CN112399518B

CN112399518B - Data returning method and device

Info

Publication number: CN112399518B
Application number: CN201910760466.4A
Authority: CN
Inventors: 杨晨晨; 李欢; 晋英豪; 韩锋
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-08-16
Filing date: 2019-08-16
Publication date: 2022-02-15
Anticipated expiration: 2039-08-16
Also published as: WO2021031861A1; CN112399518A

Abstract

The application provides a data returning method and equipment. After the terminal device moves from the first access network device to the second access network device, the second access network device receives first return data from the network device through the target network segment data return channel and first data from the second UPF. Then, the second access network device sends the first return data and the first data to the terminal device. Or after the terminal device moves from the first access network device to a second access network device, the second access network device receives second backhaul data from the network device through the target network segment data backhaul channel, and receives the second data from the terminal device; then, the second access network device sends the second backhaul data and the second data to the second UPF.

Description

Data returning method and device

Technical Field

The present application relates to the field of communications, and in particular, to a data backhaul method and device.

Background

Because the coverage area of the access network device is limited, when the place covered by the access network device 1 of the terminal device moves to the place covered by the access network device 2, the terminal device needs to be switched from the access network device 1 to the access network device 2. Taking a data downloading behavior example, before switching, the data network sends data to the access network device 1, and the access network device 1 sends the data to the terminal device, and after switching, the data network sends the data to the access network device 2, and the access network device 2 sends the data to the terminal device. In the handover process, if the data network already sends data to the access network device 1, but the data is not yet sent to the terminal device, the terminal device switches from the access network device 1 to the access network device 2, which may result in that the access network device 1 cannot send the data to the terminal device, and the data may be referred to as backhaul data.

When the access network device 1 and the access network device 2 belong to the same networking mode, that is, when the access network device 1 and the access network device 2 are switched over in the same network, a data transmission channel is usually provided between the access network device 1 and the access network device 2, and the access network device 1 can send the returned data to the access network device 2 through the data transmission channel and then the access network device 2 sends the returned data to the terminal device.

However, when the access network device 1 and the access network device 2 do not belong to the same networking mode, that is, when the access network device 1 and the access network device 2 are switched across networks, the access network device 1 cannot send the return data to the access network device 2.

Disclosure of Invention

In order to solve the above problem, the present application provides a data backhaul method, which can backhaul data across a network.

In a first aspect, a data backhaul method is provided, where a first access network device is located in a source network, a second access network device is located in a target network, the source network and the target network respectively adopt different network types, the network types include a public network and a private network, and a terminal device moves from the first access network device to the second access network device, where the method includes:

the second access network equipment receives first return data from network equipment through a target network segment data return channel, wherein the first return data is data of the target network which is sent by the first access network equipment through a source network segment data return channel and is not successfully received by the terminal equipment, the network equipment is a first User Plane Function (UPF) or a first non-third generation partnership project interworking function (N3 IWF), the first UPF is located in the source network, and the first N3IWF is located in the source network;

the second access network device receiving first data from a second UPF, the second UPF being located in the target network;

the second access network equipment sends the first return data and the first data to the terminal equipment;

or;

the second access network equipment receives second returned data from the network equipment through a target network segment data returning channel, wherein the second returned data is the disordered data received by the first access network equipment from the terminal equipment through a source network segment data returning channel or the data which is received by the first access network equipment and needs to be reordered and is sent to the network equipment through a source network segment data returning channel;

the second access network equipment receives second data from the terminal equipment;

and the second access network equipment sends the second returned data and the second data to the second UPF.

In the above scheme, a transmission channel is established between the first access network device and the second access network device which belong to different network types, so that the return data is returned from the first access network device to the second access network device.

In some possible designs, the sending, by the second access network device, the first backhaul data and the first data to the terminal device includes:

the second access network equipment receives first return data information, wherein the first return data information carries one or more of the following: the reason for data backhaul, the type of data backhaul, the protocol data unit PDU session identifier for data backhaul, the identifier of data radio bearer DRB, or the QoS flow identifier of QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

the second access network equipment sends the first return data and the first data to the terminal equipment according to the first return data information;

or;

the sending, by the second access network device, the second backhaul data and the second data to the second UPF includes:

the second access network device receives second backhaul data information, where the second backhaul data information carries one or more of the following: the reason for data backhaul, the type of data backhaul, the protocol data unit PDU session identifier for data backhaul, the identifier of data radio bearer DRB, or the QoS flow identifier of QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

and the second access network equipment sends the second return data and the second data to the second UPF according to the second return data information.

In some possible designs, at least one of the first backhaul data information and the second backhaul data information is sent to a first access and mobility management function, AMF, over an N1 interface after the terminal device moves to the second access network device, the first AMF is located in the source network and sent to the first access network device by the first AMF, and at least one of the first backhaul data information and the second backhaul data information is sent to the second access network device after the terminal device moves to the second access network device; wherein the content of the first and second substances,

the N1 interface represents an interface for the first access network device to connect to the first AMF via the second access network device, the second UPF, and the first N3 IWF.

In the above scheme, the first backhaul data information and the second backhaul data information are sent to the first AMF through the N1 interface, so that the first AMF can send the first backhaul data information and the second backhaul data information to the first access network device.

In some possible designs, at least one of the first backhaul data information and the second backhaul data information is sent by the first access network device to the terminal device before the terminal device moves to the second access network device, and is sent by the terminal device to the second access network device after the terminal device moves to the second access network device.

In the above scheme, the terminal device may be used to send the first returned data information and the second returned data information to the first access network device.

In some possible designs, the source network segment data backhaul channel is a channel from the first access network device to the first UPF; or;

and the source network segment data return channel is a channel from the first access network equipment to the first N3 IWF.

In some possible designs, the source network segment data backhaul channel is generated by the first access network device and the first UPF according to a configuration of transport network layer information, the transport network layer information includes one or more of uplink forwarding transport network layer information and downlink forwarding user plane transport network layer information, the uplink forwarding user plane transport network layer information includes an uplink transport layer address and an uplink gprs tunneling protocol GTP tunnel port identifier, and the downlink forwarding user plane transport network layer information includes a downlink transport layer address and a downlink GTP tunnel port identifier.

In some possible designs, the transport network layer information is generated by the first UPF, and the transport network layer information is sent by the first UPF to the first access network device via a first AMF.

In some possible designs, the terminal device is configured to send a movement notification to the first AMF after moving from the first access network device to the second access network device, where the movement notification is configured to notify the first AMF that the terminal device moves from the first access network device to the second access network device.

In some possible designs, the movement notification is sent by the terminal device to the first AMF through the N1 interface.

In some possible designs, the terminal device is configured to move from the first access network device to the second access network device after sending a prepare move notification to the first access network device, wherein the prepare move notification is configured to notify the first access network device that the terminal device is ready to move from the first access network device to the second access network device.

In some possible designs, the target network segment data backhaul channel is a channel from the first UPF to the second access network device; or;

and the target network segment data return channel is a channel from the first N3IWF to the second access network equipment.

In some possible designs, in case the target network segment data backhaul channel belongs to a PDU session resource established between the terminal device and the source network,

the second access network equipment instructs the terminal equipment to send the first return data and the first data to the terminal equipment through PDU session resources established between the terminal equipment and the target network; alternatively, the first and second electrodes may be,

the second access network equipment instructs the terminal equipment to send the first return data and the first data to the terminal equipment through PDU session resources established between the terminal equipment and the source network; alternatively, the first and second electrodes may be,

the second access network device instructs the terminal device to send the first backhaul data to the terminal device through the PDU session resource established between the terminal device and the source network, and sends the first data to the terminal device through the PDU session resource established between the terminal device and the target network.

In some possible designs, where the target network segment data backhaul is a dedicated data backhaul,

and the second access network equipment sends the first feedback data and the first data to the terminal equipment through a PDU session resource established between the terminal equipment and the target network.

In some possible designs, where the granularity of the backhaul data is a PDU session granularity,

the second access network equipment firstly sends the first return data to the terminal equipment, and then sends the first data to the terminal equipment; alternatively, the first and second electrodes may be,

and the second access network equipment firstly sends the second returned data to the second UPF, and then sends the second data to the second UPF.

In some possible designs, where the granularity of the backhaul data is DRB granularity,

the second access network equipment numbers the first feedback data and the first data by a Packet Data Convergence Protocol (PDCP), so that the numbered first feedback data and the first data are obtained;

the second access network equipment sends the numbered first return data and the numbered first data to the terminal equipment;

or;

the second access network equipment performs PDCP numbering on the second backhaul data and the second data so as to obtain the numbered second backhaul data and the second data;

and the second access network equipment sends the numbered second returned data and the second data to the second UPF.

In some possible designs, the first backhaul data includes a first header and a second header, where the first header is added when the first backhaul data is sent from the target network to the first access network device and passes through a first N3IWF, and the second header is added when the first backhaul data is sent from the first access network device to the second access network device and passes through the first N3IWF again.

In some possible designs, the source network is an NPN network and the target network is a PLMN network; or, the source network is a PLMN network, and the target network is an NPN network.

In a second aspect, a data backhaul method is provided, where a first access network device is located in a source network, a second access network device is located in a target network, the source network and the target network respectively adopt different network types, where the network types include a public network and a private network, and a terminal device moves from the first access network device to the second access network device, where the method includes:

the first access network device receives backhaul data sent by the target network, wherein the backhaul data is data of the target network sent by the first access network device but not successfully received by the terminal device, or data of the target network sent by the first access network device but not successfully received by the target network;

the first access network equipment sends the return data to the network equipment through the source network segment data return channel, so that the network equipment sends the return data to the second access network equipment through the target network segment data return channel.

In the above scheme, a transmission channel is established between the first access network device and the second access network device, which belong to different network types, so that the first access network device can transmit the backhaul data from the first access network device to the second access network device through the transmission channel established between the first access network device and the second access network device.

In some possible designs, the first access network device obtains backhaul data information, where the backhaul data information carries one or more of: the reason for data backhaul, the type of data backhaul, the PDU session identifier for data backhaul, the identifier of the data radio bearer DRB, or the QoS flow identifier of the QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

and the first access network equipment sends the return data information to the second access network equipment.

In some possible designs, the backhaul data information is sent to a first access and mobility management function, AMF, over an N1 interface after the terminal device moves to the second access network device, the first AMF is located in the source network and sent to the first access network device by the first AMF, and at least one of the first backhaul data information and the second backhaul data information is sent to the second access network device after the terminal device moves to the second access network device; wherein the N1 interface represents an interface for the first access network device to connect to the first AMF via the second access network device, the second UPF, and the first N3 IWF.

In some possible designs, the backhaul data information is sent by the first access network device to the terminal device before the terminal device moves to the second access network device, and is sent by the terminal device to the second access network device after the terminal device moves to the second access network device.

In some possible designs, the source network segment data backhaul channel is a channel from the first access network device to the first UPF; or; and the source network segment data return channel is a channel from the first access network equipment to the first N3 IWF.

In some possible designs, the target network segment data backhaul channel is a channel from the first UPF to the second access network device; or; and the target network segment data return channel is a channel from the first N3IWF to the second access network equipment.

In some possible designs, the target network segment data backhaul channel belongs to a PDU session resource established between the terminal device and the source network.

In some possible designs, the target network segment data backhaul is a dedicated data backhaul.

In some possible designs, the granularity of the backhaul data is a PDU session granularity.

In some possible designs, the granularity of the backhaul data is DRB granularity.

In some possible designs, the backhaul data includes a first header and a second header, where the first header is added when the backhaul data is sent from the target network to the first access network device and passes through a first N3IWF, and the second header is added when the backhaul data is sent from the first access network device to the second access network device and passes through the first N3IWF again.

In a third aspect, a data backhaul method is provided, where a first access network device is located in a source network, a second access network device is located in a target network, the source network and the target network respectively adopt different network types, the network types include a public network and a private network, and a terminal device moves from the first access network device to the second access network device, where the method includes:

a first AMF receives a movement notification or a preparation movement notification sent by a terminal device, wherein the first AMF belongs to the first access network device, the movement notification is used for notifying the first AMF that the terminal device moves from the first access network device to the second access network device, and the preparation movement notification is used for notifying the first access network device that the terminal device is prepared to move from the first access network device to the second access network device;

the first AMF sends a backhaul establishment notification to a first UPF based on the movement notification or the preparation movement notification, where the backhaul establishment notification is used to notify the first UPF1 to establish a source network segment data backhaul between the first access network device and a network device, where the source network segment data backhaul is used for the first access network device to send backhaul data to the network device, so that the network device sends the backhaul data to the second access network device through a target network segment data backhaul channel, and the backhaul data is data of the target network sent by the first access network device but not successfully received by the terminal device, or data of the target network sent by the first access network device but not successfully received by the target network.

In the above solution, the first AMF establishes a transmission channel between the first access network device and the second access network device belonging to different network types according to the mobile notification or the mobile notification preparation, so as to realize returning the returned data from the first access network device to the second access network device.

In some possible designs, the first AMF receives backhaul data information sent through an N1 interface after the terminal device moves to the second access network device, where the backhaul data information carries one or more of the following: the reason for data backhaul, the type of data backhaul, the PDU session identifier for data backhaul, the identifier of the data radio bearer DRB, or the QoS flow identifier of the QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

and the first AMF sends the return data information to the second access network equipment.

In some possible designs, the N1 interface represents an interface where the first access network device connects to the first AMF via the second access network device, the second UPF, and the first N3 IWF.

In some possible designs, the first AMF receives the transport network layer information sent by the first UPF, wherein the transport network layer information is generated by the first UPF; and the first AMF sends the transmission network layer information to the first access network equipment.

In some possible designs, the first AMF receives the movement notification sent by the terminal device through an N1 interface.

In some possible designs, the target network segment data backhaul channel is a channel from the first UPF to the second access network device; or; and the target network segment data return channel is a channel from the first N3IWF to the second access network equipment. .

In some possible designs, the target network segment data backhaul is a PDU session resource established between the terminal device and the source network, or the target network segment data backhaul is a dedicated data backhaul.

In the above scheme, two different implementation modes are provided for the data return channel of the target network segment, and the selectivity of the scheme is increased.

In a fourth aspect, an access network device is provided that includes means for implementing the method of any of the first or second aspects.

In a fifth aspect, there is provided an AMF comprising means for implementing the method of any of the third aspects.

In a sixth aspect, an access network device is provided, comprising a processor and a memory, the processor executing code in the memory to perform the elements of the method according to any one of the first or second aspects.

