Communication method, terminal, first network function, communication system and storage medium

Abstract

The embodiment of the invention provides a communication method, a first network function, a terminal, a communication system and a storage medium. The method comprises the following steps: sending first information to a terminal; wherein the first information comprises at least one of the following information: information associated with a state that the first communication technology is out of the network or is not out of the network; the information is used for indicating the access technology forbidden to be used by the terminal. According to the technical scheme provided by the embodiment of the invention, a communication mechanism can adapt to a network exit scene.

Description

Communication method, terminal, first network function, communication system and storage medium Technical Field

[0001] The present disclosure relates to the field of communication technologies, and in particular to a communication method, a terminal, a first network function, a communication system, and a storage medium. Background Art

[0002] In the field of communications technology, as mobile network deployments continue to evolve and improve, operators regularly shift their focus and investment to the latest generation of network technologies. At the same time, they also phase out older network technologies, leading to network withdrawals. Related technologies require consideration of communication mechanisms that can adapt to these withdrawals.

[0003] Summary of the Invention

[0004] In the network exit scenario, how to make the communication mechanism adapt to the network exit scenario is an issue that needs to be considered.

[0005] An embodiment of the present disclosure provides a communication method, which is performed by a first network function and includes:

[0006] Sending first information to the terminal;

[0007] The first information includes at least one of the following:

[0008] Information associated with whether the first communication technology has been de-networked or not;

[0009] Information used to indicate access technologies that are prohibited for the terminal to use.

[0010] According to a second aspect of an embodiment of the present disclosure, a communication method is provided, the method being executed by a terminal, the method including:

[0011] receiving first information sent by the first network function;

[0012] The first information includes at least one of the following:

[0013] Information associated with whether the first communication technology has been de-networked or not;

[0014] Information used to indicate access technologies that are prohibited for the terminal to use.

[0015] According to a third aspect of an embodiment of the present disclosure, a communication method is provided, the method comprising:

[0016] The first network function sends first information to the terminal;

[0017] The terminal receives the first information sent by the first network function;

[0018] The first information includes at least one of the following:

[0019] Information associated with whether the first communication technology has been de-networked or not;

[0020] Information used to indicate access technologies that are prohibited for the terminal to use.

[0021] According to a fourth aspect of an embodiment of the present disclosure, a first network function is provided, where the first network function includes:

[0022] The transceiver module is configured as follows:

[0023] Sending first information to the terminal;

[0024] The first information includes at least one of the following:

[0025] Information associated with whether the first communication technology has been de-networked or not;

[0026] Information used to indicate access technologies that are prohibited for the terminal to use.

[0027] According to a fifth aspect of an embodiment of the present disclosure, a terminal is provided, comprising:

[0028] The transceiver module is configured as follows:

[0029] receiving first information sent by the first network function;

[0030] The first information includes at least one of the following:

[0031] Information associated with whether the first communication technology has been de-networked or not;

[0032] Information used to indicate access technologies that are prohibited for the terminal to use.

[0033] According to a sixth aspect of an embodiment of the present disclosure, a communication system is provided, wherein the communication system includes a first network function and a terminal; the first network function is configured to implement the method described in the first aspect, and the terminal is configured to implement the method described in the second aspect.

[0034] According to a seventh aspect of an embodiment of the present disclosure, a first network function is provided, where the first network function includes:

[0035] one or more processors;

[0036] The first network function is used to execute the method described in the first aspect.

[0037] According to an eighth aspect of the embodiments of the present disclosure, a terminal is provided, comprising:

[0038] one or more processors;

[0039] The terminal is used to execute the method described in the second aspect.

[0040] According to a ninth aspect of an embodiment of the present disclosure, a storage medium is provided, wherein the storage medium stores instructions, which, when executed on a communication device, enable the communication device to execute the method provided in the first aspect and / or the second aspect.

[0041] The technical solution provided by the embodiments of the present disclosure can enable the communication mechanism to adapt to network exit scenarios.

[0042] It should be understood that the foregoing general description and the following detailed description are merely exemplary and explanatory and are not restrictive of the embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following drawings required for describing the embodiments are introduced. The following drawings are merely some embodiments of the present disclosure and do not impose specific limitations on the protection scope of the present disclosure.

[0044] FIG1a is a schematic diagram showing a communication system architecture according to an exemplary embodiment;

[0045] FIG2a is a schematic flow chart showing a communication method according to an exemplary embodiment;

[0046] FIG3a is a flow chart showing a communication method according to an exemplary embodiment;

[0047] FIG4a is a flow chart showing a communication method according to an exemplary embodiment;

[0048] FIG4b is a flow chart showing a communication method according to an exemplary embodiment;

[0049] FIG5a is a flow chart showing a communication method according to an exemplary embodiment;

[0050] FIG6a is a flow chart showing a communication method according to an exemplary embodiment;

[0051] FIG7a is a schematic structural diagram of a first network function according to an exemplary embodiment;

[0052] FIG7b is a schematic structural diagram of a terminal according to an exemplary embodiment;

[0053] FIG8a is a schematic structural diagram of a UE according to an exemplary embodiment;

[0054] Fig. 8b is a schematic structural diagram of a communication device according to an exemplary embodiment. DETAILED DESCRIPTION

[0055] Embodiments of the present disclosure provide a communication method, a first network function, a terminal, a communication system, and a storage medium.

[0056] In a first aspect, an embodiment of the present disclosure provides a communication method, where the method is performed by a first network function, and the method includes:

[0057] Sending first information to the terminal;

[0058] The first information includes at least one of the following:

[0059] Information associated with whether the first communication technology has been de-networked or not;

[0060] Information used to indicate access technologies that are prohibited for the terminal to use.

[0061] In the above embodiment, the first network function can send information associated with the status of whether the first communication technology has been withdrawn from the network or not withdrawn from the network and / or information used to indicate the access technology that the terminal is prohibited from using, so that the terminal can determine that the first communication technology has been withdrawn from the network, the first communication technology has not been withdrawn from the network and / or the access technology that the terminal is prohibited from using, so that the network can be better utilized for communication.

[0062] In conjunction with some embodiments of the first aspect, in some embodiments, the first communication technology includes at least one of the following:

[0063] 2nd generation mobile communication 2G technology;

[0064] 3rd generation mobile communication 3G technology.

[0065] In conjunction with some embodiments of the first aspect, in some embodiments, the first network function is one of the following:

[0066] Access and mobility management function AMF;

[0067] Mobility Management Entity MME;

[0068] Unified Data Management (UDM);

[0069] Home Subscriber Server HSS;

[0070] Policy Control Function PCF.

[0071] In conjunction with some embodiments of the first aspect, in some embodiments, the terminal is one of the following:

[0072] User equipment UE;

[0073] Universal User Identity Module USIM;

[0074] Mobile device ME.

[0075] In conjunction with some embodiments of the first aspect, in some embodiments, sending the first information to the terminal includes one of the following:

[0076] Sending a registration acceptance message to the terminal, where the registration acceptance message includes the first information;

[0077] Sending a downlink (DL) non-access stratum (NAS) transmission message to the terminal, where the DL NAS transmission message includes the first information;

[0078] Sending a tracking area update accept message to the terminal, where the tracking area update accept message includes the first information;

[0079] Sending a terminal configuration update command to the terminal, where the terminal configuration update command includes the first information;

[0080] A terminal policy container is sent to the terminal, where the terminal policy container includes the first information.

[0081] In the above embodiment, the first network function may send the first information to the terminal through different messages, and the sending method is more flexible.

[0082] In conjunction with some embodiments of the first aspect, in some embodiments, the first information includes at least one of the following:

[0083] first list information, where the first list information is used to indicate a first list of first public land mobile networks (PLMNs) supporting the first communication technology;

[0084] Second list information, where the second list information is used to indicate a second list of second PLMNs for which the first communication technology network deregistration has been completed;

[0085] Second information, the second information including one or more of the following: indication information for indicating that the home network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the visited network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the first communication technology network withdrawal has been completed;

[0086] The third information is used to indicate that the terminal is prohibited from using a first communication technology, where the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: an access technology related to the Global System for Mobile Communications GSM; an access technology related to the Global System for Mobile Communications or Enhanced Data Rate GSM Evolution Radio Access Network GERAN; an access technology related to the Universal Terrestrial Radio Access Network UTRAN.

[0087] In the above embodiment, since the first information includes at least one of the first list information, the second list information, the second information and the third information, the terminal can perform communication based on at least one of the first list information, the second list information, the second information and the third information.

[0088] In conjunction with some embodiments of the first aspect, in some embodiments, sending the first information to the terminal includes one of the following:

[0089] If it is determined that the home network has completed the first communication technology de-networking and the first communication technology is 2G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using an access technology related to GERAN or an access technology related to GSM;

[0090] If it is determined that the home network has completed the first communication technology network withdrawal and the first communication technology is 3G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of UTRAN access technology is prohibited;

[0091] If it is determined that the visited network has completed the first communication technology de-networking and the first communication technology is 2G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of access technologies related to GERAN or GSM is prohibited;

[0092] If it is determined that the visited network has completed the first communication technology withdrawal and the first communication technology is 3G technology, the first information is sent to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of UTRAN access technology is prohibited.

[0093] In the above embodiment, when the home network has completed the withdrawal of the first communication technology, third information prohibiting different access technologies will be sent according to the type of the first communication technology.

[0094] In combination with some embodiments of the first aspect, in some embodiments, the first list includes a first identifier, which is used to indicate the identifier of a first PLMN that supports the first communication technology, and the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0095] In the above embodiment, after receiving the first information, the terminal may select the corresponding access technology of the first PLMN based on the first list for access.

[0096] In combination with some embodiments of the first aspect, in some embodiments, the first list includes the first PLMN identifier and the first type of access technology supported by the first PLMN.

[0097] In the above embodiment, the first list may indicate a mapping relationship between the first PLMN identifier and the first type of access technology supported by the first PLMN.

[0098] In combination with some embodiments of the first aspect, in some embodiments, if the first list information is provided by a home public land mobile network HPLMN, the first list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and support the first type of access technology.

[0099] In the above embodiment, when the first list information is provided by the home public land mobile network HPLMN, the first list may include the identifiers of all PLMNs that have roaming agreements with the HPLMN and support the first type of access technology, so as to facilitate the terminal to select the first type of access technology corresponding to the PLMN based on the first list.

[0100] In combination with some embodiments of the first aspect, in some embodiments, if the HPLMN supports the first type of access technology, the first list includes an identifier of the HPLMN of the terminal.

[0101] In the above embodiment, when the HPLMN supports the first type of access technology, the first list includes the identifier of the HPLMN of the terminal to facilitate terminal access.

[0102] In combination with some embodiments of the first aspect, in some embodiments, if the first list information is provided by a visited public land mobile network VPLMN, the first list includes identifiers of visited public land mobile networks VPLMN that support the first type of access technology.

[0103] In the above embodiment, when the first list information is provided by a visited public land mobile network VPLMN, the first list may include identifiers of visited public land mobile networks VPLMN that support the first type of access technology, so as to facilitate the terminal to select the first type of access technology corresponding to the VPLMN based on the first list for access.

[0104] In combination with some embodiments of the first aspect, in some embodiments, the second list includes a second identifier, and the second identifier is used to indicate the identifier of the second PLMN that has completed the withdrawal of the first communication technology from the network, and the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0105] In the above embodiment, after receiving the first information, the terminal may not select the corresponding access technology of the second PLMN for access based on the second list.

[0106] In combination with some embodiments of the first aspect, in some embodiments, the second list indicates the identifier of the second PLMN and the access technology supported by the second PLMN; wherein, if the second PLMN has completed 2G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to GSM or access technology related to GERAN; if the second PLMN has completed 3G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to UTRAN.

