CN110035568B

CN110035568B - Indication method, selection method and equipment of public land mobile network

Info

Publication number: CN110035568B
Application number: CN201810032644.7A
Authority: CN
Inventors: 马玥; 吴昱民
Original assignee: Vivo Mobile Communication Co Ltd
Current assignee: Vivo Mobile Communication Co Ltd
Priority date: 2018-01-12
Filing date: 2018-01-12
Publication date: 2020-11-10
Anticipated expiration: 2038-01-12
Also published as: WO2019137461A1; CN110035568A

Abstract

The embodiment of the invention discloses an indication method, a selection method and equipment of a public land mobile network, wherein the method comprises the following steps: determining at least one PLMN supported by a current cell, wherein the at least one PLMN comprises first target PLMNs, and core networks supported by each first target PLMN comprise core networks of a first protocol supporting mobile communication; generating a system message, wherein the system message comprises a first cell access related information field conforming to a first protocol and a second cell access related information field conforming to an existing second protocol of mobile communication, the first cell access related information field carries a first PLMN list, and the first PLMN list comprises information related to a first target PLMN. The method of the invention ensures that the network equipment definitely indicates the PLMN supported by the cell to the terminal equipment under the condition that the PLMN supports a 5G core network or supports both 4G and 5G core networks, thereby meeting the requirements of future communication systems.

Description

Indication method, selection method and equipment of public land mobile network

Technical Field

The present application relates to the field of communications technologies, and in particular, to an indication method, a selection method, and a device for a public land mobile network.

Background

The third Generation Partnership Project (3 GPP) Radio Access Network (RAN) defines two evolution directions, lte and 5G NR, for a 5G system. In a 5G system, one cell may support multiple Public Land Mobile Networks (PLMNs), and one PLMN may support a 4G core Network or a 5G core Network or both 4G and 5G core networks. The current communication protocol specifies how the network device indicates the PLMN supported by the cell to the terminal device when the PLMN supports only the 4G core network, but in the case where the PLMN supports the 5G core network or supports both the 4G and 5G core networks, the network device cannot determine how to indicate the PLMN supported by the cell to the terminal device.

Disclosure of Invention

An object of the embodiments of the present invention is to provide an indication method, a selection method, and a device for a method public land mobile network PLMN, so as to solve a problem that a network device cannot determine how to indicate a PLMN supported by a cell to a terminal device in a case where a PLMN supports a 5G core network or a core network supporting both 4G and 5G.

In a first aspect, a method for indicating a public land mobile network PLMN is provided, the method including:

determining at least one Public Land Mobile Network (PLMN) supported by a current cell, wherein the at least one PLMN comprises first target PLMNs, and core networks supported by each first target PLMN comprise core networks supporting a first protocol of mobile communication;

generating a system message, where the system message includes a first cell access related information field conforming to the first protocol and a second cell access related information field conforming to an existing second protocol of mobile communication, where the first cell access related information field carries a first PLMN list, and the first PLMN list includes information related to the first target PLMN.

In a second aspect, a method for indicating a public land mobile network PLMN is provided, the method comprising:

determining that a core network supported by at least one Public Land Mobile Network (PLMN) supported by a current cell only supports a first protocol of mobile communication;

generating a system message, where the system message includes a first cell access related information field conforming to an existing second protocol of mobile communication, where the first cell access related information field carries a first PLMN list, where the first PLMN list includes information related to the at least one PLMN and first indication information, and the first indication information is used by a terminal device to determine a type of a core network supported by each PLMN; or the like, or, alternatively,

the system message comprises a second cell access related information field and an indication information field which accord with the second protocol, the second cell access related information field carries a second PLMN list, the second PLMN list comprises information related to the at least one PLMN, and the indication information field carries the first indication information; or the like, or, alternatively,

the system message includes a third cell access related information field conforming to the second protocol, the third cell access related information field carrying a third PLMN list, the third PLMN list including information related to the at least one PLMN, and a fourth cell access related information field carrying the first indication information.

In a third aspect, a method for indicating a public land mobile network PLMN is provided, the method including:

determining target PLMNs in at least one Public Land Mobile Network (PLMN) supported by a current cell, wherein the core network supported by each target PLMN comprises a core network supporting a first protocol of mobile communication and a core network supporting an existing second protocol of mobile communication;

generating a system message, where the system message includes a first cell access related information field conforming to the second protocol, and a first PLMN list is carried in the second cell access related information field, where the first PLMN list includes information related to the target PLMN and first indication information, and the first indication information is used to indicate a type of a core network supported by each target PLMN; or the like, or, alternatively,

the system message comprises a second cell access related information field and an indication information field which accord with the second protocol, the second cell access related information field carries a second PLMN list, the second PLMN list comprises information related to the target PLMN, and the indication information field carries the first indication information.

In a fourth aspect, a method for selecting a public land mobile network PLMN is provided, the method comprising:

receiving a system message, wherein the system message comprises a first cell access related information field conforming to a first protocol of mobile communication and a second cell access related information field conforming to an existing second protocol of mobile communication, the first cell access related information field carries a first PLMN list, the first PLMN list comprises information related to a first target PLMN, and a core network supported by each first target PLMN comprises a core network supporting the first protocol;

and selecting a PLMN to be accessed from at least one PLMN supported by the current cell according to the system message, wherein the at least one PLMN comprises the first target PLMN.

In a fifth aspect, a method for selecting a public land mobile network PLMN is provided, the method comprising:

receiving a system message;

selecting a PLMN to be accessed from at least one PLMN supported by the current cell according to the system message, wherein a core network supported by each PLMN only supports a first protocol of mobile communication;

the system message comprises a first cell access related information field conforming to an existing second protocol of mobile communication, a first PLMN list is carried in the first cell access related information field, the first PLMN list comprises information related to the at least one PLMN and first indication information, and the first indication information is used for determining the type of a core network supported by each PLMN by a terminal device; or the like, or, alternatively,

the system message comprises a second cell access related information field indication information field which accords with the second protocol, a second PLMN list is carried in the second cell access related information field, the second PLMN list comprises information related to the at least one PLMN, and the indication information field carries the first indication information; or the like, or, alternatively,

the system message includes a third cell access related information field conforming to the second protocol, the third cell access related information field conforming to the first protocol, the third cell access related information field carrying a third PLMN list, the third PLMN list including information related to the at least one PLMN, the fourth cell access related information field carrying the first indication information.

In a sixth aspect, a method for selecting a public land mobile network PLMN is provided, the method comprising:

receiving a system message;

selecting a PLMN to be accessed from at least one PLMN supported by the current cell according to the system message;

wherein the system message includes a first cell access related information field conforming to an existing second protocol of mobile communication, the first cell access related information field carries a first PLMN list, the first PLMN list includes information related to a target PLMN and first indication information, the first indication information is used to indicate a type of core network supported by each target PLMN, and the core networks supported by each target PLMN include a core network supporting the first protocol of mobile communication and a core network supporting the second protocol, or,

In a seventh aspect, a network device is provided, where the network device includes:

a determining module, configured to determine at least one public land mobile network PLMN supported by a current cell, where the at least one PLMN includes first target PLMNs, and a core network supported by each first target PLMN includes a core network supporting a first protocol of mobile communication;

a processing module, configured to generate a system message, where the system message includes a first cell access related information field conforming to the first protocol and a second cell access related information field conforming to an existing second protocol of mobile communication, and the first cell access related information field carries a first PLMN list, where the first PLMN list includes information related to the first target PLMN.

In an eighth aspect, a network device is provided, which includes:

a determining module, configured to determine that a core network supported by at least one public land mobile network PLMN supported by a current cell only supports a first protocol of mobile communication;

a processing module, configured to generate a system message, where the system message includes a first cell access related information field conforming to an existing second protocol of mobile communication, where the first cell access related information field carries a first PLMN list, where the first PLMN list includes information related to the at least one PLMN and first indication information, and the first indication information is used for a terminal device to determine a type of a core network supported by each PLMN; or the like, or, alternatively,

In a ninth aspect, there is provided a network device, comprising:

a determining module, configured to determine a target PLMN in at least one public land mobile network PLMN supported by a current cell, where a core network supported by each target PLMN includes a core network supporting a first protocol of mobile communication and a core network supporting an existing second protocol of mobile communication;

a processing module, configured to generate a system message, where the system message includes a first cell access related information field conforming to the second protocol, and a first PLMN list is carried in the second cell access related information field, where the first PLMN list includes information related to the target PLMN and first indication information, and the first indication information is used to indicate a type of a core network supported by each target PLMN; or the like, or, alternatively,

In a tenth aspect, there is provided a terminal device, including:

a transceiver module, configured to receive a system message, where the system message includes a first cell access related information field conforming to a first protocol of mobile communication and a second cell access related information field conforming to an existing second protocol of mobile communication, where the first cell access related information field carries a first PLMN list, the first PLMN list includes information related to a first target PLMN, and a core network supported by each first target PLMN includes a core network supporting the first protocol;

and the processing module is used for selecting a PLMN to be accessed from at least one PLMN supported by the current cell according to the system message, wherein the at least one PLMN comprises the first target PLMN.

In an eleventh aspect, there is provided a terminal device, including:

the receiving and sending module is used for receiving the system message;

a processing module, configured to select, according to the system message, a PLMN to be accessed from at least one PLMN supported by the current cell, where a core network supported by each PLMN only supports a first protocol of mobile communication;

In a twelfth aspect, a terminal device is provided, which includes:

the receiving and sending module is used for receiving the system message;

the processing module is used for selecting a PLMN to be accessed from at least one PLMN supported by the current cell according to the system message;

In a thirteenth aspect, a network device is provided, which includes: a processor, a memory and a computer program stored on the memory and executable on the processor, the computer program, when executed by the processor, implementing the steps of the method according to the first aspect.

In a fourteenth aspect, a network device is provided, which includes: a processor, a memory and a computer program stored on the memory and executable on the processor, which computer program, when executed by the processor, carries out the steps of the method according to the second aspect.

In a fifteenth aspect, a network device is provided, comprising: a processor, a memory and a computer program stored on the memory and executable on the processor, the computer program, when executed by the processor, implementing the steps of the method according to the third aspect.

In a sixteenth aspect, a terminal device is provided, which includes: a processor, a memory and a computer program stored on the memory and executable on the processor, which computer program, when executed by the processor, carries out the steps of the method according to the fourth aspect.

In a seventeenth aspect, a terminal device is provided, which includes: a processor, a memory and a computer program stored on the memory and executable on the processor, which computer program, when executed by the processor, carries out the steps of the method according to the fifth aspect.

In an eighteenth aspect, a terminal device is provided, which includes: a processor, a memory and a computer program stored on the memory and executable on the processor, the computer program, when executed by the processor, implementing the steps of the method according to the sixth aspect.

A nineteenth aspect provides a computer-readable storage medium, characterized in that a computer program is stored on the computer-readable storage medium, which computer program, when being executed by a processor, realizes the steps of the method according to the first aspect.

In a twentieth aspect, a computer-readable storage medium is provided, characterized in that a computer program is stored on the computer-readable storage medium, which computer program, when being executed by a processor, carries out the steps of the method according to the second aspect.

In a twenty-first aspect, a computer-readable storage medium is provided, on which a computer program is stored, which computer program, when being executed by a processor, carries out the steps of the method according to the third aspect.