In a seventh aspect, there is provided an AMF comprising a processor and a memory, the processor executing code in the memory to perform the elements of the method according to any one of the third aspects.

In an eighth aspect, a readable storage medium comprises instructions which, when executed on a device, cause the device to perform the method of any of the first, second or third aspects.

In a ninth aspect, there is provided a program product which, when read and executed by a device, causes a method as in any one of the first, second or third aspects to be performed.

Drawings

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

FIG. 1 is a schematic structural diagram of an NPN independent networking manner provided in the present application;

fig. 2 is a schematic diagram of a transmission channel between the access network device 1 and the DN2 when the terminal device involved in the present application is located in the range covered by the NPN network;

fig. 3 is a schematic diagram of the transmission path between access network device 2 and DN2 when the terminal device involved in the present application is located within the coverage area of the PLMN network;

FIG. 4 is a flow chart illustrating a method for establishing a data backhaul provided by the present application;

fig. 5 is a schematic diagram of a first NPN-segment data backhaul channel of the access network devices 1 to UPF1 provided in the present application;

fig. 6 is a flowchart illustrating a method for transmitting backhaul data information according to the present application;

FIG. 7 is a schematic diagram of the terminal device sending backhaul data information to AMF1 through N1 interface in the present application;

fig. 8 is a flowchart illustrating a method for transmitting backhaul data information according to the present application;

FIG. 9 is a diagram illustrating the transmission process of the backhaul data message in the present application;

fig. 10 is a schematic diagram of two channels for transmitting the backhaul data and the new data between the access network device 2 and the terminal device in the present application;

fig. 11 is a schematic diagram of the present application in which only one channel exists between the access network device 2 and the terminal device for transmitting the backhaul data and the new data;

fig. 12 is an interaction diagram of a data backhaul method of a target network according to a first embodiment of the present application;

FIG. 13 is an interaction diagram of a second method for data backhaul of a target network proposed in the present application;

FIG. 14 is an interaction diagram of a data backhaul method of a third target network proposed in the present application;

fig. 15 is a schematic diagram of a second PLMN segment data backhaul in the present application;

FIG. 16 is a schematic diagram of the structure of an apparatus provided herein;

fig. 17 is a schematic structural diagram of a network device provided in the present application.

Detailed Description

For ease of understanding, the present application will first be described in detail with respect to an NPN independent networking approach.

The NPN can be networked by way of a stand alone networking (standalone). As shown in fig. 1, in the independent networking mode, an NPN network and a PLMN network coexist. The NPN network includes an independent non-3 AGPP access network, a Core Network (CN) 1, and a data network 1. The non-3 AGPP access network may comprise an access device 1, and the access network device 1 may be an access network device of the 3AGPP access network. CN1 may include Authentication Management Function 1 (AMF), service Management Function 1 (SMF), and User Plane Function 1 (UPF), among other network elements. The PLMN network also comprises separate 3GPP access networks, a core network 2 and a data network 2. The 3GPP access network may comprise an access network device 2, which access network device 2 may be an access network device of the 3GPP access network. The core network 2 may include network elements such as AMF2, SMF2, and UPF 2. Data can be transmitted between CN1 of the NPN network and CN2 of the PLMN network through a Non-3GPP internetworking function (N3 IWF) network. The N3IWF1 of the NPN network is connected to the UPF1 of the NPN network on the one hand, and to the data network 2 of the PLMN network on the other hand. The N3IWF2 of the PLMN network is connected to the UPF2 of the PLMN network on the one hand and to the data network 1 of the NPN network on the other hand.

First, the terminal device and the network element related to the NPN independent networking method according to the present application will be described in detail below. Here, the network elements involved in the NPN independent networking mode include an access network device, an AMF, a UPF, an SMF, and an N3 IWF.

The terminal device may be an entity for receiving or transmitting signals at the user side, such as a new generation user equipment (gnee). A terminal device may also be called a terminal device (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment. The terminal device may be a station (station, ST) in a Wireless Local Area Network (WLAN), and may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA) device, a handheld device with Wireless communication function, a computing device or other processing device connected to a Wireless modem, a vehicle-mounted device, a wearable device, and a next generation communication system, for example, a terminal device in a fifth generation communication (5G) Network or a Public Land Mobile Network (PLMN) Network for future evolution, a terminal device in a New Radio (NR) communication system, and the like. By way of example, and not limitation, in embodiments of the present invention, the terminal device may also be a wearable device. Wearable equipment can also be called wearable intelligent equipment, is the general term of applying wearable technique to carry out intelligent design, develop the equipment that can dress to daily wearing, like glasses, gloves, wrist-watch, dress and shoes etc.. A wearable device is a portable device that is worn directly on the body or integrated into the clothing or accessories of the user. The wearable device is not only a hardware device, but also realizes powerful functions through software support, data interaction and cloud interaction. The generalized wearable smart device includes full functionality, large size, and can implement full or partial functionality without relying on a smart phone, such as: smart watches or smart glasses and the like, and only focus on a certain type of application functions, and need to be used in cooperation with other devices such as smart phones, such as various smart bracelets for physical sign monitoring, smart jewelry and the like.

The access network device may be an entity for transmitting or receiving signals on the network side, such as a new generation base station (gnnodeb). The Access Network device may also be a device for communicating with a Mobile device, and the Access Network device may be an Access Point (AP) in a wireless local area Network (wireless lan, WLAN), a Base Transceiver Station (BTS) in a Global System for Mobile Communication (GSM) or Code Division Multiple Access (CDMA), a Base Station (NodeB, NB) in a Wideband Code Division Multiple Access (WCDMA), an evolved Node B (eNB or eNodeB) in Long Term Evolution (Long Term Evolution, LTE), or a relay Station or an Access point, or a Network device in a vehicle-mounted device, a wearable device, and a Network device in a future 5G Network or a Network device in a future evolved Public Land Mobile Network (PLMN ) Network, or NR System, and the like. In addition, in this embodiment of the present invention, the access network device provides a service for a cell, and the terminal device communicates with the network device through a transmission resource (for example, a frequency domain resource or a spectrum resource) used by the cell, where the cell may be a cell corresponding to the network device (for example, a base station), and the cell may belong to a macro base station or a base station corresponding to a small cell (smallcell), where the small cell may include: urban cell (metrocell), micro cell (microcell), pico cell (picocell), femto cell (femtocell), etc., which have the characteristics of small coverage and low transmission power, and are suitable for providing high-rate data transmission service.

The AMF is used for being responsible for access authority and mobility management of the terminal equipment. The AMF may support the following functions: terminating RAN CP interface (N2), terminating NAS (N1), NAS ciphering and integrity protection, registration management, connection management, reachability management, mobility management, lawful interception (interface applicable to AMF events and LI systems), providing transport for SM messages between UE and SMF, transparent proxy for routing SM messages, access identity verification, access authorization, providing transport for SMs messages between UE and SMSF, security anchor function (SEAF), location service management for administrative services, providing transport for location service messages between UE and LMF and between RAN and LMF, EPS bearer ID assignment for interworking with EPS, UE mobility event notification. In addition, the AMF may also support the following functions: supporting the N2 interface with the N3IWF, over which interface some information (e.g., 3GPP cell identification) and procedures (e.g., related to mobility) defined over 3GPP access may not be applied, and non-3GPP access specific information not applicable for 3GPP access may be applied, NAS signaling is supported over UEs over N3IWF, NAS signaling is supported by UEs over 3GPP access, mobility of UEs connected over non-3GPP access or connected over both 3GPP and non-3GPP may not be applicable for untrusted non-3GPP (e.g., paging) access, authentication of UEs connected over N3IWF is supported, mobility of UEs connected over non-3GPP access or connected over both 3GPP and non-3GPP is managed, authentication and separate security context state, coordinated RM management context is supported, which context is valid for 3GPP and non-3GPP access, dedicated CM management context for UEs is supported, for connection over non-3GPP access, SMF may provide service continuity, uninterrupted user experience of the service, including situations where IP addresses and/or anchor points change.

A Protocol Data Unit (PDU) session that the UPF may be associated with can be served by the radio access network over the N3 interface between the radio access network and the UPF without the need to add a new UPF or remove/reassign a UPF in between. The UPF may support the following functions: anchor points (where applicable) for intra/inter-RAT mobility, session points at which external PDUs interconnect with the data network, packet routing and forwarding (e.g., supporting uplink classifiers to route traffic flows to instances of the data network, branch points to support multi-homed PDU sessions), packet inspection (e.g., service data flow template-based application detection and optional PFD received from SMF), user plane part policy rule enforcement, e.g., gating, redirection, traffic steering, lawful interception (UP collection), traffic usage reporting, QoS handling for the user plane, e.g., UL/DL rate enforcement, reflected QoS tagging in DL, uplink traffic verification (SDF to QoS traffic mapping), transport level packet tagging in uplink and downlink, downlink packet buffering and downlink data notification triggering, sending and forwarding one or more "end tags" to the source NG-node RAN, packet routing and forwarding, The IPv6Neighbor Solicitation Proxying, UPF of the ARP proxy and/or Ethernet PDU responds to the ARP and/or IPv6Neighbor Solicitation request by providing a MAC address corresponding to the IP address sent in the request.

SMF provides service continuity, an uninterrupted user experience of the service, including situations where IP addresses and/or anchors change. The functions of the SMF include: session management, e.g. session establishment, modification and release, including tunnel maintenance between UPF and AN nodes, UE IP address allocation and management (including optional authorization), DHCPv4 (server and client) and DHCPv6 (server and client) functions, IPv6Neighbor Solicitation Proxying of ARP proxy and/or Ethernet PDUs, SMF responding to ARP and/or IPv6Neighbor Solicitation requests by providing MAC addresses corresponding to the IP addresses sent in the request, selecting and controlling UP functions, including controlling UPF proxy ARP or IPv6Neighbor discovery, or forwarding all ARP/IPv 6Neighbor Solicitation traffic to SMF for Ethernet PDU sessions, configuring flow control of UPF, routing traffic to the correct destination, terminating interface to policy control function, lawful interception (interface for charging events and LI systems), charging data collection and supporting charging interface, control and coordinating charging data collection of UPF, The SM part of the terminating SM message, the downstream data notification, the originator of the AN specific SM message, is sent to the AN through the AMF via N2, determining the SSC pattern of the session.

It should be understood that the above examples of the terminal device and the network element involved in the NPN independent networking manner are only specific examples, and should not be construed as being particularly limited.

When the terminal device is located in the range covered by the NPN network, the terminal device can access the access network device 1 in the NPN network. When the terminal device is located within the coverage area of the PLMN network, the terminal device may access the access network device 2 in the PLMN network. Thus, when the terminal device moves from the range covered by the NPN network to the range covered by the PLMN network, the terminal device will move from the access network device 1 in the NPN network to the access network device 2 in the PLMN network. Conversely, the terminal device may also move from the access network device 2 in the PLMN network to the access network device 1 in the NPN network. Hereinafter, the network where the terminal device is located before moving will be described as an NPN network, and the network where the terminal device is located after moving will be described as a PLMN network.

Before the terminal device moves, the terminal device is located in the range covered by the NPN network, and therefore, a first transmission channel may be established between the access network device 1 and the DN2, so that the access network device 1 transmits PLMN data to the DN2 through the first transmission channel, or the DN2 transmits PLMN data to the access network device 1 through the first transmission channel. The first transport channel may employ PLMN PDU session resources, for example, as shown in fig. 2, the first transport channel may be PLMN PDU session resources (shown in bold dashed lines in fig. 2) of the approach access network device 1, UPF1, DN1, N3IWF2, UPF2, and DN 2.

After the movement of the terminal device, the terminal device is located in the coverage area of the PLMN network, so that a second transmission channel may be established between the access network device 2 and the DN2, so that the access network device 2 transmits PLMN data to the DN2 via the second transmission channel, or the DN2 transmits PLMN data to the access network device 2 via the second transmission channel. The second transmission channel may use PLMN PDU session resources, for example, as shown in fig. 3, the second transmission channel may be PLMN PDU session resources (shown by bold dashed lines in fig. 3) routed through access network device 2, UPF2, DN 2.

When the terminal device moves from the range covered by the NPN network to the range covered by the PLMN network, the terminal device switches from the access network device 1 to the access network device 2, and if D2 has already transmitted PLMN data to the access network device 1, but the access network device 1 has not yet transmitted PLMN data to the terminal device, the access network device 1 may not be able to transmit the received PLMN data to the terminal device. Similarly, when the terminal device moves from the range covered by the NPN network to the range covered by the PLMN network, the terminal device switches from the access network device 1 to the access network device 2, and if the terminal device is transmitting PLMN data to the access network device 1, the PLMN data received by the access network device 1 may be discontinuous, and at this time, the access network device 1 cannot transmit discontinuous PLMN data to D2.

For convenience of presentation, when moving, PLMN data that has been uplinked to the access network device 1 in the uplink direction but cannot be uplinked to the CN2 and PLMN data that has been downlinked to the access network device 1 in the downlink direction but cannot be downlinked to the terminal device will be collectively referred to as backhaul data hereinafter. After the movement, the PLMN data that has been uplinked to the access network device 2 in the uplink direction, is ready to be uplinked to the CN2, and the PLMN data that has been downlinked to the access network device 2 in the downlink direction, is ready to be downlinked to the terminal device, collectively referred to as new data.

Obviously, the movement of the terminal device from the access network device 2 in the PLMN network to the access network device 1 in the NPN network is similar, and will not be described here again.

In the present application, a scenario in which the UE moves from the source network to the target network across networks is not limited. For example, the UE may be moving during cross-network cell reselection, or moving during cross-network cell handover, etc.

In this application, the UE moving from the source network to the target network may be described as follows instead: reselection of the UE from the source network to the target network, handover of the UE from the source network to the target network, access of the UE from the source network to the target network, and the like.

It should be understood that the cell reselection referred to in this patent is different from the cell reselection performed by the conventional idle-state UE, and instead of the cell "handover" performed by the network side control, the connected-state UE autonomously decides to perform the cross-network cell "handover", that is, the cell reselection and handover process described in the conventional standard are not completely consistent, and may also be other terms, for example, cross-network self-handover.

It should be understood that the patent is equally applicable to the UE mobility procedure between PNI-NPN and SNPN, and also to the UE mobility procedure between SNPN and SNPN.

