Connection establishment method, device, collective access return node and storage medium

Abstract

The present application proposes a connection establishment method, device, collective access backhaul node and storage medium. The method includes: obtaining address information of a first centralized unit (CU); establishing a connection with the first CU according to the address information of the first CU. The present application can be used to solve the service continuity problem of a sub-IAB node connected to an IAB node when the IAB node switches to a new Donor CU.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular to a connection establishment method, device, collective access backhaul node and storage medium. Background Art

[0002] Integrated Access and Backhaul (IAB) is an important technology in the fifth generation of mobile communication technology (5G, 5th Generation). Its goal is to enable one or more IAB nodes to connect to the mother node through the new radio (NR) using the local mobile terminal (MT) functional part, and on this basis, form a multi-hop wireless self-backhaul network. In the current discussion, each IAB node contains a distributed unit (DU) functional part and an MT functional part. Among them, DU is used to serve the user equipment (UE, User Equipment) of this node and the MT of the next hop node, and establish a radio link layer control (RLC, Radio Link Control) connection with it; the function of MT is equivalent to a UE, which is used to access the mother node of the previous hop through the Un interface of NR and establish an RLC connection with it. Therefore, different IAB nodes can use the wireless access capability of the local MT to access the mother node of the previous hop, and the mother node can connect to the previous hop node again, until it is finally connected to the donor base station (donor gNB). The donor gNB includes a donor CU and multiple donor DUs, each of which is connected to the donor CU by wire. The donor CU and the donor DU, as well as the donor CU and the DUs of each IAB node are connected via an enhanced F1 interface. When an IAB node replaces its parent node, we call it IAB migration. In current technology, when an IAB node switches to a new donor CU, the child IAB nodes connected to the IAB node cannot maintain service continuity. Summary of the invention

[0003] In order to solve at least one of the above technical problems, the embodiments of the present application provide the following solution.

[0004] The present application provides a connection establishment method, including:

[0005] Obtain address information of the first centralized unit (CU);

[0006] Establish a connection with the first CU according to the address information of the first CU.

[0007] The present application provides a method for notifying a link status, including:

[0008] A first communication node sends link state information to a second communication node, wherein the second communication node is a child node of the first communication node;

[0009] The link status information includes at least one of the following: identification information of the CU connected to the first communication node, change information of the CU connected to the first communication node, the IP address of the CU connected to the first communication node, a link migration indication of the first communication node, and a link reconstruction indication of the first communication node.

[0010] The present application provides an interface establishment method, including:

[0011] Sending an interface establishment request message to the first CU;

[0012] Receive an interface establishment failure message sent by the first CU, wherein the cause value in the interface establishment failure message is unknown or the distribution unit (DU) identifier has been allocated; or, receive an interface establishment response message sent by the first CU, wherein the interface establishment response message includes a reallocated DU identifier.

[0013] The present application provides an information transmission method, including:

[0014] Sending a handover request message to the first CU, where the handover request message carries information of the IAB node;

[0015] A switching response message sent by the first CU is received, where the switching response message carries at least one of address information of the first CU and an identifier of the IAB DU.

[0016] The present application embodiment provides another information transmission method, including:

[0017] The identification information or address information of the first CU is sent to the IAB node.

[0018] The present application embodiment provides another interface establishment method, including:

[0019] receiving an interface establishment request message from the IAB node;

[0020] In the case that the DU identifier of the IAB node conflicts with other DU identifiers with which a connection relationship exists, an interface establishment failure message is sent to the IAB node, wherein the cause value in the interface establishment failure message is unknown or the DU identifier has been allocated; or an interface establishment response message is sent to the IAB node, wherein the interface establishment response message includes a reallocated DU identifier.

[0021] The present application provides a connection establishment device, including:

[0022] An acquisition module, used to acquire address information of the first CU;

[0023] A connection establishing module is used to establish a connection with the first CU according to the address information of the first CU.

[0024] The embodiment of the present application provides a link status notification device, which is applied to a first communication node, including:

[0025] A link status information sending module, used to send link status information to a second communication node; wherein the second communication node is a child node of the first communication node;

[0026] The link status information includes at least one of the following: identification information of the CU connected to the first communication node, change information of the CU connected to the first communication node, the IP address of the CU connected to the first communication node, a link migration indication of the first communication node, and a link reconstruction indication of the first communication node.

[0027] The embodiment of the present application provides an interface establishment device, including:

[0028] A request sending module, used to send an interface establishment request message to the first CU;

[0029] A response receiving module is used to receive an interface establishment failure message sent by the first CU, wherein the cause value in the interface establishment failure message is unknown or the DU identifier has been allocated; or to receive an interface establishment response message sent by the first CU, wherein the interface establishment response message includes a reallocated DU identifier.

[0030] The present application provides an information transmission device, including:

[0031] A switching request sending module, configured to send a switching request message to the first CU, wherein the switching request message carries information of the IAB node;

[0032] The handover response receiving module is configured to receive a handover response message sent by the first CU, wherein the handover response message carries at least one of the address information of the first CU and the identifier of the IAB DU.