[0107] In the above embodiment, after receiving the first information, the terminal may not select the corresponding access technology for access based on the second list and the communication technology corresponding to the delisted second PLMN.

[0108] In combination with some embodiments of the first aspect, in some embodiments, if the second list information is provided by the home public land mobile network HPLMN, the second list includes the identifiers of all PLMNs that have roaming agreements with the HPLMN and have completed the withdrawal of the first type of access technology.

[0109] In the above embodiment, when the second list information is provided by the home public land mobile network HPLMN, the second list may include the identifiers of all PLMNs that have roaming agreements with the HPLMN and have completed the withdrawal of the first type of access technology, so that the terminal does not select the first type of access technology corresponding to the PLMN for access.

[0110] In combination with some embodiments of the first aspect, in some embodiments, if the HPLMN has completed the first type of access technology network exit, the second list includes the identifier of the HPLMN of the terminal.

[0111] In the above embodiment, when the HPLMN has completed the first type of access technology network exit, the second list includes the identifier of the HPLMN of the terminal, so that the terminal does not select the first type of access technology access of the HPLMN.

[0112] In combination with some embodiments of the first aspect, in some embodiments, if the second list information is provided by a visited public land mobile network VPLMN, the second list indicates the identifiers of the VPLMNs that have completed the de-networking of the first type of access technology.

[0113] In the above embodiment, when the second list information is provided by a visited public land mobile network VPLMN, the second list may indicate the identifier of the VPLMN that has completed the first type of access technology de-networking, so that the terminal does not select the first access technology access of the VPLMN.

[0114] In a second aspect, an embodiment of the present disclosure provides a communication method, which is executed by a terminal and includes:

[0115] receiving first information sent by the first network function;

[0116] The first information includes at least one of the following:

[0117] Information associated with whether the first communication technology has been de-networked or not;

[0118] Information used to indicate access technologies that are prohibited for the terminal to use.

[0119] In conjunction with some embodiments of the second aspect, in some embodiments, the first communication technology includes at least one of the following:

[0120] 2nd generation mobile communication 2G technology;

[0121] 3rd generation mobile communication 3G technology.

[0122] In conjunction with some embodiments of the second aspect, in some embodiments, the first network function is one of the following:

[0123] Access and mobility management function AMF;

[0124] Mobility Management Entity MME;

[0125] Unified Data Management (UDM);

[0126] Home Subscriber Server HSS;

[0127] Policy Control Function PCF.

[0128] In conjunction with some embodiments of the second aspect, in some embodiments, the terminal is one of the following:

[0129] User equipment UE;

[0130] Universal User Identity Module USIM;

[0131] Mobile device ME.

[0132] In conjunction with some embodiments of the second aspect, in some embodiments, receiving the first information sent by the network device includes one of the following:

[0133] receiving a registration acceptance message sent by the network device, where the registration acceptance message includes the first information;

[0134] receiving a DL NAS transmission message sent by the network device, where the DL NAS transmission message includes the first information;

[0135] receiving a tracking area update accept message sent by the network device, where the tracking area update accept message includes the first information;

[0136] receiving a terminal configuration update command sent by the network device, where the terminal configuration update command includes the first information;

[0137] A terminal policy container is received, where the terminal policy container includes the first information.

[0138] In conjunction with some embodiments of the second aspect, in some embodiments, the first information includes at least one of the following:

[0139] first list information, where the first list information is used to indicate a first list of first public land mobile networks (PLMNs) supporting the first communication technology;

[0140] Second list information, where the second list information is used to indicate a second list of second PLMNs for which the first communication technology network deregistration has been completed;

[0141] Second information, the second information including any one or more of the following: indication information for indicating that the home network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the visited network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the first communication technology network withdrawal has been completed;

[0142] The third information is used to indicate that the terminal is prohibited from using a first communication technology, where the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: an access technology related to the Global System for Mobile Communications GSM; an access technology related to the Global System for Mobile Communications or Enhanced Data Rate GSM Evolution Radio Access Network GERAN; an access technology related to the Universal Terrestrial Radio Access Network UTRAN.

[0143] In combination with some embodiments of the second aspect, in some embodiments, the first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using access technology related to GERAN or access technology related to GSM; or, the first information includes the third information, and the third information is used to indicate that the use of access technology related to UTRAN is prohibited.

[0144] In combination with some embodiments of the second aspect, in some embodiments, the first list includes a first identifier, which is used to indicate the identifier of a first PLMN that supports the first communication technology, and the first communication technology includes a first type of access technology, which includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0145] In combination with some embodiments of the second aspect, in some embodiments, the first list includes the first PLMN identifier and the first type of access technology supported by the first PLMN.

[0146] In combination with some embodiments of the second aspect, in some embodiments, if the first list information is provided by the home public land mobile network HPLMN, the first list includes the identifiers of all PLMNs that have roaming agreements with the HPLMN and support the first type of access technology.

[0147] In combination with some embodiments of the second aspect, in some embodiments, if the HPLMN supports the first type of access technology, the first list includes an identifier of the HPLMN of the terminal.

[0148] In combination with some embodiments of the second aspect, in some embodiments, if the first list information is provided by a visited public land mobile network VPLMN, the first list includes identifiers of visited public land mobile networks VPLMN that support the first type of access technology.

[0149] In combination with some embodiments of the second aspect, in some embodiments, the second list includes a second identifier, and the second identifier is used to indicate the identifier of the second PLMN that has completed the withdrawal of the first communication technology from the network, and the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0150] In combination with some embodiments of the second aspect, in some embodiments, the second list indicates the identifier of the second PLMN and the access technology supported by the second PLMN; wherein, if the second PLMN has completed 2G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to GSM or access technology related to GERAN; if the second PLMN has completed 3G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to UTRAN.

[0151] In combination with some embodiments of the second aspect, in some embodiments, if the second list information is provided by the home public land mobile network HPLMN, the second list includes the identifiers of all PLMNs that have roaming agreements with the HPLMN and have completed the withdrawal of the first type of access technology.

[0152] In combination with some embodiments of the second aspect, in some embodiments, if the HPLMN has completed the first type of access technology network exit, the second list includes the identifier of the HPLMN of the terminal.

[0153] In combination with some embodiments of the second aspect, in some embodiments, if the second list information is provided by a visited public land mobile network VPLMN, the second list indicates the identifiers of the visited public land mobile networks VPLMNs that have completed the de-networking of the first type of access technology.

[0154] In conjunction with some embodiments of the second aspect, in some embodiments, the method further includes one of the following:

[0155] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the home network of the terminal has completed 2G technology network deregistration, the terminal does not select an access technology related to GERAN or an access technology related to GSM;

[0156] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the home network of the terminal has completed 3G technology network deregistration, the terminal does not select an access technology related to UTRAN;

[0157] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the visited network of the terminal has completed 2G technology network deregistration, an access technology related to GERAN or an access technology related to GSM is not selected;

[0158] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the visited network of the terminal has completed 3G technology network deregistration, the access technology related to UTRAN is not selected;

[0159] If the first information includes the second information and the indication information for the first communication technology network deregistration indicates that the 2G technology network deregistration has been completed, an access technology related to GERAN or an access technology related to GSM is not selected;

[0160] If the first information includes the second information and the indication information of the first communication technology network exit indicates that the 3G technology network exit has been completed, the access technology related to UTRAN is not selected.

[0161] In conjunction with some embodiments of the second aspect, in some embodiments, the method further includes at least one of the following:

[0162] If the first information includes the third information and the third information is used to indicate that the terminal is prohibited from selecting an access technology related to GERAN or an access technology related to GSM, the access technology related to GERAN or the access technology related to GSM is not selected;

[0163] If the first information includes the third information and the third information is used to indicate that the terminal is prohibited from selecting an access technology related to UTRAN, the access technology related to UTRAN is not selected.

[0164] In conjunction with some embodiments of the second aspect, in some embodiments, the method further includes at least one of the following:

[0165] If the first information includes the first list information, selecting an access technology corresponding to the first PLMN based on the first list information;

[0166] If the first information includes the second list information, the access technology corresponding to the second PLMN is selected based on the second list information.

[0167] In a third aspect, an embodiment of the present disclosure provides a communication method, the method comprising:

[0168] The first network function sends first information to the terminal;

[0169] The terminal receives the first information sent by the first network function;

[0170] The first information includes at least one of the following:

[0171] Information associated with whether the first communication technology has been de-networked or not;

[0172] Information used to indicate access technologies that are prohibited for the terminal to use.

[0173] In conjunction with some embodiments of the third aspect, in some embodiments, the method further includes:

[0174] It is determined that the first timer has timed out, and it is determined to cancel the first operation.

[0175] In a fourth aspect, an embodiment of the present disclosure provides a first network function, where the first network function includes:

[0176] The transceiver module is configured as follows:

[0177] Sending first information to the terminal;

[0178] The first information includes at least one of the following:

[0179] Information associated with whether the first communication technology has been de-networked or not;

[0180] Information used to indicate access technologies that are prohibited for the terminal to use.

[0181] In a fifth aspect, an embodiment of the present disclosure provides a terminal, comprising:

[0182] The transceiver module is configured as follows:

[0183] receiving first information sent by the first network function;

[0184] The first information includes at least one of the following:

[0185] Information associated with whether the first communication technology has been de-networked or not;

[0186] Information used to indicate access technologies that are prohibited for the terminal to use.

[0187] In a sixth aspect, an embodiment of the present disclosure provides that the communication system includes a first network function and a terminal; the first network function is configured to implement the method described in the first aspect, and the terminal is configured to implement the method described in the second aspect.

[0188] In a seventh aspect, an embodiment of the present disclosure provides a first network function, the first network function including:

[0189] one or more processors;

[0190] The first network function is used to execute the method provided by the first aspect.

[0191] In an eighth aspect, an embodiment of the present disclosure provides a terminal, the terminal including:

[0192] one or more processors;

[0193] The terminal is used to execute the method provided in the second aspect.

[0194] In a ninth aspect, an embodiment of the present disclosure provides a storage medium, wherein the storage medium stores instructions, which, when the instructions are executed on a communication device, enable the communication device to execute the method described in the optional implementation of the first aspect and / or the second aspect.

[0195] In a tenth aspect, an embodiment of the present disclosure proposes a program product. When the program product is executed by a communication device, the communication device executes the method described in the optional implementation of the first aspect and / or the second aspect.

[0196] In an eleventh aspect, an embodiment of the present disclosure proposes a computer program, which, when executed on a computer, enables the computer to execute the method described in the optional implementation of the first aspect and / or the second aspect.

[0197] In a twelfth aspect, an embodiment of the present disclosure provides a chip or a chip system, wherein the chip or chip system includes a processing circuit configured to execute the method described in the optional implementation of the first aspect and / or the second aspect.

[0198] It is understandable that the first network function, terminal, communication system, storage medium, program product, computer program, chip, or chip system described above are all used to perform the method proposed in the embodiment of the present disclosure. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects of the corresponding method and will not be repeated here.

[0199] The present disclosure provides a communication method, a first network function, a terminal, a communication system, and a storage medium. In some embodiments, the terms "communication method" and "information indication method," "information processing method," and "information transmission method" are interchangeable, and the terms "communication system" and "information processing system" are interchangeable.

[0200] The embodiments of the present disclosure are not exhaustive and are merely illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present disclosure. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a certain embodiment can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementation methods in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined. For example, some or all steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementation methods of other embodiments.

[0201] In each embodiment of the present disclosure, unless otherwise specified or provided for by logic, the terms and / or descriptions between the embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form a new embodiment based on their inherent logical relationships.