In a twenty-second aspect, a computer-readable storage medium is provided, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to the fourth aspect.

A twenty-third aspect provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, carries out the steps of the method according to the fifth aspect.

A twenty-fourth aspect provides a computer readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of the method of the sixth aspect.

In the embodiment of the present invention, when determining that a PLMN supported by a current cell includes a first target PLMN of a first protocol in which a core network supports mobile communication, a network device includes, in a system message, a cell access related information field conforming to the first protocol, where the cell access related information field carries a first PLMN list, and includes, in the first PLMN list, information related to the first target PLMN. Therefore, the network device can clearly indicate the PLMN supported by the cell to the terminal device under the condition that the PLMN supports the 5G core network or supports the 4G and 5G core networks simultaneously, and the requirement of a future communication system is met.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic flow chart diagram of a method of indication of a PLMN according to one embodiment of the present invention.

Fig. 2 is a schematic flow chart diagram of a method of indicating a PLMN according to another embodiment of the present invention.

Fig. 3 is another schematic flow chart diagram of a method of indication of a PLMN according to another embodiment of the present invention.

Fig. 4 is still another schematic flow chart diagram of a method of indicating a PLMN according to another embodiment of the present invention.

Fig. 5 is a schematic flow chart diagram of an indication method of a PLMN according to yet another embodiment of the present invention.

Fig. 6 is a schematic flow chart diagram of an indication method of a PLMN according to yet another embodiment of the present invention.

Fig. 7 is a schematic flow chart diagram of a method of PLMN selection in accordance with one embodiment of the present invention.

Fig. 8 is a schematic flow chart diagram of a method of PLMN selection in accordance with another embodiment of the present invention.

Fig. 9 is a schematic flow chart diagram of a PLMN selection method according to yet another embodiment of the present invention.

Fig. 10 is a schematic structural diagram of a network device according to an embodiment of the present invention.

Fig. 11 is a schematic structural diagram of a network device according to another embodiment of the present invention.

Fig. 12 is a schematic structural diagram of a network device according to still another embodiment of the present invention.

Fig. 13 is a schematic structural diagram of a terminal device according to an embodiment of the present invention.

Fig. 14 is a schematic structural diagram of a terminal device according to another embodiment of the present invention.

Fig. 15 is a schematic structural diagram of a terminal device according to still another embodiment of the present invention.

Fig. 16 is a schematic structural diagram of a network device according to an embodiment of the present invention.

Fig. 17 is a schematic structural diagram of a terminal device according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without any inventive step, are within the scope of the present invention.

The technical scheme of the invention can be applied to various communication systems, such as: an eLTE system, a 5G system, a subsequent evolution communication system and the like.

A Terminal device (UE), which may also be referred to as a Mobile Terminal (Mobile Terminal), a Mobile User Equipment (UE), or the like, may communicate with one or more core networks via a Radio Access Network (RAN, for example), and the User device may be a Mobile Terminal, such as a Mobile phone (or a "cellular" phone) and a computer having a Mobile Terminal, such as a portable, pocket, hand-held, computer-included, or vehicle-mounted Mobile device, and may exchange languages and/or data with the Radio Access Network.

The network device is a device deployed in a radio access network device and configured to provide a radio communication function for a terminal device, where the network device may be a Base Station, and the Base Station may be a Base Transceiver Station (BTS) in GSM or CDMA, a Base Station (NodeB) in WCDMA, an evolved Node B (eNB or e-NodeB) in LTE, and a 5G Base Station (gNB).

The technical solutions provided by the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

Fig. 1 shows a method for indication of a public land mobile network, PLMN, according to an embodiment of the invention, which method 100 may be performed by a network device. As shown in fig. 1, the method 100 includes:

s110, at least one public land mobile network PLMN supported by the current cell is determined, the at least one PLMN comprises first target PLMNs, and core networks supported by each first target PLMN comprise core networks supporting a first protocol of mobile communication.

Optionally, in S110, the first protocol of the mobile communication is a 5G related protocol, for example, the first protocol is a 3GPP R15 protocol, or the first protocol is a protocol with a version higher than that of the 3GPP R15 protocol. And it is to be understood that, when the first protocol is a 3GPP R15 protocol, a core network supported by each first target PLMN, including a core network supporting the first protocol of mobile communication, may be understood that each first target PLMN is capable of supporting a 5G core network.

It should be noted that the current cell in S110 may be understood as a cell to which the terminal device is currently attached.

S120, generating a system message, where the system message includes a first cell access relevant information field conforming to the first protocol and a second cell access relevant information field conforming to an existing second protocol of mobile communication, where the first cell access relevant information field carries a first PLMN list, and the first PLMN list includes information related to the first target PLMN.

Alternatively, in S120, the existing second protocol of the mobile communication is the 3GPP R8 protocol. In this case, if at least one PLMN supported by the current Cell includes a PLMN supporting a 5G core network, the system message generated by the network device includes a first Cell Access Related information field (Cell Access Related Info) conforming to the 3GPP R15 protocol and a second Cell Access Related information field conforming to the 3GPP R8 protocol. And a first cell access related information field of a 3GPP R15 protocol carries a first PLMN list, where the first PLMN list includes information related to PLMNs supporting the 5G core network.

That is, if the PLMN supported by the current Cell includes a PLMN supporting a 5G core network, a Cell Access Related Info field is newly added to the system message generated by the network device, and the information Related to the PLMN supporting the 5G core network is carried in this field.

Further, when the at least one PLMN includes a second target PLMN whose supported core network supports the second protocol, the second cell access-related information field carries a second PLMN list, where the second PLMN list includes information related to the second target PLMN. For example, when a second target PLMN supporting an Evolved Packet Core (EPC) is included in the at least one PLMN and the EPC supports a 3GPP R8 protocol, a second cell access related information field conforming to the 3GPP R8 protocol included in the system message carries a second PLMN list including information related to the second target PLMN. The information related to the second target PLMN may include an Identity (ID) of the second target PLMN and reserved cell indication information (cellreserved for operation use).

Furthermore, the system message also comprises a third cell access related information field conforming to the existing third protocol of the mobile communication, and the version of the third protocol is higher than that of the second protocol; when the at least one PLMN includes a third target PLMN whose core network supports a third protocol, a third cell access related information field carries a third PLMN list, and the third PLMN list includes information related to the third target PLMN. The third protocol here may be the 3GPP R14 protocol. And it can be appreciated that the third cell access related information field is Optional.

In the embodiment of the present invention, optionally, when at least one PLMN includes a first target PLMN, a second target PLMN, and a third target PLMN, a sum of a number of second target PLMNs included in the second PLMN list and a number of third target PLMNs included in the third PLMN list is less than or equal to a preset value, and a number of first target PLMNs included in the first PLMN list is less than or equal to the preset value. Taking the example that the second protocol is the 3GPP R8 protocol, and the third protocol is the 3GPP R14 protocol, the total number of PLMNs that the supported core network in the system message supports the 3GPP R8 protocol and the 3GPP R14 protocol is a preset value, and the number of PLMNs that the supported core network in the system message supports the 3GPP R15 protocol is the preset value, where the preset value may be 6.

Or, when at least one PLMN includes a first target PLMN, a second target PLMN, and a third target PLMN, a sum of the number of the second target PLMN included in the second PLMN list, the number of the third target PLMN included in the third PLMN list, and the number of the first target PLMN included in the first PLMN list is less than or equal to the preset value. Taking the second protocol as the 3GPP R8 protocol and the third protocol as the 3GPP R14 protocol as examples, the total number of PLMNs supported by the core network supporting the 3GPP R8 protocol and the 3GPP R14 protocol and PLMNs supported by the core network supporting the 3GPP R15 protocol included in the system message is the preset value.

Optionally, as an example, the same PLMN does not exist in the first target PLMN and the second target PLMN. Taking the first target PLMN as a PLMN supporting a 5G core network and the second target PLMN as a PLMN supporting a 4G core network as an example, the PLMN supporting the 5G core network is completely different from the PLMN supporting the 4G core network.

For example, the second PLMN List and the first PLMN List are included in the system message in table 1.1, the second PLMN List is represented by PLMN-List-r8-EPC, the first PLMN List is represented by PLMN-List-r15-5GC, the information related to PLMN a and PLMN B is included in PLMN-List-r8-EPC, the information related to PLMN D and PLMN E is included in PLMN-List-r15-5GC, and PLMN a, PLMN B, PLMN C and PLMN D are different PLMNs. The maximum number of PLMNs included in the PLMN-List-r8-EPC may be 6, and the maximum number of PLMNs included in the PLMN-List-r15-5GC may be 6. Or, as an optional example, the sum of the number of PLMNs included in the PLMN-List-r8-EPC and the number of PLMNs included in the PLMN-List-r15-5GC may be 6 at maximum. It is to be understood that 6 is only an example and not a limitation.

TABLE 1.1

Or, as shown in table 1.2, the system message further includes the third PLMN List, where PLMN-List-r14-EPC indicates the third PLMN List, PLMN-List-r8-EPC includes information related to PLMN a and PLMN B, PLMN-List-r14-EPC includes information related to PLMN C, PLMN-List-r15-5GC includes information related to PLMN D and PLMN E, and PLMN a, PLMN B, PLMN C, PLMN D, and PLMN E are different PLMNs. The maximum total number of the PLMNs included in the PLMN-List-r8-EPC and the PLMN-List-r14-EPC can be 6, and the maximum number of the PLMNs included in the PLMN-List-r15-5GC can be 6. Or, as an optional example, the sum of the number of PLMNs included in the PLMN-List-r8-EPC, the number of PLMNs included in the PLMN-List-r14-EPC, and the number of PLMNs included in the PLMN-List-r15-5GC may be 6 at maximum. It is to be understood that 6 is only an example and not a limitation.

TABLE 1.2

It should be noted that, the PLMN IDs and the reserved cell indication information of the PLMNs a to PLMN E actually represent the PLMNs a to PLMN E in tables 1.1 and 1.2.

Optionally, as another example, there is at least one identical PLMN in the first target PLMN and the second target PLMN. Taking the first target PLMN as a PLMN supporting the 5G core network and the second target PLMN as a PLMN supporting the 4G core network as an example, the PLMN supporting the 5G core network and the PLMN supporting the 4G core network have the same PLMN. Or it may be understood that at least one PLMN supporting a 5G core network also supports a 4G core network.

For example, as shown in table 2, the system message includes the first PLMN List, the second PLMN List, and the third PLMN List, as described above, PLMN-List-r15-5GC represents the first PLMN List, PLMN-List-r8-EPC represents the second PLMN List, PLMN-List-r14-EPC represents the third PLMN List, PLMN-List-r8-EPC includes information related to PLMN a and PLMN B, PLMN-List-r14-EPC includes information related to PLMN C, PLMN-List-r15-5GC includes information related to PLMN B and PLMN D, and PLMN-List-r15-5GC and PLMN-List-r8-EPC include the same PLMN B. The total number of the PLMNs included in the PLMN-List-r8-EPC and the PLMN-List-r14-EPC can be 6 at most, and the number of the PLMNs included in the PLMN-List-r15-5GC can be 6 at most. Or, as an alternative example, the sum of the number of PLMNs included in the PLMN-List-r8-EPC, the number of PLMNs included in the PLMN-List-r14-EPC, and the number of PLMNs included in the PLMN-List-r15-5GC may be 6 at maximum. It is to be understood that 6 is only an example and not a limitation.

