A data packet transmission mechanism and apparatus

Abstract

The present application relates to a data packet transmission mechanism and device. Regarding the data packet transmission mechanism, a scheme is provided in which transmission configuration information for data of various attributes is configured at a relay node so that the relay node performs transmission of the corresponding data in various manners according to the configured transmission configuration information.

Description

Technical Field

[0001] This application relates to wireless communication technology, and in particular to a data packet transmission mechanism and device. Background Technology

[0002] To meet the increased demand for wireless data communication services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or near-5G communication systems. Therefore, 5G or near-5G communication systems are also referred to as "super 4G networks" or "post-LTE systems".

[0003] Wireless communication is one of the most successful innovations in modern history. Recently, the number of subscribers to wireless communication services surpassed 5 billion and continues to grow rapidly. The demand for wireless data services is growing rapidly due to the increasing prevalence of smartphones and other mobile data devices (such as tablets, laptops, netbooks, e-book readers, and machine-type devices) among consumers and businesses. To meet the rapid growth of mobile data services and support new applications and deployments, improving the efficiency and coverage of wireless interfaces is crucial. Summary of the Invention

[0004] According to one aspect of an embodiment of this application, a method is provided performed by a first node in a communication system, comprising: receiving configuration information related to data transmission; and transmitting data of the first node and / or data of a fifth node according to the configuration information related to data transmission.

[0005] In one embodiment, the configuration information related to data transmission includes at least one of the following: data attribute indication information, data transmission configuration information, and data request information.

[0006] In one embodiment, the data attribute indication information includes at least one of the following: attribute identification information, data type indication information, indication information belonging to a first node, indication information belonging to a fifth node, indication information of the node to which it belongs, indication information of the route to which it belongs, indication information of the destination receiving node to which it belongs, indication information of the source sending node to which it belongs, indication information of the transmission path to which it belongs, indication information of the backhaul link channel used, and indication information of the information contained therein. The data transmission configuration information includes at least one of the following: cell group indication information, cell indication information, transmission method indication information, transmission network indication information, indication information of transmitting data using LTE, indication information of transmitting data using 5G or NR, indication information of transmitting data using RRC or SRB, indication information of transmitting data using a backhaul link channel, indication information of transmitting data using a primary cell group (MCG), and indication information of transmitting data using a secondary cell group (S). The information includes indications for CG transmission data, indications related to transmission routes, indications related to transmission channels, information related to transmission routes to be added, and indications for information to be removed. Furthermore, the indications for transmitting data using Radio Resource Control (RRC) or Signaling Radio Bearer (SRB) can also indicate the type of SRB for the transmitted data, including SRB1, and / or SRB2, and / or SRB3, and / or a new SRB type. The data request information includes at least one of the following: radio bearer identification information; configuration information for user plane data carried by the radio bearer, including at least one of the following: uplink tunnel information, downlink tunnel information, source address information, destination address information, route identification information, path identification information; and information on the backhaul link channel used to transmit user plane data, including at least one of the following: identification information of the backhaul link channel used to send user plane data, and identification information of the backhaul link channel used to receive user plane data.

[0007] In one embodiment, transmitting data of the first node and / or the fifth node according to the configuration information related to data transmission includes: transmitting data between the first node and the third node via a backhaul link channel, an RRC message, or an SRB according to the configuration information related to data transmission; or transmitting data between the first node and the third node via a fourth node according to the configuration information related to data transmission.

[0008] In one implementation, the data is at least one of the following: user plane data, control plane data.

[0009] In one implementation, the radio bearer is a signaling radio bearer and user plane data is transmitted using a defined new RRC message or by defining a new container in an existing RRC message, or the radio bearer is a data radio bearer or a new radio bearer.

[0010] According to another aspect of the embodiments of this application, a method performed by a third node in a communication system is provided, comprising: sending configuration information related to data transmission to a first node, and transmitting data of the first node and / or data of a fifth node according to the configuration information related to data transmission.

[0011] In one embodiment, the configuration information related to data transmission includes at least one of the following: data attribute indication information, data transmission configuration information, and data request information.

[0012] In one embodiment, the data attribute indication information includes at least one of the following: attribute identification information, data type indication information, indication information belonging to a first node, indication information belonging to a fifth node, indication information of the node to which it belongs, indication information of the route to which it belongs, indication information of the destination receiving node to which it belongs, indication information of the source sending node to which it belongs, indication information of the transmission path to which it belongs, indication information of the backhaul link channel used, and indication information of the information contained therein. The data transmission configuration information includes at least one of the following: cell group indication information, cell indication information, transmission method indication information, transmission network indication information, indication information of transmitting data using LTE, indication information of transmitting data using 5G or NR, indication information of transmitting data using RRC or SRB, indication information of transmitting data using a backhaul link channel, indication information of transmitting data using MCG, and indication information of transmitting data using SCG. The information includes indications related to transmission routes, indications related to transmission channels, information related to transmission routes to be added, and indications of information to be removed. Further, the indications for transmitting data using RRC or SRB can also indicate the type of SRB for the transmitted data, including SRB1, and / or SRB2, and / or SRB3, and / or a new SRB type, etc. The data request information includes at least one of the following: radio bearer identification information; configuration information of the user plane data carried by the radio bearer, including at least one of the following: uplink tunnel information, downlink tunnel information, source address information, destination address information, route identification information, path identification information; and information of the backhaul link channel used to transmit user plane data, including at least one of the following: identification information of the backhaul link channel used to send user plane data, and identification information of the backhaul link channel used to receive user plane data.

[0013] In one implementation, the configuration information related to data transmission is configuration information for the data of the first node or for the data of the fifth node.

[0014] In one embodiment, the method performed by the third node further includes: the third node sending a second request message to the second node including configuration information related to data transmission for the first node; and the third node receiving from the second node a second response message including configuration information related to data transmission for the first node generated by the second node in response to the second request message, wherein the configuration information related to data transmission sent to the first node is based on the second request message and / or the second response message; or, the third node sending a sixth request message to the fourth node including at least one of configuration information related to data transmission for the first node, instruction information instructing the fourth node to transmit data, instruction information instructing the fourth node to transmit data of the first node, or instruction information instructing the fourth node to transmit data of the fifth node; and the third node receiving from the fourth node a sixth response message including configuration information related to data transmission for the first node generated by the fourth node in response to the sixth request message, wherein the configuration information related to data transmission sent to the first node is based on the sixth request message and / or the sixth response message.

[0015] In one embodiment, the method performed by the third node further includes: the third node receiving from the second node a fourth request message including configuration information of the first node and / or configuration information of the first node related to data transmission; and the third node sending to the second node a fourth response message generated in response to the fourth request message regarding configuration information of the first node related to data transmission, wherein the configuration information related to data transmission sent to the first node is based on the fourth request message and / or the fourth response message; or, the third node receiving from the fourth node an eighth request message including configuration information of the first node related to data transmission; and the third node sending to the fourth node an eighth response message generated in response to the eighth request message regarding configuration information of the first node related to data transmission, wherein the configuration information related to data transmission sent to the first node is based on the eighth request message and / or the eighth response message.

[0016] In one embodiment, the method performed by the third node further includes: the third node receiving an eleventh request message from the fourth node, and the third node sending an eleventh response message in response to the eleventh request message to the fourth node, wherein the configuration information related to data transmission sent to the first node is based on the eleventh request message or the eleventh response message, wherein the eleventh request message includes one of the following: identification information of the radio bearer, configuration information of the tunnel used by the fourth node to receive user plane data, and for each tunnel, the configuration information includes one of the following: the Internet Protocol IP address of the fourth node, and the tunnel endpoint identifier; and wherein the eleventh response message includes one of the following: identification information of the radio bearer, configuration information of the tunnel used by the third node to receive user plane data, and for each tunnel, the configuration information includes one of the following: the IP address of the third node, and the tunnel endpoint identifier; indication information related to transmission routing, including one of the following: route identification information, Backhaul Adaptation Protocol (BAP) address information, and path identification information; indication information related to transmission channels, including one of the following: identification information of the backhaul link channel used to transmit user plane data, and identification information of the backhaul link channel used to receive user plane data.

[0017] In one implementation, the radio bearer is a signaling radio bearer, and user plane data is transmitted using a defined new RRC message or by defining a new container in an existing RRC message; or, the radio bearer is a data radio bearer or a new radio bearer.

[0018] In one embodiment, transmitting data from the first node and / or the fifth node according to the configuration information related to data transmission includes: the third node transmitting user plane data to the fourth node via a control message, wherein the control message includes at least one of the following: user plane data; indication information related to transmission routing, including at least one of route identification information, BAP address information, and path identification information; and indication information related to transmission channels, including at least one of the identification information of the backhaul link channel used to send user plane data and the identification information of the backhaul link channel used to receive user plane data.

[0019] In one implementation, the data is at least one of the following: user plane data, control plane data.

[0020] In one embodiment, transmitting data of the first node and / or the fifth node according to the configuration information related to data transmission includes: transmitting data between the third node and the first node via a backhaul link channel, an RRC message, or an SRB according to the configuration information related to data transmission; or transmitting data between the third node and the first node via a fourth node according to the configuration information related to data transmission.

[0021] According to another aspect of the embodiments of this application, a method performed by a fourth node in a communication system is provided, comprising: acquiring configuration information related to data transmission; and transmitting data of a first node and / or data of a fifth node according to the configuration information related to data transmission.

[0022] In one embodiment, the configuration information related to data transmission includes at least one of the following: data attribute indication information, data transmission configuration information, and data request information.

[0023] In one embodiment, the data attribute indication information includes at least one of the following: attribute identification information, data type indication information, indication information belonging to a first node, indication information belonging to a fifth node, indication information of the node to which it belongs, indication information of the route to which it belongs, indication information of the destination receiving node to which it belongs, indication information of the source sending node to which it belongs, indication information of the transmission path to which it belongs, indication information of the backhaul link channel used, and indication information of the information contained therein. The data transmission configuration information includes at least one of the following: cell group indication information, cell indication information, transmission method indication information, transmission network indication information, indication information of transmitting data using LTE, indication information of transmitting data using 5G or NR, indication information of transmitting data using RRC or SRB, indication information of transmitting data using a backhaul link channel, indication information of transmitting data using MCG, indication information of transmitting data using SCG, indication information related to transmission routes, indication information related to transmission channels, information related to transmission routes to be added, and indication information of information to be removed. Further, the indication information of transmitting data using RRC or SRB can also be... The data request information includes the type of SRB indicating the data transmission, including SRB1, and / or SRB2, and / or SRB3, and / or a new SRB type, etc., and wherein the data request information includes at least one of the following: identification information of the radio bearer; configuration information of the user plane data carried by the radio bearer, including at least one of the following: uplink tunnel information, downlink tunnel information, source address information, destination address information, routing identification information, path identification information; and information of the backhaul link channel used by the first node to transmit the user plane data, including at least one of the following: identification information of the backhaul link channel used to send the user plane data, and identification information of the backhaul link channel used to receive the user plane data.

[0024] In one embodiment, obtaining configuration information related to data transmission includes: receiving a sixth request message from a third node, the sixth request message including one of the following: configuration information related to data transmission for a first node, instruction information instructing a fourth node to transmit data, instruction information instructing a fourth node to transmit data from a first node, or instruction information instructing a fourth node to transmit data from a fifth node; and generating a sixth response message based on the sixth request message, containing configuration information related to data transmission for the first node, and sending it to the third node.

[0025] In one embodiment, obtaining configuration information related to data transmission includes: the fourth node sending an eighth request message including configuration information related to data transmission to the third node; and the fourth node receiving an eighth response message from the third node in response to the eighth request message, including configuration information related to data transmission generated by the third node.

[0026] In one implementation, the method performed by the fourth node further includes: the fourth node sending the configuration information related to data transmission to the first node.

[0027] According to one aspect of an embodiment of this application, a method is provided performed by a second node in a communication system, comprising: the second node receiving from a third node a second request message including configuration information related to data transmission for a first node, and sending to the third node a second response message including configuration information related to data transmission for the first node generated in response to the received second request message.

[0028] In one embodiment, the configuration information related to data transmission includes at least one of the following: indication information of data attributes, and data transmission configuration information.

