CN114026929A

CN114026929A - F1 interface management method and device

Info

Publication number: CN114026929A
Application number: CN201980097212.7A
Authority: CN
Inventors: 朱元萍; 刘菁; 戴明增; 卓义斌
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-08-09
Filing date: 2019-08-09
Publication date: 2022-02-08
Also published as: WO2021026706A1

Abstract

A method and a device for managing an F1 interface are provided, wherein the method comprises the following steps: a first device receives a first message from a second device, wherein the first message is used for instructing the first device to execute a suspension operation on the connection of an F1 interface of the first device; the F1 interface is an interface between a DU function entity in the first device and a CU function entity in the second device, or the F1 interface is an interface between the first device and the second device; the first device performs a suspension operation on the connection of the F1 interface according to the first message, wherein the suspension operation comprises one or more of the following operations: interrupting transmission of an F1AP message of the F1 interface; retaining context information of the first device; interrupting data transmission of a user plane of the F1 interface; the signaling connection of the F1 interface is reserved. By the method, the suspension operation of the connection of the interface 1 can be quickly and efficiently carried out, and the system efficiency is improved.

Description

F1 interface management method and device

Technical Field

The present application relates to the field of wireless communications technologies, and in particular, to a method and an apparatus for managing an F1 interface.

Background

An Integrated Access and Backhaul (IAB) network technology is introduced into a fifth generation mobile communication system (5th-generation, 5G), and an access link (access link) and a backhaul link (backhaul link) in the IAB network both adopt a wireless transmission scheme, so that optical fiber deployment is avoided, thereby reducing deployment cost and improving deployment flexibility. In the IAB network, an IAB node (IAB node) and an IAB host (IAB node) are included. The terminal side equipment can access an IAB node (IAB node), so that the service data of the terminal side equipment can be transmitted by the IAB node through connecting to an IAB host (IAB node) through a wireless backhaul link.

In the current discussion of IAB networks, it is determined that a new protocol layer is introduced in the wireless backhaul link: a Backhaul Adaptation Protocol (BAP) layer, which is located above a Radio Link Control (RLC) layer and can be used to implement functions such as routing and bearer mapping of a data packet on a wireless Backhaul link. An F1 interface may be established between the IAB node and the IAB host for information transfer. The F1 interface supports user plane protocols and control plane protocols. Through the control plane of the F1 interface, interface management can be performed between the IAB node and the IAB host, configuration of the IAB node can be performed, and context-related configuration of the terminal-side device can be performed. Through the user plane of the F1 interface, the functions of the transmission of user plane data of the terminal, feedback of downlink transmission state, and the like can be performed between the IAB node and the IAB host.

In the present discussion, only the function and the role of the F1 interface are discussed, and how to manage the F1 interface, there is no definite solution yet, which is a problem to be solved urgently.

Disclosure of Invention

An object of the present invention is to provide a method and an apparatus for managing an F1 interface, so as to solve the problem of how to manage an F1 interface.

In a first aspect, an embodiment of the present application provides an F1 interface management method, including: a first device receives a first message from a second device, wherein the first message is used for instructing the first device to execute a suspension operation on the connection of an F1 interface of the first device; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device; the first device performs a suspension operation on the connection of the F1 interface according to the first message, wherein the suspension operation comprises: interrupting transmission of a F1Application Protocol (AP) message of the F1 interface, and one or more of: retaining context information of the first device; interrupting data transmission of a user plane of the F1 interface; the signaling connection of the F1 interface is reserved.

In the above method flow, when the second device instructs the first device to perform the suspension operation on the connection of the F1 interface, the F1 interface is managed. By performing a suspending operation on the connection of the F1 interface, the configuration of the F1 interface can be retained, so that the connection of the F1 interface can be quickly restored when the activated state is entered next time.

In one possible design, the context information of the first device includes at least one of:

configuration information of a distributed unit, DU, functional entity in the first device; configuration information of a centralized unit, CU, functional entity in the second device; context information of child nodes served by the first device.

In one possible design, the method further includes: the first device instructs a Stream Control Transmission Protocol (SCTP) layer to execute a SCTP coupling turn-off process through an F1AP layer; and/or the first device instructs, through the layer F1AP, the SCTP layer to close the sending of the SCTP-coupled heartbeat packet, or to increase the sending period of the heartbeat packet.

By the method, the power consumption and the resource consumption of the first equipment can be reduced, and the resource utilization rate is improved.

In one possible design, the first message is an F1application layer protocol, AP, message sent to the first device through a control plane of the F1 interface; or, the first message is a radio resource control RRC message.

In one possible design, the method further includes:

the first device sends a second message to the second device, wherein the second message is used for indicating that the connection of the F1 interface is suspended.

In a second aspect, a method for managing an F1 interface is provided, including: the second device determines to perform a hanging operation on the connection of the F1 interface of the first device; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device; the second device sends a first message to the first device, wherein the first message is used for instructing the first device to execute a suspension operation on the connection of the F1 interface of the first device.

In the above method flow, the second device instructs the first device to perform a suspension operation on the connection of the F1 interface, so as to manage the F1 interface. By performing a suspending operation on the connection of the F1 interface, the configuration of the F1 interface can be retained, so that the connection of the F1 interface can be quickly restored when the activated state is entered next time.

In one possible design, the second device determines to perform a hanging operation on the connection of the F1 interface of the first device, including: when the second device determines that the first device enters the non-active state from the active state, determining to perform a suspension operation on the connection of the F1 interface of the first device; or when the second device determines that the first device is to perform cell handover, determining to perform suspension operation on the connection of the F1 interface of the first device.

In one possible design, the method further includes: the second device receives a second message from the first device, the second message indicating that the connection of the F1 interface has completed hanging.

In a third aspect, a method for managing an F1 interface is provided, including: the first device receives a third message from the second device, wherein the third message is used for instructing the first device to restore the connection of the F1 interface which is hung by the first device; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device; the first device restores the connection of the F1 interface according to the third message, wherein the restoring operation includes: resuming transmission of F1application protocol AP messages of the F1 interface, and one or more of: restoring and/or applying context information of the first device; resuming data transmission of the user plane of the F1 interface; and restoring the signaling connection of the F1 interface.

In the above method flow, when the second device instructs the first device to restore the connection of the suspended F1 interface, the context information of the first device can be quickly restored, signaling overhead is reduced, and the delay of the first device entering the active state is reduced.

configuration information of a distributed unit, DU, functional entity in the first device; configuration information of a centralized unit CU function entity in the second device; context information of child nodes served by the first device.

In one possible design, the third message includes a cell identity, and the method further includes: the first equipment activates the cell indicated by the cell identification; or, the third message includes cell activation indication information, and the first device activates all cells of the first device according to the cell activation indication information, or activates a cell in an activated state before suspending the connection of the F1 interface according to the cell activation indication information.

In one possible design, the third message is an F1application layer protocol AP message sent through a control plane of the F1 interface; or, the third message is a radio resource control RRC message.

In one possible design, the method further includes: the first device sends a fourth message to the second device, wherein the fourth message is used for indicating that the connection of the F1 interface is completely recovered.

In a fourth aspect, a method for managing an F1 interface is provided, including: the second device determines to restore the connection of the F1 interface from which the first device has been suspended; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device; the second device sends a third message to the first device, where the third message is used to instruct the first device to resume the connection of the F1 interface.

In the above method flow, when the second device may instruct the first device to restore the connection of the suspended F1 interface, the context information of the first device may be quickly restored, signaling overhead may be reduced, and a delay of the first device entering the active state may be reduced.

In one possible design, the determining, by the second device, to restore the connection of the F1 interface from which the first device has been suspended includes:

when the second device determines that the first device enters the active state from the inactive state, determining to restore the connection of the F1 interface; or, the second device determines that the first device is to perform cell handover, and the mobile terminal MT function entity in the first device has completed handover, and determines to recover the connection of the F1 interface.

In one possible design, the third message is an F1application layer protocol AP message sent to the first device through a control plane of the F1 interface; or, the third message is a radio resource control RRC message.

In one possible design, the method further includes: the second device receives a fourth message from the first device, the fourth message indicating that the connection of the F1 interface has completed resuming.

In a fifth aspect, a F1 interface management method is provided, including: the first IAB host sends a fifth message to the second IAB host, wherein the fifth message comprises a node identifier and is used for acquiring the context information of the IAB node indicated by the node identifier; the first IAB host is a target device which is newly connected with the IAB node, and the second IAB host is a source device which is connected with the IAB node; the first IAB host receives a sixth message from a second IAB host, the sixth message including context information for the IAB node.

In the above method flow, the first IAB host obtains the context information of the IAB node through the second IAB host, so that the connection of the F1 interface can be quickly established with the IAB node, and the time delay of the service terminal side device is reduced.

In one possible design, before the first IAB host sends the fifth message to the second IAB host, the method further comprises: the first IAB host determines to acquire the context information of the IAB node.

In one possible design, the determining, by the first IAB host, to obtain context information of the IAB node includes:

when the first IAB host determines that the IAB node enters an activated state from an inactivated state, determining to acquire the context information of the IAB node; or, when the first IAB host determines that the IAB node is connected to the first IAB host, determining to acquire context information of the IAB node.

