the present application;

[0088] Figure 13 is a flowchart of an LCH configuration method provided by an embodiment of the present application;

[0089] Figure 14 is a flowchart of an indication method provided by an embodiment of the present application;

[0090] Figure 15 is a flowchart of an LCH deletion method provided by an embodiment of the present application;

[0091] Figure 16 is a flowchart of an indication method provided by an embodiment of the present application;

[0092] Figure 17 is a schematic diagram of a cross-donor node handover method provided by an embodiment of the present application;

[0093] Figure 18 is a schematic diagram of another method for cross-host node switching provided by an embodiment of the present application;

[0094] Figure 19 is a structural schematic diagram of a terminal provided by an embodiment of the present application;

[0095] Figure 20 is a structural schematic diagram of a communication apparatus provided by an embodiment of the present application;

[0096] Figure 21 is a structural schematic diagram of an access network device provided by an embodiment of the present application;

[0097] Figure 22 is a structural schematic diagram of a communication apparatus provided by an embodiment of the present application. DETAILED DESCRIPTION

[0098] The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0099] Figure 1 is a structural schematic diagram of a communication system 100 provided by an embodiment of the present application. The communication system 100 includes at least one terminal (for example, a terminal 110 and a terminal 120), at least one relay node 130 (RN), at least one access network device 140, and at least one core network device 150. The terminal 110 and the terminal 120 are connected to the access network device 140, or the terminal 110 and the terminal 120 are connected to the access network device 140 through the relay node 130. The relay node 130 is connected to the access network device 140, or the relay node 130 is connected to the access network device 140 through another relay node. The access network device 140 is connected to the core network device 150 in a wired manner. The connection between the terminal 110, the terminal 120, the relay node 130, the access network device 140, and the core network device 150 can be wireless or wired, which is not limited in the present application.

[0100] The communication system provided in the present application may, for example, be a long term evolution (LTE) system supporting 4G access technology, a new radio (NR) system supporting 5G access technology, any cellular system related to the 3rd generation partnership project (3GPP), a wireless-fidelity (WiFi) system, a worldwide interoperability for microwave access (WiMAX) system, a multi-radio access technology (RAT) system, or other future-oriented communication technology. In the present application, a terminal is a device with wireless transceiving function, which can be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted; can also be deployed on water (such as ships, etc.); can also be deployed in the air (such as unmanned aerial vehicles, airplanes, balloons and satellites, etc.). The terminal can be a mobile phone, a tablet computer (Pad), a computer with wireless transceiving function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical treatment, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. The embodiments of the present application do not limit the application scenarios. The terminal can also be referred to as a terminal device, a user equipment (UE), an access terminal device, a station, a UE unit, a UE station, a mobile station, a mobile station, a remote station, a remote terminal device, a mobile device, a UE terminal device, a terminal device, a wireless communication device, a UE agent or a UE apparatus, or some other suitable term. The terminal can also be fixed or mobile.

[0101] An access network device can be a device on the access network side that supports terminal access to a communication system. An access network device can be called a base station (BS), such as an evolved nodeB (eNB) in a 4G access technology communication system, a next-generation nodeB (gNB) in a 5G access technology communication system, a transmission reception point (TRP), a relay node, an access point (AP), an access node in a WiFi system, a wireless backhaul node, etc. Alternatively, an access network device can be called a donor node, an IAB donor, a donor IAB, or a donor gNB (DgNB, donor gNB). A base station can be a macro base station, a micro base station, a pico base station, a small cell, or a relay station. Multiple base stations can support networks using the same or different technologies mentioned above. A base station can include one or more co-located or non-co-located transmission receiving points (TRPs). The access network device can also be a wireless controller, a central unit (CU), and / or a distributed unit (DU) in a cloud radio access network (CRAN) scenario. The access network device can also be a server, a wearable device, or a vehicle-mounted device, etc. The following description takes the access network device as a base station as an example. The multiple access network devices in the communication system can be base stations of the same type or different types. The base station can communicate with the terminal or with the terminal device through a relay station. The terminal can communicate with multiple base stations of different technologies. For example, the terminal can communicate with a base station that supports an LTE network, or with a base station that supports a 5G network, and can also support dual connections with base stations of an LTE network and base stations of a 5G network.

[0102] The core network device can be connected with one or more access network devices, and can provide one or more of session management, access authentication, Internet Protocol (IP) address allocation, and data transmission for terminals in the system. For example, the core network device can be a mobile management entity (MME) or a serving gateway (SGW) in a 4G access technology communication system, an Access and Mobility Management Function (AMF) network element or a User Plane Function (UPF) network element in a 5G access technology communication system, and the like. The core network device can also be referred to as a core network element.

[0103] The relay node can be a node providing wireless access service and / or backhaul service. The wireless access service refers to providing data and / or signaling through a wireless access link, and the wireless backhaul service refers to providing data and / or signaling backhaul service through a wireless backhaul link. The relay node is used to realize the forwarding of data and / or signaling between the terminal and the access network device. The relay node provides wireless access service for the terminal through an access link (AL) on one hand, and connects to the access network device through one-hop or multi-hop backhaul link (BL) on the other hand.

[0104] The relay node can have different names in different communication systems. For example, the relay node can be referred to as a wireless backhaul node or a wireless backhaul device. For example, in a 5G system, the relay node can be referred to as an integrated access and backhaul node (IAB node). Of course, in future communication systems, the relay node can also have different names, which are not limited here.

[0105] Figure 2 FIG. 1 is a schematic diagram of an integrated access and backhaul (IAB) network 200 provided by an embodiment of the present application. Figure 2 For Figure 1 FIG. 1 shows an application scenario of a communication system 100. The following will be further described in combination with Figure 2 , the terminal, the relay node and the access network device in Figure 1 .

[0106] In Figure 2 , terminal 1 can be Figure 1The terminal 110 in the IAB node 2, IAB node 3 and IABnode1 can be Figure 1 The relay node 130 in the IAB donor 1 can be Figure 1 The access network device 140 in the IAB donor 1 can be connected (for example, via a wired connection) to Figure 1 The core network device 150 in the IAB donor can be called a donor node, DgNB (ie, donor gNodeB) or other appropriate names, which is not limited in this application.

[0107] IAB network 200 includes one or more terminals (for clarity, Figure 2 Only terminal 1 is shown), one or more IAB nodes (as an example, Figure 2 3 IAB nodes, ie, IAB node 2, IAB node 3 and IAB node 1), and one or more host nodes (for clarity, Figure 2 Only IAB donor 1 is shown. Terminal 1 can be wirelessly connected to one or more IAB nodes, each IAB node can be wirelessly connected to one or more other IAB nodes, and one or more IAB nodes can be wirelessly connected to one or more host nodes. Optionally, one or more IAB nodes can be wirelessly connected to each other, which is not a limitation in this application.

[0108] It is understood that in an IAB network, a transmission path between a terminal and a host node may include one or more IAB nodes. If an IAB node is a node that a terminal accesses, the link between the IAB node and the child node (i.e., the terminal) may be called an access link. If an IAB node is a node that provides backhaul services to terminals under other IAB nodes, the link between the IAB node and the child node (i.e., other IAB nodes) may be called a backhaul link. For example, Figure 2 In the figure, terminal 1 is connected to IAB node 2 via a wireless access link, IAB node 2 is connected to IAB node 3 via a wireless backhaul link, IAB node 3 is connected to IAB node 1 via a wireless backhaul link, and IAB node 1 is connected to IABdonor 1 via a wireless backhaul link.

[0109] To ensure the reliability of service transmission, the IAB network supports multi-hop IAB nodes and multi-connection IAB node networking, optionally. There can be multiple transmission paths between the terminal and the IAB donor. On one path, there is a certain hierarchical relationship between the IAB nodes, and between the IAB nodes and the donor nodes serving the IAB nodes. Each IAB node regards the node providing access service for the IAB node as the parent node. Correspondingly, each IAB node can be regarded as the child node of its parent node.

[0110] For example, Figure 2 In the example, the parent node of the IAB node 1 is the IAB donor 1, the IAB node 1 is the parent node of the IAB node 3, the IAB node 3 is the parent node of the IAB node 2, and the IAB node 2 is the parent node of the terminal 1.

[0111] The uplink data packet of the terminal can be transmitted to the host node through one or more IAB nodes, and then transmitted to the core network device, such as a mobile gateway device (for example, a user plane function (UPF) network element in a 5G network) by the host node. The downlink data packet of the terminal will be received by the host node from the core network device mobile gateway device, and then transmitted to the terminal through one or more IAB nodes.

[0112] For example, Figure 2 In the example, the transmission path of the uplink data packet between the terminal 1 and the IAB donor 1 is: terminal 1→IAB node 2→IAB node 3→IAB node 1→IAB donor 1, and the transmission path of the downlink data packet between the terminal 1 and the IAB donor 1 is: IAB donor 1→IAB node 1→IAB node 3→IAB node 2→terminal 1.

[0113] In the IAB network, on a transmission path, the IAB node accessed by the terminal can be referred to as an access IAB node, and other IAB nodes on the transmission path can be referred to as intermediate IAB nodes. The intermediate IAB node can provide backhaul service for the terminal. An IAB node can serve as an access IAB node for a certain terminal, and also can serve as an intermediate IAB node for other terminals.

[0114] For example, Figure 2In the path "Terminal 1→IAB node 2→IAB node 3→IAB node 1→IAB donor 1", IAB node 2 is an access IAB node, and IAB node 3 and IAB node 1 are intermediate IAB nodes. IAB node 3 provides access service for IAB node 2 and / or backhaul service for terminal 1, and IAB node 1 provides access service for IAB node 3 and / or backhaul service for terminal 1. If terminal 2 (not shown in the figure) accesses IAB node 3, for terminal 1, IAB node 3 is an intermediate IAB node, and for terminal 2, IAB node 3 is an access IAB node. Figure 2

[0115] In the IAB network, one or more IAB nodes and one or more terminals served by an IAB node can be referred to as descendant nodes of the IAB node. It can be understood that the descendant nodes can include IAB nodes served by the IAB node, such as child nodes, grandchild nodes, and great-grandchild nodes, and terminals accessing the IAB nodes, such as terminals accessing child nodes, grandchild nodes, and great-grandchild nodes.

[0116] For example, Figure 2 In the figure, the descendant nodes of IAB node 1 include terminal 1, IAB node 2, and IAB node 3.

[0117] The above IAB network is only exemplary. In the IAB network combining multi-hop and multi-connection, there are more possibilities for the IAB network, such as a host node and another host node forming a dual connection to serve a terminal, and the like, which are not listed one by one here.

[0118] In the IAB network, for an IAB donor, the IAB donor can be composed of a centralized unit (which can be referred to as an IAB donor CU) and a distributed unit (which can be referred to as an IAB donor DU).

[0119] In the IAB network, for an IAB node, when the IAB node acts as a parent node, it can act as an access network device to provide access service for its child nodes, for example, by scheduling uplink resources for its child nodes to transmit uplink data. When the IAB node acts as a child node, it can act as a terminal device for the parent node serving the IAB node, for example, by performing cell selection, random access, and the like to establish a connection with the parent node and obtain uplink resources scheduled by the parent node for transmitting uplink data.

[0120] ​By way of example and not limitation, embodiments of the present application refer to the functional unit in an IAB node that supports the role of the terminal device implemented by the IAB node as the mobile terminal (MT) functional unit of the IAB node, referred to as IAB-MT or IAB-UE for short, and refer to the functional unit in the IAB node that supports the role of the access network device implemented by the IAB node as the DU functional unit of the IAB node, referred to as IAB-DU for short. The IAB-MT and the IAB-DU can be a logical functional unit, and both functions are implemented by the IAB node; or the IAB-MT and the IAB-DU can be a physical division, and the IAB-MT and the IAB-DU can be different physical devices in the IAB node.

[0121] It should be noted that, Figure 2 The IAB network is taken as an example for introduction, Figure 2 The content is also applicable to relay networks other than the IAB network, and the IAB in Figure 2 may be replaced by a relay, for example, the IAB node 2 can be replaced by a relay node 2, the IAB node 3 can be replaced by a relay node 3, the IAB node 1 can be replaced by a relay node 1, and the IAB donor 1 can be replaced by a host node 1. The connection relationship of each network element in the relay network, the access link and the backhaul link, and the description of the parent node and the child node, the access relay node and the intermediate access node can refer to the description of the IAB network 200.

[0122] Figure 3 is a schematic diagram of the CU-DU separation architecture provided by embodiments of the present application. Figure 1 The access network device in Figure 2 The IAB donor in Figure 3 will be described below.

[0123] The access network device 140 can be implemented through a cloud radio access network (C-RAN) architecture, part of the functions of a base station (taking gNB as an example) are implemented by a central unit (CU), and another part of the functions are implemented by a distributed unit (DU). The split of the CU and the DU can be according to a protocol stack, and one possible way is to deploy a radio resource control (RRC) layer, a service data adaptation protocol (SDAP) layer, and a packet data convergence protocol (PDCP) layer in the CU, and to deploy a radio link control (RLC) layer, a media access control (MAC) layer, and a physical (PHY) layer in the DU. One CU can be connected with one DU or multiple DUs, thereby facilitating network expansion. The CU and the DU are connected through an interface (for example, an F1 interface), and the CU and a core network are connected through an interface (for example, an NG interface).

[0124] In an implementation manner, the CU includes a user plane (UP) (referred to as CU-UP in the present application) and a control plane (CP) (referred to as CU-CP in the present application).

[0125] In a single air interface scenario, a terminal can access the CU through the DU, wherein the functions of the RLC layer, the MAC layer, and the PHY layer corresponding to the UE are implemented by the DU, and the functions of the PDCP layer, the SDAP layer, and the PDCP layer corresponding to the UE can be implemented by the CU.

[0126] Figure 4 And Figure 5 are a schematic diagram of a control plane protocol stack and a schematic diagram of a user plane protocol stack of the CU-DU in a separation architecture provided by an embodiment of the present application, which are described below in combination with Figure 4 and Figure 5 .

[0127] For the control plane, as Figure 4As shown, the UE and the CU establish peer-to-peer RRC layer and PDCP layer. The UE and the DU are connected through an interface (for example, Uu interface), and the UE and the DU establish peer-to-peer RLC layer, MAC layer and PHY layer; the DU and the CU are connected through a control plane interface (for example, F1-control plane, F1-C interface), and the DU and the CU establish peer-to-peer F1 application protocol (F1AP) layer, stream control transmission protocol (SCTP) layer, Internet Protocol (IP) layer, layer (L) 2 and layer (L) 1.

[0128] For the user plane, as shown, Figure 5 the UE and the CU establish peer-to-peer SDAP layer and PDCP layer. The UE and the DU are connected through Uu interface, and the UE and the DU establish peer-to-peer RLC layer, MAC layer and PHY layer; the DU and the CU are connected through F1-user plane (F1-U) interface, and the DU and the CU establish peer-to-peer general packet radio service (GPRS) tunneling protocol-user plane (GTP-U) layer, user datagram protocol (UDP) layer, IP layer, L2 and L1.

[0129] Figure 6 and Figure 7 are respectively a schematic diagram of a control plane protocol stack and a schematic diagram of a user plane protocol stack in an IAB network provided by an embodiment of the present application, which are described below in combination with Figure 6 and Figure 7 .

[0130] In the IAB network, the PHY layer, the MAC layer and the RLC layer peer-to-peer with the terminal are located on the access IAB node, and the PDCP layer, the SDAP layer and the RRC layer peer-to-peer with the UE are located on the IAB donor CU, if the IAB donor-CU is composed of CP and UP, then for the control plane, the PDCP layer and the RRC layer peer-to-peer with the UE are located on the CP (that is, donor-CU-CP) of the IAB donor CU, and for the user plane, the PDCP layer and the SDAP layer peer-to-peer with the UE are located on the UP (that is, donor-CU-UP) of the IAB donor CU.

[0131] For the control plane, as Figure 6 As shown, a Uu interface is established between the terminal 1 and the DU of the IAB node 2, and the peer protocol layers include the RLC layer, the MAC layer and the PHY layer. The DU of the IAB node 2 and the IAB donor CU 1 establish an F1-C interface, and the peer protocol layers include the F1AP layer, the SCTP layer. The IAB donor DU 1 and the IAB donor CU 1 establish an F1 interface within the IAB donor, and the peer protocol layers include the IP layer, the L2 and the L1. The BL is established between the IAB node 2 and the IAB node 3, between the IAB node 3 and the IAB node 1, and between the IAB node 1 and the IAB donor DU 1, and the peer protocol layers include the Backhaul Adaptation Protocol (BAP) layer, the RLC layer, the MAC layer and the PHY layer. In addition, the peer RRC layer and the PDCP layer are established between the terminal 1 and the IAB donor CU 1, and the peer IP layer is established between the DU of the IAB node 2 and the IAB donor DU 1.

[0132] As can be seen, compared with the control plane protocol stack of the single-air interface, the DU of the access IAB node implements the function of the gNB-DU of the single-air interface (i.e., the function of establishing the peer RLC layer, the MAC layer and the PHY layer with the terminal, and the function of establishing the peer F1AP layer and the SCTP layer with the CU). It can be understood that the DU of the access IAB node in the IAB network implements the function of the gNB-DU of the single-air interface; and the IAB donor CU implements the function of the gNB-CU of the single-air interface.

[0133] On the control plane, the RRC message of the UE is encapsulated in the F1AP message and transmitted between the access IAB node and the IAB donor CU.

[0134] For the user plane, as shown in FIG. 3, the PDCP layer is established between the terminal 1 and the IAB donor CU 1, and the IP layer is established between the DU of the IAB node 2 and the IAB donor DU 1. Figure 7As shown, a Uu interface is established between Terminal 1 and the DU of IAB node 2. The peer protocol layers include the RLC layer, MAC layer, and PHY layer. An F1-U interface is established between the DU of IAB node 2 and IAB donor CU 1. The peer protocol layers include the GTP-U layer and the UDP layer. An F1 interface within the IAB host is established between IAB donor DU 1 and IAB donor CU 1. The peer protocol layers include the IP layer, L2, and L1. BLs are established between IAB node 2 and IAB node 3, between IAB node 3 and IAB node 1, and between IAB node 1 and IAB donor DU 1. The peer protocol layers include the BAP layer, RLC layer, MAC layer, and PHY layer. Furthermore, peer SDAP and PDCP layers are established between Terminal 1 and IAB donor CU 1, and a peer IP layer is established between the DU of IAB node 2 and IAB donor DU 1.

[0135] As can be seen, compared to the user plane protocol stack of a single air interface, the user plane protocol stack of the IAB network implements the functions of a single air interface gNB-DU (i.e., establishing peer RLC, MAC, and PHY layers with the terminal, and establishing peer GTP-U and UDP layers with the IAB donor CU 1). It can be understood that the DU of the IAB access node implements the functions of a single air interface gNB-DU, while the IAB donor CU implements the functions of a single air interface gNB-CU.

[0136] On the user plane, the UE's PDCP packets are encapsulated and transmitted in a GTP-U tunnel between the access IAB node and the IAB donor CU. The GTP-U tunnel is established on the F1-U interface.

[0137] Figure 7 In the example, the PDCP entity, RLC entity, and GTP-U tunnel of the terminal may be established based on the bearer granularity. That is, the bearer, PDCP entity, RLC entity, and GTP-U tunnel may correspond to each other one-to-one.

