CN115866695A

CN115866695A - Feeder link switching method, device, base station and network equipment

Info

Publication number: CN115866695A
Application number: CN202111117333.9A
Authority: CN
Inventors: 李春林
Original assignee: Datang Mobile Communications Equipment Co Ltd
Current assignee: Datang Mobile Communications Equipment Co Ltd
Priority date: 2021-09-23
Filing date: 2021-09-23
Publication date: 2023-03-28

Abstract

The application provides a method, a device, a base station and network equipment for switching a feeder link. The method comprises the following steps: a base station sends a path switching request message to a core network; the path switching request message comprises the identity information of the terminal and the user surface downlink tunnel address of the terminal at the base station side; a base station receives a path switching receiving message sent by a core network; the path switching receiving message comprises the identity information of the terminal in the target UPF after the link switching and the user plane uplink tunnel address used by the terminal in the target UPF; and the base station sends the uplink data of the terminal to the target UPF unit through the user plane uplink tunnel address used by the terminal in the target UPF unit. By adopting the method, the downlink tunnel at the core network side can be prevented from being established only after the UE is successfully accessed to the target base station, so that the method can be suitable for a satellite communication system adopting a satellite-borne base station.

Description

Feeder link switching method, device, base station and network equipment

Technical Field

The present application relates to the field of wireless technologies, and in particular, to a method, an apparatus, a base station, and a network device for switching a feeder link.

Background

A Low Earth Orbit Satellite (LEO) communication system includes a user terminal, a Satellite, a gateway station, a data network, etc., wherein a radio Link between a user equipment and the Satellite is called a Service Link (Service Link) or a user Link, and a radio Link between the Satellite and the gateway station is called a Feeder Link (Feeder Link).

In a satellite communication system, as a satellite moves around, a ground gateway station connected to the satellite may not continue to serve the satellite, and instead another ground gateway station continues to serve the satellite, i.e., the old feeder link between the satellite and the old ground gateway station is broken and a connection is established with the feeder link between the new ground gateway station, which is a feeder link switch.

In a conventional transparent forwarding mode switching method of a satellite communication system, since a base station on the ground is changed, information needs to be transferred between a target base station and a source base station for a UE to access the target base station. For this situation, the core network adopts a corresponding targeted design: and the downlink tunnel at the core network side is established only after the UE is successfully accessed to the target base station, so that the waste of resources is avoided.

In a satellite-borne base station mode, a base station cannot be changed, the problem of air interface access does not exist, signaling flow on an air interface of a traditional feed link switching method in the prior art is too complicated, processing logic is complex, a mode of establishing a data transmission path in stages is adopted, uplink is established first and then downlink is established, the problem of poor user experience exists, and the method cannot be applied to the satellite-borne base station mode. In the prior art, a feed link switching method which can be suitable for a satellite-borne base station mode and can solve the problems does not exist.

Disclosure of Invention

The present application is directed to a feeder link switching method, an apparatus, a base station, and a network device, which are used to solve the problem that the feeder link switching method in the prior art cannot be applied to a satellite communication system using a satellite-based base station.

The embodiment of the application provides a feeder link switching method, wherein the method is executed by a base station, and the method comprises the following steps:

the base station sends a path switching request message to a core network; the path switching request message comprises identity information of a terminal needing to switch a feeder link and a user plane downlink tunnel address of the terminal at a base station side;

the base station receives a path switching acceptance message sent by a core network; the path switching receiving message comprises the identity information of the terminal in a target user plane management function (UPF) unit after link switching and a user plane uplink tunnel address used by the terminal in the target UPF unit;

and the base station sends the uplink data of the terminal to the target UPF unit through the user plane uplink tunnel address used by the terminal in the target UPF unit.

Optionally, in the method for switching a feeder link, the path switching request message includes at least one first list information, where each first list information records identity information of a terminal and a user plane downlink tunnel address used by the terminal in the corresponding base station;

the path switching receiving message comprises at least one second list information, and each second list information records the identity information of a terminal and the user plane uplink tunnel address used by the terminal in the corresponding target UPF unit.

Optionally, the feeder link switching method, wherein the identity information of the terminal includes at least one of:

the terminal uses the identity in the base station;

and the terminal uses the identity in the core network.

Optionally, in the method for switching feeder links, after the base station receives a path switch accept message fed back by a core network, the method further includes:

the base station caches the received uplink data transmitted by the terminal;

sending the cached uplink data to the target UPF unit according to the user plane uplink tunnel address used by the terminal in the target UPF unit; and/or receiving downlink data which is sent by the target UPF unit and cached in the process of switching the feeder link, and sending the downlink data to the terminal.

Optionally, the feeder link switching method further includes:

determining whether the feeder link needs to be switched according to at least one of the current satellite position, the gateway station position and the ephemeris information;

when the feed link switching is determined to be needed, sending a feed link switching request to the core network;

and after obtaining a feed link switching acceptance message sent by the core network according to the feed link switching request, sending a path switching request message to the core network.

Another embodiment of the present application further provides a feeder link switching method, where the method is performed by a session management function SMF unit of a core network, and the method includes:

the SMF unit acquires a PDU session update context request sent by a target access and mobile management function (AMF) unit of a switched feeder link; wherein, the PDU conversation updating context request comprises a user plane downlink tunnel address used by a terminal for switching a feed link in a base station;

the SMF unit determines a target user plane management function (UPF) unit of a switched feed link and allocates an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of an N9 interface;

after the target UPF unit establishes a session of the switched feeder link, the SMF unit sends a PDU session update response message to the target AMF unit; and the PDU session update response message comprises an uplink tunnel address used by the terminal in the target UPF unit.

Optionally, in the feeder link switching method, after allocating an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of an N9 interface, the method further includes:

the SMF unit sends a session modification request to an anchor UPF unit; the session modification request comprises a downlink tunnel address of an N9 interface in the target UPF unit;

the SMF unit receives a session modification response message sent by the anchor UPF unit according to the session modification request; the session modification response message comprises an uplink tunnel address allocated to the terminal in the anchor UPF unit;

the target UPF unit sends uplink data to the anchor UPF unit through an uplink tunnel address allocated to the terminal in the anchor UPF unit; and the anchor point UPF unit sends downlink data to the target UPF unit through the downlink tunnel address of the N9 interface in the target UPF unit.

Optionally, in the method for switching a feeder link, after allocating an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of an N9 interface, the method further includes:

sending a session establishment request message to the target UPF unit; the session establishment request message comprises a user plane downlink tunnel address of the terminal at the base station side, an uplink tunnel address used by the terminal in the target UPF unit and an uplink tunnel address used by the terminal in the anchor UPF unit;

and after receiving a session establishment response message sent by the target UPF unit according to the session establishment request message, determining that the target UPF unit establishes the session of the switched feeder link.

Optionally, the feeder link switching method further includes:

after the target UPF unit establishes the session of the switched feeder link, sending a session change request message to a source UPF unit of the switched feeder link; the session change request message comprises a forwarding tunnel address of the target UPF unit;

and the source UPF unit forwards the downlink data before switching to the target UPF unit according to the forwarding tunnel address.

Optionally, the feeder link switching method further includes:

acquiring a PDU session release context request sent by a source AMF unit of a feeder link before switching after acquiring that the link is successfully switched;

according to the PDU conversation release context request, sending a conversation release request corresponding to each terminal to a source UPF unit of a feeder link before switching, wherein the conversation release request is used for releasing resources on the source side before switching;

and acquiring a session release response message sent by the source UPF unit after releasing the resource.

The embodiment of the present application further provides a feeder link switching method, where the method is executed by an access and mobility management function AMF unit of a core network, and the method includes:

the AMF unit sends a PDU session update context request to a Session Management Function (SMF) unit; wherein, the PDU conversation updating context request comprises a user surface downlink tunnel address used by the terminal in the base station;

the AMF unit receives a PDU session update response message sent by the SMF unit;

the PDU session update response message includes an uplink tunnel address used by the terminal in a target UPF unit of the switched feeder link, and is used for the base station to send uplink data of the terminal to the target UPF unit.