[0202] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0203] In the embodiments of the present disclosure, unless otherwise specified, elements expressed in the singular, such as "a", "an", "the", "above", "said", "the", "the", etc., may mean "one and only one", or "one or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun following the article may be understood as a singular expression or a plural expression.

[0204] In the embodiments of the present disclosure, “plurality” refers to two or more.

[0205] In some embodiments, the terms "at least one," "one or more," "a plurality of," "multiple," etc. may be used interchangeably.

[0206] In some embodiments, descriptions such as "at least one of A and B," "A and / or B," "A in one case, B in another case," or "in response to one case A, in response to another case B" may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); and in some embodiments, A and B (both A and B are executed). The above is also applicable when there are more branches such as A, B, and C.

[0207] In some embodiments, "A or B" and other descriptions may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). The above is also applicable when there are more branches such as A, B, C, etc.

[0208] The prefixes such as "first" and "second" in the embodiments of the present disclosure are only used to distinguish different description objects and do not constitute any restriction on the position, order, priority, quantity or content of the description objects. For the statement of the description object, please refer to the description in the context of the claims or embodiments, and no unnecessary restriction should be constituted due to the use of prefixes. For example, if the description object is a "field", the ordinal number before the "field" in the "first field" and the "second field" does not limit the position or order between the "fields". "First" and "second" do not limit whether the "fields" they modify are in the same message, nor do they limit the order of the "first field" and the "second field". For another example, if the description object is a "level", the ordinal number before the "level" in the "first level" and the "second level" does not limit the priority between the "levels". For another example, the number of description objects is not limited by the ordinal number and can be one or more. Taking "first device" as an example, the number of "devices" can be one or more. In addition, the objects modified by different prefixes can be the same or different. For example, if the description object is "device", then the "first device" and the "second device" can be the same device or different devices, and their types can be the same or different; for another example, if the description object is "information", then the "first information" and the "second information" can be the same information or different information, and their contents can be the same or different.

[0209] In some embodiments, “including A,” “comprising A,” “used to indicate A,” and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

[0210] In some embodiments, terms such as "in response to...", "in response to determining...", "in the case of...", "at the time of...", "when...", "if...", "if...", etc. can be used interchangeably.

[0211] In some embodiments, terms such as "greater than", "greater than or equal to", "not less than", "more than", "more than or equal to", "not less than", "higher than", "higher than or equal to", "not less than", and "above" can be replaced with each other, and terms such as "less than", "less than or equal to", "not greater than", "less than", "less than or equal to", "not more than", "lower than", "lower than or equal to", "not higher than", and "below" can be replaced with each other.

[0212] In some embodiments, devices and equipment can be interpreted as physical or virtual, and their names are not limited to the names recorded in the embodiments. In some cases, they can also be understood as "equipment", "device", "circuit", "network element", "node", "function", "unit", "section", "system", "network", "chip", "chip system", "entity", "subject", etc.

[0213] In some embodiments, "network" can be interpreted as devices included in the network, such as access network equipment, core network equipment, etc.

[0214] In some embodiments, "access network device (AN device)" may also be referred to as "radio access network device (RAN device)", "base station (BS)", "radio base station", "fixed station", and in some embodiments may also be understood as "node", "access point", "transmission point (TP)", "reception point (RP)", "transmission and / or reception point (TRP)" "panel", "antenna panel", "antenna array", "cell", "macro cell", "small cell", "femto cell", "pico cell", "sector", "cell group", "serving cell", "carrier", "component carrier", "bandwidth part (BWP)", etc.

[0215] In some embodiments, "terminal" or "terminal device" may be referred to as "user equipment (UE)", "user terminal" "mobile station (MS)", "mobile terminal (MT)", subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, etc.

[0216] In some embodiments, obtaining data, information, etc. may comply with the laws and regulations of the country where the data is obtained.

[0217] In some embodiments, data, information, etc. may be obtained with the user's consent.

[0218] In addition, each element, each row, or each column in the table of the embodiment of the present disclosure can be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns can also be implemented as an independent embodiment.

[0219] FIG1a is a schematic diagram showing the architecture of a communication system according to an embodiment of the present disclosure.

[0220] As shown in FIG. 1 a , a communication system 100 includes a terminal 101 and a network device 102 .

[0221] In some embodiments, the network device 102 may include at least one of an access network device 1021 and a core network device 1022 .

[0222] In some embodiments, the access network device 1021 may be a satellite access network device.

[0223] In some embodiments, the core network device 1022 may be a core network device.

[0224] In some embodiments, the terminal includes, for example, a mobile phone, a wearable device, an Internet of Things device, a car with communication function, a smart car, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, and at least one of a wireless terminal device in a smart home, but is not limited thereto.

[0225] In some embodiments, the access network device may be, for example, a node or device that accesses a terminal to a wireless network. The access network device may include an evolved NodeB (eNB), a next generation evolved NodeB (ng-eNB), a next generation NodeB (gNB), a node B (NB), a home node B (HNB), a home evolved nodeB (HeNB), a wireless backhaul device, a radio network controller (RNC), a base station controller (BSC), a base transceiver station (BTS), a base band unit (BBU), a mobile switching center, a base station in a 6G communication system, an open base station (Open RAN), a cloud base station (Cloud RAN), a base station in other communication systems, and at least one of an access node in a Wi-Fi system, but is not limited thereto.

[0226] In some embodiments, the technical solution of the present disclosure can be applied to the Open RAN architecture. In this case, the interfaces between or within the access network devices involved in the embodiments of the present disclosure can be transformed into internal interfaces of the Open RAN, and the processes and information interactions between these internal interfaces can be implemented through software or programs.

[0227] In some embodiments, the access network device can be composed of a centralized unit (CU) and a distributed unit (DU), where the CU can also be called a control unit. The CU-DU structure can be used to split the protocol layer of the access network device, with the functions of some protocol layers centrally controlled by the CU, and the functions of the remaining part or all of the protocol layers distributed in the DU, which is centrally controlled by the CU, but is not limited to this.

[0228] In some embodiments, a core network device may be a device including one or more network elements, or may be multiple devices or device groups, each including all or part of the one or more network elements. The network element may be virtual or physical. The core network may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), and a Next Generation Core (NGC).

[0229] It can be understood that the communication system described in the embodiment of the present disclosure is for the purpose of more clearly illustrating the technical solution of the embodiment of the present disclosure, and does not constitute a limitation on the technical solution provided by the embodiment of the present disclosure. Ordinary technicians in this field can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solution provided by the embodiment of the present disclosure is also applicable to similar technical problems.

[0230] The following embodiments of the present disclosure may be applied to the communication system 100 shown in FIG1a, or a portion thereof, but are not limited thereto. The entities shown in FIG1a are illustrative only. The communication system may include all or a portion of the entities shown in FIG1a, or may include other entities other than those shown in FIG1a. The number and form of the entities may be arbitrary. The connection relationship between the entities is illustrative only. The entities may be connected or disconnected, and the connection may be in any manner, including direct or indirect, wired or wireless.

[0231] The embodiments of the present disclosure can be applied to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 5G new radio (NR), future radio access (FRA), new radio access technology (RAT), new radio (NR), new radio access (NX), future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), Public Land Mobile Network (PLMN) networks, Device-to-Device (D2D) systems, Machine-to-Machine (M2M) systems, Internet of Things (IoT) systems, Vehicle-to-Everything (V2X), systems utilizing other communication methods, and next-generation systems based on and extending these methods. Furthermore, multiple systems may be combined (for example, a combination of LTE or LTE-A with 5G).

[0232] In some embodiments, throughout the history of mobile network deployments, as mobile network systems continue to evolve and improve, operators have periodically shifted their focus and investment to the latest generation of networks, ultimately retiring older networks. This is, in fact, the case with many operators announcing the retirement of 2G or 3G networks. In such cases, allowing UEs that support all generations of networks to continue to select 2G or 3G networks is no longer appropriate. Indeed, if UEs are tricked into connecting to 2G or 3G networks, they will be vulnerable to many known attacks related to 2G and 3G. However, there are no mechanisms to enable UEs to avoid lingering on fake 2G or 3G base stations during a retirement scenario.

[0233] FIG2a is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG2a, the present disclosure embodiment relates to a communication method for a communication system 100, the method comprising:

[0234] Step S2101: The first network function sends first information to the terminal.

[0235] In some embodiments, the terminal receives first information sent by the first network function.

[0236] In some embodiments, the first network function may be sending first information to the terminal through an access network device (eg, a base station).

[0237] In some embodiments, the first network function is one of the following:

[0238] Access and Mobility Management Function (AMF);

[0239] Mobility Management Entity (MME);

[0240] Unified Data Management (UDM);

[0241] Home Subscriber Server (HSS);

[0242] Policy Control function (PCF)

[0243] In some embodiments, the terminal is one of the following:

[0244] User equipment UE;

[0245] Universal Subscriber Identity Module (USIM);

[0246] Mobile Equipment (ME).

[0247] In some embodiments, the first information includes information associated with a status in which the first communication technology has been de-networked or has not been de-networked.

[0248] In some embodiments, the first information includes information indicating an access technology prohibited from being used by the terminal.

[0249] In some embodiments, the first information includes information associated with a status in which the first communication technology has been de-networked or not de-networked and information indicating an access technology that is prohibited for the terminal to use.

[0250] In some embodiments, the first communication technology includes at least one of the following:

[0251] 2nd generation mobile communication 2G technology;

[0252] 3rd generation mobile communication 3G technology.

[0253] It should be noted that with the evolution of network communication technology, it is not limited to 2G technology and 3G technology, and can include any communication technology that needs to be decommissioned, such as 4G technology and 5G technology, but is not limited to this.

[0254] In some embodiments, the 2G technology may include at least one communication technology, for example, a technology related to Global System for Mobile Communications (GSM) and a technology related to Universal Terrestrial Radio Access Network (UTRAN).

[0255] In some embodiments, the 3G technology may include at least one communication technology, for example, a technology related to Global System for Mobile Communications or Enhanced Data Rates for GSM Evolution Radio Access Network (GERAN, GSM EDGE Radio Access Network).

[0256] In some embodiments, the access technology may be at least one of a GSM-related access technology, a UTRAN-related access technology, and a GERAN-related access technology. It should be noted that, with the evolution of network communication technologies, the access technology is not limited to the aforementioned access technologies, and any evolved access technology may be used.

[0257] In some embodiments, the first information includes first list information, where the first list information is used to indicate a first list of first public land mobile networks (PLMNs) supporting the first communication technology.

[0258] Exemplarily: Table 1 shows the first list.

[0259] Table 1:

[0260] It should be noted that the first public land mobile network PLMN supporting the first communication technology can also be understood as the first PLMN being in a state where the first communication technology has not been withdrawn from the network or the first PLMN maintaining the first communication technology, which is not limited here.

[0261] In some embodiments, the first information includes second list information, where the second list information is used to indicate a second list of second PLMNs that have completed the first communication technology network deregistration.

[0262] Exemplarily, Table 2 shows the second list.

[0263] Table 2:

[0264] It should be noted that the second PLMN from which the first communication technology has been withdrawn can also be understood as the second PLMN not maintaining the state of the first communication technology, which is not limited here.

[0265] It should be noted that if the first communication technology has been withdrawn from the network, the terminal is prohibited from accessing the corresponding network using the first communication technology.

[0266] In some embodiments, if the first communication technology has been withdrawn from the network, the terminal is prohibited from using the first communication technology.