TABLE 2

Optionally, as another example, the core network supported by each PLMN only supports the first protocol, and the second cell access related information field carries information related to a virtual padding (Dummy) PLMN. If the third cell access relevant information field is also included in the system message, the value of the third cell access relevant information field is set to null. For example, the PLMN supported by the current cell only supports a 5G core network, the information related to the Dummy PLMN is filled in the second list in the second cell access related information field, and the third list in the third cell access related field is NULL.

For example, as shown in table 3, the system message includes the first PLMN List, the second PLMN List, and the third PLMN List, the PLMN-List-r15-5GC represents the first PLMN List, the PLMN-List-r8-EPC represents the second PLMN List, the PLMN-List-r14-EPC represents the third PLMN List, all PLMNs supported by the current cell only support the 5G core network, and then the PLMN-List-r8-EPC includes information related to the Dummy PLM, the PLMN-List-r15-5GC includes information related to the PLMNs supported by the current cell, the PLMNs supported by the current cell include, for example, PLMN X, Y, and the like, wherein the total number of the PLMNs included in the PLMN-List-r8-EPC and the PLMN-List-r14-EPC may be 6 at maximum, the number of the PLMNs included in the PLMN-List-r15-5GC may be 6 at maximum, or, as an optional example, the sum of the number of PLMNs included in the PLMN-List-r8-EPC, the number of PLMNs included in the PLMN-List-r14-EPC, and the number of PLMNs included in the PLMN-List-r15-5GC may be 6 at maximum. It is to be understood that 6 is only an example and not a limitation.

TABLE 3

Optionally, as an example, the first target PLMN includes first sub-target PLMNs, and the core network supported by each first sub-target PLMN further includes a core network supporting a second protocol or a third protocol, where the third protocol is an existing protocol of mobile communication, and a version of the third protocol is higher than a version of the second protocol; the information related to the first target PLMN includes index information of each first sub-target PLMN and reserved cell indication information corresponding to each first sub-target PLMN, and the index information of each first sub-target PLMN is used for the terminal device to determine an identification ID of each first sub-target PLMN. For example, if a part of PLMNs supporting the 5G core network also support the 4G core network, the first PLMN list only includes the indexes and the reserved cell indication information of the part of PLMNs supporting the 5G core network and the 4G core network, but does not include the IDs of the part of PLMNs, thereby avoiding the introduction of redundant information and improving the system efficiency.

Further, in some embodiments, the information related to the second target PLMN includes an ID of each first sub-target PLMN and reserved cell indication information corresponding to each first sub-target PLMN; the information related to the third target PLMN includes an ID of each second sub-target PLMN and reserved cell indication information corresponding to each second sub-target PLMN. The method shown in fig. 1 further comprises: and determining the index of each first sub-target PLMN and the index of each second sub-target PLMN according to the position of each first sub-target PLMN in the second PLMN list and the position of each second sub-target PLMN in the third PLMN list.

Or, it can be understood that, if a PLMN supports both 4G and 5G core networks, the ID and the reserved cell indication information of the PLMN are included in the PLMN list carried in the cell access relevant field conforming to the 4G related protocol, and only the index information and the reserved cell indication information of the PLMN are included in the PLMN list carried in the cell access relevant field conforming to the 5G related protocol. The terminal device can obtain the ID of the PLMN according to the index information of the PLMN and information included in the PLMN list carried in the cell access related field conforming to the 4G related protocol. The indexing information of this PLMN is determined according to the position where the PLMN appears in the PLMN list carried in the cell access related field conforming to the 4G related protocol.

For example, as shown in table 4, the system message includes the first PLMN List, the second PLMN List, and the third PLMN List, as described above, the PLMN-List-r15-5GC represents the first PLMN List, the PLMN-List-r8-EPC represents the second PLMN List, the PLMN-List-r14-EPC represents the third PLMN List, and the PLMN-List-r8-EPC includes the ID and the reserved cell indication information with the PLMN a, the ID and the reserved cell indication information with the PLMN B, and the ID and the reserved cell indication information with the PLMN C. The ID of PLMN D and the reserved cell indication information are included in the PLMN-List-r 14-EPC. The PLMN-List-r15-5GC includes index information (index 1) and reserved cell indication information of PLMN B, index information (index 2) and reserved cell indication information of PLMN D, and ID and reserved cell indication information of PLMN E. The maximum total number of the PLMNs included in the PLMN-List-r8-EPC and the PLMN-List-r14-EPC can be 6, and the maximum number of the PLMNs included in the PLMN-List-r15-5GC can be 6. Or the total number of PLMNs included in the PLMN-List-r8-EPC, PLMN-List-r14-EPC, and PLMN-List-r15-5GC may be 6. It is to be understood that 6 is merely an example and not a limitation.

TABLE 4

Index1 and index2 in table 4 may be determined by the network device according to the location of PLMN B and PLMN D in PLMN-List-r8-EPC and PLMN-List-r 14-EPC. For example, when PLMN a to PLMN D are numbered uniformly, PLMN a is numbered 1, PLMN B is numbered 2, PLMN C is numbered 3, and PLMN D is numbered 4, index1 is determined to be 2, and index2 is determined to be 4. It should be noted that the invention does not limit the setting mode of index, and the value of index can be derived according to other unambiguous modes; or the index value may be a sequence number value that only refers to in a repeated PLMN, etc.

Optionally, as an example, the first target PLMN includes N first sub-target PLMNs, a core network supported by each first sub-target PLMN further includes a core network supporting the second protocol, the second cell access related information field carries a second PLMN list, the N first sub-target PLMNs are located in the first N positions of the second PLMN list, and N is a positive integer greater than or equal to 1; the information related to the first target PLMN includes N reserved cell indication information corresponding to the N first sub-target PLMNs, where the N reserved cell indication information are located at the first N positions of the first PLMN list, and a position of each reserved cell indication information in the first PLMN list is the same as a position of the first sub-target PLMN corresponding to the reserved cell indication information in the second PLMN list.

Or, it can be understood that, if a PLMN supports both 4G and 5G core networks, the ID and the reserved cell indication information of the PLMN are included in the PLMN list carried in the cell access relevant field conforming to the 4G related protocol, and only the reserved cell indication information of the PLMN is included in the PLMN list carried in the cell access relevant field conforming to the 5G related protocol. The terminal device considers that the PLMN which only includes the reserved cell indication information in the PLMN list carried in the cell access relevant field conforming to the 5G relevant protocol is the PLMN which simultaneously supports the 4G core network and the 5G core network, and the IDs of the PLMNs can be obtained according to the information included in the PLMN list carried in the cell access relevant field conforming to the 4G relevant protocol.

Further, the first cell access related information field further includes first indication information, where the first indication information is used to indicate, according to the second PLMN list, an ID of a first sub-target PLMN corresponding to each of indication information of N reserved cells in the first PLMN list, which is determined by the terminal device. For example, the cell access related information field conforming to the 5G related protocol includes first indication information indicating a value of N, and the terminal device may determine, according to the value of N, that N PLMNs in the cell access related field conforming to the 5G related protocol support both the 4G core network and the 5G core network, and then the terminal device may acquire IDs of the N PLMNs according to information included in a PLMN list carried in the cell access related field conforming to the 4G related protocol.

For example, as shown in table 5, the system message includes the first PLMN List, the second PLMN List, and the third PLMN List, as described above, the PLMN-List-r15-5GC represents the first PLMN List, the PLMN-List-r8-EPC represents the second PLMN List, the PLMN-List-r14-EPC represents the third PLMN List, and the PLMN-List-r8-EPC includes the ID and the reserved cell indication information with the PLMN a, the ID and the reserved cell indication information with the PLMN B, and the ID and the reserved cell indication information with the PLMN C. The ID of PLMN D and the reserved cell indication information are included in the PLMN-List-r 14-EPC. The PLMN-List-r15-5GC includes the first indication information (Repeat (2)), the reserved cell indication information of PLMN a, the reserved cell indication information of PLMN B, and the ID and the reserved cell indication information of PLMN E. The maximum total number of the PLMNs included in the PLMN-List-r8-EPC and the PLMN-List-r14-EPC can be 6, and the maximum number of the PLMNs included in the PLMN-List-r15-5GC can be 6. Or the total number of PLMNs included in the PLMN-List-r8-EPC, PLMN-List-r14-EPC, and PLMN-List-r15-5GC may be 6. It is to be understood that 6 is merely an example and not a limitation.

TABLE 5

It can be understood that there may be no indication information of Repeat (2) in table 5, in which case, the PLMN where the network device and the terminal device agree to only retain the cell indication information is a PLMN supporting both the 4G core network and the 5G core network.

In the embodiment of the present invention, in a case where the network device indicates, to the terminal device, PLMNs supported by a current cell by using the methods in the examples shown in tables 1.1 to 5, the terminal device needs to determine a PLMN that is a Primary (Primary) PLMN of the current cell among the PLMNs. At this time, the terminal device may default to a first PLMN in the first PLMN list as a Primary PLMN when accessing the 5G core network through the current cell, and default to a first PLMN in the second PLMN list as a Primary PLMN when accessing the 4G core network through the current cell. Or the network equipment displays and indicates the terminal equipment to use the first PLMN in the first PLMN list as a Primary PLMN when accessing the 5G core network through the current cell, and use the first PLMN in the second PLMN list as a Primary PLMN when accessing the 4G core network through the current cell. For example, the system message further includes second indication information, where the second indication information is used to indicate that one of the first target PLMNs is the first primary PLMN of the current cell and indicate that one of the second target PLMNs is the second primary PLMN of the current cell.

Or the network device displays and designates one PLMN in the second PLMN list or the third PLMN list as a Primary PLMN when the terminal device accesses the 4G core network through the current cell, and displays and designates one PLMN in the first PLMN list as a Primary PLMN when the terminal device accesses the 5G core network through the current cell. For example, the system message further includes second indication information, where the second indication information is used to indicate that one of the first target PLMNs is the primary PLMN of the current cell, or the second indication information is used to indicate that one of the second target PLMNs is the primary PLMN of the current cell.

Or, the network device indicates only the first one of PLMNs supporting the 4G core network as the Primary PLMN of the current cell, or indicates only the first one of PLMNs supporting the 5G core network as the Primary PLMN of the current row cell.

Or, the network device indicates the first PLMN appearing in the system message as Primary PLMN of the current cell. For example, the system message further includes second indication information, where the second indication information is used to determine, as the primary PLMN of the current cell, a PLMN in each PLMN whose recorded position in the system message is the most advanced PLMN.

The embodiment of the invention specifies how the network device indicates primary PLMN to the terminal device or specifies how the terminal device determines the primary PLMN to meet the requirements of future communication systems under the condition that the PLMN supported by the current cell supports a 5G core network or supports both 4G and 5G core networks.