[0033] The present application provides another information transmission device, including:

[0034] The identification or address sending module is used to send the identification information or address information of the first CU to the IAB node.

[0035] The present application embodiment provides another interface establishment device, including:

[0036] A connection establishment receiving module, used to receive an interface establishment request message from the IAB node;

[0037] A connection establishment feedback module is used to send an interface establishment failure message to the IAB node when there is a conflict between the DU identifier of the IAB node and other DU identifiers with which a connection relationship exists, wherein the cause value in the interface establishment failure message is unknown or the DU identifier has been allocated; or, send an interface establishment response message to the IAB node, wherein the interface establishment response message includes a reallocated DU identifier.

[0038] An embodiment of the present application provides an IAB node, the IAB node comprising: a processor and a memory;

[0039] The memory is used to store instructions;

[0040] The processor is configured to read the instruction to execute any one of the above-mentioned connection establishment method, link status notification method or first interface establishment method.

[0041] An embodiment of the present application provides a CU, wherein the CU includes: a processor and a memory;

[0042] The memory is used to store instructions;

[0043] The processor is configured to read the instruction to execute any one of the above-mentioned information transmission method and the second interface establishment method.

[0044] An embodiment of the present application provides a communication system, including the above-mentioned IAB node and the above-mentioned CU.

[0045] An embodiment of the present application provides a storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, any one of the methods in the embodiments of the present application is implemented.

[0046] The connection establishment method provided in the embodiment of the present application can be used to solve the service continuity problem of the sub-IAB node connected to the IAB node when an IAB node switches to a new Donor CU by obtaining the address information of the first CU and establishing a connection with the first CU according to the address information. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of a connection establishment method implementation process of the present application Figure 1 ;

[0048] Figure 2 A schematic diagram of a connection establishment method implementation process of the present application Figure 2 ;

[0049] Figure 3 A schematic diagram of the implementation process of an interface establishment method in an embodiment of the present application Figure 1 ;

[0050] Figure 4 A schematic diagram of a flow chart of an information transmission method according to an embodiment of the present application;

[0051] Figure 5 A schematic diagram of the implementation process of an interface establishment method in an embodiment of the present application Figure 2 ;

[0052] Figure 6 This is a schematic diagram of the implementation process of the first embodiment of the present application;

[0053] Figure 7 A schematic diagram of the structure of a connection establishment device according to an embodiment of the present application;

[0054] Figure 8 A schematic diagram of an interface establishment device structure of an embodiment of the present application Figure 1 ;

[0055] Fig. 9 This is a schematic diagram of the structure of an information transmission device according to an embodiment of the present application;

[0056] Fig.10 A schematic diagram of an interface establishment device structure of an embodiment of the present application Figure 2 ;

[0057] Fig.11 This is a schematic diagram of the IAB node structure used for connection establishment or interface establishment in an embodiment of the present application;

[0058] Fig.12 A schematic diagram of a CU structure for information transmission or interface establishment according to an embodiment of the present application;

[0059] Fig.13 The communication system structure of the embodiment of the present application is shown in FIG. Figure 1 ;

[0060] Fig.14 The communication system structure of the embodiment of the present application is shown in FIG. Figure 2 . DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the present application more clear, the embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0062] The present application embodiment proposes a connection establishment method, such as Figure 1 A schematic diagram of a connection establishment method implementation process of the present application Figure 1 ,include:

[0063] Step S11: Obtain address information of the first CU;

[0064] Step S12: Establish a connection with the first CU according to the address information of the first CU.

[0065] In one implementation, the first CU may be a target donor CU, and after establishing a connection with the first CU, an F1 interface establishment request (F1Setup Request) may be sent to the first CU. The execution subject of a connection establishment method of an embodiment of the present application may be an IAB node, especially a migrating IAB node and a downstream IAB node connected thereto, or an IAB node performing RRC reconstruction and a downstream IAB node connected thereto. Among them, downstream may refer to a direction away from the IAB-donor in a multi-hop backhaul.

[0066] In one implementation, the step S11 includes: receiving identification information of the first CU; searching a mapping relationship table between CU identification information and CU address information according to the identification information of the first CU to obtain the address information of the first CU.

[0067] The mapping relationship table between the CU identification information and the CU address information may be pre-stored, or obtained through a network, or configured through operation administration and maintenance (OAM).

[0068] The identification information of the first CU may be carried in an adaptation layer message, and the adaptation layer message comes from an upper layer IAB node;

[0069] The upper-layer IAB nodes include: a parent IAB node that directly provides services or all IAB nodes that participate in forwarding data to the first CU.

[0070] Alternatively, the identification information of the first CU may be carried in a radio resource control (RRC) reconfiguration message, and the RRC reconfiguration message comes from the first CU.

[0071] The RRC reconfiguration message may include a cell identity (CellIdentity) and a physical cell identity (PhysCellId), and the cell identity (CellIdentity) may include identification information of the first CU.

