CN115250511A

CN115250511A - Communication method and communication device

Info

Publication number: CN115250511A
Application number: CN202110454023.XA
Authority: CN
Inventors: 马川; 韩锋; 晋英豪; 郑黎丽
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-04-26
Filing date: 2021-04-26
Publication date: 2022-10-28
Also published as: WO2022227965A1

Abstract

The application provides a communication method and a communication device, wherein the method comprises the following steps: the terminal equipment receives first indication information, wherein the first indication information is used for indicating the network type of a switching target network, or the first indication information is used for indicating a network access mode corresponding to the network type. And the terminal equipment sets a network access mode of the terminal equipment according to the first indication information. In the application, the terminal equipment sets the network access mode according to the received first indication information, so that the problem of unmatched access modes after the terminal equipment is switched to a target network can be avoided, and the reliability and the stability of communication are improved.

Description

Communication method and communication device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication method and a communication apparatus.

Background

At present, network co-establishment and sharing become a development trend of a fifth generation mobile communication technology (5G). In order to quickly implement 5G network coverage so as to provide 5G services, different operators adopt a cooperation mode of access network multi-operator core network (MOCN) sharing, that is, each operator independently constructs a respective core network, 5G base station and frequency resource sharing. For example, china unicom and china telecom are constructed to share a 5G network, that is, a base station supports both a china unicom network and a china telecom network. Generally, a sharing mode in which one Access Network device is shared by multiple networks (or one Access Network device supports multiple networks) may be referred to as Access Network (RAN) sharing. In a handover scenario, when a target cell is a RAN shared cell, since system information of the target cell received by a terminal device includes identifiers of multiple networks, and the terminal device does not know which Network of the multiple networks is the target Network, it cannot be determined whether the target Network is a Public Land Mobile Network (PLMN) or an independent non-Public Network (SNPN), so that if types of networks where the terminal device is located before and after handover are different, normal communication of the terminal device after handover is affected.

Disclosure of Invention

The application provides a communication method and a communication device, which improve the reliability and stability of communication.

In a first aspect, the present application provides a communication method, including: the method comprises the steps that terminal equipment receives first indication information, wherein the first indication information is used for indicating a network type of a switching target network, or the first indication information is used for indicating a network access mode corresponding to the network type; and the terminal equipment sets the network access mode of the terminal equipment according to the first indication information.

In the application, the terminal equipment receives the first indication information and sets the network access mode according to the received first indication information, so that the problem that the access mode is not matched after the terminal equipment is switched to the target network can be avoided, and the reliability and the stability of communication are improved.

In one possible implementation, the receiving, by the terminal device, the first indication information includes:

and the terminal equipment receives the first indication information from the target access network equipment.

In the application, the terminal device may receive the first indication information from the target access network device, so as to adjust/set the network access mode according to the indication of the first indication information, which is beneficial to improving reliability and stability of communication.

In one possible implementation, the receiving, by the terminal device, the first indication information from a target access network device includes:

the terminal device receives a Radio Resource Control (RRC) reconfiguration message from the target access network device, wherein the RRC reconfiguration message comprises the first indication information.

In the application, the first indication information is carried through the RRC reconfiguration message, so that the signaling overhead can be saved.

and the terminal equipment receives the first indication information from the source access network equipment.

In the application, the terminal device may receive the first indication information from the source access network device, so as to adjust/set the network access mode according to the indication of the first indication information, which is beneficial to improving reliability and stability of communication.

In one possible implementation, the receiving, by the terminal device, the first indication information from a source access network device includes:

the terminal equipment receives an RRC reconfiguration message from the source access network equipment, wherein the RRC reconfiguration message comprises the first indication information.

In one possible implementation, the receiving, by the terminal device, first indication information includes:

and the terminal equipment receives the first indication information from the core network equipment.

In the application, the terminal device may receive the first indication information from the core network device, so as to adjust/set the network access mode according to the indication of the first indication information, which is beneficial to improving reliability and stability of communication.

In a possible implementation, the receiving, by the terminal device, the first indication information from a core network device includes:

and the terminal equipment receives a registration acceptance message from the core network equipment, wherein the registration acceptance message comprises the first indication information.

In a possible implementation, the first indication information is used to indicate a network type of a handover target network, and the first indication information includes an identifier of the target network;

the terminal equipment sets a network access mode of the terminal equipment according to the first indication information, and the method comprises the following steps:

the terminal equipment determines the network type of the target network according to the identification of the target network;

and the terminal equipment sets the network access mode of the terminal equipment to be the access mode corresponding to the network type.

In the application, when the first indication information is the identifier of the target network, the network type of the target network is determined according to the identifier of the target network, and then the network access mode of the terminal device is set to be the network access mode corresponding to the network type, so that the problem that the access modes are not matched after the terminal device is switched to the target network can be avoided, and the reliability and the stability of communication are improved.

In one possible implementation, the first indication information is used to indicate a network type of a handover target network, and the first indication information includes the network type of the target network;

and the terminal equipment sets the network access mode of the terminal equipment to be the network access mode corresponding to the network type according to the network type of the target network.

In the application, when the first indication information is the network type of the target network, the terminal device sets the network access mode of the terminal device to the network access mode corresponding to the network type, so that the problem that the access mode is not matched after the terminal device is switched to the target network can be avoided, and the reliability and the stability of communication are improved.

In a possible implementation, the first indication information is used to indicate a network type of a handover target network, and the first indication information includes a cell identifier corresponding to the target network;

the terminal equipment determines the network type of the target network according to the cell identification;

and the terminal equipment sets the network access mode of the terminal equipment as the network access mode corresponding to the network type according to the network type of the target network.

In the application, when the first indication information is the cell identifier corresponding to the target network, the network type of the target network is determined according to the cell identifier corresponding to the target network, and then the network access mode of the terminal device is set to the network access mode corresponding to the network type, so that the problem that the access mode is not matched after the terminal device is switched to the target network can be avoided, and the reliability and the stability of communication are improved.

In one possible implementation, the network types include a public land mobile network PLMN and an independent non-public network SNPN; the network access mode comprises an SNPN access mode and a non-SNPN access mode, wherein the SNPN corresponds to the SNPN access mode, and the PLMN corresponds to the non-SNPN access mode.

In a second aspect, the present application provides a communication method, including: the method comprises the steps that a source access network device determines first indication information, wherein the first indication information is used for indicating a network type of a switching target network, or the first indication information is used for indicating a network access mode corresponding to the network type; and the source access network equipment sends the first indication information to the terminal equipment.

In a possible implementation, the sending, by the source access network device, the first indication information to the terminal device includes:

and the source access network equipment sends a Radio Resource Control (RRC) reconfiguration message to the terminal equipment, wherein the RRC reconfiguration message comprises the first indication information.

In one possible implementation, the first indication information includes at least one of the following information: the network identification of the target network, the network type of the target network and the cell identification corresponding to the target network.

In a possible implementation, before the source access network device sends the first indication information to a terminal device, the method further includes:

the source access network equipment determines second indication information, wherein the second indication information is used for indicating an identifier of an entity having a terminal equipment certificate;

and the source access network equipment sends the second indication information to the target access network equipment.

In the application, the target access network device can know the external entity associated when the terminal device accesses the source network supported by the source access network device according to the second indication information from the source access network device, so that whether the terminal device is allowed to switch to the target network supported by the target access network device can be judged, thereby avoiding the switching failure caused by switching the terminal device to the network which does not support the current external entity, and improving the reliability and stability of communication.

In a possible implementation, the sending, by the source access network device, the second indication information to the target access network device includes:

and the source access network equipment sends a switching request message to the target access network equipment, wherein the switching request message comprises the second indication information.

In the application, the second indication information is carried by the handover request message, so that the signaling overhead can be saved.

In a third aspect, the present application provides a communication method, including: the target access network equipment determines first indication information, wherein the first indication information is used for indicating a network type of a switching target network, or the first indication information is used for indicating a network access mode corresponding to the network type; and the target access network equipment sends the first indication information to terminal equipment.

In one possible implementation, the sending, by the target access network device, the first indication information to a terminal device includes:

and the target access network equipment sends a Radio Resource Control (RRC) reconfiguration message to the terminal equipment, wherein the RRC reconfiguration message comprises the first indication information.

In one possible implementation, the method further comprises:

the target access network equipment receives second indication information from the source access network equipment, wherein the second indication information is used for indicating the identification of an entity with a terminal equipment certificate;

the target access network equipment determines whether to allow the terminal equipment to be switched from source access network equipment to the target access network equipment or not according to the second indication information;

the target access network equipment determines first indication information, including:

and if the target access network equipment determines to allow the terminal equipment to be switched from the source access network equipment to the target access network equipment according to the second indication information, the target access network equipment determines the first indication information.

In one possible implementation, the receiving, by the target access network device, the second indication information from the source access network device includes:

and the target access network equipment receives a switching request message from the source access network equipment, wherein the switching request message comprises the second indication information.

In a fourth aspect, the present application provides a communication method, including: the method comprises the steps that core network equipment determines first indication information, wherein the first indication information is used for indicating the network type of a target network, the target network is one of at least two networks supported by target access network equipment, or the first indication information is used for indicating a network access mode corresponding to the network type;

and the core network equipment sends the first indication information to the terminal equipment.

In a possible implementation, the sending, by the core network device, the first indication information to a terminal device includes:

and the core network equipment sends a registration acceptance message to the terminal equipment, wherein the registration acceptance message comprises the first indication information.

In one possible implementation, the first indication information includes at least one of the following information: a network identification of the target network, a network type of the target network.

In a fifth aspect, the present application provides a communication method, including: the target access network equipment receives second indication information from the source access network equipment, wherein the second indication information is used for indicating the identification of an entity possessing the terminal equipment certificate; and the target access network equipment determines whether to allow the terminal equipment to be switched from the source access network equipment to the target access network equipment or not according to the second indication information.

In the application, the target access network device can know the external entity associated when the terminal device accesses the source network supported by the source access network device according to the second indication information from the source access network device, so that whether the terminal device is allowed to be switched to the target network supported by the target access network device can be judged, thereby avoiding the switching failure caused by switching the terminal device to the network not supporting the current external entity, and improving the reliability and stability of communication.

In one possible implementation, the method further comprises:

if the target access network device determines, according to the second indication information, that the terminal device is allowed to switch from a source access network device to the target access network device, the target access network device determines first indication information, where the first indication information is used to indicate a network type of a switching target network, or the first indication information is used to indicate a network access mode corresponding to the network type;

and the target access network equipment sends the first indication information to terminal equipment.

In a sixth aspect, the present application provides a communication method, including: the source access network equipment determines second indication information, wherein the second indication information is used for indicating the identification of an entity having the terminal equipment certificate; and the source access network equipment sends the second indication information to the target access network equipment.

In a possible implementation, after the source access network device sends the second indication information to the target access network device, the method further includes:

the method comprises the steps that a source access network device determines first indication information, wherein the first indication information is used for indicating a network type of a switching target network, or the first indication information is used for indicating a network access mode corresponding to the network type;

and the source access network equipment sends the first indication information to the terminal equipment.

In a seventh aspect, the present application provides a communication apparatus, where the communication apparatus is a terminal device, and the apparatus includes: a transceiver unit, configured to receive first indication information, where the first indication information is used to indicate a network type of a handover target network, or the first indication information is used to indicate a network access mode corresponding to the network type; and the processing unit is used for setting the network access mode of the terminal equipment according to the first indication information.

In one possible implementation, the transceiver unit is specifically configured to:

receiving the first indication information from the target access network device.

In a possible implementation, the transceiver unit is further specifically configured to:

receiving a Radio Resource Control (RRC) reconfiguration message from the target access network device, wherein the RRC reconfiguration message comprises the first indication information.

receiving the first indication information from the source access network device.

receiving an RRC reconfiguration message from the source access network device, wherein the RRC reconfiguration message comprises the first indication information.

In a possible implementation, the transceiver unit is specifically configured to:

receiving the first indication information from the core network device.

receiving a registration acceptance message from the core network device, wherein the registration acceptance message comprises the first indication information.

the processing unit is specifically configured to:

determining the network type of the target network according to the identification of the target network;

and setting the network access mode of the terminal equipment as the access mode corresponding to the network type.

the processing unit is specifically configured to:

and setting the network access mode of the terminal equipment as the network access mode corresponding to the network type according to the network type of the target network.

the processing unit is specifically configured to:

determining the network type of the target network according to the cell identifier;

In an eighth aspect, the present application provides a communication apparatus, where the communication apparatus is a source access network device, and the apparatus includes: a processing unit, configured to determine first indication information, where the first indication information is used to indicate a network type of a handover target network, or the first indication information is used to indicate a network access mode corresponding to the network type; and the transceiver unit is used for sending the first indication information to the terminal equipment.

and sending a Radio Resource Control (RRC) reconfiguration message to the terminal equipment, wherein the RRC reconfiguration message comprises the first indication information.

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

determining second indication information, wherein the second indication information is used for indicating the identification of an entity possessing a terminal equipment certificate;

and sending the second indication information to the target access network equipment.

and sending a switching request message to the target access network equipment, wherein the switching request message comprises the second indication information.

In a ninth aspect, the present application provides a communication apparatus, where the communication apparatus is a target access network device, and the apparatus includes: a processing unit, configured to determine first indication information, where the first indication information is used to indicate a network type of a handover target network, or the first indication information is used to indicate a network access mode corresponding to the network type; and the transceiving unit is used for sending the first indication information to the terminal equipment.

In a possible implementation, the processing unit is further configured to receive second indication information from the source access network device, where the second indication information is used to indicate an identity of an entity that possesses a certificate of the terminal device;

the processing unit is further configured to determine whether to allow the terminal device to switch from a source access network device to the target access network device according to the second indication information;

the processing unit is specifically further configured to:

and if the target access network equipment determines that the terminal equipment is allowed to be switched from the source access network equipment to the target access network equipment according to the second indication information, the target access network equipment determines the first indication information.

receiving a handover request message from the source access network device, where the handover request message includes the second indication information.

In a tenth aspect, the present application provides a communication apparatus, where the communication apparatus is a core network device, and the apparatus includes: a processing unit, configured to determine first indication information, where the first indication information is used to indicate a network type of a target network, where the target network is one of at least two networks supported by a target access network device, or the first indication information is used to indicate a network access mode corresponding to the network type; and the transceiver unit is used for sending the first indication information to the terminal equipment.

and sending a registration acceptance message to the terminal equipment, wherein the registration acceptance message comprises the first indication information.