In order to solve the above problem, a data backhaul needs to be established between the access network device 1 and the access network device 2, so as to transmit backhaul data from the access network device 1 back to the access network device 2. Referring to fig. 4, fig. 4 is a schematic flow chart of the data backhaul establishing method of the present embodiment, where the method includes the following steps:

s101: the terminal device sends a move notification to the AMF 1. Accordingly, the AMF1 receives the movement notification sent by the terminal device.

In a specific embodiment of the present application, the move notification is used to notify the AMF1 that the terminal device has moved or is about to move from the access network device 1 in the NPN network to the access network device 2 in the PLMN network. The mobility notification carries one or more of a cause value, a type of mobility, location information before mobility, location information after mobility, QoS Flow Identifier (QFI), DRB Identifier (DRB ID), and a mapping list of DRB and QoS Flow. The cause value is a cause for the terminal device to send the notification message, for example, identified by SNPN, NPN, PLMN, snpntopplmn, plmntonnpn, npnntopplmn, plmntonnpn, PNI-nptopplmn, PLMNtoPNI-NPN, snpntonnpn, Non-3GPPtoPLMN, PLMNtoNon-3GPP, Non-3GPPtoNon-3GPP, or inter network-mobility. The mobility type is identified by a user moving from a cell of one network to a cell of another network, for example, from NPN to PLMN, with SNPN, NPN, PLMN, snpntonmn, plmntonsnpn, NPNtoPLMN, plmntonnp, PNI-NPNtoPLMN, plmntonni-NPN, snpntonsnpn, Non-3GPPtoPLMN, PLMNtoNon-3GPP, Non-3GPPtoNon-3GPP, or InterNetwork-mobility. The location information before the movement is location information of an NPN Network where the terminal device is located before the movement occurs, for example, an NPN Network identifier (e.g., an NPN Network deployed independently and jointly identified by a Public Land Mobile Network identifier (PLMN ID) and a Network Identifier (NID)), a Tracking Area Code (TAC), an NG-RAN cell ID, a terminal device identifier (UE ID), an NG-RAN node ID, address information of a connected N3IWF (e.g., N3IWF IP), and the like. The moved location information is location information of a PLMN Network where the terminal device is located after moving, for example, PLMN Network identifier (PLMN ID), Tracking Area Code (TAC), NG-RAN cell ID, terminal device identifier (UE ID), NG-RAN node ID, address information of a connected N3IWF (e.g., N3IWF IP), and the like. The terminal equipment identity may be a C-RNTI, an I-RATI, an NG-RAN node UE NGAP ID, or the like.

S102: the AMF1 sends a backhaul channel setup notification to the UPF1 through the SMF1 according to the movement notification. Accordingly, the UPF1 receives the backhaul channel setup notification sent by the AMF1 through the SMF 1.

In a specific embodiment of the present application, the backhaul channel establishment notification is used to notify the UPF1 to establish the first NPN segment data backhaul channel between the access network device 1 and the UPF 1. Optionally, the feedback channel establishment notification may further carry address information of the N3IWF1 connected after the terminal device moves, and a PDU Session ID, a QFI, a DRB ID, and the like that need to perform data feedback.

In a specific embodiment of the present application, after receiving the mobility notification, the AMF1 determines that a backhaul connection needs to be established between the access network device 1 and the access network device 2, and therefore, the AMF1 sends a backhaul channel establishment notification to the UPF1 through the SMF 1.

S103: the UPF1 configures the transport network layer information of the first NPN segment data backhaul channel for the backhaul data according to the backhaul channel setup notification.

In a specific embodiment of the present application, the transport network layer information is used to configure parameters for the first NPN segment data return channel. The transport network layer Information may include one or more of uplink Forwarding user plane transport network layer Information (ul Forwarding UP TNL Information) and downlink Forwarding user plane transport network layer Information (DL Forwarding UP TNL Information), the uplink Forwarding user plane transport network layer Information may include an uplink transport layer address (e.g., a port IP address) and an uplink GTP Tunnel port Identifier (e.g., a GTP-TEID, a GTP-Tunnel Endpoint Identifier, etc.), and the downlink Forwarding user plane transport network layer Information may include a downlink transport layer address (e.g., a port IP address) and a downlink GTP Tunnel port Identifier (e.g., a GTP-TEID, a GTP-Tunnel Endpoint Identifier, etc.).

S104: the UPF1 sends the transport network layer information to the AMF 1. Accordingly, the AMF1 receives the transport network layer information sent by the UPF 1.

S105: the AMF1 transmits the transport network layer information to the access network device 1. Accordingly, the access network device 1 receives the transport network layer information sent by the AMF 1.

S106: as shown in fig. 5, the access network device 1, the UPF1 in the PLMN network establishes a first NPN segment data backhaul channel from the access network device 1 to the UPF 1.

S107: as shown in fig. 5, the access network device 2 in the PLMN network, the AMF2, the UPF2, and the N3IWF1 in the NPN network collectively establish a first PLMN section data backhaul channel from the N3IWF 1- > data network 2- > UPF 2- > access network device 2.

In a specific embodiment of the present application, the establishment of the first data backhaul channel may be triggered by the terminal device, or may be triggered by the AMF 1. The terminal device triggering means that the terminal device sends NAS information to the AMF1 to request to establish the first data backhaul channel. The AMF1 trigger refers to the AMF1 establishing a first data backhaul channel based on the content in the mobile notification. And, the AMF1 has informed the UPF1 of the address information of the N3IWF1 at S102, and a second data backhaul channel is established between the UPF1 and the N3IWF 1. And splicing the first data return channel and the second data return channel to obtain a first PLMN data return channel from the access network equipment 2 to the N3IWF 1.

In a specific embodiment of the present application, the first PLMN section data backhaul channel may be carried by an established NPN PDU session resource, or may be an established PLMN section data backhaul channel (dedicated data backhaul channel) dedicated for data backhaul. It can be understood that when the first PLMN section data return channel adopts the NPN PDU session resource, a data transmission channel from the terminal device to the DN2 is actually established, and therefore, the access network device 2 can communicate with the terminal device through the NPN PDU session resource, and when the first PLMN section data return channel adopts the dedicated data return channel, a data return channel from the access network device 2 to the UPF1 is actually established, and the access network device 2 cannot communicate with the terminal device through the dedicated data return channel.

When the first PLMN section data return channel adopts the NPN PDU Session resource, the first PLMN section data return channel may be established after the terminal device successfully moves to the PLMN network, that is, after the terminal device moves to the PLMN network, the terminal device sends an NAS information request to the AMF1 to establish the NPN PDU Session resource, where the request information carries an identifier of an NPN PDU Session (PDU Session ID), an identifier list of the PLMN PDU Session, return data information corresponding to the PLMN PDU Session, data transmission sequence information, or a cause value for establishing the NPN PDU Session resource. The identification of the NPN PDU session and the PLMN PDU session identification in the identification list of the PLMN PDU session are used for indicating that the established NPN PDU session resource can be used for transmitting back the corresponding PLMN PDU session data. It should be understood that the NPN PDU session resources may or may not also be used for transmitting the corresponding NPN PDU session data. The feedback data information corresponding to the PLMN PDU session comprises: PDU session identification, QoS flow identification, DRB identification, or a mapping list of DRB and QoS flow. The data transmission sequence information is used to indicate a transmission sequence of the data of the NPN PDU session and the PLMN PDU session, for example, the sequence of the NPN PDU session identifier and the PLMN PDU session identifier is used to indicate a sequence of transmitting the corresponding data, and after the data transmission of one PDU session is finished, an end marker (end marker) is added at the end of the data, and then the data of another PDU session is continuously transmitted. The cause value is used to indicate a cause for requesting the terminal device to establish the NPN PDU session, for example, the cause value is identified by SNPN, NPN, PLMN, snpntonplmn, plmntonsnpn, npnntopplmn, plmntonnpn, PNI-nptopplmn, PLMNtoPNI-NPN, snpntonsnpn, Non-3GPPtoPLMN, PLMNtoNon-3GPP, Non-3GPPtoNon-3GPP, or inter network-mobility, so as to indicate that the terminal device needs to establish the NPN PDU session resource to maintain service continuity across the network.

The data return path established between the access network device 1 and the access network device 2 is the sum of the first NPN segment data return channel and the first PLMN segment data return channel, that is, the access network device 1 may transmit the return data to the access network device 2 through the first NPN segment data return channel and the first PLMN segment data return channel.

After the establishment of the data backhaul between the access network device 1 and the access network device 2 is completed, the access network device 1 may send the backhaul data to the UPF1 through the first NPN segment data backhaul channel, and then the UPF1 sends the backhaul data to the access network device 2 through the first PLMN segment data backhaul channel.

Because of the out-of-path reason, part of the new data (hereinafter, the new data mainly refers to this part of the data) may arrive at the access network device earlier than the backhaul data, so to ensure that the backhaul data can be correctly uplinked to the DN2 or downlinked to the terminal device by the access network device 2 after being transmitted back to the access network device 2, the terminal device needs to further transmit backhaul data information to the access network device 1 and the access network device 2, respectively, to ensure that the backhaul data information between the access network device 1 and the access network device 2 is uniform, and the access network device 2 can correctly uplink the backhaul data and the new data to the DN2 or downlink to the terminal device according to the backhaul data information.

Referring to fig. 6, fig. 6 is a schematic flow chart of a transmission method of backhaul data information provided in the present application, where the transmission method of backhaul data information includes the following steps:

s201: as shown in fig. 7, after the end device moves from access network device 1 to access network device 2, the end device sends backhaul data information to AMF1 over an N1 interface. Accordingly, the AMF1 receives the backhaul data information transmitted by the terminal device through the N1 interface. The N1 interface is an interface established by the terminal device and the AMF1 through the network elements such as the access network device 2, the UPF2, the N3IWF1, and the like.

In a specific embodiment of the present application, the backhaul data information carries one or more of the following: an identification of the NPN PDU Session (PDU Session ID), an identification list of the PLMN PDU Session, returned data information of the PLMN PDU Session, data transmission sequence information, or a cause value for NPN PDU Session resource establishment. The identification of the NPN PDU session and the PLMN PDU session identification in the identification list of the PLMN PDU session are used for indicating that the established NPN PDU session resource can be used for transmitting back the corresponding PLMN PDU session data. It should be understood that the NPN PDU session resources may or may not also be used for transmitting the corresponding NPN PDU session data. The backhaul data information of the PLMN PDU session includes one or more of: PDU session identification, QoS flow identification, DRB identification, or a mapping list of DRB and QoS flow. Optionally, the backhaul Data information of the PLMN PDU session may further include a condition that Data in the DRB needs to be carried, so as to guarantee lossless mobility, for example, uplink PDCP-SN Packet Data Convergence Protocol service Data unit Sequence Number (PDCP-SN) and HFN receiver status information (uplink PDCP-SN and HFN receiver status) and downlink PDCP SN and HFN transmitter status (downlink PDCP SN and HFN transmitter status) information are carried, and the like. The Status information may include one or more of cell UL/DL COUNT Value, Transmit Status of UL PDCP SDUs, and Receive Status of DL PDCP SDUs, among others. The Transmit Status of the UL PDCP SDUs is used for reflecting whether the corresponding UL PDCP has been successfully sent, for example, 0 indicates that the corresponding PDCP has not been successfully sent, and 1 indicates that the corresponding PDCP has been successfully sent. The Receive Status of DL PDCP SDUs is used to reflect whether the corresponding DL PDCP has been successfully received, for example, 0 indicates that the corresponding PDCP has not been successfully received, and 1 indicates that the corresponding PDCP has been successfully received. And the data transmission sequence information is used for indicating the sequence of transmitting the data of the returned PLMN PDU session and transmitting the data of the newly arrived NPN PDU session in the NPN PDU session resource. For example, the sequence of transmitting the corresponding data is indicated by the sequence of the NPN PDU session identifier and the PLMN PDU session identifier or the sequence list of the NPN PDU session identifier and the PLMN PDU session identifier, and after the data transmission of one PDU session is finished, an end marker (end marker) is added at the end of the data, and then the data of another PDU session is continuously transmitted.

The cause value is used to indicate a cause for requesting the terminal device to establish the NPN PDU session, for example, the cause value is identified by SNPN, NPN, PLMN, snpntonplmn, plmntonsnpn, npnntopplmn, plmntonnpn, PNI-nptopplmn, PLMNtoPNI-NPN, snpntonsnpn, Non-3GPPtoPLMN, PLMNtoNon-3GPP, Non-3GPPtoNon-3GPP, or inter network-mobility, so as to indicate that the terminal device needs to establish the NPN PDU session resource to maintain service continuity across the network.

In a specific embodiment of the present application, the terminal device obtains the backhaul data information stored locally, and sends the backhaul data information to the AMF1 through the N1 interface.

S202: as shown in fig. 7, the AMF1 transmits the backhaul data information to the access network apparatus 1. Accordingly, the access network device 1 receives the backhaul data information sent by the AMF 1.

It can be understood that, when the terminal device moves from the access network device 1 to the access network device 2, the connection between the terminal device and the access network device 1 is already disconnected, data transmission between the terminal device and the access network device 1 cannot be performed normally, the connection between the terminal device and the access network device 2 is already established, and data transmission between the terminal device and the access network device 2 can be performed normally. In addition, if the access network device 1 and the access network device 2 are located in the same network type (for example, when both are located in a PLMN network), the access network device 1 and the access network device 2 may have an Xn interface directly connected, at this time, the access network device 1 and the access network device 2 may directly communicate with each other, but here, the access network device 1 and the access network device 2 are located in two different network types (an NPN network and a PLMN network), respectively, and therefore, the access network device 1 and the access network device 2 cannot directly communicate with each other.

The terminal device cannot directly communicate with the access network device 1, so an N1 interface may be established between the terminal device and the AMF1, the terminal device may send the backhaul data information to the AMF1 through the N1 interface, and then the AMF1 sends the backhaul data information to the access network device 1.

S203: as shown in fig. 6 and 7, the terminal device transmits the backhaul data information to the access network device 2. Accordingly, the access network device 2 receives the returned data information sent by the terminal device.

In the specific embodiment of the present application, if the first PLMN section data backhaul channel is carried by the established NPN PDU session resource, the terminal device may further send the backhaul data information to the access network device 2. The returned data information may carry the above information.

In the specific embodiment of the present application, since the terminal device has moved to the access network device 2, the terminal device may directly send the backhaul data information to the access network device 2.