[0138] Logical channels are established between terminals and DUs connected to IAB nodes. These logical channels refer to the transmission paths between RLC entities and their lower-layer entities, specifically, the transmission paths between RLC entities and MAC entities. Each RLC entity corresponds to one logical channel. RLC channels are established between the mobile terminal (MT) connected to an IAB node and the DUs of intermediate IAB nodes (e.g., the MT of IAB node 2 and the DU of IAB node 3), the MT of intermediate IAB nodes and the DUs of intermediate IAB nodes (e.g., the MT of IAB node 3 and the DU of IAB node 1), and the DUs of intermediate IAB nodes and the IAB donor DUs (e.g., the MT of IAB node 1 and the IAB donor DU1). An RLC channel refers to the transmission path between an RLC entity and its upper-layer entity. For example, if the upper layer of the RLC entity is an adaptation (also known as the Backhaul Adaptation Protocol, BAP) layer entity, the RLC channel on the backhaul link is the channel between the RLC entity and the BAP entity. One RLC entity corresponds to one RLC channel. So, Figure 7 In the protocol, bearers, PDCP entities, RLC entities, GTP-U tunnels and logical channels all correspond to each other one by one.

[0139] That Figure 6 and Figure 7 Only Figure 2 The protocol stack in the IAB scenario shown is described as an example. It should be noted that an IAB node may have one or more roles, and the IAB node may have a protocol stack for the one or more roles; or the IAB node may have a set of protocol stacks, and the protocol stack may use the protocol layers corresponding to the different roles for processing according to the different roles of the IAB node. The following is an example of the protocol stack of the IAB node having one or more roles:

[0140] (1) Terminal protocol stack

[0141] When an IAB node accesses an IAB network, it can act as a terminal. In this case, the MT of the IAB node has the protocol stack of the terminal, for example Figure 6 and Figure 7 The protocol stack of terminal 1 in the embodiment includes the RRC layer, PDCP layer, RLC layer, MAC layer and PHY layer. On the control plane, the RRC message of the IAB node is encapsulated in the F1AP message between the parent node of the IAB node and the IAB donor CU for transmission; on the user plane, the PDCP data packet of the IAB node is encapsulated in the GTP-U tunnel between the parent node of the IAB node and the IAB donor CU for transmission.

[0142] In addition, after the IAB node accesses the IAB network, the IAB node can still act as a role of a terminal, for example, transmitting own uplink and / or downlink data packets (e.g., OAM data packets) with the IAB donor, performing measurement through the RRC layer, and the like.

[0143] (2) Protocol stack of an access IAB node

[0144] After the IAB node accesses the IAB network, the IAB node can provide access service for terminals, thereby acting as a role of an access IAB node, at this time, the IAB node has a protocol stack of an access IAB node, for example, the protocol stack of the IAB node 2 in Figure 6 and Figure 7 .

[0145] (3) Protocol stack of an intermediate IAB node

[0146] After the IAB node accesses the IAB network, the IAB node can act as a role of an intermediate IAB node, at this time, the IAB node has a protocol stack of an intermediate IAB node, for example, the protocol stack of the IAB node 3 or the IAB node 1 in Figure 6 and Figure 7 .

[0147] The IAB node can have the protocol stack of one or more roles described above, for example, after the IAB node accesses the IAB network, the IAB node can act as a role of a terminal and a role of an access IAB node, in this case, the IAB node can have two sets of protocol stacks on the interface facing its parent node, one set of protocol stacks is the protocol stack of a terminal, and the other set of protocol stacks is the protocol stack of an access IAB node (i.e., the protocol stack of a terminal providing backhaul service). For another example, after the IAB node accesses the IAB network, the IAB node can act as a role of a terminal and a role of an intermediate IAB node, in this case, the IAB node can have two sets of protocol stacks on the interface facing its parent node, one set of protocol stacks is the protocol stack of a terminal, and the other set of protocol stacks is the protocol stack of an intermediate IAB node. For another example, after the IAB node accesses the IAB network, the IAB node can act as a role of a terminal, a role of an access IAB node, and a role of an intermediate IAB node (for example, the IAB node can be an access IAB node for some terminals and an intermediate IAB node for other terminals, in addition, the IAB node needs to transmit own operation, administration and maintenance (OAM) data packets with the IAB donor), at this time, the IAB node can have three sets of protocol stacks, one set of protocol stacks is the protocol stack of a terminal, one set of protocol stacks is the protocol stack of an access IAB node, and one set of protocol stacks is the protocol stack of an intermediate IAB node.

[0148] It should be noted that, Figure 6 and Figure 7 The IAB network is taken as an example for introduction, Figure 6 and Figure 7 The content is also applicable to a relay network other than the IAB network, and the control plane protocol stack architecture of the relay network can refer to Figure 6 , and the user plane protocol stack architecture of the relay network can refer to Figure 7 .

[0149] In a single-air-interface scenario, a terminal can perform handover, and when the terminal switches from a source base station to a target base station, the connection with the source base station is disconnected first, the service transmission of the terminal is interrupted, and after the terminal accesses the target base station, the service transmission of the terminal is restored. In order to reduce the problem of service transmission interruption of the single-air-interface terminal, a dual-active protocol stack (DAPS) scheme is introduced.

[0150] First, the DAPS scheme for a single air interface is described in combination with Figure 8 and Figure 9 .

[0151] Figure 8 is a schematic diagram of a DAPS provided by an embodiment of the present application, as Figure 8As shown in the figure, the source base station receives downlink data from the terminal from the core network. During the terminal handover process, the source base station can send part of the received downlink data to the terminal and forward the other part to the target base station (this part of the data can be called forwarded data). After the terminal accesses the target base station, the target base station sends it to the terminal. The source base station and the target base station each have their own user plane protocol stacks. The terminal has two sets of protocol stacks. One protocol stack corresponds to the source base station, including the corresponding PHY entity, MAC entity, and RLC entity; the other protocol stack corresponds to the target base station, including the corresponding PHY layer, MAC entity, and RLC entity. Although the terminal has two sets of protocol stacks, for the forwarding data of the terminal, one PDCP entity will be associated with two RLC entities, where one RLC entity corresponds to the source base station and one RLC entity corresponds to the target base station. The PDCP entity is configured at the bearer granularity. This means that for each bearer of a terminal, there is a corresponding PDCP entity. However, within this PDCP entity, functions such as header compression, header decompression, security processing, header addition, and header removal are independent for the source and target base stations, while the reordering function is common to both. The PDCP sequence number (SN) required for reordering can be uniformly allocated by the source base station.

[0152] Figure 9 This is a flow chart of a DAPS-based switching process under a single air interface provided by an embodiment of the present application. Figure 9 As shown, the method includes:

[0153] S901: The source base station makes a handover decision.

[0154] Before S901, the terminal has the following Figure 8 The protocol stack corresponding to the source base station is shown, and uplink data transmission and downlink data transmission are performed with the source base station based on the protocol stack corresponding to the source base station.

[0155] S902: The source base station sends a handover request message to the target base station.

[0156] The handover request message includes the context information of the terminal, so that the target base station can generate the configuration information of the air interface resources of the target base station for the terminal.

[0157] S903: The target base station sends a handover request confirmation message to the source base station.

[0158] The handover request acknowledgement message comprises a handover command message generated by the target base station, wherein the handover command message comprises configuration information of air interface resources generated by the target base station for the terminal, and the configuration information of the air interface resources comprises configuration information of air interface resources allocated by the target base station for forwarding data. The forwarding data of the terminal comprises data forwarded by the source base station to the target base station from the terminal data received by the source base station from the core network, and the target base station sends the forwarding data to the terminal. The configuration information of the air interface resources allocated by the target base station for the forwarding data comprises configuration information of one or more of a PDCP layer, an RLC layer, a MAC layer and a PHY layer, and the PDCP layer configuration information can comprise security configuration information and / or a robust header compression (ROHC) profile. The security configuration information can comprise security algorithms (such as encryption algorithms and / or integrity protection algorithms) and / or key-related parameters.

[0159] S904: The source base station sends the handover command message generated by the target base station to the terminal.

[0160] The handover command message comprises configuration information of air interface resources generated by the target base station for the terminal. According to the configuration information, the terminal can establish a protocol stack corresponding to the target base station as shown in FIG. 4B. Figure 8 At this point, the terminal has established a protocol stack corresponding to the source base station and a protocol stack corresponding to the target base station as shown in FIG. 4A and FIG. 4B. Figure 8

[0161] Optionally, the handover command message can additionally carry an indication information corresponding to a service bearer of the terminal, which is used to indicate that the service bearer is configured for DAPS handover. The service bearer can be a data radio bearer (DRB).

[0162] S905: The terminal starts DAPS.

[0163] After the terminal starts DAPS operation for the service bearer corresponding to the indication information carried in the handover command message, since the terminal has not successfully accessed the target base station at this time, the terminal can continue to use the protocol stack corresponding to the source base station to perform uplink data and downlink data transmission for the service bearer with the source base station, and simultaneously attempt to access the target base station.

[0164] S906-S907 describe the process of forwarding sequence number (SN) status and data by the source base station. The source base station can forward part of the downlink data of the terminal received from the core network to the target base station, which is sent to the terminal by the target base station, and the other part of the data is continuously sent to the terminal by the source base station.

[0165] ​S906: The source base station forwards the SN status to the target base station.

[0166] S907: The source base station forwards data to the target base station.

[0167] The terminal data forwarded by the source base station to the target base station is PDCP service data unit (SDU). The source base station uniformly allocates PDCP SNs to the PDCP SDUs and forwards the PDCP SDUs and their corresponding PDCP SNs to the target base station. After the terminal successfully accesses the target base station, the target base station processes the PDCP SDUs according to the received PDCP SNs and their PDCP layer configuration information and sends them to the terminal.

[0168] S908: The terminal sends a preamble to the target base station.

[0169] S909: The target base station sends a random access response (RAR) to the terminal.

[0170] S910: The terminal performs physical uplink shared channel (PUSCH) switching.

[0171] Before performing the PUSCH switching, the terminal receives an uplink (UL) grant allocated by the target base station. For example, for non-contention-based random access, the UL grant is carried in the RAR of S909, and for contention-based random access, the UL grant can be carried in the downlink control information (DCI) sent to the terminal. After receiving the UL grant, the terminal performs the PUSCH switching operation, i.e., stops the transmission of uplink data with the source base station and starts the transmission of uplink data with the target base station. In other words, the PUSCH of the terminal is switched from the source base station to the target base station. It should be noted that although the PUSCH of the terminal is switched to the target base station, the terminal cannot transmit uplink data with the source base station, but can still transmit downlink data with the source base station.

[0172] As described above, in S904 to S910, the terminal and the source base station can perform downlink data transmission and uplink data transmission.

[0173] S911: The terminal sends an RRC reconfiguration complete message to the target base station.

[0174] After the PUSCH of the terminal switches to the target base station, the terminal can send an RRC reconfiguration complete message to the target base station on the resource indicated by the UL grant, indicating that the terminal has successfully accessed the target base station, and the terminal can perform downlink data transmission with the target base station.

[0175] S912: The target base station sends a handover success message to the source base station, instructing the source base station to stop sending downlink data to the terminal.

[0176] As described above, in S911 to S912, the terminal and the source base station can perform downlink data transmission, the terminal and the target base station can perform downlink data transmission, and the terminal and the target base station can perform uplink data transmission.

[0177] Specifically, the terminal processes the downlink data received from the source base station through the ROHC profile, security algorithm and key configured by the source base station, and processes the downlink data received from the target base station through the ROHC profile, security algorithm and key configured by the target base station, and then sends the processed packets to the common buffer in the PDCP layer for reordering, and then submits them to the upper layer in sequence.

[0178] S913: The source base station stops sending downlink (DL) data to the UE.

[0179] After receiving the handover success message sent by the target base station, the source base station stops sending downlink data to the terminal, and sends the remaining downlink data of the terminal on the source base station to the target base station through S914 to S915 below, which is sent to the terminal by the target base station.

[0180] S914: The source base station forwards the SN status to the target base station.

[0181] S915: The source base station forwards data to the target base station.

[0182] S916: The target base station sends an RRC message to the terminal, instructing the terminal to release the air interface resource corresponding to the source base station.

[0183] S917: The terminal switches from DAPS handover to single active protocol stack.

[0184] After the terminal switches to the single active protocol stack, the terminal stops all transmissions with the source base station, including physical uplink control channel (PUCCH) and the like.

[0185] As described above, in S913 to S917, the terminal and the target base station perform downlink data transmission and uplink data transmission.

[0186] In the scheme of the application, the terminal initiates DAPS, and the terminal can maintain the connection with the source base station in the cross-base station handover process of a single air interface, thereby ensuring uninterrupted uplink and downlink data transmission of the terminal and improving the user experience. Figure 9 In the scheme of the application, the terminal initiates DAPS, and the terminal can maintain the connection with the source base station in the cross-base station handover process of a single air interface, thereby ensuring uninterrupted uplink and downlink data transmission of the terminal and improving the user experience.

[0187] In a relay network, a relay node can be handed over, Figure 10 is a schematic diagram of relay node handover provided by an embodiment of the application, as Figure 10 shown, the relay node is handed over from the source donor node to the target donor node, which can be understood as that the source donor node is the source donor node of the relay node handover, and the target donor node is the target donor node of the relay node handover.

[0188] Optionally, for the handover of the relay node, it can be understood that the relay node takes the relay node and the descendant nodes of the relay node as a group, and switches the group from the source donor node to the target donor node. In the embodiment of the application, the node whose parent node changes is referred to as the relay node that is handed over or switched.

[0189] Optionally, the relay node that is handed over can be referred to as the handover relay node or the migrated relay node.

[0190] Optionally, the migrated relay node can be the parent node of the terminal, that is, the migrated relay node is directly connected to the terminal, that is, the migrated relay node is the access relay node (in the embodiment of the application, the relay node accessed by the terminal is referred to as the access relay node), or the migrated relay node can be connected to the terminal through one or more other relay nodes, that is, the migrated relay node is the intermediate relay node (in the embodiment of the application, the relay node that provides backhaul service for the terminal is referred to as the intermediate relay node).

[0191] Optionally, the source donor node is the source donor node of the relay node handover, which can be understood as that the donor node before the handover of the relay node is the source donor node, or the relay node is connected to the source donor node before the handover. The connection mode of the relay node and the source donor node is not limited in the application, for example, the source donor node can be the parent node of the relay node, or the source donor node can be connected to the relay node through one or more other relay nodes.

[0192] Optionally, the target host node is a host node after the relay node switches, and it can be understood that the target host node is the target host node to which the relay node performs switching. However, the relay node may finally successfully switch or fail to switch, and the embodiments of the present application do not limit this. The present application does not limit the connection mode of the relay node and the target host node. For example, the target host node can be a parent node of the relay node, or the target host node can be connected to the relay node through one or more other relay nodes.

[0193] Optionally, the source parent node of the relay node switching can be referred to as a source parent node, and the target parent node of the relay node switching can be referred to as a target parent node. It can be understood that before the relay node switches, the relay node is connected to the source parent node, and the source parent node provides access services for the relay node. After the relay node switches, the relay node is connected to the target parent node, and the target parent node provides access services for the relay node.

[0194] Optionally, the source parent node can be a source host node, or the source parent node is connected to the source host node through m other relay nodes, and m is an integer greater than or equal to 1. The target parent node can be a target host node, or the target parent node is connected to the target host node through n other relay nodes, and n is an integer greater than or equal to 1. Optionally, the host node can include a CU and / or a DU.

[0195] Optionally, the source host node can include a source CU, and optionally, the source host node can further include a source DU. The target host node can include a target CU, and optionally, the target host node can further include a target DU. The source CU and the target CU are different, and the source DU and the target DU are different.

[0196] The switching of the relay node from the source host node to the target host node can be referred to as cross-host node switching or cross-CU switching.

[0197] The following further describes the cross-host node switching by taking the IAB scenario as an example, taking the relay node as an IAB node, and taking the source host node including a source IAB donor CU and the target host node including a target IAB donor CU as an example.

[0198] Figure 11 is a schematic diagram of Inter-donor CU switching provided by an embodiment of the present application. Taking the Inter-donor CU switching of the IAB node 3 in Figure 2 as an example, as shown in Figure 11As shown, the parent node of the IAB node 3 before the handover (i.e., the source parent node of the IAB node 3) is the IAB node 1, the source IAB donor DU is the IAB donor DU 1, and the source IAB donor CU is the IAB IAB donor CU 1; the parent node of the IAB node 3 after the handover (i.e., the target parent node of the IAB node 3) is the IAB node 4, the target IAB donor DU is the IAB donor DU 2, and the target IAB donor CU is the IAB IAB donor CU 2.

[0199] The handover of the IAB node 3 can be considered as the handover of the MT of the IAB node 3. Wherein, the source host node can include the IAB donor CU 1, or the source host node can include the IAB donor CU 1 and the IAB donor DU 1. The target host node can include the IAB donor CU 2, or the target host node can include the IAB donor CU 2 and the IAB donor DU 2.

[0200] It should be noted that, Figure 11 Only the case that the intermediate IAB node has a cross-host node handover is introduced, and the access IAB node (for example, the IAB node 2) can also have a cross-host node handover.

[0201] In the scenario of the relay node, in the cross-host node handover, the host node connected by the relay node performing the handover has changed, and the relay node needs to disconnect the connection with the source host node first (i.e., the relay node cannot receive the downlink data of the terminal from the source host node, nor can it send the uplink data of the terminal to the source host node), causing the relay node to stop serving the terminal, and the data transmission of the terminal is interrupted, and then the terminal detects that the link with the relay node has RLF, and triggers the RRC re-establishment process to restore the data transmission. In this process, the service transmission of the terminal is interrupted, which greatly reduces the user experience.

[0202] Therefore, the above-mentioned single-air-interface DAPS scheme can be applied to the cross-host node handover scenario, so as to ensure that the uplink and downlink data transmission of the relay node as the terminal is not interrupted. Specifically, the relay node has Figure 8As shown in the DAPS function in the middle, the relay node has two sets of protocol stacks, in one set of protocol stacks, the PHY layer, MAC layer and RLC layer of the relay node correspond to the source parent node of the relay node; in the other set of protocol stacks, the PHY layer, MAC layer and RLC layer of the relay node correspond to the target parent node of the relay node. The relay node contains a PDCP entity, which is associated with two RLC entities, one RLC entity corresponding to the source parent node and one RLC entity corresponding to the target parent node.

[0203] For example, the relay node can perform Figure 9 The actions performed by the terminal, the source host node can perform Figure 9 The actions performed by the source base station, the target host node can perform Figure 9 The actions performed by the target base station.

[0204] After the above-mentioned single-air-interface DAPS scheme is applied to the cross-host node switching scenario, it can be ensured that the data (which can be understood as data terminated at the relay node, such as OAM data) of the relay node is not interrupted during the switching process. In addition, the relay node can provide backhaul services for the terminal (i.e., as an access relay node or an intermediate relay node) during the switching process. Similar to the DAPS scheme, the relay node can have a protocol stack equivalent to the source parent node and a protocol stack equivalent to the target parent node, so that the relay node can transmit data (including uplink data and downlink data) between the terminal and the source host node during the switching process, and can also transmit data (including uplink data and downlink data) between the terminal and the target host node.