In an eleventh aspect, the present application provides a communication apparatus, which is a target access network device, and includes: a transceiving unit, configured to receive second indication information, where the second indication information is used to indicate an identifier of an entity that possesses a terminal device certificate; and the processing unit is used for determining whether to allow the terminal equipment to be switched from the source access network equipment to the target access network equipment according to the second indication information.

In a possible implementation, the processing unit is further configured to determine first indication information if it is determined that the terminal device is allowed to be switched from a source access network device to the target access network device according to the second indication information, where the first indication information is used to indicate a network type of a switching target network, or the first indication information is used to indicate a network access mode corresponding to the network type;

the transceiver unit is further configured to send the first indication information to a terminal device.

In a possible implementation, the transceiver unit is further configured to:

In a twelfth aspect, the present application provides a communication apparatus, where the communication apparatus is a source access network device, and the apparatus includes: the processing unit is used for determining second indication information, and the second indication information is used for indicating the identification of an entity which possesses the terminal equipment certificate; and the transceiving unit is used for sending the second indication information to the target access network equipment.

In a possible implementation, the processing unit is further configured to determine first indication information, where the first indication information is used to indicate a network type of a handover target network, or the first indication information is used to indicate a network access mode corresponding to the network type;

In a thirteenth aspect, the present application provides a communication apparatus, which may be a terminal device, an apparatus in a terminal device, or an apparatus capable of being used with a terminal device. Wherein, the communication device can also be a chip system. The communication device may perform the method of the first aspect. The functions of the communication device can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more units or modules corresponding to the above functions. The unit or module may be software and/or hardware. The operations and advantageous effects performed by the communication device may refer to the method and advantageous effects described in the first aspect, and repeated details are not repeated.

In a fourteenth aspect, the present application provides a communication apparatus, which may be an access network device (e.g., the source access network device or the target access network device), an apparatus in the access network device, or an apparatus capable of being used in cooperation with the access network device. Wherein, the communication device can also be a chip system. The communications device may perform the method of the second or third or fifth or sixth aspect. The functions of the communication device can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more units or modules corresponding to the above functions. The unit or module may be software and/or hardware. For the operations and the advantageous effects performed by the communication device, reference may be made to the method and the advantageous effects described in the second aspect, the third aspect, the fifth aspect, or the sixth aspect, and repeated descriptions are omitted.

In a fifteenth aspect, the present application provides a communication apparatus, where the apparatus may be a core network device, an apparatus in a core network device, or an apparatus capable of being used in cooperation with a core network device. Wherein, the communication device can also be a chip system. The communication device may perform the method of the fourth aspect. The functions of the communication device can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more units or modules corresponding to the above functions. The unit or module may be software and/or hardware. The operations and advantageous effects performed by the communication device may refer to the method and advantageous effects described in the fourth aspect, and repeated details are not repeated.

In a sixteenth aspect, the present application provides a communication device comprising a processor and a transceiver for executing a computer program or instructions stored in at least one memory to cause the device to perform the method of any one of the first to sixth aspects.

In a seventeenth aspect, the present application provides a communication device comprising a processor, a transceiver, and a memory, the processor, transceiver, and memory coupled; the processor and the transceiver are for implementing the method as in any one of the first to sixth aspects.

In an eighteenth aspect, the present application provides a computer-readable storage medium having stored thereon a computer program or instructions for implementing the method of any one of the first to sixth aspects when executed by a computer.

Nineteenth aspect, the present application provides a computer program product comprising instructions, the computer program product comprising computer program code to, when run on a computer, implement the method of any one of the first to sixth aspects.

Drawings

Fig. 1 is a schematic diagram of a 5G network architecture provided in an embodiment of the present application;

FIG. 2 is a flow chart of Xn handover;

fig. 3 is a flow diagram of NG handover;

fig. 4 is a schematic diagram of system information of a cell provided in an embodiment of the present application;

fig. 5 is a schematic view of a cross-network handover scenario provided in an embodiment of the present application;

fig. 6 is a flow chart of a communication method according to an embodiment of the present application;

fig. 7 is another schematic flow chart of a communication method provided in an embodiment of the present application;

fig. 8 is another schematic flow chart of a communication method provided in an embodiment of the present application;

fig. 9 is another schematic flow chart of a communication method provided in an embodiment of the present application;

fig. 10 is another schematic flow chart of a communication method provided in an embodiment of the present application;

fig. 11 is another schematic flow chart diagram of a communication method provided in an embodiment of the present application;

fig. 12 is another schematic flow chart diagram of a communication method provided in an embodiment of the present application;

fig. 13 is another schematic flow chart of a communication method provided in an embodiment of the present application;

fig. 14 is another schematic flow chart of a communication method provided in an embodiment of the present application;

fig. 15 is another schematic flow chart of a communication method provided in an embodiment of the present application;

fig. 16 is another schematic flow chart diagram of a communication method provided in an embodiment of the present application;

fig. 17 is another schematic flow chart of a communication method provided in an embodiment of the present application;

fig. 18 is another schematic flow chart of a communication method provided in an embodiment of the present application;

fig. 19 is a schematic view of a scenario of external authentication provided in an embodiment of the present application;

fig. 20 is a switching diagram in an external authentication scenario provided by an embodiment of the present application;

fig. 21 is another schematic flow chart diagram of a communication method provided in an embodiment of the present application;

fig. 22 is another schematic flow chart of a communication method provided in an embodiment of the present application;

fig. 23 is another schematic flow chart diagram of a communication method provided in an embodiment of the present application;

fig. 24 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 25 is a schematic structural diagram of another communication device according to an embodiment of the present application.

Detailed Description

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.

In the description of this application, "/" means "or" unless otherwise stated, for example, A/B may mean A or B. "and/or" herein is merely an association relationship describing an associated object, and means that there may be three relationships, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. Further, "at least one" means one or more, "a plurality" means two or more. The terms "first," "second," and the like do not denote any order or importance, but rather the terms "first," "second," and the like do not denote any order or importance.

In this application, the words "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present relevant concepts in a concrete fashion.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: a global system for mobile communication (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, a General Packet Radio Service (GPRS), a long term evolution (long term evolution, LTE) system, a LTE Frequency Division Duplex (FDD) system, a LTE Time Division Duplex (TDD) system, a universal mobile telecommunication system (universal mobile telecommunication system, UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a fifth generation (generation, or new radio system (UMTS), etc., and future communication systems are not limited.

For convenience of understanding, in this application, the 5G system is taken as an example, and details of relevant network elements in the 5G system are described below:

referring to fig. 1, fig. 1 is a schematic diagram of a 5G network architecture according to an embodiment of the present disclosure. As shown in fig. 1, the network architecture may include a terminal device portion, a (radio) access network (R) AN, a Core Network (CN), and a Data Network (DN). Where (R) AN (hereinafter RAN) is used to access the terminal device to the wireless network and CN is used to manage the terminal device and provide a gateway for communication with the DN.

The terminal devices, RAN, CN and DN referred to in fig. 1 are explained in detail below, respectively.

1. Terminal device

The terminal equipment part includes terminal equipment 210 in fig. 1, and terminal equipment 210 may also be referred to as User Equipment (UE). The terminal device 210 in this embodiment is a device having a wireless transceiving function, and may communicate with network elements of one or more Core Networks (CN) through AN access network device in AN Access Network (AN) 240. Terminal equipment 210 can also be called an access terminal, subscriber unit, subscriber station, mobile, remote station, remote terminal, mobile device, user terminal, wireless network device, user agent, or user equipment, etc. The terminal device 210 may be deployed on land, including indoors or outdoors, hand-held, or vehicle-mounted; can also be deployed on the water surface (such as a ship and the like); and may also be deployed in the air (e.g., airplanes, balloons, satellites, etc.). The terminal device 210 may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a smart phone, a mobile phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication function, a computing device or other device connected to a wireless modem, a vehicle-mounted device, a wearable device, a drone device or internet of things, a terminal in a vehicle networking, a terminal in a fifth generation mobile communication (5G) network and any form of terminal in a future network, a relay user device or a terminal in a public land mobile communication network (PLMN) for future evolution, and the like, wherein the relay user device may be, for example, a 5G home gateway (RG). For example, the terminal device 210 may be a Virtual Reality (VR) terminal, an Augmented Reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in telemedicine, a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, and the like. The embodiment of the present application does not limit this.

2. RAN (radio access network)

As shown in fig. 1, the RAN includes access network equipment 240. It should be noted that the RAN may include one or more RAN devices (or access network devices), and an interface between an access network device and a terminal device may be a Uu interface (or air interface). Of course, in future communications, the names of these interfaces may be unchanged or replaced by other names, which are not limited in this application.

An access network device is a node or device that accesses a terminal device to a wireless network, and the access network device includes, but is not limited to: a new generation base station (gbb), an evolved node B (eNB), a next generation evolved node B (next-eNB), a wireless backhaul device, a Radio Network Controller (RNC), a Node B (NB), a Base Station Controller (BSC), a Base Transceiver Station (BTS), a home base station ((home evolved node B, heNB) or (home node B, HNB)), a Base Band Unit (BBU), a transmission and reception point (TP), a transmission point (TRP), a mobile switching center, etc. in the 5G communication system, no limitation is made herein. In addition, the access network device may also be a base station in a 6G communication system, or an Open base station (Open RAN) or a Cloud base station (Cloud RAN), and under the Open RAN, interfaces between the access network devices or in the access network device related to the present invention may become internal interfaces of the Open RAN, and flows and information interaction between the internal interfaces may be implemented by software or programs. In the embodiment of the present application, an access network device may be a base station, and a scheme provided in the embodiment of the present application is schematically described.

3. CN

As shown in fig. 1, the CN includes a network open function (NEF) 231, a network storage function (NRF) 232, a Policy Control Function (PCF) 233, a Unified Data Management (UDM) network element 234, an Application Function (AF) 235, an authentication server function (AUSF) 236, an access and mobility management function (AMF) 237, a Session Management Function (SMF) 238, a user plane function (user plane function, UPF) 239, and a wireless network. For convenience of description, the access network device (which may also be referred to as a base station) mentioned in the following description of the embodiments of the present application is illustrated by using RAN as an example. The core network device mentioned in the following of the embodiments of the present application may be understood as a generic term of a CN functional network element.

The AMF network element is a control plane network element provided by an operator network, and is responsible for access control and mobility management of terminal equipment accessing the operator network, for example, including functions of mobility state management, user temporary identity allocation, user authentication and user authorization.

The SMF network element is a control plane network element provided by an operator network and is responsible for managing a PDU session of the terminal device. A PDU session is a channel for transmitting PDUs, and a terminal device needs to transfer PDUs to and from the DN through the PDU session. The PDU session is established, maintained, deleted and the like by the SMF network element. The SMF network element includes session management (such as session establishment, modification, and release, including tunnel maintenance between the UPF and the RAN), selection and control of the UPF network element, service and Session Continuity (SSC) mode selection, roaming, and other session-related functions.

The UPF network element is a gateway provided by the operator and is a gateway for the operator network to communicate with the DN. The UPF network element includes user plane related functions such as packet routing and transmission, packet detection, quality of service (QoS) processing, lawful interception, uplink packet detection, downlink packet storage, and the like.

The PCF network element is a control plane function provided by the operator for providing the policy of the PDU session to the SMF network element. The policies may include charging related policies, qoS related policies, authorization related policies, and the like.

The AF network element is a functional network element providing various service services, and can interact with a core network through other network elements and interact with a policy management framework to perform policy management.

In addition, although not shown, other possible network elements, such as a network open function (NEF) network element and a network element Unified Data Repository (UDR) network element, may also be included in the CN.

4. DN

As shown in fig. 1, the data network DN220, which may also be referred to as a Packet Data Network (PDN), is typically a network located outside of the operator's network, such as a third party network. The operator network may access a plurality of data network DNs 220, and the data network DNs 220 may be configured with a plurality of services, and may provide services such as data and/or voice for the terminal device 210. For example, the data network DN220 may be a private network of an intelligent factory, a sensor installed in a workshop of the intelligent factory may be the terminal device 210, and a control server for the sensor is disposed in the data network DN220, and the control server may provide a service for the sensor. The sensor can communicate with the control server, obtain the instruction of the control server, transmit the sensor data gathered to the control server, etc. according to the instruction. For another example, the data network DN220 may be an internal office network of a company, the mobile phone or computer of the employee of the company may be the terminal device 210, and the mobile phone or computer of the employee may access information, data resources, and the like on the internal office network of the company.

In fig. 1, nnef, nausf, nrf, namf, npcf, nudm, nsmf, naf, N1, N2, N3, N4, and N6 are interface serial numbers. The meaning of these interface sequence numbers can be referred to as that defined in the relevant standard protocol, and is not limited herein.

It can be understood that fig. 1 illustrates a 5G communication system as an example, and the scheme in the embodiment of the present application may also be applied to other possible communication systems, such as an LTE communication system or a future sixth generation (6G) communication system. The network element or the function may be a network element in a hardware device, a software function running on dedicated hardware, or a virtualization function instantiated on a platform (e.g., a cloud platform). Optionally, the network element or the function may be implemented by one device, or may be implemented by multiple devices together, or may be a functional module in one device, which is not specifically limited in this embodiment of the present application.

Understandably, along with the development trend that the network co-construction sharing becomes 5G, in order to efficiently realize the 5G network coverage, quickly form the 5G service capability, enhance the market competitiveness of the 5G network and the service, improve the network benefit and the asset operation efficiency, and achieve mutual profit and win-win between two parties, the cooperation mode of MOCN sharing is adopted among different operators, namely, each operator independently constructs a respective core network, 5G base stations and frequency resource sharing. For example, china unicom and china telecommunications are constructed to share a 5G network, that is, a base station supports both the china unicom network and the china telecommunications network. In general, a sharing mode in which one access network device is shared by multiple networks (or one access network device supports multiple networks) may be referred to as RAN sharing. For example, a base station is shared by PLMN1, PLMN2, PLMN3, SNPN1, SNPN2 (or the base station supports PLMN1, PLMN2, PLMN3, SNPN1, SNPN 2).

Here, the non-public network (NPN) may be referred to as a private network, which is a network corresponding to a PLMN (also referred to as a public network). Generally, NPN can be used for non-public purposes, e.g. internal networks built in factories, schools, and commercial districts belong to private networks. Wherein NPN can be classified into two types: stand-alone NPN (i.e., SNPN) and public network integrated NPN (PNI-NPN). Generally, SNPN does not depend on the function of the public network, and PNI-NPN needs to depend on the function of the public network. It is understood that the NPN referred to in the following embodiments of the present application are SNPN. One SNPN may correspond to a network identifier (SNPN ID), which is formed by concatenating a PLMN ID and a NID, that is, SNPN ID = PLMN ID + NID. The PLMN ID may be a private network-dedicated PLMN ID (for example, some PLMN IDs reserved by the international telecommunications union are dedicated to private networks), or may be a PLMN ID owned by an operator (for example, SNPN established by an operator for assisting enterprises, whose PLMN ID may be set as the PLMN ID owned by the operator).