In one possible design, the context information of the IAB node includes at least one of: configuration information of a Distributed Unit (DU) functional entity in the IAB node; configuration information of a centralized unit CU functional entity of the second IAB host; context information of child nodes served by the IAB node.

In a sixth aspect, a F1 interface management method is provided, including: the IAB host determines that the first IAB node accesses the IAB host through the second IAB node; the first IAB node is a child node of the second IAB node; the IAB host sends indication information to the second IAB node, where the indication information is used to indicate that the first IAB node is an IAB node.

By the method, the time required by the first IAB node to enter the activated state can be reduced, and further the time consumed by the terminal side equipment accessing the first IAB node to enter the RRC connected state from the RRC inactive state is reduced.

In a seventh aspect, a method for managing an F1 interface is provided, including: the second IAB node receives indication information from the IAB host, wherein the indication information is used for indicating that the first IAB node is the IAB node; the first IAB node is a child node of the second IAB node; and when the second IAB node determines that the second IAB node enters an inactive state and determines that the first IAB node is the IAB node according to the indication information, the second IAB node reserves the context information of the first IAB node.

In an eighth aspect, the present application further provides a communication device having a method for implementing any one of the methods provided in the first to seventh aspects. The communication device may be implemented by hardware, or may be implemented by hardware executing corresponding software. The hardware or software includes one or more units or units corresponding to the above functions.

In one possible implementation, the communication device includes: a processor configured to support the communication apparatus to perform a corresponding function of the receiving device in the above-illustrated communication method. The communication device may also include a memory, which may be coupled to the processor, that retains program instructions and data necessary for the communication device. Optionally, the communication apparatus further comprises a communication interface for supporting communication between the communication apparatus and the tag device, the transmitting device, or the like.

In one possible implementation, the communication device comprises corresponding functional units, each for implementing the steps in the above method. The functions may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units corresponding to the above functions.

In a possible implementation manner, the structure of the communication device includes a processing unit and a communication unit, and these units may perform corresponding functions in the foregoing method example, which is specifically referred to the detailed description in the method example, and is not described herein again.

In a ninth aspect, embodiments of the present application provide a computer-readable storage medium having computer-readable instructions stored thereon, which, when read and executed by a computer, cause the computer to perform the method of any one of the above possible designs.

In a tenth aspect, embodiments of the present application provide a computer program product, which when read and executed by a computer, causes the computer to perform the method of any one of the above possible designs.

In an eleventh aspect, embodiments of the present application provide a chip, where the chip is connected to a memory, and is configured to read and execute a software program stored in the memory, so as to implement the method in any one of the above possible designs.

In a twelfth aspect, the present application provides a chip system, where the chip system includes a processor and may further include a memory, and is configured to implement the method in any one of the above possible designs. The chip system may be formed by a chip, and may also include a chip and other discrete devices.

In a thirteenth aspect, embodiments of the present application provide a system, which includes the first device in the first aspect, and the second device in the second aspect.

In a fourteenth aspect, embodiments of the present application provide a system, which includes the first device in the third aspect, and the second device in the fourth aspect.

In a fifteenth aspect, the present application provides a system, which includes the first IAB host, the IAB node, and the second IAB host in the fifth aspect.

Sixthly, an embodiment of the present application provides a system, where the system includes the IAB host, the first IAB node, and the second IAB node in the sixth aspect.

Drawings

Fig. 1 is a schematic diagram of a network architecture suitable for use in embodiments of the present application;

FIG. 2 is a schematic diagram of a network architecture suitable for use in embodiments of the present application;

FIG. 3 is a schematic diagram of another network architecture suitable for use in embodiments of the present application;

fig. 4(a) to 4(b) are schematic diagrams of a protocol stack structure provided in an embodiment of the present application;

fig. 5 is a schematic flowchart of an F1 interface management method according to an embodiment of the present disclosure;

fig. 6 is a schematic flowchart of an F1 interface management method according to an embodiment of the present disclosure;

fig. 7 is a schematic flowchart of an F1 interface management method according to an embodiment of the present disclosure;

fig. 8 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a communication device according to an embodiment of the present application.

Detailed Description

Embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

The embodiment of the application can be applied to various mobile communication systems, such as: a New Radio (NR) system, a Long Term Evolution (LTE) system, an advanced long term evolution (LTE-a) system, an evolved Long Term Evolution (LTE) system, a future communication system, and other communication systems, and in particular, is not limited herein.

For the convenience of understanding the embodiments of the present application, a communication system applicable to the embodiments of the present application will be first described in detail by taking the communication system shown in fig. 1 as an example. Fig. 1 shows a schematic diagram of a communication system suitable for the communication method of the embodiment of the present application. As shown in fig. 1, the communication system includes a sub-IAB host, an IAB node, and a terminal side device. Fig. 2 is another form of the communication system shown in fig. 1, which is substantially identical in meaning and will not be described again.

In addition, in fig. 1 and fig. 2, interface names between devices are also shown, for example, an NR Uu interface between the terminal side device and the IAB node and an NR Un interface between the IAB node and the IAB host, the names of these interfaces are only examples and do not represent the limitation of the interfaces, and when the communication system version is changed, the corresponding names may be replaced by the names of the corresponding functions in other wireless communication networks.

The IAB network shown in fig. 1 supports multi-hop networking, for example, between the IAB nodes and the IAB hosts shown in fig. 1 and 2, there may also be one or more intermediate IAB nodes.

The IAB network shown in fig. 1 supports not only multihop networking but also multi-connection networking. Between the terminal-side devices served by the IAB node and the IAB hosts, there may be at least one transmission path consisting of multiple segments of links. There may also be one or more transmission paths between the IAB node and the IAB host, and there may be one or more IAB nodes on each transmission path. On one transmission path, each IAB node treats its neighboring nodes providing backhaul service as parent nodes, and accordingly, each IAB node can be treated as a child node of its parent node. For example, in the scenarios shown in fig. 1 and 2, the parent node of the IAB node is the IAB host, and the IAB host treats the IAB node as a child node.

It should be noted that the IAB networking scenario shown in fig. 1 is only an example, and in an IAB scenario in which multiple hops and multiple connections are combined, other connection forms may also exist, for example, the present application may also be applied to a scenario of dual connections, and may be specifically shown in fig. 3. Fig. 3 shows a network architecture diagram of a dual connectivity system. As shown in fig. 3, the communication system includes an Evolved Packet Core (EPC) device, a base station, an IAB host, an IAB node, and a terminal side device. The steps for other cases are described in detail.

In the embodiment of the present application, a node supporting integrated access and backhaul is referred to as an IAB node, which may also be referred to as a Relay Node (RN), and for convenience of description, the IAB node is hereinafter referred to as an IAB node. The IAB node may include at least one Mobile Terminal (MT) unit and at least one Distributed Unit (DU), which are only described in fig. 1 and 2 as examples where the IAB node includes one MT unit and a DU. An MT unit in an IAB node implements the IAB as a terminal to communicate with the parent node of the IAB node and an IAB host node. The DU in the IAB node provides access service for the terminal side device attached to the IAB node or other IAB nodes, and may also communicate with the IAB host node based on the F1 interface. The MT in the IAB node may also be referred to as an MT functional entity in the IAB node, and the DU in the IAB node may also be referred to as a DU functional entity in the IAB node. For convenience of description, the MT in the IAB node and the MT functional entity in the IAB node are both referred to as "IAB node MT", and the DU in the IAB node and the DU functional entity in the IAB node are both referred to as "IAB node DU".

The IAB node may provide a wireless access service for the terminal-side device, and the service data or control information of the terminal-side device is transmitted by the IAB node through a wireless backhaul link to an IAB host (IAB donor) or a network-side device. The IAB host may be an access network element with a complete base station function, or may be an access network element with a Centralized Unit (CU) and a Distributed Unit (DU) in separate forms. The CU in the IAB host may also be referred to as a CU functional entity in the IAB host, and the DU in the IAB host may also be referred to as a DU functional entity in the IAB host.

For convenience of description, in the embodiment of the present application, a CU in an IAB host and a CU functional entity in the IAB host are referred to as an IAB host CU for short, and a DU in the IAB host and a DU functional entity in the IAB host are referred to as an IAB host DU for short, where the IAB host CU may also be in a form in which a Control Plane (CP) and a User Plane (UP) are separated, for example, one IAB host CU is composed of one CU-CP and a plurality of CUs-UPs, and the embodiment of the present application is not limited thereto.

The F1 interface according to the embodiment of the present application is an interface between an IAB node DU and an IAB host or an IAB host CU, and the F1 interface may also be referred to as an F1 interface, and for convenience of description, the F1 interface may be referred to in the embodiment of the present application, but the names are not limited.

It should be noted that the F1 interface may also be an interface between functional entities inside a device, for example, for a base station including a DU and a CU, the F1 interface may be an interface between the DU in the base station and the CU in the base station.

The F1 interface and the F1 interface related to the embodiment of the application support a user plane protocol and a control plane protocol. Exemplarily, as shown in fig. 4(a), a schematic diagram of a protocol stack of a user plane protocol provided in an embodiment of the present application is shown. In fig. 4(a), a link between the terminal-side device and the IAB host includes the terminal-side device, the IAB node 2, the IAB node 1, and the IAB host, which is taken as an example for description.