[0029] In one embodiment, the data attribute indication information includes at least one of the following: attribute identification information, data type indication information, indication information belonging to a first node, indication information belonging to a fifth node, indication information of the node to which it belongs, indication information of the route to which it belongs, indication information of the destination receiving node to which it belongs, indication information of the source sending node to which it belongs, indication information of the transmission path to which it belongs, indication information of the backhaul link channel used, and indication information of the information contained therein. The data transmission configuration information includes at least one of the following: cell group indication information, cell indication information, transmission method indication information, transmission network indication information, and so on. Indication information for transmitting data using LTE, 5G or NR, RRC or SRB, backhaul link channel, MCG, SCG, transmission routing, transmission channel, information to be added, and information to be removed. Furthermore, the indication information for transmitting data using RRC or SRB can also indicate the type of SRB for the transmitted data, including SRB1, SRB2, SRB3, and / or a new SRB type.

[0030] According to another aspect of this application, a first node in a communication system is provided, comprising: a transceiver configured to receive and transmit signals; a memory configured to store data; and a processor coupled to the memory and configured to perform a method of the first node according to an embodiment of this application.

[0031] According to another aspect of this application, a third node in a communication system is provided, comprising: a transceiver configured to receive and transmit signals; a memory configured to store data; and a processor coupled to the memory and configured to perform a method of the third node according to an embodiment of this application.

[0032] According to another aspect of this application, a fourth node in a communication system is provided, comprising: a transceiver configured to receive and transmit signals; a memory configured to store data; and a processor coupled to the memory and configured to perform a method of the fourth node according to an embodiment of this application.

[0033] According to another aspect of this application, a second node in a communication system is provided, comprising: a transceiver configured to receive and transmit signals; a memory configured to store data; and a processor coupled to the memory and configured to perform a method of the second node according to an embodiment of this application. Attached Figure Description

[0034] Figure 1 This is an exemplary system architecture for System Architecture Evolution (SAE);

[0035] Figure 2 These are exemplary system architectures based on various embodiments of this disclosure;

[0036] Figure 3 This is a schematic diagram of a multi-hop network architecture;

[0037] Figure 4 This is an example of a data transmission scenario;

[0038] Figure 5 This is an example method for data transmission according to an embodiment of this application;

[0039] Figure 6 This is yet another example method of data transmission according to embodiments of this application;

[0040] Figure 7 This is an example diagram illustrating the configuration process for data transmission according to an embodiment of this application;

[0041] Figure 8 This is another example diagram of the configuration process for data transmission according to an embodiment of this application;

[0042] Figure 9This is yet another example diagram of the configuration process for data transmission according to an embodiment of this application;

[0043] Figure 10 This is an example diagram illustrating the configuration process for user plane data transmission according to an embodiment of this application;

[0044] Figure 11 This is yet another example diagram of the configuration process for user plane data transmission according to an embodiment of this application;

[0045] Figure 12 A simplified block diagram illustrating an example configuration of the hardware components of a communication device 1200 according to various embodiments of the present disclosure is shown;

[0046] Figure 13 A simplified block diagram illustrating an example configuration of the hardware components of a communication device 1300 according to various embodiments of the present disclosure is shown;

[0047] Figure 14 A simplified block diagram illustrating an example configuration of the hardware components of a communication device 1400 according to various embodiments of the present disclosure is shown;

[0048] Figure 15 A simplified block diagram illustrating an example configuration of the hardware components of a communication device 1500 according to various embodiments of the present disclosure is shown. Detailed Implementation

[0049] The following discussion Figures 1 to 15 The various embodiments used to describe the principles of this disclosure in this patent document are for illustrative purposes only and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged system or device.

[0050] Figure 1This is an exemplary system architecture 100 of System Architecture Evolution (SAE). User Equipment (UE) 101 is a terminal device used to receive data. Evolved Universal Terrestrial Radio Access Network (E-UTRAN) 102 is a radio access network, including macro base stations (eNodeB / NodeB) that provide the UE with an interface to access the radio network. Mobility Management Entity (MME) 103 is responsible for managing the UE's mobility context, session context, and security information. Serving Gateway (SGW) 104 primarily provides user plane functions; MME 103 and SGW 104 may reside in the same physical entity. Packet Data Network Gateway (PGW) 105 is responsible for functions such as charging and lawful interception, and may also reside in the same physical entity as SGW 104. Policy and Charging Rules Function Entity (PCRF) 106 provides Quality of Service (QoS) policies and charging criteria. Universal Packet Radio Service Support Node (SGSN) 108 is a network node device in the Universal Mobile Telecommunications System (UMTS) that provides routing for data transmission. The Home Subscriber Server (HSS) 109 is the UE's home subsystem, responsible for protecting user information including the UE's current location, the address of the serving node, user security information, and the UE's packet data context.

[0051] Figure 2 This is an exemplary system architecture 200 according to various embodiments of the present disclosure. Other embodiments of the system architecture 200 can be used without departing from the scope of the present disclosure.

[0052] User Equipment (UE) 201 is the terminal equipment used to receive data. Next-Generation Radio Access Network (NG-RAN) 202 is the radio access network, which includes base stations (gNBs or eNBs connected to the 5G core network 5GC; eNBs connected to the 5GC are also called ng-gNBs) that provide the UE with an access radio network interface. Access Control and Mobility Management Function Entity (AMF) 203 is responsible for managing the UE's mobility context and security information. User Plane Function Entity (UPF) 204 primarily provides user plane functions. Session Management Function Entity (SMF) 205 is responsible for session management. Data Network (DN) 206 includes services such as operator services, internet access, and third-party services.

[0053] Exemplary embodiments of this disclosure are further described below with reference to the accompanying drawings.

[0054] The text and accompanying drawings are provided by way of example only to aid in understanding this disclosure. They should not be construed as limiting the scope of this disclosure in any way. Although certain embodiments and examples have been provided, it will be apparent to those skilled in the art, based on the content disclosed herein, that changes may be made to the illustrated embodiments and examples without departing from the scope of this disclosure.

[0055] In NR (New Radio) networks, a relay network architecture called IAB (Integrated Access and Backhaul) was proposed to extend network coverage. Figure 3A schematic architecture of a multi-hop relay network (IAB network) is presented. The figure shows a network architecture including an anchor node (e.g., IAB donor / anchor) and two relay nodes (e.g., IABnode, IAB node). Users in this multi-hop network can access the network through the anchor node, its distribution unit, or the relay node. For example, users 1, 2, and 3 can access the relay network through the distribution unit of the anchor node, the distribution unit of relay node 1, and the distribution unit of relay node 2, respectively. The anchor node can be an independent base station or a base station composed of a central unit (CU) and a distributed unit (DU). A relay node includes a mobile terminal function and a distributed unit function (or, in another example, a relay node comprising a mobile terminal function portion and a distributed unit function portion). The mobile terminal function portion of the relay node is used to communicate with its upstream node (e.g., the mobile terminal portion of relay node 1 communicates with the anchor node or the anchor node's distributed unit, and the mobile terminal portion of relay node 2 communicates with the distributed unit portion of relay node 1). The distributed unit function portion of the relay node is used to communicate with its downstream node (e.g., the distributed unit portion of relay node 1 communicates with user 2, and can also communicate with the mobile terminal portion of relay node 2). The mobile terminal portion of the relay node can be considered as a user accessing the network, and therefore has the functions of a regular user (non-relay node) (e.g., the mobile terminal portion can establish a signaling radio bearer (SRB) with its upstream node to send RRC messages, and can also establish a data radio bearer (DRB) to send data). The centralized unit of the anchor node includes the following protocol stacks: a service control plane protocol stack, which includes the Radio Resource Control (RRC) protocol layer and the Packet Data Convergence Protocol (PDCP) layer; and a service user plane protocol stack, which includes the Service Data Adaptation Protocol (SDAP) layer and the PDCP layer. The distribution unit of the anchor node or the distribution unit portion of the relay node includes the following protocol stacks: service control plane and user plane protocol stacks, which include the Radio Link Control (RLC) protocol layer, the Media Access Control (MAC) protocol layer, and the Physical Layer (PHY). The interface between the centralized unit and the distribution unit of the anchor node, and between the centralized unit and the distribution unit of the relay node, is the F1 interface (see 3GPP TS38.473, the entire contents of which are incorporated herein by reference).

[0056] In a relay network, the link between a relay node and an anchor node or the distribution unit of an anchor node, or between relay nodes, is called a backhaul link. One or more different backhaul channels can be established on this backhaul link, for example... Figure 3 The diagram shows backhaul link channel 1 and backhaul link channel 2. A non-limiting example of a backhaul link channel is the backhaul Radio Link Control (RLC) channel. In a relay network, each backhaul link channel can be used to transmit data packets belonging to the same or different users. These data packets can be user data radio bearer (DRB) packets, user signaling radio bearer (SRB) packets, control plane packets on the F1 interface, user plane packets on the F1 interface, or packets from non-F1 interfaces (such as IPSec packets, SCTP protocol packets, OAM packets, etc.).

[0057] To enable user data transmission in multi-hop relay networks, 3GPP defines a new protocol layer, the Backhaul Adaptation Protocol layer (BAP). This layer is configured in the distribution unit of the anchor node and relay nodes (such as the mobile terminal portion and / or the distribution unit portion of the relay node), located above the RLC layer. Its main function is packet routing and packet mapping. For user data to be sent between relay nodes and anchor nodes, the backhaul link configuration and the F1 interface configuration between the distribution unit portion of the relay node and the anchor node need to be completed. These configurations include, but are not limited to, the following types: BAP address, routing configuration (such as routing identification information, which indicates different transmission routes and includes the BAP address and path identifier of the destination receiving node), backhaul link channel configuration, tunnel configuration, and backhaul link configuration for tunnels.

[0058] In a relay network, the centralized unit of the anchor node and the distributed unit of the relay node can establish an F1 interface. This interface needs to transmit control plane data (such as the F1-C data stream) and user plane data (such as the F1-U data stream). When the relay node is in single-connection mode (i.e., the relay node maintains a connection with only one base station, which is the anchor node), both the F1-C and F1-U data streams need to be transmitted through the link between the anchor node and the relay node. However, when the relay node is in dual-connection mode (i.e., the relay node maintains a connection with two base stations, at least one of which is the anchor node), the F1-C and F1-U data streams can be transmitted through both base stations.

[0059] In current research, control plane data streams and user plane data streams between relay nodes and anchor nodes may be transmitted using the same transmission path, the same network technology, or, in the case of dual connectivity, by the same base station. However, in real-world systems, control plane data streams require higher reliability and lower latency, while user plane data streams require faster rates. Therefore, existing transmission methods may lead to performance degradation in control plane data streams (such as decreased reliability and increased latency).

[0060] Furthermore, when a relay node is in a dual-connectivity state, the PScell ​​(Primary Secondary Cell) of the serving relay node may change. During this process, data communication between the relay node and the secondary base station will be interrupted. This will cause data transmission interruption for the users served by the relay node.

[0061] For the transmission of control plane data streams and user plane data streams, one solution is to separate the transmission of control plane data and user plane data of relay nodes, such as by having them transmitted by two different base stations. However, this solution still has the following problems: 1. It is impossible to complete the configuration of separating control plane data and user plane data; 2. It does not consider how to transmit control plane data and user plane data of the relay node's child nodes.

[0062] One aspect of the solution in this application is to configure data transmission by having the relay node interact with one or more base stations it is connected to via signaling, thereby enabling data transmission on the relay node and its connected child nodes.

[0063] There is no solution in the prior art for the data interruption problem that occurs when the PSCell of a service relay node changes. One aspect of the solution proposed in this application is to reduce data transmission interruptions by using a method where the relay node transmits user data to the master node it is connected to.

[0064] It should be understood that the message names used in the description of this application are merely examples, and other message names may also be used. Furthermore, the use of terms such as "first," "second," etc., in the message names in the description of this application are merely examples of message names used to distinguish one message from another, and do not represent the order of execution, nor imply any relationship between the messages. Moreover, steps that include response messages (such as second response message, fourth response message, sixth response message, eighth response message, eleventh response message) may be mandatory or optional.

[0065] Furthermore, in order to avoid obscuring the key points of this application, detailed descriptions of steps unrelated to the key points of this application have been omitted in this application.

[0066] Furthermore, in this application, the terms "mobile terminal function of relay node" and "mobile terminal part of relay node" are used interchangeably, as are the terms "distribution unit function of relay node" and "distribution unit part of relay node".

[0067] Before proceeding with the detailed description of this application, it is advantageous to clarify the meanings of the various terms used in the following detailed description, some of which are described below:

[0068] In this application, the control plane data includes at least one of the following:

[0069] ■F1-C data refers to control plane data on the F1 interface (the interface between the centralized unit and the distributed unit of the base station, or the interface between the centralized unit and the distributed unit of the anchor node, or the interface between the centralized unit of the anchor node and the functional part of the distributed unit of the relay node).