[0205] However, for the terminal, the terminal is always connected to the relay node, and the terminal does not undergo switching, so the terminal cannot know whether the data is from the source host node or the target host node, i.e., for downlink data, the terminal cannot know whether the downlink data received from the relay node is from the source host node or the target host node; for uplink data, the terminal cannot know whether the uplink data sent will be sent to the source host node or the target host node by the relay node. For simplicity of description, we will refer to data from or to the source host node as source host node data, and data from or to the target host node as target host node data.

[0206] Because the configuration information required for processing the data of the source host node and the data of the target host node is different, i.e., the data of the source host node needs to be processed through the configuration information of the source host node, and the data of the target host node needs to be processed through the configuration information of the target host node. Since the terminal cannot know whether the source host node configuration information or the target host node configuration information should be used to process the data packet, the terminal service is interrupted.

[0207] For example, for downlink data, the terminal cannot know whether the received data packet is from the source donor node or the target donor node, which causes the terminal to fail to use the correct configuration information to parse the received data packet. Once the terminal fails to parse, it will cause packet loss, resulting in service interruption. For uplink data, the terminal cannot know whether the uplink data packet is to be sent to the source donor node or the target donor node, which causes the terminal to fail to use the correct configuration information to process the uplink data. Once the donor node fails to parse, it will cause packet loss, resulting in service interruption of the terminal.

[0208] In addition, even if the cross-donor node switching scenario does not use the above DAPS scheme, that is, during the cross-donor node switching process, the relay node first disconnects the connection with the source donor node (that is, cannot transmit the uplink and / or downlink data of the terminal with the source donor node), but the relay node can still have previously received downlink data from the source donor node but not yet sent to the terminal. At this time, the relay node can continue to send the previously cached downlink data from the source donor node to the terminal during the switching process. When the relay node successfully switches to the target donor node, the relay node can receive downlink data from the target donor node and send the received downlink data from the target donor node to the terminal. Therefore, the cross-donor node switching of the relay node can cause the terminal to receive two kinds of downlink data, i.e., the downlink data of the source donor node and the downlink data of the target donor node. The terminal cannot know whether to use the configuration information of the source donor node or the configuration information of the target donor node to process the data, thereby causing service interruption of the terminal.

[0209] Based on this, the embodiments of the present application provide a scheme that can reduce the probability of service interruption of the terminal in the cross-donor node switching scenario and improve user experience. In the scheme, the access relay node of the terminal can configure two logical channels (LCHs) for one bearer (such as a DRB) of the terminal. One LCH is used to transmit data corresponding to the source donor node, and the other LCH is used to transmit data corresponding to the target donor node. The terminal can distinguish the data corresponding to the source donor node and the data corresponding to the target donor node through different LCHs, which can ensure that the terminal uses the correct configuration information to process the data, reduces the probability of service interruption, and improves the continuity of service transmission.

[0210] Specifically, for a bearer of the terminal, there is a GTP-U tunnel (hereinafter referred to as a GTP-U tunnel corresponding to the source host node) between the access relay node and the source host node, and there is another GTP-U tunnel (hereinafter referred to as a GTP-U tunnel corresponding to the target host node) between the access relay node and the target host node. For a bearer of the terminal, there are two LCHs on the terminal, one LCH of the terminal corresponds to the GTP-U tunnel corresponding to the source host node, and the other LCH of the terminal corresponds to the GTP-U tunnel corresponding to the target host node.

[0211] The user plane protocol stack of the dual LCH in the handover process across the host nodes in the embodiment of the application is introduced below.

[0212] Figure 12 A schematic diagram of the user plane protocol stack of the dual LCH provided in the embodiment of the application.

[0213] The terminal has a set of protocol stacks, including a PHY layer, a MAC layer, an RLC layer, and a PDCP layer. The RLC layer, the MAC layer, and the PHY layer of the terminal correspond to the RLC layer, the MAC layer, and the PHY layer of the parent node of the terminal. The PDCP layer of the terminal corresponds to the PDCP layer of the source host node (namely, the IAB donor CU 1 in the figure) and the PDCP layer of the target host node (namely, the IAB donor CU 2 in the figure). Figure 12 Figure 12

[0214] Optionally, the PDCP layer is composed of a PDCP entity, the RLC layer is composed of an RLC entity, the MAC layer is composed of a MAC entity, and the PHY layer is composed of a PHY entity. The MAC entity and the PHY entity of the terminal are configured in the granularity of the terminal, and the terminal has one MAC entity and one PHY entity. The PDCP entity of the terminal is configured in the granularity of a bearer. For a bearer of the terminal, there can be one corresponding PDCP entity.

[0215] Specifically, for a bearer, the terminal has only one PDCP entity, but the PDCP entity is configured with the PDCP configuration information corresponding to the source host node and the PDCP configuration information corresponding to the target host node. It can be understood that the PDCP entity can use or maintain the PDCP configuration information corresponding to the source host node and the PDCP configuration information corresponding to the target host node at the same time. The PDCP configuration information corresponding to the source host node can be used to process data (including uplink data and / or downlink data) corresponding to the source host node, and the PDCP configuration information corresponding to the target host node can be used to process data (including uplink data and / or downlink data) corresponding to the target host node.

[0216] ​​It can be understood that the terminal can have two sets of PDCP configuration information, one set of PDCP configuration information corresponding to the PDCP configuration information of the source donor node, and the other set of PDCP configuration information corresponding to the PDCP configuration information of the target donor node.

[0217] Corresponding or corresponding to the configuration information can be understood as the configuration information can be used in pairs or pairs.

[0218] Optionally, the corresponding configuration information can include the case that the configuration information is the same, for example, one set of PDCP configuration information of the terminal is the same as the PDCP configuration information corresponding to the source donor node, and / or the other set of PDCP configuration information of the terminal is the same as the PDCP configuration information corresponding to the target donor node. Optionally, the corresponding configuration information can include the case that the configuration information is not the same, for example, one set of PDCP configuration information of the terminal is not the same as the PDCP configuration information corresponding to the source donor node, and / or the other set of PDCP configuration information of the terminal is not the same as the PDCP configuration information corresponding to the target donor node.

[0219] Optionally, the PDCP configuration information corresponding to the PDCP configuration information corresponding to the source donor node on the terminal can be allocated by the source donor node, for example, the source donor node sends the PDCP configuration information corresponding to the PDCP configuration information corresponding to the source donor node to the terminal through the relay node. The PDCP configuration information corresponding to the PDCP configuration information corresponding to the source donor node on the terminal can be referred to as the PDCP configuration information allocated by the source donor node or the PDCP configuration information corresponding to the source donor node. Similarly, the PDCP configuration information corresponding to the PDCP configuration information corresponding to the target donor node on the terminal can be allocated by the target donor node, for example, the target donor node sends the PDCP configuration information corresponding to the PDCP configuration information corresponding to the target donor node to the terminal through the relay node. The PDCP configuration information corresponding to the PDCP configuration information corresponding to the target donor node on the terminal can be referred to as the PDCP configuration information allocated by the target donor node or the PDCP configuration information corresponding to the target donor node.

[0220] Specifically, for the PDCP entity, one or more functions of head compression, head decompression, security processing, adding header and removing header are independent of each other for the source donor node and the target donor node. In the PDCP entity, the reordering function is common to the source donor node and the target donor node, and can be referred to the description of the PDCP entity in the Figure 8 source donor node and the target donor node.

[0221] As shown in FIG. 1, the terminal has one PDCP entity, two RLC entities and one MAC entity. The PDCP entity corresponds to the two RLC entities. The MAC entity has one logical channel (LCH) with one of the RLC entities, and another LCH with the other RLC entity. Figure 7 Unlike the terminal, one PDCP entity of the access relay node can correspond to two RLC entities, one RLC entity corresponding to the source donor node and one RLC entity corresponding to the target donor node. The access relay node has one MAC entity, wherein the MAC entity and the RLC entity corresponding to the source donor node have one LCH, and the MAC entity and the RLC entity corresponding to the target donor node have another LCH. As shown in FIG. 2, one PDCP entity of the access relay node corresponds to two RLC entities, and at the same time, the access relay node only has one MAC entity, wherein the MAC entity and one of the RLC entities, i.e., RLC 1, have LCH 1, and the MAC entity and the other RLC entity, i.e., RLC 2, have LCH 2. One RLC entity of the access relay node is used to process data corresponding to the source donor node, and the LCH corresponding to the RLC entity is used to transmit data corresponding to the source donor node. The other RLC entity of the access relay node is used to process data corresponding to the target donor node, and the LCH corresponding to the other RLC entity is used to transmit data corresponding to the target donor node. As shown in FIG. 2, RLC 1 of the access relay node is used to process data corresponding to the source donor node, LCH 1 is used to transmit data corresponding to the source donor node, RLC 2 of the access relay node is used to process data corresponding to the target donor node, and LCH 2 is used to transmit data corresponding to the target donor node. Figure 12 Figure 12 The protocol stack on the DU of the access relay node is the same as that of the terminal, and here the same can be understood as peer-to-peer. That is, the DU of the access relay node has two RLC entities, one MAC entity and one PHY entity, which are peer-to-peer with the two RLC entities, the MAC entity and the PHY entity of the terminal. Each of the two RLC entities of the access relay node has one LCH with the MAC entity, and the two LCHs of the DU of the access relay node are peer-to-peer with the two LCHs of the terminal. As shown in FIG. 3, the DU of the access relay node has two RLC entities, one MAC entity and one PHY entity, which are peer-to-peer with the two RLC entities, the MAC entity and the PHY entity of the terminal. Each of the two RLC entities of the access relay node has one LCH with the MAC entity, and the two LCHs of the DU of the access relay node are peer-to-peer with the two LCHs of the terminal.

[0222] The protocol stack on the DU of the access relay node is the same as that of the terminal, and here the same can be understood as peer-to-peer. That is, the DU of the access relay node has two RLC entities, one MAC entity and one PHY entity, which are peer-to-peer with the two RLC entities, the MAC entity and the PHY entity of the terminal. Each of the two RLC entities of the access relay node has one LCH with the MAC entity, and the two LCHs of the DU of the access relay node are peer-to-peer with the two LCHs of the terminal. As shown in FIG. 3, the DU of the access relay node has two RLC entities, one MAC entity and one PHY entity, which are peer-to-peer with the two RLC entities, the MAC entity and the PHY entity of the terminal. Each of the two RLC entities of the access relay node has one LCH with the MAC entity, and the two LCHs of the DU of the access relay node are peer-to-peer with the two LCHs of the terminal. Figure 12 ​As shown, for one bearer of the terminal, the IAB node 2 has two RLC entities, i.e., RLC 1 and RLC 2, the RLC 1 of the IAB node 2 and the RLC 1 of the terminal are peer-to-peer, and the RLC 2 of the IAB node 2 and the RLC 2 of the terminal are peer-to-peer. There is one LCH between the RLC 1 of the IAB node 2 and the MAC entity, i.e., LCH 1, and for example, in downlink transmission, the data sent by the IAB node 2 on the LCH 1 of the IAB node 2 is received by the terminal 1 on the LCH 1 of the terminal 1. There is one LCH between the RLC 2 of the IAB node 2 and the MAC entity, i.e., LCH 2, and for example, in downlink transmission, the data sent by the IAB node 2 on the LCH 2 of the IAB node 2 is received by the terminal 1 on the LCH 2 of the terminal 1.

[0223] Similar to the terminal, one RLC entity on the DU of the access relay node is used to process data corresponding to the source donor node, and the LCH corresponding to the RLC entity is used to transmit data corresponding to the source donor node. Another RLC entity on the DU of the access relay node is used to process data corresponding to the target donor node, and the LCH corresponding to the another RLC entity is used to transmit data corresponding to the target donor node. For details, reference can be made to the content of the RLC entity and the LCH of the terminal, which will not be described here again. It needs to be explained that the LCHs on the terminal and the access relay node can be matched, paired or correspondingly used, and the LCHs on the terminal and the access relay node (or the configuration information of the LCHs on the terminal and the access relay node) can be the same or different, and the embodiments of the present application do not limit this.

[0224] The DU of the access relay node can establish corresponding GTP-U tunnels with the source donor node and the target donor node respectively in the granularity of the bearer of the terminal, for example, for one bearer of the terminal, one corresponding GTP tunnel is established between the IAB node 2 and the IAB donor CU 1, and one corresponding GTP tunnel is also established between the IAB node 2 and the IAB donor CU 2. As shown, Figure 12 As shown, for one bearer of the terminal, there is one GTP-U tunnel between the IAB donor CU 1 and the DU of the IAB node 2, i.e., GTP-U 1, and the GTP-U 1 is used to transmit data corresponding to the source donor node, and there is another GTP-U tunnel between the IAB donor CU 2 and the DU of the IAB node 2, i.e., GTP-U 2, and the GTP-U 2 is used to transmit data corresponding to the target donor node.

[0225] One LCH on the access relay node corresponds to one GTP-U tunnel. In other words, LCH and GTP-U tunnel are one-to-one corresponding to each other. In the uplink direction, data received through one LCH is mapped to the GTP-U tunnel corresponding to the LCH. In the downlink direction, data received through one GTP-U tunnel is mapped to the LCH corresponding to the GTP-U tunnel. Figure 12 For example, on IAB node 2, there is a one-to-one correspondence between LCH 1 and GTP-U 1, and a one-to-one correspondence between LCH 2 and GTP-U 2. In the uplink direction, data received through LCH 1 is mapped to GTP-U 1 and sent to IAB donor CU 1, and data received through LCH 2 is mapped to GTP-U 2 and sent to IAB donor CU 2. In the downlink direction, data received from IAB donor CU 1 through GTP-U 1 is mapped to LCH 1, and data received from IAB donor CU 2 through GTP-U 2 is mapped to LCH 2.

[0226] For example, Figure 12 Taking the transmission of uplink data corresponding to the source host node (i.e., IAB donor CU 1) in the example, on terminal 1, the PDCP entity can process the uplink data according to the PDCP configuration information corresponding to the IAB donor CU 1, and then the PDCP entity sends the uplink data processed according to the PDCP configuration information corresponding to the source host node to the RLC 1 of terminal 1. The RLC 1 of terminal 1 sends the uplink data to the MAC entity of terminal 1 through LCH 1. The MAC entity of terminal 1 can encapsulate the data received from the LCH 1 of terminal 1, add the identifier of the LCH 1 of terminal 1 to the MAC header, and send it to IAB node 2 after being processed by the PHY entity of terminal 1. Accordingly, after IAB node 2 receives data from terminal 1, the MAC layer of IAB node 2 can obtain the identifier of the terminal's LCH 1 by parsing the MAC header. IAB node 2 sends the data to RLC 1 through the LCH equivalent to the terminal's LCH 1, that is, LCH 1 of IAB node 2. After extracting the terminal's uplink data from RLC 1, IAB node 2 maps it to the corresponding GTP-U tunnel 1. Based on the current routing configuration information, IAB node 2 further sends the data mapped to GTP-U tunnel 1 to IAB donor CU 1 via the backhaul link. After extracting the terminal's uplink data from GTP-U tunnel 1, IAB donor CU 1 processes the uplink data based on the PDCP configuration information of IAB donor CU 1.

[0227] The transmission of uplink data corresponding to the target donor node (ie, IAB donor CU 2) is similar to the transmission of uplink data corresponding to the source donor node. For details, please refer to the content of the transmission of uplink data corresponding to the source donor node.

[0228] For example, Figure 12 Taking the transmission of downlink data corresponding to the source host node (i.e., IAB donor CU 1) in as an example, IAB donor CU 1 processes the downlink data according to the PDCP configuration information of IAB donor CU 1, and then IAB donor CU 1 sends the downlink data to the DU of IAB node 2 through GTP-U tunnel 1. After receiving the downlink data from GTP-U tunnel 1, the DU of IAB node 2 maps the downlink data to the RLC 1 corresponding to GTP-U tunnel 1. After processing, RLC 1 sends the downlink data to the MAC entity through LCH 1. The MAC entity can add the identifier of the LCH on terminal 1 that is equivalent to the LCH 1 of the DU of IAB node 2 (i.e., the identifier of LCH 1 of terminal 1) in the MAC header, and send the data to terminal 1 after being processed by the PHY layer of the DU of IAB node 2. Correspondingly, after terminal 1 receives data from the DU of IAB node 2, the MAC entity of terminal 1 can obtain the identifier of LCH 1 of terminal 1 by parsing the MAC header, and then terminal 1 sends the data to RLC 1 of terminal 1 through LCH 1 of terminal 1. After processing by RLC 1 of terminal 1, it is sent to the corresponding PDCP entity. The PDCP entity processes the downlink data according to the configuration information corresponding to the source host node.

[0229] The transmission of downlink data corresponding to the target donor node (ie, IAB donor CU 2) is similar to the transmission of downlink data corresponding to the source donor node. For details, please refer to the content of the transmission of uplink data corresponding to the source donor node.

[0230] The MT accessing the relay node has a BAP entity, an RLC entity, a MAC entity, and a PHY entity.

[0231] The DU of the migrating relay node has a protocol stack equivalent to that of the MT of the child node. Figure 12 As shown, the DU of IAB node 3 has a BAP entity, an RLC entity, a MAC entity, and a PHY entity that are equivalent to the MT of IAB node 2.

[0232] Optionally, the source donor node can configure rules of routing and / or bearer mapping on the path between the access relay node and the source donor node, and the target donor node can configure rules of routing and / or bearer mapping on the path between the access relay node and the target donor node, which are used for transmission of signaling / data.

[0233] In order to ensure that both the data corresponding to the source donor node and the data corresponding to the target donor node can be transmitted on the path between the access relay node and the migration relay node, one or more nodes (including the access relay node, the migration relay node, and one or more other relay nodes between the access relay node and the migration relay node) on the path between the access relay node and the migration relay node need to support two sets of BAP configurations on the MT and / or DU of the node, one set of BAP configurations being provided by the source donor node and including the configuration of routing and / or bearer mapping, and the other set of BAP configurations being provided by the target donor node and including the configuration of routing and / or bearer mapping.

[0234] As an example, the access relay node is not the migration relay node, and since the parent node of the migration relay node changes, the migration relay node is configured with two sets of BAP configurations, one set of BAP configurations being the routing and / or bearer mapping configuration provided by the source donor node, and the other set of BAP configurations being the routing and / or bearer mapping configuration provided by the target donor node. Since the parent node of the access relay node does not change, the bearer mapping on the link between the access relay node and the parent node can remain unchanged, but the routing configuration on the link between the access relay node and the parent node can change (for example, the BAP address of the access relay node in the routing configuration changes), and therefore, the access relay node is configured with two sets of BAP configurations, one set of BAP configurations being the routing configuration provided by the source donor node, and the other set of BAP configurations being the routing configuration provided by the target donor node.

[0235] Optionally, the MT (or DU) of the one or more nodes can only exist one BAP entity, which supports the above-mentioned two sets of BAP configurations. Alternatively, the MT (or DU) can exist two BAP entities, one BAP entity supporting the BAP configuration provided by the source donor node, and the other BAP entity supporting the BAP configuration provided by the target donor node.

[0236] Optionally, the target donor node can send indication information to the one or more nodes through the source donor node respectively, each indication information indicating that the corresponding node starts two sets of BAP configuration information, wherein starting can be understood as activating or enabling, and starting two sets of BAP configuration information can be understood as starting the dual configuration of the BAP layer. Alternatively, the source donor node can send the indication information to the one or more nodes respectively.