In fig. 4(a), the peer Protocol layers between the terminal side device and the IAB host include a Service Data Attachment Protocol (SDAP) layer and a Packet Data Convergence Protocol (PDCP) layer. The peer-to-peer protocol between the terminal side device and the IAB node 2 includes a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer.

The peer-to-peer Protocol includes a General Packet Radio Service (GPRS) tunneling Protocol User Plane (GTP-U) layer, a User Datagram Protocol (UDP) layer, and an Internet Protocol (IP) layer, on a User Plane of an F1 interface between the IAB node 2 and the IAB host. Optionally, the user plane protocol layer of the F1 interface further includes a PDCP layer and/or an IP Security (IPsec) layer. In one possible implementation, the IPsec layer or the PDCP layer is located above the IP layer and below the GTP-U layer.

The peer Protocol layers between the IAB node 2 and the IAB node 1 include a Backhaul Adaptation Protocol (BAP) layer, an RLC layer, a MAC layer, and a PHY layer. Accordingly, the peering protocol between IAB node 1 and IAB home includes a BAP layer, an RLC layer, a MAC layer, and a PHY layer.

With reference to fig. 4(a), as shown in fig. 4(b), an exemplary protocol stack diagram of a control plane protocol provided in an embodiment of the present application is shown.

In fig. 4(b), the peer-to-peer protocol between the terminal side device and the IAB host includes a Radio Resource Control (RRC) layer and a PDCP layer. The protocol of peering between the terminal side device and the IAB node 2 includes an RLC layer, a MAC layer, and a PHY layer.

The control plane between the IAB node 2 and the IAB host at the F1 interface includes an F1application layer protocol (F1application protocol, F1AP) layer, a Stream Control Transport Protocol (SCTP) layer, and an IP layer. Optionally, the control plane protocol layer of the F1 interface further includes one or more of a PDCP layer, an IPsec layer, and a data packet transport layer security (DTLS) layer. In one possible implementation, the IPsec layer, PDCP layer, or DTLS layer is located above the IP layer below the F1AP layer.

The protocol for peering between IAB node 2 and IAB node 1 includes a BAP layer, an RLC layer, a MAC layer, and a PHY layer. Accordingly, the peering protocol between IAB node 1 and IAB home includes a BAP layer, an RLC layer, a MAC layer, and a PHY layer.

The BAP layer has at least one of the following capabilities: the method comprises the steps of adding Routing information (Routing info) capable of being recognized by a wireless backhaul node to a data packet, performing Routing selection based on the Routing information capable of being recognized by the wireless backhaul node, adding identification information related to quality of service (QoS) requirements capable of being recognized by the wireless backhaul node to the data packet, performing QoS mapping on a multi-segment link containing the wireless backhaul node to the data packet, adding packet type indication information to the data packet, and sending flow control feedback information to a node with flow control capability. It should be noted that the name of the protocol layer with these capabilities is not necessarily the BAP layer, and those skilled in the art can understand that the protocol layer with these capabilities can be understood as the BAP layer in the embodiment of the present application.

The routing information that can be identified by the wireless backhaul node may be one or more of an identifier of the terminal, an identifier of an IAB node to which the terminal accesses, an identifier of a host node, an identifier of a Donor-DU, an identifier of a Donor-CU, an identifier of a transmission path, and the like.

The QoS mapping on the multi-segment link may be: performing mapping from the RB of the terminal to an RLC bearer or an RLC channel or a logical channel on the wireless backhaul link based on the identification of the RB of the terminal carried by the data packet in the wireless backhaul link; mapping from the RB or RLC bearer or RLC channel or logical channel of the ingress link to the RB or RLC bearer or RLC channel or logical channel of the egress link is performed based on a correspondence between any two or more of the RB, RLC bearer, RLC channel, and logical channel of the ingress link and the egress link.

The packet type indication information may be used to indicate that the content encapsulated in the BAP layer includes any one or more of the following types: user plane data of the terminal, RRC message of the IAB node, control layer application message (e.g., F1AP message) on the interface between the IAB node and the host node (or Donor CU-CP), flow control feedback message generated by the IAB node, header compression feedback message generated by the IAB node, data PDU of BAP layer, control PDU of BAP layer, etc.

The identification information related to the QoS requirement may be a QoS Flow Identifier (QFI) of the terminal, an RB of the terminal, a Differentiated Services Code Point (DSCP) of the terminal, a flow label (flow label) in a header of an IP packet of internet protocol version 6 (IPv 6), or the like.

Illustratively, the node with flow control capability may be a node that provides backhaul service for an IAB node, such as a host node, a Donor-DU, a Donor-CU, a parent node of the IAB node, and so on. The content of the flow control feedback information may include one or more of the following information: the buffer status and the load degree of the IAB node, the status of a certain link including the IAB node (such as link blocking (block) or link recovery (resume) or link quality information), the bandwidth and the transmission delay of a certain link including the IAB node, the packet sequence number lost by the IAB node, the packet sequence number successfully sent by the IAB node to the terminal or a child node thereof, and the like.

In addition, the function of the BAP layer can also be extended by the function of any one layer (e.g., RLC layer, MAC layer, PDCP layer, etc.) or any plurality of layers included in the layer 2, as a possible case, without an additional protocol layer.

It should be noted that, the functions and functions of the protocol layers described above may refer to the descriptions in the existing standard, and are not described in detail here.

It should be noted that the IAB node MT may have a protocol stack of the UE, and a communication protocol stack between the IAB host and the parent node, which can be understood with reference to the protocol stack of the UE in fig. 4(a) and fig. 4 (b). In this case, the IAB node may also have an RRC layer, and may establish an RRC connection with the IAB host and perform communication based on the RRC layer.

It is to be understood that the protocol stack architecture in the IAB network shown in fig. 4(a) to 4(b) in the embodiment of the present application is merely an example, and the method provided by the embodiment of the present application is not dependent on the example, but makes the method provided by the embodiment of the present application more easily understood through the example.

In the embodiment of the present application, the terminal-side device is a device having a wireless transceiving function or a chip that can be disposed in the device. The device with wireless transceiving function may also be referred to as a User Equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a user agent, or a user equipment. In practical applications, the terminal-side device in the embodiment of the present application may be a mobile phone (mobile phone), a tablet computer (Pad), a computer with a wireless transceiving function, a Virtual Reality (VR) terminal, an Augmented Reality (AR) terminal, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety, a wireless terminal in city (smart city), a wireless terminal in smart home (smart home), and the like. The embodiments of the present application do not limit the application scenarios. The device having the wireless transceiving function and the chip that can be provided in the device are collectively referred to as a terminal-side device in the present application.

In this embodiment, the network side device may be a wireless access device in various systems, such as an evolved Node B (eNB), a Radio Network Controller (RNC) or a Node B (NB), a Base Station Controller (BSC), a Base Transceiver Station (BTS), a home base station (e.g., home evolved Node B or home Node B, HNB), a Base Band Unit (BBU), an Access Point (AP) in a wireless fidelity (WIFI) system, a wireless relay Node, a wireless backhaul Node, a transmission point (TRP or transmission point, TP), and the like, and may also be a gbb or a transmission point (TRP or transmission point, TP) in a 5G (nr) system, one antenna or a group of antennas of the base station(s) in the 5G (TP) system includes multiple panels, alternatively, it may also be a network node constituting a gNB or a transmission point, such as a baseband unit (BBU), or a DU under a centralized-distributed (CU-DU) architecture.

The network architecture and the service scenario described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present application, and do not form a limitation on the technical solution provided in the embodiment of the present application, and as a person of ordinary skill in the art knows that along with the evolution of the network architecture and the appearance of a new service scenario, the technical solution provided in the embodiment of the present application is also applicable to similar technical problems.

Some of the scenarios in the embodiment of the present application are described by taking a scenario of an IAB in a wireless communication network as an example, it should be noted that the scheme in the embodiment of the present application may also be applied to other wireless communication networks, and corresponding names may also be replaced with names of corresponding functions in other wireless communication networks.

The F1 interface management method provided by the embodiment of the present application relates to the suspension of the F1 interface, the recovery of the F1 interface, and the like, which will be described separately below.

The first embodiment is as follows:

in this embodiment, when the second device determines to perform a suspension operation on the connection of the F1 interface of the first device, a first message may be sent to the first device, where the first message is used to instruct the first device to perform a suspension operation on the connection of the F1 interface of the first device.

Wherein the F1 interface may be an interface between a DU function entity in the first device and a CU function entity in the second device, or the F1 interface may be an interface between the first device and the second device.

It should be noted that the connection of the F1 interface may refer to a connection established over the F1 interface, include a signaling connection of the F1 interface, and may also include a user plane connection of the F1 interface. Wherein the signaling connection of the F1 interface includes one or more of: one or more signaling connections (UE-associated signaling connections) for transmitting user equipment-associated (UE-associated) F1AP messages; a signaling connection (non UE-associated signaling connection) for transmitting non UE-related F1AP messages. The user plane connection of the F1 interface may be understood as a GTP-U tunnel established by the F1 interface for transmitting data packets corresponding to a Data Radio Bearer (DRB) of the UE.