Optionally, as an example, in a case that the network device indicates, to the terminal device, PLMNs supported by the current cell by using the method in the example shown in table 4 or table 5, and defaults the first PLMN in the first PLMN List as a Primary PLMN when accessing the 5G core network through the current cell, and defaults the first PLMN in the second PLMN List as a Primary PLMN when accessing the 4G core network through the current cell, the network device implements, using a choicee structure, information related to PLMNs carried in the PLMN-List-r15-5 GC. Specifically, the choice structure is as follows:

further, in the case that the network device indicates the PLMN supported by the current cell to the terminal device by using the methods in the examples shown in tables 1.1 to 5, the terminal device needs to inform the network device of the selected PLMN. The method shown in fig. 1 further comprises: sending a system message to the terminal equipment, and receiving third indication information sent by the terminal equipment after the system message is sent to the terminal equipment, wherein the third indication information is used for determining a PLMN to be accessed selected by the terminal equipment from PLMNs indicated by a current cell by the network equipment; and determining the PLMN to be accessed according to the third indication information.

Optionally, in some embodiments, the third indication information is used to indicate a location of the PLMN to be accessed in the system message.

For example, if the PLMN selected by the terminal device is a PLMN that only supports a 4G core network, the location indicated by the third indication information actually refers to a location of the PLMN to be accessed in the cell access related information field conforming to the 4G related protocol, and the network device may determine the PLMN to be accessed selected by the terminal device according to a manner of determining the PLMN to be accessed indicated by the terminal device in the existing LTE communication system. That is, if the terminal device selects a PLMN that only supports a 4G core network, the third indication information does not carry the indication flag of 5G, and the location (or PLMN sequence number) carried in the third indication information indicates the corresponding PLMN in an LTE manner.

Or for another example, the network device and the terminal device may agree in advance to uniformly number PLMNs in the system message, for example, uniformly number PLMNs included in the PLMN-List-r8-EPC, PLMN-List-r14-EPC, and PLMN-List-r15-5GC in the system message, in this case, the position (or understood as a PLMN sequence number) indicated in the third indication information may be a number greater than 6, and the network device may determine the PLMN to-be-accessed selected by the terminal device according to the position in the third indication information.

Optionally, in some embodiments, the third indication information is used to indicate an ID of the PLMN to be accessed and a type of a core network supported by the PLMN to be accessed. Or, the terminal device displays the ID of the selected PLMN to be accessed and the supported core network type to inform the network device.

Optionally, in other embodiments, the third indication information is generated by the terminal device according to the type of the core network supported by the PLMN to be accessed before sending the third indication information; when the core network supported by the to-be-accessed PLMN supports the first protocol, the third indication information comprises first sub information used for indicating that the to-be-accessed PLMN belongs to the first PLMN list and second sub information used for indicating the position of the to-be-accessed PLMN in the first PLMN list. Or, it is understood that, if the PLMN supporting the 5G core network is selected, the terminal device carries, in the third indication information, first sub-information indicating that the PLMN to be accessed supports the 5G core network, where the first sub-information may be, for example, an indication flag of 5G, and the indication flag of 5G is set to Ture, and in addition, the third indication information further includes second sub-information for indicating a location of the PLMN in a PLMN list in a cell access related information field conforming to a 5G related protocol. The network device may determine the PLMN to be accessed in the PLMN list in the cell access related information field conforming to the 5G related protocol according to the first sub information and the second sub information in the third indication information.

The embodiment of the invention specifies how the terminal device indicates the selected PLMN to the network device or specifies how the network device determines the selected PLMN of the terminal device under the condition that the PLMN supported by the current cell supports the 5G core network or supports the 4G and 5G core networks simultaneously, thereby meeting the requirements of future communication systems.

Fig. 2 shows a method for indication of a public land mobile network, PLMN, according to another embodiment of the invention, which method 200 may be performed by a network device. As shown in fig. 2, the method 200 includes:

s210, it is determined that the core network supported by at least one public land mobile network PLMN supported by the current cell only supports a first protocol of mobile communication.

Optionally, in S210, the first protocol of the mobile communication is a 5G related protocol, for example, the first protocol is a 3GPP R15 protocol, or the first protocol is a protocol with a version higher than that of the 3GPP R15 protocol. And it is to be understood that, when the first protocol is a 3GPP R15 protocol, the first protocol in which at least one PLMN supported by the current cell supports mobile communication may be understood as that at least one PLMN supported by the current cell supports a 5G core network.

S220, generating a system message, where the system message includes a first cell access relevant information field conforming to an existing second protocol of mobile communication, where the first cell access relevant information field carries a first PLMN list, the first PLMN list includes information related to the at least one PLMN and first indication information, and the first indication information is used by the terminal device to determine a type of a core network supported by each PLMN.

That is, it is assumed that the existing second protocol of mobile communication is the 3GPP R8 protocol. In this case, it can be understood that if at least one PLMN supported by the current cell only supports the 5G core network, the system message may include only a cell access related field conforming to the 3GPP R8 protocol, and carry a PLMN list in this field, where the at least one PLMN related information and the first indication information are included in this PLMN list. Or, it is understood that the multiplexing of the cell access related field conforming to the 3GPP R8 protocol carries information related to PLMNs supporting 5G core networks and indication information indicating types of core networks supported by each PLMN.

Or as shown in fig. 3, S220 includes: generating a system message, where the system message includes a second cell access related information field conforming to the second protocol and an indication information field, where the second cell access related information field carries a second PLMN list, the second PLMN list includes information related to the at least one PLMN, and the indication information field carries the first indication information.

That is, an indication information field may be added to the system message to display that the PLMN in the PLMN list carried in the cell access related information field indicating that the terminal device conforms to the 3GPP R8 protocol is actually a PLMN supporting a 5G core network.

Optionally, as an example, the first indication information is used to indicate types of core networks supported by each PLMN. For example, the first indication information includes a plurality of sub-indication information, each sub-indication information corresponds to a PLMN and is used for indicating the type of the core network supported by the PLMN. Or the first indication information collectively indicates the core network types supported by each PLMN, in this case, a bit may be used to carry the first indication information, and when the value of the bit is 1, it indicates that each PLMN supports a 5G core network.

Or as shown in fig. 4, S220 includes: generating a system message, where the system message includes a third cell access related information field conforming to the second protocol and a fourth cell access related information field conforming to the first protocol, the third cell access related information field carries a third PLMN list, the third PLMN list includes information related to the at least one PLMN, and the fourth cell access related information field carries the first indication information.

Optionally, as an example, the first indication information includes indication information of a reserved cell corresponding to each PLMN.

That is, the system message includes a cell access related information field conforming to the 3GPP R15 protocol, and the field includes a PLMN list, where the PLMN list includes only the reserved cell indication information corresponding to the PLMN included in the PLMN list included in the cell access related information field conforming to the 3GPP R8 protocol. I.e. implicitly indicating that the PLMN included in the PLMN list included in the cell access related information field of the terminal device complying with the 3GPP R8 protocol is actually a PLMN supporting a 5G core network.

Optionally, in some embodiments, the system message further includes a fifth cell access related information field conforming to a third protocol of mobile communication, the third protocol version being higher than the second protocol version. Or it can be understood that the system message may also include a cell access related information field conforming to the 3GPP R14 protocol.

For example, as shown in table 6.1, the above-mentioned first PLMN List is included in the system message, the first PLMN List is represented by PLMN-List-r8-EPC, the PLMN-List-r8-EPC includes information related to PLMN X and PLMN Y and indication information (5GC) indicating that PLMN X and PLMN Y support a 5G core network, and the number of PLMNs included in the PLMN-List-r8-EPC may be up to 6. It is to be understood that 6 is only an example and not a limitation.

TABLE 6.1

Alternatively, as shown in table 6.2, the system message includes PLMN-List-r8-EPC and PLMN-List-r15-5GC, the PLMN-List-r8-EPC includes information related to PLMN X, PLMN Y, and the like, and the PLMN-List-r15-5GC includes reserved cell indication information corresponding to PLMN X and reserved cell indication information corresponding to PLMX Y. The number of PLMNs included in the PLMN-List-r8-EPC may be 6 at maximum, and the number of PLMNs included in the PLMN-List-r8-EPC may be 6 at maximum. Or, as an optional example, the sum of the number of PLMNs included in the PLMN-List-r8-EPC and the number of PLMNs included in the PLMN-List-r15-5GC may be 6 at maximum. It is to be understood that 6 is only an example and not a limitation.

TABLE 6.2

It should be noted that, in the methods shown in fig. 2 to 4, the PLMN placed in the PLMN-List-r8-EPC is substantially a PLMN supporting a 5G core network. In this case, legacy cell bar in the system message is used for bar legacy UEs, and 5GC cell bar is newly added in the system message to bar UEs supporting 5 GC.

In the embodiment of the present invention, in a case that the network device indicates, to the terminal device, PLMNs supported by a current cell by using the method in the example shown in fig. 2 to 4, the terminal device needs to determine a PLMN that is a Primary (Primary) PLMN of the current cell among the PLMNs. At this time, the terminal device may determine the first PLMN in the system message as Primary PLMN of the current cell by default. Or the network device may display a Primary PLMN indicating that the terminal device determines a certain PLMN in the system message as the current cell.

Further, the method shown in fig. 2 to 4 further includes: and sending the system message to a terminal device, and after sending the system message to the terminal device, receiving second indication information sent by the terminal device, where the second indication information is used to indicate a position of a PLMN to be accessed, selected from the at least one PLMN, of the terminal device in the first PLMN list. That is, since all PLMNs supported by the current cell only support the 5G core network, the location (or PLMN code number) indicated in the second indication information corresponds to the PLMN in the first PLMN list.

Fig. 5 shows a method of indication of a public land mobile network, PLMN, according to a further embodiment of the invention, which method 300 may be performed by a network device. As shown in fig. 3, the method 300 includes:

s310, determining a target PLMN in at least one public land mobile network PLMN supported by the current cell, wherein core networks supported by each target PLMN comprise a core network supporting a first protocol of mobile communication and a core network supporting an existing second protocol of mobile communication.

Optionally, in S310, the first protocol of the mobile communication is a 5G related protocol, for example, the first protocol is a 3GPP R15 protocol, or the first protocol is a protocol with a version higher than that of the 3GPP R15 protocol. The second existing protocol is the 3GPP R8 protocol. In this case, it can be understood that each target PLMN supports both 4G and 5G core networks.

S320, generating a system message, where the system message includes a first cell access relevant information field conforming to the second protocol, the second cell access relevant information field carries a first PLMN list, the first PLMN list includes information related to the target PLMN and first indication information, and the first indication information is used to indicate a type of a core network supported by each target PLMN.

That is, if PLMNs supporting both 4G and 5G core networks exist in the PLMN supported by the current cell, the system message may include only a cell access related field conforming to the 3GPP R8 protocol, and this field carries a PLMN list, and this list includes information related to these PLMNs and first indication information, where the first indication information is used to indicate the type of core network supported by each target PLMN.

Optionally, the first indication information includes a plurality of sub-indication information, each sub-indication information corresponds to a PLMN and is used to indicate a type of a core network supported by the PLMN.

Or as shown in fig. 6, S320 includes: generating a system message, where the system message includes a second cell access related information field conforming to the second protocol and an indication information field, the second cell access related information field carries a second PLMN list, the second PLMN list includes information related to the target PLMN, and the indication information field carries the first indication information.

That is, if there is a PLMN supporting both 4G and 5G core networks among PLMNs supported by the current cell, the system message may include only a cell access related field conforming to the 3GPP R8 protocol and an indication information field, and this field carries a PLMN list, and the indication information field carries first indication information indicating the type supported by each target PLMN.