[0237] For downlink transmission, after receiving downlink data from the source host node, one of the one or more nodes sends the downlink data to the next-hop node of the node according to the BAP configuration of the source host node, and / or, after receiving downlink data from the target host node, one of the one or more nodes sends the downlink data to the next-hop node of the node according to the BAP configuration of the target host node. Data transmission in the uplink direction is similar and will not be described here.

[0238] The MT of the migration relay node has a protocol stack similar to DAPS. The protocol stack similar to DAPS can be understood as the MT of the migration relay node has a set of protocol stacks equivalent to the source parent node and a set of protocol stacks equivalent to the target parent node. The source downlink data received by the migration relay node from the source parent node can be processed by the protocol stack corresponding to the source parent node; the target downlink data received by the migration relay node from the target parent node can be processed by the protocol stack corresponding to the target parent node. For example, Figure 12 As shown, the MT of IAB node 3 has BAP entity, RLC entity, MAC entity and PHY entity equivalent to IAB node 1 and IAB node 4. It should be noted that the migration relay node may have only one BAP entity or two BAP entities, which can be referred to the above description.

[0239] Optionally, one or more other relay nodes may exist between the access relay node and the migration relay node. In this case, on the link from the access relay node to the migration relay node, each node's DU has a BAP entity, RLC entity, MAC entity, and PHY entity that are equivalent to the child node's MT. This embodiment of the present application does not impose any restrictions on this.

[0240] Optionally, the access relay node and the migration relay node can be the same node, that is, the access relay node is switched, and the access relay node has Figure 12 The protocol stack of the DU of IAB node 2 and the protocol stack of the MT of IAB node 3.

[0241] The two adjacent nodes from the source parent node to the source host node, or from the target parent node to the target host node have equivalent protocol stacks, such as Figure 12 For details, please refer to Figure 7 The content in will not be repeated here.

[0242] In the above embodiments, for downlink, the access relay node distinguishes the data from the source donor node and / or the data from the target donor node according to different GTP-U tunnels, so as to map the data to different LCHs for sending to the terminal, thereby enabling the terminal to distinguish the data from the source donor node and / or the data from the target donor node. For uplink, the access relay node distinguishes the data to the source donor node and / or the data to the target donor node according to different LCHs, so as to map the data to different GTP-U tunnels for sending to the source donor node and / or the target donor node.

[0243] As another possible implementation, for downlink, the downlink data packet can carry routing ID information, and the access relay node can distinguish the data from the source donor node and / or the data from the target donor node according to the routing ID information.

[0244] Specifically, the routing ID information includes a BAP address of the access relay node and a path ID, and the access relay node can distinguish whether the downlink data packet is from the source donor node or the target donor node according to the BAP address carried in the routing ID information, so as to further map the downlink data packet to different LCHs for sending to the terminal. The source donor node and the target donor node are respectively assigned two different BAP addresses by the access relay node, the routing ID information in the downlink data packet sent by the source donor node carries the BAP address assigned to the access relay node by the source donor node, and the routing ID information in the downlink data packet sent by the target donor node carries the BAP address assigned to the access relay node by the target donor node.

[0245] In order to ensure that the BAP addresses assigned to the access relay node by the source donor node and the target donor node are different, in the handover preparation process, the source donor node can send the BAP address assigned to the access relay node by the source donor node to the target donor node, so that the target donor node generates a BAP address different from the BAP address assigned to the access relay node by the source donor node. As an example, the source donor node can send the BAP address assigned to the access relay node by the source donor node to the target donor node in a handover request message. The target donor node can carry the BAP address assigned to the access relay node by the target donor node in a handover command message (which can be referred to as an RRC reconfiguration message) and send it to the access relay node through the source donor node.

[0246] The following will be described in combination with Figures 13 to 16 The scheme provided in the present application is introduced. Figures 13 to 16 The content of the protocol stack Figure 12 can be cross-referenced and referenced.

[0247] Figure 13 , Figure 14 、 Figure 15 and Figure 16 In the method, the first relay node is an access relay node of the terminal (or can be understood as the first relay node being a parent node of the terminal), the first relay node can be referred to as an access relay node, the first relay node can perform cross-donor node switching, that is, the first relay node switches from a source donor node to a target donor node; or a relay node (which can be referred to as a second relay node) on a link between the first relay node and the source donor node performs cross-donor node switching, that is, the first relay node is connected with the second relay node, and the second relay node switches from the source donor node to the target donor node. The content of the cross-donor node switching can refer to the content in Figure 10 and Figure 11 For example, the cross-donor node switching in Figure 11 , the first relay node can be the IAB node 2 in Figure 11 , and the second relay node can be the IAB node 3 in Figure 11 , and the IAB node 3 switches from the IAB donor CU 1 to the IAB donor CU 2.

[0248] Figure 13 is a flowchart of a LCH configuration method provided by an embodiment of the present application, as shown in Figure 13 , the method includes the following steps. Figure 13

[0249] S100: The source donor node or the target donor node sends first indication information to the first relay node.

[0250] S100 is optional.

[0251] The first relay node can generate configuration information of a second LCH corresponding to the first bearer according to the first indication information. The second LCH is used to transmit PDCP data corresponding to the target donor node.

[0252] Optionally, the first indication information can be carried in a first message.

[0253] Optionally, before S100, the first bearer of the terminal corresponds to a first LCH, and the first LCH is used to transmit PDCP data corresponding to the source donor node.

[0254] Optionally, the first bearer in the present application can be a first data radio bearer (DRB).

[0255] ​Exemplarily, before the first relay node or the second relay node performs the cross-donor node switching, the first relay node has configured the first LCH for the terminal, and the first LCH is used to transmit PDCP data corresponding to the source donor node.

[0256] Specifically, before the first relay node or the second relay node performs the cross-donor node switching, the first relay node sends, to the terminal through the source donor node, configuration information of an air interface of a first bearer, where the air interface configuration information of the first bearer includes configuration information of an underlying layer (which can include one or more of an RLC layer, a MAC layer, a PHY layer, and the first LCH) generated by the first relay node for the terminal.

[0257] Optionally, the first LCH can be Figure 12 LCH 1 of the terminal in the first relay node, and the second LCH can be Figure 12 LCH 2 of the terminal in the first relay node, and details can be referred to the content in the first relay node. Figure 12

[0258] The content indicated by the first indication information can be various, and the following will be described in combination with several examples.

[0259] As an example, the first indication information can be at a bearer granularity. That is, the first indication information is in one-to-one correspondence with one bearer of the terminal. The first indication information can indicate that the first relay node generates configuration information of a second LCH corresponding to one bearer, or can indicate that data transmission of one bearer is not interrupted in the cross-donor node switching, or can indicate that one bearer is configured for DAPS switching, or the first indication information can indicate other content, which is not limited by the embodiments of the present application.

[0260] In this example, optionally, the first indication information can include an identifier of one bearer, and the one bearer includes the first bearer.

[0261] In this example, the first relay node receives a plurality of first indication information, each of which is in one-to-one correspondence with one bearer, and the first relay node can generate configuration information of a second LCH for each of one or more bearers of the terminal. The present application takes the first bearer as an example for introduction, and those skilled in the art can know that the content of the embodiments of the present application is also applicable to other one or more bearers.

[0262] As another example, the first indication information can be at a terminal granularity. That is, the first indication information does not indicate a specific bearer. The first indication information can indicate that the first relay node generates configuration information of a second LCH for each bearer of the terminal, or can indicate that data transmission of the terminal is not interrupted in the cross-donor node switching, or can indicate that the terminal is configured for DAPS switching, or the first indication information can indicate other content, which is not limited by the embodiments of the present application.​

[0263] In this example, the first indication information can not include the identity of the bearer.

[0264] In this example, the first relay node can generate configuration information of the second LCH for each bearer of the terminal (including the first bearer). The present application takes the first bearer as an example for description, and those skilled in the art can know that the content of the embodiments of the present application is also applicable to one or more other bearers.

[0265] The first indication information can be carried in the first message. The source host node or the target host node can send the first message at different times. The following describes several examples.

[0266] It should be noted that if the first relay node performs cross-host node switching, the first relay node can perceive the cross-host node switching. For example, the first relay node can receive a switching command from the target host node through the source host node. The first relay node can initiate a random access request to the target host node. After the first relay node accesses the target host node, the first relay node can establish a connection with the target host node. If the second relay node performs cross-host node switching, the second relay node can perceive the cross-host node switching. Those skilled in the art can understand that the actions performed by the first relay node can be replaced by the second relay node. However, the second relay node performs cross-host node switching, and the first relay node can not perceive the switching. However, after the second relay node accesses the target host node, the second relay node establishes a connection with the target host node. The descendant nodes of the second relay node will successively establish a connection with the target host node to provide data transmission services for the terminal. Therefore, the first relay node can perceive the establishment of the connection with the target host node. Therefore, whether the first relay node or the second relay node performs cross-host node switching, the first relay node will establish a connection with the target host node. Here, the establishment of the connection can include one or more of the establishment of the F1 interface and the GTP-U tunnel.

[0267] As an example, the first relay node can receive the first message from the target host node after establishing a connection with the target host node.

[0268] Optionally, in this example, the first message can be a UE context setup request message.

[0269] As another example, the first relay node can receive the first message from the source host node before establishing a connection with the target host node.

[0270] Specifically, when the source donor node determines that the first relay node or the second relay node has a cross-donor node handover, the source donor node can send a handover request message to the target donor node. The first relay node receives the first message from the source donor node before the source donor node determines the handover and sends the handover request message to the target donor node, or after the source donor node sends the handover request message to the target donor node.

[0271] Optionally, in another example, the first message can be in a UE context modification request message.

[0272] S101: The first relay node generates configuration information of the second LCH.

[0273] Optionally, S100 can exist, and the first relay node generates the second LCH configuration information according to the first indication information.

[0274] Optionally, S100 can not exist. In one example, after the first relay node receives the connection establishment request from the target donor node, the first relay node generates the configuration information of the second LCH. Optionally, the connection establishment request can be a GTP tunnel establishment request and / or an F1 interface establishment request, or the connection establishment request can have other names, which are not limited by the embodiments of the present application.

[0275] In the above example, after the first relay node receives the connection establishment request from the target donor node, the first relay node can generate the configuration information of the second LCH for each bearer of the terminal (including the first bearer). Here, the first bearer is taken as an example for introduction, and those skilled in the art can know that the content of the embodiments of the present application is also applicable to one or more other bearers.

[0276] S102: The first relay node sends the configuration information of the second LCH to the terminal.

[0277] It can be understood that through S101 and S102, the first relay node configures the second LCH for the first DRB of the terminal, so that the first bearer corresponds to the first LCH and the second LCH.

[0278] Optionally, the first bearer corresponds to the first LCH and the second LCH, which can be understood as the first bearer is configured with the first LCH and the second LCH, or the first bearer is associated with the first LCH and the second LCH, or the first bearer can use the first LCH and the second LCH, or the first bearer has the ability to use the first LCH and the second LCH, but whether the first bearer actually uses the first LCH and the second LCH depends on whether there is PDCP data corresponding to the source host node and PDCP data corresponding to the target host node. The embodiment of the present application does not limit this. For example, within a certain period of time, there is only PDCP data corresponding to the source host node and no PDCP data corresponding to the target host node, so only the first LCH is used and the second LCH is not used. Alternatively, the first bearer corresponds to the first LCH and the second LCH, which can be understood as, when the first bearer uses the second LCH, the first LCH is maintained, not released, or is still in an activated state, etc.

[0279] Optionally, the first bearer corresponds to the first LCH and the second LCH, which can be understood as the first bearer corresponding to the first LCH and the second LCH at the same time, that is, at one or more time points, or within a certain time range, the first bearer corresponds to both the first LCH and the second LCH.

[0280] Optionally, the configuration information of the second LCH includes one or more of the identifier of the second LCH, the priority of the second LCH and the bearer identifier of the first DRB.

[0281] The first LCH is used to transmit PDCP data corresponding to the source host node, and the second LCH is used to transmit PDCP data corresponding to the target host node.

[0282] Optionally, the first LCH corresponds to the GTP-U tunnel between the first relay node and the source host node, and the second LCH corresponds to the GTP-U tunnel between the first relay node and the target host node. For details, please refer to Figure 12 The content will not be repeated here.

[0283] Optionally, the first LCH corresponds to the BAP address assigned by the source host node to the first relay node, and the second LCH corresponds to the BAP address assigned by the target host node to the first relay node. Figure 12 The content will not be repeated here.

[0284] As a possible implementation manner, S102 may include: the first relay node sends configuration information of the second LCH to the terminal through the target donor node.

[0285] Specifically, the first relay node can send the configuration information of the second LCH to the target donor node, and the target donor node generates a second message, which includes a third message including the configuration information of the second LCH. The target donor node sends the second message to the source donor node, and then the source donor node sends the third message to the terminal through the first relay node. Exemplarily, the third message can be an RRC reconfiguration message, which can be referred to as a handover command, and the second message can be a handover request response message.

[0286] By forwarding the third message to the target donor node by the source donor node, the situation that the target donor node cannot send a message to the terminal by itself before the target donor node and the terminal perform security negotiation based on the PDCP configuration information corresponding to the target donor node can be avoided.

[0287] Optionally, in addition to the configuration information of the second LCH, the third message can further include one or more of the following: air interface configuration information of the first bearer, PDCP configuration information corresponding to the source donor node, and PDCP configuration information corresponding to the target donor node, and a BAP address allocated by the target donor node for the first relay node. The air interface configuration information of the first bearer and the PDCP configuration information corresponding to the source donor node can be sent by the first relay node or the source donor node to the target donor node, and the PDCP configuration information corresponding to the target donor node can be generated by the target donor node. The following describes.

[0288] Optionally, the third message can include the air interface configuration information of the first bearer. Optionally, the air interface configuration information of the first bearer can include the configuration information of the first LCH, which can be referred to the description above. By including the configuration information of the second LCH and the air interface configuration information of the first bearer in the third message, for the air interface configuration, the terminal can replace the existing air interface configuration between the terminal and the first relay node with the received configuration information of the second LCH and the air interface configuration information of the first bearer in a full configuration manner, so that the terminal transmits data with the first relay node according to the updated air interface configuration. Since the first bearer is configured with two LCHs, one for transmitting data corresponding to the source donor node and the other for transmitting data corresponding to the target donor node, the uninterrupted transmission of services during the switching process of the first relay node or the second relay node is ensured.

[0289] Optionally, the third message can not include the air interface configuration information of the first bearer, but include the configuration of the second LCH. At this time, after receiving the third message, the terminal can increase the second LCH based on the existing air interface configuration of the first bearer in an incremental configuration manner, which can save communication resources.

[0290] Optionally, the third message can include the PDCP configuration information corresponding to the target host node, and does not include the PDCP configuration information corresponding to the source host node. After receiving the third message, the terminal adds the PDCP configuration information corresponding to the target host node to the PDCP entity of the first bearer. It can be understood that before receiving the third message, the PDCP entity of the first DRB of the terminal includes the PDCP configuration information corresponding to the source host node. After receiving the third message, for the PDCP configuration of the first bearer, the terminal can adopt an incremental configuration manner, and add the PDCP configuration information corresponding to the target host node to the original PDCP entity of the first bearer. In addition, since the third message includes the configuration information of the second LCH and the PDCP configuration information corresponding to the target host node, it can be implicitly indicated that the configuration information of the second LCH and the PDCP configuration information corresponding to the target host node are corresponding, that is, in the downlink direction, the data received by the terminal through the second LCH is processed through the PDCP configuration information corresponding to the target host node, and in the uplink direction, the uplink data processed by the terminal through the PDCP configuration information corresponding to the target host node is transmitted through the second LCH.

[0291] Optionally, the third message can include the PDCP configuration information corresponding to the target host node and the PDCP configuration information corresponding to the source host node. Thus, for the PDCP configuration of the first bearer, the terminal can replace the PDCP configuration information corresponding to the source host node with the PDCP configuration information corresponding to the source host node and the PDCP configuration information corresponding to the target host node through full configuration, so that the terminal transmits data with the first relay node according to the updated air interface configuration. Since the first bearer is configured with two LCHs, one is used to transmit data corresponding to the source host node, which is processed through the PDCP configuration information corresponding to the source host node, and the other is used to transmit data corresponding to the target host node, which is processed through the PDCP configuration information corresponding to the target host node, so as to ensure uninterrupted service transmission of the terminal during the switching process of the first relay node or the second relay node.

[0292] Optionally, the first relay node can send the configuration information of the second LCH to the target host node at multiple time points, for example, after the first relay node establishes a connection with the target host node or before the first relay node establishes a connection with the target host node. The first relay node sends the configuration information of the second LCH to the target host node. The following will be described in combination with several embodiments.

[0293] As an embodiment, the first relay node sends the configuration information of the second LCH to the target host node after establishing a connection with the target host node.

[0294] Exemplarily, the first relay node sends a fourth message to the target donor node, the fourth message comprising the configuration information of the second LCH, and then the target donor node sends a second message to the source donor node, and the source donor node sends a third message to the terminal, wherein the content of the second message and the third message can refer to the description above.

[0295] It can be understood that when the S100 exists, after the first relay node establishes the connection with the target donor node, the first relay node can first receive the first message carrying the first indication information from the target donor node, and then the first relay node sends a fourth message to the target donor node.

[0296] Optionally, the first message can be a UE context setup request message, and the fourth message can be a UE context setup response message.

[0297] Optionally, the S100 can not exist, and after the first relay node receives the first message from the target donor node, the first relay node generates the configuration information of the second LCH, and then the first relay node sends a fourth message to the target donor node. For details, please refer to the content above.

[0298] Optionally, the fourth message can further comprise the configuration information of the air interface of the first bearer, so that the third message forwarded by the target donor node to the terminal through the source donor node can comprise the configuration information of the air interface of the first bearer.

[0299] Optionally, the fourth message can not comprise the configuration information of the air interface of the first bearer, and after the source donor node decides to switch the migrating relay node (i.e. the first relay node or the second relay node) from the source donor node to the target donor node, the source donor node can send the context of the descendant node of the migrating relay node to the target donor node, the descendant node comprising the terminal, and the context of the descendant node of the migrating relay node comprising the context of the terminal, the context of the terminal comprising the PDCP configuration information corresponding to the source donor node and the configuration information of the air interface of the first DRB. Thus, the target donor node can obtain the PDCP configuration information corresponding to the source donor node and the configuration information of the air interface of the first DRB.

[0300] As another implementation, before the first relay node establishes the connection with the target donor node, the first relay node sends the configuration information of the second LCH to the source donor node, and then the source donor node sends the configuration information of the second LCH to the target donor node.

[0301] It can be understood that since the first relay node has not established the connection with the target donor node, the first relay node cannot directly send information to the target donor node, and can send information to the target donor node through the source donor node.

[0302] For example, the first relay node sends a fifth message to the source host node, and the source host node sends a sixth message to the target host node. The fifth message and the sixth message include configuration information of the second LCH. Then the target host node sends a second message to the source host node, and the source host node sends a third message to the terminal. The contents of the second message and the third message can refer to the above content.

[0303] It can be understood that when S100 exists, before the first relay node establishes a connection with the target host node, the first relay node can first receive a first message carrying first indication information from the source host node, and then the first relay node sends a fifth message to the source host node, and the source host node sends a sixth message to the target host node.