It can be understood that, in step 203, the terminal device directly sends the backhaul data information to the access network device 2 is taken as an example for explanation, however, the terminal device may not directly send the backhaul data information to the access network device 2, but the terminal device first sends the backhaul data information to the AMF2 through the NAS message, and the AMF2 then forwards the backhaul data information to the access network device 2.

Referring to fig. 8, fig. 8 is a schematic flow chart of a transmission method of backhaul data information provided in the present application, where the transmission method of backhaul data information includes the following steps:

s301: before the terminal device moves from the access network device 1 to the access network device 2, the terminal device sends a notification of the preparation for handover to the access network device 1. Accordingly, the access network device 1 receives the preparation handover notification sent by the terminal device.

S302: as shown in fig. 9, the access network device 1 sends the backhaul data information to the terminal device. Accordingly, the terminal device receives the returned data information sent by the access network device 1.

In a specific embodiment of the present application, the backhaul data information carries one or more of the following: an identification of the NPN PDU Session (PDU Session ID), an identification list of the PLMN PDU Session, returned data information of the PLMN PDU Session, data transmission sequence information, or a cause value for NPN PDU Session resource establishment. The identification of the NPN PDU session and the PLMN PDU session identification in the identification list of the PLMN PDU session are used for indicating that the established NPN PDU session resource can be used for transmitting back the corresponding PLMN PDU session data. It should be understood that the NPN PDU session resources may or may not also be used for transmitting the corresponding NPN PDU session data. The backhaul data information of the PLMN PDU session includes one or more of: PDU session identification, QoS flow identification, DRB identification, or a mapping list of DRB and QoS flow. Optionally, the backhaul Data information of the PLMN PDU session may further include a condition that Data in the DRB needs to be carried, so as to guarantee lossless mobility, for example, uplink PDCP-SN Packet Data Convergence Protocol service Data unit Sequence Number (PDCP-SN) and HFN receiver status information (uplink PDCP-SN and HFN receiver status) and downlink PDCP-SN and HFN transmitter status (downlink PDCP SN and HFN transmitter status) information are carried, and the like. The Status information may include one or more of cell UL/DL COUNT Value, Transmit Status of UL PDCP SDUs, and Receive Status of DL PDCP SDUs, among others. The Transmit Status of the UL PDCP SDUs is used for reflecting whether the corresponding UL PDCP has been successfully sent, for example, 0 indicates that the corresponding PDCP has not been successfully sent, and 1 indicates that the corresponding PDCP has been successfully sent. The Receive Status of DL PDCP SDUs is used to reflect whether the corresponding DL PDCP has been successfully received, for example, 0 indicates that the corresponding PDCP has not been successfully received, and 1 indicates that the corresponding PDCP has been successfully received. And the data transmission sequence information is used for indicating the sequence of transmitting the data of the returned PLMN PDU session and transmitting the data of the newly arrived NPN PDU session in the NPN PDU session resource. For example, the sequence of transmitting the corresponding data is indicated by using the sequence of the NPN PDU session identifier and the PLMN PDU session identifier or the sequence list of the NPN PDU session identifier and the PLMN PDU session identifier, and after the data transmission of one PDU session is finished, an end marker (end marker) is added at the end of the data, and then the data of another PDU session is continuously transmitted.

In a specific embodiment of the present application, the access network device 1 obtains locally stored backhaul data information, and sends the backhaul data information to the terminal device through the wireless interface.

S302: as shown in fig. 9, after the terminal device moves from the access network device 1 to the access network device 2, the terminal device transmits the backhaul data information to the access network device 2. Correspondingly, the access network device 2 receives the returned data information sent by the terminal device.

It should be understood that what is shown in fig. 6 and fig. 8 are only two examples of sending the backhaul data information to the access network device 1 and the access network device 2, and should not be specifically limited, for example, after the terminal device moves to the second access network device, sending a movement notification information to the AMF1, the AMF1 inquiring whether the access network device 1 has data to backhaul, if the access network device 1 needs to backhaul data, the access network device 1 sends the data backhaul information to the AMF1, the AMF1 sends the data backhaul information to the terminal device and the UPF1, respectively, or the AMF1 sends the data backhaul information to the terminal device and the N3IWF1, respectively, and the terminal device sends the data backhaul information to the access network device 2. For another example, before the terminal device moves from the access network device 1 to the access network device 2, the terminal device sends a movement notification to the access network device 1. The access network device 1 transmits the backhaul data information to the terminal device, and the access network device 1 transmits the backhaul data information to the AMF 1. The end device also sends the backhaul data information to the access network device 2, and the AMF1 may also send the backhaul data information to the UPF1 or the N3IWF 1.

From the perspective of the transmission channel, the channel between the access network device 2 and the terminal device for transmitting the backhaul data and the new data at least includes the following two cases:

in the first mode, the first PLMN section data backhaul channel is an NPN PDU session resource. At this time, as shown by a dashed line box in fig. 10, two channels for transmitting the backhaul data and the new data exist between the access network device 2 and the terminal device, where the first access network device 2 may communicate with the terminal device by using the first PLMN section data backhaul channel (i.e., NPN PDU session resource) shown in fig. 5, and the second access network device 2 may communicate with the terminal device by using the second transmission channel (i.e., PLMN PDU session resource) shown in fig. 3.

Since the PLMN PDU session needs to be transmitted on the NPN PDU session resource, the access network device 2 needs to inform the terminal device of the mapping relationship and usage between the NPN PDU session resource and the PLMN PDU session to be transmitted back, so as to inform the terminal device to transmit the transmitted back data of one or more PLMN PDU sessions on one or more NPN PDU session resources, where the NPN PDU session may be indicated by one or more of the following identifiers: NPN PDU Session ID, NPN DRB ID, QFI, etc., a PLMN PDU Session may be indicated by one or more of the following identifiers: PLMN PDU Session ID, PLMN DRB ID, PLMN QFI, etc. Optionally, the access network device 2 needs to inform the terminal device of the mapping relationship and the usage between the PLMN PDU session resource and the PLMN PDU session to be transmitted back, so as to inform the terminal device to transmit the transmission data of one or more PLMN PDU sessions on one or more PLMN PDU session resources.

In a second mode, the first PLMN section data backhaul is a dedicated data backhaul. At this time, as shown by the dashed square in fig. 11, there is only one channel for transmitting the return data and the new data between the access network device 2 and the terminal device, that is, the access network device 2 can communicate with the terminal device by using the second transmission channel (i.e., the PLMN PDU session resource) shown in fig. 3.

It is understood that the above-mentioned channel for transmitting the backhaul data and the new data between the access network device 2 and the terminal device is only an example and should not be construed as a specific limitation.

From the viewpoint of granularity of transmission data, granularity of backhaul data transmitted between the access network device 2 and the terminal device includes at least the following two ways:

in the first way, the granularity of the backhaul data is the PDU session granularity. When the granularity of the backhaul data is the PDU session granularity, the information to be backhaul received by the access network device 2 does not include PDCP-SN and HFN information, and in order to ensure that the order of the backhaul data and the new data transmitted between the access network device 2 and the terminal device is correct, the access network device 2 needs to transmit the data in the order. For example, since the generation of the backhaul data is before the generation of the new data (the backhaul data is generated before the terminal device moves, and the new data is generated after the terminal device moves), the access network device 2 needs to first transmit the backhaul data to the terminal device, and then the access network device 2 transmits the new data to the terminal device, so as to ensure that the transmission sequence of the terminal device for receiving the backhaul data and the new data is correct.

In the second approach, the granularity of the backhaul data and the new data is DRB granularity. When the granularity of the backhaul data is the PDU session granularity, the information to be backhaul received by the access network device 2 does not include the PDCP-SN and HFN information, and the access network device 2 may reorder the backhaul data and the new data according to the PDCP-SN and HFN information. Therefore, the backhaul data and the new data transmitted between the access network device 2 and the terminal device may be transmitted out of order. For example, although the generation of the backhaul data precedes the generation of new data (the backhaul data is data generated before the terminal device moves, and the new data is data generated after the terminal device moves), the access network device 2 may transmit the new data received first to the terminal device and then transmit the backhaul data received later to the terminal device. After receiving the new data and the backhaul data, the terminal device reorders according to the sequence flag (e.g., PDCP SN number). However, after receiving the backhaul data and the new data, the access network device 2 needs to correctly order the backhaul data and the new data and mark the order (e.g., PDCP SN number) with the received PDCP-SN and HFN information.

It is understood that the granularity of the backhaul data and the new data transmitted between the access network device 2 and the terminal device is only an example and should not be specifically limited.

The access network device 2 may transmit the backhaul data and the new data to the terminal device according to the backhaul data information, and the access network device 2 may transmit the backhaul data and the new data to a device (e.g., the UPF2) of the PLMN core network according to the backhaul data information. According to four specific combinations of the granularity of the first PLMN section data return channel and the return data, the method for the access network device 2 to transmit the return data and the new data to the terminal device according to the return data information, and the method for the access network device 2 to transmit the return data and the new data to the device (for example, UPF2) of the PLMN core network according to the return data information at least includes the following methods:

the PLMN PDU session may be a PDU session established between the terminal device and the PLMN network, and the PNN PDU session may be a PDU session established between the terminal device and the NPN network, and for simplicity, the PLMN PDU session and the PNN PDU session are simply referred to as a PLMN PDU session and a PNN PDU session below.

In the first mode, the first PLMN section data return channel is an NPN PDU session resource, and the granularity of the return data is the PDU session granularity. The access network device 2 informs the terminal device of the mapping relationship and usage between the NPN PDU session resources and the PLMN PDU sessions to be backtransmitted, so as to inform the terminal device of the backtransmission data of one or more PLMN PDU sessions to be transmitted on one or more NPN PDU session resources, where the NPN PDU session may be indicated by one or more of the following identifiers: NPN PDU Session ID, NPN DRB ID, QFI, etc., a PLMN PDU Session may be indicated by one or more of the following identifiers: PLMN PDU Session ID, PLMN DRB ID, PLMN QFI, etc. Then, the access network device 2 first sends the received to-be-returned PLMN PDU session data from the NPN PDU session resource to the terminal device through the NPN PDU session resource, and then sends the newly arrived PLMN PDU session data received from the PLMN PDU session resource to the terminal device through the PLMN PDU session resource. And the terminal equipment sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to a high-level application of the terminal equipment in sequence, and the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data are analyzed by the high-level application. Or, the access network device 2 sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to the higher-level application of the terminal device in sequence according to any one of the NPN PDU session resource and the PLMN PDU session resource (i.e., the air interface DRB resource), and the higher-level application analyzes the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data. The access network device 2 sends a notification to the terminal device before sending the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data. The sending notification is used for indicating the type of the Session resource carried by the to-be-transmitted PLMN PDU Session data and the newly-arrived PLMN PDU Session data, the resource type is any one of NPN PDU Session resources and PLMN PDU Session resources, and the resource type can be identified by a PLMN PDU Session ID, a PLMN DRB ID, an NPN PDU Session ID or an NPN DRB ID. In addition, the access network device 2 may also send PLMN PDU session data to be returned and newly arrived PLMN PDU session data through a default resource type, where the default resource type is an NPN PDU session resource or a PLMN PDU session resource. The transmission modes of the uplink user plane data and the downlink user plane data are similar, and only the receiving end needs to replace the terminal device with a device (e.g., UPF2) of the PLMN core network. After the transmission of the backhaul data of one PLMN PDU session is finished in the session resource, an end marker (end marker) is added at the end of the data, and then the backhaul data of another PLMN PDU session or the newly arrived data of the NPN PDU session is continuously transmitted. Optionally, before sending the data to the terminal device, the access network device 2 may first notify the terminal device of data transmission sequence information, where the data transmission sequence information is used to indicate a sequence of data of the PLMN PDU session transmitted and returned in the PDU session resource and data of a new arrival of the PLMN PDU session or data of an NPN PDU session. For example, the sequence of transmitting the corresponding data is indicated by the sequence of the NPN PDU session identifier and the PLMN PDU session identifier or the sequence list of the NPN PDU session identifier and the PLMN PDU session identifier, and after the data transmission of one PDU session is finished, an end marker (end marker) is added at the end of the data, and then the data of another PDU session is continuously transmitted.

In the second mode, the first PLMN section data backhaul channel is a PLMN section data backhaul channel (dedicated data backhaul channel) established specifically for data backhaul, and the granularity of the backhaul data is the PDU session granularity. For user plane data in the downlink direction: the access network device 2 firstly sends the received PLMN PDU session data to be returned from the dedicated data return channel to the terminal device through the PLMN PDU session resource, and then sends the newly arrived PLMN PDU session data received from the PLMN PDU session resource to the terminal device through the PLMN PDU session resource. And the terminal equipment sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to a high-level application of the terminal equipment in sequence, and the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data are analyzed by the high-level application. The transmission modes of the uplink user plane data and the downlink user plane data are similar, and only the receiving end needs to replace the terminal device with a device (e.g., UPF2) of the PLMN core network.

In the third mode, the first PLMN section data backhaul channel is carried in the NPN PDU session resource, and the granularity of the backhaul data is the DRB granularity. The access network equipment 2 performs PDCP numbering, reordering and transmission on the PLMN PDU session data to be transmitted back received from the NPN PDU session resources and the newly arrived PLMN PDU session data received from the PLMN PDU session resources. At the time of transmission, no uplink data having a PDCP SN value lower than the provided UL PDCP SN value should be transmitted, and the provided DL PDCP SN value should be used as the PDCP SN value of the first downlink packet to be transmitted to which no PDCP-SN has been allocated yet, so as to perform in-sequence transmission of data and avoid repeated transmission of data. For user plane data in the downlink direction: the access network device 2 informs the terminal device of the mapping relationship and usage between the NPN PDU session resources and the PLMN PDU sessions to be backtransmitted, so as to inform the terminal device of the backtransmission data of one or more PLMN PDU sessions to be transmitted on one or more NPN PDU session resources, where the NPN PDU session may be indicated by one or more of the following identifiers: NPN PDU Session ID, NPN DRB ID, QFI, etc., a PLMN PDU Session may be indicated by one or more of the following identifiers: PLMN PDU Session ID, PLMN DRB ID, PLMN QFI, etc. Then, the access network device 2 sends the received PLMN PDU session data to be returned from the NPN PDU session resource to the terminal device through the NPN DRB session resource, sends the newly arrived PLMN PDU session data received from the PLMN PDU session resource to the terminal device through the PLMN DRB session resource (the two paths of data may be transmitted in no-sequencing order), the terminal device sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to the upper layer application of the terminal device according to the PDCP SN number, and the upper layer application resolves the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data. Or, the access network device 2 may also send the PLMN PDU session data to be returned received from the NPN PDU session resource and the newly arrived PLMN PDU session data received from the PLMN PDU session resource to the terminal only through one of the NPN DRB resource and the PLMN DRB resource, and the terminal sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data received from the PLMN PDU session resource to the upper layer according to the PDCP SN number, and the upper layer parses the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data, where the access network device 2 informs the terminal to send the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data only through which one of the NPN DRB resource and the PLMN DRB resource (which one may also be used by default to send data, and thus not explicitly informed to the terminal), which may be identified by a PLMN PDU Session ID, a PLMN DRB ID, an NPN PDU Session ID, or an NPN DRB ID. The transmission modes of the uplink user plane data and the downlink user plane data are similar, and only the receiving end needs to be replaced from the terminal device to a device of the PLMN core network (for example, UPF2), and in addition, the access network device 2 sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to the device of the PLMN core network through the PLMN PDU session resource/NPN PDU session resource, instead of the PLMN DRB session resource/NPN DRB session resource.