[0072] In one implementation, the step S11 includes: receiving address information of the first CU from the second CU.

[0073] The address information of the first CU may be carried in an F1 message or an RRC reconfiguration message.

[0074] In the embodiment of the present application, the second CU may be a source donor CU.

[0075] Figure 2 A schematic diagram of a connection establishment method implementation process of the present application Figure 2 .like Figure 2 As shown, in one implementation manner, before establishing a connection with the first CU in the above step S12, the following steps may also be included:

[0076] Step S21: receiving link connection success indication information from the upper-layer IAB node; wherein the link connection success indication information includes at least one of the following: identification information of the first CU, cell identification, CU change identification, IP address of the first CU, link migration success indication, link reconstruction success indication, identification of the IAB node of link migration, and identification of the IAB node of link reconstruction.

[0077] In one implementation, the step S11 includes: receiving address information of the first CU from the first CU.

[0078] The address information of the first CU may be carried in the RRC reconfiguration message.

[0079] The embodiment of the present application also provides a method for notifying a link status, comprising: a first communication node sending link status information to a second communication node, wherein the second communication node is a child node of the first communication node;

[0080] The link status information includes at least one of the following: identification information of the CU connected to the first communication node, change information of the CU connected to the first communication node, the IP address of the CU connected to the first communication node, a link migration indication of the first communication node, and a link reconstruction indication of the first communication node.

[0081] In one implementation, the first communication node and the second communication node are IAB nodes.

[0082] The first communication node may send link status information to the second communication node when performing link migration;

[0083] Alternatively, the first communication node may send link status information to the second communication node when performing RRC reconstruction.

[0084] In one embodiment, the first communication node link migration indication includes at least one of the following: a link migration start indication, a link migration success indication, and a link migration failure indication.

[0085] The present application also provides an interface establishment method. Figure 3 A schematic diagram of the implementation process of an interface establishment method in an embodiment of the present application Figure 1 ,include:

[0086] Step S31: Sending an interface establishment request message to the first CU;

[0087] Step S32: receiving an interface establishment failure message sent by the first CU, wherein the cause value in the interface establishment failure message is unknown or the DU identifier has been allocated; or, receiving an interface establishment response message sent by the first CU, wherein the interface establishment response message includes a reallocated DU identifier.

[0088] The present application also proposes an information transmission method, such as Figure 4 A schematic diagram of a flow chart of an information transmission method according to an embodiment of the present application includes:

[0089] Step S41: Sending a handover request message to the first CU, where the handover request message carries information of the IAB node;

[0090] Step S42: receiving a switching response message sent by the first CU, where the switching response message carries at least one of the address information of the first CU and an identifier of the IAB DU.

[0091] The information transmission method proposed in this embodiment can be applied to the source donor CU.

[0092] In a possible implementation, the information of the IAB node includes at least one of: an identifier of the IAB node, context information of a backhaul channel of the IAB node, context information of a UE served by the IAB node, and context information of a downlink IAB node of the IAB node.

[0093] like Figure 4 As shown, an information transmission method proposed in an embodiment of the present application may also include:

[0094] Step S43: sending at least one of the address information of the first CU and the identifier of the IAB DU to the IAB node.

[0095] In one implementation manner, at least one of the address information of the first CU and the identifier of the IAB DU is carried in an RRC reconfiguration message or an F1 message.

[0096] The embodiment of the present application further proposes another information transmission method, including: sending identification information or address information of the first CU to the IAB node.

[0097] The information transmission method proposed in this embodiment can be applied to the target donor CU.

[0098] The identification information or address information of the first CU may be carried in the RRC reconfiguration message.

[0099] In one implementation, the RRC reconfiguration message includes a cell identifier and a PhysCellId, and the cell identifier carries identification information of the first CU.

[0100] The present application embodiment also proposes another interface establishment method. Figure 5 A schematic diagram of the implementation process of an interface establishment method in an embodiment of the present application Figure 2 ,include:

[0101] S51: receiving an interface establishment request message from the IAB node;

[0102] S52: When the DU identifier of the IAB node conflicts with other DU identifiers with which a connection relationship exists, an interface establishment failure message is sent to the IAB node, wherein a cause value in the interface establishment failure message is unknown or the DU identifier has been allocated; or, an interface establishment response message is sent to the IAB node, wherein the interface establishment response message includes a reallocated DU identifier.

[0103] The following is a detailed description of specific embodiments with reference to the accompanying drawings.

[0104] Embodiment 1:

[0105] In this embodiment, IAB-node3 is a child node of IAB-node1. When IAB-node1 is switched, the source donor CU needs to send the context information of IAB-node1 to the target donor CU.

[0106] like Figure 6 This is a schematic diagram of the implementation process of the first embodiment of the present application, including:

[0107] Step S61: The source donor CU sends a switching request message to the target donor CU, where the switching request message carries the information of the migrated IAB-node1.