[0304] Specifically, when the source host node determines that the first relay node or the second relay node performs switching, the source host node sends a first message to the first relay node, and then the first relay node sends a fifth message to the source host node so that the source host node sends a sixth message to the target host node.

[0305] Optionally, the first message may be a UE context modification request message, the fifth message may be a UE context modification response message, and the sixth message may be a handover request message.

[0306] Optionally, the fifth message may include configuration information of the air interface of the first bearer. Alternatively, the fifth message may not include configuration information of the air interface of the first bearer, and the source host node has configuration information of the air interface of the first bearer. For example, before the terminal establishes a connection with the source host node, the source host node receives configuration information of the air interface of the first bearer from the first relay node and saves the configuration information of the air interface of the first bearer.

[0307] Optionally, the sixth message may include configuration information of the air interface of the first bearer and / or PDCP configuration information corresponding to the source host node. Optionally, the sixth message may be sent by the source host node to the target host node after the source host node determines to switch the migration relay node (i.e., the first relay node or the second relay node) from the source host node to the target host node.

[0308] S103: The terminal receives the second indication information.

[0309] The terminal may configure the second LCH for the first bearer according to the second indication information.

[0310] The second indication information may indicate various contents, which are described below with reference to several examples.

[0311] As an example, the second indication information may be of bearer granularity. That is, the second indication information corresponds one-to-one to a bearer. The second indication information may indicate that the terminal configures the first LCH and the second LCH for a bearer, or the second indication information may indicate that the terminal configures the second LCH for a bearer, or the second indication information may indicate that a bearer is associated with two LCHs, namely the first LCH and the second LCH, or the second indication information may indicate that the first LCH and the second LCH of a bearer are both used for data transmission of the bearer, or the second indication information may indicate that the terminal should not replace the first LCH of the bearer with the second LCH of a bearer, or the second indication information may indicate that the terminal starts or activates the PDCP dual configuration function for a bearer, wherein the PDCP dual configuration may include the PDCP configuration information corresponding to the source host node and the PDCP configuration information corresponding to the target host node, or the second indication information may indicate that the data transmission of a bearer is not interrupted during switching across host nodes, or may indicate that a bearer is configured for DAPS switching, or the first indication information may indicate other content, and the embodiments of the present application are not limited to this.

[0312] In this example, optionally, the second indication information may include an identifier of a bearer, where the bearer includes the first bearer.

[0313] In this example, the first relay node receives multiple second indication messages, each of which corresponds to a bearer. The first relay node can configure a second LCH corresponding to each of the one or more bearers of the terminal. This application uses the first bearer as an example. Those skilled in the art will appreciate that the contents of the embodiments of this application are also applicable to one or more other bearers.

[0314] As another example, the second indication information may be at the terminal granularity. That is, the second indication information does not indicate a specific bearer. The second indication information may instruct the first relay node to configure the first LCH and the second LCH for each bearer of the terminal, or instruct the terminal to configure the second LCH for each bearer, or instruct each bearer to associate two LCHs, or instruct not to replace the first LCH of the bearer with the second LCH of each bearer, and so on. Other contents that the second indication information may indicate may refer to the contents that the second indication information may be at the terminal granularity, the difference being that the object indicated by the second indication information is the terminal or each bearer of the terminal. Alternatively, the second indication information may indicate that the data transmission of the terminal is not interrupted during switching across host nodes, or may indicate that a DAPS switching has occurred, or the second indication information may indicate other contents, and the embodiments of the present application are not limited thereto.

[0315] In this example, optionally, the second indication information may not include the bearer identifier.

[0316] In this example, the first relay node can configure a second LCH for each bearer (including the first bearer) of the terminal. This application takes the first bearer as an example. Those skilled in the art will know that the content of the embodiments of the present application is also applicable to one or more other bearers. At this time, in S102, the terminal can receive the configuration information of the second LCH corresponding to the other one or more bearers.

[0317] There are many ways for the terminal to receive the second indication information, which are described below in conjunction with several possible implementations.

[0318] As a possible implementation manner, the target host node sends the second indication information to the terminal through the first relay node.

[0319] In this embodiment, the second indication information is generated by the target host node.

[0320] In this embodiment, the second indication information can be carried in a message together with the configuration information of the second LCH sent by the target host node to the terminal in S102. For example, the message is the third message in S102. The third message can also include the air interface configuration information of the first bearer, the PDCP configuration information corresponding to the source host node and the PDCP configuration information corresponding to the target host node, and one or more of the BAP address allocated by the target host node to the first relay node. For details, please refer to the process of the relay node sending the configuration information of the second LCH to the terminal through the target host node in S102.

[0321] As another implementation manner, the first relay node sends second indication information to the terminal.

[0322] In this implementation manner, the second indication information is generated by the first relay node.

[0323] Optionally, when the first relay node generates the second LCH configuration information, the first relay node may generate second indication information and then send it to the terminal.

[0324] For example, the second indication information may be carried in a MAC CE.

[0325] As another implementation manner, the second indication information may be sent by the source host node to the terminal, which is not limited in this embodiment of the present application.

[0326] By receiving the second indication information through the terminal, the terminal can avoid receiving the configuration information of the second LCH and mistakenly thinking that the configuration information of the first LCH is to be deleted, thereby ensuring that the first bearer of the terminal can be configured with the first LCH and the second LCH at the same time, thereby reducing the probability of data transmission being interrupted during switching across host nodes and improving business continuity.

[0327] S103 is optional.

[0328] S104: The terminal configures the second LCH for the first bearer.

[0329] Optionally, after S104, the terminal can transmit PDCP data corresponding to the source donor node by using the first LCH, and the terminal can transmit PDCP data corresponding to the target donor node by using the second LCH. The following describes several embodiments.

[0330] Optionally, Figure 13 The method of the source donor node can further include: sending, by the target donor node, an indication of starting the dual configuration of the BAP layer to one or more nodes (including the access relay node, the migration relay node, and one or more other nodes between the access relay node and the migration relay node) on the link between the access relay node and the migration relay node, the dual configuration of the BAP layer including the BAP configuration corresponding to the source donor node and the BAP configuration corresponding to the target donor node. For details, refer to the content of the method of the target donor node, which will not be described here. Alternatively, the indication of starting the dual configuration of the BAP layer can be sent by the source donor node to the one or more nodes. Figure 12

[0331] Optionally, in the method of the source donor node, Figure 13 In the method of the source donor node, the PDCP data corresponding to the source donor node includes PDCP downlink data and / or PDCP uplink data. Optionally, the PDCP data corresponding to the target donor node includes PDCP downlink data and / or PDCP uplink data.

[0332] Optionally, the PDCP data corresponding to the source donor node is processed by using PDCP configuration information corresponding to the source donor node, which can be processed by the source donor node or by the terminal; and the PDCP data corresponding to the target donor node is processed by using PDCP configuration information corresponding to the target donor node, which can be processed by the target donor node or by the terminal.

[0333] Optionally, the PDCP entity of the first bearer of the terminal includes configuration information corresponding to the source donor node and configuration information corresponding to the target donor node. For details, refer to the content of the method of the terminal, which will not be described here. Figure 12

[0334] ​​When the PDCP data corresponding to the source host node is PDCP downlink data, the first LCH being used for transmitting the PDCP data corresponding to the source host node can be understood as that the first LCH is used for receiving the PDCP downlink data corresponding to the source host node. Similarly, when the PDCP data corresponding to the target host node is PDCP downlink data, the second LCH being used for transmitting the PDCP data corresponding to the target host node can be understood as that the second LCH is used for receiving the PDCP data corresponding to the target host node.

[0335] As an example, the source host node sends the PDCP downlink data processed by the PDCP configuration information corresponding to the source host node to the first relay node, the first relay node maps the PDCP downlink data corresponding to the source host node to the first LCH and sends it to the terminal, and the terminal can receive the PDCP downlink data corresponding to the source host node mapped to the first LCH from the first relay node (which can be understood as that the terminal receives the PDCP downlink data corresponding to the source host node through the first LCH). The terminal processes the PDCP downlink data corresponding to the source host node through the PDCP configuration information corresponding to the source host node.

[0336] As another example, the target host node sends the PDCP downlink data processed by the PDCP configuration information corresponding to the target host node to the first relay node, the first relay node maps the PDCP downlink data corresponding to the target host node to the second LCH and sends it to the terminal, and the terminal receives the PDCP downlink data corresponding to the target host node mapped to the second LCH from the first relay node (which can be understood as that the terminal receives the PDCP downlink data corresponding to the target host node through the second LCH). The terminal processes the PDCP downlink data corresponding to the target host node through the PDCP configuration information corresponding to the target host node.

[0337] For downlink data, only one of the above two examples can occur, or both of the above two examples can occur. Optionally, for downlink data, in the process of cross-host node switching (including the process of deciding cross-host node switching from the source host node to releasing the context of the migration relay node by the source parent node of the migration relay node in the embodiments of the present application), the time when the source host node sends the PDCP downlink data corresponding to the source host node to the terminal and the time when the target host node can send the PDCP downlink data corresponding to the target host node to the terminal can coincide with each other, that is, the terminal can receive the PDCP downlink data corresponding to the source host node and the PDCP downlink data corresponding to the target host node at the same time.

[0338] When the PDCP data corresponding to the source host node is PDCP uplink data, the first LCH is used to transmit the PDCP data corresponding to the source host node, which can be understood as the first LCH is used to send the PDCP uplink data corresponding to the source host node. Similarly, when the PDCP data corresponding to the target host node is PDCP uplink data, the second LCH is used to transmit the PDCP data corresponding to the target host node, which can be understood as the second LCH is used to send the PDCP uplink data corresponding to the target host node.

[0339] As an example, the terminal processes the uplink data through the PDCP configuration information corresponding to the source host node to obtain the uplink PDCP data corresponding to the source host node; and maps the uplink PDCP data corresponding to the source host node to the first LCH, and the terminal sends the uplink PDCP data corresponding to the source host node mapped to the first LCH to the first relay node (it can be understood that the terminal sends the uplink PDCP data corresponding to the source host node through the first LCH). After receiving the PDCP uplink data corresponding to the source host node mapped to the first LCH, the first relay node sends it to the source host node. Finally, the source host node processes the PDCP uplink data through the configuration information corresponding to the source host node.

[0340] As another example, the terminal processes the uplink data through the PDCP configuration information corresponding to the target host node to obtain the uplink PDCP data corresponding to the target host node; and maps the uplink PDCP data corresponding to the target host node to the second LCH, and the terminal sends the uplink PDCP data corresponding to the target host node mapped to the second LCH to the first relay node (it can be understood that the terminal sends the uplink PDCP data corresponding to the target host node through the second LCH). After receiving the PDCP uplink data corresponding to the target host node mapped to the second LCH, the first relay node sends it to the target host node, and finally the target host node processes the PDCP uplink data through the configuration information corresponding to the target host node.

[0341] Optionally, for downlink data, the first relay node may distinguish between PDCP downlink data corresponding to the source host node and PDCP downlink data corresponding to the target host node based on the GTP-U tunnel used for downlink data transmission. Alternatively, the first relay node may distinguish between PDCP downlink data corresponding to the source host node and PDCP downlink data corresponding to the target host node based on the BAP address carried in the downlink data.

[0342] For uplink data, the above two examples can only occur one or both of them. Optionally, for uplink data, in the process of the above cross-host node switching, the time point at which the terminal sends the PDCP uplink data corresponding to the source host node to the source host node and the time point at which the terminal sends the PDCP uplink data corresponding to the target host node to the target host node can be staggered, that is, at the same time, the terminal can send the PDCP uplink data corresponding to the source host node to the source host node or send the PDCP uplink data corresponding to the target host node to the target host node.

[0343] The transmission process of the above downlink data and uplink data can refer to the content of Figure 12 , which will not be repeated here.

[0344] In addition, before the migration relay node (i.e. the first relay node or the second relay node) establishes a connection with the target host node, the terminal sends uplink data to the source host node, and after the migration relay node establishes a connection with the target host node, the terminal sends uplink data to the target host node. However, the terminal does not perceive when the migration relay node establishes a connection with the target host node, resulting in that the terminal is uncertain whether to process the uplink PDCP data using the PDCP configuration information corresponding to the source host node and send it to the source host node, or to process the uplink PDCP data using the PDCP configuration information corresponding to the target host node and send it to the target host node. The embodiments of the present application provide the following scheme, which can ensure that the terminal uses correct configuration information to process uplink data and avoid service interruption caused by packet loss.

[0345] Figure 14 is a flowchart of an indication method provided by the embodiments of the present application. Figure 14 The method of Figure 13 may be executed alone or on the basis of the method of Figure 14 . The content of Figure 13 may be mutually referred to and referred to.

[0346] In the method of Figure 14 , the first bearer of the terminal is configured with a first LCH and a second LCH, wherein the first LCH transmits PDCP data corresponding to the source host node, and the second LCH is used to transmit PDCP data corresponding to the target host node. The first LCH, the second LCH and how to configure the second LCH can refer to the content in Figure 13 .

[0347] As shown in Figure 14 , the method of Figure 14 comprises:

[0348] S200: The terminal receives third indication information. The terminal can determine to process uplink data by PDCP configuration information corresponding to the target donor node according to the third indication information.

[0349] Optionally, the third indication information can indicate the terminal to send data to the target donor node, or the third indication information can indicate the terminal to process data using configuration information corresponding to the target donor node, or the third indication information can indicate that the migrating relay node has accessed the target parent node or the relay node switching is completed, or the third indication information can indicate that the migrating relay node has completed PUSCH conversion.

[0350] As an implementation manner, the migrating relay node sends the third indication information to the terminal after performing the PUSCH conversion.

[0351] In the embodiments of the present application, performing the PUSCH conversion can be understood as converting the PUSCH of the migrating relay node from the source parent node to the target parent node, that is, the migrating relay node originally sends PUSCH data (such as PDCP uplink data of the terminal) to the source parent node through the PUSCH, and then sends the PUSCH data (such as PDCP uplink data of the terminal) to the target parent node through the PUSCH. Specifically, when the migrating relay node sends a preamble to the target donor node and receives a random access response (RAR) message sent by the target donor node, the migrating relay node performs the PUSCH conversion, wherein the RAR message includes an UL grant resource.

[0352] As another implementation manner, the migrating relay node sends the third indication information to the terminal after connecting with the target donor node.

[0353] In the embodiments of the present application, the migrating relay node connecting with the target donor node can include the migrating relay node and the target donor node establishing an F1 interface for a first bearer, establishing a GTP tunnel, and / or the migrating relay node and the target donor node completing routing and bearer mapping configuration of a path.

[0354] Optionally, in the above two implementation manners, the third indication information can be carried in downlink data and sent to the terminal, for example, carried in a MAC header field or an RLC header field of the downlink data. Alternatively, optionally, the third indication information can be carried in control signaling and sent to the terminal, and the control signaling can be a MAC CE or a downlink control information (DCI).

[0355] As still another implementation, the target host node can send the third indication information to the terminal after receiving the RRC reconfiguration complete message of the migrating relay node.

[0356] Optionally, the target host node can send the third indication information to the terminal through an RRC message.

[0357] Optionally, the above three implementations can be applied to a scenario in which the terminal receives the configuration information of the second LCH before the first relay node establishes a connection with the target host node. In this scenario, the target host node sends the third indication information to the terminal after the migrating relay node performs the PUSCH switching or after the migrating relay node establishes a connection with the target host node or after the target host node receives the RRC reconfiguration complete message, which can avoid the following situation: once the terminal receives the configuration information of the second LCH, the terminal uses the PDCP configuration information corresponding to the target host node to process the uplink data by default and sends the uplink data to the migrating relay node, and the migrating relay node can only send the uplink data to the source host node because the migrating relay node has not established a connection with the target host node, and the source host node cannot parse the uplink data, resulting in loss of the uplink data.

[0358] As still another implementation, the target host node can send the second LCH configuration information and the third indication information to the terminal through the source host node. Illustratively, the target host node sends a second message to the source host node, the second message including a third message, and the source host node sends the third message to the terminal, the third message including the second LCH configuration information and the third indication information.

[0359] S201: The terminal processes the uplink data through the PDCP configuration information corresponding to the target host node according to the third indication information. Optionally, the terminal can also map the PDCP uplink data corresponding to the target host node to the second LCH and send the PDCP uplink data to the target host node.

[0360] Specifically, after the terminal processes the uplink data through the PDCP configuration information corresponding to the target host node, the terminal can obtain the PDCP uplink data corresponding to the target host node, then map the PDCP uplink data corresponding to the target host node to the second LCH, and then send the PDCP uplink data corresponding to the target host node through the second LCH. After the first relay node receives the PDCP uplink data corresponding to the target host node mapped to the second LCH, the first relay node sends the PDCP uplink data to the target host node, and finally the target host node processes the PDCP uplink data through the configuration information corresponding to the target host node.

[0361] Optionally, before the terminal receives the third indication information, the terminal processes the PDCP uplink data by using the PDCP configuration information corresponding to the source donor node, and after receiving the third indication information, the terminal processes the subsequent PDCP uplink data by using the PDCP configuration information corresponding to the target donor node. For details of processing the PDCP uplink data by using the PDCP configuration information corresponding to the source donor node or processing the PDCP uplink data by using the PDCP configuration information corresponding to the target donor node, refer to the content in Figure 13 , which will not be repeated here.

[0362] By the method in Figure 14 , in the cross-donor node handover, the parent node of the terminal can always not change, and the terminal does not perceive when the migration relay node performs the PUSCH conversion. By sending the third indication information to the terminal, the terminal can determine to process the uplink data by using the PDCP configuration information corresponding to the target donor node, so as to ensure that the terminal processes the uplink data by using correct configuration information, avoid service interruption caused by packet loss, and improve the continuity of service transmission.

[0363] Optionally, as another alternative embodiment of S200 and S201, S200 and S201 can not exist, and after the terminal receives the configuration information of the second LCH, the terminal performs S202, that is, the terminal processes the uplink data by using the PDCP configuration information corresponding to the target donor node, maps the PDCP uplink data corresponding to the target donor node to the second LCH, and sends the PDCP uplink data corresponding to the target donor node to the target donor node.

[0364] Optionally, this embodiment can be applied to the scenario that the terminal receives the configuration information of the second LCH after the first relay node establishes a connection with the target donor node. In this scenario, once the terminal receives the configuration information of the second LCH, the terminal processes the uplink data by using the PDCP configuration information corresponding to the target donor node by default, and sends the uplink data to the target donor node, thereby ensuring the continuity of service transmission and saving signaling overhead.

[0365] Figure 15 is a flowchart of a LCH deletion method provided by an embodiment of the present application. Figure 15 The method in Figure 13 and Figure 14 may be executed alone or on the basis of one or two methods in Figure 13 and Figure 14 . Figure 15 , Figure 14 and Figure 13 .

[0366] In Figure 15In the method, the first bearer of the terminal is configured with a first LCH and a second LCH, wherein the first LCH transmits PDCP data corresponding to the source host node, and the second LCH is used to transmit PDCP data corresponding to the target host node. For details on the first LCH, the second LCH, and how to configure the second LCH, please refer to Figure 14 The content in.

[0367] like Figure 15 As shown, Figure 15 The methods include:

[0368] S301: The first relay node sends fourth indication information to the target host node.

[0369] The fourth indication information is used by the target host node to instruct the terminal to delete the first LCH.