There may be a plurality of situations for which the first device and the second device are specific. In the following, the first device is taken as an IAB node, the second device is taken as an IAB host, and so on.

With reference to the foregoing description, as shown in fig. 5, a flowchart of an F1 interface management method provided in this embodiment of the present application is shown. Referring to fig. 5, the method includes:

step 500: the IAB host triggers the IAB node to perform a hangup operation on the connection of the F1 interface between the IAB node and the IAB host.

For example, the IAB host determines to trigger the IAB node to perform a suspend operation on the connection of the F1 interface when any of the following conditions are met.

In condition 1, the IAB host determines that the IAB node enters an inactive state (inactive mode) from an active state (active mode). The IAB node is in an active state, meaning that its MT part is in an RRC connected state (RRC connected), and its DU part maintains an F1 interface connection with the IAB host or IAB host CU, and a cell served by its DU part may provide access service for the UE, and the IAB node may serve transmission of traffic data and control signaling for the UE. The IAB node is in an inactive state, which means that the MT part is in an inactive (RRC inactive) state of the RRC or an idle (RRC idle) state of the RRC, and the IAB node cannot provide service for transmission of traffic data and control signaling of the UE, and optionally, the DU part of the IAB node cannot provide access service for the UE. For example, if the IAB host determines to send an RRC release (RRC release) message to the IAB node or the IAB node MT, it may determine that the IAB node will enter the inactive state.

And 2, the IAB host determines to perform cell switching on the IAB node.

The cell handover described herein may refer to a handover of an IAB node from one cell served by the same IAB home to another cell served by the same IAB home, or may refer to a handover of an IAB node between cells served by different IAB home.

The condition 2 may specifically be when the IAB host determines to send an RRC reconfiguration (RRC reconfiguration) message including the handover command to the IAB node (specifically, to the IAB node MT).

Step 501: the IAB host sends a first message to the IAB node.

Wherein the first message is used for instructing the IAB node to execute a suspension operation on the connection of the F1 interface of the IAB node. The F1 interface may be an interface between the IAB node DU and the IAB host CU.

The name of the first message is not limited in the embodiment of the present application, for example, the first message may also be referred to as an F1 suspend request message, and the like, and is not illustrated one by one here.

Illustratively, the first message may be an F1AP message, or may be an RRC message.

When the first message is the F1AP message, the IAB host may send the F1AP message to the IAB node (specifically, to the IAB node DU) through the control plane of the F1 interface.

The first message may also be an RRC release message, in which case the RRC release message may be sent by the IAB host CU to the IAB node, which may thus determine to perform a suspension operation on the connection of the F1 interface of the IAB node DU. Specifically, an RRC release message may be sent by the IAB host to the IAB node MT, which may indicate to the IAB node DU over the internal interface that the connection to the F1 interface is to be suspended.

Alternatively, the first message may be an RRC reconfiguration message or an RRC release message, and in this case, the RRC reconfiguration message or the RRC release message may further include a message container (container) or an information element for instructing the IAB node to perform a suspension operation on the connection of the F1 interface. In this case, an RRC reconfiguration message or an RRC release message may be sent by the IAB host to the IAB node MT, which may forward the message container or information element to the IAB node DU over the internal interface, which may then determine to perform a suspension operation on the connection of the F1 interface.

Illustratively, steps 500 and 501 may be performed by the IAB host CU if the IAB host includes a CU and a DU. In the subsequent steps, the method executed by the IAB host may also be executed by the IAB host CU, which is not described in detail later.

Illustratively, steps 500 and 501 may be performed by the IAB host CU-CP if the IAB host CU includes a CP and a UP. In the subsequent steps, the method executed by the IAB host may also be executed by the IAB host CU-CP, which is not described in detail later.

Step 502: and after receiving the first message from the IAB host, the IAB node executes suspension operation on the connection of the F1 interface according to the first message.

In the embodiment of the present application, when the IAB node performs a suspension operation on the connection of the F1 interface, the suspension operation includes but is not limited to: interrupting transmission of a F1Application Protocol (AP) message of the F1 interface, and one or more of: reserving context information of the IAB node; interrupting or stopping data transmission of a user plane of the F1 interface; the signaling connection of the F1 interface is reserved. In this case, "interrupt" means to suspend an operation, not to terminate the operation, but to resume the operation.

Wherein the context information of the IAB node may include at least one of:

configuration information of the IAB node DU; configuration information of the IAB host CU; the context information of the child node served by the IAB node may be a terminal side device, or may be another IAB node served by the IAB node.

For example, in the embodiment of the present application, the configuration information of the IAB node DU includes, but is not limited to: DU identification of an IAB node DU; the DU name; configuration information of cells served by IAB node DU.

The configuration information of the cell served by the IAB node DU may include one or more of the following: a Cell Global Identity (CGI) of the cell; NR Physical Cell Identities (PCIs) of the cells; a Tracking Area Code (TAC) of a cell, a Public Land Mobile Network (PLMN) identification of a service; slice identification supported; frequency points and transmission bandwidths supported by a cell; measurement Time Configuration (MTC); a Radio Access Network Area Code (RANAC) to which the cell belongs; a transmission direction supported by a cell, wherein the transmission direction only supports downlink transmission, only supports uplink transmission, or supports both uplink transmission and downlink transmission; system information of IAB node DU; active state of the cell. The cell activation state comprises two states, namely an activated state (activated) state and an inactivated state (deactivated), and the cell in the activated state can normally send information such as reference signals and system information broadcasts and provide access service for the terminal; in the cell in the deactivated state, information such as a reference signal and system information broadcast cannot be sent, and access service cannot be provided for the terminal.

For example, in the embodiment of the present application, the configuration information of the IAB host CU includes, but is not limited to: an identification of the IAB host CU; the name of the IAB host CU; system information of the IAB host CU, etc.

Illustratively, the context information of the child node may include, for example, one or more of the following: a Cell radio network temporary identity (C-RNTI) of a child node, special Cell (SpCell) information of the child node, Secondary Cell (SCell) information of the child node, Data Radio Bearer (DRB) information of the child node, GPRS tunneling Protocol User Plane (GTP-U) information established by the DRB of the child node on an F1 interface User Plane, Signaling Radio Bearer (SRB) information of the child node, an F1AP identifier allocated by the IAB node to the child node, an F1AP identifier allocated by the IAB host to the child node, and the like. The DRB information of the child node may include a DRB identifier, a slice identifier, a quality of service (QoS) parameter, an RLC mode, a PDCP Sequence Number (SN) length, and other information.

Illustratively, the first message may further include a cell identity served by the IAB node. The IAB node may save the activation state of the cell indicated by the cell identifier, or may perform deactivation operation on the cell indicated by the cell identifier.

For example, the first message may further include cell deactivation indication information, which is used to instruct the IAB node to deactivate all cells served by the IAB node, or deactivate all cells in an activated state in the cells served by the IAB node;

after receiving the first message from the IAB host, the IAB node may further perform any of the following operations:

1. the SCTP layer is instructed by the F1AP layer to perform a shutdown procedure of SCTP association (association). The SCTP association herein may refer to an SCTP association between an IAB node and an IAB home.

The IAB node may send SCTP association shutdown indication information to the SCTP layer through the F1AP layer, and according to the SCTP association shutdown indication information, the IAB node sends a message including a shutdown (shunt down) block (chunk) or an abort (abort) block to another endpoint of the SCTP association, that is, the IAB host, through the SCTP layer, thereby starting a shutdown process of the SCTP association.

Optionally, before the IAB node sends the message containing the short down chunk or the abort chunk, the IAB node may store at least one of the following information: the SCTP coupling number which can be used for carrying F1AP messages on an F1 interface between the IAB node and the IAB host; number of streams (streams) in each SCTP association; the correspondence between the F1AP message and SCTP association, stream identification.

2. And instructing the SCTP layer to close the sending of the heartbeat packet (heartbeat beat chunk) coupled with the SCTP by the F1AP layer or increasing the sending period of the heartbeat packet.

The sending period of the heartbeat packet can be increased to the maximum period which can be set by the IAB node, so that the sending times of the heartbeat packet is reduced. Because the heartbeat packet is mainly used for detecting the Round Trip Time (RTT) of a link between two devices, and the IAB node is not communicated with a wireless backhaul link between parent nodes of the IAB node and cannot transmit the heartbeat packet when executing a cell switching process or after entering an inactive state, it is possible to avoid frequently transmitting the heartbeat packet which cannot be correctly transmitted by not transmitting the heartbeat packet or increasing the transmission period of the heartbeat packet, reduce resources used for transmitting the heartbeat packet, and reduce resource consumption of the IAB node.

Optionally, in this case, the IAB node may not turn off the SCTP association between the IAB node and the IAB-hosting CU, and the SCTP association between the IAB node and the IAB-hosting CU may also be continuously maintained.

Step 503: the IAB node sends a second message to the IAB host indicating that the connection of the F1 interface has completed hanging.

Step 503 is optional and may not be performed, for example, if after step 502, the MT part of the IAB node enters the RRC inactive state, or the SCTP coupling between the IAB node and the IAB home is turned off, then step 503 is not performed.

The name of the second message is not limited in the embodiment of the present application, for example, the second message may be referred to as an F1 suspend response message, and the like, and is not illustrated in a specific manner here.