Optionally, the feeder link switching method further includes:

acquiring a feed link switching request sent by the base station;

sending a feed link switching acceptance message to the base station according to the feed link switching request; the feeder link switching acceptance message comprises the failure time of the link before switching and the effective time of the link after switching.

Optionally, the feeder link switching method further includes:

receiving a path switching request message sent by the base station after the base station acquires the feeder link switching acceptance message; the path switching request message comprises identity information of a terminal needing to switch a feeder link and a user plane downlink tunnel address of the terminal at a base station side;

wherein, according to the path switching request message, the AMF unit sends the PDU session update context request to the SMF unit.

Optionally, in the feeder-link switching method, after receiving a PDU session update response message sent by the SMF unit, the method further includes:

sending a path switch acceptance message to the base station; the path switching receiving message comprises the identity information of the terminal in a target user plane management function (UPF) unit after link switching and a user plane uplink tunnel address used by the terminal in the target UPF unit.

Optionally, in the feeder-link switching method, before sending the PDU session update context request to the session management function SMF unit, the method further includes:

receiving a request for establishing a terminal context sent by a source AMF unit of a link before switching of the base station; the request for establishing the terminal context comprises a user surface downlink tunnel address of the terminal at a base station side;

the source AMF unit acquires a feed link switching request sent by the base station, sends a feed link switching acceptance message to the base station according to the feed link switching request, and sends the request for establishing the terminal context to the target AMF unit after receiving a path switching request message sent by the base station after acquiring the feed link switching acceptance message; the path switching request message comprises the user plane downlink tunnel address of the terminal needing to switch the feeder link at the base station side and the identity information of the terminal needing to switch the feeder link.

Optionally, in the feeder link switching method, after receiving a PDU session update response message sent by the SMF unit, the method further includes:

sending a response message for establishing a terminal context to a source AMF unit of a link before switching, so that the source AMF unit sends a path switching acceptance message to the base station; the establishing terminal context response message comprises an uplink tunnel address used by the terminal in the target UPF unit, and the path switching receiving message comprises a user plane uplink tunnel address in the target UPF unit of the switched link of the terminal and identity information of the terminal; and the response message for establishing the terminal context comprises the user plane uplink tunnel address used by the terminal in the target UPF unit.

An embodiment of the present application further provides a base station, which includes a memory, a transceiver, and a processor:

a memory for storing a computer program; a transceiver for transceiving data under the control of the processor; a processor for reading the computer program in the memory and performing the following operations:

sending a path switching request message to a core network; the path switching request message comprises identity information of a terminal needing to switch a feeder link and a user plane downlink tunnel address of the terminal at a base station side;

receiving a path switching acceptance message sent by a core network; the path switching receiving message comprises the identity information of the terminal in a target user plane management function (UPF) unit after link switching and a user plane uplink tunnel address used by the terminal in the target UPF unit;

and the base station sends the uplink data of the terminal to the target UPF unit through the user plane uplink tunnel address used by the terminal in the target UPF unit. .

Optionally, in the base station, the path switching request message includes at least one first list information, and each first list information records identity information of a terminal and a user plane downlink tunnel address used by the terminal in the corresponding base station;

Optionally, the base station, wherein the identity information of the terminal includes at least one of:

the terminal uses the identity in the base station;

and the terminal is used for identifying the identity in the core network.

Optionally, in the base station, after receiving the path switch accept message fed back by the core network, the processor is further configured to:

caching uplink data transmitted to the core network by the terminal;

sending the cached uplink data to the target UPF unit according to a user plane uplink tunnel address used by the terminal in the target UPF unit; and/or receiving downlink data which is sent by the target UPF unit and cached in the process of switching the feeder link, and sending the downlink data to the terminal.

Optionally, the base station, wherein the processor is further configured to:

An embodiment of the present application further provides a network device, where the network device is a session management function SMF unit of a core network, and the network device includes a memory, a transceiver, and a processor: a memory for storing a computer program; a transceiver for transceiving data under the control of the processor; a processor for reading the computer program in the memory and performing the following operations:

acquiring a PDU session update context request sent by a target access and mobility management function (AMF) unit of a switched feeder link; wherein, the PDU conversation updating context request comprises a user plane downlink tunnel address used by a terminal for switching a feed link in a base station;

determining a target user plane management function (UPF) unit of a switched feeder link, and allocating an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of an N9 interface;

after the target UPF unit establishes a session of a post-handover feeder link, the SMF unit sends a PDU session update response message to the target AMF unit; and the PDU session update response message comprises an uplink tunnel address used by the terminal in the target UPF unit.

Optionally, in the network device, after allocating the uplink tunnel address of the terminal in the target UPF unit and the downlink tunnel address of the N9 interface, the processor is further configured to:

sending a session modification request to an anchor UPF unit; the session modification request comprises a downlink tunnel address of an N9 interface in the target UPF unit;

receiving a session modification response message sent by the anchor UPF unit according to the session modification request; the session modification response message comprises an uplink tunnel address allocated to the terminal in the anchor UPF unit;

Optionally, the network device, wherein the processor is further configured to:

acquiring a PDU session release context request sent by a source AMF unit of a feeder link before switching after knowing that the link is successfully switched;

according to the PDU conversation release context request, sending a conversation release request corresponding to each terminal to a source UPF unit of a feed link before switching, wherein the conversation release request is used for releasing resources at the source side before switching;

An embodiment of the present application further provides a network device, where the network device is an access and mobility management function AMF unit of a core network, and the network device includes a memory, a transceiver, and a processor:

a memory for storing a computer program; a transceiver for transceiving data under control of the processor; a processor for reading the computer program in the memory and performing the following:

when the AMF unit is a target AMF unit for switching the feed link of the base station, sending a PDU session update context request to a Session Management Function (SMF) unit; wherein, the PDU conversation updating context request includes the user surface downlink tunnel address used by the terminal in the base station;

receiving a PDU session update response message sent by the SMF unit;

wherein, the PDU conversation updating response message includes the uplink tunnel address used by the terminal in the target UPF unit of the switched feeder link; and the base station sends the uplink data of the terminal to the target UPF unit through the user plane uplink tunnel address used by the terminal in the target UPF unit.

Optionally, the network device, wherein the processor is further configured to:

acquiring a feed link switching request sent by the base station;

Optionally, the network device, wherein the processor is further configured to:

Optionally, in the network device, after receiving the PDU session update response message sent by the SMF unit, the processor is further configured to:

Optionally, in the network device, before sending the PDU session update context request to the session management function SMF unit, the processor is further configured to:

receiving a request for establishing a terminal context sent by a source AMF unit of a link before switching of the base station; the request for establishing the terminal context comprises a user plane downlink tunnel address of the terminal at a base station side;

sending a response message for establishing a terminal context to a source AMF unit of a link before switching, so that the source AMF unit sends a path switching acceptance message to the base station; the establishing terminal context response message comprises an uplink tunnel address used by the terminal in the target UPF unit, and the path switching receiving message comprises a user plane uplink tunnel address in the target UPF unit of the switched link of the terminal and identity information of the terminal; and the response message for creating the terminal context comprises the user plane uplink tunnel address used by the terminal in the target UPF unit.

An embodiment of the present application further provides a device for switching a feeder link, where the device is executed by a base station, and the device includes:

a first message sending unit, configured to send a path switching request message to a core network; the path switching request message comprises identity information of a terminal needing to switch a feeder link and a user plane downlink tunnel address of the terminal at a base station side;

a first message receiving unit, configured to receive a path switch acceptance message sent by a core network; the path switching receiving message comprises the identity information of the terminal in a target user plane management function (UPF) unit after link switching and a user plane uplink tunnel address used by the terminal in the target UPF unit;

An embodiment of the present application further provides a feeder link switching apparatus, where the apparatus is executed by a session management function SMF unit of a core network, and the apparatus includes:

the request acquisition unit is used for acquiring a PDU session update context request sent by a target access and mobility management function (AMF) unit of a switched feeder link; the PDU conversation updating context request comprises a user surface downlink tunnel address used by a terminal for switching a feed link in a base station;

a determining unit, configured to determine a target user plane management function (UPF) unit of the switched feeder link, and allocate an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of the N9 interface;

a second message sending unit, configured to send a PDU session update response message to the target AMF unit after the target UPF unit establishes a session of a post-handover feeder link; and the PDU session update response message comprises an uplink tunnel address used by the terminal in the target UPF unit.