Understandably, the UE has two access modes (or referred to as network access modes): SNPN access mode and non-SNPN access mode. When the UE is set to be in an SNPN access mode, the UE can only access the SNPN network; when the UE is set to a non-SNPN access mode, the UE can only access the PLMN network. In a handover scenario, if the networks in which the UE is located are different before and after handover, the handover is called an inter-network handover. In the cross-network handover, the source network and the target network of the UE may be the same type or different types of networks. For example, the UE may switch between two PLMNs, or between two SNPNs, or between a PLMN and an SNPN. When switching across networks, if the UE is switched from one type of network to another type of network, the UE needs to adjust the access mode. For example, when the UE is switched from PLMN to SNPN, the non-SNPN access mode needs to be adjusted to SNPN access mode, so that the UE can normally operate in the target network.

It can be understood that in 5G communication, there are two switching methods: xn handover and NG handover. The Xn handover refers to the handover between a source access network device (or called source base station) and a target access network device (or called target base station) through an Xn interface. It will be appreciated that the Xn interface is the interface between base stations. And NG switching means that the source access network equipment and the target access network equipment are switched through an NG interface. It is understood that the NG interface is the interface between the base station and the core network device. The core network device in the embodiment of the present application may be understood as an AMF. For example, please refer to fig. 2, fig. 2 is a flow chart illustrating Xn handover.

As shown in fig. 2, the Xn switching process may include the following steps 1 to 7:

step 1, the source access network equipment sends a HANDOVER REQUEST message to the target access network equipment. Specifically, when the source access network device confirms that the terminal device needs to perform handover, the source access network device may send a handover request message to the target access network device.

And step 2, the target access network equipment sends a HANDOVER REQUEST ACKNOWLEDGE (HANDOVER REQUEST ACKNOWLEDGE) message to the source access network equipment. Specifically, after the target access network device receives the handover request message sent by the source access network device, the target access network device determines not to allow the terminal device to access (i.e., the target access network device performs admission control) according to the number of connections of the target access network device, and sends a handover request acknowledgement message to the source access network device if the target access network device allows the terminal device to access. Wherein, the handover request confirm message includes a container (container), and the container carries an RRC RECONFIGURATION (RRC RECONFIGURATION) message sent to the terminal device. The RRC reconfiguration message may include information such as a Physical Cell Identifier (PCI) of the target cell, or the RRC reconfiguration message may also include information such as a Physical Cell Identifier (PCI) of the target cell and system information of the target cell, which is not limited herein.

And 3, the source access network equipment sends a switching command to the terminal equipment. Specifically, the source access network device may send a handover command to the terminal device after receiving the handover request acknowledgement message sent by the target access network device. The RRC reconfiguration message in step 2 may be included in the handover command, that is, the source access network device may forward the RRC reconfiguration message in the handover request acknowledgement message to the terminal device (which is equivalent to that the layer of the source access network device is transparent).

And 4, the terminal equipment synchronizes to the target cell and sends an RRC RECONFIGURATION COMPLETE (RRC RECONFIGURATION COMPLETE) message to the target access network equipment. Specifically, after receiving the RRC reconfiguration message, the terminal device may exit from the original cell and synchronize to the target cell according to the indication of the RRC reconfiguration message, and after synchronizing to the target cell, send an RRC reconfiguration complete message to the target access network device.

And 5, the target access network equipment sends a UE CONTEXT RELEASE (UE CONTEXT RELEASE) message to the source access network equipment. Specifically, after the target access network device receives the RRC reconfiguration complete message sent by the terminal device, the target access network device may further send a terminal device context release message to the source access network device.

And 6, the terminal equipment sends a REGISTRATION REQUEST (REGISTRATION REQUEST) message to the core network equipment.

And 7, the core network equipment sends a REGISTRATION acceptance (REGISTRATION ACCEPT) message to the terminal equipment.

It can be understood that the steps 1 to 5 are necessary steps for Xn switching, and the steps 6 to 7 are optional steps for Xn switching.

For another example, please refer to fig. 3, fig. 3 is a schematic flow chart of NG handover. As shown in fig. 3, the flow of NG handover may include the following steps 1 to 11:

step 1, the source access network equipment sends a HANDOVER REQUIRED (HANDOVER REQUIRED) message to the core network equipment. Specifically, when the source access network device confirms that the terminal device needs to perform handover, the source access network device may send a handover requirement message to the core network device. The handover required message may include information such as an identifier of the target network.

And 2, the core network equipment sends a HANDOVER REQUEST message to the target access network equipment. Specifically, after the core network device receives the handover request message sent by the source access network device, the core network device may send a handover request message to the target access network device. The handover request message may include information such as an identifier of the target network.

And 3, the target access network equipment sends a HANDOVER REQUEST ACKNOWLEDGE (HANDOVER REQUEST ACKNOWLEDGE) message to the core network equipment. Specifically, after the target access network device receives the handover request message sent by the core network device, the target access network device determines not to allow the access of the terminal device according to the conditions such as the number of its own connections (i.e., the target access network device performs admission control), and if the access is allowed, sends a handover request confirmation message to the core network device. The handover request acknowledgement message includes a container carrying an RRC configuration (RRC RECONFIGURATION) message sent to the terminal device. The RRC configuration message includes information such as a physical cell identifier PCI of the target cell, or the RRC configuration message includes information such as a physical cell identifier PCI of the target cell and system information of the target cell, which is not limited herein.

And 4, the core network equipment sends a HANDOVER COMMAND (HandOVER COMMAND) message to the source access network equipment. Specifically, after the core network device receives the handover request acknowledgement message sent by the target access network device, the core network device may send a handover command message to the source access network device. The handover command message contains a container in which the RRC configuration message sent to the terminal device is carried. Generally, the RRC configuration message includes information such as a physical cell identity PCI of the target cell, or the RRC configuration message includes information such as a physical cell identity PCI of the target cell and system information of the target cell, which is not limited herein. That is, the core network device may forward the RRC configuration message included in the handover request confirm message to the source access network device.

And 5, the source access network equipment sends the RRC reconfiguration message to the terminal equipment. Specifically, after receiving the handover command, the source access network device may send (or is called to forward) the RRC reconfiguration message included in the handover command to the terminal device.

And 6, the terminal equipment synchronizes to the target cell and sends an RRC RECONFIGURATION COMPLETE (RRC RECONFIGURATION COMPLETE) message to the target access network equipment. Specifically, after receiving the RRC reconfiguration message, the terminal device may exit from the original cell and synchronize to the target cell by parsing the RRC reconfiguration message according to the indication of the RRC reconfiguration message, and send an RRC reconfiguration complete message to the target access network device.

And 7, the target access network equipment sends a HANDOVER notification (HANDOVER NOTIFY) message to the core network equipment.

And 8, the target access network equipment sends a UE CONTEXT RELEASE COMMAND (UE CONTEXT RELEASE COMMAND) message to the source access network equipment.

And 9, the source access network equipment sends a UE CONTEXT RELEASE COMPLETE (UE CONTEXT RELEASE COMPLETE) message to the target access network equipment.

Step 10, the terminal equipment sends a REGISTRATION REQUEST (REGISTRATION REQUEST) message to the core network equipment.

And step 11, the core network equipment sends a REGISTRATION acceptance (REGISTRATION ACCEPT) message to the terminal equipment.

It can be understood that the steps 1 to 9 are necessary steps for NG handover, and the steps 10 to 11 are optional steps for NG handover.

The System Information (SI) of the target cell may include a Physical Cell Identity (PCI) and a cell identity (cell identity) of at least one logical cell. The network comprises a cell identifier, a network identifier and a network identifier, wherein the cell identifier corresponds to at least one network, and the at least one network corresponding to the cell identifier is the same type of network. The type of network (hereinafter referred to as network type for convenience of description) referred to in the present application may include PLMN and SNPN. For example, please refer to fig. 4, fig. 4 is a schematic diagram of system information of a cell according to an embodiment of the present application. As shown in fig. 4, the cell supports 5 networks, which are PLMN1 to PLMN3 and SNPN1 to SNPN2, respectively, wherein the system information of the cell includes 1 physical cell identifier PCI and cell identifiers x, y and z of 3 logical cells. The logical cell marked by the cell identifier x corresponds to the network PLMN1, the logical cell marked by the cell identifier y corresponds to the networks PLMN2 and PLMN3, and the logical cell marked by the cell identifier z corresponds to the networks SNPN1 and SNPN2.

It can be understood that, in a handover scenario, when a target cell is a RAN shared cell, since system information of the target cell received by a terminal device includes identifiers of multiple networks, and the terminal device does not know which network of the multiple networks is the target network, it cannot determine whether the target network is a PLMN or an SNPN, so that if network types of networks where the terminal device is located before and after handover are different, the terminal device after handover cannot normally operate, for example, cannot normally register or acquire a service in the target network. Based on this, the application provides a communication method, and the method is suitable for a cross-network switching scene. The source network and the target network in the scene have the same core network device, or an interface is arranged between the core network devices of the source network and the target network. For example, please refer to fig. 5, and fig. 5 is a schematic view of a cross-network handover scenario provided in the embodiment of the present application. As shown in fig. 5, there is an interface between the core network device of the source network and the core network device of the target network, wherein when the terminal device moves, for example, the location of the terminal device moves from cell 1 (i.e., the source cell) to cell 2 (i.e., the target cell), the terminal device needs to switch from the network supported by the source access network device (e.g., the source network shown in fig. 5) to the network supported by the target access network device (e.g., the target network shown in fig. 5). The network types of the networks in which the terminal device is located before and after the switching may be different, so that the terminal device may set/adjust the access mode of the terminal device according to the first indication information by receiving the first indication information from the network devices (the source access network device, the target access network device, and the core network device), thereby avoiding a problem that the terminal device cannot normally communicate due to an access mode error of the terminal device.

The technical solutions provided in the present application will be described in detail below with reference to more drawings.

Referring to fig. 6, fig. 6 is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in fig. 6, the method includes the following steps S601 to S602:

s601, the terminal equipment receives the first indication information.

In some possible embodiments, the terminal device receives first indication information, where the first indication information may be used to indicate a network type of a handover target network, or the first indication information may also be used to indicate a network access mode corresponding to the network type of the target network. Specifically, the first indication information may be sent to the terminal device by the target access network device, the source access network device, or the core network device. That is, the above terminal device receiving the first indication information may be understood as: the terminal device receives first indication information from the target access network device, or the terminal device receives the first indication information from the source access network device, or the terminal device receives the first indication information from the core network device. Wherein the target network is one of at least two networks supported by the target access network device.

It can be understood that, when the terminal device switches from the source access network device to the target access network device by using Xn/NG handover, if the source access network device sends the first indication information to the terminal device in the handover process, the source access network device may carry the first indication information in the RRC reconfiguration message to send to the terminal device, or the source access network device may also carry the first indication information in other RRC messages to send to the terminal device, which is not limited herein.

Optionally, when the terminal device switches from the source access network device to the target access network device by using Xn switching, if the target access network device sends the first indication information to the terminal device in the switching process, the target access network device may carry the first indication information in the RRC reconfiguration message, so as to forward the first indication information to the terminal device through the source access network device, or the target access network device may also carry the first indication information in other RRC messages, so as to send the first indication information to the terminal device through the source access network device. Optionally, when the terminal device switches from the source access network device to the target access network device by using NG switching, if the target access network device sends the first indication information to the terminal device in the switching process, the target access network device may carry the first indication information in an RRC reconfiguration message, forward the RRC reconfiguration message to the source access network device through the core network device, and forward the RRC reconfiguration message to the terminal device through the source access network device, or the target access network device may also carry the first indication information in other RRC messages, forward the RRC message carrying the first indication information to the source access network device through the core network device, and forward the RRC message carrying the first indication information to the terminal device through the source access network device.

Optionally, when the terminal device switches from the source access network device to the target access network device by using Xn/NG switching, if the core network device sends the first indication information to the terminal device during the switching process, the core network device may carry the first indication information in the registration acceptance message to send to the terminal device, or the core network device may also carry the first indication information in other messages to send to the terminal device, which is not limited herein.

Optionally, in some possible embodiments, before the source access network device, or the target access network device, or the core network device sends the first indication information to the terminal device, the source access network device may further determine the second indication information. The second indication information is used for indicating the identification of the entity possessing the terminal equipment certificate, or the second indication information is used for indicating the identification of the entity authenticating the terminal equipment. The entity may be an entity in another network (or referred to as a network other than the target network), or an independent authentication server, or may be an external entity group, or a home service provider group, and the like, which is not limited herein. The source access network device may then send the second indication information to the target access network device. If the terminal device switches from the network supported by the source access network device (i.e., the source network) to the network supported by the target access network device (i.e., the target network) by using Xn, the second indication information may be carried in the handover request message sent by the source access network device to the target access network device. That is, the sending of the second indication information by the source access network device to the target access network device may be understood as: and the source access network equipment sends a switching request message to the target access network equipment, wherein the switching request message can comprise second indication information, identification of the target network and other information. If the terminal device adopts NG handover to switch from a network supported by the source access network device (i.e., a source network) to a network supported by the core network device (i.e., a target network), the source access network device may send the second indication information to the target access network device through the core network device. That is, the sending of the second indication information by the source access network device to the target access network device may be understood as: and the source access network equipment sends a switching requirement message to the core network equipment, wherein the switching requirement message can comprise second indication information, identification of the target network and other information. The core network device sends a handover request message to the target access network device, wherein the handover request message may include information such as second indication information and an identifier of the target network. Therefore, the target access network device may determine whether to allow the terminal device to switch from the source access network device to the target access network device according to the received second indication information, or in other words, the target access network device may determine whether to allow the terminal device to access (i.e., admission control) according to the second indication information. Generally speaking, if the target access network device determines that the target network supports the entity corresponding to the certificate used by the UE, the terminal device is allowed to be switched/allowed to access, and if the target access network device determines that the target network does not support the entity corresponding to the certificate used by the UE, the terminal device is not allowed to be switched/allowed to access. It can be understood that, if the target access network device allows the terminal device to HANDOVER from the source access network device to the target access network device (i.e. allows the terminal device to access), the target access network device may send the first indication information to the terminal device, and if the target access network device does not allow the terminal device to HANDOVER from the source access network device to the target access network device (i.e. does not allow the terminal device to access), the target access network device may send a HANDOVER PREPARATION FAILURE (HANDOVER prepare FAILURE) message to the source access network device, where a cause value included in the HANDOVER PREPARATION FAILURE message may be: the entity does not support.