In the fourth mode, the first PLMN section data backhaul is a PLMN section data backhaul (dedicated data backhaul) established specifically for data backhaul, and the granularity of the backhaul data is DRB granularity. The access network equipment 2 performs PDCP numbering, reordering and transmission on the PLMN PDU session data to be transmitted back received from the NPN PDU session resource and the newly arrived PLMN PDU session data received from the PLMN PDU session resource. At the time of transmission, no uplink data having a PDCP SN value lower than the provided UL PDCP SN value should be transmitted, and the provided DL PDCP SN value should be used as the PDCP SN value of the first downlink packet to be transmitted to which no PDCP-SN has been allocated yet, so as to perform in-sequence transmission of data and avoid repeated transmission of data. For user plane data in the downlink direction: the access network equipment 2 sends the PLMN PDU session data to be returned received from the dedicated return channel and the newly arrived PLMN PDU session data received from the PLMN PDU session resource to the terminal equipment through the PLMN DRB resource, the terminal equipment sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to the upper layer of the terminal equipment according to the PDCP number, and the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data are analyzed by the upper layer application of the terminal equipment. The transmission modes of the uplink user plane data and the downlink user plane data are similar, and only the receiving end needs to be replaced from the terminal device to a device of the PLMN core network (for example, UPF2), and in addition, the access network device 2 sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to the device of the PLMN core network through the PLMN PDU session resource/NPN PDU session resource, instead of the PLMN DRB session resource/NPN DRB session resource.

Before the access network device 2 can transmit the return data and the new data to the terminal device according to the return data information, the access network device 2 may send indication information to the terminal device, where the indication information informs the terminal device of how the access network device 2 will send the return data and the new data to the terminal device. Of course, the access network device 2 may not send the indication information to the terminal device, but send the backhaul data and the new data to the terminal device in a default manner.

For convenience of description, the above description respectively describes the establishment process of the data backhaul channel, the transmission process of the backhaul data information, the backhaul data backhaul process, and the like, and in practical applications, these processes are usually interleaved together. The data returning method of the present application will be described with reference to two specific embodiments. The first embodiment is after the terminal device moves from the access network device 1 in the source network to the access network device 2 in the destination network, and the second embodiment is before the terminal device moves from the access network device 1 in the source network to the access network device 2 in the destination network, which will be described in detail below.

Referring to fig. 12, fig. 12 is an interaction diagram of a data backhaul method of a target network according to a first embodiment of the present disclosure. In combination with the NPN independent networking mode shown in fig. 1, taking an example that a source network is an NPN network, a destination network is a PLMN network, and target network data is PLMN data, the data returning method of this embodiment includes the following steps:

s401: after the terminal device moves from access network device 1 in the NPN network to access network device 2 in the PLMN network, the terminal device establishes an N1 interface with the AMF 1. The N1 interface is an interface established by the terminal device and the AMF1 through the network elements such as the access network device 2, the UPF2, the N3IWF1, and the like.

S402: the terminal device sends the movement notification information to the AMF 1. Accordingly, the AMF1 receives the movement notification information transmitted by the terminal device.

In a specific embodiment of the present application, the movement notification information is used to notify the AMF1 that the terminal device has moved from the access network device 1 in the NPN network to the access network device 2 in the PLMN network. The movement notification information carries one or more of the following: cause value, type of movement, location information before movement, location information after movement. The cause value is the cause of the notification message sent by the terminal device, e.g., moving across networks. The mobility type is the type where a user has mobile access from a cell of one network to a cell of another network, e.g. from an NPN to a PLMN. The location information before the movement is location information of an NPN Network where the terminal device is located before the movement occurs, for example, an NPN Network identifier (for example, an NPN Network deployed independently identified by a Public Land Mobile Network identifier (PLMN ID) and a Network Identifier (NID) in combination), a Tracking Area Code (TAC), an NG-RAN cell ID, a terminal device identifier (UE ID), an NG-RAN node ID, address information of a connected N3IWF (for example, N3IWF IP), and the like. The moved location information is location information of a PLMN Network where the terminal device is located after moving, for example, PLMN Network identifier (PLMN ID), Tracking Area Code (TAC), NG-RAN cell ID, terminal device identifier (UE ID), NG-RAN node ID, address information of a connected N3IWF (e.g., N3IWF IP), and the like. The terminal equipment identity may be a C-RNTI, an I-RATI, an NG-RAN node UE NGAP ID, a UE IP address, a RAN UE ID, etc.

The cause value is used to indicate a cause for the terminal device to send the notification message, for example, when the source network and the target network are implemented differently, the cause value is identified by SNPN, NPN, PLMN, snpntonplmn, plmntonsnpn, NPNtoPLMN, plmntonnpn, PNI-NPNtoPLMN, plmntonni-NPN, snpntonsntopnnpn, Non-3GPPtoPLMN, PLMNtoNon-3GPP, Non-3GPPtoNon-3GPP, or InterNetwork-mobility to indicate the notification message sent due to the terminal device moving across networks. It should be understood that the above possible cases are only examples to illustrate possible expressions of the cause value, and the protection scope of the present application is not limited in any way, and the cause value is not described in detail in the present application.

S403: and the terminal equipment transmits the return data information to the AMF1 through the N1 interface. Accordingly, the AMF1 receives the backhaul data information transmitted by the terminal device through the N1 interface.

In the specific embodiment of the present application, after acquiring the backhaul data information locally, the terminal device needs to send the backhaul data information to the access network device 1 and the access network device 2, so that the backhaul data information in the access network device 1 and the access network device 2 can be aligned.

S404: the AMF1 will send the backhaul data information and the mobility notification information to the access network device 1 according to the mobility notification. Accordingly, the access network device 1 receives the backhaul data information and the mobility notification information sent by the AMF1 according to the mobility notification.

In a specific embodiment of the present application, the backhaul data information may be carried by a radio access network state Transfer signaling (RAN Status Transfer), and the like. Optionally, the AMF1 may also send pre-movement and/or post-movement location information of the terminal device to the access network device 1, where the post-movement location information may include address information (e.g., NPN-N3IWF IP) of the N3IWF to which the terminal device is connected after movement. The address information of the N3IWF connected after the terminal device moves may also be used to notify the access network device 1 to return data to the address information of the N3IWF connected after the terminal device moves.

In a specific embodiment of the present application, the AMF1 may find the access network device 1 according to the location information before moving.

S405: the AMF1 sends the backhaul data information to the N3IWF 1. Accordingly, the N3IWF1 receives the backhaul data information sent by the AMF 1.

S406: the AMF1 sends a backhaul channel setup notification to the UPF1 through the SMF 1. Accordingly, the UPF1 receives the backhaul channel setup notification sent by the AMF1 through the SMF 1.

In a specific embodiment of the present application, the backhaul channel establishment notification is used to notify the UPF1 to establish the first NPN segment data backhaul channel between the access network device 1 and the UPF 1. The backhaul channel setup notification includes the backhaul data information. For example, the feedback channel establishment notification may also carry address information of an N3IWF connected after the terminal device moves, and a PDU Session ID, a QFI, a DRB ID, and the like that need to perform data feedback.

S407: the UPF1 configures the transport network layer information of the first NPN segment data backhaul channel for the backhaul data according to the backhaul channel setup notification.

S408: the UPF1 sends the transport network layer information to the AMF 1. Accordingly, the AMF1 receives the transport network layer information sent by the UPF 1.

S409: the AMF1 transmits the transport network layer information to the access network device 1. Accordingly, the access network device 1 receives the transport network layer information sent by the AMF 1.

In this specific embodiment of the present application, after the access network device 1 receives the transport network layer information, the UPF1 and the access network device 1 establish a first data backhaul channel from the UPF1 to the access network device 1, and the AMF1 has informed the UPF1 of the address information of the N3IWF1 at S406, and a second data backhaul channel is established between the UPF1 and the N3IWF 1. And splicing the first data return channel and the second data return channel to obtain a first NPN-section data return channel between the access network equipment 1 and the N3IWF 1.

S410: the access network device 1 sends the backhaul data to the UPF 1. Accordingly, the UPF1 receives the backhaul data sent by the access network device 1.

S411: the UPF1 sends the backhaul data to the N3IWF 1. Accordingly, the N3IWF1 receives the backhaul data sent by the UPF 1.

S412: the access network device 2 in the PLMN network, the AMF2, the UPF2, the SMF2, and the N3IWF1 in the NPN network collectively establish a first PLMN section data backhaul channel from the N3IWF 1- > data network 2- > UPF 2- > access network device 2.

In a specific embodiment of the present application, the establishment of the data backhaul channel of the first PLMN segment may be triggered by the terminal device, or may be triggered by the AMF 1. The terminal device triggering means that the terminal device sends NAS information to the AMF1 to request to establish a first PLMN section data backhaul channel. The AMF1 trigger means that the AMF1 establishes a first PLMN segment data backhaul channel based on the content in the mobile notification.

In a specific embodiment of the present application, the first PLMN section data backhaul channel may be carried by an established NPN PDU session resource, or may be an established PLMN section data backhaul channel (dedicated data backhaul channel) dedicated for data backhaul.

In a specific embodiment of the present application, the first NPN segment data return channel and the first PLMN segment data return channel form a data return channel from the access network device 1 to the access network device 2.

S413: optionally, the terminal device sends the backhaul data information to the access network device 2. Accordingly, the access network device 2 receives the returned data information sent by the terminal device.

The return data information includes one or more of the following: an identification of the NPN PDU Session (PDU Session ID), an identification list of the PLMN PDU Session, returned data information of the PLMN PDU Session, data transmission sequence information, or a cause value for NPN PDU Session resource establishment. The identification of the NPN PDU session and the PLMN PDU session identification in the identification list of the PLMN PDU session are used for indicating that the established NPN PDU session resource can be used for transmitting back the corresponding PLMN PDU session data. It should be understood that the NPN PDU session resources may or may not also be used for transmitting the corresponding NPN PDU session data. The backhaul data information of the PLMN PDU session includes one or more of: PDU session identification, QoS flow identification, DRB identification, or a mapping list of DRB and QoS flow. Optionally, the backhaul Data information of the PLMN PDU session may further include a condition that Data in the DRB needs to be carried, so as to guarantee lossless mobility, for example, uplink PDCP-SN Packet Data Convergence Protocol service Data unit Sequence Number (PDCP-SN) and HFN receiver status information (uplink PDCP-SN and HFN receiver status) and downlink PDCP-SN and HFN transmitter status (downlink PDCP SN and HFN transmitter status) information are carried, and the like. The Status information may include one or more of cell UL/DL COUNT Value, Transmit Status of UL PDCP SDUs, and Receive Status of DL PDCP SDUs, among others. The Transmit Status of the UL PDCP SDUs is used for reflecting whether the corresponding UL PDCP has been successfully sent, for example, 0 indicates that the corresponding PDCP has not been successfully sent, and 1 indicates that the corresponding PDCP has been successfully sent. The Receive Status of DL PDCP SDUs is used to reflect whether the corresponding DL PDCP has been successfully received, for example, 0 indicates that the corresponding PDCP has not been successfully received, and 1 indicates that the corresponding PDCP has been successfully received. And the data transmission sequence information is used for indicating the sequence of transmitting the data of the returned PLMN PDU session and transmitting the data of the newly arrived NPN PDU session in the NPN PDU session resource. For example, the sequence of transmitting the corresponding data is indicated by using the sequence of the NPN PDU session identifier and the PLMN PDU session identifier or the sequence list of the NPN PDU session identifier and the PLMN PDU session identifier, and after the data transmission of one PDU session is finished, an end marker (end marker) is added at the end of the data, and then the data of another PDU session is continuously transmitted.

In the specific embodiment of the present application, if the first PLMN section data return channel is carried by the established NPN PDU session resource, the terminal device may further send the return data information to the access network device 2 when the first PLMN section data return channel is established. Since the NPN PDU session resource is carried on the PLMN PDU session resource, in the engineering of establishing the PLMN PDU session resource for carrying the NPN PDU session, the terminal device may directly send the return data information to the access network device 2, or the terminal device sends the return data information to the AMF2, and the AMF2 further forwards the return data information to the access network device 2.

S414: the N3IWF1 transmits the return data to the access network equipment 2 through the data return channels of the first PLMN segment of the data network 2 and the UPF 2.

S415: and the access network equipment 2, UPF2 and DN2 in the PLMN network establish PLMN PDU session resources for the terminal equipment to transmit the new PLMN PDU session data.

S416: the access network device 2 may transmit the backhaul data and the new data to the terminal device according to the backhaul data information, or the access network device 2 may transmit the backhaul data and the new data to the second UPF according to the backhaul data information.

In a specific embodiment of the present application, the manner in which the access network device 2 transmits the backhaul data and the new data to the terminal device according to the backhaul data information, and the access network device 2 transmits the backhaul data and the new data to the device (e.g., the UPF2) of the PLMN core network according to the backhaul data information has been described in detail above, and it is specifically referred to the above and related matters, and is not specifically described herein.

Various alternatives to the embodiment shown in fig. 12 will be described in detail below, corresponding to the embodiment shown in fig. 12.