[0070] ■The data carried by the SRB, such as data containing RRC messages,

[0071] ■Xn-C data, i.e., control plane data on the Xn interface (the interface between gNBs).

[0072] ■X2 data, namely control plane data on the X2 interface (the interface between the LTE eNB and gNB).

[0073] In one embodiment, the control plane data may be an IP packet (which contains at least one of an IP header, an SCTP header, a PDCP PDU, and an F1AP / RRC / XnAP / X2AP message); in another embodiment, the control plane data may be a BAP packet (which contains at least one of a BAP header, an IP header, an SCTP header, a PDCP header, and an F1AP / RRC / XnAP / X2AP message); in yet another embodiment, the control plane data may be a PDCP PDU; and in yet another embodiment, the control plane data may be an F1AP / RRC / XnAP / X2AP message.

[0074] In this application, the user plane data can be at least one of the following:

[0075] ■F1-U data, i.e., user plane data on the F1 interface.

[0076] ■The data carried by the DRB is the user plane data of the wireless air interface.

[0077] ■Xn-U data, i.e., user plane data on the Xn interface.

[0078] ■X2-U data, i.e., user plane data on the X2 interface.

[0079] In one embodiment, user plane data may be an IP packet (which contains at least one of an IP header, a GTP-U header, and a PDCP PDU); in another embodiment, user plane data may be a BAP packet carrying data (which contains at least one of a BAP header, an IP header, a GTP-U header, and a PDCP PDU); in yet another embodiment, user plane data may be a PDCP PDU.

[0080] In this application, unless otherwise specified, the term "data" may refer to control plane data, user plane data, or both. Throughout the description of this application, "data transmission" refers to the receipt and / or transmission of data.

[0081] In this application, the BAP header of the data packet includes at least one of the following information:

[0082] ■The purpose is to receive the address information of the receiving node, such as the BAP address.

[0083] ■ Path identification information, such as path ID,

[0084] ■ Routing identification information, such as the BAP routing ID, includes the BAP address of the destination receiving node and path identification information.

[0085] ■ Flow control feedback information, such as backhaul link channel identifier information, available buffer size information for a backhaul link channel, route identifier information, and available buffer size information for a route identifier, etc.

[0086] ■ Flow control polling information

[0087] ■ Backhaul RLF Indication

[0088] For details of the BAP header, please refer to 3GPP TS38.340, the entire contents of which are incorporated herein by reference.

[0089] The main nodes involved in this application are as follows:

[0090] ■ First Node: First relay node, or the distribution unit functional part of the first relay node, or the mobile terminal functional part of the first relay node, or a regular user, or the distribution unit of a base station.

[0091] ■ Second node: The parent node (ascendant node) of the first node. This node can be an anchor node, or a distribution unit of an anchor node, or another relay node (second relay node), or a distribution unit functional part of another relay node, or a mobile terminal functional part of another relay node, or a base station, or a distribution unit of a base station.

[0092] ■ Third Node: A first base station (or a centralized unit of the first base station, or a control plane portion of the centralized unit of the first base station) serving the first node. The first base station can be a 5G base station, a 4G base station, or other types of network entities. In one embodiment, the node can be a first anchor node (or a centralized unit of the first anchor node, or a control plane portion of the centralized unit portion of the first anchor node, or a user plane portion of the centralized unit portion of the first anchor node) serving the first node, and the anchor node is a node that supports a relay network; in another embodiment, the node can be a base station (or a centralized unit of a base station, or a control plane portion of the centralized unit portion of a base station, or a user plane portion of the centralized unit portion of a base station) that does not support a relay network.

[0093] ■ Fourth Node: A second base station (or a centralized unit of a base station, or a control plane portion of a centralized unit of a base station, or a user plane portion of a centralized unit of a base station) serving the first node, which is distinct from the third node (or a centralized unit of a base station, or a control plane portion of a centralized unit of a base station, or a user plane portion of a centralized unit of a base station); this base station can be a 5G base station, a 4G base station, or other types of network entities. In one embodiment, this node can be an anchor node distinct from the third node, i.e., a second anchor node (or a centralized unit of a second anchor node, or a control plane portion of a centralized unit of a second anchor node, or a user plane portion of a centralized unit of a second anchor node) serving the first node, which is a node supporting relay network functions. In another embodiment, this node can be a base station (or a centralized unit of a base station, or a control plane portion of a centralized unit of a base station, or a user plane portion of a centralized unit of a base station) distinct from the third node, which is a node supporting some relay network functions or not supporting relay network functions.

[0094] Furthermore, when the first node establishes a dual connection, it can establish dual connections with the third and fourth nodes, and the first node establishes an interface (such as an F1 interface) with the third node. In one implementation, the third node is the master node and the fourth node is the secondary node; in another implementation, the third node is the secondary node and the fourth node is the master node.

[0095] ■ Fifth Node: A node distinct from the first node, which can be one or more other relay nodes. In one embodiment, the fifth node is a node (child node, descendant node) directly or indirectly (an indirect connection means connecting to the first node through one or more intermediate nodes) connected to the first node. The fifth node needs to communicate with the first node in the network.

[0096] The "data configuration information" mentioned in the detailed description of this application is defined and described as follows:

[0097] Data configuration information: This information is used to configure data transmission (i.e., sending and / or receiving) at the first node. This data can be data from the first node (or its distribution unit functional portion), or data from a fifth node (or its distribution unit functional portion) connected to the first node. This fifth node is distinct from the first node and can be another relay node or a distribution unit of another base station. In one embodiment, the fifth node is directly or indirectly (an indirect connection means connecting to the first node through one or more intermediate nodes) connected to the first node, and these nodes need to communicate with the third or fourth node through the first node. The receiving node for this configuration information can be one or more of the aforementioned first / second / third / fourth / fifth nodes; the specific process is described below.

[0098] The data configuration information contains configuration information related to data transmission, which includes at least one of the following:

[0099] ■ Data attribute indication information, which indicates information related to the transmitted data. Upon receiving this indication information, the receiving node will transmit the data indicated by the indication information according to one or more of the following "Data Transmission Configuration Information" (such as one or more of the following "Cell Group Indication Information," "Cell Indication Information," "Transmission Method Indication Information," and "Transmission Network Indication Information"). The data attribute indication information includes at least one of the following:

[0100] Attribute identification information, such as index information,

[0101] The data type indication information indicates whether the data is control plane data or user plane data.

[0102] The information indicates that the data transmitted by the first node belongs to the first node.

[0103] The indication information belongs to the fifth node, or to a node other than the first node. This information indicates that the data transmitted by the first node belongs to a node other than the first node.

[0104] The information indicates the node to which the data transmitted by the first node belongs. This information includes the identification information of one or more nodes, such as node ID, BAP address, gNB-DU ID, etc.

[0105] The information indicates the route to which the data transmitted by the first node belongs. This information is used to indicate the identification information of one or more routes to which the data belongs, such as the BAP routing ID (including the BAP address and path identification information of the destination receiving node).

[0106] The indication information is the destination receiving node identification information, which indicates the identification information of one or more destination receiving nodes to which the data transmitted by the first node belongs, such as BAP address, IP address, etc. Furthermore, this indication information may also include port information, etc.

[0107] The indication information identifies one or more source sending nodes to which the data transmitted by the first node belongs. This information may include BAP address, IP address, etc. Furthermore, this indication information may also include port information, etc.

[0108] The information indicates the transmission path to which the data transmitted by the first node belongs, including identification information such as path ID.

[0109] The information indicates the backhaul link channel used, which identifies one or more backhaul link channels used by the first node to transmit (receive or send) data. This backhaul link channel may be the channel used by the first node to receive data (e.g., Ingress BH RLC CH). Furthermore, it may include the identification information of the prior-hop node serving the backhaul link channel, such as its BAP address, and / or the channel used to transmit data (e.g., Egress BH RLC CH). Further, it may also include the identification information of the next-hop node serving the backhaul link channel, such as its BAP address.

[0110] If the data contains information indicated by the included information, then the first node will transmit the data according to the corresponding configuration information contained in the "Data Transmission Configuration Information" below. The included information may indicate that the included information is at least one of the following:

[0111] IP address information

[0112] Port information,

[0113] Source IP address information

[0114] Source port information,

[0115] Destination IP address information

[0116] Destination port information

[0117] Routing identification information, such as the BAP routing ID. In one embodiment, this identification information includes the BAP address of the destination receiving node and the path ID.

[0118] BAP address information. In one embodiment, this address information may be the address information of the destination receiving node; in another embodiment, this address information may be the address information of the source sending node.

[0119] Path identification information, such as path ID.

[0120] ■ Data transmission configuration information, used to configure the transmission of data with various attributes. For example, data with a certain attribute may correspond to one type of data transmission configuration information, and data with another attribute may correspond to another type of data transmission configuration information. In one embodiment, the data transmission configuration information may be configuration information for transmitting control plane data (such as F1-C data streams); in another embodiment, the data transmission configuration information may be configuration information for transmitting user plane data (such as F1-U data streams); and in yet another embodiment, the data transmission configuration information may be configuration information used when transmitting data indicated by the aforementioned "data attribute indication information". The data transmission configuration information includes at least one of the following:

[0121] Cell group indication information is used to indicate the cell group used for data transmission, which is the cell group serving the first node. The cell group indicated by this information can be at least one of the following cell groups:

[0122] In a Master Cell Group (MCG), the first node can utilize the Master Cell Group to transmit data. This Master Cell Group is the cell group served by the master base station. The master base station can be a master base station in dual-connectivity service mode or a multi-connectivity service mode.

[0123] A secondary cell group (SCG) is used by the primary node to transmit data. This secondary cell group is the group of cells served by the secondary base station. The secondary base station can be in dual-connectivity service mode or multi-connectivity service mode.

[0124] If there are primary and secondary cell groups, the first node can utilize both groups to transmit data. In one embodiment, an indication message can be used to indicate that both the primary and secondary cell groups can be used simultaneously for data transmission, such as "both".

[0125] Cell group identification information, such as Cell Group ID, is used to indicate the identification information of one or more cell groups transmitting data. In one implementation, the cell group identification information may include the identifiers of one or more cell groups, or it may indicate one or more cell groups in a bitmap format (i.e., in a bit string, each bit position corresponds to a cell group, and the value of each bit represents whether its corresponding cell group is used for data transmission, such as "1" indicating that it is used for data transmission).

[0126] "0" means no data is transmitted, or vice versa.

[0127] The cell indication information is used to indicate the cell used for data transmission, which is the cell serving the first node. In one implementation, the indication information may include the identifiers of one or more cells, or it may indicate one or more cells using a bitmap (i.e., in a bit string, each bit position corresponds to a cell, and the value of each bit represents whether its corresponding cell is used for data transmission, such as "1" for data transmission and "0" for no data transmission, or "1" for no data transmission and "0" for data transmission).

[0128] The transmission method indication information, which indicates the mode of data transmission, includes at least one of the following modes:

[0129] Data is transmitted using RRC messages (or signaling radio bearers, SRBs). This indication information indicates whether the first node can use RRC messages (or SRBs) to transmit data (e.g., indicating whether RRC messages (or SRBs) can be used, or indicating that RRC messages (or SRBs) cannot be used). The RRC message can be an LTE RRC message (as defined in 3GPP TS36.331) or a 5G NR (New Radio) RRC message (as defined in 3GPP TS38.331). Furthermore, this indication information can also be used to indicate the type of RRC message for transmitted data, such as LTE RRC messages and / or 5G NR RRC messages (e.g., indicating that LTE RRC messages and / or 5G NR RRC messages can be used, or indicating that LTE RRC messages and / or 5G NR RRC messages cannot be used). This indication information can also be used to indicate the type of SRB for transmitted data, such as SRB1, SRB2, SRB3, and / or new SRB types.

[0130] The indication information indicates that the first node can use the configured backhaul link channel to transmit data. This indication information can be explicit or implicit. In one implementation, once a backhaul link channel for transmitting data (such as control plane data, user plane data, or both) is configured for the first node, it can be explicitly indicated whether the configured backhaul link channel needs to be used to send data. In another implementation, it can be implicitly determined whether to use the backhaul link for data transmission based on whether a backhaul link channel for data transmission (and / or routing information, such as routing identification information like a BAP routing ID) is configured. For example, if configured, it implicitly indicates that the configured backhaul link needs to be used to send data; if not configured, it implicitly indicates that the backhaul link cannot be used to send data.