[0267] In some embodiments, the first information includes second information, and the second information includes one or more of the following: indication information for indicating that the home network of the terminal has completed the first communication technology network exit; indication information for indicating that the visited network of the terminal has completed the first communication technology network exit; indication information for indicating that the first communication technology network exit has been completed.

[0268] In some embodiments, the first information includes second information, where the second information is used to indicate that the home network (HPLMN) of the terminal has completed the first communication technology de-networking. The home network may be part of the PLMN to which the terminal belongs.

[0269] In some embodiments, the first information includes second information, where the second information is used to indicate that a visited PLMN (VPLMN) of the terminal has completed de-networking using the first communication technology.

[0270] In some embodiments, the first information includes second information, and the second information is used to indicate that the first communication technology has been de-networked.

[0271] In some embodiments, the first information includes third information, and the third information is used to indicate that the terminal is prohibited from using a first communication technology, and the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to the Global System for Mobile Communications GSM; access technology related to the Global System for Mobile Communications or Enhanced Data Rate GSM Evolution Radio Access Network GERAN; access technology related to the Universal Terrestrial Radio Access Network UTRAN.

[0272] It should be noted that if an access technology is prohibited, the terminal will be prohibited from using the access technology.

[0273] In some embodiments, the first network function sends a registration accept message to the terminal, where the registration accept message includes the first information.

[0274] In some embodiments, the terminal receives a registration acceptance message sent by the first network function, where the registration acceptance message includes the first information.

[0275] In some embodiments, the first network function sends a downlink (DL) non-access stratum (NAS) transport message to the terminal, where the DL NAS transport message includes the first information.

[0276] In some embodiments, the terminal receives a downlink (DL) non-standalone networking access stratum (NAS) transmission message sent by a first network function, where the DL NAS transmission message includes the first information.

[0277] In some embodiments, the first network function sends a tracking area update accept message to the terminal, where the tracking area update accept message includes the first information.

[0278] In some embodiments, the terminal receives a tracking area update accept message sent by a first network function, where the tracking area update accept message includes the first information.

[0279] In some embodiments, the first network function sends a terminal configuration update command to the terminal, where the terminal configuration update command includes the first information.

[0280] In some embodiments, the terminal receives a terminal configuration update command sent by a first network function, where the terminal configuration update command includes the first information.

[0281] In some embodiments, the first network function sends a terminal policy container to the terminal, where the terminal policy container includes the first information.

[0282] In some embodiments, the terminal receives a terminal policy container sent by a first network function, where the terminal policy container includes the first information.

[0283] In some embodiments, if it is determined that the home network has completed the withdrawal of the first communication technology and the first communication technology is 2G technology, the first information is sent to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using access technology related to GERAN or access technology related to GSM.

[0284] In some embodiments, if it is determined that the home network has completed the withdrawal of the first communication technology and the first communication technology is 3G technology, the first information is sent to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of UTRAN access technology is prohibited.

[0285] In some embodiments, if it is determined that the visited network has completed the withdrawal of the first communication technology and the first communication technology is 2G technology, the first information is sent to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using access technology related to GERAN or access technology related to GSM.

[0286] In some embodiments, if it is determined that the visited network has completed the first communication technology withdrawal and the first communication technology is 3G technology, the first information is sent to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of UTRAN access technology is prohibited.

[0287] In some embodiments, the first list includes a first identifier, which is used to indicate the identifier of a first PLMN that supports the first communication technology, and the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0288] In some embodiments, the first list includes the first PLMN identifier and a first type of access technology supported by the first PLMN.

[0289] Exemplarily, Table 3 shows the first list.

[0290] Table 3

[0291] In some embodiments, if the first list information is provided by a Home Public Land Mobile Network (HPLMN), the first list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and support the first type of access technology.

[0292] In some embodiments, if the HPLMN supports the first type of access technology, the first list includes an identifier of the HPLMN of the terminal.

[0293] In some embodiments, if the first list information is provided by a visited public land mobile network (VPLMN), the first list includes identifiers of visited public land mobile networks (VPLMNs) that support the first type of access technology.

[0294] In some embodiments, the second list includes a second identifier, which is used to indicate the identifier of a second PLMN that has completed the withdrawal of the first communication technology, and the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0295] In some embodiments, the second list indicates the identifier of the second PLMN and the access technology supported by the second PLMN; wherein, if the second PLMN has completed 2G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to GSM or access technology related to GERAN; if the second PLMN has completed 3G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to UTRAN.

[0296] Exemplarily, Table 4 shows the second list.

[0297] Table 4:

[0298] For example, referring to Tables 5 and 6, PLMN5 has completed the decommissioning of GSM-related access technologies and GERAN-related access technologies. The second list may also indicate supported access technologies. For example, the second list corresponding to Table 5 shows the relationship between the second PLMN and the supported communication technologies. The second list corresponding to Table 6 shows both the supported communication technologies and the decommissioned communication technologies.

[0299] Table 5:

[0300] Table 6:

[0301] In some embodiments, if the second list information is provided by a home public land mobile network HPLMN, the second list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and have completed de-networking of the first type of access technology.

[0302] In some embodiments, if the HPLMN has completed the first type of access technology network exit, the second list includes the identifier of the HPLMN of the terminal.

[0303] In some embodiments, if the second list information is provided by a visited public land mobile network VPLMN, the second list indicates identifiers of VPLMNs that have completed de-networking of the first type of access technology.

[0304] Step S2102: The terminal performs access technology selection.

[0305] In some embodiments, the terminal performs access technology selection based on the first information.

[0306] In some embodiments, if the first information includes the second information and the indication information of the first communication technology network exit indicates that the terminal's home network has completed 2G technology network exit, the terminal does not select an access technology related to GERAN or an access technology related to GSM.

[0307] In some embodiments, if the first information includes the second information and the indication information of the first communication technology network exit indicates that the home network of the terminal has completed 3G technology network exit, the terminal does not select an access technology related to UTRAN.

[0308] In some embodiments, if the first information includes the second information and the indication information of the first communication technology network exit indicates that the visited network of the terminal has completed 2G technology network exit, the terminal does not select access technology related to GERAN or access technology related to GSM.

[0309] In some embodiments, if the first information includes the second information and the indication information of the first communication technology network exit indicates that the visited network of the terminal has completed 3G technology network exit, the terminal does not select an access technology related to UTRAN.

[0310] In some embodiments, if the first information includes the second information and the indication information of the first communication technology network exit indicates that the 2G technology network exit has been completed, the terminal does not select an access technology related to GERAN or an access technology related to GSM.

[0311] In some embodiments, if the first information includes the second information and the indication information of the first communication technology network exit indicates that the 3G technology network exit has been completed, the terminal does not select an access technology related to UTRAN.

[0312] In some embodiments, if the first information includes the third information and the third information is used to indicate that the terminal is prohibited from selecting an access technology related to GERAN or an access technology related to GSM, the terminal does not select an access technology related to GERAN or an access technology related to GSM.

[0313] In some embodiments, if the first information includes the third information and the third information is used to indicate that the terminal is prohibited from selecting an access technology related to UTRAN, the terminal does not select an access technology related to UTRAN.

[0314] In some embodiments, if the first information includes the first list information, selecting an access technology corresponding to the first PLMN based on the first list information;

[0315] In some embodiments, if the first information includes the second list information, the access technology corresponding to the second PLMN is selected based on the second list information.

[0316] In some embodiments, the term "information" can be interchangeable with terms such as "message", "signal", "signaling", "report", "configuration", "indication", "instruction", "command", "channel", "parameter", "field", and "data".

[0317] In some embodiments, the term "send" can be interchanged with terms such as "transmit", "report", and "transmit".

[0318] The information indication method involved in the embodiments of the present disclosure may include at least one of steps S2101 and S2102. For example, step S2101 may be implemented as an independent embodiment, and step S2102 may be implemented as an independent embodiment. For example, step S2101 combined with step S2102 may be implemented as independent embodiments, but the present disclosure is not limited thereto.

[0319] Figure 3a is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in Figure 3a, the embodiment of the present disclosure relates to a communication method, which is performed by a first network function, and the method includes:

[0320] Step S3101: Send first information to the terminal.

[0321] In some embodiments, the first information includes at least one of the following:

[0322] Information associated with whether the first communication technology has been de-networked or not;

[0323] Information used to indicate access technologies that are prohibited for the terminal to use.

[0324] In some embodiments, the first communication technology includes at least one of the following:

[0325] 2nd generation mobile communication 2G technology;

[0326] 3rd generation mobile communication 3G technology.

[0327] In some embodiments, the first network function is one of the following:

[0328] Access and mobility management function AMF;

[0329] Mobility Management Entity MME;

[0330] Unified Data Management (UDM);

[0331] Home Subscriber Server HSS;

[0332] Policy Control Function PCF.

[0333] In some embodiments, the terminal is one of the following:

[0334] User equipment UE;

[0335] Universal User Identity Module USIM;

[0336] Mobile device ME.

[0337] In some embodiments, the sending the first information to the terminal includes one of the following:

[0338] Sending a registration acceptance message to the terminal, where the registration acceptance message includes the first information;

[0339] Sending a downlink (DL) non-access stratum (NAS) transmission message to the terminal, where the DL NAS transmission message includes the first information;

[0340] Sending a tracking area update accept message to the terminal, where the tracking area update accept message includes the first information;

[0341] Sending a terminal configuration update command to the terminal, where the terminal configuration update command includes the first information;

[0342] A terminal policy container is sent to the terminal, where the terminal policy container includes the first information.

[0343] In some embodiments, the first information includes at least one of the following:

[0344] first list information, where the first list information is used to indicate a first list of first public land mobile networks (PLMNs) supporting the first communication technology;

[0345] Second list information, where the second list information is used to indicate a second list of second PLMNs for which the first communication technology network deregistration has been completed;

[0346] Second information, the second information including one or more of the following: indication information for indicating that the home network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the visited network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the first communication technology network withdrawal has been completed;

[0347] The third information is used to indicate that the terminal is prohibited from using a first communication technology, where the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: an access technology related to the Global System for Mobile Communications GSM; an access technology related to the Global System for Mobile Communications or Enhanced Data Rate GSM Evolution Radio Access Network GERAN; an access technology related to the Universal Terrestrial Radio Access Network UTRAN.

[0348] In some embodiments, the sending the first information to the terminal includes one of the following:

[0349] If it is determined that the home network has completed the first communication technology de-networking and the first communication technology is 2G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using an access technology related to GERAN or an access technology related to GSM;

[0350] If it is determined that the home network has completed the first communication technology network withdrawal and the first communication technology is 3G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of UTRAN access technology is prohibited;

[0351] If it is determined that the visited network has completed the first communication technology de-networking and the first communication technology is 2G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using an access technology related to GERAN or an access technology related to GSM;

[0352] If it is determined that the visited network has completed the first communication technology withdrawal and the first communication technology is 3G technology, the first information is sent to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of UTRAN access technology is prohibited.

[0353] In some embodiments, the first list includes a first identifier, which is used to indicate the identifier of a first PLMN that supports the first communication technology, and the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0354] In some embodiments, the first list includes the first PLMN identifier and a first type of access technology supported by the first PLMN.

[0355] In some embodiments, if the first list information is provided by a home public land mobile network HPLMN, the first list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and support the first type of access technology.

[0356] In some embodiments, if the HPLMN supports the first type of access technology, the first list includes an identifier of the HPLMN of the terminal.

[0357] In some embodiments, if the first list information is provided by a visited public land mobile network VPLMN, the first list includes identifiers of visited public land mobile networks VPLMN that support the first type of access technology.