For example, the second message may be an F1AP message or an RRC message.

When the second message is F1AP message, the IAB node may send F1AP message to the IAB host CU through the control plane of F1 interface; when the second message is an RRC message, the RRC message may be an RRC Reconfiguration Complete (RRC Reconfiguration Complete).

It should be noted that the connection of the F1 interface has completed suspension, which means that the IAB node has successfully performed the operation in step 502.

Optionally, if in step 502, the IAB node does not execute the SCTP association shutdown procedure, the IAB node may execute the SCTP association shutdown procedure after sending the second message.

If the IAB host CU contains CP and UP parts, embodiment one may also contain the following optional steps:

optionally, the above process further includes the following steps: the IAB host CU-CP sends an eighth message to the IAB host CU-UP containing the identity of the mth IAB node. This eighth message is used to instruct the IAB host CU-UP to suspend the user plane connection of the F1 interface between it and the mth IAB node.

Optionally, the eighth message may include one or more specified uplink and/or downlink user plane transport layer information. The uplink user plane transport layer information may include an uplink Tunnel Endpoint Identifier (TEID) allocated by the IAB host CU-UP for the user plane GTP-U tunnel, an IP address of the IAB host CU-UP, and the like. The downlink user plane transport layer information may include a downlink Tunnel Endpoint Identifier (TEID) allocated by the mth IAB node for the user plane GTP-U tunnel, an IP address of the mth IAB node, and the like.

Upon receiving the eighth message, the IAB host CU-UP may stop the user plane transmission of the F1 interface between itself and the mth IAB node, i.e. stop the transmission of all user plane tunnels with the mth IAB node. Optionally, the IAB host CU-UP may further store one or more user plane tunnel information between it and the mth IAB node, where the user plane tunnel information includes one or more of the following: the uplink user plane transmission layer information corresponding to the user plane tunnel, the downlink user plane transmission layer information corresponding to the user plane tunnel, the serial number of the uplink/downlink transmitted data packet of the user plane tunnel, and the serial number of the uplink/downlink to-be-transmitted data packet of the user plane tunnel. The one or more user plane tunnels may be user plane tunnels corresponding to the one or more uplink and/or downlink user plane transport layer information specified in the eighth message, or may be all user plane tunnels between the IAB host CU-UP and the mth IAB node.

Optionally, the above process further includes the following steps: the IAB host CU-UP sends a YY message to the IAB host CU-CP indicating that the IAB host CU-UP completed the hangup operation for the F1 interface user plane connection between it and the mth IAB node.

In the above method flow, when the IAB host determines that the IAB enters the inactive state or the IAB node performs cell handover, the IAB node may be instructed to perform suspension operation on the connection of the F1 interface. By performing the suspension operation on the connection of the F1 interface, the configuration of the F1 interface and the context information of the IAB node can be reserved, so that the connection of the F1 interface and the context information of the IAB node can be quickly restored when the activated state is entered next time.

Example two:

in this embodiment, when the second device determines that the connection of the F1 interface from which the first device has been suspended is to be restored, a third message may be sent to the first device, where the third message is used to instruct the first device to restore the connection of the F1 interface from which the first device has been suspended.

The meaning of the F1 interface can refer to the foregoing description, and is not described herein again.

In the second embodiment, which kind of device the first device and the second device are specifically, there may be a plurality of cases, and the following description will be given by taking the first device as an IAB node and the second device as an IAB host as an example, and the other cases may be similar to each other.

With reference to the foregoing description, as shown in fig. 6, a flowchart of an F1 interface management method provided in this embodiment of the present application is shown. Referring to fig. 6, the method includes:

step 600: the IAB host determines to restore the connection of the F1 interface from which the IAB node has been suspended.

Illustratively, the IAB host determines to trigger the IAB node to restore the connection of the already suspended F1 interface when either of the following conditions is met.

In condition 1, the IAB host determines that the IAB node enters an active state (active mode) from an inactive state (inactive mode), and the description of the inactive state and the active state of the IAB node can be described with reference to the previous embodiment. For example, if the IAB host determines to send an RRC recovery (RRC resume) message or an RRC setup (RRC setup) message to the IAB node MT, it may determine that the IAB node (specifically, the IAB node MT) will enter an RRC connected state and the IAB node will also enter an activated state.

Condition 2, the IAB host determines that the IAB node is handed over from one cell served by the same IAB host to another cell served by the IAB host, and the IAB node MT has completed the handover; or the IAB host determines that the IAB node is switched to the cell served by the IAB host from the cell served by other IAB hosts. In any case, when the IAB anchor CU receives an RRC reconfiguration complete (reconfiguration complete) message fed back by the IAB node MT, it may be determined that the IAB node MT has completed the cell handover. In this embodiment, the cell served by the IAB host may be a cell served by the IAB host node, for example, a cell served by an IAB host DU, or a cell served by another IAB node connected to the IAB host.

Optionally, step 601: the IAB node instructs the SCTP layer to perform the SCTP association establishment procedure through the F1AP layer. The SCTP association herein may refer to an SCTP association between an IAB node and an IAB anchor CU.

It should be noted that, if the IAB host connected when the F1 interface performs the suspension operation and the IAB host connected when the F1 interface is to be recovered are the same IAB host, and the IP addresses of the IAB node and the IAB host are not changed, and the IAB node does not perform the SCTP association shutdown procedure when the F1 interface performs the suspension operation, it may not need to perform step 601.

Step 602: the IAB node sends a seventh message to the IAB host.

This step 602 is an optional step that is performed when the IAB node can actively request the restoration of the F1 interface.

The seventh message is used for requesting to the IAB host to restore the connection of the suspended F1 interface between the IAB node and the IAB host.

The name of the seventh message is not limited in the embodiment of the present application, and for example, the seventh message may be referred to as an F1resume request (F1resume request) message or the like.

The seventh message may also be an RRC recovery request message (for example, RRC resume request sent by the IAB node MT, or RRC resume request 1), which carries a message container or information element for requesting the IAB host to recover the connection of the F1 interface.

Step 603: the IAB host sends a third message to the IAB node.

Illustratively, steps 600 and 602 may be performed by the IAB host CU if the IAB host includes a CU and a DU.

Illustratively, steps 600 and 602 may be performed by the IAB host CU-CP if the IAB host CU includes a CP and a UP.

The third message is used to instruct the IAB node to resume connection of the F1 interface from which the IAB node has hung.

The name of the third message is not limited in the embodiment of the present application, for example, the first message may also be referred to as an F1resume (resume) indication message, and the like, which are not illustrated in sequence here.

Illustratively, the third message may be an F1AP message, or may be an RRC message.

When the third message is the F1AP message, the IAB host may send the F1AP message to the IAB node (specifically, the IAB node DU) through the control plane of the F1 interface.

The third message may also be an RRC recovery message or an RRC setup message.

In one case, an RRC recovery message or an RRC setup message may be sent by the IAB host to the IAB node (specifically, the IAB node MT), and the RRC recovery message or the RRC setup message includes a message container or an information element for instructing to perform a recovery operation on the connection of the F1 interface. The IAB node MT may forward the message container or information element to the IAB node DU over the internal interface, and the IAB node (which may specifically be the IAB node DU) may thus determine to perform a recovery operation on the connection of the F1 interface.

In another case, the IAB host may send an RRC recovery message or an RRC setup message to the IAB node (specifically, the IAB node MT), and the IAB node (specifically, the IAB node DU) may determine to perform a recovery operation on the connection of the F1 interface. In this case, the IAB node MT may indicate to the IAB node DU over the internal interface that the connection to the F1 interface is to be restored.

Step 604: the IAB node resumes connection of the F1 interface.

In this embodiment of the present application, the recovery operation includes: resuming transmission of F1application protocol AP messages of the F1 interface, and one or more of: restoring and/or applying context information of the first device; resuming data transmission of the user plane of the F1 interface; and restoring the signaling connection of the F1 interface.

It should be noted that the recovery operation may be to restore the information that was previously retained. For example, the IAB node performs the suspending operation on the connection of the F1 interface in step 502, and then the connection of the F1 interface can be restored through step 604.

The specific content of the context information of the IAB node may refer to the description in step 502, and is not described herein again.

Illustratively, the third message may further include a cell identity served by the IAB node. The IAB node may restore the cell indicated by the cell identity to an active state.

Illustratively, the third message may further include cell activation indication information. The cell activation indication information may be used to indicate that all cells of the IAB node are activated, and then the IAB node may activate all cells of the IAB node; alternatively, when the cell activation indication information may be used to indicate that the cell in the active state before the connection suspension of the F1 interface of the IAB node is activated, the IAB node may activate the cell in the active state before the connection suspension of the F1 interface.

Step 605: the IAB node sends a fourth message to the IAB host indicating that the connection of the F1 interface has completed resuming.

Step 605 is an optional step, and the IAB node may not send the fourth message.

The connection of the F1 interface has already been restored, which may refer to that transmission of the F1AP message of the F1 interface has been restored, context information of the IAB node has been restored, data transmission of the user plane of the F1 interface has been restored, and signaling connection of the F1 interface has been restored.