[0131] Using RRC messages (or SRBs) and a backhaul link channel to transmit data indicates that the first node can use these two methods to transmit data. In one embodiment, the method of transmitting data (i.e., using RRC messages (or SRBs) and a backhaul link channel) can be indicated by a single indication (e.g., "both" indicating the use of RRC messages (or SRBs) and a backhaul link channel). In another embodiment, the method of transmitting data can be indicated by multiple indications, for example, by an indication that "data can be transmitted using RRC messages (or SRBs)," and implicitly by configuring a backhaul link channel for data transmission.

[0132] This is a network indication information, used to indicate the network used for data transmission, and that this network serves the first node. The network indicated by this information...

[0133] The network includes at least one of the following:

[0134] In the case of an LTE network, the "transmission network indication information" indicates that the first node can utilize the LTE network to transmit data.

[0135] If the network is 5G (or NR), then the "indication information of the transmission network" indicates that the first node can use the 5G (or NR) network to transmit data.

[0136] If the network is LTE and 5G (or NR), then the "indication information of the transmission network" indicates that the first node can utilize LTE and 5G (or NR) to transmit data. In one embodiment, the network for transmitting data can be indicated by an indication message (e.g., "both" indicating that it can utilize LTE and 5G).

[0137] (or NR) to transmit data).

[0138] In one embodiment, the aforementioned "transmission network indication information" can be represented by F1-C transmission path indication information (such as f1c-TransferPath), and the network indicated by this information can be LTE, NR, or both (i.e., LTE and NR).

[0139] The information used in this embodiment indicates whether to use the LTE network for data transmission. In one embodiment, this information can indicate whether to use the LTE network for transmitting control plane data (such as F1-C data). For example, this information could be named f1c-via-LTE. If the information indicates "true," it means that the LTE network can be used to transmit control plane data; otherwise (if this information is not included, or if it indicates "false"), it means that the LTE network cannot be used to transmit control plane data. In another embodiment, this information can indicate whether to use the LTE network for transmitting user plane data (such as F1-U data). For example, this information could be named f1u-via-LTE. If this information indicates "true," it means that the LTE network can be used to transmit user plane data; otherwise (if this information is not included, or if it indicates "false"), it means that the LTE network cannot be used to transmit user plane data. In yet another embodiment, this information can indicate whether to use the LTE network for transmitting both control plane data (such as F1-C data) and user plane data (such as F1-U data). Upon receiving this information, the receiving node can determine whether the LTE network can be used to transmit data. Furthermore, the receiving node can determine the network for data transmission based on other configurations. For example, if a backhaul link channel for data transmission is configured at the receiving node, the NR network can be used for data transmission by default, and this indication information is used to indicate whether the LTE network can also be used for data transmission.

[0140] This information indicates whether or not to use a 5G (or NR) network for data transmission. Upon receiving this information, the receiving node can determine whether or not a 5G (or NR) network can be used for data transmission.

[0141] The indication information uses RRC (or SRB) to transmit data. This information indicates whether RRC (or SRB) should be used for data transmission. Upon receiving this information, the receiving node can determine whether RRC (or SRB) can be used for data transmission. Furthermore, this indication information can also be used to indicate the type of SRB used for data transmission, such as SRB1, SRB2, SRB3, and / or a new SRB type.

[0142] The information indicates whether or not the backhaul link channel should be used for data transmission. Upon receiving this information, the receiving node can determine whether the backhaul link channel can be used for data transmission.

[0143] The information used for MCG data transmission indicates whether or not MCG should be used for data transmission. Upon receiving this information, the receiving node can determine whether or not MCG can be used for data transmission.

[0144] The information indicating whether to use SCG for data transmission serves to specify whether SCG should be used. Upon receiving this information, the receiving node can determine whether SCG can be used for data transmission.

[0145] Indication information related to transmission routing, which includes at least one of the following:

[0146] Routing identification information, such as the BAP routing ID, indicates the routing identifier used to transmit data. For example, this routing identifier might contain the BAP address and path identification information of the destination receiving node.

[0147] BAP address information, which is the BAP address of the destination receiving node for the data.

[0148] Path identification information, which is the path used to send data to the destination receiving node.

[0149] Indication information related to the transmission channel, which includes at least one of the following:

[0150] The information includes the identification information of the backhaul link channel used to send data, such as the Egress BH RLC CH ID. This identification information can be the identification information of one or more channels. Upon receiving this information, the first node will use this channel to send the data. Furthermore, it may also include the identification information of the next-hop node serving this backhaul link channel, such as the BAP address.

[0151] The identification information of the backhaul link channel used to receive data, such as the Ingress BH RLC CH ID, can be the identification information of one or more channels. Furthermore, it can also include the identification information of the previous-hop node serving the backhaul link channel, such as the BAP address.

[0152] Information related to the transport routing that needs to be added, indicating the information that the node needs to add for received data packets. This information includes at least one of the following:

[0153] Routing identification information, such as the BAP routing ID, indicates the routing identifier used to transmit data. For example, this routing identifier might contain the BAP address and path identification information of the destination receiving node.

[0154] BAP address information, which is the BAP address of the destination receiving node for the data.

[0155] Path identification information, which is the path used to send data to the destination receiving node.

[0156] In one embodiment, upon receiving the "information about the transmission route to be added", the first node will add the information to the data packet before sending it out.

[0157] This is an indication of information to be removed, specifying which information a node needs to remove before sending received data packets. This information must include at least one of the following:

[0158] Routing identification information, such as the BAP routing ID, indicates the routing identifier used to transmit data. For example, this routing identifier might contain the BAP address and path identification information of the destination receiving node.

[0159] BAP address information, which is the BAP address of the destination receiving node for the data.

[0160] Path identification information, which is the path used to send data to the destination receiving node.

[0161] In one embodiment, after receiving the "instruction information for information to be removed", the first node will remove the information indicated by the instruction information contained in the data packet before sending it out.

[0162] ■ Data request information, which helps determine the configuration of the user plane data to be transmitted, includes at least one of the following:

[0163] Identification information carried by the wireless bearer

[0164] Configuration information for the user plane data carried by the radio bearer, which includes at least one of the following:

[0165] Information about the uplink tunnel, which includes at least one of the IP address of the third node and the tunnel endpoint identifier.

[0166] Information about the downlink tunnel, which includes at least one of the IP address of the first node and the tunnel endpoint identifier.

[0167] Source address information, such as IP address and / or BAP address, etc.

[0168] Destination address information, such as IP address and / or BAP address, etc.

[0169] Routing identification information, such as the BAP routing ID, in one embodiment includes the BAP address and path identification information of the destination receiving node.

[0170] Path identification information, such as path ID

[0171] Information about the backhaul link channel used for transmitting user plane data, wherein the backhaul link channel is the backhaul link channel used by the first node to transmit the user plane data, and such information includes at least one of the following:

[0172] The identification information of the backhaul link channel used to transmit user plane data, such as the Egress BH RLC CH ID, can be the identification information of one or more channels. Furthermore, it can also include the identification information of the next-hop node serving the backhaul link channel, such as the BAP address.

[0173] The identification information of the backhaul link channel used to receive user plane data, such as Ingress BH RLC CHID, can be the identification information of one or more channels. Furthermore, it can also include the identification information of the previous-hop node serving the backhaul link channel, such as the BAP address.

[0174] Furthermore, the aforementioned "data transmission configuration information" can be provided separately for data with different attributes indicated by "indication information of different data attributes".

[0175] Throughout the description of this application, it mainly concerns Figure 4 The three scenarios shown:

[0176] Scene 1

[0177] The first node is in single-connection mode. An F1 interface has been established between the first node and the third node.

[0178] Scene 2

[0179] The first node is in dual-connection mode. An F1 interface has been established between the first node and the third node. The third node acts as a secondary base station, and the fourth node acts as the primary base station.

[0180] Scene 3:

[0181] The first node is in dual-connection mode. An F1 interface has been established between the first node and the third node. The third node acts as the primary base station, and the fourth node acts as the secondary base station.

[0182] It should be understood that the above scenario is merely an example, and the scenarios to which this application can be applied are not limited to this. Furthermore, the number of relay nodes between the third node and the first node is only an example, and the number of child nodes connected to the first node is also only an example; other numbers are possible and not limited to those shown in the diagram. There may be other nodes between the first node and the fifth node. Therefore, the solution of this application is not limited to... Figure 2 The scenario shown is applicable to other scenarios as well.

[0183] Next, this application will be described from three aspects: data transmission, configuration of data transmission in relay nodes, and transmission of user plane data during PSCell changes.

[0184] First aspect: Data transmission

[0185] This section provides an example process for transferring data between a third (or fourth) node and a first node. The first node can transfer data with the third node in a single-connection mode, such as... Figure 4 (a) Alternatively, data can be transmitted between the third (or fourth) node in a dual-connection mode, such as... Figure 4 (b) and Figure 4 (c) The data may be transmitted on the interface (such as the F1 interface) between the first node (or the distribution unit functional part of the first node) and the third node, or it may be transmitted on the interface (such as the F1 interface) between the fifth node (or the distribution unit functional part of the fifth node) connected to the first node and the third node.

[0186] It should be understood that when data transmission occurs at the first node, the communication system has already been configured for data transmission at the relevant nodes in the network. This configuration process will be described later in the second aspect. Since configuration has already been performed at the relevant nodes in the network, as can be seen from the foregoing description of "data configuration information," since "data transmission configuration information" can be provided separately for data with different attributes, nodes can obtain information about data attributes based on the method of receiving data. This detail will be elaborated in the description of the second aspect. Here, we first describe the data transmission process between nodes after configuration has been performed.

[0187] Specifically, such as Figure 4 As shown, it may include at least one of the following methods for transmitting data.

[0188] Method 1: Data transmission between the first node and the third node is performed via the backhaul link channel and / or RRC messages (or SRB).

[0189] In this method, such as Figure 4 As shown, the backhaul link channel is the backhaul link channel established between the first node and its superior node (such as the second node), while the RRC message is the RRC message of the first node (or the mobile terminal function part of the first node). The SRB can be SRB1, and / or SRB2, and / or SRB3, and / or a new SRB type, etc.

[0190] In this method, the transmission of downlink data includes the following steps, such as... Figure 5 As shown in (a):

[0191] Step 1-1-a1: The third node sends a first downlink message to the first node. This message is sent directly or indirectly (through one or more intermediate nodes) by the third node to the first node. This message is used to send data to the first node and can be sent via the backhaul link channel and / or RRC message (or SRB). The first downlink message includes at least one of the following information:

[0192] ■ The data of the first node includes at least one of the following:

[0193] Control plane data between the first node and the third node

[0194] User plane data between the first node and the third node

[0195] The data includes an F1AP message, which is an F1-C interface control message sent from the third node to the first node. Furthermore, the data may also include at least one of an SCTP header and an IP header.

[0196] Data carrying non-F1AP messages (such as non-F1 data) on the F1-C interface, which is the interface between the first and third nodes. Furthermore, this data may also contain at least one of an SCTP header and an IP header.

[0197] ■ The data of the fifth node includes at least one of the following:

[0198] The data includes identification information, such as index information. This information helps identify the attributes of the data, such as the route identifier and the destination receiving node identifier. For specific attributes, please refer to the "Data Attribute Indication Information" included in the "Data Configuration Information" above. Through this identification information, the first node that receives the data can know whether the data is to be further sent to the fifth node or whether the data comes from the fifth node.

[0199] Control plane data between the fifth node and the third node

[0200] User plane data between the fifth node and the third node

[0201] The data includes an F1AP message, which is an F1-C interface control message sent from the third node to the fifth node. Furthermore, the data may also include at least one of a BAP header, an SCTP header, and an IP header.

[0202] Data carrying non-F1AP messages (such as non-F1 data) on the F1-C interface, which is the interface between the fifth node and the third node. Furthermore, this data may also contain at least one of a BAP header, an SCTP header, and an IP header.

[0203] ■ Indication information related to transmission routing, which includes at least one of the following:

[0204] Routing identification information, which indicates the routing identifier used for transmitting data, such as the BAP routing ID. This routing identifier contains the BAP address and path identification information of the destination receiving node.

[0205] BAP address information, this BAP address is the BAP address of the destination receiving node of the data.

[0206] Path identification information, which is the path used to send data to the destination receiving node.

[0207] In one embodiment, upon receiving this information, the first node adds the "transmission routing related indication information" to the received data packet (which contains the aforementioned "data from the fifth node," and in one embodiment, the data packet is the aforementioned first downlink message) before sending it out. Further, the data packet may be a data packet containing the data from the fifth node.

[0208] ■ Indication information related to the transmission channel, which includes at least one of the following:

[0209] The identification information of the backhaul link channel used to send data, such as the Egress BH RLC CH ID, can be the identification information of one or more channels. After receiving this information, the first node will use this channel to send the data out. Furthermore, it can also include the identification information of the next-hop node serving this backhaul link channel, such as the BAP address.