[0358] In some embodiments, the second list includes a second identifier, which is used to indicate the identifier of a second PLMN that has completed the withdrawal of the first communication technology, and the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0359] In some embodiments, the second list indicates the identifier of the second PLMN and the access technology supported by the second PLMN; wherein, if the second PLMN has completed 2G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to GSM or access technology related to GERAN; if the second PLMN has completed 3G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to UTRAN.

[0360] In some embodiments, if the second list information is provided by a home public land mobile network HPLMN, the second list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and have completed de-networking of the first type of access technology.

[0361] In some embodiments, if the HPLMN has completed the de-networking of the first type of access technology, the second list includes the identifier of the HPLMN of the terminal.

[0362] In some embodiments, if the second list information is provided by a visited public land mobile network VPLMN, the second list indicates identifiers of VPLMNs that have completed de-networking of the first type of access technology.

[0363] Figure 4a is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in Figure 4a, the embodiment of the present disclosure relates to a communication method, which is executed by a terminal. The method includes:

[0364] Step S4101: Receive first information sent by a first network function.

[0365] In some embodiments, optional implementations of step S4101 may refer to other related parts of the embodiment involved in step S2101 in FIG. 2 a , which will not be described in detail here.

[0366] Step S4102: Execute access technology selection.

[0367] In some embodiments, optional implementations of step S4102 can be found in other related parts of the embodiment involved in step S2102 in Figure 2a, and will not be repeated here.

[0368] The information indication method involved in the embodiments of the present disclosure may include at least one of steps S4101 and S4102. For example, step S4101 may be implemented as an independent embodiment, and step S4102 may be implemented as an independent embodiment. For example, step S4101 combined with step S4102 may be implemented as independent embodiments, but the present disclosure is not limited thereto.

[0369] Figure 4b is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in Figure 4b, the embodiment of the present disclosure relates to a communication method, which is executed by a terminal, and the method includes:

[0370] Step S4201: Receive first information sent by a first network function.

[0371] In some embodiments, the first information includes at least one of the following:

[0372] Information associated with whether the first communication technology has been de-networked or not;

[0373] Information used to indicate access technologies that are prohibited for the terminal to use.

[0374] In some embodiments, optional implementations of step S4201 can be found in FIG. 2b and other related parts of the embodiments involved in the steps in 2b, which will not be repeated here.

[0375] In some embodiments, the first communication technology includes at least one of the following:

[0376] 2nd generation mobile communication 2G technology;

[0377] 3rd generation mobile communication 3G technology.

[0378] In some embodiments, the first network function is one of the following:

[0379] Access and mobility management function AMF;

[0380] Mobility Management Entity MME;

[0381] Unified Data Management (UDM);

[0382] Home Subscriber Server HSS;

[0383] Policy Control Function PCF.

[0384] In some embodiments, the terminal is one of the following:

[0385] User equipment UE;

[0386] Universal User Identity Module USIM;

[0387] Mobile device ME.

[0388] In some embodiments, the receiving the first information sent by the network device includes one of the following:

[0389] receiving a registration acceptance message sent by the network device, where the registration acceptance message includes the first information;

[0390] receiving a DL NAS transmission message sent by the network device, where the DL NAS transmission message includes the first information;

[0391] receiving a tracking area update accept message sent by the network device, where the tracking area update accept message includes the first information;

[0392] receiving a terminal configuration update command sent by the network device, where the terminal configuration update command includes the first information;

[0393] A terminal policy container is received, where the terminal policy container includes the first information.

[0394] In some embodiments, the first information includes at least one of the following:

[0395] first list information, where the first list information is used to indicate a first list of first public land mobile networks (PLMNs) supporting the first communication technology;

[0396] Second list information, where the second list information is used to indicate a second list of second PLMNs for which the first communication technology network deregistration has been completed;

[0397] Second information, the second information including any one or more of the following: indication information for indicating that the home network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the visited network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the first communication technology network withdrawal has been completed;

[0398] The third information is used to indicate that the terminal is prohibited from using a first communication technology, where the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: an access technology related to the Global System for Mobile Communications GSM; an access technology related to the Global System for Mobile Communications or Enhanced Data Rate GSM Evolution Radio Access Network GERAN; an access technology related to the Universal Terrestrial Radio Access Network UTRAN.

[0399] In some embodiments, the first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using access technology related to GERAN or access technology related to GSM; or, the first information includes the third information, and the third information is used to indicate that the access technology related to UTRAN is prohibited.

[0400] In some embodiments, the first list includes a first identifier, which is used to indicate the identifier of a first PLMN that supports the first communication technology, and the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0401] In some embodiments, the first list includes the first PLMN identifier and a first type of access technology supported by the first PLMN.

[0402] In some embodiments, if the first list information is provided by a home public land mobile network HPLMN, the first list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and support the first type of access technology.

[0403] In some embodiments, if the HPLMN supports the first type of access technology, the first list includes an identifier of the HPLMN of the terminal.

[0404] In some embodiments, if the first list information is provided by a visited public land mobile network VPLMN, the first list includes identifiers of visited public land mobile networks VPLMN that support the first type of access technology.

[0405] In some embodiments, the second list includes a second identifier, which is used to indicate the identifier of a second PLMN that has completed the withdrawal of the first communication technology, and the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0406] In some embodiments, the second list indicates the identifier of the second PLMN and the access technologies supported by the second PLMN; wherein, if the second PLMN has completed 2G technology network withdrawal, the access technologies supported by the second PLMN do not include access technologies related to GSM or access technologies related to GERAN; if the second PLMN has completed 3G technology network withdrawal, the access technologies supported by the second PLMN do not include access technologies related to UTRAN.

[0407] In some embodiments, if the second list information is provided by a home public land mobile network HPLMN, the second list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and have completed de-networking of the first type of access technology.

[0408] In some embodiments, if the HPLMN has completed the de-networking of the first type of access technology, the second list includes the identifier of the HPLMN of the terminal.

[0409] In some embodiments, if the second list information is provided by a visited public land mobile network VPLMN, the second list indicates identifiers of visited public land mobile networks VPLMNs that have completed de-networking of the first type of access technology.

[0410] In some embodiments, the method further comprises one of the following:

[0411] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the home network of the terminal has completed 2G technology network deregistration, the terminal does not select an access technology related to GERAN or an access technology related to GSM;

[0412] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the home network of the terminal has completed 3G technology network deregistration, the terminal does not select an access technology related to UTRAN;

[0413] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the visited network of the terminal has completed 2G technology network deregistration, the terminal does not select an access technology related to GERAN or an access technology related to GSM;

[0414] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the visited network of the terminal has completed 3G technology network deregistration, the terminal does not select an access technology related to UTRAN;

[0415] If the first information includes the second information and the indication information for the first communication technology network deregistration indicates that 2G technology network deregistration has been completed, the terminal does not select an access technology related to GERAN or an access technology related to GSM;

[0416] If the first information includes the second information and the indication information of the first communication technology network exit indicates that the 3G technology network exit has been completed, the terminal does not select the access technology related to UTRAN.

[0417] In some embodiments, the method further comprises at least one of the following:

[0418] If the first information includes the third information and the third information is used to indicate that the terminal is prohibited from selecting an access technology related to GERAN or an access technology related to GSM, the terminal does not select an access technology related to GERAN or an access technology related to GSM;

[0419] If the first information includes the third information and the third information is used to indicate that the terminal is prohibited from selecting an access technology related to UTRAN, the terminal does not select an access technology related to UTRAN.

[0420] In some embodiments, the method further comprises at least one of the following:

[0421] If the first information includes the first list information, selecting an access technology corresponding to the first PLMN based on the first list information;

[0422] If the first information includes the second list information, the access technology corresponding to the second PLMN is selected based on the second list information.

[0423] Figure 5a is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in Figure 5a, the embodiment of the present disclosure relates to a communication method, which is used in a communication system 100. The method includes one of the following steps:

[0424] Step S5101: The first network function sends first information to the terminal.

[0425] In some embodiments, the terminal receives the first information sent by the first network function;

[0426] The first information includes at least one of the following:

[0427] Information associated with whether the first communication technology has been de-networked or not;

[0428] Information used to indicate access technologies that are prohibited for the terminal to use.

[0429] The optional implementation of step S5101 can refer to the optional implementation of steps S2101 to S2102 in Figure 2a and other related parts in the embodiment involved in Figure 2a, which will not be repeated here.

[0430] In some embodiments, the above method may include the methods of the above-mentioned communication system side, core network equipment, access network equipment, etc., which will not be repeated here.

[0431] In order to better understand the embodiments of the present disclosure, some exemplary embodiments are further described below:

[0432] Example 1

[0433] Referring to FIG6a , a communication method is shown, the method comprising:

[0434] Step S6101: Sending list information and / or network withdrawal information. The core network function (e.g., AMF / MME sends to the terminal, UDM / HSS sends to the terminal through AMF / MME, PCF sends to the terminal through AMF / MME) can send the 2G / 3G supported PLMN list (List 1), or the completed 2G / 3G network withdrawal PLMN list (List 2), or the 2G / 3G network withdrawal information of the home network to the UE.

[0435] In some embodiments, the following procedures may be multiplexed to convey the network withdrawal information. The network function may send the network withdrawal message via a Registration Accept message (i.e., step 21 in section 4.2.2.2.2 of 3GPP TS 23.502 [1]), a DL NAS Transport message (i.e., step 5 in section 6.14.2.2 of 3GPP TS 33.501 [2] and step 5 in section 6.15.2.1 of 3GPP TS 33.501 [2]), a Tracking Area Update Accept message (i.e., step 20 in section 5.3.3.1 of 3GPP TS 23.401 [3] and step 20 in section 5.3.3.2 of 3GPP TS 23.401 [3]), a UE Configuration Update Command (i.e., step 1 in section 4.2.4.2 of 3GPP TS 33.501 [2]), and a UE Policy Container (i.e., step 3 in section 4.2).

[0436] In some embodiments, List 1 is a list of PLMNs supporting 2G / 3G, including identifiers of PLMNs that still deploy and maintain GERAN / GSM and / or UTRAN radio access technologies. This list may be provided by the HPLMN (i.e., UDM or PCF), the serving PLMN (i.e., AMF / MME), or the VPLMN (i.e., AMF / MME). In some embodiments, List 1 may include identifiers of the PLMNs and identifiers of the access technologies supported by the PLMNs (e.g., GERAN, etc.).

[0437] In some embodiments, if List 1 is provided by the HPLMN, the List 1 may include the identities of all PLMNs that have roaming agreements with the HPLMN and still support 2G / 3G. If the HPLMN still maintains 2G / 3G, the List 1 may also include the identity of the UE's HPLMN.

[0438] In some embodiments, if List 1 is provided by a serving PLMN, List 1 may indicate that the serving PLMN to which the UE is connected still maintains 2G / 3G.

[0439] In some embodiments, the above-mentioned List 2 is a list of PLMNs that have completed 2G / 3G network deregistration, and the List 2 includes the identifiers of PLMNs that have completed GERAN / GSM and / or UTRA radio access technology deregistration. The list can be provided by the HPLMN (i.e., UDM or PCF) or the serving PLMN (i.e., AMF / MME) or the VPLMN (i.e., AMF / MME). In some embodiments, List 2 may include the identifiers of the PLMNs and the identifiers of the access technologies supported by the PLMNs (e.g., GERAN, etc.), and the access technologies do not include the access technologies that have been deregistered from the PLMNs. In some embodiments, List 2 may include the identifiers of the PLMNs and the identifiers of the access technologies that the PLMNs do not support (e.g., GERAN, etc.).

[0440] In some embodiments, if provided by the HPLMN, List 2 may include the identifiers of all PLMNs that have roaming agreements with the HPLMN and have completed 2G / 3G network deregistration. If the HPLMN has completed 2G / 3G network deregistration, List 2 may also include the identifier of the UE's home PLMN.