(1) In the embodiment shown in fig. 12, the terminal device sends the backhaul data information to the access network device 2 in step S413 for example, but in practical application, this step may occur at any position between S403 and S415, and is not limited here. In addition, the terminal device may not directly send the backhaul data information to the access network device 2, but the terminal device first sends the backhaul data information to the AMF2 through the NAS message, and the AMF2 then forwards the backhaul data information to the access network device 2. Or, after receiving the movement notification sent by the terminal device, the AMF1 sends the movement notification to the access network device 1 by the AMF 1. After the access network device 1 receives the mobility notification, the access network device 1 locally acquires the backhaul data information and sends the backhaul data information to the AMF 1. After receiving the backhaul data information, the AMF1 sends the backhaul data information to the terminal device, and after receiving the backhaul data information, the terminal device sends the backhaul data information to the access network device 2.

(2) In the embodiment shown in fig. 12, between step 405 and step S406, the N3IWF1 may configure the backhaul tunneling network layer information. Wherein, the backhaul tunneling network layer information is a backhaul tunnel port at the N3IWF side, for example, an IP address of the N3 IWF. Then, the N3IWF sends the backhaul tunneling network layer information to the AMF1, and the AMF1 sends the backhaul tunneling information to the UPF1 through the SMF1 in step S406. At this time, the IP address of the N3IWF may not be carried additionally in step S406.

(3) In the embodiment shown in fig. 12, in step S412, the PLMN section data backhaul channel may be a special NPN PDU session tunnel used for data backhaul. When establishing the NPN PDU session tunnel, the AMF2 may send information such as tunnel identifier or indication information to notify the access network device 2, the UPF2, and the SMF2 that the NPN PDU session tunnel is used for data backhaul.

(4) In the embodiment shown in fig. 12, the step S403 of sending the movement notification to the AMF1 by the terminal device through the N1 interface may be replaced by: the AMF1 informs the access network device 1 that the terminal device has moved and sends the identification of the terminal device and the cause value to the access network device 1. The access network device 1 informs the AMF1 to establish an NPN-segment data backhaul channel, and sends backhaul data information to the AMF 1. The AMF1 transmits the backhaul data information to the terminal device.

(5) In the embodiment shown in fig. 12, step S412 may occur anywhere between S401 and S415, and is not specifically limited herein.

(6) In the embodiment shown in fig. 12, when the first PLMN section data return channel is the NPN PDU session resource, the return data in step S414 includes two IPsec headers. When the backhaul data is sent to the access network device 1, the first IPsec header is carried, and then when the access network device 1 sends the backhaul data to the N3IWF2, the N3IWF2 adds a second IPsec header to the backhaul data, and then sends the backhaul data added with the second IPsec header to the access network device 2. Therefore, when the terminal device parses the backhaul data sent by the access network device 2 to the terminal device, it needs to perform IPsec header twice.

(7) Step S410 and step S411 may also follow step S412.

(8) Step S402 and step S403 may be merged into the same piece of information.

Referring to fig. 13, fig. 13 is an interaction diagram of a data backhaul method of a second target network proposed in the present application. In combination with the NPN independent networking mode shown in fig. 13, taking an example that the source network is an NPN network, the destination network is a PLMN network, and the source network data is PLMN data, the data returning method of this embodiment includes the following steps:

s501: in the case where the terminal device accesses the access network device 1 of the source network, the terminal device transmits the preparation movement notification information to the access network device 1. Accordingly, the access network device 1 receives the preparation movement notification information transmitted by the terminal device.

In a specific embodiment of the present application, the preparation of the movement notification is used to notify the access network device 1 that the terminal device is ready to move from the access network device 1 of the source network to the access network device 2 of the destination network.

The movement notification carries one or more of the following: cause value, type of movement, post-movement location information (i.e., target network location information). The cause value is the cause of the notification message sent by the terminal device, e.g., moving across networks. The mobility type is the type where a user has mobile access from a cell of one network to a cell of another network, e.g. from an NPN to a PLMN. The moved location information is location information of a PLMN Network where the terminal device is located after moving, for example, PLMN Network identifier (PLMN ID), Tracking Area Code (TAC), NG-RAN cell ID, terminal device identifier (UE ID), NG-RAN node ID, address information of a connected N3IWF (e.g., N3IWF IP), and the like.

S502: and the access network equipment 1 sends back data information to the terminal equipment according to the prepared movement notification. Correspondingly, the terminal device receives the returned data information sent by the access network device 1 according to the prepared mobile notification.

In a specific embodiment of the present application, the backhaul data information carries one or more of the following: the returned data information and the reason value of the PLMN PDU session. The backhaul data information of the PLMN PDU session includes one or more of: PDU session identification, QoS flow identification, DRB identification, or a mapping list of DRB and QoS flow. Optionally, the backhaul Data information of the PLMN PDU session may further include a condition that Data in the DRB needs to be carried, so as to guarantee lossless mobility, for example, uplink PDCP-SN Packet Data Convergence Protocol service Data unit Sequence Number (PDCP-SN) and HFN receiver status information (uplink PDCP-SN and HFN receiver status) and downlink PDCP-SN and HFN transmitter status (downlink PDCP SN and HFN transmitter status) information are carried, and the like. The Status information may include one or more of cell UL/DL COUNT Value, Transmit Status of UL PDCP SDUs, and Receive Status of DL PDCP SDUs, among others. The Transmit Status of the UL PDCP SDUs is used for reflecting whether the corresponding UL PDCP has been successfully sent, for example, 0 indicates that the corresponding PDCP has not been successfully sent, and 1 indicates that the corresponding PDCP has been successfully sent. The Receive Status of DL PDCP SDUs is used to reflect whether the corresponding DL PDCP has been successfully received, for example, 0 indicates that the corresponding PDCP has not been successfully received, and 1 indicates that the corresponding PDCP has been successfully received. The cause value is used to indicate a cause for the terminal device to send the notification information, for example, SNPN, NPN, PLMN, snpntoplm, plmntonnpn, npnntopmn, plmntonnp, PNI-npnntopmn, PLMNtoPNI-NPN, snpntonsnpn, Non-3GPPtoPLMN, PLMNtoNon-3GPP, Non-3GPPtoNon-3GPP, or InterNetwork-mobility is used to identify the cause value, which is used to indicate that the terminal device sends the movement notification information due to the movement across the network.

S503: the access network device 1 sends the backhaul data information to the AMF 1. Accordingly, the AMF1 receives the backhaul data information sent by the access network device 1. The information to be returned includes the information in S502.

In a specific embodiment of the present application, the access network device 1 may further send address information of the N3IWF to be connected after the terminal device moves, for example, N3IWF1IP to the AMF 1.

S504: the AMF1 sends the backhaul data information to the N3IWF 1. Accordingly, the N3IWF1 receives the backhaul data information sent by the AMF 1.

S505: the AMF1 sends a backhaul channel setup notification to the UPF1 through the SMF 1. Accordingly, the UPF1 receives the backhaul channel setup notification sent by the AMF1 through the SMF 1.

In a specific embodiment of the present application, the backhaul channel establishment notification is used to notify the UPF1 to establish the first NPN segment data backhaul channel between the access network device 1 and the UPF 1. Optionally, the backhaul channel establishment notification may carry the backhaul data information, and may also carry address information of an N3IWF connected after the terminal device moves to the second network.

S506: the UPF1 configures the transport network layer information of the first NPN segment data backhaul channel for the backhaul data according to the backhaul channel setup notification.

S507: the UPF1 sends the transport network layer information to the AMF 1. Accordingly, the AMF1 receives the transport network layer information sent by the UPF 1.

S508: the AMF1 transmits the transport network layer information to the access network device 1. Accordingly, the access network device 1 receives the transport network layer information sent by the AMF 1.

In this specific embodiment of the present application, after the access network device 1 receives the transport network layer information, the UPF1 and the access network device 1 establish a first data backhaul channel from the access network device 1 to the UPF1, and the AMF1 has informed the UPF1 of the address information of the N3IWF1 at S505, and a second data backhaul channel is established between the UPF1 and the N3IWF 1. And splicing the first data return channel and the second data return channel to obtain a first NPN-section data return channel between the access network equipment 1 and the N3IWF 1.

S509: the access network device 1 sends the backhaul data to the UPF 1. Accordingly, the UPF1 receives the backhaul data sent by the access network device 1.

S510: the UPF1 sends the backhaul data to the N3IWF 1. Accordingly, the N3IWF1 receives the backhaul data sent by the UPF 1.

S511: the access network device 2 in the PLMN network, the AMF2, the UPF2, the SMF2, and the N3IWF1 in the NPN network collectively establish a first PLMN section data backhaul channel from the N3IWF 1- > data network 2- > UPF 2- > access network device 2.

S512: optionally, the terminal device sends the backhaul data information to the access network device 2. Accordingly, the access network device 2 receives the returned data information sent by the terminal device.

In the specific embodiment of the present application, if the PLMN section data return channel is carried by the established NPN PDU session resource, the terminal device may further send the return data information to the access network device 2 when establishing the PLMN PDU session resource for carrying the NPN PDU session. The backhaul data information may carry one or more of the following: an identification of the NPN PDU Session (PDU Session ID), an identification list of the PLMN PDU Session, returned data information of the PLMN PDU Session, data transmission sequence information, or a cause value for NPN PDU Session resource establishment. The identification of the NPN PDU session and the PLMN PDU session identification in the identification list of the PLMN PDU session are used for indicating that the established NPN PDU session resource can be used for transmitting back the corresponding PLMN PDU session data. It should be understood that the NPN PDU session resources may or may not also be used for transmitting the corresponding NPN PDU session data. The backhaul data information of the PLMN PDU session includes one or more of: PDU session identification, QoS flow identification, DRB identification, or a mapping list of DRB and QoS flow. Optionally, the backhaul Data information of the PLMN PDU session may further include a condition that Data in the DRB needs to be carried, so as to guarantee lossless mobility, for example, uplink PDCP-SN Packet Data Convergence Protocol service Data unit Sequence Number (PDCP-SN) and HFN receiver status information (uplink PDCP-SN and HFN receiver status) and downlink PDCP-SN and HFN transmitter status (downlink PDCP SN and HFN transmitter status) information are carried, and the like. The Status information may include one or more of cell UL/DL COUNT Value, Transmit Status of UL PDCP SDUs, and Receive Status of DL PDCP SDUs, among others. The Transmit Status of the UL PDCP SDUs is used for reflecting whether the corresponding UL PDCP has been successfully sent, for example, 0 indicates that the corresponding PDCP has not been successfully sent, and 1 indicates that the corresponding PDCP has been successfully sent. The Receive Status of DL PDCP SDUs is used to reflect whether the corresponding DL PDCP has been successfully received, for example, 0 indicates that the corresponding PDCP has not been successfully received, and 1 indicates that the corresponding PDCP has been successfully received. And the data transmission sequence information is used for indicating the sequence of transmitting the data of the returned PLMN PDU session and transmitting the data of the newly arrived NPN PDU session in the NPN PDU session resource. For example, the sequence of transmitting the corresponding data is indicated by using the sequence of the NPN PDU session identifier and the PLMN PDU session identifier or the sequence list of the NPN PDU session identifier and the PLMN PDU session identifier, and after the data transmission of one PDU session is finished, an end marker (end marker) is added at the end of the data, and then the data of another PDU session is continuously transmitted.

S513: the N3IWF1 transmits the return data to the access network equipment 2 through the data return channels of the first PLMN segment of the data network 2 and the UPF 2.

S514: the access network device 2, AMF2, UPF2, SMF2 in the PLMN network establishes PLMN PDU session resources for the terminal device to transmit new data.

S515: the access network device 2 may transmit the backhaul data and the new data to the terminal device according to the backhaul data information, or the access network device 2 may transmit the backhaul data and the new data to the second UPF according to the backhaul data information.

In addition, the application also provides a new data returning method of the target network, which is completely different from the data returning method of the target network. Referring to fig. 14, fig. 14 is an interaction diagram of a data backhaul method of a third target network proposed in the present application. In combination with the NPN independent networking manner shown in fig. 1, taking an example that the source network is an NPN network and the destination network is a PLMN network, the data backhaul method of this embodiment includes the following steps:

s601: in case the terminal device accesses the access network device 1 of said source network, the terminal device sends a prepare-to-move notification to the access network device 1. Accordingly, the access network device 1 receives the preparation movement notification sent by the terminal device.

In a specific embodiment of the present application, the preparation of the movement notification is used to notify the access network device 1 that the terminal device is ready to move from the access network device 1 of the source network to the access network device 2 of the destination network. The movement notification carries one or more of the following: cause value, type of movement, location information after movement (i.e., target network location information), location information before movement. The cause value is the cause of the notification message sent by the terminal device, e.g., moving across networks. The mobility type is the type where a user has mobile access from a cell of one network to a cell of another network, e.g. from an NPN to a PLMN. The moved location information is location information of a PLMN Network where the terminal device is located after moving, for example, PLMN Network identifier (PLMN ID), Tracking Area Code (TAC), NG-RAN cell ID, terminal device identifier (UE ID), NG-RAN node ID, and address information of a connected N3IWF (e.g., N3IWF IP). The pre-movement location information may carry address information of the N3IWF connected before movement, e.g., N3IWF IP), and so on.

S602: the access network device 1 sends back transmission data information to the AMF1 according to the preparation movement notification. Accordingly, the AMF1 receives the backhaul data information sent by the access network device 1 according to the preparation mobility notification.

S603: the AMF1 sends the backhaul data information to the terminal device. Accordingly, the terminal device receives the backhaul data information sent by the AMF 1.

S604: the end device sends the backhaul data information to the AMF 2. Accordingly, the AMF2 receives backhaul data information sent by the terminal device. For example, the UE establishes an N1 interface with the AMF2 through RAN1> UPF1> DN1> N3IWF2, and the UE sends NAS information to the AMF 2.

S605: the AMF2 forwards the backtransmission data information to the UPF 2. Accordingly, the UPF2 receives the backhaul data information sent by the AMF 2.

S606: the UPF2 configures the transport network layer information of the second NPN segment data backhaul channel for the backhaul data, and sends it to the AMF 2.

In a specific embodiment of the present application, the transport network layer information is used to configure parameters for the second NPN segment data return channel. The transport network layer Information may include one or more of uplink Forwarding user plane transport network layer Information (ul Forwarding UP TNL Information) and downlink Forwarding user plane transport network layer Information (DL Forwarding UP TNL Information), the uplink Forwarding user plane transport network layer Information may include an uplink transport layer address (e.g., port IP address) and an uplink GTP Tunnel port Identifier (e.g., GTP-TEID, GTP-Tunnel Endpoint Identifier, etc.), and the downlink Forwarding user plane transport network layer Information may include a downlink transport layer address (e.g., port IP address) and a downlink GTP Tunnel port Identifier (e.g., GTP-TEID, GTP-Tunnel Endpoint Identifier, etc.)