An embodiment of the present application further provides a feeder link switching apparatus, where the apparatus is executed by an access and mobility management function AMF unit of a core network, and the apparatus includes:

a request sending unit, configured to send a PDU session update context request to a session management function SMF unit; wherein, the PDU conversation updating context request includes the user surface downlink tunnel address used by the terminal in the base station;

a second message receiving unit, configured to receive a PDU session update response message sent by the SMF unit;

Embodiments of the present application further provide a processor-readable storage medium, where the processor-readable storage medium stores a computer program, and the computer program is configured to cause the processor to execute the steps of the feeder link switching method as described in any one of the above.

At least one of the above technical solutions of the specific embodiment of the present application has the following beneficial effects:

by adopting the feeder link switching method in the embodiment of the application, before the feeder link is interrupted, the user plane downlink tunnel address of the terminal at the base station side is sent to the core network in advance, so that the core network sends the user plane downlink tunnel address of the terminal at the base station side to the target UPF after the link is switched, and the uplink tunnel address of the terminal at the target UPF side can be distributed and informed to the base station before the feeder link is interrupted, and the session of the switched feeder link is established, so that uplink and downlink data can be sent in time after the feeder link is established.

Drawings

Fig. 1 is a schematic structural diagram of an implementation of a system to which the feeder link switching method according to the embodiment of the present application is applied;

fig. 2 is a schematic flowchart of a first implementation manner of a feeder link switching method according to an embodiment of the present application;

fig. 3 is a schematic processing flow diagram of each network node according to the feeder link switching method in the embodiment of the present application;

fig. 4 is a schematic structural diagram of another implementation of a system to which the feeder link switching method according to the embodiment of the present application is applied;

fig. 5 is a flowchart illustrating a second implementation manner of a feeder link switching method according to an embodiment of the present application;

fig. 6 is a schematic flowchart of a third implementation manner of the feeder link switching method according to the embodiment of the present application;

fig. 7 is a schematic structural diagram of a first implementation manner of a network device according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a second implementation manner of a network device according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a third implementation manner of a network device according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a first embodiment of a feeder link switching apparatus according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of a second embodiment of a feeder link switching apparatus according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of a third implementation manner of the feeder link switching apparatus according to the embodiment of the present application.

Detailed Description

In the embodiment of the present application, the term "and/or" describes an association relationship of associated objects, and means that there may be three relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

In the embodiments of the present application, the term "plurality" means two or more, and other terms are similar thereto.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.

The embodiment of the application provides a method and a device for switching a feeder link, which are used for solving the problem that the method for switching the feeder link in the prior art cannot be applied to a satellite communication system adopting a satellite-borne base station.

The method and the device are based on the same application concept, and because the principles of solving the problems of the method and the device are similar, the implementation of the device and the method can be mutually referred, and repeated parts are not repeated.

At present, for the feed link switching in a transparent forwarding mode, a base station is positioned on the ground, the problem of base station change exists in the link switching process, resources are distributed in a target base station, and information is transmitted to a source side and then is notified to UE; after receiving the information, the UE synchronizes with the target base station, initiates a random access process and finally completes the switching. Therefore, due to the change of the base station, information needs to be transferred between the target base station and the source base station for the UE to use when accessing the target base station. Due to uncertain factors such as resource availability, complexity of wireless transmission, wireless interference and the like at the target base station side, a high failure probability exists in the downlink synchronization, random access and the like of the UE and the target base station. For this situation, the core network adopts a corresponding targeted design: and the downlink tunnel at the core network side is established only after the UE is successfully accessed to the target base station, so that the waste of resources is avoided.

However, if the above-mentioned feed link switching in the conventional transparent forwarding mode is applied to the feed link switching in the satellite-borne base station mode, the feed link switching is no longer applicable, because the base station is not changed in the satellite-borne base station mode, and the access problem on the air interface does not exist, that is, the air interface process is continuous and uninterrupted, and there is no failure, so that it is not necessary for the core network side to start establishing the downlink tunnel processing mode on the core network side after the UE successfully accesses the target base station.

To make the technical problems, technical solutions and advantages to be solved by the present application clearer, the following detailed description is made with reference to the accompanying drawings and specific embodiments.

Fig. 1 is a schematic structural diagram of an embodiment of a system to which the feeder link switching method according to the embodiment of the present application is applied.

An application system using the feeder link switching method according to the embodiment of the present application includes a base station and a core network, and optionally, the core network includes an Access and Mobility Management Function (AMF) unit, a User Plane Management Function (UPF) unit, and a Session Management Function (SMF) unit. The base station 10 is connected to one of the AMF unit and the UPF unit at one time, and the AMF unit and the UPF unit are respectively connected to the SMF unit 60; the base station 10 transmits data transmitted between the terminal 20 and the external network to the anchor UPF 30 through the UPF unit currently connected.

In the embodiment of the present application, the base station 10 is a satellite-borne base station, the connection between the terminal and the satellite-borne base station is kept continuous and is not changed, when the feeder link is switched, the link is switched between the base station 10 and the core network, the connection of the connected feeder link is switched from the source AMF (S-AMF) 41 to the destination AMF (T-AMF) 51, and the connection of the connected feeder link is switched from the source UPF (S-UPF) 42 to the destination UPF (T-UPF) 52.

An embodiment of the present application provides a feeder link switching method, where in an implementation manner, the method is performed by a base station, and as shown in fig. 2, the method includes:

s210, sending a path switching request message to a core network; the path switching request message comprises identity information of a terminal needing to switch a feeder link and a user plane downlink tunnel address of the terminal at a base station side;

s220, receiving a path switching receiving message sent by a core network; the path switching receiving message comprises the identity information of the terminal in a target user plane management function (UPF) unit after link switching and a user plane uplink tunnel address used by the terminal in the target UPF unit;

Optionally, the core network sends the path switching acceptance message after the target UPF unit allocates the uplink tunnel address of the terminal and the downlink tunnel address of the N9 interface after the link is switched, and establishes a session of the switched feeder link according to the path switching request message.

By adopting the feeder link switching method in the embodiment of the application, when the feeder link is switched and before the feeder link is interrupted, the user plane downlink tunnel address of the terminal at the base station side is sent to the core network in advance, so that the core network sends the user plane downlink tunnel address of the terminal at the base station side to the target UPF after the link is switched, and can allocate the uplink tunnel address of the terminal at the target UPF side and inform the base station before the feeder link is interrupted, and establish the session of the feeder link after the switch so as to be capable of sending uplink and downlink data in time after the feeder link is established.

In an embodiment of the present application, the method further includes:

Specifically, the base station makes a decision on the feeder link handover, and optionally, may determine whether the feeder link handover is required according to at least one of the current satellite position, the gateway station position, and the ephemeris information; optionally, the operation rule of the satellite may be analyzed according to preconfigured information of operation and management O & M, and when it is determined that the original feeder link cannot provide service for the satellite any more, the feeder link needs to be switched.

A specific implementation process of the feeder link switching method according to the embodiment of the present application is described below with reference to fig. 3.