[0108] In this embodiment, the information of IAB-node1 may include: identification information of IAB-node1, context information of the backhaul channel of IAB-node1, context information of the UE served by IAB-node1, and at least one of the context information of the downlink IAB node of IAB-node1 (for example, IAB-node3).

[0109] Step S62: the target donor CU sends a switching response message to the source donor CU, where the switching response message carries at least one of the address information of the target donor CU and the identifier of the IAB DU.

[0110] The identifier of the IAB DU includes at least one of the following: a DU identifier of a migration node (eg, IAB-node1), and a DU identifier of a downstream node of the migration node (eg, IAB-node3).

[0111] Embodiment 2:

[0112] When IAB-node1 is switched, this embodiment solves the problem of how IAB-node1 obtains the IP address of the target donor CU, and if the migrated IAB node continues to serve the downstream IAB node, then how its downstream IAB node obtains the IP address of the target donor CU.

[0113] In this embodiment, IAB-node3 is a child node of IAB-node1. For the downlink IAB node (i.e., IAB-node3), although its parent IAB node (parent IAB-node), i.e., IAB-node1, has not changed, the donor CU has changed. Therefore, it is necessary to notify IAB-node3 that the donor CU has changed. In addition, in order to establish a new F1 connection, IAB-node3 needs to obtain the IP address of the target donor CU. This is because the gNB-DU needs to establish a transport network layer (TNL) connection of the gNB-DU before sending an F1 interface establishment request message (F1Setup Request message) to the gNB-DU, and establishing a TNL connection requires obtaining an IP address. This embodiment proposes the following ways for the downlink IAB node to obtain the IP address of the target donor CU:

[0114] Method 1:

[0115] Each IAB node (including the migrated IAB node and its downstream IAB node) can pre-configure a mapping table of CU Id to CU IP address, or download a mapping table of CU Id to CU IP address from the network side, or configure a mapping table of CU Id to CU IP address through OAM, so that the IAB node only needs to obtain the gNBId of the target donor CU (i.e., the CU Id of the target donor CU) to search the above mapping table, thereby obtaining the IP address of the target donor CU. The IP address can be a transport layer address (Transport Layer Address). Specifically, the IAB node can obtain the new radio cell global identifier (NCGI, NR Cell Global Identifier) ​​of the target donorCU, and obtain the CU Id of the target donor CU according to the NCGI.

[0116] For the migrated IAB node, the CU Id of the target donor CU can be obtained during the MT switching process.

[0117] If the migrated IAB node continues to serve the downlink IAB node, then for the downlink IAB node, there are at least two ways to obtain the CU Id of the target donor CU: First, the migrated IAB node directly informs the lower IAB node through the adapter layer message after completing the handover, and the lower IAB node continues to inform its lower IAB node. Specifically: the adapter layer message includes at least one of the following: the identification information of the target, the cell identification, the CU change identification, the IP address of the first CU, the link migration success indication, etc.

[0118] The second type is that after the switching of the migrated IAB node is completed, the target donor CU notifies IAB-node3 through RRC signaling (such as RRC reconfiguration message) that the migration has occurred without changing the DU but changing the CU. For example, the cell identifier (CellIdentity) and the physical cell identifier (PhysCellId) are carried in the RRC reconfiguration message, and the CellIdentity is used to indicate the CUId of the target donor CU (such as the target cell gNB id). Since the donor CU has changed, the CellIdentity will also change; but since the DU has not changed, the PhysCellId may not change. It should be noted that in addition to carrying the above-mentioned identifiers, the RRC reconfiguration message may also contain other information.

[0119] Based on the above information, the IAB MT or UE can determine that a handover has occurred in which the CU is changed but the DU remains unchanged, and there is no need to re-execute the cell access process, but it is necessary to receive updates to the configuration information later. Then, the downlink IAB node (such as IAB-node3 in this embodiment) can look up the above mapping table, obtain the IP address of the target donor CU, establish a TNL connection with the target donor CU, and then initiate an F1 connection establishment process to the target donor CU.

[0120] Method 2: The source donor CU sends the IP address of the target donor CU to the downstream IAB node. This step should be performed before the source donor CU sends a switching command to the migrated IAB node.

[0121] Method 2 can have the following two specific forms:

[0122] Method 2a: The source donor CU sends the IP address of the target donor CU to the DU part of the downstream IAB node through the F1 interface;

[0123] Mode 2b: The source donor CU sends the IP address of the target donor CU to the MT part of the downlink IAB node via an RRC message.

[0124] In case of method 2, the source donor CU needs to obtain the IP address of the target donor CU. The IP address of the target donor CU can be obtained in the following ways: obtaining the IP address of the target donor CU during the switching preparation process; or pre-configuring a mapping table of CU Id to CU IP address; or downloading a mapping table of CU Id to CU IP address from the network side; or configuring a mapping table of CU Id to CU IP address through OAM.