S607: the AMF2 sends the transport network layer information to the N3IWF 2. Accordingly, the N3IWF2 receives the transport network layer information sent by the AMF 2.

The N3IWF2 knows the address of the UPF2 side based on the transport network layer information, thereby establishing a data backhaul channel from the N3IWF2 to the UPF 2.

S608: the terminal device sends a prepare move notification to the AMF1, the prepare move notification being used to notify the AMF1 that the terminal device is ready to move from the access network device 1 of the source network to the access network device 2 of the destination network. The prepare movement notification carries one or more of: cause value, type of movement, location information after movement (i.e., target network location information), location information before movement. The cause value is the cause of the notification message sent by the terminal device, e.g., moving across networks. The mobility type is the type where a user has mobile access from a cell of one network to a cell of another network, e.g. from an NPN to a PLMN. The moved location information is location information of a PLMN Network where the terminal device is located after moving, for example, PLMN Network identifier (PLMN ID), Tracking Area Code (TAC), NG-RAN cell ID, terminal device identifier (UE ID), NG-RAN node ID, and address information of a connected N3IWF (e.g., N3IWF IP). The pre-movement location information may carry address information of the N3IWF connected before movement, e.g., N3IWF IP), and so on.

It should be understood that the prepare mobility notification may also be sent by the access network device 1 to the AMF1 after S602, where the prepare mobility notification carries the above information.

S609: the AMF1 transmits the information carried by the above preparation movement notification (e.g., address information of the N3IWF connected before movement) and the backhaul data information received in S602 to the UPF 1.

S610: the UPF1 configures the backhaul transport layer network information based on the backhaul data information. The UPF1 sends transport network layer information to the AMF 1.

S611: the AMF1 transmits the transport network layer information to the access network device 1. The access network device 1 establishes a backhaul channel from the access network device 1 to the UPF1 based on the transport network layer information, the UPF1 establishes a backhaul channel from the UPF1 to the N3IWF2 based on the address information of the N3IWF connected before the terminal device moves in S608, and the N3IWF2 establishes a backhaul channel from the N3IWF2 based on the transport network layer information on the UPF2 side in S607. Thus, a second NPN segment data backhaul channel between the access network device 1 to the UPF2 is established.

It should be understood that the AMF2 may also send the transport network layer information of the UPF2 to the terminal device through the N1 interface, the terminal device sends the AMF1, the AMF1 sends the UPF1, and the UPF1 may establish backhaul channel information of the UPF1 to the UPF2 based on the transport network layer information of the UPF 2. Thus, a second NPN segment data backhaul channel between the access network device 1 to the UPF2 is established.

S612: the access network device 1 sends the return data to the UPF2 through the second NPN-segment data return channel. Accordingly, the UPF2 receives the return data via the second NPN segment data return channel.

S613: the terminal equipment moves from the access network equipment 1 of the source network to the access network equipment 2 of the destination network.

S614: the end device sends the backhaul data information to the AMF 2. Accordingly, the AMF2 receives backhaul data information sent by the terminal device.

S615: the AMF2 sends a channel setup request to the UPF 2. Accordingly, the UPF2 receives the channel setup request of the AMF 2. Wherein the channel establishment request is used for establishing PLMN PDU session resources for the terminal equipment.

S616: the UPF2 configures transport network layer information for PLMN PDU session resources.

S617: the UPF2 sends the transport network layer information to the AMF 2. Accordingly, the AMF2 receives transport network layer information sent by the UPF 2.

S618: the AMF2 sends the backhaul data information and transport network layer information to the access network device 2. Accordingly, the access network device 2 receives the backhaul data information sent by the AMF2 and the transport network layer information.

It should be understood that the return data information may also be sent by the terminal device to the access network device 2.

S619: as shown in fig. 15, the access network device 2 configures the transport network layer information to establish the second PLMN section data backhaul. Wherein, the second PLMN segment data backhaul refers to the data backhaul from the UPF2 to the access network device 2

In a specific embodiment of the present application, as shown in fig. 15, the second NPN segment data backhaul channel and the second PLMN segment data backhaul channel form a data backhaul channel from the access network device 1 to the access network device 2.

S620: and establishing corresponding DRB between the access network equipment 2 and the terminal equipment.

S621: the UPF2 transmits the return data back to the access network device 2 through the second PLMN section data return channel. The terminal device transmits new uplink data to the access network device 2 through the DRB, and the access network device 2 transmits newly arrived PLMN PDU session uplink data and the newly received PLMN PDU session uplink data back to the UPF2, or the access network device 2 transmits downlink newly arrived PLMN PDU session data and downlink newly arrived PLMN PDU session data to the terminal device through the DRB.

The second NPN segment data return channel and the second PLMN segment data return channel in the above are both dedicated return channels, and the granularity of the return data may be PDU session granularity or DRB granularity. The details of the two specific ways of granularity of the returned data are described in detail below.

In the first mode, both the second NPN segment data backhaul channel and the second PLMN segment data backhaul channel are dedicated backhaul channels, and the granularity of the backhaul data may be PDU session granularity. In the downlink data direction, the access network device 2 successively sends the received PLMN PDU session data to be returned and newly arrived PLMN PDU session data to the terminal device through the DRB, the terminal device successively sends the PLMN PDU session data to be returned and newly arrived PLMN PDU session data to the higher layer application according to the above sequence, and the higher layer application analyzes the PLMN PDU session data to be returned and newly arrived PLMN PDU session data. The transmission modes of the uplink user plane data and the downlink user plane data are similar, except that the receiving end is the UPF2, that is, the access network device 2 sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to the PLMN-UPF.

In the second manner, both the second NPN segment data backhaul channel and the second PLMN segment data backhaul channel are dedicated backhaul channels, and the granularity of the backhaul data may be a DRB granularity. The access network equipment 2 performs PDCP numbering, reordering and transmission on the PLMN PDU data to be transmitted back and newly arrived PLMN PDU session data. At the time of transmission, no uplink data having a PDCP SN value lower than the provided UL PDCP SN value should be transmitted, and the provided DL PDCP SN value should be used as the PDCP SN value of the first downlink packet to be transmitted to which no PDCP-SN has been allocated yet, so as to perform in-sequence transmission of data and avoid repeated transmission of data. For user plane data in the downlink direction: (the provided DL PDCP SN value should be used as the PDCP SN value of the first downlink packet to be transmitted to which the PDCP-SN has not been allocated): the access network equipment 2 sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to the terminal equipment through the DRB, the terminal equipment sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to the high-level application according to the PDCP SN number, and the high-level application analyzes the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data. The transmission modes of the user plane data in the uplink direction and the user plane data in the downlink direction are similar, only the receiving end needs to be replaced by the UPF2 from the terminal device, the access network device 2 sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to the UPF2, and in addition, the access network device 2 sends the PLMN PDU session data to be returned and the newly arrived PLMN PDU session data to the UPF2 through the NG port resource instead of the DRB resource.

Referring to fig. 16, fig. 16 is a schematic structural diagram of an apparatus proposed in the present application. As shown in fig. 16, the apparatus includes: a receiving module 110, a transmitting module 120 and a processing module 130.

When the access network equipment is first access network equipment, the first access network equipment is located in a source network, the second access network equipment is located in a target network, the source network and the target network respectively adopt different network types, the network types comprise a public network and a private network, and the terminal equipment moves from the first access network equipment to the second access network equipment.

The processing module 130 indicates the receiving module 110 to receive backhaul data sent by the target network, where the backhaul data is data of the target network sent by the first access network device but not successfully received by the terminal device, or data of the target network sent by the first access network device but not successfully received by the target network;

the processing module 130 indicates the sending module 120 to send the backhaul data to the network device through the source network segment data backhaul channel, so that the network device sends the backhaul data to the second access network device through the target network segment data backhaul channel.

The processing module 130 indicates that the sending module 120 is further configured to obtain backhaul data information, where the backhaul data information carries one or more of the following: the reason for data backhaul, the type of data backhaul, the PDU session identifier for data backhaul, the identifier of the data radio bearer DRB, or the QoS flow identifier of the QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

the processing module 130 indicates that the sending module 120 is further configured to send the backhaul data information to the second access network device.

For the sake of simplicity, the first access network device is not described in detail here, and please refer to fig. 1 to 15 and the description related thereto about the access network device 1, which will not be described here.

The processing module 130 indicates the receiving module 110 to receive first backhaul data from a network device through a target network segment data backhaul channel, where the first backhaul data is data of the target network that is sent by the first access network device but is not successfully received by the terminal device, the network device is a first User Plane Function (UPF) or a first non-third generation partnership project interworking function (N3 IWF), the first UPF is located in the source network, and the first N3IWF is located in the source network;

the processing module 130 instructs the receiving module 110 to receive the first data from a second UPF, the second UPF being located in the target network;

the processing module 130 instructs the sending module 120 to send the first return data and the first data to the terminal device;

or;

the processing module 130 indicates the receiving module 110 to be configured to receive second backhaul data from a network device through a target network segment data backhaul, where the second backhaul data is sent by the first access network device to the network device through a source network segment data backhaul, and the second backhaul data is out-of-order data from a terminal device received by the first access network device or data that needs to be reordered from the terminal device received by the first access network device; for example, the first access network device receives the uplink out-of-order data from the terminal device, and cannot upload the data to the core network, so data is transmitted back. For another example, in the process that the first access device receives uplink data from the terminal device, the mapping relationship between the DRB and the QoS flow changes, for example, a certain QoS flow data of the original terminal device is transmitted on the DRB1 and then transmitted on the DRB2, the data of the QoS flow in the DRB2 can be transmitted only after the data of the QoS flow in the DRB1 is completely uploaded to the core network, if the terminal device further needs to upload the data of the QoS flow on the DRB1 under the target RAN, the QoS flow data in the DRB2 needs to be transmitted back to the target RAN, and the QoS flow data in the DRB1 under the target RAN are reordered and sequentially uploaded to the core network;

the processing module 130 instructs the receiving module 110 to receive the second data from the terminal device;

the processing module 130 instructs the sending module 120 to send the second backhaul data and the second data to the second UPF.

The processing module 130 indicates that the receiving module 110 is further configured to receive first returned data information, where the first returned data information carries one or more of the following: the reason for data backhaul, the type of data backhaul, the protocol data unit PDU session identifier for data backhaul, the identifier of data radio bearer DRB, or the QoS flow identifier of QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

the processing module 130 indicates that the sending module 120 is further configured to send the first loopback data and the first data to the terminal device according to the first loopback data information;

or;

the processing module 130 indicates that the receiving module 110 is further configured to receive second backhaul data information, where the second backhaul data information carries one or more of the following: the reason for data backhaul, the type of data backhaul, the protocol data unit PDU session identifier for data backhaul, the identifier of data radio bearer DRB, or the QoS flow identifier of QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

the processing module 130 indicates the sending module 120 to send the second backhaul data and the second data to the second UPF according to the second backhaul data information.

the processing module 130 instructs the sending module 120 to instruct the second access network device to send the first backhaul data and the first data to the terminal device through a PDU session resource established between the terminal device and the target network; alternatively, the first and second electrodes may be,

the processing module 130 instructs the sending module 120 to instruct the second access network device to send the first backhaul data and the first data to the terminal device through a PDU session resource established between the terminal device and the source network; alternatively, the first and second electrodes may be,

the processing module 130 instructs the sending module 120 to instruct the second access network device to send the first backhaul data to the terminal device through the PDU session resource established between the terminal device and the source network, and send the first data to the terminal device through the PDU session resource established between the terminal device and the target network.

the processing module 130 instructs the sending module 120 to send the first return data to the terminal device, and then sends the first data to the terminal device; alternatively, the first and second electrodes may be,

the processing module 130 indicates the sending module 120 to send the second backhaul data to the second UPF first, and then send the second data to the second UPF.

the processing module 130 instructs the sending module 120 to perform packet data convergence protocol PDCP (packet data convergence protocol) numbering on the first loopback data and the first data, so as to obtain the numbered first loopback data and the numbered first data;

the processing module 130 instructs the sending module 120 to send the numbered first return data and the numbered first data to the terminal device;

or;

the processing module 130 indicates the sending module 120 to perform PDCP numbering on the second backhaul data and the second data, so as to obtain the numbered second backhaul data and the second data;

the processing module 130 instructs the sending module 120 to send the numbered second backhaul data and the second data to the second UPF.

In some possible designs, the source network is an NPN network and the target network is a PLMN network; alternatively, the first and second electrodes may be,

the source network is a PLMN network and the target network is an NPN network.

For the sake of simplicity, the second access network device is not described in detail here, and please refer to fig. 1 to 15 and the description related thereto regarding the access network device 2, which will not be described here.

When the access network equipment is the first AMF, the first access network equipment is located in a source network, the second access network equipment is located in a target network, the source network and the target network respectively adopt different network types, the network types comprise a public network and a private network, and the terminal equipment moves from the first access network equipment to the second access network equipment.

The processing module 130 indicates the receiving module 110 to receive a mobility notification or a ready mobility notification sent by a terminal device, where the first AMF belongs to the first access network device, the mobility notification is used to notify the first AMF that the terminal device moves from the first access network device to the second access network device, and the ready mobility notification is used to notify the first access network device that the terminal device is ready to move from the first access network device to the second access network device;

the processing module 130 instructs the sending module 120 to send a return channel setup notification to the first UPF based on the movement notification or the ready movement notification, wherein the backhaul channel establishment notification is used to notify the first UPF1 to establish a source network segment data backhaul channel between the first access network device and the network device, wherein the source network segment data backhaul channel is used for the first access network device to send backhaul data to the network device, such that the network device transmits the backhaul data to the second access network device via a target network segment data backhaul channel, the backhaul data is data of the target network sent by the first access network device but not successfully received by the terminal device, or, the data of the target network sent by the first access network device but not successfully received by the target network.

In some possible designs, the receiving module 110 is configured to receive backhaul data information sent through an N1 interface after the terminal device moves to the second access network device, where the backhaul data information carries one or more of the following: the reason for data backhaul, the type of data backhaul, the PDU session identifier for data backhaul, the identifier of the data radio bearer DRB, or the QoS flow identifier of the QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

the processing module 130 instructs the sending module 120 to send the backhaul data information to the second access network device.