Referring to fig. 3, in an embodiment, a specific implementation process of the feeder link switching method according to the embodiment of the present application includes:

s301, the base station gNB determines whether the feed link switching is needed according to at least one of the current satellite position, the gateway station position and the ephemeris information; or the base station analyzes the satellite operation rule according to the pre-configuration information of the O & M, and determines that the original feeder link can not provide service for the satellite any more, and then makes a decision for switching the feeder link;

s302, a base station gNB sends a feed link switching request message to an AMF (such as marked as S-AMF) of a source core network; wherein, the feeder link switching request message is used for requesting to switch the link; optionally, the feeder link handover request message includes information of a target gateway station requiring handover and/or includes information of a target AMF (e.g. labeled T-AMF) of a target core network requiring handover; optionally, the feeder link handover request message may further include a handover reason for feeder link handover, which is indicated as that the message is used for feeder link handover, so that the core network performs a corresponding handover processing operation according to the feeder link handover request message;

s303, the S-AMF responds to the received feed link switching request and sends a feed link switching receiving message to the base station gNB; optionally, the feeder link handover accept message includes an expiration time of a current link before handover and an effective time of a link after handover;

s304, after obtaining a feed link switching acceptance message sent by the S-AMF according to the feed link switching request, the base station gNB sends a path switching request message to the core network (namely, the S-AMF);

optionally, the path switching request message includes identity information of a terminal that needs to perform feeder link switching, and a user plane downlink tunnel address of the terminal at the base station side; wherein the content of the first and second substances,

for the identity information of the terminal that needs to perform feeder link handover, optionally, the identity information of the terminal includes an identity identifier used by the terminal in the base station, such as an identity identifier denoted as "RAN UE NGAP ID", for uniquely identifying one UE in the base station; alternatively, the identity information of the terminal includes an identity used by the terminal in the core network, such as an identity used in the AMF, which is denoted as "AMF UE NGAP ID" and is used to uniquely identify a UE in the AMF. The AMF can search the context information of the terminal UE through the identity of the terminal;

for a User plane downlink Tunnel address of the terminal at the base station side, that is, a General Packet Radio Service (GPRS) Tunnel Protocol (GPRS tunneling Protocol for the User plane, GTP-U) downlink Tunnel address of a User plane facing the T-UPF side for the base station gNB (optionally, including an IP address of the gNB and a downlink Tunnel Endpoint Identifier (TEID)), as denoted as N3-DL-TEID, used for the T-UPF to send downlink data to the User plane downlink Tunnel address of the terminal at the base station side. Since the base station gNB does not change during the feeder link handover, the parameter N3-DL-TEID does not have to be changed during the link handover;

in this embodiment of the present application, optionally, a path switching request message sent by a base station gNB to an S-AMF includes at least one first list information, and each first list information records identity information of a terminal and a user plane downlink tunnel address used by the terminal in a corresponding base station; optionally, the different first list information records identity information of different terminals and corresponding user plane downlink tunnel addresses used in the base station. By adopting the embodiment, for a plurality of terminals needing to be switched in the path switching request message, the request message is sent to the S-AMF in a batch sending mode and is used for switching the feeder link; optionally, the path switching request message includes information of a target AMF unit to be switched;

s305, the S-AMF determines whether a target AMF unit (e.g. marked as T-AMF) designated for handover in the path handover request message is the S-AMF itself, and if not, sends a create terminal context request, such as denoted as Namf _ Communication _ createeuecontextrequest, to the handed over T-AMF for requesting the AMF on the handed over target side to create a terminal context. In the embodiment of the application, a request for creating the terminal context sent by an S-AMF to a T-AMF comprises a user surface downlink tunnel address N3-DL-TEID of the terminal at a base station side;

in the embodiment of the application, optionally, for a plurality of pieces of first list information in the path switching request message, the S-AMF processes one by one, determines a T-AMF unit for each terminal UE, and sends a request for creating a terminal context to the corresponding T-AMF;

in addition, optionally, when the S-AMF determines that the T-AMF specified for handover in the path handover request message is the S-AMF itself, the request for creating the terminal context for executing the step is abandoned, and the following step S306 is directly executed;

s306, the T-AMF sends a PDU session update context request to the SMF to request to update the SM context of the PDU session, optionally, the PDU session update context request can be marked as Nsmf _ PDScession _ UpdateSMContextRequest; in the embodiment of the application, the PDU session update context request sent to the SMF includes a user plane downlink tunnel address N3-DL-TEID of the terminal at the base station side;

s307, the SMF unit determines a target UPF unit of a switched feeder link, and allocates an uplink tunnel address (such as marked as N3-UL-TEID) of the UE in the target UPF unit and a downlink tunnel address (such as marked as N9-DL-TEID) of an N9 interface;

s308, the SMF sends a session modification request to the anchor UPF; specifically, the SMF sends the Session Modification Request to the anchor UPF on an N4 interface, and optionally, the Session Modification Request may be marked as an N4Session Modification Request;

wherein, the session modification request includes the downlink tunnel address of the N9 interface.

Alternatively, the Anchor point UPF may also be referred to as a PDU Session Anchor (PSA). Specifically, in a session modification request sent by the SMF to the anchor UPF, a downlink Tunnel address of the N9 interface is downlink Tunnel information DL CN Tunnel Info facing the PSA, so that the PSA sends downlink data to the T-UPF through the downlink Tunnel address of the N9 interface; optionally, the downlink tunnel address of the N9 interface may be identified as N9-DL-TEID, where the downlink tunnel address of the N9 interface includes an IP address of T-UPF and a downlink tunnel endpoint identification TEID, so that the PSA can know a sending address of downlink data;

s309, the anchor UPF (PSA) sends a session modification response message to the SMF; alternatively, the Session Modification Response message may be marked as an N4Session Modification Response message. In addition, the session modification response message includes the uplink tunnel address of the terminal in the anchor point UPF (PSA) unit, so that the T-UPF sends uplink data to the anchor point UPF (PSA) unit through the uplink tunnel address of the terminal in the anchor point UPF (PSA) unit; optionally, the uplink tunnel address of the terminal in the anchor UPF (PSA) unit may be marked as N9-UL-TEID, including the IP address of the anchor UPF (PSA), and the uplink tunnel endpoint identification TEID;

s310, SMF sends a session establishment request message to T-UPF for requesting to establish N4 session; optionally, the Session Establishment Request message may be represented as an N4Session Establishment Request message; optionally, the sent session establishment request message includes: a user interface downlink tunnel address N3-DL-TEID used by the terminal in a base station, an uplink tunnel address N3-UL-TEID used by the terminal in a target UPF unit and an uplink tunnel address N9-UL-TEID used by the terminal in an anchor UPF unit;

s311, the T-UPF successfully establishes the Session and sends a Session Establishment Response message to the SMF, wherein the Session Establishment Response message can be represented as an N4Session Establishment Response message;

s312, when data forwarding is needed, the SMF sends a session change request message to the S-UPF, wherein the session change request message comprises a forwarding tunnel address of a target UPF (T-UPF) so as to inform a forwarding tunnel at the T-UPF side, and the S-UPF forwards downlink data to the T-UPF;

s313, the S-UPF sends a session change response message to the SMF according to the session change request message, and the session change response message is used for confirming the session change; alternatively, the Session Modification Response message may be represented as a Session Modification Response message;

s314, the SMF sends a PDU session update response message (for example, marked as Nsmf _ PDU _ update smcontextresponse) to the T-AMF, where the PDU session update response message includes an uplink tunnel address of the UE in the target UPF unit, that is, includes N3-UL-TEID, and the N3-UL-TEID correspondingly includes (an IP address of the T-UPF, and an uplink tunnel endpoint identification TEID);

s315, the T-AMF sends a response message for establishing the terminal context to the S-AMF; wherein, the terminal context response message includes the uplink tunnel address N3-UL-TEID of the terminal in the target UPF unit;

s316, the S-AMF sends a path switching acceptance message to the base station; wherein, the path switching receiving message includes the identity information of the terminal in a target UPF (T-UPF) unit after link switching and the user plane uplink tunnel address used by the terminal in a target user plane management function UPF; wherein, the first and the second end of the pipe are connected with each other,

the identity information of the terminal comprises an identity identifier used by the terminal in the base station, such as an identifier expressed as 'RAN UE NGAP ID', and is used for uniquely identifying one UE in the base station; alternatively, the identity information of the terminal includes an identity used by the terminal in the core network, such as an identity used in the AMF, which is denoted as "AMF UE NGAP ID" and is used to uniquely identify a UE in the AMF. The base station can search the context information of the corresponding terminal UE through the identity information of the terminal;

the user plane uplink tunnel address used by the terminal in the target user plane management function UPF, that is, the GTP-U uplink tunnel address on the T-UPF side (including the IP address of the T-UPF and the tunnel endpoint identification parameter TEID), may be represented as N3-UL-TEID, and is used for the base station to send uplink data to the N3-UL-TEID.