[0125] For the migrated IAB node, for mode 2b, the source donor CU sends an RRC reconfiguration message to the MT of the IAB node (such as IAB-node1 in this embodiment), and the RRC reconfiguration message may include the IP address of the target donor CU and other information, such as CellIdentity and PhysCellId. For mode 2a, the source donor CU sends an F1 message to the DU of the IAB node (such as IAB-node1 in this embodiment), and the F1 message may include the IP address of the target donor CU, which is used to instruct the DU of the downlink IAB node to release the F1 connection with the source donor CU and establish an F1 connection with the target donor CU.

[0126] If the migrated IAB node continues to serve the downlink IAB node, then, the source donor CU decides which downlink IAB nodes need to switch to the target donor CU. For mode 2b, the source donor CU sends an RRC reconfiguration message to the MT of the downlink IAB node (such as IAB-node3 in this embodiment), and the RRC reconfiguration message may include the IP address of the target donor CU and other information, such as CellIdentity and PhysCellId. For mode 2a, the source donor CU sends an F1 message to the DU of the downlink IAB node (such as IAB-node3 in this embodiment), and the F1 message may include the IP address of the target donor CU, which is used to instruct the DU of the downlink IAB node to release the F1 connection with the source donor CU and establish an F1 connection with the target donor CU.

[0127] Since the above information is sent before the switching of the migrated IAB node, and the switching of the migrated IAB node may fail, the downlink IAB node that receives the above information cannot immediately initiate a new F1 connection establishment process. In view of this, when the downlink IAB node (such as IAB-node3 in this embodiment) receives the above information, it does not immediately initiate the F1 connection establishment process, but waits for the parent IAB node (such as IAB-node1 in this embodiment) to switch successfully before releasing the F1 connection with the source donor CU and establishing an F1 connection with the target donor CU. Then, after the migrating IAB node completes the switching, it needs to send an indication message to IAB-node3. After receiving the indication message, IAB-node3 starts to execute the switching process of not changing the DU but only changing the CU to establish a new F1 connection.

[0128] For the migrated IAB node, directly carrying the IP address of the target donor CU in the RRC reconfiguration message is a relatively simple method.

[0129] In one implementation, the F1 connection may refer to an F1 access protocol (AP, Application Protocol) connection.

[0130] Method 3: The target donor CU sends its own IP address to the MT part of the downlink IAB node through an RRC message.

[0131] For the migrated IAB, after the MT part of the IAB establishes an RRC connection with the target donor CU, the target donor CU sends the IP address to the MT of the IAB through an RRC reconfiguration message, and then the MT of the IAB informs the DU part to obtain the IP address of the target donor CU.

[0132] If the migrated IAB node continues to serve the downlink IAB node, then, for the downlink IAB node of the migrated IAB node (such as IAB-node3 in this embodiment), specifically, after the DU part of the migrated IAB node is activated, the target donor CU can send an RRC reconfiguration message to its child IAB node (such as IAB-node3 in this embodiment), and the RRC reconfiguration message carries the IP address of the target donor CU. After receiving the RRC reconfiguration message, the child IAB node can determine that the donor CU has changed, and therefore initiates the F1 connection establishment process with the target donor CU. The F1 connection here can be specifically an F1-C connection. After the F1 connection between IAB-node3 and the target donor CU is established, the target donor CU can continue to notify the child IAB node of IAB-node3 of the IP address through RRC messages, and so on.

[0133] Embodiment three:

[0134] If the UE needs to switch with the migrated IAB node, although the service DU is not updated, it is necessary to notify the UE of the cell id and some configuration information because the CU has been replaced. Then, after the DU function of the migrated IAB node is activated, the donor CU can send an RRC reconfiguration message to notify the updated information, such as carrying the target cell id. In order to avoid too much impact on the UE, only the CellIdentity can be changed after the DU changes the CU, but the physical cell identifier (PCI) of the cell is not changed. In this way, for the UE, the access is still the same DU, and there is no need to perform a random access process to find a new cell, and the resources of the physical layer and the media access control (MAC) layer will not change. Since the CU changes, the PDCP-related configuration information and the SDAP-related configuration information will also change. Then, the donor CU can inform the UE of the updated cell configuration information (new CellIdentity and unchanged PCI) and bearer configuration information through the RRC reconfiguration message, where the bearer configuration information can include the above-mentioned PDCP-related configuration information and SDAP-related configuration information. In addition, the updated cell configuration information may also include public land mobile network (PLMN, Public Land Mobile Network) information, tracking area code (Tracking Area Code, TAC), uplink and downlink time slot (slot) configuration information.

[0135] Embodiment 4:

[0136] According to the prior art, the gNB-DU ID is unique within a gNB-CU, but if the CU is replaced, there is a possibility of conflict. Therefore, after the DU replaces the CU, when the CU receives the connection establishment request initiated by the DU with the CU, if it is found that the current gNB-DU ID conflicts with the gNB-DU ID of other connections, an F1 connection establishment failure message (F1SETUPFAILURE) can be sent, and the cause (Cause) value can be set to unknown (Unknown) or the DU identifier has been allocated (alreadyallocated gNB-DU ID). Alternatively, an F1 connection establishment response message (F1SETUP RESPONSE) can be sent, and the new DU identifier allocated by the CU for the gNB-DU can be carried in the F1SETUP RESPONSE.