For example, as shown in table 7.1, the system message includes PLMN-List-r8-EPC, and PLMN-List-r8-EPC includes ID of PLMN a and corresponding reserved cell indication information, ID of PLMN B and corresponding reserved cell indication information, ID of PLMN C and corresponding reserved cell indication information, and first indication information (EPC +5GC), where the first indication information indicates that PLMN a and PLMN B support both 4G core network and 5G core network.

TABLE 7.1

Or further, as shown in 7.2, the system message includes PLMN-List-r8-EPC, PLMN-List-r14-EPC, PLMN-List-r15-5GC, and PLMN-List-r8-EPC includes ID of PLMN a and corresponding reserved cell indication information, ID of PLMN B and corresponding reserved cell indication information, ID of PLMN C and corresponding reserved cell indication information, and first indication information (EPC +5GC), where the first indication information indicates that PLMN a and PLMN B support both 4G core network and 5G core network. The ID of the PLMN D and the corresponding reserved cell indication information are contained in the PLMN-List-r14-EPC, and the corresponding reserved cell indication information of the ID of the PLMN E is contained in the PLMN-List-r15-5 GC. In this case, the total number of PLMNs included in the PLMN-List-r8-EPC and the PLMN-List-r14-EPC may be 6 at maximum, and the number of PLMNs included in the PLMN-List-r15-5GC may be 6 at maximum. Or the total number of PLMNs included in the PLMN-List-r8-EPC, PLMN-List-r14-EPC, and PLMN-List-r15-5GC may be 6. It is to be understood that 6 is merely an example and not a limitation.

TABLE 7.2

For another example, as shown in table 8.1, the system message includes PLMN-List-r8-EPC and indication information field, PLMN-List-r8-EPC includes ID of PLMN a and corresponding reserved cell indication information, ID of PLMN B and corresponding reserved cell indication information, and ID of PLMN C and corresponding reserved cell indication information, the indication information field (CN type) carries first indication information, and the first indication information indicates that PLMN a supports 5G core network and indicates that PLMN B supports 5G core network.

TABLE 8.1

Or further, as shown in 8.2, the system message includes PLMN-List-r8-EPC, PLMN-List-r14-EPC, and PLMN-List-r15-5GC, the PLMN-List-r8-EPC includes the ID of PLMN a and corresponding reserved cell indication information, the ID of PLMN B and corresponding reserved cell indication information, the ID of PLMN C and corresponding reserved cell indication information, the PLMN-List-r14-EPC includes the ID of PLMN D and corresponding reserved cell indication information, and the PLMN-List-r15-5GC includes the ID of PLMN E and corresponding reserved cell indication information. The indication information field (CN type) carries first indication information indicating that PLMN a supports a 5G core network and indicating that PLMN B supports a 5G core network.

TABLE 8.2

In the embodiment of the present invention, in a case that the network device indicates, to the terminal device, PLMNs supported by a current cell by using the methods in the examples shown in tables 7.1 to 8.2, the terminal device needs to determine a PLMN that is a Primary (Primary) PLMN of the current cell among the PLMNs. At this time, the terminal device may determine the Primary PLMN by using the method for determining a Primary PLMN shown in fig. 1, and details are not described herein again to avoid repetition.

Further, the method shown in fig. 5 and 6 further includes: sending a system message to the terminal equipment; after sending a system message to a terminal device, receiving second indication information sent by the terminal device, where the second indication information is used to indicate a type of a core network supported by a to-be-accessed PLMN selected by the terminal device from the at least one PLMN and a serial number M related to the to-be-accessed PLMN; when the second indication information indicates that the core network supported by the PLMN to be accessed supports the first protocol, determining that the Mth PLMN in the PLMNs which support the first protocol is the PLMN to be accessed; and when the second indication information indicates that the core network supported by the PLMN to be accessed supports the second protocol, determining that the Mth PLMN in the PLMN of which the core network supports the second protocol is the PLMN to be accessed.

That is, if the network device indicates the PLMN supported by the current cell to the terminal device by using the method shown in fig. 5 and 6, the terminal device needs to indicate the type of the core network supported by the selected PLMN to be accessed and the sequence number of the PLMN simultaneously when indicating the selected PLMN to be accessed to the network device. For example, if the second indication information indicates that the PLMN to be accessed supports the 5G core network and the sequence number X of the PLMN to be accessed, the network device determines that the PLMN supporting the 5G core network appearing at the xth in the system message is the PLMN to be accessed selected by the terminal device, and if the second indication information indicates that the PLMN to be accessed supports the 4G core network and the sequence number X of the PLMN to be accessed, the network device determines that the PLMN supporting the 4G core network appearing at the xth in the system message is the PLMN to be accessed.

Or, if the second indication information indicates that the PLMN to be accessed supports the 5G core network, the network device determines that the xth PLMN supporting the 5G core network in the system message is the PLMN to be accessed selected by the terminal device, and if the second indication information does not indicate that the PLMN to be accessed supports the 5G core network, the network device determines that the xth PLMN supporting the 4G core network in the system message is the PLMN to be accessed.

Optionally, in some embodiments, the method shown in fig. 5 and 6 further comprises: and sending the system message to a terminal device, and after sending the system message to the terminal device, receiving second indication information sent by the terminal device, wherein the second indication information is used for indicating a number of a to-be-accessed PLMN selected from the at least one PLMN by the terminal device, and the number of the to-be-accessed PLMN is determined by uniformly numbering each target PLMN when the terminal device determines that the to-be-accessed PLMN belongs to the target PLMN.

In other words, the network device and the terminal device may agree in advance that the PLMNs that simultaneously support the 4G core network and the 5G core network are individually numbered, and if the PLMN to be accessed selected by the terminal device is one of the PLMNs that simultaneously support the 4G core network and the 5G core network, the number (or index) of the selected PLMN to be accessed is directly indicated in the second indication information.

Fig. 7 is a method of PLMN selection according to one embodiment of the present invention. The method 400 may be performed by a terminal device. It is to be understood that the interaction between the network device and the terminal device described from the terminal device side is the same as that described in the network device side in the method shown in fig. 1, and the related description is appropriately omitted to avoid redundancy. As shown in fig. 7, the method 400 includes:

s410, receiving a system message, wherein the system message comprises a first cell access related information field conforming to a first protocol of mobile communication and a second cell access related information field conforming to an existing second protocol of the mobile communication, the first cell access related information field carries a first PLMN list, the first PLMN list comprises information related to a first target PLMN, and a core network supported by each first target PLMN comprises a core network supporting the first protocol;

s420, according to the system message, selecting a PLMN to be accessed from at least one PLMN supported by the current cell, wherein the at least one PLMN comprises the first target PLMN.

Optionally, as an embodiment, when the at least one PLMN includes a second target PLMN whose supported core network supports the second protocol, the second cell access-related information field carries a second PLMN list, where the second PLMN list includes information related to the second target PLMN.

Optionally, as an embodiment, the system message further includes a third cell access related information field conforming to an existing third protocol of mobile communication, where the version of the third protocol is higher than that of the second protocol;

wherein, when the at least one PLMN includes a third target PLMN whose supported core network supports the third protocol, the third cell access-related information field carries a third PLMN, and the third PLMN list includes information related to the third target PLMN.

Optionally, as an embodiment, when the at least one PLMN includes the first target PLMN, the second target PLMN, and the third target PLMN, a sum of a number of the second target PLMN included in the second PLMN list and a number of the third target PLMN included in the third PLMN list is less than or equal to a preset value, and a number of the first target PLMN included in the first PLMN list is less than or equal to the preset value; or the like, or, alternatively,

when the first target PLMN, the second target PLMN, and the third target PLMN are included in the at least one PLMN, a sum of the number of the second target PLMN included in the second PLMN list, the number of the third target PLMN included in the third PLMN list, and the number of the first target PLMN included in the first PLMN list is less than or equal to the preset value.

Optionally, as an embodiment, there is no same PLMN in the first target PLMN and the second target PLMN; or at least one identical PLMN exists in the first target PLMN and the second target PLMN.

Optionally, as an embodiment, the core network supported by each PLMN only supports the first protocol, and the second cell access related information field carries information related to a virtual padding PLMN.

Optionally, as an embodiment, the first target PLMN includes first sub-target PLMNs, a core network supported by each first sub-target PLMN further includes a core network supporting the second protocol or the third protocol, where the third protocol is an existing protocol of mobile communication, a version of the third protocol is higher than a version of the second protocol, the information related to the first target PLMN includes index information of each first sub-target PLMN and reserved cell indication information corresponding to each first sub-target PLMN, the index information of each first sub-target PLMN is used for a terminal device to determine an identification ID of each first sub-target PLMN, and the method shown in fig. 7 further includes:

and determining the ID of each first sub-target PLMN according to the index information of each first sub-target PLMN.

Optionally, as an embodiment, the first target PLMN includes a first sub-target PLMN and a second sub-target PLMN, a core network supported by each first sub-target PLMN further includes a core network supporting the second protocol, and a core network supported by each second sub-target PLMN further includes a core network supporting the third protocol, wherein the information related to the first target PLMN comprises index information of each first sub-target PLMN and indication information of a reserved cell corresponding to each first sub-target PLMN, the index information of each first sub-target PLMN is used for a terminal device to determine an ID of each first sub-target PLMN, the information related to the first target PLMN further comprises index information of each second sub-target PLMN and reserved cell indication information corresponding to each second sub-target PLMN, wherein the index information of each second sub-target PLMN is used for the terminal equipment to determine the ID of each second sub-target PLMN;

wherein, the method shown in fig. 7 further comprises:

determining the ID of each first sub-target PLMN according to the index information of each first sub-target PLMN;

and determining the ID of each second sub-target PLMN according to the index information of each second sub-target PLMN.

Optionally, as an embodiment, the information related to the second target PLMN includes an ID of each first target sub-PLMN and reserved cell indication information corresponding to each first sub-target PLMN, and the information related to the third target PLMN includes an ID of each second sub-target PLMN and reserved cell indication information corresponding to each second sub-target PLMN;

wherein the index of each first sub-destination PLMN is determined by the network device according to the position of each first sub-destination PLMN in the second PLMN list, and the index of each second sub-destination PLMN is determined by the network device according to the position of each second sub-destination PLMN in the third PLMN list.

Optionally, as an embodiment, the first target PLMN includes N first sub-target PLMNs, the core networks supported by each first sub-destination PLMN further comprise a core network supporting the second protocol, a second PLMN list is carried in the second cell access related information field, the N first sub-target PLMNs are positioned at the first N positions of the second PLMN list, N is a positive integer which is greater than or equal to 1, the information related to the first target PLMN includes N reserved cell indication information corresponding to the N first sub-target PLMNs, the N pieces of reserved cell indication information are located at the first N positions of the first PLMN list, and the position of each piece of reserved cell indication information in the first PLMN list is the same as the position of a first sub-target PLMN corresponding to the piece of reserved cell indication information in the second PLMN list;

wherein, the method shown in fig. 7 further comprises:

and determining the ID of the first sub-target PLMN corresponding to each reserved cell indication information according to the information included in the second PLMN list.

Optionally, as an embodiment, the first cell access related information field further includes first indication information, where the first indication information is used to indicate, by the terminal device, an ID of a first sub-target PLMN corresponding to each indication information of N reserved cells in the first PLMN list, according to the second PLMN list.