In this embodiment of the present application, optionally, the path switching acceptance message includes at least one second list information, and each second list information records identity information of one terminal and a user plane uplink tunnel address of the terminal in a corresponding target UPF unit.

And the terminal in each second list information in the path switching receiving message is a terminal for performing link switching. Optionally, the different second list information records identity information of different terminals and user plane uplink tunnel addresses corresponding to the different terminals in the target UPF unit.

By adopting the embodiment, the batch path conversion acceptance form is adopted to send the plurality of terminals needing to be switched in the path switching acceptance message to the terminals, and the message comprises all the terminals needing to be subjected to link switching in a list form.

By adopting the above steps S301 to S316, the uplink data transmission channel and the downlink data transmission channel between the terminal, the base station and the core network are completely through.

Further, after the uplink data transmission channel is communicated with the downlink data transmission channel, the method further comprises the following steps:

s317, after the switched feed link takes effect, in the downlink direction, the T-UPF preferentially transmits the downlink forwarding data cached from the S-UPF to the base station gNB, then the base station gNB transmits the downlink data to the UE, and after the cached downlink data is transmitted, the downlink data from the external network is transmitted; in the uplink transmission direction, the base station gNB first sends the buffered uplink data to the T-UPF, and then sends the uplink data sent by the UE to the T-UPF, and the T-UPF then sends the data to the external network. Then the T-AMF sends a session notification message (such as a Namf _ Communication _ N2Info Notify message) to the S-AMF, and notifies that the handover process of the UE is successful;

according to the above, in the embodiment of the present invention, optionally, after the base station receives the path switch accept message fed back by the core network, the method further includes:

the base station caches the received uplink data transmitted by the terminal;

sending the cached uplink data to the target UPF unit according to the user plane uplink tunnel address used by the terminal in the target UPF unit; and/or receiving downlink data which is sent by the target UPF unit and cached in the process of switching the feeder link, and sending the downlink data to the terminal;

s318, aiming at each UE in Communication, the S-AMF sends a notification acknowledgement message (such as a Namf _ Communication _ N2Info notification Ack message) to the T-AMF, and the notification acknowledgement message is used for responding to the session notification message sent by the T-AMF;

s319, the S-AMF sends a PDU session release context request (such as represented as an Nsmf _ PDSUSession _ ReleaseSchontextRequest message) to the SMF, and the PDU session release context request is used for releasing resources corresponding to the UE on the source core network side;

s320, aiming at each UE, the SMF sends a Session Release Request (such as an N4Session Release Request message) to the S-UPF, and the Session Release Request is used for releasing resources at the link source side;

s321, the S-UPF sends a Session Release Response message to the SMF, where the Session Release Response message may be represented as an N4Session Release Response message.

In this embodiment, different gateway stations use different core networks, and the AMF may be changed, i.e. the S-AMF and the T-AMF in the above-mentioned flow chart are located at different positions. At this time, the communication context of the terminal UE is not stored in the T-AMF, and thus needs to be reestablished. In addition, although the feeder link switching occurs, since the satellite-borne base station does not change, the downlink tunnel address on the base station side does not change (although the gNB can perform address allocation again in principle, it does not make sense).

By adopting the embodiment, the T-AMF informs the SMF of the user plane downlink tunnel address (N3-DL-TEID) of the terminal at the base station side, and the SMF informs the T-UPF of the user plane downlink tunnel address (N3-DL-TEID), so that the T-UPF knows which tunnel of the satellite-borne gNB downlink data is sent to. The SMF also allocates an uplink tunnel address (N3-UL-TEID) facing the gNB on the T-UPF side, informs the AMF of the uplink tunnel address (N3-UL-TEID) in a corresponding message, and informs the AMF of the uplink tunnel information (N3-UL-TEID) to the satellite-borne gNB, so that the base station knows which tunnel of the T-UPF the uplink data are to be sent to after the new feeding is effective. SMF will also assign downstream tunnel address (N9-DL-TEID) of T-UPF facing UPF (PSA), PSA will send downstream data to T-UPF through the downstream tunnel address (N9-DL-TEID); the T-UPF is also informed of the upstream tunnel address (N9-UL-TEID) facing the UPF (PSA) through which the T-UPF sends upstream data to the PSA.

In the feeder link switching method in the embodiment of the application, the implementation process is adopted to realize the switching of the feeder link adopting the satellite-borne base station, before the feeder link is interrupted, a downlink tunnel address (namely, N3-DL-TEID) distributed by the base station side is informed to the core network in advance, and the core network informs the T-UPF of the information so as to send downlink data in time after the new feeder is established; before a feed link is interrupted, an uplink tunnel on a core network T-UPF side is well distributed, related network elements are informed, and uplink data are sent in time after new feed is established; in addition, in the feeder link switching method according to the embodiment of the present application, downlink tunnel information of all communicating UEs is notified to a core network in a form of a list, thereby avoiding complex operation and time delay caused by single notification.

In another embodiment of the feeder link switching method according to the embodiment of the present application, optionally, different gateway stations may use the same core network according to different network deployments, and in this implementation, the AMF may not be changed, that is, in the foregoing embodiment, the S-AMF and the T-AMF belong to the same device, and all communication contexts of the UE are stored in the AMF, and do not need to be re-established. Therefore, although the link switching occurs, since the satellite-borne base station does not change, the downlink tunnel address at the base station side does not change, and with reference to fig. 3 and 4, with this embodiment, the specific implementation process of the feeder link switching method according to the embodiment of the present application includes:

AMF (S-AMF and T-AMF are same AMF) informs SMF of the user surface downlink tunnel address (N3-DL-TEID) of the terminal at the base station side, and SMF informs T-UPF of the address information, so that the T-UPF knows which tunnel of the base station the downlink data is sent to. The SMF also allocates an uplink tunnel address (N3-UL-TEID) facing the gNB on the T-UPF side, and informs the AMF in a corresponding message, and the AMF sends the address information to the base station, so that the base station knows to which tunnel of the T-UPF the uplink data is sent after the new feeder link becomes effective. The SMF also assigns a downstream tunnel address (N9-DL-TEID) of the T-UPF to the UPF (PSA), and the PSA sends downstream data to the T-UPF through the downstream tunnel information (N9-DL-TEID); the T-UPF is also informed of the upstream tunnel address (N9-UL-TEID) facing the UPF (PSA) through which the T-UPF sends upstream data to the PSA.

Therefore, with this embodiment, in conjunction with fig. 3, when the S-AMF and the T-AMF belong to different devices, compared to the case that the S-AMF and the T-AMF belong to the same AMF device, the step of sending the request for creating the terminal context to the T-AMF in step S305 is not required to be performed, and in other steps, the S-AMF and the T-AMF indicate the same AMF, and the specific implementation process is not described in detail here.

Another aspect of the embodiments of the present application further provides a feeder link switching method, which is executed by a session management function SMF unit of a core network, as shown in fig. 5, where the method includes:

s510, the SMF unit obtains a PDU session update context request sent by a target access and mobile management function (AMF) unit of a switched feeder link; wherein, the PDU conversation updating context request comprises a user plane downlink tunnel address used by a terminal for switching a feed link in a base station;

s520, the SMF unit determines a target user plane management function (UPF) unit of the switched feeder link, and allocates an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of an N9 interface;

s530, after the target UPF unit establishes the session of the switched feeder link, the SMF unit sends a PDU session update response message to the target AMF unit; and the PDU session update response message comprises an uplink tunnel address used by the terminal in the target UPF unit.

By adopting the feeder link switching method in the embodiment of the application, when the feeder link is switched, the base station sends the user plane downlink tunnel address of the terminal at the base station side to the target AMF unit in advance, and the target AMF unit sends a PDU session update context request to the SMF unit, wherein the PDU session update context request comprises the user plane downlink tunnel address of the terminal at the base station side; therefore, before the feeder link is interrupted, the SMF unit sends the user plane downlink tunnel address of the terminal at the base station side to the target UPF after link switching, and can distribute the uplink tunnel address of the terminal at the target UPF side and inform the base station before the feeder link is interrupted, and establish the session of the feeder link after switching, so as to send uplink and downlink data in time after the feeder link is established.