The name of the fourth message is not limited in the embodiment of the present application, for example, the fourth message may also be referred to as an F1 recovery response message, and the like, which are not illustrated in sequence here.

Illustratively, the fourth message may be an F1AP message, or may be an RRC message.

When the fourth message is F1AP message, the IAB node may send F1AP message to the IAB host CU through the control plane of F1 interface; when the fourth message is an RRC message, the RRC message may be an RRC setup Complete (RRC setup Complete) message, an RRC recovery Complete (RRC Resume Complete) message, or an RRC Reconfiguration Complete (RRC Reconfiguration Complete) message.

Illustratively, the fourth message may further include at least one of a cell identity of a cell that the IAB node has activated and a cell identity of a cell that is not activated.

If the IAB host CU contains CP and UP parts, embodiment two may also contain the following optional steps:

optionally, the above process further includes the following steps: the IAB host CU-CP sends a ninth message to the IAB host CU-UP containing the identity of the mth IAB node. This ninth message is used to instruct the IAB host CU-UP to resume the user plane connection of the F1 interface between it and the mth IAB node.

Optionally, the ninth message may include one or more specified uplink and/or downlink user plane transport layer information. The uplink user plane transport layer information may include an uplink Tunnel Endpoint Identifier (TEID) allocated by the IAB host CU-UP for the user plane GTP-U tunnel, an IP address of the IAB host CU-UP, and the like. The downlink user plane transport layer information may include a downlink Tunnel Endpoint Identifier (TEID) allocated by the mth IAB node for the user plane GTP-U tunnel, an IP address of the mth IAB node, and the like.

After receiving the ninth message, the IAB host CU-UP may resume all user plane transmissions of the F1 interface with the mth IAB node, i.e. continue all user plane tunnels with the mth IAB node; or, resuming transmission of one or more user plane tunnels corresponding to the one or more uplink and/or downlink user plane transport layer information specified in the ninth message.

Optionally, the above process further includes the following steps: the IAB host CU-UP sends a KK message to the IAB host CU-CP indicating that the IAB host CU-UP completed the restore operation of the F1 interface user plane connection between it and the mth IAB node.

It should be noted that the method provided in the first embodiment and the method provided in the second embodiment may be used separately or in combination, and the embodiments of the present application do not limit this.

In the above method flow, when the IAB host determines that the IAB enters the active state, or the IAB node performs cell switching, the IAB node may be instructed to restore the connection of the suspended F1 interface, so that the context information of the IAB node may be quickly restored, signaling overhead may be reduced, and the time delay for the IAB node to enter the active state may be reduced.

EXAMPLE III

If the IAB node enters the active state from the inactive state, the connected IAB host is replaced, or the IAB node completes handover between different IAB hosts, and the new IAB host does not have context information about the IAB node.

Fig. 7 is a schematic flowchart of a method for managing context information according to an embodiment of the present application. Referring to fig. 7, the method includes:

step 701: the first IAB host determines to acquire the context information of the IAB node.

Step 701 includes two cases, described separately below.

In case 1, the first IAB host determines that the IAB node enters the active state from the inactive state, and the IAB node is newly connected to a cell served by the first IAB host.

For example, after receiving an RRC recovery request message (e.g., an RRC resume request message or an RRC resume request 1) from the IAB node, the first IAB host determines to send an RRC resume message or an RRC setup message to the IAB node, and at this time, the IAB host may determine that the IAB node will enter an active state according to the RRC recovery request message sent by the IAB node, and determine whether the IAB node is a node in a cell newly connected to a service of the first IAB host.

In case 2, the first IAB host determines that the IAB node is newly connected to the first IAB host from the old host node.

For example, the first IAB host receives an RRC reconfiguration complete message from the IAB node (specifically, the IAB node MT), and at this time, the first IAB host may determine that the IAB is a node in a cell served by being handed over to the first IAB host, and may determine that the IAB node MT has completed the handover.

Step 702: the first IAB host sends a fifth message to the second IAB host.

The fifth message includes an identifier of an IAB node newly connected to the first IAB host, and the fifth message is used to acquire context information of the IAB node indicated by the identifier of the IAB node. Further, the context information of the IAB node may refer to the context information of the IAB node DU.

The first IAB host is connected equipment after the IAB node is switched, and the second IAB host is connected equipment before the IAB node is switched.

The names of the fifth messages in the embodiments of the present application are not limited, and are not illustrated one by one here. The fifth message may be sent over an Xn interface between the first IAB host and the second IAB host.

Step 703: the second IAB host sends a sixth message to the first IAB host.

The sixth message includes context information for the IAB node. The context information of the IAB node comprises at least one of: configuration information of the IAB node DU; configuration information of the second IAB host CU; context information of child nodes served by the IAB node.

For example, the sixth message may be sent over an Xn interface between the first IAB host and the second IAB host.

The configuration information of the cell served by the IAB node DU may include one or more of the following: an NR global cell identity of the cell; NR PCI of a cell; TAC of a cell, PLMN identity of service; supported slice identification; frequency points and transmission bandwidths supported by a cell; MTC; the RANAC to which the cell belongs; the transmission direction supported by the cell; system information of IAB node DU; active state of the cell.

For example, in the embodiment of the present application, the configuration information of the second IAB host CU includes, but is not limited to: an identification of a second IAB host CU; the name of the second IAB host CU; system information of the second IAB host CU, etc.

Illustratively, the context information of the child node may include, for example, one or more of the following: the method comprises the steps of cell C-RNTI of a child node, SpCell information of the child node, SCell information of the child node, DRB information of the child node, GTP-U information established by the DRB of the child node on an F1 interface user plane, SRB information of the child node, an F1AP identifier distributed by an IAB node for the child node, an F1AP identifier distributed by an IAB host for the child node and the like. The DRB information of the child node may include information such as DRB identifier, slice identifier, QoS parameter, RLC mode, PDCP SN length, and the like.

Through the above process, the first IAB host can quickly acquire the context information of the IAB node, so that the connection of the F1 interface can be quickly established with the IAB node, and the time delay of the device at the service terminal side is reduced.

Example four

In the conventional technique, if the parent node of the first IAB node is the second IAB node and the parent node of the second IAB node is the IAB host (specifically, the IAB host DU), when the UE served by the first IAB node in the inactive state is to enter the RRC connected state from the RRC inactive state, the first IAB node is required to enter the active state from the inactive state, and then the second IAB node details the re-establishment of the context information of the first IAB node on the F1 interface between the second IAB node and the IAB host. If a plurality of IAB nodes are included between the first IAB node and the IAB host, and some or all of the plurality of IAB nodes are in an inactive state, each IAB node in the inactive state needs to restore its own context information at the parent node step by step, wait until all the IAB nodes on the path between the first IAB node and the IAB host are in an active state, and the IAB node establishes the context of the UE on the F1 interface between the IAB node and the IAB host, so that the UE served by the first IAB node can be served by the UE, which takes too long to enter the RRC connected state. The embodiment of the present application further provides a method, which may reduce a time period required for the first IAB node to enter the active state, and further reduce a time period consumed for the UE to enter the RRC connected state from the RRC inactive state.

The following is described separately for different scenarios.

In the first scenario, the first IAB node accesses the IAB host through the second IAB node, that is, the parent node of the first IAB node is the second IAB node.

The method comprises the following steps: the IAB host determines that the first IAB node accesses the IAB host through the second IAB node.

The IAB host specifically determines how the first IAB node accesses the IAB host through the second IAB node, which is not limited in this embodiment of the present application.

Step two: and the IAB host sends indication information to a second IAB node, wherein the indication information is used for indicating that the first IAB node is different from the ordinary UE and is the IAB node.

Illustratively, the indication information may be an explicit indication (indication), and the IAB host may send a terminal-side device context setup (UE context setup) message about the first IAB node (specifically, the first IAB node MT) to the second IAB node through the F1 interface, where the indication information is included.

For example, the indication information may also be an implicit (explicit) indication, where the IAB host may send a UE context setup (UE context setup) message about the first IAB node (specifically, the first IAB node MT) to the second IAB node through the F1 interface, where the UE context setup message includes a list of RLC channels or RLC bearers to be established, and then implicitly indicates that the first IAB node accessing the second IAB node is the IAB node, rather than the general UE.

Through the indication information, the second IAB node can be enabled to determine that the first IAB node is not the terminal side device, but the IAB node, so that the second IAB node does not delete the context information of the first IAB node when the first IAB node enters the inactive state.

For specific content of the context information of the first IAB node, reference may be made to the foregoing description of the context information of the child node, which is not described herein again.

Exemplary, step three: and the second IAB node receives the indication information from the IAB host, and when the second IAB node determines that the first IAB node enters the inactive state, the second IAB node reserves the context information of the first IAB node according to the indication information.

The second IAB node can directly recover the context information of the first IAB node when the first IAB node enters the active state again by retaining the context information of the first IAB node, so that the first IAB node quickly enters the active state and provides services for the terminal device and the child node as soon as possible.

In the second scenario, the first IAB node directly accesses the IAB host, and the IAB host includes DU and CU, that is, the parent node of the first IAB node is the IAB host DU.

The method comprises the following steps: and the IAB host CU determines that the first IAB node accesses the IAB host DU.

The embodiment of the present application is not limited to how the IAB host CU specifically determines how the first IAB node accesses the IAB host DU.