[0210] The identification information of the backhaul link channel used to receive data, such as the Ingress BHRLC CH ID, can be the identification information of one or more channels. Furthermore, it can also include the identification information of the previous-hop node serving the backhaul link channel, such as the BAP address.

[0211] In one embodiment, the first node will send the received data packet to the backhaul link channel indicated by the "indication information related to the transmission channel".

[0212] Step 1-1-a2: The first node processes the received first downlink message. In one embodiment, if the received first downlink message contains data from the first node, the first node processes it but does not resend it or send it to the user accessing the first node; in another embodiment, if the received first downlink message contains data from the fifth node, the first node sends it out. Furthermore, it can add information before sending it out. The added information can be the "indication information related to transmission routing" included in step 1-1-a1 above, or it can be pre-configured information (in one embodiment, the pre-configured information can be found in the "data configuration information" above, such as the "information related to transmission routing to be added" included in the "data configuration information" above).

[0213] In method one, the transmission of uplink data includes the following steps, such as... Figure 5 As shown in (b):

[0214] Step 1-1-b1: The first node sends a first uplink message to the third node. This message is sent directly or indirectly (through one or more intermediate nodes) by the first node to the third node. This message is used to send data to the third node. The message can be sent via the backhaul link channel or via an RRC message (or SRB). The message includes at least one of the following information:

[0215] ■ The data of the first node includes at least one of the following:

[0216] Control plane data between the first node and the third node

[0217] User plane data between the first node and the third node

[0218] The data includes an F1AP message, which is an F1-C interface control message sent from the first node to the third node. Furthermore, the data may also include at least one of an SCTP header and an IP header.

[0219] Data carrying non-F1AP messages (such as non-F1 data) on the F1-C interface, which is the interface between the first and third nodes. Furthermore, this data may also contain at least one of an SCTP header and an IP header.

[0220] ■ The data of the fifth node includes at least one of the following:

[0221] Control plane data between the fifth node and the third node

[0222] User plane data between the fifth node and the third node

[0223] The data includes an F1AP message, which is an F1-C interface control message sent from the fifth node to the third node. Furthermore, the data may also include at least one of a BAP header, an SCTP header, and an IP header.

[0224] Data carrying non-F1AP messages (such as non-F1 data) on the F1-C interface, which is the interface between the fifth node and the third node. Furthermore, the data may also contain at least one of the BAP header, SCTP header, and IP header.

[0225] Optionally, before step 1-1-b1, step 1-1-b0 may be included: the first node processes the received data, which may be sent to the first node by the fifth node, and may contain data from the fifth node, including at least one of the following information:

[0226] ■ Control plane data between the fifth node and the third node

[0227] ■ User plane data between the fifth node and the third node

[0228] ■ Data containing an F1AP message, which is an F1-C interface control message sent from the fifth node to the third node. Furthermore, this data may also contain at least one of a BAP header, an SCTP header, and an IP header.

[0229] ■ Data carrying non-F1AP messages (such as non-F1 data) on the F1-C interface, which is the interface between the fifth node and the third node. Furthermore, the data may also contain at least one of the BAP header, SCTP header, and IP header.

[0230] Furthermore, after receiving data from the fifth node, the first node may optionally remove some information from the data before retransmitting it, based on the configuration (which can be found in the "Data Configuration Information" mentioned above, such as the "Indication Information for Information to be Removed" included in the "Data Configuration Information"), wherein the removed information includes at least one of the following:

[0231] ■ Routing identification information, which indicates the routing identifier used for transmitting data, such as the BAP routing ID. This routing identifier contains the BAP address and path identification information of the destination receiving node.

[0232] ■BAP address information: This BAP address is the BAP address of the destination receiving node for the data.

[0233] ■ Path identification information, which is the path used to send data to the destination receiving node.

[0234] Furthermore, the first node will determine the data that needs to be processed in the manner described above (i.e., removing some information from the data) based on the configuration (which can be found in the "Data Configuration Information" mentioned above, such as the "Indication Information Related to the Transmission Channel" included in the "Data Configuration Information"). As a non-limiting example, for instance, the first node may determine that the data received through the configured backhaul link channel needs to be processed in the manner described above because the attribute information corresponding to the data received through the configured backhaul link channel is the data of the fifth node, and the transmission configuration information corresponding to this attribute includes "Indication Information of Information to be Removed".

[0235] In steps 1-1-a1 and / or 1-1-b1 above, the first downlink message and / or the first uplink message may be sent only through the backhaul link channel established between the first node and its superior node (such as the second node); or it may be sent only through the RRC message (or SRB) of the first node; or it may be sent through the backhaul link channel established between the first node and its superior node (such as the second node) or through the RRC message (or SRB) of the first node, depending on the choice of the first node or the third node.

[0236] In the above process, if the data packet is sent via an RRC message (or SRB), the first downlink message can be an RRC message, such as DLInformationTransfer, or other messages; the first uplink message can be an RRC message, such as ULInformationTransfer, or other messages. Furthermore, the SRB carrying the aforementioned first downlink message and / or first uplink message can be SRB1, and / or SRB2, and / or SRB3, and / or a new SRB type, etc.

[0237] In one embodiment of Method 1, the first node can be in a single-connection mode, meaning the first node only establishes a connection with the third node; in another embodiment, the first node can be in a dual-connection mode, meaning the first node establishes a connection with both the third and fourth nodes, in which case the third and fourth nodes can be the primary node and the secondary node, or the secondary node and the primary node, respectively. Method 1 provides a method for data transmission between the third node and the first node, where data can be transmitted using RRC messages (or SRBs) and / or backhaul link channels according to the node's configuration, and the data does not pass through the fourth node.

[0238] The effects that can be achieved by the above method one include at least the following: the first node (relay node) can send its own and its child nodes' user plane data and / or control plane data to the third node (anchor node) or receive them from the third node (anchor node) through independent RRC messages (or SRB) or backhaul link channels, according to appropriate configuration. This can avoid the data of the control plane and user plane being transmitted together, thereby improving the reliability of control plane data, reducing the latency of control plane data transmission, and increasing the throughput of user plane data transmission.

[0239] For scenarios where the first node is in dual-connection or multi-connection mode, the following method two can be used for data transmission with the third node. It should be understood that although the following description pertains to the case where the first node is connected to the third and fourth nodes, method two can also be similarly applied to cases where the first node is connected to a larger number of base stations.

[0240] Method 2: Data transmission between the first and third nodes is performed through a fourth node. In Method 2, the downlink data transmission includes the following steps: Figure 6 (a):

[0241] Step 1-2-a1: The third node sends a second downlink message to the fourth node. The information contained in this message can be found in the first downlink message in Step 1-1-a1 above. This second downlink message can be an XnAP or X2AP message, such as an F1-C Traffic Transfer message, an F1-U Traffic Transfer message, or other messages.

[0242] Step 1-2-a2: The fourth node sends a third downlink message to the first node. The information contained in this message can be found in the first downlink message of Step 1-1-a1 above. This third downlink message can be an RRC message (or SRB), such as a DLInformationTransfer message, or other messages. Furthermore, the SRB carrying the third downlink message can be SRB1, and / or SRB2, and / or SRB3, and / or a new SRB type, etc.

[0243] Step 1-2-a3: The first node processes the received third downlink message. The processing method can be found in step 1-1-a2 above.

[0244] In method two, the transmission of uplink data includes the following steps, such as... Figure 6 As shown in (b):

[0245] Step 1-2-b1: The first node sends a second uplink message to the fourth node. The information contained in this message can be found in the first uplink message of Step 1-1-b1 above. This second uplink message can be an RRC message (or SRB), such as a ULInformationTransfer message, or other messages. Furthermore, the SRB carrying the aforementioned third uplink message can be SRB1, and / or SRB2, and / or SRB3, and / or a new SRB type, etc.

[0246] Step 1-2-b2: The fourth node sends a third uplink message to the third node. The information contained in this message can be found in the first uplink message in Step 1-1-b1 above. This third uplink message can be an XnAP or X2AP message, such as an F1-CTraffic Transfer message, an F1-U Traffic Transfer message, or other messages.

[0247] Optionally, before step 1-2-b1, step 1-2-b0 may also be included: the first node processes the received data according to the transmission configuration information corresponding to the received data. This data may be sent from the fifth node to the first node. The information contained in this data can be found in the description of the information contained in the data in step 1-1-b0 above.

[0248] The technical effects achievable by Method 2 described above include at least the following: the first node (such as a relay node) can, according to its configuration, transmit its own and its child nodes' user plane data and / or control plane data to the anchor node it is connected to via other base stations, or receive data from the anchor node connected to it via other base stations. In this way, by appropriately configuring the transmission of data with various attributes, the transmission path of control plane data can be separated from the transmission path of user plane data, thereby improving the reliability of data transmission and reducing data transmission latency.

[0249] Method 3: Data transmission can be performed between the first and third nodes either through the backhaul link channel and / or RRC messages (or SRBs), or through the fourth node.

[0250] This method combines Method 1 and Method 2, and details can be found in Method 1 and Method 2 respectively. Whether the first node uses Method 1 or Method 2 for data transmission is determined by the first node or the third node, and can be achieved by appropriately configuring the data transmission settings for the corresponding attributes.

[0251] The three methods described above can be used to transmit control plane data only, user plane data only, or both control plane data and user plane data simultaneously.

[0252] As a non-limiting example, for instance, by configuring different transmission configuration information for the control plane data of the first node and the user plane data of the fifth node, the control plane data of the first node can be configured to be transmitted between the first node and the third node via another base station (the fourth base station) connected to the first node, while the user plane data of the fifth node can be configured to be transmitted between the first node and the third node via a backhaul link channel.

[0253] The effects that the above method can achieve include at least the following: the data of the first node (such as a relay node) and the data of its child nodes can be determined by flexible selection and appropriate transmission configuration to determine their transmission path (such as transmission through other base stations connected to the first node, or transmission through the backhaul link channel and / or RRC messages (or SRB) between the first node and the anchor node), thereby improving the reliability of control plane data, reducing the latency of control plane data transmission, and increasing the throughput of user plane data transmission.

[0254] The second aspect: configuration of data transmission in relay nodes.

[0255] The configuration of data transmission for a relay node involves a signaling interaction process between a third (or fourth) node and the first node. This process may include the third (or fourth) node directly or indirectly (through one or more intermediate nodes) sending configuration information related to data transmission to the first node. The process includes the following steps, such as... Figure 7 As shown:

[0256] Step 2-1: The third node (or fourth node) sends a first request message to the first node. This message is used to configure the first node to transmit (send and / or receive) data. This first configuration message includes at least one of the following information:

[0257] ■ Configuration information for transmitting data of the first node. This data is the data of the first node, such as the data required to be transmitted by the distribution unit function part of the first node. The contents of this configuration information can be found in the above "Data Configuration Information", which contains information specific to the data of the first node.

[0258] ■ Configuration information for transmitting data from the fifth node. This data is the data of the fifth node, such as the data required to be transmitted by the distribution unit function of the fifth node. The contents of this configuration information can be found in the "Data Configuration Information" above, and all of its contents are specific to the data of the fifth node.

[0259] In one embodiment, the "configuration information for transmitting data of the fifth node" may include the aforementioned "indication information for data attributes" and / or the aforementioned "data transmission configuration information"; in another embodiment, the configuration information may only include the aforementioned "indication information for data attributes", and the transmission configuration of the data of the fifth node may adopt the "data transmission configuration information" included in the aforementioned "configuration information for transmitting data of the first node". In other words, the data of the fifth node can be transmitted using the same transmission configuration as the data of the first node.

[0260] Step 2-2: The first node transmits (receives or sends) data to itself or the fifth node based on the configuration information received in Step 2-1. In one embodiment, the first node may transmit data in a single-connection mode, i.e., data transmission occurs between the first node and the third node; in another embodiment, the first node may transmit data in a dual-connection mode, i.e., the first node maintains a connection with both the third and fourth nodes, and the transmitted data is data on the interface between the first and third nodes (such as signaling on the F1-C interface, or data on the F1-U interface). The data transmission method in this step can be found in Method 1, Method 2, and / or Method 3 of the first aspect of this application.

[0261] In the above process, the first request message can be an RRC message (such as an RRCReconfiguration message) (or an SRB, such as SRB1, and / or SRB2, and / or SRB3, and / or a new SRB type, etc.), or an F1AP message, or other types of messages.

[0262] The above process can be used to configure the transmission of control plane data, the transmission of user plane data, or both.