[0441] In some embodiments, if List 2 is provided by a serving PLMN, List 2 may indicate that the serving PLMN to which the UE is connected has completed 2G / 3G network deregistration.

[0442] In some embodiments, if the home network has completed the deregistration of 2G / 3G technology, the 2G / 3G deregistration information may include an indication that 2G / 3G has been deregistered in the home network or an indication that the UE should not select GERAN, GSM, or UTRAN-related access technologies. This information is provided to the terminal by the network function in the HPLMN (e.g., UDM / UDR / PCF / AMF / MME) or the network function in the VPLMN (e.g., AMF / MME). In some embodiments, if the home network has completed the deregistration of 2G technology, the UE should not select GSM-related access technologies or GERAN-related access technologies. If the home network has completed the deregistration of 3G technology, the UE should not select UTRAN-related access technologies.

[0443] Step S6102: Access is performed based on the list information and / or network exit information. If the UE receives a PLMN list supporting 2G / 3G (i.e., List 1), the UE will only select GSM / GERAN / UTRAN access technologies associated with PLMN IDs broadcast in List 1 (because GSM / GERAN / UTRAN cells broadcasting PLMN IDs not in List 1 are considered to be fake base stations).

[0444] If the UE receives a list of PLMNs that have withdrawn from the 2G / 3G network (ie, list 2), the UE does not select a GSM / GERAN / UTRAN access technology that is not supported by the PLMNs in the broadcast list 2.

[0445] In some embodiments, in the case where a fake base station fakes a GSM / GERAN / UTRAN cell that broadcasts a PLMN ID that is not in List 2, the UE may use a combination of List 1 and List 2 to detect the fake base station.

[0446] In some embodiments, if the UE receives 2G / 3G network detachment information from the home network, the UE will not select a GSM / GERAN / UTRAN cell. Specifically, if the UE receives 2G network detachment information from the home network, the UE will not select GSM-related access technologies or GERAN-related access technologies; if the UE receives 3G network detachment information from the home network, the UE will not select UTRAN-related access technologies.

[0447] In some embodiments, the first information received by the UE has a higher priority than the PLMN or access technology combination information in the USIM and ME. That is, if the first information is present, the UE should select an access technology based on the first information rather than based on the PLMN or access technology combination information.

[0448] In the embodiments of the present disclosure, some or all of the steps and their optional implementations may be arbitrarily combined with some or all of the steps in other embodiments, or may be arbitrarily combined with the optional implementations of other embodiments.

[0449] The embodiments of the present disclosure further provide an apparatus for implementing any of the above methods. For example, an apparatus is provided, comprising units or modules for implementing each step performed by a terminal in any of the above methods. For another example, another apparatus is provided, comprising units or modules for implementing each step performed by a network device (e.g., an access network device, a core network function node, a core network device, etc.) in any of the above methods.

[0450] It should be understood that the division of the various units or modules in the above device is merely a division of logical functions. In actual implementation, they may be fully or partially integrated into a physical entity, or they may be physically separated. In addition, the units or modules in the device may be implemented in the form of a processor calling software: for example, the device includes a processor, the processor is connected to a memory, and the memory stores instructions. The processor calls the instructions stored in the memory to implement any of the above methods or implement the functions of the various units or modules of the above device, wherein the processor is, for example, a general-purpose processor, such as a central processing unit (CPU) or a microprocessor, and the memory is a memory within the device or a memory outside the device. Alternatively, the units or modules in the device can be implemented in the form of hardware circuits, and the functions of some or all of the units or modules can be realized by designing the hardware circuits. The above-mentioned hardware circuits can be understood as one or more processors; for example, in one implementation, the above-mentioned hardware circuit is an application-specific integrated circuit (ASIC), which realizes the functions of some or all of the above units or modules by designing the logical relationship of the components in the circuit; for example, in another implementation, the above-mentioned hardware circuit can be realized by a programmable logic device (PLD). Taking a field programmable gate array (FPGA) as an example, it can include a large number of logic gate circuits, and the connection relationship between the logic gate circuits is configured by configuring the configuration file, thereby realizing the functions of some or all of the above units or modules. All units or modules of the above devices can be realized in the form of software called by the processor, or in the form of hardware circuits, or in part by the form of software called by the processor, and the rest by hardware circuits.

[0451] In the embodiments of the present disclosure, the processor is a circuit with signal processing capabilities. In one implementation, the processor can be a circuit with instruction reading and execution capabilities, such as a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU) (which can be understood as a microprocessor), or a digital signal processor (DSP). In another implementation, the processor can implement certain functions through the logical relationship of the hardware circuit. The logical relationship of the above-mentioned hardware circuit is fixed or reconfigurable. For example, the processor is a hardware circuit implemented by an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as an FPGA. In a reconfigurable hardware circuit, the process of the processor loading a configuration document and implementing the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units or modules. In addition, it can also be a hardware circuit designed for artificial intelligence, which can be understood as an ASIC, such as a neural network processing unit (NPU), a tensor processing unit (TPU), a deep learning processing unit (DPU), etc.

[0452] Figure 6a is a schematic diagram of the structure of a first network device 6100 proposed in an embodiment of the present disclosure. As shown in Figure 6a, the first network device 6100 may include at least one of a transceiver module 6101 and a processing module 6102. In some embodiments, the transceiver module is used to send and receive information. Optionally, the transceiver module is used to perform at least one of the communication steps, such as sending and / or receiving, performed by the first network device in any of the above methods, which are not further described here. Optionally, the processing module is used to perform at least one of the other steps performed by the first terminal in any of the above methods, which are not further described here.

[0453] In some embodiments, the transceiver module 6101 is configured to:

[0454] Sending first information to the terminal;

[0455] The first information includes at least one of the following:

[0456] Information associated with whether the first communication technology has been de-networked or not;

[0457] Information used to indicate access technologies that are prohibited for the terminal to use.

[0458] In some embodiments, the transceiver module 6101 is further configured to:

[0459] The first communication technology includes at least one of the following:

[0460] 2nd generation mobile communication 2G technology;

[0461] 3rd generation mobile communication 3G technology.

[0462] In some embodiments, the transceiver module 6101 is further configured to:

[0463] The first network function is one of the following:

[0464] Access and mobility management function AMF;

[0465] Mobility Management Entity MME;

[0466] Unified Data Management (UDM);

[0467] Home Subscriber Server HSS;

[0468] Policy Control Function PCF.

[0469] In some embodiments, the transceiver module 6101 is further configured to:

[0470] The terminal is one of the following:

[0471] User equipment UE;

[0472] Universal User Identity Module USIM;

[0473] Mobile device ME.

[0474] In some embodiments, the transceiver module 6101 is further configured to:

[0475] The sending of the first information to the terminal includes one of the following:

[0476] Sending a registration acceptance message to the terminal, where the registration acceptance message includes the first information;

[0477] Sending a downlink (DL) non-access stratum (NAS) transmission message to the terminal, where the DL NAS transmission message includes the first information;

[0478] Sending a tracking area update accept message to the terminal, where the tracking area update accept message includes the first information;

[0479] Sending a terminal configuration update command to the terminal, where the terminal configuration update command includes the first information;

[0480] A terminal policy container is sent to the terminal, where the terminal policy container includes the first information.

[0481] In some embodiments, the transceiver module 6101 is further configured to:

[0482] The first information includes at least one of the following:

[0483] first list information, where the first list information is used to indicate a first list of first public land mobile networks (PLMNs) supporting the first communication technology;

[0484] Second list information, where the second list information is used to indicate a second list of second PLMNs for which the first communication technology network deregistration has been completed;

[0485] Second information, the second information including one or more of the following: indication information for indicating that the home network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the visited network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the first communication technology network withdrawal has been completed;

[0486] The third information is used to indicate that the terminal is prohibited from using a first communication technology, where the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: an access technology related to the Global System for Mobile Communications GSM; an access technology related to the Global System for Mobile Communications or Enhanced Data Rate GSM Evolution Radio Access Network GERAN; an access technology related to the Universal Terrestrial Radio Access Network UTRAN.

[0487] In some embodiments, the transceiver module 6101 is further configured to:

[0488] The sending of the first information to the terminal includes one of the following:

[0489] If it is determined that the home network has completed the first communication technology de-networking and the first communication technology is 2G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using an access technology related to GERAN or an access technology related to GSM;

[0490] If it is determined that the home network has completed the first communication technology network withdrawal and the first communication technology is 3G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of UTRAN access technology is prohibited;

[0491] If it is determined that the visited network has completed the first communication technology de-networking and the first communication technology is 2G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using an access technology related to GERAN or an access technology related to GSM;

[0492] If it is determined that the visited network has completed the first communication technology withdrawal and the first communication technology is 3G technology, the first information is sent to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of UTRAN access technology is prohibited.

[0493] In some embodiments, the transceiver module 6101 is further configured to:

[0494] The first list includes a first identifier, which is used to indicate the identifier of a first PLMN that supports the first communication technology. The first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0495] In some embodiments, the transceiver module 6101 is further configured to:

[0496] The first list includes the first PLMN identifier and a first type of access technology supported by the first PLMN.

[0497] In some embodiments, the transceiver module 6101 is further configured to:

[0498] If the first list information is provided by a home public land mobile network HPLMN, the first list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and support the first type of access technology.

[0499] In some embodiments, the transceiver module 6101 is further configured to:

[0500] If the HPLMN supports the first type of access technology, the first list includes an identifier of the HPLMN of the terminal.

[0501] In some embodiments, the transceiver module 6101 is further configured to:

[0502] If the first list information is provided by a visited public land mobile network VPLMN, the first list includes identifiers of visited public land mobile networks VPLMN that support the first type of access technology.

[0503] In some embodiments, the transceiver module 6101 is further configured to:

[0504] The second list includes a second identifier, which is used to indicate the identifier of the second PLMN that has completed the withdrawal of the first communication technology. The first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0505] In some embodiments, the transceiver module 6101 is further configured to:

[0506] The second list indicates the identifier of the second PLMN and the access technology supported by the second PLMN; wherein, if the second PLMN has completed 2G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to GSM or access technology related to GERAN; if the second PLMN has completed 3G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to UTRAN.

[0507] In some embodiments, the transceiver module 6101 is further configured to:

[0508] If the second list information is provided by a home public land mobile network HPLMN, the second list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and have completed network deregistration of the first type of access technology.

[0509] In some embodiments, the transceiver module 6101 is further configured to:

[0510] If the HPLMN has completed the de-networking of the first type of access technology, the second list includes the identifier of the HPLMN of the terminal.

[0511] In some embodiments, the transceiver module 6101 is further configured to:

[0512] If the second list information is provided by a visited public land mobile network VPLMN, the second list indicates the identifiers of the VPLMNs that have completed the de-networking of the first type of access technology.

[0513] Figure 6b is a schematic diagram of the structure of the terminal 6200 proposed in an embodiment of the present disclosure. As shown in Figure 6b, the terminal 6200 may include: at least one of a transceiver module 6201, a processing module 6202, etc. In some embodiments, the above-mentioned transceiver module is used to send and receive information. Optionally, the above-mentioned transceiver module is used to perform at least one of the communication steps such as sending and / or receiving performed by the terminal in any of the above methods, which will not be repeated here. In some embodiments, the transceiver module may include a sending module and / or a receiving module, and the sending module and the receiving module may be separate or integrated together. Optionally, the transceiver module can be interchangeable with the transceiver.