[0370] As an implementation manner, after the first relay node completes sending the PDCP data corresponding to the source host node cached by the first relay node to the terminal, the first relay node sends the fourth indication information to the target host node.

[0371] The PDCP data corresponding to the source host node cached by the first relay node will be mapped to the first LCH of the terminal for transmission, and therefore may also be referred to as PDCP data corresponding to the first LCH.

[0372] In this embodiment, optionally, before S301, the method also includes: the first relay node receives a seventh message, the seventh message is used to delete the F1 interface and / or GTP-U tunnel between the first relay node and the source host node, and the first relay node can receive the seventh message and complete sending the PDCP data corresponding to the source host node cached by the first relay node to the terminal. The first relay node sends the fourth indication information to the target host node.

[0373] As an example, the method further includes: the target host node sending an eighth message to the source host node to trigger the source host node to send a seventh message to the first relay node. Exemplarily, the seventh message and the eighth message may be UE context release messages.

[0374] Optionally, the seventh message may include the ID of the first LCH, and / or indication information instructing the first relay node to delete the GTP-U tunnel between the first relay node and the source host node.

[0375] Optionally, the first relay node completes sending the PDCP data corresponding to the source host node buffered by the first relay node to the terminal. It can be understood that the first relay node has sent all the PDCP data corresponding to the source host node buffered on the first relay node to the terminal, or that there is no PDCP data corresponding to the source host node buffered on the first relay node, or that the buffer corresponding to the first LCH on the first relay node is empty.

[0376] Optionally, the indication content of the fourth indication information can have various cases. For example, the fourth indication information can indicate deleting the first LCH, or can indicate that the first relay node completes sending the PDCP data corresponding to the first LCH buffered by the first relay node to the terminal, or can indicate that the buffer corresponding to the first LCH on the first relay node is empty, or can indicate other content, which is not limited by the embodiments of the present application. Optionally, the fourth indication information can include the ID of the first LCH and / or the identifier of the first bearer.

[0377] Optionally, the fourth indication information can be carried in a UE context modification requirement message. S302: The target host node sends fifth indication information to the first relay node.

[0378] After receiving the fourth indication information, the target host node can determine the fifth indication information.

[0379] Optionally, the fifth indication information can be the same as or different from the fourth indication information.

[0380] Optionally, the indication content of the fifth indication information can have various cases. For example, the fifth indication information can indicate that the terminal deletes the first LCH, or indicates that the terminal releases the function of PDCP double configuration, or indicates that the terminal deletes the PDCP configuration information corresponding to the source host node, or can indicate other content, which is not limited by the embodiments of the present application.

[0381] Optionally, the fifth indication information can be carried in an RRC message, which is carried in a UE context modification request message. The UE context modification request message can be an F1AP message.

[0382] Optionally, the fifth indication information can include the ID of the first LCH and / or the identifier of the first bearer.

[0383] S303: The first relay node sends the fifth indication information to the terminal.

[0384] Optionally, S303 can be that the first relay node sends the above-mentioned RRC message to the terminal.

[0385] S304: The terminal deletes the first LCH of the first bearer according to the fifth indication information.

[0386] Optionally, when the fifth indication information includes the ID of the first LCH, the terminal deletes the first LCH according to the fifth indication information.

[0387] Optionally, when the fifth indication information does not include the ID of the first LCH, the terminal can delete the first LCH by default after receiving the fifth indication information, that is, delete the LCH corresponding to the source donor node by default.

[0388] Optionally, Figure 15 The method of the first relay node can further include deleting the configuration information of the first LCH, deleting one or more of the F1 interface and the GTP-U tunnel between the source donor node, and the like. As an example, the first relay node can perform one or more of the following operations after S302 or S303: deleting the configuration information of the first LCH, deleting the F1 interface between the source donor node, and the GTP-U tunnel between the source donor node, and the like. It can be understood that after S302 or S303, the first relay node no longer needs to perform message or data transmission between the terminal and the source donor node, and deleting the configuration information of the first LCH, deleting the F1 interface between the source donor node, and / or the GTP-U tunnel between the source donor node by the first relay node can save resources. Alternatively, as another example, the first relay node can perform one or more of the following operations before S302: deleting the F1 interface between the source donor node, and the GTP-U tunnel between the source donor node, and the like.

[0389] Through the method of the first relay node, Figure 15 Through the method of the terminal, the terminal can delete the first LCH according to the indication of the network side, which can save air interface resources. In addition, after the first relay node completes sending the PDCP data corresponding to the source donor node to the terminal, the first relay node sends the fourth indication information to the target donor node, so that the target donor node instructs the terminal to delete the first LCH, which can ensure that the terminal deletes the first LCH only after all the PDCP data corresponding to the source donor node is sent to the terminal through the first LCH, ensuring the continuity of data transmission and avoiding the interruption of data transmission caused by the terminal being unable to process or parse the PDCP data corresponding to the source donor node after the terminal deletes the first LCH.

[0390] Figure 16 The method of the first relay node is a flowchart of an indication method provided by an embodiment of the application, Figure 16 The method of the terminal can be executed independently, or can be executed on the basis of one or more methods of the first relay node, Figure 13 、 Figure 14 and Figure 16 the first relay node. Figures 13 to 16 The contents can be referenced and learned from each other. Figure 16 As shown, the method includes:

[0391] S401: The source host node sends capability indication information to the target host node.

[0392] Optionally, the capability indication information is used to indicate that the migration relay node supports a certain capability. For example, the capability indication information is used to indicate that the migration relay node supports maintaining a connection with the source host node during the switching process, or the migration relay node supports maintaining a connection with the source host node and the target host node at the same time during the switching process, or it can indicate that the migration relay node supports DAPS, or it can indicate that during the switching process, the migration relay node supports parallel PDSCH data transmission, or during the switching process, the migration relay node supports parallel PUSCH data transmission, or the capability indication information can indicate other content, which is not limited in the embodiments of the present application.

[0393] It should be noted that this article introduces the capability indication information at the granularity of the migration relay node as an example. Those skilled in the art can understand that the capability indication information here can also be at the granularity of the terminal's bearer. For example, the capability indication information can indicate that the first bearer of the terminal supports DAPS during the switching process, supports parallel PDSCH transmission or PUSCH transmission, etc. The embodiments of the present application do not limit this.

[0394] Optionally, the capability indication information may be generated by the source host node.

[0395] Optionally, the capability indication information may be sent by the migration relay node to the source host node.

[0396] As an example, the capability indication information may be carried in a handover request message sent by the source host node to the target host node.

[0397] Optionally, in this example, the handover request message may further include context information of the migrating relay node and the descendant nodes of the migrating relay node. The context information of the migrating relay node and the descendant nodes includes an identifier of the relay node to which the migrating relay node and the descendant nodes access (e.g., IAB-DU id), an identifier of the cell to which the migrating relay node and the descendant nodes access (e.g., global cell identity (cell group identifier, CGI)), and one or more of the cell radio network temporary identifiers (C-RNTI) of the migrating relay node and the descendant nodes in the cell to which they access.

[0398] Optionally, the switching request message can be a switching request message for group switching. Group switching can be understood as when the migration relay node performs switching, the descendant nodes of the migration relay node will also switch along with the migration relay node. The migration relay node and the descendant nodes can be regarded as a group, and the group is switched.

[0399] S401 is optional.

[0400] S402: The target host node sends sixth indication information to the source host node.

[0401] As an example, the sixth indication information is carried in an RRC reconfiguration message, and the RRC reconfiguration message is carried in a handover request response message sent by the target host node to the source host node. It can be understood that the target host node sends a handover request response message to the source host node, including an RRC reconfiguration message, and the RRC reconfiguration message includes the sixth indication information.

[0402] Optionally, when S401 exists, the target host node determines the sixth indication information based on the capability indication information; when S402 does not exist, the target host node assumes that the migration relay node has the capability indicated by the above capability indication information, thereby generating the sixth indication information.

[0403] Optionally, the content indicated by the sixth indication information may have multiple situations. For example, the sixth indication information may indicate that the migration relay node maintains a connection with the source host node during the switching process, or may indicate that the migration relay node maintains a connection with both the source host node and the target host node during the switching process, or may indicate that the source host node will send PDCP data corresponding to the source host node to the migration relay node during the switching process, or may indicate that the migration relay node starts DAPS, or may indicate that during the switching process, the migration relay node performs parallel PDSCH data transmission, or during the switching process, the migration relay node performs parallel PUSCH data transmission, or the sixth indication information may indicate other content, which is not limited in the embodiments of the present application. The switching process in the present application may include the process from the migration relay node receiving an RRC reconfiguration message from the source host node to the migration relay node receiving a message from the target host node indicating the release of protocol stack resources between the node and the source parent node.

[0404] It should be noted that the migrating relay node performing parallel PDSCH data transmission can be understood as the migrating relay node being able to transmit both the PDSCH data corresponding to the source host node and the PDSCH data corresponding to the target host node. Similarly, the migrating relay node performing parallel PUSCH data transmission can be understood as the migrating relay node being able to transmit both the PUSCH data corresponding to the source host node and the PUSCH data corresponding to the target host node.

[0405] Optionally, the sixth indication information is introduced above as the granularity of migrating IAB nodes. Optionally, the sixth indication information may be the granularity of the terminal's bearer. For details, please refer to the description that the capability indication information may be the granularity of the terminal's bearer, which will not be described here.

[0406] Optionally, the capability indication information and the sixth indication information may be the same and may be carried in the same information element; or, the capability indication information and the sixth indication information may be different.

[0407] Optionally, S402 is optional. S401 and S402 may occur one or both.

[0408] S403: The source host node sends sixth indication information to the migration relay node.

[0409] As an example, the sixth indication information may be carried in an RRC reconfiguration message sent by the source host node to the migrating relay node.

[0410] S404: The migrating relay node maintains the connection with the source host node during the handover process according to the sixth indication information.

[0411] S404 is optional.

[0412] Figures 13 to 16 One or more of the methods can be combined to implement the following. Figures 17 and 18 The contents in the embodiments of the present application are further described. It should be noted that, Figure 17 and Figure 18 by Figure 11 The cross-host node switching scenario is introduced as an example. Figure 17 and Figure 18 The content in is not only applicable to Figure 11 It can also be applied to other scenarios of cross-host node switching.

[0413] Figure 17 and Figure 18Schematic diagrams of a cross-host node handover method provided by an embodiment of the present application, respectively, describe the handover process of IAB node 3 from IAB node 1 to IAB node 4. The handover process is mainly divided into three stages: handover preparation, handover execution, and handover completion. In each stage, the terminal can transmit data with IAB donor CU 1 and / or IABdonor CU 2. Figure 17 and Figure 18 The difference is that Figure 17 In the process of handover completion, the second LCH of the first bearer is configured for the terminal. Figure 18 In the handover preparation process, the second LCH of the first bearer is configured for the terminal. Figure 17 and Figure 18 Provide explanation.

[0414] like Figure 17 As shown, the method includes:

[0415] The process from S501 to S508 describes the handover preparation process, which can be Figure 17 The contents refer to each other.

[0416] S501: IAB node 3 sends a measurement report to IAB donor CU 1.

[0417] The IAB node 3 may measure the serving cell of the connected IAB node 1 and the neighboring cells under the IAB node 4 according to the measurement configuration received from the IAB donor CU 1, obtain a measurement report, and send it to the IAB donor CU 1.

[0418] S502: IAB donor CU 1 makes a handover decision.

[0419] IAB node CU 1 may decide to switch IAB node 3 from IAB node 1 to IAB node 4 according to the received measurement report.

[0420] For example, when the signal quality of the cell of IAB node 4 is better than the signal quality of the cell of IAB node 1 , IAB donor CU 1 may decide to switch IAB node 3 from IAB node 1 to IAB node 4 .

[0421] S503: IAB donor CU 1 sends a handover request message including capability indication information to IAB donor CU 2.

[0422] Optionally, the handover request message may carry context information of IAB node 3 and its descendant nodes. For example, if the descendant nodes of IAB node 3 include IAB node 2 and terminal 1, the handover request message may carry context information of IAB node 3, IAB node 2, and terminal 1. For details, refer to the context information of the migration relay node and its descendant nodes in S401.

[0423] The handover request message may include capability indication information, and reference may be made to the content of S401 .

[0424] S504: IAB donor CU 2 sends a context establishment request message to IAB node 4.

[0425] S505: The IAB node 4 sends a context establishment response message to the IAB donor CU 2.

[0426] S506: IAB donor CU 2 sends a handover request response message to IAB donor CU1, including the first RRC reconfiguration message, where the first RRC reconfiguration message includes sixth indication information.

[0427] The content of the sixth indication information may refer to the content in S402.

[0428] The process from S509 to S513 describes the handover execution process, that is, the random access process between the IAB node 3 and the IAB donor DU 2.

[0429] S507: IAB node CU 1 sends a first RRC reconfiguration message to IAB node 3, including sixth indication information.

[0430] S508: The IAB node 3 starts DAPS according to the sixth instruction information.

[0431] For more information about DAPS, please refer to Figure 8 and Figure 12 content.

[0432] It can be understood that the IAB node 3 starts the DAPS, which can be understood as the IAB node 3 can maintain the connection with the IAB donor CU 1 during the handover.

[0433] S509: IAB node 3 sends a preamble to IAB node 4.

[0434] S510: IAB node 4 sends a RAR to IAB node 3.

[0435] S511: IAB node 3 performs PUSCH switch.

[0436] When IAB node 3 performs a PUSCH switch, it can be understood that IAB node 3 will stop transmitting uplink data (e.g., terminal uplink data) with IAB node 1 and start transmitting uplink data (e.g., terminal uplink data) with IAB node 4. That is, the PUSCH of IAB node 3 is switched from IAB node 1 to IAB node 4. It should be noted that although the PUSCH of IAB node 3 is switched to IAB node 4, IAB node 3 can no longer transmit uplink data with IAB node 1, but IAB node 3 can still transmit downlink data with IAB node 1. For details about PUSCH switch, please refer to the description above.

[0437] Optionally, after S511, IAB node 3 may send seventh indication information to terminal 1, and terminal 1 may stop processing uplink data using the PDCP configuration information corresponding to the source host node and map it to the first LCH based on the seventh indication information. For example, the seventh indication information may instruct the terminal to stop sending uplink data to the source host node. This can avoid the situation where, after the PUSCH conversion, IAB node 3 still receives uplink data corresponding to the source host node, IAB node 3 sends the uplink data corresponding to the source host node to the target host node, and the target host node is unable to parse it, resulting in packet loss, data transmission interruption, and waste of cache resources of nodes between IAB node 3 and the target host node.

[0438] S512: IAB node 3 sends an RRC reconfiguration complete message to IAB donor DU 2.

[0439] S513: The IAB donor DU 2 sends an uplink RRC message transfer (UL RRC transfer) message including an RRC reconfiguration complete message to the IAB donor CU2.

[0440] S514 to S536 describe the handover completion process.

[0441] S514: The IAB node 3 and the IAB donor CU 2 establish an F1 interface.

[0442] Optionally, after obtaining the cell identifier of the IAB node 3 under the IAB donor CU 2, the IAB node 3 may initiate an F1 connection establishment process to the IAB donor CU 2, and then the IAB node 3 and the IAB donor CU 2 establish an F1 interface.

[0443] S515: IAB node 2 and IAB donor CU 2 establish an F1 interface.

[0444] S516 to S521 describe the process of configuring the second LCH of the first bearer, which can be Figure 13 The contents in the reference to each other, for example, may correspond to the situation where after the first relay node establishes a connection with the target host node, the first relay node receives the first indication information from the target host node, and the first relay node sends the configuration information of the second LCH to the target host node. It can be understood that Figure 13 The first message in S516 is the context establishment request message, and the fourth message is the UE context establishment response message in S518. Figure 13 The second message in S506 is the handover request response message, Figure 13 The third message is the second RRC reconfiguration message in S519 to S521.

[0445] S516: IAB donor CU 2 sends a UE context establishment request message to IAB node 2, including the first indication information.

[0446] Optionally, the UE context establishment request message may be used to establish a GTP tunnel, and may be referred to as a GTP tunnel establishment request message. Optionally, the UE context establishment message may include a GTP tunnel identifier.

[0447] As another implementation of S516, the UE context establishment request message may not include the first indication information.

[0448] S517: IAB node 2 generates configuration information of the second LCH corresponding to the first bearer.

[0449] Optionally, when the UE context establishment request message includes the first indication information, the IAB node 2 may generate the configuration information of the second LCH based on the first indication information; or, when the UE context establishment request message does not include the first indication information, after receiving the UE context establishment request message, the IAB node 2 may generate the configuration information of the second LCH for each bearer of the terminal, and send it to the IAB donor CU 2 through the UE context establishment request response message of S517.

[0450] S518: The IAB node 2 sends a UE context setup response message to the IAB donor CU 2, including the configuration information of the second LCH corresponding to the first bearer.

[0451] Through S516 to S518, the IAB node 2 and the IAB donor CU 2 can establish a GTP-U tunnel corresponding to the second LCH for the first bearer.

[0452] Optionally, in S516 to S518, the configuration of routing and bearer mapping on the path from the IAB node 2 to the IAB donor CU 2 can be completed.

[0453] S519: The IAB donor CU 2 sends a handover request response message to the IAB donor CU 1, including a second RRC reconfiguration message, and the first RRC reconfiguration message includes the configuration information of the second LCH corresponding to the first bearer and the second indication information.

[0454] S520: The IAB donor CU 1 sends a UE context modification request message to the IAB node 2, including the second RRC reconfiguration message.

[0455] S521: The IAB node 2 sends a second RRC reconfiguration message to the terminal.

[0456] The second RRC reconfiguration message includes one or more of the air interface configuration information of the first bearer, the PDCP configuration information corresponding to the source donor node, and the PDCP configuration information corresponding to the target donor node, which can be referred to the content in S102.

[0457] Optionally, the second RRC reconfiguration message further includes third indication information, and the terminal 1 can use the PDCP configuration information corresponding to the target donor node to process the uplink data according to the third indication information, and map the processed uplink data to the second LCH. Alternatively, the second RRC reconfiguration message can not include the third indication information, and after receiving the second RRC reconfiguration message, the terminal 1 defaults to using the PDCP configuration information corresponding to the target donor node to process the uplink data if the second RRC reconfiguration message carries the configuration information of the second LCH, and maps the processed uplink data to the second LCH.

[0458] S522: The terminal configures the second LCH for the first bearer.

[0459] The specific content can be referred to the content of S104 of Figure 13 .

[0460] S523: The IAB donor CU 2 sends a handover success message to the IAB donor CU 1, indicating the IAB donor CU 1 to stop sending the source downlink data to the IAB node 3.

[0461] S524: The IAB donor CU 1 stops sending the source downlink data to the IAB node 3.

[0462] Optionally, although the IAB donor CU 1 stops sending the source downlink data to the IAB node 3, the IAB node 3 can continue to send the source downlink data that has been buffered on the IAB node 3 to the terminal 1.

[0463] S525 to S531 describe the process of deleting the first LCH of the first bearer, which can be mutually referred to the contents in Figure 15 . For example, the UE context release message in S525 is the seventh message in Figure 15 , and the UE context release message in S526 is the eighth message in Figure 15 .

[0464] S525: The IAB donor CU 2 sends a UE context release message to the IAB donor CU 1.