In this embodiment of the application, optionally, as shown in fig. 3, in step S510, the SMF unit obtains a PDU session update context request sent by a target access and mobility management function AMF unit, which may correspond to step S306 in fig. 3; in step S520, the SMF unit determines a target UPF unit of the switched feeder link, and allocates an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of the N9 interface, which may correspond to step S307 in fig. 3; in step S530, the SMF unit sends a PDU session update response message to the target AMF unit, which may correspond to step S314 in fig. 3. The specific implementation process can be referred to the description in fig. 3 above, and will not be described in detail here.

In this embodiment of the present application, optionally, in step S520, after allocating the uplink tunnel address of the terminal in the target UPF unit and the downlink tunnel address of the N9 interface, the method further includes:

Specifically, the implementation steps in which the SMF unit sends a session modification request to the anchor UPF unit, and the SMF unit receives a session modification response message sent by the anchor UPF unit according to the session modification request may correspond to steps S308 and S309 in the embodiment of fig. 3.

Optionally, in this embodiment of the present application, in step S520, after the uplink tunnel address of the terminal in the target UPF unit and the downlink tunnel address of the N9 interface are allocated, the method further includes:

Specifically, in the foregoing implementation steps, the steps of sending, by the SMF, the session establishment request message to the target UPF unit, and receiving, by the target UPF unit, the session establishment response message sent according to the session establishment request message may correspond to steps S310 and S311 in the implementation manner of fig. 3.

Optionally, the feeder link switching method, in an embodiment, the method further includes:

Specifically, in the foregoing implementation steps, the step of sending, by the SMF unit, the session change request message to the source UPF unit of the feeder link before switching may correspond to step S312 in the implementation of fig. 3.

and acquiring a session release response message sent by the source UPF unit after releasing the resources.

Specifically, in the foregoing implementation steps, the step of acquiring, by the SMF unit, the PDU session release context request sent by the source AMF unit of the feeder link before switching, the step of sending, by the SMF unit, the session release request corresponding to each terminal to the source UPF unit of the feeder link before switching, and the step of acquiring the session release response message sent after the source UPF unit releases the resource may correspond to step S319 to step S321 in the embodiment of fig. 3, and details are not described here.

An embodiment of the present application further provides a feeder link switching method implemented by an access and mobility management function AMF unit of a core network, as shown in fig. 6, where the method includes:

s610, sending a PDU session update context request to a Session Management Function (SMF) unit; wherein, the PDU conversation updating context request includes the user surface downlink tunnel address used by the terminal in the base station;

s620, the AMF unit receives a PDU session update response message sent by the SMF unit;

Optionally, the SMF unit determines a target UPF unit of the switched feeder link, allocates an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of the N9 interface, and sends the PDU session update response message to the target AMF unit after the target UPF unit establishes a session of the switched feeder link; and the PDU session update response message comprises an uplink tunnel address used by the terminal in the target UPF unit.

When the feed link switching method is adopted to carry out feed link switching, a target AMF unit sends a PDU session update context request to an SMF unit, wherein the PDU session update context request comprises a user surface downlink tunnel address of a terminal at a base station side; therefore, before the feed link is interrupted, the SMF unit sends the user plane downlink tunnel address of the terminal at the base station side to the target UPF after link switching, and can allocate the uplink tunnel address of the terminal at the target UPF side and inform the base station before the feed link is interrupted, and establish the session of the feed link after switching, so that uplink and downlink data can be sent in time after the feed link is established.

In an embodiment of the present application, optionally, the method further includes:

acquiring a feed link switching request sent by the base station;

In this embodiment, the source AMF unit and the target AMF unit may be the same device, and with this embodiment, the implementation process of using the AMF unit as the source AMF unit, acquiring the feeder link handover request sent by the base station, and sending the feeder link handover accept message to the base station may correspond to step S302 and step S303 in the embodiment of fig. 3, and will not be described in detail herein.

In an embodiment, optionally, the method further includes:

receiving a path switching request message sent by the base station after the base station acquires the feed link switching acceptance message; the path switching request message comprises identity information of a terminal needing to switch a feeder link and a user plane downlink tunnel address of the terminal at a base station side;

In this embodiment, the receiving of the path switching request message sent by the base station may correspond to step S304 in the embodiment of fig. 3, and will not be described in detail here.

Optionally, in the feeder link switching method, in an embodiment, after receiving a PDU session update response message sent by the SMF unit, the method further includes:

sending a path switch acceptance message to the base station; the path switching receiving message comprises the identity information of the terminal in the target UPF unit after the link switching and the user plane uplink tunnel address used by the terminal in the target UPF unit.

Optionally, in this embodiment, the sending of the path switch acceptance message to the base station may correspond to step S316 in the embodiment of fig. 3, and will not be described in detail here.

In an embodiment of this application, before sending a session update context request of a protocol data unit PDU to a session management function SMF unit, the method further includes:

In this embodiment, the AMF unit only serves as a target AMF unit for feeder link handover, and also receives a request for creating a terminal context sent by the source AMF unit, and the specific implementation process may refer to steps S302 to S305 in the embodiment of fig. 3, which will not be described in detail here.

In this embodiment of this application, in another embodiment, optionally, after receiving the PDU session update response message sent by the SMF unit, the method further includes:

sending a response message for establishing a terminal context to a source AMF unit of a link before switching, so that the source AMF unit sends a path switching acceptance message to the base station; the context response message of the terminal is established and comprises an uplink tunnel address used by the terminal in the target UPF unit, and the path switching receiving message comprises a user plane uplink tunnel address in a target user plane management function (UPF) unit of a link after the terminal is switched and identity information of the terminal; and the response message for creating the terminal context comprises the user plane uplink tunnel address used by the terminal in the target UPF unit.

Specifically, the implementation process may refer to step S315 shown in fig. 3, and will not be described in detail here.

In another aspect, an embodiment of the present invention further provides a base station, as shown in fig. 7, including a memory 720, a transceiver 700, and a processor 710:

a memory 720 for storing a computer program; a transceiver 700 for transceiving data under the control of the processor 710; a processor 710 for reading the computer program in the memory 720 and performing the following operations:

the path switching receiving message comprises at least one second list information, and the identity information of a terminal and the user plane uplink tunnel address used by the terminal in the corresponding target UPF unit are recorded in each second list information.

the terminal uses the identity in the base station;

and the terminal uses the identity in the core network.

Optionally, the base station, wherein the processor 710 is further configured to:

caching uplink data transmitted to the core network by the terminal in the process of switching the feed link; and

after receiving the path switch accept message sent by the core network, the processor 710 is further configured to:

sending the cached uplink data to the target UPF unit according to a user plane uplink tunnel address used by the terminal in the target UPF unit; and/or

And receiving downlink data which is sent by the target UPF unit and cached in the process of switching the feeder link, and sending the downlink data to the terminal.

Wherein in fig. 7, the bus architecture may include any number of interconnected buses and bridges, with one or more processors, represented by processor 710, and various circuits, represented by memory 720, being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 700 may be a number of elements including a transmitter and a receiver that provide a means for communicating with various other apparatus over a transmission medium including wireless channels, wired channels, fiber optic cables, and the like. The processor 710 is responsible for managing the bus architecture and general processing, and the memory 720 may store data used by the processor 710 in performing operations.

The processor 710 may be a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or a Complex Programmable Logic Device (CPLD), and may also have a multi-core architecture.