S602, the terminal device sets a network access mode of the terminal device according to the first indication information.

In some possible embodiments, after the terminal device receives the first indication information from the source access network device/the target access network device/the core network device, the terminal device may set a network access mode of the terminal device according to the first indication information. Specifically, when the first indication information is used to indicate a network type of a target network to be switched, the terminal device may first determine a network access mode (for convenience of description, hereinafter referred to as a target access mode) corresponding to the network type according to the network type of the target network, and then compare the target access mode with a current network access mode of the terminal device, if the target access mode is the same as the current network access mode of the terminal device, the terminal device may maintain the current network access mode unchanged, and if the target access mode is different from the current network access mode of the terminal device, the terminal device may adjust its network access mode to be the target access mode. When the first indication information is used for indicating a network access mode (namely, a target access mode) corresponding to the network type of the target network, the terminal device may directly compare the target access mode with a current network access mode of the terminal device, if the target access mode is the same as the current network access mode of the terminal device, the terminal device may maintain the current network access mode unchanged, and if the target access mode is different from the current network access mode of the terminal device, the terminal device may adjust the network access mode of the terminal device to the target access mode.

When the first indication information is used for indicating the network type of the handover target network, the first indication information may be an identifier of the target network, and/or the first indication information may be the network type of the target network, and/or the first indication information may be a cell identifier corresponding to the target network. That is, the first indication information may include at least one of an identity of the target network, a network type of the target network, and a cell identity corresponding to the target network. Specifically, (1) when the first indication information includes an identifier of the target network, if the target network is a PLMN, the identifier is a PLMN ID, and if the target network is an SNPN, the identifier is an SNPN ID. It can be understood that, since the SNPN ID corresponding to the SNPN consists of the PLMN ID and the NID, when the terminal device receives the identifier of the target network, it may determine, according to the length of the received identifier, whether the network type of the target network corresponding to the identifier is PLMN or SNPN, and further set the network access mode of the terminal device to the access mode corresponding to the network type of the target network. (2) When the first indication information is the network type of the target network, the terminal device may directly set the network access mode of the terminal device as the network access mode corresponding to the network type of the target network according to the network type of the target network. Generally, when the first indication information is the network type of the target network, the value of the first indication information may be directly set to "PLMN" or "SNPN". Alternatively, the value of the first indication information may also be set to "0" or "1", where 0 represents PLMN and 1 represents SNPN, or 0 represents SNPN and 1 represents PLMN, and the like, which is not limited herein. (3) When the first indication information includes a cell identifier corresponding to the target network, the terminal device may determine the network type of the target network according to the cell identifier, and further set the network access mode of the terminal device as the network access mode corresponding to the network type of the target network according to the network type of the target network. Specifically, the determining, by the terminal device, the network type of the target network according to the cell identifier may be understood as: and the terminal equipment determines the network type supported by the target cell according to the received system information of the target cell and the cell identifier corresponding to the target network. The system information of the target cell includes a physical cell identity PCI, cell identities of at least two logical cells, and at least two networks corresponding to each cell identity. At least two networks corresponding to one cell identifier are the same type of network. That is, one cell identity corresponds to one network type. Therefore, according to the cell identifier corresponding to the target network, the network type corresponding to the cell identifier can be determined.

Understandably, after the terminal device sets the network access mode of the terminal device to the network access mode corresponding to the network type according to the network type of the target network indicated by the first indication information, or after the terminal device adjusts the network access mode of the terminal device to the network access mode indicated by the first indication information according to the network access mode indicated by the first indication information, the terminal device can acquire service in the target network. For example, without limitation, a packet may be received via the target network, etc.

In the embodiment of the application, the terminal device sets the network access mode according to the received first indication information, so that the problem of unmatched access modes after the terminal device is switched to the target network can be avoided, and the reliability and the stability of communication are improved. Specifically, (1) when the first indication information is used to indicate the network type of the handover target network, the terminal device may set a corresponding access mode by determining whether the network type of the target network is PLMN or SNPN. (2) When the first indication information is used to indicate a network access mode corresponding to the network type of the target network (i.e., a target access mode), the terminal device may directly set the access mode according to the indication. It can be understood that, in the scheme that the terminal device directly sets the access mode according to the indication, since the terminal device does not need to judge how to set the access mode, the processing complexity of the terminal device can be further reduced.

For easy understanding, the technical solutions provided in the present application will be further described below with reference to fig. 7 to 18.

Exemplarily, please refer to fig. 7, and fig. 7 is another flow chart of the communication method according to the embodiment of the present application. As shown in fig. 7, when the first indication information is used to indicate a network type of a handover target network, and the terminal device switches from the source access network device to the target access network device by using Xn handover, and the source access network device sends the first indication information to the terminal device, the related handover procedure includes the following steps:

step 1, the source access network equipment sends a switching request message to the target access network equipment. Wherein, the handover request message includes information such as the identifier of the target network. Optionally, the handover request message may further include information such as an identifier of the target network and second indication information, which is not limited herein.

And 2, the target access network equipment sends the RRC reconfiguration message to the source access network equipment. Generally, after the target access network device receives the handover request message, the target access network device may determine not to allow the access of the terminal device (that is, the target base station performs admission control) according to its own condition and/or the second indication information, and if the access of the terminal device is allowed, send an RRC reconfiguration message to the source access network device. The RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell, or the RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell and system information of the target cell. It is to be understood that the RRC reconfiguration message may be carried in a handover request acknowledgement message to be sent to the source access network device (i.e. the handover request acknowledgement message includes the RRC reconfiguration message), and therefore, the sending of the RRC reconfiguration message to the source access network device by the target access network device may be understood as: and the target access network equipment sends a switching request confirmation message to the source access network equipment.

And 3, the source access network equipment sends first indication information to the terminal equipment. The first indication information includes at least one of the following information: (1) identification of the target network. If the target network is PLMN, the identification is PLMN ID; if the target network is SNPN, the identification is SNPN ID. (2) The type of target network. For example, the value of the first indication information may be "PLMN" or "SNPN". For another example, the value of the first indication information may be "0" or "1", where 0 and 1 respectively represent PLMN and SNPN. (3) The cell identifier corresponding to the target network, or the system information of the target cell and the cell identifier corresponding to the target network. The first indication information may be carried in an RRC reconfiguration message or other RRC messages, which is not limited herein. For example, after the source access network device receives the handover request acknowledgement message from the target access network device, the first indication information may be carried in the RRC reconfiguration message and sent to the terminal device. For another example, after the source access network device receives the handover request acknowledgement message from the target access network device, the source access network device sends another RRC message to the terminal device before forwarding the RRC reconfiguration message in the handover request acknowledgement message to the terminal device, or after forwarding the RRC reconfiguration message in the handover request acknowledgement message to the terminal device, where the RRC message carries the first indication information.

And 4, the terminal equipment judges the type of the target network according to the first indication information and sets a network access mode of the terminal equipment according to the type of the target network. Specifically, if the identifier of the target network is included in the first indication information, the terminal device may determine whether the target network is a PLMN or an SNPN according to whether the NID is included in the identifier, or the terminal device may determine whether the target network is a PLMN or an SNPN according to the length of the identifier. If the type of the target network is included in the first indication information, the terminal device may directly obtain the type of the target network. If the first indication information includes a cell identifier corresponding to the target network, the terminal device may determine the type of the target network according to the system information of the target cell and the cell identifier corresponding to the target network. Further, the terminal device sets its own access mode according to the acquired network type of the target network. Wherein, the access modes which can be set comprise: SNPN access mode, non-SNPN access mode. For example, if the network type of the target network is SNPN, the access mode may be set to an SNPN access mode, and if the network type of the target network is PLMN, the access mode may be set to a non-SNPN access mode.

And 5, the terminal equipment synchronizes to the target cell and sends an RRC reconfiguration completion message to the target access network equipment. It can be understood that steps 4 and 5 are not in sequence, that is, the terminal device may first adjust the access mode and then synchronize to the target cell, or may first synchronize to the target cell and then adjust the access mode, which is not limited herein.

Exemplarily, please refer to fig. 8, and fig. 8 is another flow chart of the communication method according to the embodiment of the present application. As shown in fig. 8, when the first indication information is used to indicate a network type of a handover target network, and the terminal device is handed over from the source access network device to the target access network device by using Xn handover, and the target access network device sends the first indication information to the terminal device, the handover procedure involved includes the following steps:

And 2, the target access network equipment sends the RRC reconfiguration message to the source access network equipment. Generally, after the target access network device receives the handover request message, the target access network device may determine not to allow the access of the terminal device according to its own condition and/or the second indication information (i.e., the target base station performs admission control), and if the access of the terminal device is allowed, send an RRC reconfiguration message to the source access network device. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and the first indication information, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, the first indication information, and system information of the target network. It can be understood that, the sending of the RRC reconfiguration message by the target access network device to the source access network device may be: and the target access network equipment sends a switching request confirmation message to the source access network equipment. And the switching request confirms the RRC reconfiguration message in the message. Wherein the first indication information comprises at least one of the following information: (1) identification of the target network. If the target network is PLMN, the identification is PLMN ID; if the target network is SNPN, the identification is SNPN ID. (2) The type of target network. For example, the value of the first indication information may be "PLMN" or "SNPN". For another example, the value of the first indication information may be "0" or "1", where 0 and 1 respectively represent PLMN and SNPN. (3) The cell identifier corresponding to the target network, or the system information of the target cell and the cell identifier corresponding to the target network.

And 3, the source access network equipment sends the RRC reconfiguration message to the terminal equipment. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and the first indication information, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, the first indication information, and system information of the target network. That is, the source access network device may forward the RRC reconfiguration message received in step 2 to the terminal device.

And 4, judging the type of the target network according to the first indication information, and setting the network access mode of the terminal equipment according to the type of the target network. Specifically, after receiving the RRC reconfiguration message, the terminal device may determine the type of the target network according to the first indication information included in the RRC reconfiguration message. Specifically, if the identifier of the target network is included in the first indication information, the terminal device may determine whether the target network is a PLMN or an SNPN according to whether the NID is included in the identifier, or the terminal device may determine whether the target network is a PLMN or an SNPN according to the length of the identifier. If the type of the target network is included in the first indication information, the terminal device may directly obtain the type of the target network. If the first indication information includes a cell identifier corresponding to the target network, the terminal device may determine the type of the target network according to the system information of the target cell and the cell identifier corresponding to the target network. Further, the terminal device sets its own access mode according to the acquired network type of the target network. Wherein, the access modes which can be set comprise: SNPN access mode, non-SNPN access mode. For example, if the network type of the target network is SNPN, the SNPN access mode is set, and if the network type of the target network is PLMN, the non-SNPN access mode is set.

And 5, the terminal equipment synchronizes to the target cell and sends an RRC reconfiguration completion message to the target access network equipment. It can be understood that the above steps 4 and 5 are not in sequence, that is, the terminal device may first adjust the access mode and then synchronize to the target cell, or may first synchronize to the target cell and then adjust the access mode, which is not limited herein.

Exemplarily, please refer to fig. 9, where fig. 9 is another schematic flow chart of the communication method provided in the embodiment of the present application. As shown in fig. 9, when the first indication information is used to indicate a network type of a handover target network, and the terminal device is handed over from the source access network device to the target access network device by using Xn handover, and the core network device sends the first indication information to the terminal device, the handover procedure involved includes the following steps:

step 1, the source access network equipment can send a switching request message to the target access network equipment. Specifically, when the source access network device confirms that the terminal device needs to perform handover, the source access network device may send a handover request message to the target access network device. Wherein, the handover request message includes information such as the identifier of the target network. Optionally, the handover request message may further include information such as an identifier of the target network and second indication information, which is not limited herein.

And 2, the target access network equipment sends the RRC reconfiguration message to the source access network equipment. Generally, after the target access network device receives the handover request message, the target access network device may determine not to allow the access of the terminal device according to its own condition and/or the second indication information (i.e., the target base station performs admission control), and if the access of the terminal device is allowed, send an RRC reconfiguration message to the source access network device. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and system information of the target network. It can be understood that the RRC reconfiguration message may be carried in the handover request acknowledgement message, that is, the sending of the RRC reconfiguration message to the source access network device by the target access network device may be understood as: and the target access network equipment sends a switching request confirmation message to the source access network equipment. Wherein, the switching request confirmation message includes an RRC reconfiguration message.

And 3, the source access network equipment sends (or is called forwarding) the RRC reconfiguration message to the terminal equipment. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and system information of the target network. The RRC reconfiguration message may be carried in the handover command, that is, the sending of the RRC reconfiguration message to the terminal device by the source access network device may be: and the source access network equipment sends a switching command to the terminal equipment, wherein the switching command comprises the RRC reconfiguration message related to the step 2.

And 4, the terminal equipment synchronizes to the target cell and sends an RRC reconfiguration completion message to the target access network equipment. Specifically, after receiving the RRC reconfiguration message, the terminal device exits from the original cell and synchronizes to the target cell according to the indication of the RRC reconfiguration message, and sends an RRC reconfiguration complete message to the target access network device after synchronizing to the target cell.

And 5, the target access network equipment sends the UE context release message to the source access network equipment. Specifically, after receiving the RRC reconfiguration complete message sent by the terminal device, the target access network device sends a UE context release message to the source access network device.

And 6, the terminal equipment sends a registration request message to the core network equipment.

And 7, the core network equipment sends a registration acceptance message to the terminal equipment. Wherein, the registration acceptance message may include first indication information, and the first indication information includes at least one of the following information: (1) identification of the target network. If the target network is PLMN, the identification is PLMN ID; if the target network is SNPN, the identification is SNPN ID. (2) The type of target network. For example, the value of the first indication information may be "PLMN" or "SNPN". For another example, the value of the first indication information may be "0" or "1", where 0 and 1 respectively represent PLMN and SNPN.

And 8, the terminal equipment judges the type of the target network according to the first indication information and sets the network access mode of the terminal equipment according to the type of the target network. Specifically, if the first indication information includes an identifier of the target network, the terminal device may determine whether the type of the target network is PLMN or SNPN according to whether the NID is included in the identifier, or the terminal device may determine whether the type of the target network is PLMN or SNPN according to the length of the identifier, and then set its access mode according to the determined type of the target network. If the first indication information includes the type of the target network, the terminal device may directly acquire the type of the target network, and then set an access mode of the terminal device according to the determined type of the target network. Wherein, the access modes which can be set comprise: SNPN access mode, non-SNPN access mode. For example, if the network type of the target network is SNPN, the access mode may be set to an SNPN access mode, and if the network type of the target network is PLMN, the access mode may be set to a non-SNPN access mode.