[0514] In some embodiments, the transceiver module 6201 is configured to:

[0515] receiving first information sent by the first network function;

[0516] The first information includes at least one of the following:

[0517] Information associated with whether the first communication technology has been de-networked or not;

[0518] Information used to indicate access technologies that are prohibited for the terminal to use.

[0519] The transceiver module 6201 is further configured to: the first communication technology includes at least one of the following:

[0520] 2nd generation mobile communication 2G technology;

[0521] 3rd generation mobile communication 3G technology.

[0522] The transceiver module 6201 is further configured to: the first network function is one of the following:

[0523] Access and mobility management function AMF;

[0524] Mobility Management Entity MME;

[0525] Unified Data Management (UDM);

[0526] Home Subscriber Server HSS;

[0527] Policy Control Function PCF.

[0528] The transceiver module 6201 is further configured as follows: the terminal is one of the following:

[0529] User equipment UE;

[0530] Universal User Identity Module USIM;

[0531] Mobile device ME.

[0532] The transceiver module 6201 is further configured to: receive the first information sent by the network device, including one of the following:

[0533] receiving a registration acceptance message sent by the network device, where the registration acceptance message includes the first information;

[0534] receiving a DL NAS downlink non-access layer transmission message sent by the network device, where the DL NAS transmission message includes the first information;

[0535] receiving a tracking area update accept message sent by the network device, where the tracking area update accept message includes the first information;

[0536] receiving a terminal configuration update command sent by the network device, where the terminal configuration update command includes the first information;

[0537] A terminal policy container is received, where the terminal policy container includes the first information.

[0538] The transceiver module 6201 is further configured to: the first information includes at least one of the following:

[0539] first list information, where the first list information is used to indicate a first list of first public land mobile networks (PLMNs) supporting the first communication technology;

[0540] Second list information, where the second list information is used to indicate a second list of second PLMNs for which the first communication technology network deregistration has been completed;

[0541] Second information, the second information including any one or more of the following: indication information for indicating that the home network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the visited network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the first communication technology network withdrawal has been completed;

[0542] The third information is used to indicate that the terminal is prohibited from using a first communication technology, where the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: an access technology related to the Global System for Mobile Communications GSM; an access technology related to the Global System for Mobile Communications or Enhanced Data Rate GSM Evolution Radio Access Network GERAN; an access technology related to the Universal Terrestrial Radio Access Network UTRAN.

[0543] The transceiver module 6201 is also configured as follows: the first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using access technology related to GERAN or access technology related to GSM; or the first information includes the third information, and the third information is used to indicate that the access technology related to UTRAN is prohibited.

[0544] The transceiver module 6201 is also configured as follows: the first list contains a first identifier, the first identifier is used to indicate the identifier of the first PLMN that supports the first communication technology, the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0545] The transceiver module 6201 is further configured to: the first list includes the first PLMN identifier and the first type of access technology supported by the first PLMN.

[0546] The transceiver module 6201 is further configured to: if the first list information is provided by a home public land mobile network HPLMN, the first list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and support the first type of access technology.

[0547] The transceiver module 6201 is further configured to: if the HPLMN supports the first type of access technology, the first list includes the identifier of the HPLMN of the terminal.

[0548] The transceiver module 6201 is further configured to: if the first list information is provided by a visited public land mobile network VPLMN, the first list includes identifiers of visited public land mobile networks VPLMN that support the first type of access technology.

[0549] The transceiver module 6201 is also configured as follows: the second list contains a second identifier, the second identifier is used to indicate the identifier of the second PLMN that has completed the withdrawal of the first communication technology from the network, the first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

[0550] The transceiver module 6201 is also configured as follows: the second list indicates the identifier of the second PLMN and the access technology supported by the second PLMN; wherein, if the second PLMN has completed 2G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to GSM or access technology related to GERAN; if the second PLMN has completed 3G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to UTRAN.

[0551] The transceiver module 6201 is further configured to: if the second list information is provided by the home public land mobile network HPLMN, the second list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and have completed the first type of access technology network deregistration.

[0552] The transceiver module 6201 is further configured to: if the HPLMN has completed the first type of access technology network exit, the second list includes the identifier of the HPLMN of the terminal.

[0553] The transceiver module 6201 is further configured to: if the second list information is provided by a visited public land mobile network VPLMN, the second list indicates the identifiers of the visited public land mobile networks VPLMNs that have completed the deregistration of the first type of access technology.

[0554] The transceiver module 6201 is further configured to: the method further includes one of the following:

[0555] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the home network of the terminal has completed 2G technology network deregistration, the terminal does not select an access technology related to GERAN or an access technology related to GSM;

[0556] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the home network of the terminal has completed 3G technology network deregistration, the terminal does not select an access technology related to UTRAN;

[0557] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the visited network of the terminal has completed 2G technology network deregistration, the terminal does not select an access technology related to GERAN or an access technology related to GSM;

[0558] If the first information includes the second information and the first communication technology network deregistration indication information indicates that the visited network of the terminal has completed 3G technology network deregistration, the terminal does not select an access technology related to UTRAN;

[0559] If the first information includes the second information and the indication information for the first communication technology network deregistration indicates that 2G technology network deregistration has been completed, the terminal does not select an access technology related to GERAN or an access technology related to GSM;

[0560] If the first information includes the second information and the indication information of the first communication technology network exit indicates that the 3G technology network exit has been completed, the terminal does not select the access technology related to UTRAN.

[0561] The transceiver module 6201 is further configured to: the method further includes at least one of the following:

[0562] If the first information includes the third information and the third information is used to indicate that the terminal is prohibited from selecting an access technology related to GERAN or an access technology related to GSM, the access technology related to GERAN or the access technology related to GSM is not selected;

[0563] If the first information includes the third information and the third information is used to indicate that the terminal is prohibited from selecting an access technology related to UTRAN, the access technology related to UTRAN is not selected.

[0564] The transceiver module 6201 is further configured to: the method further includes at least one of the following:

[0565] If the first information includes the first list information, selecting an access technology corresponding to the first PLMN based on the first list information;

[0566] If the first information includes the second list information, the access technology corresponding to the second PLMN is selected based on the second list information.

[0567] In some embodiments, the processing module can be a single module or can include multiple submodules. Optionally, the multiple submodules each execute all or part of the steps required to be executed by the processing module. Optionally, the processing module can be interchangeable with the processor.

[0568] Figure 7a is a schematic diagram of the structure of a communication device 9100 proposed in an embodiment of the present disclosure. Communication device 9100 can be a network device (e.g., an access network device, a core network device, etc.), a terminal (e.g., a user equipment, etc.), a chip, a chip system, or a processor that supports a network device to implement any of the above methods, or a chip, a chip system, or a processor that supports a terminal to implement any of the above methods. Communication device 9100 can be used to implement the methods described in the above method embodiments. For details, please refer to the description of the above method embodiments.

[0569] As shown in Figure 7a, the communication device 9100 includes one or more processors 9101. The processor 9101 can be a general-purpose processor or a dedicated processor, for example, a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the communication device (such as a base station, baseband chip, terminal device, terminal device chip, DU or CU, etc.), execute programs, and process program data. The communication device 9100 is used to perform any of the above methods.

[0570] In some embodiments, the communication device 9100 further includes one or more memories 9102 for storing instructions. Optionally, all or part of the memories 9102 may be located outside the communication device 9100.

[0571] In some embodiments, the communication device 9100 further includes one or more transceivers 9103. When the communication device 9100 includes one or more transceivers 9103, the transceiver 9103 performs at least one of the communication steps such as sending and / or receiving in the above method (for example, step S2101 and step S3101, but not limited thereto), and the processor 9101 performs at least one of the other steps.

[0572] In some embodiments, a transceiver may include a receiver and / or a transmitter. The receiver and transmitter may be separate or integrated. Optionally, the terms transceiver, transceiver unit, transceiver, and transceiver circuit may be used interchangeably; the terms transmitter, transmitting unit, transmitter, and transmitting circuit may be used interchangeably; and the terms receiver, receiving unit, receiver, and receiving circuit may be used interchangeably.

[0573] In some embodiments, the communication device 9100 may include one or more interface circuits 9104. Optionally, the interface circuit 9104 is connected to the memory 9102. The interface circuit 9104 may be configured to receive signals from the memory 9102 or other devices, and may be configured to send signals to the memory 9102 or other devices. For example, the interface circuit 9104 may read instructions stored in the memory 9102 and send the instructions to the processor 9101.

[0574] The communication device 9100 described in the above embodiment may be a network device or a terminal, but the scope of the communication device 9100 described in the present disclosure is not limited thereto, and the structure of the communication device 9100 may not be limited by FIG. 7a. The communication device may be an independent device or may be part of a larger device. For example, the communication device may be: 1) an independent integrated circuit IC, or a chip, or a chip system or subsystem; (2) a collection of one or more ICs, optionally, the above IC collection may also include a storage component for storing data or programs; (3) an ASIC, such as a modem; (4) a module that can be embedded in other devices; (5) a receiver, a terminal device, an intelligent terminal device, a cellular phone, a wireless device, a handheld device, a mobile unit, an in-vehicle device, a network device, a cloud device, an artificial intelligence device, etc.; (6) others, etc.

[0575] FIG7 b is a schematic diagram of the structure of the chip 9200 proposed in an embodiment of the present disclosure. If the communication device 9100 can be a chip or a chip system, please refer to the schematic diagram of the structure of the chip 9200 shown in FIG7 b , but the present disclosure is not limited thereto.

[0576] The chip 9200 includes one or more processors 9201 , and the chip 9200 is configured to execute any of the above methods.

[0577] In some embodiments, the chip 9200 further includes one or more interface circuits 9202. Optionally, the interface circuit 9202 is connected to the memory 9203. The interface circuit 9202 can be used to receive signals from the memory 9203 or other devices, and can be used to send signals to the memory 9203 or other devices. For example, the interface circuit 9202 can read instructions stored in the memory 9203 and send the instructions to the processor 9201.

[0578] In some embodiments, the interface circuit 9202 executes at least one of the communication steps such as sending and / or receiving in the above method (for example, step S2101, step S3101, but not limited thereto), and the processor 9201 executes at least one of the other steps.

[0579] In some embodiments, terms such as interface circuit, interface, transceiver pin, and transceiver may be used interchangeably.

[0580] In some embodiments, the chip 9200 further includes one or more memories 9203 for storing instructions. Alternatively, all or part of the memories 9203 may be located outside the chip 9200.

[0581] The present disclosure also proposes a storage medium having instructions stored thereon, which, when executed on the communication device 9100, causes the communication device 9100 to execute any of the above methods. Optionally, the storage medium is an electronic storage medium. Optionally, the storage medium is a computer-readable storage medium, but is not limited thereto and may also be a storage medium readable by other devices. Optionally, the storage medium may be a non-transitory storage medium, but is not limited thereto and may also be a temporary storage medium.

[0582] The present disclosure also provides a program product, which, when executed by the communication device 9100, enables the communication device 9100 to perform any of the above methods. Optionally, the program product is a computer program product.

[0583] The present disclosure also proposes a computer program, which, when executed on a computer, causes the computer to perform any one of the above methods.

Claims

1. A communication method, characterized in that: The method is performed by a first network function, and the method includes: Sending first information to the terminal; The first information includes at least one of the following: Information associated with whether the first communication technology has been de-networked or not; Information used to indicate access technologies that are prohibited for the terminal to use.

2. The method according to claim 1, characterized in that The first communication technology includes at least one of the following: 2nd generation mobile communication 2G technology; 3rd generation mobile communication 3G technology.

3. The method according to claim 1 or 2, characterized in that The first network function is one of the following: Access and mobility management function AMF; Mobility Management Entity MME; Unified Data Management (UDM); Home Subscriber Server HSS; Policy Control Function PCF.