[0137] In addition, gNB-CU UE F1AP ID, gNB-CU-CP UE E1AP ID, and gNB-CU-UP UE E1AP ID are also processed in the same way.

[0138] Embodiment five:

[0139] According to the prior art, the gNB-DU ID is unique within a gNB-CU. However, if the CU is replaced, if the previously assigned DU ID continues to be used, there is a possibility of conflict. Therefore, when the DU replaces the CU, in order to avoid the possibility of conflict, the target CU can allocate a new DU ID to the DU in advance. The embodiments of the present application can adopt at least the following two solutions:

[0140] Method 1:

[0141] Step 1: The source CU sends a handover request message to the target CU, where the handover request message carries the information of the IAB node;

[0142] Step 2: The source CU receives a handover response message sent by the target CU, where the handover response message carries identification information of the IAB DU.

[0143] The source CU sends the identification information of the above IAB DU to the IAB node, and then the IAB node can use the identification information to establish an F1 connection with the target CU.

[0144] If the migrated IAB node continues to serve the downlink IAB node, then for the downlink IAB of the migrated IAB (such as IAB-node3 in this embodiment), the source CU can also use a similar method to send the identification information of the downlink IAB DU to the downlink IAB node, and then the downlink IAB node can use the identification information to establish an F1 connection with the target CU.

[0145] Method 2:

[0146] For the migrated IAB, after the MT part of the IAB establishes an RRC connection with the target donor CU, the target donor CU sends the identification information of the IAB DU to the MT of the IAB node through an RRC reconfiguration message, and then the MT of the IAB node informs the DU part, and then the IAB node can use the identification information to establish an F1 connection with the target CU.

[0147] If the migrated IAB node continues to serve the downlink IAB node, then the downlink IAB of the migrated IAB (such as IAB-node3 in this embodiment) can also adopt the above method. After the MT part of the downlink IAB establishes an RRC connection with the target donor CU, the target donor CU sends the identification information of the downlink IAB DU to the MT of the downlink IAB node through an RRC reconfiguration message; then the MT of the downlink IAB node informs the DU part, and then the downlink IAB node can use the identification information to establish an F1 connection with the target CU.

[0148] Embodiment six:

[0149] When the IAB node needs to perform RRC reconstruction due to link failure or other reasons, if the selected reconstructed cell is connected to a new target donor CU, then the IP address of the target CU needs to be re-acquired. For example, the target donor CU sends its IP address information to the MT of the IAB node through an RRC reconfiguration message, and then the MT of the IAB node informs the DU part, and then the DU part of the IAB node can use the IP address to establish a TNL connection with the target CU, and then establish an F1 connection.

[0150] In addition, if the IAB continues to serve the downlink IAB node after rebuilding to a new target donor CU, the downlink IAB node also needs to re-establish an F1 connection with the new target donor CU and also needs to obtain the IP address of the target donor CU. One way is: the target donor CU sends its IP address information to the MT of the downlink IAB node through an RRC reconfiguration message, and then the MT of the downlink IAB node informs the DU part, and then the DU part of the downlink IAB node can use the IP address to establish a TNL connection with the target CU, and then establish an F1 connection. Another way is: after the IAB node performs RRC reconstruction, it sends an indication of the completion of the reconstruction to the downlink IAB node through an adaptation layer message (adapter layer), specifically: the adapter layer message includes at least one of the following: the identification information of the target, the cell identification, the CU change identification, the IP address of the first CU, and the link reconstruction success indication.

[0151] The above specific implementation methods are similar to some of the methods in the above embodiments, and will not be repeated here.

[0152] Embodiment seven:

[0153] When the IAB node needs to perform RRC reconstruction due to link failure or other reasons, if the reconstructed cell is connected to a new target donor CU, there is a possibility of conflict if the previously allocated DU identifier continues to be used. Therefore, when the DU changes the CU, in order to avoid the possibility of conflict, the target CU can allocate a new DU identifier to the DU in advance.

[0154] For example, the target donor CU sends the identification information of the IAB DU to the MT of the IAB node through the RRC reconfiguration message, and then the MT of the IAB node informs the DU part, and then the DU part of the IAB node can use the identification information to establish an F1 connection with the target CU. The specific implementation method is similar to some of the methods in the above embodiments, and will not be repeated here.

[0155] Embodiment eight:

[0156] In this embodiment, the first communication node (e.g., the parent IAB node) may send link status information to the second communication node (e.g., the child IAB node of the first communication node) when performing link migration or performing RRC reconstruction. The link status information may include at least one of the following: identification information of the CU connected to the first communication node, change information of the CU connected to the first communication node, the IP address of the CU connected to the first communication node, the link migration indication of the first communication node, and the link reconstruction indication of the first communication node. Among them, the link migration indication of the first communication node may include at least one of the following: link migration start indication, link migration success indication, and link migration failure indication.