Exemplarily, please refer to fig. 10, and fig. 10 is another schematic flow chart of the communication method according to the embodiment of the present application. As shown in fig. 10, when the first indication information is used to indicate a handover target access mode, the terminal device switches from the source access network device to the target access network device by using Xn handover, and the source access network device sends the first indication information to the terminal device, the involved handover procedure includes the following steps:

And 2, the target access network equipment sends RRC reconfiguration information to the source access network equipment. Generally, after the target access network device receives the handover request message, the target access network device may determine not to allow the access of the terminal device according to its own condition and/or the second indication information (i.e., the target base station performs admission control), and if the access of the terminal device is allowed, send an RRC reconfiguration message to the source access network device. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and system information of the target network. It can be understood that the RRC reconfiguration message may be carried in the handover request acknowledgement message, that is, the sending of the RRC reconfiguration message to the source access network device by the target access network device may be understood as: and the target access network equipment sends a switching request confirmation message to the source access network equipment. Wherein, the switching request confirmation message includes an RRC reconfiguration message.

And 3, the source access network equipment determines a target access mode and generates first indication information according to the target access mode. That is to say, the source access network device may determine how the terminal device sets the access mode according to the network type to which the target network selected by the source access network device for the terminal device belongs, and then generate the first indication information according to the determined access mode (i.e., the target access mode). Briefly, the first indication information may be used to indicate a target access mode. The access modes referred to in the present application include SNPN access mode and non-SNPN access mode. For example, when the network type of the target network is SNPN, the corresponding network access mode is SNPN access mode, and when the network type of the target network is PLMN, the corresponding network access mode is non-SNPN access mode. Specifically, it may be defined that when a value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the SNPN access mode, and when a value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the non-SNPN access mode. Or, it may also be defined that when the value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the non-SNPN access mode, and when the value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the SNPN access mode, which is not limited herein.

And 4, the source access network equipment sends the first indication information to the terminal equipment. The first indication information may be carried in an RRC reconfiguration message or other RRC messages, which is not limited herein. For example, after the source access network device receives the handover request acknowledgement message from the target access network device, the first indication information may be carried in the RRC reconfiguration message and sent to the terminal device. For another example, after the source access network device receives the handover request acknowledgement message from the target access network device, the source access network device sends another RRC message to the terminal device before forwarding the RRC reconfiguration message in the handover request acknowledgement message to the terminal device, or after forwarding the RRC reconfiguration message in the handover request acknowledgement message to the terminal device, where the RRC message carries the first indication information.

And 5, the terminal equipment sets the access mode of the terminal equipment (namely the terminal equipment) according to the first indication information. Specifically, if the network access mode indicated by the first indication information is the same as the current network access mode of the terminal device, the terminal device may maintain the current network access mode unchanged, and if the network access mode indicated by the first indication information is different from the current network access mode of the terminal device, the terminal device may adjust its network access mode to the network access mode indicated by the first indication information.

And 6, the terminal equipment synchronizes to the target cell and sends an RRC reconfiguration completion message to the target access network equipment.

It can be understood that, the step 5 and the step 6 are not in sequence, that is, the terminal device may first adjust the access mode and then synchronize to the target cell, or the terminal device may first synchronize to the target cell and then adjust the access mode, which is not limited herein.

Exemplarily, please refer to fig. 11, where fig. 11 is another schematic flow chart of the communication method provided in the embodiment of the present application. As shown in fig. 11, when the first indication information is used to indicate a handover target access mode, the terminal device switches from the source access network device to the target access network device by using Xn handover, and the source access network device sends the first indication information to the terminal device, the related handover procedure includes the following steps:

And step 2, the target access network equipment determines a target access mode and generates first indication information according to the target access mode. Generally, after the target access network device receives the handover request message, the target access network device may determine not to allow the access of the terminal device (i.e., the target base station performs admission control) according to its own condition and/or the second indication information, and if the access of the terminal device is allowed, determine the network type of the target network according to information, such as the identifier of the target network, included in the handover request message, and further determine how the terminal device sets the access mode according to the determined network type of the target network, so as to generate the first indication information according to the determined access mode (i.e., the target access mode). That is, the first indication information may be used to indicate the target access mode. The access modes referred to in the present application include SNPN access mode and non-SNPN access mode. For example, when the network type of the target network is SNPN, the corresponding network access mode is SNPN access mode, and when the network type of the target network is PLMN, the corresponding network access mode is non-SNPN access mode. Specifically, it may be defined that when a value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the SNPN access mode, and when a value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the non-SNPN access mode. Or, it may also be defined that, when the value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the non-SNPN access mode, and when the value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the SNPN access mode, which is not limited herein.

And 3, the target access network equipment sends RRC reconfiguration information to the source access network equipment. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and the first indication information, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, the first indication information, and system information of the target network. It is to be understood that the RRC reconfiguration message may be carried in a handover request acknowledgement message to be sent to the source access network device, that is, the handover request acknowledgement message includes the RRC reconfiguration message.

And 4, the source access network equipment forwards the RRC reconfiguration message to the terminal equipment. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and the first indication information, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, the first indication information, and system information of the target network, which is not limited herein. It can be understood that the RRC reconfiguration message may be carried in a handover command to be sent to the source access network device, or the handover command may include the RRC reconfiguration message.

And 5, the terminal equipment sets the access mode of the terminal equipment according to the first indication information. Specifically, after receiving the RRC reconfiguration message, the terminal device may set an access mode of the terminal device according to the first indication information included in the RRC reconfiguration message. If the network access mode indicated by the first indication information is the same as the current network access mode of the terminal device, the terminal device may maintain the current network access mode unchanged, and if the network access mode indicated by the first indication information is different from the current network access mode of the terminal device, the terminal device may adjust its network access mode to the network access mode indicated by the first indication information.

And 6, the terminal equipment synchronizes to the target cell and sends an RRC reconfiguration completion message to the target access network equipment. It can be understood that, the steps 5 and 6 are not in sequence, that is, the terminal device may first adjust the access mode and then synchronize to the target cell, or the terminal device may first synchronize to the target cell and then adjust the access mode, which is not limited herein.

Exemplarily, please refer to fig. 12, and fig. 12 is another schematic flow chart of the communication method according to the embodiment of the present application. As shown in fig. 12, when the first indication information is used to indicate a handover target access mode, the terminal device switches from the source access network device to the target access network device by using Xn handover, and the source access network device sends the first indication information to the terminal device, the related handover procedure includes the following steps:

And 4, the terminal equipment synchronizes to the target cell and sends an RRC reconfiguration completion message to the target access network equipment. Specifically, after receiving the RRC reconfiguration message, the terminal device quits from the original cell and synchronizes to the target cell according to the indication of the RRC reconfiguration message, and after synchronizing to the target cell, sends an RRC reconfiguration complete message to the target access network device.

And 7, the core network equipment determines a target access mode and generates first indication information according to the target access mode. Specifically, the core network device may receive information such as an identifier of the target network from the source access network device (not shown in the figure), and then determine the network type of the target network according to the received information such as the identifier of the target network. Further, determining how the terminal device sets the access mode according to the determined network type of the target network, so as to generate the first indication information according to the determined access mode (i.e. the target access mode). That is, the first indication information may be used to indicate the target access mode. The access modes referred to in the present application include SNPN access mode and non-SNPN access mode. For example, when the network type of the target network is SNPN, the corresponding network access mode is SNPN access mode, and when the network type of the target network is PLMN, the corresponding network access mode is non-SNPN access mode. Specifically, it may be defined that when a value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the SNPN access mode, and when a value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the non-SNPN access mode. Or, it may also be defined that when the value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the non-SNPN access mode, and when the value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the SNPN access mode, which is not limited herein.

And 8, the core network equipment sends a registration acceptance message to the terminal equipment. Wherein, the registration acceptance message may include the first indication information.

And 9, the terminal equipment sets the access mode of the terminal equipment according to the first indication information. Specifically, if the network access mode indicated by the first indication information is the same as the current network access mode of the terminal device, the terminal device may maintain the current network access mode unchanged, and if the network access mode indicated by the first indication information is different from the current network access mode of the terminal device, the terminal device may adjust its network access mode to the network access mode indicated by the first indication information.

Exemplarily, please refer to fig. 13, and fig. 13 is another schematic flow chart of the communication method according to the embodiment of the present application. As shown in fig. 13, when the first indication information is used to indicate a network type of a handover target network, and the terminal device adopts NG handover to handover from the source access network device to the target access network device, and the source access network device sends the first indication information to the terminal device, the handover procedure involved includes the following steps:

step 1, the source access network equipment sends a switching requirement message to the core network equipment. Specifically, when the source access network device confirms that the terminal device needs to perform handover, the source access network device may send a handover required message to the core network device. The handover required message may include information such as an identifier of the target network. Optionally, the handover requirement message may further include information such as an identifier of the target network and second indication information, which is not limited herein.

And 2, the core network equipment sends a switching request message to the target access network equipment. Specifically, after receiving a handover request message sent by a source access network device, a core network device sends a handover request message to a target access network device. The handover request message may include information such as an identifier of the target network. Optionally, the handover request message may further include information such as an identifier of the target network and second indication information, which is not limited herein.

And 3, the target access network equipment sends the RRC reconfiguration message to the core network equipment. Generally, after the target access network device receives the handover request message, the target access network device may determine not to allow the access of the terminal device (that is, the target base station performs admission control) according to its own condition and/or the second indication information, and if the access of the terminal device is allowed, send an RRC reconfiguration message to the core network device. The RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell, or the RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell and system information of the target cell. It can be understood that the RRC reconfiguration message may be carried in the handover request acknowledgement message to be sent to the source access network device (that is, the handover request acknowledgement message includes the RRC reconfiguration message), and therefore, the sending, by the target access network device, the RRC reconfiguration message to the source access network device may be understood as: and the target access network equipment sends a switching request confirmation message to the source access network equipment.

And 4, the core network equipment sends the RRC reconfiguration message to the source access network equipment. Wherein, the RRC reconfiguration message is the RRC reconfiguration message in step 3. That is to say, the RRC reconfiguration message may include information such as a physical cell identity PCI of the target cell, or the RRC reconfiguration message may include information such as a physical cell identity PCI of the target cell and system information of the target cell. It is understood that the RRC reconfiguration message may be carried in the handover command message to be sent to the source access network device (i.e. the handover command message includes the RRC reconfiguration message), and therefore, the sending of the RRC reconfiguration message to the source access network device by the target access network device may be understood as: and the target access network equipment sends a switching command message to the source access network equipment.

And 5, the source access network equipment sends first indication information to the terminal equipment. The first indication information includes at least one of the following information: (1) identification of the target network. If the target network is PLMN, the identification is PLMN ID; if the target network is SNPN, the identification is SNPN ID. (2) The type of target network. For example, the value of the first indication information may be "PLMN" or "SNPN". For another example, the value of the first indication information may be "0" or "1", where 0 and 1 respectively represent PLMN and SNPN. (3) The cell identifier corresponding to the target network, or the system information of the target cell and the cell identifier corresponding to the target network. The first indication information may be carried in an RRC reconfiguration message or other RRC messages, which is not limited herein. For example, when the source access network device receives a handover request acknowledgement message (the handover request acknowledgement message includes an RRC reconfiguration message) from the target access network device, the source access network device may carry the first indication information in the RRC reconfiguration message to send the first indication information to the terminal device. For another example, after the source access network device receives the handover request confirmation message (the handover request confirmation message includes the RRC reconfiguration message) from the target access network device, the source access network device may send another RRC message to the terminal device before forwarding the RRC reconfiguration message included in the handover request confirmation message to the terminal device, or after forwarding the RRC reconfiguration message included in the handover request confirmation message to the terminal device, where the RRC message carries/includes the first indication information.

And 6, the terminal equipment judges the type of the target network according to the first indication information and sets the network access mode of the terminal equipment according to the type of the target network. Specifically, if the first indication information includes an identifier of the target network, the terminal device may determine whether the target network is a PLMN or an SNPN according to whether the NID is included in the identifier, or the terminal device may determine whether the target network is a PLMN or an SNPN according to a length of the identifier. If the type of the target network is included in the first indication information, the terminal device may directly obtain the type of the target network. If the first indication information includes a cell identifier corresponding to the target network, the terminal device may determine the type of the target network according to the system information of the target cell and the cell identifier corresponding to the target network. Further, the terminal device sets its own access mode according to the acquired network type of the target network. Wherein, the access modes which can be set comprise: SNPN access mode, non-SNPN access mode. For example, if the network type of the target network is SNPN, the access mode may be set to an SNPN access mode, and if the network type of the target network is PLMN, the access mode may be set to a non-SNPN access mode.

And 7, the terminal equipment synchronizes to the target cell and sends an RRC reconfiguration completion message to the target access network equipment. It can be understood that step 6 and step 7 are not in sequence, that is, the terminal device may first adjust the access mode and then synchronize to the target cell, or may first synchronize to the target cell and then adjust the access mode, which is not limited herein.

Exemplarily, please refer to fig. 14, and fig. 14 is another schematic flow chart of the communication method according to the embodiment of the present application. As shown in fig. 14, when the first indication information is used to indicate a network type of a handover target network, and the terminal device adopts NG handover to handover from the source access network device to the target access network device, and the target access network device sends the first indication information to the terminal device, the handover procedure involved includes the following steps:

step 1, the source access network equipment sends a switching requirement message to the core network equipment. Specifically, when the source access network device confirms that the terminal device needs to be switched, the source access network device sends a switching requirement message to the core network device. The handover required message may include information such as an identifier of the target network. Optionally, the handover requirement message may further include information such as an identifier of the target network and second indication information, which is not limited herein.