Optionally, as an embodiment, the system message further includes second indication information, where the second indication information is used to indicate that a PLMN in the system message, which is located at the most front of the recorded position in each PLMN, is determined as a primary PLMN of the current cell;

wherein, the method shown in fig. 7 further comprises:

and determining the PLMN with the highest recorded position in the system message as the main PLMN of the current cell.

Optionally, as an embodiment, the system message further includes second indication information, where the second indication information is used to indicate that one of the first target PLMNs is used as a primary PLMN of the current cell, or the second indication information is used to indicate that one of the second target PLMNs is used as a primary PLMN of the current cell;

wherein, the method shown in fig. 7 further comprises:

and determining the PLMN indicated by the second indication information as the primary PLMN of the current cell.

Optionally, as an embodiment, the system message further includes second indication information, where the second indication information is used to indicate that one of the first target PLMNs is to be the first primary PLMN of the current cell, and indicate that one of the second target PLMNs is to be the second primary PLMN of the current cell;

wherein, the method shown in fig. 7 further comprises:

and determining one of the first target PLMNs indicated by the second indication information as a first main PLMN of the current cell, and determining one of the second target PLMNs indicated by the second indication information as a second main PLMN of the current cell.

Optionally, as an embodiment, the method shown in fig. 7 further includes:

determining a first target PLMN with the most front position in the first PMLN list as a first main PLMN of the current cell;

and determining a second target PLMN with the most front position in the second PLMN list as a second main PLMN of the current cell.

Optionally, as an embodiment, the method shown in fig. 7 further includes:

and sending third indication information to the network equipment, wherein the third indication information is used for the network equipment to determine the PLMN to be accessed.

Optionally, as an embodiment, the third indication information is used to indicate a location of the PLMN to be accessed in the system message; or the like, or, alternatively,

the third indication information is used for indicating the ID of the PLMN to be accessed and the type of the core network supported by the PLMN to be accessed.

Optionally, as an embodiment, before sending the third indication information to the network device, the method shown in fig. 7 further includes:

determining the type of a core network supported by the PLMN to be accessed;

generating the third indication information according to the type of the core network supported by the PLMN to be accessed;

when the core network supported by the to-be-accessed PLMN supports the first protocol, the generated third indication information comprises first sub information used for indicating that the to-be-accessed PLMN belongs to the first PLMN list and second sub information used for indicating the position of the to-be-accessed PLMN in the first PLMN list.

Fig. 8 is a method of PLMN selection according to one embodiment of the present invention. The method 500 may be performed by a terminal device. It is to be understood that the interaction between the network device and the terminal device described from the terminal device side is the same as that described in the network device side in the method shown in fig. 2 to 4, and the related description is appropriately omitted to avoid redundancy. As shown in fig. 8, the method 500 includes:

s510, receiving a system message;

s520, selecting a PLMN to be accessed from at least one PLMN supported by the current cell according to the system message, wherein a core network supported by each PLMN only supports a first protocol of mobile communication;

Optionally, as an embodiment, the system message further includes a fifth cell access related information field conforming to a third protocol of mobile communication, where the third protocol is higher in version than the second protocol.

Optionally, as an embodiment, the system message includes the second cell access related information field and the indication information field, where the first indication information is used to indicate a type of a core network supported by each PLMN.

Optionally, as an embodiment, the system message includes the third cell access related information field and the fourth cell access related information field, and the first indication information includes reserved cell indication information corresponding to each PLMN.

Optionally, as an embodiment, the method shown in fig. 8 further includes:

and sending second indication information to network equipment, wherein the second indication information is used for indicating the position of the PLMN to be accessed in the first PLMN list.

Fig. 9 is a method of PLMN selection according to yet another embodiment of the present invention. The method 600 may be performed by a terminal device. It is to be understood that the interaction of the network device and the terminal device described from the terminal device side is the same as that of the network device side in the methods shown in fig. 5 and 6, and the related description is omitted appropriately to avoid repetition. As shown in fig. 9, the method 600 includes:

s610, receiving a system message;

s620, selecting a PLMN to be accessed from at least one PLMN supported by the current cell according to the system message;

Optionally, as an embodiment, the method shown in fig. 9 further includes:

and sending second indication information to network equipment, wherein the second indication information is used for indicating the type of the core network supported by the PLMN to be accessed and the serial number M related to the PLMN to be accessed.

Optionally, as an embodiment, the method shown in fig. 9 further includes:

when the PLMN to be accessed belongs to the target PLMN, uniformly numbering each target PLMN;

and sending second indication information to network equipment, wherein the second indication information is used for indicating the number of the PLMN to be accessed.

The indication method and the selection method of the PLMN according to the embodiment of the present invention are described in detail above in conjunction with fig. 1 to 9. A network device according to an embodiment of the present invention will be described in detail below with reference to fig. 10.

Fig. 10 is a schematic structural diagram of a network device according to an embodiment of the present invention. As shown in fig. 10, the network device 10 includes:

a determining module 11, configured to determine at least one public land mobile network PLMN supported by a current cell, where the at least one PLMN includes first target PLMNs, and a core network supported by each first target PLMN includes a core network supporting a first protocol of mobile communication;

a processing module 12, configured to generate a system message, where the system message includes a first cell access related information field conforming to the first protocol and a second cell access related information field conforming to an existing second protocol of mobile communication, and the first cell access related information field carries a first PLMN list, where the first PLMN list includes information related to the first target PLMN.

When determining that the PLMN supported by the current cell includes a first target PLMN of a first protocol in which a core network supports mobile communication, the network device according to the embodiment of the present invention includes a cell access related information field conforming to the first protocol in the system message, where the cell access related information field carries a first PLMN list, and includes information related to the first target PLMN in the first PLMN list. Therefore, the network device can clearly indicate the PLMN supported by the cell to the terminal device under the condition that the PLMN supports the 5G core network or supports the 4G and 5G core networks simultaneously, and the requirement of a future communication system is met.

wherein, when the at least one PLMN includes a third target PLMN whose supported core network supports the third protocol, the third cell access-related information field carries a third PLMN list, and the third PLMN list includes information related to the third target PLMN.

Optionally, as an embodiment, the first target PLMN includes first sub-target PLMNs, and a core network supported by each first sub-target PLMN further includes a core network supporting the second protocol or a third protocol, where the third protocol is an existing protocol of mobile communication, and a version of the third protocol is higher than a version of the second protocol;

the information related to the first target PLMN includes index information of each first sub-target PLMN and reserved cell indication information corresponding to each first sub-target PLMN, and the index information of each first sub-target PLMN is used by the terminal device to determine an identification ID of each first sub-target PLMN.

Optionally, as an embodiment, the first target PLMN includes a first sub-target PLMN and a second sub-target PLMN, where a core network supported by each first sub-target PLMN further includes a core network supporting the second protocol, and a core network supported by each second sub-target PLMN further includes a core network supporting the third protocol;

the information related to the first target PLMN comprises index information of each first sub-target PLMN and reserved cell indication information corresponding to each first sub-target PLMN, wherein the index information of each first sub-target PLMN is used for a terminal device to determine the ID of each first sub-target PLMN;

the information related to the first target PLMN further includes index information of each second sub-target PLMN and reserved cell indication information corresponding to each second sub-target PLMN, and the index information of each second sub-target PLMN is used for the terminal device to determine an ID of each sub-second target PLMN.

Optionally, as an embodiment, the information related to the second target PLMN includes an ID of each first sub-target PLMN and reserved cell indication information corresponding to each first sub-target PLMN;

the information related to the third target PLMN comprises an ID of each second sub-target PLMN and reserved cell indication information corresponding to each second sub-target PLMN;

wherein the processing module 12 is further configured to:

and determining the index of each first sub-target PLMN and the index of each second sub-target PLMN according to the position of each first sub-target PLMN in the second PLMN list and the position of each second sub-target PLMN in the third PLMN list.

Optionally, as an embodiment, the first target PLMN includes N first sub-target PLMNs, a core network supported by each first sub-target PLMN further includes a core network supporting the second protocol, the second cell access related information field carries a second PLMN list, the N first sub-target PLMNs are located in the first N positions of the second PLMN list, and N is a positive integer greater than or equal to 1;

wherein the information related to the first target PLMN includes N reserved cell indication information corresponding to the N first sub-target PLMNs, the N reserved cell indication information being located at the first N positions of the first PLMN list, and a position of each reserved cell indication information in the first PLMN list is the same as a position of the first sub-target PLMN corresponding to the reserved cell indication information in the second PLMN list.

Optionally, as an embodiment, the system message further includes second indication information, where the second indication information is used to indicate that a PLMN in each PLMN, which is located at the most front of the recorded position in the system message, is determined as a primary PLMN of the current cell.

Optionally, as an embodiment, the system message further includes second indication information, where the second indication information is used to indicate that one of the first target PLMNs is used as the primary PLMN of the current cell, or the second indication information is used to indicate that one of the second target PLMNs is used as the primary PLMN of the current cell.

Optionally, as an embodiment, the system message further includes second indication information, where the second indication information is used to indicate that one of the first target PLMNs is to be the first primary PLMN of the current cell, and indicate that one of the second target PLMNs is to be the second primary PLMN of the current cell.

Optionally, as an embodiment, as shown in fig. 10, the network device further includes a transceiver module 13;

the transceiver module 13 is configured to send the system message to a terminal device;

the transceiver module 13 is further configured to receive third indication information sent by the terminal device after the system message is sent to the terminal device, where the third indication information is used by the network device to determine a PLMN to be accessed, which is selected by the terminal device from PLMNs supported by the current cell;

the processing module 13 is further configured to determine the PLMN to be accessed according to the third indication information.

Optionally, as an embodiment, the third indication information is generated by the terminal device according to a type of a core network supported by the PLMN to be accessed before sending the third indication information;

when the core network supported by the to-be-accessed PLMN supports the first protocol, the third indication information comprises first sub information used for indicating that the to-be-accessed PLMN belongs to the first PLMN list and second sub information used for indicating the position of the to-be-accessed PLMN in the first PLMN list.

The network device according to the embodiment of the present invention may refer to the flow corresponding to the method 100 according to the embodiment of the present invention, and each unit/module and the other operations and/or functions in the network device are respectively for implementing the corresponding flow in the method 100, and are not described herein again for brevity.

Fig. 11 is a schematic structural diagram of a network device according to an embodiment of the present invention. As shown in fig. 11, the network device 20 includes:

a determining module 21, configured to determine that a core network supported by at least one public land mobile network PLMN supported by a current cell only supports a first protocol of mobile communication;

a processing module 22, configured to generate a system message, where the system message includes a first cell access related information field conforming to an existing second protocol of mobile communication, where the first cell access related information field carries a first PLMN list, where the first PLMN list includes information related to the at least one PLMN and first indication information, and the first indication information is used for a terminal device to determine a type of a core network supported by each PLMN; or the like, or, alternatively,

Optionally, as an embodiment, the system message further includes a fifth cell access related information field conforming to an existing third protocol of mobile communication, where the third protocol is higher in version than the second protocol.

Optionally, as an embodiment, the system message includes the second cell access related information field and the indication information field, and the first indication information is used to indicate a type of a core network supported by each PLMN.