[0157] The present application also provides a connection establishment device, such as Figure 7 A schematic diagram of a connection establishment device structure of an embodiment of the present application includes:

[0158] An acquisition module 701 is used to acquire address information of a first CU;

[0159] The connection establishing module 702 is used to establish a connection with the first CU according to the address information of the first CU.

[0160] In one implementation, the acquisition module 701 is used to: receive identification information of the first CU; search for a mapping relationship between CU identification information and CU address information according to the identification information of the first CU to obtain the address information of the first CU.

[0161] The mapping relationship table between the CU identification information and the CU address information may be pre-stored, obtained through a network, or configured through OAM.

[0162] In one implementation, the acquisition module 701 is used to receive address information of the first CU from the second CU or the first CU.

[0163] like Figure 7 The above device may further include:

[0164] The link connection success indication information receiving module 703 is used to receive the link connection success indication information from the upper-layer IAB node; the link connection success indication information includes at least one of the following: the identification information of the first CU, the cell identification, the CU change identification, the IP address of the first CU, the link migration success indication, the link reconstruction success indication, the identification of the IAB node of the link migration, and the identification of the IAB node of the link reconstruction.

[0165] The embodiment of the present application further provides a link status notification device, which can be applied to a first communication node, and includes:

[0166] A link status information sending module, used to send link status information to a second communication node; wherein the second communication node is a child node of the first communication node;

[0167] The link status information includes at least one of the following: identification information of the CU connected to the first communication node, change information of the CU connected to the first communication node, the IP address of the CU connected to the first communication node, a link migration indication of the first communication node, and a link reconstruction indication of the first communication node.

[0168] The first communication node and the second communication node may be IAB nodes.

[0169] The present application also provides an interface establishment device, such as Figure 8 A schematic diagram of an interface establishment device structure of an embodiment of the present application Figure 1 ,include:

[0170] A request sending module 801 is used to send an interface establishment request message to the first CU;

[0171] The response receiving module 802 is used to receive an interface establishment failure message sent by the first CU, wherein the cause value in the interface establishment failure message is unknown or the DU identifier has been allocated; or to receive an interface establishment response message sent by the first CU, wherein the interface establishment response message includes a reallocated DU identifier.

[0172] The present application also provides an information transmission device, such as Fig. 9 This is a schematic diagram of the structure of an information transmission device according to an embodiment of the present application, comprising:

[0173] A handover request sending module 901 is configured to send a handover request message to the first CU, where the handover request message carries information of the IAB node;

[0174] The handover response receiving module 902 is configured to receive a handover response message sent by the first CU, where the handover response message carries at least one of the address information of the first CU and the identifier of the IAB DU.

[0175] like Fig. 9 The above device may further include:

[0176] The sending module 903 is configured to send at least one of the address information of the first CU and the identifier of the IAB DU to the IAB node.

[0177] The embodiment of the present application further proposes another information transmission device, including: an identification or address sending module, used to send identification information or address information of a first CU to an IAB node.

[0178] The present application also provides another interface establishment device, such as Fig.10 A schematic diagram of an interface establishment device structure of an embodiment of the present application Figure 2 ,include:

[0179] The connection establishment receiving module 1001 is used to receive an interface establishment request message from the IAB node;

[0180] The connection establishment feedback module 1002 is used to send an interface establishment failure message to the IAB node when there is a conflict between the DU identifier of the IAB node and the DU identifier of other IAB nodes with which a connection relationship exists, and the cause value in the interface establishment failure message is unknown or the DU identifier has been allocated; or, send an interface establishment response message to the IAB node, and the interface establishment response message includes a reallocated DU identifier.

[0181] Fig.11 This is a schematic diagram of the IAB node structure of an embodiment of the present application, such as Fig.11 As shown, the IAB node 110 provided in the embodiment of the present application includes: a memory 1103 and a processor 1104. The IAB node 110 may also include an interface 1101 and a bus 1102. The interface 1101, the memory 1103 and the processor 1104 are connected via the bus 1102. The memory 1103 is used to store instructions. The processor 1104 is configured to read the instructions to execute the technical solution of the method embodiment applied to the IAB node, and its implementation principle and technical effect are similar, which will not be repeated here.

[0182] Fig.12 This is a schematic diagram of the CU structure of an embodiment of the present application, such as Fig.12 As shown, the CU 120 provided in the embodiment of the present application includes: a memory 1203 and a processor 1204. The CU 120 may also include an interface 1201 and a bus 1202. The interface 1201, the memory 1203 and the processor 1204 are connected via the bus 1202. The memory 1203 is used to store instructions. The processor 1204 is configured to read the instructions to execute the technical solution of the method embodiment applied to the CU, and its implementation principle and technical effect are similar, which will not be repeated here.

[0183] Fig.13 The communication system structure of the embodiment of the present application is shown in FIG. Figure 1 ,like Fig.13 As shown, the system includes: the IAB node 110 of the above embodiment, and the CU 120 of the above embodiment.