[0263] The beneficial effects that the above process can achieve include that the first node can transmit its own data and / or the data of its connected child nodes according to the configuration information, and different data can be transmitted using different configurations through appropriate configuration.

[0264] In some implementations, configuring the first node to transmit data may also include a signaling interaction process between the third node and the parent node (such as the second node) to which the first node is connected. This process is primarily for configuring the data transmission of the first node at the second node. Methods for implementing this configuration process include the following.

[0265] Method 1: Configuration initiated by a third node

[0266] Method 1 includes the following steps, such as Figure 8 As shown in (a):

[0267] Step 2-a-1: The third node sends a second request message to the second node. The purpose of this message is to configure the second node to transmit data from the first node (this data may be the first node's own data, the fifth node's data, or a combination of the first node's own data and the fifth node's data). This message may include at least one of the following information:

[0268] ■Indication information of data attributes

[0269] ■ Data transmission configuration information. In one embodiment, this data transmission configuration information may be configuration information for transmitting control plane data (such as F1-C data streams). In another embodiment, this data transmission configuration information may be configuration information for transmitting user plane data (such as F1-U data streams). In yet another embodiment, this data transmission configuration information may be configuration information used when transmitting the data indicated by the aforementioned "data attribute indication information". This information includes at least one of the following:

[0270] Cell group indication information, such as MCG, SCG, MCG and SCG (the word "both" can be used to indicate that both MCG and SCG can be used to transmit data).

[0271] Community signage

[0272] Indication information for transmission methods, such as RRC messages (or SRBs), backhaul link channels, or RRC messages (or SRBs) and backhaul link channels (the term "both" can be used to indicate that both RRC messages (or SRBs) and backhaul link channels can be used to transmit data).

[0273] Indication information of the transmission network, such as LTE network, 5G (or NR) network, or LTE and 5G (or NR) networks ("both" can be used to indicate that both LTE and 5G networks can be used to transmit data). In one embodiment, the above "indication information of the transmission network" can be represented by F1-C transmission path indication information (such as f1c-TransferPath), which indicates that the network can be LTE, NR, or both (i.e., LTE and NR).

[0274] Indication information for transmitting data using LTE

[0275] Indication information for transmitting data using 5G (or NR)

[0276] Indication information for transmitting data using RRC (or SRB)

[0277] Indication information for transmitting data using the backhaul link channel

[0278] Indication information for transmitting data using MCG

[0279] Indication information for transmitting data using SCG

[0280] For details on the "Indication Information of Data Attributes" and "Data Transmission Configuration Information" mentioned above, please refer to the "Data Configuration Information" above.

[0281] Step 2-a-2: The second node sends a second response message to the third node. The message has at least one of the following functions: confirming receipt of the first request message in step 2-a-1; configuring the second node to transmit data from the first node; and sending the data transmission-related configuration information generated by the second node for the first node (such as CellGroupConfig information in TS38.331).

[0282] Optionally, in step 2-a-3: the third node sends a third request message to the first node, or the third node sends a third request message to the first node through the fourth node. This message is used to configure the first node to transmit data. The content of this request message can be found in the first request message in step 2-1 above.

[0283] In the above process, the second request message and the second response message can be F1AP messages (such as UE ContextSetup / Modification Request message and UE Context Setup / Modification Response message), or other messages.

[0284] The process in Method 1 above can be used only to configure the transmission of control plane data (such as F1-C data), or only to configure the transmission of user plane data, or simultaneously to configure the transmission of both control plane data (such as F1-C data) and user plane data.

[0285] The beneficial effects that can be achieved by the above method one include: by using the configuration information related to data transmission sent by the second node to the first node, the third node can better match the actual situation of each relevant node when configuring the data transmission of the first node.

[0286] Method 2: Configuration initiated by the second node

[0287] Method 2 includes the following steps, such as Figure 8 As shown in (b):

[0288] Step 2-b-1: The second node sends a fourth request message to the third node. This message informs the third node of the configuration information regarding the transmission of the first node's data (which may be the first node's own data, the fifth node's data, or both the first node's own data and the fifth node's data). This message may include at least one of the following information:

[0289] ■Indication information of data attributes

[0290] ■ Data transmission configuration information, which includes at least one of the following:

[0291] Cell group indication information, such as MCG, SCG, MCG and SCG (the word "both" can be used to indicate that both MCG and SCG can be used to transmit data).

[0292] Community signage

[0293] Indication information for transmission methods, such as RRC messages (or SRBs), backhaul link channels, or RRC messages (or SRBs) and backhaul link channels (the term "both" can be used to indicate that both RRC messages (or SRBs) and backhaul link channels can be used to transmit data).

[0294] Indication information of the transmission network, such as LTE network, 5G (or NR) network, or LTE and 5G (or NR) networks ("both" can be used to indicate that both LTE and 5G networks can be used to transmit data). In one embodiment, the above "indication information of the transmission network" can be represented by F1-C transmission path indication information (such as f1c-TransferPath), which indicates that the network can be LTE, NR, or both (i.e., LTE and NR).

[0295] Indication information for transmitting data using LTE

[0296] Indication information for transmitting data using 5G (or NR)

[0297] Indication information for transmitting data using RRC (or SRB)

[0298] Indication information for transmitting data using the backhaul link channel

[0299] Indication information for transmitting data using MCG

[0300] Indication information for transmitting data using SCG

[0301] For details regarding the "data attribute indication information" and "data transmission configuration information" mentioned above, please refer to the "data configuration information" section above.

[0302] ■ Configuration information of the first node, such as CellGroupConfig information in TS38.331.

[0303] Step 2-b-2: The third node sends a fourth response message to the second node. The purpose of this message is to confirm that the second request message in step 2-b-1 has been received.

[0304] Step 2-b-3: The third node sends a fifth request message to the first node, or the third node sends a fifth request message to the first node through the fourth node. This message is used to configure the first node to transmit data. The content of the fifth request message can be found in the first request message in step 2-1 above.

[0305] In the above process, the fourth request message and the fourth response message can be F1AP messages (such as UE ContextModification Required message and UE Context Modification Confirm message), or other messages.

[0306] The process in Method 2 above can be used only to configure the transmission of control plane data (such as F1-C data), or only to configure the transmission of user plane data, or simultaneously to configure the transmission of both control plane data (such as F1-C data) and user plane data.

[0307] The beneficial effects that can be achieved by the second method mentioned above include: enabling the second node to provide the third node with information about data transmission configuration based on the actual situation, so that the transmission configuration performed by the third node can better match the actual situation of each relevant node.

[0308] The beneficial effects that can be achieved by the processes in Method 1 and Method 2 mentioned above also include, for example, the second node can generate the configuration information required for the first node to transmit data, thereby helping to configure the first node, and then the first node can transmit data according to the configuration generated by the second node. In addition, it can also help the second node determine the resources for transmitting the data of the first node.

[0309] When the first node is in a dual-connection configuration, configuring the first node to transmit data also includes a signaling interaction process between the third and fourth nodes, thereby completing the configuration for the first node to transmit data. Specifically, this process includes the following two methods.

[0310] Method 1: Configuration initiated by a third node

[0311] The method includes the following steps, such as Figure 9 As shown in (a):

[0312] Step 2-c-1: The third node sends a sixth request message to the fourth node, which is used to send configuration information related to data transmission for the first node (the transmitted data may be the first node's own data, the fifth node's data, or both the first node's own data and the fifth node's data). The sixth request message may include at least one of the following information:

[0313] ■ The configuration information related to data transmission for the first node can be found in the "Data Configuration Information" section above.

[0314] ■ Instruction information indicating the transmission of data by the fourth node; in one embodiment, this data is F1-C data.

[0315] ■ Instruction information that instructs the fourth node to transmit data from the first node; in one embodiment, this data is F1-C data.

[0316] ■ Instruction information that instructs the fourth node to transmit data from the fifth node; in one embodiment, this data is F1-C data.

[0317] Step 2-c-2: Optionally, the fourth node sends a sixth response message to the third node. This message includes at least one of the following functions: confirming that the sixth request message in step 2-c-1 has been correctly received, generating configuration information related to data transmission for the first node, such as configuration information for SRB3, or the aforementioned "data configuration information".

[0318] Optionally, step 2-c-3: The third or fourth node sends a seventh request message to the first node. The information contained in this message can be found in the first request message in step 2-1 above.

[0319] In the above process, the sixth request message and the sixth response message can be XnAP messages (such as S-NodeAddition / Modification Request message and S-Node Addition / Modification RequestAcknowledge message, or S-Node Modification Required message and S-Node Modification Confirm message, respectively), or X2AP messages (such as SgNB Addition / Modification Request message and SgNB Addition / Modification Request Acknowledge message, SgNB ModificationRequired message and SgNB Modification Confirm message, respectively), or other messages.

[0320] The process in Method 1 above can be used only to configure the transmission of control plane data (such as F1-C data), or only to configure the transmission of user plane data, or simultaneously to configure the transmission of both control plane data (such as F1-C data) and user plane data.

[0321] The beneficial effects that can be achieved by the above method include, for example, the third node can collect information related to data transmission configuration as needed, thereby helping the third node to make transmission configurations that are more in line with the actual situation of each relevant node, thus making communication more efficient.

[0322] Method 2: Configuration initiated by the fourth node

[0323] As a non-limiting example, for instance, in the case where the fourth node is the primary base station, the configuration can be initiated by the fourth node. Method two includes the following steps, such as... Figure 9 As shown in (b):

[0324] Step 2-d-1: The fourth node sends an eighth request message to the third node, which transmits configuration information related to data transmission for the first node (the transmitted data may be the first node's own data, the fifth node's data, or both the first node's own data and the fifth node's data). This eighth request message includes at least one of the following:

[0325] ■Indication information of data attributes

[0326] ■ Data transmission configuration information, which includes at least one of the following:

[0327] Cell group indication information, such as MCG, SCG, MCG and SCG (the word "both" can be used to indicate that both MCG and SCG can be used to transmit data).

[0328] Community signage

[0329] Indication information for transmission methods, such as RRC messages (or SRBs), backhaul link channels, or RRC messages (or SRBs) and backhaul link channels (the term "both" can be used to indicate that both RRC messages (or SRBs) and backhaul link channels can be used to transmit data).

[0330] Indication information of the transmission network, such as LTE network, 5G (or NR) network, or LTE and 5G (or NR) networks ("both" can be used to indicate that both LTE and 5G networks can be used to transmit data). In one embodiment, the above "indication information of the transmission network" can be represented by F1-C transmission path indication information (such as f1c-TransferPath), which indicates that the network can be LTE, NR, or both (i.e., LTE and NR).

[0331] Indication information for transmitting data using LTE

[0332] Indication information for transmitting data using 5G (or NR)

[0333] Indication information for transmitting data using RRC (or SRB)

[0334] Indication information for transmitting data using the backhaul link channel

[0335] Indication information for transmitting data using MCG

[0336] Indication information for transmitting data using SCG

[0337] For details on the "Indication Information of Data Attributes" and "Data Transmission Configuration Information" mentioned above, please refer to the "Data Configuration Information" above.

[0338] Step 2-d-2: The third node sends an eighth response message to the fourth node. The message has at least one of the following functions: confirming receipt of the eighth request message in step 2-d-1, and sending data transmission configuration information related to the first node generated by the third node. The contents of this configuration information can be found in the "Data Configuration Information" section above.

[0339] Optionally, step 2-d-3: The fourth node (or the third node) sends a ninth request message to the first node. The content of this message can be found in the first request message in step 2-1 above.

[0340] In the above process, the eighth request message and the eighth response message can be XnAP messages (such as S-NodeAddition / Modification Request message and S-Node Addition / Modification RequestAcknowledge message, or S-Node Modification Required message and S-Node Modification Confirm message, respectively), or X2AP messages (such as SgNB Addition / Modification Request message and SgNB Addition / Modification Request Acknowledge message, SgNB ModificationRequired message and SgNB Modification Confirm message, respectively), or other messages.

[0341] The process in Method 2 above can be used only to configure the transmission of control plane data (such as F1-C data), or only to configure the transmission of user plane data, or simultaneously to configure the transmission of both control plane data (such as F1-C data) and user plane data.

[0342] The beneficial effects that can be achieved by the second method mentioned above include, for example, that nodes can interact with configuration information related to data transmission, thereby making the configuration of data transmission more in line with the actual situation of each relevant node, and thus optimizing communication efficiency.

[0343] The beneficial effects that can be achieved by the processes in Method 1 and Method 2 mentioned above also include, for example, the fourth node can generate the configuration information required to help the first node transmit data, and then the first node can transmit the data of the corresponding attributes through the fourth node according to the configuration information.