[0465] S526: The IAB donor CU 1 sends a UE context release message to the IAB node 2.

[0466] S527: The IAB node 2 judges that the buffer of the first LCH is empty.

[0467] S528: The IAB node 2 sends a UE context modification application message to the IAB donor CU 2, including fourth indication information.

[0468] The fourth indication information can refer to the contents in Figure 15 .

[0469] S529: The IAB donor CU 2 sends a UE context modification request message to the IAB node 2, including a third RRC reconfiguration message, wherein the third RRC reconfiguration message includes fifth indication information.

[0470] S530: The IAB node 2 sends the third RRC reconfiguration message to the terminal 1, including the fifth indication information.

[0471] S531: The terminal deletes the first LCH of the first bearer according to the fifth indication information.

[0472] The fifth indication information can refer to the content of S302 to S304.

[0473] S532: The IAB donor CU 2 sends an F1AP message to the IAB node 3, instructing the IAB node 3 to release the protocol stack resources between the IAB node 3 and the IAB node 1.

[0474] S533: The IAB node 3 switches from DAPS to a single-activated protocol stack.

[0475] The single-activated protocol stack can be understood as the IAB node 3 only has protocol stack resources corresponding to the target parent node. That is, the IAB node 3 releases the protocol stack resources between the IAB node 3 and the IAB node 1.

[0476] S534: The IAB donor CU 2 sends a context release message to the IAB donor CU 1.

[0477] S535: The IAB donor CU 1 sends a context release message to the IAB node 1.

[0478] S536: The IAB node 1 releases the context of the IAB node 3.

[0479] In the method of Figure 17 In the method of

[0480] Optionally, between S501 to S511, the IAB donor CU 1 can send the source downlink data to the terminal, and the terminal can send the source uplink data to the IAB donor CU 1.

[0481] Optionally, between S511 to S522, the IAB donor CU 1 can send the source downlink data to the terminal.

[0482] Optionally, between S522 and S524, the IAB donor CU 1 can send source downlink data to the terminal, the IAB donor CU 2 can send target downlink data to the terminal, and the terminal can send target uplink data to the IAB donor CU 2.

[0483] Optionally, between S524 and S527, the IAB node 3 or the IAB node 2 can continue to send the terminal the source downlink data packets buffered on the IAB node 3 or the IAB node 2, the IAB donor CU 2 can send target downlink data to the terminal, and the terminal can send target uplink data to the IAB donor CU 2.

[0484] Optionally, between S527 and S536, the IAB donor CU 2 can send target downlink data to the terminal, and the terminal can send target uplink data to the IAB donor CU 2.

[0485] The processing methods of the source uplink data, the source downlink data, the target uplink data and / or the target downlink data can refer to the content described above, which will not be repeated here.

[0486] By the method of Figure 17 , the data transmission of the terminal is uninterrupted during the switching process of the IAB node 3, and the continuity of data transmission is ensured.

[0487] Figure 18 is a schematic diagram of another method of cross-host node switching provided by the embodiments of the present application. As shown in Figure 18 , the method comprises:

[0488] The processes of S601 to S616 describe the switching preparation process, which can be mutually referred to the content of Figure 17 .

[0489] S601: The IAB node 3 sends a measurement report to the IAB donor CU 1.

[0490] S602: The IAB donor CU 1 makes a switching decision.

[0491] S603: The IAB donor CU 1 sends a switching request message to the IAB donor CU 2, including capability indication information.

[0492] S604 to S606 describe the process of configuring the second LCH of the first bearer, which can be mutually referred to the content of Figure 13The contents in the first indication information and the configuration information of the second LCH refer to each other, for example, the first indication information can correspond to the first relay node receiving the first indication information from the source donor node before the first relay node establishes a connection with the target donor node, the first relay node sending the configuration information of the second LCH to the source donor node, and the source donor node sending the configuration information of the second LCH to the target donor node. It can be understood that Figure 13 The first message in the first indication information is the UE context modification request message in S604, Figure 13 The fifth message in the first indication information is the UE context modification response message in S606, Figure 13 The sixth message in the first indication information is the handover request message in S609, Figure 13 The second message in the first indication information is the handover request response message in S613, Figure 13 The first message in the first indication information is the second RRC reconfiguration message in S613 to S615.

[0493] S604: The IAB donor CU 1 sends a UE context modification request message to the IAB node 2, including the first indication information.

[0494] S605: The IAB node 2 generates configuration information of the second LCH corresponding to the first bearer.

[0495] The IAB node 2 can generate the configuration information of the second LCH according to the first indication information.

[0496] S606: The IAB node 2 sends a UE context modification response message to the IAB donor CU 2, including the configuration information of the second LCH.

[0497] S607: The IAB donor CU 2 sends a context setup request message to the IAB node 4.

[0498] S608: The IAB node 4 sends a context setup response message to the IAB donor CU 2.

[0499] S609: The IAB donor CU 1 sends a handover request message to the IAB donor CU 2, including the configuration information of the second LCH.

[0500] Optionally, S609 and S603 can be a handover request message.

[0501] Optionally, S609 can occur before S607, or between S607 and S608, or after S608, and the embodiments of the present application do not limit this.

[0502] S610: The IAB donor CU 2 sends a handover request response message to the IAB donor CU 1, including a first RRC reconfiguration message, the first RRC reconfiguration message including the sixth indication information.

[0503] S611: The IAB node CU 1 sends the first RRC reconfiguration message to the IAB node 3, including the sixth indication information.

[0504] S612: The IAB node 3 starts DAPS according to the sixth indication information.

[0505] S613: The IAB donor CU 2 sends a handover request response message to the IAB donor CU 1, including a second RRC reconfiguration message, the first RRC reconfiguration message including configuration information of the second LCH corresponding to the first bearer and second indication information.

[0506] S614: The IAB donor CU 1 sends a UE context modification request message to the IAB node 2, including the second RRC reconfiguration message.

[0507] S615: The IAB node 2 sends the second RRC reconfiguration message to the terminal.

[0508] Optionally, S610 and S613 can be the same handover request response message, the handover request response message including the first RRC reconfiguration message and the second RRC reconfiguration message.

[0509] S616: The terminal configures the second LCH for the first bearer.

[0510] The processes of S617 to S621 describe the handover execution process. That is, the process of random access between the IAB node 3 and the IAB donor DU 2.

[0511] S617: The IAB node 3 sends a preamble to the IAB node 4.

[0512] S618: The IAB node 4 sends a RAR to the IAB node 3.

[0513] S619: The IAB node 3 performs PUSCH switch.

[0514] S620: The IAB node 3 sends an RRC reconfiguration complete message to the IAB donor DU 2.

[0515] S621: The IAB donor DU 2 sends an uplink RRC message transfer (UL RRC transfer) message including an RRC reconfiguration complete message to the IAB donor CU2.

[0516] S622: IAB node 3 sends third indication information to the terminal.

[0517] Optionally, the IAB node 3 may send third indication information to the terminal after performing PUSCH conversion or establishing a connection with the target host node. For details, please refer to the content in S200.

[0518] S623: The IAB node 3 and the IAB donor CU 2 establish an F1 interface.

[0519] S624: IAB node 2 and IAB donor CU 2 establish an F1 interface.

[0520] S625: IAB donor CU 2 sends a UE context establishment request message to IAB node 2.

[0521] S626: IAB node 2 sends a UE context establishment request response message to IAB donor CU 2.

[0522] S627: IAB donor CU 2 sends a handover success message to IAB donor CU 1, instructing IAB donor CU 1 to stop sending source downlink data to IAB node 3.

[0523] S628: IAB donor CU 1 stops sending source downlink data to IAB node 3.

[0524] S629: IAB donor CU 2 sends a UE context release message to IAB donor CU 1.

[0525] S630: IAB donor CU 1 sends a UE context release message to IAB node 2.

[0526] S631: IAB node 2 determines that the buffer of the first LCH is empty.

[0527] S632: IAB node 2 sends a UE context modification request message to IAB donor CU 2, including the fourth indication information.

[0528] S633: The IAB donor CU 2 sends a UE context modification request message to the IAB node 2, including a third RRC reconfiguration message, wherein the third RRC reconfiguration message includes the fifth indication information.

[0529] S634: The IAB node 2 sends the third RRC reconfiguration message to the terminal 1, including the fifth indication information.

[0530] S635: The terminal deletes the first LCH of the first bearer according to the fifth indication information.

[0531] S636: The IAB donor CU 2 sends an F1 message to the IAB node 3, instructing the IAB node 3 to release the protocol stack resources between the IAB node 1.

[0532] S637: The IAB node 3 switches from DAPS to single active protocol stack.

[0533] S638: The IAB donor CU 2 sends a context release message to the IAB donor CU 1.

[0534] S639: The IAB donor CU 1 sends a context release message to the IAB node 1.

[0535] S640: The IAB node 1 releases the context of the IAB node 3.

[0536] Figure 18 The content of each step of the method can refer to the content of the method of Figure 17 , which will not be repeated here.

[0537] Optionally, between S601 and S622, the IAB donor CU 1 can send source downlink data to the terminal, and the terminal can send source uplink data to the IAB donor CU 1.

[0538] Optionally, between S622 and S630, the IAB donor CU 1 can send source downlink data to the terminal, and the IAB donor CU 2 can send target downlink data to the terminal, and the terminal can send source uplink data to the IAB donor CU 2.

[0539] Optionally, between S630 and S640, the IAB donor CU 2 can send target downlink data to the terminal, and the terminal can send target uplink data to the IAB donor CU 2.

[0540] The processing methods of source uplink data, source downlink data, target uplink data and / or target downlink data can refer to the above content and will not be repeated here.

[0541] The following combination Figures 19 to 22 Introduce the device provided in the embodiment of this application, Figures 19 to 22 The device can complete Figure 13 Figure 18 The contents of the method and device can refer to the contents of the method.

[0542] Figure 19 This is a schematic diagram of the structure of a terminal provided in an embodiment of the present application, which can implement the functions of the terminal in the above method embodiment. For the convenience of explanation, Figure 19 The main components of the terminal are shown in Figure 1. Figure 19 As shown:

[0543] The terminal includes at least one processor 611, at least one transceiver 612, and at least one memory 613. The processor 611, memory 613, and transceiver 612 are connected. Optionally, the terminal may also include an output device 614, an input device 615, and one or more antennas 616. Antenna 616 is connected to transceiver 612, and output device 614 and input device 615 are connected to processor 611.

[0544] The processor 611 is mainly used to process communication protocols and communication data, as well as to control the entire terminal, execute software programs, and process data of software programs.

[0545] As an optional implementation, the terminal device may include a baseband processor and a central processing unit. The baseband processor is primarily used to process communication protocols and communication data. The central processing unit is primarily used to control the entire terminal device, execute software programs, and process software program data.

[0546] Figure 19 The processor in the can integrate the functions of the baseband processor and the central processing unit. Those skilled in the art will understand that the baseband processor and the central processing unit can also be independent processors that are interconnected through technologies such as buses. Those skilled in the art will understand that the terminal device can include multiple baseband processors to adapt to different network standards, and the terminal device can include multiple central processing units to enhance its processing capabilities. The various components of the terminal device can be connected through various buses. The baseband processor can also be expressed as a baseband processing circuit or a baseband processing chip. The central processing unit can also be expressed as a central processing circuit or a central processing chip. The function of processing communication protocols and communication data can be built into the processor, or it can be stored in the memory in the form of a software program, and the processor executes the software program to implement the baseband processing function.

[0547] The memory 613 is mainly used for storing software programs and data. The memory 613 can exist independently and be connected to the processor 611. Alternatively, the memory 613 can be integrated with the processor 611, for example, integrated in a chip, that is, an on-chip memory, or the memory 613 is a separate storage element, and the embodiments of the present application do not make any limitation in this regard. Among them, the memory 613 can store program codes for executing the technical solutions of the embodiments of the present application, and the execution is controlled by the processor 611. Various computer programs executed can also be regarded as a driver of the processor 611.

[0548] The transceiver 612 can be used for conversion between baseband signals and radio frequency signals and processing of the radio frequency signals. The transceiver 612 can be connected to the antenna 616. The transceiver 612 includes a transmitter (Tx) and a receiver (Rx). Specifically, one or more antennas 616 can receive radio frequency signals, the receiver Rx of the transceiver 612 is used to receive the radio frequency signals from the antenna and convert the radio frequency signals into digital baseband signals or digital intermediate frequency signals, and provide the digital baseband signals or digital intermediate frequency signals to the processor 611, so that the processor 611 further processes the digital baseband signals or digital intermediate frequency signals, such as demodulation processing and decoding processing. In addition, the transmitter Tx in the transceiver 612 is used to receive the modulated digital baseband signals or digital intermediate frequency signals from the processor 611, and convert the modulated digital baseband signals or digital intermediate frequency signals into radio frequency signals, and send the radio frequency signals through one or more antennas 616. Specifically, the receiver Rx can selectively perform one or more levels of down-mixing and analog-to-digital conversion to obtain digital baseband signals or digital intermediate frequency signals, and the order of the down-mixing and analog-to-digital conversion can be adjusted. The transmitter Tx can selectively perform one or more levels of up-mixing and digital-to-analog conversion on the modulated digital baseband signals or digital intermediate frequency signals to obtain radio frequency signals, and the order of the up-mixing and digital-to-analog conversion can be adjusted. The digital baseband signals and the digital intermediate frequency signals can be collectively referred to as digital signals. Alternatively, the transmitter Tx and the receiver Rx can be implemented by different physical structures / circuits, or can be implemented by the same physical structure / circuit, that is, the transmitter Tx and the receiver Rx can be inherited together.

[0549] The transceiver can also be referred to as a transceiving unit, a transceiver, a transceiving device, etc. Optionally, a device in the transceiving unit for implementing a receiving function can be regarded as a receiving unit, and a device in the transceiving unit for implementing a sending function can be regarded as a sending unit, i.e., the transceiving unit includes the receiving unit and the sending unit, the receiving unit can also be referred to as a receiver, an input port, a receiving circuit, etc., and the sending unit can be referred to as a transmitter, a transmitter, or a transmitting circuit, etc. Alternatively, a combination of Tx, Rx, and an antenna can be a transceiver.

[0550] The output device 614 displays information in various ways. For example, the output device 614 can be a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display device, a Cathode Ray Tube (CRT) display device, or a projector, etc. The input device 615 can accept user input in various ways. For example, the input device 615 can be a mouse, a keyboard, a touch screen device, a sensor device, etc.

[0551] For example, the processor 611 (e.g., a baseband processor) can implement functions of a dual configuration protocol stack of the terminal 1, acquire first indication information, process received downlink data or to-be-sent uplink data using configuration information corresponding to a source host node or configuration information corresponding to a target host node, activate configuration information corresponding to the source host node and / or configuration information corresponding to the target host node, and delete configuration information corresponding to the source host node, etc. Details can be referred to the contents in the above method embodiments. Figure 12

[0552] For example, the memory 613 can store program code for performing operations performed by the terminal in the above method embodiments, and be controlled to execute by the processor 611. For example, the memory 613 can store configuration information corresponding to the source host node and / or configuration information corresponding to the target host node, the memory 613 can store indication information, the memory 613 can store received downlink data from the relay node, or store to-be-sent uplink data, etc. Details can be referred to the contents in the above method embodiments.

[0553] For example, the transceiver 612 and the antenna 616 can implement transmission between the parent node of the terminal, such as receiving downlink data or sending uplink data, or receiving indication information, etc. Details can be referred to the contents in the above method embodiments.

[0554] Figure 20 ​This is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. The communication device can be a relay node, which can implement the functions of the relay node in the above method embodiment; or the communication device can be a host node, which can implement the functions of the source host node or the target host node in the above method embodiment. For the convenience of explanation, Figure 20 The main components of the communication device are shown in FIG. Figure 20 As shown:

[0555] The communication device includes at least one processor 711, at least one memory 712, at least one transceiver 713, at least one network interface 714, and one or more antennas 715. The processor 711, memory 712, transceiver 713, and network interface 714 are connected, for example, via a bus. In the embodiment of the present application, the connection may include various interfaces, transmission lines, or buses, and this embodiment is not limited to this. The antenna 715 is connected to the transceiver 713. The network interface 714 is used to connect the communication device to other network devices via a communication link.

[0556] The transceiver 713, the memory 712 and the antenna 716 can be referred to as Figure 19 to achieve similar functions.

[0557] When the communication device is a first relay node, the processor 711 may be configured to support the first relay node in performing the actions described in the above method embodiment. For example, the processor 711 may generate the configuration information of the second LCH generated by the first relay node in the above method embodiment, and send the configuration information of the second LCH to the terminal. Specifically, the first relay node may generate the configuration information of the second LCH after receiving a GTP tunnel establishment request from the target host node. For another example, the processor 711 may generate the configuration information of the second LCH based on the received first indication information. For details, please refer to the content of the above method embodiment.

[0558] The transceiver 713 and the antenna 715 may enable the first relay node to connect to a source host node or to connect to a target host node.

[0559] The transceiver 713 and the antenna 715 can realize transmission with the parent node of the first relay node and / or the child node of the relay node, for example, receiving data of the source host node and / or the target host node from the parent node of the first relay node, sending data of the source host node and / or the target host node to the terminal, receiving data of the terminal, and sending data of the terminal to the parent node of the first relay node, etc.; receiving indication information generated by other nodes (such as the source host node and / or the target host node) from the parent node of the first relay node, and sending the received indication information or the indication information generated by the first relay node to the terminal, etc., or you can refer to the content of the above-mentioned method embodiment for details.

[0560] The memory 712 may store program code and / or data for executing the operations performed by the first relay node in the above-described method embodiments, and the execution thereof may be controlled by the processor 711. For example, the memory 712 may store data or indication information received from a parent node and / or child node of the first relay node, or may store indication information generated by the first relay node. For details, reference may be made to the contents of the above-described method embodiments.

[0561] When the communication device is a target host node, the processor 711 may be configured to support the target host node in performing the actions described in the above method embodiment. For example, the processor 711 may generate indication information or data generated by the target host node in the above method embodiment. For details, reference may be made to the contents of the above method embodiment.

[0562] The transceiver 713 and antenna 715 can realize the connection between the target host node and the relay node. The transceiver 713 and antenna 715 can realize transmission with the child node of the target host node, such as sending data and / or instruction information to the child node, receiving data and / or instruction information from the child node, etc. For details, please refer to the content of the above method embodiment.

[0563] The memory 712 can store program code and / or data for executing the operations performed by the target host node in the above method embodiments, and the execution is controlled by the processor 711. For example, the memory 712 can store data or indication information received from other nodes, or can store data or indication information generated by the target host node. For details, please refer to the content of the above method embodiments.

[0564] The network interface 714 may include a network interface between the target host node and the core network element, such as an S1 interface. The network interface may include a network interface between an access network device and other network devices, such as a network interface between a source host node and a target host node, such as an X2 or Xn interface.

[0565] When the communication device is a source host node, the processor 711 may be configured to support the source host node in performing the actions described in the above method embodiments. For example, the processor 711 may generate indication information or data generated by the source host node in the above method embodiments. For details, reference may be made to the contents of the above method embodiments.

[0566] The transceiver 713 and antenna 715 can realize the connection between the source host node and the relay node. The transceiver 713 and antenna 715 can realize transmission with the child node of the source host node, such as sending data and / or instruction information to the child node, receiving data and / or instruction information from the child node, etc. For details, please refer to the content of the above method embodiment.