And 3, the target access network equipment sends the RRC reconfiguration message to the core network equipment. Generally, after the target access network device receives the handover request message, the target access network device may determine not to allow the access of the terminal device according to its own condition and/or the second indication information (i.e., the target base station performs admission control), and if the access of the terminal device is allowed, send an RRC reconfiguration message to the core network device. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and the first indication information, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, the first indication information, and system information of the target network. It can be understood that the RRC reconfiguration message may be carried in the handover request acknowledgement message, that is, the sending of the RRC reconfiguration message to the core network device by the target access network device may be understood as: and the target access network equipment sends a switching request confirmation message to the core network equipment. Wherein, the switching request confirmation message includes an RRC reconfiguration message. Wherein the first indication information comprises at least one of the following information: (1) identification of the target network. If the target network is PLMN, the identification is PLMN ID; if the target network is SNPN, the identification is SNPN ID. (2) The type of target network. For example, the value of the first indication information may be "PLMN" or "SNPN". For another example, the value of the first indication information may be "0" or "1", where 0 and 1 respectively represent PLMN and SNPN. (3) The cell identifier corresponding to the target network, or the system information of the target cell and the cell identifier corresponding to the target network.

And 4, the core network equipment sends the RRC reconfiguration message to the source access network equipment. Wherein, the RRC reconfiguration message is the RRC reconfiguration message in step 3. That is, the RRC reconfiguration message includes information such as the physical cell identity PCI of the target cell and the first indication information, or the RRC reconfiguration message includes information such as the physical cell identity PCI of the target cell, the first indication information, and the system information of the target network. It is understood that the RRC reconfiguration message may be carried in the handover command message to be sent to the source access network device (i.e. the handover command message includes the RRC reconfiguration message), and therefore, the sending of the RRC reconfiguration message by the core network device to the source access network device may be understood as: and the core network equipment sends a switching command message to the source access network equipment.

And 5, the source access network equipment sends (or is called forwarding) the RRC reconfiguration message to the terminal equipment. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and the first indication information, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, the first indication information, and system information of the target network. That is to say, the RRC reconfiguration message is the RRC reconfiguration message included in the handover command message in step 4 (or step 3).

And 6, the terminal equipment judges the type of the target network according to the first indication information and sets the network access mode of the terminal equipment according to the type of the target network. Specifically, after receiving the RRC reconfiguration message, the terminal device may determine the type of the target network according to the first indication information included in the RRC reconfiguration message. Specifically, if the first indication information includes the identifier of the target network, the terminal device may determine whether the target network is a PLMN or an SNPN according to whether the NID is included in the identifier, or the terminal device may determine whether the target network is a PLMN or an SNPN according to the length of the identifier. If the type of the target network is included in the first indication information, the terminal device may directly obtain the type of the target network. If the first indication information includes a cell identifier corresponding to the target network, the terminal device may determine the type of the target network according to the system information of the target cell and the cell identifier corresponding to the target network. Further, the terminal device sets its own access mode according to the determined network type of the target network. Wherein, the access modes which can be set comprise: SNPN access mode, non-SNPN access mode. For example, if the network type of the target network is SNPN, the SNPN access mode is set, and if the network type of the target network is PLMN, the non-SNPN access mode is set.

And 7, the terminal equipment synchronizes to the target cell and sends an RRC reconfiguration completion message to the target access network equipment. It can be understood that the above step 6 and step 7 are not in sequence, that is, the terminal device may first adjust the access mode and then synchronize to the target cell, or may first synchronize to the target cell and then adjust the access mode, which is not limited herein.

Exemplarily, please refer to fig. 15, where fig. 15 is another schematic flow chart of the communication method according to the embodiment of the present application. As shown in fig. 15, when the first indication information is used to indicate a network type of a handover target network, and the terminal device adopts NG handover to handover from the source access network device to the target access network device, and the core network device sends the first indication information to the terminal device, the handover procedure involved includes the following steps:

step 1, the source access network equipment sends a switching demand message to the core network equipment. Specifically, when the source access network device confirms that the terminal device needs to perform handover, the source access network device may send a handover requirement message to the core network device. The handover required message may include information such as an identifier of the target network. Optionally, the handover required message may further include information such as an identifier of the target network and second indication information, which is not limited herein.

And 2, the core network equipment sends a switching request message to the target access network equipment. Specifically, after the core network device receives the handover request message sent by the source access network device, the core network device sends a handover request message to the target access network device. The handover request message may include information such as an identifier of the target network. Optionally, the handover request message may further include information such as an identifier of the target network and second indication information, which is not limited herein.

And 3, the target access network equipment sends the RRC reconfiguration message to the core network equipment. Generally, after the target access network device receives the handover request message, the target access network device may determine not to allow the access of the terminal device (that is, the target base station performs admission control) according to its own condition and/or the second indication information, and if the access of the terminal device is allowed, send an RRC reconfiguration message to the core network device. The RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell, or the RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell and system information of the target cell. It is to be understood that the RRC reconfiguration message may be carried in a handover request acknowledgement message to be sent to the source access network device (i.e. the handover request acknowledgement message includes the RRC reconfiguration message), and therefore, the sending of the RRC reconfiguration message to the source access network device by the target access network device may be understood as: and the target access network equipment sends a switching request confirmation message to the source access network equipment.

And 4, the core network equipment sends the RRC reconfiguration message to the source access network equipment. The RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell, or the RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell and system information of the target cell. It is understood that the RRC reconfiguration message may be carried in the handover command message to be sent to the source access network device (i.e. the handover command message includes the RRC reconfiguration message), and therefore, the sending of the RRC reconfiguration message to the source access network device by the target access network device may be understood as: and the target access network equipment sends a switching command message to the source access network equipment.

And 5, the source access network equipment sends (or is called forwarding) the RRC reconfiguration message to the terminal equipment. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and system information of the target network. That is to say, the RRC reconfiguration message is the handover command message in step 4 above, which includes the RRC reconfiguration message.

And 6, the terminal equipment synchronizes to the target cell and sends an RRC reconfiguration completion message to the target access network equipment. That is, after receiving the RRC reconfiguration message, the terminal device may exit from the original cell and synchronize to the target cell according to the indication of the RRC reconfiguration message, and after synchronizing to the target cell, send an RRC reconfiguration complete message to the target access network device.

And 7, the target access network equipment sends a switching notification message to the core network equipment.

And 8, the target access network equipment sends a UE context release command message to the source access network equipment.

And 9, the source access network equipment sends a UE context release completion message to the target access network equipment.

And step 10, the terminal equipment sends a registration request message to the core network equipment.

And 11, the core network equipment sends a registration acceptance message to the terminal equipment. Wherein, the registration acceptance message may include first indication information, and the first indication information includes at least one of the following information: (1) identification of the target network. If the target network is PLMN, the identification is PLMN ID; if the target network is SNPN, the identification is SNPN ID. (2) The type of target network. For example, the value of the first indication information may be "PLMN" or "SNPN". For another example, the value of the first indication information may be "0" or "1", where 0 and 1 respectively represent PLMN and SNPN.

And step 12, the terminal equipment judges the type of the target network according to the first indication information, and sets the network access mode of the terminal equipment according to the type of the target network. Specifically, if the first indication information includes an identifier of the target network, the terminal device may determine whether the type of the target network is PLMN or SNPN according to whether the identifier includes NID, or the terminal device may determine whether the type of the target network is PLMN or SNPN according to the length of the identifier, and further set its access mode according to the determined type of the target network. If the first indication information includes the type of the target network, the terminal device may directly acquire the type of the target network, and then set its own access mode according to the determined type of the target network. Wherein, the access modes which can be set comprise: SNPN access mode, non-SNPN access mode. For example, if the network type of the target network is SNPN, the access mode may be set to an SNPN access mode, and if the network type of the target network is PLMN, the access mode may be set to a non-SNPN access mode.

Exemplarily, please refer to fig. 16, and fig. 16 is another schematic flow chart of the communication method according to the embodiment of the present application. As shown in fig. 16, when the first indication information is used to indicate a handover target access mode, the terminal device switches from the source access network device to the target access network device by using NG handover, and the source access network device sends the first indication information to the terminal device, the related handover procedure includes the following steps:

step 1, the source access network equipment sends a switching requirement message to the core network equipment. Specifically, when the source access network device confirms that the terminal device needs to perform handover, the source access network device may send a handover requirement message to the core network device. The handover required message may include information such as an identifier of the target network. Optionally, the handover requirement message may further include information such as an identifier of the target network and second indication information, which is not limited herein.

And 3, the target access network equipment sends the RRC reconfiguration message to the core network equipment. Generally, after the target access network device receives the handover request message, the target access network device may determine not to allow the access of the terminal device according to its own condition and/or the second indication information (i.e., the target base station performs admission control), and if the access of the terminal device is allowed, send an RRC reconfiguration message to the core network device. The RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell, or the RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell and system information of the target cell. It can be understood that the RRC reconfiguration message may be carried in the handover request acknowledgement message to be sent to the source access network device (that is, the handover request acknowledgement message includes the RRC reconfiguration message), and therefore, the sending, by the target access network device, the RRC reconfiguration message to the source access network device may be understood as: and the target access network equipment sends a switching request confirmation message to the source access network equipment.

And 4, the core network equipment sends the RRC reconfiguration message to the source access network equipment. Wherein, the RRC reconfiguration message is the RRC reconfiguration message in step 3. That is, the RRC reconfiguration message may include information such as a physical cell identity PCI of the target cell, or the RRC reconfiguration message may include information such as a physical cell identity PCI of the target cell and system information of the target cell. It can be understood that, the RRC reconfiguration message may be carried in the handover command message to be sent to the source access network device (that is, the handover command message includes the RRC reconfiguration message), and therefore, the sending, by the target access network device, the RRC reconfiguration message to the source access network device may be understood as: and the target access network equipment sends a switching command message to the source access network equipment.

And 5, the source access network equipment determines a target access mode and generates first indication information according to the target access mode. That is to say, the source access network device may determine how the terminal device sets the access mode according to the network type to which the target network selected by the source access network device for the terminal device belongs, and then generate the first indication information according to the determined access mode (i.e., the target access mode). Briefly, the first indication information may be used to indicate a target access mode. The access modes referred to in the present application include SNPN access mode and non-SNPN access mode. For example, when the network type of the target network is SNPN, the corresponding network access mode is SNPN access mode, and when the network type of the target network is PLMN, the corresponding network access mode is non-SNPN access mode. Specifically, it may be defined that when a value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the SNPN access mode, and when a value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the non-SNPN access mode. Or, it may also be defined that, when the value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the non-SNPN access mode, and when the value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the SNPN access mode, which is not limited herein.

And 6, the source access network equipment sends the first indication information to the terminal equipment. The first indication information may be carried in an RRC reconfiguration message or other RRC messages, which is not limited herein. For example, after the source access network device receives the handover request acknowledgement message from the target access network device, the first indication information may be carried in the RRC reconfiguration message and sent to the terminal device. For another example, after the source access network device receives the handover request acknowledgement message from the target access network device, the source access network device sends another RRC message to the terminal device before forwarding the RRC reconfiguration message in the handover request acknowledgement message to the terminal device, or after forwarding the RRC reconfiguration message in the handover request acknowledgement message to the terminal device, where the RRC message carries the first indication information.

And 7, the terminal equipment sets the access mode of the terminal equipment according to the first indication information. Specifically, if the network access mode indicated by the first indication information is the same as the current network access mode of the terminal device, the terminal device may maintain the current network access mode unchanged, and if the network access mode indicated by the first indication information is different from the current network access mode of the terminal device, the terminal device may adjust its network access mode to the network access mode indicated by the first indication information.

And 8, the terminal equipment synchronizes to the target cell and sends an RRC reconfiguration completion message to the target access network equipment.

It can be understood that step 7 and step 8 do not have a sequence, that is, the terminal device may first adjust the access mode and then synchronize to the target cell, or the terminal device may first synchronize to the target cell and then adjust the access mode, which is not limited herein.

Exemplarily, please refer to fig. 17, and fig. 17 is another schematic flow chart of the communication method according to the embodiment of the present application. As shown in fig. 17, when the first indication information is used to indicate to switch the target access mode, and the terminal device switches from the source access network device to the target access network device by using NG handover, and the target access network device sends the first indication information to the terminal device, the related handover procedure includes the following steps:

And 3, the target access network equipment determines a target access mode and generates first indication information according to the target access mode. Generally, after the target access network device receives the handover request message, the target access network device may determine not to allow the access of the terminal device (i.e., the target base station performs admission control) according to its own condition and/or the second indication information, and if the access of the terminal device is allowed, determine the network type of the target network according to information, such as the identifier of the target network, included in the handover request message, and further determine how the terminal device sets the access mode according to the determined network type of the target network, so as to generate the first indication information according to the determined access mode (i.e., the target access mode). That is, the first indication information may be used to indicate the target access mode. The access modes referred to in the present application include SNPN access mode and non-SNPN access mode. For example, when the network type of the target network is SNPN, the corresponding network access mode is SNPN access mode, and when the network type of the target network is PLMN, the corresponding network access mode is non-SNPN access mode. Specifically, it may be defined that when a value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the SNPN access mode, and when a value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the non-SNPN access mode. Or, it may also be defined that, when the value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the non-SNPN access mode, and when the value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the SNPN access mode, which is not limited herein.

And 4, the target access network equipment sends the RRC reconfiguration message to the core network equipment. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and the first indication information, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, the first indication information, and system information of the target network. It can be understood that the RRC reconfiguration message may be carried in the handover request acknowledgement message, that is, the sending of the RRC reconfiguration message to the core network device by the target access network device may be understood as: and the target access network equipment sends a switching request confirmation message to the core network equipment. Wherein, the switching request confirmation message includes an RRC reconfiguration message.

And 5, the core network equipment sends the RRC reconfiguration message to the source access network equipment. Wherein, the RRC reconfiguration message is the RRC reconfiguration message in step 4. That is to say, the RRC reconfiguration message includes information such as the physical cell identity PCI of the target cell and the first indication information, or the RRC reconfiguration message includes information such as the physical cell identity PCI of the target cell, the first indication information, and system information of the target network. It is understood that the RRC reconfiguration message may be carried in the handover command message to be sent to the source access network device (i.e. the handover command message includes the RRC reconfiguration message), and therefore, the sending of the RRC reconfiguration message by the core network device to the source access network device may be understood as: and the core network equipment sends a switching command message to the source access network equipment.

And 6, the source access network equipment sends (or is called forwarding) the RRC reconfiguration message to the terminal equipment. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and the first indication information, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, the first indication information, and system information of the target network. That is to say, the RRC reconfiguration message is the RRC reconfiguration message included in the handover command message in step 5 (or step 4).

And 7, the terminal equipment sets the access mode of the terminal equipment (namely the terminal equipment) according to the first indication information. Specifically, if the network access mode indicated by the first indication information is the same as the current network access mode of the terminal device, the terminal device may maintain the current network access mode unchanged, and if the network access mode indicated by the first indication information is different from the current network access mode of the terminal device, the terminal device may adjust its network access mode to the network access mode indicated by the first indication information.