[0344] Third aspect: Transmission of user plane data during PSCell modification

[0345] When a relay node is in dual connectivity, its PSCell (i.e., the primary cell served by the secondary base station) may change. This change may be due to a change in the secondary base station, a change in the upstream node serving the relay node, or other reasons. The method in this application does not impose any restrictions on the reasons for the change of PSCell.

[0346] During the PSCell change process, the signaling interaction required to configure the link from the first node to the third node will cause a communication interruption between the first and third nodes. This interruption will lead to the interruption of data transmission for users accessing the relay node. To solve this problem, the method proposed in this application is as follows: during the PSCell change process (e.g., handover process), the relay node transmits user plane data through the main base station and its connected anchor node.

[0347] The user plane data involved in this aspect includes the following two types: user plane data of the first node; and user plane data of the fifth node.

[0348] To implement this method, this application includes, as follows: Figure 10 The interactive flow is shown. Figure 10 This document presents an example flow for configuring the first node (e.g., a relay node) to perform user plane data transmission with its connected third node (e.g., an anchor node) through a fourth node (e.g., a main base station) in a scenario where the PSCell changes (e.g., the parent node of the first node serving it changes). It should be understood that... Figure 10 The process shown occurs during the switching process when the PSCell changes, and the description of the switching process is omitted to avoid obscuring the focus of this disclosure.

[0349] 1. Transmission of user plane data between relay nodes and the main base station

[0350] This method includes the following signaling interaction process, such as... Figure 10 As shown in (a):

[0351] Step 3-a-1: The third or fourth node sends a tenth request message to the first node. This message configures user plane data transmission between the first and fourth nodes. To transmit user plane data, one or more radio bearers need to be established between the fourth and first nodes. In one embodiment, this radio bearer is used to transmit the user plane data of the first node; in another embodiment, it is used to transmit the user plane data of the fifth node. For each radio bearer, the tenth request message includes at least one of the following:

[0352] ■ Identification information of wireless bearers

[0353] ■ Configuration information of the user plane data carried by the wireless bearer, which includes at least one of the following:

[0354] Information about the uplink tunnel, which includes at least one of the IP address of the third node and the tunnel endpoint identifier.

[0355] Information about the downlink tunnel, which includes at least one of the IP address of the first node and the tunnel endpoint identifier.

[0356] Source address information, such as IP address and / or BAP address, etc.

[0357] Destination address information, such as IP address and / or BAP address, etc.

[0358] Routing identification information, such as the BAP routing ID, in one embodiment includes the BAP address and path identification information of the destination receiving node.

[0359] Path identification information, such as path ID

[0360] ■ Information about the backhaul link channel used for transmitting user plane data, wherein the backhaul link channel is the backhaul link channel used by the first node to transmit the user plane data, and such information includes at least one of the following:

[0361] The identification information of the backhaul link channel used to transmit user plane data, such as the Egress BH RLC CH ID, can be the identification information of one or more channels. Furthermore, it can also include the identification information of the next-hop node serving the backhaul link channel, such as the BAP address.

[0362] The identification information of the backhaul link channel used to receive user plane data, such as Ingress BH RLC CHID, can be the identification information of one or more channels. Furthermore, it can also include the identification information of the previous-hop node serving the backhaul link channel, such as the BAP address.

[0363] As a non-limiting example, for instance, the aforementioned tenth request message can be carried in the switching command, and other messages described below can also be similarly transmitted in commands or messages related to the switching process, which will not be described further below to avoid obscuring the focus of this application.

[0364] Step 3-a-2: User plane data is transmitted between the first node and the fourth node according to the configuration. This step can also be a standalone step, i.e., it does not need to be performed after step 3-a-1. In this step, if signaling radio bearers are used to transmit user plane data, in one embodiment, it is necessary to define a new RRC message or define a new container in an existing RRC message. The new RRC message or the new container in the existing RRC message contains user plane data. Specifically, the fourth node sends the new RRC message or the existing RRC message to the first node (or the first node sends it to the fourth node). This message can be described as a twelfth request message, which contains at least one of the following information:

[0365] ■ User plane data, such as the "User plane data of the first node" and / or the "User plane data of the fifth node" mentioned above.

[0366] ■ Indication information related to transmission routing, which includes at least one of the following:

[0367] Routing identification information, such as the BAP Prouting ID, indicates the routing identifier used to transmit user plane data. This routing identifier includes the BAP address of the destination receiving node and path identification information.

[0368] BAP address information; this BAP address is the BAP address of the destination receiving node.

[0369] Path identification information, which is the path used to send user plane data to the destination receiving node.

[0370] ■ Indication information related to the transmission channel, which includes at least one of the following:

[0371] The identification information of the backhaul link channel used to send user plane data, such as the Egress BH RLC CH ID, can be the identification information of one or more channels. After receiving this information, the first node will use this channel to send out the user plane data. Furthermore, it can also include the identification information of the next-hop node serving this backhaul link channel, such as the BAP address.

[0372] The identification information of the backhaul link channel used to receive user plane data, such as Ingress BH RLC CHID, can be the identification information of one or more channels. Furthermore, it can also include the identification information of the prior-hop node serving the backhaul link channel, such as the BAP address.

[0373] Upon receiving the "instruction information related to the transmission channel", the first node needs to transmit data according to the backhaul link channel indicated by the information.

[0374] ■ Information related to the transport route that needs to be added, which includes at least one of the following:

[0375] Routing identification information, such as the BAP Prouting ID, indicates the routing identifier used to transmit user plane data. This routing identifier includes the BAP address of the destination receiving node and path identification information.

[0376] BAP address information; this BAP address is the BAP address of the destination receiving node.

[0377] Path identification information, which is the path used to send user plane data to the destination receiving node.

[0378] Upon receiving the "information related to the transmission route to be added", the first node needs to add one or more of the aforementioned information indicated by it to the user plane data packet.

[0379] In the above process, the radio bearer established in step 3-a-1 can be a data radio bearer (DRB), a signaling radio bearer (SRB), or a new radio bearer (e.g., a radio bearer different from DRB and SRB; in this case, a PDCP header needs to be added to the data when transmitting data using this radio bearer; in another embodiment, data packets transmitted using this radio bearer (or with other newly defined names) do not need to have a PDCP header). Furthermore, in one embodiment, all user plane data can be transmitted in the same radio bearer, or different radio bearers can be established for different user plane data and then transmitted by different radio bearers.

[0380] The aforementioned tenth request message can be an RRC message (such as an RRCReconfiguration message), an F1AP message, or other messages.

[0381] The beneficial effects that the above process can achieve include, for example, rapidly establishing a path for sending user plane data between the relay node and the base station during the handover process, thereby reducing data transmission latency, reducing the possibility of communication interruption, and thus improving user experience and optimizing the communication environment.

[0382] 2. Transmission of user plane data between the main base station and the anchor node

[0383] This method includes the following signaling interaction process, such as... Figure 10 As shown in (b):

[0384] Step 3-b-1: The fourth node sends an eleventh request message to the third node. This message configures data transmission in the user plane and includes at least one of the following information:

[0385] ■ Identification information of the wireless bearer. In one embodiment, the wireless bearer may be the wireless bearer used by the fourth node and the first node for user plane data transmission.

[0386] ■ Configuration information of the tunnel used by the fourth node to receive user plane data. The function of this tunnel is to receive user plane data sent from the third node to the fourth node. There may be one or more tunnels. For each tunnel, this information includes at least one of the following:

[0387] IP address of the fourth node

[0388] Tunnel endpoint identifier

[0389] Step 3-b-2: Optionally, the third node sends an eleventh response message to the fourth node. This message configures the transmission of user plane data and includes at least one of the following information:

[0390] ■ Identification information of the wireless bearer. In one embodiment, the wireless bearer may be the wireless bearer used by the fourth node and the first node for user plane data transmission.

[0391] ■ Configuration information of the tunnel used by the third node to receive user plane data. The function of this tunnel is to receive user plane data sent from the fourth node to the third node. There may be one or more tunnels. For a single tunnel, this information includes at least one of the following:

[0392] IP address on the third node side

[0393] Tunnel endpoint identifier

[0394] ■ Indication information related to the transmission route, which is a transmission route for user plane data, and the indication information includes at least one of the following:

[0395] Routing identification information, such as the BAP Prouting ID, indicates the routing identifier used to transmit user plane data. This routing identifier includes the BAP address of the destination receiving node and path identification information.

[0396] BAP address information; this BAP address is the BAP address of the destination receiving node.

[0397] Path identification information, which is the path used to send user plane data to the destination receiving node.

[0398] ■ Indication information related to the transmission channel, which is a user plane data transmission channel, and the indication information includes at least one of the following:

[0399] The identification information of the backhaul link channel used to send user plane data, such as the Egress BH RLC CH ID, can be the identification information of one or more channels. After receiving this information, the first node will use this channel to send out the user plane data. Furthermore, it can also include the identification information of the next-hop node serving this backhaul link channel, such as the BAP address.

[0400] The identification information of the backhaul link channel used to receive user plane data, such as Ingress BH RLC CHID, can be the identification information of one or more channels. Furthermore, it can also include the identification information of the previous-hop node serving the backhaul link channel, such as the BAP address.

[0401] Step 3-b-3: User plane data is transmitted between the third node and the fourth node. This step can also be a standalone step, i.e., it does not need to be executed after steps 3-b-1 and 3-b-2. In one embodiment, user plane data can be sent using the tunnel information exchanged in steps 3-b-1 and 3-b-2. In another embodiment, user plane data can be sent using a new control message defined between the third node and the fourth node (such as a new control message sent from the third node to the fourth node, or a new control message sent from the fourth node to the third node). This new control message can be expressed as a thirteenth request message, which includes at least one of the following information:

[0402] ■ User plane data, such as the "User plane data of the first node" and / or the "User plane data of the fifth node" mentioned above.

[0403] ■ Indication information related to transmission routing, which includes at least one of the following:

[0404] Routing identification information, such as the BAP Prouting ID, indicates the routing identifier used to transmit user plane data. This routing identifier includes the BAP address of the destination receiving node and path identification information.

[0405] BAP address information; this BAP address is the BAP address of the destination receiving node.

[0406] Path identification information, which is the path used to send user plane data to the destination receiving node.

[0407] ■ Indication information related to the transmission channel, which includes at least one of the following:

[0408] The identification information of the backhaul link channel used to send user plane data, such as the Egress BH RLC CH ID, can be the identification information of one or more channels. After receiving this information, the first node will use this channel to send out the user plane data. Furthermore, it can also include the identification information of the next-hop node serving this backhaul link channel, such as the BAP address.

[0409] The identification information of the backhaul link channel used to receive user plane data, such as Ingress BH RLC CHID, can be the identification information of one or more channels. Furthermore, it can also include the identification information of the prior-hop node serving the backhaul link channel, such as the BAP address.

[0410] Upon receiving the "instruction information related to the transmission channel", the first node needs to transmit data according to the backhaul link channel indicated by the information.

[0411] The above signaling interaction processes can also be combined with each other, such as... Figure 11 As shown, it includes the following steps:

[0412] Step 3-c-1: The fourth node sends an eleventh request message to the third node. The specific content of this message can be found in step 3-b-1 above.

[0413] Step 3-c-2: The third node sends an eleventh response message to the fourth node. The specific content of this message can be found in step 3-b-2 above.

[0414] Step 3-c-3: The fourth node sends the tenth request message to the first node. The specific content of this message can be found in step 3-a-1 above.

[0415] Step 3-c-4: User plane data is transmitted between the first node, the fourth node, and the third node. The transmission of user plane data between the first node and the fourth node can be referred to in step 3-a-2 above, and the transmission of user plane data between the fourth node and the third node can be referred to in step 3-b-3 above.

[0416] The eleventh request message and the eleventh response message mentioned above can be X2AP or XnAP messages, or other messages.

[0417] The aforementioned thirteenth request message can be an X2AP or XnAP message, or it can be any other message.

[0418] The beneficial effects that the above process can achieve include: when the PSCell changes, user plane data between the relay node and the anchor node can be transmitted through other nodes (such as the main base station), thereby reducing the adverse effects of interruption of user plane data transmission.

[0419] The beneficial effects that this application can achieve include: relay nodes can select appropriate methods to transmit their own data and the data of their child nodes according to the configuration, which can improve data reliability, reduce data transmission latency, and increase data transmission throughput.

[0420] Furthermore, the beneficial effects achievable by this application include: when the PSCell of the serving relay node changes, the user plane data of the relay node can continue to be transmitted through the main base station, thereby avoiding interruption of user plane data transmission.