[0567] The memory 712 can store program code and / or data for executing the operations performed by the source host node in the above method embodiments, and the execution is controlled by the processor 711. For example, the memory 712 can store data or indication information received from other nodes, or can store data or indication information generated by the target host node. For details, please refer to the content of the above method embodiments.

[0568] The network interface 714 may include a network interface between the target host node and the core network element, such as an S1 interface. The network interface may include a network interface between an access network device and other network devices, such as a network interface between a target host node and a source host node, such as an X2 or Xn interface.

[0569] Figure 21 This is a schematic diagram of the structure of an access network device provided in an embodiment of the present application, which can be exemplarily a schematic diagram of the structure of a host node, wherein the DU included therein can refer to a host DU, and the CU included therein can refer to a host CU. Figure 21 As shown, the base station can be applied to Figure 1 、 Figure 2 、 Figure 3 and Figure 11 In the system shown, the functions of the host node (including the source host node and / or the target host node) in the above method embodiment are executed.

[0570] The access network device may include one or more DUs 1101 and one or more CUs 1102. The DU 1101 may include at least one antenna 11011, at least one radio frequency unit 11012, at least one processor 11013, and at least one memory 11014. The DU 1101 is primarily used for transmitting and receiving radio frequency signals, converting radio frequency signals into baseband signals, and performing some baseband processing. The CU 1102 may include at least one processor 11022 and at least one memory 11021. The CU 1102 and the DU 1101 may communicate via interfaces, where the control plane interface may be F1-C and the user plane interface may be F1-U.

[0571] The CU 1102 is primarily used for baseband processing and base station control. The DU 1101 and CU 1102 can be physically located together or separately, i.e., in a distributed base station. The CU 1102 is the control center of the base station, also known as a processing unit, and is primarily used to perform baseband processing functions. For example, the CU 1102 can be used to control the base station to execute the network device operation process described in the above method embodiments.

[0572] Specifically, the baseband processing on the CU and the DU can be divided according to the protocol layer of the wireless network, and details can be referred to the content in Figure 3

[0573] In addition, optionally, the host base station 110 can include one or more radio units (RU), one or more DUs and one or more CUs. Among them, the DU can include at least one processor 11013 and at least one memory 11014, the RU can include at least one antenna 11011 and at least one radio frequency unit 11012, and the CU can include at least one processor 11022 and at least one memory 11021.

[0574] In one example, the CU 1102 can be composed of one or more single boards, and multiple single boards can jointly support a single access indicated wireless access network (such as a 5G network), or can separately support wireless access networks of different access systems (such as an LTE network, a 5G network or other networks). The memory 11021 and the processor 11022 can serve one or more single boards. That is, the memory and the processor can be separately arranged on each single board. Multiple single boards can also share the same memory and processor. In addition, necessary circuits can also be arranged on each single board. The DU 1101 can be composed of one or more single boards, and multiple single boards can jointly support a single access indicated wireless access network (such as a 5G network), or can separately support wireless access networks of different access systems (such as an LTE network, a 5G network or other networks). The memory 11014 and the processor 11013 can serve one or more single boards. That is, the memory and the processor can be separately arranged on each single board. Multiple single boards can also share the same memory and processor. In addition, necessary circuits can also be arranged on each single board.

[0575] For example, when the access network device is a target host node, the CU of the target host node can transmit data to the child node through the DU, for example, in the downlink direction, the CU of the target host node can generate data (such as PDCP data) and / or indication information, and then send it to the DU of the target host node through the interface between the CU and the DU, and the DU of the target host node sends the data to the child node of the DU through the antenna; in the uplink direction, the DU of the target host node can receive data from the child node through the antenna, and then send it to the CU of the target host node through the interface between the CU and the DU.

[0576] ​For example, when the access network device is a source host node, the CU of the source host node can transmit data to the child node through the DU, for example, in the downlink direction, the CU of the source host node can generate data (for example, PDCP data) and / or indication information, and then send the data to the DU of the source host node through the interface between the CU and the DU, and the DU of the source host node sends the data to the child node of the DU through an antenna; in the uplink direction, the DU of the source host node can receive data from the child node through the antenna, and then send the data to the CU of the source host node through the interface between the CU and the DU.

[0577] Figure 22 A structural diagram of a communication apparatus is provided for an embodiment of the present application. The communication apparatus can perform the method described in the method embodiment, and the description of the method embodiment can be referred to. The communication apparatus can be used in a communication device, a circuit, a hardware component, or a chip, for example, the communication apparatus can be a terminal, a chip in a terminal, a host node (including a source host node or a target host node), a chip in a host node (including a source host node or a target host node), a relay node (including a first relay node and a second relay node), or a chip in a relay node.

[0578] The communication apparatus 1900 includes a processing unit 1901 and a communication unit 1902. Optionally, the communication apparatus 1900 further includes a storage unit 1903.

[0579] The processing unit 1901 can be a device with processing functions, and can include one or more processors. The processor can be a general-purpose processor or a special-purpose processor, etc. The processor can be a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the apparatus (such as a host node, a terminal, or a chip, etc.), execute software programs, and process data of the software programs.

[0580] The communication unit 1902 can be a device with input (reception) or output (transmission) of signals, used for signal transmission with other network devices or other devices in the device.

[0581] The storage unit 1903 can be a device with storage functions, and can include one or more memories.

[0582] Optionally, the processing unit 1901, the communication unit 1902, and the storage unit 1903 are connected through a communication bus.

[0583] Optionally, the storage unit 1903 can exist independently, and is connected with the processing unit 1901 through a communication bus. The storage unit 1903 can also be integrated with the processing unit 1901.

[0584] Optionally, the communication apparatus 1900 can be a terminal or a chip in a host node in the embodiments. The communication unit 1902 can be an input or output interface, a pin or a circuit, etc. The storage unit 1903 can be a register, a cache or a RAM, etc. The storage unit 1903 can be integrated with the processing unit 1901; the storage unit 1903 can be a ROM or other type of static storage device that can store static information and instructions, and the storage unit 1903 can be independent of the processing unit 1901. Optionally, with the development of wireless communication technology, the transceiver can be integrated on the communication apparatus 1900, for example, the communication unit 1902 integrates the transceiver 612 shown in FIG. 6. Figure 19

[0585] In a possible design, the processing unit 1901 can include instructions that can be run on the processor, so that the communication apparatus 1900 performs the method of the terminal or the host node in the above-described embodiments.

[0586] In another possible design, the storage unit 1903 stores instructions that can be run on the processing unit 1901, so that the communication apparatus 1900 performs the method of the terminal or the host node in the above-described embodiments. Optionally, the storage unit 1903 can also store data. Optionally, the processing unit 1901 can also store instructions and / or data.

[0587] The communication apparatus 1900 can be a terminal in the embodiments. A schematic diagram of the terminal can be as shown in FIG. 6. Optionally, the communication unit 1902 of the apparatus 1900 can include an antenna and a transceiver of the terminal, for example, the antenna 612 and the transceiver 616 in FIG. 6. Optionally, the communication unit 1902 can also include an output device and an input device, for example, the output device 614 and the input device 615 in FIG. 6. Figure 19 Figure 19 Figure 19

[0588] When the communication apparatus 1900 is a terminal or a chip of the terminal in the embodiments, the communication apparatus 1900 can implement the functions of the terminal in the above-described method embodiments.

[0589] ​​​​For example, the processing unit 1901 can configure the first LCH and / or the second LCH and the like for the first bearer, process the received downlink data or the to-be-sent uplink data using the configuration information corresponding to the source host node or the configuration information corresponding to the target host node, map the uplink data processed by the configuration information corresponding to the source host node or the configuration information corresponding to the target host node to the first LCH or the second LCH and the like, process the uplink data according to the second indication information by using the PDCP configuration information corresponding to the target host node, and delete the first LCH according to the indication information. The communication unit 1902 can implement the transmission between the parent node of the terminal, for example, receiving downlink data or sending uplink data, or receiving indication information and the like.

[0590] When the communication apparatus 1900 is the source host node or the chip of the source host node in the embodiments of the present application, the communication apparatus 1900 can implement the functions of the source host node in the above method embodiments.

[0591] For example, the processing unit 1901 can generate the indication information or data and the like generated by the source host node in the above method embodiments. For example, the communication unit 1902 can perform transmission with the child node of the target source host node, for example, sending data and / or indication information to the child node, receiving data and / or indication information from the child node and the like.

[0592] When the communication apparatus 1900 is the target host node or the chip of the target host node in the embodiments of the present application, the communication apparatus 1900 can implement the functions of the target host node in the above method embodiments.

[0593] For example, the processing unit 1901 can generate the indication information or data and the like generated by the target host node in the above method embodiments. For example, the communication unit 1902 can perform transmission with the child node of the target host node, for example, sending data and / or indication information to the child node, receiving data and / or indication information from the child node and the like.

[0594] It should be understood that the terminal can have a function unit (means) corresponding to the method or steps of the terminal, the relay node can have a function unit corresponding to the method or steps of the relay node, the source host node (for example, CU and / or DU) can have a function unit corresponding to the method (for example, CU and / or DU) or steps of the source host node, the target host node (for example, CU and / or DU) can have a function unit corresponding to the method or steps of the target host node (for example, CU and / or DU), the CU of the source host node can have a function unit corresponding to the method or steps of the CU of the source host node, and other nodes in the relay system can have a function unit corresponding to the other nodes. One or more of the above modules or units can be implemented in software, hardware, or a combination of both. When any of the above modules or units is implemented in software, the software exists in the form of computer program instructions and is stored in a memory, and a processor can be used to execute the program instructions to implement the above method processes.

[0595] The processor in the present application can include but is not limited to at least one of the following: a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a microcontroller unit (MCU), or an artificial intelligence processor, and various computing devices running software, each of which can include one or more cores for executing software instructions to perform calculations or processing. The processor can be a separate semiconductor chip, or can be integrated with other circuits as a semiconductor chip, for example, it can be integrated with other circuits (such as coding and decoding circuits, hardware acceleration circuits, or various bus and interface circuits) to form a SoC (system on a chip), or it can be integrated as a built-in processor in an ASIC (application-specific integrated circuit). The ASIC integrated with the processor can be packaged separately or packaged together with other circuits. In addition to including cores for executing software instructions to perform calculations or processing, the processor can further include necessary hardware accelerators, such as FPGAs (field programmable gate arrays), PLDs (programmable logic devices), or logic circuits that implement special logic operations.

[0596] The memory in the embodiments of the present application can include at least one of the following types: read-only memory (ROM) or other types of static storage devices that can store static information and instructions, random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, and can also be electrically erasable programmable read-only memory (EEPROM). In some scenarios, the memory can also be a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage medium or other magnetic storage device, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and capable of being accessed by a computer, but not limited thereto.

[0597] The bus can include not only a data bus, but also a power bus, a control bus, and a status signal bus, etc. However, for the purpose of clarity, all kinds of buses are marked as bus in the figure.

[0598] In the implementation process, each step of the above method can be completed by integrated logic circuits of hardware in the processor or instructions in the form of software. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as hardware processor execution completion, or executed by a combination of hardware and software modules in the processor. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, a register, or other mature storage media in the art. The storage medium is located in the memory, and the processor reads the information in the memory and combines the hardware to complete the steps of the above method. To avoid repetition, it will not be described in detail here.

[0599] According to the method provided in the embodiments of the present application, the embodiments of the present application also provide a system, which includes the foregoing device and one or more network devices.

[0600] It should also be understood that the first, second, third, fourth, and various numerical numbers involved herein are only for the convenience of differentiation in description, and are not used to limit the scope of the embodiments of the present application, and the numerical numbers can be replaced by other numerical numbers.

[0601] It should be understood that the term "and / or" as used herein merely describes association between associated objects, and can indicate that three conditions can exist, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " generally indicates that the associated objects before and after the " / " have an "or" relationship.

[0602] It should be understood that the size of the sequence number of each process described above in various embodiments of the present application does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0603] Those of ordinary skill in the art can realize that the various illustrative logical blocks and steps described in connection with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0604] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed objects can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0605] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) manner. The computer readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be magnetic media (such as floppy disk, hard disk, magnetic tape), optical media (such as digital versatile disc (DVD)), or semiconductor media (such as solid state disk), etc.

[0606] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for configuring a logical channel LCH, characterized in that: The first data radio bearer DRB of the terminal corresponds to a first LCH, and the first LCH is used to transmit packet data convergence protocol PDCP data corresponding to the source donor node. The method includes: The first relay node generates configuration information of a second LCH corresponding to the first DRB, where the second LCH is used to transmit PDCP data corresponding to the target donor node; The first relay node sends configuration information of the second LCH to the terminal; Among them, the first relay node is the access relay node of the terminal, the source host node is the source host node switched by the first relay node, and the target host node is the target host node switched by the first relay node, or the source host node is the source host node switched by the second relay node, the target host node is the target host node switched by the second relay node, and the second relay node is a relay node on the link between the first relay node and the source host node.

2. The method according to claim 1, characterized in that The PDCP data corresponding to the source host node is processed through the PDCP configuration information corresponding to the source host node, and the PDCP data corresponding to the target host node is processed through the PDCP configuration information corresponding to the target host node.

3. The method according to claim 1 or 2, characterized in that The method further comprises: The first relay node receives first indication information from the source host node or the target host node; The first relay node generates configuration information of the second LCH according to the first indication information.

4. The method according to claim 3, characterized in that The first indication information is carried in a user equipment (UE) context modification request message received by the first relay node from the source donor node, or in a UE context establishment request message received by the first relay node from the target donor node.

5. The method according to claim 1 or 2, characterized in that: The method further comprises: After the first relay node receives the first message from the target host node, the first relay node generates configuration information of the second LCH.

6. The method according to claim 5, characterized in that The first message is a user equipment UE context establishment request message.

7. The method according to any one of claims 1 to 2, 4 and 6, characterized in that: The method further comprises: The first relay node sends second indication information to the terminal, where the second indication information is used to configure the second LCH for the first DRB, or to instruct the terminal to associate two LCHs for the first DRB.

8. The method according to any one of claims 1-2, 4 and 6, characterized in that: The method further comprises: The first relay node sends third indication information to the terminal, where the third indication information is used to instruct the terminal to use the PDCP configuration information corresponding to the target host node to process uplink data.

9. The method according to claim 8, characterized in that The source host node is a source host node for switching of the first relay node, and the target host node is a target host node for switching of the first relay node. The method includes: After the first relay node performs PUSCH conversion, or after the first relay node establishes a GTP tunnel with the target host node, the first relay node sends the third indication information to the terminal.

10. The method according to any one of claims 1-2, 4, 6, and 9, characterized in that: The method further comprises: The first relay node sends fourth indication information to the target host node, where the fourth indication information is used by the target host node to instruct the terminal to delete the first LCH.

11. The method according to claim 10, characterized in that After the first relay node completes sending the PDCP data corresponding to the source host node cached by the first relay node to the terminal, the first relay node sends the fourth indication information to the target host node.

12. The method according to any one of claims 1-2, 4, 6, 9 and 11, characterized in that: The source host node is a source host node for switching of the first relay node, and the target host node is a target host node for switching of the first relay node. The method further includes: The first relay node receives fifth indication information from the target host node through the source host node; The first relay node maintains the connection with the source host node during the handover process according to the fifth indication information.

13. The method according to claim 12, characterized in that The method further comprises: The first relay node sends capability indication information to the target host node through the source host node, where the capability indication information is used to indicate the capability of the first relay node to support maintaining a connection with the source host node during a handover process.

14. The method according to any one of claims 1-2, 4, 6, 9, 11, and 13, characterized in that: The first LCH corresponds to a General Packet Radio Service Tunneling Protocol user plane GTP-U tunnel between the first relay node and the source host node, and the second LCH corresponds to a GTP-U tunnel between the first relay node and the target host node.

15. The method according to any one of claims 1-2, 4, 6, 9, 11, and 13, characterized in that: The method further comprises: The first relay node receives information about the Backhaul Adaptation Protocol (BAP) address assigned by the target host node through the source host node, wherein the BAP address assigned by the target host node to the first relay node is different from the BAP address assigned by the source host node to the first relay node.

16. The method according to any one of claims 1-2, 4, 6, 9, 11, and 13, characterized in that: The method also includes: the first relay node receives sixth indication information from the target host node, and the sixth indication information is used to instruct the first relay node to start, activate or enable the dual configuration of the BAP layer, and the dual configuration of the BAP layer includes the BAP configuration corresponding to the source host node and the BAP configuration corresponding to the target host node.

17. A method for configuring a logical channel LCH, characterized in that: The first DRB of the terminal corresponds to the first LCH, and the first LCH is used to transmit PDCP data corresponding to the source donor node. The method includes: The terminal receives configuration information of a second LCH from the first relay node, where the second LCH is used to transmit PDCP data corresponding to the target donor node; The terminal configures the second LCH for the first DRB; Among them, the first relay node is the access relay node of the terminal, the source host node is the source host node switched by the first relay node, and the target host node is the target host node switched by the first relay node, or the source host node is the source host node switched by the second relay node, the target host node is the target host node switched by the second relay node, and the second relay node is a relay node on the link between the first relay node and the source host node.

18. The method according to claim 17, characterized in that The PDCP data corresponding to the source host node is processed through the PDCP configuration information corresponding to the source host node, and the PDCP data corresponding to the target host node is processed through the PDCP configuration information corresponding to the target host node.

19. The method according to claim 17 or 18, characterized in that The method further comprises: The terminal receives first indication information from the first relay node; Configuring, by the terminal, the second LCH for the first DRB includes: The terminal configures the second LCH for the first DRB according to the first indication information, so that the first DRB is associated with two LCHs.

20. The method according to claim 17 or 18, characterized in that The PDCP data corresponding to the target donor node includes PDCP uplink data corresponding to the target donor node, and the method further includes: The terminal receives second indication information from the first relay node; The terminal processes the uplink data according to the second indication information using the PDCP configuration information corresponding to the target host node to obtain the PDCP uplink data corresponding to the target host node.

21. The method according to claim 17 or 18, characterized in that The PDCP data corresponding to the target donor node includes PDCP uplink data corresponding to the target donor node, and the method further includes: After the terminal receives the configuration information of the second LCH from the target host node through the first relay node, the terminal processes the uplink data according to the PDCP configuration information corresponding to the target host node to obtain the PDCP uplink data corresponding to the target host node.

22. The method according to claim 17 or 18, characterized in that The method further comprises: The terminal receives third indication information from the first relay node; The terminal deletes the first LCH according to the third indication information.

23. A communication device, characterized in that: The method comprises at least one processor and a memory coupled to the at least one processor, wherein the at least one processor is configured to execute the method according to any one of claims 1 to 16.

24. The device according to claim 23, characterized in that The device is a relay node or a chip in a relay node.

25. A communication device, characterized in that: The method comprises at least one processor and a memory coupled to the at least one processor, wherein the at least one processor is configured to execute the method according to any one of claims 17 to 22.

26. The device according to claim 25, characterized in that The device is a terminal or a chip in a terminal.

27. A computer-readable storage medium, characterized in that A program or instruction for implementing the method according to any one of claims 1 to 16 or any one of claims 17 to 22 is stored.

28. A computer program product, characterized in that A program or instruction for implementing the method according to any one of claims 1 to 16 or any one of claims 17 to 22 is stored.

Images