Step two: and the IAB host CU sends indication information to the IAB host DU, wherein the indication information is used for indicating that the first IAB node is different from the common UE and is the IAB node.

Illustratively, the indication information may be an indication of display (explicit), and the IAB host CU may send a terminal-side device context setup (UE context setup) message about the first IAB node (specifically, the first IAB node MT) to the IAB host DU through the F1 interface, where the indication information is included.

For example, the indication information may also be an implicit (explicit) indication, where the IAB host CU may send a terminal-side device context setup (UE context setup) message about the first IAB node (specifically, the first IAB node MT) to the IAB host DU through the F1 interface, where the UE context setup message includes a list of backhaul link RLC channels or RLC bearers to be established, and then implicitly indicates that the first IAB node accessing the second IAB node is the IAB node, rather than the normal UE.

By the indication information, the IAB host DU can be made to determine that the first IAB node is not a terminal side device, but an IAB node, so that the context information of the first IAB node is not deleted when the first IAB node enters an inactive state.

Exemplary, step three: and when the IAB host DU determines that the first IAB node enters the non-activated state, reserving the context information of the first IAB node according to the indication information.

The IAB host DU may directly recover the context information of the first IAB node when the first IAB node enters the active state again by retaining the context information of the first IAB node, so that the first IAB node quickly enters the active state to provide services to its serving child nodes as soon as possible.

For example, in the first scenario and the second scenario, if the IAB host includes the CU and the DU, the method executed by the IAB host may be specifically executed by the IAB host CU.

For example, in the first scenario and the second scenario, if the IAB host CU includes a CP and a UP, the method executed by the IAB host CU or the IAB host CU may be specifically executed by the IAB host CU-CP.

In the embodiments provided in the present application, the method provided in the embodiments of the present application is introduced from the perspective of interaction between the devices. In order to implement the functions in the method provided by the embodiments of the present application, the IAB node and the IAB host may include a hardware structure and/or a software module, and implement the functions in the form of a hardware structure, a software module, or a hardware structure and a software module. Whether any of the above-described functions is implemented as a hardware structure, a software module, or a hardware structure plus a software module depends upon the particular application and design constraints imposed on the technical solution.

Similar to the above concept, as shown in fig. 8, an apparatus 800 is further provided in this embodiment of the present application to implement the functions of the first device or the second device or the IAB node or the IAB host in the above method. The device may be a software module or a system-on-a-chip, for example. In the embodiment of the present application, the chip system may be composed of a chip, and may also include a chip and other discrete devices. The apparatus 800 may include: a processing unit 801 and a communication unit 802.

The division of the modules in the embodiment of the present application is schematic, and is only a logic function division, and there may be another division manner in actual implementation. In addition, functional modules in the embodiments of the present application may be integrated into one processor, may exist alone physically, or two or more modules are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode.

Illustratively, when the apparatus 800 implements the function of the first device in the flow shown in fig. 5:

a communication unit 802, configured to receive a first message from a second device, where the first message is used to instruct a first device to perform a suspension operation on a connection of an F1 interface of the first device; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device;

a processing unit 801, configured to perform a suspension operation on the connection of the F1 interface according to the first message, where the suspension operation includes: interrupting transmission of a F1Application Protocol (AP) message of the F1 interface, and one or more of: interrupting transmission of an F1Application Protocol (AP) message of the F1 interface; retaining context information of the first device; interrupting data transmission of a user plane of the F1 interface; the signaling connection of the F1 interface is reserved.

In one possible design, the processing unit 801 is further configured to:

indicating a Stream Control Transmission Protocol (SCTP) layer to execute a turn-off process of SCTP coupling through an F1AP layer;

and/or instructing the SCTP layer to close the sending of the heartbeat packet coupled by the SCTP through the F1AP layer, or increasing the sending period of the heartbeat packet.

In one possible design, the first message is an F1application layer protocol AP message sent to the first device through a control plane of the F1 interface;

or, the first message is a radio resource control RRC message.

Illustratively, when the apparatus 800 implements the function of the second device in the flow shown in fig. 5:

a processing unit 801 for determining to perform a suspension operation on a connection of an F1 interface of a first device; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in a second device, or the F1 interface is an interface between the first device and the second device;

a communication unit 802, configured to send a first message to the first device, where the first message is used to instruct the first device to perform a suspension operation on the connection of the F1 interface of the first device.

The first device suspends the F1 interface according to the first message.

In one possible design, the processing unit 801 is specifically configured to:

when the first device is determined to enter the non-active state from the active state, determining to perform a hanging operation on the connection of the F1 interface of the first device;

or when the first device is determined to perform cell switching, determining to perform suspension operation on the connection of the F1 interface of the first device.

or, the first message is a radio resource control RRC message.

In one possible design, the communication unit 802 is further configured to:

receiving a second message from the first device, the second message indicating that the connection of the F1 interface has completed hanging.

Illustratively, when the apparatus 800 implements the function of the first device in the flow shown in fig. 6:

a communication unit 802, configured to receive a third message from a second device, where the third message is used to instruct the first device to resume connection of the F1 interface from which the first device has hung; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device;

a processing unit 801, configured to recover, according to the third message, the connection of the F1 interface, where the recovering operation includes: resuming transmission of F1application protocol AP messages of the F1 interface, and one or more of: restoring and/or applying context information of the first device; resuming data transmission of the user plane of the F1 interface; and restoring the signaling connection of the F1 interface.

In one possible design, the third message includes a cell identity, and the apparatus further includes:

the processing unit 801 is further configured to activate the cell indicated by the cell identifier;

or, the third message includes cell activation indication information, and the processing unit 801 is further configured to activate all cells of the first device according to the cell activation indication information, or activate a cell in an activated state before suspending a connection of the F1 interface according to the cell activation indication information.

In one possible design, the third message is an F1application layer protocol AP message sent through a control plane of the F1 interface;

or, the third message is a radio resource control RRC message.

Illustratively, when the apparatus 800 implements the function of the second device in the flow shown in fig. 6:

a processing unit 801 configured to determine that the connection of the F1 interface from which the first device has been suspended is restored; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device;

a communication unit 802, configured to send a third message to the first device, where the third message is used to instruct the first device to resume the connection of the F1 interface.

In one possible design, the processing unit 801 is specifically configured to:

determining to restore the connection of the F1 interface when the first device is determined to enter the active state from the inactive state;

or determining that the first device is to perform cell handover and the mobile terminal MT function entity in the first device has completed handover, and determining to recover the connection of the F1 interface.

In one possible design, the third message is an F1application layer protocol AP message sent to the first device through a control plane of the F1 interface;

or, the third message is a radio resource control RRC message.

In one possible design, the communication unit 802 is further configured to:

receiving a fourth message from the first device, the fourth message indicating that the connection of the F1 interface has completed resuming.

Illustratively, when the apparatus 800 implements the function of the first IAB host in the flow shown in fig. 7:

a processing unit 801, configured to send a fifth message to the second IAB host through the communication unit 802, where the fifth message includes a node identifier, and the fifth message is used to acquire context information of an IAB node indicated by the node identifier; the first IAB host is a target device which is newly connected with the IAB node, and the second IAB host is a source device which is connected with the IAB node;

a processing unit 801, configured to receive a sixth message from the second IAB host through the communication unit 802, where the sixth message includes context information of the IAB node.

In one possible design, before the first IAB host sends the fifth message to the second IAB host, the method further comprises:

the first IAB host determines to acquire the context information of the IAB node.

Illustratively, when the apparatus 800 implements the functions of the IAB host in embodiment four:

a processing unit 801, configured to determine that the first IAB node accesses the IAB host through the second IAB node; the first IAB node is a child node of the second IAB node;

a communication unit 802, configured to send indication information to the second IAB node, where the indication information is used to indicate that the first IAB node is an IAB node.

Illustratively, when the apparatus 800 implements the functionality of the second IAB node in the fourth embodiment:

a communication unit 802, configured to receive indication information from an IAB host, where the indication information is used to indicate that a first IAB node is an IAB node; the first IAB node is a child node of the second IAB node;

a processing unit 801, configured to, when it is determined that the second IAB node enters the inactive state, and it is determined that the first IAB node is the IAB node according to the indication information, reserve context information of the first IAB node.

As shown in fig. 9, which is a device 900 provided in the embodiment of the present application, the device shown in fig. 9 may be implemented as a hardware circuit of the device shown in fig. 8. The communication apparatus may be adapted to the flowcharts shown in fig. 5 to 7, and perform the functions of the first device or the second device or the first IAB host or the second IAB host or the IAB node or the IAB host in the above method embodiments. For convenience of explanation, fig. 9 shows only the main components of the communication apparatus.

The apparatus 900 shown in fig. 9 includes at least one processor 920 configured to implement any one of the methods provided in the embodiments of the present application in fig. 5 to 7.

The apparatus 900 may also include at least one memory 930 for storing program instructions and/or data. A memory 930 is coupled to the processor 920. The coupling in the embodiments of the present application is an indirect coupling or a communication connection between devices, units or modules, and may be an electrical, mechanical or other form for information interaction between the devices, units or modules. The processor 920 may operate in conjunction with the memory 930. Processor 920 may execute program instructions stored in memory 930. At least one of the at least one memory may be included in the processor.