It can be understood that there is no sequence between step 7 and step 8, that is, the terminal device may first adjust the access mode and then synchronize to the target cell, or may first synchronize to the target cell and then adjust the access mode, which is not limited herein.

Exemplarily, please refer to fig. 18, and fig. 18 is another schematic flow chart of the communication method according to the embodiment of the present application. As shown in fig. 18, when the first indication information is used to indicate a handover target access mode, the terminal device adopts NG handover to handover from the source access network device to the target access network device, and the core network device sends the first indication information to the terminal device, the handover procedure involved includes the following steps:

step 1, the source access network equipment sends a switching requirement message to the core network equipment. Specifically, when the source access network device confirms that the terminal device needs to perform handover, the source access network device may send a handover required message to the core network device. The handover required message includes information such as an identifier of the target network. Optionally, the handover requirement message may further include information such as an identifier of the target network and second indication information, which is not limited herein.

And 3, the target access network equipment sends the RRC reconfiguration message to the core network equipment. Generally, after the target access network device receives the handover request message, the target access network device may determine not to allow the access of the terminal device according to its own condition and/or the second indication information (i.e., the target base station performs admission control), and if the access of the terminal device is allowed, send an RRC reconfiguration message to the core network device. The RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell, or the RRC reconfiguration message may include information such as a physical cell identifier PCI of the target cell and system information of the target cell. It is to be understood that the RRC reconfiguration message may be carried in a handover request acknowledgement message to be sent to the source access network device (i.e. the handover request acknowledgement message includes the RRC reconfiguration message), and therefore, the sending of the RRC reconfiguration message to the source access network device by the target access network device may be understood as: and the target access network equipment sends a switching request confirmation message to the source access network equipment.

And 5, the source access network equipment sends (or is called forwarding) the RRC reconfiguration message to the terminal equipment. The RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell, or the RRC reconfiguration message includes information such as a physical cell identifier PCI of the target cell and system information of the target network. That is to say, the RRC reconfiguration message is the handover command message in step 4 includes the RRC reconfiguration message.

And step 11, the core network equipment determines a target access mode and generates first indication information according to the target access mode. Specifically, the core network device may determine the network type of the target network according to information such as an identifier of the target network received from the source access network device. Further, determining how the terminal device sets the access mode according to the determined network type of the target network, so as to generate the first indication information according to the determined access mode (i.e. the target access mode). That is, the first indication information may be used to indicate the target access mode. The access modes referred to in the present application include SNPN access mode and non-SNPN access mode. For example, when the network type of the target network is SNPN, the corresponding network access mode is SNPN access mode, and when the network type of the target network is PLMN, the corresponding network access mode is non-SNPN access mode. Specifically, it may be defined that when a value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the SNPN access mode, and when a value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the non-SNPN access mode. Or, it may also be defined that, when the value of the first indication information is "0", the first indication information is used to indicate that the network access mode is the non-SNPN access mode, and when the value of the first indication information is "1", the first indication information is used to indicate that the network access mode is the SNPN access mode, which is not limited herein.

And 12, the core network equipment sends a registration acceptance message to the terminal equipment. Wherein, the registration acceptance message may include the first indication information.

And step 13, the terminal equipment sets the access mode of the terminal equipment according to the first indication information. Specifically, if the network access mode indicated by the first indication information is the same as the current network access mode of the terminal device, the terminal device may maintain the current network access mode unchanged, and if the network access mode indicated by the first indication information is different from the current network access mode of the terminal device, the terminal device may adjust its network access mode to the network access mode indicated by the first indication information.

Fig. 7 to 12 illustrate the procedure of transmitting and receiving the first instruction information from the viewpoint of Xn switching, and fig. 13 to 18 illustrate the procedure of transmitting and receiving the first instruction information from the viewpoint of NG switching. The first indication information related to fig. 7 to 9 and 13 to 15 is used to indicate the network type of the handover target network, and is sent from the source access network device, the target access network device, and the core network device to the terminal device, respectively. The first indication information related to fig. 10 to 12 and fig. 16 to 18 is used to indicate the network access mode corresponding to the network type of the target network, and is exemplarily described in that the first indication information is transmitted from the source access network device, the target access network device, and the core network device to the terminal device. The terminal equipment sets the network access mode according to the received first indication information, so that the problem that the access mode is not matched after the terminal equipment is switched to a target network can be avoided, and the reliability and the stability of communication are improved.

It is understood that when a UE accesses a network, the network typically authenticates the newly accessed UE (authentication), otherwise known as identity verification. Typically, the UE possesses a certificate (credential) of the accessed network, and therefore, the network can authenticate the UE according to the certificate. The external authentication means that the UE has a certificate of an external entity, so that when the UE accesses a certain network, the network can authenticate the UE on the external entity according to the certificate of the external entity. Referring to fig. 19, fig. 19 is a schematic view of a scenario of external authentication according to an embodiment of the present application. As shown in fig. 19, if a terminal device (e.g., UE1 shown in fig. 19) possesses a certificate of an external entity, when the UE1 accesses a certain network (e.g., network 1 shown in fig. 19), the network 1 may authenticate the UE on the external entity 1 according to the certificate of the external entity 1 owned by the UE. An external entity refers to an entity independent from the accessed network (e.g., network 1), such as an entity in another network (e.g., network 2), or an independent authentication server. The external entity, or owner of the external entity, is called a Home-Service Provider (H-SP). Several home servers may form a home server group (H-SP group).

Understandably, when the UE accesses the network through the external authentication manner, it can only switch to the network supporting the same external entity. For convenience of understanding, please refer to fig. 20, where fig. 20 is a schematic switching diagram in an external authentication scenario provided in the embodiment of the present application. As shown in fig. 20, since the network 1 and the network 2 are connected to the same external entity 1, the UE1 can switch between the two networks, i.e. the UE1 can switch from the network 1 to the network 2. Generally, during the handover process, the target access network device can only allow the handover if it is confirmed that the external entity associated with the target network (such as network 2 shown in fig. 20) supported by the target access network device is the same as the external entity associated with the source network (such as network 1 shown in fig. 20) supported by the source access network device. Therefore, the source access network device needs to notify the target access network device of the information of the external entity associated with the source network (i.e. network 1) accessed by the UE, so that the target access network device can make admission control/handover decision according to the external entity information received from the source access network device.

Referring to fig. 21, fig. 21 is another schematic flow chart of a communication method according to an embodiment of the present disclosure. As shown in fig. 21, the method includes the following steps S2101 to S2103:

s2101, the source access network equipment determines second indication information.

In some possible embodiments, the source access network device determines the second indication information. The second indication information is used for indicating the identification of the entity possessing the terminal equipment certificate, or the second indication information is used for indicating the identification of the entity authenticating the terminal equipment. The entity may be an entity in another network (or referred to as a network other than the target network), or an independent authentication server, or may be an external entity group, or a home service provider group, and the like, which is not limited herein.

S2102, the source access network device sends second indication information to the target access network device.

In some possible embodiments, the source access network device sends the second indication information to the target access network device. If the terminal device switches from the network supported by the source access network device (i.e., the source network) to the network supported by the target access network device (i.e., the target network) by using Xn, the second indication information may be carried in the handover request message sent by the source access network device to the target access network device. That is, the sending of the second indication information by the source access network device to the target access network device may be understood as: and the source access network equipment sends a switching request message to the target access network equipment, wherein the switching request message can comprise second indication information, identification of the target network and other information. If the terminal device adopts NG handover to switch from a network supported by the source access network device (i.e., a source network) to a network supported by the core network device (i.e., a target network), the source access network device may send the second indication information to the target access network device through the core network device. Specifically, the sending of the second indication information by the source access network device to the target access network device may be: and the source access network equipment sends a switching requirement message to the core network equipment, wherein the switching requirement message can comprise second indication information, identification of the target network and other information. The core network device sends a handover request message to the target access network device, wherein the handover request message may include information such as second indication information and an identifier of the target network.

S2103, the target access network device determines whether to allow the terminal device to switch from the source access network device to the target access network device according to the second indication information.

In some possible embodiments, after the target access network device receives the second indication information from the source access network device, the target access network device may determine whether to allow the terminal device to switch from the source access network device to the target access network device according to the second indication information, or the target access network device may determine whether to allow the terminal device to access according to the second indication information. That is, the target access network device may perform admission control according to the second indication information. Generally speaking, if the target access network device determines that the target network supports the entity corresponding to the certificate used by the UE, the terminal device is allowed to be switched/allowed to access, and if the target access network device determines that the target network does not support the entity corresponding to the certificate used by the UE, the terminal device is not allowed to be switched/allowed to access. It can be understood that, if the target access network device allows the terminal device to HANDOVER from the source access network device to the target access network device (i.e. allows the terminal device to access), the target access network device may send a HANDOVER request acknowledgement message to the source access network device, and if the target access network device does not allow the terminal device to HANDOVER from the source access network device to the target access network device (i.e. does not allow the terminal device to access), the target access network device may send a HANDOVER PREPARATION FAILURE (HANDOVER PREPARATION FAILURE) message to the source access network device, where a cause value included in the HANDOVER PREPARATION FAILURE message may be: the entity does not support.

Optionally, in some possible embodiments, if the target access network device determines, according to the second indication information, to allow the terminal device to switch from the source access network device to the target access network device (that is, to allow the terminal device to access the target network supported by the target access network device), the target access network device determines first indication information, where the first indication information is used to indicate a network type of the target network to be switched, or the first indication information is used to indicate a network access mode corresponding to the network type. Further, the target access network device sends the first indication information to the terminal device. The process of determining the first indication information by the target access network device and sending the first indication information to the terminal device by the target access network device may refer to the implementation processes described in fig. 6, fig. 8, fig. 11, fig. 14, and fig. 17, which are not described herein again.

In the application, the target access network device receives the second indication information from the source access network device, and acquires the external entity associated when the UE accesses the source network supported by the source access network device according to the second indication information, so as to determine whether to allow the UE to switch to the target network, thereby avoiding a switching failure caused by switching the UE to the target network that does not support the current external entity, and improving reliability and stability of communication.

For example, please refer to fig. 22, fig. 22 is another flowchart of the communication method according to the embodiment of the present application. As shown in fig. 22, when the terminal device switches from the source access network device to the target access network device by using Xn handover, the involved matching process includes the following steps:

step 1, the source access network equipment sends a switching request message to the target access network equipment. The handover request message includes information such as an identifier of the target network and the second indication information.

And step 2, the target access network equipment performs access control. Specifically, after the target access network device receives the handover request message sent by the source access network device, the target access network device determines not to allow the terminal device to access (i.e., the target access network device performs admission control/admission control) according to the second indication information and the like. And if the source access network equipment is not allowed, sending a switching preparation failure message to the source access network equipment.

And 3a, the target base station sends a switching request confirmation message to the source base station. Specifically, if the target base station allows handover, a handover request confirm message is transmitted to the source base station. Wherein, the switching request confirmation message comprises an RRC configuration message. It can be understood that, if the target base station allows the handover/allows the access of the terminal device, the following handover process may also refer to the implementation processes described in fig. 6 and fig. 7 to fig. 12, which are not described herein again.

And 3b, the target base station sends a switching preparation failure message to the source base station. Specifically, if the target base station does not allow handover, a handover preparation failure message is sent to the source base station, where the handover preparation failure message may include a cause value: the entity does not support.

For example, please refer to fig. 23, fig. 23 is another schematic flow chart of the communication method according to the embodiment of the present application. As shown in fig. 23, when the terminal device adopts NG handover to handover from the source access network device to the target access network device, the involved matching procedure includes the following steps:

step 1, the source access network equipment sends a switching requirement message to the core network equipment. Specifically, when the source access network device confirms that the terminal device needs to perform handover, the source access network device may send a handover requirement message to the core network device. The handover required message may include information such as an identifier of the target network and the second indication information.

And 2, the core network equipment sends a switching request message to the target access network equipment. Specifically, after the core network device receives the handover request message sent by the source access network device, the core network device may send a handover request message to the target access network device. The handover request message may include information such as an identifier of the target network and second indication information.

And 3, performing admission control on the target access network equipment. Specifically, after the target access network device receives the second indication information sent by the source access network device through the core network device, the target access network device determines not to allow the access of the terminal device according to the second indication information and the like (that is, the target access network device performs admission control/admission control). If the HANDOVER preparation FAILURE message is allowed, the core network equipment sends a HANDOVER preparation FAILURE message to the source access network equipment. The handover failure message and the handover preparation failure message may include a cause value: the entity does not support.

And 4a, the target base station sends a switching request confirmation message to the core network equipment. Specifically, if the target base station allows handover, a handover request acknowledgement message is sent to the core network device. The handover request confirm message includes an RRC configuration message. It can be understood that, if the target base station allows the handover/access of the terminal device, the subsequent handover process may also refer to the implementation processes described in fig. 6 and fig. 13 to fig. 18, which are not described herein again.

And 5a, the core network equipment sends a switching command message to the source base station. Wherein, the switching command message includes the RRC configuration message.

And 4b, the target base station sends a switching failure message to the core network equipment. Specifically, if the target base station does not allow handover, a handover failure message is sent to the core network device, where the handover failure message may include a cause value: the entity does not support.

And 5b, the core network equipment sends a switching preparation failure message to the source base station. The handover preparation failure message may include a cause value: the entity does not support.

Fig. 22 to 23 illustrate the transmission/reception process of the second indication information from the viewpoint of Xn handover and NG handover, respectively. The target access network device can acquire the external entity associated when the UE accesses the source network supported by the source access network device according to the second indication information, and then can judge whether the UE is allowed to be switched to the target network, so that switching failure caused by switching the UE to the target network which does not support the current external entity can be avoided, and reliability and stability of communication are improved.

The communication device provided by the present application will be described in detail below with reference to fig. 24 to 25.

Referring to fig. 24, fig. 24 is a schematic structural diagram of a communication device according to an embodiment of the present application. The communication apparatus shown in fig. 24 may be used to perform part or all of the functions of the terminal device in the method embodiments described in fig. 6 to 18. The apparatus may be a terminal device, an apparatus in the terminal device, or an apparatus capable of being used in cooperation with the terminal device. The communication device can also be a chip system. The communication device shown in fig. 24 may include a transceiving unit 2401 and a processing unit 2402. The processing unit 2402 is configured to perform data processing. The transceiver 2401 is integrated with a receiving unit and a transmitting unit. The transceiving unit 2401 may also be referred to as a communication unit. Alternatively, transmitting/receiving section 2401 may be divided into a receiving section and a transmitting section. The processing unit 2402 and the transceiver unit 2401 are similar in structure, and are not described in detail below. Wherein:

in an implementation manner, the transceiving unit 2401 is configured to receive first indication information, where the first indication information is used to indicate a network type of a handover target network, or the first indication information is used to indicate a network access mode corresponding to the network type; a processing unit 2402, configured to set a network access mode of the terminal device according to the first indication information.