In some possible designs, the processing module 130 instructs the receiving module 110 to receive the transport network layer information sent by the first UPF, wherein the transport network layer information is generated by the first UPF; the sending module 120 is configured to send the transport network layer information to the first access network device.

In some possible designs, the processing module 130 instructs the receiving module 110 to receive the movement notification sent by the terminal device through the N1 interface.

For simplicity, the first AMF is not described in detail herein, and is described with reference to fig. 1-15 and related description regarding AMF1, which will not be described herein.

Referring to fig. 17, fig. 17 is a schematic structural diagram of a network device according to an embodiment of the present application. The network device of the present embodiment may include: a transmitter 210, a receiver 220, a memory 230, and a processor 240. Wherein the processor is coupled to the transmitter 210, the receiver 220, and the memory 230, respectively, via a bus 250. Wherein the content of the first and second substances,

the transmitter 210 and the receiver 220 may be provided separately or integrally. Wherein the transmitter 210 may be used to transmit data and the receiver 220 may be used to receive data.

Memory 230 may include Volatile Memory (Volatile Memory), such as Random Access Memory (RAM); the Memory may also include a Non-Volatile Memory (Non-Volatile Memory), such as a Read-Only Memory (ROM), a Flash Memory (Flash Memory), a Hard Disk Drive (HDD), or a Solid-State Drive (SSD) Memory, which may also include a combination of the above types of memories. External memory 230 may store program codes as well as program data.

Processor 240 includes one or more general-purpose processors, which may be any type of device capable of Processing electronic instructions, including a Central Processing Unit (CPU), a microprocessor, a microcontroller, a main processor, a controller, and an ASIC (Application Specific Integrated Circuit), among others. Processor 240 executes various types of digitally stored instructions, such as software or firmware programs stored in memory 230, which enable the identification device to provide a wide variety of services. For example, the processor 240 may be capable of executing programs or processing data to perform at least a portion of the methods discussed herein.

When the network device is a first access network device, the processor 240 is configured to instruct the receiver 220 to receive backhaul data sent by the target network, where the backhaul data is data of the target network sent by the first access network device but not successfully received by the terminal device, or data of the target network sent by the first access network device but not successfully received by the target network;

the processor 240 is configured to instruct the transmitter 210 to transmit the backhaul data to the network device through the source network segment data backhaul channel, so that the network device transmits the backhaul data to the second access network device through the target network segment data backhaul channel.

For the sake of simplicity, the first access network device is not described in detail here, and please refer to fig. 1 to 15 and the description related thereto regarding the access network device 2, which will not be described here.

When the network device is the second access network device, the processor 240 is configured to instruct the receiver 220 to receive first backhaul data from a network device through a target network segment data backhaul channel, where the first backhaul data is data sent by the first access network device to the network device through a source network segment data backhaul channel, the first backhaul data is data of the target network sent by the first access network device but not successfully received by the terminal device, the network device is a first User Plane Function (UPF) or a first non-third generation partnership project interworking function (N3 IWF), the first UPF is located in the source network, and the first N3IWF is located in the source network;

the processor 240 is configured to instruct the receiver 220 to receive first data from a second UPF, the second UPF being located in the target network;

the processor 240 is configured to instruct the transmitter 210 to transmit the first backhaul data and the first data to the terminal device;

or;

the processor 240 is configured to instruct the receiver 220 to receive second backhaul data from a network device through a target network segment data backhaul, where the second backhaul data is sent by the first access network device to the network device through a source network segment data backhaul, and the second backhaul data is out-of-order data from a terminal device received by the first access network device or data that needs to be reordered from a terminal device received by the first access network device;

processor 240 is configured to instruct receiver 220 to receive second data from the terminal device;

the processor 240 is configured to instruct the transmitter 210 to transmit the second backhaul data and the second data to the second UPF.

When the network device is a first AMF, the processor 240 is configured to instruct the receiver 220 to receive a mobility notification or a preparation mobility notification sent by a terminal device, where the first AMF belongs to the first access network device, the mobility notification is configured to notify the first AMF that the terminal device moves from the first access network device to the second access network device, and the preparation mobility notification is configured to notify the first access network device that the terminal device is ready to move from the first access network device to the second access network device;

the processor 240 is configured to instruct the transmitter 210 to transmit a backhaul channel setup notification to the first UPF based on the movement notification or the preparation movement notification, wherein the backhaul channel establishment notification is used to notify the first UPF1 to establish a source network segment data backhaul channel between the first access network device and the network device, wherein the source network segment data backhaul channel is used for the first access network device to send backhaul data to the network device, such that the network device transmits the backhaul data to the second access network device via a target network segment data backhaul channel, the backhaul data is data of the target network sent by the first access network device but not successfully received by the terminal device, or, the data of the target network sent by the first access network device but not successfully received by the target network.

For the sake of simplicity, the first AMF is not described in detail herein, and please refer to fig. 1 to fig. 15 and the related description about the access network device 2, which will not be described herein.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (e.g., coaxial cable, fiber optic, digital subscriber line) or wirelessly (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, memory Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

Claims

1. A data backhaul method is characterized in that a first access network device is located in a source network, a second access network device is located in a target network, the source network and the target network respectively adopt different network types, the network types include a public network and a private network, and a terminal device moves from the first access network device to the second access network device, the method comprising:

the second access network equipment sends the first return data and the first data to the terminal equipment based on first return data information;

or;

the second access network equipment receives second returned data from the network equipment through a target network segment data returning channel, wherein the second returned data is out-of-order data received by the first access network equipment from the terminal equipment or data which is received by the first access network equipment and needs to be reordered and is from the terminal equipment, and the network equipment is a first user plane function UPF or a first non-third generation partnership project interworking function N3 IWF;

the second access network device sends the second backhaul data and the second data to the second UPF based on second backhaul data information, and the second UPF is located in the target network;

at least one of the first backhaul data information and the second backhaul data information is sent to a first access and mobility management function (AMF) through an N1 interface after the terminal device moves to the second access network device, the first AMF is located in the source network and sent to the first access network device by the first AMF, and at least one of the first backhaul data information and the second backhaul data information is sent to the second access network device after the terminal device moves to the second access network device; wherein the content of the first and second substances,

2. The method of claim 1,

the second access network device sends the first return data and the first data to the terminal device, and the method includes:

the second access network equipment receives the first return data information, wherein the first return data information carries one or more of the following: the reason for data backhaul, the type of data backhaul, the protocol data unit PDU session identifier for data backhaul, the identifier of data radio bearer DRB, or the QoS flow identifier of QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

or;

the second access network device receives the second backhaul data information, where the second backhaul data information carries one or more of the following: the reason for data backhaul, the type of data backhaul, the protocol data unit PDU session identifier for data backhaul, the identifier of data radio bearer DRB, or the QoS flow identifier of QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

3. The method of claim 2,

at least one of the first return data information and the second return data information is sent to the terminal device by the first access network device before the terminal device moves to the second access network device, and is sent to the second access network device by the terminal device after the terminal device moves to the second access network device.

4. The method according to any one of claims 1 to 3,

the source network segment data return channel is a channel from the first access network device to the first UPF; or;

5. The method of claim 4,

the source network segment data return channel is generated by the first access network device and the first UPF according to the configuration of transmission network layer information, the transmission network layer information comprises one or more of uplink forwarding transmission network layer information and downlink forwarding user plane transmission network layer information, the uplink forwarding user plane transmission network layer information comprises an uplink transmission layer address and an uplink general packet radio service technology tunnel protocol GTP tunnel port identifier, and the downlink forwarding user plane transmission network layer information comprises a downlink transmission layer address and a downlink GTP tunnel port identifier.

6. The method of claim 5, wherein the transport network layer information is generated by the first UPF, and wherein the transport network layer information is sent by the first UPF to the first access network device via a first AMF.

7. The method according to any one of claims 1 to 3, 5 and 6,

the target network segment data return channel is a channel from the first UPF to the second access network device; or;

8. The method according to claim 7, wherein in case the target network segment data backhaul channel belongs to a PDU session resource established between the terminal device and the source network,

9. The method according to claim 7, wherein in case the target network segment data backhaul is a dedicated data backhaul,

10. The method according to any of claims 1 to 3, 5, 6, 8, 9, wherein in case the granularity of the backtransmission data is a PDU session granularity,

11. The method according to any of claims 1 to 3, 5, 6, 8, 9, wherein in case the granularity of the backhaul data is DRB granularity,

or;

12. The method according to any of claims 1 to 3, 5, 6, 8, and 9, wherein the first backhaul data comprises a first header and a second header, wherein the first header is added when the first backhaul data is sent from the target network to the first access network device and passes through a first N3IWF, and the second header is added when the first backhaul data is sent from the first access network device to the second access network device and passes through the first N3IWF again.

13. The method according to any one of claims 1 to 3, 5, 6, 8, 9,

the source network is an NPN network, and the target network is a PLMN network; alternatively, the first and second electrodes may be,

the source network is a PLMN network and the target network is an NPN network.

14. A second access network device is characterized in that a first access network device is located in a source network, a second access network device is located in a target network, the source network and the target network respectively adopt different network types, the network types comprise a public network and a private network, a terminal device moves from the first access network device to the second access network device, and the device comprises a processing module, a receiving module and a sending module,

the processing module indicates the receiving module to be used for receiving first loopback data from a network device through a target network segment data loopback channel, wherein the first loopback data is data of the target network which is sent by a first access network device but is not successfully received by the terminal device, the network device is a first User Plane Function (UPF) or a first non-third generation partnership project interworking function (N3 IWF), the first UPF is located in the source network, and the first N3IWF is located in the source network;

the processing module instructing the receiving module to receive first data from a second UPF, the second UPF being located in the target network;

the processing module indicates the sending module to send the first return data and the first data to the terminal equipment based on first return data information;

or;

the processing module indicates the receiving module to be used for receiving second returned data from a network device through a target network segment data returning channel, wherein the second returned data is out-of-order data received by the first access network device from a terminal device or data which is received by the first access network device and needs to be reordered and is sent to the network device through a source network segment data returning channel, and the network device is a first User Plane Function (UPF) or a first non-third generation partnership project interworking function (N3 IWF);

the processing module indicates the receiving module to receive second data from the terminal device;

the processing module indicates the sending module to send the second backhaul data and the second data to the second UPF based on second backhaul data information, the second UPF being located in the target network;

15. The apparatus of claim 14,

the processing module indicates the receiving module to be further configured to receive the first return data information, where the first return data information carries one or more of the following: the reason for data backhaul, the type of data backhaul, the protocol data unit PDU session identifier for data backhaul, the identifier of data radio bearer DRB, or the QoS flow identifier of QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

the processing module indicates the sending module to be further used for sending the first return data and the first data to the terminal equipment according to the first return data information;

or;

the processing module indicates that the receiving module is further configured to receive the second backhaul data information, where the second backhaul data information carries one or more of the following: the reason for data backhaul, the type of data backhaul, the protocol data unit PDU session identifier for data backhaul, the identifier of data radio bearer DRB, or the QoS flow identifier of QoS flow corresponding to the DRB, where the reason for data backhaul includes mobility, and the type of data backhaul includes backhaul from the source network to the target network;

and the processing module indicates the sending module to send the second backhaul data and the second data to the second UPF according to the second backhaul data information.

16. The apparatus of claim 15,

17. The apparatus according to any one of claims 14 to 16,

18. The apparatus of claim 17,

19. The device of claim 18, wherein the transport network layer information is generated by the first UPF, and wherein the transport network layer information is sent by the first UPF to the first access network device via a first AMF.

20. The apparatus according to any one of claims 14 to 16, 18, 19,

21. The apparatus according to claim 20, wherein in case the target network segment data backhaul channel belongs to a PDU session resource established between the terminal device and the source network,

the processing module instructs the sending module to further instruct the second access network device to send the first backhaul data and the first data to the terminal device through a PDU session resource established between the terminal device and the target network; alternatively, the first and second electrodes may be,

the processing module instructs the sending module to further instruct the second access network device to send the first backhaul data and the first data to the terminal device through a PDU session resource established between the terminal device and the source network; alternatively, the first and second electrodes may be,

the processing module instructs the sending module to further instruct the second access network device to send the first backhaul data to the terminal device through the PDU session resource established between the terminal device and the source network, and to send the first data to the terminal device through the PDU session resource established between the terminal device and the target network.

22. The apparatus according to claim 20, wherein in case the target network segment data backhaul is a dedicated data backhaul,

the processing module indicates the sending module to be further configured to send the first backhaul data and the first data to the terminal device through a PDU session resource established between the terminal device and the target network.

23. The apparatus according to any of claims 14-16, 18, 19, 21, 22, wherein in case the granularity of the backtransmission data is a PDU session granularity,

the processing module indicates the sending module to be further used for sending the first return data to the terminal equipment by the equipment and then sending the first data to the terminal equipment; alternatively, the first and second electrodes may be,

and the processing module indicates that the sending module is further configured to send the second backhaul data to the second UPF first, and then send the second data to the second UPF.

24. The apparatus according to any of claims 14-16, 18, 19, 21, 22, wherein in case the granularity of the backhaul data is DRB granularity,

the processing module indicates the sending module to be further used for carrying out Packet Data Convergence Protocol (PDCP) numbering on the first return data and the first data so as to obtain the numbered first return data and the numbered first data;

the processing module instructs the sending module to send the numbered first return data and the first data to the terminal device;

or;

the processing module indicates the sending module to further perform PDCP numbering on the second backhaul data and the second data, so as to obtain the numbered second backhaul data and the second data;

and the processing module indicates the sending module to be further used for sending the numbered second returned data and the second data to the second UPF.

25. The apparatus according to any of claims 14 to 16, 18, 19, 21, 22, wherein the first backhaul data comprises a first header and a second header, wherein the first header is added when the first backhaul data is sent from the target network to the first access network apparatus and passes through a first N3IWF, and the second header is added when the first backhaul data is sent from the first access network apparatus to the second access network apparatus and passes through the first N3IWF again.

26. The apparatus according to any one of claims 14 to 16, 18, 19, 21, 22,

the source network is a PLMN network and the target network is an NPN network.

27. A second access network device comprising a processor and memory, the processor executing code in the memory to perform the method of any of claims 1 to 13.

28. A readable storage medium, comprising instructions which, when executed on a second access network device, cause the second access network device to perform the method of any one of claims 1 to 13.