Apparatus 900 may also include a communication interface 910 for communicating with other devices over a transmission medium such that the apparatus used in apparatus 900 may communicate with other devices. In embodiments of the present application, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface. In the embodiments of the present application, the transceiver may be a stand-alone receiver, a stand-alone transmitter, a transceiver with integrated transceiving function, or an interface circuit. The processor 920 utilizes the communication interface 910 to receive and transmit data, and is configured to implement the method executed by the first device, the second device, the first IAB host, the second IAB host, the IAB node, or the IAB host in the embodiment corresponding to fig. 5 to fig. 7, which may specifically refer to the foregoing description and is not described herein again.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

An F1 interface management method, comprising:

a first device receives a first message from a second device, wherein the first message is used for instructing the first device to execute a suspension operation on the connection of an F1 interface of the first device; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device;

the first device performs a suspension operation on the connection of the F1 interface according to the first message, wherein the suspension operation comprises: interrupting transmission of a F1Application Protocol (AP) message of the F1 interface, and one or more of: retaining context information of the first device; interrupting data transmission of a user plane of the F1 interface; the signaling connection of the F1 interface is reserved.
The method of claim 1, wherein the context information of the first device comprises at least one of:

configuration information of a distributed unit, DU, functional entity in the first device; configuration information of a centralized unit, CU, functional entity in the second device; context information of child nodes served by the first device.
The method according to claim 1 or 2, characterized in that the method further comprises:

the first device instructs a Stream Control Transmission Protocol (SCTP) layer to execute a SCTP coupling turn-off process through an F1AP layer;

and/or the first device instructs, through the layer F1AP, the SCTP layer to close the sending of the SCTP-coupled heartbeat packet, or to increase the sending period of the heartbeat packet.
The method according to any of claims 1 to 3, wherein the first message is an F1application layer protocol (AP) message sent to the first device via a control plane of the F1 interface;

or, the first message is a radio resource control RRC message.
An F1 interface management method, comprising:

the second device determines to perform a hanging operation on the connection of the F1 interface of the first device; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device;

the second device sends a first message to the first device, wherein the first message is used for instructing the first device to execute a suspension operation on the connection of the F1 interface of the first device.
The method of claim 5, wherein the second device determining to perform the hanging operation on the connection of the F1 interface of the first device comprises:

when the second device determines that the first device enters the non-active state from the active state, determining to perform a suspension operation on the connection of the F1 interface of the first device;

or when the second device determines that the first device is to perform cell handover, determining to perform suspension operation on the connection of the F1 interface of the first device.
The method according to claim 5 or 6, wherein the first message is a F1application layer protocol (AP) message sent to the first device through a control plane of the F1 interface;

or, the first message is a radio resource control RRC message.
An F1 interface management method, comprising:

the first device receives a third message from the second device, wherein the third message is used for instructing the first device to restore the connection of the F1 interface which is hung by the first device; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device;

the first device restores the connection of the F1 interface according to the third message, wherein the restoring operation includes: resuming transmission of F1application protocol AP messages of the F1 interface, and one or more of: restoring and/or applying context information of the first device; resuming data transmission of the user plane of the F1 interface; and restoring the signaling connection of the F1 interface.
The method of claim 8, wherein the context information of the first device comprises at least one of:

configuration information of a distributed unit, DU, functional entity in the first device; configuration information of a centralized unit, CU, functional entity in the second device; context information of child nodes served by the first device.
The method according to claim 8 or 9, wherein the third message includes a cell identity, the method further comprising:

the first equipment activates the cell indicated by the cell identification;

or, the third message includes cell activation indication information, and the first device activates all cells of the first device according to the cell activation indication information, or activates a cell in an activated state before suspending the connection of the F1 interface according to the cell activation indication information.
The method according to any of claims 8 to 10, wherein the third message is a F1application layer protocol AP message sent through a control plane of the F1 interface;

or, the third message is a radio resource control RRC message.
An F1 interface management method, comprising:

the second device determines to restore the connection of the F1 interface from which the first device has been suspended; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device;

the second device sends a third message to the first device, where the third message is used to instruct the first device to resume the connection of the F1 interface.
The method of claim 12, wherein the second device determining that the connection of the F1 interface from which the first device has been suspended is restored comprises:

when the second device determines that the first device enters the active state from the inactive state, determining to restore the connection of the F1 interface;

or, the second device determines that the first device is to perform cell handover, and the mobile terminal MT function entity in the first device has completed handover, and determines to recover the connection of the F1 interface.
A communications apparatus, comprising:

a communication unit, configured to receive a first message from a second device, where the first message is used to instruct a first device to perform a suspension operation on a connection of an F1 interface of the first device; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device;

a processing unit, configured to perform a suspension operation on the connection of the F1 interface according to the first message, where the suspension operation includes: interrupting transmission of a F1Application Protocol (AP) message of the F1 interface, and one or more of: retaining context information of the first device; interrupting data transmission of a user plane of the F1 interface; the signaling connection of the F1 interface is reserved.
The apparatus of claim 14, wherein the context information of the first device comprises at least one of:

configuration information of a distributed unit, DU, functional entity in the first device; configuration information of a centralized unit, CU, functional entity in the second device; context information of child nodes served by the first device.
The apparatus according to claim 14 or 15, wherein the processing unit is further configured to:

indicating a Stream Control Transmission Protocol (SCTP) layer to execute a turn-off process of SCTP coupling through an F1AP layer;

and/or instructing the SCTP layer to close the sending of the heartbeat packet coupled by the SCTP through the F1AP layer, or increasing the sending period of the heartbeat packet.
The apparatus according to any of claims 14 to 16, wherein the first message is an F1application layer protocol AP message sent to the first device through the control plane of the F1 interface;

or, the first message is a radio resource control RRC message.
An F1 interface management device, comprising:

a processing unit for determining to perform a suspension operation on a connection of an F1 interface of a first device; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in a second device, or the F1 interface is an interface between the first device and the second device;

a communication unit, configured to send a first message to the first device, where the first message is used to instruct the first device to perform a suspension operation on a connection of an F1 interface of the first device.
The apparatus according to claim 18, wherein the processing unit is specifically configured to:

when the first device is determined to enter the non-active state from the active state, determining to perform a hanging operation on the connection of the F1 interface of the first device;

or when the first device is determined to perform cell switching, determining to perform suspension operation on the connection of the F1 interface of the first device.
The apparatus according to claim 18 or 19, wherein the first message is a F1application layer protocol, AP, message sent to the first device over the control plane of the F1 interface;

or, the first message is a radio resource control RRC message.
An F1 interface management device, comprising:

a communication unit configured to receive a third message from a second device, the third message being used to instruct the first device to resume connection of the F1 interface from which the first device has been suspended; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device;

a processing unit, configured to recover, according to the third message, the connection of the F1 interface, where the recovery operation includes: resuming transmission of F1application protocol AP messages of the F1 interface, and one or more of: restoring and/or applying context information of the first device; resuming data transmission of the user plane of the F1 interface; and restoring the signaling connection of the F1 interface.
The apparatus of claim 21, wherein the context information of the first device comprises at least one of:

configuration information of a distributed unit, DU, functional entity in the first device; configuration information of a centralized unit, CU, functional entity in the second device; context information of child nodes served by the first device.
The apparatus according to claim 21 or 22, wherein the third message includes a cell identity, the apparatus further comprising:

the processing unit is further configured to activate the cell indicated by the cell identifier;

or, the third message includes cell activation indication information, and the processing unit is further configured to activate all cells of the first device according to the cell activation indication information, or activate a cell in an activated state before suspending a connection of the F1 interface according to the cell activation indication information.
The apparatus according to any of the claims 21 to 23, wherein the third message is a F1application layer protocol AP message sent through a control plane of the F1 interface;

or, the third message is a radio resource control RRC message.
An F1 interface management device, comprising:

a processing unit for determining that connection of the F1 interface from which the first device has been suspended is restored; the F1 interface is an interface between a distributed unit, DU, functional entity in the first device and a centralized unit, CU, functional entity in the second device, or the F1 interface is an interface between the first device and the second device;

a communication unit, configured to send a third message to the first device, where the third message is used to instruct the first device to resume the connection of the F1 interface.
The apparatus according to claim 25, wherein the processing unit is specifically configured to:

determining to restore the connection of the F1 interface when the first device is determined to enter the active state from the inactive state;

or determining that the first device is to perform cell handover and the mobile terminal MT function entity in the first device has completed handover, and determining to recover the connection of the F1 interface.
The apparatus according to claim 25 or 26, wherein the third message is a F1application layer protocol, AP, message sent to the first device over the control plane of the F1 interface;

or, the third message is a radio resource control RRC message.
A communications apparatus, comprising: a memory for storing instructions and a processor for executing the instructions stored by the memory, and execution of the instructions stored in the memory causes the processor to perform the method of any of claims 1 to 13.
A computer readable storage medium comprising computer readable instructions which, when read and executed by a communication device, cause the communication device to perform the method of any of claims 1 to 13.
A computer program product comprising computer readable instructions which, when read and executed by a communication device, cause the communication device to perform the method of any one of claims 1 to 13.