4. The method according to any one of claims 1 to 3, characterized in that The terminal is one of the following: User equipment UE; Universal User Identity Module USIM; Mobile device ME.

5. The method according to any one of claims 1 to 4, characterized in that The sending of the first information to the terminal includes one of the following: Sending a registration acceptance message to the terminal, where the registration acceptance message includes the first information; Sending a downlink (DL) non-access stratum (NAS) transmission message to the terminal, where the DL NAS transmission message includes the first information; Sending a tracking area update accept message to the terminal, where the tracking area update accept message includes the first information; Sending a terminal configuration update command to the terminal, where the terminal configuration update command includes the first information; A terminal policy container is sent to the terminal, where the terminal policy container includes the first information.

6. The method according to any one of claims 1 to 4, characterized in that The first information includes at least one of the following: first list information, where the first list information is used to indicate a first list of first public land mobile networks (PLMNs) supporting the first communication technology; Second list information, where the second list information is used to indicate a second list of second PLMNs for which the first communication technology network deregistration has been completed; Second information, the second information including any one or more of the following: indication information for indicating that the home network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the visited network of the terminal has completed the first communication technology network withdrawal; Indication information used to indicate that the first communication technology network withdrawal has been completed; third information, the third information being used to indicate that the terminal is prohibited from using a first communication technology, where the first communication technology includes a first type of access technology, where the first type of access technology includes at least one of the following: an access technology related to a Global System for Mobile Communications (GSM); Access technologies related to the Global System for Mobile Communications or GSM Evolution Radio Access Network (GERAN); Access technologies related to the Universal Terrestrial Radio Access Network (UTRAN).

7. The method according to claim 6, characterized in that The sending of the first information to the terminal includes one of the following: If it is determined that the home network has completed the first communication technology de-networking and the first communication technology is 2G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using an access technology related to GERAN or an access technology related to GSM; If it is determined that the home network has completed the first communication technology network withdrawal and the first communication technology is 3G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of UTRAN access technology is prohibited; If it is determined that the visited network has completed the first communication technology de-networking and the first communication technology is 2G technology, sending the first information to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of access technologies related to GERAN or GSM is prohibited; If it is determined that the visited network has completed the first communication technology withdrawal and the first communication technology is 3G technology, the first information is sent to the terminal; wherein the first information includes the third information, and the third information is used to indicate that the use of UTRAN access technology is prohibited.

8. The method according to claim 6, characterized in that The first list includes a first identifier, which is used to indicate the identifier of a first PLMN that supports the first communication technology. The first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

9. The method according to claim 6 or 8, characterized in that: The first list includes the first PLMN identifier and a first type of access technology supported by the first PLMN.

10. The method according to claim 6 or 8, characterized in that: If the first list information is provided by a home public land mobile network HPLMN, the first list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and support the first type of access technology.

11. The method according to claim 10, characterized in that If the HPLMN supports the first type of access technology, the first list includes an identifier of the HPLMN of the terminal.

12. The method according to claim 6 or 8, characterized in that: If the first list information is provided by a visited public land mobile network VPLMN, the first list includes identifiers of visited public land mobile networks VPLMN that support the first type of access technology.

13. The method according to claim 6, characterized in that The second list includes a second identifier, which is used to indicate the identifier of the second PLMN that has completed the withdrawal of the first communication technology. The first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

14. The method according to claim 6 or 13, characterized in that: The second list indicates the identifier of the second PLMN and the access technology supported by the second PLMN; wherein, if the second PLMN has completed 2G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to GSM or access technology related to GERAN; if the second PLMN has completed 3G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to UTRAN.

15. The method according to claim 6 or 13, characterized in that: If the second list information is provided by a home public land mobile network HPLMN, the second list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and have completed network deregistration of the first type of access technology.

16. The method according to claim 15, characterized in that If the HPLMN has completed the de-networking of the first type of access technology, the second list includes the identifier of the HPLMN of the terminal.

17. The method according to claim 6 or 13, characterized in that: If the second list information is provided by a visited public land mobile network VPLMN, the second list indicates the identifiers of the VPLMNs that have completed the de-networking of the first type of access technology.

18. A communication method, characterized in that: The method is executed by a terminal, and includes: receiving first information sent by the first network function; The first information includes at least one of the following: Information associated with whether the first communication technology has been de-networked or not; Information used to indicate access technologies that are prohibited for the terminal to use.

19. The method according to claim 18, characterized in that The first communication technology includes at least one of the following: 2nd generation mobile communication 2G technology; 3rd generation mobile communication 3G technology.

20. The method according to claim 18 or 19, characterized in that The first network function is one of the following: Access and mobility management function AMF; Mobility Management Entity MME; Unified Data Management (UDM); Home Subscriber Server HSS; Policy Control Function PCF.

21. The method according to any one of claims 18 to 20, characterized in that The terminal is one of the following: User equipment UE; Universal User Identity Module USIM; Mobile device ME.

22. The method according to any one of claims 18 to 21, characterized in that The receiving of the first information sent by the network device includes one of the following: receiving a registration acceptance message sent by the network device, where the registration acceptance message includes the first information; receiving a DL NAS transmission message sent by the network device, where the DL NAS transmission message includes the first information; receiving a tracking area update accept message sent by the network device, where the tracking area update accept message includes the first information; receiving a terminal configuration update command sent by the network device, where the terminal configuration update command includes the first information; A terminal policy container is received, where the terminal policy container includes the first information.

23. The method according to any one of claims 18 to 23, characterized in that The first information includes at least one of the following: first list information, where the first list information is used to indicate a first list of first public land mobile networks (PLMNs) supporting the first communication technology; Second list information, where the second list information is used to indicate a second list of second PLMNs for which the first communication technology network deregistration has been completed; Second information, the second information including any one or more of the following: indication information for indicating that the home network of the terminal has completed the first communication technology network withdrawal; indication information for indicating that the visited network of the terminal has completed the first communication technology network withdrawal; Indication information used to indicate that the first communication technology network withdrawal has been completed; third information, the third information being used to indicate that the terminal is prohibited from using a first communication technology, where the first communication technology includes a first type of access technology, where the first type of access technology includes at least one of the following: an access technology related to a Global System for Mobile Communications (GSM); Access technologies related to the Global System for Mobile Communications or GSM Evolution Radio Access Network (GERAN); Access technologies related to the Universal Terrestrial Radio Access Network (UTRAN).

24. The method according to claim 23, wherein The first information includes the third information, and the third information is used to indicate that the terminal is prohibited from using access technology related to GERAN or access technology related to GSM; or, the first information includes the third information, and the third information is used to indicate that the access technology related to UTRAN is prohibited.

25. The method according to claim 23, characterized in that The first list includes a first identifier, which is used to indicate the identifier of a first PLMN that supports the first communication technology. The first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

26. The method according to claim 23 or 25, characterized in that The first list includes the first PLMN identifier and a first type of access technology supported by the first PLMN.

27. The method according to claim 23 or 25, characterized in that If the first list information is provided by a home public land mobile network HPLMN, the first list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and support the first type of access technology.

28. The method according to claim 27, characterized in that If the HPLMN supports the first type of access technology, the first list includes an identifier of the HPLMN of the terminal.

29. The method according to claim 23 or 25, characterized in that If the first list information is provided by a visited public land mobile network VPLMN, the first list includes identifiers of visited public land mobile networks VPLMN that support the first type of access technology.

30. The method according to claim 23, wherein The second list includes a second identifier, which is used to indicate the identifier of the second PLMN that has completed the withdrawal of the first communication technology. The first communication technology includes a first type of access technology, and the first type of access technology includes at least one of the following: access technology related to GSM; access technology related to GERAN; access technology related to UTRAN.

31. The method according to claim 23 or 30, characterized in that The second list indicates the identifier of the second PLMN and the access technology supported by the second PLMN; wherein, if the second PLMN has completed 2G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to GSM or access technology related to GERAN; if the second PLMN has completed 3G technology network withdrawal, the access technology supported by the second PLMN does not include access technology related to UTRAN.

32. The method according to claim 23 or 25, characterized in that If the second list information is provided by a home public land mobile network HPLMN, the second list includes identifiers of all PLMNs that have roaming agreements with the HPLMN and have completed network deregistration of the first type of access technology.

33. The method according to claim 32, characterized in that If the HPLMN has completed the de-networking of the first type of access technology, the second list includes the identifier of the HPLMN of the terminal.

34. The method according to claim 23 or 30, characterized in that If the second list information is provided by a visited public land mobile network VPLMN, the second list indicates identifiers of visited public land mobile networks VPLMNs that have completed de-networking of the first type of access technology.

35. The method according to any one of claims 23 to 34, characterized in that The method further comprises one of the following: If the first information includes the second information and the first communication technology network deregistration indication information indicates that the home network of the terminal has completed 2G technology network deregistration, the terminal does not select an access technology related to GERAN or an access technology related to GSM; If the first information includes the second information and the first communication technology network deregistration indication information indicates that the home network of the terminal has completed 3G technology network deregistration, the terminal does not select an access technology related to UTRAN; If the first information includes the second information and the first communication technology network deregistration indication information indicates that the visited network of the terminal has completed 2G technology network deregistration, an access technology related to GERAN or an access technology related to GSM is not selected; If the first information includes the second information and the first communication technology network deregistration indication information indicates that the visited network of the terminal has completed 3G technology network deregistration, the access technology related to UTRAN is not selected; If the first information includes the second information and the indication information for the first communication technology network deregistration indicates that the 2G technology network deregistration has been completed, an access technology related to GERAN or an access technology related to GSM is not selected; If the first information includes the second information and the indication information of the first communication technology network exit indicates that the 3G technology network exit has been completed, the access technology related to UTRAN is not selected.

36. The method according to any one of claims 23 to 35, wherein: The method further comprises at least one of the following: If the first information includes the third information and the third information is used to indicate that the terminal is prohibited from selecting an access technology related to GERAN or an access technology related to GSM, the access technology related to GERAN or the access technology related to GSM is not selected; If the first information includes the third information and the third information is used to indicate that the terminal is prohibited from selecting an access technology related to UTRAN, the access technology related to UTRAN is not selected.

37. The method according to any one of claims 23 to 36, wherein: The method further comprises at least one of the following: If the first information includes the first list information, selecting an access technology corresponding to the first PLMN based on the first list information; If the first information includes the second list information, the access technology corresponding to the second PLMN is selected based on the second list information.

38. A communication method, characterized in that: The method comprises: The first network function sends first information to the terminal; The terminal receives the first information sent by the first network function; The first information includes at least one of the following: Information associated with whether the first communication technology has been de-networked or not; Information used to indicate access technologies that are prohibited for the terminal to use.

39. A first network function, characterized in that The first network function includes: The transceiver module is configured as follows: Sending first information to the terminal; The first information includes at least one of the following: Information associated with whether the first communication technology has been de-networked or not; Information used to indicate access technologies that are prohibited for the terminal to use.

40. A terminal, characterized in that: The terminal includes: The transceiver module is configured as follows: receiving first information sent by the first network function; The first information includes at least one of the following: Information associated with whether the first communication technology has been de-networked or not; Information used to indicate access technologies that are prohibited for the terminal to use.

41. A first network function, characterized in that The first network function includes: one or more processors; The first network function is configured to execute the method according to any one of claims 1 to 17.

42. A terminal, characterized in that: The terminal includes: one or more processors; The terminal is used to execute the method according to any one of claims 18 to 37.

43. A storage medium, characterized in that The storage medium stores instructions, and when the instructions are executed on a communication device, the communication device executes the method according to any one of claims 1 to 17 and claims 18 to 37.

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