Optionally, as an embodiment, as shown in fig. 11, the network device further includes a transceiver module 23;

the transceiver module 23 is configured to send the system message to a terminal device;

the transceiver module 23 is further configured to receive second indication information sent by the terminal device after the system message is sent to the terminal device, where the second indication information is used to indicate a position of a PLMN to be accessed, selected from the at least one PLMN, of the terminal device in the first PLMN list.

The network device according to the embodiment of the present invention may refer to the flow corresponding to the method 200 according to the embodiment of the present invention, and each unit/module and the other operations and/or functions in the network device are respectively for implementing the corresponding flow in the method 200, and are not described herein again for brevity.

Fig. 12 is a schematic structural diagram of a network device according to an embodiment of the present invention. As shown in fig. 12, the network device 30 includes:

a determining module 31, configured to determine a target PLMN in at least one public land mobile network PLMN supported by a current cell, where each target PLMN supports a core network that includes a core network supporting a first protocol for mobile communication and a core network supporting an existing second protocol for mobile communication;

a processing module 32, configured to generate a system message, where the system message includes a first cell access related information field conforming to the second protocol, and a first PLMN list is carried in the second cell access related information field, where the first PLMN list includes information related to the target PLMN and first indication information, and the first indication information is used to indicate a type of a core network supported by each target PLMN; or the like, or, alternatively,

Optionally, as an embodiment, as shown in fig. 13, the network device further includes a transceiver module 33;

the transceiver module 33 is configured to send the system message to a terminal device;

the transceiver module 33 is further configured to receive second indication information sent by the terminal device after the system message is sent to the terminal device, where the second indication information is used to indicate a type of a core network supported by a to-be-accessed PLMN selected by the terminal device from the at least one PLMN and a serial number M related to the to-be-accessed PLMN;

when the second indication information indicates that the core network supported by the PLMN to be accessed supports the first protocol, determining that the Mth PLMN in the PLMNs which support the first protocol is the PLMN to be accessed;

and when the second indication information indicates that the core network supported by the PLMN to be accessed supports the second protocol, determining that the Mth PLMN in the PLMN of which the core network supports the second protocol is the PLMN to be accessed.

Optionally, as an embodiment, as shown in fig. 12, the network device further includes a transceiver module 33;

the transceiver module 33 is further configured to receive second indication information sent by the terminal device after the system message is sent to the terminal device, where the second indication information is used to indicate a number of a PLMN to be accessed, which is selected by the terminal device from the at least one PLMN, and the number of the PLMN to be accessed is determined by the terminal device by uniformly numbering each target PLMN when it is determined that the PLMN to be accessed belongs to the target PLMN.

The network device according to the embodiment of the present invention may refer to the flow corresponding to the method 300 according to the embodiment of the present invention, and each unit/module and the other operations and/or functions in the network device are respectively for implementing the corresponding flow in the method 300, and are not described herein again for brevity.

Fig. 13 is a schematic structural diagram of a terminal device according to an embodiment of the present invention. As shown in fig. 13, the terminal device 40 includes:

a transceiver module 41, configured to receive a system message, where the system message includes a first cell access related information field conforming to a first protocol of mobile communication and a second cell access related information field conforming to an existing second protocol of mobile communication, where the first cell access related information field carries a first PLMN list, the first PLMN list includes information related to a first target PLMN, and a core network supported by each first target PLMN includes a core network supporting the first protocol;

a processing module 42, configured to select, according to the system message, a PLMN to be accessed from at least one PLMN supported by the current cell, where the at least one PLMN includes the first target PLMN.

Optionally, as an embodiment, the first target PLMN includes first sub-target PLMNs, the core network supported by each first sub-target PLMN further includes a core network supporting the second protocol or the third protocol, where the third protocol is an existing protocol of mobile communication, a version of the third protocol is higher than a version of the second protocol, the information related to the first target PLMN includes index information of each first sub-target PLMN and reserved cell indication information corresponding to each first sub-target PLMN, the index information of each first sub-target PLMN is used by a terminal device to determine an identification ID of each first sub-target PLMN, and the processing module 42 is further configured to:

wherein the processing module 42 is further configured to:

Optionally, as an embodiment, the processing module 42 is further configured to:

Optionally, as an embodiment, the transceiver module 42 is further configured to:

Optionally, as an embodiment, before sending the third indication information to the network device, the processing module 42 is further configured to:

determining the type of a core network supported by the PLMN to be accessed;

The terminal device according to the embodiment of the present invention may refer to the flow corresponding to the method 500 of the embodiment of the present invention, and each unit/module and the other operations and/or functions in the terminal device are respectively for implementing the corresponding flow in the method 500, and are not described herein again for brevity.

Fig. 14 is a schematic structural diagram of a terminal device according to an embodiment of the present invention. As shown in fig. 14, the terminal device 50 includes:

a transceiving module 51 for receiving a system message;

a processing module 52, configured to select, according to the system message, a PLMN to be accessed from at least one PLMN supported by the current cell, where a core network supported by each PLMN only supports a first protocol of mobile communication;

Optionally, as an embodiment, the transceiver module 51 is further configured to:

The terminal device according to the embodiment of the present invention may refer to the process corresponding to the method 600 of the embodiment of the present invention, and each unit/module and the other operations and/or functions in the terminal device are respectively for implementing the corresponding process in the method 600, and are not described herein again for brevity.

Fig. 15 is a schematic structural diagram of a terminal device according to an embodiment of the present invention. As shown in fig. 15, the terminal device 60 includes:

a transceiver module 61, configured to receive a system message;

a processing module 62, configured to select a PLMN to be accessed from at least one PLMN supported by the current cell according to the system message;

Optionally, as an embodiment, the transceiver module 61 is further configured to:

Optionally, as an embodiment, the processing module 61 is further configured to:

the transceiver module is further configured to: and sending second indication information to network equipment, wherein the second indication information is used for indicating the number of the PLMN to be accessed.

The terminal device according to the embodiment of the present invention may refer to the flow corresponding to the method 700 of the embodiment of the present invention, and each unit/module and the other operations and/or functions in the terminal device are respectively for implementing the corresponding flow in the method 700, and are not described herein again for brevity.

Fig. 16 shows a schematic structural diagram of a network device according to another embodiment of the present invention. As shown in fig. 16, the network device 100 includes a processor 110, a transceiver 120, a memory 130, and a bus interface. Wherein:

in this embodiment of the present invention, the network device 100 further includes: a computer program stored in the memory 130 and capable of running on the processor 110, wherein the computer program, when executed by the processor 110, implements the processes of the methods 100 to 300, and can achieve the same technical effects, and therefore, in order to avoid repetition, the details are not repeated herein.

In FIG. 16, the bus architecture may include any number of interconnected buses and bridges, with various circuits linking together one or more processors, represented by processor 110, and memory, represented by memory 130. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 120 may be a number of elements including a transmitter and a receiver that provide a means for communicating with various other apparatus over a transmission medium.

The processor 110 is responsible for managing the bus architecture and general processing, and the memory 130 may store data used by the processor 110 in performing operations.

Fig. 17 shows a schematic structural diagram of a terminal device according to another embodiment of the present invention, and as shown in fig. 17, the terminal device 200 includes: at least one processor 210, memory 220, at least one network interface 230, and a user interface 240. The various components in the terminal device 200 are coupled together by a bus system 150. It will be appreciated that the bus system 250 is used to enable communications among the components. The bus system 150 includes a power bus, a control bus, and a status signal bus in addition to a data bus. For clarity of illustration, however, the various buses are labeled as bus system 250 in FIG. 17.

The user interface 240 may include, among other things, a display, a keyboard, or a pointing device (e.g., a mouse, trackball, touch pad, or touch screen, among others.

It will be appreciated that memory 220 in embodiments of the invention may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The non-volatile memory may be a Read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash memory. The volatile Memory may be a Random Access Memory (RAM), which acts as an external cache Memory. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (statram, SRAM), dynamic random access memory (dynamic RAM, DRAM), Synchronous dynamic random access memory (Synchronous DRAM, SDRAM), Double data rate Synchronous dynamic random access memory (Double data rate SDRAM, DDRSDRAM), Enhanced Synchronous SDRAM (ESDRAM), Synchronous link SDRAM (Synclink DRAM, SLDRAM), and Direct memory bus RAM (DRRAM). The memory 120 of the systems and methods described in this embodiment of the invention is intended to comprise, without being limited to, these and any other suitable types of memory.

In some embodiments, memory 220 stores elements, executable modules or data structures, or a subset thereof, or an expanded set thereof: an operating system 221 and application programs 222.

The operating system 221 includes various system programs, such as a framework layer, a core library layer, a driver layer, and the like, and is used for implementing various basic services and processing hardware-based tasks. The application 222 includes various applications, such as a Media Player (Media Player), a Browser (Browser), and the like, for implementing various application services. A program implementing a method according to an embodiment of the invention may be included in the application 222.

In this embodiment of the present invention, the terminal device 200 further includes: a computer program stored on the memory 220 and capable of running on the processor 210, wherein the computer program, when executed by the processor 210, implements the processes of the method 200, and can achieve the same technical effects, and further description is omitted here to avoid repetition.

The method disclosed in the above embodiments of the present invention may be applied to the processor 210, or implemented by the processor 210. The processor 210 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by instructions in the form of hardware, integrated logic circuits or software in the processor 210. The Processor 210 may be a general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, or discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software modules may reside in ram, flash memory, rom, prom, or eprom, registers, among other computer-readable storage media known in the art. The computer readable storage medium is located in the memory 220, and the processor 210 reads the information in the memory 220 and performs the steps of the above method in combination with the hardware thereof. In particular, the computer-readable storage medium has stored thereon a computer program which, when executed by the processor 210, implements the steps of the method embodiments as described above in the methods 400 to 600.

It is to be understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For a hardware implementation, the Processing units may be implemented within one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), general purpose processors, controllers, micro-processors, other electronic units configured to perform the functions described herein, or a combination thereof.

For software implementation, the techniques described in this disclosure may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described in this disclosure. The software codes may be stored in a memory and executed by a processor. The memory may be implemented within the processor or external to the processor.

An embodiment of the present invention further provides a computer-readable storage medium, where a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the computer program implements the processes of the methods 100 to 600, and can achieve the same technical effects, and in order to avoid repetition, the detailed description is omitted here. The computer-readable storage medium may be a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Through the above description of the embodiments, those skilled in the art will clearly understand that the above embodiment method can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solution of the present invention may be substantially or partially embodied in the form of a software product stored in a storage medium (e.g., ROM/RAM, magnetic disk, optical disk), and including instructions for enabling a terminal (e.g., a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.

While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for indicating Public Land Mobile Network (PLMN) is applied to network equipment, and is characterized by comprising the following steps:

generating a system message comprising a first cell access related information field conforming to the first protocol and a second cell access related information field conforming to an existing second protocol of mobile communication, the first cell access related information field carrying a first PLMN list comprising information relating to the first target PLMN,

the first target PLMN includes first sub-target PLMNs, and in a case that a core network supported by each first sub-target PLMN further includes a core network supporting the second protocol, the information related to the first target PLMN includes index information of each first sub-target PLMN and reserved cell indication information corresponding to each first sub-target PLMN, the index information of each first sub-target PLMN is used for a terminal device to determine an ID of each first sub-target PLMN, the first protocol is 5G, and the second protocol is 4G.