Another embodiment of the present application further provides a network device, where the network device is a session management function SMF unit of a core network, and the network device includes the memory 820, the transceiver 800, and the processor 810: a memory 820 for storing a computer program; a transceiver 800 for transceiving data under the control of the processor; a processor 810 for reading the computer program in the memory and performing the following operations:

determining a target UPF unit of a switched feeder link, and allocating an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of an N9 interface;

Optionally, in the network device, after allocating the uplink tunnel address of the terminal in the target UPF unit and the downlink tunnel address of the N9 interface, the processor 810 is further configured to:

Optionally, in the network device, the processor 810 is further configured to:

Where in fig. 8, the bus architecture may include any number of interconnected buses and bridges, with one or more processors, represented by processor 810, and various circuits, represented by memory 820, being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 800 may be a number of elements including a transmitter and a receiver that provide a means for communicating with various other apparatus over a transmission medium including wireless channels, wired channels, fiber optic cables, and the like. The processor 810 is responsible for managing the bus architecture and general processing, and the memory 820 may store data used by the processor 810 in performing operations.

The processor 810 may be a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or a Complex Programmable Logic Device (CPLD), and may also have a multi-core architecture.

An embodiment of the present application further provides a network device, where the network device is an access and mobility management function AMF unit of a core network, as shown in fig. 9, and the network device includes a memory 920, a transceiver 900, and a processor 910:

a memory 920 for storing a computer program; a transceiver 900 for transceiving data under the control of the processor; a processor 910 for reading the computer program in the memory and performing the following operations:

sending a PDU session update context request to a Session Management Function (SMF) unit; wherein, the PDU conversation updating context request comprises a user surface downlink tunnel address used by the terminal in the base station;

receiving a PDU session update response message sent by the SMF unit;

Optionally, the SMF unit determines a target user plane management function UPF unit of the switched feeder link, allocates an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of the N9 interface, and sends the PDU session update response message to the target AMF unit after the target UPF unit establishes a session of the switched feeder link; and the PDU session update response message comprises an uplink tunnel address used by the terminal in the target UPF unit.

Optionally, in the network device, the processor 910 is further configured to:

acquiring a feed link switching request sent by the base station;

Optionally, the network device, wherein the processor 910 is further configured to:

Optionally, in the network device, after receiving the PDU session update response message sent by the SMF unit, the processor 910 is further configured to:

sending a path switch acceptance message to the base station; the path switching receiving message comprises the identity information of the terminal in a target user plane management function UPF unit after link switching and a user plane uplink tunnel address used by the terminal in the target user plane management function UPF.

Optionally, in the network device, before sending a session update context request of a protocol data unit PDU to a session management function SMF unit, the processor 910 is further configured to:

Wherein in fig. 9, the bus architecture may include any number of interconnected buses and bridges, with one or more processors, represented by processor 910, and various circuits, represented by memory 920, being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 900 may be a number of elements including a transmitter and a receiver that provide a means for communicating with various other apparatus over a transmission medium including wireless channels, wired channels, fiber optic cables, and the like. The processor 910 is responsible for managing the bus architecture and general processing, and the memory 920 may store data used by the processor 910 in performing operations.

Another embodiment of the present application further provides a feeder link switching apparatus, implemented by a base station, as shown in fig. 10, the apparatus including:

a first message sending unit 1010, configured to send a path switching request message to a core network when performing feeder link switching; the path switching request message comprises identity information of a terminal needing to switch a feeder link and a user plane downlink tunnel address of the terminal at a base station side;

a first message receiving unit 1020, configured to receive a path switch accept message sent by a core network; the path switching receiving message comprises the identity information of the terminal in a target user plane management function (UPF) unit after link switching and a user plane uplink tunnel address used by the terminal in the target UPF unit;

Optionally, the feeder link switching apparatus, wherein the path switching request message includes at least one first list information, and each first list information records identity information of a terminal and a user plane downlink tunnel address used by the terminal in the corresponding base station;

Optionally, the feeder link switching apparatus, wherein the identity information of the terminal includes at least one of:

the terminal uses the identity in the base station;

and the terminal uses the identity in the core network.

Optionally, the feeder link switching apparatus, wherein the apparatus further includes:

the buffer unit is used for buffering uplink data transmitted to the core network by the terminal in the process of switching the feed link; and

the apparatus further includes a data transmission unit, where after the first message receiving unit 1020 receives the path switch accept message sent by the core network, the data transmission unit is configured to:

sending the cached uplink data to the target UPF unit according to the user plane uplink tunnel address used by the terminal in the target UPF unit; and/or

a switching judgment unit for determining whether the feeder link switching is required according to at least one of the current satellite position, the gateway station position and the ephemeris information;

An embodiment of the present application further provides a feeder link switching apparatus, which is executed by a session management function SMF unit of a core network, and as shown in fig. 11, the apparatus includes:

a request obtaining unit 1110, configured to obtain a PDU session update context request sent by a target access and mobility management function AMF unit of a switched feeder link; wherein, the PDU conversation updating context request comprises a user plane downlink tunnel address used by a terminal for switching a feed link in a base station;

a determining unit 1120, configured to determine a target user plane management function UPF unit of the switched feeder link, and allocate an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of the N9 interface;

a second message sending unit 1130, configured to send a PDU session update response message to the target AMF unit after the target UPF unit establishes a session of the post-handover feeder link; and the PDU session update response message comprises an uplink tunnel address used by the terminal in the target UPF unit.

Optionally, in the feeder-link switching apparatus, after the determining unit 1120 allocates the uplink tunnel address of the terminal in the target UPF unit and the downlink tunnel address of the N9 interface, the second message sending unit 1130 is further configured to:

the request obtaining unit 1110 is further configured to receive a session modification response message sent by the anchor UPF unit according to the session modification request; the session modification response message comprises an uplink tunnel address allocated to the terminal in the anchor UPF unit;

Optionally, in the feeder link switching apparatus, after allocating the uplink tunnel address of the terminal in the target UPF unit and the downlink tunnel address of the N9 interface, the second message sending unit 1130 is further configured to:

Optionally, in the feeder link switching apparatus, the second message sending unit 1130 is further configured to:

Optionally, the feeder link switching apparatus, wherein:

the request obtaining unit 1110 is further configured to obtain a PDU session release context request sent by the source AMF unit of the feeder link before the handover after knowing that the link handover is successful;

the second message sending unit 1130 is further configured to send, according to the PDU session release context request, a session release request corresponding to each terminal to a source UPF unit of a feeder link before handover, where the session release request is used to release resources on a source side of the handover;

the request obtaining unit 1110 is further configured to obtain a session release response message sent by the source UPF unit after releasing the resource.

An embodiment of the present application further provides a feeder link switching apparatus, where the apparatus is executed by an access and mobility management function AMF unit of a core network, and as shown in fig. 12, the apparatus includes:

a request sending unit 1210, where the request sending unit 1210 is configured to send a PDU session update context request to a session management function SMF unit; wherein, the PDU conversation updating context request includes the user surface downlink tunnel address used by the terminal in the base station;

a second message receiving unit 1220, configured to receive a PDU session update response message sent by the SMF unit;

Optionally, the feeder link switching apparatus, wherein:

the second message receiving unit 1220 is further configured to obtain a feeder link switching request sent by the base station;

the request sending unit 1210 is further configured to send a feeder link handover accept message to the base station according to the feeder link handover request; the feeder link switching acceptance message comprises the failure time of the link before switching and the effective time of the link after switching.

Optionally, in the feeder-link switching apparatus, the second message receiving unit 1220 is further configured to:

Optionally, in the feeder-link switching apparatus, after the second message receiving unit 1220 receives the PDU session update response message sent by the SMF unit, the request sending unit 1210 is further configured to:

sending a path switch acceptance message to the base station; the path switching receiving message comprises the identity information of the terminal in a target user plane management function (UPF) unit after link switching and a user plane uplink tunnel address used by the terminal in the target user plane management function (UPF).

Optionally, in the feeder-link switching apparatus, before the request sending unit 1210 sends the PDU session update context request to the SMF unit, the second message receiving unit 1220 is further configured to:

sending a response message for creating a terminal context to a source AMF unit of a link before switching, so that the source AMF unit sends a path switching acceptance message to the base station; the establishing terminal context response message comprises an uplink tunnel address used by the terminal in the target UPF unit, and the path switching receiving message comprises a user plane uplink tunnel address in the target UPF unit of the switched link of the terminal and identity information of the terminal; and the response message for establishing the terminal context comprises the user plane uplink tunnel address used by the terminal in the target UPF unit.