[0184] Fig.14 The communication system structure of the embodiment of the present application is shown in FIG. Figure 2 ,like Fig.14 As shown, the system includes: the IAB node 110 of the above embodiment and the CU 120 of the above embodiment. Each IAB node is divided into an MT part and a DU part, the MT part of each IAB node is respectively connected to the DU by Uu, and the DU part of each IAB node is respectively connected to the CU by F1.

[0185] The present application provides a storage medium storing a computer program. When the computer program is executed by a processor, the method in the above embodiment is implemented.

[0186] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of hardware embodiments, software embodiments, or embodiments in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that include computer-usable program codes.

[0187] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0188] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0189] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0190] The above description is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application.

Claims

1. A connection establishment method, applied to an IAB node, characterized in that: include: Obtain address information of the first centralized unit CU; The acquiring the address information of the first CU includes: receiving the address information of the first CU from the second CU; the address information of the first CU is carried in an F1 message or an RRC reconfiguration message; the first CU is a target donor CU; the second CU is a source donor CU; Establish a connection with the first CU according to the address information of the first CU.

2. The method according to claim 1, characterized in that The acquiring the address information of the first CU includes: Receiving identification information of the first CU; A mapping relationship between CU identification information and CU address information is searched according to the identification information of the first CU to obtain the address information of the first CU.

3. The method according to claim 2, characterized in that The identification information of the first CU is carried in an adaptation layer message, and the adaptation layer message comes from an upper layer set access backhaul IAB node; The upper-layer IAB node includes: a parent IAB node that directly provides services or an IAB node that participates in forwarding data to the first CU.

4. The method according to claim 2, characterized in that: The identification information of the first CU is carried in a radio resource control RRC reconfiguration message, and the RRC reconfiguration message comes from the first CU.

5. The method according to claim 4, characterized in that The RRC reconfiguration message includes a cell identifier and a physical cell identifier, and the cell identifier includes identification information of the first CU.

6. The method according to claim 1 or 2, characterized in that: Before establishing the connection with the first CU, the method further includes: receiving link connection success indication information from an upper layer IAB node; The link connection success indication information includes at least one of the following: identification information of the first CU, a cell identification, a CU change identification, an IP address of the first CU, a link migration success indication, a link reconstruction success indication, an identification of an IAB node for link migration, and an identification of an IAB node for link reconstruction.

7. The method according to claim 1, characterized in that The acquiring the address information of the first CU includes: receiving the address information of the first CU from the first CU.

8. The method according to claim 7, characterized in that The address information of the first CU is carried in the RRC reconfiguration message.

9. An information transmission method, applied to a source donor CU, characterized in that: include: Sending address information of a first CU to an IAB node; the address information of the first CU comes from a second CU; the address information of the first CU is carried in an F1 message or an RRC reconfiguration message; the first CU is a target donor CU; and the second CU is a source donor CU.

10. The method according to claim 9, characterized in that The RRC reconfiguration message includes a cell identifier and a physical cell identifier, and the cell identifier carries identification information of the first CU.

11. A connection establishment device, applied to an IAB node, characterized in that: include: An acquisition module, used to acquire address information of the first CU; The acquiring the address information of the first CU includes: receiving the address information of the first CU from the second CU; the address information of the first CU is carried in an F1 message or an RRC reconfiguration message; the first CU is a target donor CU; the second CU is a source donor CU; A connection establishing module is used to establish a connection with the first CU according to the address information of the first CU.

12. The device according to claim 11, characterized in that The acquisition module is used to: Receiving identification information of the first CU; A mapping relationship between CU identification information and CU address information is searched according to the identification information of the first CU to obtain the address information of the first CU.

13. The device according to claim 11, characterized in that The acquisition module is used to: Address information of the first CU is received from a first CU.

14. The device according to claim 11 or 12, characterized in that: The device also includes: A link connection success indication information receiving module is used to receive link connection success indication information from an upper-layer IAB node; the link connection success indication information includes at least one of the following: identification information of the first CU, a cell identification, a CU change identification, an IP address of the first CU, a link migration success indication, a link reconstruction success indication, an identification of the IAB node of the link migration, and an identification of the IAB node of the link reconstruction.

15. An information transmission device, applied to a source donor CU, characterized in that: include: An identification or address sending module, used to send address information of a first CU to an IAB node; the address information of the first CU comes from a second CU; the address information of the first CU is carried in an F1 message or an RRC reconfiguration message; the first CU is a target donor CU; and the second CU is a source donor CU.

16. An IAB node, characterized in that: The IAB node includes: a processor and a memory; The memory is used to store instructions; The processor is configured to read the instructions to execute the method according to any one of claims 1 to 8.

17. A CU, characterized in that: The CU includes: a processor and a memory; The memory is used to store instructions; The processor is configured to read the instructions to execute the method according to any one of claims 9 to 10.

18. A communication system, characterized in that: The system comprises the IAB node according to claim 16 and the CU according to claim 17.

19. A storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 10 is implemented.

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