2. The method of claim 1, wherein when a second target PLMN of the second protocol is supported by a supported core network in the at least one PLMN, a second PLMN list is carried in the second cell access related information field, and the second PLMN list includes information related to the second target PLMN.

3. The method of claim 2, wherein the system message further comprises a third cell access related information field conforming to an existing third protocol for mobile communications, wherein the third protocol is higher in version than the second protocol;

4. The method of claim 3, wherein when the first target PLMN, the second target PLMN and the third target PLMN are included in the at least one PLMN, a sum of a number of the second target PLMNs included in the second PLMN list and a number of the third target PLMNs included in the third PLMN list is less than or equal to a preset value, and a number of the first target PLMNs included in the first PLMN list is less than or equal to the preset value; or the like, or, alternatively,

5. The method of claim 2, wherein the first target PLMN does not exist as the same PLMN as the second target PLMN; or at least one identical PLMN exists in the first target PLMN and the second target PLMN.

6. The method according to claim 1, wherein each of the core networks supported by the first sub-destination PLMN further includes a core network supporting a third protocol, the third protocol is an existing protocol of mobile communication, and a version of the third protocol is higher than a version of the second protocol.

7. The method according to claim 3, wherein the first target PLMN includes a first sub-target PLMN and a second sub-target PLMN, and each of the core networks supported by the first sub-target PLMN further includes a core network supporting the second protocol, and each of the core networks supported by the second sub-target PLMN further includes a core network supporting the third protocol;

8. The method according to claim 7, wherein the information related to the second target PLMN includes an ID of each first sub-target PLMN and corresponding reserved cell indication information of each first sub-target PLMN;

wherein the method further comprises:

9. The method according to claim 2, wherein the first target PLMN includes N first sub-target PLMNs, each of the core networks supported by the first sub-target PLMNs includes a core network supporting the second protocol, the second cell access-related information field carries a second PLMN list, the N first sub-target PLMNs are located in the first N positions of the second PLMN list, N is a positive integer greater than or equal to 1;

10. The method according to claim 9, wherein the first cell access-related information field further includes first indication information, and the first indication information is used to indicate, by the terminal device, an ID of a first sub-target PLMN corresponding to each indication information of N reserved cells in the first PLMN list, which is determined according to the second PLMN list.

11. The method of claim 1, further comprising second indication information in the system message, wherein the second indication information is used to indicate that a PLMN with a highest recorded position in the system message in each PLMN is determined as a primary PLMN of the current cell.

12. The method of claim 2, further comprising second indication information in the system message, wherein the second indication information is used to indicate that one of the first target PLMNs is the primary PLMN of the current cell, or the second indication information is used to indicate that one of the second target PLMNs is the primary PLMN of the current cell.

13. The method of claim 2, further comprising second indication information indicating one of the first target PLMNs as a first primary PLMN of the current cell and indicating one of the second target PLMNs as a second primary PLMN of the current cell.

14. The method according to any one of claims 1 to 13, further comprising:

sending the system message to a terminal device;

after the system message is sent to the terminal equipment, third indication information sent by the terminal equipment is received, wherein the third indication information is used for the network equipment to determine a PLMN to be accessed, which is selected by the terminal equipment from the PLMNs supported by the current cell;

and determining the PLMN to be accessed according to the third indication information.

15. The method of claim 14, wherein the third indication information is used to indicate a location of the PLMN to be accessed in the system message; or the like, or, alternatively,

16. The method according to claim 14, wherein the third indication information is generated by a terminal device according to a type of core network supported by the PLMN to be accessed before sending the third indication information;

17. A method for selecting a Public Land Mobile Network (PLMN) is applied to a terminal device, and is characterized by comprising the following steps:

receiving a system message including a first cell access-related information field conforming to a first protocol of mobile communication and a second cell access-related information field conforming to an existing second protocol of mobile communication, the first cell access related information field carries a first PLMN list, the first PLMN list comprises information related to first target PLMNs, core networks supported by each first target PLMN comprise core networks supporting the first protocol, the first target PLMN comprises a first sub-target PLMN, in case that each first sub-destination PLMN supports a core network further comprising a core network supporting said second protocol, the information related to the first target PLMN comprises index information of each first sub-target PLMN and reserved cell indication information corresponding to each first sub-target PLMN, wherein the index information of each first sub-target PLMN is used for a terminal device to determine an identification ID of each first sub-target PLMN;

and selecting a PLMN to be accessed from at least one PLMN supported by the current cell according to the system message, wherein the at least one PLMN comprises the first target PLMN, the first protocol is 5G, and the second protocol is 4G.

18. The method of claim 17, wherein when a second target PLMN of the second protocol is supported by a supported core network in the at least one PLMN, a second PLMN list is carried in the second cell access related information field, and the second PLMN list includes information related to the second target PLMN.

19. The method of claim 18, wherein the system message further comprises a third cell access related information field conforming to an existing third protocol for mobile communications, wherein the third protocol is higher in version than the second protocol;

20. The method of claim 19, wherein when the first target PLMN, the second target PLMN, and the third target PLMN are included in the at least one PLMN, a sum of a number of the second target PLMN included in the second PLMN list and a number of the third target PLMN included in the third PLMN list is less than or equal to a preset value, and a number of the first target PLMN included in the first PLMN list is less than or equal to the preset value; or the like, or, alternatively,

21. The method of claim 18, wherein the first target PLMN does not exist as a same PLMN as the second target PLMN; or at least one identical PLMN exists in the first target PLMN and the second target PLMN.

22. The method according to claim 17, wherein each of the core networks supported by the first sub-destination PLMN further includes a core network supporting a third protocol, wherein the third protocol is an existing protocol of mobile communication, and a version of the third protocol is higher than a version of the second protocol, and the method further comprises:

23. The method of claim 19, wherein the first target PLMN comprises a first sub-target PLMN and a second sub-target PLMN, wherein each of the core networks supported by the first sub-target PLMN further comprises a core network supporting the second protocol, and wherein each of the core networks supported by the second sub-target PLMN further comprises a core network supporting the third protocol, wherein the information related to the first target PLMN comprises index information of each first sub-target PLMN and indication information of a reserved cell corresponding to each first sub-target PLMN, the index information of each first sub-target PLMN is used for a terminal device to determine an ID of each first sub-target PLMN, the information related to the first target PLMN further comprises index information of each second sub-target PLMN and reserved cell indication information corresponding to each second sub-target PLMN, wherein the index information of each second sub-target PLMN is used for a terminal device to determine the ID of each second sub-target PLMN;

wherein the method further comprises:

24. The method according to claim 23, wherein the information related to the second target PLMN includes an ID of each first target sub-PLMN and reserved cell indication information corresponding to each first sub-target PLMN, and the information related to the third target PLMN includes an ID of each second sub-target PLMN and reserved cell indication information corresponding to each second sub-target PLMN;

wherein the index of each first sub-target PLMN is determined by the network device according to the position of each first sub-target PLMN in the second PLMN list, and the index of each second sub-target PLMN is determined by the network device according to the position of each second sub-target PLMN in the third PLMN list.

25. The method of claim 17, wherein the first target PLMN comprises N first sub-target PLMNs, the core networks supported by each first sub-destination PLMN further comprise a core network supporting the second protocol, a second PLMN list is carried in the second cell access related information field, the N first sub-target PLMNs are positioned at the first N positions of the second PLMN list, N is a positive integer greater than or equal to 1, the information related to the first target PLMN includes N reserved cell indication information corresponding to the N first sub-target PLMNs, the N pieces of reserved cell indication information are located at the first N positions of the first PLMN list, and the position of each piece of reserved cell indication information in the first PLMN list is the same as the position of a first sub-target PLMN corresponding to the piece of reserved cell indication information in the second PLMN list;

wherein the method further comprises:

26. The method according to claim 25, wherein the first cell access-related information field further includes first indication information, and the first indication information is used to indicate, by the terminal device, an ID of a first sub-target PLMN corresponding to each indication information of N reserved cells in the first PLMN list, which is determined according to the second PLMN list.

27. The method of claim 17, wherein the system message further includes second indication information, and the second indication information is used to indicate that a PLMN with a top recorded position in the system message in each PLMN is determined as a primary PLMN of the current cell;

wherein the method further comprises:

28. The method of claim 18, wherein the system message further includes second indication information indicating one of the first target PLMNs as a primary PLMN of the current cell, or wherein the second indication information indicates one of the second target PLMNs as a primary PLMN of the current cell;

wherein the method further comprises:

29. The method of claim 18, further comprising second indication information indicating one of the first target PLMNs as a first primary PLMN of the current cell and indicating one of the second target PLMNs as a second primary PLMN of the current cell;

wherein the method further comprises:

30. The method of claim 18, further comprising:

31. The method of any one of claims 17 to 30, further comprising:

32. The method of claim 31, wherein the third indication information is used to indicate a location of the PLMN to be accessed in the system message; or the like, or, alternatively,

33. The method of claim 32, further comprising, before sending the third indication information to a network device:

determining the type of a core network supported by the PLMN to be accessed;

34. A network device, comprising:

a processing module, configured to generate a system message, where the system message includes a first cell access related information field conforming to the first protocol and a second cell access related information field conforming to an existing second protocol of mobile communication, where the first cell access related information field carries a first PLMN list, and the first PLMN list includes information related to the first target PLMN,

the first target PLMN includes first sub-target PLMNs, and in a case that a core network supported by each first sub-target PLMN further includes a core network supporting the second protocol, the information related to the first target PLMN includes index information of each first sub-target PLMN and reserved cell indication information corresponding to each first sub-target PLMN, the index information of each first sub-target PLMN is used for a terminal device to determine an identifier ID of each first sub-target PLMN, the first protocol is 5G, and the second protocol is 4G.

35. A terminal device, comprising:

a transceiver module, configured to receive a system message, where the system message includes a first cell access related information field conforming to a first protocol of mobile communication and a second cell access related information field conforming to an existing second protocol of mobile communication, a first PLMN list is carried in the first cell access related information field, the first PLMN list includes information related to a first target PLMN, each first target PLMN includes a core network supporting the first protocol, the first target PLMN includes a first sub-target PLMN, and in a case that a core network supporting the second protocol is also included in a core network supported by each first sub-target PLMN, the information related to the first target PLMN includes index information of each first sub-target PLMN and reserved cell indication information corresponding to each first sub-target PLMN, and the index information of each first sub-target PLMN is used by a terminal device to determine an identification ID of each first sub-target PLMN, the first protocol is 5G, and the second protocol is 4G;

36. A network device, comprising: memory, processor and computer program stored on the memory and executable on the processor, which computer program, when executed by the processor, performs the steps of the method of indication of a public land mobile network, PLMN, according to any one of claims 1 to 16.

37. A terminal device, comprising: memory, processor and computer program stored on the memory and executable on the processor, which computer program, when being executed by the processor, carries out the steps of the method for selecting a public land mobile network, PLMN, according to any one of claims 17 to 33.

38. A computer-readable medium, characterized in that a computer program is stored thereon, which computer program, when being executed by a processor, carries out the steps of the method for indication of a public land mobile network, PLMN, according to any one of the claims 1 to 16 and the method for selection of a public land mobile network, PLMN, according to any one of the claims 17 to 33.