For other possible implementation manners of the communication apparatus, reference may be made to the related description of the functions of the terminal device in the method embodiments corresponding to fig. 6 to fig. 18, which is not described herein again.

Referring to fig. 24, fig. 24 is a schematic structural diagram of a communication device according to an embodiment of the present application. The communication apparatus shown in fig. 24 may be used to perform part or all of the functions of the source access network device in the method embodiments described in fig. 6 or fig. 7 or fig. 10 or fig. 13 or fig. 16. The device may be a source access network device, may also be a device in the source access network device, or may be a device that can be used in cooperation with the source access network device. The communication device can also be a chip system. The communication device shown in fig. 24 may include a transceiving unit 2401 and a processing unit 2402. Wherein:

in an implementation manner, the processing unit 2402 is configured to determine first indication information, where the first indication information is used to indicate a network type of a handover target network, or the first indication information is used to indicate a network access mode corresponding to the network type; a transceiving unit 2401, configured to send the first indication information to a terminal device.

For other possible implementation manners of the communication apparatus, reference may be made to the related description of the function of the source access network device in the method embodiment corresponding to fig. 6, or fig. 7, or fig. 10, or fig. 13, or fig. 16, which is not described herein again.

Referring to fig. 24, fig. 24 is a schematic structural diagram of a communication device according to an embodiment of the present application. The communication apparatus shown in fig. 24 may be configured to perform part or all of the functions of the target access network device in the method embodiments described in fig. 6, 8, 11, 14, or 17. The device may be a target access network device, may also be a device in the target access network device, or may be a device that can be used in cooperation with the target access network device. Wherein, the communication device can also be a chip system. The communication device shown in fig. 24 may include a transceiving unit 2401 and a processing unit 2402. Wherein:

in one implementation, the processing unit 2402 is configured to determine first indication information, where the first indication information is used to indicate a network type of a handover target network, or the first indication information is used to indicate a network access mode corresponding to the network type; a transceiving unit 2401, configured to send the first indication information to a terminal device.

For other possible implementation manners of the communication apparatus, reference may be made to related descriptions of functions of the terminal device in the method embodiments corresponding to fig. 6, or fig. 8, or fig. 11, or fig. 14, or fig. 17, which are not described herein again.

Referring to fig. 24, fig. 24 is a schematic structural diagram of a communication device according to an embodiment of the present application. The communication apparatus shown in fig. 24 may be configured to perform part or all of the functions of the core network device in the method embodiments described in fig. 6, 9, 12, 15, or 18. The apparatus may be a core network device, or an apparatus in a core network device, or an apparatus capable of being used in cooperation with a core network device. The communication device can also be a chip system. The communication device shown in fig. 24 may include a transceiving unit 2401 and a processing unit 2402. Wherein:

in an implementation manner, the processing unit 2402 is configured to determine first indication information, where the first indication information is used to indicate a network type of a target network, where the target network is one of at least two networks supported by a target access network device, or the first indication information is used to indicate a network access mode corresponding to the network type; a transceiving unit 2401, configured to send the first indication information to a terminal device.

For other possible implementation manners of the communication apparatus, reference may be made to related descriptions of functions of the terminal device in the method embodiments corresponding to fig. 6, fig. 9, fig. 12, fig. 15, or fig. 18, which are not described herein again.

Referring to fig. 25, fig. 25 is a schematic structural diagram of another communication device according to an embodiment of the present disclosure. Fig. 25 shows a communication apparatus 250 according to an embodiment of the present application, configured to implement the functions of the terminal devices in fig. 6 to fig. 18. The apparatus may be a terminal device or an apparatus for a terminal device. The means for the terminal device may be a system of chips or a chip within the terminal device. The chip system may be composed of a chip, or may include a chip and other discrete devices.

Or, the communication device 250 is configured to implement the function of the source access network device in fig. 6 or fig. 7 or fig. 10 or fig. 13 or fig. 16. The apparatus may be a source access network device or an apparatus for a source access network device. The means for the source access network device may be a system-on-chip or a chip within the source access network device. The chip system may be composed of a chip, or may include a chip and other discrete devices.

Or, the communication device 250 is configured to implement the function of the target access network device in fig. 6 or fig. 8 or fig. 11 or fig. 14 or fig. 17. The apparatus may be a target access network device or an apparatus for a target access network device. The means for the target access network device may be a system-on-chip or a chip within the target access network device. The chip system may be formed by a chip, and may also include a chip and other discrete devices.

Or, the communication device 250 is configured to implement the function of the core network device in fig. 6, 9, 12, 15, or 18. The apparatus may be a core network device or an apparatus for a core network device. The means for the core network device may be a system-on-chip or a chip within the core network device. The chip system may be composed of a chip, or may include a chip and other discrete devices.

The communication apparatus 250 includes at least one processor 2520, configured to implement a data processing function of an access network device, a terminal device, or a core network device in the method provided in the embodiment of the present application. The apparatus 250 may further include a communication interface 2510, configured to implement transceiving operations of an access network device, a terminal device, or a core network device in the method provided in the embodiment of the present application. In embodiments of the present application, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface for communicating with other devices over a transmission medium. For example, communication interface 2510 provides that an apparatus in apparatus 250 may communicate with other devices. Processor 2520 uses communication interface 2510 to send and receive data and is configured to implement the methods described above with respect to the method embodiments described above with respect to fig. 6-18.

The apparatus 250 may also include at least one memory 2530 for storing program instructions and/or data. Memory 2530 is coupled to processor 2520. The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units or modules, and may be in an electrical, mechanical or other form, which is used for information interaction between the devices, units or modules. Processor 2520 may operate in conjunction with memory 2530. Processor 2520 may execute program instructions stored in memory 2530. At least one of the at least one memory may be included in the processor.

When the device 250 is powered on, the processor 2520 can read the software program stored in the memory 2530, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be sent wirelessly, the processor 2520 performs baseband processing on the data to be sent, and outputs a baseband signal to a radio frequency circuit (not shown), and the radio frequency circuit performs radio frequency processing on the baseband signal and sends the radio frequency signal to the outside in the form of electromagnetic waves through an antenna. When there is data to be sent to device 250, the rf circuit receives an rf signal through the antenna, converts the rf signal to a baseband signal, and outputs the baseband signal to processor 2520, and processor 2520 converts the baseband signal to data and processes the data.

In another implementation, the rf circuitry and antennas described above may be provided separate from the processor 2520 for baseband processing, e.g., in a distributed scenario, the rf circuitry and antennas may be in a remote arrangement separate from the communication device.

The specific connection medium between communication interface 2510, processor 2520 and memory 2530 is not limited in the embodiments of the present application. In fig. 25, the memory 2530, the processor 2520 and the communication interface 2510 are connected by a bus 2540, the bus is indicated by a thick line in fig. 25, and the connection manner among other components is only schematically illustrated and not limited. The above-mentioned bus may be classified into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 25, but that does not indicate only one bus or one type of bus.

When apparatus 250 is specifically an apparatus for access network equipment or terminal equipment or core network equipment, for example, when apparatus 250 is specifically a chip or a chip system, communication interface 2510 may output or receive baseband signals. When apparatus 250 is specifically an access network device, a terminal device, or a core network device, communication interface 2510 may output or receive radio frequency signals. In the embodiments of the present application, the processor may be a general-purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, operations, and logic blocks disclosed in the embodiments of the present application. A general purpose processor may be a microprocessor or any conventional processor or the like. The operations of the methods disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in a processor.

Embodiments of the present application further provide a computer-readable storage medium, in which instructions are stored, and when the computer-readable storage medium is executed on a processor, the method flows of the method embodiments in fig. 6 to 18 are implemented.

Embodiments of the present application further provide a computer program product, where when the computer program product runs on a processor, the method flows of fig. 6 to 18 of the above method embodiments are implemented.

It is noted that, for simplicity of explanation, the foregoing method embodiments are described as a series of acts or combination of acts, but those skilled in the art will appreciate that the present application is not limited by the order of acts, as some acts may, in accordance with the present application, occur in other orders and/or concurrently. Further, those skilled in the art should also appreciate that the embodiments described in the specification are preferred embodiments and that the acts and modules referred to are not necessarily required in this application.

The descriptions of the embodiments provided in the present application may be referred to each other, and the descriptions of the embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments. For convenience and brevity of description, for example, the functions and operations performed by the devices and apparatuses provided in the embodiments of the present application may refer to the related descriptions of the method embodiments of the present application, and may also be referred to, combined with or cited among the method embodiments and the device embodiments.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of communication, comprising:

the method comprises the steps that terminal equipment receives first indication information, wherein the first indication information is used for indicating a network type of a switching target network, or the first indication information is used for indicating a network access mode corresponding to the network type;

and the terminal equipment sets the network access mode of the terminal equipment according to the first indication information.

2. The method of claim 1, wherein the terminal device receives the first indication information, and comprises:

3. The method of claim 2, wherein the terminal device receiving the first indication information from a target access network device comprises:

4. The method of claim 1, wherein the terminal device receives the first indication information, and comprises:

5. The method of claim 4, wherein the receiving, by the terminal device, the first indication information from a source access network device comprises:

6. The method of claim 1, wherein the terminal device receives the first indication information, and comprises:

7. The method of claim 6, wherein the receiving, by the terminal device, the first indication information from a core network device comprises:

8. The method according to any of claims 1-7, wherein the first indication information is used to indicate a network type of a handover target network, and the first indication information includes an identifier of the target network;

the terminal device sets a network access mode of the terminal device according to the first indication information, and the method comprises the following steps:

and the terminal equipment sets the network access mode of the terminal equipment to be the network access mode corresponding to the network type.

9. The method according to any of claims 1-7, wherein the first indication information is used to indicate a network type of a handover target network, and the first indication information includes the network type of the target network;

10. The method according to any of claims 1-5, wherein the first indication information is used to indicate a network type of a handover target network, and the first indication information includes a cell identifier corresponding to the target network;

11. Method according to any of the claims 1-10, wherein said network types comprise a public land mobile network, PLMN, and an independent non-public network, SNPN; the network access mode comprises an SNPN access mode and a non-SNPN access mode, wherein the SNPN corresponds to the SNPN access mode, and the PLMN corresponds to the non-SNPN access mode.

12. A method of communication, comprising:

13. The method of claim 12, wherein the sending, by the source access network device, the first indication information to a terminal device comprises:

14. The method according to claim 12 or 13, wherein the first indication information comprises at least one of the following information: the network identification of the target network, the network type of the target network and the cell identification corresponding to the target network.

15. Method according to any of the claims 12-14, wherein said network types comprise a public land mobile network, PLMN, and an independent non-public network, SNPN; the network access mode comprises an SNPN access mode and a non-SNPN access mode, wherein the SNPN corresponds to the SNPN access mode, and the PLMN corresponds to the non-SNPN access mode.

16. A method of communication, comprising:

the target access network equipment determines first indication information, wherein the first indication information is used for indicating a network type of a switching target network, or the first indication information is used for indicating a network access mode corresponding to the network type;

17. The method of claim 16, wherein the target access network device sends the first indication information to a terminal device, and wherein the sending comprises:

18. The method according to claim 16 or 17, wherein the first indication information comprises at least one of the following information: the network identification of the target network, the network type of the target network and the cell identification corresponding to the target network.

19. The method according to any of claims 16-18, wherein the network types comprise public land mobile network, PLMN, and independent non-public network, SNPN; the network access mode comprises an SNPN access mode and a non-SNPN access mode, wherein the SNPN corresponds to the SNPN access mode, and the PLMN corresponds to the non-SNPN access mode.

20. A method of communication, comprising:

the method comprises the steps that core network equipment determines first indication information, wherein the first indication information is used for indicating the network type of a target network, the target network is one of at least two networks supported by target access network equipment, or the first indication information is used for indicating a network access mode corresponding to the network type;

21. The method of claim 20, wherein the sending, by the core network device, the first indication information to a terminal device includes:

22. The method according to claim 20 or 21, wherein the first indication information comprises at least one of the following information: a network identification of the target network, a network type of the target network.

23. A method according to any of claims 20-22, characterized in that the network types comprise public land mobile networks, PLMNs, and independent non-public networks, SNPN; the network access mode comprises an SNPN access mode and a non-SNPN access mode, wherein the SNPN corresponds to the SNPN access mode, and the PLMN corresponds to the non-SNPN access mode.

24. A communication apparatus, wherein the communication apparatus is a terminal device, comprising:

a transceiver unit, configured to receive first indication information, where the first indication information is used to indicate a network type of a handover target network, or the first indication information is used to indicate a network access mode corresponding to the network type;

and the processing unit is used for setting the network access mode of the terminal equipment according to the first indication information.

25. A communications apparatus, wherein the communications apparatus is a source access network device, comprising:

a processing unit, configured to determine first indication information, where the first indication information is used to indicate a network type of a handover target network, or the first indication information is used to indicate a network access mode corresponding to the network type;

and the transceiver unit is used for sending the first indication information to the terminal equipment.

26. A communications apparatus, wherein the communications apparatus is a target access network device, comprising:

and the transceiving unit is used for sending the first indication information to the terminal equipment.

27. A communication apparatus, wherein the communication apparatus is a core network device, and comprises:

a processing unit, configured to determine first indication information, where the first indication information is used to indicate a network type of a target network, where the target network is one of at least two networks supported by a target access network device, or the first indication information is used to indicate a network access mode corresponding to the network type;

28. A communications apparatus comprising a processor and a transceiver to execute a computer program or instructions stored in at least one memory to cause the apparatus to implement a method as claimed in any one of claims 1 to 11, or to implement a method as claimed in any one of claims 12 to 15, or to implement a method as claimed in any one of claims 16 to 19, or to implement a method as claimed in any one of claims 20 to 23.

29. A computer-readable storage medium, in which a computer program or instructions is stored, which, when executed by a computer, implements a method according to any one of claims 1 to 11, or implements a method according to any one of claims 12 to 15, or implements a method according to any one of claims 16 to 19, or implements a method according to any one of claims 20 to 23.

30. A computer program product comprising computer program code to, when run on a computer, implement the method of any one of claims 1 to 11, or to implement the method of any one of claims 12 to 15, or to implement the method of any one of claims 16 to 19, or to implement the method of any one of claims 20 to 23.