It should be noted that the apparatus provided in the embodiment of the present application can implement all the method steps implemented by the method embodiment and achieve the same technical effects, and detailed descriptions of the same parts and beneficial effects as the method embodiment in this embodiment are omitted here.

It should be noted that the division of the unit in the embodiment of the present application is schematic, and is only a logic function division, and there may be another division manner in actual implementation. In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit may be implemented in the form of hardware, or may also be implemented in the form of a software functional unit.

The integrated unit, if implemented as a software functional unit and sold or used as a stand-alone product, may be stored in a processor readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, a network device, or the like) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

It should be noted that the processor-readable storage medium can be any available medium or data storage device that can be accessed by the processor, including but not limited to magnetic memory (e.g., floppy disk, hard disk, magnetic tape, magneto-optical disk (MO), etc.), optical memory (e.g., CD, DVD, BD, HVD, etc.), and semiconductor memory (e.g., ROM, EPROM, EEPROM, non-volatile memory (NAND FLASH), solid State Disk (SSD)), etc.

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

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

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

These processor-executable instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

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

Claims

1. A feeder link switching method, performed by a base station, the method comprising:

a base station sends a path switching request message to a core network; the path switching request message comprises identity information of a terminal needing to switch a feeder link and a user plane downlink tunnel address of the terminal at a base station side;

the base station receives a path switching acceptance message sent by a core network; the path switching receiving message comprises the identity information of the terminal in a target user plane management function (UPF) unit after link switching and a user plane uplink tunnel address used by the terminal in the target UPF unit; and the base station sends the uplink data of the terminal to the target UPF unit through the user plane uplink tunnel address used by the terminal in the target UPF unit.

2. The method according to claim 1, wherein the path switching request message includes at least one first list information, and each first list information records an identity information of a terminal and a user plane downlink tunnel address used by the terminal in the corresponding base station;

3. The feeder-link switching method according to claim 1, wherein the identity information of the terminal includes at least one of:

the terminal uses the identity in the base station;

and the terminal uses the identity in the core network.

4. The feeder link switching method according to claim 1, wherein after the base station receives the path switch acceptance message fed back by the core network, the method further comprises:

the base station caches the received uplink data transmitted by the terminal;

5. The feeder-link switching method of claim 1, further comprising:

6. A feeder-link switching method, performed by a session management function, SMF, unit of a core network, the method comprising:

the SMF unit determines a target user plane management function (UPF) unit of a switched feeder link and allocates an uplink tunnel address of the terminal in the target UPF unit and a downlink tunnel address of an N9 interface;

7. The feeder-link switching method according to claim 6, wherein after assigning the uplink tunnel address of the terminal in the target UPF unit and the downlink tunnel address of the N9 interface, the method further comprises:

8. The feeder-link switching method according to claim 7, wherein after assigning the uplink tunnel address of the terminal in the target UPF unit and the downlink tunnel address of the N9 interface, the method further comprises:

9. The feeder-link switching method of claim 6, further comprising:

10. The feeder-link switching method of claim 6, further comprising:

11. A feeder link handover method, performed by an access and mobility management function, AMF, unit of a core network, the method comprising:

the AMF unit sends a PDU session update context request to a Session Management Function (SMF) unit; wherein, the PDU conversation updating context request includes the user surface downlink tunnel address used by the terminal in the base station;

12. The feeder-link switching method of claim 11, further comprising:

acquiring a feed link switching request sent by the base station;

13. The feeder-link switching method of claim 12, further comprising:

14. The feeder-link switching method of claim 13, wherein after receiving the PDU session update response message sent by the SMF unit, the method further comprises:

15. The feeder-link switching method of claim 11, wherein prior to sending the PDU session update context request to the session management function, SMF, unit, the method further comprises:

16. The feeder-link switching method of claim 15, wherein after receiving the PDU session update response message sent by the SMF unit, the method further comprises:

17. A base station, comprising a memory, a transceiver, and a processor:

18. The base station of claim 17, wherein the path switching request message includes at least one first list information, and each first list information records identity information of a terminal and a user plane downlink tunnel address used by the terminal in the corresponding base station;

19. The base station of claim 17, wherein the identity information of the terminal comprises at least one of:

the terminal uses the identity in the base station;

and the terminal uses the identity in the core network.

20. The base station of claim 17, wherein after receiving the path switch accept message fed back by the core network, the processor is further configured to:

caching uplink data transmitted to the core network by the terminal;

21. The base station of claim 17, wherein the processor is further configured to:

22. A network device, wherein the network device is a Session Management Function (SMF) unit of a core network, and the network device comprises a memory, a transceiver, and a processor: a memory for storing a computer program; a transceiver for transceiving data under control of the processor; a processor for reading the computer program in the memory and performing the following operations:

23. The network device of claim 22, wherein after assigning the uplink tunnel address of the terminal in the target UPF unit and the downlink tunnel address of the N9 interface, the processor is further configured to:

24. The network device of claim 23, wherein after assigning the uplink tunnel address of the terminal in the target UPF unit and the downlink tunnel address of the N9 interface, the processor is further configured to:

and after receiving a session establishment response message fed back by the target UPF unit according to the session establishment request message, determining that the target UPF unit establishes the session of the switched feeder link.

25. The network device of claim 22, wherein the processor is further configured to:

26. The network device of claim 22, wherein the processor is further configured to:

27. A network device, wherein the network device is an access and mobility management function, AMF, unit of a core network, and the network device comprises a memory, a transceiver, and a processor:

sending a PDU session update context request to a Session Management Function (SMF) unit; wherein, the PDU conversation updating context request includes the user surface downlink tunnel address used by the terminal in the base station;

receiving a PDU session update response message sent by the SMF unit;

wherein the PDU session update response message includes an uplink tunnel address used by the terminal in a target UPF unit of the feeder link after switching,

and the base station is used for sending the uplink data of the terminal to the target UPF unit.

28. The network device of claim 27, wherein the processor is further configured to:

acquiring a feed link switching request sent by the base station;

29. The network device of claim 28, wherein the processor is further configured to:

30. The network device of claim 29, wherein after receiving the PDU session update response message sent by the SMF unit, the processor is further configured to:

31. The network device of claim 27, wherein prior to sending the PDU session update context request to the session management function, SMF, unit, the processor is further configured to:

32. The network device of claim 31, wherein after receiving the PDU session update response message sent by the SMF unit, the processor is further configured to:

sending a response message for establishing a terminal context to a source AMF unit of a link before switching, so that the source AMF unit sends a path switching acceptance message to the base station; the response message for establishing the terminal context comprises an uplink tunnel address used by the terminal in the target UPF unit, and the receiving message for switching the path comprises a user plane uplink tunnel address in the target UPF unit of the link after the terminal is switched and the identity information of the terminal; and the response message for creating the terminal context comprises the user plane uplink tunnel address used by the terminal in the target UPF unit.

33. A feeder link switching apparatus, performed by a base station, the apparatus comprising:

34. A feeder-link switching apparatus, performed by a session management function, SMF, unit of a core network, the apparatus comprising:

the request acquisition unit is used for acquiring a PDU session update context request sent by a target access and mobility management function (AMF) unit of a switched feeder link; wherein, the PDU conversation updating context request comprises a user plane downlink tunnel address used by a terminal for switching a feed link in a base station;

35. A feeder link switching apparatus, performed by an access and mobility management function, AMF, unit of a core network, the apparatus comprising:

a request sending unit, configured to send a PDU session update context request to a session management function SMF unit; wherein, the PDU conversation updating context request comprises a user surface downlink tunnel address used by the terminal in the base station;

36. A processor-readable storage medium, characterized in that the processor-readable storage medium stores a computer program for causing the processor to perform the steps of the feeder-link switching method of any one of claims 1 to 5; or computer program for causing a processor to perform the steps of the feeder link switching method of any one of claims 6 to 10; or computer program for causing a processor to perform the steps of the feeder link switching method of any one of claims 11 to 16.