[0421] Figure 12 A simplified block diagram illustrating an example configuration of the hardware components of a communication device 1200 according to various embodiments of the present disclosure is shown, the communication device being capable of implementing the method of the first node according to various embodiments of the present disclosure.

[0422] like Figure 12 As shown, the communication device 1200 includes a transceiver unit 1201, a processor 1202, and a memory 1203.

[0423] The transceiver unit 1201 is configured to receive and / or transmit signals.

[0424] Processor 1202 is operatively connected to transceiver unit 1201 and memory 1203. Processor 1202 may be implemented as one or more processors for operating the methods performed by the first node according to various embodiments of the present disclosure.

[0425] Memory 1203 is configured to store data. Memory 1203 may include non-transitory memory for storing operations and / or code instructions executable by processor 1202. Memory 1203 may include processor-readable non-transitory instructions that, when executed, cause processor 1202 to perform steps of a method executed by a first node according to various embodiments of this disclosure. Memory 1203 may also include random access memory or buffer(s) to store intermediate processing data from various functions performed by processor 1202.

[0426] Figure 13 A simplified block diagram illustrating an example configuration of hardware components of a communication device 1300 according to various embodiments of the present disclosure, the communication device being capable of implementing the third node method according to various embodiments of the present disclosure.

[0427] like Figure 13 As shown, the communication device 1300 includes a transceiver unit 1301, a processor 1302, and a memory 1303.

[0428] The transceiver unit 1301 is configured to receive and / or transmit signals.

[0429] Processor 1302 is operatively connected to transceiver unit 1301 and memory 1303. Processor 1302 may be implemented as one or more processors for operating the methods performed by the third node as described in various embodiments of this disclosure.

[0430] Memory 1303 is configured to store data. Memory 1303 may include non-transitory memory for storing operations and / or code instructions executable by processor 1302. Memory 1303 may include processor-readable non-transitory instructions that, when executed, cause processor 1302 to perform steps of methods executed by a third node according to various embodiments of this disclosure. Memory 1303 may also include random access memory or buffers(s) for storing intermediate processing data from various functions performed by processor 1302.

[0431] Figure 14 A simplified block diagram illustrating an example configuration of the hardware components of a communication device 1400 according to various embodiments of the present disclosure is shown, the communication device being capable of implementing the fourth node method according to various embodiments of the present disclosure.

[0432] like Figure 14 As shown, the communication device 1400 includes a transceiver unit 1401, a processor 1402, and a memory 1403.

[0433] The transceiver unit 1401 is configured to receive and / or transmit signals.

[0434] Processor 1402 is operatively connected to transceiver unit 1401 and memory 1403. Processor 1402 may be implemented as one or more processors for operating the methods performed by the fourth node as described in various embodiments of this disclosure.

[0435] Memory 1403 is configured to store data. Memory 1403 may include non-transitory memory for storing operations and / or code instructions executable by processor 1402. Memory 1403 may include processor-readable non-transitory instructions that, when executed, cause processor 1402 to perform steps of methods executed by a fourth node according to various embodiments of this disclosure. Memory 1403 may also include random access memory or buffers(s) for storing intermediate processing data from various functions performed by processor 1402.

[0436] Figure 15 A simplified block diagram illustrating an example configuration of the hardware components of a communication device 1500 according to various embodiments of the present disclosure is shown, the communication device being capable of implementing the second node method according to various embodiments of the present disclosure.

[0437] like Figure 15 As shown, the communication device 1500 includes a transceiver unit 1501, a processor 1502, and a memory 1503.

[0438] The transceiver unit 1501 is configured to receive and / or transmit signals.

[0439] Processor 1502 is operatively connected to transceiver unit 1501 and memory 1503. Processor 1502 may be implemented as one or more processors for operating the methods performed by the second node as described in various embodiments of this disclosure.

[0440] Memory 1503 is configured to store data. Memory 1503 may include non-transitory memory for storing operations and / or code instructions executable by processor 1502. Memory 1503 may include processor-readable non-transitory instructions that, when executed, cause processor 1502 to perform steps of methods executed by a second node according to various embodiments of this disclosure. Memory 1503 may also include random access memory or buffers(s) for storing intermediate processing data from various functions performed by processor 1502.

[0441] Those skilled in the art will recognize that the description of the data packet transmission mechanism and device is illustrative only and is not intended to be limiting in any way. Other embodiments will be readily apparent to those skilled in the art upon receiving this disclosure.

[0442] For clarity, not all conventional features of implementations of packet transmission mechanisms and devices have been shown and described. It should be understood, of course, that in the development of any such actual implementation of a packet transmission mechanism and device, many implementation-specific decisions may need to be made to achieve the developer’s specific goals, such as compliance with application, system, network, and business-related constraints, and these specific goals will vary depending on the implementation and the developer.

[0443] The modules, processing operations, and / or data structures described in this disclosure can be implemented using various types of operating systems, computing platforms, network devices, computer programs, and / or general-purpose machines. Furthermore, those skilled in the art will recognize that less general-purpose devices, such as hardwired devices, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), etc., can also be used. Where a method comprising a series of operations and sub-operations is implemented by a processor, computer, or machine, and those operations and sub-operations can be stored as a series of non-transitory code instructions readable by the processor, computer, or machine, they can be stored on a tangible and / or non-transitory medium.

[0444] The modules of the data packet transmission mechanisms and devices described herein may include software, firmware, hardware, or any combination of software, firmware, or hardware suitable for the purposes described herein.

[0445] In the packet transmission mechanism described in this paper, various operations and sub-operations can be executed in various orders, and some of the operations and sub-operations can be optional.

[0446] Although the foregoing disclosure of this application has been made by way of non-limiting illustrative embodiments, these embodiments may be modified in any way within the scope of the appended claims without departing from the spirit and essence of this disclosure.

Claims

1. A method executed by a centralized unit (CU) of a first base station in a communication system, the method comprising: Send a first request message to the distribution unit (DU) of the first base station, including information indicating the transmission path of the F1-C data stream (F1-C traffic), wherein the transmission path is the F1-C data stream transmission path in the dual-connection DC. Receive a first response message from the DU of the first base station in response to the first request message; and A configuration message including information indicating the transmission path of the F1-C data stream is sent to the user equipment (UE).

2. The method according to claim 1, wherein, The dual connectivity is Evolved Universal Terrestrial Radio Access - New Radio NR Dual Connectivity EN-DC, and the information indicating the transmission path of the F1-C data stream indicates one of the following three as the transmission path of the F1-C data stream in the EN-DC: Long Term Evolution (LTE), New Radio NR, or both LTE and NR.

3. The method according to claim 1, wherein, The dual connectivity is NR dual connectivity NR-DC, and the information indicating the transmission path of the F1-C data stream indicates one of the following three as the transmission path of the F1-C data stream in the NR-DC: primary cell group (MCG), secondary cell group (SCG), or both MCG and SCG.

4. The method according to claim 1, further comprising: Send a second request message to the CU of the second base station to provide configuration information for the F1-C data stream; and Receive a second response message from the CU of the second base station, which includes information about the F1-C data stream.

5. The method according to any one of claims 1-4, wherein, The UE is a mobile terminal that integrates access and backhaul of IAB nodes.

6. The method according to claim 5, further comprising: Receive F1-C data packets from the UE. The F1-C data packet is control plane data on the F1 interface between the IAB node and the CU of the first base station. The information indicating the transmission path of the F1-C data stream is used by the UE to transmit the F1-C data packet.

7. A method performed by a distribution unit (DU) of a first base station in a communication system, the method comprising: The first request message, which includes information indicating the transmission path of the F1-C data stream, is received from the central unit (CU) of the first base station, wherein the transmission path is the F1-C data stream transmission path in the dual-connection DC. Send a first response message in response to the first request message to the CU of the first base station. Among them, a configuration message including information indicating the transmission path of the F1-C data stream is sent to the user equipment (UE).

8. The method according to claim 7, wherein, The dual connectivity is Evolved Universal Terrestrial Radio Access - New Radio NR Dual Connectivity EN-DC, and the information indicating the transmission path of the F1-C data stream indicates one of the following three as the transmission path of the F1-C data stream in the EN-DC: Long Term Evolution (LTE), New Radio NR, or both LTE and NR.

9. The method according to claim 7, wherein, The dual connectivity is NR dual connectivity NR-DC, and the information indicating the transmission path of the F1-C data stream indicates one of the following three as the transmission path of the F1-C data stream in the NR-DC: primary cell group (MCG), secondary cell group (SCG), or both MCG and SCG.

10. The method according to claim 7, wherein, The second request message is sent by the CU of the first base station to the CU of the second base station to provide the configuration information of the F1-C data stream, and A second response message, including information about the F1-C data stream, is received by the CU of the first base station from the CU of the second base station.

11. The method according to any one of claims 7-10, wherein, The UE is a mobile terminal that integrates access and backhaul of IAB nodes.

12. The method according to claim 11, wherein, The information indicating the transmission path of the F1-C data stream is used by the UE to transmit F1-C data packets to the CU of the first base station. The F1-C data packet is control plane data on the F1 interface between the IAB node and the CU of the first base station.

13. A method performed by a user equipment (UE) in a communication system, the method comprising: The CU of the first base station receives a configuration message including information indicating the transmission path of the F1-C data stream, wherein the transmission path is the F1-C data stream transmission path in the dual-connectivity DC. The F1-C data packet is sent to the CU of the first base station using the information indicating the transmission path of the F1-C data stream. Specifically, a first request message, including information indicating the transmission path of the F1-C data stream, is sent by the CU of the first base station to the DU of the first base station.

14. The method according to claim 13, wherein, The dual connectivity is Evolved Universal Terrestrial Radio Access - New Radio (NR) Dual Connectivity EN-DC, and the information indicating the transmission path of the F1-C data stream indicates one of the following three as the transmission path of the F1-C data stream in the EN-DC: Long Term Evolution (LTE), New Radio (NR), or both LTE and NR, or... The dual connectivity is NR dual connectivity NR-DC, and the information indicating the transmission path of the F1-C data stream indicates one of the following three as the transmission path of the F1-C data stream in the NR-DC: primary cell group (MCG), secondary cell group (SCG), or both MCG and SCG.

15. The method according to claim 13, wherein, The second request message is sent by the CU of the first base station to the CU of the second base station to provide the configuration information of the F1-C data stream, and A second response message, including information about the F1-C data stream, is received by the CU of the first base station from the CU of the second base station.

16. The method according to any one of claims 13-15, wherein, The UE is a mobile terminal that integrates access and backhaul of IAB nodes.

17. The method according to claim 16, wherein, The F1-C data packet is control plane data on the F1 interface between the IAB node and the CU of the first base station.

18. A method executed by a CU of a second base station in a communication system, comprising: Receive a second request message from the CU of the first base station, providing configuration information for the F1-C data stream; and Send a second response message, including information about the F1-C data stream, to the CU of the first base station. Specifically, a first request message, including information indicating the transmission path of the F1-C data stream, is sent by the CU of the first base station to the DU of the first base station, wherein the transmission path is the F1-C data stream transmission path in the dual-connectivity DC. The configuration message, which includes information indicating the transmission path of the F1-C data stream, is sent by the CU of the first base station to the user equipment (UE).

19. The method according to claim 18, wherein, The dual connectivity is Evolved Universal Terrestrial Radio Access - New Radio (NR) Dual Connectivity EN-DC, and the information indicating the transmission path of the F1-C data stream indicates one of the following three as the transmission path of the F1-C data stream in the EN-DC: Long Term Evolution (LTE), New Radio (NR), or both LTE and NR, or... The dual connectivity is NR dual connectivity NR-DC, and the information indicating the transmission path of the F1-C data stream indicates one of the following three as the transmission path of the F1-C data stream in the NR-DC: primary cell group (MCG), secondary cell group (SCG), or both MCG and SCG.

20. The method according to claim 18 or 19, wherein, The UE is a mobile terminal that integrates access and backhaul of IAB nodes.

21. A centralized unit (CU) of a first base station, comprising: A transceiver is configured to transmit and / or receive signals; The controller is configured to control the CU to perform the method according to any one of claims 1-6.

22. A distribution unit DU of a first base station, comprising: A transceiver is configured to transmit and / or receive signals; The controller is configured to control the DU to perform the method according to any one of claims 7-12.

23. A user equipment (UE), comprising: A transceiver is configured to transmit and / or receive signals; The controller is configured to control the UE to perform the method according to any one of claims 13-17.

24. A CU for a second base station, comprising: A transceiver is configured to transmit and / or receive signals; The controller is configured to control the CU to perform the method according to any one of claims 18-20.

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